Platycodin D relieves rheumatoid arthritis by promoting apoptosis of mitochondria to inhibit activation of hedgehog pathway

Rheumatoid arthritis (RA) displays very similar characteristics to those of tumor cells, platycodin D (PD) is a triterpenoid saponin abundant in Platycodon grandiflorum (PG), plays an important role in the inhibition of tumor growth. Our previous experiments confirmed that PD inhibited MH7A cell proliferation and migration, but it’s possible mechanism remain unclear. This study aimed to reveal the mechanism of PD on RA, based on network pharmacology analysis. Rat of CIA was treated with the different doses PD. The arthritis score and paw volume were evaluated, ankle imaging changes were observed via myosseous ultrasound, all rats were anaesthetized by intraperitoneal injection of 25% urethane (1 mL/100 g), and ankle histopathology was observed using hematoxylin and eosin (HE) staining. Cell (MH7A) Counting Kit 8 (CCK8) was used to measure cell activity, and JC-1 assay kit and flow cytometry were employed to examine the cell mitochondrial membrane potential and apoptosis. The expression levels of Sonic hedgehog (Shh) signaling pathway-related proteins were observed by Western blotting. Cell inflammation levels of tumor necrosis factor alpha (TNF-α) and interleukin (IL)-6 being determined via enzyme-linked immunoassay ELISA and q-PCR. In total, the saponin PD significantly improves joint synovium inflammation and apoptosis in CIA rats. The activity of administered MH7A was significantly inhibited, the mitochondrial membrane potential decreased, the expression level of the Shh signaling pathway-related protein SuFu increased, the expression levels of SHh and Gli decreased, and cell serum levels of TNF-a and IL-6 decreased significantly. Therefore, PD exhibits therapeutic potential for synovial hyperplasia in RA

Oncogenic K-ras Induces Mitochondrial OPA3 Expression to Promote Energy Metabolism in Pancreatic Cancer Cells

K-ras (Kirsten ras GTPase) mutations are oncogenic events frequently observed in many cancer types especially in pancreatic cancer. Although mitochondrial dysfunction has been associated with K-ras mutation, the molecular mechanisms by which K-ras impacts mitochondria and maintains metabolic homeostasis are not fully understood. In this study, we used two K-ras inducible cell systems, human pancreatic epithelial/ K-rasG12D (HPNE/K-rasG12D) and human embryonic kidney cells with tetracycline repressorT-Rex/K-rasG12V, to evaluate the role of oncogenic K-ras in regulating mitochondrial function. Among a panel of genes known to affect mitochondria, only the expression of OPA3 (optic atrophy protein 3) was consistently up-regulated by K-ras activation in both cell lines. Importantly, high expression of OPA3 was also observed in clinical pancreatic cancer tissues. Genetic knockdown of OPA3 caused a significant decrease of energy metabolism, manifested by a suppression of oxygen consumption rate (OCR) and a decrease in cellular ATP content, leading to inhibition of cell proliferation capacity and reduced expression of epithelial–mesenchymal transition (EMT) markers. Our study suggests that OPA3 may promote cellular energy metabolism and its up-regulation in K-ras-driven cancer is likely a mechanism to offset the negative impact of K-ras on mitochondria to maintain energy homeostasis. As such, OPA3 could be a potential target to kill cancer cells with K-ras mutations

SLAMF8 promotes the proliferation and migration of synovial fibroblasts by regulating the ERK/MMPs signalling pathway

Rheumatoid arthritis is troublesome to treat effectively and often requires concomitant long-term treatment. Meanwhile, synovial fibroblasts could induce inflammation response and lead to joint erosion, finally causing progressive joint destruction, disability, and increased mortality. This study focussed on the role of SLAM family member 8 (SLAMF8) in mediating cell function from rheumatoid arthritis synovial fibroblasts stimulated with TNF-α. Cell Counting Kit-8 (CCK-8) and colony-forming unit assay were used to evaluate cell proliferation. SLAMF8 expression was analysed by reverse transcription-quantitative PCR (RT-qPCR) and western blot. Annexin V‐FITC/PI double staining was used to measure the apoptosis rate. The cell migration and invasion in TNF-α-stimulated MH7A (human rheumatoid arthritis synovial cell line) and HFLS-RA cells (human fibroblast-like synoviocytes: rheumatoid arthritis) were tested via wound healing assay and transwell migration assay. In the present study, after TNF-α treatments, the SLAMF8 mRNA and protein expression in both MH7A and HFLS-RA cell lines have a time-dependent increase. The attenuation of SLAMF8 ameliorated TNF-α-induced proliferation, invasion and migration in MH7A and HFLS-RA cells. Simultaneously, when SLAMF8 was silenced, the expression of p-ERK, MMP-1, and MMP-13 was suppressed significantly. In summary, these results indicated that the knockdown of the SLAMF8 significantly attenuated TNF-α-induced proinflammatory responses in MH7A and HFLS-RA cells. Therefore, SLAMF8 exhibits therapeutic potential for the management of inflammation in rheumatoid arthritis