Scd1 controls de novo beige fat biogenesis through succinate-dependent regulation of mitochondrial complex II

Preadipocytes can give rise to either white adipocytes or beige adipocytes. Owing to their distinct abilities in nutrient storage and energy expenditure, strategies that specifically promote “beiging” of adipocytes hold great promise for counterbalancing obesity and metabolic diseases. Yet, factors dictating the differentiation fate of adipocyte progenitors remain to be elucidated. We found that stearoyl-coenzyme A desaturase 1 (Scd1)-deficient mice, which resist metabolic stress, possess augmentation in beige adipocytes under basal conditions. Deletion of Scd1 in mature adipocytes expressing Fabp4 or Ucp1 did not affect thermogenesis in mice. Rather, Scd1 deficiency shifted the differentiation fate of preadipocytes from white adipogenesis to beige adipogenesis. Such effects are dependent on succinate accumulation in adipocyte progenitors, which fuels mitochondrial complex II activity. Suppression of mitochondrial complex II by Atpenin A5 or oxaloacetic acid reverted the differentiation potential of Scd1-deficient preadipocytes to white adipocytes. Furthermore, supplementation of succinate was found to increase beige adipocyte differentiation both in vitro and in vivo. Our data reveal an unappreciated role of Scd1 in determining the cell fate of adipocyte progenitors through succinate-dependent regulation of mitochondrial complex II.

Download Full-text

A regulatory network of microRNAs confers lineage commitment during early developmental trajectories of B and T lymphocytes

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2104297118 ◽

2021 ◽

Vol 118 (46) ◽

pp. e2104297118

Author(s):

Sameena Nikhat ◽

Anurupa D. Yadavalli ◽

Arpita Prusty ◽

Priyanka K. Narayan ◽

Dasaradhi Palakodeti ◽

...

Keyword(s):

Gene Expression ◽

T Lymphocytes ◽

Cell Fate ◽

T Lymphocyte ◽

De Novo ◽

Gene Expression Pattern ◽

Lymphocyte Development ◽

Motif Analysis ◽

Differentiation Potential ◽

B And T Lymphocytes

The commitment of hematopoietic multipotent progenitors (MPPs) toward a particular lineage involves activation of cell type–specific genes and silencing of genes that promote alternate cell fates. Although the gene expression programs of early–B and early–T lymphocyte development are mutually exclusive, we show that these cell types exhibit significantly correlated microRNA (miRNA) profiles. However, their corresponding miRNA targetomes are distinct and predominated by transcripts associated with natural killer, dendritic cell, and myeloid lineages, suggesting that miRNAs function in a cell-autonomous manner. The combinatorial expression of miRNAs miR-186-5p, miR-128-3p, and miR-330-5p in MPPs significantly attenuates their myeloid differentiation potential due to repression of myeloid-associated transcripts. Depletion of these miRNAs caused a pronounced de-repression of myeloid lineage targets in differentiating early–B and early–T cells, resulting in a mixed-lineage gene expression pattern. De novo motif analysis combined with an assay of promoter activities indicates that B as well as T lineage determinants drive the expression of these miRNAs in lymphoid lineages. Collectively, we present a paradigm that miRNAs are conserved between developing B and T lymphocytes, yet they target distinct sets of promiscuously expressed lineage-inappropriate genes to suppress the alternate cell-fate options. Thus, our studies provide a comprehensive compendium of miRNAs with functional implications for B and T lymphocyte development.

Download Full-text

Breaking BAT: can browning create a better white?

