To characterize the timeliness of β3 adrenergic receptor agonist CL316,243-induced browning of white adipose tissues in mice.
 Methods: Male C57BL/6J mice at 10 weeks of age were housed in conventional cages and given sterile saline for the control group or CL316,243 (1 μg/g) for the experimental group via intraperitoneal injection for 1, 3, and 5 days. Food intake and body weight were measured daily. Interscapular brown adipose tissue (iBAT), inguinal subcutaneous white adipose (sWAT) and epididymal white adipose tissue (eWAT) were harvested for histological and gene expression analysis.
 Results: Compared with the control group, intraperitoneal injection of CL316,243 reduced the weight of eWAT on the first day. Meanwhile, CL316,243 continuously promoted the mRNA and protein expression of uncoupling protein-1 (UCP-1) in sWAT and eWAT. Furthermore, CL316,243 injection significantly decreased the food intake and weight gain of the mice, and reduced the diameter of adipocyte and accumulation of small lipid droplets in adipose tissues.
 Conclusion: CL316,243 can induce the brown-like remodeling in adipose tissues of mice in vivo, which show different time-dependent manners in different adipose tissues.
Adipose Tissue, Brown ; Adipose Tissue, White ; Adrenergic beta-Agonists ; Animals ; Male ; Mice ; Mice, Inbred C57BL ; Uncoupling Protein 1

β3-adrenergic agonists induce adaptive thermogenesis and promote beiging of white fat. However, it remains unclear which metabolites mediate the stimulatory effects of β3-adrenergic agonists on thermogenesis of brown and beige fat. In this study, adipose tissue was isolated from 8-week-old C57/BL6J male mice by intraperitoneal administration of β3-adrenergic agonist CL316,243 for RNA-Seq, which revealed that histidine decarboxylase, a key enzyme in histamine synthesis, was strongly induced in adipose by CL316,243. Therefore, we speculated that histamine might be involved in the process of thermogenesis in adipose tissue. We determined the physiological role and mechanism by which histamine promotes fat thermogenesis by intravenous administering histamine to C57BL/6J mice fed a normal or a high-fat diet. The results showed that intravenous injection of histamine into C57BL/6J mice fed a normal diet stimulated the expression of thermogenic genes, including peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and uncoupling protein 1 (UCP1), in brown adipose tissue (BAT) and inguinal white adipose tissue (iWAT). H&E staining also suggested that histamine treatment decreased the size of lipid droplets in adipocytes. Moreover, histamine treatment also enhanced thermogenesis of fat in high-fat diet induced obese mice, and improved glucose intolerance and fatty liver phenotype. Finally, we demonstrated that the effects of histamine on the thermogenic program were cell autonomous. Our data suggest that histamine may mediate the effects of β3-adrenergic agonists on thermogenesis of fat.
Adipose Tissue, Beige ; Adipose Tissue, Brown ; Animals ; Histamine ; Male ; Mice ; Mice, Inbred C57BL ; Thermogenesis ; Uncoupling Protein 1/genetics*

The aim of the present study was to investigate the effects of short-term ketogenic diet on the low temperature tolerance of mice and the involvement of peroxisome proliferator-activated receptor α (PPARα). C57BL/6J mice were divided into two groups: normal diet (WT+ND) group and ketogenic diet (WT+KD) group. After being fed with normal or ketogenic diet at room temperature for 2 d, the mice were exposed to 4 °C low temperature for 12 h. The changes in core temperature, blood glucose, blood pressure of mice under low temperature condition were detected, and the protein expression levels of PPARα and mitochondrial uncoupling protein 1 (UCP1) were detected by Western blot. PPARα knockout mice were divided into normal diet (PPARα^-/-+ND) group and ketogenic diet (PPARα^-/-+KD) group. After being fed with the normal or ketogenic diet at room temperature for 2 d, the mice were exposed to 4 °C low temperature for 12 h. The above indicators were also detected. The results showed that, at room temperature, the protein expression levels of PPARα and UCP1 in liver and brown adipose tissue of WT+KD group were significantly up-regulated, compared with those of WT+ND group. Under low temperature condition, compared with WT+ND, the core temperature and blood glucose of WT+KD group were increased, while mean arterial pressure was decreased; The ketogenic diet up-regulated PPARα protein expression in brown adipose tissue, as well as UCP1 protein expression in liver and brown adipose tissue of WT+KD group. Under low temperature condition, compared to WT+ND group, PPARα^-/-+ND group exhibited decreased core temperature and down-regulated PPARα and UCP1 protein expression levels in liver, skeletal muscle, white and brown adipose tissue. Compared to the PPARα^-/-+ND group, the PPARα^-/-+KD group exhibited decreased core temperature and did not show any difference in the protein expression of UCP1 in liver, skeletal muscle, white and brown adipose tissue. These results suggest that the ketogenic diet promotes UCP1 expression by up-regulating PPARα, thus improving low temperature tolerance of mice. Therefore, short-term ketogenic diet can be used as a potential intervention to improve the low temperature tolerance.
Animals ; Mice ; Adipose Tissue, Brown/metabolism* ; PPAR alpha/pharmacology* ; Diet, Ketogenic ; Uncoupling Protein 1/metabolism* ; Blood Glucose/metabolism* ; Temperature ; Mice, Inbred C57BL ; Liver ; Adipose Tissue/metabolism*

