MCP-1 deficiency enhances browning of adipose tissue via increased M2 polarization

Obesity is strongly associated with chronic inflammation for which adipose tissue macrophages play a critical role. The objective of this study is to identify monocyte chemoattractant protein-1 (MCP-1, CCL2) as a key player governing M1–M2 macrophage polarization and energy balance. We evaluated body weight, fat mass, adipocyte size and energy expenditure as well as core body temperature of Ccl2 knockout mice compared with wild-type mice. Adipose tissues, differentiated adipocyte and bone marrow-derived macrophages were assessed by qPCR, Western blot analysis and histochemistry. MCP-1 deficiency augmented energy expenditure by promoting browning in white adipose tissue and brown adipose tissue activity via increasing the expressions of Ucp1, Prdm16, Tnfrsf9, Ppargc1a, Nrf1 and Th and mitochondrial DNA copy number. MCP-1 abrogation promoted M2 polarization which is characterized by increased expression of Arg1, Chil3, Il10 and Klf4 whereas it decreased M1 polarization by decreased p65 nuclear translocation and attenuated expression of Itgax, Tnf and Nos2, leading to increased browning of adipocytes. Enhanced M2 polarization and attenuated M1 polarization in the absence of MCP-1 are independent. Collectively, our results suggest that the action of MCP-1 in macrophages modulates energy expenditure by impairing browning in adipose tissue.

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Urolithin A, a Gut Metabolite, Induces Metabolic Reprogramming of Adipose Tissue by Promoting M2 Macrophage Polarization and Mitochondrial Function (OR12-02-19)

Current Developments in Nutrition ◽

10.1093/cdn/nzz049.or12-02-19 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Cited By ~ 1

Author(s):

Ashley Toney ◽

Soonkyu Chung

Keyword(s):

Adipose Tissue ◽

Mitochondrial Function ◽

Macrophage Polarization ◽

Peritoneal Macrophages ◽

M2 Macrophage ◽

M2 Polarization ◽

M1 Polarization ◽

Urolithin A ◽

M2 Macrophage Polarization

Abstract Objectives Macrophage polarization into pro-inflammatory M1 status is associated with the pathologic progression of adipose remodeling, while M2 polarization is linked with the resolution of inflammation. Urolithin A (UroA) is a gut metabolite derived from ellagic acid found in berries and nuts. Emerging evidence suggests UroA exerts anti-inflammatory function, but the underlying mechanism remains unknown. This study aims to test the hypothesis that UroA attenuates adipose inflammation by promoting M2 macrophage polarization. Methods To investigate the direct role of UroA in vitro, primary bone marrow-derived macrophages (BMDM) were stimulated with LPS for M1 polarization or IL-4/IL-13 for M2 polarization. Oxygen consumption rate was determined in BMDM by Seahorse extracellular flux analyzer. The anti-inflammatory role of UroA is validated by pro-IL-1β Gaussia luciferase (iGLuc) reporter assay and IL-1β secretion in J774 macrophages. Additionally, C57BL/6 mice were fed with a HF diet for 12 weeks along with UroA administration. The M1/M2 polarization status were examined in adipose tissue macrophages (ATM) and peritoneal macrophages by qPCR and protein markers. Results UroA treatment in BMDM in vitro significantly decreased Il-1β (P < 0.001), while increasing M2 markers of Arg1, Ch313 and Mgl2 (P < 0.01). UroA treatment suppressed NLRP3 inflammasome activation in J774 macrophages by decreasing iGLuc activity and IL-1β secretion in a dose-dependent manner. In vivo, UroA administration reduced HF-induced adipocyte hypertrophy, inflammatory markers, and ATM recruitment (P < 0.01) in the adipose tissue. Consistently, UroA suppressed M1 polarization but switched to M2 polarization in peritoneal macrophages, evidenced by decreased M1 signature genes of Cd11c, Tnf-α, Il-6, and Il-1β (P < 0.01), while elevated M2 markers of Ch313 and Mgl2 (P < 0.05). Lastly, UroA not only inhibits HF-driven pathogenic remodeling of adipose tissue, but also promote mitochondrial function and biogenesis. Conclusions UroA attenuates HF-driven pathologic remodeling of adipose tissue by favoring M2 macrophage polarization and augmenting mitochondrial function. Intake of UroA-producing foods may be a promising intervention strategy to mitigate obesity-mediated chronic inflammation and metabolic dysfunction. Funding Sources United States Department of Agriculture National Institute for Food and Agriculture.

