Nanozymes as artificial enzymes that mimicked natural enzyme-like activities have received great attention in cancer diagnosis and therapy. Biomimetic nanozymes require more consideration regarding complicated tumor microenvironments to mimic biological enzymes, thus achieving superior nanozyme activity in vivo. Here we report a biomimetic hybrid nanozyme (named rMGB) which integrates natural enzyme glucose oxidase (GOx) with nanozyme manganese dioxide (MnO 2 ) by mutual promotion for maximizing the enzymatic activity of MnO 2 and GOx. Under hypoxia environment, we observed that MnO 2 could react with endogenous H 2 O 2 to produce O 2 for enhancing the catalytic efficiency of GOx for starvation therapy. Meanwhile, we confirmed that glucose oxidation generated gluconic acid and further improved the catalytic efficiency of MnO 2 subsequently. The biochemical reaction cycle, consisting of MnO 2 , O 2 , GOx, and H + , was triggered by the tumor microenvironment and accelerated each other so as to achieve self-supplied H + and accelerate O 2 generation, enhancing the starvation therapy, alleviating tumor hypoxia and accelerating the reactive oxygen species generation in photodynamic therapy. This biomimetic hybrid nanozyme would further facilitate the development of biological nanozymes for cancer treatment.

Background Diabetic nephropathy (DN) is a lethal diabetic microvascular complication characterized by chronic low-grade inflammation. The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome is implicated in the progression of DN. MCC950 is a selective and potent inhibitor of NLRP3; however, its efficacy in DN requires further investigation. Methods To investigate the efficacy of MCC950 in DN, eight-week-old type 2 diabetic db/db mice received injections of MCC950 intraperitoneally (10 mg/kg) twice per week for 12 weeks. Urinary albumin-to-creatinine ratio (ACR) and neutrophil gelatinase-associated lipocalin (NGAL), renal function, pathological changes, markers of podocyte and fibrosis and NLPR3/caspase-1/IL-1β expression in the renal cortices of db/db mice were evaluated. High-glucose (HG)-treated rat glomerular mesangial cells were treated with various concentrations of MCC950 for 48 hrs. Markers of fibrosis and NLPR3/caspase-1/IL-1β expression in the glomerular mesangial cells were measured. Results The NLRP3 inflammasome was activated in db/db mice and HG-induced mesangial cells by upregulating NLRP3/caspase-1/IL-1β pathway. Inhibition of the NLRP3 inflammasome with MCC950 reduced the production of active caspase-1 and active IL-1β in db/db mice and HG-induced mesangial cells. MCC950 reduced serum creatinine, urinary ACR and NGAL, attenuated mesangial expansion with increased matrix and tubular dilatation, alleviated thickened glomerular basement membrane (GBM) and foot process fusion without affecting body weight and blood glucose levels in db/db mice. MCC950 increased the expression of podocin in db/db mice, and decreased the expression of TGF-β1, fibronectin, collagen I and α-smooth muscle actin (α-SMA) in renal cortices of db/db mice and HG-induced mesangial cells. Conclusion MCC950 ameliorated renal function, thickened GBM, podocyte injury and renal fibrosis in db/db mice, and decreased the production of fibrosis markers in HG-induced mesangial cells. MCC950 effectively ameliorated diabetic kidney injury by inhibiting NLRP3/caspase-1/IL-1β pathway, which may be a potential therapeutic strategy to prevent the progression of DN.

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The abundant glutathione (GSH) in “cold” tumors weakens ferroptosis therapy and the immune response. Inspired by lipids, we fabricated cinnamaldehyde dimers (CDC) into lipid‐like materials to form dimersomes capable of depleting GSH and delivering therapeutics to potentiate the ferroptosis and immunotherapy of breast cancer. The dimersomes exhibited superior storage stability for over one year. After reaching the tumor, they quickly underwent breakage in the cytosol owing to the conjugation of hydrophilic GSH on CDC by Michael addition, which not only triggered the drug release and fluorescence switch “ON”, but also led to the depletion of intracellular GSH. Ferroptosis was significantly enhanced after combination with sorafenib (SRF) and elicited a robust immune response in vivo by promoting the maturation of dendritic cells and the priming of CD8+ T cells. As a result, the CDC@SRF dimersomes cured breast cancer in all the mice after four doses of administration.

