Fluid shear stress (FSS) regulates the metastasis of hepatocellular carcinoma (HCC). In the present study, we aimed to study the role of autophagy in HCC cells under FSS. The results showed that FSS upregulated the protein markers of autophagy, induced LC3B aggregation and formation of autophagosomes. Inhibition of integrin by Cliengitide (Cli) or inhibition of the microfilaments formation both inhibited the activation of autophagy in HepG2 under FSS. In addition, Cli inhibited the microfilaments formation and expressions of Rac1 and RhoA in HepG2 cells under FSS. Finally, inhibition of autophagy suppressed the cell migration and invasion in HepG2 under FSS. In conclusion, FSS induced autophagy to promote migration and invasion of HepG2 cells via integrin/cytoskeleton pathways.

Observational studies have demonstrated that cardiovascular risk factors are associated with chronic kidney disease (CKD). However, these observational associations are potentially influenced by the residual confounding, including some unmeasured lifestyle factors and interaction risk factors. Two-sample mendelian randomization analysis was conducted in this study to evaluate whether genetically predicted cardiovascular risk factors have a causal effect on the risk of CKD. We selected genetic variants associated with cardiovascular risk factors and extracted the corresponding effect sizes from the largest GWAS summary-level dataset of CKD. Cardiovascular risk factors contain high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglyceride (TG), glycated hemoglobin (HbA1c), fasting glucose, systolic blood pressure (SBP) and diastolic blood pressure (DBP). A Bonferroni corrected threshold of P = 0.006 was considered as significant, and 0.006 < P < 0.05 was considered suggestive of evidence for a potential association. Genetically predicted DBP was significantly associated with CKD [odds ratio (OR) was 1.35 (95% confidence interval (CI) (1.10, 1.65); P = 0.004)]. There was suggestive evidence for potential associations between genetically predicted higher HDL cholesterol [OR: 0.88, 95%CI (0.80, 0.98), P = 0.025] and lower adds of CKD, and between higher SBP [OR: 1.36, 95%CI (1.07, 1.73), P = 0.013] and higher adds of CKD. However, genetically predicted LDL cholesterol, TC, TG, HbA1c, and fasting glucose did not show any causal association with CKD.

The autophagy in cancer cells is recognized as an essential hallmark of tumors, which can enhance cancer cell migration and invasion, and result in high incidence of tumor metastasis. The fluid shear stress (FSS) in tumor mechanical microenvironment plays a pivotal role in mediating the behaviors and functions of cells. In this study, the hepatocellular carcinoma cells were exposed to 1.4 dyn/cm2 FSS to explore whether FSS could induce autophagy. The results of TEM, Ad-mCherry-GFP labeled LC3B, and mRNA and protein expression of autophagy markers confirmed that FSS could induce autophagy in a time-dependent manner. Additionally, the inhibition of autophagy significantly downregulated the expression of PI3K, FAK and Rho GTPases, and attenuated the ability of cell migration, suggesting that FSS-induced autophagy depended on PI3K- FAK-Rho GTPases pathway. This study elucidated the role of FSS in inducing autophagy during tumor progression, which has emerged as a promising clinical strategy for cancer.

Epithelial-mesenchymal transition (EMT) mediated by fluid shear stress (FSS) in the tumor microenvironment plays an important role in driving metastasis of the malignant tumor. As a mechanotransducer, Yes-associated protein (YAP) is known to translocate into the nucleus to initiate transcription of genes involved in cell proliferation upon extracellular biophysical stimuli.Here, we showed that FSS facilitated cytoskeleton rearrangement in hepatocellular carcinoma cells, which led to the release of YAP from its binding partner, integrin β subunit, in the cytomembrane. Moreover, we found that upregulation of GEF-H1, a microtubule-associated Rho guanine nucleotide exchange factor (GEF), is a critical step in the FSS-induced translocation of YAP. Nuclear YAP activated the expression of the EMT-regulating transcription factor SNAI1, but suppressed the expression of N6-methyladenosine (m 6 A) modulators; together, this promoted the expression of EMT-related genes. We also observed that FSS-treated HepG2 cells showed markedly increased tumorigenesis and metastasis in vivo. Collectively, our findings unravel the underlying molecular processes by which FSS induces translocation of YAP from the cytomembrane to the nucleus, contributes to EMT and enhances metastasis in hepatocellular carcinoma.

Hepatocellular carcinoma is a highly fatal disease and threatens human health seriously. Fluid shear stress (FSS), which is caused by the leakage of plasma from abnormally permeable tumor blood vessels and insufficient lymphatic drainage, has been identified as contributing pathologically to cancer metastasis. Autophagy and epithelial–mesenchymal transition (EMT) are both reported to be involved in cancer cell migration and invasion, but little has been revealed about the interaction between autophagy and EMT under a tumor mechanical microenvironment. Here, we identified that exposure to 1.4 dyne/cm2 FSS could promote the formation of autophagosomes and significantly increase the expressions of autophagy‐related markers of beclin1 and ATG7, and the ratio of LC3Ⅱ/Ⅰ in both of HepG2 and QGY‐7703 cells. The FSS loading also elevated the levels of mesenchymal markers N‐cadherin, Vimentin, Twist, Snail, and β‐catenin, while the epithelial markers E‐cadherin showed a decrease. Once the autophagy was blocked by 3‐methyladenine (3‐MA) or knocking ATG5 down, the occurrence of FSS‐induced EMT was inhibited dramatically according to the expression and translocation of E‐cadherin, N‐cadherin, and β‐catenin. Given the effect of EMT on cell migration, we observed that inhibition of autophagy could impede FSS‐induced cell migration. Collectively, this study demonstrated that autophagy played a crucial role in FSS‐induced EMT and cell migration in hepatocellular carcinoma.