The induction of brown-like adipocyte development in white adipose tissue (WAT) confers numerous metabolic benefits by decreasing adiposity and increasing energy expenditure. Therefore, WAT browning has gained considerable attention for its potential to reverse obesity and its associated co-morbidities. However, this perspective has been tainted by recent studies identifying the detrimental effects of inducing WAT browning. This review aims to highlight the adverse outcomes of both overactive and underactive browning activity, the harmful side effects of browning agents, as well as the molecular brake-switch system that has been proposed to regulate this process. Developing novel strategies that both sustain the metabolic improvements of WAT browning and attenuate the related adverse side effects is therefore essential for unlocking the therapeutic potential of browning agents in the treatment of metabolic diseases.
Adipocytes, Beige ; cytology ; Adipose Tissue, Brown ; cytology ; metabolism ; Adipose Tissue, White ; cytology ; Aging ; metabolism ; Animals ; Humans

Brown adipose tissue (BAT) is a specialized thermoregulatory organ that has a critical role in the regulation of energy metabolism. Specifically, energy expenditure can be enhanced by the activation of BAT function and the induction of a BAT-like catabolic phenotype in white adipose tissue (WAT). Since the recent recognition of metabolically active BAT in adult humans, BAT has been extensively studied as one of the most promising targets identified for treating obesity and its related disorders. In this review, we summarize information on the developmental origin of BAT and the progenitors of brown adipocytes in WAT. We explore the transcriptional control of brown adipocyte differentiation during classical BAT development and in WAT browning. We also discuss the neuronal control of BAT activity and summarize the recently identified non-canonical stimulators of BAT that can act independently of beta-adrenergic stimulation. Finally, we review new findings on the beneficial effects of BAT activation and development with respect to improving metabolic profiles. We highlight the therapeutic potential of BAT and its future prospects, including pharmacological intervention and cell-based therapies designed to enhance BAT activity and development.
Adipocytes/cytology/metabolism ; Adipogenesis ; Adipose Tissue, Brown/cytology/metabolism/*physiology ; Animals ; Humans ; Obesity/therapy

Adipose tissue contains a population of multipotent cells called adipose-derived stem cells (ADSCs). With the similar properties of marrow-derived mesenchymal stem cells, ADSCs have the ability to differentiate differentiate towards adipogenic, osteogenic, chondrogenic, myogenic, endothelial, hematopoietic, hepatic, islet, and neurogenic cell lineages. As adipose tissue in harvested in large amounts with minimal morbidity, it can be widely used in tissue engineering, organ repair and gene therapy. This paper focused on the plasticity of ADSCs and reviewed the new advances of this field. Finally, the problems and prospect for application was also discussed.
Adipose Tissue ; cytology ; metabolism ; Animals ; Antigens, CD ; metabolism ; Cell Culture Techniques ; Cell Differentiation ; Genetic Therapy ; Humans ; Multipotent Stem Cells ; cytology ; metabolism ; Stem Cells ; cytology ; metabolism ; Tissue Engineering

OBJECTIVETo explore the possibility of building tissue-engineered adipose tissue and looking for a new approach for the repair of soft tissue defects.

METHODSThe cells using enzymatic digestion from human liposuction part of the lipid extract were used as adipose tissue-derived cells and labeled with DiI fluorescent marker, the induced group using I collagen scaffold material as a carrier, the induced cell were planted into left back subcutaneously in nude mice at 1 x 10(7)/ml cell density, in the uninduced group cells were not induced by any, in the same cell density and type I collagen scaffold composite inoculated in nude right mouse back skin, the blank control group I collagen scaffold gaps in nude mice inoculated subcutaneously center of the neck, each of the six mice; Remove implants after 12 weeks and judge the adipogenic capacity through general and fluorescence microscopy, wet - determination, histological detection and oil red O staining qualitative.