OBJECTIVE: In this study, the combined effect of two stressors, namely, electromagnetic fields (EMFs) from mobile phones and fructose consumption, on hypothalamic and hepatic master metabolic regulators of the AMPK/SIRT1-UCP2/FOXO1 pathway were elucidated to delineate the underlying molecular mechanisms of insulin resistance. METHODS: Weaned Wistar rats (28 days old) were divided into 4 groups: Normal, Exposure Only (ExpO), Fructose Only (FruO), and Exposure and Fructose (EF). Each group was provided standard laboratory chow ad libitum for 8 weeks . Additionally, the control groups, namely, the Normal and FruO groups, had unrestricted access to drinking water and fructose solution (15%), respectively. Furthermore, the respective treatment groups, namely, the ExpO and EF groups, received EMF exposure (1,760 MHz, 2 h/day x 8 weeks). In early adulthood, mitochondrial function, insulin receptor signaling, and oxidative stress signals in hypothalamic and hepatic tissues were assessed using western blotting and biochemical analysis. RESULT: In the hypothalamic tissue of EF, SIRT1, FOXO 1, p-PI3K, p-AKT, Complex III, UCP2, MnSOD, and catalase expressions and OXPHOS and GSH activities were significantly decreased ( P < 0.05) compared to the Normal, ExpO, and FruO groups. In hepatic tissue of EF, the p-AMPKα, SIRT1, FOXO1, IRS1, p-PI3K, Complex I, II, III, IV, V, UCP2, and MnSOD expressions and the activity of OXPHOS, SOD, catalase, and GSH were significantly reduced compared to the Normal group ( P < 0.05). CONCLUSION The findings suggest that the combination of EMF exposure and fructose consumption during childhood and adolescence in Wistar rats disrupts the closely interlinked and multi-regulated crosstalk of insulin receptor signals, mitochondrial OXPHOS, and the antioxidant defense system in the hypothalamus and liver.
Humans ; Rats ; Animals ; Adult ; Rats, Wistar ; Fructose/metabolism* ; Catalase ; Receptor, Insulin/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Electromagnetic Fields/adverse effects* ; Sirtuin 1/metabolism* ; Cell Phone ; Phosphatidylinositol 3-Kinases/metabolism* ; Forkhead Box Protein O1/metabolism* ; Uncoupling Protein 2

OBJECTIVETo evaluate the effect of bone morphogenetic protein(BMP7)on the differentiation of adipose derived mesenchymal stem cells(AD-MSCs)isolated from different adipose tissues into brown adipocytes in rats.

METHODSPrimary AD-MSCs were isolated from rate interscapular brown adipose tissue(iBAT),inguinal subcutaneous white adipose tissue(sWAT),and epididymal white adipose tissue(eWAT),respectively,and then cultivated in vitro. Differentiation of AD-MSCs into brown adipocytes was induced by BMP7. The characteristics of brown adipocytes were detected by immunofluorescence staining and oil red staining of cells. The expression levels of brown adipocyte-related genes were detected by polymerase chain reaction.

RESULTSAD-MSCs from iBAT and sWAT were differentiated into cluster multilocular cells,which were stained red by oil red "O"staining and showed uncoupling protein 1-positive by immunofluorescent staining method. AD-MSCs from eWAT had a small number of scattered multilocular cells and showed uncoupling protein 1-negative. The results of reverse transcription-polymerase chain reaction showed that the uncoupling protein 1 gene was highly expressed in the iBAT group and sWAT group but was negative in the eWAT group.

CONCLUSIONAD-MSCs isolated from different adipose tissues in rats have different gene expression profiles and differentiation potentials.

Adipocytes, Brown ; physiology ; Adipose Tissue ; metabolism ; Adipose Tissue, Brown ; physiology ; Animals ; Bone Morphogenetic Protein 7 ; metabolism ; Cell Differentiation ; physiology ; Ion Channels ; metabolism ; Mesenchymal Stromal Cells ; physiology ; Mitochondrial Proteins ; metabolism ; Obesity ; metabolism ; Rats ; Uncoupling Protein 1

OBJECTIVETo investigate the expressions of inflammation- and fibrosis-related genes in perinephric and subcutaneous adipose tissues in patients with adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome.

