Regulation of gene expression by FSP27 in white and brown adipose tissue

<p>Abstract</p> <p>Background</p> <p>Brown and white adipose tissues (BAT and WAT) play critical roles in controlling energy homeostasis and in the development of obesity and diabetes. The mouse Fat-Specific protein 27 (FSP27), a member of the cell death-inducing DFF45-like effector (CIDE) family, is expressed in both BAT and WAT and is associated with lipid droplets. Over-expression of FSP27 promotes lipid storage, whereas <it>FSP27 </it>deficient mice have improved insulin sensitivity and are resistant to diet-induced obesity. In addition, <it>FSP27</it>-deficient white adipocytes have reduced lipid storage, smaller lipid droplets, increased mitochondrial activity and a higher expression of several BAT-selective genes. To elucidate the molecular mechanism by which FSP27 controls lipid storage and gene expression in WAT and BAT, we systematically analyzed the gene expression profile of <it>FSP27-</it>deficient WAT by microarray analysis and compared the expression levels of a specific set of genes in WAT and BAT by semi-quantitative real-time PCR analysis.</p> <p>Results</p> <p>BAT-selective genes were significantly up-regulated, whereas WAT-selective genes were down-regulated in the WAT of <it>FSP27-</it>deficient mice. The expression of the BAT-selective genes was also dramatically up-regulated in the WAT of <it>leptin/FSP27 </it>double deficient mice. In addition, the expression levels of genes involved in multiple metabolic pathways, including oxidative phosphorylation, the TCA cycle, fatty acid synthesis and fatty acid oxidation, were increased in the <it>FSP27-</it>deficient WAT. In contrast, the expression levels for genes involved in extracellular matrix remodeling, the classic complement pathway and TGF-β signaling were down-regulated in the <it>FSP27-</it>deficient WAT. Most importantly, the expression levels of regulatory factors that determine BAT identity, such as CEBPα/β, PRDM16 and major components of the cAMP pathway, were markedly up-regulated in the WAT of <it>FSP27-</it>deficient mice. The expression levels of these regulatory factors were also up-regulated in <it>leptin/FSP27 </it>double deficient mice. Interestingly, distinct gene expression profiles were observed in the BAT of <it>FSP27-</it>deficient mice. Taken together, these data suggest that the WAT of <it>FSP27-</it>deficient mice have a gene expression profile similar to that of BAT.</p> <p>Conclusions</p> <p>FSP27 acts as a molecular determinant that controls gene expression for a diversity of metabolic and signaling pathways and, in particular, the expression of regulatory factors, including CEBPα/β, PRDM16 and components of the cAMP signaling pathway, that control the identity of WAT and BAT.</p

The multidrug-resistant Pseudomonas fluorescens strain: a hidden threat in boar semen preservation

Although the bacterial composition of boar ejaculate has been extensively studied, the bacterial composition of extended boar semen is often overlooked, despite the potential risks these microorganisms may pose to the long-term preservation of extended boar semen at 15–17°C. In this study, we characterized the bacterial community composition of extended semen and discovered that Pseudomonas spp. was the dominant flora. The dominant strains were further isolated and identified as a potential new species in the Pseudomonas fluorescens group and named GXZC strain, which had adverse effects on sperm quality and was better adapted to growth at 17°C. Antimicrobial susceptibility testing showed that the GXZC strain was resistant to all commonly used veterinary antibiotics. Whole-genome sequencing (WGS) and genome annotation revealed the large genetic structure and function [7,253,751 base pairs and 6,790 coding sequences (CDSs)]. Comparative genomic analysis with the closest type strains showed that the GXZC strain predicted more diversity of intrinsic and acquired resistance genes to multi-antimicrobial agents. Taken together, our study highlights a problem associated with the long-term storage of extended boar semen caused by a P. fluorescens group strain with unique biological characteristics. It is essential to develop a new antibacterial solution for the long-term preservation of boar semen

Tip60-mediated lipin 1 acetylation and ER translocation determine triacylglycerol synthesis rate

