Treatment with MG53 ameliorates traumatic brain injury–associated acute kidney injury

Abstract

INTRODUCTION:

Multiorgan dysfunction (MOD) after traumatic brain injury (TBI) results in increased morbidity and mortality. There is emerging evidence demonstrating TBI-induced inflammatory responses; however, the mechanisms driving TBI-induced organ injury remains unknown and understudied. MG53, a cell membrane repair protein, has been shown to reduce brain lesion size following TBI. In this study, we aimed to establish a large animal model of post-TBI MOD, determine MG53’s role in renal protection following TBI, and explore a mechanistic link between endothelial cell dysfunction and post-TBI MOD.

METHODS:

Female Yorkshire swine (n = 5/group) were subjected to controlled cortical impact TBI and randomized to receive (1) MG53 protein therapy or (2) normal saline (control). Biomarkers of acute kidney injury were compared between the groups. Kidneys were analyzed for histologic evidence of acute injury. Top-down proteomics were performed on swine plasma at various times post-TBI.

RESULTS:

Control animals had a significant increase in creatinine from baseline by 6 hours post-TBI (p = 0.007), which was attenuated in the MG53-treated animals (p = 0.089). Control animals had a significant increase in plasma NGAL from baseline starting at 4 hours from baseline (p = 0.014). Animals treated with MG53 had no change in serum NGAL from baseline (p = 0.163). Histologic analysis showed protection of proximal tubular epithelial cell damage in animals treated with MG53. Proteoform data showed differential expression of apolipoprotein 1, fibrinogen β, and osteocalcin.

CONCLUSION:

Traumatic brain injury can induce distant organ damage, possibly through endothelial cell dysfunction, and treatment with a cell membrane repair protein (MG53) can protect against this injury.

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality among trauma patients, contributing to more than one third of injury-related deaths.¹ Nonneurologic multiorgan dysfunction (MOD) has been estimated to occur in 60% to 90% of patients with brain injury.^2–4 Multiorgan dysfunction significantly impacts mortality and functional outcomes in the acute and chronic periods following brain injury.^5,6 While every organ system is at risk, acute kidney injury (AKI) following TBI is common (incidence of 8–14%) and has consistently been associated with poor clinical outcomes.^4,7–10 The mechanism of TBI-induced MOD remains poorly understood, largely because of the lack of animal models that can robustly recapitulate the phenomenon. It is increasingly recognized that central nervous system injuries (stroke and TBI) can induce endothelial cell activation and dysfunction in distant organs.^11–16 This is becoming increasingly investigated as a possible mechanism of distant organ injury contributing to MOD.^8,15 Understanding the mechanisms contributing to post-TBI distant MOD, particularly TBI-induced endotheliopathy, may have tremendous implications in improving the prognosis of these patients.

MG53 protein (encoded by TRIM72 gene) is a member of the tripartite motif family and constitutes a major repair mechanism for cell plasma membrane damage. Studies have demonstrated the benefits of MG53 protein therapy in a variety of disease models,^17–19 including a recent study demonstrating neuronal protection in a swine model of severe TBI.²⁰ While MG53 is highly expressed in skeletal muscle, it has very low expression in nonmuscle organs that are susceptible to TBI-induced organ dysfunction, such as the kidney.¹⁴ Recent studies suggest that MG53 offers renal protection in murine models of ischemia-reperfusion injury and contrast-induced AKI.^18,19,21 Currently, it is unknown whether systemic administration can also offer kidney protection following severe TBI.

In this current study, we aim to establish a robust large animal model that could recapitulate the extracranial/distant MOD after severe isolated TBI. We hypothesized that, following severe isolated TBI, we would see evidence of AKI, and systemic MG53 protein therapy could attenuate the extracranial injury, possibly via directly modulating endothelial cell dysfunction in distant organs.

