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. Author manuscript; available in PMC: 2026 Jul 15.
Published in final edited form as: Mech Ageing Dev. 2025 Nov 4;228:112122. doi: 10.1016/j.mad.2025.112122

Diminished CEACAM1 level plays a critical role in age-related hepatic fibrosis

Sobia Zaidi a, Suman Asalla a, Raziyeh Abdolahipour a, Agnes O Portuphy a, Marziyeh S Jahromi a, Harrison T Muturi a,b, Getachew D Belew a, Ramiro Malgor a, Sivarajan Kumarasamy a, Sonia M Najjar a,b,*
PMCID: PMC13367331  NIHMSID: NIHMS2185845  PMID: 41197675

Abstract

Background:

Hepatic fibrosis increases with aging, but its physiological progression and underlying mechanisms remain poorly defined. Given that CEACAM1 repression causes metabolic dysfunction and liver injury, the current studies investigated whether it mediates age-related hepatic fibrosis.

Materials and methods:

The metabolic phenotype, histological, immunochemical and Western blot analyses were performed in male C57BL6/J wild-type and LCC1 mice with liver-specific CEACAM1 overexpression at 2–17 months of age.

Results:

Progression of metabolic dysfunction during physiological aging began with increased lipolysis-derived fatty acids, followed by hepatic insulin resistance with compensatory increase in insulin secretion and a decline in hepatic insulin clearance mediated initially by compromised CEACAM1 phosphorylation and then expression. Resultant hyperinsulinemia drove hepatic steatosis, followed by Th1 inflammatory response and subsequently, hepatic fibrosis at 17 months of age. These histological abnormalities regressed in LCC1 mice with protected hepatic CEACAM1 levels. Accordingly, LCC1 mice exhibited survival advantage.

Discussion:

This age-related mapping demonstrated that early metabolic alterations impaired insulin clearance with a progressive loss of CEACAM1. Resultant hyperinsulinemia drove hepatic steatosis followed by inflammation and ultimately, hepatic fibrosis in wild-type but not LCC1 mice. Together with survival benefit of LCC1, these observations propose that protecting hepatic CEACAM1 prevents age-related hepatic fibrosis and bestows longevity.

Keywords: hepatic fibrosis; fatty acid synthase; steatosis; inflammation; insulin clearance, insulin secretion

1. Introduction

Advancement in medical care and socioeconomic development have remarkably increased the global aging population. Aging is a progressive deterioration of the homeostatic process that leads to metabolic and structural dysfunction, making the organism vulnerable to chronic diseases such as diabetes, hepatic fibrosis, cardiac dysfunction and other cardiometabolic diseases (Georgieva et al., 2023; Lopez-Otin et al., 2023). Thus, it has become imperative to delineate the etiology of metabolic dysregulation in physiological aging.

The liver plays an important role in maintaining systemic homeostasis. Age-associated liver diseases are common, particularly fibrosis resulting from chronic injuries (Georgieva et al., 2023; Hunt et al., 2019; Wahid et al., 2024; Radonjic et al., 2022). However, the precise molecular mechanisms that link normal physiological aging to progressive hepatic fibrosis remain poorly defined. Insulin action, a key metabolic pathway, has a cause-and-effect relationship with aging-related diseases (Fontana et al., 2010). Insulin action, mediated by well-characterized signaling pathways, is regulated by the amount of insulin that circulates in the blood, which is determined by the net effect of insulin secretion and insulin clearance (Bergman et al., 2022; Najjar et al., 2023).

We have identified a critical role for Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 (CEACAM1) in maintaining insulin sensitivity by promoting insulin clearance in liver without affecting insulin secretion (Poy et al., 2002; DeAngelis et al., 2008). Consistent with this role, CEACAM1 is predominantly expressed in hepatocytes, the primary site of insulin clearance (Najjar and Perdomo, 2019). This transmembrane glycoprotein is rapidly phosphorylated by the insulin receptor tyrosine kinase in response to acute rise of secreted insulin pulses in the portal vein to chaperone insulin via its receptor to its degradation process. Bolstering the key role of CEACAM1 in insulin clearance, mice with global (Cc1−/−) (DeAngelis et al., 2008) and liver-specific deletion (AlbCre+Cc1fl/fl) (Ghadieh et al., 2019) or inactivation (L-SACC1) (Lee et al., 2008) of CEACAM1 manifest impairment of insulin clearance that drive hyperinsulinemia followed by hepatic insulin resistance and steatosis, visceral obesity (due to substrate redistribution to adipose tissue for storage) and systemic insulin resistance (in response to the release of adipokines and non-esterified fatty acids–NEFA). These genetic modulations also cause spontaneous hepatic fibrosis, which with excess fat intake become more robust and lead to apoptosis (Lee et al., 2008; Ghosh et al., 2010; Helal et al., 2021). Interestingly, cell-specific deletions of Ceacam1 in hepatocytes, (Zaidi et al., 2024) endothelial cells (Muturi et al., 2023) and hepatic stellate cells (HSCs) (Muturi et al., 2024) cause spontaneous hepatic fibrosis in the presence of insulin resistance and steatohepatitis (hepatocytes) or with inflammation alone (endothelial cells and HSCs). In contrast, fat-inducible overexpression of CEACAM1 in liver (as in LCC1 mice) protects against diet-induced insulin resistance and hepatic steatosis (Al-Share et al., 2015). Moreover, liver-specific reconstitution of Ceacam1 in Cc1−/− null mice prevents metabolic dysfunction and hepatic fibrosis even when mice are fed a high-fat diet (Helal et al., 2021). These findings underscore the protective role of CEACAM1 against liver fibrosis in genetically-modified mice. While the role of CEACAM1 in insulin clearance and diet-induced metabolic dysfunction is well established, its contribution to age-related hepatic pathology has not been systematically characterized.

Several studies in humans have increasingly unraveled the importance of CEACAM1 as a potential biomarker. We have recently shown in a Portuguese PREVADIAB2 cohort of 1019 subjects reduced circulating CEACAM1 levels and insulin clearance in parallel to progression of insulin resistance and dysglycemia simultaneously to elevation in body mass index and hepatic steatosis prevalence (Patarrao et al., 2024). Another study demonstrated a positive correlation between circulating CEACAM1 levels and insulin sensitivity in patients with gestational diabetes (Wu et al., 2020). A study in individuals from South Korea showed a direct correlation between declining hepatic CEACAM1 protein levels in obese subjects with high grade fatty liver (Lee, 2011). Recapitulating our findings in mouse models, (Lee et al., 2008; Ghosh et al., 2010; Helal et al., 2021; Zaidi et al., 2024; Muturi et al., 2023; Ghadieh et al., 2020) hepatic CEACAM1 levels significantly decrease in patients with MASH and they gradually decline as hepatic fibrosis advances (Zaidi et al., 2024; Muturi et al., 2023).

Hepatic CEACAM1 levels progressively decreased in wild-type (WT) C57BL/6 J mice until 9–10 months of age, but without adversely affecting insulin clearance (Ghadieh et al., 2019; Ghanem et al., 2017). However, insulin clearance was reported to be compromised in mice at 17 versus 3 months of age in parallel to reduced CEACAM1 and insulin degrading enzyme (IDE) levels and IDE activity (Marmentini et al., 2021). Despite this association, no study has yet mapped the progression of the metabolic and histological changes that lead to hepatic fibrosis during physiological aging. The current systematic analysis of hepatic fibrosis progression identified age-related decline in CEACAM1 levels as a molecular mechanism linking metabolic dysfunction to hepatic steatosis, inflammation, and fibrosis in wild-type (WT) C57BL/6 J male mice. This observation was bolstered by the absence of steatohepatitis and hepatic fibrosis in LCC1 mice with forced hepatic overexpression of CEACAM1 (Al-Share et al., 2015) and by their survival advantage.

