Effect of COP1 in Promoting the Tumorigenesis of Gastric Cancer by Down-Regulation of CDH18 via PI3K/AKT Signal Pathway.

In recent years, the involvement of E3 ubiquitin ligase constitutive photomorphogenesis 1 (COP1) in the tumorigenesis of gastric cancer (GC) has been elucidated. However, the exact underlying mechanism remains to be clarified. In the present study, the expression profiles of COP1 in GC were derived from the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) databases, followed by verification via immunohistochemical staining (IHC), Western blotting (WB), and quantitative real-time polymerase chain reaction (qRT-PCR) reaction assays on clinical samples. In vitro, the gain- and loss-of-function experiments of COP1 protein were conducted to explore its role in GC cell lines HGC-27 and SGC-7901. Furthermore, we screened the interaction protein of COP1 by yeast two-hybrid experiment and verified their combination by co-immunoprecipitation (co-IP). We preliminary explored the possible underlying mechanisms of COP1 protein in GC cell lines via WB. COP1 was upregulated in GC tissues compared with the corresponding non-carcinoma tissues. In vitro, the upregulation of COP1 protein promoted the proliferation and migration of GC cells. The yeast two-hybrid experiment and co-IP indicated that Cadherin 18 (CDH18) could constitute a complex with COP1. Moreover, cells with COP1 over-expression showed low levels of CDH18 expression, with the intracellular PI3K/AKT pathway activated and the malignancy of GC cell lines enhanced. Our findings demonstrated that COP1 promoted the GC tumorigenesis by downregulated CDH18 with the involvement of PI3K/AKT signaling pathway in cell lines, suggesting the potential of COP1 as a prognostic biomarker and therapeutic target for GC.

CircCHD2/miR-200b-3p/HLF Axis Promotes Liver Cirrhosis.

Inactivation of hepatic stellate cells (HSCs) slows down liver cirrhosis (LC) advancement. The role of circular RNAs (circRNAs) in LC is largely undiscovered. Here, we clarified the effect of circCHD2 on HSCs. LX-2 cells were stimulated with TGF-ß1 to establish a cell model. The circCHD2, miR-200b-3p, and HLF were inspected using quantitative real-time PCR (qPCR). Cell counting kit-8, 5-Ethynyl-2'-deoxyuridine, together with colony formation assays were all conducted to analyze cell proliferation. α-SMA and Col1A1 were evaluated by qPCR and Western blot. The targets of circCHD2 and miR-200b-3p were verified by luciferase reporter assay. We found the circCHD2 was upregulated in the patients with LC and transforming growth factor beta 1 (TGF-ß1)-stimulated LX-2 cells. Interfering of circCHD2 inhibited the proliferation induced by TGF-ß1, downregulated α-SMA, and Col1A1. CircCHD2 served as a miR-200b-3p sponge, which directly targeted downstream HLF. Downregulated miR-200b-3p abrogated suppression on the cellular process, α-SMA and Col1A1 levels induced by knockdown of circCHD2. Enforced HLF reversed the effect induced by miR-200b-3p overexpression. Taken together, a loss of circCHD2/miR-200b-3p/HLF axis contributed to alleviate LC progression. The findings suggested that circCHD2 may have potential to be a therapeutic target of LC.

Protective effect of HCN2-induced SON sensitization on chronic visceral hypersensitivity in neonatal-CRD rat model.

Abnormal brain-gut interactions contribute to the development of chronic visceral hypersensitivity (CVH), which is the pivotal feature of irritable bowel syndrome (IBS). Despite the consensus with respect to the vital role of hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) channels in promoting painful symptoms in the peripheral nervous system, we identified that the upregulation of HCN2 in supraoptic nucleus (SON) was involved in the modulation of CVH in rat model of neonatal colorectal distention (n-CRD). Specifically, colorectal distention (CRD) upregulated the expression of c-Fos in SON in adult CVH rats, indicating the involvement of SON sensitazation in visceral sensation. Moreover, the administration of ZD7288 (the pan-HCN channel inhibitor) rather than 8-Br-cAMP (the non-specific HCN channel agonist) aggravated the CVH symptoms and reduced the phosphorylation level of CaMKII-CREB cascade. Together, the findings indicated that the upregulation of supraoptic HCN2 contributed to the sensitization of SON, which had protective effects on the modulation of CVH with the involvement of CaMKII-CREB cascade in n-CRD rat model.

The implication of transient receptor potential canonical 6 in BDNF-induced mechanical allodynia in rat model of diabetic neuropathic pain.

AIMS: Brain-derived neurotrophic factor (BDNF) is vital in the pathogenesis of mechanical allodynia with a paucity of reports available regarding diabetic neuropathy pain (DNP). Herein we identified the involvement of BDNF in driving mechanical allodynia in DNP rats via the activation of transient receptor potential canonical 6 (TRPC6) channel. MATERIALS AND METHODS: The DNP rat model was established via streptozotocin (STZ) injection, and allodynia was assessed by paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL). The expression profiles of BDNF and TRPC6 in dorsal root ganglia (DRG) and spinal cord were illustrated by immunofluorescence and Western blotting. Intrathecal administration of K252a or TrkB-Fc was performed to inhibit BNDF/TrkB expression, and respective injection of GsMTX-4, BTP2 and TRPC6 antisense oligodeoxynucleotides (TRPC6-AS) was likewise conducted to inhibit TRPC6 expression in DNP rats. Calcium influx in DRG was monitored by calcium imaging. KEY FINDINGS: The time-dependent increase of BDNF and TRPC6 expression in DRG and spinal cord was observed since the 7th post-STZ day, correlated with the development of mechanical allodynia in DNP rats. Intrathecal administration of K252a, TrkB-Fc, GsMTX-4 and BTP2 prevented mechanical allodynia in DNP rats. Pre-treatment of TRPC6-AS reversed the BDNF-induced pain-like responses in DNP rats rather than the naïve rats. In addition, the TRPC6-AS reversed BDNF-induced increase of calcium influx in DRG neurons in DNP rats. SIGNIFICANCE: The intrathecal inhibition of TRPC6 alleviated the BDNF-induced mechanical allodynia in DNP rat model. This finding may validate the application of TRPC6 antagonists as interesting strategy for DNP management.