scholarly journals Species-specific alternative splicing generates a catalytically inactive form of human hormone-sensitive lipase

1997 ◽  
Vol 328 (1) ◽  
pp. 137-143 ◽  
Author(s):  
Henrik LAURELL ◽  
Jacques GROBER ◽  
Cécile VINDIS ◽  
Thierry LACOMBE ◽  
Michèle DAUZATS ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Alternative Splicing ◽  
Cell Lines ◽  
Catalytic Triad ◽  
Hormone Sensitive Lipase ◽  
Human Adipocytes ◽  
Brown Adipose ◽  
Specific Alternative ◽  
Hormone Sensitive ◽  
Species Specific

Hormone-sensitive lipase (HSL) catalyses the rate-limiting step of adipose tissue lipolysis. The enzyme is also expressed in steroidogenic tissues, mammary gland, muscle tissues and macrophages. A novel HSL mRNA termed hHSL-S, 228 bp shorter than the full-length HSL mRNA, was detected in human adipocytes. hHSL-S mRNA results from the in-frame skipping of exon 6, which encodes the serine residue of the catalytic triad. The corresponding 80 kDa protein was identified in human adipocytes after immunoprecipitation. The truncated protein expressed in COS cells showed neither lipase nor esterase activity but was phosphorylated by cAMP-dependent protein kinase. hHSL-S mRNA was found in all human tissues expressing HSL, except brown adipose tissue from newborns. It represented approx. 20% of total HSL transcripts in human subcutaneous adipocytes. No alternative splicing was detected in other mammals. Human and mouse three-exon HSL minigenes transfected into primate and rodent cell lines reproduced the splicing pattern of the endogenous HSL genes. Analysis of hybrid human/mouse minigenes transfected into human cell lines showed that cis-acting elements responsible for the skipping of human exon 6 were restricted to a 247 bp region including exon 6 and the first 19 nt of intron 6. Moreover, divergence in exonic splicing elements between mouse and human was shown to be critical for the species-specific alternative splicing.

scholarly journals Domain-structure analysis of recombinant rat hormone-sensitive lipase

1996 ◽  
Vol 319 (2) ◽  
pp. 411-420 ◽  
Author(s):  
Torben ØSTERLUND ◽  
Birgitta DANIELSSON ◽  
Eva DEGERMAN ◽  
Juan Antonio CONTRERAS ◽  
Gudrun EDGREN ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Domain Structure ◽  
Expression System ◽  
Guanidine Hydrochloride ◽  
Catalytic Triad ◽  
Water Soluble ◽  
Hormone Sensitive Lipase ◽  
Structural Domain ◽  
Hydrolase Fold ◽  
Hormone Sensitive

Hormone-sensitive lipase (HSL) plays a key role in lipid metabolism and overall energy homoeostasis, by controlling the release of fatty acids from stored triglycerides in adipose tissue. Lipases and esterases form a protein superfamily with a common structural fold, called the α/β-hydrolase fold, and a catalytic triad of serine, aspartic or glutamic acid and histidine. Previous alignments between HSL and lipase 2 of Moraxella TA144 have been extended to cover a much larger part of the HSL sequence. From these extended alignments, possible sites for the catalytic triad and α/β-hydrolase fold are suggested. Furthermore, it is proposed that HSL contains a structural domain with catalytic capacity and a regulatory module attached, as well as a structural N-terminal domain unique to this enzyme. In order to test the proposed domain structure, rat HSL was overexpressed and purified to homogeneity using a baculovirus/insect-cell expression system. The purification, resulting in > 99% purity, involved detergent solubilization followed by anion-exchange chromatography and hydrophobic-interaction chromatography. The purified recombinant enzyme was identical to rat adipose-tissue HSL with regard to specific activity, substrate specificity and ability to serve as a substrate for cAMP-dependent protein kinase. The recombinant HSL was subjected to denaturation by guanidine hydrochloride and limited proteolysis. These treatments resulted in more extensive loss of activity against phospholipid-stabilized lipid substrates than against water-soluble substrates, suggesting that the hydrolytic activity can be separated from recognition of lipid substrates. These data support the concept that HSL has at least two major domains.

scholarly journals Glucocorticoids antagonize tumor necrosis factor-α-stimulated lipolysis and resistance to the antilipolytic effect of insulin in human adipocytes