2. Materials and methods

2.1. Mice

The study was conducted on male C57BL6/J mice (Jackson Lab) at 2–17 months of age and on LCC1 transgenic mice (17–20 months of age), previously generated by the Najjar laboratory on C57BL6/J background (Al-Share et al., 2015). LCC1 mice harbor liver-specific overexpression of rat CEACAM1–4L that shares ~94 % homology of its cytoplasmic domain including phosphorylation sites, with the mouse amino acid sequence. CEACAM1 expression was driven by 519 nucleotides of proximal human apolipoprotein-A1 (APOA1) promoter/enhancer element.

All animals were housed in a 12h-dark/light cycle and fed standard chow ad libitum. All procedures and animal experiments were approved by the institutional Animal Care and Utilization Committee.

2.2. Body composition and indirect calorimetry

Body composition was assessed by nuclear magnetic resonance technology (Bruker Minispec; Billerica, MA) before mice at 2, 5, 8 and 9 months of age (n = 4/age group) were individually caged (CLAMS system, Columbus Instruments, Columbus, OH) over a 5 day-period after being acclimated for 2 days (Heinrich et al., 2010). Mice had access to food and water ad libitum except during fasting-refeeding, when food was removed at 1900 h and replaced at 0700 h the next morning for 7 h to allow the release of insulin, as routinely done (Najjar et al., 2005). Spontaneous physical activity was measured on the x axis (locomotor), y axis (ambulatory), and z axis (standing). Total activity was calculated as the average of the sum of x and z activities. Oxygen consumption (VO2), CO2 production (VCO2), and heat generation were sampled every 16 min and normalized to fat-free lean mass. The respiratory exchange rate (RER) was calculated as the VCO2/VO2 ratio. Data were represented as mean ± SEM of light (700–1900 h) and dark (1900–700 h) cycles. At the end of the fifth day, food was removed overnight and returned the next morning to measure the respiratory quotient as hourly average from 1 h prior to refeeding (−1) to 9 h post-refeeding (Heinrich et al., 2010).

2.3. Glucose and Insulin tolerance tests

As routinely done (Ghanem et al., 2017) male mice were housed in cages with Alpha-dri bedding (Shepherd Specialty Papers) and fasted for 6 h before being injected intraperitoneally with either 1.5 g/kg body weight (BW) dextrose solution (for Glucose Tolerance Test – GTT, n = 6/age group) or 0.75 units/kg BW human regular insulin (Novo Nordisk, Princeton, NJ) (for Insulin Tolerance Test- ITT, n ≥ 4/age group). Tail blood glucose levels were measured at 0–120 min (GTT) or 0–180 min post-injection (ITT).

2.4. Insulin secretion and clearance

Overnight-fasted mice were anaesthetized with pentobarbital (1.1 mg/kg body weight) before receiving an intraperitoneal (IP) dextrose injection of 3 g/kg BW of 50 % Dextrose, USP (Hospira Inc. Lake Forest, IL). Retro-orbital blood was drawn to assess glucose-stimulated insulin secretion (GSIS) by measuring insulin levels at 0, 2, 7, 15, 30 and 120 min post-IP glucose injection in WT mice (n ≥ 4/age group). For insulin clearance, retro-orbital venous blood was drawn from mice kept on Alpha-dri after 18 hr-fasting [1700 one day to 1100 am (the next day)] into heparinized micro-hematocrit capillary tubes (Fisherbrand, Waltham, MA), and plasma were processed. Plasma was analyzed by ELISA (ALPCO, Salem, NH) for insulin and C-peptide levels to calculate steady-state C-peptide/insulin molar ratio as a measure of hepatic insulin clearance (n ≥ 5/age group).

2.5. Kaplan–Meier survival analysis

Mice were monitored until natural death or humane endpoint and survival time was recorded in months. Survival curves were generated using the Kaplan–Meier method, and comparisons between groups (WT, n = 13; LCC1, n = 16) were performed using the Mantel–Cox log-rank test to assess statistical significance. Median survival was estimated with 95 % confidence intervals (CIs). Hazard ratios (HRs) and their 95 % confidence intervals (Cis) were calculated to quantify the risk of death between groups. All statistical analyses were conducted using GraphPad Prism (version 10.3.1).

2.6. Biochemical parameters

Retro-orbital venous blood was drawn from mice kept on Alpha-dri after 18 hr-fasting. Plasma was processed as above and livers were excised to determine hepatic triacylglycerol as previously described (Al-Share et al., 2015). Plasma levels of NEFA were analyzed by enzymatic colorimetry (Wako, Richmond, VA), and of free glycerol by Glycerol Assay Kit (MAK117–1KT, Sigma-Aldrich, Milwaukee, WI), per manufacturer instructions (Muturi et al., 2024). To determine leptin levels, mice were fasted 2–4 h before leptin was assayed by ELISA kit (Crystal Chem, Grove Village, IL) (n ≥ 4/age group).

2.7. Fatty acid synthase activity

As described earlier, (Najjar et al., 2005) fatty acid synthase (FASN) activity was measured in liver homogenates using acetyl-CoA as the starting substrate, and a mixture of 0.1 μCi [14 C] malonyl-coenzyme A (Perkin-Elmer, Shelton, CT) and 25 nmol malonyl-CoA as substrates for elongation (n ≥ 4/age group). 500 μM nicotinamide adenine dinucleotide phosphate (NADPH; Sigma-Aldrich) was used as the reducing agent in the reaction, which drives the elongation of the fatty acid chain. Activity was calculated as [14C] cpm/mg.

2.8. Western blot analysis

For fasting-refeeding experiments, mice (3–8 months of age; randomly selected 2–4 mice/age group) were fasted overnight (F), and sacrificed for dissection at 9 a.m. the next morning while another set of mice was refed for 7 h before tissues were collected (RF). Western blot analysis was carried out on tissue lysates by immunoblotting (Ib) with an antibody against phospho-insulin receptor beta - pIRβ (phospho-Y1361; Abcam, Waltham, MA) normalized against total insulin receptor beta (IRβ) (Abcam, C18C4). Another set of protein lysates was subjected to immunoprecipitation (Ip) with fatty acid synthase (FASN) antibody (Cell Signaling, Danvers, MA) followed by immunoblotting with a custom-made phospho-CEACAM1 antibody (Bethyl Laboratories, Montgomery, TX) (Pereira et al., 2014; Ghanem et al., 2016) normalized against FASN to assess CEACAM1 levels in the FASN immunopellet. For Western blot analysis of signaling proteins, tissue lysates of ON fasted mice were analyzed by immunoprobing with antibodies (Cell Signaling) against phosphorylated NF-κB, Stat3 and Smad3 normalized against antibodies of total NF-κB, Stat3 and Smad3, respectively. Antibodies against MMP9, MMP13, TIMP1 (Cell signaling) and custom-made polyclonal antibodies against rat (α-rCC1) (Al-Share et al., 2015) and mouse CEACAM1 (α-mCC1) (Muturi et al., 2023) were used to immunodetect their protein content against Vinculin (monoclonal, Proteintech Group Inc, Rose-mont, IL) or Tubulin (polyclonal, Cell Signaling Tech). Blots were incubated with horseradish peroxidase-conjugated goat anti-rabbit IgG antibody (Cell Signaling) or anti-mouse IgG antibody (GE Healthcare Life Sciences, Amersham) and detected by ECL. Gels were scanned and the density of the test band was divided by that of its corresponding loading control using image J (v1.53t) and represented in arbitrary units (a.u) in the accompanying graph.

2.9. Liver histology, Sirius Red Stain and immunohistochemical analysis

Liver sections harvested from overnight fasted mice (n = 5/age group) were fixed in 10 % neutral buffered formalin (Sigma-Aldrich), paraffin-embedded before sections were cut, mounted and stained with hematoxylin-eosin (H&E). 0.1 % Sirius Red stain (Direct Red 80, Sigma-Aldrich) was used to assess fibrosis in deparaffinized and rehydrated sections, as previously described (Zaidi et al., 2024). Images were taken using Nikon Eclipse 90i Microscope (Nikon, Melville, NY) as routinely done (Muturi et al., 2023). Fibrosis score was assessed per Brunt’s NASH CRN Fibrosis staging system (Brunt et al., 2021).

