Regulation of adipocyte differentiation of 3T3-L1 cells by PDZRN3

2013 ◽  
Vol 304 (11) ◽  
pp. C1091-C1097 ◽  
Author(s):  
Takeshi Honda ◽  
Aiko Ishii ◽  
Makoto Inui
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Adipocyte Differentiation ◽  
Early Stage ◽  
Adipogenic Differentiation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Protein Levels ◽  
Upstream Regulator ◽  
Pparγ Expression

PDZRN3, a member of the PDZRN (or LNX) family of proteins, is essential for the differentiation of mesenchymal stem cells into myotubes, but it plays an inhibitory role in the differentiation of these cells into osteoblasts. Given that mesenchymal stem cells also differentiate into adipocytes, we examined the possible role of PDZRN3 in adipogenesis in mouse 3T3-L1 preadipocytes. The expression of PDZRN3 decreased at both the mRNA and protein levels during adipogenic differentiation. RNAi-mediated depletion of PDZRN3 enhanced the differentiation of 3T3-L1 cells into adipocytes as assessed on the basis of lipid accumulation. The upregulation of aP2 and CCAAT/enhancer-binding protein (C/EBP)-β during adipocyte differentiation was also enhanced in the PDZRN3-depleted cells, as was the induction of peroxisome proliferator-activated receptor-γ (PPARγ), an upstream regulator of aP2 and C/EBPα, at both the mRNA and protein levels. Among transcription factors that control the expression of PPARγ, we found that STAT5b, but not STAT5a, was upregulated in PDZRN3-depleted cells at both mRNA and protein levels. Tyrosine phosphorylation of STAT5b, but not that of STAT5a, was also enhanced at an early stage of differentiation by PDZRN3 depletion. In addition, the expression of C/EBPβ during the induction of differentiation was enhanced at the mRNA and protein levels in PDZRN3-depleted cells. Our results thus suggest that PDZRN3 negatively regulates adipogenesis in 3T3-L1 cells through downregulation of STAT5b and C/EBPβ and consequent suppression of PPARγ expression.

scholarly journals Transcription Suppression of Peroxisome Proliferator-Activated Receptor γ2 Gene Expression by Tumor Necrosis Factor α via an Inhibition of CCAAT/ Enhancer-binding Protein δ during the Early Stage of Adipocyte Differentiation

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 4948-4956 ◽  
Author(s):  
Masataka Kudo ◽  
Akira Sugawara ◽  
Akira Uruno ◽  
Kazuhisa Takeuchi ◽  
Sadayoshi Ito
Keyword(s):  
Gene Expression ◽  
Insulin Resistance ◽  
Gene Transcription ◽  
Adipocyte Differentiation ◽  
Early Stage ◽  
Binding Protein ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Protein Levels ◽  
Enhancer Binding Protein

Abstract TNFα is known to inhibit adipocyte differentiation and induce insulin resistance. Moreover, TNFα is known to down-regulate peroxisome proliferator-activated receptor (PPAR)γ2, an adipocyte-specific nuclear receptor of insulin-sensitizer thiazolidinediones. To clarify molecular mechanisms of TNFα- mediated PPARγ2 down-regulation, we here examined the effect of TNFα on transcription regulation of PPARγ2 gene expression during the early stage of adipocyte differentiation. 3T3-L1 preadipocytes (2 d after 100% confluent) were incubated in a differentiation mixture (dexamethasone, insulin, 3-isobutyl-1-methlxanthine), with or without 50 ng/ml TNFα, for 24 h. TNFα significantly decreased PPARγ2 expression both at mRNA and protein levels (to ∼40%), as well as aP2 mRNA expression. The mouse PPARγ2 gene promoter region (2.2-kb) was isolated and was used for luciferase reporter assays by transient transfection. TNFα significantly suppressed PPARγ2 gene transcription (to ∼50%), and deletion analyses demonstrated that the suppression was mediated via CCAAT/enhancer-binding protein (C/EBP) binding elements at the −320/−340 region of the promoter. Moreover, TNFα significantly decreased expression of C/EBPδ mRNA and protein levels (to ∼40%). EMSA, using 3T3-L1 cells nuclear extracts with the −320/−340 region as a probe, demonstrated the binding of C/EBPδ to the element, which was significantly decreased by TNFα treatment. Overexpression of CEBP/δ prevented the TNFα-mediated suppression of PPARγ2 transactivation. Taken together, TNFα suppresses PPARγ2 gene transcription by the inhibition of C/EBPδ expression and its DNA binding during the early stage of adipocyte differentiation, which may contribute to the inhibition of adipocyte differentiation, as well as the induction of insulin resistance.

scholarly journals Energy Balance, Myostatin, and GILZ: Factors Regulating Adipocyte Differentiation in Belly and Bone

PPAR Research ◽  
2007 ◽  
Vol 2007 ◽  
pp. 1-12 ◽  
Author(s):  
Xingming Shi ◽  
Mark Hamrick ◽  
Carlos M. Isales
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Energy Balance ◽  
Therapeutic Strategy ◽  
Adipocyte Differentiation ◽  
Bone Development ◽  
Nuclear Hormone Receptor ◽  
Liver Fat ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