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Dot1l interacts with Zc3h10 to activate Ucp1 and other thermogenic genes

eLife ◽

10.7554/elife.59990 ◽

2020 ◽

Vol 9 ◽

Author(s):

Danielle Yi ◽

Hai P Nguyen ◽

Jennie Dinh ◽

Jose A Viscarra ◽

Ying Xie ◽

...

Keyword(s):

Adipose Tissue ◽

Energy Expenditure ◽

Target Genes ◽

Critical Role ◽

Direct Interaction ◽

Fat Cell ◽

Methyltransferase Activity ◽

Promoter Regions ◽

Brown Adipose ◽

Thermogenic Capacity

Brown adipose tissue is a metabolically beneficial organ capable of dissipating chemical energy into heat, thereby increasing energy expenditure. Here, we identify Dot1l, the only known H3K79 methyltransferase, as an interacting partner of Zc3h10 that transcriptionally activates the Ucp1 promoter and other BAT genes. Through a direct interaction, Dot1l is recruited by Zc3h10 to the promoter regions of thermogenic genes to function as a coactivator by methylating H3K79. We also show that Dot1l is induced during brown fat cell differentiation and by cold exposure and that Dot1l and its H3K79 methyltransferase activity is required for thermogenic gene program. Furthermore, we demonstrate that Dot1l ablation in mice using Ucp1-Cre prevents activation of Ucp1 and other target genes to reduce thermogenic capacity and energy expenditure, promoting adiposity. Hence, Dot1l plays a critical role in the thermogenic program and may present as a future target for obesity therapeutics.

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46 Inhibition of Lipolysis with Acipimox Targets Post-burn White Adipose Browning by Altering Macrophage Polarity

Journal of Burn Care & Research ◽

10.1093/jbcr/iraa024.050 ◽

2020 ◽

Vol 41 (Supplement_1) ◽

pp. S30-S31

Author(s):

Dalia Barayan ◽

Roohi Vinaik ◽

Marc G Jeschke

Keyword(s):

Adipose Tissue ◽

Uncoupling Protein ◽

Polarization State ◽

Critical Role ◽

Metabolic Effects ◽

Inhibitory Effects ◽

Macrophage Recruitment ◽

M2 Polarization ◽

Brown Adipose ◽

Major Burn

Abstract Introduction Severe burns are accompanied by a detrimental hypermetabolic stress response that can persist for years post-injury. Our previous work revealed that, under prolonged stress, white adipose tissue (WAT) adopts brown adipose-like traits in a process termed ‘browning’. This switch, characterized by the presence of uncoupling protein 1 (UCP1), is driven by the polarization of macrophages towards an M2 phenotype. Recently, we demonstrated that inhibiting lipolysis with the clinically approved drug, Acipimox, represses the burn-induced thermogenic activation of WAT. These findings raise the possibility that elevated rates of lipolysis may play a role in regulating the macrophage polarization state after major burn. However, the interconnection between post-burn lipolysis and inflammation remains unclear. In the present study, we investigated the mechanism underlying Acipimox’s inhibitory effects on burn-induced browning. Using a mouse model of thermal injury, we determine the metabolic effects of reducing WAT lipolysis on burn-induced macrophage recruitment and M2-polarization. Methods Adult C57BL/6 mice received a 30% total body surface area scald burn. Mice were then given daily intraperitoneal injections of APX (50 mg/Kg). On day 7 post-burn, the inguinal adipose tissue depot (iWAT) was harvested for histological analyses. Flow cytometry and F4/80 staining were used to assess adipose macrophage distribution and profile, and gene expression was analyzed via qPCR. Results APX administration significantly increased mitochondrial coupling, reflected by the decrease in UCP-1 (p< 0.05) and PGC-1a (p< 0.01) levels relative to the iWAT of untreated burn mice. F4/80 immunostaining of iWAT demonstrated decreased macrophage recruitment in Acipimox treated mice (p< 0.05). Flow cytometric analysis indicated decreased macrophage infiltration at 7 days in Acipimox treated mice (p< 0.05). Furthermore, iWAT from Acipimox treated mice demonstrated a pro-inflammatory profile, indicated by a greater distribution of TLR4 positive macrophages (p< 0.05). Conclusions Previously, we showed that the administration of Acipimox effectively suppressed PKA-mediated lipolysis and improved mitochondrial coupling in adipose tissue post-burn. Here, we elucidate the mechanism underlying these metabolic changes. Importantly, we show Acipimox exerts its inhibitory effects on burn-induced WAT browning by directly modulating macrophage recruitment and the M2-polarization state. Applicability of Research to Practice Our study highlights the critical role of lipolysis in mediating the key post-burn metabolic phenomena browning and inflammation. The data presented herein validate the pharmacological inhibition of lipolysis as a potentially powerful therapeutic strategy to counteract the detrimental metabolic effects induced by burn.

