Effect of ramipril on kidney, lung and heart ACE2 in a diabetic mice model.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the current coronavirus disease 2019 (COVID-19). The main organ affected in this infection is the lung and the virus uses the angiotensin-converting enzyme 2 (ACE2) as a receptor to enter the target cells. In this context, a controversy raised regarding the use of renin-angiotensin system (RAAS) blockers, as these drugs might increase ACE2 expression in some tissues and potentially increase the risk for SARS-CoV-2 infection. This is specially concerning in diabetic patients as diabetes is a risk factor for COVID-19. METHODS: 12-week old diabetic mice (db/db) were treated with ramipril, or vehicle control for 8 weeks. Non-diabetic db/m mice were included as controls. ACE2 expression and activity were studied in lung, kidney and heart of these animals. RESULTS: Kidney ACE2 activity was increased in the db/db mice as compared to the db/m (143.2% ± 23% vs 100% ± 22.3%, p = 0.004), whereas ramipril had no significant effect. In the lung, no differences were found in ACE2 when comparing db/db mice to db/m and ramipril also had no significant effect. In the heart, diabetes decreased ACE2 activity (83% ± 16.8%, vs 100% ± 23.1% p = 0.02), and ramipril increased ACE2 significantly (83% ± 16.8% vs 98.2% ± 15%, p = 0.04). CONCLUSIONS: In a mouse model of type 2 diabetes, ramipril had no significant effect on ACE2 activity in either kidneys or in the lungs. Therefore, it is unlikely that RAAS blockers or at least angiotensin-converting enzyme inhibitors increase the risk of SARS-CoV-2 infection through increasing ACE2.

Quercetin/Zinc complex and stem cells: A new drug therapy to ameliorate glycometabolic control and pulmonary dysfunction in diabetes mellitus: Structural characterization and genetic studies.

Medicinal uses and applications of metals and their complexes are of increasing clinical and commercial importance. The ligation behavior of quercetin (Q), which is a flavonoid, and its Zn (II) (Q/Zn) complex were studied and characterized based on elemental analysis, molar conductance, Fourier-transform infrared (FTIR) spectra, electronic spectra, proton nuclear magnetic resonance (1H-NMR), thermogravimetric analysis, and transmission electron microscopy (TEM). FTIR spectral data revealed that Q acts as a bidentate ligand (chelating ligand) through carbonyl C(4) = O oxygen and phenolic C(3)-OH oxygen in conjugation with Zn. Electronic, FTIR, and 1H-NMR spectral data revealed that the Q/Zn complex has a distorted octahedral geometry, with the following chemical formula: [Zn(Q)(NO3)(H2O)2].5H2O. Diabetes was induced by streptozotocin (STZ) injection. A total of 70 male albino rats were divided into seven groups: control, diabetic untreated group and diabetic groups treated with either MSCs and/or Q and/or Q/Zn or their combination. Serum insulin, glucose, C-peptide, glycosylated hemoglobin, lipid profile, and enzymatic and non-enzymatic antioxidant levels were determined. Pancreatic and lung histology and TEM for pancreatic tissues in addition to gene expression of both SOD and CAT in pulmonary tissues were evaluated. MSCs in combination with Q/Zn therapy exhibited potent protective effects against STZ induced hyperglycemia and suppressed oxidative stress, genotoxicity, glycometabolic disturbances, and structural alterations. Engrafted MSCs were found inside pancreatic tissue at the end of the experiment. In conclusion, Q/Zn with MSC therapy produced a synergistic effect against oxidative stress and genotoxicity and can be considered potential ameliorative therapy against diabetes with pulmonary dysfunction, which may benefit against COVID-19.