P2Y2 promotes fibroblasts activation and skeletal muscle fibrosis through AKT, ERK, and PKC.

BACKGROUND: Skeletal muscle atrophy and fibrosis are pathological conditions that contribute to morbidity in numerous conditions including aging, cachexia, and denervation. Muscle atrophy is characterized as reduction of muscle fiber size and loss of muscle mass while muscle fibrosis is due to fibroblasts activation and excessive production of extracellular matrix. Purinergic receptor P2Y2 has been implicated in fibrosis. This study aims to elucidate the roles of P2Y2 in sleketal muscle atrophy and fibrosis. METHODS: Primary muscle fibroblasts were isolated from wild type and P2Y2 knockout (KO) mice and their proliferating and migrating abilities were assessed by CCK-8 and Transwell migration assays respectively. Fibroblasts were activated with TGF-ß1 and assessed by western blot of myofibroblast markers including α-SMA, CTGF, and collagen I. Muscle atrophy and fibrosis were induced by transection of distal sciatic nerve and assessed using Masson staining. RESULTS: P2Y2 KO fibroblasts proliferated and migrated significantly slower than WT fibroblasts with or without TGF-ß1.The proliferation and ECM production were enhanced by P2Y2 agonist PSB-1114 and inhibited by antagonist AR-C118925. TGF-ß1 induced fibrotic activation was abolished by P2Y2 ablation and inhibited by AKT, ERK, and PKC inhibitors. Ablation of P2Y2 reduced denervation induced muscle atrophy and fibrosis. CONCLUSIONS: P2Y2 is a promoter of skeletal muscle atrophy and activation of fibroblasts after muscle injury, which signaling through AKT, ERK and PKC. P2Y2 could be a potential intervention target after muscle injury.

Jervine exhibits anticancer effects on nasopharyngeal carcinoma through promoting autophagic apoptosis via the blockage of Hedgehog signaling.

Nasopharyngeal carcinoma (NPC) is a malignant tumor originating from the superior mucosal epithelium of the nasopharynx. However, effective therapies for NPC are still required. Reducing Hedgehog signaling pathway has been shown to suppress tumor growth. In this study, we attempted to explore whether Jervine (JV), an inhibitor of Hedgehog signaling, had anti-cancer effects on NPC, and the underlying mechanisms. Our findings showed that JV treatments markedly reduced the proliferation of NPC cells in a dose- and time-dependent manner. Cell cycle arrest in G2/M phase was significantly enhanced by JV, along with evident DNA damage. Moreover, JV treatment effectively induced apoptosis in NPC cells through improving Caspase-3 activation. Furthermore, ROS production and mitochondrial impairments were detected in JV-incubated NPC cells with elevated releases of Cyto-c from mitochondria. JV also dramatically triggered autophagy through blocking AKT/mTOR and increasing AMPK signaling pathways. Intriguingly, we showed that JV-induced apoptosis was mainly via an autophagy-dependent manner. In addition, the expression levels of SHH, PTCH1, SMO and GLI1 were markedly suppressed in NPC cells, demonstrating the hindered Hedgehog signaling. Importantly, we found that JV-induced apoptosis and autophagy were closely associated with the blockage of Hedgehog signaling. Our in vivo studies confirmed the anti-cancer effects of JV on NPC through inducing autophagy, as evidenced by the markedly reduced tumor growth rate and weight without side effects and toxicity. Taken together, JV may be a promising and effective agent for human NPC treatment through repressing Hedgehog signaling pathway and inducing autophagic cell death.

A case of hidroacanthoma simplex.

We report a case of hidroacanthoma simplex with giant lesion that was found on the left lumbar part which was treated with surgical excision.