Journal of Endocrinology ◽

10.1530/joe-15-0408 ◽

2015 ◽

Vol 228 (1) ◽

pp. R19-R29 ◽

Cited By ~ 24

Author(s):

Amy Warner ◽

Jens Mittag

Keyword(s):

Energy Expenditure ◽

Metabolic Diseases ◽

Uncoupling Protein ◽

Whole Body ◽

Direct Stimulation ◽

White Adipocytes ◽

Beige Adipocytes ◽

Beige Fat ◽

Underlying Mechanisms ◽

Body Energy

Obesity and its comorbidities are a growing problem worldwide. In consequence, several new strategies have been proposed to promote weight loss and improve insulin sensitivity. Recently, it has been demonstrated that certain populations of white adipocytes can be ‘browned’, i.e., recruited to a more brown-like adipocyte, capable of thermogenesis through increased expression of uncoupling protein 1. The list of browning agents that induce these so-called beige adipocytes is growing constantly. However, the underlying mechanisms are often poorly understood, with the possibility that some of these agents cause browning as a secondary effect. Moreover, it remains unclear whether beige adipocytes can contribute sufficiently to affect whole-body energy expenditure in a functionally significant manner. This review presents an overview of the different molecular pathways leading to the induction of beige fat, including direct stimulation and indirect actions on the CNS or the immune system. We discuss the available evidence on the capacity of beige adipocytes to influence whole-body energy expenditure in rodents, and lastly outline the potential problems of translating browning capacity into the potential treatment of human metabolic diseases.

Download Full-text

Human adipocyte differentiation and composition of disease-relevant lipids are regulated by miR-221-3p

10.1101/2020.06.30.180083 ◽

2020 ◽

Author(s):

Maria A. Ahonen ◽

Muhammad Yasir Asghar ◽

Suvi J. Parviainen ◽

Gerhard Liebisch ◽

Marcus Höring ◽

...

Keyword(s):

Gene Expression ◽

Cancer Progression ◽

Adipocyte Differentiation ◽

Metabolic Diseases ◽

De Novo ◽

Terminal Differentiation ◽

Adaptor Protein ◽

Atp Citrate Lyase ◽

White Adipocytes ◽

Lipidome Analysis

AbstractMicroRNA-221-3p (miR-221-3p) is associated with both metabolic diseases and cancers. However, its role in terminal adipocyte differentiation, adipocyte lipid metabolism, and lipid signaling in human disease are uncharacterized. miR-221-3p or its inhibitor were transfected into differentiating or mature human adipocytes. Triglyceride (TG) content and adipogenic gene expression were monitored, global lipidome analysis was carried out, and mechanisms underlying the effects of miR-221-3p were investigated. Finally, cross-talk between miR-221-3p expressing adipocytes and MCF-7 breast carcinoma (BC) cells was studied, and miR-221-3p expression in tumor-proximal adipose biopsies from BC patients analyzed. miR-221-3p overexpression inhibited terminal differentiation of adipocytes, as judged from reduced TG storage and gene expression of the adipogenic markers SCD1, GLUT4, FAS, DGAT1/2, AP2, ATGL and AdipoQ. The signaling adaptor protein 14-3-3γ was identified as a potential mediator of the miR-221-3p effects. Importantly, miR-221-3p overexpression inhibited de novo lipogenesis but increased the concentrations of ceramides and sphingomyelins, while reducing diacylglycerols, concomitant with suppression of sphingomyelin phosphodiesterase, ATP citrate lyase, and acid ceramidase. miR-221-3p expression was elevated in tumor proximal adipose tissue from patients with invasive BC. Conditioned medium of miR-221-3p overexpressing adipocytes stimulated the invasion and proliferation of BC cells, while medium of the BC cells enhanced miR-221-3p expression in adipocytes. miR-221-3p plays a pivotal role in the terminal differentiation of white adipocytes and their lipid composition. Elevated miR-221-3p impairs adipocyte lipid storage and differentiation, and modifies their ceramide, sphingomyelin, and diacylglycerol content. These alterations are relevant for metabolic diseases but may also affect cancer progression.

