ROLE OF ANGIOTENSIN CONVERTING ENZYME 2 (ACE2) IN OBESITY-ASSOCIATED HYPERTENSION

The purpose of this research was to determine whether adipocytes express ACE2 and its role in obesity-associated hypertension with diet-induced obesity. To determine if ACE2 was expressed in adipose tissue and its regulation in the setting of diet-induced obesity, we fed male mice either a low fat (LF) or high fat (HF) diet acutely (1 week) or chronically ( 4 months). We demonstrated that ACE2 was regulated specifically in adipose tissue with consumption of a HF diet. However, with chronic HF feeding adipose ACE2 was dysregulated resulting in activation of the systemic RAS and increased blood pressure. To determine the role of ACE2 in obesity-associated hypertension, we used ACE2 deficient male and female mice. Wild type and ACE2 deficient mice were chronically fed either a LF or HF diet. Metabolic parameters were measured during the entire course of the study and blood pressure was measured by telemetry at the end of the study. Results from these studies demonstrate that HF diet promotes obesity-associated hypertension in male mice which is further augmented with ACE2 deficiency. Further, ACE2 deficiency resulted in marked glucose intolerance suggesting that stimulation of ACE2 may blunt the progression of obesity-associated diabetes. In contrast to the males, females are protected against obesity-associated hypertension. However, this protection in the females is lost with ovariectomy and ACE2 deficiency. These results suggest that female sex hormones protect the females against obesity-associated hypertension by regulating ACE2. To define mechanisms for HF diet-induced regulation of ACE2 in adipose tissue we examined various fatty acids for their ability to regulate ACE2 mRNA abundance in 3T3-L1 adipocytes. We revealed that omega-3 fatty acids, known regulators of PPARγ, increased ACE2 mRNA abundance in adipocytes. Therefore, we examined in vitro and in vivo regulation of ACE2 in 3T3-L1 cells and adipose tissue by PPARγ receptor ligands (TZDs). Results demonstrate regulatory effects of PPARγ to promote ACE2 gene transcription. These effects were associated with changes in glucose tolerance. Taken together, these results demonstrate that adipose ACE2 plays a protective role against obesity-associated hypertension in male and female mice and is regulated by natural and synthetic ligands of PPARγ

Deficiency of ACE2 in Bone-Marrow-Derived Cells Increases Expression of TNF-α in Adipose Stromal Cells and Augments Glucose Intolerance in Obese C57BL/6 Mice

Deficiency of ACE2 in macrophages has been suggested to promote the development of an inflammatory M1 macrophage phenotype. We evaluated effects of ACE2 deficiency in bone-marrow-derived stem cells on adipose inflammation and glucose tolerance in C57BL/6 mice fed a high fat (HF) diet. ACE2 activity was increased in the stromal vascular fraction (SVF) isolated from visceral, but not subcutaneous adipose tissue of HF-fed mice. Deficiency of ACE2 in bone marrow cells significantly increased mRNA abundance of F4/80 and TNF-α in the SVF isolated from visceral adipose tissue of HF-fed chimeric mice, supporting increased presence of inflammatory macrophages in adipose tissue. Moreover, deficiency of ACE2 in bone marrow cells modestly augmented glucose intolerance in HF-fed chimeric mice and increased blood levels of glycosylated hemoglobin. In summary, ACE2 deficiency in bone marrow cells promotes inflammation in adipose tissue and augments obesity-induced glucose intolerance

A criança asmática: Relação e terreno alérgico.

Relata-se o caso clínico de uma criança com asma alérgica. Efectua-se uma abordagem compreensiva através do modelo multidimensional de somatização proposto por Sami-Ali.ABSTRACT: Clinical report on a case study of a child with a psychosomatic disorder: bronquial asthma. The main focus of this paper is on an approach based on the Sami-Ali's somatization multidimensional model.info:eu-repo/semantics/publishedVersio

Chronic neuregulin-1β treatment mitigates the progression of postmyocardial infarction heart failure in the setting of Type 1 diabetes mellitus by suppressing myocardial apoptosis, fibrosis, and key oxidant-producing enzymes.

BACKGROUND: Type 1 diabetes mellitus (DM) patients surviving myocardial infarction (MI) have substantially higher cardiovascular morbidity and mortality compared to their nondiabetic counterparts owing to the more frequent development of subsequent heart failure (HF). Neuregulin (NRG)-1β is released from cardiac microvascular endothelial cells and acts as a paracrine factor via the ErbB family of tyrosine kinase receptors expressed in cardiac myocytes to regulate cardiac development and stress responses. Because myocardial NRG-1/ErbB signaling has been documented to be impaired during HF associated with type 1 DM, we examined whether enhancement of NRG-1β signaling via exogenous administration of recombinant NRG-1β could exert beneficial effects against post-MI HF in the type 1 diabetic heart. METHODS AND RESULTS: Type 1 DM was induced in male Sprague Dawley rats by a single injection of streptozotocin (STZ) (65 mg/kg). Two weeks after induction of type 1 DM, rats underwent left coronary artery ligation to induce MI. STZ-diabetic rats were treated with saline or NRG-1β (100 µg/kg) twice per week for 7 weeks, starting 2 weeks before experimental MI. Residual left ventricular function was significantly greater in the NRG-1β-treated STZ-diabetic MI group compared with the vehicle-treated STZ-diabetic MI group 5 weeks after MI as assessed by high-resolution echocardiography. NRG-1β treatment of STZ-diabetic MI rats was associated with reduced myocardial fibrosis and apoptosis as well as decreased gene expression of key oxidant-producing enzymes. CONCLUSIONS: These results suggest that recombinant NRG-1β may be a promising therapeutic for HF post-MI in the setting of type 1 DM

