LncSIK1 enhanced the sensitivity of AML cells to retinoic acid by the E2F1/autophagy pathway.

OBJECTIVES: This study aimed to investigate the biological impacts and possible mechanisms of a novel lncRNA, LncSIK1, in AML progression and retinoic acid-regulated AML cell development. MATERIALS AND METHODS: The expression pattern of LncSIK1 was evaluated by qPCR and fluorescence in situ hybridization. CCK-8 assay, immunofluorescence, Wright-Giemsa staining, flow cytometry and Western blotting were performed to assess cell proliferation and differentiation. Bioluminescence imaging and H&E staining were used to detect AML progression in vivo. RNA or chromatin immunoprecipitation assays were conducted to measure the interaction of E2F1 and LncSIK1 or the LC3 and DRAM promoters. Autophagy was measured by transmission electron microscopy and Western blotting. RESULTS: LncSIK1 was silenced in bone marrow mononuclear cells from AML patients compared with those from healthy donors. LncSIK1 strengthened the effect of retinoic acid in inducing cell differentiation and inhibiting cell proliferation in AML cells. Moreover, the silencing of LncSIK1 was critical to maintaining AML leukaemogenesis, as LncSIK1 enhancement retarded AML progression in vivo. Mechanistically, in NB4 cells, LncSIK1 recruited the E2F1 protein to the promoters of LC3 and DRAM and induced autophagy-dependent degradation of the oncoprotein PML-RARa. However, LncSIK1 blocked E2F1 expression and the E2F1-mediated transcription of LC3 and DRAM, thereby relieving aggressive autophagy in Molm13 cells. CONCLUSIONS: Taken together, these data indicated that LncSIK1 was an important regulator of AML development through regulating the E2F1/autophagy signalling pathway.

Blockage of Kv1.3 regulates macrophage migration in acute liver injury by targeting δ-catenin through RhoA signaling.

Background: Activation of macrophages and infiltration are key events in acute liver injury (ALI). Kv1.3 plays an important role in regulating immunologic functions of macrophages and is extensively recognized as a potential ion channel for immunological diseases. Objective: We hypothesized that blockage of Kv1.3 may influence ALI by inhibiting macrophages infiltration in damaged liver tissues. Methods: Margatoxin was administered into the peritoneal cavity of ALI mice. The impact of this treatment on ALI and macrophage migration in vivo and in vitro was determined using immunohistochemistry, transwell migration, and wound healing assays. Results: MgTX treatment alleviated ALI in mice, as evidenced by reduced macrophage infiltration in liver tissues and lower serum levels of liver ALT and AST. RNA-seq profiling analysis showed that the most obvious change by MgTX treatment was downregulation of δ-catenin, a protein known to be associated with macrophage migration. The effect of MgTX on macrophage migration and involvement of δ-catenin was confirmed by transwell and wound healing assays. Overexpression of δ-catenin in RAW264.7 cells promoted migration, an event that was suppressed upon silencing of δ-catenin. Mechanistically, the expression of RhoA was regulated by the overexpression or knockdown of δ-catenin. Conclusion: These findings suggest a role for blockage of Kv1.3 channel in macrophage migration and reveal a new target in the treatment of ALI.

Margatoxin mitigates CCl4­induced hepatic fibrosis in mice via macrophage polarization, cytokine secretion and STAT signaling.

A number of macrophage phenotypes have been previously identified as crucial regulators in the progression of hepatic fibrosis (HF). Cytokines from macrophages or Kupffer cells (KCs) have also been identified to be important regulators in HF. Blocking Kv1.3 in models of HF, regulating macrophage polarization and cytokine secretion have not yet been assessed as potential treatments options for this condition. In the current study, a model of carbon tetrachloride (CCl4)­induced HF was established and examined the effects of margatoxin (MgTX; an inhibitor of Kv1.3) on HF. Hematoxylin and eosin, Masson's trichrome and immunohistochemistry staining were performed to determine whether MgTX can alleviate liver fibrosis. To elucidate the mechanisms through which MgTX attenuates liver injury, reverse transcription­quantitative PCR and western blot analysis were used to detect polarized macrophage markers in RAW264.7 cells and cytokines were examined using ELISA. Furthermore, macrophage polarization signal transducer and activator of transcription (STAT) signaling, which is associated with macrophage polarization, was identified in RAW264.7 cells. The results revealed that MgTX protected the mice from CCl4­induced liver fibrosis. Furthermore, MgTX decreased the expression of M1 phenotype biomarkers, and increased the expression of M2 phenotype biomarkers in CCl4­induced HF. Additionally, the production of pro­inflammatory cytokines was decreased and interleukin­10 production was increased in the serum of mice with HF injected with MgTX. Furthermore, MgTX was found to regulate the expression of M1 markers by suppressing p­STAT1 activity and increasing the expression of M2 markers by promoting p­STAT6 activity. On the whole, the findings of this study demonstrate that MgTX is able to alleviate CCl4­induced HF in mice, possibly via macrophage polarization, cytokine secretion and STAT signaling.

miR-203 Inhibits Alcohol-Induced Hepatic Steatosis by Targeting Lipin1.

