Table 5.

miRNA analysis of plasma, serum, PBMC, saliva and salivary gland tissue.

Author (year)	No. of subjects	Material and methods	Findings
Alevizos I, et al., 2011 (95)	16 pSS 5 HC 1 non-pSS, sicca 1 myositis 1 peripheral neuropathy	MSGT RT-qPCR	MiRNA expression patterns in minor salivary gland tissue accurately distinguished pSS patients from healthy controls. Validation of miR-768-3p and miR-574 in an independent cohort revealed increased expression of miR-768-3p, and decreased expression of miR-574 with an increasing focus score. Comparison of miRNAs from patients with preserved or low salivary flow identified a set of differentially expressed miRNA, most of which were increased in in the group with decreased salivary gland function, suggesting that the targets of miRNA may have a protective effect on epithelial cells.
Zilahi E, et al., 2012 (96)	21 pSS 10 HC	PBMC qRT-PCR	Increased expression of miR-146a and miR-146b and the gene of TRAF6 in patients with pSS compared to healthy controls. Decreased expression of IRAK1 gene suggests transcriptional repression of IRAK1 in PBMC of pSS patients, whereas the other NF-κB pathway-regulating gene, TRAF6, is overexpressed.
Tandon M, et al., 2012 (97)	6 pSS 3 HC	MSGT qPCR	Six previously unidentified miRNA sequences (hsa-miR-4524b-3p, hsa-miR-4524b-5p, hsa-miR-5571-3p, hsa-miR-5571-5p, hsamiR-5100, and hsa-miR-5572) found in patient samples and in several cell lines. Validation of hsa-miR-5100 showed decreased expression in pSS patients with low salivary flow rates.
Peng L, et al., 2014 (98)	33 pSS 10 HC	PBMC Microassay, qRT-PCR	202 miRNA were upregulated and 180 were downregulated in pSS patients compared to healthy controls. MiR-181a differed most profoundly. No difference in miRNA-181a expression between patients with different disease phenotypes.
Shi H, et al., 2014 (99)	27 pSS 22 HC	PBMC RT-PCR	Higher expression levels of miR-146a in patients with pSS than in healthy controls, and levels correlated with the VAS scores for parotid swelling and dry eyes). Low miR-155 expression level in the patients with pSS, levels correlated with the VAS score for dry eyes.
Chen JQ, et al., 2015 (100)	23 pSS 10 HC	PBMC RT-PCR	MiR-155 is regarded as a central modulator of T-cell responses. This study evaluated the expression rate of miR-155 and its functional linked gene (SOCS1). MiR-155 and SOCS1 gene was both overexpressed in the PBMC of patients with pSS. However, there was no significant correlation between expression values of SOCS1 and miR-155 in the pSS patients.
Gourzi VC, et al., 2015 (101)	29 pSS 24 non-pSS, sicca	PBMC, MSG tissue, SGEC RT-PCR	Higher levels of miR16 in minor salivary gland tissue of miR200b-3p in salivary gland epithelial cells and miR483-5p in PBMCs from pSS patients than in non-pSS, sicca controls. Levels of let7b, miR16, miR181a, miR223 and miR483-5p correlated with Ro52/TRIM21-mRNA. MiR181a and miR200b-3p correlated negatively with Ro52/TRIM21 and Ro60/TROVE2 mRNAs in salivary epithelial cells, respectively, whereas let7b, miR200b-5p and miR223 correlated with La/SSB-mRNA. In PBMCs, let7b, miR16, miR181a and miR483-5p correlated with Ro52/TRIM21, whereas let7b, miR16 and miR181a correlated with La/SSB-mRNA expression. Lower levels of miR200b-5p in pSS patients with MALT-lymphoma than in those without.
Willams AEG, et al., 2016 (102)	21 pSS 9 sSS 17 SLE 18 RA 17 HC	PBMC CD4+ qRT-PCR	Higher levels of miRNAs monocytes from patients with SS than in healthy controls. MiR-34b-3p was differentially expressed between SS patients and healthy controls and RA. Higher levels of miR4701-5p and miR-3162.3p in SS patients. QRT-PCR supported co-regulation of miR-34b-3p, miR-4701-5p, miR-609, miR-300, miR-3162-3p, and miR-877-3p in SS monocytes (43%) in comparison with SLE (5.8%) and RA (5.6%). MiRNA-target pathway predictions identified SS-associated miRNAs appear to preferentially target the TGFβ signaling pathway as opposed to the IL-12 and Toll-like receptor/NFkB-pathways.
Yan T, et al., 2017 (103)	57 pSS - group 1: FS=1 - group 2: FS=2 - group 3: FS=3 13 HC	MSGT qRT-PCR	The differences between HC and the 3 pSS subgroups were statistically significant for positive findings of salivary flow rate, Schirmer test and laboratory indices. In LMSG tissues: expression level of miR-18a was ↑ in patients of the 3 pSS subgroups compared to HC, while expression level of miR-92a was ↓. MiR-18a was progressively ↑ along the advanced histological stages of the 3 pSS subgroups, while the miR-92a was progressively ↓. There was no notable difference in the expression levels of miR-17, miR-19a, miR-19b, and miR-20a.
