Publications by authors named "Vijayakumar Sukumaran"

High resolution assessment of cardiac functional parameters is crucial in translational animal research. The chick embryo is a historically well-used in vivo model for cardiovascular research due to its many practical advantages, and the conserved form and function of the chick and human cardiogenesis programs. This review aims to provide an overview of several different technical approaches for chick embryo cardiac assessment.

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Experimental and clinical evidence suggests that diabetic subjects are predisposed to a distinct cardiovascular dysfunction, known as diabetic cardiomyopathy (DCM), which could be an autonomous disease independent of concomitant micro and macrovascular disorders. DCM is one of the prominent causes of global morbidity and mortality and is on a rising trend with the increase in the prevalence of diabetes mellitus (DM). DCM is characterized by an early left ventricle diastolic dysfunction associated with the slow progression of cardiomyocyte hypertrophy leading to heart failure, which still has no effective therapy.

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The SARS-CoV-2 virus utilizes angiotensin converting enzyme () for cell entry and infection. This enzyme has important functions in the renin-angiotensin aldosterone system to preserve cardiovascular function. In addition to the heart, it is expressed in many tissues including the lung, intestines, brain, and kidney, however, its functions in these organs are mostly unknown.

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A high salt intake exacerbates insulin resistance, evoking hypertension due to systemic perivascular inflammation, oxidative-nitrosative stress and endothelial dysfunction. Angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blockers (ARBs) have been shown to abolish inflammation and redox stress but only partially restore endothelial function in mesenteric vessels. We investigated whether sympatho-adrenal overactivation evokes coronary vascular dysfunction when a high salt intake is combined with insulin resistance in male Goto-Kakizaki (GK) and Wistar rats treated with two different classes of β-blocker or vehicle, utilising synchrotron-based microangiography in vivo.

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Ghrelin is a small peptide with important roles in the regulation of appetite, gut motility, glucose homeostasis as well as cardiovascular protection. This review highlights the role that acyl ghrelin plays in maintaining normal endothelial function by maintaining the balance of vasodilator-vasoconstrictor factors, inhibiting inflammatory cytokine production and immune cell recruitment to sites of vascular injury and by promoting angiogenesis.

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Background: Obesity, hypertension and prediabetes contribute greatly to coronary artery disease, heart failure and vascular events, and are the leading cause of mortality and morbidity in developed societies. Salt sensitivity exacerbates endothelial dysfunction. Herein, we investigated the effect of chronic glucagon like peptide-1 (GLP-1) receptor activation on the coronary microcirculation and cardiac remodeling in Zucker rats on a high-salt diet (6% NaCl).

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Coronary microvessel endothelial dysfunction and nitric oxide (NO) depletion contribute to elevated passive tension of cardiomyocytes, diastolic dysfunction and predispose the heart to heart failure with preserved ejection fraction. We examined if diastolic dysfunction at the level of the cardiomyocytes precedes coronary endothelial dysfunction in prediabetes. Further, we determined if myofilaments other than titin contribute to impairment.

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Metabolic syndrome is a common risk factor in chronic kidney disease. We investigated whether liraglutide [(LIRA), a glucagon-like peptide-1 receptor (GLP-1R) agonist] treatment improved renal vascular function and renal remodeling in male Zucker rats on a high-salt diet (6% NaCl). Zucker lean (+/+) and obese (fa/fa) rats (8 weeks old) were treated with vehicle or LIRA (0.

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Basal cell carcinoma (BCC) is the most frequent cancer in humans and results from constitutive activation of the Hedgehog pathway. Several Smoothened inhibitors are used to treat Hedgehog-mediated malignancies, including BCC and medulloblastoma. Vismodegib, a Smoothened inhibitor, leads to BCC shrinkage in the majority of patients with BCC, but the mechanism by which it mediates BCC regression is unknown.

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Cardiopulmonary bypass (CPB) induced systemic inflammation significantly contributes to the development of postoperative complications, including respiratory failure, myocardial, renal and neurological dysfunction and ultimately can lead to failure of multiple organs. Ghrelin is a small endogenous peptide with wide ranging physiological effects on metabolism and cardiovascular regulation. Herein, we investigated the protective effects of ghrelin against CPB-induced inflammatory reactions, oxidative stress and acute organ damage.

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Hyperglycemia up-regulates intracellular angiotensin II (ANG-II) production in cardiac myocytes. This study investigated the hemodynamic and metabolic effects of azilsartan (AZL) treatment in a mouse model of diabetic cardiomyopathy and whether the cardioprotective effects of AZL are mediated by the angiotensin converting enzyme (ACE)-2/ANG 1-7/Mas receptor (R) cascade. Control db/+ and db/db mice (n=5 per group) were treated with vehicle or AZL (1 or 3mg/kg/d oral gavage) from the age of 8 to 16weeks.

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Sox9 is a transcription factor expressed in most solid tumors. However, the molecular mechanisms underlying Sox9 function during tumorigenesis remain unclear. Here, using a genetic mouse model of basal cell carcinoma (BCC), the most frequent cancer in humans, we show that Sox9 is expressed from the earliest step of tumor formation in a Wnt/β-catenin-dependent manner.

