The mRNA expression degree of was positively correlated with the abundance of fibroblasts (= 0.63, 0.0001), endothelial cells (= 0.43, 0.0001), and monocytes (= 0.26, = 0.0021). assessed by immunohistochemistry. In addition, functional enrichment and pathway analysis were conducted. Results: Compared with healthy controls, the mRNA and protein levels of were upregulated in the skin of SSc patients. Further analysis indicated that the mRNA expression levels of were positively correlated with modified Rodnan skin thickness score (mRSS). Functional enrichment and pathway analysis showed that integrin members may play multiple roles in the pathogenesis of SSc. Among them, might synergistically promote SSc through affecting extracellular matrix (ECM) turnover, ECMCreceptor interaction, focal adhesion, and leukocyte trans-endothelial migration, while and also might affect angiogenesis and endothelial cell function. In addition, were associated with different pathways, respectively. was uniquely enriched for actin organization, while was for TGF- signaling and for immune cell activation. Conclusion: Our results implied that the abnormal expression of integrin family genes including may participate in multiple pathological processes in SSc. Further investigations are required for confirming this speculation. are well-studied integrin members in SSc, which can form 51, v3, and v5 heterodimeric receptors. Among them, integrin V3 and integrin V5 were found overexpressed in SSc patients and animal models, which were related to lymphocyte infiltration, TGF- activation, and collagen accumulation (13). On the other hand, studies on other integrin members still remain sparse. Gene analysis revealed that inflammation mediated by the integrin signaling pathway was a common shared pathway related to SSc (14). All these discoveries made integrin an attractive therapeutic target for SSc. Neutralizing antibody and small molecule inhibitors of integrin V and 1 were protective in animal models of SSc (13, 15, 16). However, integrin-targeted therapy has not shown significant efficacy in patients yet. Phase II clinical trials of an V6 antibody (BG00011) in the treatment of idiopathic pulmonary fibrosis (IPF) and an integrin V monoclonal antibody (abituzumab) in the treatment of SSc-ILD were terminated due to safety and efficacy problems or difficulties in patient inclusion, respectively (clinicaltrials.gov identifier “type”:”clinical-trial”,”attrs”:”text”:”NCT03573505″,”term_id”:”NCT03573505″NCT03573505 and “type”:”clinical-trial”,”attrs”:”text”:”NCT02745145″,”term_id”:”NCT02745145″NCT02745145). The failure of the above clinical trials may be partly due to the complexity of Rabbit Polyclonal to DVL3 the integrins in the progression of SSc. This study aimed to explore the key members and roles of integrins in the pathogenesis of SSc, therefore providing insight into its potential value as a therapeutic target for SSc. Methods Microarray Data Acquisition and Processing To explore the changes of expression profiling and reveal biological processes in the skin of patients with SSc, eligible microarray datasets were downloaded from the Gene Expression Omnibus (GEO, http://www.ncbi.nlm.nih.gov/geo) database. The inclusion criteria of microarray datasets were as follows: (1) datasets should be the expression profile of genome-wide mRNA transcriptome data, (2) datasets consisted of expression profiles in the skin of patients with SSc and normal controls, and (3) datasets were standardized or raw datasets. All gene expression data have previously been published on the GEO database. Identification of Differentially Expressed Integrin Family Genes Normalization and log2 24, 25-Dihydroxy VD2 transformation were performed for the raw data to minimize heterogeneity. Probes without gene symbols or genes with more than one probe were removed or averaged, respectively. The merged data were preprocessed by sav package to remove batch effects with R software (version 3.5.1). After performing batch normalization, limma package was utilized to screen differentially expressed integrin family member genes between SSc patients and healthy controls. Adjusted 0.05 was considered statistically significant. The correlations between mRNA expression of integrin members and clinical characteristics were analyzed. Immunohistochemistry (IHC) Immunohistochemical analysis was performed on 3-mm sections of formalin-fixed, paraffin-embedded tissue. Antigen retrieval was performed by a microwave 24, 25-Dihydroxy VD2 oven with buffer of citric acid (pH 6.0). Then, endogenous peroxidase activity and 24, 25-Dihydroxy VD2 non-specific binding were blocked with peroxidase block buffer and 1% bovine serum albumin, respectively. After blocking, sections were incubated with primary antibodies (anti-integrin 5 antibody, 1:400, ab150361, Abcam, Cambridge, MA, USA; anti-integrin 7 antibody, 1:800, ab203254, Abcam, Cambridge, MA, USA; anti-integrin 2 antibody, 1:2,000, ab131044, Abcam, Cambridge, MA, USA; anti-integrin 5 antibody, 1:400, 3629S, CST, Danvers, MA, USA) at 4C overnight. Subsequently, sections were incubated with HRP conjugate before chromogenic detection using DAB. For the semiquantitative analysis, the H-score method assigned a 24, 25-Dihydroxy VD2 score of 0C300.