Reduced Sirtuin1 signalling exacerbates diabetic mice hindlimb ischaemia injury and inhibits the protective effect of a liver X receptor agonist

Diabetes mellitus causes endothelial dysfunction, which further exacerbates peripheral arterial disease (PAD). Improving endothelial function via reducing endothelial oxidative stress (OS) may be a promising therapy for diabetic PAD. Activation of liver X receptor (LXR) inhibits excessive OS and provides protective effects on endothelial cells in diabetic individuals. Therefore, we investigated the effects of LXR agonist treatment on diabetic PAD with a focus on modulating endothelial OS. We used a streptozotocin-induced diabetes mouse model combined with a hindlimb ischaemia (HLI) injury to mimic diabetic PAD, which was followed by LXR agonist treatment. In our study, the LXR agonist T0901317 protected against HLI injury in diabetic mice by attenuating endothelial OS and stimulating angiogenesis. However, a deficiency in endothelial Sirtuin1 (SIRT1) largely inhibited the therapeutic effects of T0901317. Furthermore, we found that the underlying therapeutic mechanisms of T0901317 were related to SIRT1 and non-SIRT1 signalling, and the isoform LXRβ was involved in LXR agonist-elicited SIRT1 regulation. In conclusion, LXR agonist treatment protected against HLI injury in diabetic mice via mitigating endothelial OS and stimulating cellular viability and angiogenesis by LXRβ, which elicited both SIRT1-mediated and non-SIRT1-mediated signalling pathways. Therefore, LXR agonist treatment may be a promising therapeutic strategy for diabetic PAD.     

Exogenous neuritin treatment improves survivability and functions of Schwann cells with improved outgrowth of neurons in rat diabetic neuropathy

Pathogenesis and treatment for diabetic neuropathy are still complex. A deficit of neurotrophic factors affecting Schwann cells is a very important cause of diabetic neuropathy. Neuritin is a newly discovered potential neurotrophic factor. In this study, we explored the effect of exogenous neuritin on survivability and functions of diabetic Schwann cells of rats with experimental diabetic neuropathy. Diabetic neuropathy was induced in rats. 12‐week diabetic rats contrasted with non‐diabetic normal rats had decreased levels of serum neuritin and slowed nerve conduction velocities (NCVs). Schwann cells isolated from these diabetic rats and cultured in high glucose showed reduced cell neuritin mRNA and protein and supernatant neuritin protein, increased apoptosis rates, increased caspase‐3 activities and progressively reduced viability. In contrast, exogenous neuritin treatment reduced apoptosis and improved viability, with elevated Bcl‐2 levels (not Bax) and decreased caspase‐3 activities. Co‐cultured with diabetic Schwann cells pre‐treated with exogenous neuritin in high glucose media, and diabetic DRG neurons showed lessened decreased neurite outgrowth and supernatant NGF concentration occurring in co‐culture of diabetic cells. Exogenous neuritin treatment ameliorated survivability and functions of diabetic Schwann cells of rats with diabetic neuropathy. Our study may provide a new mechanism and potential treatment for diabetic neuropathy.     

A novel lncRNA PLK4 up‐regulated by talazoparib represses hepatocellular carcinoma progression by promoting YAP‐mediated cell senescence

A growing number of studies recognize that long non‐coding RNAs (lncRNAs) are essential to mediate multiple tumorigenic processes, including hepatic tumorigenesis. However, the pathological mechanism of lncRNA‐regulated liver cancer cell growth remains poorly understood. In this study, we identified a novel function lncRNA, named polo‐like kinase 4 associated lncRNA (lncRNA PLK4, GenBank Accession No. RP11‐50D9.3), whose expression was dramatically down‐regulated in hepatocellular carcinoma (HCC) tissues and cells. Interestingly, talazoparib, a novel and highly potent poly‐ADP‐ribose polymerase 1/2 (PARP1/2) inhibitor, could increase lncRNA PLK4 expression in HepG2 cells. Importantly, we showed that talazoparib‐induced lncRNA PLK4 could function as a tumour suppressor gene by Yes‐associated protein (YAP) inactivation and induction of cellular senescence to inhibit liver cancer cell viability and growth. In summary, our findings reveal the molecular mechanism of talazoparib‐induced anti‐tumor effect, and suggest a potential clinical use of talazoparib‐targeted lncRNA PLK4/YAP‐dependent cellular senescence for the treatment of HCC.     

