RPA-CRISPR-Cas13a-assisted detection method of transmissible gastroenteritis virus.

Background and aim: Transmissible gastroenteritis virus (TGEV) is a highly contagious gastrointestinal virus that causes diarrhea, vomiting, anorexia, dehydration, and weight loss in piglets. In clinical practice, it often occurs in mixed infections with other pathogens, and is therefore difficult to diagnose and prevent. It mainly harms piglets of about 2 weeks old, causing huge losses on farms. The clinical confirmation of TGEV usually requires a laboratory diagnosis, but traditional PCR and immunofluorescence assays have some limitations. Moreover, most farms in China are ill-equipped to accurately diagnose the disease. Therefore, a new detection method with high sensitivity and specificity and less dependence on instrumentation is required. Methods: We used recombinase polymerase amplification (RPA), combined with the nuclease characteristics of the activated Cas13a protein to establish a visual CRISPR-Cas13a-assisted detection method for TGEV by adding a reporter RNA with fluorescent and quenching moieties to the system. Result: We selected the optimal RPA primer and best CRISPR RNA (crRNA). The reaction system was optimized and its repeatability, specificity, and sensitivity verified. The TGEV detection system did not cross-react with other common diarrhea viruses, and its detection limit was 101 copies, which is similar with the sensitivity of qPCR. We successfully established an RPA-CRISPR-Cas13a-assisted detection method, and used this detection system to analyze 123 pig blood samples. qPCR was used as the gold standard method. The sensitivity, specificity, positive coincidence rate, and negative coincidence rate of the new method were 100, 98.93, 96.66, and 100%, respectively.

HIV coinfection exacerbates HBV-induced liver fibrogenesis through a HIF-1α- and TGF-ß1-dependent pathway.

BACKGROUND & AIMS: Persons with chronic HBV infection coinfected with HIV experience accelerated progression of liver fibrosis compared to those with HBV monoinfection. We aimed to determine whether HIV and its proteins promote HBV-induced liver fibrosis in HIV/HBV-coinfected cell culture models through HIF-1α and TGF-ß1 signaling. METHODS: The HBV-positive supernatant, purified HBV viral particles, HIV-positive supernatant, or HIV viral particles were directly incubated with cell lines or primary hepatocytes, hepatic stellate cells, and macrophages in mono or 3D spheroid coculture models. Cells were incubated with recombinant cytokines and HIV proteins including gp120. HBV sub-genomic constructs were transfected into NTCP-HepG2 cells. We also evaluated the effects of inhibitor of HIF-1α and HIV gp120 in a HBV carrier mouse model that was generated via hydrodynamic injection of the pAAV/HBV1.2 plasmid into the tail vein of wild-type C57BL/6 mice. RESULTS: We found that HIV and HIV gp120, through engagement with CCR5 and CXCR4 coreceptors, activate AKT and ERK signaling and subsequently upregulate hypoxia-inducible factor-1α (HIF-1α) to increase HBV-induced transforming growth factor-ß1 (TGF-ß1) and profibrogenic gene expression in hepatocytes and hepatic stellate cells. HIV gp120 exacerbates HBV X protein-mediated HIF-1α expression and liver fibrogenesis, which can be alleviated by inhibiting HIF-1α. Conversely, TGF-ß1 upregulates HIF-1α expression and HBV-induced liver fibrogenesis through the SMAD signaling pathway. HIF-1α small-interfering RNA transfection or the HIF-1α inhibitor (acriflavine) blocked HIV-, HBV-, and TGF-ß1-induced fibrogenesis. CONCLUSIONS: Our findings suggest that HIV coinfection exacerbates HBV-induced liver fibrogenesis through enhancement of the positive feedback between HIF-1α and TGF-ß1 via CCR5/CXCR4. HIF-1α represents a novel target for antifibrotic therapeutic development in HBV/HIV coinfection. IMPACT AND IMPLICATIONS: HIV coinfection accelerates the progression of liver fibrosis compared to HBV monoinfection, even among patients with successful suppression of viral load, and there is no sufficient treatment for this disease process. In this study, we found that HIV viral particles and specifically HIV gp120 promote HBV-induced hepatic fibrogenesis via enhancement of the positive feedback between HIF-1α and TGF-ß1, which can be ameliorated by inhibition of HIF-1α. These findings suggest that targeting the HIF-1α pathway can reduce liver fibrogenesis in patients with HIV and HBV coinfection.

Hepatitis B and Hepatitis C Virus Infection Promote Liver Fibrogenesis through a TGF-ß1-Induced OCT4/Nanog Pathway.

Hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection accelerates liver fibrosis progression compared with HBV or HCV monoinfection. Octamer binding transcription factor 4 (OCT4) and Nanog are direct targets of the profibrogenic TGF-ß1 signaling cascade. We leveraged a coculture model to monitor the effects of HBV and HCV coinfection on fibrogenesis in both sodium taurocholate cotransporting polypeptide-transfected Huh7.5.1 hepatoma cells and LX2 hepatic stellate cells (HSCs). We used CRISPR-Cas9 to knock out OCT4 and Nanog to evaluate their effects on HBV-, HCV-, or TGF-ß1-induced liver fibrogenesis. HBV/HCV coinfection and HBx, HBV preS2, HCV Core, and HCV NS2/3 overexpression increased TGF-ß1 mRNA levels in sodium taurocholate cotransporting polypeptide-Huh7.5.1 cells compared with controls. HBV/HCV coinfection further enhanced profibrogenic gene expression relative to HBV or HCV monoinfection. Coculture of HBV and HCV monoinfected or HBV/HCV coinfected hepatocytes with LX2 cells significantly increased profibrotic gene expression and LX2 cell invasion and migration. OCT4 and Nanog guide RNA independently suppressed HBV-, HCV-, HBV/HCV-, and TGF-ß1-induced α-SMA, TIMP-1, and Col1A1 expression and reduced Huh7.5.1, LX2, primary hepatocyte, and primary human HSC migratory capacity. OCT4/Nanog protein expression also correlated positively with fibrosis stage in liver biopsies from patients with chronic HBV or HCV infection. In conclusion, HBV and HCV independently and cooperatively promote liver fibrogenesis through a TGF-ß1-induced OCT4/Nanog-dependent pathway.

HBV/HIV Coinfection: Impact on the Development and Clinical Treatment of Liver Diseases.

Hepatitis B virus (HBV) infection is a common contributor to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Approximately 10% of people with human immunodeficiency virus (HIV) also have chronic HBV co-infection, owing to shared transmission routes. HIV/HBV coinfection accelerates the progression of chronic HBV to cirrhosis, end-stage liver disease, or hepatocellular carcinoma compared to chronic HBV mono-infection. HBV/HIV coinfection alters the natural history of hepatitis B and renders the antiviral treatment more complex. In this report, we conducted a critical review on the epidemiology, natural history, and pathogenesis of liver diseases related to HBV/HIV coinfection. We summarized the novel therapeutic options for these coinfected patients.

Gamma-Glutamyltransferase Elevation Is Frequent in Patients With COVID-19: A Clinical Epidemiologic Study.

A newly identified coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes the infectious coronavirus disease 2019 (COVID-19), emerged in December 2019 in Wuhan, Hubei Province, China, and now poses a major threat to global public health. Previous studies have observed highly variable alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in patients with COVID-19. However, circulating levels of the cholangiocyte injury biomarker gamma-glutamyltransferase (GGT) have yet to be reported in the existing COVID-19 case studies. Herein, we describe the relationship between GGT levels and clinical and biochemical characteristics of patients with COVID-19. Our study is a retrospective case series of 98 consecutive hospitalized patients with confirmed COVID-19 at Wenzhou Central Hospital in Wenzhou, China, from January 17 to February 5, 2020. Clinical data were collected using a standardized case report form. Diagnosis of COVID-19 was assessed by symptomatology, reverse-transcription polymerase chain reaction (RT-PCR), and computed tomography scan. The medical records of patients were analyzed by the research team. Of the 98 patients evaluated, elevated GGT levels were observed in 32.7%; increased C-reactive protein (CRP) and elevated ALT and AST levels were observed in 22.5%, 13.3%, and 20.4%, respectively; and elevated alkaline phosphatase (ALP) and triglycerides (TGs) were found in 2% and 21.4%, respectively. Initially, in the 82 patients without chronic liver disease and alcohol history, age older than 40 years (P = 0.027); male sex (P = 0.0145); elevated CRP (P = 0.0366), ALT (P < 0.0001), and ALP (P = 0.0003); and increased TGs (P = 0.0002) were found to be associated with elevated GGT levels. Elevated GGT (P = 0.0086) and CRP (P = 0.0162) levels had a longer length of hospital stay. Conclusion: A sizable number of patients with COVID-19 infection have elevated serum GGT levels. This elevation supports involvement of the liver in persons with COVID-19.

Microrna-130a Downregulates HCV Replication through an atg5-Dependent Autophagy Pathway.

We previously identified that miR-130a downregulates HCV replication through two independent pathways: restoration of host immune responses and regulation of pyruvate metabolism. In this study, we further sought to explore host antiviral target genes regulated by miR-130a. We performed a RT² Profiler™ PCR array to identify the host antiviral genes regulated by miR-130a. The putative binding sites between miR-130a and its downregulated genes were predicted by miRanda. miR-130a and predicted target genes were over-expressed or knocked down by siRNA or CRISPR/Cas9 gRNA. Selected gene mRNAs and their proteins, together with HCV replication in JFH1 HCV-infected Huh7.5.1 cells were monitored by qRT-PCR and Western blot. We identified 32 genes that were significantly differentially expressed more than 1.5-fold following miR-130a overexpression, 28 of which were upregulated and 4 downregulated. We found that ATG5, a target gene for miR-130a, significantly upregulated HCV replication and downregulated interferon stimulated gene expression. miR-130a downregulated ATG5 expression and its conjugation complex with ATG12. ATG5 and ATG5-ATG12 complex affected interferon stimulated gene (ISG) such as MX1 and OAS3 expression and subsequently HCV replication. We concluded that miR-130a regulates host antiviral response and HCV replication through targeting ATG5 via the ATG5-dependent autophagy pathway.