Mannose receptor C type 2 mediates 1,25(OH)2D3/vitamin D receptor-regulated collagen metabolism through collagen type 5, alpha 2 chain and matrix metalloproteinase 13 in murine MC3T3-E1 cells

MRC2 Promotes Proliferation and Inhibits Apoptosis of Diabetic Nephropathy

Diabetic nephropathy (DN) is an important microvascular complication of diabetes and is the main cause of end-stage renal disease. Type 2 mannose receptor C (MRC2) is a member of the mannose receptor protein family, which has been confirmed to have the ability to promote the cell migration signaling pathway and invasion. By complementary DNA chip screening and analysis, we found that the expression of MRC2 was upregulated in the kidneys of mice with diabetic nephropathy. However, the role of MRC2 in diabetic nephropathy is still unclear. This work studied the effect of MRC2 on diabetic nephropathy. After verifying the results of the chip by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting, we used small interfering RNAs (siRNAs) to knock down the expression of MRC2 in mouse mesangial cells (MMCs) and analyzed the level of cell proliferation and apoptosis using western blotting, Cell Counting Kit-8, and flow cytometry. The results showed that the MRC2 knockdown inhibited MMC proliferation and induced cell apoptosis. These results suggest that MRC2 may be a molecular marker and a therapeutic target for diabetic nephropathy.

MiR-23b-3p promotes postmenopausal osteoporosis by targeting MRC2 and regulating the Wnt/β-catenin signaling pathway

Postmenopausal osteoporosis (PMOP) is one of the most common metabolic bone diseases in postmenopausal women. Increasing evidence has indicated that microRNAs (miRNAs) play vital regulatory roles during osteoporosis progression. This study aimed to investigate the potential function of miR-23b-3p in the osteogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs). PMOP was induced in mice by bilateral ovariectomy. X-ray absorptiometry was applied to detect BMD and BMC in PMOP mice. Luciferase reporter assay and RIP assay were utilized to investigate the relationship between miR-23b-3p and MRC2. We found the upregulation of miR-23b-3p in bone tissues of PMOP mice. Silencing of miR-23b-3p relieved PMOP in mice. Moreover, miR-23b-3p knockdown facilitated the osteogenic differentiation of hMSCs by increasing the expression of Runx2, OCN, Osterix and promoting ALP activity. Mechanistically, MRC2 is a downstream target gene of miR-23b-3p. MRC2 knockdown significantly rescued the promoting effect of lenti-miR-23b-3p inhibitor on osteogenic differentiation of hMSCs. Furthermore, miR-23b-3p targeted MRC2 to inhibit the Wnt/β-catenin pathway during the osteogenic differentiation of hMSCs. In summary, inhibition of miR-23b-3p alleviates PMOP by targeting MRC2 to inhibit the Wnt/β-catenin signaling, which may provide a novel molecular insight for osteoporosis therapy.

Association Between Vitamin D Receptor Gene Polymorphism rs2228570 and Allergic Rhinitis

Background

Vitamin D receptor (VDR) gene polymorphisms are involved in a variety of immune-related diseases, and VDR is associated with allergic rhinitis. The present study explored the associations between VDR gene polymorphisms and allergic rhinitis in the Chinese population.

Methods

The study population consisted of 400 patients with allergic rhinitis and 400 healthy controls. General characteristics were determined by interview. Blood DNA was extracted and genotyping was performed via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The associations of each genetic variant with risk for AR were assessed by calculating the odds ratio (OR) with 95% confidence interval (95% CI).

Results

No significant differences were observed in general characteristics between cases and controls. The distributions of genotypes at the rs2228570 locus of the VDR gene conformed to Hardy–Weinberg equilibrium. There was a significant difference in the distribution of rs2228570 genotype (P<0.001) between cases and controls. Compared to GG and GA genotypes, the AA genotype increased the risk of AR (OR=3.27, 95% CI: 2.10–5.11, P=0.000; OR=2.58, 95% CI:1.63–4.08, P<0.001). Similar results were also observed in the dominant model (OR=1.64, 95% CI:1.24–2.17, P<0.001) and codominant model (OR=2.95, 95% CI:1.93–4.51, P<0.001). The A allele was still associated with elevated risk gene for AR after adjusting for potential confounding factors. Subgroup analyses indicated an interaction between alcohol and rs2228570 in the risk of allergic rhinitis. The A allele also increased the risk for AR in the population without asthma (OR=1.85, 95% CI:1.46–2.34, P<0.001).

Conclusion

VDR gene polymorphism is associated with AR, and the AA genotype of rs2228570 is associated with the increased risk of AR in the Chinese population.