Rab26 restricts insulin secretion via sequestering Synaptotagmin-1.

Rab26 is known to regulate multiple membrane trafficking events, but its role in insulin secretion in pancreatic ß cells remains unclear despite it was first identified in the pancreas. In this study, we generated Rab26-/- mice through CRISPR/Cas9 technique. Surprisingly, insulin levels in the blood of the Rab26-/- mice do not decrease upon glucose stimulation but conversely increase. Deficiency of Rab26 promotes insulin secretion, which was independently verified by Rab26 knockdown in pancreatic insulinoma cells. Conversely, overexpression of Rab26 suppresses insulin secretion in both insulinoma cell lines and isolated mouse islets. Islets overexpressing Rab26, upon transplantation, also failed to restore glucose homeostasis in type 1 diabetic mice. Immunofluorescence microscopy revealed that overexpression of Rab26 results in clustering of insulin granules. GST-pulldown experiments reveal that Rab26 interacts with synaptotagmin-1 (Syt1) through directly binding to its C2A domain, which interfering with the interaction between Syt1 and SNAP25, and consequently inhibiting the exocytosis of newcomer insulin granules revealed by TIRF microscopy. Our results suggest that Rab26 serves as a negative regulator of insulin secretion, via suppressing insulin granule fusion with plasma membrane through sequestering Syt1.

Global burden of acute viral hepatitis and its association with socioeconomic development status, 1990-2019.

BACKGROUND & AIMS: Acute viral hepatitis (AVH) represents an important global health problem; however, the progress in understanding AVH is limited because of the priority of combating persistent HBV and HCV infections. Therefore, an improved understanding of the burden of AVH is required to help design strategies for global intervention. METHODS: Data on 4 major AVH types, including acute hepatitis A, B, C, and E, excluding D, were collected by the Global Burden of Disease (GBD) 2019 database. Age-standardized incidence rates and disability-adjusted life year (DALY) rates for AVH were extracted from GBD 2019 and stratified by sex, level of socio-demographic index (SDI), country, and territory. The association between the burden of AVH and socioeconomic development status, as represented by the SDI, was described. RESULTS: In 2019, there was an age-standardized incidence rate of 3,615.9 (95% CI 3,360.5-3,888.3) and an age-standardized DALY rate of 58.0 (47.3-70.0) per 100,000 person-years for the 4 major types of AVH. Among the major AVH types, acute hepatitis A caused the heaviest burden. There was a significant downward trend in age-standardized DALY rates caused by major incidences of AVH between 1990 and 2019. In 2019, regions or countries located in West and East Africa exhibited the highest age-standardized incidence rates of the 4 major AVH types. These rates were stratified by SDI: high SDI and high-middle SDI locations recorded the lowest incidence and DALY rates of AVH, whereas the low-middle SDI and low SDI locations showed the highest burden of AVH. CONCLUSIONS: The socioeconomic development status and burden of AVH are associated. Therefore, the GBD 2019 data should be used by policymakers to guide cost-effective interventions for AVH. LAY SUMMARY: We identified a negative association between socioeconomic development status and the burden of acute viral hepatitis. The lowest burden of acute viral hepatitis was noted for rich countries, whereas the highest burden of acute viral hepatitis was noted for poor countries.

Inhibition of autophagy improves resistance and enhances sensitivity of gastric cancer cells to cisplatin.

