Transcription factor PATZ1 promotes adipogenesis by controlling promoter regulatory loci of adipogenic factors [ChIPseq_D0_D5]
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ABSTRACT: White adipose tissue (WAT) plays a central role in lipid storage and systemic energy, lipid, and glucose homeostasis. Understanding the intricacies of adipocyte formation could inform therapies for obesity and metabolic disorders. We have identified the POZ/BTB and AT Hook Containing Zinc Finger 1 (PATZ1) protein as an adipogenic transcription factor through an unbiased high-throughput cDNA screen for transcriptional modulators of adipogenesis. PATZ1 is expressed by both human and mouse adipocyte precursor cells (APCs) and adipocytes, and in cell models, PATZ1 expression promotes adipogenesis through a mechanism dependent on protein-protein interaction and DNA binding. Both adipocyte-specific and APC-specific ablation of PATZ1 in mice leads to decreased fat mass and hypertrophied adipocytes. Genome-wide PATZ1 DNA binding analyses using ChIP-Seq suggest PATZ1 facilitates adipogenesis through interactions with transcription factor machinery at the promoter regions of critical early adipogenic factors and histone modifiers. Purification of the PATZ1 complex showed that General Transcription Factor 2I (GTF2I) associates with PATZ1 in a differentiation-dependent manner. Downregulation of GTF2I levels during adipogenesis markedly augments PATZ1 adipogenic function, suggesting a repressive interaction between GTF2I and PATZ1. These findings identify PATZ1 as a regulator of both adiposity and adipocyte differentiation programs and advance our understanding of the complex transcriptional mechanisms underlying adipose tissue development and homeostasis.
Project description:White adipose tissue (WAT) plays a central role in lipid storage and systemic energy, lipid, and glucose homeostasis. Understanding the intricacies of adipocyte formation could inform therapies for obesity and metabolic disorders. We have identified the POZ/BTB and AT Hook Containing Zinc Finger 1 (PATZ1) protein as an adipogenic transcription factor through an unbiased high-throughput cDNA screen for transcriptional modulators of adipogenesis. PATZ1 is expressed by both human and mouse adipocyte precursor cells (APCs) and adipocytes, and in cell models, PATZ1 expression promotes adipogenesis through a mechanism dependent on protein-protein interaction and DNA binding. Both adipocyte-specific and APC-specific ablation of PATZ1 in mice leads to decreased fat mass and hypertrophied adipocytes. Genome-wide PATZ1 DNA binding analyses using ChIP-Seq suggest PATZ1 facilitates adipogenesis through interactions with transcription factor machinery at the promoter regions of critical early adipogenic factors and histone modifiers. Purification of the PATZ1 complex showed that General Transcription Factor 2I (GTF2I) associates with PATZ1 in a differentiation-dependent manner. Downregulation of GTF2I levels during adipogenesis markedly augments PATZ1 adipogenic function, suggesting a repressive interaction between GTF2I and PATZ1. These findings identify PATZ1 as a regulator of both adiposity and adipocyte differentiation programs and advance our understanding of the complex transcriptional mechanisms underlying adipose tissue development and homeostasis.
Project description:White adipose tissue (WAT) plays a central role in lipid storage and systemic energy, lipid, and glucose homeostasis. Understanding the intricacies of adipocyte formation could inform therapies for obesity and metabolic disorders. We have identified the POZ/BTB and AT Hook Containing Zinc Finger 1 (PATZ1) protein as an adipogenic transcription factor through an unbiased high-throughput cDNA screen for transcriptional modulators of adipogenesis. PATZ1 is expressed by both human and mouse adipocyte precursor cells (APCs) and adipocytes, and in cell models, PATZ1 expression promotes adipogenesis through a mechanism dependent on protein-protein interaction and DNA binding. Both adipocyte-specific and APC-specific ablation of PATZ1 in mice leads to decreased fat mass and hypertrophied adipocytes. Genome-wide PATZ1 DNA binding analyses using ChIP-Seq suggest PATZ1 facilitates adipogenesis through interactions with transcription factor machinery at the promoter regions of critical early adipogenic factors and histone modifiers. Purification of the PATZ1 complex showed that General Transcription Factor 2I (GTF2I) associates with PATZ1 in a differentiation-dependent manner. Downregulation of GTF2I levels during adipogenesis markedly augments PATZ1 adipogenic function, suggesting a repressive interaction between GTF2I and PATZ1. These findings identify PATZ1 as a regulator of both adiposity and adipocyte differentiation programs and advance our understanding of the complex transcriptional mechanisms underlying adipose tissue development and homeostasis.
