Systemic sclerosis (SSc) is a complex autoimmune disease. The pathogenesis of SSc is currently unclear, although like other rheumatic diseases its pathogenesis is complicated. However, the ongoing development of bioinformatics technology has enabled new approaches to research this disease using microarray technology to screen and identify differentially expressed genes (DEGs) in the skin of patients with SSc compared with individuals with healthy skin. Publicly available data were downloaded from the Gene Expression Omnibus (GEO) database and intra‑group data repeatability tests were conducted using Pearson's correlation test and principal component analysis. DEGs were identified using an online tool, GEO2R. Functional annotation of DEGs was performed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Finally, the construction and analysis of the protein‑protein interaction (PPI) network and identification and analysis of hub genes was carried out. A total of 106 DEGs were detected by the screening of SSc and healthy skin samples. A total of 10 genes [interleukin‑6, bone morphogenetic protein 4, calumenin (CALU), clusterin, cysteine rich angiogenic inducer 61, serine protease 23, secretogranin II, suppressor of cytokine signaling 3, Toll‑like receptor 4 (TLR4), tenascin C] were identified as hub genes with degrees ≥10, and which could sensitively and specifically predict SSc based on receiver operator characteristic curve analysis. GO and KEGG analysis showed that variations in hub genes were mainly enriched in positive regulation of nitric oxide biosynthetic processes, negative regulation of apoptotic processes, extracellular regions, extracellular spaces, cytokine activity, chemo‑attractant activity, and the phosphoinositide 3 kinase‑protein kinase B signaling pathway. In summary, bioinformatics techniques proved useful for the screening and identification of biomarkers of disease. A total of 106 DEGs and 10 hub genes were linked to SSc, in particular the TLR4 and CALU genes.

Autoimmunity is involved in the valvular damage caused by rheumatic heart disease (RHD). Increased evidence has linked microRNAs (miRNAs/miRs) to autoimmune disease. Signal transducer and activator of transcription 3 (STAT3) and sphingosine‑1‑phosphate receptor 1 (S1PR1) and suppressor of cytokine signaling 1 (SOCS1) have been widely studied for their roles in autoimmunity and inflammation. Thus, the current study aims to investigate the role played by miR‑155‑5p in RHD‑induced valvular damage via the S1PR1, SOCS1/STAT3 and interleukin (IL)‑6/STAT3 signaling pathways. An RHD rat model was induced by inactivated Group A streptococci and complete Freund's adjuvant. A recombinant adeno‑associated virus (AAV‑miR155‑inhibitor) was used to inhibit the expression of miR‑155‑5p in the heart. Inflammation and fibrosis were assessed by hematoxylin and eosin staining and Sirius red staining. The expression of miR‑155‑5p in valvular tissues and serum exosomes was detected by reverse transcription‑quantitative PCR. S1PR1, SOCS1, STAT3, phosphorylated STAT3, IL‑6 and IL‑17 protein expression was detected by western blotting and immunohistochemistry. The relationships between miR‑155‑5p and S1PR1 and SOCS1 were detected by dual luciferase assays. Cytokine concentrations were measured by ELISA. The expression of miR‑155‑5p in valve tissues and serum exosomes was increased along with decreased S1PR1 and activated SOCS1/STAT3 signaling in the RHD model. The expression of IL‑6 and IL‑17 was increased in the valves and the serum. Dual luciferase assays showed that miR‑155‑5p directly targeted S1PR1 and SOCS1. Inhibition of valvular miR‑155‑5p through AAV pretreatment increased S1PR1 expression and inhibited activation of the SOCS1/STAT3 signal pathway as a result of attenuated valvular inflammation and fibrosis as well as a decrease in IL‑6 and IL‑17 in the valves and serum. These results suggest that inhibition of miR‑155‑5p can reduce RHD‑induced valvular damage via the S1PR1, SOCS1/STAT3 and IL‑6/STAT3 signaling pathways.