Autophagy plays critical roles in tumorigenesis, while the effects of autophagy on chemoresistance of cancer cells had great disparity. This study aims to explore the impacts of autophagy on the sensitivity and resistance of gastric cancer cells to cisplatin (DDP). We firstly demonstrated that there was stronger autophagy activity in gastric cancer SGC-7901 cells than that in DDP-resisting SGC-7901/DDP cells. Then, we discovered that inhibiting autophagy by chloroquine (CQ) significantly enhanced the proliferation-inhibiting and apoptosis-inducing effects of DDP to SGC-7901 and SGC-7901/DDP cells. Moreover, CQ could partially reverse the resistance of SGC-7901/DDP cells to DDP in a concentration-dependent manner. However, the autophagy inducer everolimus (RAD001) had no obvious effects on the sensitivity of gastric cells to DDP. Mechanistically, we demonstrated that CQ might enhance the sensitivity of SGC-7901cells and improve the resistance of SGC-7901/DDP cells to DDP through inhibiting the mTORC1 pathway, especially to SGC-7901/DDP cells. Additionally, we found interfering Beclin-1 using Beclin-1 shRNA also enhanced the proliferation-inhibiting and apoptosis-inducing effects of DDP on gastric cancer cells by inhibiting phosphorylation of Akt. Our study shows that inhibiting autophagy could improve the chemoresistance and enhanced sensitivity of gastric cancer cells to DDP and provide a rationale for the administration of cisplatin combined with CQ for treating patients with gastric cancer.

Elevated serum triglyceride and low-density lipoprotein cholesterol promotes the formation of colorectal polyps.

BACKGROUND: Hyperlipidaemia may be a potential risk factor for the occurrence of intestinal polyps. This study aimed to evaluate correlation between lipidaemia and the formation of colorectal polyps. METHODS: One hundred and fourteen patients with colorectal polyps and forty-eight healthy controls were included in this study. Colonoscopies were performed for all patients and controls within 1 week before blood samples were taken. The concentrations of serum lipids and lipoproteins were measured simultaneously using an automatic biochemical analyser. The colorectal lesions were classified based on pathological characteristics, and four types were identified in the study: hyperplastic polyp (HP), tubular adenoma (TA), tubulovillous adenoma (TVA) and adenoma with high-grade dysplasia (A-HGD). Advanced adenoma was classified according to the number, size and histological type of polyps. RESULTS: The value of low-density lipoprotein cholesterol (LDL-C) was significantly higher in the group with advanced adenoma than in the controls (p < 0.05). Moreover, the LDL-C values in the HP and TA groups were higher when compared to that of controls (p < 0.05). Obesity, age, and increased TG and LDL-C were independent risk factors for the formation of colorectal polyps. The cut-off values of triglyceride (TG) and LDL-C to distinguish polyp patients from healthy controls were 0.96 mmol/L (AUC = 0.604, p = 0.036) and 3.05 mmol/L (AUC = 0.654, p = 0.002). The combined use of increased LDL-C and TG levels to distinguish polyp patients was effective, with a sensitivity of 50.0% and a specificity of 89.6% (AUC = 0.733, p < 0.01). CONCLUSIONS: Colorectal polyps are more often found in obese and older patients. Increased LDL-C and TG were correlated with the occurrence of polyps. Combination of the two serum indicators was useful to assess risk of colorectal lesions, maybe more effective in screening hyperplastic polyp, tubular adenoma and advanced adenoma.

Class A1 scavenger receptor antibody improves murine colitis by influencing macrophage and gut microbiota.

This study aimed to investigate whether class A1 scavenger receptor (SR-A1) regulated macrophage polarization and gut microbial alteration during intestinal inflammation of colitis. A murine colitis model was established by feeding with dextran sulfate sodium (DSS), and treatment groups were injected intravenously with SR-A1 antibody. Results showed a preventive effect on colitis symptoms and fewer inflammatory cell infiltrates in treatment groups. Down-regulation of inflammatory cytokines and up-regulation of anti-inflammatory cytokine related to macrophages were seen in murine PBMC and LPMC after injected with SR-A1 antibody. The percentage of M2 macrophages was also elevated in treatment groups. In addition, SR-A1 antibody treatment resulted in the decreased apoptosis and increased proliferation of colonic epithelial cells. Other findings indicated that SR-A1 antibody injection could mediate its anti-inflammatory effect via inhibiting TLR4-MyD88-NF-kB signaling pathway and alterating the gut microbiota composition. Our research identified SR-A1 as a potential therapeutic target in inflammatory bowel disease (IBD).