METHODSThe perinephric and subcutaneous adipose tissues adipose tissues were obtained from 8 patients with ACTH-independent Cushing's syndrome undergoing laparoscopic retroperitoneal adrenalectomy. Real-time PCR was used to detect the mRNA expression levels of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), matrix metallopeptidase 2 (MMP-2), TIMP metallopeptidase inhibitor 1 (TIMP-1), early growth response 1 (EGR1), CCAAT/enhancer binding protein β(CEBPβ), uncoupling protein 1(UCP-1), PPARγ coactivator 1 alpha (PGC1α) and cell death-inducing DFFA-like effector a (CIDEA).

RESULTSThe mRNA level of CIDEA was significantly higher in the perinephric adipose tissue (peri-N) than in the subcutaneous adipose tissue (subQ) (P<0.05). The expressions of CEBPβ, UCP-1, and PGC1α mRNA in the peri-N were similar with those in the subQ. The expressions of IL-6, TIMP1 and EGR1 mRNA in the subQ were significantly higher than those in the peri-N (P<0.05). No significant difference in TNF-α and MMP-2 mRNA levels was found between peri-N and subQ.

CONCLUSIONThe expression levels of the inflammation- and fibrosis-related genes are higher in the subQ than in the peri-N of patients with ACTH-independent Cushing's syndrome, suggesting that chronic exposure to endogenous hypercortisolism may cause adipose tissue dysfunction.

Adrenalectomy ; Adrenocorticotropic Hormone ; CCAAT-Enhancer-Binding Protein-beta ; metabolism ; Cushing Syndrome ; metabolism ; surgery ; Early Growth Response Protein 1 ; metabolism ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; metabolism ; Real-Time Polymerase Chain Reaction ; Subcutaneous Fat ; metabolism ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; Uncoupling Protein 1 ; metabolism

OBJECTIVE: To investigate the effects of genipin on promoting brown adipose tissue activation and white adipose tissue browning. METHODS: The male C57BL/6J mice were divided into three groups: normal control group, genipin group and cold-stimulus group.Genipin group were treated consecutively with genipin at a dose of 15 mg/kg once a day for 9 days, normal control group were treated with the saline.The mice with cold-stimulus were exposed to 4℃ environment for 5 days.Daily food amount and body weight were measured.Morphological changes were observed in the subscapular region, inguinal region and epididymis around the adipose tissue.The expression of uncoupling protein 1 (UCP1) was determined by real-time PCR and Western blot respectively. RESULTS: The wet weight of white fat in genipin-treated mice was decreased by 16% , and 28% in that of cold-stimulus mice, compared with the normal control group (P＜0.05).After treatments of genipin and cold-stimulus, the color of white adipose tissues was darker, and the size of lipid droplets in adipocytes was smaller, whereas the number was increased.Compared with the normal control group, UCP1 expression was increased obviously in fat tissues, including the subcutaneous and visceral white adipose tissues, and brown adipose tissue after treated with genipin and cold-stimulus (P＜0.05). CONCLUSION Genipin promoted activation of brown adipose tissue and browning of white adipose tissue by upregulating UCP1 expression, which could contribute to the loss of body weight against obesity.
Adipose Tissue, Brown ; drug effects ; Adipose Tissue, White ; drug effects ; Animals ; Cholagogues and Choleretics ; pharmacology ; Iridoids ; pharmacology ; Male ; Mice ; Mice, Inbred C57BL ; Obesity ; drug therapy ; Uncoupling Protein 1 ; drug effects ; Up-Regulation

AIMTo investigate the effect of cold stress on the energy metabolism in Yisha chickens.

METHODSMale Yisha chickens were subjected to acute (0.25, 1, 3, 6, 12 and 24 h) and chronic (5, 10 and 20 d) cold stress (12 +/- 1 degrees C). This study detected uncoupling protein (UCP) mRNA levels in gastrocnemius, glucagons (GLU) content in blood plasma and insulin (INS), blood glucose (BG) and free fatty acid (FFA) content in serum in the chicken.

RESULTSThe results were as follow: with the time lapsing during acute cold stress, UCP mRNA levels gradually increased, the content of INS and FFA showed fluctuant change, GLU content gradually increased, and BG content first increased and then decreased. During chronic cold stress, UCP mRNA levels significantly increased compared with their control group at every stress time point, and the content of INS, GLU, BG and FFA were all gradually increased with the time lapsing.

CONCLUSIONCold stress could change the energy metabolism in chickens. And the different extent cold stress would produce different effects on the energy metabolism.

