The downregulation of Tapasin in dendritic cell regulates CD8+ T cell autophagy to hamper hepatitis B viral clearance in the induced pluripotent stem cell-derived hepatocyte organoid.

Tapasin, a crucial molecular chaperone involved viral antigen processing and presentation, plays an important role in antivirus immunity. However, its impact on T cell differentiation in the context of virus clearance remains unclear. In this study, we employed induced pluripotent stem cells to differentiate into hepatocyte-like cell, which were subsequently inserted to the inverted colloidal crystal scaffolds, thus establishing a hepatocyte organoid (HO). By inoculating hepatitis B virus (HBV) particles in the system, we successfully engineered a robust in vitro HBV infection model for at least 3 weeks. Furthermore, we aimed to explore the effects of lentivirus-mediated short hairpin RNA (shRNA) targeting human Tapasin on the differentiation and antiviral function of CD8+ T cells. Specifically, we transfected dendritic cells (DCs) with Tapasin-shRNA and cocultured with T cells. The results demonstrated that Tapasin-shRNA transfected DCs effectively suppressed T cell proliferation and impeded HBV-specific cytotoxic T lymphocyte responses. Our investigation also revealed the role of mTOR pathway activation in reducing autophagy activity within CD8+ T cells. Expressions of autophagy-related proteins, beclin-1, LC3II/LC3I were decreased and PI3K/AKT/mTOR activity was increased in Tapasin-shRNA group. Collectively, our findings elucidate that shRNA targeting the Tapasin gene within DCs inhibits T cell differentiation by reducing autophagy activity to hamper viral clearance in the HBV-infected HO.

Efficacy and Safety of Nirmatrelvir/Ritonavir in Severe Hospitalized Patients with COVID-19 and in Patients at High Risk for Progression to Critical Illness: A Real-World Study.

Background: Nirmatrelvir/Ritonavir is an orally administered anti-SARS-Cov-2 drug used in mild-to-moderate COVID-19 patients. Our retrospective cohort study aims to evaluate the efficacy and safety of Nirmatrelvir/Ritonavir in severe hospitalized patients with Omicron infection, as well as in patients at high risk for progression to critical illness in real-world settings. Methods: A total of 350 patients received Nirmatrelvir/Ritonavir while 350 matched controls did not. Patients with confirmed COVID-19 were administered Nirmatrelvir 300 mg and Ritonavir 100 mg orally twice a day for 5 days, with the medication initiated on the first day after admission. The primary endpoint of the study was a composite outcome of hospitalization or death from any cause within 28 days. Secondary endpoints included the occurrence of adverse events and the evaluation of serum levels of IL-6 and viral load. Results: We documented the mortality risk from any cause within 28 days, viral load, serum IL-6 levels, and adverse events. Nirmatrelvir/Ritonavir reduced the 28-day risk of all-cause mortality by 86% (P = .011, hazard ratio (HR) = 0.14, 95% confidence interval (CI) = 0.03, 0.64). At baseline, the serum level of IL-6 was significantly higher in the antiviral treatment group compared to the control group (P < .001), but no significant difference (P = .990) was found between the two groups at discharge. In CKD patients undergoing hemodialysis, no significant worsening of renal function was observed in the Nirmatrelvir/Ritonavir treatment group compared to the control group. Conclusion: Nirmatrelvir/Ritonavir may reduce the 28-day risk of all-cause mortality in critically ill patients with COVID-19 and in patients at high risk for critical disease progression.

Collagen XV mediated the epithelial-mesenchymal transition to inhibit hepatocellular carcinoma metastasis.