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Basal cell carcinoma, the most frequent human skin cancer, arises from activating hedgehog (HH) pathway mutations; however, little is known about the temporal changes that occur in tumour-initiating cells from the first oncogenic hit to the development of invasive cancer. Using an inducible mouse model enabling the expression of a constitutively active Smoothened mutant (SmoM2) in the adult epidermis, we carried out transcriptional profiling of SmoM2-expressing cells at different times during cancer initiation. We found that tumour-initiating cells are massively reprogrammed into a fate resembling that of embryonic hair follicle progenitors (EHFPs).

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Intestinal fibrosis is a common and severe complication of inflammatory bowel disease (IBD), especially Crohn's disease (CD). To investigate the therapeutic approach to intestinal fibrosis, we have developed a mouse model of intestinal fibrosis by administering dextran sulfate sodium (DSS) and examining the effects of irsogladine maleate (IM) [2,4-diamino-6-(2,5-dichlorophenyl)-s-triazine maleate], which has been widely used as an antiulcer drug for gastric mucosa in Japan, on DDS-induced chronic colitis. In this experimental colitis lesion, several pathognomonic changes were found: increased deposition of collagen, increased number of profibrogenic mesenchymal cells such as fibroblasts (vimentin(+), α-SMA(-)) and myofibroblasts (vimentin(+), α-SMA(+)) in both mucosa and submucosa of the colon with infiltrating inflammatory cells, and increased mRNA expressions of collagen type I, transforming growth factor (TGF)-β, matrix metalloproteinase (MMP)-2, and tissue inhibitor of matrix metalloproteinase (TIMP)-1.

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Diabetic kidney disease has been associated with the presence of lipid deposits. We assumed that curcumin, a polyphenol, would attenuate the tissue dyslipidemic condition through activation of 5' adenosine monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation and suppression of sterol regulatory element-binding protein (SREBP)-1c in the kidney and would prevent renal progression in experimental type 1 diabetic rats. Diabetes was induced with streptozotocin (STZ) (55 mg/kg) by intraperitoneal injection in male Sprague-Dawley rats.

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The development of diabetic cardiomyopathy is accompanied with a high membrane-bound protein kinase C (PKC) levels. Curcumin is a naturally occurring compound which is known to inhibit PKC activity. However, the effects of curcumin on ameliorating diabetic cardiomyopathy are still undefined.

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Angiotensin converting enzyme-2 (ACE-2) is a monocarboxypeptidase that metabolises angiotensin (ANG)-II into angiotensin 1-7 (ANG 1-7), thereby functioning as a negative regulator of the renin-angiotensin system. We investigated whether treatment with ANG-II type 1 receptor blocker, olmesartan medoxomil is associated with the attenuation of cardiac myosin-induced dilated cardiomyopathy (DCM) through recently established new axis of ACE-2/ANG 1-7 mas receptor. DCM was elicited in Lewis rats by immunisation with cardiac myosin, and 28 days after immunisation, the surviving Lewis rats were divided into two groups and treated with either olmesartan medoxomil (10 mg/kg/day) or vehicle.

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Mulberry is commonly used as silkworm diet and an alternative medicine in Japan and China, has recently reported to contain many antioxidative flavanoid compounds and having the free radical scavenging effects. Antioxidants reduce cardiac oxidative stress and attenuate cardiac dysfunction in animals with pacing-induced congestive heart failure. Hence we investigated the cardioprotective effect of mulberry leaf powder in rats with experimental autoimmune myocarditis.

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Aim: Recent findings have suggested that a therapeutic approach to amplify or stimulate the angiotensin-converting enzyme-2 [ACE-2]-angiotensin 1-7 [ANG 1-7] mas axis could provide protection against the development of cardiovascular diseases. We investigated the cardioprotective effects of telmisartan in rats with dilated cardiomyopathy [DCM] after experimental autoimmune myocarditis [EAM].

Main Methods: DCM was elicited in Lewis rats by immunization with cardiac myosin, and twenty-eight days after immunization, the surviving Lewis rats were divided into two groups and treated with either telmisartan (10mg/kg/day) or vehicle.

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Angiotensin-converting enzyme 2 (ACE-2) is a membrane-associated carboxy-peptidase catalyzes the conversion of the vasoconstrictor angiotensin (ANG)-II to the vasodilatory peptide ANG 1-7. In view of the expanding axis of the renin angiotensin system, we have investigated the cardioprotective effects of olmesartan (10mg/kg/day) in experimental autoimmune myocarditis. Olmesartan treatment effectively suppressed the myocardial protein expressions of inflammatory markers in comparison to the vehicle-treated rats.

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There are evidences that the activation of AMPK is playing pivotal role in the lipid and glucose metabolism. It has been reported that both the AMPK and angiotensin-II acts as a negative regulator for each protein. It has been well proven that the MAPK cascade could be modulated by the presence of angiotensin-II.

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Anthracyclines, most powerful anticancer agents, suffer from their cardiotoxic effects, which may be due to the induction of oxidative stress. Carvedilol, a third-generation, nonselective β-adrenoreceptor antagonist, possesses both reactive oxygen species (ROS) scavenging and ROS suppressive effects. It showed protective effects against daunorubicin- (DNR-) induced cardiac toxicity by reducing oxidative stress and apoptosis.

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Scope: We hypothesized that curcumin, a potent anti-oxidant, might be beneficial in ameliorating the development of diabetic nephropathy through inhibition of PKC-α and PKC-β1 activity-ERK1/2 pathway.

Methods And Results: Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) (55 mg/kg) in rats. Three weeks after STZ injection, rats were divided into three groups, namely, normal, diabetic and diabetic treated with curcumin at 100 mg/kg/day, p.

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