Chen JQ, et al., 2017 (104)	8 pSS 8 SLE 7 HC	Peripheral blood Illumina next-generation sequencing	135 miRNA and 26 miRNAs showed altered expression in SLE and pSS, respectively, compared to HC. The 25 miRNAs including miR-146a, miR-16 and miR-21, which were over-expressed in pSS patients, were also found to be elevated in SLE group. miR-150-5p was ↓ in pSS. Levels of several miRNAs over-expressed in SLE, were not changed in pSS, such as miR-148a-3p, miR-152, miR-155, miR-223, miR-224, miR-326 and miR-342. Expression levels of miR-223-5p, miR-150-5p, miR-155-5p and miR-342-3p, which miRNAs are potentially linked to B cell functions, showed associations with the B cell proportions within PBMC.
Jiang Z, et al., 2017 (105)	60 pSS 53 RA 23 HC 45 SSc 49 DM 11 PM	PBMC qRT-PCR	The miR-200c level in the SSc group was significantly ↑ than in the DM/PM, pSS, and RA groups, and the levels in the DM/PM and pSS groups were significantly ↑ than in the RA group. The level of miR-200c in the CTD+ILD group was significantly ↑ than in the CTD–ILD group, and the level in the severe ILD group was significantly ↑ than in the mild ILD group. FVC and FEV1 were significantly different among the different CTD groups, and among the different CTD+ILD groups. There was a negative correlation between the level of miR-200c and FVC and FEV1.
Lopes AP, et al., 2018 (106)	37 pSS 17 HC 21 non-pSS, sicca	Serum RT-qPCR	10 sncRNAs were differentially expressed between the groups in the array. In the validation cohort, the ↑ expression of U6-snRNA and miR-661 in the iSS group as compared to HC was confirmed, but none of the differentially expressed sncRNA from the discovery cohort were validated in the validation cohort. However, within this group several miRNAs correlated with laboratory parameters. Unsupervised clustering distinguished three clusters of pSS patients. Patients in one cluster showed ↑ serum IgG, prevalence of anti-SSB, IFN-score, and ↓ leukocyte counts compared to the two other clusters. Patients with pSS, being anti-SSA/-SBB positive, showed ↓ expression of several sncRNAs when compared to antibody-negative patients with pSS.
Kapsogeorgou EK, et al., 2018 (107)	79 pSS - 27 low-risk who did not develop lymphoma during follow-up. - 17 high risk diagnosed with NHL during follow up, 35 SS-associated lymphoma. 8 non-pSS sialadenitis - 4 associated with sarcoidosis - 4 associated with HCV infection.	MSGT qPCR	The MSG levels of miR200b-5p were significantly ↓in pSS patients, who will develop or have NHL, and strongly discriminated (p<0.0001) them from those without lymphoma or non-SS sialadenitis. Furthermore, they were reduced long before clinical onset of lymphoma, did not significantly change on transition to lymphoma and, importantly, were proved strong independent predictors of patients, who will develop NHL (p<0.0001). MiR200b-5p levels correlated negatively with ESSDAI and biopsy focus score, and positively with serum C4 levels.
Jiang CR, et al., 2018 (108)	70 pSS 60 HC	PBMC qRT-PCR	The expressions of miR-146a and miR-4484 in the pSS group were significantly ↑ compared to HC. After treatment, the expressions of miR-146a and miR-4484 were significantly ↓ compared with those before treatment (p<0.05). Combined detection of miR-146a and miR-4484 was superior to single index detection in the diagnosis and prognosis of pSS (p<0.05). The 3-years follow-up showed that the incidences of renal injury and pulmonary interstitial lesion in patients with low miR-146a and miR-4484 expressions were significantly lower than those with high expressions (p<0.05). No significant differences in the survival rate between the two groups (p>0.05).
Wang-Renault SF, et al., 2018 (109)	Discovery cohort: 17 pSS, 15 HC Replication cohort: 27 pSS 12 HC	Purified B- and T lymphocytes RT-qPCR	In CD4+ T-cells, hsa-let-7d-3p, hsa-miR-155-5 p, hsa-miR-222-3 p, hsa-miR-30c-5p, hsa-miR-146a-5p, hsa-miR-378a-3p and hsa-miR-28-5 p were significantly differentially expressed in both cohorts. In B cells, hsa-miR-378a-3p, hsa-miR-222-3 p, hsa-miR-26a-5p, hsa-miR-30b-5p and hsa-miR-19b-3p were significantly differentially expressed. Potential target mRNAs were enriched in disease relevant pathways. There was an inverse correlation between expression of BAFF and hsa-miR-30b-5p in B cells from pSS patients. Functional experiments showed increased expression of BAFF after inhibiting hsa-miR-30b-5p.