人类遗传学家James V. Neel在1962年首次提出了“节俭基因”这一概念，认为现今人类导致包括肥胖症、糖尿病和高血压等代谢障碍的基因是因为生理系统为了适应远古环境食物富足和食物缺乏的周期性改变而筛选出的，可以让远古人类在食物富足的短暂时期中快速增肥，以应对随时将到来的食物缺乏时期。这类基因在当时环境下有很大的优越性，但对于当今食物富足的社会则截然相反。这篇论文中林圣彩教授团队揭示了乙酰转移酶TIP60通过乙酰化脂肪合成途径的代谢酶lipin 1并促进其向内质网转运，从而提高脂肪合成速率，揭示了TIP60作为一个“节俭基因”的功能和作用机制。该研究阐明了脂肪合成途径中首个受蛋白质乙酰化修饰调控的途径，揭示了TIP60作为经典转录调控因子之外的又一重要生物学功能，为开发防治肥胖症及其相关代谢紊乱疾病提供了新的药物作用靶点。博士后李阳、博士生宋林涛和硕士生孙玉是该论文的共同第一作者。【Abstract】Obesity is characterized by excessive fatty acid conversion to triacylglycerols (TAGs) in adipose tissues. However, how signaling networks sense fatty acids and connect to the stimulation of lipid synthesis remains elusive. Here, we show that homozygous knock-in mice carrying a point mutation at the Ser86 phosphorylation site of acetyltransferase Tip60 (Tip60SA/SA) display remarkably reduced body fat mass, and Tip60SA/SA females fail to nurture pups to adulthood due to severely reduced milk TAGs. Mechanistically, fatty acids stimulate Tip60-dependent acetylation and endoplasmic reticulum translocation of phosphatidic acid phosphatase lipin 1 to generate diacylglycerol for TAG synthesis, which is repressed by deacetylase Sirt1. Inhibition of Tip60 activity strongly blocks fatty acid-induced TAG synthesis while Sirt1 suppression leads to increased adiposity. Genetic analysis of loss-of-function mutants in Saccharomyces cerevisiae reveals a requirement of ESA1, yeast ortholog of Tip60, in TAG accumulation. These findings uncover a conserved mechanism linking fatty acid sensing to fat synthesis.This work was supported by grants from the National Natural Science Foundation of China (#31690101, #31430094, #31600961 and #31571214) and National Key Research and Development Project of China (2016YFA0502001). 该研究受到了国家自然科学基金和中国国家重点研发计划项目的资助

Insulin resistance and white adipose tissue inflammation are uncoupled in energetically challenged Fsp27-deficient mice.

Fsp27 is a lipid droplet-associated protein almost exclusively expressed in adipocytes where it facilitates unilocular lipid droplet formation. In mice, Fsp27 deficiency is associated with increased basal lipolysis, 'browning' of white fat and a healthy metabolic profile, whereas a patient with congenital CIDEC deficiency manifested an adverse lipodystrophic phenotype. Here we reconcile these data by showing that exposing Fsp27-null mice to a substantial energetic stress by crossing them with ob/ob mice or BATless mice, or feeding them a high-fat diet, results in hepatic steatosis and insulin resistance. We also observe a striking reduction in adipose inflammation and increase in adiponectin levels in all three models. This appears to reflect reduced activation of the inflammasome and less adipocyte death. These findings highlight the importance of Fsp27 in facilitating optimal energy storage in adipocytes and represent a rare example where adipose inflammation and hepatic insulin resistance are disassociated.This work was supported by grants from the National Basic Research Program (2013CB530602 and 2011CB910801 to P.L.), from the National Natural Science Foundation of China (31430040, 31321003 and 31030038), from the China Postdoctoral Science Foundation (2012M520249 and 2013T60103 to L.Z.) and from the Wellcome Trust (091551 to D.S.). This work was also supported by the Bio and Medical Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2013M3A9D5072563 to C.C.) and Korea Healthcare Technology R&D Project, Ministry for Health, Welfare and Family Affairs, Korea (A102060 to C.C.).This is the final published version. It first appeared at http://www.nature.com/ncomms/2015/150107/ncomms6949/full/ncomms6949.html?WT.ec_id=NCOMMS-20150114

Current Status of Drug Development and Implementation for Diseases Included in the Second Catalog of Rare Diseases

The National Health Commission of the People′s Republic of China and six other departments jointly released the Second Catalog of Rare Diseases, which expanded the definition of rare diseases in China. The expansion of the catalog means greater attention to rare diseases at the national level, and is also expected to accelerate the launch of relevant rare disease drugs and benefit more rare disease patients. When the new rare disease catalog released, it is necessary to quickly sort out the availability of drugs and find out the base number for the advancement of subsequent relevant measures. This paper searched official medical information websites and medical databases such as the National Medical Products Administration (NMPA), the Center for Drug Evaluation (CDE), and foreign drug regulatory agencies, and sorted out and summarized the subject categories of diseases included in the Second Catalog of Rare Diseases, the corresponding global research and development and implementation of drugs, as well as the medical insurance access situation in China, elaborates on the differences in the accessibility of orphan drugs at home and abroad. As China′s prevention, treatment and protection of rare diseases has reached a new point, plans and prospects are made for the introduction of relevant policies in the future, as well as the promotion of research and development and protection and other key tasks