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These authors contributed equally to this workBackground: Apoptosis has been repeatedly linked with diabetic kidney disease (DKD), which is a programmed cell death mediated by effector caspases-3, 6 and 7, targeting >600 substrates. However, the pathophysiologic correlations of this process remain obscure. As a putative tumor suppressor, gasdermin E (GSDME) was recently reported to be cleaved by caspase-3 to produce a GSDME-N fragment which targets the plasma membrane to switch apoptosis to secondary necrosis. However, it remains elusive whether GSDME is involved in the regulation of DKD. Methods: To evaluate the therapeutic potential of caspase-3 inhibition in DKD, we administered caspase-3 inhibitor Z-DEVD-FMK to STZ-induced diabetic mice for eight weeks. Albuminuria, renal function, pathological changes, and indicators of secondary necrosis and fibrosis were evaluated. In vitro, human tubule epithelial cells (HK-2 cells) were subjected to high-glucose treatment. Secondary necrosis was determined by LDH release, GSDME cleavage, and morphological feature under confocal microscopy. Z-DEVD-FMK and GSDME inhibition by shRNA were administered to suppress the cleavage and expression of GSDME. Flow cytometry, cytotoxicity assay and immunoblot were used to assess cell death and fibrogenesis. Results: Caspase-3 inhibition by Z-DEVD-FMK ameliorated albuminuria, renal function, and tubulointerstitial fibrosis in diabetic mice. The nephroprotection mediated by Z-DEVD-FMK was potentially associated with inhibition of GSDME. In vitro, molecular and morphological features of secondary necrosis were observed in glucose-stressed HK-2 cells, evidenced by active GSDME cleavage, ballooning of the cell membrane, and release of cellular contents. Here we showed that caspase-3 inhibition prevented GSDME activation and cell death in glucose-treated tubular cells. Specifically, knocking down GSDME directly inhibited secondary necrosis and fibrogenesis. Conclusion: These data suggest GSDME-dependent secondary necrosis plays a crucial role in renal injury, and provides a new insight into the pathogenesis of DKD and a promising target for its treatment.

BackgroundEndometrial cancer (EC) is one of the most common gynecological malignancies globally. Although progress has been made in surgical and other adjuvant therapies, there is still a great need to develop new approaches to further reduce the incidence and mortality of EC. Oncolytic virotherapy offers a novel promising option of cancer treatment and has demonstrated good efficacy in preclinical models and clinical trials. However, only few oncolytic viruses have been tested for EC treatment. In this study, the potential of an oncolytic coxsackievirus B3 (CV-B3) strain 2035A (CV-B3/2035A) was investigated as a novel biotherapeutic agent against EC.MethodsHuman EC cell lines (Ishikawa, HEC-1-A and HEC-1-B) were infected with CV-B3/2035A, and viral replication and cytotoxic effects were evaluated in vitro. CV-B3/2035A-induced oncolysis was also investigated in nude mice bearing EC xenografts in vivo and in patient-derived EC samples ex vivo.ResultsHuman EC cell lines expressing different levels of CAR and DAF were all susceptible to infection by CV-B3/2035A and supported efficient viral replication in vitro. In the EC xenograft/nude mouse model, both intratumoral and intravenous administrations of CV-B3-2035A exerted significant therapeutic effects against pre-established EC tumors without causing significant treatment-related toxicity and mortality in nude mice. Moreover, CV-B3/2035A treatment resulted in decreased viability of patient-derived EC samples ex vivo.ConclusionsCV-B3/2035A showed oncolytic activity in human EC cell lines both in vitro and in vivo as well as in patient-derived EC samples ex vivo and thus could be used as an alternative virotherapy agent for the treatment of EC.Electronic supplementary materialThe online version of this article (10.1186/s12985-018-0975-x) contains supplementary material, which is available to authorized users.