Immunohistochemical (IHC) analysis had been described (Zaidi et al., 2024; Muturi et al., 2023). Briefly, liver sections were blocked with goat serum (Vector labs, Burlingame, CA) for 1 h at room temperature, and stained overnight at 4°C with antibodies from Abcam [α-CD68 (polyclonal,1:150), α-Mac2 (monoclonal, 1:250), α-MPO (monoclonal, 1:1000), α-CD4 (monoclonal, 1:1000), α-CD8 (monoclonal, 1:2000) and α-Ki67 (monoclonal, 1:100)], α-Foxp3 (polyclonal, 1:100; Invitrogen, Waltham, MA), and α-Cleaved Caspase 3 (polyclone, al1:200; Cell Signaling). Slides were then incubated with appropriate species-specific biotinylated ImmPRESS HRP goat secondary antibody (Vector Labs, Burlingame, CA) for 30 min before being treated with 3, 3’-Diaminobenzidine (DAB, Vectastain kit-Vector labs) and counter-stained with Mayer’s hematoxylin. Images were taken using Nikon Eclipse 90i Microscope (Nikon). Sections were evaluated blindly and independently by three scientists (RM; GDB; and AOP), and positively stained cells were counted in 5 fields/mouse at 40X magnification.

2.10. Reverse transcription quantitative PCR (RT-qPCR)

RNA was isolated with NucleoSpin RNA, Mini kit (MACHEREYNAGEL Inc. Allentown, PA). cDNA was synthesized by iScript cDNA Synthesis Kit (Bio-Rad, Hercules, CA), using 1 μg of total RNA and oligodT primers. cDNA was evaluated with RT-qPCR (Bio-Rad, Hercules, CA), and mRNA was normalized against 18 s (n ≥ 3/age group).

2.11. Statistical analysis

Data were collected from independent cohorts of mice at each age (2–17 months). Data were analyzed using one-way ANOVA analysis with Bonferroni correction or two-tailed Student t-test using GraphPad Prism 10.3.1. software. Data were presented as mean ± SEM. p < 0.05 was considered statistically significant.

3. Results

3.1. Age-related changes in body fat composition and energy balance in wild-type mice

As shown in Fig. 1A, male mice exhibited a progressive increase in body weight gain, accompanied by a significant rise in visceral obesity at ~7 months of age (Fig. 1B), with a parallel rise in plasma NEFA (Fig. 1C) that was captured as glycerol (Fig. 1D) starting at ~5 months. NMR analysis revealed a gradual increase in fat mass coupled with an inverse decline in lean mass beginning at 7 months (Fig. 1E).

Fig. 1.

Fig. 1.

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Age-related alteration in fat metabolism. Male C57BL6/J mice (WT, 2–28 months of age) were analyzed for: (A) body weight (BW) (n ≥ 6/age group); (B) visceral obesity (% of white adipose tissue to BW) (n ≥ 11/age group); (C) steady-state plasma non-esterified fatty acids (NEFA) (n ≥ 4/age group); (D) steady-state plasma glycerol (n ≥ 4/age group); (E) lean mass and fat mass body composition using Nuclear Mass Resonance spectroscopy (n = 5/age group). Values were expressed as means ± SEM. *p < 0.05, vs youngest age group.

Indirect calorimetry analysis showed that the rise in fat mass did not correlate with any change in food consumption, which remained normal until 9 months of age (the oldest age studied) (Fig. 2A), in agreement with a recent study showing no significant increase in food intake until 18 months (Ogiso et al., 2025). Consistently, hyperleptinemia (a marker of hyperphagia) (Ghanem et al., 2016) did not develop until 16 months of age (Figure S1A) and the hypothalamic Ceacam1 and Ceacam2 mRNA levels were not reduced by > 50 % to cause hyperphagia (Figure S1B) (Ghadieh et al., 2019; Ghanem et al., 2016; Russo et al., 2017; Heinrich et al., 2016).

Fig. 2.

Fig. 2.

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Age-related changes in energy balance and substrate switching. WT mice at 2, 5, 8, 9 months of age (n = 4/age group) were subjected to indirect calorimetry to assess: (A) food intake, (B) locomotor activity, (C) heat produced, (D) VO2, (E) VCO2, and (F) RER respiratory quotient. (G) mice were fasted overnight at the end of the fifth day, and the respiratory quotient was measured as hourly average from 1 h prior to refeeding for 9 additional hours. Values were expressed as means ±SEM. *p < 0.05, vs youngest age group.

Indirect calorimetry data showed a progressive reduction in locomotor activity beginning at 5 months (Fig. 2B), with a parallel decline in body heat (Fig. 2C), and in VO2 consumption (Fig. 2D) and VCO2 production (Fig. 2E) in both light and dark cycles. These changes became more markedly significant by ~8 months, eventually resulting in a lower respiratory exchange ratio (RER) in the dark cycle at 9 months (Fig. 2F). The latter revealed a shift of macronutrient metabolism toward more fat than carbohydrate utilization, as supported by delayed ability to switch from lipolytic to glycolytic metabolism upon refeeding following an overnight fast at this age (Fig. 2G).

3.2. Age-dependent development of insulin resistance in wild-type mice

Next, we investigated whether the increase in lipolysis-derived plasma NEFA impacted hepatic metabolism. Whereas glucose tolerance was intact up to 16 months of age (Fig. 3A), a progressive intolerance to intraperitoneally administered insulin was evident starting at 7 months of age (Fig. 3B).

Fig. 3.

Fig. 3.

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Age-related changes in insulin action. WT mice (aged 5–16 mos) were subjected to: (A) intraperitoneal glucose tolerance test (n = 6/age group) and (B) intraperitoneal insulin tolerance test (n ≥ 4/age group). The accompanying bar graphs represent the area under the curve (AUC). Values were expressed as means ± SEM. *p < 0.05, vs youngest age group. (C) WT mice (3–8 mos) were fasted overnight (F) and refed for 7 hrs (RF) and retro-orbital blood was removed to analyze plasma insulin levels (a. upper panel). Values were expressed as means ± SEM. *p < 0.05, vs F. (c-d) lower panels are Western blot analysis in liver (b), hypothalamus (c) and white adipose tissue (WAT) (d) to analyze IRβ phosphorylation in RF vs F, and to detect CEACAM1 in the FASN immunopellet (Ip). (D) FASN activity was measured in duplicate by [14C]-malonyl-CoA incorporation (n = 5/age group). Values were expressed as mean ±SEM. *p < 0.05 vs 5 mos, †p < 0.05 vs 8 mos.

To identify which tissue developed insulin resistance by this age, we assessed insulin signaling in hepatic and extra-hepatic tissues post-insulin release in mice refed for 7 h (RF) following an overnight fast (F) (Fig. 3C.a, bar graph), as routinely done (Najjar et al., 2005). Western blot analysis showed blunted insulin-induced IRβ phosphorylation in liver lysates at 7 months (Fig. 3C.b; RF vs F lane; α-pIRβ blot normalized against loaded IRβ). This impaired CEACAM1 phosphorylation (pCC1) and lowered its interaction with fatty acid synthase (FASN), as indicated by its reduced detection in the FASN immunopellet (Fig. 3C.b; RF vs F lane, α-pCC1 blot relative to α-FASN blot). Consistent with our previous findings, (Najjar et al., 2005) reduced FASN-CEACAM1 binding removed the inhibition of FASN activity at 10 months of age (Fig. 3D). In the hypothalamus, IRβ phosphorylation, followed by that of CEACAM1 and its binding to FASN in response to insulin remained detectable up to 8 months of age (Fig. 3C.c), consistent with intact food intake at this age (Ghadieh et al., 2019). In white adipose tissue (WAT), IRβ phosphorylation was unchanged (Fig. 3C.d), indicating intact insulin signaling in adipocytes and ruling out systemic insulin resistance at 8 months. These findings demonstrated that hepatic insulin resistance preceded insulin resistance in extra-hepatic tissues in wild-type mice, phenocopying mice with liver-specific loss of Ceacam1 gene (Ghadieh et al., 2019).