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CXCL16/CXCR6 Axis in Adipocytes Differentiated from Human Adipose Derived Mesenchymal Stem Cells Regulates Macrophage Polarization

Cells ◽

10.3390/cells10123410 ◽

2021 ◽

Vol 10 (12) ◽

pp. 3410

Author(s):

Seung-Cheol Lee ◽

Yoo-Jung Lee ◽

Inho Choi ◽

Min Kim ◽

Jung-Suk Sung

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Adipose Tissue ◽

Macrophage Polarization ◽

Inflammatory Factors ◽

M2 Macrophage ◽

M2 Polarization ◽

Chemokine Ligand ◽

Anti Inflammatory ◽

Underlying Mechanisms

Adipocytes interact with adipose tissue macrophages (ATMs) that exist as a form of M2 macrophage in healthy adipose tissue and are polarized into M1 macrophages upon cellular stress. ATMs regulate adipose tissue inflammation by secreting cytokines, adipokines, and chemokines. CXC-motif receptor 6 (CXCR6) is the chemokine receptor and interactions with its specific ligand CXC-motif chemokine ligand 16 (CXCL16) modulate the migratory capacities of human adipose-derived mesenchymal stem cells (hADMSCs). CXCR6 is highly expressed on differentiated adipocytes that are non-migratory cells. To evaluate the underlying mechanisms of CXCR6 in adipocytes, THP-1 human monocytes that can be polarized into M1 or M2 macrophages were co-cultured with adipocytes. As results, expression levels of the M1 polarization-inducing factor were decreased, while those of the M2 polarization-inducing factor were significantly increased in differentiated adipocytes in a co-cultured environment with additional CXCL16 treatment. After CXCL16 treatment, the anti-inflammatory factors, including p38 MAPK ad ERK1/2, were upregulated, while the pro-inflammatory pathway mediated by Akt and NF-κB was downregulated in adipocytes in a co-cultured environment. These results revealed that the CXCL16/CXCR6 axis in adipocytes regulates M1 or M2 polarization and displays an immunosuppressive effect by modulating pro-inflammatory or anti-inflammatory pathways. Our results may provide an insight into a potential target as a regulator of the immune response via the CXCL16/CXCR6 axis in adipocytes.

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Dot1L interacts with Zc3h10 to activate UCP1 and other thermogenic genes

10.1101/2020.06.22.154963 ◽

2020 ◽

Author(s):

Danielle Yi ◽

Hai P. Nguyen ◽

Jennie Dinh ◽

Jose A. Viscarra ◽

Ying Xie ◽

...

Keyword(s):

Adipose Tissue ◽

Energy Expenditure ◽

Target Genes ◽

Critical Role ◽

Direct Interaction ◽

Fat Cell ◽

Methyltransferase Activity ◽

Promoter Regions ◽

Brown Adipose ◽

Thermogenic Capacity

ABSTRACTBrown adipose tissue is a metabolically beneficial organ capable of dissipating chemical energy into heat, thereby increasing energy expenditure. Here, we identify Dot1L, the only known H3K79 methyltransferase, as an interacting partner of Zc3h10 that transcriptionally activates the UCP1 promoter and other BAT genes. Through a direct interaction, Dot1L is recruited by Zc3h10 to the promoter regions of thermogenic genes to function as a coactivator by methylating H3K79. We also show that Dot1L is induced during brown fat cell differentiation and by cold exposure and that Dot1L and its H3K79 methyltransferase activity is required for thermogenic gene program. Furthermore, we demonstrate that Dot1L ablation in mice using UCP1-Cre prevents activation of UCP1 and other target genes to reduce thermogenic capacity and energy expenditure, promoting adiposity. Hence, Dot1L plays a critical role in the thermogenic program and may present as a future target for obesity therapeutics.

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Version up-date: The CDKN2B-AS1/ MIR497/TXNIP axis regulated macrophages

10.21203/rs.3.rs-806497/v1 ◽

2021 ◽

Author(s):

JianZhong Xu

Keyword(s):