The present study aimed to identify shared microRNAs (miRNAs) in ovarian cancer (OC) cells and their exosomes using microarray data (accession number GSE103708) available from the Gene Expression Omnibus database, including exosomal samples from 13 OC cell lines and 3 normal ovarian surface epithelial cell lines, and their original cell samples. Differentially expressed miRNAs (DE‑miRNAs) were identified using the Linear Models for Microarray data method, and mRNA targets of DE‑miRNAs were predicted using the miRWalk2 database. The potential functions of target genes were analyzed using Database for Annotation, Visualization and Integrated Discovery and intersected with known OC‑associated pathways downloaded from the Comparative Toxicogenomics Database. The associations between crucial miRNAs and target genes, and their clinical associations, were validated using data from The Cancer Genome Atlas. As a result, 16 upregulated and 6 downregulated DE‑miRNAs were shared in OC cell lines and their exosomes compared with normal controls. The target genes of 11 common DE‑miRNAs were predicted. Among these DE‑miRNAs, a low expression of homo sapiens (hsa)‑miR‑145‑5p was significantly correlated with a poor prognosis and higher stages. Although 91 target genes were predicted for hsa‑miR‑145‑5p, only 4 genes [connective tissue growth factor (CTGF), myotubularin‑related protein 14, protein phosphatase 3 catalytic subunit alpha and suppressor of cytokine signaling 7] were suggested as risk factors for prognosis. The subsequent Pearson's correlation analysis validated a significant negative correlation between hsa‑miR‑145‑5p and CTGF (r=‑0.1126, P=0.02188). According to the results of the functional analysis, CTGF is involved in the Hippo signaling pathway (hsa04390). In conclusion, decreased expression of hsa‑miR‑145 in OC and OC‑derived exosomes may be a crucial biomarker for the diagnosis and treatment of OC.

Diabetic patients with high glucose exhibit vascular smooth muscle cell (VSMC) alteration. Thrombotic disease is related to erosion of an unstable plaque, the instability of which leads to ruptures, for example, a thin fibrous cap derived from VSMCs. VSMC proliferation, migration and invasion are related to thrombotic diseases, including atherosclerosis. MicroRNA‑19a (miR‑19a) has been reported to have pleiotropic functions in cancer cell survival, apoptosis and migration. The present study aimed to investigate the effect of miR‑19a on VSMC proliferation, migration and invasion, and its mechanism. Cell Counting Kit‑8 and a propidium iodide kit were used to determine the proliferation and cycle of VSMCs. A cell migration assay was performed by scratching and Matrigel was used in a cell invasion assay. miR‑19a binding to Ras homolog family member B (RHOB), and their protein and mRNA expressions were determined by performing a dual luciferase assay, western blotting and reverse transcription‑quantitative PCR, respectively. It was demonstrated that miR‑19a promoted the proliferation, migration and invasion of VSMCs, promoted the expressions of dual specificity phosphatase Cdc25A (CDC25A), cyclinD1, matrix metalloproteinase (MMP)‑2, MMP‑9, α‑smooth muscle actin (α‑SMA) and smooth muscle 22α (SM22α), and inhibited suppressor of cytokine signaling 3 and RHOB expressions in VSMCs, while miR‑19a had no effect on the expression of T‑cell intracellular antigen‑1. The miR‑19a site bound to the RHOB gene position and inhibited RHOB to promote VSMC proliferation, invasion and migration, and increased MMP‑2, MMP‑9, α‑SMA and SM22α expressions. The present study suggested that miR‑19a could promote VSMC proliferation, migration and invasion via the cyclinD1/CDC25A and MMP/α‑SMA/SM22α signaling pathways. Moreover, miR‑19a promoted proliferation, migration and invasion via the MMP/α‑SMA/SM22α signaling pathway by inhibiting RHOB, suggesting that miR‑19a is a possible regulatory factor of RHOB.