3.3. Age-related changes in insulin metabolism in wild-type mice

Consistent with hepatic insulin resistance, mice developed significant hyperinsulinemia starting at ~8 months of age (Fig. 4A). This preceded the reduction in hepatic insulin clearance, as supported by the gradual decline in steady-state C-peptide-to-insulin ratio that reached statistical significance starting at 10 months (Fig. 4A). These early changes in insulin clearance could not be primarily attributed to reduced Ceacam1 and Ceacam2 expression since their > 50 % loss that is required to impair insulin clearance in liver and kidney, respectively, was not reached until 16 months of age (Fig. 4B) (Marmentini et al., 2021). Thus, the initial reduction of insulin clearance by 10 months of age could be attributed in part to insulin resistance-driven decrease in CEACAM1 phosphorylation, as supported by the early onset of impaired insulin clearance in L-SACC1 transgenic mice bearing a phosphorylation-defective dominant-negative CEACAM1 mutant in the liver (Poy et al., 2002). Given that ligand-activated PPARγ (Peroxisome proliferator-activated receptor gamma) and RXRα (Retinoid X Receptor alpha) induce Ceacam1 transcription, (Muturi et al., 2024; Ghadieh et al., 2017) the gradual decline in their hepatic content with aging (Fig. 4B) could mediate the remarkable reduction of hepatic Ceacam1 mRNA levels by 16 months of age.

Fig. 4.

Fig. 4.

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Effect of aging on insulin metabolism. (A) Steady-state plasma insulin and C-peptide levels were assayed in duplicate, and C-peptide/Insulin molar ratio was calculated as a measure of hepatic insulin clearance (n ≥ 5/age group). (B) Tissues were extracted to assess mRNA levels in duplicate of hepatic Ceacam1 (Cc1), PPARγ and RXRα; and renal Cc1 and Cc2 against 18 s in n = 3–4/age group. (C) Glucose-stimulated insulin secretion (GSIS) was assessed by measuring insulin levels at 0–120 min post intraperitoneal (IP) glucose injection in WT mice (3–18 months of age; n ≥ 4/age group). The accompanying graph represents AUC for acute insulin release between 0 and 15 min. In B and C, values were expressed as means±SEM. *p < 0.05, vs youngest age group.

We then assessed glucose-stimulated insulin secretion in mice at 3–18 months of age (Fig. 4C). Acute insulin release showed a progressive increase starting at 8 months, corroborating with the increase in plasma C-peptide levels (Fig. 4A). The rise in insulin release was likely compensatory to hepatic insulin resistance that emerged at 7 months (Fig. 3B), confirming intact β-cell function. The higher insulin excursion at 120 min post-glucose injection in 18-month-old relative to younger mice likely reflected systemic insulin resistance at this age (Fig. 4C).

3.4. Age-related development of steatosis and inflammation in wild-type mice

Next, we investigated age-related changes in liver histology. H&E staining of liver sections from mice at 8, 10, 13 and 17 months of age (Fig. 5A) revealed deposition of micro-vesicular fat droplets beginning at 10 months, followed by lobular inflammatory cell infiltration at 13 months, as depicted in the accompanying graph and in Table S1.

Fig. 5.

Fig. 5.

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Age-related progression of hepatic steatosis and inflammation. Livers of WT mice (8–17 months of age, n ≥ 4/age group) were subjected to (A) H&E staining to detect micro- and macro-vesicular fat deposits and foci of inflammatory cells. The NAFLD Activity Score (NAS) was presented in the accompanying graph. (B) liver sections were subjected to immunochemical analysis with Mac2, MPO, CD4, CD8 and Foxp3. Representative images were taken at 50 μm magnification and shown with insets at 20 μm. Graphs to the right show the number of positively stained cells at 40X magnification in five fields/mouse. Values were expressed as means ± SEM. *p < 0.05, vs youngest age group. (C) Livers were extracted from randomly selected WT (8 and 17 months-old) and LCC1 (17–20 months-old) mice and their lysates analyzed by immunoblotting (Ib) with phosphor NF-κB and Stat3 antibodies. The band density was assessed relative to the loaded NF-kB protein and presented in the accompanying graph in arbitrary units (a.u). Values were expressed as means ± SEM. *p < 0.05, vs youngest age group; ǂp < 0.05 LCC1 mice versus 17-month-old WT mice.

Hepatic steatosis in aged mice was likely related to increased NEFA uptake, as supported by elevated mRNA of CD36 fatty acid transporter starting at 10 months of age (Table S2), and to hyperinsulinemia-driven de novo lipogenesis, as supported by elevated FASN activity by this age (Fig. 3D).

RT-qPCR analysis showed a six-fold increase in F4/80 mRNA by 10 months (Table S2), indicating an expansion of the macrophage pool, followed by their increased recruitment (CD68 mRNA-Table S2) and activation starting at 13 months, as shown by immunohistochemical (IHC) analysis of Mac2 (Fig. 5B). Moreover, mRNA levels of neutrophil markers, MPO and elastase, were elevated by 5-to-15–fold at 10 months, followed by increased protein content by 13 months, as indicated by elevated MPO immunostaining in the hepatic parenchyma (Fig. 5B). In concert with macrophage activation, TNFα and IL-6 mRNA were elevated by 10 and 13 months, respectively (Table S2). Although no difference was observed in CD4 +T cells pool either at the mRNA (Table S2) or protein levels (Fig. 5B), IHC analysis revealed an increase in the immunostaining of CD8 +T cells in the liver parenchyma by 17 months (Fig. 5B). The increase in the mRNA levels of pro-inflammatory cytokine IFNγ at 13 months of age (Table S2) without any change in the mRNA levels of the anti-inflammatory cytokines such as IL-10 and IL-13 (Table S2) or the protein levels of Foxp3 (Fig. 5B) indicated a shift toward a Th1-driven immune response.

Consistent with less Shc sequestration and the reciprocal increase in its coupling to the insulin receptor in the absence of CEACAM1, (Ghadieh et al., 2020; Muturi et al., 2021) NF-κB was more activated (phosphorylated) in mice at 17 than at 8 months of age (Fig. 5C). This would contribute to the sustained higher production of the transcriptional targets of NF-κB (such as IL-6) which would in turn, sustain the activation of Stat3 inflammatory pathways (Fig. 5C).

3.5. Age-related development of fibrosis in wild-type mice

In addition to inflammation, chronic liver injury and oxidative stress drive apoptosis to bolster fibrosis (Friedman, 2025; Kostallari et al., 2025; Schwabe and Brenner, 2025). Consistently, the mRNA levels of markers of hepatic injury (Nqo, Hgf and Txn) and oxidative stress (Nox4 and Hif1α) substantially increased starting at 13 months of age (Table S3). This was followed by increased hepatocytic apoptosis of 17-month-old mice, as shown by Cleaved Caspase 3 staining (Fig. 6A). Bridging chicken-wire fibrosis, as shown by Sirius Red staining and Brunt’s Fibrosis Score (Fig. 6B; and accompanied graph) also developed in the liver parenchyma at 17 months. Consistently, mRNA levels of profibrogenic genes (Acta2, Tgfβ, and Col3α) (Table S3) were elevated at this age with no change in the mRNA levels of Smad7, a negative regulator of TGFβ-Smad2/3 profibrogenic signaling pathway.

Fig. 6.

Fig. 6.

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Age-related development of hepatic injury and fibrosis. Liver sections of WT mice were subjected to: (A) immunostaining with Cleaved caspase 3, marker for cell death. The number of positively stained cells was counted at 40X magnification in five fields/mouse and represented in the accompanying graph (n = 5/age group) and (B) staining with Sirius Red to detect interstitial and bridging fibrosis. Representative images were taken at 100 μm magnification and shown with insets at 50 μm (n = 5/age group). Accompanying graph shows fibrosis scoring per Brunt’s criteria. Values were expressed as means ±SEM. *p < 0.05, vs youngest age group.

