Background: Tumor cells require proficient autophagy to meet high metabolic demands and resist chemotherapy, which suggests that reducing autophagic flux might be an attractive route for cancer therapy. However, this theory in clinical cancer research remains controversial due to the limited number of drugs that specifically inhibit autophagy-related (ATG) proteins.Methods: We screened FDA-approved drugs using a novel platform that integrates computational docking and simulations as well as biochemical and cellular reporter assays to identify potential drugs that inhibit autophagy-required cysteine proteases of the ATG4 family. The effects of ATG4 inhibitors on autophagy and tumor suppression were examined using cell culture and a tumor xenograft mouse model.Results: Tioconazole was found to inhibit activities of ATG4A and ATG4B with an IC50 of 1.3 µM and 1.8 µM, respectively. Further studies based on docking and molecular dynamics (MD) simulations supported that tioconazole can stably occupy the active site of ATG4 in its open form and transiently interact with the allosteric regulation site in LC3, which explained the experimentally observed obstruction of substrate binding and reduced autophagic flux in cells in the presence of tioconazole. Moreover, tioconazole diminished tumor cell viability and sensitized cancer cells to autophagy-inducing conditions, including starvation and treatment with chemotherapeutic agents.Conclusion: Tioconazole inhibited ATG4 and autophagy to enhance chemotherapeutic drug-induced cytotoxicity in cancer cell culture and tumor xenografts. These results suggest that the antifungal drug tioconazole might be repositioned as an anticancer drug or chemosensitizer.
Hydroxychloroquine (HCQ) is an antimalarial drug also used in treating autoimmune diseases. Its antiviral activity was demonstrated in restricting HIV infection in vitro; however, the clinical implications remain controversial. Infection with dengue virus (DENV) is a global public health problem, and we lack an antiviral drug for DENV. Here, we evaluated the anti-DENV potential of treatment with HCQ. Immunofluorescence assays demonstrated that HCQ could inhibit DENV serotype 1-4 infection in vitro. RT-qPCR analysis of HCQtreated cells showed induced expression of interferon (IFN)-related antiviral proteins and certain inflammatory cytokines. Mechanistic study suggested that HCQ activated the innate immune signaling pathways of IFN-b, AP-1, and NFkB. Knocking down mitochondrial antiviral signaling protein (MAVS), inhibiting TANK binding kinase 1 (TBK1)/inhibitor-kB kinase e (IKKe), and blocking type I IFN receptor reduced the efficiency of HCQ against DENV-2 infection. Furthermore, HCQ significantly induced cellular production of reactive oxygen species (ROS), which was involved in the host defense system. Suppression of ROS production attenuated the innate immune activation and anti-DENV-2 effect of HCQ. In summary, HCQ triggers the host defense machinery by inducing ROS-and MAVS-mediated innate immune activation against DENV infection and may be a candidate drug for DENV infection.
Bullous pemphigoid (BP), a common autoimmune blistering disease, is increasing in incidence and conveys a high mortality. Detection of autoantibodies targeting the noncollagenous 16A (NC16A) domain of type XVII collagen using enzyme-linked immunosorbent assay (ELISA) has demonstrated high sensitivity and specificity for diagnosing BP. We have developed a rapid, low-cost, and widely applicable ELISA-based system to detect the NC16A autoimmune antibody and then diagnose and monitor BP disease activity using a piece of filter paper, a wax-printer, and NC16A antigens. Both sera and/or blister fluids from 14 untreated BP patients were analyzed. The control group included healthy volunteers and patients with other blistering disorders such as pemphigus vulgaris. In our established paper-based ELISA (P-ELISA) system, only 2 μL of serum or blister fluid and 70 min were required to detect anti-NC16A autoimmune antibodies. The relative color intensity was significantly higher in the BP group than in the control groups when using either serum (P < 0.05) or blister fluid (P < 0.001) specimens from BP patients. The results of P- ELISA were moderately correlated with the titer of the commercial ELISA kit (MBL, Japan) (rho = 0.5680, P = 0.0011). This newly developed system allows for rapid and convenient diagnosis and/or monitoring of BP disease activity.
SUMMARY
Innate immunity controls pathogen replication and spread. Yet, certain pathogens, such as Hepatitis C Virus (HCV), escape immune elimination and establish persistent infections that promote chronic inflammation and related diseases. Whereas HCV regulatory proteins that attenuate anti-viral responses are known, those that promote inflammation and liver injury remain to be identified. Here we describe that transient expression of HCV RNA-dependent RNA polymerase (RdRp), NS5B, in mouse liver and human hepatocytes results in production of small RNA species that activate innate immune signaling via TBK1-IRF3 and NF-κB and induce cytokine production including type I interferons (IFN) and IL-6. NS5B-expression also results in liver damage.
Background and Aims-HCV related liver disease is one of the most important complications in persons with HIV, with accelerated fibrosis progression in coinfected persons compared to those with HCV alone. We hypothesized that HIV coinfection increases HCV related hepatocyte apoptosis and that HCV and HIV influence TRAIL signaling in hepatocytes.
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Lifelong caloric restriction increases median and maximum life span and retards the aging process in many organ systems of rodents. Because the small intestine absorbs a reduced amount of nutrients each day, does lifelong caloric restriction induce adaptations in intestinal nutrient transport? We initially compared intestinal transport of sugars and amino acids between 24-mo-old mice allowed free access to food [ad libitum (AL)] and those provided a calorically restricted [40% less than ad libitum (CR)] diet since 3 mo of age. We found that CR mice had significantly greater transport rates for D-glucose, D-fructose, and several amino acids and had significantly lower villus heights. Total intestinal absorptive capacities for D-glucose, D-fructose, and L-proline were each 40-50% greater in CR mice; absorptive capacity normalized to metabolic mass (body weight 0.75) was approximately 80% greater in CR mice. Comparison of uptakes in aged AL and CR mice with previously published results in young AL mice suggests that caloric restriction delays age-related decreases in nutrient transport. In contrast to published studies in hibernation and starvation, chronic caloric restriction enhances not only uptake per milligram but also uptake per centimeter. We then switched 24-mo-old AL mice to a calorie-restricted diet for 1 mo and found that short-term caloric restriction has no effect on intestinal nutrient transport, intestinal mass, and total absorptive capacity. Thus chronic but not short-term caloric restriction increases intestinal nutrient transport rates in aged mice, and the main mechanism underlying these increases is enhanced transport rates per unit intestinal tissue weight.
IMAR, reflecting liver function and oxidative stress, is a more objective liver function test as it was not affected after a 3-day albumin infusion. More investigations, however, are needed to validate the use of IMAR in cases of chronic liver disease.
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