scholarly journals Exosome-Mediated Transfer of ACE2 (Angiotensin-Converting Enzyme 2) from Endothelial Progenitor Cells Promotes Survival and Function of Endothelial Cell

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Jinju Wang ◽  
Shuzhen Chen ◽  
Ji Bihl
Keyword(s):  
Membrane Potential ◽  
Angiotensin Converting Enzyme ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Protective Effects ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Endothelial Progenitor ◽  
Angiotensin Converting Enzyme 2 ◽  
Mitochondrial Functions

Angiotensin-converting enzyme 2 (ACE2) is an emerging cardiovascular protective target that mediates the metabolism of angiotensin (Ang) II into Ang (1–7). Our group has demonstrated that ACE2 overexpression enhances the function of endothelial progenitor cells (EPCs). Here, we investigated whether ACE2-primed EPCs (ACE2-EPCs) can protect cerebral microvascular endothelial cells (ECs) against injury and dysfunction in an in vitro model, with focusing on their exosomal and cytokine paracrine effects on endothelial mitochondria. Human EPCs were transfected with lentivirus containing null or human ACE2 cDNA (denoted as Null-EPCs and ACE2-EPCs, respectively). Their conditioned culture media, w/wo depletion of exosomes (ACE2-EPC-CMEX-, Null-EPC-CMEX-, ACE2-EPC-CM, and Null-EPC-CM), were used for coculture experiments. EC injury and dysfunction model was induced by Ang II before coculture. Apoptosis, angiogenic ability, mitochondrion functions (ROS production, membrane potential, fragmentation), and gene expressions (ACE2, Nox2, and Nox4) of ECs were analyzed. The supernatant was collected for measuring the levels of ACE2, Ang II/Ang-(1–7), and growth factors (VEGF and IGF). Our results showed that (1) ACE2-EPC-CM had higher levels of ACE2, Ang (1–7), VEGF, and IGF than that of Null-EPC-CM. (2) Ang II-injured ECs displayed an increase of apoptotic rate and reduction in tube formation and migration abilities, which were associated with ACE2 downregulation, Ang II/Ang (1–7) imbalance, Nox2/Nox4 upregulation, ROS overproduction, an increase of mitochondrion fragmentation, and a decrease of membrane potential. (3) ACE2-EPC-CM had better protective effects than Null-EPC-CM on Ang II-injured ECs, which were associated with the improvements on ACE2 expression, Ang II/Ang (1–7) balance, and mitochondrial functions. (4) ACE2-EPC-CMEX- and Null-EPC-CMEX- showed reduced effects as compared to ACE2-EPCs-CM and Null-EPCs-CM. In conclusion, our data demonstrate that ACE2 overexpression can enhance the protective effects of EPCs on ECs injury, majorly through the exosomal effects on mitochondrial function.

scholarly journals Combination of Angiotensin (1-7) Agonists and Convalescent Plasma as a New Strategy to Overcome Angiotensin Converting Enzyme 2 (ACE2) Inhibition for the Treatment of COVID-19

2021 ◽  
Vol 8 ◽  
Author(s):  
Hawraa Issa ◽  
Ali H. Eid ◽  
Bassam Berry ◽  
Vahideh Takhviji ◽  
Abbas Khosravi ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Viral Infection ◽  
Viral Entry ◽  
The Body ◽  
Protective Effects ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Neutralizing Capacity ◽  
New Strategy

