scholarly journals PPARγ marks splenic precursors of multiple nonlymphoid-tissue Treg compartments

2021 ◽  
Vol 118 (13) ◽  
pp. e2025197118
Author(s):  
Chaoran Li ◽  
Andrés R. Muñoz-Rojas ◽  
Gang Wang ◽  
Alexander O. Mann ◽  
Christophe Benoist ◽  
...  

Foxp3+CD4+ regulatory T cells (Tregs) regulate most types of immune response as well as several processes important for tissue homeostasis, for example, metabolism and repair. Dedicated Treg compartments—with distinct transcriptomes, T cell receptor repertoires, and growth/survival factor dependencies—have been identified in several nonlymphoid tissues. These Tregs are specifically adapted to function and operate in their home tissue—When, where, and how do they take on their specialized characteristics? We recently reported that a splenic Treg population expressing low levels of the transcription factor PPARγ (peroxisome proliferator-activated receptor gamma) contains precursors of Tregs residing in visceral adipose tissue. This finding made sense given that PPARγ, the “master regulator” of adipocyte differentiation, is required for the accumulation and function of Tregs in visceral adipose tissue but not in lymphoid tissues. Here we use single-cell RNA sequencing, single-cell Tcra and Tcrb sequencing, and adoptive-transfer experiments to show that, unexpectedly, the splenic PPARγlo Treg population is transcriptionally heterogeneous and engenders Tregs in multiple nonlymphoid tissues beyond visceral adipose tissue, such as skin and liver. The existence of a general pool of splenic precursors for nonlymphoid-tissue Tregs opens possibilities for regulating their emergence experimentally or therapeutically.

2020 ◽  
Vol 10 (2) ◽  
pp. 106-117
Author(s):  
Maryam Mostafavian ◽  
◽  
Ahmad Abdi ◽  
Javad Mehrabani ◽  
Alireza Barari ◽  
...  

Objective: Decreased physical activity coupled with increased High‐Fat Diet (HFD) intake prompts obesity. Current research suggests that changing White Adipose Tissue (WAT) to brown promotes energy expenditure to counter obesity. The purpose of this study was to investigate the effects of aerobic Progressive training and Capsaicin (Cap) on Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and Uncoupling protein-1 (UPC-1) gene expression in rat fed a high-fat diet. Methods: 40 male Wistar rats aged 8-12 weeks, were fed a Normal Diet (ND) (n=8) or HFD (n=32) for 8 weeks. After 8 weeks, rats were divided into 5 groups: ND, HFD, High-Fat Diet-Training (HFDT), High-Fat Diet-Capsaicin (HFDCap), high-fat diet-training-capsaicin (HFDTCap). Training groups have performed a progressive aerobic running program on a motor-driven treadmill for eight weeks. Capsaicin (4 mg/kg/day) were administered orally, by gavage, once a day. PGC-1α and UCP-1 gene expression levels in the VAT were measured by Real-time PCR method. Results: The results of this study showed that PGC-1α and UCP-expression was decreased in HFD group compared to ND group. Also, the expression of PGC-1α and UPC-1 in HFDT, HFDCap and HFDTCap groups was significantly increased compared to HFD. The expression of PGC-1α and UPC-1 in HFDTCap was also significantly increased compared to HFDT and HFDCap groups. Conclusion: Possibly, eight weeks of progressive training combined with capsaicin administration has an effect on the browning of visceral adipose tissue in HFD rats by increasing expression of PGC-1α and UCP-1.


Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1629 ◽  
Author(s):  
Hatim Boughanem ◽  
Amanda Cabrera-Mulero ◽  
Pablo Hernández-Alonso ◽  
Borja Bandera-Merchán ◽  
Alberto Tinahones ◽  
...  

Obesity is well accepted as crucial risk factor that plays a critical role in the initiation and progression of colorectal cancer (CRC). More specifically, visceral adipose tissue (VAT) in people with obesity could produce chronic inflammation and an altered profile expression of key transcription factors that promote a favorable microenvironment to colorectal carcinogenesis. For this, the aim of this study was to explore the relationship between adipogenic and inflammatory transcription factors in VAT from nonobese, obese, and/or CRC patients. To test this idea, we studied the expression and methylation of CCAAT-enhancer binding protein type alpha (C/EBP-α), peroxisome proliferator-activated receptor gamma (PPAR-γ), peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) in VAT from non-obese control, non-obese CRC subjects, overweight/obese control, and overweight/obese CRC patients and their correlation with anthropometric and biochemical variables. We found decreased expression of C/EBP-α in overweight/obese CRC patients in comparison with overweight/obese control subjects. PGC-1α and NF-κB were overexpressed in CRC patients independently of the BMI. NF-κB promoter was hypomethylated in overweight/obese CRC patients when compared to overweight/obese control individuals. In addition, multiple significant correlations between expression, methylation, and biochemical parameters were found. Finally, linear regression analysis showed that the expression of C/EBP-α and NF-κB and that NF-κB methylation were associated with CRC and able to explain up to 55% of CRC variability. Our results suggest that visceral adipose tissue may be a key factor in tumor development and inflammatory state. We propose C/EBP-α, PGC-1α and NF-κB to be interesting candidates as potential biomarkers in adipose tissue for CRC patients.