Rheumatoid Arthritis ◽

Macrophage Polarization ◽

Critical Role ◽

M2 Macrophages ◽

Macrophage Cell Line ◽

Macrophage Cell ◽

Surface Polarization ◽

M2 Polarization ◽

M1 Polarization ◽

Healthy Donors

Abstract The polarization of macrophages plays a critical role in the pathophysiology of rheumatoid arthritis. The macrophages can have pro-inflammatory M1 polarization and various types of alternative anti-inflammatory M2 polarization. Our preliminary results showed that the CDKN2B-AS1/MIR497/TXNIP axis might regulate macrophages of rheumatoid arthritis patients. Therefore, we hypothesized that this axis regulated the polarization of rheumatoid macrophages. Flow cytometry was used to determine the surface polarization markers in M1 or M2 macrophages from healthy donors and rheumatoid arthritis patients. The QPCR and Western Blotting were used to compare the expression of the CDKN2B-AS1/MIR497/TXNIP axis in these macrophages. We Knocked down and overexpressed the axis in the macrophage cell line MD to test its roles in macrophage polarization. Compared to cells from healthy donors, cells from rheumatoid arthritis patients expressed higher levels of CD40 and CD80 and lower levels of CD16, CD163, CD206, and CD200R after polarization, they also expressed higher CDKN2B-AS1, lower MIR497, and higher TXNIP. In macrophages from healthy donors, there was no correlation among CDKN2B-AS1, MIR497, and TXNIP. But in macrophages from patients, there were significant correlations. The CDKN2B-AS1 knockdown, MIR497 mimics suppressed the M1 polarization but promoted the M2 polarization in MD cells, while the MIR497 knockdown and the TXNIP overexpression did the opposite. This study demonstrated that elevated CDKN2B-AS1 in macrophages promotes the M1 polarization and inhibited the M2 polarization of macrophages by the CDKN2B-AS1/ MIR497/TXNIP axis.

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Mesenchymal stem cell-derived extracellular vesicles alter disease outcomes via endorsement of macrophage polarization

Stem Cell Research & Therapy ◽

10.1186/s13287-020-01937-8 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Jiangmei Wang ◽

Jie Xia ◽

Ruoqiong Huang ◽

Yaoqin Hu ◽

Jiajie Fan ◽

...

Keyword(s):

Extracellular Vesicles ◽

Stromal Cells ◽

Macrophage Polarization ◽

Critical Role ◽

Cell Contact ◽

Central Nervous System Diseases ◽

The Past ◽

Disease Outcomes ◽

M2 Polarization ◽

M1 Polarization

Abstract Mesenchymal stem cells (MSCs) are adult stromal cells that reside in virtually all postnatal tissues. Due to their regenerative and immunomodulatory capacities, MSCs have attracted growing attention during the past two decades. MSC-derived extracellular vesicles (MSC-EVs) are able to duplicate the effects of their parental cells by transferring functional proteins and genetic materials to recipient cells without cell-to-cell contact. MSC-EVs also target macrophages, which play an essential role in innate immunity, adaptive immunity, and homeostasis. Recent studies have demonstrated that MSC-EVs reduce M1 polarization and/or promote M2 polarization in a variety of settings. In this review, we discuss the mechanisms of macrophage polarization and roles of MSC-EV-induced macrophage polarization in the outcomes of cardiovascular, pulmonary, digestive, renal, and central nervous system diseases. In conclusion, MSC-EVs may become a viable alternative to MSCs for the treatment of diseases in which inflammation and immunity play a critical role.

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The CDKN2B-AS1/ MIR497/TXNIP axis regulated macrophages

10.21203/rs.3.rs-701832/v1 ◽

2021 ◽

Author(s):

Jianzhong Xu ◽

Yu Li ◽

Chenxi Gu ◽

Guanlei Liu ◽

Yang Yu

Keyword(s):

Rheumatoid Arthritis ◽

Macrophage Polarization ◽

Critical Role ◽

Macrophage Cell Line ◽

Macrophage Cell ◽

Surface Polarization ◽

M2 Polarization ◽

M1 Polarization ◽

Healthy Donors ◽

And Function

Abstract Abstract The polarization of macrophages plays a critical role in the pathophysiology of rheumatoid arthritis. The polarization states include pro-inflammatory M1 polarization and various alternative anti-inflammatory M2 polarization. Our preliminary results showed that CDKN2B-AS1/MIR497/TXNIP axis might play a role in macrophages extracted from rheumatoid arthritis patients. Therefore, we hypothesized that this axis regulated the polarization of rheumatoid macrophages. Flow cytometry was used to determine the surface polarization markers in M1 or M2 macrophages from healthy donors and rheumatoid arthritis patients. QPCR and western blotting were used to compare the expression of the CDKN2B-AS1/MIR497/TXNIP axis in these macrophages. We interfered with the expression and function of the axis from upstream to downstream in the macrophage cell line MD to test its roles in macrophage polarization. Compared to cells from healthy donors, cells from rheumatoid arthritis patients expressed a higher level of CD40 and CD80 and a lower level of CD16, CD163, CD206, and CD200R after polarization, they also expressed higher CDKN2B-AS1, lower MIR497, and higher TXNIP. In macrophages from healthy donors, there was no correlation among CDKN2B-AS1, MIR497, and TXNIP. But in macrophages patients, they showed significant correlations. The CDKN2B-AS1 knockdown, MIR497 mimics suppressed M1 polarization but promoted M2 polarization in MD cells, while MIR497 knockdown and TXNIP overexpression did the opposite. This study demonstrated that elevated CDKN2B-AS1 in macrophages promotes M1 polarization and inhibits M2 polarization of macrophage by negatively regulating MIR497, thereby upregulated the expression of TXNIP.

