Ketogenic diet improves low temperature tolerance in mice by up-regulating PPARα in the liver and brown adipose tissue / 生理学报

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.

Histamine stimulates thermogenesis of brown and beige fat / 生理学报

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.

Timeliness of β3 adrenergic receptor agonist-induced browning of white adipose tissues in mice / 中南大学学报(医学版)

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.

Effects of Genipin on the expression of uncoupling protein 1 in brown adipose and white adipose tissues in mice / 中国应用生理学杂志

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.

Supplementation of Fermented Barley Extracts with Lactobacillus Plantarum dy-1 Inhibits Obesity via a UCP1-dependent Mechanism / 生物医学与环境科学（英文）

OBJECTIVE@#We aimed to explore how fermented barley extracts with Lactobacillus plantarum dy-1 (LFBE) affected the browning in adipocytes and obese rats.@*METHODS@#In vitro, 3T3-L1 cells were induced by LFBE, raw barley extraction (RBE) and polyphenol compounds (PC) from LFBE to evaluate the adipocyte differentiation. In vivo, obese SD rats induced by high fat diet (HFD) were randomly divided into three groups treated with oral gavage: (a) normal control diet with distilled water, (b) HFD with distilled water, (c) HFD with 800 mg LFBE/kg body weight (bw).@*RESULTS@#In vitro, LFBE and the PC in the extraction significantly inhibited adipogenesis and potentiated browning of 3T3-L1 preadipocytes, rather than RBE. In vivo, we observed remarkable decreases in the body weight, serum lipid levels, white adipose tissue (WAT) weights and cell sizes of brown adipose tissues (BAT) in the LFBE group after 10 weeks. LFBE group could gain more mass of interscapular BAT (IBAT) and promote the dehydrogenase activity in the mitochondria. And LFBE may potentiate process of the IBAT thermogenesis and epididymis adipose tissue (EAT) browning via activating the uncoupling protein 1 (UCP1)-dependent mechanism to suppress the obesity.@*CONCLUSION@#These results demonstrated that LFBE decreased obesity partly by increasing the BAT mass and the energy expenditure by activating BAT thermogenesis and WAT browning in a UCP1-dependent mechanism.

[Comparison of moderate and high volume aerobic training on gene expression of uncoupling protein 1 [UCP-1] in subcutaneous white adipose tissue of wistar rats]

Introduction: The aim of this study was to investigate the effect of moderate and high volume aerobic training on the expression of Uncoupling Protein 1[UCP-1] gene in subcutaneous WAT [sub-WAT]

Materials and Methods: Twenty-four rats were assigned randomly into three groups: 1] control [n=8] 2] moderate-volume aerobic training [n=8] and 3] high-volume aerobic training [n=8]. Subjects of training groups underwent continuous aerobic training on the treadmill for 8 weeks, 5 sessions per week at two different volumes of training. The Real Time-PCR method was used to measure the expression ratio of UCP-1 gene

Results: Data showed that although the expression ratio of UCP1 gene in the moderate volume aerobic training group was significantly higher than control group [P=0.014], its expression ratio in the high volume aerobic training group did not differ significantly from controls [P=0.36]; neither was the gene expression ratio different between moderate and high volume aerobic training groups [P=0.59]

Conclusion: Results indicate that moderate volume aerobic training, had an obvious effect in inducing UCP1 gene expression in subcutaneous adipose tissue, while the high volume aerobic training did not. Thus, increasing the volume of aerobic training to high levels may not be a key factor in promoting the non-shivering theremogenesis of sub-WAT

Expressions of inflammatory and fibrogenic factors in perinephric and subcutaneous adipose tissues of patients with adrenocorticotropic hormone-independent Cushing's syndrome / 南方医科大学学报

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>The 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).</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>The 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.</p>

Bofutsushosan ameliorates obesity in mice through modulating PGC-1α expression in brown adipose tissues and inhibiting inflammation in white adipose tissues / 中国天然药物

The inducible co-activator PGC-1α plays a crucial role in adaptive thermogenesis and increases energy expenditure in brown adipose tissue (BAT). Meanwhile, chronic inflammation caused by infiltrated-macrophage in the white adipose tissue (WAT) is a target for the treatment of obesity. Bofutsushosan (BF), a traditional Chinese medicine composed of 17 crude drugs, has been widely used to treat obesity in China, Japan, and other Asia countries. However, the mechanism underlying anti-obesity remains to be elucidated. In the present study, we demonstrated that BF oral administration reduced the body weight of obese mice induced by high-fat diet (HFD) and alleviated the level of biochemical markers (P < 0.05), including blood glucose (Glu), total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL-C) and insulin. Our further results also indicated that oral BF administration increased the expression of PGC-1α and UCP1 in BAT. Moreover, BF also reduced the expression of inflammatory cytokines in WAT, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). These findings suggested that the mechanism of BF against obesity was at least partially through increasing gene expression of PGC-1α and UCP1 for energy consumption in BAT and inhibiting inflammation in WAT.