Deletion of Cardiomyocyte Glycogen Synthase Kinase-3 Beta (GSK-3β) Improves Systemic Glucose Tolerance with Maintained Heart Function in Established Obesity

Obesity is an independent risk factor for cardiovascular diseases (CVD), including heart failure. Thus, there is an urgent need to understand the molecular mechanism of obesity-associated cardiac dysfunction. We recently reported the critical role of cardiomyocyte (CM) Glycogen Synthase Kinase-3 beta (GSK-3β) in cardiac dysfunction associated with a developing obesity model (deletion of CM-GSK-3β prior to obesity). In the present study, we investigated the role of CM-GSK-3β in a clinically more relevant model of established obesity (deletion of CM-GSK-3β after established obesity). CM-GSK-3β knockout (GSK-3βfl/flCre+/−) and controls (GSK-3βfl/flCre−/−) mice were subjected to a high-fat diet (HFD) in order to establish obesity. After 12 weeks of HFD treatment, all mice received tamoxifen injections for five consecutive days to delete GSK-3β specifically in CMs and continued on the HFD for a total period of 55 weeks. To our complete surprise, CM-GSK-3β knockout (KO) animals exhibited a globally improved glucose tolerance and maintained normal cardiac function. Mechanistically, in stark contrast to the developing obesity model, deleting CM-GSK-3β in obese animals did not adversely affect the GSK-3αS21 phosphorylation (activity) and maintained canonical β-catenin degradation pathway and cardiac function. As several GSK-3 inhibitors are in the trial to treat various chronic conditions, including metabolic diseases, these findings have important clinical implications. Specifically, our results provide critical pre-clinical data regarding the safety of GSK-3 inhibition in obese patients

Isoform-Specific Role of GSK-3 in High Fat Diet Induced Obesity and Glucose Intolerance

Obesity-associated metabolic disorders are rising to pandemic proportions; hence, there is an urgent need to identify underlying molecular mechanisms. Glycogen synthase kinase-3 (GSK-3) signaling is highly implicated in metabolic diseases. Furthermore, GSK-3 expression and activity are increased in Type 2 diabetes patients. However, the isoform-specific role of GSK-3 in obesity and glucose intolerance is unclear. Pharmacological GSK-3 inhibitors are not isoform-specific, and tissue-specific genetic models are of limited value to predict the clinical outcome of systemic inhibiion. To overcome these limitations, we created novel mouse models of ROSA26CreERT2-driven, tamoxifen-inducible conditional deletion of GSK-3 that allowed us to delete the gene globally in an isoform-specific and temporal manner. Isoform-specific GSK-3 KOs and littermate controls were subjected to a 16-week high-fat diet (HFD) protocol. On an HFD, GSK-3α KO mice had a significantly lower body weight and modest improvement in glucose tolerance compared to their littermate controls. In contrast, GSK-3β-deletion-mediated improved glucose tolerance was evident much earlier in the timeline and extended up to 12 weeks post-HFD. However, this protective effect weakened after chronic HFD (16 weeks) when GSK-3β KO mice had a significantly higher body weight compared to controls. Importantly, GSK-3β KO mice on a control diet maintained significant improvement in glucose tolerance even after 16 weeks. In summary, our novel mouse models allowed us to delineate the isoform-specific role of GSK-3 in obesity and glucose tolerance. From a translational perspective, our findings underscore the importance of maintaining a healthy weight in patients receiving lithium therapy, which is thought to work by GSK-3 inhibition mechanisms

Immunomodulatory effect of a proprietary polyherbal formulation on healthy participants: A single- blind, randomized, placebo- controlled, exploratory clinical study

