Project description:In this study, we analyze the role of Lsr2 as a transcription factor in M. smegmatis, a saprophytic bacterium whose natural habitat (soil and water) substantially differs from that of the obligatory mycobacterial pathogens. In summary, the combined RNA-seq and ChIP-seq data revealed that Lsr2 controls gene expression either directly by binding their promoter regions or indirectly through DNA loop formation.
2021-04-22 | GSE164708 | GEO
Project description:study of bacteria on smartphone surface
| PRJNA657188 | ENA
Project description:Bacteria present on external body surface of Musca domestica
Project description:Adipose tissues play a pivotal role in energy homeostasis. They are existent in two forms: white adipose tissue and brown adipose tissue (BAT). Being the primary source of non-shivering thermogenesis of mammals, BAT plays an irreplaceable role in maintaining body temperature . Damaged DNA binding protein 1 (DDB1) is usually recognized as a component of the CUL4-DDB1 E3 complex. We have previously shown that DDB1 functions independently of CUL4 to promote adipogenesis. In the thesis, we focus on the function of DDB1 in mature adipocytes. We crossed Ddb1f/f mice with Adipoq-Cre or Ucp1-Cre mice to generate adipose tissue or BAT-specific mice, designated Ddb1-AKO and Ddb1-BKO mice respectively. At 8-12 weeks, BAT in these mice was servely whitened with decreased mitochdiral content. The thermogenic genes were also significantly downregulated at both RNA and protein levels. To further characterize the effect of DDB1 on thermogenesis, we first examined the bdy temperature of the pulps on postnatal day 3, and found that depletion of DDB1 caused a significant decrease in surface temperature.When the adult mice were subjected to cold challenge, both Ddb1-AKO and Ddb1-BKO mice showed dramatically decreased body temperature compared with control mice. At the end of the experiment, Ddb1-AKO and Ddb1-BKO mice had higher contents in BAT triglycerides and lower blood glucose level. Furthermore, the oxygen comsumption in Ddb1-AKO and Ddb1-BKO mice failed to respond to epinephrine injection. . All these results above demonstrated that lacking of DDB1 in brown adipocytes leads to a destruction in thermogenesis of BAT. We have also examined the phenotypes of Ddb1-AKO and Ddb1-BKO mice on high-fat-diet feeding. Compared with control mice, these mice showed decreased body weight, but significantly glucose intolerance and increased triglycierde content in liver, indicating that these mice have partial lipodystrophy. To study whether the effect of DDB1 was dependent on CUL4, we generated adipose tissue-specific Cul4a or CUl4b knockout mice, and found that these mice have no visible defect in BAT morphology compared with control mice, indicating a CUL4-independent function of DDB1. RNA-Seq analysis revealed that DDB1 is required for cold-induced expression of around 900 genes. ChIP-Seq analysis revelaed that these genes were subjected to regulation of promoter-proximally paused RNA polymerase II (Pol II), and that DDB1 is required for the release of paused Pol II upon cold stimulation. Our findings have thus revealed that DDB1 plays an important role in maintaining the theremogenic function of BAT by regulating the expression of thermogenic genes upon cold stimulation. Our studies will shed insights into transcriptional regulation of thermogenic gene
Project description:The mitochondrial calcium uniporter has been proposed to coordinate the organelle’s energetics with cytosolic calcium signaling. Previous studies have shown that the uniporter current is extremely high in mitochondria from brown adipose tissue (BAT), yet the contribution of the uniporter to BAT physiology in vivo is not known. Here, we report the generation and characterization of a mouse model lacking Mcu, the pore forming subunit of the uniporter, specifically in BAT (BAT-Mcu-KO). BAT-Mcu-KO mice are born in Mendelian ratios on a C57BL6/J genetic background, without any overt phenotypes. Although uniporter based calcium uptake is selectively ablated in BAT mitochondria, these mice are able to defend their body temperature in response to cold challenge and exhibit a normal body weight trajectory on a high fat diet. BAT transcriptional profiles at baseline and following cold-challenge are intact and not impacted by loss of Mcu. Unexpectedly, we found that cold powerfully activates the ATF4-dependent integrated stress response in BAT, and increases both circulating FGF21 and GDF15 levels, raising the hypothesis that the integrated stress response partly underlies the pleiotropic effects of BAT on systemic metabolism. Our study demonstrates that the uniporter is largely dispensable for BAT thermogenesis, and unexpectedly, uncovers a striking activation of the integrated stress response of BAT to cold challenge.