3.6. Liver-specific overexpression of Ceacam1 prevents age-related steatohepatitis and hepatic fibrosis and bestows survival advantage

We have previously shown that high-fat diet (HF) causes insulin resistance and other metabolic abnormalities initially by reducing hepatic CEACAM1 expression before inflammation starts (Al-Share et al., 2015) and that acute adenoviral-mediated redelivery of CEACAM1 (Russo et al., 2016) and its forced liver-specific overexpression (i.e. LCC1 mice) (Al-Share et al., 2015) attenuates HF-induced metabolic alterations. Thus, we next investigated whether LCC1 mice were protected against age-related fibrosis. Of note, the rat CEACAM1 transgene was used because of the ~94 % shared homology of its intracellular domain that is implicated in insulin internalization with that of the mouse protein (Formisano et al., 1995).

Western blot analysis using species-specific antibodies (Fig. 7A) showed comparable mouse CEACAM1 protein levels (mCC1) with sustained transgenic rat (rCC1) expression in the livers of LCC1 mice at 17–20 months of age. As aforementioned, H&E staining revealed diffuse micro- and macro-vesicular fat deposits in the liver of WT mice at 17 months (Fig. 7B), whereas LCC1 mice (17–20 months, Fig. 7B) exhibited only sparse micro-vesicular fat distribution in the liver parenchyma. Additionally, H&E staining revealed large lobular infiltrates of immune cells in 17-month-old WT mice, whereas LCC1 mice showed almost negligible infiltration of inflammatory cells within the hepatic parenchyma at ≥ 17 months of age. In sum, NAS score [Nonalcoholic Fatty Liver Disease (NAFLD) Activity Score] regressed from 5.40 in WT to 2.60 in LCC1 mice at ≥ 17 months of age (Fig. 7, accompanying graph).

Fig. 7.

Fig. 7.

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Overexpressing CEACAM1 bestowed protection against age-induced inflammation. (A) Livers lysates from WT mice (17-months-old) and LCC1 mice (17–20 months old) were analyzed by immunoblotting with polyclonal CEACAM1 antibodies against rat (rCC1) and mouse (mCC1) protein (n = 3/genotype). Accompanying graphs show quantification in arbitrary units (a.u.). Values were expressed as means ± SEM. *p < 0.05, LCC1 vs 17-month-old mice. (B-C) Livers of WT (17 months of age) and LCC1 mice (17–20 months) (n = 5/genotype) were extracted and sectioned for (B) H&E (n = 5/age group) and (C) immunohistochemical analyses (n ≥ 4/age group) with Mac2, CD8 and Foxp3, as in Fig. 5B. Representative images were taken at 50 μm and shown with insets at 20 μm. Accompanying graphs represent the quantification that was assessed by counting the number of positively stained cells at 40X magnification in five fields/mouse. (D) RT-qPCR analysis of inflammatory markers in liver lysates performed in duplicate and normalized to 18 s (n ≥ 3/age group). Values were expressed as means ± SEM. *p < 0.05, LCC1 vs WT mice.

RT-qPCR and IHC analyses revealed markedly lower macrophage recruitment [F4/80 and CD68 mRNA levels (Fig. 7D) and activation [Mac-2 immunostaining (Fig. 7C)] in LCC1 compared to WT mice at ≥ 17 months of age. Similarly, LCC1 mice displayed reduced MPO (neutrophil, Fig. 7C) and CD8 +T (Fig. 7C) immunostaining as well as lower mRNA levels of pro-inflammatory IFNγ relative to WT (Fig. 7D). Reciprocally, the mRNA levels of the anti-inflammatory cytokines IL-10 and IL-13, released by regulatory T cells (Tregs), were significantly upregulated in LCC1 mice (Fig. 7D). This was consistent with CEACAM1 enhancing Treg activation, leading to the secretion of anti-inflammatory cytokines like IL-10, which in turn suppress macrophage activation (Horst et al., 2018). Whereas NF-κB was not commonly inactivated in all of the LCC1 mice tested (Fig. 5C), TNFα and IL-6 mRNA levels were normal (Fig. 7D) and Stat3 was inactivated in aged LCC1 mice (Fig. 5C). Together, the data showed that overexpressing CEACAM1 in the liver protected against age-related increase in the inflammatory milieu of the liver.

Similarly to inflammation, LCC1 livers manifested a remarkable drop in apoptosis, as shown by Cleaved Caspase 3 staining (Fig. 8A). This occurred in parallel to a drop in the mRNA levels of some liver injury markers (Nqo and Hgf) but not others (Txn and Nrf1) (Figure S2). Sirius Red-stained liver sections showed a remarkable drop of Brunt fibrosis score from ~2.2 in WT to 0.7 in LCC1 mice that hardly displayed any collagen staining (Fig. 8C). This was supported by lower mRNA of Acta2, Col3α1 and tgfβ genes with a reciprocal increase in Smad7 expression level in LCC1 relative to WT mice (Fig. 8B). The increase in Smad7 was consistent with blunted activation (phosphorylation) of the TGFβ/Smad3 pathway, as Western blot analysis revealed (Fig. 8D).

Fig. 8.

Fig. 8.

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Forced overexpression of hepatic CEACAM1 protected against age-related hepatic fibrosis and bestowed survival advantage. Livers from WT (17 months of age) and LCC1 (17–20 months) mice (n = 5/genotype) were extracted to be analyzed: (A) immunostaining liver sections with Cleaved caspase 3. (B) RT-qPCR in duplicate of fibrosis markers, normalized to 18 s. Values were expressed as means ±SEM. *p < 0.05, LCC1 vs WT mice. (C) staining liver sections with Sirius Red to detect interstitial and bridging fibrosis. Representative images were taken at 100 μm magnification and shown with insets at 50 μm for the WT and LCC1 mice (n = 5/age group). Accompanying graphs showed fibrosis scoring per Brunt’s criteria. (D) Western blot analysis of Liver lysates for TGFβ/Smad3 activation and for collagen deposition (MMP9, MMP13 and TIMP1) and resolution (MMP13) (n = 3–4 mice/genotype). Accompanying graphs show quantification in arbitrary units (a.u.). (E) WT (n = 13, black line) and LCC1 mice (n = 16, red line) were monitored for survival over time. The number of mice at risk left after deceased mice were removed because of natural death was tabulated and presented below the curve.

Matrix metalloproteinases (MMPs) and Tissue Inhibitor of Metalloproteinases (TIMPs) are involved in myofibroblast activation and extracellular matrix resolution during fibrogenesis (Duarte et al., 2015; Giannandrea and Parks, 2014) and are activated by TGFβ and NFκB pathways (Vincenti and Brinckerhoff, 2007). Consistently, the protein content of pro-fibrogenic MMP9 and TIMP1 in the livers of aged LCC1 were lower than WT mice (Fig. 8D), with no difference in the levels of MMP13 that plays a dual role as myofibroblast activator and contributor to ECM resolution. This demonstrated that the balance shifted toward collagen resolution in aged LCC1 relative to WT livers.

Kaplan–Meier survival analysis (Fig. 8E) revealed that the calculated median survival to be 27 weeks for WT (n = 13) and 31 weeks for LCC1 (n = 16) mice. While the difference in median survival was not statistically significant (survival ratio = 0.871; 95 % CI: 0.419–1.811), analysis of the overall survival distribution using the Mantel–Cox log-rank test demonstrated a significant survival advantage in LCC1 mice, with a hazard ratio of 3.517 (95 % CI: 1.385–8.933; p < 0.0001). This indicated that WT mice had a more than threefold higher risk of death over time. Together, the data demonstrated that forced overexpressing of CEACAM1 in the liver protected against age-related fibrosis and bestowed a survival advantage, which likely emanated from reversed hepatic fibrosis.

