Inhibitory effect of Tanshinone IIA on inverted formin-2 protects HaCaT cells against oxidative injury via regulating mitochondrial stress

Context: Epidermal cells play an important role in regulating the regeneration of skin after burns and wounds.

Objective: The aim of our study is to explore the role of Tanshinone IIA (Tan IIA) in the apoptosis of epidermal HaCaT cells induced by H₂O₂, with a focus on mitochondrial homeostasis and inverted formin-2 (INF2).

Materials and methods: Cellular viability was determined using the MTT assay, TUNEL staining, western blot analysis and LDH release assay. Adenovirus-loaded INF2 was transfected into HaCaT cells to overexpress INF2 in the presence of Tan IIA treatment. Mitochondrial function was determined using JC-1 staining, mitochondrial ROS staining, immunofluorescence and western blotting.

Results: Oxidative stress promoted the death of HaCaT cells and this effect could be reversed by Tan IIA. At the molecular levels, Tan IIA treatment sustained mitochondrial energy metabolism, repressed mitochondrial ROS generation, stabilized mitochondrial potential, and blocked the mitochondrial apoptotic pathway. Furthermore, we demonstrated that Tan IIA modulated mitochondrial homeostasis via affecting INF2-related mitochondrial stress. Overexpression of INF2 could abolish the protective effects of Tan IIA on HaCaT cells viability and mitochondrial function. Besides, we also reported that Tan IIA regulated INF2 expression via the ERK pathway; inhibition of this pathway abrogated the beneficial effects of Tan IIA on HaCaT cells survival and mitochondrial homeostasis.

Conclusions: Overall, our results indicated that oxidative stress-mediated HaCaT cells apoptosis could be reversed by Tan IIA treatment via reducing INF2-related mitochondrial stress in a manner dependent on the ERK signaling pathway.     

Production of recombinant beta-amylase of Bacillus aryabhattai

In this study, the effects of carbon source, nitrogen source, and metal ions on cell growth and Bacillus aryabhattai β-amylase production in recombinant Brevibacillus choshinensis were investigated. The optimal medium for β-amylase production, containing glucose (7.5?g·L^?1), pig bone peptone (40.0?g·L^?1), Mg²⁺ (0.05?mol·L^?1), and trace metal elements, was determined through single-factor experiments in shake flasks. When cultured in the optimized medium, the β-amylase yield reached 925.4?U mL^?1, which was 7.2-fold higher than that obtained in the initial medium. Besides, a modified feeding strategy was proposed and applied in a 3-L fermentor fed with glucose, which achieved a dry cell weight of 15.4?g L^?1. Through this cultivation approached 30?°C with 0?g·L^?1 initial glucose concentration, the maximum β-amylase activity reached 5371.8?U mL^?1, which was 41.7-fold higher than that obtained with the initial medium in shake flask.     

Single-Cell Heterogeneity Analysis and CRISPR Screen Identify Key β-Cell-Specific Disease Genes

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Efficient and green aqueous−solid system for transphosphatidylation to produce phosphatidylhydroxybutyrate: Potential drugs for central nervous system's diseases

The synthesis of nonnatural phospholipid, phosphatidylhydroxybutyrate (PB), was firstly introduced by phospholipase D (PLD)-mediated transphosphatidylation of phosphatidylcholine (PC) with sodium γ-hydroxybutyrate (NaGHB) in the aqueous–solid system. Nanoscale silicon dioxide (NSD) was employed as a carrier to provide an “artificial interphase” between PC and PLD. Special attention has been paid to the effect of the PC coverage on the surface area of hybrids of NSD-PC, the PC loading and the yield of PB. Results indicated that the highest PC loading of 98.3% and the highest PB yield of 97.3% were achieved. In addition, the free PLD in the aqueous–solid system showed the greater stability and pH tolerance than that in the traditional liquid–liquid system. The operational stability of free PLD solution was investigated. The yield of PB remained 70.7% after being used for five batches. The authors provide a new idea for drug design and the potential source of PB for medical experiments. PB is a potential drug and may have the excellent performance in the treatment of central nervous system's diseases. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2726, 2019     

Insulin-like growth factor receptor 1b is required for zebrafish primordial germ cell migration and survival

Insulin-like growth factor (IGF) signaling is a critical regulator of somatic growth during fetal and adult development, primarily through its stimulatory effects on cell proliferation and survival. IGF signaling is also required for development of the reproductive system, although its precise role in this regard remains unclear. We have hypothesized that IGF signaling is required for embryonic germline development, which requires the specification and proliferation of primordial germ cells (PGCs) in an extragonadal location, followed by directed migration to the genital ridges. We tested this hypothesis using loss-of-function studies in the zebrafish embryo, which possesses two functional copies of the Type-1 IGF receptor gene (igf1ra, igf1rb). Knockdown of IGF1Rb by morpholino oligonucleotides (MO) results in mismigration and elimination of primordial germ cells (PGCs), resulting in fewer PGCs colonizing the genital ridges. In contrast, knockdown of IGF1Ra has no effect on PGC migration or number despite inducing widespread somatic cell apoptosis. Ablation of both receptors, using combined MO injections or overexpression of a dominant-negative IGF1R, yields embryos with a PGC-deficient phenotype similar to IGF1Rb knockdown. TUNEL analyses revealed that mismigrated PGCs in IGF1Rb-deficient embryos are eliminated by apoptosis; overexpression of an antiapoptotic gene (Bcl2l) rescues ectopic PGCs from apoptosis but fails to rescue migration defects. Lastly, we show that suppression of IGF signaling leads to quantitative changes in the expression of genes encoding CXCL-family chemokine ligands and receptors involved in PGC migration. Collectively, these data suggest a novel role for IGF signaling in early germline development, potentially via cross-talk with chemokine signaling pathways.     