Extracellular nanovesicles‐transmitted circular RNA has_circ_0000190 suppresses osteosarcoma progression

Under the microenvironment, tumour progression is substantially affected by cell‐cell communication. In spite of the mediating effect of extracellular nanovesicles (EVs) on cell‐cell communication by packaging into circRNAs, the effect of EVs circRNA hsa_circ_0000190 (circ‐0000190) in osteosarcoma is still not clear. Circ‐0000190 expressions in tissues and EVs from plasma were compared between osteosarcoma patients and controls. Thereafter, receiver operating characteristic (ROC) curve was drawn and area under the curve was calculated to examine whether the diagnostic results were accurate, and the effect of EVs circ‐0000190 was dug out via the determination of cell phenotypes and animal assays. Results showed circ‐0000190 exhibited an obvious reduction in EVs and tissues of osteosarcoma patients (P < .05). It was also discovered that EVs encapsulated the majority of circ‐0000190, and EVs‐encapsulated circ‐0000190 could be applied to make a distinction between osteosarcoma patients and controls. Besides, EVs circ‐0000190 in osteosarcoma cells transported from normal cells weakened the capacities of osteosarcoma cells to migrate, proliferate and invade, so as to block their biological malignant behaviours (P < .05). In addition, under the action of EVs circ‐0000190, tumour growth was impeded and the expression of TET1 was inhibited via the competitive binding to miR‐767‐5p. In all, EVs circ‐0000190 has a good prospect as it can be regarded as a new biomarker for detecting osteosarcoma. EVs circ‐0000190 transported from normal cells to osteosarcoma cells impeded the in vitro and in vivo development of osteosarcoma, implying that EVs circ‐0000190 exerts an effect on communication between normal cells and osteosarcoma cells in the carcinogenesis process of osteosarcoma.     

Endothelial S1pr1 regulates pressure overload‐induced cardiac remodelling through AKT‐eNOS pathway

Cardiac vascular microenvironment is crucial for cardiac remodelling during the process of heart failure. Sphingosine 1‐phosphate (S1P) tightly regulates vascular homeostasis via its receptor, S1pr1. We therefore hypothesize that endothelial S1pr1 might be involved in pathological cardiac remodelling. In this study, heart failure was induced by transverse aortic constriction (TAC) operation. S1pr1 expression is significantly increased in microvascular endothelial cells (ECs) of post‐TAC hearts. Endothelial‐specific deletion of S1pr1 significantly aggravated cardiac dysfunction and deteriorated cardiac hypertrophy and fibrosis in myocardium. In vitro experiments demonstrated that S1P/S1pr1 praxis activated AKT/eNOS signalling pathway, leading to more production of nitric oxide (NO), which is an essential cardiac protective factor. Inhibition of AKT/eNOS pathway reversed the inhibitory effect of EC‐S1pr1‐overexpression on angiotensin II (AngII)‐induced cardiomyocyte (CM) hypertrophy, as well as on TGF‐β‐mediated cardiac fibroblast proliferation and transformation towards myofibroblasts. Finally, pharmacological activation of S1pr1 ameliorated TAC‐induced cardiac hypertrophy and fibrosis, leading to an improvement in cardiac function. Together, our results suggest that EC‐S1pr1 might prevent the development of pressure overload‐induced heart failure via AKT/eNOS pathway, and thus pharmacological activation of S1pr1 or EC‐targeting S1pr1‐AKT‐eNOS pathway could provide a future novel therapy to improve cardiac function during heart failure development.     