MATERIALS AND METHODS

Animal Protocol

We adhered to the Animal Welfare Act Regulations and other federal statutes relating to the ethical treatment of animals involved in experiments set forth in the current version of the Guide for Care and Use of Laboratory Animals, National Research Council. All animal protocols were approved by the Institutional Animal Care and Use Committee. This study adhered to the Animal Research: Reporting of In Vivo Experiments guidelines (Supplemental Digital Content, Supplementary Table S1, http://links.lww.com/TA/E530). The animal protocol for the swine experiment has been published previously.²⁰ In brief, female Yorkshire swine (n = 10) between 40 and 45 kg were used (Oak Hill Genetics, Ewing, IL). After sedation, endotracheal intubation, and placement of the right femoral arterial line and cystostomy tube, the animals were prepared for induction of TBI. The head was secured in a stereotactic frame. A U-shaped scalp incision was made, and a skin flap was raised to expose the bregma. A 20-mm burr hole was made just anterior and to the right of the bregma to expose the dura. A controlled cortical impact device was used to induce the TBI through the 20-mm burr hole at a velocity of 4 m/s, with 100-ms dwell time, and 12-mm depth. Immediately following TBI (within 10 minutes), animals were randomized to receive either normal saline (NS) vehicle (NS group n = 5) or 2 mg/kg recombinant human MG53 (rhMG53) in saline (MG53 group; n = 5) intravenously over 30 minutes. Two animals who did not undergo TBI or instrumentation were euthanized to serve as histology controls. The preparation of the rhMG53 has been previously described,¹⁷ and the dose of rhMG53 was chosen based on dose escalation experiments in swine and mice.^22–24 All animals were included in the study. Animals who experienced severe cardiac events after induction of anesthesia, but before randomization, were excluded (n = 0).

Sample Collection

Blood samples were collected serially at baseline (prior to injury), 1 hour, 2 hours, 4 hours, and 6 hours post injury (just prior to euthanasia). After euthanasia, a necropsy was performed, and all organs were harvested. The organs were fixed in 10% formalin for 48 hours then preserved in 70% ethanol until paraffin blocks were made. The slides of the anterior cortex of the kidney samples were stained with periodic acid-Schiff staining. Slides were reviewed by a blinded pathologist.

NGAL Enzyme-Linked Immunosorbent Assay

Blood samples were collected in EDTA tubes, centrifuged at 3000 g for 10 minutes and plasma was stored at −80°C until analysis. A sandwich enzyme-linked immunosorbent assay (ELISA) technique was used to quantify plasma neutrophil gelatinase lipocalin (NGAL) levels, a biomarker for AKI, at baseline, 4 hours post-TBI, and 6 hours post-TBI. NGAL concentrations were measured using a commercially available ELISA kit (AB207924; Abcam Inc., Waltham, MA) with antibody directed against pig lipocalin-2, the swine equivalent for NGAL, following the manufacturer’s instructions. Absorbance of the microplate was measured at 450 nm in a microplate reader (BioTek Synergy LX, Winooski, VT) using reference wave-length 650 nm per manufacturer recommendation. Standards and blanks were included to ensure assay accuracy.

Proteoform Analysis

Abundant plasma proteins from samples collected at baseline, 2 hours, 4 hours, and 6 hours from control swine (12 samples) were precipitated following a published protocol.²⁵ Final protein concentrations were determined using a bicinchoninic acid protein assay kit (ThermoFisher Scientific, Waltham, MA), adhering to the manufacturer’s instructions. Prior to liquid chromatography–mass spectrometry analysis, samples were diluted with 0.1% formic acid. Each plasma sample was measured in triplicate, and 1 μg of protein was separated using a Vanquish Neo UHPLC system (ThermoFisher Scientific) connected to an Orbitrap Eclipse mass spectrometer (ThermoFisher Scientific) in intact protein mode with 2 mTorr of N2 pressure in the ion routing multipole. Reversed-phase liquid chromatography was performed on a MAbPac EASY-Spray column (150 mm length by 150 μm i.d.; ThermoFisher Scientific) and an in-house packed PLRP-S trap (25 mm length by 150 μm i.d.; Agilent, Santa Clara, CA) using a 120-minute gradient of mobile phase A (99.9% water, 0.1% formic acid) and mobile phase B (19.9% water, 80% acetonitrile, 0.1% diethylamino).

The raw data files were analyzed using the publicly accessible standard workflow on TDPortal (https://portal.nrtdp.northwestern.edu , Code Set 4.0.0). Raw data were deconvoluted and searched against a database of Sus scrofa (pig), derived from Swiss-Prot (October 2024), maintaining a 1% false discovery rate at the protein, isoform, and proteoform levels.²⁶ For quantitative proteoform analysis, an isotopic fitting algorithm was applied across all first-pass (MS1) spectra, and peak intensities were aggregated across all scans and charge states to report a single intensity value for each proteoform reported in the study.²⁷

Statistical Analysis

All data are presented as mean ± SD, unless mentioned otherwise. Creatinine levels, aspartate aminotransferase levels, and NGAL concentrations were compared using unpaired Student’s t test using GraphPad Prism 9.4.1 (GraphPad Software, San Diego, CA). Statistical significance was defined as p < 0.05. For the swine studies, the sample size calculated using a 90% power and the 95% confidence interval to detect laboratory markers of acute organ injury, was n = 5/group. Our primary outcome was evidence of acute organ injury.

