Ganoderma spore lipid protects mouse bone marrow mesenchymal stem cells and hematopoiesis from the cytotoxicity of the chemotherapeutic agent

Cancer chemotherapeutic agents are frequently toxic to bone marrow and impair bone marrow functions. It is unclear whether ganoderma spore lipid (GSL) can protect bone marrow cells from the cytotoxicity of chemotherapy. To investigate the protective effects of GSL on bone marrow mesenchymal stem cells (MSCs) and hematopoiesis, we examined the effects of GSL on MSCs in vitro and hematopoiesis in vivo after treatment with the chemotherapeutic agent cyclophosphamide. MSCs and peripheral blood cells were isolated and counted from the bone marrow of normal mice were pre-treated with GSL before CTX treatment or co-treated with GSL and CTX, followed by examining the changes in phenotype, morphology, proliferation, apoptosis, and differentiation potentials. The results showed that GSL could reduce the CTX-induced changes in the phenotype of MSCs and maintain the elongated fibroblast-like morphology. MTT and annexin V/propidium iodide (PI) analyses found that GSL pre-treatment and co-treatment increased the proliferation and decreased the apoptosis in CTX-treated MSCs. Furthermore, GSL improved the osteogenic and adipogenic differentiation potentials of CTX-treated MSCs. In vivo, GSL treatment increased the number of peripheral blood cells including white blood cells (WBC) and platelets (PLT) in the CTX-treated mice and enhanced the in vitro formation of hematopoietic lineage colonies (erythrocyte colony forming unit, CFU-E; erythroid burst-forming units, BFU-E; and granulocyte macrophage colony-forming units, CFU-GM) from bone marrow cells in these mice. These findings suggest GSL could protect MSCs and hematopoiesis from the cytotoxicity of CTX and might become an effective adjuvant to attenuate side effects of chemotherapy during cancer treatment.     

Rodent intestinal folate transporters (SLC46A1): secondary structure, functional properties, and response to dietary folate restriction

This laboratory recently identified a human gene that encodes a novel folate transporter [Homo sapiens proton-coupled folate transporter (HsPCFT); SLC46A1] required for intestinal folate absorption. This study focused on mouse (Mus musculus) PCFT (MmPCFT) and rat (Rattus norvegicus) PCFT (RnPCFT) and addresses their secondary structure, specificity, tissue expression, and regulation by dietary folates. Both rodent PCFT proteins traffic to the cell membrane with the NH(2)- and COOH-termini accessible to antibodies targeted to these domains only in permeabilized HeLa cells. This, together with computer-based topological analyses, is consistent with a model in which rodent PCFT proteins likely contain 12 transmembrane domains. Transport of [(3)H]folates was optimal at pH 5.5 and decreased with increasing pH due to an increase in K(m) and a decrease in V(max). At pH 7.0, folic acid and methotrexate influx was negligible, but there was residual (6S)5-methyltetrahydrofolate transport. Uptake of folates in PCFT-injected Xenopus oocytes was electrogenic and pH dependent. Folic acid influx K(m) values of MmPCFT and RnPCFT, assessed electrophysiologically, were 0.7 and 0.3 microM at pH 5.5 and 1.1 and 0.8 microM at pH 6.5, respectively. Rodent PCFTs were highly specific for monoglutamyl but not polyglutamyl methotrexate. MmPCFT mRNA was highly expressed in the duodenum, proximal jejunum, liver, and kidney with lesser expression in the brain and other tissues. MmPCFT protein was localized to the apical brush-border membrane of the duodenum and proximal jejunum. MmPCFT mRNA levels increased approximately 13-fold in the proximal small intestine in mice fed a folate-deficient vesus folate-replete diet, consistent with the critical role that PCFT plays in intestinal folate absorption.     

Demonstration of phycobilisome mobility by the time- and space-correlated fluorescence imaging of a cyanobacterial cell

The cell-wide mobility of PBSs was confirmed by synchronously monitoring the fluorescence recovery after photobleaching (FRAP) and the fluorescence loss in photobleaching (FLIP). On the other hand, a fluorescence recovery was still observed even if PBSs were immobile (PBSs fixed on the membranes by betaine and isolated PBSs fixed on the agar plate) or PBS mobility was unobservable (cell wholly bleached). Furthermore, it was proved that some artificial factors were involved not only in FRAP but also in FLIP, including renaturation of the reversibly denatured proteins, laser scanning-induced fluorescence loss and photo-damage to the cell. With consideration of the fast renaturation component in fluorescence recovery, the diffusion coefficient was estimated to be tenfold smaller than that without the component. Moreover, it was observed that the fluorescence intensity on the bleached area was always lower than that on the non-bleached area, even after 20 min, while it should be equal if PBSs were mobile freely. Based on the increasing proportion of the PBSs anti-washed to Triton X-100 (1%) with prolonged laser irradiation to the cells locked in light state 1 by PBQ, it was concluded that some PBSs became immobile due to photo-linking to PSII.     