RILP Induces Cholesterol Accumulation in Lysosomes by Inhibiting Endoplasmic Reticulum-Endolysosome Interactions.

Endoplasmic reticulum (ER)-endolysosome interactions regulate cholesterol exchange between the ER and the endolysosome. ER-endolysosome membrane contact sites mediate the ER-endolysosome interaction. VAP-ORP1L (vesicle-associated membrane protein-associated protein- OSBP-related protein 1L) interaction forms the major contact site between the ER and the lysosome, which is regulated by Rab7. RILP (Rab7-interacting lysosomal protein) is the downstream effector of Rab7, but its role in the organelle interaction between the ER and the lysosome is not clear. In this study, we found RILP interacts with ORP1L to competitively inhibit the formation of the VAP-ORP1L contact site. Immunofluorescence microscopy revealed that RILP induces late endosome/lysosome clustering, which reduces the contact of endolysosomes with the ER, interfering with the ER-endolysosome interaction. Further examination demonstrated that over-expression of RILP results in the accumulation of cholesterol in the clustered endolysosomes, which triggers cellular autophagy depending on RILP. Our results suggest that RILP interferes with the ER-endolysosome interaction to inhibit cholesterol flow from the endolysosome to the ER, which feedbacks to trigger autophagy.

Decreased serum iron concentration and total iron binding capacity are associated with serious Crohn's disease.

This study aimed to investigate whether serum indicators related to iron stores in the body are associated with clinical and endoscopic disease severity. Eighty-four patients with Crohn's disease (CD) and twenty-four healthy volunteers were included. The indicators related to iron stores were detected within one week after endoscopic and CT enterography examinations. Patients were divided into three groups according to the CDAI(Crohn's disease activity index)scores. Serum iron levels were decreased in all groups (p < 0.05), and the values of remission group were higher than those of moderate group (p < 0.001). The total iron binding capacity(TIBC)values of the moderate group were lower than those of the controls and the other groups (p < 0.05). None of the indicators differed significantly among the patients classified by SES-CD (p > 0.05). Underweight, decreased serum iron and TIBC were independent risk factors for moderate clinical disease. Combined detection of decreased serum iron and TIBC was helpful in differentiating severe patients. The sensitivity and specificity were 32.7% and 100%, respectively (AUC = 0.812, p < 0.01). Decreases in serum iron and TIBC were associated with the clinical activity of CD. Combined detection of the two indicators was conducive to screening serious disease.

Inhibiting autophagy enhances sulforaphane-induced apoptosis via targeting NRF2 in esophageal squamous cell carcinoma.

Sulforaphane (SFN), a natural anti-tumor compound from cruciferous vegetables, has been reported to induce protective autophagy to cancer cells, which might impair the anti-tumor efficiency of SFN. However, the accurate function and mechanism of SFN inducing autophagy in cancers are still obscure, especially in esophageal squamous cell carcinoma (ESCC), one of malignancies with high incidence in North China. Here, we mainly explored the potential function of autophagy upon SFN treatment in ESCC and molecular mechanism. We demonstrated that SFN could inhibit cell proliferation and induce apoptosis by activating caspase pathway. Moreover, we found activation of NRF2 pathway by SFN was responsible for the induction of autophagy and also a disadvantage element to the anti-tumor effects of SFN on ESCC, indicating that SFN might induce protective autophagy in ESCC. We, therefore, investigated effects of autophagy inhibition on sensitivity of ESCC cells to SFN and found that chloroquine (CQ) could neutralize the activation of SFN on NRF2 and enhance the activation of SFN on caspase pathway, thus improved the anti-tumor efficiency of SFN on ESCC in vitro and in vivo. Our study provides a preclinical rationale for development of SFN and its analogs to the future treatment of ESCC.

Liver Chemistries in Patients With COVID-19 Who Were Discharged Alive or Died: A Meta-analysis.