RESULTSThe primary source of fat cultured stem cells, similar to the fibroblast morphology, and has a strong proliferative capacity. In the role of adipose differentiation medium, it can be the mature fat cells in which cytoplasmic lipid droplets gather, oil red O staining was positive. In the induced group, newborn tissue were found in the experimental groups of nude mice and its average weight is about 0.020 g. Conventional pathological slices and oil red O staining confirmed it is mature adipose tissue, the fluorescence staining positive confirm them are exogenous. Uninduced group newborn tissue are found in the experimental groups of nude mice and its average weight is about 0.014 g. Conventional pathological slices and oil red O staining confirmed it include some mature adipose tissue, the fluorescence staining positive confirm them are exogenous. Two groups of the new wet weight with have statistical significance (P < 0.01); gaps in the control group no new organization formed.

CONCLUSIONSThe cells using enzymatic digestion from human liposuction part of the lipid extract are adipose tissue-derived cells. The cells can be as seed cells and with solid scaffold of collagen type I it can become fat tissue in vivo successfully.

Adipose Tissue ; cytology ; metabolism ; Animals ; Cell Culture Techniques ; Collagen Type I ; biosynthesis ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Stem Cells ; cytology ; Tissue Engineering ; methods ; Tissue Scaffolds

OBJECTIVETo isolate human adipose tissue-derived stromal cells and study the potential of osteogenic differentiation after inductive culture.

METHODSLiposuction human adipose tissues were minced and digested with collagenase type I. The obtained stromal cells were plated in BGJb medium as primary culture for ten days. The second passage cells were harvested and plated in DMEM/F12 medium supplemented with 10% FBS, 5% horse serum and 50 micromol/L hydrocortisone for myogenic induction culture. The cell-anchored slips were removed and fixed in 4% formaldehydam polymerisatum. Toluidine blue, Mallory's phosphotungstic hematoxylin staining and monoclonal antibody to human skeletal muscle myosin heavy chain immunocytochemical methods were used to assay the differentiation of cells.

RESULTSIt was observed that the size and shape of induced cells were much different from those of non-induced cells. Toluidine blue, Mallory's phosphotungstic hematoxylin staining demonstrated there were many basophilic striations within cytoplasm and multinucleated myotubes were formed. Immunocytochemical stain indicated that characterastic skeletal myosin heavy chain was positive in myogenic induced cells.

CONCLUSIONIt seems that human adipose tissue represents an abundant reservoir of adult stem cells that have multi-germline potential to differentiate into myoblasts. Adipose tissue derived stromal cells will be another alternative source for cell-based tissue engineering in skeletal muscle reconstruction.

Adipose Tissue ; cytology ; Adult Stem Cells ; cytology ; Cell Differentiation ; Cell Separation ; Cells, Cultured ; Culture Media ; Humans ; Myoblasts ; cytology ; Myosin Heavy Chains ; metabolism ; Stromal Cells ; cytology

Diabetes mellitus is a complex metabolic disorder characterized by chronic hyperglycemia due to absolute or relative lack of insulin. Though great efforts have been made to investigate the pathogenesis of diabetes, the underlying mechanism behind the development of diabetes and its complications remains unexplored. Cumulative evidence has linked mitochondrial modification to the pathogenesis of diabetes and its complications and they are also observed in various tissues affected by diabetes. Proteomics is an attractive tool for the study of diabetes since it allows researchers to compare normal and diabetic samples by identifying and quantifying the differentially expressed proteins in tissues, cells or organelles. Great progress has already been made in mitochondrial proteomics to elucidate the role of mitochondria in the pathogenesis of diabetes and its complications. Further studies on the changes of mitochondrial protein specifically post-translational modifications during the diabetic state using proteomic tools, would provide more information to better understand diabetes.
Adipose Tissue ; metabolism ; Diabetes Complications ; Diabetes Mellitus ; metabolism ; pathology ; Humans ; Insulin ; metabolism ; Insulin-Secreting Cells ; cytology ; metabolism ; Liver ; metabolism ; Mitochondria ; metabolism ; Muscle, Skeletal ; metabolism ; Proteome ; metabolism ; Proteomics

OBJECTIVETo explore the effect of N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide(W7) on the differentiation from human adipose-derived mesenchymal stem cells (hADSCs) to endothelial cells.