黄河口西南侧小岛河河口天然牡蛎礁的牡蛎种群结构

牡蛎礁是生态系统服务价值高、但退化最严重及受关注度最高的海洋生境之一,牡蛎礁修复亦成为国际海洋生态修复的热点。掌握牡蛎自然种群状况及动态变化是评估牡蛎礁修复效果的基础。目前,我国天然牡蛎礁的牡蛎种群状况相关的背景资料较为缺乏。在黄河口西南侧的小岛河河口新发现天然活体牡蛎礁,但该牡蛎礁曾被大规模的商业采捕,亟需推进针对性的保护和修复研究工作。基于2021年11月对该牡蛎礁开展的牡蛎种群生态调查,分析其种类组成、年龄结构及生长特征。结果显示:该牡蛎礁分布有近江牡蛎(Crassostrea ariakensis)和长牡蛎(Crassostrea gigas)。牡蛎礁上以活体牡蛎为主,死亡牡蛎壳体数仅占6.1%-6.7%。活体牡蛎的密度和生物量分别为(2811±778)个/m²和(21.97±30.43)kg/m²,近江牡蛎较多,其密度和生物量分别占比55.7%和76.4%。近江牡蛎和长牡蛎的年龄分别介于0+-4+ 龄和0+-2+ 龄,它们都以壳高介于30-40 mm及壳质量<5 g的0+ 龄个体数量居多(>80%)。近江牡蛎的壳体形态参数均值都高于同龄组长牡蛎的相应值。两种牡蛎壳体均呈负异速增长,不同龄级的壳体延展方向不同。拟合von Bertalanffy生长方程得到,近江牡蛎和长牡蛎的渐近壳高分别为286 mm和173 mm,估算的拐点年龄分别为5.47 龄和2.56 龄,两种牡蛎的生长曲线分布存在极显著差异(P<0.001)。以上结果表明,小岛河河口的天然牡蛎礁的牡蛎自然种群资源较丰富,具有高密度、低龄和低死亡率等特点,有较好的活力和扩张潜力,有利于被采捕后的礁体的恢复。两种牡蛎中,近江牡蛎因其具有较高的生物量和较长的生长年龄,对礁体形成和扩繁可能更为重要。建议对该天然牡蛎礁及牡蛎种群开展周期>3年的原位保护、修复和连续监测计划。     

利用转座标签mTn-lacZ/leu2插入突变发酵性丝孢酵母2.1368-Leu?筛选高效产油突变株

为提高微生物油脂产率,降低其生产成本,以转座标签mTn-lacZ/leu2插入突变发酵性丝孢酵母2.1368-Leu?筛选高效产油突变株。利用LacZ显色反应、脂肪酸合成酶抑制剂Cerulenin和磷酸香草醛反应,最终在玉米秸秆糖化液中筛选出一株高效产油突变株2.1368-Leu?-7。结果表明其油脂含量为38.30％,比对照的29.33％高了8.97％,而其产油率为8.35％,比对照的6.92％提高了20.63％;在玉米秸秆糖化液中的糖利用率为77％,每100 g玉米秸秆可转化油脂8.32 g。可为未来生物柴油产业提供了廉价原料。     

Enhanced production of succinic acid from methanol–organosolv pretreated Strophanthus preussii by recombinant Escherichia coli

Bioprocess and Biosystems Engineering - A biorefinery process for high yield production of succinic acid from biomass sugars was investigated using recombinant Escherichia coli. The major problem...     

蛋白质的棕榈酰化修饰

棕榈酰化修饰是蛋白质翻译后脂质修饰的重要形式,是调控蛋白质的转运、稳定、定位和功能的重要机制,同时,棕榈酰化修饰还参与多种细胞生物学进程,与许多疾病的发生发展密切相关。本文主要就蛋白质棕榈酰化及其修饰酶与蛋白质功能、相关疾病的关系做一综述。     

Inside Front Cover: Selective and sensitive Escherichia coli detection based on a T4 bacteriophage‐immobilized multimode microfiber (J. Biophotonics 9/2018)

Sensitive Escherichia coli detection based on a T4 bacteriophageimmobilized multimode microfiber is proposed and demonstrated in this article. Different modes are excited and guided in the microfiber as evanescent field that can interact with surrounding E. coli directly. The change of E. coli concentration and corresponding binding of E. coli on microfiber surface will lead to the shift of optical spectrum, which can be exploited for the application of biosensing. Further details can be found in the article by Yanpeng Li, Hui Ma, Lin Gan, et al. ( e201800012 ).

     

The Ngal reporter mouse detects the response of the kidney to injury in real time

Many proteins have been proposed to act as surrogate markers of organ damage, yet for many candidates the essential biomarker characteristics that link the protein to the injured organ have not yet been described. We generated an Ngal reporter mouse by inserting a double-fusion reporter gene encoding luciferase-2 and mCherry (Luc2-mC) into the Ngal (Lcn2) locus. The Ngal-Luc2-mC reporter accurately recapitulated the endogenous message and illuminated injuries in vivo in real time. In the kidney, Ngal-Luc2-mC imaging showed a sensitive, rapid, dose-dependent, reversible, and organ- and cell-specific relationship with tubular stress, which correlated with the level of urinary Ngal (uNgal). Unexpectedly, specific cells of the distal nephron were the source of uNgal. Cells isolated from Ngal-Luc2-mC mice also revealed both the onset and the resolution of the injury, and the actions of NF-κB inhibitors and antibiotics during infection. Thus, imaging of Ngal-Luc2-mC mice and cells identified injurious and reparative agents that affect kidney damage.