Characteristics of lipid droplets and the expression of proteins involved in lipolysis in the murine cervix during mid-pregnancy

2020 ◽  
Vol 32 (11) ◽  
pp. 967
Author(s):  
Longlong Tao ◽  
Hongyan Zhang ◽  
Hongmei Wang ◽  
Liuhui Li ◽  
Libo Huang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lipid Droplets ◽  
Smooth Muscles ◽  
Hormone Sensitive Lipase ◽  
Apical Region ◽  
Pge2 Synthesis ◽  
Dependent Protein ◽  
Hormone Sensitive ◽  
Cervical Epithelial Cells ◽  
Pg E2

Lipid droplets (LDs) are reservoirs of arachidonoyl lipids for prostaglandin (PG) E2 synthesis, and progesterone can stimulate PGE2 synthesis; however, the relationship between progesterone and LD metabolism in the murine cervix remains unclear. In the present study we examined LD distribution and changes in the expression of proteins involved in lipolysis and autophagy in the murine cervix during pregnancy, and compared the findings with those in dioestrous mice. During mid-pregnancy, LDs were predominantly distributed in the cervical epithelium. Electron microscopy revealed the transfer of numerous LDs from the basal to apical region in the luminal epithelium, marked catabolism of LDs, an elevated number of LDs and autophagosomes and a higher LD:mitochondrion size ratio in murine cervical epithelial cells (P<0.05). In addition, immunohistochemical and western blotting analyses showed significantly higher cAMP-dependent protein kinase, adipose triglyceride lipase and hormone-sensitive lipase expression, and a higher light chain 3 (LC3) II:LC3I ratio in the stroma and smooth muscles and, particularly, in murine cervical epithelial cells, during mid-pregnancy than late dioestrus. In conclusion, these results suggest that the enhanced lipolysis of LDs and autophagy in murine cervical tissues were closely related to pregnancy and were possibly controlled by progesterone because LD catabolism may be necessary for energy provision and PGE2 synthesis to maintain a closed pregnant cervix.

scholarly journals Expression of hormone-sensitive lipase and its regulation by adrenaline in skeletal muscle

1999 ◽  
Vol 340 (2) ◽  
pp. 459-465 ◽  
Author(s):  
Jozef LANGFORT ◽  
Thorkil PLOUG ◽  
Jacob IHLEMANN ◽  
Michele SALDO ◽  
Cecilia HOLM ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Soleus Muscle ◽  
Lipase Activity ◽  
Glycogen Phosphorylase ◽  
Hormone Sensitive Lipase ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Hormone Sensitive ◽  
Neutral Lipase

The enzymic regulation of triacylglycerol breakdown in skeletal muscle is poorly understood. Western blotting of muscle fibres isolated by collagenase treatment or after freeze-drying demonstrated the presence of immunoreactive hormone-sensitive lipase (HSL), with the concentrations in soleus and diaphragm being more than four times the concentrations in extensor digitorum longus and epitrochlearis muscles. Neutral lipase activity determined under conditions optimal for HSL varied directly with immunoreactivity. Expressed relative to triacylglycerol content, neutral lipase activity in soleus muscle was about 10 times that in epididymal adipose tissue. In incubated soleus muscle, both neutral lipase activity against triacylglycerol (but not against a diacylglycerol analogue) and glycogen phosphorylase activity increased in response to adrenaline (epinephrine). The lipase activation was completely inhibited by anti-HSL antibody and by propranolol. The effect of adrenaline could be mimicked by incubation of crude supernatant from control muscle with the catalytic subunit of cAMP-dependent protein kinase, while no effect of the kinase subunit was seen with supernatant from adrenaline-treated muscle. The results indicate that HSL is present in skeletal muscle and is stimulated by adrenaline via β-adrenergic activation of cAMP-dependent protein kinase. The concentration of HSL is higher in oxidative than in glycolytic muscle, and the enzyme is activated in parallel with glycogen phosphorylase.

scholarly journals Perilipin A is essential for the translocation of hormone-sensitive lipase during lipolytic activation

2003 ◽  
Vol 161 (6) ◽  
pp. 1093-1103 ◽  
Author(s):  
Carole Sztalryd ◽  
Guoheng Xu ◽  
Heidi Dorward ◽  
John T. Tansey ◽  
Juan A. Contreras ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Chinese Hamster Ovary ◽  
Lipid Droplets ◽  
Chinese Hamster ◽  
Hormone Sensitive Lipase ◽  
Ovary Cell ◽  
Perilipin A ◽  
Hormone Sensitive ◽  
Kinase A

Akey step in lipolytic activation of adipocytes is the translocation of hormone-sensitive lipase (HSL) from the cytosol to the surface of the lipid storage droplet. Adipocytes from perilipin-null animals have an elevated basal rate of lipolysis compared with adipocytes from wild-type mice, but fail to respond maximally to lipolytic stimuli. This defect is downstream of the β-adrenergic receptor–adenylyl cyclase complex. Now, we show that HSL is basally associated with lipid droplet surfaces at a low level in perilipin nulls, but that stimulated translocation from the cytosol to lipid droplets is absent in adipocytes derived from embryonic fibroblasts of perilipin-null mice. We have also reconstructed the HSL translocation reaction in the nonadipocyte Chinese hamster ovary cell line by introduction of GFP-tagged HSL with and without perilipin A. On activation of protein kinase A, HSL-GFP translocates to lipid droplets only in cells that express fully phosphorylatable perilipin A, confirming that perilipin is required to elicit the HSL translocation reaction. Moreover, in Chinese hamster ovary cells that express both HSL and perilipin A, these two proteins cooperate to produce a more rapidly accelerated lipolysis than do cells that express either of these proteins alone, indicating that lipolysis is a concerted reaction mediated by both protein kinase A–phosphorylated HSL and perilipin A.