2012 ◽  
Vol 303 (9) ◽  
pp. E1126-E1133 ◽  
Author(s):  
Mi-Jeong Lee ◽  
Susan K. Fried
Keyword(s):  
Adipose Tissue ◽  
Cell Types ◽  
Hormone Sensitive Lipase ◽  
Human Adipocytes ◽  
Adipose Tissue Triglyceride ◽  
Hormone Sensitive ◽  
Phosphodiesterase 3B ◽  
High Concentrations ◽  
Factor Α ◽  
Tnf Induction

High concentrations of TNF within obese adipose tissue increase basal lipolysis and antagonize insulin signaling. Adipocytes of the obese are also exposed to elevated levels of glucocorticoids (GCs), which antagonize TNF actions in many cell types. We tested the hypothesis that TNF decreases sensitivity to the antilipolytic effect of insulin and that GCs antagonize this effect in differentiated human adipocytes. Lipolysis and expression levels of lipolytic proteins were measured after treating adipocytes with TNF, dexamethasone (DEX), or DEX + TNF for up to 48 h. TNF not only increased basal lipolysis, it caused resistance to the antilipolytic effects of insulin in human adipocytes. DEX alone did not significantly affect lipolysis. Cotreatment with DEX blocked TNF induction of basal lipolysis and insulin resistance by antagonizing TNF stimulation of PKA-mediated phosphorylation of hormone-sensitive lipase (HSL) at Ser563 and Ser660 and perilipin. TNF did not affect perilipin, HSL, or phosphodiesterase-3B mass but paradoxically suppressed adipose tissue triglyceride lipase expression, and this effect was blocked by DEX. The extent to which GCs can restrain the lipolytic actions of TNF may both diminish the potentially deleterious effects of excess lipolysis and contribute to fat accumulation in obesity.

scholarly journals EFFECT OF MYOKINES ON THE QUANTITY OF HORMONE SENSITIVE LIPASE IN MSCS AND THE PRODUCTS OF THEIR ADIPOGENIC DIFFERENTIATION

2021 ◽  
Vol 10 (4) ◽  
pp. 29-35
Author(s):  
A. Mishra ◽  
E. V. Tsypandina ◽  
A. M. Gaponov ◽  
S. A. Rumyantsev ◽  
R. A. Khanferyan ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Skeletal Muscles ◽  
Adipogenic Differentiation ◽  
Hormone Sensitive Lipase ◽  
Adrenergic Agonist ◽  
Differentiation Protocol ◽  
Healthy Donors ◽  
Brown Adipose ◽  
Hormone Sensitive ◽  
Hydrolysis Of

The basic metabolic process associated with white and beige/brown adipose tissues is lipolysis – the sequential enzymatic process of the hydrolysis of triglycerides in the adipose tissue. It has been repeatedly shown that physical activity activates lipolysis. It has recently been shown that skeletal muscles have an endocrine role; producing a host of myogenic hormones – myokines. Current literature has an incomplete understanding of the interdependent relationship between skeletal muscles and adipose tissue. We researched the influence of myocyte secreted cytokines (myokines) – meteorin-like protein (METRNL) and β-aminoisobutyric acid (BAIBA), and the adrenergic agonist isoproterenol on the levels of total and phosphorylated (Ser552) hormone sensitive lipase (HSL) in adipose tissue derived mesenchymal stromal cells (MSCs) and the cellular products of their adipogenic differentiation. The MSCs were obtained from 5 healthy donors. The adipogenic differentiation protocol was carried out for a span of 21 days. After procuring the adipocyte cultures, the following stimulators were added – 5 μM METRNL, 5 μM BAIBA, and 5 μM isoproterenol. With the help of western blot, the change in the amount of total and activated levels of HSL were monitored in cells of three different adipogenic differentiation protocols in MSCs. We observed that HSL and its activated form are produced in cell cultures induced with factors for white, beige, and brown adipogenic differentiation.

scholarly journals Central melanocortin stimulation increases phosphorylated perilipin A and hormone-sensitive lipase in adipose tissues

2010 ◽  
Vol 299 (1) ◽  
pp. R140-R149 ◽  
Author(s):  
Y. B. Shrestha ◽  
C. H. Vaughan ◽  
B. J. Smith ◽  
C. K. Song ◽  
D. J. Baro ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Sympathetic Nerves ◽  
Hormone Sensitive Lipase ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Perilipin A ◽  
Hormone Sensitive

Norepinephrine (NE) released from the sympathetic nerves innervating white adipose tissue (WAT) is the principal initiator of lipolysis in mammals. Central WAT sympathetic outflow neurons express melanocortin 4-receptor (MC4-R) mRNA. Single central injection of melanotan II (MTII; MC3/4-R agonist) nonuniformly increases WAT NE turnover (NETO), increases interscapular brown adipose tissue (IBAT) NETO, and increases the circulating lipolytic products glycerol and free fatty acid. The WAT pads that contributed to this lipolysis were inferred from the increases in NETO. Because phosphorylation of perilipin A (p-perilipin A) and hormone-sensitive lipase are necessary for NE-triggered lipolysis, we tested whether MTII would increase these intracellular markers of lipolysis. Male Siberian hamsters received a single 3rd ventricular injection of MTII or saline. Trunk blood was collected at 0.5, 1.0, and 2.0 h postinjection from excised inguinal, retroperitoneal, and epididymal WAT (IWAT, RWAT, and EWAT, respectively) and IBAT pads. MTII increased circulating glycerol concentrations at 0.5 and 1.0 h, whereas free fatty acid concentrations were increased at 1.0 and 2.0 h. Western blot analysis showed that MTII specifically increased p-perilipin A and hormone-sensitive lipase only in fat pads that previously had MTII-induced increases in NETO. Phosphorylation increased in IWAT at all time points and IBAT at 0.5 h, but not RWAT or EWAT at any time point. These results show for the first time in rodents that p-perilipin A can serve as an in vivo, fat pad-specific indictor of lipolysis and extend our previous findings showing that central melanocortin stimulation increases WAT lipolysis.

Hormone-sensitive lipase in brown adipose tissue: Identification and effect of cold exposure

1987 ◽  
Vol 7 (11) ◽  
pp. 897-904 ◽  
Author(s):  
Cecilia Holm ◽  
Gudrun Fredrikson ◽  
Barbara Cannon ◽  
Per Belfrage
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Specific Effect ◽  
Hormone Sensitive Lipase ◽  
Tissue Identification ◽  
Brown Adipose ◽  
Hormone Sensitive ◽  
Specific Activities ◽  
White Fat

Hormone-sensitive lipase (HSL) in brown adipose tissue from mice was identified through immunoprecipitation with a polyclonal antibody (anti-HSL) towards rat white fat HSL and Western blotting. An 82 kDa polypeptide, slightly smaller than the rat white fat HSL 84 kDa subunit, was detected and its identity as HSL verified by inhibition properties. The HSL concentration per g tissue was several-fold higher in the mouse brown adipose tissue than in the rat white adipose tissue, but the specific activities per mg protein were similar. Cold-exposure (4°C of the mice for 24 h approximately doubled the HSL concentration but this increase parallelled the overall protein increase and did not reflect a specific effect on the HSL.

scholarly journals Methylation of estrogens, obesity and breast cancer

2018 ◽  
Vol 64 (4) ◽  
pp. 244-251
Author(s):  
Natalia B. Chagay ◽  
Ashot M. Mkrtumyan
Keyword(s):  
Adipose Tissue ◽  
Methylation Status ◽  
The Body ◽  
Hormone Sensitive Lipase ◽  
Main Function ◽  
Adrenergic Stimulation ◽  
Brown Adipocytes ◽  
Brown Adipose ◽  
Hormone Sensitive ◽  
Stimulation Of

Methylation of catechol estrogens is catalyzed by catechol-O-methyltransferase. Synthesis and activity of this enzyme is encoded by the COMT gene. Downregulation of COMT expression is responsible for the risk of developing estrogen-dependent tumors. Obesity is a factor determining the overall methylation status in the body. There are two main types of adipose tissue differing in their functional and metabolic characteristics, as well as the microscopic structure: white adipose tissue (WAT) and brown adipose tissue (BAT). Lipolysis of WAT is controlled by hormone-sensitive lipase, which depends is catecholamine dependent. BAT is a special type of adipose tissue whose main function is to produce heat. Activation of β3-adrenergic receptors by catecholamines, both at the central and peripheral levels, is the primary mechanism regulating thermogenesis in mature BAT. Obese patients develop adipose tissue hypoxia, as well as WAT and BAT dysfunction. Adrenergic stimulation of thermogenesis is unclaimed because of «whitening» of brown adipocytes, which manifests itself as degradation of mitochondria. Redirection of stimulation of hormone-sensitive lipase by catecholamines to WAT and the increased need to enhance COMT expression are the potential consequences of modifying the BAT metabolism. Estrogens are natural modulators of lipolysis (as they selectively affect activity of hormone-sensitive lipase) and regulators of BAT thermogenesis. Obesity is accompanied by elevated synthesis of estrone. However, in postmenopausal women it is characterized by a decrease in the total mass and activity of BAT. The role of BAT in the progression or inhibition of growth of the estrogen-dependent tumor tissue at premenopausal and postmenopausal age has not been studied yet and is of interest to researchers. The possible correlation between the activity of brown adipocytes and the COMT expression level is discussed in the context of the risk of developing benign breast dysplasia and cancer.

scholarly journals Hormone-sensitive lipase of rat adipose tissue. Purification and some properties.

1981 ◽  
Vol 256 (12) ◽  
pp. 6311-6320
Author(s):  
G. Fredrikson ◽  
P. Strålfors ◽  
N.O. Nilsson ◽  
P. Belfrage
Keyword(s):  
Adipose Tissue ◽  
Hormone Sensitive Lipase ◽  
Hormone Sensitive ◽  
Rat Adipose Tissue

scholarly journals Effects of Physiological Hypercortisolemia on the Regulation of Lipolysis in Subcutaneous Adipose Tissue1

1998 ◽  
Vol 83 (2) ◽  
pp. 626-631 ◽  
Author(s):  
Jaswinder S. Samra ◽  
Mo L. Clark ◽  
Sandy M. Humphreys ◽  
Ian A. MacDonald ◽  
Peter A. Bannister ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Sodium Succinate ◽  
Hormone Sensitive Lipase ◽  
Whole Body ◽  
Constant Infusion ◽  
Nonesterified Fatty Acid ◽  
Significant Difference ◽  
Hormone Sensitive ◽  
Subcutaneous Adipose

Cortisol is known to increase whole body lipolysis, yet chronic hypercortisolemia results in increased fat mass. The main aim of the study was to explain these two apparently opposed observations by examining the acute effects of hypercortisolemia on lipolysis in subcutaneous adipose tissue and in the whole body. Six healthy subjects were studied on two occasions. On one occasion hydrocortisone sodium succinate was infused iv to induce hypercortisolemia (mean plasma cortisol concentrations, 1500 ± 100 vs. 335± 25 nmol/L; P < 0.001); on the other occasion (control study) no intervention was made. Lipolysis in the sc adipose tissue of the anterior abdominal wall was studied by measurement of arterio-venous differences, and lipolysis in the whole body was studied by constant infusion of[ 1,2,3-2H5]glycerol for measurement of the systemic glycerol appearance rate. Hypercortisolemia led to significantly increased arterialized plasma nonesterified fatty acid (NEFA; P < 0.01) and blood glycerol concentrations (P < 0.05), with an increase in systemic glycerol appearance (P < 0.05). However, in sc abdominal adipose tissue, hypercortisolemia decreased veno-arterialized differences for NEFA (P < 0.05) and reduced NEFA efflux (P < 0.05). This reduction was attributable to decreased intracellular lipolysis (P < 0.05), reflecting decreased hormone-sensitive lipase action in this adipose depot. Hypercortisolemia caused a reduction in arterialized plasma TAG concentrations (P < 0.05), but without a significant change in the local extraction of TAG (presumed to reflect the action of adipose tissue lipoprotein lipase). There was no significant difference in plasma insulin concentrations between the control and hypercortisolemia study. Site-specific regulation of the enzymes of intracellular lipolysis (hormone-sensitive lipase) and intravascular lipolysis (lipoprotein lipase) may explain the ability of acute cortisol treatment to increase systemic glycerol and NEFA appearance rates while chronically promoting net central fat deposition.

scholarly journals Activation of hormone-sensitive lipase in extracts of adipose tissue

1970 ◽  
Vol 11 (5) ◽  
pp. 466-472
Author(s):  
SU-CHEN TSAI ◽  
PER BELFRAGE ◽  
MARTHA VAUGHAN
Keyword(s):  
Adipose Tissue ◽  
Hormone Sensitive Lipase ◽  
Hormone Sensitive
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