Coronavirus disease-2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the most concerning health problem worldwide. SARS-CoV-2 infects cells by binding to angiotensin-converting enzyme 2 (ACE2). It is believed that the differential response to SARS-CoV-2 is correlated with the differential expression of ACE2. Several reports proposed the use of ACE2 pharmacological inhibitors and ACE2 antibodies to block viral entry. However, ACE2 inhibition is associated with lung and cardiovascular pathology and would probably increase the pathogenesis of COVID-19. Therefore, utilizing ACE2 soluble analogs to block viral entry while rescuing ACE2 activity has been proposed. Despite their protective effects, such analogs can form a circulating reservoir of the virus, thus accelerating its spread in the body. Levels of ACE2 are reduced following viral infection, possibly due to increased viral entry and lysis of ACE2 positive cells. Downregulation of ACE2/Ang (1-7) axis is associated with Ang II upregulation. Of note, while Ang (1-7) exerts protective effects on the lung and cardiovasculature, Ang II elicits pro-inflammatory and pro-fibrotic detrimental effects by binding to the angiotensin type 1 receptor (AT1R). Indeed, AT1R blockers (ARBs) can alleviate the harmful effects associated with Ang II upregulation while increasing ACE2 expression and thus the risk of viral infection. Therefore, Ang (1-7) agonists seem to be a better treatment option. Another approach is the transfusion of convalescent plasma from recovered patients with deteriorated symptoms. Indeed, this appears to be promising due to the neutralizing capacity of anti-COVID-19 antibodies. In light of these considerations, we encourage the adoption of Ang (1-7) agonists and convalescent plasma conjugated therapy for the treatment of COVID-19 patients. This therapeutic regimen is expected to be a safer choice since it possesses the proven ability to neutralize the virus while ensuring lung and cardiovascular protection through modulation of the inflammatory response.

scholarly journals Stimulation of Angiotensin Converting Enzyme 2: A Novel Treatment Strategy for Diabetic Nephropathy

2022 ◽  
Vol 12 ◽  
Author(s):  
Haru Nomura ◽  
Sanjaya Kuruppu ◽  
Niwanthi W. Rajapakse
Keyword(s):  
Diabetic Nephropathy ◽  
Angiotensin Converting Enzyme ◽  
Protective Effects ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Converting Enzyme Inhibitors ◽  
Kidney Fibrosis ◽  
Angiotensin Converting Enzyme 2 ◽  
Promising Therapeutic Approach ◽  
End Stage

Despite current therapies for diabetic nephropathy, many patients continue to progress to end-stage renal disease requiring renal replacement therapy. While the precise mechanisms underlying diabetic nephropathy remain to be determined, it is well established that chronic activation of the renin angiotensin aldosterone system (RAAS) plays a substantial role in the pathogenesis of diabetic nephropathy. Angiotensin converting enzyme 2 (ACE2), the enzyme responsible for activating the reno-protective arm of the RAAS converts angiotensin (Ang) II into Ang 1-7 which exerts reno-protective effects. Chronic RAAS activation leads to kidney inflammation and fibrosis, and ultimately lead to end-stage kidney disease. Currently, angiotensin converting enzyme inhibitors and Ang II receptor blockers are approved for renal fibrosis and inflammation. Targeting the reno-protective arm of the RAAS should therefore, provide further treatment options for kidney fibrosis and inflammation. In this review, we examine how targeting the reno-protective arm of the RAAS can ameliorate kidney inflammation and fibrosis and rescue kidney function in diabetic nephropathy. We argue tissue ACE2 stimulation provides a unique and promising therapeutic approach for diabetic nephropathy.

scholarly journals Effects of Angiotensin-Converting Enzyme Inhibition on Circulating Endothelial Progenitor Cells in Patients with Acute Ischemic Stroke

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Monika Gołąb-Janowska ◽  
Edyta Paczkowska ◽  
Bogusław Machaliński ◽  
Dariusz Kotlęga ◽  
Agnieszka Meller ◽  
...  
Keyword(s):  
Stem Cells ◽  
Ischemic Stroke ◽  
Angiotensin Converting Enzyme ◽  
Acute Ischemic Stroke ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Neurological Deficit ◽  
Converting Enzyme ◽  
Endothelial Progenitor ◽  
Group I