Project description:Brown adipose tissue (BAT) plays a pivotal role in maintaining body temperature and energy homeostasis. To identify the fuction of Ssu72 phosphatase in BAT thermogenesis, we analyzed gene expression of BAT from SSU72 WT and SSU72aKO.
Project description:The presence of genetic groups of the entomopathogenic fungus Metarhizium anisopliae in soil is shaped by its adaptability to specific soil and habitat types, and by soil insect populations. Although the entomopathogenic life style of this fungus is well studied, its saprophytic life style has received little consideration. While a set of functionally related genes can be commonly expressed for the adaptability of this fungus to different environments (insect cuticle, insect blood and root exudates), a different subset of genes is also expected for each environment. In order to increase the knowledge of the potential use of M. anisopliae as a rhizosphere competent organism, in this study we evaluated the genetic expression of this fungus while growing on plant root exudates in laboratory conditions during a time course.
Project description:Brown adipose tissue (BAT) is best known for thermogenesis. Whereas numerous studies in rodents found tight associations between the metabolic benefits of BAT and enhanced whole-body energy expenditure, emerging evidence in humans suggests that BAT is protective against Type 2 diabetes independent of body-weight. The underlying mechanism for this dissociation remained unclear. Here, we report that impaired mitochondrial flux of branched-chain amino acids (BCAA) in BAT, by deleting mitochondrial BCAA carrier (MBC, encoded by Slc25a44), was sufficient to cause systemic insulin resistance without affecting whole-body energy expenditure or body-weight. We found that brown adipocytes catabolized BCAAs in the mitochondria as essential nitrogen donors for the biosynthesis of glutamate, N-acetylated amino acids, and one of the products, glutathione. BAT-selective impairment in mitochondrial BCAA flux led to elevated oxidative stress and insulin resistance in the liver, accompanied by reduced levels of BCAA-nitrogen derived metabolites in the circulation. In turn, supplementation of glutathione restored insulin sensitivity of BAT-specific MBC knockout mice. Notably, a high-fat diet rapidly impaired BCAA catabolism and the synthesis of BCAA-nitrogen derived metabolites in the BAT, while cold-induced BAT activity is coupled with an active synthesis of these metabolites. Together, the present work uncovers a mechanism through which brown fat controls metabolic health independent of thermogenesis via BCAA-derived nitrogen carriers acting on the liver.
Project description:Brown adipose tissue (BAT) is best known for thermogenesis. Whereas numerous studies in rodents found tight associations between the metabolic benefits of BAT and enhanced whole-body energy expenditure, emerging evidence in humans suggests that BAT is protective against Type 2 diabetes independent of body-weight. The underlying mechanism for this dissociation remained unclear. Here, we report that impaired mitochondrial flux of branched-chain amino acids (BCAA) in BAT, by deleting mitochondrial BCAA carrier (MBC, encoded by Slc25a44), was sufficient to cause systemic insulin resistance without affecting whole-body energy expenditure or body-weight. We found that brown adipocytes catabolized BCAAs in the mitochondria as essential nitrogen donors for the biosynthesis of glutamate, N-acetylated amino acids, and one of the products, glutathione. BAT-selective impairment in mitochondrial BCAA flux led to elevated oxidative stress and insulin resistance in the liver, accompanied by reduced levels of BCAA-nitrogen derived metabolites in the circulation. In turn, supplementation of glutathione restored insulin sensitivity of BAT-specific MBC knockout mice. Notably, a high-fat diet rapidly impaired BCAA catabolism and the synthesis of BCAA-nitrogen derived metabolites in the BAT, while cold-induced BAT activity is coupled with an active synthesis of these metabolites. Together, the present work uncovers a mechanism through which brown fat controls metabolic health independent of thermogenesis via BCAA-derived nitrogen carriers acting on the liver.
Project description:Brown adipose tissue (BAT) has metabolic and endocrine effects to the whole-body, secreting molecules that target different tissues. Using transcriptomic analysis from isolated BAT from mice treated with isoproterenol in WT or UCP1-knockout mice, which have disfunctional BAT, we identified Bmp3b as an adipokine produced and secreted by activated BAT.