Publications by authors named "Giani J"

Article Synopsis
  • - The study explored how early life stress from maternal separation and early weaning (MSEW) impacts blood pressure in obese male mice, focusing on the role of the renin-angiotensin-aldosterone system.
  • - Both control and MSEW mice on a high-fat diet showed similar increases in angiotensinogen levels, but there was no activation of the renin-angiotensin system in their fat or kidneys.
  • - Despite a reduction in blood pressure after treating with an angiotensin-converting enzyme inhibitor, MSEW mice still experienced heightened sympathetic tone, indicating that other mechanisms beyond angiotensin II contribute to their elevated blood pressure.
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Testis angiotensin-converting enzyme (tACE) plays a critical role in male fertility, but the mechanism is unknown. By using ACE C-domain KO (CKO) mice which lack tACE activity, we found that ATP in CKO sperm was 9.4-fold lower than WT sperm.

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The renin-angiotensin system (RAS) has been widely known as a circulating endocrine system involved in the control of blood pressure. However, components of RAS have been found to be localized in rather unexpected sites in the body including the kidneys, brain, bone marrow, immune cells, and reproductive system. These discoveries have led to steady, growing evidence of the existence of independent tissue RAS specific to several parts of the body.

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Aims: The metabolic failure of macrophages to adequately process lipid is central to the aetiology of atherosclerosis. Here, we examine the role of macrophage angiotensin-converting enzyme (ACE) in a mouse model of PCSK9-induced atherosclerosis.

Methods And Results: Atherosclerosis in mice was induced with AAV-PCSK9 and a high-fat diet.

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Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive disease with poor prognosis, which is mainly due to drug resistance. The biology determining the response to chemo-radiotherapy in HNSCC is poorly understood. Using clinical samples, we found that miR124-3p and miR766-3p are overexpressed in chemo-radiotherapy-resistant (non-responder) HNSCC, as compared to responder tumors.

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Growth hormone (GH) exerts major actions in cardiac growth and metabolism. Considering the important role of insulin in the heart and the well-established anti-insulin effects of GH, cardiac insulin resistance may play a role in the cardiopathology observed in acromegalic patients. As conditions of prolonged exposure to GH are associated with a concomitant increase of circulating GH, IGF1 and insulin levels, to dissect the direct effects of GH, in this study, we evaluated the activation of insulin signaling in the heart using four different models: (i) transgenic mice overexpressing GH, with chronically elevated GH, IGF1 and insulin circulating levels; (ii) liver IGF1-deficient mice, with chronically elevated GH and insulin but decreased IGF1 circulating levels; (iii) mice treated with GH for a short period of time; (iv) primary culture of rat cardiomyocytes incubated with GH.

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Background: Chronic renal inflammation has been widely recognized as a major promoter of several forms of high blood pressure including salt-sensitive hypertension. In diabetes, IL (interleukin)-6 induces salt sensitivity through a dysregulation of the epithelial sodium channel. However, the origin of this inflammatory process and the molecular events that culminates with an abnormal regulation of epithelial sodium channel and salt sensitivity in diabetes are largely unknown.

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Angiotensin converting enzyme (ACE) is well known for its role producing the vasoconstrictor angiotensin II and ACE inhibitors are commonly used for treating hypertension and cardiovascular disease. However, ACE has many different substrates besides angiotensin I and plays a role in many different physiologic processes. Here, we discuss the role of ACE in the immune response.

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Introduction: Palliative care aims to improve the quality of life of patients with a life-limiting or life-threatening illness and is multifaceted involving comprehensive interdisciplinary assessments and interventions. Interdisciplinary palliative care in the setting of untreatable cancer diagnoses is of particular importance due to additional considerations that must be taken as patients are often undergoing palliative chemotherapy and/or radiation therapy. These patients' complexity warrants special considerations and attentiveness to drug-related problems.

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Angiotensin-converting enzyme inhibitors (ACEIs) are used by millions of patients to treat hypertension, diabetic kidney disease, and heart failure. However, these patients are often at increased risk of infection. To evaluate the impact of ACEIs on immune responses to infection, we compared the effect of an ACEI versus an angiotensin receptor blocker (ARB) on neutrophil antibacterial activity.

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The renal nephron consists of a series of distinct cell types that function in concert to maintain fluid and electrolyte balance and blood pressure. The renin-angiotensin system (RAS) is central to Na and volume balance. We aimed to determine how loss of angiotensin II signaling in the proximal tubule (PT), which reabsorbs the bulk of filtered Na and volume, impacts solute transport throughout the nephron.

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The observation that all components of the renin angiotensin system (RAS) are expressed in the kidney and the fact that intratubular angiotensin (Ang) II levels greatly exceed the plasma concentration suggest that the synthesis of renal Ang II occurs independently of the circulating RAS. One of the main components of this so-called intrarenal RAS is angiotensin-converting enzyme (ACE). Although the role of ACE in renal disease is demonstrated by the therapeutic effectiveness of ACE inhibitors in treating several conditions, the exact contribution of intrarenal versus systemic ACE in renal disease remains unknown.

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Background: Hypertension is considered a major risk factor for the progression of diabetic kidney disease. Type 2 diabetes is associated with increased renal sodium reabsorption and salt-sensitive hypertension. Clinical studies show that men have higher risk than premenopausal women for the development of diabetic kidney disease.

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Granulocytes are key players in cancer metastasis. While tumor-induced expansion of immunosuppressive myeloid-derived suppressor cells (MDSCs) is well-described, the fate and contribution of terminally differentiated mature neutrophils to the metastatic process remain poorly understood. Here, we show that in experimental metastatic cancer models, CXCR4CD62L aged neutrophils accumulate via disruption of neutrophil circadian homeostasis and direct stimulation of neutrophil aging mediated by angiotensin II.

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Environmental stress during early life is an important factor that affects the postnatal renal development. We have previously shown that male rats exposed to maternal separation (MatSep), a model of early life stress, are normotensive but display a sex-specific reduced renal function and exacerbated angiotensin II (AngII)-mediated vascular responses as adults. Since optimal AngII levels during postnatal life are required for normal maturation of the kidney, this study was designed to investigate both short- and long-term effect of MatSep on (1) the renal vascular architecture and function, (2) the intrarenal renin-angiotensin system (RAS) components status, and (3) the genome-wide expression of genes in isolated renal vasculature.

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Article Synopsis
  • The AT receptor helps with metabolism and can improve how the body uses insulin in diabetes.
  • In a study, mice with diabetes were given a special drug (C21) for a month, which improved their glucose tolerance and reduced fat in their liver.
  • The positive effects happened because of increased nitric oxide (NO) production, but when another substance was used to block NO, the benefits went away.
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Colorectal cancer is one of the most common malignancies diagnosed in Canada. Currently, adjuvant colorectal cancer treatment primarily includes chemotherapeutic regimens such as FOLFOX6 (5-fluorouracil, leucovorin, oxaliplatin) or CAPOX (capecitabine, oxaliplatin), as well as alternative regimens such as TOMOX (raltitrexed, oxaliplatin). However, the prevalence of drug shortages in today's society may make these preferred regimens inaccessible.

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Angiotensin-converting enzyme (ACE), a dicarboxypeptidase, plays a major role in the regulation of blood pressure by cleaving angiotensin I into angiotensin II (Ang II), a potent vasoconstrictor. Because of its wide substrate specificity and tissue distribution, ACE affects many diverse biological processes. In inflammatory diseases, including granuloma, atherosclerosis, chronic kidney disease and bacterial infection, ACE expression gets upregulated in immune cells, especially in myeloid cells.

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Aim: Sexual dimorphisms are evident along the nephron: Females (F) exhibit higher ratios of renal distal to proximal Na transporters' abundance, greater lithium clearance (C ) more rapid natriuresis in response to saline infusion and lower plasma [K ] vs. males (M). During angiotensin II infusion hypertension (AngII-HTN) M exhibit distal Na transporter activation, lower proximal and medullary loop transporters, blunted natriuresis in response to saline load, and reduced plasma [K ].

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To review recent studies exploring how myeloid cell overexpression of angiotensin-converting enzyme (ACE) affects the immune response and to formulate an approach for considering the effectiveness of inflammation in cardiovascular disease RECENT FINDINGS: While it is widely appreciated that the renin-angiotensin system affects aspects of inflammation through the action of angiotensin II, new studies reveal a previously unknown role of ACE in myeloid cell biology. This was apparent from analysis of two mouse lines genetically modified to overexpress ACE in monocytes/macrophages or neutrophils. Cells overexpressing ACE demonstrated an increased immune response.

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Angiotensin-converting enzyme (ACE) affects blood pressure. In addition, ACE overexpression in myeloid cells increases their immune function. Using MS and chemical analysis, we identified marked changes of intermediate metabolites in ACE-overexpressing macrophages and neutrophils, with increased cellular ATP (1.

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Background We have previously reported that female mice exposed to maternal separation and early weaning (MSEW), a model of early life stress, show exacerbated diet-induced obesity associated with hypertension. The goal of this study was to test whether MSEW promotes angiotensin II-dependent hypertension via activation of the renin-angiotensin system in adipose tissue. Methods and Results MSEW was achieved by daily separations from the dam and weaning at postnatal day 17, while normally reared controls were weaned at postnatal day 21.

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Background: Macrophages are ubiquitous in all stages of atherosclerosis, exerting tremendous impact on lesion progression and plaque stability. Because macrophages in atherosclerotic plaques express angiotensin-converting enzyme (ACE), current dogma posits that local myeloid-mediated effects worsen the disease. In contrast, we previously reported that myeloid ACE overexpression augments macrophage resistance to various immune challenges, including tumors, bacterial infection and Alzheimer's plaque deposition.

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The renin-angiotensin system modulates insulin action. Pharmacological stimulation of angiotensin type 2 receptor (AT2R) was shown to have beneficial metabolic effects in various animal models of insulin resistance and type 2 diabetes and also to increase insulin sensitivity in wild type mice. In this study we further explored the role of the AT2R on insulin action and glucose homeostasis by investigating the glycemic profile and in vivo insulin signaling status in insulin-target tissues from both male and female AT2R knockout (KO) mice.

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