METHODShADSCs were cultured with serum-free differential medium containing 40 ng/ml vascular endothelial growth factor (VEGF) and 10ng/ml basic fibroblast growth factor (bFGF). Cells were divided into control group (differential medium without W7), high-dose group (containing 30 μmol/L W7), medium-dose group (containing 20 μmol/L W7), and low-dose group ( containing 10 μmol/L W7). The hADSCs were cultured for 8 days, and then the changes in the phenotypes of von Willebrand factor (vWF) and vessel-selective cadherin (VE-Cadherin) were detected by flow cytometry (FCM). The intracellular Ca(2+) labeled with Fluo-3 was detected by laser confocal microscopy. After hADSCs planting on Matrigel, their angiogenic potentials were observed under the inverted phase contrast microscope, and the expression of extracellular regulated kinase (ERK) and phosphorylated extracellular regulated kinase (p-ERK) were evaluated by Western blot.

RESULTSAfter the hADSCs were cultured for 8 days, compared with the control group, the expressions of vWF and VE-Cadherin significantly increased along with the decrease of W7 level and the intracellular Ca(2+) also significantly increased (Pü0.01). Lumina-like vascular structure was formed in W7 treatment groups, but not in the blank control group. Compared with the blank control group, the expression of ERK showed no significant in W7 treatment groups (high-, medium-, and low-dose groups)(P>0.05); however, along with the decrease of W7 levels, the expression of p-ERK significantly increased(P<0.05).

CONCLUSIONW7 in proper levels can effectively induce the differentiation from hADSCs to endothelium by increasing the intracellular Ca(2+) level and thus activating the ERK/MAPK pathway.

Adipose Tissue ; cytology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Endothelial Cells ; cytology ; drug effects ; metabolism ; Humans ; Mesenchymal Stromal Cells ; cytology ; drug effects ; metabolism ; Sulfonamides ; pharmacology

OBJECTIVETo investigate whether adipose-derived stem cells (ADSCs) induced by retinoic acid (RA) in vitro express primordial germ cell marker alkaline phosphatase (ALP) and vasa.

METHODSADSCs were isolated from adult female SD rats and cultured in vitro. The third passage of ADSCs was identified by adipogenic differentiation, osteogenic differentiation and cell surface marker detection. The ADSCs were treated with 1×10(-5), 1×10(-6), or 1×10(-7) mol/L RA for 7 or 14 days, and the cellular expression of ALP was detected. vasa mRNA expression in ADSCs treated with 1×10(-5) mol/L RA for 7 days was detected using RT-PCR.

RESULTSThe OD value of ADSCs treated with 1×10(-5), 1×10(-6), or 1×10(-7) mol/L RA was 0.59∓0.04, 0.27∓0.07, and 0.15∓0.03 after a 7-day treatment, and was 0.42∓0.02, 0.34∓0.01, and 0.19∓0.02 after a 14-day treatment, respectively, demonstrating significantly enhanced ALP expression in RA-treated ADSCs compared with that in the control cells (0.07∓0.01 and 0.07∓0.01 at 7 and 14 days, respectively, P<0.01). The ADSCs showed a negative vasa mRNA expression after 1×10(-5) mol/L RA treatment for 7 days.

CONCLUSIONRA-induced ADSCs express ALP, a marker of primordial germ cells, but does not express the primordial germ cell marker vasa.

Adipose Tissue ; cytology ; Adult Stem Cells ; cytology ; enzymology ; Alkaline Phosphatase ; metabolism ; Animals ; Cell Differentiation ; Cells, Cultured ; Female ; Germ Cells ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tretinoin ; pharmacology

BACKGROUNDSeveral studies have revealed that adipose-derived mesenchymal stem cells (ADSCs) can be used as seed cells for the treatment of spinal cord injury (SCI). Chondroitinase ABC (ChABC) decomposes chondroitin sulfate proteoglycans in the glial scar that forms following SCI, allowing stem cells to penetrate through the scar and promote recovery of nerve function. This study aimed to establish ADSCs that stably express ChABC (ChABC-ADSCs) and evaluate the migratory capability of ChABC-ADSCs in vitro.