scholarly journals Amber Extract Reduces Lipid Content in Mature 3T3-L1 Adipocytes by Activating the Lipolysis Pathway

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4630
Author(s):  
Erica Sogo ◽  
Siqi Zhou ◽  
Haruna Haeiwa ◽  
Reiko Takeda ◽  
Kazuma Okazaki ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Lipid Droplets ◽  
Hormone Sensitive Lipase ◽  
Physiological Effects ◽  
Glycerol Release ◽  
Rosin Acids ◽  
Genes Encoding ◽  
Triglyceride Content ◽  
Hormone Sensitive ◽  
Release Of Glycerol

Amber—the fossilized resin of trees—is rich in terpenoids and rosin acids. The physiological effects, such as antipyretic, sedative, and anti-inflammatory, were used in traditional medicine. This study aims to clarify the physiological effects of amber extract on lipid metabolism in mouse 3T3-L1 cells. Mature adipocytes are used to evaluate the effect of amber extract on lipolysis by measuring the triglyceride content, glucose uptake, glycerol release, and lipolysis-related gene expression. Our results show that the amount of triacylglycerol, which is stored in lipid droplets in mature adipocytes, decreases following 96 h of treatment with different concentrations of amber extract. Amber extract treatment also decreases glucose uptake and increases the release of glycerol from the cells. Moreover, amber extract increases the expression of lipolysis-related genes encoding perilipin and hormone-sensitive lipase (HSL) and promotes the activity of HSL (by increasing HSL phosphorylation). Amber extract treatment also regulates the expression of other adipocytokines in mature adipocytes, such as adiponectin and leptin. Overall, our results indicate that amber extract increases the expression of lipolysis-related genes to induce lipolysis in 3T3-L1 cells, highlighting its potential for treating various obesity-related diseases.

scholarly journals Absence of cardiac lipid accumulation in transgenic mice with heart-specific HSL overexpression

2001 ◽  
Vol 281 (4) ◽  
pp. E857-E866 ◽  
Author(s):  
Jinya Suzuki ◽  
Wen-Jun Shen ◽  
Brett D. Nelson ◽  
Shailja Patel ◽  
Jacques H. Veerkamp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Adipose Tissue ◽  
Lipid Droplets ◽  
Cytoskeletal Proteins ◽  
Hormone Sensitive Lipase ◽  
Acid Oxidation ◽  
Histocompatibility Antigens ◽  
Altered Expression ◽  
Hormone Sensitive ◽  
Responsive Element

Hormone-sensitive lipase (HSL) hydrolyzes triglyceride (TG) in adipose tissue. HSL is also expressed in heart. To explore the actions of cardiac HSL, heart-specific, tetracycline (Tc)-controlled HSL-overexpressing mice were generated. Tc-responsive element-HSL transgenic (Tg) mice were generated and crossed with myosin heavy chain (MHC)α-tTA Tg mice, which express the Tc-responsive transactivator (tTA) in the heart. The double-Tg mice (MHC-HSL) were maintained with doxycycline (Dox) to suppress Tg HSL. Upon removal of Dox, cardiac HSL activity and protein increased 12- and 8-fold, respectively, and the expression was heart specific. Although cardiac TG content increased twofold in control mice after an overnight fast, it did not increase in HSL-induced mice. Electron microscopy showed numerous lipid droplets in the myocardium of fasted control mice, whereas fasted HSL-induced mice showed virtually no droplets. Microarray analysis showed altered expression of cardiac genes for fatty acid oxidation, transcription factors, signaling molecules, cytoskeletal proteins, and histocompatibility antigens in HSL-induced mice. Thus cardiac HSL plays a role in controlling accumulation of triglyceride droplets and can affect the expression of a number of cardiac genes.

scholarly journals The presence and role of hormone-sensitive lipase in heart muscle

1989 ◽  
Vol 258 (1) ◽  
pp. 67-72 ◽  
Author(s):  
C A Small ◽  
A J Garton ◽  
S J Yeaman
Keyword(s):  
Adipose Tissue ◽  
Heart Muscle ◽  
Lipolytic Activity ◽  
Hormone Sensitive Lipase ◽  
Energy Store ◽  
Dependent Protein ◽  
Hormone Sensitive ◽  
Rat Myocytes ◽  
Adipose Tissue Lipolysis

Hormone-sensitive lipase (HSL) catalyses the initial, rate-limiting, reaction in adipose-tissue lipolysis. Hormone-stimulated lipolytic activity has also been observed in the heart, where endogenous triacylglycerol is the major energy store. However, the identity of the intracellular lipase responsible has yet to be established. We have partially purified a neutral lipase from bovine heart muscle and compared its properties with those of HSL from bovine adipose tissue. The heart lipase has the same subunit Mr as HSL, is immunoprecipitated by antiserum raised against purified HSL and is phosphorylated by cyclic AMP-dependent protein kinase, apparently at the same site as HSL (as judged by h.p.l.c. of tryptic phosphopeptides). Phosphorylation of the heart lipase was found to result in increased enzyme activity, demonstrating the lipase's potential to respond to hormonal stimuli. The heart lipase was shown to be present in myocytes by its immunoprecipitation from homogenates of rat myocytes by anti-HSL antiserum. These findings are consistent with the conclusion that HSL is responsible for intracellular lipolysis in heart.

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