Although abnormal liver chemistries are linked to a higher risk of coronavirus disease 2019 (COVID-19)-related death, liver manifestations may be diverse and even confusing. Thus, we performed a meta-analysis of published liver manifestations and described the liver damage in patients with COVID-19 who died or discharged alive. We searched PubMed, Google Scholar, medRxiv, bioRxiv, the Cochrane Library, Embase, and three Chinese electronic databases through April 22, 2020. We analyzed pooled data on liver chemistries stratified by the main clinical outcome of COVID-19, using a fixed or random-effects model. In our meta-analysis of 19 studies, which included a total of 4,103 patients, the pooled mean alanine aminotransferase and aspartate aminotransferase levels were, respectively, 31.7 IU/L and 51.0 IU/L in the patients with COVID-19 who died and 27.7 IU/L and 32.9 IU/L in those discharged alive (both P < 0.0001). Compared with the patients discharged alive, those who died tended to have lower albumin levels but longer prothrombin time and higher international normalized ratio. Conclusion: In this meta-analysis, according to the main clinical outcome of COVID-19, we comprehensively describe three patterns of liver impairment related to COVID-19: hepatocellular injury, cholestasis, and hepatocellular disfunction. The patients who died from COVID-19 tended to have different liver chemistries from those discharged alive. Special caution should be given to the patients with a relatively higher index of liver chemistries.

RICTOR/mTORC2 affects tumorigenesis and therapeutic efficacy of mTOR inhibitors in esophageal squamous cell carcinoma.

Dysregulation of mTORC1/mTORC2 pathway is observed in many cancers and mTORC1 inhibitors have been used clinically in many tumor types; however, the mechanism of mTORC2 in tumorigenesis is still obscure. Here, we mainly explored the potential role of mTORC2 in esophageal squamous cell carcinoma (ESCC) and its effects on the sensitivity of cells to mTOR inhibitors. We demonstrated that RICTOR, the key factor of mTORC2, and p-AKT (Ser473) were excessively activated in ESCC and their overexpression is related to lymph node metastasis and the tumor-node-metastasis (TNM) phase of ESCC patients. Furthermore, we found that mTORC1/ mTORC2 inhibitor PP242 exhibited more efficacious anti-proliferative effect on ESCC cells than mTORC1 inhibitor RAD001 due to RAD001-triggered feedback activation of AKT signal. Another, we demonstrated that down-regulating expression of RICTOR in ECa109 and EC9706 cells inhibited proliferation and migration as well as induced cell cycle arrest and apoptosis. Noteworthy, knocking-down stably RICTOR significantly suppresses RAD001-induced feedback activation of AKT/PRAS40 signaling, and enhances inhibition efficacy of PP242 on the phosphorylation of AKT and PRAS40, thus potentiates the antitumor effect of RAD001 and PP242 both in vitro and in vivo. Our findings highlight that selective targeting mTORC2 could be a promising therapeutic strategy for future treatment of ESCC.

Obesity-Induced Upregulation of ZBTB7A Promotes Lipid Accumulation through SREBP1.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) is among the most common chronic liver diseases. However, the pathogenesis of NAFLD is not still unclear. This study aims at evaluating the role of zinc finger and BTB domain-containing 7A (ZBTB7A) in NAFLD. METHODS: Western blotting, real-time reverse transcription PCR (RT-PCR), and immunohistochemistry were submitted to evaluate the level of ZBTB7A in the high fatty diet- (HFD-) induced NAFLD mouse model. In vitro, the expression of ZBTB7A was assessed in oleic acid- (OA-) induced HepG2 cells with western blotting and RT-PCR. The luciferase reporter assay was used to estimate the effect of ZBTB7A on the SREBP1 and NF-κB, and the ChIP assay was subjected to evaluate the direct binding to the SREBP1 promoter. Oil Red staining was used to detect lipid accumulation, and the ELISA was used to verify the levels of TG, T-CHO, and MDA. ZBTB7A was knocked down with siRNA, and RT-PCR was performed to analyze the lipogenesis-, fatty acid transporter-, and oxidation metabolism-related genes expression. The levels of ZBTB7A in primary hepatocyte, Kupffer, and hepatic stellate cells (HSCs) were tested by RT-PCR. RESULTS: The upregulation of ZBTB7A expression was assessed in NAFLD mice, and ZBTB7A expression was positively correlated with TNFα, IL-6, TG, T-CHO, and MDA. ZBTB7A was highly expressed in the hepatocytes. In vitro, OA-induced ZBTB7A expression and ZBTB7A expression were closely associated with SREBP1c. ZBTB7A could activate the promoter activity of SREBP1 and activate NF-κB activity. Interestingly, the direct binding of ZBTB7A in the SREBP1 promoter was acquired in HepG2 cells. Inhibition of ZBTB7A expression could attenuate OA-induced lipid accumulation, inhibit the expression of the lipogenesis-related genes and fatty acid transporter genes, and promote the expression of oxidation metabolism-related genes. CONCLUSION: ZBTB7A plays a significant role in the development process of NAFLD, and obesity-induced upregulation of ZBTB7A promotes lipid accumulation through activation of SREBP1 and NF-κB. ZBTB7A may be a potential novel target for the therapy of NAFLD.