Genetic differentiation of Arthrobacter population from heavy metal-contaminated environment

Six samples containing extremely high concentration of Pb, Zn, and Cd were obtained from the layers of 5–10 cm and 25–30 cm three tailing piles, with ages of about 10, 20 and more than 80 years, respectively. Then, 48 bacterial strains were obtained from these samples, and subsequently their phylogenetic positions were determined by analysis on the partial sequence of 16S rRNA gene (fragment length ranging from 474 to 708 bp). These isolates were members of the Arthrobacter genus, phylogenetically close to A. keyseri and A. ureafaciens, with sequence ranging from 99.1% to 100%. Furthermore, genetic variation between subpopulations from different samples was revealed by analysis on their randomly amplified polymorphic DNA profile. Nei genetic distance showed that the greatest differentiation occurred between subpopulation A and C. Notably, either genetic distance between subpopulations from the layers of 5–10 cm and 25–30 cm of each tailing pile or between same layers of different tailing pile increased with the history of tailings. Moreover, correlation analysis showed that soluble Pb has a significantly negative relationship with Nei’ gene diversity of subpopulation. It was assumed that soluble Pb may be responsible for the reduced genetic diversity of the Arthrobacter population. Our data provided evidence that genetic differentiation of microbial populations was consistent with the changes of environmental factors, particularly heavy metals. Translated from Acta Ecologica Sinica, 2005, 25(10): 2569–2573 [译自: 生态学报]     

The Chinese species of skipper butterflies in the tribe Tagiadini Mabille, 1878 (Lepidoptera: Hesperiidae): insights from phylogeny,hostplants, and biogeography

Organisms Diversity & Evolution - The butterfly tribe Tagiadini Mabille, 1878 is a large group of skippers. Although there are a few species which are limited in distribution to some countries...     

Erratum: “CTAB-PEG DNA Extraction from Fungi with High Contents of Polysaccharides”

Molecular Biology - The original article can be found online at DOI: 10.1134/S0026893318040088 Page 622, in Reagents and Solutions should read 20 mg/mL proteinase K; Page 622, in Reagents...     

海草根际微生物与海草植株的互作效应

【目的】本文以三亚湾泰来草根际沉积物为主要研究对象,研究室内培养条件下泰来草根际沉积物微生物对于高温处理和海草定殖的响应。【方法】通过对培养过程中水体物理化学参数(如pH、溶解氧、磷酸盐、硝酸盐、亚硝酸盐和铵盐)的监测以分析环境因子的变化;16S rRNA扩增子测序研究微生物群落结构的动态响应;通过荧光定量分析16SrRNA基因丰度变化。【结果】研究表明高温处理组在培养35 d后海水中磷酸盐、硝酸盐、亚硝酸盐和铵盐含量以及pH均要高于模拟原位环境的对照组,高温处理组根际沉积物微生物丰度在培养过程中呈现先上升后降低的趋势,同时,高温处理组根际微生物中初始阶段由厚壁菌门(32.4%)、变形菌门(22.92%)和梭杆菌门(27.21%)占据优势,培养一段时间后,厚壁菌门和梭杆菌门大幅度减少,逐渐被蓝细菌门和放线菌门所替代,最终由变形菌门(51.1%)占据主导地位,其中,属于硫还原细菌的脱硫杆菌科(Desulfobacteraceae)和硫氧化细菌的螺杆菌科(Helicobacteraceae)的细菌丰度不断提高。【结论】揭示了海草的定殖会提高高温处理后沉积物的多样性,并塑造和改善其根际沉积物微生物群落组成。     

Streptomycin-induced ribosome engineering complemented with fermentation optimization for enhanced production of 10-membered enediynes tiancimycin-A and tiancimycin-D

Tiancimycins (TNMs) are a group of 10-membered anthraquinone-fused enediynes, newly discovered from Streptomyces sp. CB03234. Among them, TNM-A and TNM-D have exhibited excellent antitumor performances and could be exploited as very promising warheads for the development of anticancer antibody-drug conjugates (ADCs). However, their low titers, especially TNM-D, have severely limited following progress. Therefore, the streptomycin-induced ribosome engineering was adopted in this work for strain improvement of CB03234, and a TNMs high producer S. sp. CB03234-S with the K43N mutation at 30S ribosomal protein S12 was successfully screened out. Subsequent media optimization revealed the essential effects of iodide and copper ion on the production of TNMs, while the substitution of nitrogen source could evidently promote the accumulation of TNM-D, and the ratio of produced TNM-A and TNM-D was responsive to the change of carbon and nitrogen ratio in the medium. Further amelioration of the pH control in scaled up 25 L fermentation increased the average titers of TNM-A and TNM-D up to 13.7 ± 0.3 and 19.2 ± 0.4 mg/L, respectively. The achieved over 45-fold titer improvement of TNM-A, and 109-fold total titer improvement of TNM-A and TNM-D enabled the efficient purification of over 200 mg of each target molecule from 25 L fermentation. Our efforts have demonstrated a practical strategy for titer improvement of anthraquinone-fused enediynes and set up a solid base for the pilot scale production and preclinical studies of TNMs to expedite the future development of anticancer ADC drugs.