Context: Clinical study for immunity. Aims: The present study aimed to assess the effect of proprietary polyherbal formulation (PPHF), labelled as Kofol immunity tablets (KIT) on innate and adaptive immune responses in healthy individuals, on the backdrop of COVID-19 pandemic. Settings and Design: Single-blind, randomized, placebo-controlled, exploratory study in institutional setting. Materials and Methods: Post Ethics Committee permission, screened healthy individuals of either sex aged 18–35 years were randomized to PPHF/Placebo for 2 months. Major assessment variables included peak expiratory flow rate (PEFR), questionnaire-based immune status, perceived stress, and quality of life (QOL) with immune-specific cell counts (CD4+, CD8+), cytokines (interferon gamma [IFN-γ], tumor necrosis factor-alpha [TNF-α], interleukin 10 [IL-10]), and oxidative stress in red blood cells (RBCs) (malondialdehyde (MDA), glutathione peroxidase [GPx]), done at day 60. Statistical Analysis Used: Mean ± standard deviation and paired/unpaired t-test for parametric data analysis while median (range) and Wilcoxon Rank sum test/Mann–Whitney test for nonparametric data analysis, were done. Categorical data was analyzed using Chi-square test. GraphPad InStat software, version 9 was used with p < 0.05, as the level of statistical significance. Results: Of 52 recruited, 28 individuals completed the study. PPHF significantly increased PEFR, improved immune status along with QOL compared to baseline. It also decreased perceived stress from moderate and severe grade to mild. Serum IFN-γ levels remained almost constant post-PPHF treatment. PPHF significantly decreased MDA and increased GPx in RBCs. Significant decrease and increase in TNF-α and IL-10, respectively, were seen in PPHF group. The safety parameters post-PPHF treatment remained within normal reference ranges. Conclusions: PPHF is an efficacious and safe formulation with immunomodulatory potential

ANG II infusion promotes abdominal aortic aneurysms independent of increased blood pressure in hypercholesterolemic mice

Infusion of ANG II in hyperlipidemic mice augments atherosclerosis and causes formation of abdominal aortic aneurysms (AAAs). The purpose of this study was to define the contribution of ANG II-induced hypertension to these vascular pathologies. Male apolipoprotein E (apoE)- and LDL receptor (LDLr)-deficient mice were infused with ANG II (1,000 ng·kg−1·min−1) or norepinephrine (NE; 5.6 mg·kg−1·day−1) for 28 days. Infusion of ANG II or NE increased mean arterial pressure (MAP; ANG II, 133 ± 2.8; NE, 129 ± 13 mmHg) to a similar extent compared with baseline blood pressures (MAP, 107 ± 2 mmHg). Abdominal aortic width increased in both apoE-deficient (apoE−/−) or LDLr-deficient (LDLr−/−) mice infused with ANG II (apoE−/−: 1.4 ± 0.1; LDLr−/−: 1.6 ± 0.2 mm). In contrast, NE did not change diameters of abdominal aortas (apoE−/−: 0.91 ± 0.03; LDLr−/−: 0.87 ± 0.02 mm). Similarly, atherosclerotic lesions in aortic arches were much greater in mice infused with ANG II compared with NE. At a subpressor infusion rate of ANG II (500 ng·kg−1·min−1), AAAs developed in 50% of apoE−/− mice. Alternatively, administration of hydralazine (250 mg/l) to ANG II-infused apoE−/− mice (1,000 ng·kg−1·min−1) lowered systolic blood pressure (day 28: ANG II, 157 ± 6; ANG II/hydralazine, 135 ± 6 mmHg) but did not prevent AAA formation or atherosclerosis. These results demonstrate that infusion of ANG II to hyperlipidemic mice induces AAAs and augments atherosclerosis independent of increased blood pressure

ACE2 is expressed in mouse adipocytes and regulated by a high-fat diet

Adipose tissue expresses components of the renin-angiotensin system (RAS). Angiotensin converting enzyme (ACE2), a new component of the RAS, catabolizes the vasoconstrictor peptide ANG II to form the vasodilator angiotensin 1-7 [ANG-(1-7)]. We examined whether adipocytes express ACE2 and its regulation by manipulation of the RAS and by high-fat (HF) feeding. ACE2 mRNA expression increased (threefold) during differentiation of 3T3-L1 adipocytes and was not regulated by manipulation of the RAS. Male C57BL/6 mice were fed low- (LF) or high-fat (HF) diets for 1 wk or 4 mo. At 1 wk of HF feeding, adipose expression of angiotensinogen (twofold) and ACE2 (threefold) increased, but systemic angiotensin peptide concentrations and blood pressure were not altered. At 4 mo of HF feeding, adipose mRNA expression of angiotensinogen (twofold) and ACE2 (threefold) continued to be elevated, and liver angiotensinogen expression increased (twofold). However, adipose tissue from HF mice did not exhibit elevated ACE2 protein or activity. Increased expression of ADAM17, a protease responsible for ACE2 shedding, coincided with reductions in ACE2 activity in 3T3-L1 adipocytes, and an ADAM17 inhibitor decreased media ACE2 activity. Moreover, ADAM17 mRNA expression was increased in adipose tissue from 4-mo HF-fed mice, and plasma ACE2 activity increased. However, HF mice exhibited marked increases in plasma angiotensin peptide concentrations (LF: 2,141 ± 253; HF: 6,829 ± 1,075 pg/ml) and elevated blood pressure. These results demonstrate that adipocytes express ACE2 that is dysregulated in HF-fed mice with elevated blood pressure compared with LF controls