4. Discussion

Aging is associated with metabolic disorders, metabolic inflexibility (Osmond et al., 2024) and liver diseases (Radonjic et al., 2022) that have also been strongly linked to Western diet intake (Ghosh et al., 2010; Helal et al., 2021; Al-Share et al., 2015; Pereira et al., 2014; Najjar et al., 2022). This raises the question whether the metabolic disorders induced by a high-fat diet share similar underlying mechanisms as aging-related abnormalities. Adipose tissue dysfunction and excessive abdominal fat deposition induces lipolysis-derived NEFA, a critical instigator not only of insulin resistance (Najjar et al., 2022; Nahle et al., 2021) but also of hepatic fibrosis even in lean patients with MASH (Saponaro et al., 2022). Consistently, the current study demonstrated that lipolysis-derived NEFA ignited the progression of metabolic and histological changes related to normal aging since its induction was the first abnormality detected at 5 months of age before other features of lipid and insulin dysregulation emerged, followed by the diverse histological manifestations of MASLD/MASH in aged WT male mice.

At 5 months of age, plasma NEFA levels rose with a simultaneous decrease in spontaneous locomotor activity in the absence of increased food intake which would develop at about 16 months of age, as supported by the chronic hyperleptinemia state at this age and as recently observed (Ogiso et al., 2025). The increase in NEFA release preceded the gradual gain in fat mass, including visceral fat, and body weight with a reciprocal loss in lean mass. Further emphasizing the role of NEFA in lipid dysregulation, its plasma levels increased before the delayed transition from lipolytic to glycolytic metabolism following an overnight fast occurred at 9 months. This sustained reliance on fatty acid oxidation, driven by increased availability of plasma NEFA is in agreement with recent observations of post-refeeding delay in energy substrate partitioning between fat to carbohydrates in older individuals (Osmond et al., 2024). Together, this demonstrated that excessive NEFA release caused age-related dysregulation of lipid metabolism and energy imbalance in WT mice.

Increase in lipolysis-derived NEFA in response to dietary fat intake causes hepatic insulin resistance initially by progressively down-regulating CEACAM1 expression via a PPARα-mediated mechanism before inflammation starts (Russo et al., 2016). This bestows a positive feedback mechanism on fatty acid β-oxidation at an early stage when CEACAM1 levels remain ≥ 50 %, (Russo et al., 2016) mediated by the removal of the suppressive effect of CEACAM1 on FASN activity (Najjar et al., 2005) and providing substrates for PPARα activation. When the loss of CEACAM1 is > 60 %, insulin clearance is impaired and the resultant hyperinsulinemia drives hepatic insulin resistance and hepatic steatosis. Additionally, lipolysis-derived NEFA activate PKCδ, which subsequently induces oxidative stress and activates the JKK/iKK pathway (Pereira et al., 2014). This releases TNFα to stem insulin receptor substrate 1 phosphorylation and downstream signaling pathways (Pereira et al., 2014; Najjar et al., 2022). Accordingly, insulin intolerance progressively developed in WT mice starting at 7 months of age, following the release of NEFA, in association with defective insulin signaling, including blunted insulin-induced CEACAM1 phosphorylation in the liver. Consistent with the phenotype of L-SACC1 mice overexpressing a dominant-negative phosphorylation-defective isoform of CEACAM1 in the liver, (Poy et al., 2002) this impaired insulin clearance. Combined with the progressive increase in glucose-induced insulin secretion beginning at 8 months, the decline in insulin clearance compensated for hepatic insulin resistance, which eventually progressed to systemic insulin resistance, as indicated by the robust increase in the chronic phase of insulin secretion at 18 months of age. The delayed systemic insulin resistance likely resulted from the remarkable > 90 % decrease in Ceacam1 expression by 16 months, as expected from the phenotype of mice with liver-specific loss of CEACAM1 (Ghadieh et al., 2019). Consistent with the transcriptional activation of Ceacam1 by insulin, (Ghadieh et al., 2018) PPARγ and RxRα (Muturi et al., 2024; Ghadieh et al., 2018), its loss in aged WT mice likely resulted from insulin resistance in addition to the significant decline of these transcriptional nuclear receptors with age. Collectively, the data provide an in vivo demonstration of how NEFA release could ignite age-related impairment of insulin clearance and chronic hyperinsulinemia mediated by the remarkable loss of CEACAM1 phosphorylation and expression.

Consistent with chronic hyperinsulinemia driving de novo lipogenesis, WT mice developed hepatic micro-steatosis at 10 months of age, followed by inflammation and oxidative stress at 13 months leading to macro-steatosis, apoptosis and fibrosis at 17 months. This was expected from the central role of lipogenesis and inflammation in hepatocellular injury (Friedman, 2025; Kostallari et al., 2025) and consistent with lipotoxicity amplifying advanced features of MASLD/MASH, including fibrosis (Friedman, 2025; Najjar and Russo, 2014). Hyperinsulinemia could also drive hepatic fibrosis by inducing collagen type I production via activating the α5β1 integrin-FAK pathway, as shown in L-SACC1 mice (Dodig et al., 2024). That reduced CEACAM1 expression caused these metabolic and histological abnormalities is consistent with its metabolic and immune regulation of liver function, (Horst et al., 2018; Dery et al., 2024; Najjar and Shively, 2024; Nakamura et al., 2020) and by the phenotype of mice with germ-line inactivation (L-SACC1) (Lee et al., 2008) and deletion of Ceacam1 in liver (Zaidi et al., 2024).

Underscoring the critical role of the significant loss of CEACAM1 in the aging process, its forced APOA1-driven overexpression in the liver (as in LCC1 mice) protected C57BL6/J mice against the deleterious metabolic effect of high-fat diet, including insulin resistance and hepatic steatohepatitis (Al-Share et al., 2015) and adipose tissue inflammation and fibrosis (Lester et al., 2015). The current study similarly demonstrated reversal of steatohepatitis and regression of NAS score from 5.40 in WT to 2.60 in LCC1 mice at ≥ 17 months of age, and for the first time, age-related apoptosis and hepatic fibrosis. While reversal of hyperinsulinemia and steatosis could contribute to the suppression of inflammation in aged LCC1 mice, (Friedman, 2025) the latter could result from the restoration of the anti-inflammatory action of CEACAM1 long isoform (−4L) (Horst et al., 2018; Najjar and Russo, 2014; Dery et al., 2024). This is consistent with the reversal of diet-induced pro-inflammatory state in C57BL6/J mice by adenoviral-mediated delivery of the anti-inflammatory WT CEACAM1–4L but not its phosphorylation-defective mutants (Russo et al., 2016). Reversal of fibrosis in LCC1 mice was mediated by blunted TGFβ/Smad3 signaling pathway, which contributed to reduced extracellular matrix protein expression (MMPs, TIMP) in aged LCC1 mice. The data lend support to the critical role of CEACAM1 in age-related hepatic fibrosis. The survival advantage bestowed by forced overexpression of CEACAM1 in the liver of LCC1 mice suggests that protecting hepatic CEACAM1 expression can prolong life, likely by mitigating hepatic fibrosis.

The reversal of fibrosis and MASH in aged mice, and their survival advantage upon protecting hepatic CEACAM1 expression underscores its crucial role in maintaining normal liver architecture and function, even in the face of aging which is associated with liver susceptibility to injury and fibrosis in humans and rodents. These findings suggest a potential therapeutic role for hepatic CEACAM1 in reversing/preventing age-related liver damage and dysfunction.

Supplementary Material

1

Financial Support

This work was supported by NIH grants: R01-DK054254, R01-DK124126 and R01-DK129877 to SMN. The work was also supported by the Osteopathic Heritage Foundation John J. Kopchick Eminent Research Chair to SMN.

Abbreviations:

CEACAM1

Carcinoembryonic Antigen-related Cell Adhesion Molecule 1

Ceacam1

Gene encoding CEACAM1 protein in mice

LCC1

Transgenic mice with forced liver-specific overexpression of rat CEACAM1–4 L driven by human APOA1 promoter

FASN

Fatty acid synthase

NEFA

Non-esterified fatty acids

WAT

White adipose tissue

WT

Wild-type mice on C57BL/6 J background

HSCs

Hepatic Stellate Cells

PPARγ

Peroxisome proliferator-activated receptor gamma

RXRα

Retinoid X Receptor alpha

NAS score

Nonalcoholic Fatty Liver Disease NAFLD Activity Score

Appendix A. Supporting information

Supplementary data associated with this article can be found in the online version at doi:10.1016/j.mad.2025.112122.