Download Full-text

Critical review of beige adipocyte thermogenic activation and contribution to whole-body energy expenditure

Hormone Molecular Biology and Clinical Investigation ◽

10.1515/hmbci-2017-0042 ◽

2017 ◽

Vol 31 (2) ◽

Cited By ~ 8

Author(s):

Érique Castro ◽

Tiago E. Oliveira Silva ◽

William T. Festuccia

Keyword(s):

Energy Expenditure ◽

Metabolic Diseases ◽

Uncoupling Protein ◽

Whole Body ◽

Beige Adipocyte ◽

White Adipocytes ◽

Beige Adipocytes ◽

Whole Body Metabolism ◽

Beige Cells ◽

Body Energy

AbstractBeige (or brite, “brown in white”) adipocytes are uncoupling protein 1 (UCP1)-positive cells residing in white adipose depots that, depending on the conditions, behave either as classic white adipocytes, storing energy as lipids, or as brown adipocytes, dissipating energy from oxidative metabolism as heat through non-shivering thermogenesis. Because of their thermogenic potential and, therefore, possible usage to treat metabolic diseases such as obesity and type 2 diabetes, beige cells have attracted the attention of many scientists worldwide aiming to develop strategies to safely recruit and activate their thermogenic activity. Indeed, in recent years, a large variety of conditions, molecules (including nutrients) and signaling pathways were reported to promote the recruitment of beige adipocytes. Despite of those advances, the true contribution of beige adipocyte thermogenesis to whole-body energy expenditure is still not completely defined. Herein, we discuss some important aspects that should be considered when studying beige adipocyte biology and the contribution to energy balance and whole-body metabolism.

Download Full-text

Enhancement of the Antiobesity and Antioxidant Effect of Purple Sweet Potato Extracts and Enhancement of the Effects by Fermentation

Antioxidants ◽

10.3390/antiox10060888 ◽

2021 ◽

Vol 10 (6) ◽

pp. 888

Author(s):

Seul Gi Lee ◽

Jongbeom Chae ◽

Dong Se Kim ◽

Jung-Bok Lee ◽

Gi-Seok Kwon ◽

...

Keyword(s):

Sweet Potato ◽

Ipomoea Batatas ◽

Radical Scavenging ◽

The Body ◽

Brown Adipocyte ◽

Obese Mice ◽

Adipose Tissues ◽

White Adipocytes ◽

Beige Adipocytes ◽

Purple Sweet Potato

The browning of white adipocytes, which transforms energy-storing white adipocytes to heat-producing beige adipocytes, is considered a strategy against metabolic diseases. Several dietary compounds, such as anthocyanins, flavonoids, and phenolic acids, induce a brown adipocyte-like phenotype in white adipocytes. In this study, we demonstrated that purple sweet potato (Ipomoea batatas) extract (PSP) exhibited potent radical scavenging activity. In addition, PSP was found to contain large amounts of phenolic, flavonoid, and anthocyanin compounds; the amount of these compounds was affected by fermentation. Functionally, PSP-induced adipose browning in high-fat-diet (HFD)-induced obese mice. The administration of PSP significantly suppressed the body weight gain and abnormal expansion of white adipose tissues in the obese mice. The expression of adipose browning-related genes was higher in the inguinal white adipose tissues from the PSP-treated mice than those in the HFD-fed mice. Moreover, PSP-treated 3T3-L1 adipocytes formed multilocular lipid droplets, similar to those formed in the 3T3-L1 adipocytes treated with a browning induction cocktail. The PSP-treated cells had an increased expression level of mitochondria and lipolysis-related genes. The browning effects of PSP were enhanced by fermentation with Lactobacillus. This study, to our knowledge, is the first to identify a new mechanism to increase the antiobesity effects of PSP by inducing adipocyte browning of adipocytes.