Background: Hepatocellular carcinoma (HCC) is a malignant cancer with rapid progression, vascular invasion, a high recurrence rate and poor prognosis, so it is necessary to take early measures to halt this process. Accumulating evidence indicates that collagen XV (translated by Col15a1) is a basement membrane molecule related to tumour metastasis in several organs. However, the potential function of collagen XV in the liver associated with HCC remains to be further elucidated. Methods: Col15a1 was overexpressed in HepG2 and HCCLM3 cells. CCK8 and colony formation assays were used to assess the capacity of cell proliferation, and Transwell and wound healing assays were utilized to measure cell migration. Western blotting and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) quantified the protein and mRNA expression levels of genes related to the epithelial-mesenchymal transition (EMT). Then, the effect of collagen XV on tumour metastasis was confirmed in vivo. Finally, we inhibited discoidin domain receptor 1 (DDR1) via DDR1-IN-1 to explore whether the collagen XV interacted with DDR1 to regulate EMT. Results: Patients of HCC with higher expression of Col15a1 showed better survival than patients with low expression. Overexpression of collagen XV in HepG2 and HCCLM3 cells suppressed cell proliferation and migration in vitro and inhibited pulmonary and liver metastasis in vivo. In addition, collagen XV downregulated the DDR1 and transcription factor (Snail, Slug), regulated the EMT markers (Vimentin, E-cadherin, N-cadherin, and MMP9). Furthermore, inhibition of the DDR1 receptor by DDR1-IN-1 suppressed the gene promoting the EMT. Conclusions: Collagen XV functioned as a metastasis inhibitor in HCC by regulating the DDR1-Snail/Slug axis to regulate EMT.

Identification of CKD, bedridden history and cancer as higher-risk comorbidities and their impact on prognosis of hospitalized Omicron patients: a multi-centre cohort study.

To further describe the effect of the "fragile population" and their "higher-risk" comorbidities on prognosis among hospitalized Omicron patients, this observational cohort study enrolled hospitalized patients confirmed with SARS-CoV-2 during the 2022 Omicron wave in Shanghai, China. The primary outcome was progression to severe or critical cases. The secondary outcome was viral shedding time from the first positive SARS-CoV-2 detection. A total of 847 participants were enrolled, most of whom featured as advanced age (>70 years old: 30.34%), not fully vaccinated (55.84%), combined with at least 1 comorbidity (65.41%). Multivariate cox regression suggested age >70 years old (aHR[95%CI] 0.78[0.61-0.99]), chronic kidney disease (CKD) stage 4-5 (aHR[95%CI] 0.61[0.46-0.80]), heart conditions (aHR[95%CI] 0.76[0.60-0.97]) would elongate viral shedding time and fully/booster vaccination (aHR[95%CI] 1.4 [1.14-1.72]) would shorten this duration. Multivariate logistic regression suggested CKD stage 4-5 (aHR[95%CI] 3.21[1.45-7.27]), cancer (aHR[95%CI] 9.52[4.19-22.61]), and long-term bedridden status (aHR[95%CI] 4.94[2.36-10.44]) were the "higher" risk factor compared with the elderly, heart conditions, metabolic disorders, isolated hypertension, etc. for severity while female (aHR[95%CI] 0.34[0.16-0.68]) and fully/booster Vaccination (aHR[95%CI] 0.35[0.12-0.87]) could provide protection from illness progression. CKD stage 4-5, cancer and long-term bedridden history were "higher-risk" factors among hospitalized Omicron patients for severity progression while full vaccination could provide protection from illness progression.

Astragalus polysaccharide alleviated hepatocyte senescence via autophagy pathway.

Aging is characterized by inevitable organ function decline over time, with consequent body deterioration and increased susceptibility to death. Astragalus polysaccharide (APS) has been reported to have anti-oxidative, anti-apoptotic, and anti-inflammatory properties. We investigated the potential protective effects of APS on hydrogen peroxide (H2 O2 ) induced hepatocyte senescence and identified related mechanisms in L02, Huh7, and LM3 cell lines. Aged female C57BL/6 mice were given APS for 1 week by intraperitoneal injection, and APS provided the strongest protective effect against H2 O2 -induced damage at 100 µM. APS reduced the expression of cell senescence markers and alleviated pathological damage in aged mouse liver. APS treatment decreased oxidative stress, apoptosis, NOD-like receptor protein-3-mediated pyroptosis, and maintained mitochondrial homeostasis. Notably, the protective effect of APS was weakened in the presence of chloroquine. APS might enrich autophagy by activating AMP-activated protein kinase (AMPK) and inhibiting mammalian target of rapamycin (mTOR). In conclusion, APS reduced reactive oxygen species levels, inhibited apoptosis and pyroptosis, and promoted mitophagy via AMPK/mTOR pathway to alleviate hepatocyte senescence in vitro and in vivo.