Footnotes

Ethical Statement

The submitted work had not been previously published or considered for publication by another journal. All authors have read the manuscript and approved its submission to the journal to be considered for publication.

CRediT authorship contribution statement

Sobia Zaidi: Writing – review & editing, Writing – original draft, Project administration, Methodology, Investigation, Formal analysis, Data curation. Suman Asalla: Methodology, Formal analysis, Data curation. Raziyeh Abdolahipour: Methodology, Investigation, Formal analysis, Data curation. Portuphy Agnes O: Methodology, Investigation, Data curation. Jahromi Marziyeh Salehi: Investigation, Formal analysis, Data curation. Muturi Harrison T: Investigation, Formal analysis, Data curation. Belew Getachew Debas: Data curation. Ramiro Malgor: Formal analysis. Sivarajan Kumarasamy: Methodology, Investigation, Data curation. Najjar Sonia M: Writing – review & editing, Supervision, Resources, Project administration, Funding acquisition, Formal analysis, Conceptualization.

Declaration of Competing Interest

All authors declare no conflict of interest

Data availability

Data will be made available on request.

References

  1. Al-Share QY, DeAngelis AM, Lester SG, et al. , 2015. Forced Hepatic Overexpression of CEACAM1 Curtails Diet-Induced Insulin Resistance (Aug). Diabetes 64 (8), 2780–2790. 10.2337/db14-1772. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bergman RN, Kabir M, Ader M, 2022. The Physiology of Insulin Clearance. Feb 5 Int J. Mol. Sci 23 (3). 10.3390/ijms23031826. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Brunt EM, Kleiner DE, Carpenter DH, et al. , 2021. NAFLD: Reporting Histologic Findings in Clinical Practice (May). Hepatology 73 (5), 2028–2038. 10.1002/hep.31599. [DOI] [PubMed] [Google Scholar]
  4. DeAngelis AM, Heinrich G, Dai T, et al. , 2008. Carcinoembryonic antigen-related cell adhesion molecule 1: a link between insulin and lipid metabolism (Sep). Diabetes 57 (9), 2296–2303. 10.2337/db08-0379. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dery KJ, Najjar SM, Beauchemin N, Shively JE, Kupiec-Weglinski JW, 2024. Mechanism and function of CEACAM1 splice isoforms (Dec). Eur. J. Clin. Invest 54 (2), e14350. 10.1111/eci.14350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Dodig M, Li M, Dasarathy S, et al. , 2024. Insulin increases type I collagen synthesis in hepatic stellate cells via α5β1 integrin ([Accept]). Metab. Target Organ Damage 5. 10.20517/mtod.2024.59. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Duarte S, Baber J, Fujii T, Coito AJ, 2015. Matrix metalloproteinases in liver injury, repair and fibrosis. May–Jul Matrix Biol. 44–46, 147–156. 10.1016/j.matbio.2015.01.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Fontana L, Partridge L, Longo VD, 2010. Extending healthy life span–from yeast to humans. Apr 16 Science 328 (5976), 321–326. 10.1126/science.1172539. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Formisano P, Najjar SM, Gross CN, et al. , 1995. Receptor-mediated internalization of insulin. Potential role of pp120/HA4, a substrate of the insulin receptor kinase. Comparative Study. Oct 13 J. Biol. Chem 270 (41), 24073–24077. [DOI] [PubMed] [Google Scholar]
  10. Friedman SL, 2025. Fat, fibrosis, and the future: navigating the maze of MASLD/MASH. Apr 1 J. Clin. Invest 135 (7). 10.1172/JCI186418. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Georgieva M, Xenodochidis C, Krasteva N, 2023. Old age as a risk factor for liver diseases: Modern therapeutic approaches (Dec). Exp. Gerontol 184, 112334. 10.1016/j.exger.2023.112334. [DOI] [PubMed] [Google Scholar]
  12. Ghadieh HE, Muturi HT, Najjar SM, 2017. Exenatide Prevents Diet-induced Hepatocellular Injury in A CEACAM1-Dependent Mechanism. J. Diabetes Treat 2017 (4). 10.29011/2574.7568.000033. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Ghadieh HE, Muturi HT, Russo L, et al. , 2018. Exenatide induces carcinoembryonic antigen-related cell adhesion molecule 1 expression to prevent hepatic steatosis (Jan). Hepatol. Commun 2 (1), 35–47. 10.1002/hep4.1117. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Ghadieh HE, Russo L, Muturi HT, et al. , 2019. Hyperinsulinemia drives hepatic insulin resistance in male mice with liver-specific Ceacam1 deletion independently of lipolysis (Apr). Metabolism 93, 33–43. 10.1016/j.metabol.2019.01.008. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Ghadieh HE, Abu Helal R, Muturi HT, et al. , 2020. Loss of Hepatic Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 Links Nonalcoholic Steatohepatitis to Atherosclerosis (Nov). Hepatol. Commun 4 (11), 1591–1609. 10.1002/hep4.1590. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Ghanem SS, Heinrich G, Lester SG, et al. , 2016. Increased Glucose-induced Secretion of Glucagon-like Peptide-1 in Mice Lacking the Carcinoembryonic Antigen-related Cell Adhesion Molecule 2 (CEACAM2). Jan 08 J. Biol. Chem 291 (2), 980–988. 10.1074/jbc.M115.692582. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Ghanem SS, Muturi HT, DeAngelis AM, et al. , 2017. Age-dependent insulin resistance in male mice with null deletion of the carcinoembryonic antigen-related cell adhesion molecule 2 gene (Sep). Diabetologia 60 (9), 1751–1760. 10.1007/s00125-017-4307-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Ghosh S, Kaw M, Patel PR, et al. , 2010. Mice with null mutation of Ceacam I develop nonalcoholic steatohepatitis (May). Hepat. Med. Res Evid 2010 (2), 69–78. 10.2147/HMER.S8902. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Giannandrea M, Parks WC, 2014. Diverse functions of matrix metalloproteinases during fibrosis (Feb). Dis. Model Mech 7 (2), 193–203. 10.1242/dmm.012062. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Heinrich G, Ghosh S, Deangelis AM, et al. , 2010. Carcinoembryonic antigen-related cell adhesion molecule 2 controls energy balance and peripheral insulin action in mice (Aug). Gastroenterology 139 (2), 644–652. 10.1053/j.gastro.2010.03.056. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Heinrich G, Russo L, Castaneda TR, et al. , 2016. Leptin resistance contributes to obesity in mice with null mutation of carcinoembryonic antigen-related cell adhesion molecule 1. May 20 J. Biol. Chem 291 (21), 11124–11132. 10.1074/jbc.M116.716431. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Helal RA, Russo L, Ghadieh HE, et al. , 2021. Regulation of hepatic fibrosis by carcinoembryonic antigen-related cell adhesion molecule 1 (Aug). Metabolism 121, 154801. 10.1016/j.metabol.2021.154801. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Horst AK, Najjar SM, Wagener C, Tiegs G, 2018. CEACAM1 in Liver Injury, Metabolic and Immune Regulation. Oct 11 Int J. Mol. Sci 19 (10). 10.3390/ijms19103110. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Hunt NJ, Kang SWS, Lockwood GP, Le Couteur DG, Cogger VC, 2019. Hallmarks of Aging in the Liver. Comput. Struct. Biotechnol. J 17, 1151–1161. 10.1016/j.csbj.2019.07.021. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Kostallari E, Schwabe RF, Guillot A, 2025. Inflammation and immunity in liver homeostasis and disease: a nexus of hepatocytes, nonparenchymal cells and immune cells. Jul 1 Cell Mol. Immunol. 10.1038/s41423-025-01313-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Lee SJ, Heinrich G, Fedorova L, et al. , 2008. Development of nonalcoholic steatohepatitis in insulin-resistant liver-specific S503A carcinoembryonic antigen-related cell adhesion molecule 1 mutant mice (Dec). Gastroenterology 135 (6), 2084–2095. 10.1053/j.gastro.2008.08.007. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Lee W, 2011. The CEACAM1 expression is decreased in the liver of severely obese patients with or without diabetes. Diagn. Pathol 6, 40. 10.1186/1746-1596-6-40. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Lester SG, Russo L, Ghanem SS, et al. , 2015. Hepatic CEACAM1 over-expression protects against diet-induced fibrosis and inflammation in white adipose tissue. Front Endocrinol. (Lausanne: ) 6, 116–122. 10.3389/fendo.2015.00116. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Lopez-Otin C, Blasco MA, Partridge L, Serrano M, Kroemer G, 2023. Hallmarks of aging: An expanding universe. Jan 19 Cell 186 (2), 243–278. 10.1016/j.cell.2022.11.001. [DOI] [PubMed] [Google Scholar]