Medium-Chain Triglyceride Activated Brown Adipose Tissue and Induced Reduction of Fat Mass in C57BL/6J Mice Fed High-fat Diet / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate activation of brown adipose tissue (BAT) stimulated by medium-chain triglyceride (MCT).</p><p><b>METHODS</b>30 Male C57BL/6J obese mice induced by fed high fat diet (HFD) were divided into 2 groups, and fed another HFD with 2% MCT or long-chain triglyceride (LCT) respectively for 12 weeks. Body weight, blood biochemical variables, interscapular brown fat tissue (IBAT) mass, expressions of mRNA and protein of beta 3-adrenergic receptors (β3-AR), uncoupling protein-1 (UCP1), hormone sensitive lipase (HSL), protein kinase A (PKA), and adipose triglyceride lipase (ATGL) in IBAT were measured.</p><p><b>RESULTS</b>Significant decrease in body weight and body fat mass was observed in MCT group as compared with LCT group (P<0.05) after 12 weeks. Greater increases in IBAT mass was observed in MCT group than in LCT group (P<0.05). Blood TG, TC, LDL-C in MCT group were decreased significantly, meanwhile blood HDL-C, ratio of HDL-C/LDL-C and norepinephrine were increased markedly. Expressions of mRNA and protein of β3-AR, UCP1, PKA, HSL, ATGL in BAT were greater in MCT group than in LCT group (P<0.05).</p><p><b>CONCLUSION</b>Our results suggest that MCT stimulated the activation of BAT, possible via norepinephrine pathway, which might partially contribute to reduction of the body fat mass in obese mice fed high fat diet.</p>

Effect of bone morphogenetic protein 7 on differentiation of adipose derived mesenchymal stem cells into brown adipocytes in rats / 中国医学科学院学报

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Primary 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.</p><p><b>RESULTS</b>AD-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.</p><p><b>CONCLUSION</b>AD-MSCs isolated from different adipose tissues in rats have different gene expression profiles and differentiation potentials.</p>

Analysis of -3826A/G polymorphism in the promoter of the uncoupling protein-1 gene in Chinese non-obese and obese populations / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the -3826A/G polymorphism in the promoter of the uncoupling protein-1 (UCP1) gene and its relations to obesity in Chinese population.</p><p><b>METHODS</b>Three hundred and eighty-four subjects (257 non-obese and 127 obese individuals) from a population of Chinese Han nationality in Chengdu area were studied using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs). Serum lipids were measured by enzymatic kits and apolipoproteins A I, A II, B100, C II, C III and E were measured by the RID kits.</p><p><b>RESULTS</b>The frequencies of A and G alleles at -3826A/G site in obese and non-obese groups were 0.508 and 0.492, and 0.467 and 0.533, respectively. It showed no significant difference in allele frequencies between non-obese and obese groups (P > 0.05). In the obese group, subjects with genotype GG had higher serum apo B100 concentrations, and those with genotype AG had higher apo C II and apo C III levels, than those with genotype AA, respectively (P < 0.05). In non-obese male subgroup, subjects with genotype GG had lower serum HDL-C and apo A I levels than those with genotype AA, respectively (P < 0.05), whereas those with genotype AG had lower apo A II levels than those with genotype AA. In addition, in obese males with genotype GG had elevated apo B100 levels compared with those with genotype AA, whereas in obese females with genotype GG had decreased apo AI levels and genotype AG had increased apo C II and apo C III levels compared with those with genotype AG and AA, respectively (P < 0.05).</p><p><b>CONCLUSION</b>-3826A/G polymorphism in the promoter of the uncoupling protein-1 gene was not associated with obesity in Chinese Han population of Chengdu area. It may be associated with serum HDL-C, apo A I and apo B100 levels in non-obese and/or obese subjects of certain genders.</p>

Effects of cold stress on energy metabolism in the chicken / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effect of cold stress on the energy metabolism in Yisha chickens.</p><p><b>METHODS</b>Male 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.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>Cold stress could change the energy metabolism in chickens. And the different extent cold stress would produce different effects on the energy metabolism.</p>

Effects of palmitic acid on activity of uncoupling proteins and proton leak in in vitro cerebral mitochondria from the rats exposed to simulated high altitude hypoxia / 生理学报

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.