calpastatin and Obesity

Adipose tissue macrophages have been proposed as a link between obesity and insulin resistance. However, the mechanisms underlying these processes are not completely defined. Calpains are calcium-dependent neutral cysteine proteases that modulate cellular function and have been implicated in various inflammatory diseases. To define whether activated calpains influence diet-induced obesity and adipose tissue macrophage accumulation, mice that were either wild type (WT) or overexpressing calpastatin (CAST Tg), the endogenous inhibitor of calpains were fed with high (60% kcal) fat diet for 16 weeks. CAST overexpression did not influence high fat diet-induced body weight and fat mass gain throughout the study. Calpain inhibition showed a transient improvement in glucose tolerance at 5 weeks of HFD whereas it lost this effect on glucose and insulin tolerance at 16 weeks HFD in obese mice. However, CAST overexpression significantly reduced adipocyte apoptosis, adipose tissue collagen and macrophage accumulation as detected by TUNEL, Picro Sirius and F4/80 immunostaining, respectively. CAST overexpression significantly attenuated obesity-induced inflammatory responses in adipose tissue. Furthermore, calpain inhibition suppressed macrophage migration to adipose tissue in vitro. The present study demonstrates a pivotal role for calpains in mediating HFD-induced adipose tissue remodeling by influencing multiple functions including apoptosis, fibrosis and inflammation.

Topics: 3T3 Cells; Adipocytes; Adipose Tissue; Animals; Apoptosis; Calcium-Binding Proteins; Calpain; Collagen; Diet, High-Fat; Disease Models, Animal; Fibrosis; Inflammation; Liver; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Myocardium; Obesity; Weight Gain

The effects of coronary perivascular adipose tissue (PVAT) on vasomotor tone are influenced by an obese phenotype and are distinct from other adipose tissue depots. The purpose of this investigation was to examine the effects of lean and obese coronary PVAT on end-effector mechanisms of coronary vasodilation and to identify potential factors involved.. Hematoxylin and eosin staining revealed similarities in coronary perivascular adipocyte size between lean and obese Ossabaw swine. Isometric tension studies of isolated coronary arteries from Ossabaw swine revealed that factors derived from lean and obese coronary PVAT attenuated vasodilation to adenosine. Lean coronary PVAT inhibited K(Ca) and KV7, but not KATP channel-mediated dilation in lean arteries. In the absence of PVAT, vasodilation to K(Ca) and KV7 channel activation was impaired in obese arteries relative to lean arteries. Obese PVAT had no effect on K(Ca) or KV7 channel-mediated dilation in obese arteries. In contrast, obese PVAT inhibited KATP channel-mediated dilation in both lean and obese arteries. The differential effects of obese versus lean PVAT were not associated with changes in either coronary KV7 or K(ATP) channel expression. Incubation with calpastatin attenuated coronary vasodilation to adenosine in lean but not in obese arteries.. These findings indicate that lean and obese coronary PVAT attenuates vasodilation via inhibitory effects on vascular smooth muscle K(+) channels and that alterations in specific factors such as calpastatin are capable of contributing to the initiation or progression of smooth muscle dysfunction in obesity.

Topics: Adenosine Triphosphate; Adipose Tissue; Animals; Calcium-Binding Proteins; Coronary Vessels; Muscle, Smooth, Vascular; Obesity; Potassium Channels; Potassium Channels, Calcium-Activated; Potassium Channels, Voltage-Gated; Swine; Thinness; Vasodilation

This investigation examined the mechanisms by which coronary perivascular adipose tissue (PVAT)-derived factors influence vasomotor tone and the PVAT proteome in lean versus obese swine.. Coronary arteries from Ossabaw swine were isolated for isometric tension studies. We found that coronary (P=0.03) and mesenteric (P=0.04) but not subcutaneous adipose tissue augmented coronary contractions to KCl (20 mmol/L). Inhibition of CaV1.2 channels with nifedipine (0.1 µmol/L) or diltiazem (10 µmol/L) abolished this effect. Coronary PVAT increased baseline tension and potentiated constriction of isolated arteries to prostaglandin F2α in proportion to the amount of PVAT present (0.1-1.0 g). These effects were elevated in tissues obtained from obese swine and were observed in intact and endothelium denuded arteries. Coronary PVAT also diminished H2O2-mediated vasodilation in lean and, to a lesser extent, in obese arteries. These effects were associated with alterations in the obese coronary PVAT proteome (detected 186 alterations) and elevated voltage-dependent increases in intracellular [Ca(2+)] in obese smooth muscle cells. Further studies revealed that the Rho-kinase inhibitor fasudil (1 µmol/L) significantly blunted artery contractions to KCl and PVAT in lean but not obese swine. Calpastatin (10 μmol/L) also augmented contractions to levels similar to that observed in the presence of PVAT.. Vascular effects of PVAT vary according to anatomic location and are influenced by an obese phenotype. Augmented contractile effects of obese coronary PVAT are related to alterations in the PVAT proteome (eg, calpastatin), Rho-dependent signaling, and the functional contribution of K(+) and CaV1.2 channels to smooth muscle tone.