Download Full-text

The effects of locomotion on bone marrow mesenchymal stem cell fate: insight into mechanical regulation and bone formation

Cell & Bioscience ◽

10.1186/s13578-021-00601-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yuanxiu Sun ◽

Yu Yuan ◽

Wei Wu ◽

Le Lei ◽

Lingli Zhang

Keyword(s):

Bone Marrow ◽

Cell Fate ◽

Differentiation Potential ◽

Stem Cell Fate ◽

Proliferation And Differentiation ◽

Marrow Mesenchymal Stem Cells ◽

Adipocytic Differentiation ◽

Regulatory Effects ◽

Insight Into ◽

Mechanical Regulation

AbstractBone marrow mesenchymal stem cells (BMSCs) refer to a heterogeneous population of cells with the capacity for self-renewal. BMSCs have multi-directional differentiation potential and can differentiate into chondrocytes, osteoblasts, and adipocytes under specific microenvironment or mechanical regulation. The activities of BMSCs are closely related to bone quality. Previous studies have shown that BMSCs and their lineage-differentiated progeny (for example, osteoblasts), and osteocytes are mechanosensitive in bone. Thus, a goal of this review is to discuss how these ubiquious signals arising from mechanical stimulation are perceived by BMSCs and then how the cells respond to them. Studies in recent years reported a significant effect of locomotion on the migration, proliferation and differentiation of BMSCs, thus, contributing to our bone mass. This regulation is realized by the various intersecting signaling pathways including RhoA/Rock, IFG, BMP and Wnt signalling. The mechanoresponse of BMSCs also provides guidance for maintaining bone health by taking appropriate exercises. This review will summarize the regulatory effects of locomotion/mechanical loading on BMSCs activities. Besides, a number of signalling pathways govern MSC fate towards osteogenic or adipocytic differentiation will be discussed. The understanding of mechanoresponse of BMSCs makes the foundation for translational medicine.

Download Full-text

Bone marrow stromal cells from MDS and AML patients show increased adipogenic potential with reduced Delta-like-1 expression

Scientific Reports ◽

10.1038/s41598-021-85122-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Marie-Theresa Weickert ◽

Judith S. Hecker ◽

Michèle C. Buck ◽

Christina Schreck ◽

Jennifer Rivière ◽

...

Keyword(s):

Bone Marrow ◽

Cell Fate ◽

Stromal Cells ◽

Adipogenic Differentiation ◽

Cell Types ◽

Bone Marrow Niche ◽

Differentiation Potential ◽

Hematopoietic Stem ◽

Bm Niche

AbstractMyelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are clonal hematopoietic stem cell disorders with a poor prognosis, especially for elderly patients. Increasing evidence suggests that alterations in the non-hematopoietic microenvironment (bone marrow niche) can contribute to or initiate malignant transformation and promote disease progression. One of the key components of the bone marrow (BM) niche are BM stromal cells (BMSC) that give rise to osteoblasts and adipocytes. It has been shown that the balance between these two cell types plays an important role in the regulation of hematopoiesis. However, data on the number of BMSC and the regulation of their differentiation balance in the context of hematopoietic malignancies is scarce. We established a stringent flow cytometric protocol for the prospective isolation of a CD73+ CD105+ CD271+ BMSC subpopulation from uncultivated cryopreserved BM of MDS and AML patients as well as age-matched healthy donors. BMSC from MDS and AML patients showed a strongly reduced frequency of CFU-F (colony forming unit-fibroblast). Moreover, we found an altered phenotype and reduced replating efficiency upon passaging of BMSC from MDS and AML samples. Expression analysis of genes involved in adipo- and osteogenic differentiation as well as Wnt- and Notch-signalling pathways showed significantly reduced levels of DLK1, an early adipogenic cell fate inhibitor in MDS and AML BMSC. Matching this observation, functional analysis showed significantly increased in vitro adipogenic differentiation potential in BMSC from MDS and AML patients. Overall, our data show BMSC with a reduced CFU-F capacity, and an altered molecular and functional profile from MDS and AML patients in culture, indicating an increased adipogenic lineage potential that is likely to provide a disease-promoting microenvironment.

Download Full-text