Peroxisome proliferator-activated receptor gamma (PPAR-γ) belongs to the nuclear hormone receptor subfamily of transcription factors. PPARs are expressed in key target tissues such as liver, fat, and muscle and thus they play a major role in the regulation of energy balance. Because of PPAR-γ's role in energy balance, signals originating from the gut (e.g., GIP), fat (e.g., leptin), muscle (e.g., myostatin), or bone (e.g., GILZ) can in turn modulate PPAR expression and/or function. Of the two PPAR-γisoforms, PPAR-γ2 is the key regulator of adipogenesis and also plays a role in bone development. Activation of this receptor favors adipocyte differentiation of mesenchymal stem cells, while inhibition of PPAR-γ2 expression shifts the commitment towards the osteoblastogenic pathway. Clinically, activation of this receptor by antidiabetic agents of the thiazolidinedione class results in lower bone mass and increased fracture rates. We propose that inhibition of PPAR-γ2 expression in mesenchymal stem cells by use of some of the hormones/factors mentioned above may be a useful therapeutic strategy to favor bone formation.

scholarly journals PPAR-γSignaling Crosstalk in Mesenchymal Stem Cells

PPAR Research ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Ichiro Takada ◽  
Alexander P. Kouzmenko ◽  
Shigeaki Kato
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Target Gene ◽  
Adipocyte Differentiation ◽  
Protein Complexes ◽  
Regulatory Function ◽  
Target Cells ◽  
Peroxisome Proliferator ◽  
Gene Promoters ◽  
Peroxisome Proliferator Activated Receptor

Peroxisome proliferator-activated receptor-gamma (PPAR-γ) is a member of the nuclear receptor (NR) superfamily of ligand-activated transcriptional factors. Among other functions, PPAR-γacts as a key regulator of the adipogenesis. Since several cytokines (IL-1, TNF-α, TGF-β) had been known to inhibit adipocyte differentiation in mesenchymal stem cells (MSCs), we examined the effect of these cytokines on the transactivation function of PPAR-γ. We found that the TNF-α/IL-1-activated TAK1/TAB1/NIK (NFκB-inducible kinase) signaling cascade inhibited both the adipogenesis and Tro-induced transactivation by PPAR-γby blocking the receptor binding to the cognate DNA response elements. Furthermore, it has been shown that the noncanonical Wnts are expressed in MSCs and that Wnt-5a was capable to inhibit transactivation by PPAR-γ. Treatment with Wnt5a-activated NLK (nemo-like kinase) induced physical association of the endogenous NLK and H3K9 histone methyltransferase (SETDB1) protein complexes with PPAR-γ. This resulted in histoneH3K9 tri-methylation at PPAR-γtarget gene promoters. Overall, our data show that cytokines and noncanonical Wnts play a crucial role in modulation of PPAR-γregulatory function in its target cells and tissues.

scholarly journals Chorionic villus-derived mesenchymal stem cell-mediated autophagy promotes proliferation and invasiveness of trophoblasts under hypoxia by activating the JAK2/STAT3 signalling pathway

2020 ◽  
Author(s):  
Yijing Chu ◽  
Chongyu Yue ◽  
Wei Peng ◽  
Weiping Chen ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Chorionic Villus ◽  
Pcr Analysis ◽  
Rna Seq ◽  
Protein Levels ◽  
Hypoxic Conditions ◽  
Upstream Regulator ◽  
Pathway Analyses ◽  
Stat3 Signalling

Abstract Objectives Trophoblast dysfunction during pregnancy is fundamentally involved in preeclampsia. The aim of this study was to understand how human chorionic villous mesenchymal stem cells (CV-MSCs) operate in regulation of trophoblast function.Materials and Methods We treated trophoblasts with CV-MSC supernatant under hypoxic conditions, and transcriptome and pathway analyses of trophoblasts were performed. Western blotting and PCR analysis were used to examine the JAK2, STAT3 and autophagy associated protein expression levels in trophoblasts.Results The CV-MSC supernatant treatment markedly enhanced proliferation, invasion and autophagy. The RNA-seq revealed JAK2/STAT3 signalling as an upstream regulator, and STAT3 mRNA and protein levels increased during CV-MSC treatment. Inhibition of JAK2/STAT3 signalling reduced autophagy, survival and invasion of trophoblasts even in the presence of CV-MSCs, and blocking autophagy did not affect STAT3 activation in trophoblasts treated with CV-MSCs. Importantly, overexpression of STAT3 increased the levels of autophagy in trophoblasts; thus, it regulated positively autophagy in hypoxic trophoblasts. Human placental explants also proved our finding, in which STAT3 was activated and LC3B-II levels were increased by CV-MSC treatment.Conclusions Our data suggest that CV-MSC-dependent activation of JAK2/STAT3 signalling is a prerequisite for upregulation of autophagy in trophoblasts.

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