Cavin1 Deficiency Causes Disorder of Hepatic Glycogen Metabolism and Neonatal Death by Impacting Fenestrations in Liver Sinusoidal Endothelial Cells

ADAMTS18-fibronectin interaction regulates the morphology of liver sinusoidal endothelial cells

Liver sinusoidal endothelial cells (LSECs) have a unique morphological structure known as "fenestra" that plays a crucial role in liver substance exchange and homeostasis maintenance. In this study, we demonstrate that ADAMTS18 protease is primarily secreted by fetal liver endothelial cells. ADAMTS18 deficiency leads to enlarged fenestrae and increased porosity of LSECs, microthrombus formation in liver vessels, and an imbalance of liver oxidative stress. These defects worsen carbon tetrachloride (CCl4)-induced liver fibrosis and diethylnitrosamine (DEN)/high-fat-induced hepatocellular carcinoma (HCC) in adult Adamts18-deficient mice. Mechanically, ADAMTS18 functions as a modifier of fibronectin (FN) to regulate the morphological acquisition of LSECs via the vascular endothelial growth factor A (VEGFA) signaling pathways. Collectively, a mechanism is proposed for LSEC morphogenesis and liver homeostasis maintenance via ADAMTS18-FN-VEGFA niches.

Transcription of the Envelope Protein by 1-L Protein–RNA Recognition Code Leads to Genes/Proteins That Are Relevant to the SARS-CoV-2 Life Cycle and Pathogenesis

The theoretical protein–RNA recognition code was used in this study to research the compatibility of the SARS-CoV-2 envelope protein (E) with mRNAs in the human transcriptome. According to a review of the literature, the spectrum of identified genes showed that the virus post-transcriptionally promotes or represses the genes involved in the SARS-CoV-2 life cycle. The identified genes/proteins are also involved in adaptive immunity, in the function of the cilia and wound healing (EMT and MET) in the pulmonary epithelial tissue, in Alzheimer’s and Parkinson’s disease and in type 2 diabetes. For example, the E-protein promotes BHLHE40, which switches off the IL-10 inflammatory “brake” and inhibits antiviral T_Hαβ cells. In the viral cycle, E supports the COPII-SCAP-SREBP-HSP90α transport complex by the lowering of cholesterol in the ER and by the repression of insulin signaling, which explains the positive effect of HSP90 inhibitors in COVID-19 (geldanamycin), and E also supports importin α/β-mediated transport to the nucleus, which explains the positive effect of ivermectin, a blocker of importins α/β. In summary, transcription of the envelope protein by the 1-L protein–RNA recognition code leads to genes/proteins that are relevant to the SARS-CoV-2 life cycle and pathogenesis.

Cepharanthine sensitizes human triple negative breast cancer cells to chemotherapeutic agent epirubicin via inducing cofilin oxidation-mediated mitochondrial fission and apoptosis

Inhibition of autophagy has been accepted as a promising therapeutic strategy in cancer, but its clinical application is hindered by lack of effective and specific autophagy inhibitors. We previously identified cepharanthine (CEP) as a novel autophagy inhibitor, which inhibited autophagy/mitophagy through blockage of autophagosome-lysosome fusion in human breast cancer cells. In this study we investigated whether and how inhibition of autophagy/mitophagy by cepharanthine affected the efficacy of chemotherapeutic agent epirubicin in triple negative breast cancer (TNBC) cells in vitro and in vivo. In human breast cancer MDA-MB-231 and BT549 cells, application of CEP (2 μM) greatly enhanced cepharanthine-induced inhibition on cell viability and colony formation. CEP interacted with epirubicin synergistically to induce apoptosis in TNBC cells via the mitochondrial pathway. We demonstrated that co-administration of CEP and epirubicin induced mitochondrial fission in MDA-MB-231 cells, and the production of mitochondrial superoxide was correlated with mitochondrial fission and apoptosis induced by the combination. Moreover, we revealed that co-administration of CEP and epirubicin markedly increased the generation of mitochondrial superoxide, resulting in oxidation of the actin-remodeling protein cofilin, which promoted formation of an intramolecular disulfide bridge between Cys39 and Cys80 as well as Ser3 dephosphorylation, leading to mitochondria translocation of cofilin, thus causing mitochondrial fission and apoptosis. Finally, in mice bearing MDA-MB-231 cell xenografts, co-administration of CEP (12 mg/kg, ip, once every other day for 36 days) greatly enhanced the therapeutic efficacy of epirubicin (2 mg/kg) as compared with administration of either drug alone. Taken together, our results implicate that a combination of cepharanthine with chemotherapeutic agents could represent a novel therapeutic strategy for the treatment of breast cancer.