Project description:Aerobic exercise training leads to a physiological, nonpathological left ventricular hypertrophy; however, the underlying biochemical and molecular mechanisms of physiological left ventricular hypertrophy are unknown. The role of microRNAs regulating the classic and the novel cardiac renin-angiotensin (Ang) system was studied in trained rats assigned to 3 groups: (1) sedentary; (2) swimming trained with protocol 1 (T1, moderate-volume training); and (3) protocol 2 (T2, high-volume training). Cardiac Ang I levels, Ang-converting enzyme (ACE) activity, and protein expression, as well as Ang II levels, were lower in T1 and T2; however, Ang II type 1 receptor mRNA levels (69% in T1 and 99% in T2) and protein expression (240% in T1 and 300% in T2) increased after training. Ang II type 2 receptor mRNA levels (220%) and protein expression (332%) were shown to be increased in T2. In addition, T1 and T2 were shown to increase ACE2 activity and protein expression and Ang (1-7) levels in the heart. Exercise increased microRNA-27a and 27b, targeting ACE and decreasing microRNA-143 targeting ACE2 in the heart. Left ventricular hypertrophy induced by aerobic training involves microRNA regulation and an increase in cardiac Ang II type 1 receptor without the participation of Ang II. Parallel to this, an increase in ACE2, Ang (1-7), and Ang II type 2 receptor in the heart by exercise suggests that this nonclassic cardiac renin-angiotensin system counteracts the classic cardiac renin-angiotensin system. These findings are consistent with a model in which exercise may induce left ventricular hypertrophy, at least in part, altering the expression of specific microRNAs targeting renin-angiotensin system genes. Together these effects might provide the additional aerobic capacity required by the exercised heart.
Project description:Angiotensin converting enzyme (ACE) is well known for its dual actions to convert inactive Ang I to active Ang II, and degrades active bradykinin (BK), which plays an important role in controlling blood pressure. Because it is the bottleneck step for the production of pressor Ang II, it was targeted pharmacologically in the 1970s. Successful ACE inhibitors such as captopril were produced to treat hypertension. Studies on domain-specific ACE inhibitors are continuing to produce effective hypertension-controlling drugs with fewer side effects. ACE2 was discovered in 2000 and it converts Ang II into Ang(1–7), thereby reducing the concentration of Ang II as well as increasing that of Ang(1–7), an important enzyme for Ang(1–7)/Mas receptor signaling. ACE2 also acts as the receptor in the lung for the coronavirus, causing the infamous severe acute respiratory syndrome (SARS) in 2003.
Project description:The rapid spread of the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has brought into focus the key role of angiotensin-converting enzyme 2 (ACE2), which serves as a cell surface receptor required for the virus to enter cells. SARS-CoV-2 can decrease cell surface ACE2 directly by internalization of ACE2 bound to the virus and indirectly by increased ADAM17 (a disintegrin and metalloproteinase 17)-mediated shedding of ACE2. ACE2 is widely expressed in the heart, lungs, vasculature, kidney and the gastrointestinal (GI) tract, where it counteracts the deleterious effects of angiotensin II (AngII) by catalyzing the conversion of AngII into the vasodilator peptide angiotensin-(1-7) (Ang-(1-7)). The down-regulation of ACE2 by SARS-CoV-2 can be detrimental to the cardiovascular system and kidneys. Further, decreased ACE2 can cause gut dysbiosis, inflammation and potentially worsen the systemic inflammatory response and coagulopathy associated with SARS-CoV-2. This review aims to elucidate the crucial role of ACE2 both as a regulator of the renin-angiotensin system and a receptor for SARS-CoV-2 as well as the implications for Coronavirus disease 19 and its associated cardiovascular and renal complications.
Project description:BackgroundSepsis-induced endothelial dysfunction is proposed to cause angiotensin-converting enzyme (ACE) dysfunction and renin-angiotensin-aldosterone system (RAAS) derangement, exacerbating vasodilatory shock and acute kidney injury (AKI). Few studies test this hypothesis directly, including none in children. We measured serum ACE concentrations and activity, and assessed their association with adverse kidney outcomes in pediatric septic shock.MethodsA pilot study of 72 subjects aged 1 week-18 years from an existing multicenter, observational study. Serum ACE concentrations and activity were measured on Day 1; renin + prorenin concentrations were available from a previous study. The associations between individual RAAS components and a composite outcome (Day 1-7 severe persistent AKI, kidney replacement therapy use, or mortality) were assessed.Results50/72 subjects (69%) had undetectable ACE activity (< 2.41 U/L) on Day 1 and 27/72 (38%) developed the composite outcome. Subjects with undetectable ACE activity had higher Day 1 renin + prorenin compared to those with activity (4533 vs. 2227 pg/ml, p = 0.017); ACE concentrations were no different between groups. Children with the composite outcome more commonly had undetectable ACE activity (85% vs. 65%, p = 0.025), and had higher Day 1 renin + prorenin (16,774 pg/ml vs. 3037 pg/ml, p < 0.001) and ACE concentrations (149 vs. 96 pg/ml, p = 0.019). On multivariable regression, increasing ACE concentrations (aOR 1.01, 95%CI 1.002-1.03, p = 0.015) and undetectable ACE activity (aOR 6.6, 95%CI 1.2-36.1, p = 0.031) retained associations with the composite outcome.ConclusionsACE activity is diminished in pediatric septic shock, appears uncoupled from ACE concentrations, and is associated with adverse kidney outcomes. Further study is needed to validate these findings in larger cohorts.