Animals ; Chickens ; Cold Temperature ; Energy Metabolism ; physiology ; Fatty Acids, Nonesterified ; blood ; Insulin ; blood ; Ion Channels ; genetics ; metabolism ; Male ; Mitochondrial Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Stress, Physiological ; physiology ; Uncoupling Protein 1

OBJECTIVETo observe the expression of SIRT1 and mitochondrial uncoupling protein 2 (UCP2) in the liver of rats with type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver (NAFLD) and explore the possible pathogenesis of T2DM and NAFLD.

METHODSTwenty-four male SD rat were randomized equally into control group and T2DM and NAFLD group (MC group), fed with standard diet and high-fat and high-sugar diet, respectively. At 12 weeks, the rats in MC group received a single dose of STZ (30 mg/kg) injected into the abdominal cavity for pancreatic islet destruction, and those in the control group received an equivalent volume of citric acid buffer. At 14 weeks, the body weight, FBG, hepatic function, blood lipid levels, FFAs, FINs and HOMA-IR of the rats were measured, and the liver pathology was examined with HE staining. The expression of SIRT1 and UCP2 in the rat liver was detected by immunohistochemistry and real-time quantitative PCR.

RESULTSAt 14 weeks, FBG, ALT, AST, TC, TG, LDL-C, VLDL, FFAs, FINs and HOMA-IR were significantly higher and HDL-C was significantly lower in MC group than in the control group (P<0.05). Pathological examination showed good structural integrity of the liver in the control group, and the liver cells were closely arranged with rich cytoplasm and round cell nuclei; in MC group, moderate to severe fatty liver was detected, and the liver cells showed severe ballooning degeneration and contained lipid vacuoles in the cytoplasm. The expression of SIRT1 was significantly lower and UCP2 significantly higher in MC group than in the control group (P<0.05).

CONCLUSIONThe expression of SIRT1 is significantly lowered and UCP2 increased in the liver of rats with T2DM and NAFLD.

Animals ; Diabetes Mellitus, Type 2 ; complications ; metabolism ; Fatty Liver ; complications ; metabolism ; Ion Channels ; metabolism ; Liver ; metabolism ; Male ; Mitochondrial Proteins ; metabolism ; Non-alcoholic Fatty Liver Disease ; Rats ; Rats, Sprague-Dawley ; Sirtuin 1 ; metabolism ; Uncoupling Protein 2

To reveal the roles of uncoupling proteins (UCPs) in disorder of mitochondrial oxidative phosphorylation induced by free fatty acid during hypoxic exposure, the effects of palmitic acid on activity of UCPs, proton leak and mitochondrial membrane potential in hypoxia-exposed rat brain mitochondria were observed in vitro. Adult Sprague-Dawley (SD) rats were set randomly into control, acute hypoxia and chronic hypoxia groups (n=8 in each group). The acute and chronic hypoxic rats were exposed to simulated 5000 m high altitude in a hypobaric chamber 23 h/d for 3 d and 30 d, respectively. The brain mitochondria were isolated by centrifugation. UCP content and activity were detected by [(3)H]-GTP binding method. The proton leak was measured by TPMP(+) electrode and oxygen electrode. The membrane potential of mitochondria was calculated by detecting the fluorescence from Rodamine 123. Hypoxic exposure resulted in an increase in UCP activity and content as well as proton leak, but a decrease in the membrane potential of rat brain mitochondria. Palmitic acid resulted in further increases in UCP activity and content as well as proton leak, and further decrease in membrane potential of brain mitochondria in vitro from hypoxia-exposed rats, but hypoxic exposure decreased the reactivity of cerebral mitochondria to palmitic acid, especially in the acute hypoxia group. There was a negative correlation between mitochondrial proton leak and K(d) value (representing derivative of UCP activity, P<0.01, r = -0.906), and a positive correlation between proton leak and B(max) (representing the maximal content of UCPs in mitochondrial inner membrane, P<0.01, r = 0.856). Cerebral mitochondrial membrane potential was negatively correlated with proton leak (P<0.01, r = -0.880). It is suggested that hypoxia-induced proton leak enhancement and membrane potential decrease are correlated with the increased activity of UCPs. Hypoxia can also decrease the sensitivity of cerebral mitochondria to palmitic acid, which may be a self-protective mechanism in high altitude environment.
Altitude ; Animals ; Brain ; metabolism ; Cell Hypoxia ; Ion Channels ; metabolism ; Membrane Potential, Mitochondrial ; Mitochondria ; metabolism ; Mitochondrial Proteins ; metabolism ; Oxidative Phosphorylation ; Oxygen ; metabolism ; Palmitic Acid ; pharmacology ; Protons ; Rats ; Rats, Sprague-Dawley ; Uncoupling Protein 1