miR-195 contributes to human osteoarthritis via targeting PTHrP

Crosstalk Among circRNA/lncRNA, miRNA, and mRNA in Osteoarthritis

Osteoarthritis (OA) is a joint disease that is pervasive in life, and the incidence and mortality of OA are increasing, causing many adverse effects on people's life. Therefore, it is very vital to identify new biomarkers and therapeutic targets in the clinical diagnosis and treatment of OA. ncRNA is a nonprotein-coding RNA that does not translate into proteins but participates in protein translation. At the RNA level, it can perform biological functions. Many studies have found that miRNA, lncRNA, and circRNA are closely related to the course of OA and play important regulatory roles in transcription, post-transcription, and post-translation, which can be used as biological targets for the prevention, diagnosis, and treatment of OA. In this review, we summarized and described the various roles of different types of miRNA, lncRNA, and circRNA in OA, the roles of different lncRNA/circRNA-miRNA-mRNA axis in OA, and the possible prospects of these ncRNAs in clinical application.

Effect of Type 1 Collagen Bioactive Material Scaffold on the Recovery of Sports-Caused Cartilage Injury

This study was aim to investigate the effect of type 1 collagen (Col I) bioactive scaffold on regeneration and repair of motor cartilage injury. Fifteen New Zealand rabbits were randomly divided into sham operation group (Sham group, only cartilage was exposed, no defect was made), model group Focal cortical dysplasias (FCD) group, cartilage defect model], and treatment group (Col I group, cartilage defect + Col I bioactive scaffold treatment). The cartilage tissue of each group was detected 16 weeks after the operation. Immunohistochemistry and Western Blot were adopted to detect the expression of cartilage related proteins in each group. The results showed that Col I bioactive scaffold could repair the gross morphology of cartilage defect, promote the regeneration and repair of chondrocytes in defect area, and reduce the mast cells in defect area. Western Blot detection of the expression of signal pathway marker proteins showed that expression of Wnt protein, β-catenin protein, and phosphofructokinase-1 (PFK-1) protein in the FCD group were significantly reduced than Sham group (P < 0.05), while the expression of phosphoenolpyruvate carboxykinase 1 (PEPCK1) protein was significantly increased (P < 0.05). Expression of Wnt protein, β-catenin protein, and PFK-1 protein in Col I group increased significantly versus FCD group (P < 0.05), while the expression of PEPCK1 protein significantly decreased (P < 0.05). In conclusion, Col I bioactive scaffolds could regenerate and repair cartilage defects, and the mechanism may be related to Wnt signaling pathway and glycolysis/gluconeogenesis pathway.

Expression of miR-195 and its target gene Bcl-2 in human intervertebral disc degeneration and their effects on nucleus pulposus cell apoptosis

Objective

To investigate the expression of miR-195 and its target gene Bcl-2 in intervertebral disc degeneration (IVDD) and its effect on nucleus pulposus (NP) cell apoptosis.

Methods

The expressions of miR-195 and Bcl-2 in NP tissues of IVDD patients were quantified by qRT-PCR and western blotting, respectively. NP cells were divided into blank group, TNF-α group, TNF-α + miR-NC group, TNF-α + siBcl-2 group, and TNF-α + miR-195 inhibitors + siBcl-2 group. Cell proliferation was detected by MTT assay, cell apoptosis evaluated by flow cytometry, and mitochondrial membrane potential (MMP) tested by JC-1 staining. Moreover, the function of miR-195 on IVDD in vivo was investigated using a puncture-induced IVDD rat model.

Results

IVDD patients had significantly increased miR-195 expression and decreased Bcl-2 protein expression in NP tissues. The expression of miR-195 was negatively correlated with the expression of Bcl-2 in IVDD patients. Dual-luciferase reporter gene assay indicated that Bcl-2 was a target gene of miR-195. In comparison with blank group, TNF-α group showed decreased cell proliferation and MMP, increased cell apoptosis, upregulated expression of miR-195, Bax, and cleaved caspase 3, and downregulated Bcl-2 protein, while these changes were attenuated by miR-195 inhibitors. Additionally, siBcl-2 can reverse the protective effect of miR-195 inhibitors on TNF-α-induced NP cells. Besides, inhibition of miR-195 alleviated IVDD degeneration and NP cell apoptosis in the rat model.

Conclusion

MiR-195 was significantly upregulated in NP tissues of IVDD patients, and inhibition of miR-195 could protect human NP cells from TNF-α-induced apoptosis via upregulation of Bcl-2.

