Project description:Mesenchymal stem cells (MSCs) are a multipotent cell type that can differentiate into non-hematopoietic cells, such as adipocytes. Adipocyte tissue is central to regulate energy balance. PGC-1 alpha controls several aspects of mitochondrial biogenesis. However, roles of PGC-1 alpha in brown fat differentiation of MSCs remain uncertain. To investigate roles of PGC-1 alpha in brown fat differentiation immortalized human MSCs were used for all experiments. The changes in genetic profiling between MSCs and PGC-1 alpha-expressing MSCs were analyzed by microarray analysis. The genetic profiling of PGC-1 alpha-expressing MSCs shows the significant increase of genes related to mitochondrial functions and lipid metabolism compared to that of MSCs. When expressed in MSCs, PGC-1 alpha activates a robust mitochondrial biogenesis and respiration. The expression of thermogenic markers, such as cytochrome C and complex II, was significantly increased in MSCs with treatment of adenovirus expressing PGC-1 alpha. Our microarray results also indicate that genetic pattern of PGC-1 alpha-expressing MSCs is very closed to that of adipose tissues. Bone marrow-derived MSCs were infected with Ad-GFP, or Ad-PGC-1? at a multiplicity of infection (m.o.i.) of 500 overnight.
Project description:Mesenchymal stem cells (MSCs) are a multipotent cell type that can differentiate into non-hematopoietic cells, such as adipocytes. Adipocyte tissue is central to regulate energy balance. PGC-1 alpha controls several aspects of mitochondrial biogenesis. However, roles of PGC-1 alpha in brown fat differentiation of MSCs remain uncertain. To investigate roles of PGC-1 alpha in brown fat differentiation immortalized human MSCs were used for all experiments. The changes in genetic profiling between MSCs and PGC-1 alpha-expressing MSCs were analyzed by microarray analysis. The genetic profiling of PGC-1 alpha-expressing MSCs shows the significant increase of genes related to mitochondrial functions and lipid metabolism compared to that of MSCs. When expressed in MSCs, PGC-1 alpha activates a robust mitochondrial biogenesis and respiration. The expression of thermogenic markers, such as cytochrome C and complex II, was significantly increased in MSCs with treatment of adenovirus expressing PGC-1 alpha. Our microarray results also indicate that genetic pattern of PGC-1 alpha-expressing MSCs is very closed to that of adipose tissues.
Project description:Mitochondria play an essential role in the ability of brown fat to generate heat, and the PGC-1 coactivators control several aspects of mitochondrial biogenesis. To investigate their specific roles in brown fat cells, we generated immortal preadipocyte lines from the brown adipose tissue of mice lacking PGC-1±. We could then efficiently knockdown PGC-1β expression by shRNA expression. Loss of PGC-1± did not alter brown fat differentiation but severely reduced the induction of thermogenic genes. Cells deficient in either PGC-1α or PGC-1β coactivators showed a small decrease in the differentiation-dependant program of mitochondrial biogenesis and respiration; however, this increase in mitochondrial number and function was totally abolished during brown fat differentiation when both PGC-1± and PGC-1 were deficient. These data show that PGC-1± is essential for brown fat thermogenesis but not brown fat differentiation, and the PGC-1 coactivators play an absolutely essential but complementary function in differentiation-induced mitochondrial biogenesis. Affymetrix microarray analysis of total RNA from wt, PGC-1± KO and PGC-1± KO; cells expressing an RNAi specific for PGC-1 knockdown was performed. Of the 461; mitochondrial genes analyzed, 181 were found to be at least 20% different between wt; and defective PGC-1± and β adipocytes (p < 0.05). More than 85% of these genes were downregulated in cells deficient for PGC-1alpha and PGC-1beta. Experiment Overall Design: Brown preadipocytes that were either WT, KO for PGC-1alpha, or KO for PGC-1alpha and deficient for PGC-1beta (knockdown through siRNA expression) were differentiated for seven days. RNA was made from biological replicates of the three different types of brown adipocytes (WT, KO expressing a control siRNA, KO expressing a siRNA specific for PGC-1beta knockdown).