To assess differentially expressed proteoforms, log2 intensities were z score normalized across samples and used as a dependent variable in a hierarchical mixed linear regression model using “lmer” function from “lme4 (v.1.1.35.5)” R package.²⁸ Bio- and technical replicates were set as random nested variates in the model. p Values were adjusted using a Benjamini and Hochberg²⁹ approach to control the false discovery rate induced by multiple comparison tests. Proteoforms with p values <0.01, adjusted p values <0.1, and fold change greater than 1.5 or less than 0.66 compared with baseline were considered significantly differentially expressed. The analysis was done on RStudio (v. 2024.12.0+467) platform 6 using R (v4.3.2)7 programming language.

Volcano plots were generated, displaying each proteoform as a function of estimated effect size (log2 fold change) and the statistical confidence of differences between the two groups (−log10 of adjusted p value). The heatmap was created using “ComplexHeatmap (v.2.18.0)” R package.

RESULTS

Isolated TBI Induces AKI in a Swine/Large Animal Model

Hemodynamics and Survival

All animals (swine, n = 10) survived to the end of the experiment. Hemodynamic data from this study have been previously published.²⁰ None of the animals experienced hypotension or a low flow state, and there were no differences in mean arterial pressure, cardiac output, heart rate, or intracranial pressure between the two groups.²⁰

Evidence of AKI

Serum and plasma samples were collected at baseline, 2 hours, 4 hours, and 6 hours following TBI. In the control group, there was a statistically significant increase in serum creatinine at 6 hours post injury compared with baseline (Fig. 1, p = 0.007). Aspartate aminotransferase levels were also measured. There was no difference in aspartate aminotransferase levels at 6 hours post injury compared with baseline (p = 0.89; Supplemental Digital Content, Supplementary Fig. S1, http://links.lww.com/TA/E531).

Figure 1.

Serum creatinine significantly increases after isolated TBI and is mitigated by MG53. Serum samples were obtained at baseline (0 hours), 1 hour, 4 hours, and 6 hours following isolated TBI in animals treated with MG53 (n = 5) and saline controls (n = 5). In the control group, creatinine increased significantly by 6 hours from baseline (**p = 0.007, post hoc unpaired Student’s t test). In the MG53 groups, creatinine was similar to baseline at 6 hours (p = 0.089 post hoc unpaired Student’s t test). At 6 hours post injury, creatinine was significantly lower in the MG53-treated group compared with controls (#p = 0.012, post hoc unpaired Student’s t test). Error bars represented SD. Cr, creatinine; MG53, recombinant human MG53 protein.

Post-TBI MG53 Protein Therapy Prevented AKI

Contrasting the rapid onset of AKI in the control group, animals treated with MG53 protein therapy post-TBI displayed no significant changes in the creatinine level over baseline (prior to TBI) (Fig. 1, p = 0.089). At 6 hours post injury, animals treated with MG53 had significantly lower creatinine values compared with the non-treated control group (Fig. 1, p = 0.012). We chose to explore a secondary biomarker of kidney injury, NGAL, to support the creatinine data. In the control animals, NGAL level was significantly elevated starting at 4 hours post injury (p = 0.014) and persisted until 6 hours post injury (p = 0.002, Fig. 2). In stark contrast, no significant changes to NGAL levels were observed when animals received MG53 protein therapy (p = 0.163 and p = 0.79 at 4 hours and 6 hours compared with baseline, respectively). When comparing both groups, animals in the MG53 group had significantly lower NGAL values compared with controls at 6 hours post injury (p = 0.0419).

Figure 2.

Isolated TBI results in elevated NGAL that is mitigated with treatment with MG53. Neutrophil gelatinase lipocalin is a biomarker for AKI. The ELISA assay using swine plasma showed a significant increase in NGAL at 4 hours and 6 hours post injury compared with baseline (*p = 0.014 and ***p = 0.002, respectively, post hoc unpaired Student’s t test). In the MG53 group, NGAL was similar to baseline at 4 hours and 6 hours post injury (p = 0.163 and p = 0.79, respectively, post hoc unpaired Student’s t test). At 6 hours, NGAL was significantly lower in the MG53 group compared with controls (#p = 0.042 post hoc unpaired Student’s t test). TBI, Traumatic Brain Injury; NGAL, Neutrophil gelatinase lipocalin; ng, nanogram; mL, mililiter; NS, normal saline.

Next, we examined kidney tissue collected at the time of euthanasia in the control animals and the animals treated with MG53 and compared histologic features to kidney tissue collected from healthy sham animals. Kidney specimens from the control group (TBI without treatment) demonstrated morphological changes that suggest proximal tubular epithelial damage, a hallmark of AKI (Fig. 3B). Animals treated with MG53, on the other hand, showed no evidence of proximal tubular epithelial injury (Fig. 3C) and instead resembled tissue of sham animals (Fig. 3A).

Figure 3.

MG53 protects against acute proximal tubular epithelial injury. Kidney tissues were stained with periodic acid-Schiff stain. Representative images for (A) sham, uninjured swine (B), swine 6 hours post-isolated TBI controls, and (C) swine 6 hours post-isolated TBI treated with MG53. The black line outlines evidence of proximal tubular epithelial injury seen in animals subjected to TBI alone (B). After treatment with MG53, kidneys no longer showed evidence of proximal tubular injury (C).

Exploring Potential Mechanisms Driving Early Distant Organ Dysfunction Post-TBI

Proteoform Analysis

The very significant increases in creatinine and NGAL, as well as the histologic changes in the kidney occurring just hours after TBI, prompted us to further explore the potential mechanisms driving this TBI-associated kidney injury. Top-down proteomics on plasma of TBI swine showed distinct temporal clustering of differentially expressed proteoforms, with significant differences occurring at 2 hours post injury, and gradually recovering to baseline by 6 hours (Fig. 4)

Figure 4.

Proteoforms of APOA1, FGB, and BGLAP were differentially expressed at 2 hours and 6 hours following TBI when compared with baseline. Heatmap demonstrating differentially expressed proteoforms where red intensities represent significant upregulation, and blue intensities signify significant downregulation. Plasma collected at 2 hours post-TBI injury, 4 hours post-TBI injury, and 6 hours post-TBI injury were all compared with BL plasma prior to injury. At 2 hours post injury, the under carboxylated form of osteocalcin was significantly downregulated, and different forms of the APOA1 protein were both significantly upregulated and downregulated. At 6 hours post injury, fibrinogen β was significantly upregulated. APOA1, apolipoprotein A1; BGLAP, undercarboxylated osteocalcin; BL, baseline; h, hours; FGB, fibrinogen β.

Heatmapping demonstrates the intensity of differentially expressed proteoforms at various time points following TBI (Fig. 4; Supplemental Digital Content, Supplementary Tables S2 and S3, http://links.lww.com/TA/E532). At 2 hours following injury, a total of 18 apolipoprotein A1 (APOA1) proteoforms were either significantly upregulated or downregulated (p < 0.05). APOA1 proteoforms that were upregulated were mainly truncated forms of the protein, while those that were downregulated were mostly oxidized forms (Supplemental Digital Content, Supplementary Table S4, http://links.lww.com/TA/E532). Almost all APOA1 proteoforms recovered their expression after 6 hours (Supplemental Digital Content, Supplementary Table S4, http://links.lww.com/TA/E532). Additionally, at 2 hours following TBI, the undercarboxylated form of osteocalcin was significantly downregulated (p < 0.05; Supplemental Digital Content, Supplementary Table S5, http://links.lww.com/TA/E532), while the canonical form of osteocalcin was detected (Supplemental Digital Content, Supplementary Table S5, http://links.lww.com/TA/E532) but did not change. At 6 hours following injury, there was a significant upregulation of fibrinogen β (p < 0.05), while the canonical form of fibrinogen was not differentially expressed (Supplemental Digital Content, Supplementary Table S2, http://links.lww.com/TA/E532).

DISCUSSION

In this study, we were able to demonstrate that isolated TBI (in the absence of shock and other associated trauma) was associated with the development of AKI within just a few hours. Additionally, we have shown that administration of systemic MG53 immediately after TBI was protective against kidney injury. Furthermore, our preliminary proteomic data provide hypothesis generating information regarding the mechanisms that may be driving the TBI-induced kidney injury.