LncRNA H19 ameliorates myocardial infarction‐induced myocardial injury and maladaptive cardiac remodelling by regulating KDM3A

Myocardial infarction (MI) remains the leading cause of morbidity and mortality worldwide, and novel therapeutic targets still need to be investigated to alleviate myocardial injury and the ensuing maladaptive cardiac remodelling. Accumulating studies have indicated that lncRNA H19 might exert a crucial regulatory effect on cardiovascular disease. In this study, we aimed to explore the biological function and molecular mechanism of H19 in MI. To investigate the biological functions of H19, miRNA‐22‐3p and KDM3A, gain‐ and loss‐of‐function experiments were performed. In addition, bioinformatics analysis, dual‐luciferase reporter assays, RNA immunoprecipitation (RIP) assays, RNA pull‐down assays, quantitative RT‐PCR and Western blot analyses as well as rescue experiments were conducted to reveal an underlying competitive endogenous RNA (ceRNA) mechanism. We found that H19 was significantly down‐regulated after MI. Functionally, enforced H19 expression dramatically reduced infarct size, improved cardiac performance and alleviated cardiac fibrosis by mitigating myocardial apoptosis and decreasing inflammation. However, H19 knockdown resulted in the opposite effects. Bioinformatics analysis and dual‐luciferase assays revealed that, mechanistically, miR‐22‐3p was a direct target of H19, which was also confirmed by RIP and RNA pull‐down assays in primary cardiomyocytes. In addition, bioinformatics analysis and dual‐luciferase reporter assays also demonstrated that miRNA‐22‐3p directly targeted the KDM3A gene. Moreover, subsequent rescue experiments further verified that H19 regulated the expression of KDM3A to ameliorate MI‐induced myocardial injury in a miR‐22‐3p‐dependent manner. The present study revealed the critical role of the lncRNAH19/miR‐22‐3p/KDM3A pathway in MI. These findings suggest that H19 may act as a potential biomarker and therapeutic target for MI.     

Epigenetic silencing of LncRNA ANRIL enhances liver fibrosis and HSC activation through activating AMPK pathway

Long non‐coding RNAs (LncRNAs) and DNA methylation are important epigenetic mark play a key role in liver fibrosis. Currently, how DNA methylation and LncRNAs control the hepatic stellate cell (HSC) activation and fibrosis has not yet been fully characterized. Here, we explored the role of antisense non‐coding RNA in the INK4 locus (ANRIL) and DNA methylation in HSC activation and fibrosis. The expression levels of DNA methyltransferases 3A (DNMT3A), ANRIL, α‐Smooth muscle actin (α‐SMA), Type I collagen (Col1A1), adenosine monophosphate‐activated protein kinase (AMPK) and p‐AMPK in rat and human liver fibrosis were detected by immunohistochemistry, qRT‐PCR and Western blotting. Liver tissue histomorphology was examined by haematoxylin and eosin (H&E), Sirius red and Masson staining. HSC was transfected with DNMT3A‐siRNA, over‐expressing ANRIL and down‐regulating ANRIL. Moreover, cell proliferation ability was examined by CCK‐8, MTT and cell cycle assay. Here, our study demonstrated that ANRIL was significantly decreased in activated HSC and liver fibrosis tissues, while Col1A1, α‐SMA and DNMT3A were significantly increased in activated HSC and liver fibrosis tissues. Further, we found that down‐regulating DNMT3A expression leads to inhibition of HSC activation. Reduction in DNMT3A elevated ANRIL expression in activated HSC. Furthermore, we performed the over expression ANRIL suppresses HSC activation and AMPK signalling pathways. In sum, our study found that epigenetic DNMT3A silencing of ANRIL enhances liver fibrosis and HSC activation through activating AMPK pathway. Targeting epigenetic modulators DNMT3A and ANRIL, and offer a novel approach for liver fibrosis therapy.     