LSD1 regulates Notch and PI3K/Akt/mTOR pathways through binding the promoter regions of Notch target genes in esophageal squamous cell carcinoma.

Background: The aberrant activation of Lysine-specific demethylase 1(LSD1), Notch and PI3K/Akt/mTOR signaling pathways were frequently happened in many cancers, including esophageal squamous cell carcinoma (ESCC). However, the regulatory relationship between LSD1 and Notch as well as PI3K/Akt/mTOR pathways is still unclear. Purpose: This study aimed to explore the regulatory effects and mechanisms of LSD1 on Notch and PI3K/Akt/mTOR pathway in ESCC. Results: Firstly, we demonstrated that LSD1 and proteins in Notch and PI3K/Akt/mTOR pathway were expressed in ESCC cells. Secondly, inhibition of LSD1 by tranylcypromine (TCP) or shRNA could decrease the expressions of related proteins in Notch and PI3K/Akt/mTOR signaling pathways in ESCC cells. Finally, we found that LSD1 could bind to the promoter regions of Notch3, Hes1 and CR2, and the combinations between them were reduced by TCP in ESCC. Conclusion: Summarily, this study indicated that LSD1 might positively regulate Notch and PI3K/Akt/mTOR pathways through binding the promoter regions of related genes in Notch pathway in ESCC.

FLI-06 suppresses proliferation, induces apoptosis and cell cycle arrest by targeting LSD1 and Notch pathway in esophageal squamous cell carcinoma cells.

Aberrant activation of the Notch signaling plays an important role in progression of esophageal squamous cell carcinoma (ESCC) and may represent a potential therapeutic target for ESCC. FLI-06 is a novel Notch inhibitor, preventing the early secretion of Notch signaling. However, little information about the antitumor activity of FLI-06 has been reported so far. To evaluate the anti-tumor activity and possible molecular mechanism of FLI-06 to ESCC cells, the effects of FLI-06 on cell viability, apoptosis and cell cycle were evaluated by CCK-8 and flow cytometry assays, respectively, in ESCC cell lines ECa109 and EC9706, and the expressions of proteins in Notch signaling pathway and LSD1 were investigated after cells were treated with FLI-06 by Western blotting. The results showed that FLI-06 blocked proliferation, induced apoptosis and G1 phase arrest of ESCC cells in a dose-dependent manner. Mechanistically, we found FLI-06 could inhibit Notch signaling pathway by decreasing the expressions of Notch3, DTX1 and Hes1. Interestingly, we also found that the expression of LSD1 (histone lysine specific demethylase 1), which is dysregulated in multiple tumors, was also inhibited by FLI-06. In addition, inhibition of Notch pathway by γ-secretase inhibitor GSI-DAPT could also inhibit LSD1 expression. The current study demonstrated that FLI-06 exerts antitumor activity on ESCC by inhibiting both LSD1 and Notch pathway, which provides the theory support for the treatment of ESCC with FLI-06.