Alcoholic liver disease (ALD) is a global liver disease which characterized by liver inflammation, fatty liver, alcoholic hepatitis, or liver cirrhosis. Alcohol abuse is one of the main reasons for liver disease. Alcoholic fatty liver (AFL) disease is the early stage of ALD and associated with the excessive lipids accumulation in hepatocytes as well as oxidative stress. MicroRNA-203 (miR-203) is known to suppress the proliferation and metastasis of hepatocellular carcinoma, but the role in the progression of alcoholic liver disease is not clear and is warranted for further investigation. In the present study, we have found the expression of miR-203 is down-regulated in Gao-Binge alcoholic mice model and ethanol-induced AML-12 cell lines in vitro. Furthermore, over-expression of miR-203 decrease the lipids accumulation in liver and ethanol-induced AML-12 cells. Mechanistically, we identified that Lipin1 is a key regulator of hepatic lipid metabolism, and acts as a downstream target for miR-203. In summary, our results suggested that over-expression of miR-203 inhibited the liver lipids accumulation and the progression of AFL by targeting Lipin1.

MeCP2 Regulates PTCH1 Expression Through DNA Methylation in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease, in which pathogenesis is not clear. Many research demonstrated that fibroblast-like synoviocytes (FLSs) play a key role in RA pathogenesis, join in the cartilage injury and hyperplasia of the synovium, and contribute to the release of inflammatory cytokines. We used adjuvant arthritis (AA) rats as RA animal models. The methyl-CpG-binding protein 2 (MeCP2) enables the suppressed chromatin structure to be selectively detected in AA FLSs. Overexpression of this protein leads to an increase of integral methylation levels. Some research has confirmed the hedgehog (Hh) signaling pathway plays an important role in RA pathogenesis; furthermore, patched 1 (PTCH1) is a negative fraction of Hh signaling pathway. We used 5-aza-2'-deoxycytidine (5-azadc) as DNA methylation inhibitor. In our research, we found MeCP2 reduced PTCH1 expression in AA FLSs; 5-azadc obstructed the loss of PTCH1 expression. 5-Azadc, treatment of AA FLSs, also blocks the release of inflammatory cytokines. In order to probe the potential molecular mechanism, we assumed the epigenetic participation in the regulation of PTCH1. Results demonstrated that PTCH1 hypermethylation is related to the persistent FLS activation and inflammation in AA rats. Knockdown of MeCP2 using small-interfering RNA technique added PTCH1 expression in AA FLSs. Our results indicate that DNA methylation may offer molecule mechanisms, and the reduced PTCH1 methylation level could regulate inflammation through knockdown of MeCP2. Graphical Abstract PTCH1 is an inhibitory protein of the Hedgehog signaling pathway. Increased expression of PTCH1 can inhibit the expression of Gli1 and Shh, thereby inhibiting the activation of Hedgehog signaling pathway. Inactivated Hedgehog signaling pathway inhibits the secretion of IL-6 and TNF-α. MeCP2 mediates hypermethylation of PTCH1 gene and decreases the expression of PTCH1 protein, thus activating Hedgehog signaling pathway and increasing secretion of IL-6 and TNF-α.

Meta-analysis of the relation between the VDR gene TaqIpolymorphism and genetic susceptibility to prostate cancer in Asian populations.

BACKGROUND: Polymorphisms of the Taq I gene have been associated with prostate cancer risk. METHODS: We applied a fixed-effects model to combine odds ratios (ORs) and 95% confidence intervals (95% CI). The Egger's test was carried out to evaluate potential publication bias. RESULTS: A total of 10 case-control studies enrolling 1,141 prostate cancer patients and 1,685 controls were included in this meta-analysis. Compared with the T allele, the OR for the C allele was 0.81 (0.70-0.94). The ORs for CT and CC+CT genotypes were 0.86 (0.74-1.01) and 0.84 (0.73-0.97) compared to wide type genotype (homozygote TT). CONCLUSIONS: The present meta-analysis suggests that the TF gene Taq I polymorphism may reduce the prostate cancer risk in Asian populations.