Wang J, et al., 2019 (110)	20 pSS 20 HC	PBMC qRT-PCR, Western Blot, ELISA	Expression of miR-let-7d-3p was dramatically regulated in CD4+ T cells from pSS-ptt. Expression of miR-let-7d-3p was negatively correlated with the expression of IL-17 in pSS patients on both mRNA and protein levels. Besides, the AKT1/mTOR signaling pathway was found critical for miR-let-7d-3p-mediated IL-17 expression. AKT1 was proved to be the direct target of miR-let-7d-3p; miR-let-7d-3p targeted AKT1 to bridge the regulation of IL-17. It was also verified that AKT1 co-expression could rescue IL-17 downregulation caused by miR-let-7d-3p.
Hillen MR, et al., 2019 (111)	30 pSS 16 HC	Peripheral blood OpenArray Q-PCR-based technique	20 miRNAs were differentially expressed at a lower level in pSS pDCs compared with HC pDCs. Differential expression of 10 miRNAs was confirmed in the replication cohort (miR-29a and miR-29c showed the most robust fold-change difference between pSS and HC). The dysregulated miRNAs were involved in phosphoinositide 3-kinase-Ak strain transforming and mammalian target of rapamycin signaling, as well as regulation of cell death. In addition, a set of novel protein targets of miR-29a and miR-29c were identified, including five targets that were regulated by both miRs (FSTL1, CASP7, CD276, SEPINH1, F11R).
Gallo A, et al., 2019 (112)	5 pSS (high salivary flow) 6 pSS (low salivary flow) 5 non-pSS, sicca	MSGT In silico analysis, Human glycosylation-RT2 Profiler PCR array.	126 out of 754 miRNA were significantly deregulated in pSS vs. HC, with a trend that was inversely proportional with the impairment of salivary flow rates. In silico approach pinpointed several upregulated miRNA in patients with pSS target important genes in the mucin O-glycosylation. This was confirmed by RT-qPCR highlighting downregulation of some glycosyltransferase and glycosidase genes in pSS samples compared to HC, such as GALNT1, responsible for mucin-7 glycosylation.
Talotta R, et al., 2019 (113)	28 pSS 23 HC	UWS, plasma miRNA RT-qPCR	No significant difference in salivary miRNA expression between patients and HC. Patients with SS had higher expression of salivary miR146a than HC. Salivary miR146b was significantly more expressed in the ptt. with worse ESSPRI scores (p=0.02), whereas salivary miR17 and 146b and plasma miR17 expression was ↓ in the patients with higher ultrasound scores (respectively p=0.01, p=0.01 and p=0.04). Salivary miR18a expression was significantly ↑ in the patients who were anti-La/SSB positive (p=0.04). Neither salivary nor plasma miRNAs correlated with disease duration or concomitant therapies.
Sembler-Møller M, et al., 2020 (114)	24 pSS 16 non-pSS, sicca	WS, plasma, MSGT miRNA RT-qPCR	In saliva 14 miRNAs were significantly differentially expressed between pSS and non-pSS; 11 of these were downregulated incl. the miR-17 family in pSS. In MSGT of pSS-ptt. miR-29a-3p was significantly upregulated. Plasma miRNAs did not differ between the two groups. The combination of miR-17-5p and let-7i-5p in saliva yielded an AUC of 97% (CI 92%-100%). Several miRNAs correlated significantly with one another and with salivary flow rates and histopathology.
Yang Y, et al., 2020 (115)	8 pSS X? HC	MSGT RT-qPCR, western blot, Annexin-V-FITC, TUNEL	TRIM21-targeting miRNAs were identified, miR-1207-5p and miR-4695-3p. Transfection of miR-1207-5p or miR-4695-3p mimics lower expression of TRIM21 and the levels of pro-apoptotic genes BAX, CASP-9 and CASP-8, leading to antiapoptotic phenotypes in HSG cells. Consistent with the antiapoptotic activity, transfection of microRNA inhibitors ↑ the expression of TRIM21 and led to a pro-apoptotic phenotype. Thus, proposing that miR-1207-5p and miR-4695-3p are antiapoptotic microRNAs functioning through apoptosis pathway. Assays performed with MSGT revealed ↓ of miR-1207-5p and miR-4695-3p + ↑ of TRIM21 and pro-apoptotic CASP-8 gene in pSS patients.
Gong B, et al., 2021 (116)	13 pSS 13 HC	PBMC RT-qPCR	The numbers of aberrant miRNAs in pSS naïve (vs. healthy naïve), pSS activation (vs. pSS naïve), MSC treatment and pre−IFN−γ MSC treatment (vs. pSS activation) groups were 42, 55, 27 and 32, respectively. Gene enrichment analysis revealed 259 pathways associated with CD4+ T cell stimulation, and 240 pathways associated with MSC treatment. Increased miRNA−7150 and miRNA−5096 and ↓ miRNA−125b−5p and miRNA−22−3p levels in activated CD4+ T cells from patients with pSS were reversed by MSC treatment. Notably, the proliferation of CD4+ T cells and CD4+ IFN−γ+ cells, expression levels of miRNA−125b−5p and miRNA−155 in CD4+ T cells and supernatant IFN−γ secretion were associated with disease activity. MiRNA may play a vital role in MSC treatment for activated CD4+ T cells.

Arrow up: upregulated.

Arrow down: downregulated.