Nonneurologic organ dysfunction is an important determinant of patient outcomes following TBI. Several clinical studies analyzing outcomes of pediatric and adult patients demonstrate that development of MOD increases the mortality and morbidity following severe TBI.^{3,4,6,7,30–32} Additionally, MOD in TBI patients has implications beyond the care of the TBI patient. Organs procured from brain dead donors are known to have higher posttransplant graft failure compared with live donor organs.³³ While TBI-induced MOD has been shown to have important implications for patient outcomes, the mechanisms behind it remain unknown and understudied. Our work contributes to the growing body of literature aimed at uncovering the mechanisms behind brain-organ “cross-talk”; understanding of which has tremendous implications for a variety of clinical contexts.

Acute kidney injury following TBI has independently been shown to worsen short-term and long-term patient outcomes.^9,10 There are many hypothesized causes of the observed AKI in patients with TBI. First, circulatory dysfunction and shock can lead to hypotensive events leading to malperfusion of the kidneys and subsequent AKI. Additionally, prevention of secondary brain injury using hyperosmolar agents and vasopressors to improve intracranial pressure and cerebral perfusion can increase the risk of kidney injury.^8,34 Other theories to explain the presence of AKI following TBI include catecholamine release resulting in vasoconstriction and a pro-inflammatory state with cytokine release resulting in tubular injury.^34,35

To our knowledge, our study is the first to use a large animal swine model to study the impact of isolated TBI on the kidney and a potential therapeutic for kidney injury. In this model, hemodynamic parameters were similar between the experimental groups, no vasopressors were used, and animals did not undergo treatment with hyperosmolar agents. In only 6 hours, animals with severe TBI had evidence of kidney injury in the form of elevated creatinine consistent with Kidney Disease: Improving Global Outcomes (KDIGO) definitions of AKI, elevated NGAL (a sensitive biomarker of tubular injury),^35,36 and histologic evidence of proximal tubular cell injury. These findings show that the TBI was independently associated with development of significant kidney injury in a very short time period.

MG53 is a critical member of cellular repair pathways. Several studies have shown that the absence of MG53 in rodent models results in susceptibility to stress-induced injury of the heart, lungs, skin, kidney, cornea, brain, and liver.^18,37,38 Rodent models of kidney ischemia-reperfusion injury, contrast-induced AKI, and chemotherapy-induced nephrotoxicity have all shown renal protective benefits after systemic administration of MG53.^19,21 The proximal tubular epithelium was shown to be highly susceptible to stress induced injury in these models.^19,21,35 While MG53 is expressed endogenously at low levels in the proximal tubule epithelium, systemic administration of MG53 leads to localization of MG53 to this region and amelioration of injury.²¹ Our results in a swine model are consistent with these previous findings and show that MG53 is a powerful renal protectant against TBI-associated kidney injury.

To uncover the potential mechanisms driving distant organ injury, we used a novel top-down proteomic strategy to identify specific proteoforms that were differentially expressed in the plasma of animals subjected to severe TBI. “Proteoform” is a newly accepted term used to designate the different molecular forms in which the protein product of a single gene can be found, which includes changes to proteins because of genetic variation, alternatively spliced RNA transcripts, and posttranslational modifications.³⁹ Top-down proteomics aims to identify uniquely expressed proteoforms by forgoing protein digestion into peptides (as in traditional bottom-up proteomics). This identification strategy allows us to isolate proteins in their most physiologically accurate form.

Interestingly, our results showed temporal expression of proteoforms with unique patterns of differentially expressed proteins at 2 hours following TBI that then resembled baseline expressions by 6 hours post injury. This temporal expression of proteoforms may suggest a potential therapeutic window of MG53 administration. One study using a rat model of ischemic stroke demonstrated that MG53 lost its neuroprotective effects when delivered 6 hours after reperfusion.²² Examining our findings in the context of this prior study may suggest that 2 hours may be the optimal therapeutic window for the delivery of MG53 following TBI.