Project description:Mitochondria play an essential role in the ability of brown fat to generate heat, and the PGC-1 coactivators control several aspects of mitochondrial biogenesis. To investigate their specific roles in brown fat cells, we generated immortal preadipocyte lines from the brown adipose tissue of mice lacking PGC-1α. We could then efficiently knockdown PGC-1β expression by shRNA expression. Loss of PGC-1α did not alter brown fat differentiation but severely reduced the induction of thermogenic genes. Cells deficient in either PGC-1α or PGC-1β coactivators showed a small decrease in the differentiation-dependant program of mitochondrial biogenesis and respiration; however, this increase in mitochondrial number and function was totally abolished during brown fat differentiation when both PGC-1α and PGC-1β were deficient. These data show that PGC-1α is essential for brown fat thermogenesis but not brown fat differentiation, and the PGC-1 coactivators play an absolutely essential but complementary function in differentiation-induced mitochondrial biogenesis. Affymetrix microarray analysis of total RNA from wt, PGC-1α KO and PGC-1α KO cells expressing an RNAi specific for PGC-1β knockdown was performed. Of the 461 mitochondrial genes analyzed, 181 were found to be at least 20% different between wt and defective PGC-1α and β adipocytes (p < 0.05). More than 85% of these genes were downregulated in cells deficient for PGC-1alpha and PGC-1beta. Keywords: Analysis of mitochondrial gene expression
Project description:To investigate the specific role of PGC-1 coactivators in brown fat cells, we generated immortal preadipocyte lines from the brown adipose tissue of mice lacking PGC-1alpha. We could then efficiently knockdown PGC-1beta expression by shRNA expression. Loss of PGC-1alpha did not alter brown fat differentiation but severly reduced the induction of thermogenic genes. In order to assess the specific requirement for PGC-1± in the global transcriptional response to cAMP, we used Affymetrix arrays to compare the sets of genes induced in response to a 4 hr dbcAMP treatment in differentiated wt and KO cells. This analysis revealed that 88 genes were induced more than 3-fold in the wt cells; of these, 54 (61% of total) were similarly increased in both wt and KO. However, 28 genes (32% of total) were decreased by at least 50% in the KO cells compared to wt cells. These data were confirmed by quantitative PCR for a subset of genes. These data indicate that PGC-1± is required for proper expression of approximately one third of the genes induced in response to cAMP in brown fat cells, but this set of sensitive genes is enriched in those involved in adaptative thermogenesis. Experiment Overall Design: WT and PGC-1alpha KO brown preadipocytes were differentiated into mature brown adipocytes for seven days. Cells were then treated with dibutyryl cAMP for four hours. Two replicates were made for each condition: WT non treated, WT treated with cAMP, KO non treated, KO treated with cAMP. Transcription profiling of wild type and PGC-1 alpha knockout mouse mature brown adipocytes treated with dibutyryl cAMP to investigate the specific role of PGC-1 coactivators in brown fat cells
Project description:We performed a genome-wide deep sequencing analysis of the microRNAs abundant in mesenchymal stem cells (MSCs) derived from murine brown adipose tissue and in in vitro differentiated mature brown adipocytes. Several microRNAs were identified as differentially regulated when comparing datasets from MSCs vs. mature fat cells. These microRNAs may have an implication in the regulation of adipogenesis as well as thermogenesis in brown adipose tissue (BAT).
Project description:To investigate the specific role of PGC-1 coactivators in brown fat cells, we generated immortal preadipocyte lines from the brown adipose tissue of mice lacking PGC-1alpha. We could then efficiently knockdown PGC-1beta expression by shRNA expression. Loss of PGC-1alpha did not alter brown fat differentiation but severly reduced the induction of thermogenic genes. In order to assess the specific requirement for PGC-1α in the global transcriptional response to cAMP, we used Affymetrix arrays to compare the sets of genes induced in response to a 4 hr dbcAMP treatment in differentiated wt and KO cells. This analysis revealed that 88 genes were induced more than 3-fold in the wt cells; of these, 54 (61% of total) were similarly increased in both wt and KO. However, 28 genes (32% of total) were decreased by at least 50% in the KO cells compared to wt cells. These data were confirmed by quantitative PCR for a subset of genes. These data indicate that PGC-1α is required for proper expression of approximately one third of the genes induced in response to cAMP in brown fat cells, but this set of sensitive genes is enriched in those involved in adaptative thermogenesis. Keywords: thermogenic gene program
Project description:We performed a genome-wide deep sequencing analysis of the microRNAs abundant in mesenchymal stem cells (MSCs) derived from murine brown adipose tissue and in in vitro differentiated mature brown adipocytes. Several microRNAs were identified as differentially regulated when comparing datasets from MSCs vs. mature fat cells. These microRNAs may have an implication in the regulation of adipogenesis as well as thermogenesis in brown adipose tissue (BAT). Examination of BAT-derived MSCs (BAT-MSC; 1 sample) and in vitro differentiated mature brown fat cells (BAT-DIFF; 1 sample) vertis biotechnologie AG, D-85354 Freising, Germany (library construction and sequencing)
Project description:This study aimed at determining the transcriptional changes associated with the white-to-brown conversion of human mesenchymal adipose-derived stem cells firstly differentiated into white adipocytes (in the presence of rosiglitazone from day 2 to day 9). White differentiation was completed within 14 days, and PPARg (rosiglitazone) or PPARa (GW7647) agonists were added to the medium for 4 additional days to induce the brown phenotype. Cells were harvested at day 18 and processed for microarray experiments (Agilent).
Project description:Human multipotent adipose-derived stem (hMADS) cells are differentiated in white or brown adipocytes with Rosiglitazone between days 14 and 18. PPAR alpha was silenced by siRNA transfections at day 10.