Protosappanin‐A and oleanolic acid protect injured podocytes from apoptosis through inhibition of AKT‐mTOR signaling

Protosappanin‐A (PrA) and oleanolic acid (OA), which are important effective ingredients isolated from Caesalpinia sappan L., exhibit therapeutic potential in multiple diseases. This study focused on exploring the mechanisms of PrA and OA function in podocyte injury. An in vitro model of podocyte injury was induced by the sC5b‐9 complex and assays such as cell viability, apoptosis, immunofluorescence, quantitative real‐time polymerase chain reaction, and western blot were performed to further investigate the effects and mechanisms of PrA and OA in podocyte injury. The models of podocyte injury were verified to be successful as seen through significantly decreased levels of nephrin, podocin, and CD2AP and increased level of desmin. The sC5b‐9‐induced podocyte apoptosis was inhibited in injured podocytes treated with PrA and OA, accompanied by increased protein levels of nephrin, podocin, CD2AP, and Bcl2 and decreased levels of desmin and Bax. The p‐AKT/p‐mTOR levels were also reduced by treatment of PrA and OA while AKT/mTOR was unaltered. Further, the effects of PrA and OA on injured podocytes were similar to that of LY294002 (a PI3K‐AKT inhibitor). PrA and OA were also seen to inhibit podocyte apoptosis and p‐AKT/p‐mTOR levels induced by IGF‐1 (a PI3K‐AKT activator). Our data demonstrate that PrA and OA can protect podocytes from injury or apoptosis, which may occur through inhibition of the abnormal activation of AKT‐mTOR signaling.     

(Z)-3-Hexenol Induces Tea Defense against Ectropis grisescens in the Field

Russian Journal of Plant Physiology - The tea geometrid Ectropis grisescens is an important pest of tea plant (Camellia sinensis (L.) O. Kuntze). It feeds on the new leaves and tender...     

Transmission competence of a new mesonivirus,Yichang virus,in mosquitoes and its interference with representative flaviviruses

Advances in technology have greatly stimulated the understanding of insect-specific viruses (ISVs). Unfortunately, most of these findings are based on sequencing technology, and laboratory data are scarce on the transmission dynamics of ISVs in nature and the potential effects of these viruses on arboviruses. Mesonivirus is a class of ISVs with a wide geographical distribution. Recently, our laboratory reported the isolation of a novel strain of mesonivirus, Yichang virus (YCV), from Culex mosquitoes, China. In this study, the experimental infection of YCV by the oral route for adult and larvae mosquitoes, and the vertical transmission has been conducted, which suggests that YCV could adopt a mixed-mode transmission. Controlled experiments showed that the infectivity of YCV depends on the mosquito species, virus dose, and infection route. The proliferation curve and tissue distribution of YCV in Cx. quinquefasciatus and Ae. albopictus showed that YCV is more susceptible to Ae. albopictus and is located in the midgut. Furthermore, we also assessed the interference of YCV with flaviviruses both in vitro and in vivo. YCV significantly inhibited the proliferation of DENV-2 and ZIKV, in cell culture, and reduced transmission rate of DENV-2 in Ae. albopictus. Our work provides insights into the transmission of ISVs in different mosquito species during ontogeny and their potential ability to interact with mosquito-borne viruses.     

Ferroptosis is involved in alcohol-induced cell death in vivo and in vitro

ABSTRACT

A critical pathogenic factor in the development of lethal liver failure is cell death induced by the accumulation of lipid reactive oxygen species. In this study, we discovered and illuminated a new mechanism that led to alcoholic liver disease via ferroptosis, an iron-dependent regulated cell death. Study in vitro showed that both necroptosis inhibitor and ferroptosis inhibitors performed significantly protective effect on alcohol-induced cell death, while apoptosis inhibitor and autophagy inhibitor had no such effect. Our data also indicated that alcohol caused the accumulation of lipid peroxides and the mRNA expression of prostaglandin-endoperoxide synthase 2, reduced the protein expression of the specific light-chain subunit of the cystine/glutamate antiporter and glutathione peroxidase 4. Importantly, ferrostatin-1 significantly ameliorated liver injury that was induced by overdosed alcohol both in vitro and in vivo. These findings highlight that targeting ferroptosis serves as a hepatoprotective strategy for alcoholic liver disease treatment.     

Coordinated regulation of anthranilate metabolism and bacterial virulence by the GntR family regulator MpaR in Pseudomonas aeruginosa

The GntR family regulators are widely distributed in bacteria and play critical roles in metabolic processes and bacterial pathogenicity. In this study, we describe a GntR family protein encoded by PA4132 that we named MpaR (M vfR-mediated P QS and a nthranilate r egulator) for its regulation of Pseudomonas quinolone signal (PQS) production and anthranilate metabolism in Pseudomonas aeruginosa. The deletion of mpaR increased biofilm formation and reduced pyocyanin production. RNA sequencing analysis revealed that the mRNA levels of antABC encoding enzymes for the synthesis of catechol from anthranilate, a precursor of the PQS, were most affected by mpaR deletion. Data showed that MpaR directly activates the expression of mvfR, a master regulator of pqs system, and subsequently promotes PQS production. Accordingly, deletion of mpaR activates the expression of antABC genes, and thus, increases catechol production. We also demonstrated that MpaR represses the rhl quorum-sensing (QS) system, which has been shown to control antABC activity. These results suggested that MpaR function is integrated into the QS regulatory network. Moreover, mutation of mpaR promotes bacterial survival in a mouse model of acute pneumonia infection. Collectively, this study identified a novel regulator of pqs system, which coordinately controls anthranilate metabolism and bacterial virulence in P. aeruginosa.     

ATP binding cassette transporters ABCG1 and ABCG16 affect reproductive development via auxin signalling in Arabidopsis

Angiosperm reproductive development is a complex event that includes floral organ development, male and female gametophyte formation and interaction between the male and female reproductive organs for successful fertilization. Previous studies have revealed the redundant function of ATP binding cassette subfamily G (ABCG) transporters ABCG1 and ABCG16 in pollen development, but whether they are involved in other reproductive processes is unknown. Here we show that ABCG1 and ABCG16 were not only expressed in anthers and stamen filaments but also enriched in pistil tissues, including the stigma, style, transmitting tract and ovule. We further demonstrated that pistil‐expressed ABCG1 and ABCG16 promoted rapid pollen tube growth through their effects on auxin distribution and auxin flow in the pistil. Moreover, disrupted auxin homeostasis in stamen filaments was associated with defective filament elongation. Our work reveals the key functions of ABCG1 and ABCG16 in reproductive development and provides clues for identifying ABCG1 and ABCG16 substrates in Arabidopsis.     

miRNA和lncRNA在动物脂肪沉积中的研究进展

微小RNA(MicroRNA,miRNA)是一类由18–25个核苷酸组成的高度保守的核苷酸序列,它可以特异性结合信使RNA (mRNA)的3′-非编码区域,进而发挥降解mRNA或阻遏mRNA翻译的负调控作用。长链非编码RNA (Long non-coding RNA,lncRNA)是一类长度超过200个核苷酸、不能编码蛋白质或只能编码蛋白质微肽的核苷酸序列,它可以在表观遗传、转录水平和转录后水平调控基因表达。脂肪作为一种重要的储能物质,在调节动物体能量平衡过程中发挥着重要的作用,并与动物产肉量、肉品质等产肉性状密切相关。而脂肪功能的紊乱可导致高血脂、Ⅱ型糖尿病以及一系列心血管疾病发生,因此动物脂肪沉积的分子调控机制备受人们关注。近年来,越来越多的研究发现miRNA和lncRNA在动物脂肪沉积中发挥重要作用。文中就现阶段miRNA和lncRNA在动物脂肪沉积中的研究进展进行综述,以期为进一步揭示动物脂肪沉积的分子调控机制提供理论指导和新思路。