Dataset Information

DDB1 Prepares Brown Adipocytes for Cold-Induced Thermogenesis [ChIP-seq]

ABSTRACT: 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

ORGANISM(S): Mus musculus

PROVIDER: GSE192457 | GEO | 2024/12/21

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other
	GSE192457_RAW.tar	Raw
	filelist.txt	Txt

Items per page:

1 - 3 of 3

Similar Datasets

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:Non-shivering thermogenesis in adipocytes is mediated by brown adipose tissue, purportedly through the sole action of uncoupling protein 1 (UCP1). The physiological relevance of UCP1-dependent thermogenesis has primarily been inferred from the attenuation of thermogenic output of mice genetically lacking Ucp1 from birth (germline Ucp1-/-). However, germline Ucp1-/- mice harbor secondary changes within brown adipose tissue beyond UCP1, such as reduced electron transport chain abundance. We show here that these secondary changes also encompass reduced expression of genes regulating fuel liberation, changes that would attenuate the capacity of any thermogenic pathway. Therefore, the quantitative contribution of UCP1-dependent and -independent thermogenesis is not fully understood. To mitigate the potentially confounding ancillary changes to brown adipose tissue of germline Ucp1-/- mice, we constructed mice with inducible adipocyte-selective disruption of Ucp1. We find that, while germline Ucp1-/- mice succumb to cold-induced hypothermia with complete penetrance, most mice with inducible deletion of Ucp1 maintain homeothermy in the cold. However, inducible adipocyte-selective co-deletion of Ucp1 and creatine kinase B (Ckb, an effector of UCP1-independent thermogenesis) exacerbates cold-intolerance, indicative of a negative genetic interaction and thus a parallel thermogenic function. We find no evidence for impairments in insulation or non-shivering thermogenesis in skeletal muscle that would drive this phenotype. Furthermore, following UCP1 deletion or UCP1/CKB co-deletion from mature adipocytes, moderate cold exposure triggers the regeneration of mature adipocytes that coordinately restore UCP1 and CKB to brown adipose tissue, providing further evidence of their parallel thermogenic relationship. Our findings suggest that thermogenic adipocytes utilize non-paralogous protein redundancy – through UCP1 and CKB – to promote cold-induced energy dissipation.

Dataset Information

DDB1 Prepares Brown Adipocytes for Cold-Induced Thermogenesis [ChIP-seq]

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets