Expression of hormone sensitive lipase and carnitine acyl transferase-1 in obese diabetic rats after sleeve gastrectomy / 中华内分泌外科杂志

Objective To investigate the expression of hormone sensitive lipase (HSL) and carnitine acyl transferase-1 (CAT-1) in Zucker rats after sleeve gastrectomy and to discuss the weight loss mechanism.Methods 30 male Zucker rats aging 10 weeks were randomly divided into 3 groups:the operation group (10 rats),the sham operation group (10 rats) and the diet-pairing group (10 rats).The rats were decapitated to retrieve the retroperitoneal adipose,mRNA and protein expression of HSL and CAT-1 gene of were detected by RTPCR and Western blot.Results As for the operation group,the weight decreased significantly after the operation comparing to the other two groups ((250±5.8) g,(370±10.0) g,(310±9.6) g,P＜0.05).mRNA and protein expressions of HSL and CAT-1 gene were all significantly higher in the operation group (P＜0.05).Conclusion SG can up-regulate the expressions of lipolysis gene HSL and CAT-1 in adipose in Zucker rats,promoting fat hydrolysis and increasing the energy expenditure,which is one of the important mechanisms of weight loss.

Lipolysis and lipases in white adipose tissue – An update

Lipolysis is defined as the sequential hydrolysis of triacylglycerol (TAG) stored in cell lipid droplets. For many years, it was believed that hormone-sensitive lipase (HSL) and monoacylglycerol lipase (MGL) were the main enzymes catalyzing lipolysis in the white adipose tissue. Since the discovery of adipose triglyceride lipase (ATGL) in 2004, many studies were performed to investigate and characterize the actions of this lipase, as well as of other proteins and possible regulatory mechanisms involved, which reformulated the concept of lipolysis. Novel findings from these studies include the identification of lipolytic products as signaling molecules regulating important metabolic processes in many non-adipose tissues, unveiling a previously underestimated aspect of lipolysis. Thus, we present here an updated review of concepts and regulation of white adipocyte lipolysis with a special emphasis in its role in metabolism homeostasis and as a source of important signaling molecules.

Antiobesity effects of the water-soluble fraction of the ethanol extract of Smilax china L. leaf in 3T3-L1 adipocytes

BACKGROUND/OBJECTIVES: Several medicinal properties of Smilax china L. have been studied including antioxidant, anti-inflammatory, and anti-cancer effects. However, the antiobesity activity and mechanism by which the water-soluble fraction of this plant mediates its effects are not clear. In the present study, we investigated the lipolytic actions of the water-soluble fraction of Smilax china L. leaf ethanol extract (wsSCLE) in 3T3-L1 adipocytes. MATERIALS/METHODS: The wsSCLE was identified by measuring the total polyphenol and flavonoid content. The wsSCLE was evaluated for its effects on cell viability, lipid accumulation, glycerol, and cyclic adenosine monophosphate (cAMP) contents. In addition, western blot analysis was used to evaluate the effects on protein kinase A (PKA), PKA substrates (PKAs), and hormone-sensitive lipase (HSL). For the lipid accumulation assay, 3T3-L1 adipocytes were treated with different doses of wsSCLE for 9 days starting 2 days post-confluence. In other cell experiments, mature 3T3-L1 adipocytes were treated for 24 h with wsSCLE. RESULTS: Results showed that treatment with wsSCLE at 0.05, 0.1, and 0.25 mg/mL had no effect on cell morphology and viability. Without evidence of toxicity, wsSCLE treatment decreased lipid accumulation compared with the untreated adipocyte controls as shown by the lower absorbance of Oil Red O stain. The wsSCLE significantly induced glycerol release and cAMP production in mature 3T3-L1 cells. Furthermore, protein levels of phosphorylated PKA, PKAs, and HSL significantly increased following wsSCLE treatment. CONCLUSION: These results demonstrate that the potential antiobesity activity of wsSCLE is at least in part due to the stimulation of cAMP-PKA-HSL signaling. In addition, the wsSCLE-stimulated lipolysis induced by the signaling is mediated via activation of the beta-adrenergic receptor.

Novel organic solvent-tolerant esterase isolated by metagenomics: insights into the lipase/esterase classification / Nueva esterasa tolerante a los solventes orgánicos aislada por metagenómica: ideas sobre la clasificación de las esterasas/lipasas

In order to isolate novel organic solvent-tolerant (OST) lipases, a metagenomic library was built using DNA derived from a temperate forest soil sample. A two-step activity-based screening allowed the isolation of a lipolytic clone active in the presence of organic solvents. Sequencing of the plasmid pRBest recovered from the positive clone revealed the presence of a putative lipase/esterase encoding gene. The deduced amino acid sequence (RBest1) contains the conserved lipolytic enzyme signature and is related to the previously described OST lipase from Lysinibacillus sphaericus 205y, which is the sole studied prokaryotic enzyme belonging to the 4.4 a/ß hydrolase subgroup (abH04.04). Both in vivo and in vitro studies of the substrate specificity of RBest1, using triacylglycerols or nitrophenyl-esters, respectively, revealed that the enzyme is highly specific for butyrate (C4) compounds, behaving as an esterase rather than a lipase. The RBest1 esterase was purified and biochemically characterized. The optimal esterase activity was observed at pH 6.5 and at temperatures ranging from 38 to 45 °C. Enzymatic activity, determined by hydrolysis of p-nitrophenyl esters, was found to be affected by the presence of different miscible and non-miscible organic solvents, and salts. Noteworthy, RBest1 remains significantly active at high ionic strength. These findings suggest that RBest1 possesses the ability of OST enzymes to molecular adaptation in the presence of organic compounds and resistance of halophilic proteins.

Con el fin de aislar nuevas variantes de lipasas tolerantes a solventes organicos (OST), se construyo una libreria metagenomica a partir de ADN obtenido de una muestra de suelo de bosque templado. A traves de un monitoreo en dos etapas, basado en la deteccion de actividades, se aislo un clon con actividad lipolitica en presencia de solventes organicos. La secuenciacion del plasmido pRBest recuperado del clon positivo revelo la presencia de un gen codificante de una hipotetica lipasa/esterasa. La secuencia deducida de amino acidos (RBest1) contiene los motivos conservados de enzimas lipoliticas y esta relacionada con la lipasa OST previamente descrita de Lysinibacillus sphaericus 205y, que es la unica enzima procariota estudiada perteneciente al subgrupo 4.4 de a/ß hidrolasas (abH4.04). Estudios in vivo e in vitro sobre la especificidad de sustratos de RBest1, utilizando triacil-gliceroles o p-nitrofenil-esteres, respectivamente, revelaron que la enzima es altamente especifica para compuestos butiricos (C4), comportandose como una esterasa y no como una lipasa. La esterasa RBest1 fue purificada y caracterizada bioquimicamente. La actividad optima de esterasa fue observada a pH 6,5 y las temperaturas optimas fueron entre 38 y 45 °C. Se establecio que la actividad enzimatica, determinada por hidrolisis de p-nitrofenil esteres, es afectada en presencia de diferentes solventes organicos miscibles y no miscibles, y tambien sales. Notoriamente, RBest1 permanece significativamente activa a elevadas fuerzas ionicas. Estos hallazgos sugieren que RBest1 posee la capacidad de las enzimas OST de la adaptacion molecular en presencia de compuestos organicos, asi como la resistencia de las proteinas halofilas.

Effect of glucose on hormone sensitive lipase in NTT-1 cell / 中华内分泌代谢杂志

NIT-1 cells were exposed to various concentrations of glucose for 24,48,and 72 hours.The content of triglyceride in NIT-1 cells increased in dose-and time-dependent manners (P ＜ 0.05).Long-term exposure of NIT-1 cells to high glucose concentrations caused an inverse "v"-like induction of HSL mRNA and protein expressions,which increased from beginning,and then decreased,along with similar changes of lipolysis.These results suggest that the adaptation of HSL may play an important role in regulating the intracellular triglyceride pool and the development of glucolipotoxicity in pancreatic β cells.

Distribution of the hormone-sensitive lipase gene i6 polymorphism in Zunyi region / 基础医学与临床

Objective To explore the polymorphism distribution of the hormone-sensitive lipase (HSL) gene i6 in Zunyi region. Methods HSL i6 in the Zunyi population was examined with ploymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), and analyzed for its distribution. Results Six different alleles and 11 different genotypes were found in the HSL i6. The PIC is more than 0.7, in which allele 6 and allele 7 were most widely distributed. Conclusion The polymorphism of HSL i6 was identified and the result suggests in Zunyi HSL as a candidate gene of glucose and lipid metabolism.