Specific isoforms of APOA1 were both upregulated and downregulated at 2 hours post injury, undercarboxylated osteocalcin was downregulated at 2 hours post-TBI, and fibrinogen β was upregulated at 6 hours post injury. APOA1 is abundant in the cerebrospinal fluid of mammals as a component of high-density lipoproteins and is a well-known negative acute phase reactant.⁴⁰ There is very little information identifying the role of APOA1 in brain injury; however, one review by Sengupta and Mukhopadhyay⁴⁰ discussed the potential role of APOA1 in neuronal healing. Interestingly, their laboratory has shown that, following spinal cord injury, different isoforms of APOA1 were present in the CSF in differing abundance in complete spinal cord injury versus incomplete spinal cord injury.⁴⁰ In our study, different forms of APOA1 were either up- or downregulated in the peripheral plasma of swine subjected to TBI. While it remains unclear at this time why APOA1 is differently expressed in our model, it is possible that the different posttranslational modifications of APOA1 immediately following severe TBI could provide prognostic value in the future.

Additionally, at 2 hours post injury, undercarboxylated osteocalcin was significantly downregulated. Osteocalcin mainly functions as a negative regulator of osteogenesis, by limiting bone formation without impairing bone resorption.⁴¹ One study has shown that osteocalcin is expressed by neutrophils in the skull following TBI, and these osteocalcin expressing neutrophils may regulate the function of peripheral neutrophils and promote neuroprotection.⁴² Furthermore, the undercarboxylated form of osteocalcin has been linked to behavioral changes in mice, in particular, the absence of undercarboxylated osteocalcin results in “passivity” and deficits in spatial learning and memory in both male and female mice.⁴³ While it remains unclear the role downregulation of undercarboxylated osteocalcin may play in post-TBI distant organ injury, our findings in the context of these other studies may suggest some link between inflammatory responses in the brain, the inflammatory response of the periphery, and overall neurorecovery.

Regarding our findings of an upregulation of fibrinogen β at 6 hours post-TBI, it is unclear if this upregulation represents cleaved fibrinogen preparing to interact with thrombin to form a clot, or if it represents products of fibrinolysis. Studies have shown that isolated TBI can result in unique patterns of coagulopathy⁴⁴ and that traumatic coagulopathy following isolated TBI is associated with higher incidence of MOD.⁴⁵ Unfortunately, we did not perform thromboelastography in this experiment, which limits our ability to explore patterns in coagulopathy to compare with these proteoform findings.

Endotheliopathy of trauma can manifest in a variety of ways: coagulopathy, impaired vasodilation, vascular permeability, and/or pro-inflammatory states. It has been shown in a variety of animal models that TBI results in endothelial cell dysfunction,^11,15,46,47 suggesting a possible role of the “neuroendothelial axis” in driving this distant organ injury. Currently, there are very few studies that link the mechanism of TBI to kidney injury. Much for these studies come from the transplant literature and propose a procoagulant-mediated endothelial cell dysfunction and/or cytokine induced endothelial cell immune activation.¹⁵ Prior studies in swine have shown the presence of endothelial barrier dysfunction, increased shedding of endothelial glycocalyx, and coagulopathy following severe TBI; however, these models also included severe hemorrhagic shock or multiple injuries in addition to severe TBI.^46,48,49 While the results in this study do not yet clearly link endothelial dysfunction with development of kidney injury, we were able to establish swine as a useful large animal model of distant organ injury (namely, kidney injury), and our proteoform results provide some hypothesis generating data to connect isolated TBI with coagulopathy and impaired inflammatory responses. These results will allow us to further delve into the neuroendothelial axis and its role in TBI-driven organ dysfunction in the future.

Limitations

There are a few important limitations to this study. First, both animal models used had small sample sizes, which increases the risk of type II error. Second, animals in porcine experiments were euthanized within 8 hours of TBI, which prevents us from identifying long-term implications of MG53 treatment or to show renal recovery over time. Long-term studies in these models are needed to explore this further. Additionally, we only studied one dose of MG53 given immediately following TBI. Additional dose-response studies using various dosing and administration intervals of MG53 are needed to determine an optimal regimen. Finally, since the swine model is particularly novel in investigating the role of TBI-induced endotheliopathy and MOD, the results of this study are meant to be hypothesis generating and not conclusive. In particular, the novel techniques used in our proteoform analysis have never been done in a porcine model, and so the results are preliminary. Traditional proteomics studies are currently underway to compare.

CONCLUSION

In this study, isolated TBI in a swine model was associated with evidence of AKI within a few hours after brain injury. While the exact mechanisms of TBI-induced organ injury remain unknown, our results provide hypothesis generating data for designing future experiments. Additionally, this injury was mitigated by treatment with MG53, and the therapeutic potential of MG53 deserves further attention.

Supplementary Material

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