IGFBP‐4 enhances VEGF‐induced angiogenesis in a mouse model of myocardial infarction

Vascular endothelial growth factor (VEGF) is a well‐known angiogenic factor, however its ability in promoting therapeutic angiogenesis following myocardial infarction (MI) is limited. Here, we aimed to investigate whether dual treatment with insulin‐like growth factor binding protein‐4 (IGFBP‐4), an agent that protects against early oxidative damage, can be effective in enhancing the therapeutic effect of VEGF following MI. Combined treatment with IGFBP‐4 enhanced VEGF‐induced angiogenesis and prevented cell damage via enhancing the expression of a key angiogenic factor angiopoietin‐1. Dual treatment with the two agents synergistically decreased cardiac fibrosis markers collagen‐I and collagen‐III following MI. Importantly, while the protective action of IGFBP‐4 occurs at an early stage of ischemic injury, the action of VEGF occurs at a later stage, at the onset angiogenesis. Our findings demonstrate that VEGF treatment alone is often not enough to protect against oxidative stress and promote post‐ischemic angiogenesis, whereas the combined treatment with IGFBP4 and VEGF can utilize the dual roles of these agents to effectively protect against ischemic and oxidative injury, and promote angiogenesis. These findings provide important insights into the roles of these agents in the clinical setting, and suggest new strategies in the treatment of ischemic heart disease.     

Down‐regulation of Suv39h1 attenuates neointima formation after carotid artery injury in diabetic rats

Patients with diabetes have an increased risk of vascular complications. Suv39h1, a histone methyltransferase, plays a protective role against myocardial injury in diabetes. Herein, we intend to explore whether Suv39h1 could affect neointimal formation after vascular injury in diabetic rats and reveal the underlying mechanism. In this study, we generated adenovirus expressing Suv39h1 as well as lentivirus expressing Suv39h1‐targeting shRNA and evaluated the significance of Suv39h1 in vascular smooth muscle cells (VSMCs) under diabetic conditions. In vitro, we examined proliferative and migratory behaviours as well as the underlying signalling mechanisms in VSMCs in response to high glucose treatment. In vivo, we induced diabetes in SD rats with streptozocin and established the common carotid artery balloon injury model. Suv39h1 was found to be both necessary and sufficient to promote VSMC proliferation and migration under high glucose conditions. We observed corresponding changes in intracellular signalling molecules including complement C3 and phosphor‐ERK1/2. However, either up‐regulating or down‐regulating Suv39h1, phosphor‐p38 level was not significantly affected. Consistently, Suv39h1 overexpression led to accelerated neointima formation, while knocking down Suv39h1 reduced it following carotid artery injury in diabetic rats. Using microarray analyses, we showed that altering the Suv39h1 level in vivo dramatically altered the expression of myriad genes mediating different biological processes and molecular function. This study reveals the novel role of Suv39h1 in VSMCs of diabetes and suggests its potential role as a therapeutic target in diabetic vascular injury.     

Antibacterial potential of Forsythia suspensa polysaccharide against resistant Enterobacter cloacae with SHV‐12 extended‐spectrum β‐lactamase (ESBL)

In this study, a homogenous polysaccharide (FSP), with an average molecular weight of 9.08 × 10⁴ Da, was isolated from Forsythia suspense and its antibacterial potential against Enterobacter cloacae producing SHV‐12 ESBL was investigated. Growth kinetics, in vitro competition and biofilm formation experiments demonstrated that SHV‐12 ESBL contributed to a fitness benefit to E cloacae strain. The antibacterial activity of FSP (2.5, 5.0 and 10.0 μg/mL) was tested against E cloacae bearing SHV‐12 ESBL gene using bacterial sensitivity, agar bioassay and agar well diffusion assays. It was found that the addition of FSP demonstrated potent antibacterial activities against this bacterial as showed by the decrease of bacterial growth and the increase of the inhibition zone diameter. Furthermore, SHV‐12 ESBL gene expression was decreased in E cloacae strain following different FSP treatment in a concentration‐dependent manner. In conclusion, these data showed that FSP exhibited potent good antibacterial activity against E cloacae producing SHV‐12 ESBL via inhibition of SHV‐12 ESBL gene expression, which may promote the development of novel natural antibacterial agents to treat infections caused by this drug‐resistant bacterial pathogen.     