Background. Therapeutic neovascularization might represent an important strategy to salvage tissue after ischemia. Circulating bone marrow-derived endothelial progenitor cells (EPCs) were previously shown to augment the neovascularization of ischemic tissue. Angiotensin-converting enzyme inhibitors (ACEIs) might modulate EPC mobilization. We evaluated populations of circulating stem cells and early EPCs in acute ischemic stroke (AIS) patients and the effect of ACEI on circulating EPCs in these patients with respect to aspects of stroke pathogenesis. Methods. We studied 43 AIS patients (group I), comprising 33 treated with ACEI (group Ia) and 10 untreated (group Ib). Risk factor controls (group II) included 22 subjects. EPCs were measured by flow cytometry. Results. In AIS patients, the number of circulating stem cells and early EPCs upon admission was similar to that in control group individuals. There were no significant differences in the numbers of stem cells and early EPCs over subsequent days after AIS. There were also no significant differences in stem cell and early EPC numbers over the first 3 days between group Ia and group Ib. However, on day 7, these numbers were significantly higher in group Ib than in group Ia (p<0.05). In AIS patients chronically treated with ACEI, there was a negative correlation between CD133+ cell number and neurological deficit on the first, third, and seventh days (p<0.005). Conclusions. An increased number of circulating stem cells and early EPCs were not observed in stroke patients chronically treated with ACEI. In patients chronically treated with ACEI, a significant correlation was observed between decreased neurological deficit and higher levels of CD133+ cells; this could be due to the positive influence of these cells on the regeneration of the endothelium and improved circulation in the ischemic penumbra.

scholarly journals Dysregulation of ACE (Angiotensin-Converting Enzyme)-2 and Renin-Angiotensin Peptides in SARS-CoV-2 Mediated Mortality and End-Organ Injuries

Hypertension ◽  
2021 ◽  
Author(s):  
Kaiming Wang ◽  
Mahmoud Gheblawi ◽  
Anish Nikhanj ◽  
Matt Munan ◽  
Erika MacIntyre ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Tumor Necrosis Factor Receptor ◽  
Renin Angiotensin System ◽  
Adverse Outcomes ◽  
Blood Collection ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Angiotensin Peptides

ACE (angiotensin-converting enzyme)-2 as the target for SARS-CoV-2 also negatively regulates the renin-angiotensin system. Pathological activation of ADAM17 (A disintegrin and metalloproteinase-17) may potentiate inflammation and diminish ACE2-mediated tissue protection through proteolytic shedding, contributing to SARS-CoV-2 pathogenesis. We aim to examine plasma soluble ACE2 and angiotensin profiles in relation to outcomes by enrolling consecutive patients admitted for COVID-19 with baseline blood collection at admission and repeated sampling at 7 days. The primary outcome was 90-day mortality, and secondary outcomes were the incidence of end-organ injuries. Overall, 242 patients were included, the median age was 63 (52–74) years, 155 (64.0%) were men, and 57 (23.6%) patients reached the primary end point. Baseline soluble ACE2 was elevated in COVID-19 but was not associated with disease severity or mortality. In contrast, an upward trajectory of soluble ACE2 at repeat sampling was independently associated with an elevated risk of mortality and incidence of acute myocardial injury and circulatory shock. Similarly, an increase in soluble tumor necrosis factor receptor levels was also associated with adverse outcomes. Plasma Ang I, Ang 1-7 (angiotensin 1–7) levels, and the Ang 1-7/Ang II (angiotensin II) ratio were elevated during SARS-CoV-2 infection related to downregulation of ACE activity at baseline. Moreover, patients having an upward trajectory of soluble ACE2 were characterized by an imbalance in the Ang 1-7/Ang II ratio. The observed dysregulation of ACE2 and angiotensin peptides with disease progression suggest a potential role of ADAM17 inhibition and enhancing the beneficial Ang 1-7/Mas axis to improve outcomes against SARS-CoV-2 infection.

scholarly journals ACE2 the Janus-faced protein – from cardiovascular protection to severe acute respiratory syndrome-coronavirus and COVID-19

2020 ◽  
Vol 134 (7) ◽  
pp. 747-750 ◽  
Author(s):  
Rhian M. Touyz ◽  
Hongliang Li ◽  
Christian Delles
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Basic Science ◽  
Physiological Role ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Sars Coronavirus ◽  
Multifunctional Protein ◽  
Angiotensin Converting Enzyme 2

Abstract Angiotensin converting enzyme 2 (ACE2) is the major enzyme responsible for conversion of Ang II into Ang-(1-7). It also acts as the receptor for severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2, which causes Coronavirus Disease (COVID)-19. In recognition of the importance of ACE2 and to celebrate 20 years since its discovery, the journal will publish a focused issue on the basic science and (patho)physiological role of this multifunctional protein.

scholarly journals Ox-LDL induced endothelial progenitor cells oxidative stress via p38/Keap1/Nrf2 pathway

2021 ◽  
Author(s):  
Qijun Jiang ◽  
Chengpeng Li ◽  
Zhigang Gong ◽  
Zhigang Li ◽  
Shifang Ding
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Nuclear Translocation ◽  
Tube Formation ◽  
Ros Generation ◽  
Endothelial Progenitor ◽  
Migration Ability ◽  
Nrf2 Pathway

Abstract Background In many studies, endothelial progenitor cells (EPCs) highly expressing antioxidant protein were induced oxidative stress and apoptosis by Oxidized-low density lipoprotein (ox-LDL). Nrf2 which was resently reported to regulate the antioxidant genes and cellular redox regulators was highly expressed in EPCs. However, its role in ox-LDL induced EPCs oxidative stress and apoptosis has not been fully illustrated. Methods EPCs isolated from human peripheral blood mononuclear cells were treated with different concentration of ox-LDL, Keap1 siRNA and a specific p38 MAPK inhibitor SB203580, then used to assay the whole cellular Nrf2 (total Nrf2, t-Nrf2), cytoplasmic Nrf2 (c-Nrf2), nuclear Nrf2 (n- Nrf2), NAD(P) H:quinone oxidoreductase 1 (NQO1) protein levels and Bax /Bcl-2 with western blot, NQO1 mRNA levels with RT-PCR, ROS level with H2DCF-DA, the loss/disruption of mitochondrial membrane potential (MMP) with JC-1, apoptosis with Annexin-V and PI,migration ability with transwell chambers and tube formation. Results The ox-LDL treatment decreased the n-Nrf2/Histone H3 to c-Nrf2/GAPDH ratio, NQO1 mRNA and protein expression levels. Treatment of ox-LDL enhanced the ROS production, induced loss of membrane potential, increase in cell shrinkage, pyknotic nuclei and apoptosis of EPCs. The Keap1 knockdown with Keap1 siRNA increased the nuclear translocation of Nrf2, the NQO1 mRNA and protein transcription levels, and prevented ox-LDL induced ROS generation and formation of JC-1 monomers. Treatment of ox-LDL increased the activation of p38. Pretreatment with SB203580 significantly eliminated ox-LDL induced the inhibition of Nrf2 nuclear translocation, the depression of the mRNA transcription levels of NQO-1, the ROS generation and the formation of JC-1 monomers in EPCs. The pretreatment of Keap1 siRNA decreased the Bax/Bcl-2 ratio which was increased by the treatment of ox-LDL in EPCs. The ox-LDL treatment decreased EPCs migration activity and tube formation. Whereas the pre-treatment with Keap1 siRNA preserved the migration ability and tube formation of EPCs Conclusion Ox-LDL induced EPCs oxidative stress and apoptosis via p38/Keap1/Nrf2 pathway.

scholarly journals Overexpression of Central ACE2 (Angiotensin-Converting Enzyme 2) Attenuates the Pressor Response to Chronic Central Infusion of Ang II (Angiotensin II)