Down-regulation of Rictor enhances cell sensitivity to PI3K inhibitor LY294002 by blocking mTORC2-medicated phosphorylation of Akt/PRAS40 in esophageal squamous cell carcinoma.

PI3K/Akt/mTOR signaling pathway plays a vital role in regulating cell survival, differentiation, metabolism and migration, which is frequently hyperactive in a number of cancers, including esophageal squamous cell carcinoma (ESCC). As the core subunit of mTORC2, Rictor is shown to be amplified in ESCC patients' tissues and plays an important role in regulation of Akt. The objective of this study is to evaluate the effects of Rictor knockdown on cell sensitivity to PI3K inhibitor LY294002 in ESCC cells and ESCC xenografts as well as its mechanisms. We found LY294002 obviously restrained cell proliferation in dose-dependent and time-dependent manners by inhibiting PI3K/Akt/mTOR/p70S6K signaling pathway, whereas triggered mTORC2-medicated phosphorylation of Akt (Ser473)/PRAS40 (Thr246) in ECa109 and EC9706 cells. Stable knockdown of Rictor by shRNA enhanced the inhibitory effects of LY294002 on cell proliferative, migration and colony formation, as well as promoted its effects on cell cycle arrest and cell apoptosis in vitro. Furthermore, stable knockdown of Rictor enhanced the antitumor effects of LY294002 by inhibiting tumor growth and promoting cell apoptosis in vivo. Mechanistic assay revealed that knockdown of Rictor could attenuate LY294002-induced phosphorylation of Akt (Ser473)/PRAS40 (Thr246). Our results provide rationale that combined inhibition of Rictor/mTORC2 and PI3K for the treatment of ESCC.

Noninvasive scoring system for significant inflammation related to chronic hepatitis B.

Although a liver stiffness measurement-based model can precisely predict significant intrahepatic inflammation, transient elastography is not commonly available in a primary care center. Additionally, high body mass index and bilirubinemia have notable effects on the accuracy of transient elastography. The present study aimed to create a noninvasive scoring system for the prediction of intrahepatic inflammatory activity related to chronic hepatitis B, without the aid of transient elastography. A total of 396 patients with chronic hepatitis B were enrolled in the present study. Liver biopsies were performed, liver histology was scored using the Scheuer scoring system, and serum markers and liver function were investigated. Inflammatory activity scoring models were constructed for both hepatitis B envelope antigen (+) and hepatitis B envelope antigen (-) patients. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve were 86.00%, 84.80%, 62.32%, 95.39%, and 0.9219, respectively, in the hepatitis B envelope antigen (+) group and 91.89%, 89.86%, 70.83%, 97.64%, and 0.9691, respectively, in the hepatitis B envelope antigen (-) group. Significant inflammation related to chronic hepatitis B can be predicted with satisfactory accuracy by using our logistic regression-based scoring system.

MicroRNA-17~92 inhibits colorectal cancer progression by targeting angiogenesis.

The miR-17~92 microRNA (miRNA) cluster host gene is upregulated in a broad spectrum of human cancers including colorectal cancer (CRC). Previous studies have shown that miR-17~92 promotes tumorigenesis and cancer angiogenesis in some tumor models. However, its role in the initiation and progression of CRC remains unknown. In this study, we found that transgenic mice overexpressing miR-17~92 specifically in epithelial cells of the small and large intestines exhibited decreased tumor size and tumor angiogenesis in azoxymethane and dextran sulfate sodium salt (AOM-DSS)-induced CRC model as compared to their littermates control. Further study showed that miR-17~92 inhibited the progression of CRC via suppressing tumor angiogenesis through targeting multiple tumor angiogenesis-inducing genes, TGFBR2, HIF1α, and VEGFA in vivo and in vitro. Collectively, we demonstrated that miR-17~92 suppressed tumor progression by inhibiting tumor angiogenesis in a genetically engineered mouse model, indicating the presence of cellular context-dependent pro- and anti-cancer effects of miR-17~92.