Gene expression profile in the fat tissue of Fsp27 deficient mice

Fsp27 is a lipid droplet-associated protein almost exclusively expressed in adipocytes where it facilitates unilocular lipid droplet formation. In mice, Fsp27 deficiency is associated with increased basal lipolysis, browning of white fat and a healthy metabolic profile, whereas energetically challenged Fsp27 deficient mice (ob/ob/Fsp27−/−) show dramatically reduced fat mass, hepatic steatosis and insulin resistance which represents a typical lipodystrophy phenotype. Here, we investigate the effect of Fsp27 depletion on the gene expression of gonadal white adipose tissue (GWAT) under normal or energetically challenged condition (Fsp27−/− vs Wild type; ob/ob/Fsp27−/− vs ob/ob). We systematically analyzed the change in signaling pathway in Fsp27 deficient mice. The raw data have been deposited into Gene Expression Omnibus (GEO): GSE59807 and GSE22693

An Experimental and Numerical Study of the Influence of Temperature on Mode II Fracture of a T800/Epoxy Unidirectional Laminate

Studies on mode II fracture have promoted the establishment of the delamination theory for unidirectional composite laminates at room temperature. However, under thermal conditions, the fracture behavior of composite laminates will exhibit certain differences. The delamination theory should be extended to consider the temperature effect. To achieve this goal, in this study, the mode II static delamination growth behavior of an aerospace-grade T800/epoxy composite is investigated at 23 °C, 80 °C and 130 °C. The mode II fracture resistance curve (R-curve) is experimentally determined. A fractographic study on the fracture surface is performed using a scanning electron microscope (SEM), in order to reveal the failure mechanism. In addition, a numerical framework based on the cohesive zone model with a bilinear constitutive law is established for simulating the mode II delamination growth behavior at the thermal condition. The effects of the interfacial parameters on the simulations are investigated and a suitable value set for the interfacial parameters is determined. Good agreements between the experimental and numerical load–displacement responses illustrate the applicability of the numerical model. The research results provide helpful guidance for the design of composite laminates and an effective numerical method for the simulation of mode II delamination growth behavior

Cidea controls lipid droplet fusion and lipid storage in brown and white adipose tissue

Excess lipid storage in adipose tissue results in the development of obesity and other metabolic disorders including diabetes, fatty liver and cardiovascular diseases. The lipid droplet (LD) is an important subcellular organelle responsible for lipid storage. We previously observed that Fsp27, a member of the CIDE family proteins, is localized to LD-contact sites and promotes atypical LD fusion and growth. Cidea, a close homolog of Fsp27, is expressed at high levels in brown adipose tissue. However, the exact role of Cidea in promoting LD fusion and lipid storage in adipose tissue remains unknown. Here, we expressed Cidea in Fsp27-knockdown adipocytes and observed that Cidea has similar activity to Fsp27 in promoting lipid storage and LD fusion and growth. Next, we generated Cidea and Fsp27 double-deficient mice and observed that these animals had drastically reduced adipose tissue mass and a strong lean phenotype. In addition, Cidea/Fsp27 double-deficient mice had improved insulin sensitivity and were intolerant to cold. Furthermore, we observed that the brown and white adipose tissues of Cidea/Fsp27 double-deficient mice had significantly reduced lipid storage and contained smaller LDs compared to those of Cidea or Fsp27 single deficient mice. Overall, these data reveal an important role of Cidea in controlling lipid droplet fusion, lipid storage in brown and white adipose tissue, and the development of obesity

LRRK2 mediated Rab8a phosphorylation promotes lipid storage

Abstract Background Several mutations in leucine rich repeat kinase 2 (LRRK2) gene have been associated with pathogenesis of Parkinson’s disease (PD), a neurodegenerative disorder marked by resting tremors, and rigidity, leading to Postural instability. It has been revealed that mutations that lead to an increase of kinase activity of LRRK2 protein are significantly associated with PD pathogenesis. Recent studies have shown that some Rab GTPases, especially Rab8, serve as substrates of LRRK2 and undergo phosphorylation in its switch II domain upon interaction. Current study was performed in order to find out the effects of the phosphorylation of Rab8 and its mutants on lipid metabolism and lipid droplets growth. Methods The phosphorylation status of Rab8a was checked by phos-tag gel. Point mutant construct were generated to investigate the function of Rab8a. 3T3L1 cells were transfected with indicated plasmids and the lipid droplets were stained with Bodipy. Fluorescent microscopy experiments were performed to examine the sizes of lipid droplets. The interactions between Rab8a and Optineurin were determined by immunoprecipitation and western blot. Results Our assays demonstrated that Rab8a was phosphorylated by mutated LRRK2 that exhibits high kinase activity. Phosphorylation of Rab8a on amino acid residue T72 promoted the formation of large lipid droplets. T72D mutant of Rab8a had higher activity to promote the formation of large lipid droplets compared with wild type Rab8a, with increase in average diameter of lipid droplets from 2.10 μm to 2.46 μm. Moreover, phosphorylation of Rab8a weakened the interaction with its effector Optineurin. Conclusions Y1699C mutated LRRK2 was able to phosphorylate Rab8a and phosphorylation of Rab8a on site 72 plays important role in the fusion and enlargement of lipid droplets. Taken together, our study suggests an indirect relationship between enhanced lipid storage capacity and PD pathogenesis