Downregulation of microRNA-29b by DNMT3B decelerates chondrocyte apoptosis and the progression of osteoarthritis via PTHLH/CDK4/RUNX2 axis

The correlation between DNA methyltransferases (DNMTs) and microRNAs (miRNAs) has been well-established, but its interaction in osteoarthritis (OA) has been barely clarified. This study aimed to analyze the relationship between DNMT3B and miR-29b as well as their implications in OA. Our results revealed that DNMT3B was downregulated while miR-29b was upregulated in OA cartilage tissues relative to normal cartilage tissues. Hypermethylation of specific CpG sites in the miR-29b promoter region induced by DNMT3B contributed to downregulation of miR-29b in OA chondrocytes. Furthermore, luciferase activity determination demonstrated that miR-29b targeted and negatively regulated the parathyroid hormone-like hormone (PTHLH). Moreover, the PTHLH upregulation induced by miR-29b methylation led to the enhancement of chondrocyte growth and suppression of their apoptosis and extracellular matrix degradation, which was achieved by the upregulation cyclin-dependent kinase 4 (CDK4) expression. Co-IP suggested that CDK4 induced ubiquitination of RUNX2, which could be enhanced by DNMT3B. In the OA mouse model induced by destabilization of the medial meniscus, overexpression of DNMT3B was observed to downregulate the expression of RUNX2 whereby preventing OA-induced loss of chondrocytes. Hence, the DNMT3B/miR-29b/PTHLH/CDK4/RUNX2 axis was found to be involved in the apoptosis of chondrocytes induced by OA, highlighting a novel mechanism responsible for OA progression.

MiR-195-5p Inhibits Malignant Progression of Cervical Cancer by Targeting YAP1

Purpose

Our previous studies have shown that miR-195 is reduced in cervical cancer tissues, and that upregulation of miR-195 suppressed cervical cancer cell growth and induced a cell cycle block. In this study, we aimed to further elucidate the mechanism of action between miR-195-5p and Yes-associated protein 1 (YAP1) in the malignant progression of cervical cancer.

Methods

MiR-195-5p and YAP1 were detected using qRT-PCR in cervical cancer cells transfected with miR-195-5p mimics or inhibitor. Cell proliferation, migration, and invasion ability were detected using MTT, wound healing, and transwell invasion assays. Dual luciferase reporter assay, qRT-PCR, and Western blot analysis were used to demonstrate that YAP1 was a target of miR-195-5p.

Results

Our results showed that miR-195-5p is negatively correlated with YAP1 protein levels but not with mRNA expression. Moreover, upregulation of miR-195-5p by transient transfection with miR-195-5p mimics in HeLa and SiHa cells inhibited cell proliferation, migration ability, invasiveness, and the EMT. Conversely, miR-195-5p downregulation produced opposite results. In addition, multiple miRNA target prediction sites showed that YAP1 was a potential target gene; this was confirmed by dual luciferase assay. Rescue experiments further confirmed that YAP1 is involved in miR-195-5p-mediated inhibition of proliferation, migration ability, invasiveness, and the EMT of cervical cancer cells.

Conclusion

Taken together, our data suggest that miR-195-5p may act as a tumor suppressor which could provide a theoretical basis for cervical cancer patient targeted therapy.

MicroRNA Tough Decoy Knockdowns miR-195 and Represses Hypertrophy in Chondrocytes

Cartilage hypertrophy is a condition in which the cells are completely differentiated, and new morphological changes and mineralization prevent proper cellular functions. The occurrence of hypertrophy during differentiation fails current regenerative strategies for treatment. Strategies to minimize hypertrophy in chondrocytes are categorized into two levels of protein and gene. Among these strategies, one way to affect multiple pathways involved in the development of hypertrophy is to manage microRNA activity in cells. Recent miRNA profiling studies have shown that miR-195-5p upregulates through the transition from chondrogenic to hypertrophic state. Bioinformatics assessment of microRNA targets also indicates that several genes repressed by miR-195-5p play important roles in processes related to hypertrophy. The aim of this study was to develop a microRNA Tough Decoy to suppress miR-195-5p and investigate whether it can prevent a hypertrophic state in chondrocytes. The Tough Decoy (TUD) was designed and evaluated bioinformatically and then cloned into the pLVX-Puro plasmid. The TUD function was validated by Dual-Luciferase assay and qRT-PCR. After delivering TUD to C28/I2 chondrocytes cultured in a hypertrophic medium, hypertrophic differentiation was assessed by histochemical staining, quantitative RT-PCR of hypertrophy marker genes, and alkaline phosphatase activity. Results showed that the TUD could inhibit miRNA efficiently and downregulate hypertrophic markers such as RUNX2, alkaline phosphatase, and collagen 10 significantly compared with the control group. Alcian blue and alizarin red staining also demonstrated the optimal effect of gene constructs on tissue properties and mineralization of the TUD group. Delivering the miR-195-5p Tough Decoy to the cartilage cells can prevent the occurrence of hypertrophy in chondrocytes and could be considered as a candidate for the treatment of other diseases such as osteoarthritis.

Handling Parathormone Receptor Type 1 in Skeletal Diseases: Realities and Expectations of Abaloparatide

Musculoskeletal disorders represent an elevated socioeconomic burden for developed aging societies. Osteoporosis (OP) has been treated with antiresorptive therapies or with teriparatide that was until recently the only anabolic therapy. However, approval of osteoporosis treatment in postmenopausal women with abaloparatide, which is an analog of parathyroid hormone-related peptide (PTHrP), has created a new alternative for OP management. The success of this new treatment is related to differential mechanisms of activation of PTH receptor type 1 (PTH1R) by abaloparatide and PTH. Here, we address the distinguishing mechanisms of PTH1R activation; the effects of PTH1R stimulation in osteoblast, osteocytes, and chondrocytes; the differences between PTH and abaloparatide actions on PTH1R; potential safety concerns; and future perspectives about abaloparatide use in other musculoskeletal disorders.