Panminerva medica最新文献

Background: The p38 mitogen-activated protein kinase pathway plays an important role in the pathogenesis of osteoarthritis (OA) involving in hypertrophy, calcification, and apoptosis of chondrocytes (CHs). In this study, we focused on a p38 inhibitor named Pamapimod (PAM) in the effect of CH hypertrophy degeneration.

Methods: CHs were isolated from the cartilage collected from OA patients. Insulin-Transferrin-Selenium (ITS) medium was used as a hypertrophic inducer to establish CH hypertrophy model. Asiatic acid (AA) was used to activate p38 phosphorylation. We transfected CHs with myocyte enhancer factor 2C (MEF2C)-plasmid to upregulate MEF2C expression. Chondrogenic gene expression such as type II collagen and SOX-9, and hypertrophic genes such as type X collagen, MMP-13, and Runx-2 were analyzed by western blot, real-time polymerase chain reaction or immunofluorescence.

Results: ITS and AA all contributed to the CHs hypertrophy with an upregulation of p-p38 and MEF2C protein expression. PAM treatments significantly inhibited p-p38 and MEF2C expression, down-regulated type X collagen, MMP-13, and Runx-2 expression and upregulated type II collagen and SOX-9 levels. PAM indirectly affected MEF2C expression and resulted in CHs hypertrophy suppression.

Conclusions: PAM protects CHs hypertrophy by the inhibition of the p38/MEF2C pathway.

Background: The aim of this study is to explore the effect of micro ribonucleic acid (miR)-21-5p on spinal cord injury (SCI) in rats and its mechanism of action.

Methods: The rat model of SCI was established, and the key miRNAs were screened using the microarray assay and miRNA-mRNA interaction network. After intrathecal injection of agomir-21 and antagomir-21, the effect of miR-21 expression on motor function recovery of rats was evaluated using the Basso-Beattie-Bresnahan (BBB) score. The expression level of miR-21 in spinal cord tissues was determined via quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and the effect of miR-21 expression on apoptosis in spinal cord tissues was determined via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and Western blotting. Moreover, the effects of agomir-21 and antagomir-21 on SCI-induced expressions of inflammatory factors interleukin-8 (IL-8), IL-1β, IL-6 and tumor necrosis factor-α (TNF-α) in spinal cord tissues were detected through qRT-PCR. Finally, Western blotting was performed to detect the effects of agomir-21 and antagomir-21 on the phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (AKT) signaling pathway and its downstream molecules in each group.

Results: The screening results of the microarray assay revealed that the mRNA and miRNA expression profiles in spinal cord tissues had significant differences in model group from those in sham group. The BBB score was significantly higher in agomir-21 group than that in model group. Compared with that in model group, the apoptosis of spinal cord tissues was obviously weakened in agomir-21 group, while it was obviously enhanced in antagomir-21 group. Agomir-21 group had evidently lower Bax/Bcl-2, and Caspase-3 and Caspase-9 protein expressions, while antagomir-21 group had evidently higher Bax/Bcl-2 and Caspase-3 protein expression than model group. Besides, the expressions of inflammatory factors IL-8, IL-1β, IL-6 and TNF-α were remarkably lower in agomir-21 group than those in model group, while they were remarkably higher in antagomir-21 group than those in model group. Finally, it was found that the protein expressions of phosphorylated PI3K (p-PI3K)/PI3K and p-AKT/AKT rose markedly, while the protein expressions of phosphatase and tensin homolog deleted on chromosome ten (PTEN) and endothelial nitric oxide synthase (eNOS) declined markedly in agomir-21 group compared with those in model group. However, the opposite results were observed in antagomir-21 group compared with those in model group.

Conclusions: MiR-21-5p may reduce the apoptosis and inflammation in spinal cord tissues of rats through the PI3K/AKT pathway.