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Inhibition of a Novel CLK1-THRAP3-PPARγ Axis Improves Insulin Sensitivity

Frontiers in Physiology ◽

10.3389/fphys.2021.699578 ◽

2021 ◽

Vol 12 ◽

Author(s):

Zhenguo Wang ◽

Xiaojing Gao ◽

Qingrun Li ◽

Hongwen Zhu ◽

Xiangjie Zhao ◽

...

Keyword(s):

Adipose Tissue ◽

Insulin Sensitivity ◽

Energy Expenditure ◽

Cold Exposure ◽

Thyroid Hormone Receptor ◽

Critical Role ◽

Peroxisome Proliferator ◽

Peroxisome Proliferator Activated Receptor ◽

Receptor Associated Protein ◽

Brown Adipose

Increasing energy expenditure by promoting “browning” in adipose tissues is a promising strategy to prevent obesity and associated diabetes. To uncover potential targets of cold exposure, which induces energy expenditure, we performed phosphoproteomics profiling in brown adipose tissue of mice housed in mild cold environment at 16°C. We identified CDC2-like kinase 1 (CLK1) as one of the kinases that were significantly downregulated by mild cold exposure. In addition, genetic knockout of CLK1 or chemical inhibition in mice ameliorated diet-induced obesity and insulin resistance at 22°C. Through proteomics, we uncovered thyroid hormone receptor-associated protein 3 (THRAP3) as an interacting partner of CLK1, further confirmed by co-immunoprecipitation assays. We further demonstrated that CLK1 phosphorylates THRAP3 at Ser243, which is required for its regulatory interaction with phosphorylated peroxisome proliferator-activated receptor gamma (PPARγ), resulting in impaired adipose tissue browning and insulin sensitivity. These data suggest that CLK1 plays a critical role in controlling energy expenditure through the CLK1-THRAP3-PPARγ axis.

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Polarization of rheumatoid macrophages is regulated by the CDKN2B-AS1/ MIR497/TXNIP axis

10.21203/rs.3.rs-701830/v1 ◽

2021 ◽

Author(s):

JianZhong Xu

Keyword(s):

Rheumatoid Arthritis ◽

Macrophage Polarization ◽

Critical Role ◽

Macrophage Cell Line ◽

Macrophage Cell ◽

Surface Polarization ◽

M2 Polarization ◽

M1 Polarization ◽

Healthy Donors ◽

And Function

Abstract The polarization of macrophages plays a critical role in the pathophysiology of rheumatoid arthritis. The polarization states include pro-inflammatory M1 polarization and various alternative anti-inflammatory M2 polarization. Our preliminary results showed that CDKN2B-AS1/MIR497/TXNIP axis might play a role in macrophages extracted from rheumatoid arthritis patients. Therefore, we proposed that this axis regulated the polarization of rheumatoid macrophages. Flow cytometry was used to determine the surface polarization markers in M1 or M2 macrophages from healthy donors and rheumatoid arthritis patients. QPCR and western blotting were used to compare the expression of CDKN2B-AS1/MIR497/TXNIP axis in these macrophages. We interfered with the expression and function of the CDKN2B-AS1/ MIR497/TXNIP axis from upstream to downstream in the macrophage cell line MD to test its roles in macrophage polarization. Compared to cells from healthy donors, cells from rheumatoid arthritis patients expressed a higher level of CD40 and CD80 and a lower level of CD16, CD163, CD206, and CD200R after polarization, they also expressed higher CDKN2B-AS1, lower MIR497, and higher TXNIP. In macrophages from healthy donors, there was no correlation among CDKN2B-AS1, MIR497, and TXNIP. But in macrophages patients, they showed significant correlations. The CDKN2B-AS1 knockdown, MIR497 mimics suppressed M1 polarization but promoted M2 polarization in MD cells, while MIR497 knockdown and TXNIP overexpression did the opposite. Elevated CDKN2B-AS1 in macrophages promotes M1 polarization and inhibits M2 polarization of macrophage by negative regulating MIR497, thereby upregulated the expression of TXNIP.

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