  30. Marmentini C, Soares GM, Bronczek GA, et al. , 2021. Aging Reduces Insulin Clearance in Mice. Front Endocrinol. (Lausanne: ) 12, 679492. 10.3389/fendo.2021.679492. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Muturi HT, Khuder SS, Ghadieh HE, et al. , 2021. Insulin Sensitivity Is Retained in Mice with Endothelial Loss of Carcinoembryonic Antigen Cell Adhesion Molecule 1. Aug 14 Cells 10 (8). 10.3390/cells10082093. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Muturi HT, Ghadieh HE, Abdolahipour R, et al. , 2023. Loss of CEACAM1 in endothelial cells causes hepatic fibrosis (Jul). Metabolism 144, 155562. 10.1016/j.metabol.2023.155562. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Muturi HT, Ghadieh HE, Asalla S, et al. , 2024. Conditional deletion of CEACAM1 in hepatic stellate cells causes their activation (Oct). Mol. Metab 88, 102010. 10.1016/j.molmet.2024.102010. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Nahle A, Joseph YD, Pereira S, et al. , 2021. Nicotinamide Mononucleotide Prevents Free Fatty Acid-Induced Reduction in Glucose Tolerance by Decreasing Insulin Clearance. Dec 8 Int J. Mol. Sci 22 (24). 10.3390/ijms222413224. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Najjar SM, Perdomo G, 2019. Hepatic Insulin Clearance: Mechanism and Physiology. May 1 Physiol. (Bethesda: ) 34 (3), 198–215. 10.1152/physiol.00048.2018. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Najjar SM, Russo L, 2014. CEACAM1 loss links inflammation to insulin resistance in obesity and non-alcoholic steatohepatitis (NASH). Nov 21 Semin Immunopathol. 36 (1), 55–71. 10.1007/s00281-013-0407-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Najjar SM, Shively JE, 2024. Regulation of lipid storage and inflammation in the liver by CEACAM1 (Dec). Eur. J. Clin. Invest 54 (2), e14338. 10.1111/eci.14338. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Najjar SM, Yang Y, Fernstrom MA, et al. , 2005. Insulin acutely decreases hepatic fatty acid synthase activity (Jul). Cell Metab. 2 (1), 43–53. 10.1016/j.cmet.2005.06.001. [DOI] [PubMed] [Google Scholar]
  39. Najjar SM, Abdolahipour R, Ghadieh HE, et al. , 2022. Regulation of Insulin Clearance by Non-Esterified Fatty Acids. Aug 5 Biomedicines 10 (8). 10.3390/biomedicines10081899. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Najjar SM, Caprio S, Gastaldelli A, 2023. Insulin Clearance in Health and Disease. Feb 10 Annu Rev. Physiol 85, 363–381. 10.1146/annurev-physiol-031622-043133. [DOI] [PubMed] [Google Scholar]
  41. Nakamura K, Kageyama S, Kaldas FM, et al. , 2020. Hepatic CEACAM1 expression indicates donor liver quality and prevents early transplantation injury. May 1 J. Clin. Invest 130 (5), 2689–2704. 10.1172/JCI133142. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Ogiso N, Almunia JA, Munesue Y, et al. , 2025. Biological characteristics of age-related changes in C57BL/6 mice sub-strains in the national center for geriatrics and gerontology aging farm. Apr 20 Exp. Anim 74 (2), 229–238. 10.1538/expanim.24-0095. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Osmond AD, Leija RG, Arevalo JA, et al. , 2024. Aging delays the suppression of lipolysis and fatty acid oxidation in the postprandial period. Nov 1 J. Appl. Physiol. (1985) 137 (5), 1200–1219. 10.1152/japplphysiol.00437.2024. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Patarrao RS, Meneses MJ, Ghadieh HE, et al. , 2024. Insights into circulating CEACAM1 in insulin clearance and disease progression: Evidence from the Portuguese PREVADIAB2 study (Dec). Eur. J. Clin. Invest 54 ((2), e14344. 10.1111/eci.14344. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Pereira S, Park E, Mori Y, et al. , 2014. FFA-induced hepatic insulin resistance in vivo is mediated by PKCδ, NADPH oxidase, and oxidative stress. Am. J. Physiol. Endocrinol. Metab 307 (1), E34–E46. 10.1152/ajpendo.00436.2013. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Poy MN, Yang Y, Rezaei K, et al. , 2002. CEACAM1 regulates insulin clearance in liver (Mar). Nat. Genet 30 (3), 270–276. 10.1038/ng840. [DOI] [PubMed] [Google Scholar]
  47. Radonjic T, Dukic M, Jovanovic I, et al. , 2022. Aging of Liver in Its Different Diseases. Oct 28 Int J. Mol. Sci 23 (21). 10.3390/ijms232113085. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Russo L, Ghadieh HE, Ghanem SS, et al. , 2016. Role for hepatic CEACAM1 in regulating fatty acid metabolism along the adipocyte-hepatocyte axis (Dec). J. Lipid Res 57 (12), 2163–2175. 10.1194/jlr.M072066. [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Russo L, Muturi HT, Ghadieh HE, et al. , 2017. Liver-specific reconstitution of CEACAM1 reverses the metabolic abnormalities caused by its global deletion in male mice (Dec). Diabetologia 60 (12), 2463–2474. 10.1007/s00125-017-4432-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Saponaro C, Sabatini S, Gaggini M, et al. , 2022. Adipose tissue dysfunction and visceral fat are associated with hepatic insulin resistance and severity of NASH even in lean individuals (Nov). Liver Int 42 (11), 2418–2427. 10.1111/liv.15377. [DOI] [PubMed] [Google Scholar]
  51. Schwabe RF, Brenner DA, 2025. Hepatic stellate cells: balancing homeostasis, hepatoprotection and fibrogenesis in health and disease (Jul). Nat. Rev. Gastroenterol. Hepatol 22 (7), 481–499. 10.1038/s41575-025-01068-6. [DOI] [PubMed] [Google Scholar]
  52. Vincenti MP, Brinckerhoff CE, 2007. Signal transduction and cell-type specific regulation of matrix metalloproteinase gene expression: can MMPs be good for you? (Nov). J. Cell Physiol 213 (2), 355–364. 10.1002/jcp.21208. [DOI] [PubMed] [Google Scholar]
  53. Wahid RM, Hassan NH, Samy W, et al. , 2024. Unraveling the hepatic stellate cells mediated mechanisms in aging’s influence on liver fibrosis. Jun 12 Sci. Rep 14 (1), 13473. 10.1038/s41598-024-63644-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  54. Wu Y, Yang Z, Zhu L, Su Q, Qin L, 2020. Association of circulating CEACAM1 levels and insulin sensitivity in gestational diabetes mellitus. May 15 BMC Endocr. Disord 20 (1), 66. 10.1186/s12902-020-00550-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Zaidi S, Asalla S, Muturi HT, et al. , 2024. Loss of CEACAM1 in hepatocytes causes hepatic fibrosis (Jul). Eur. J. Clin. Invest 54 (7), e14177. 10.1111/eci.14177. [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

1
NIHMS2185845-supplement-1.docx (769.9KB, docx)

Data Availability Statement

Data will be made available on request.

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