Melatonin against acute ischaemic stroke dependently via suppressing both inflammatory and oxidative stress downstream signallings

This study tested the hypothesis that melatonin (Mel) therapy preserved the brain architectural and functional integrity against ischaemic stroke (IS) dependently through suppressing the inflammatory/oxidative stress downstream signalling pathways. Adult male B6 (n = 6 per each B6 group) and TLR4 knockout (ie TLR4^?/?) (n = 6 per each TLR4^?/? group) mice were categorized into sham control (SC^B6), SC^TLR4?/?, IS^B6, IS^TLR4?/?, IS^B6 + Mel (i.p. daily administration) and IS^TLR4?/? + Mel (i.p. daily administration). By day 28 after IS, the protein expressions of inflammatory (HMBG1/TLR2/TLR4/MAL/MyD88/RAM TRIF/TRAF6/IKK‐α/p‐NF‐κB/nuclear‐NF‐κB/nuclear‐IRF‐3&7/IL‐1β/IL‐6/TNF‐α/IFN‐γ) and oxidative stress (NOX‐1/NOX‐2/ASK1/p‐MKK4&7/p‐JNK/p‐c‐JUN) downstream pathways as well as mitochondrial‐damaged markers (cytosolic cytochrome C/cyclophilin D/SRP1/autophagy) were highest in group IS^B6, lowest in groups SC^B6 and SC^TLR4?/?, lower in group IS^TLR4?/? + Mel than in groups IS^TLR4?/? and IS^B6 + Mel and lower in group IS^B6 + Mel than in group IS^TLR4?/? (all P < .0001). The brain infarct volume, brain infarct area and the number of inflammatory cells in brain (CD14/F4‐88) and in circulation (MPO+//Ly6C+/CD11b+//Ly6G+/CD11b+) exhibited an identical pattern, whereas the neurological function displayed an opposite pattern of inflammatory protein expression among the six groups (all P < .0001). In conclusion, TLR inflammatory and oxidative stress signallings played crucial roles for brain damage and impaired neurological function after IS that were significantly reversed by Mel therapy.     

Methyltransferase like 3 promotes colorectal cancer proliferation by stabilizing CCNE1 mRNA in an m6A-dependent manner

m6A modification is the most prevalent RNA modification in eukaryotes. As the critical N6-methyladenosine (m6A) methyltransferase, the roles of methyltransferase like 3 (METTL3) in colorectal cancer (CRC) are controversial. Here, we confirmed that METTL3, a critical m6A methyltransferase, could facilitate CRC progression in vitro and in vivo. Further, we found METTL3 promoted CRC cell proliferation by methylating the m6A site in 3′-untranslated region (UTR) of CCNE1 mRNA to stabilize it. Moreover, we found butyrate, a classical intestinal microbial metabolite, could down-regulate the expression of METTL3 and related cyclin E1 to inhibit CRC development. METTL3 promotes CRC proliferation by stabilizing CCNE1 mRNA in an m6A-dependent manner, representing a promising therapeutic strategy for the treatment of CRC.     

Seasonal variation and correlation analysis of vitamin D and parathyroid hormone in Hangzhou,Southeast China