Project description:White adipose tissue (WAT) plays a central role in lipid storage and systemic energy, lipid, and glucose homeostasis. Understanding the intricacies of adipocyte formation could inform therapies for obesity and metabolic disorders. We have identified the POZ/BTB and AT Hook Containing Zinc Finger 1 (PATZ1) protein as an adipogenic transcription factor through an unbiased high-throughput cDNA screen for transcriptional modulators of adipogenesis. PATZ1 is expressed by both human and mouse adipocyte precursor cells (APCs) and adipocytes, and in cell models, PATZ1 expression promotes adipogenesis through a mechanism dependent on protein-protein interaction and DNA binding. Both adipocyte-specific and APC-specific ablation of PATZ1 in mice leads to decreased fat mass and hypertrophied adipocytes. Genome-wide PATZ1 DNA binding analyses using ChIP-Seq suggest PATZ1 facilitates adipogenesis through interactions with transcription factor machinery at the promoter regions of critical early adipogenic factors and histone modifiers. Purification of the PATZ1 complex showed that General Transcription Factor 2I (GTF2I) associates with PATZ1 in a differentiation-dependent manner. Downregulation of GTF2I levels during adipogenesis markedly augments PATZ1 adipogenic function, suggesting a repressive interaction between GTF2I and PATZ1. These findings identify PATZ1 as a regulator of both adiposity and adipocyte differentiation programs and advance our understanding of the complex transcriptional mechanisms underlying adipose tissue development and homeostasis.
Project description:The LIM-domain-only protein FHL2 is a modulator of signal transduction and has been shown to direct the differentiation of mesenchymal stem cells toward osteoblasts and myocytes phenotypes. We hypothesized that FHL2 may simultaneously interfere with the induction of the adipocyte lineage. Therefore, we investigated the role of FHL2 in adipocyte differentiation using pre-adipocytes isolated from mouse adipose tissue and the 3T3-L1 (pre)adipocyte cell line. Here we report that FHL2 is expressed in pre-adipocytes and for accurate adipocyte differentiation, this protein needs to be downregulated during the early stages of adipogenesis. More specifically, constitutive overexpression of FHL2 drastically inhibits adipocyte differentiation in 3T3-L1 cells, which was demonstrated by suppressed activation of the adipogenic gene expression program as shown by extensive RNAseq analyses, and diminished lipid accumulation. To identify the protein-protein interactions mediating this repressive activity of FHL2 on adipogenesis, we performed affinity-purification mass spectrometry (AP-MS). This analysis revealed the interaction of FHL2 with the Nuclear factor of activated T-cells 5 (NFAT5), an established inhibitor of adipocyte differentiation. NFAT5 knockdown rescued the inhibitory effect of FHL2 overexpression on 3T3-L1 differentiation, indicating that these proteins act cooperatively. In conclusion, we present a new regulatory function of FHL2 in early adipocyte differentiation and revealed that FHL2-mediated inhibition of pre-adipocyte differentiation is dependent on its interaction with NFAT5.