Postmenopausal osteoporosis (PMOP) is a common skeletal disorder in postmenopausal women. The present study aimed to identify the key long non‑coding RNAs (lncRNAs) in PMOP through RNA sequencing. RNA sequencing was performed to obtain the expression profile of lncRNAs and mRNAs in blood samples of patients with PMOP and normal controls (NCs). Following the identification of differentially expressed mRNAs (DEmRNAs) and differentially expressed lncRNAs (DElncRNAs), the DElncRNA-DEmRNA co‑expression network was constructed. A search was performed for the DEGs transcribed within a 100‑kb window upstream or downstream of DElncRNAs, which served as nearby DEmRNAs of DElncRNAs. Functional annotation of the DEmRNAs co‑expressed with DElncRNAs was performed. The GSE56815 dataset was used to verify the expression of selected DEmRNAs and DElncRNAs. Three blood samples from patients with PMOP and two blood samples from NCs were used for RNA sequencing. Compared with the NC group, a total of 185 DEmRNAs and 51 DElncRNAs were obtained in PMOP. A total of 3,057 co‑expression DElncRNA‑DEmRNA pairs and 97 DElncRNA‑nearby DEmRNA pairs were obtained. Six DEmRNAs [diacylglycerol O‑acyltransferase 2, potassium voltage‑gated channel subfamily S member 1, peptidase inhibitor 3, secretory leukocyte peptidase inhibitor, galectin‑related protein and alkaline phosphatase, liver/bone/kidney (ALPL)] were nearby co‑expressed genes of four DElncRNAs, including LOC105376834, LOC101929866, LOC105374771 and LOC100506113. Three PMOP-associated DEmRNAs, including ALPL, suppressor of cytokine signaling 3 and adrenomedullin, were co‑expressed with the hub DElncRNAs (LINC00963, LOC105378415, LOC105377067, HCG27, LOC101928143 and LINC01094) of the positively and negatively co‑expressed DElncRNA‑DEmRNA interaction network. The expression of selected DEmRNAs and DElncRNAs was consistent with the RNA‑sequencing results. In conclusion, the present study identified the key DEmRNAs and DElncRNAs in PMOP, which may provide clues for understanding the mechanism and developing novel biomarkers for PMOP.

The tumor suppressive role of CYLD lysine 63 deubiquitinase (CYLD) is known in melanoma. To the best of our knowledge, however, the precise mechanism underlying the tumor suppressive function of CYLD has yet to be clarified. In the present study, a novel melanoma mouse model was generated, which revealed accelerated tumor growth in Cyld‑knockout (Cyld‑/‑) compared with Cyld‑wild‑type (Cyld+/+) mice. To determine the underlying molecular mechanism, mutation analysis of primary tumor‑derived cell lines from Cyld+/+ and Cyld‑/‑ mice was performed using RNA sequencing data. Variant calling revealed no common mutations in Cyld‑/‑ compared with Cyld+/+ cells. Thus, the epigenetic processes influencing development and progression of melanoma were investigated. Initial analysis of expression pattern of known hypermethylated genes in melanoma (suppressor of cytokine signalling, methylthioadenosine phosphorylase, cadherin 1) in the presence or absence of 5'‑Aza‑deoxyctidine treatment revealed that CYLD does not play a key role in DNA methylation. Chromatin accessibility and histone H3 modification assay uncovered a role of CYLD in the formation of chromatin structure. Subsequent inhibitor experiments confirmed the effect of CYLD on H3K9me2 level associated with heterochromatin. Furthermore, enhanced H3K9 dimethylation in Cyld‑/‑ melanoma cells was associated with upregulation of euchromatic histone lysine methyltransferase 2 (EHMT2). Moreover, the specific inhibitor of EHMT2, CM272, resulted in decreased proliferation and relaxation of compact chromatin in Cyld‑deficient melanoma cells. These results reveal a novel role of CYLD in histone methylation and chromatin packaging.