METHODSADSCs were obtained from Sprague-Dawley rats using secondary collagenase digestion. Their phenotypes were characterized using flow cytometry detection of cell surface antigens and their stem cell properties were confirmed by induction of differentiation. After successful culture, ADSCs were transfected with lentiviral vectors and ChABC-ADSCs were obtained. Proliferation curves of ChABC-ADSCs were determined using the Cell Counting Kit-8 method, ChABC expression was verified using Western blotting, and the migration of ChABC-ADSCs was analyzed using the transwell assay.

RESULTSSecondary collagenase digestion increased the isolation efficiency of primary ADSCs. Following transfection using lentiviral vectors, the proliferation of ChABC-ADSCs was reduced in comparison with control ADSCs at 48 h (P < 0.05). And the level of ChABC expression in the ChABC-ADSC group was significantly higher than that of the ADSC group (P < 0.05). Moreover, ChABC-ADSC migration in matrigel was significantly enhanced in comparison with the control (P < 0.05).

CONCLUSIONSSecondary collagenase digestion can be used to effectively isolate ADSCs. ChABC-ADSCs constructed using lentiviral vector transfection stably express ChABC, and ChABC expression significantly enhances the migratory capacity of ADSCs.

Adipocytes ; cytology ; metabolism ; Adipose Tissue ; cytology ; Animals ; Cell Differentiation ; physiology ; Cell Movement ; physiology ; Cell Proliferation ; physiology ; Cells, Cultured ; Chondrocytes ; cytology ; metabolism ; Chondroitin ABC Lyase ; metabolism ; Flow Cytometry ; Male ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Osteoblasts ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley

Mesenchymal stem cells (MSCs) are attractive candidates for clinical repair or regeneration of damaged tissues. Oct4 and Sox2, which are essential transcription factors for pluripotency and self-renewal, are naturally expressed in MSCs at low levels in early passages, and their levels gradually decrease as the passage number increases. Therefore, to improve MSC proliferation and stemness, we introduced human Oct4 and Sox2 for conferring higher expansion and differentiation capabilities. The Oct4-IRES-Sox2 vector was transfected into human adipose tissue MSCs (ATMSCs) by liposomal transfection and used directly. Oct4 and Sox2 were successfully transfected into ATMSCs, and we confirmed maintenance of MSC surface markers without alterations in both red fluorescent protein (RFP) (control) and Oct4/Sox2-ATMSCs. Enhanced proliferative activity of Oct4/Sox2-ATMSCs was shown by WST-1 assay, and this result was further confirmed by cell counting using trypan blue exclusion for a long period. In addition, FACs cell cycle analysis showed that there was a reduction in the fraction of Oct4/Sox2-ATMSCs in G1 with a concomitant increase in the fraction of cells in S, compared with RFP-ATMSCs. Increased levels of cyclin D1 were also seen in Oct4/Sox2-ATMSCs, indicating acceleration in the transition of cells from G1 to S phase. Furthermore, Oct4/Sox2-overexpressing ATMSCs showed higher differentiation abilities for adipocytes or osteoblasts than controls. The markers of adipogenic or osteogenic differentiation were also upregulated by Oct4/Sox2 overexpression. The improvement in cell proliferation and differentiation using Oct4/Sox2 expression in ATMSCs may be a useful method for expanding the population and increasing the stemness of ATMSCs.
Adipose Tissue/cytology ; *Cell Differentiation ; *Cell Proliferation ; Cells, Cultured ; Humans ; Mesenchymal Stromal Cells/cytology/*metabolism/physiology ; Octamer Transcription Factor-3/genetics/*metabolism ; SOXB1 Transcription Factors/genetics/*metabolism