Are functional variants of the microRNA-146a gene associated with primary knee OA? Evidence in Mexican mestizo population

Indirect influence of microRNA-146a on the association of IL-6 and TNF-α genetic polymorphisms with the increased risk of hip osteoarthritis

Primary osteoarthritis (POA) is a complex hereditary disease that involves the interplay between genetics and epigenetics. MicroRNA molecules play important roles in epigenetic mechanisms. MicroRNA-146a (miR-146a) is a negative regulator of the immune response in osteoarthritis (OA). So, variations in the miR-146a gene could affect OA risk. The aim of this study was to investigate the relationships between single nucleotide polymorphisms (SNPs) in the miR-146a, interleukin-6 (IL-6), Toll-like receptor 10 (TLR10), and tumor necrosis factor-alpha (TNFA) genes and the risk for development of advanced-stage primary hip osteoarthritis (PHOA) and primary knee osteoarthritis (PKOA) in the Croatian population. A total of 609 POA patients and 656 healthy donors were genotyped for SNPs in the miR-146a (rs2910164, G>C). Since we used same patients and controls as two studies before us, we already had information about IL-6 (rs1800795, C>G), TLR10 (rs11096957, C>T), and TNFA (rs1800629, C>T) genotypes of our subjects. None of the differences were statistically significant comparing either allelic or genotypic frequencies of miR-146a SNP rs2910164 (G>C) between the PHOA and PKOA patients and controls. However, we found a significant association with risk to PHOA for the combination of genotypes (stratified miR-146a genotype with the IL-6, and stratified miR-146a genotype with the TNFA). In a multifactorial disease such as POA, we have shown the indirect relevance of a second modifying factor (miR-146a), which apparently contributes to the overall risk of PHOA. There was no risk association with the PKOA, indicating that these two localities (hip and knee) might have different risk-modifying factors.

MiR-146a expression profiles in osteoarthritis in different tissue sources: a meta-analysis of observational studies

Background

MiR-146a has been widely studied in the pathogenesis of osteoarthritis (OA); however, the results are still controversial.

Objective

This meta-analysis analyzes the expression profile of miR-146a in various tissues of OA patients.

Methods

Public databases were searched for appropriate studies published up to September 1, 2021. A case–control study comparing the OA population and a non-OA healthy population was included.

Results

26 articles were included in analysis. The results showed that the expression level of miR-146a in peripheral blood mononuclear cells (PBMCs) was significantly higher in OA patients than in controls (SMD: 1.23; 95% CI 0.08–2.37; p = 0.035) but not in plasma (SMD: 1.09; 95% CI − 0.06, 2.24; p = 0.064). The expression level of miR-146a in cartilage was also significantly higher in OA patients than in controls (SMD: 6.39; 95% CI 0.36, 12.4; p = 0.038) but not in chondrocytes (SMD: − 0.71; 95% CI − 4.15, 2.73; p = 0.687). The miR-146a level was significantly lower in synoviocytes in the OA population than in control patients (SMD: − 0.97; 95% CI − 1.68, − 0.26; p = 0.008). In synovial tissue, synovial fluid, and regulatory T cells, there was no significant difference.

Conclusion

The expression level of miR-146a in cartilage tissue and PBMCs was significantly higher in OA patients than in non-OA healthy controls. Due to the limitations of this study, more research is needed to confirm these results in the future.

Trial registration: retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-02989-7.