Project description:The nuclear receptor PPAR gamma is required for adipocyte differentiation, but its role in mature adipocytes is less clear. Here we report that knockdown of PPAR gamma expression in 3T3-L1 adipocytes returned the expression of most adipocyte genes towards preadipocyte levels. Consistently, down regulated but not up regulated genes showed strong enrichment of PPAR gamma binding. Surprisingly, not all adipocyte genes were reversed and the adipocyte morphology was maintained for an extended period after PPAR gamma depletion. To explain this, we focused on transcriptional regulators whose adipogenic regulation was not reversed upon PPAR gamma depletion. We identified GATA2, a transcription factor whose down-regulation early in adipogenesis is required for preadipocyte differentiation, remaining low after PPAR gamma knockdown. Forced expression of GATA2 in mature adipocytes complemented PPAR gamma depletion and impaired adipocyte functionality with a more preadipocyte- like gene expression profile. Ectopic expression of GATA2 in adipose tissue in vivo had similar effect on adipogenic gene expression. These results suggest that PPAR gamma-independent down regulation of GATA2 prevents reversion of mature adipocytes after PPAR gamma depletion. Experiment Overall Design: This dataset consists of three sample groups: preadipocytes, control siRNA treated adipocytes, and PPAR gamma siRNA treated adipocytes. Each sample group consists of three replicates samples. Each sample was hybridized to a separate array for a total of nine arrays. Experiment Overall Design: Technical replicates: Pread 1, Pread 2, Pread 3 Experiment Overall Design: Technical replicates: Cont siRNA 1, Cont siRNA 2, Cont siRNA 3 Experiment Overall Design: Technical replicates: PPAR gamma siRNA 1, PPAR gamma siRNA 2, PPAR gamma siRNA 3
Project description:Adipose tissue metabolism is actively involved in the regulation of energy balance. Adipose-derived stem cells (ASCs) play a critical role in maintaining adipose tissue function through their differentiation into mature adipocytes. The aim of this study was to investigate the effect of an obesogenic environment on the epigenetic landscape of ASCs and its impact on adipocyte differentiation and its metabolic consequences. Our results showed that ASCs from mice fed a high-fat sucrose (HFS) diet exhibited reduced adipogenic capacity, increased fat accumulation, and formed larger adipocytes than those from the control group (C). The results showed that ASCs from mice fed the HFS diet had reduced adipogenic capacity. Mitochondrial analysis showed increased mitochondrial activity in undifferentiated ASC-HFS, but decreased respiratory and glycolytic capacity in mature adipocytes. The HFS diet significantly altered the H3K4me3 acetylation profile of ASCs in genes related to adipogenesis, mitochondrial function, inflammatory response and immunomodulation. After differentiation, adipocytes retained H3K4me3 alterations in genes related to inflammatory response and immunomodulation. RNA-seq confirmed the upregulation of genes associated with inflammatory and immunomodulatory pathways in adipocytes. This study demonstrates that HFS diet induces profound epigenetic and transcriptomic changes in ASCs, leading to impaired differentiation and dysfunctional adipocyte formation.
Project description:Adipose tissue metabolism is actively involved in the regulation of energy balance. Adipose-derived stem cells (ASCs) play a critical role in maintaining adipose tissue function through their differentiation into mature adipocytes. The aim of this study was to investigate the effect of an obesogenic environment on the epigenetic landscape of ASCs and its impact on adipocyte differentiation and its metabolic consequences. Our results showed that ASCs from mice fed a high-fat sucrose (HFS) diet exhibited reduced adipogenic capacity, increased fat accumulation, and formed larger adipocytes than those from the control group (C). The results showed that ASCs from mice fed the HFS diet had reduced adipogenic capacity. Mitochondrial analysis showed increased mitochondrial activity in undifferentiated ASC-HFS, but decreased respiratory and glycolytic capacity in mature adipocytes. The HFS diet significantly altered the H3K4me3 acetylation profile of ASCs in genes related to adipogenesis, mitochondrial function, inflammatory response and immunomodulation. After differentiation, adipocytes retained H3K4me3 alterations in genes related to inflammatory response and immunomodulation. RNA-seq confirmed the upregulation of genes associated with inflammatory and immunomodulatory pathways in adipocytes. This study demonstrates that HFS diet induces profound epigenetic and transcriptomic changes in ASCs, leading to impaired differentiation and dysfunctional adipocyte formation.
