Peroxiredoxin 2 deficiency reduces white adipogenesis due to the excessive ROS generation

Reactive oxygen species (ROS) act as signaling molecules to regulate various cell functions. Numerous studies have demonstrated ROS to be essential for the differentiation of adipocytes. Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant enzymes in mammalian cells. Prx2 is present in the cytoplasm and cell membranes and demonstrates ROS scavenging activity. We focused on Prx2 involvement in regulating adipogenesis and lipid accumulation and demonstrated that Prx2 expression was upregulated during adipocyte differentiation. In addition, the silencing of Prx2 (shPrx2) inhibited adipogenesis by modulating adipogenic gene expression, and cell death was enhanced via increased ROS production in shPrx2‐3T3‐L1 cells. These results demonstrate that shPrx2 triggers adipocyte cell death and weakens adipocyte function via ROS production. Taken together, our data suggest the participation of Prx2 in adipocyte function and differentiation. Our results also imply that the downregulation of Prx2 activity could help prevent obesity. Overall, findings support the development of ROS‐based therapeutic solutions for the treatment of obesity and obesity‐related metabolic disorders.     

A ROCK inhibitor promotes keratinocyte survival and paracrine secretion,enhancing establishment of primary human melanocytes and melanocyte–keratinocyte co‐cultures

Primary melanocytes isolated from skin and expanded in culture have been widely used for laboratory research and clinical applications. The conventional method to isolate primary melanocytes from skin usually requires about 3–4 weeks of culture for melanocytes to grow sufficiently to passage. Considering that melanocytes comprise only 3%–7% of epidermal cells in normal human skin, it would be extremely helpful to increase the isolation efficiency and shorten the initial culture time to quickly meet various application needs. Here, we report that adding Y‐27632, a Rho kinase inhibitor, into the initial culture medium for 2 days can dramatically increase the yield of melanocytes. We found that Y‐27632 can promote keratinocyte attachment and survival in the melanocyte culture system, resulting in not only better recovery, but also increased proliferation of melanocytes by a paracrine signaling pathway. More specifically, Y‐27632 significantly induced keratinocyte expression of stem cell factor, which played an important role in enhancing the growth of melanocytes. In summary, Y‐27632 could profoundly enhance the yield of primary melanocytes in the initial culture through paracrine effects on keratinocytes.     

Nanobiohybrid Material‐Based Bioelectronic Devices

Biomolecules, especially proteins and nucleic acids, have been widely studied to develop biochips for various applications in scientific fields ranging from bioelectronics to stem cell research. However, restrictions exist due to the inherent characteristics of biomolecules, such as instability and the constraint of granting the functionality to the biochip. Introduction of functional nanomaterials, recently being researched and developed, to biomolecules have been widely researched to develop the nanobiohybrid materials because such materials have the potential to enhance and extend the function of biomolecules on a biochip. The potential for applying nanobiohybrid materials is especially high in the field of bioelectronics. Research in bioelectronics is aimed at realizing electronic functions using the inherent properties of biomolecules. To achieve this, various biomolecules possessing unique properties have been combined with novel nanomaterials to develop bioelectronic devices such as highly sensitive electrochemical‐based bioelectronic sensing platforms, logic gates, and biocomputing systems. In this review, recently reported bioelectronic devices based on nanobiohybrid materials are discussed. The authors believe that this review will suggest innovative and creative directions to develop the next generation of multifunctional bioelectronic devices.     

The effect of intrauterine inflammation on mTOR signaling in mouse fetal brain

Fetuses exposed to an inflammatory environment are predisposed to long‐term adverse neurological outcomes. However, the mechanism by which intrauterine inflammation (IUI) is responsible for abnormal fetal brain development is not fully understood. The mechanistic target of rapamycin (mTOR) signaling pathway is closely associated with fetal brain development. We hypothesized that mTOR signaling might be involved in fetal brain injury and malformation when fetuses are exposed to the IUI environment. A well‐established IUI model was utilized by intrauterine injection of lipopolysaccharide (LPS) to explore the effect of IUI on mTOR signaling in mouse fetal brains. We found that microglia activation in LPS fetal brains was increased, as demonstrated by elevated Iba‐1 protein level and immunofluorescence density. LPS fetal brains also showed reduced neuronal cell counts, decreased cell proliferation demonstrated by low Ki67‐positive density, and elevated neuron apoptosis evidenced by high expression of cleaved Caspase 3. Furthermore, we found that mTOR signaling in LPS fetal brains was elevated at 2 hr after LPS treatment, declined at 6 hr and showed overall inhibition at 24 hr. In summary, our study revealed that LPS‐induced IUI leads to increased activation of microglia cells, neuronal damage, and dynamic alterations in mTOR signaling in the mouse fetal brain. Our findings indicate that abnormal changes in mTOR signaling may underlie the development of future neurological complications in offspring exposed to prenatal IUI.     