This study aimed to describe the 25‐hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) status of Southeast Chinese individuals influenced by season. The secondary aim was to determine the cutoff for sufficient 25(OH)D in a four‐season region. From January 2011 to June 2014, a total of 17 646 individuals were evaluated in our study. The serum levels of PTH were detected simultaneously in 5579 cases. A total of 25(OH)D and intact PTH were measured by the electrochemiluminescent immunoassay. The distribution of the concentration, prevalence and seasonal variability of 25(OH)D and PTH were studied. The mean 25(OH)D concentration in our study was 43.00(30.40) nmol/L. The prevalence of insufficiency (25(OH)D < 50 nmol/L) was 62.87% and that of deficiency (<30 nmol/L) was 28.54%. Mean serum 25(OH)D levels revealed a limited sinusoidal profile throughout the year and were significantly higher in Autumn. On the other hand, PTH levels showed an opposite response to seasonal effects relative to 25(OH)D. Age, BMI and daylight were not significantly correlated with 25(OH)D and serum PTH reached a plateau at higher values of serum 25(OH)D of 42.86 nmol/L. This study demonstrated that Vitamin D insufficiency is highly prevalent in Southeast China. The concentration of 25(OH)D in the male group was generally higher than that in the female group. Seasonal variation was an important aspect of 25(OH)D and PTH concentration. This study revealed that the optimal serum threshold of 25(OH)D for bone health should be between 40 and 50 nmol/L for Southeast Chinese individuals.     

Association between METTL3 gene polymorphisms and neuroblastoma susceptibility: A nine‐centre case‐control study

Neuroblastoma ranks as the most commonly seen and deadly solid tumour in infancy. The aberrant activity of m⁶A‐RNA methyltransferase METTL3 is involved in human cancers. Therefore, functional genetic variants in the METTL3 gene may contribute to neuroblastoma risk. In the current nine‐centre case‐control study, we aimed to analyse the association between the METTL3 gene single nucleotide polymorphisms (SNPs) and neuroblastoma susceptibility. We genotyped four METTL3 gene SNPs (rs1061026 T>G, rs1061027 C>A, rs1139130 A>G, and rs1263801 G>C) in 968 neuroblastoma patients and 1814 controls in China. We found significant associations between these SNPs and neuroblastoma risk in neither single‐locus nor combined analyses. Interestingly, in the stratified analysis, we observed a significant risk association with rs1061027 AA in subgroups of children ≤ 18 months of age (adjusted OR = 1.87, 95% CI = 1.03‐3.41, P = .040) and females (adjusted OR = 1.86, 95% CI = 1.07‐3.24, P = .028). Overall, we identified a significant association between METTL3 gene rs1061027 C>A polymorphism and neuroblastoma risk in children ≤18 months of age and females. Our findings provide novel insights into the genetic determinants of neuroblastoma.     

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.     

Dihydromyricetin increases endothelial nitric oxide production and inhibits atherosclerosis through microRNA-21 in apolipoprotein E-deficient mice

Natural products were extracted from traditional Chinese herbal emerging as potential therapeutic drugs for treating cardiovascular diseases. This study examines the role and underlying mechanism of dihydromyricetin (DMY), a natural compound extracted from Ampelopsis grossedentata, in atherosclerosis. DMY treatment significantly inhibits atherosclerotic lesion formation, proinflammatory gene expression and the influx of lesional macrophages and CD4-positive T cells in the vessel wall and hepatic inflammation, whereas increases nitric oxide (NO) production and improves lipid metabolism in apolipoprotein E-deficient (Apoe^−/−) mice. Yet, those protective effects are abrogated by using NOS inhibitor L-NAME in Apoe^−/− mice received DMY. Mechanistically, DMY decreases microRNA-21 (miR-21) and increases its target gene dimethylarginine dimethylaminohydrolase-1 (DDAH1) expression, an effect that reduces asymmetric aimethlarginine (ADMA) levels, and increases endothelial NO synthase (eNOS) phosphorylation and NO production in cultured HUVECs, vascular endothelium of atherosclerotic lesions and liver. In contrast, systemic delivery of miR-21 in Apoe^−/− mice or miR-21 overexpression in cultured HUVECs abrogates those DMY-mediated protective effects. These data demonstrate that endothelial miR-21-inhibited DDAH1-ADMA-eNOS-NO pathway promotes the pathogenesis of atherosclerosis which can be rescued by DMY. Thus, DMY may represent a potential therapeutic adjuvant in atherosclerosis management.