Distribution of the hormone-sensitive lipase gene i6 polymorphism in Zunyi region / 基础医学与临床

Objective To explore the polymorphism distribution of the hormone-sensitive lipase (HSL) gene i6 in Zunyi region. Methods HSL i6 in the Zunyi population was examined with ploymerase chain reaction-single strand conformation polymorphism (PCR-SSCP),and analyzed for its distribution. Results Six different alleles and 11 different genotypes were found in the HSL i6. The PIC is more than 0.7,in which allele 6 and allele 7 were most widely distributed.Conclusion The polymorphism of HSL i6 was identified and the result suggests in Zunyi HSL as a candidate gene of glucose and lipid metabolism.

The Effects of Ginseng Saponin-Re, Rc and Green Tea Catechine; ECGC (Epigallocatechin Gallate) on Leptin, Hormone Sensitive Lipase and Resistin mRNA Expressions in 3T3-L1 Adipocytes

The purpose of this study was to find out effects of treatment of ginsenoside Re, Rc and EGCG on mRNA expressions of leptin, hormone sensitive lipase (HSL) and resistin in 3T3-L1 adipocytes. The concentrations of EGCG were treated with 0.01 x 10(-7), 0.1 x 10(-7), 1 x 10(-7) and 1 x 10(-6) M or 100 microgram/ml ginsenoside Re, Rc in culture cell for 13 days. mRNA expression of leptin wasn't expressed in preadipocyte but according to differentiation of adipocyte, the that of mRNA expression was decreased at gensenosids or EGCG treated cells compared with non treated adipocyte. Expression of HSL mRNA was increased in G-Re, G-Rc and EGCG treated cells compared with non treated cells. The resistin level was significantly decreased in adipocytes treated with G-Re, G-Rc and EGCG. These pattern was similar to leptin expression.These results support that treatment of gensenosides or EGCG in 3T3-L1 adipocyte resulted to affect of leptin and resistin as well as HSL mRNA levels, accordingly, levels of leptin and HSL will be acted by signalling body fat stores to the hypothalamus which in turn regulates food intake and energy expenditure to maintain body weight homeostasis. And also regulation of resistin mRNA will prevent to diabetics attacked with obesity. In conclusion, we suggest that consumption of ginseng saponine or EGCG might prevent human diabetics or/and obesity.

Studies on the antiobesity action and mechanisms of daidzein derivative:LRXH609 / 中国临床药理学与治疗学

AIM: To approach the antiobesity action and mechanisms of the daidzein derivative: LRXH609(LRX).METHODS: The body weight,Lee′s index,total weight of celiac fat tissue,food intake,serum glucose and lipids in obese rats induced by a high-fat diet were measured and the antiobesity action was tested after LRX was administered for 30 days.3T3-L1 pre-adipocytes were induced by in vitro culture,the effects of LRX on cell proliferation,lipogenesis,lipolysis were observed.RESULTS: The body weight,Lee′s index,fat tissue weight in obese rats were significantly decreased by LRX,and the concentrations of TC,FFA in serum were decreased,the proliferation of 3T3-L1 pre-adipocytes was inhibited,the activities of hormone sensitive lipase in 3T3-L1 pre-adipocytes were significantly elevated,the glycerine release from adipocytes was promoted and the concentrations of TG in adipocytes were decreased.CONCLUSION: LRX plays a role in antiobesity action and regulating blood lipid and the mechanism might be related to inhibiting proliferation and differentiation of pre-adipocytes,stimulating TG decomposition by activating hormone-sensitive lipase and decreasing the TG storage in adipocyte.

Effect of mandur bhasma on lipolytic activities of liver, kidney and adipose tissue of albino rat during CCl4 induced hepatic injury.

'Mandur bhasma', an ayurvedic preparation of iron is used in traditional medicine against hepatitis. In the present study the hepatoprotective property of this drug was tested in albino rats during CC14 induced hepatic injury. The effect of mandur bhasma on the activities of the lipolytic enzymes of rat liver, kidney and adipose tissue were studied during hepatitis induced by CCl4. The activities of acid lipase, alkaline lipase, lipoprotein lipase and hormone sensitive lipase exhibited significant alterations during CCl4 induced hepatic injury, indicating a role for these enzymes in the mobilization of fat from adipose tissue and accumulation of fat in liver and kidney. Simultaneous treatment with mandur bhasma prevented the paraffin mediated and CC14 mediated changes in the enzyme activities. These results suggest the hepatoprotective role of mandur bhasma during CC14 induced hepatic injury.