Project description:Attempt to identify genes whose expression changed in the kidney cortex with angiotensin converting enzyme inhibition. Eleven week-old male C57BL6 mice were treated with captopril at 10mg/kg/day in drinking water for 7 days. The kidney cortex was surgically excised and total RNA was isolated using Trizol (Invitrogen) from three treated and three control mice and was further purified using RNeasy MinElute Cleanup spin columns (Qiagen) according to manufacturer’s instructions. Probes generated from the resulting RNA were hybridized to Illumina Expression BeadChips (mouseWG-6_V2).
Project description:The third edition of the Handbook of Proteolytic Enzymes aims to be a comprehensive reference work for the enzymes that cleave proteins and peptides, and contains over 850 chapters. Each chapter is organized into sections describing the name and history, activity and specificity, structural chemistry, preparation, biological aspects, and distinguishing features for a specific peptidase. The subject of Chapter 100 is Angiotensin-Converting Enzyme-2. Keywords: Angiotensin, angiotensin-converting enzyme 2 (ACE2), apelin, bradykinin, carboxypeptidase, cardiovascular, collectrin, renin-angiotensin system, SARS virus, shedding, transmembrane, vasoactive, zinc-binding motif.
Project description:Since the worldwide outbreak of coronavirus disease 2019, angiotensin-converting enzyme 2 (ACE2) has received widespread attention as the cell receptor of the severe acute respiratory syndrome coronavirus 2 virus. At the same time, as a key enzyme in the renin-angiotensin-system, ACE2 is considered to be an endogenous negative regulator of vasoconstriction, proliferation, fibrosis, and proinflammation caused by the ACE-angiotensin II-angiotensin type 1 receptor axis. ACE2 is now implicated as being closely connected to diabetes, cardiovascular, kidney, and lung diseases, and so on. This review covers the available information on the host factors regulating ACE2 and discusses its role in a variety of pathophysiological conditions in animal models and humans.
Project description:OBJECTIVE:To assess the patterns of angiotensin converting enzyme inhibitors and angiotensin receptor blockers (ACE-I/ARB) discontinuation in the setting of chronic kidney disease (CKD) progression in real-world clinical practice. PATIENTS AND METHODS:We identified incident ACE-I/ARB users with a baseline estimated glomerular filtration rate (eGFR) ≥15 mL/min/1.73 m2 and without end-stage renal disease in the Geisinger Health System between January 1, 2004, and December 31, 2015. We investigated the associations of CKD stage, hospitalizations with and without acute kidney injury (AKI), serum potassium, bicarbonate level, thiazide, and loop diuretic use with ACE-I/ARB discontinuation. RESULTS:Among the 53,912 ACE-I/ARB users, the mean age was 59.9 years, and 50.6% were female. More than half of users discontinued ACE-I/ARB within 5 years of therapy initiation. The risk of ACE-I/ARB discontinuation increased with more advanced CKD stage. For example, patients who initiated ACE-I/ARB with CKD stage G4 (eGFR: 15-29 mL/min/1.73 m2) were 2.09-fold (95% CI, 1.87-2.34) more likely to discontinue therapy than those with eGFR ≥ 90 mL/min/1.73 m2. Potassium level greater than 5.3 mEq/L, systolic blood pressure ≤ 90 mm Hg, bicarbonate level < 22 mmol/L, and intervening hospitalization-particularly AKI-related-were also strong risk factors for ACE-I/ARB discontinuation. Thiazide diuretic use was associated with lower risk, whereas loop diuretic use was associated with higher risk of discontinuation. CONCLUSION:In a real-world cohort, discontinuation of ACE-I/ARB was common, particularly in patients with lower eGFR. Hyperkalemia, hypotension, low bicarbonate level, and hospitalization (AKI-related, in particular) were associated with a higher risk of ACE-I/ARB discontinuation. Additional studies are needed to evaluate the risk-benefit balance of discontinuing ACE-I/ARB in the setting of CKD progression.