Insecticidal and insect growth regulatory activities of secondary metabolites from entomopathogenic fungi,Lecanicillium attenuatum

Insect growth regulators (IGRs) are effective alternatives to chemical insecticides because of their specificity and low environmental toxicity. Entomopathogenic fungi are an important natural pathogen of insects and have been developed as biological control agents. They produce a wide range of secondary metabolites such as antibiotics, pesticides, growth-promoting or inhibiting compounds and insect attracting agents. In this study, to explore novel IGR substances from entomopathogenic fungi, culture extracts of 189 entomopathogenic fungi isolated from Korean soil samples were investigated for their juvenile hormone (JH)-based IGR activities. Whereas none of the culture extracts exhibited JH agonist (JHA) activity, 14 extracts showed high levels of JH antagonist (JHAN) activity. Among them, culture extract of JEF-145 strain, which was identified as Lecanicillium attenuatum, showed the highest insecticidal against Aedes albopictus and Plutella xylostella. At liquid culture condition, JHAN activity was observed in culture soup rather than mycelial cake, indicating that substances with JHAN activity are released from the JEF-145 strain during culture. Furthermore, while extract from solid cultured JEF-145 strain showed insecticidal activities against both A. albopictus and P. xylostella, that from liquid cultured fungi showed insecticidal activity only against A. albopictus, indicating that L. attenuatum JEF-145 strain produces different kinds of secondary metabolites with JHAN activity depending on culture conditions. These results suggested that JHAN substances derived from entomopathogenic fungi could be usefully exploited to develop novel eco-friendly IGR insecticides.     

圈养林麝麝香分泌时间节律及影响因素

在2016年和2017年的5—8月,我们对川西马尔康麝场圈养林麝（Moschus berezovskii）的麝香分泌进行了行为与生理监测,对麝香分泌的各阶段进行了准确判定,记录了泌香启动、泌香盛期开始、泌香盛期终止及泌香结束的时间阶段及持续时间长,分析了林麝麝香分泌的时间阶段与体重和年龄等因素的关系。结果表明,马尔康麝场的雄性林麝平均泌香启动日在6月16日[（167.06±7.75）d,n=141],于6月17日进入泌香盛期[（168.52±7.67）d,n=141],6月21日[（172.17±7.26）d, n=138]泌香活动减弱,至6月25日[（176.27±8.11）d, n=131]泌香结束;雄麝体重与其泌香启动、泌香盛期停止及泌香结束时间呈显著负相关（r_PS = -0.234,P_PS =0.028;r _VSF = -0.215,P_VSF = 0.047;r _SE = -0.229,P_SE = 0.043）,即雄麝的体重越大,其泌香越早;各年龄组间的平均泌香时长差异显著（F _{17, 113} = 3.482, P = 0.003）,其中2岁雄麝平均泌香时长最长[（13.07±2.08）d, n=20],显著高于3岁[（9.38±0.76）d, n=12, P = 0.042]和4岁[（7.80±1.60）d, n=5, P = 0.013]个体;马尔康林麝平均泌香量为（11.85g±0.96）g, （n=114）,随泌香时长延长有增加趋势,但不显著（P = 0.854）。基于上述林麝雄体的泌香时间、泌香量与年龄和体重等因素间的关联,可对圈养的林麝个体间的泌香力、泌香量等进行区分和预判,作为圈养林麝驯养生产力优化的依据,并可为圈养林麝优质品系的选育提供参考。     

Maximizing antibody production in a targeted integration host by optimization of subunit gene dosage and position

Historically, therapeutic protein production in Chinese hamster ovary (CHO) cells has been accomplished by random integration (RI) of expression plasmids into the host cell genome. More recently, the development of targeted integration (TI) host cells has allowed for recombination of plasmid DNA into a predetermined genomic locus, eliminating one contributor to clone-to-clone variability. In this study, a TI host capable of simultaneously integrating two plasmids at the same genomic site was used to assess the effect of antibody heavy chain and light chain gene dosage on antibody productivity. Our results showed that increasing antibody gene copy number can increase specific productivity, but with diminishing returns as more antibody genes are added to the same TI locus. Random integration of additional antibody DNA copies in to a targeted integration cell line showed a further increase in specific productivity, suggesting that targeting additional genomic sites for gene integration may be beneficial. Additionally, the position of antibody genes in the two plasmids was observed to have a strong effect on antibody expression level. These findings shed light on vector design to maximize production of conventional antibodies or tune expression for proper assembly of complex or bispecific antibodies in a TI system.     

GeSUT4 mediates sucrose import at the symbiotic interface for carbon allocation of heterotrophic Gastrodia elata (Orchidaceae)

Gastrodia elata, a fully mycoheterotrophic orchid without photosynthetic ability, only grows symbiotically with the fungus Armillaria. The mechanism of carbon distribution in this mycoheterotrophy is unknown. We detected high sucrose concentrations in all stages of Gastrodia tubers, suggesting sucrose may be the major sugar transported between fungus and orchid. Thick symplasm‐isolated wall interfaces in colonized and adjacent large cells implied involvement of sucrose importers. Two sucrose transporter (SUT)‐like genes, GeSUT4 and GeSUT3, were identified that were highly expressed in young Armillaria‐colonized tubers. Yeast complementation and isotope tracer experiments confirmed that GeSUT4 functioned as a high‐affinity sucrose‐specific proton‐dependent importer. Plasma‐membrane/tonoplast localization of GeSUT4‐GFP fusions and high RNA expression of GeSUT4 in symbiotic and large cells indicated that GeSUT4 likely functions in active sucrose transport for intercellular allocation and intracellular homeostasis. Transgenic Arabidopsis overexpressing GeSUT4 had larger leaves but were sensitive to excess sucrose and roots were colonized with fewer mutualistic Bacillus, supporting the role of GeSUT4 in regulating sugar allocation. This is not only the first documented carbon import system in a mycoheterotrophic interaction but also highlights the evolutionary importance of sucrose transporters for regulation of carbon flow in all types of plant‐microbe interactions.     

Preclinical Assessment of the Analgesic Pharmacology of NKTR-181 in Rodents

Cellular and Molecular Neurobiology - Pharmacological evaluation of the mu-opioid receptor (MOR) agonist properties of NKTR-181 in rodent models. Graded noxious stimulus intensities were used in...