Absent in melanoma 2 enhances anti‐tumour effects of CAIX promotor controlled conditionally replicative adenovirus in renal cancer

Conditionally replicative adenoviruses (CRAds) were promising approach for solid tumour treatment, but its oncolytic efficiency and toxicity are still not satisfactory for further clinical application. Here, we developed the CAIX promotor (CAIX^promotor)‐controlled CRAd armed with a tumour suppressor absent in melanoma 2 (AIM2) to enhance its oncolytic potency. The CAIX^promotor‐AIM2 adenoviruses (Ad‐CAIX^promotor‐AIM2) could efficiently express E1A and AIM2 in renal cancer cells. Compared with Ad‐CAIX^promotor, Ad‐CAIX^promotor‐AIM2 significantly inhibited cell proliferation and enhanced cell apoptosis and cell killing, thus resulting in the oncolytic efficiency in 786‐O cells or OSRC‐2 cells. To explore the therapeutic effect, various Ads were intratumourally injected into OSRC‐2‐xenograft mice. The tumour growth was remarkably inhibited in Ad‐CAIX^promotor‐AIM2‐treated group as demonstrated by reduced tumour volume and weight with a low toxicity. The inflammasome inhibitor YVAD‐CMK resulted in the reduction of anti‐tumour activity by Ad‐CAIX^promotor‐AIM2 in vitro or in vivo, suggesting that inflammasome activation response was required for the enhanced therapeutic efficiency. Furthermore, lung metastasis of renal cancer mice was also suppressed by Ad‐CAIX^promotor‐AIM2 treatment accompanied by the decreased tumour fossil in lung tissues. These results indicated that the tumour‐specific Ad‐CAIX^promotor‐AIM2 could be applied for human renal cancer therapy. The therapeutic strategy of AIM2‐based CRAds could be a potential and promising approach for the therapy of primary solid or metastasis tumours.     

Investigation of the Effects of Squalene and Squalene Epoxides on the Homeostasis of Coenzyme Q10 in Rats by UPLC‐Orbitrap MS

Squalene has been used as a dietary supplement for a long history due to its potential cancer‐preventive function. However, the mechanism has not been investigated in detail yet. Therefore, the aim of this study is to see if the plasma coenzyme Q10 (CoQ10) level will be altered by gavage of squalene and oxidosqualenes to rats. In the present work, a sensitive and simple high‐performance analytical method based on ultra‐high‐performance liquid chromatography coupled with an Orbitrap mass spectrometry (UPLC‐Orbitrap‐MS) was developed for the quantification of CoQ10 in rat plasma. Coenzyme Q9 (CoQ9) was employed as the internal standard. CoQ10 was determined after acetonitrile‐mediated plasma protein precipitation using UPLC‐Orbitrap‐MS in negative ion mode. Intragastric administration of squalene and the two squalene epoxides into rats once daily for several days elevated the level of CoQ10 in their plasma, but there was no significant difference between high‐dose (286 mg/kg) and low‐dose (143 mg/kg) groups. Intragastric administration of squalene once a day for 5 consecutive days and oxidosqualenes once a day for 3 consecutive days is necessary for reaching the steady‐state level of CoQ10. Our present findings indicate that squalene and oxidosqualenes may be useful for stimulating the synthesis of CoQ10 in rats.     

High‐Efficiency CsPbI2Br Perovskite Solar Cells with Dopant‐Free Poly(3‐hexylthiophene) Hole Transporting Layers

CsPbI₂Br is emerging as a promising all‐inorganic material for perovskite solar cells (PSCs) due to its more stable lattice structure and moisture resistance compared to CsPbI₃, although its device performance is still much behind this counterpart. Herein, a preannealing process is developed and systematically investigated to achieve high‐quality CsPbI₂Br films by regulating the nucleation and crystallization of perovskite. The preannealing temperature and time are specifically optimized for a dopant‐free poly(3‐hexylthiophene) (P3HT)‐based device to target dopant‐induced drastic performance degradation for spiro‐OMeTAD‐based devices. The resulting P3HT‐based device exhibits comparable power conversion efficiency (PCE) to spiro‐OMeTAD‐based devices but much enhanced ambient stability with over 95% PCE after 1300 h. A diphenylamine derivative is introduced as a buffer layer to improve the energy‐level mismatch between CsPbI₂Br and P3HT. A record‐high PCE of 15.50% for dopant‐free P3HT‐based CsPbI₂Br PSCs is achieved by alleviating the open‐circuit voltage loss with the buffer layer. These results demonstrate that the preannealing processing together with a suitable buffer layer are applicable strategies for developing dopant‐free P3HT PSCs with high efficiency and stability.