2007 ◽  
Vol 98 (3) ◽  
pp. 497-503 ◽  
Author(s):  
Constance Gayet ◽  
Veronique Leray ◽  
Masayuki Saito ◽  
Brigitte Siliart ◽  
Patrick Nguyen

Visceral adipose tissue and skeletal muscle have central roles in determining whole-body insulin sensitivity. The peroxisome proliferator-activated receptor-γ (PPARγ) is a potential mediator of insulin sensitivity. It can directly modulate the expression of genes that are involved in glucose and lipid metabolism, including GLUT4, lipoprotein lipase (LPL) and adipocytokines (leptin and adiponectin). In this study, we aimed to determine the effects of obesity-associated insulin resistance on mRNA expression of PPARγ and its target genes. Dogs were studied when they were lean and at the end of an overfeeding period when they had reached a steady obese state. The use of a sensitive, real-time PCR assay allowed a relative quantification of mRNA expression for PPARγ, LPL, GLUT4, leptin and adiponectin, in adipose tissue and skeletal muscle. In visceral adipose tissue and/or skeletal muscle, mRNA expression of PPARγ, LPL and GLUT4 were at least 2-fold less in obese and insulin-resistant dogs compared with the same animals when they were lean and insulin-sensitive. The mRNA expression and plasma concentration of leptin was increased, whereas the plasma level and mRNA expression of adiponectin was decreased, by obesity. In adipose tissue, PPARγ expression was correlated with leptin and adiponectin. These findings, in an original model of obesity induced by a prolonged period of overfeeding, showed that insulin resistance is associated with a decrease in PPARγ mRNA expression that could dysregulate expression of several genes involved in glucose and lipid metabolism.


2021 ◽  
Vol 22 (7) ◽  
pp. 3675
Author(s):  
Yujin Shin ◽  
Mijeong Lee ◽  
Dongju Lee ◽  
Joonseong Jang ◽  
Soon Shik Shin ◽  
...  

Fibrates, including fenofibrate, are a class of hypolipidemic drugs that activate peroxisome proliferator-activated receptor α (PPARα), which in-turn regulates the expression of lipid and lipoprotein metabolism genes. We investigated whether fenofibrate can reduce visceral obesity and nonalcoholic fatty liver disease via adipose tissue PPARα activation in female ovariectomized (OVX) C57BL/6J mice fed a high-fat diet (HFD), a mouse model of obese postmenopausal women. Fenofibrate reduced body weight gain (−38%, p < 0.05), visceral adipose tissue mass (−46%, p < 0.05), and visceral adipocyte size (−20%, p < 0.05) in HFD-fed obese OVX mice. In addition, plasma levels of alanine aminotransferase and aspartate aminotransferase, as well as free fatty acids, triglycerides, and total cholesterol, were decreased. Fenofibrate also inhibited hepatic lipid accumulation (−69%, p < 0.05) and infiltration of macrophages (−72%, p < 0.05), while concomitantly upregulating the expression of fatty acid β-oxidation genes targeted by PPARα and decreasing macrophage infiltration and mRNA expression of inflammatory factors in visceral adipose tissue. These results suggest that fenofibrate inhibits visceral obesity, as well as hepatic steatosis and inflammation, in part through visceral adipose tissue PPARα activation in obese female OVX mice.


2019 ◽  
Vol 2 (6) ◽  
pp. e201900561 ◽  
Author(s):  
Dong Seong Cho ◽  
Bolim Lee ◽  
Jason D Doles

Obesity is a serious health concern and is associated with a reduced quality of life and a number of chronic diseases, including diabetes, heart disease, stroke, and cancer. With obesity rates on the rise worldwide, adipose tissue biology has become a top biomedical research priority. Despite steady growth in obesity-related research, more investigation into the basic biology of adipose tissue is needed to drive innovative solutions aiming to curtail the obesity epidemic. Adipose progenitor cells (APCs) play a central role in adipose tissue homeostasis and coordinate adipose tissue expansion and remodeling. Although APCs are well studied, defining and characterizing APC subsets remains ambiguous because of ill-defined cellular heterogeneity within this cellular compartment. In this study, we used single-cell RNA sequencing to create a cellular atlas of APC heterogeneity in mouse visceral adipose tissue. Our analysis identified two distinct populations of adipose tissue–derived stem cells (ASCs) and three distinct populations of preadipocytes (PAs). We identified novel cell surface markers that, when used in combination with traditional ASC and preadipocyte markers, could discriminate between these APC subpopulations by flow cytometry. Prospective isolation and molecular characterization of these APC subpopulations confirmed single-cell RNA sequencing gene expression signatures, and ex vivo culture revealed differential expansion/differentiation capabilities. Obese visceral adipose tissue featured relative expansion of less mature ASC and PA subpopulations, and expression analyses revealed major obesity-associated signaling alterations within each APC subpopulation. Taken together, our study highlights cellular and transcriptional heterogeneity within the APC pool, provides new tools to prospectively isolate and study these novel subpopulations, and underscores the importance of considering APC diversity when studying the etiology of obesity.


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