Topics: Animals; Body Weight; Calcium-Binding Proteins; Coronary Artery Disease; Coronary Vessels; Cysteine Proteinase Inhibitors; Disease Models, Animal; Intra-Abdominal Fat; Isometric Contraction; Mesenteric Arteries; Muscle, Smooth, Vascular; Obesity; Proteomics; Subcutaneous Fat; Sus scrofa; Vasoconstriction

Adipose tissue maintains a subpopulation of cells, referred to as adipose-derived stromal/stem cells (ASCs), which have been associated with increased breast cancer tumorigenesis and metastasis. For ASCs to affect breast cancer cells, it is necessary to delineate how they mobilize and home to cancer cells, which requires mobilization and invasion through extracellular matrix barriers. In this study, ASCs were separated into four different categories based on the donor's obesity status and depot site of origin. ASCs isolated from the subcutaneous abdominal adipose tissue of obese patients (Ob(+)Ab(+)) demonstrated increased invasion through Matrigel as well as a chick chorioallantoic membrane, a type I collagen-rich extracellular matrix barrier. Detailed mRNA and protein analyses revealed that calpain-4, calpastatin, and MMP-15 were associated with increased invasion, and the silencing of each protease or protease inhibitor confirmed their role in ASC invasion. Thus, the data indicate that both the donor's obesity status and depot site of origin distinguishes the properties of subcutaneous-derived ASCs with respect to enhanced invasion and this is associated with the dysregulation of calpain-4, calpastatin, and MMP-15.

Topics: Adipocytes; Animals; Breast Neoplasms; Calcium-Binding Proteins; Cell Culture Techniques; Cell Differentiation; Cell Line, Tumor; Cell Movement; Chick Embryo; Dipeptides; Female; Humans; Matrix Metalloproteinase 15; Neoplasm Invasiveness; Obesity; RNA, Messenger; RNA, Small Interfering; Stem Cells; Stromal Cells; Transfection

Sex differences are observed in many aspects of mammalian cardiovascular function and pathology. Hypertension is more common in men than in women of the same age. Although the effects of gonadal hormones on blood pressure are considered contributing factors, the reasons for sex differences in hypertension are still not fully understood. The present study was undertaken to compare the differences in several environmental and genetic factors between men and women in the Hei Yi Zhuang, an isolated subgroup of the Zhuang minority in China.. Information on demography, diet, and lifestyle was collected in 835 women and 834 men aged 15 to 84 years. Genotyping of angiotensin-converting enzyme, adrenergic receptor beta(3), aldehyde dehydrogenase 2, calpastatin, connexin 37, hepatic lipase, lipoprotein lipase, peroxisome proliferator-activated receptor gamma, thyrotropin-releasing hormone receptor, and von Willebrand factor also was performed in these subjects.. The levels of systolic and diastolic blood pressure, and the prevalence, awareness, and treatment of hypertension were lower in women than in men (P < .05). Hypertension was positively associated with age, physical activity, alcohol consumption, body mass index, waist circumference, hyperlipidemia, total energy, total fat, sodium intake, and sodium/potassium ratio, and negatively associated with education level, total dietary fiber, potassium intake, angiotensin-converting enzyme, aldehyde dehydrogenase 2, and hepatic lipase genotypes in men (P < .05). Hypertension was positively associated with age, hyperlipidemia, total energy, total fat, sodium intake, sodium/potassium ratio, calpastatin, and von Willebrand factor genotypes, and negatively associated with education level, total dietary fiber, potassium, calcium intake, lipoprotein lipase, and thyrotropin-releasing hormone receptor genotypes in women (P < .05).. Sex differences in the prevalence of hypertension in the Hei Yi Zhuang population may be mainly attributed to the differences in dietary habits, lifestyle choices, sodium and potassium intakes, physical activity level, and some genetic polymorphisms.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aldehyde Dehydrogenase; Aldehyde Dehydrogenase, Mitochondrial; Calcium-Binding Proteins; China; Connexins; Female; Gap Junction alpha-4 Protein; Genotype; Humans; Hypertension; Life Style; Lipase; Lipoprotein Lipase; Male; Middle Aged; Obesity; Peptidyl-Dipeptidase A; Polymorphism, Genetic; PPAR gamma; Prevalence; Receptors, Adrenergic, beta-3; Receptors, Thyrotropin-Releasing Hormone; Risk Factors; Sex Factors; von Willebrand Factor

The mode(s) of skeletal muscle protein turnover as well as muscle and animal growth may be studied by using lean and obese animals as models. The objectives of this study were to look at proteolytic variables implicated in these processes. A lean and obese strain of swine from similar genetic lineage (Duroc x Yorkshire, 50:50) have been well established and may prove ideal for this purpose. This study was done in two phases. Phase I included eight lean and eight obese pigs at 2.5 months of age, and phase II was identical, but the pigs were 7 months old. Longissimus muscle samples were processed immediately after euthanasia for activity measurements of mu-calpain, m-calpain, calpastatin, and lysosomal cathepsins B and B + L. Additional samples were taken for DNA, RNA, and total protein determinations. In phase I, total calpastatin activity, total and specific cathepsin B+L activity, and total protein/g muscle were greater in the obese pigs than in the lean pigs. In contrast, DNA and RNA/g muscle were greater in the lean pigs. No other differences were observed in phase I. In phase II, total calpastatin activity and total cathepsin B activity were greater in the obese pigs than in the lean pigs. No other differences were observed in phase II. From phase I to phase II, mu-calpain total activity increased in the lean pigs but not in the obese pigs and calpastatin activity decreased in both lean and obese pigs; however, the phase-II-obese and phase-I-lean total calpastatin concentrations were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aging; Animals; Calcium-Binding Proteins; Calpain; Cathepsin B; Cathepsin L; Cathepsins; Cysteine Endopeptidases; DNA; Endopeptidases; Muscles; Obesity; RNA; Swine