The present study aimed to investigate the roles of the microRNA‑29a/DNA methyltransferase 3B/suppressor of cytokine signalling 1 (miR‑29a/DNMT3B/SOCS1) axis in the invasion and the migration of osteosarcoma (OS). The expression levels of miR‑29a, DNMT3B and SOCS1 were determined in tissue samples and OS cell lines by reverse transcription‑quantitative polymerase chain reaction (PCR). Apoptosis was measured using flow cytometry analysis. Transwell and wound healing assays were conducted to measure the invasion and migration abilities of OS cells, respectively. A dual‑luciferase reporter assay was also conducted to determine the interaction between DNMT3B and miR‑29a, while methylation‑specific PCR was used to detect the methylation of SOCS1. Western blotting was performed to determine the protein levels of DNMT3B and SOCS1, as well as the levels of proteins associated with epithelial‑mesenchymal transition (EMT), apoptosis and the nuclear factor (NF)‑κB signalling pathway. The results demonstrated that miR‑29a and SOCS1 were downregulated, and DNMT3B was upregulated in both OS tissues and cell lines. The expression of miR‑29a and SOCS1 was found to be associated with advanced clinical stage and distant metastasis. In addition, the dual‑luciferase reporter assay revealed that DNMT3B was a direct target of miR‑29a. Overexpression using miR‑29a mimics decreased DNMT3B expression and the methylation level of SOCS1, which resulted in the upregulation of SOCS1 in U2OS and MG‑63 cells, while miR‑29a inhibition led to the opposite results. Transfection with miR‑29a mimics also promoted the apoptosis, and inhibited the invasion, migration and EMT process of OS cells, while it markedly reduced the nuclear translocation of p65 and IκB‑α degradation. Treatment with 5‑aza‑2'‑deoxycytidine worked together with miR‑29a mimics to synergistically enhance the aforementioned effects. By contrast, the effects induced by miR‑29a were partly reversed upon co‑transfection with SOCS1 siRNA. In conclusion, miR‑29a promoted the apoptosis, and inhibited the invasion, migration and EMT process of OS cells via inhibition of the SOCS1/NF‑κB signalling pathway by directly targeting DNMT3B.

TGF‑β1 is a pleiotropic cytokine that can either promote or inhibit cancer development and progression. It was previously found that TGF‑β1 can regulate the expression of several microRNAs (miR or miRNA) involved in the progression of renal cell carcinoma (RCC). Therefore, the present study aimed to analyze the effects of TGF‑β1 on the global RCC miRNome. It was found that TGF‑β1 can regulate a complex network consisting of miRNAs and mRNAs involved in RCC transformation. In particular, TGF‑β1 was revealed to regulate the proliferation of RCC cells while concomitantly modifying the expression of oncogenic regulators, including avian erythroblastosis virus E26 (V‑Ets) oncogene homolog‑1 (ETS1). In addition, TGF‑β1 was demonstrated to regulate the expression of a number of miRNAs including miR‑30c‑5p, miR‑155‑5p, miR‑181a‑5p and miR‑181b‑5p. By contrast, TGF‑β1 reciprocally modified the expression of genes encoding TGF‑β1 receptors and SMADs, indicating a novel regulatory feedback mechanism mediated through the miRNAs. These data suggested that ETS1 served different roles in different subtypes of RCC tumors, specifically by functioning as an oncogene in clear cell RCC while as a tumor suppressor in papillary RCC.

Tubule injury is a characteristic pathological feature of acute kidney injury (AKI) and determines the prognosis of kidney disease. However, the exact mechanism of tubule injury remains largely unclear. In the present study, the exact mechanism of tubule injury was investigated. Bilateral renal ischemia/reperfusion (I/R) injury (I/RI) was induced in mice and exosome secretion inhibitor GW4869 and miRNA‑155 inhibitor were used. In addition, the exosomal microRNA (miR)‑155‑mediated cross‑talk between macrophage and tubular cells was also investigated. It was determined that tubular injury was observed in an I/R‑induced AKI model, which was closely associated with macrophage infiltration. Interestingly, blocking exosome production using GW4869 ameliorated tubular injury in I/R‑induced AKI. Mechanistically, once released, activated macrophage‑derived exosomal miR‑155 was internalized by tubular cells, resulting in increased tubule injury through targeting of suppressor of cytokine signaling‑1 (SOCS‑1), a negative regulator of NF‑κB signaling. In addition, a dual‑luciferase reporter assay confirmed that SOCS‑1 was the direct target of miR‑155 in tubular cells. Notably, injection of these miR‑155‑enriched exosomes into renal parenchyma resulted in increased tubule injury in vivo. Thus, the present study demonstrated that exosomal miR‑155 mediated the communication between activated macrophages and injured tubules, leading to progression of AKI, which not only provide novel insights into the pathophysiology of AKI but also offer a new therapeutic strategy for kidney diseases.