Angiotensin-converting enzyme limits inflammation elicited by Trypanosoma cruzi cysteine proteases: a peripheral mechanism regulating adaptive immunity via the innate kinin pathway

2008 ◽  
Vol 389 (8) ◽  
Author(s):  
Julio Scharfstein ◽  
Ana Carolina Monteiro ◽  
Veronica Schmitz ◽  
Erik Svensjö
Keyword(s):  
Trypanosoma Cruzi ◽  
Angiotensin Converting Enzyme ◽  
Tissue Injury ◽  
Cysteine Proteases ◽  
Interferon Γ ◽  
Converting Enzyme ◽  
Potential Threat ◽  
Kinin System ◽  
Dc Maturation

AbstractTissue injury by pathogens induces a stereotyped inflammatory response that alerts the innate immune system of the potential threat to host integrity. Here, we review knowledge emerging from investigations of the role of the kinin system in the mechanisms that link innate to the adaptive phase of immunity. Progress in this field started with results demonstrating that bradykinin is an endogenous danger signal that induces dendritic cell (DC) maturation via G protein-coupled bradykinin B2receptors (B2R). The immunostimulatory role of kinins was recently confirmed in two different mouse models ofTrypanosoma cruziinfection, a parasitic protozoan equipped with kinin-releasing cysteine proteases (cruzipain). Infection by the intraperitoneal route showed that DCs from B2R-/-mice (susceptible phenotype) failed to sense kinin ‘danger’ signals proteolytically released by parasites, explaining why these mutant mice display lower frequencies of interferon-γ-producing effector T-cells. Studies of the dynamics of inflammation in the subcutaneous model of infection revealed that the balance between cruzipain and angiotensin-converting enzyme, respectively acting as kinin-generating and degrading enzymes, governs extent of DC maturation and TH1 development via the B2R-dependent innate pathway. Studies of the kinin role in immunity may shed light on the relationship between proteolytic networks and the cytokine circuits that guide T-cell development.

scholarly journals Angiotensin-Converting Enzyme 2 as a Possible Correlation between COVID-19 and Periodontal Disease

2020 ◽  
Vol 10 (18) ◽  
pp. 6224 ◽  
Author(s):  
Leonardo Mancini ◽  
Vincenzo Quinzi ◽  
Stefano Mummolo ◽  
Giuseppe Marzo ◽  
Enrico Marchetti
Keyword(s):  
Angiotensin Ii ◽  
Inflammatory Response ◽  
Angiotensin Converting Enzyme ◽  
Transforming Growth Factor ◽  
Tissue Injury ◽  
Interleukin 2 ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Cell Functions

SARS-CoV-2 propagation in the world has led to rapid growth and an acceleration in the discoveries and publications of various interests. The main focus of a consistent number of studies has been the role of angiotensin-converting enzyme 2 (ACE2) in binding the virus and its role in expression of the inflammatory response after transmission. ACE2 is an enzyme involved in the renin–angiotensin system (RAS), whose key role is to regulate and counter angiotensin-converting enzyme (ACE), reducing the amount of angiotensin II and increasing angiotensin 1–7 (Ang1–7), making it a promising drug target for treating cardiovascular diseases. The classical RAS axis, formed by ACE, angiotensin II (Ang II), and angiotensin receptor type 1 (AT1), activates several cell functions and molecular signalling pathways related to tissue injury and inflammation. In contrast, the RAS axis composed of ACE2, Ang1–7, and Mas receptor (MasR) exerts the opposite effect concerning the inflammatory response and tissue fibrosis. Recent studies have shown the presence of the RAS system in periodontal sites where osteoblasts, fibroblasts, and osteoclasts are involved in bone remodelling, suggesting that the role of ACE2 might have a fundamental function in the under- or overexpression of cytokines such as interleukin-6 (IL-6), interleukin-7 (IL-7), tumour necrosis factor alpha (TNF-α), interleukin-2 (IL-2), interleukin-1 beta (IL-1β), monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-beta (TGF-β), associated with a periodontal disorder, mainly during coinfection with SARS-CoV-2, where ACE2 is underexpressed and cannot form the ACE2–Ang1–7–MasR axis. This renders the patient unresponsive to an inflammatory process, facilitating periodontal loss.

Role of angiotensin-converting enzyme 2 (ACE2) in diabetic cardiovascular complications

2013 ◽  
Vol 126 (7) ◽  
pp. 471-482 ◽  
Author(s):  
Vaibhav B. Patel ◽  
Nirmal Parajuli ◽  
Gavin Y. Oudit
Keyword(s):  
Diabetes Mellitus ◽  
Angiotensin Converting Enzyme ◽  
Vascular Function ◽  
Systolic Dysfunction ◽  
Cardiovascular Complications ◽  
Converting Enzyme ◽  
Converting Enzyme Inhibitors ◽  
Obesity And Diabetes

Diabetes mellitus results in severe cardiovascular complications, and heart disease and failure remain the major causes of death in patients with diabetes. Given the increasing global tide of obesity and diabetes, the clinical burden of diabetes-induced cardiovascular disease is reaching epidemic proportions. Therefore urgent actions are needed to stem the tide of diabetes which entails new prevention and treatment tools. Clinical and pharmacological studies have demonstrated that AngII (angiotensin II), the major effector peptide of the RAS (renin–angiotensin system), is a critical promoter of insulin resistance and diabetes mellitus. The role of RAS and AngII has been implicated in the progression of diabetic cardiovascular complications and AT1R (AngII type 1 receptor) blockers and ACE (angiotensin-converting enzyme) inhibitors have shown clinical benefits. ACE2, the recently discovered homologue of ACE, is a monocarboxypeptidase which converts AngII into Ang-(1–7) [angiotensin-(1–7)] which, by virtue of its actions on the MasR (Mas receptor), opposes the effects of AngII. In animal models of diabetes, an early increase in ACE2 expression and activity occurs, whereas ACE2 mRNA and protein levels have been found to decrease in older STZ (streptozotocin)-induced diabetic rats. Using the Akita mouse model of Type 1 diabetes, we have recently shown that loss of ACE2 disrupts the balance of the RAS in a diabetic state and leads to AngII/AT1R-dependent systolic dysfunction and impaired vascular function. In the present review, we will discuss the role of the RAS in the pathophysiology and treatment of diabetes and its complications with particular emphasis on potential benefits of the ACE2/Ang-(1–7)/MasR axis activation.

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