Project description:Adipocytes are the main cell type in adipose tissue, a critical regulator of metabolism, highly specialized in storing energy as fat. Adipocytes differentiate from multipotent mesenchymal stromal cells through adipogenesis. Using RNA-seq we explored the effect of manipulating NAD+ bioavailability during adipogenic differentiation from human mesenchymal stem cells. Cells were harvested either undifferentiated (hMSC) or after days 8 and 16 of adipogenic induction. During adipogenesis, cells were treated with either NAD+ (5 mM), or FK866 (1 nM) or EX527 (50 μM).
Project description:Skin is the largest organ in the body and comprises several types of cells. The intercellular plasticity of keratinocytes, fibroblasts, and skin adipocytes contributes to wound healing and dermal adipogenesis. Although keratinocyte activates dermal adipose tissue (dWAT) differentiation upon hair follicular cycle, regulating dWAT hyperplasia through keratinocyte reprogramming is still unknown. We used the CRISPR/Cas9 base editor to induce single nucleotide polymorphisms in Forkhead-box N1 (Foxn1) and identified the p.L19M variant that induced the formation of a thicker dWAT regardless of hair follicular cycle or wound healing. Foxn1 p.L19M activates Wnt5β through transcriptional activity. Wnt5β signaling induces the conversion of dWAT dermal fibroblasts into adipose precursor cells (APCs) and promotes APC adipocyte differentiation through keratinocyte epithelial-mesenchymal transition (EMT) and adipogenic signaling. Wnt5β is involved in the entire process of dWAT hyperplasia through APC supply and adipogenic signaling as a single factor. Foxn1 p.L19M and Wnt5β are expressed in keratinocytes, and a keratinocyte-derived adipogenic signal is critical for dermal adipogenesis. In addition, transient expression of Foxn1 p.L19M or Wnt5β using adeno-associated virus reproduced dermal adipocyte hyperplasia in mice. Considering the increasing importance of dWAT in functions such as the immune response, wound healing, hair follicle growth, and temperature control, this finding has potential applications in skin regeneration
Project description:Adipose tissue abundance relies partly on the factors that regulate adipogenesis, i.e. proliferation and differentiation of adipocytes. While the transcriptional program that initiates adipogenesis is well-known, the importance of microRNAs in adipogenesis is less well studied. We thus set out to investigate whether miRNAs would be actively modulated during adipogenesis and obesity. Several models exist to study adipogenesis in vitro, of which the cell line 3T3-L1 is probably the most well known, albeit not the most physiologically appropriate. We used a microarray strategy to provide a global profile of miRNAs in brown and white primary murine adipocytes (prior to and following differentiation) and evaluated the similarity of the responses to non-primary cell models, through literature data-mining. We found 65 miRNAs regulated during in vitro adipogenesis in primary adipocytes. When we compared our primary adipocyte profiles with those of cell lines reported in the literature, we found a high degree of difference in adipogenesis-regulated miRNAs. We evaluated the expression of 10 of our adipogenesis-regulated miRNAs using real-time qPCR and then selected 5 miRNAs that showed robust expression levels and profiled these by qPCR in subcutaneous adipose tissue of 20 humans with a range of body mass indices (BMI, range=21-48). Of the miRNAs tested, mir-21 was both highly expressed in human adipose tissue and positively correlated with BMI (R2=0.49, p<0.001). In conclusion, we provide the preliminary analysis of miRNAs important for primary cell in vitro adipogenesis and find that the inflammation-associated miRNA, mir-21, is up-regulated in subcutaneous adipose tissue in human obesity. 3 samples of pre adipocytes isolated from brown adipose tissue examined pre and post differentiation to brown adipocytes. 3 samples of pre-adipocytes isolated from white adipose tissue and examined pre and post differentiation to adipocytes.