Hypertension ◽  
2020 ◽  
Vol 76 (5) ◽  
pp. 1514-1525
Author(s):  
Anyun Ma ◽  
Lie Gao ◽  
Ahmed M. Wafi ◽  
Li Yu ◽  
Tara Rudebush ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Angiotensin Converting Enzyme ◽  
Pressor Response ◽  
Rostral Ventrolateral Medulla ◽  
Ventrolateral Medulla ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Intracerebroventricular Infusion

We investigated the mechanism by which ACE2 (angiotensin-converting enzyme 2) overexpression alters neurohumoral outflow and central oxidative stress. Nrf2 (nuclear factor [erythroid-derived 2]-like 2) is a master antioxidant transcription factor that regulates cytoprotective and antioxidant genes. We hypothesized that upregulation of central ACE2 inhibits the pressor response to Ang II (angiotensin II) by reducing reactive oxygen species through a Nrf2/antioxidant enzyme–mediated mechanism in the rostral ventrolateral medulla. Synapsin human Angiotensin Converting Enzyme 2 positive (SynhACE2 +/+ ) mice and their littermate controls synhACE2 −/− were used to evaluate the consequence of intracerebroventricular infusion of Ang II. In control mice, Ang II infusion evoked a significant increase in blood pressure and norepinephrine excretion, along with polydipsia and polyuria. The pressor effect of central Ang II was completely blocked in synhACE2 +/+ mice. Polydipsia, norepinephrine excretion, and markers of oxidative stress in response to central Ang II were also reduced in synhACE2 +/+ mice. The MasR (Mas receptor) agonist Ang 1–7 and blocker A779 had no effects on blood pressure. synhACE2 +/+ mice showed enhanced expression of Nrf2 in the rostral ventrolateral medulla which was blunted following Ang II infusion. Ang II evoked nuclear translocation of Nrf2 in cultured Neuro 2A (N2A) cells. In synhACE2 −/− mice, the central Ang II pressor response was attenuated by simultaneous intracerebroventricular infusion of the Nrf2 activator sulforaphane; blood pressure was enhanced by knockdown of Nrf2 in the rostral ventrolateral medulla in Nrf2 floxed (Nrf2 f/f ) mice. These data suggest that the hypertensive effects of intracerebroventricular Ang II are attenuated by selective overexpression of brain synhACE2 and may be mediated by Nrf2-upregulated antioxidant enzymes in the rostral ventrolateral medulla.

scholarly journals Constitutive Atg5 overexpression in mouse bone marrow endothelial progenitor cells improves experimental acute kidney injury

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Daniel Patschan ◽  
Katrin Schwarze ◽  
Björn Tampe ◽  
Jan Ulrich Becker ◽  
Samy Hakroush ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Kidney Injury ◽  
Mouse Bone Marrow ◽  
Protective Effects ◽  
Endothelial Progenitor ◽  
Matrix Deposition ◽  
Peritubular Capillaries ◽  
Clinical Consequences

Abstract Background Endothelial Progenitor Cells have been shown as effective tool in experimental AKI. Several pharmacological strategies for improving EPC-mediated AKI protection were identified in recent years. Aim of the current study was to analyze consequences of constitutive Atg5 activation in murine EPCs, utilized for AKI therapy. Methods Ischemic AKI was induced in male C57/Bl6N mice. Cultured murine EPCs were systemically injected post-ischemia, either natively or after Atg5 transfection (Adenovirus-based approach). Mice were analyzed 48 h and 6 weeks later. Results Both, native and transfected EPCs (EPCsAtg5) improved persisting kidney dysfunction at week 6, such effects were more pronounced after injecting EPCsAtg5. While matrix deposition and mesenchymal transdifferentiation of endothelial cells remained unaffected by cell therapy, EPCs, particularly EPCsAtg5 completely prevented the post-ischemic loss of peritubular capillaries. The cells finally augmented the augophagocytic flux in endothelial cells. Conclusions Constitutive Atg5 activation augments AKI-protective effects of murine EPCs. The exact clinical consequences need to be determined.

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