Molecular and cellular mechanisms involved in tissue-specific metabolic modulation by SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is triggered by the SARS-CoV-2, which is able to infect and cause dysfunction not only in lungs, but also in multiple organs, including central nervous system, skeletal muscle, kidneys, heart, liver, and intestine. Several metabolic disturbances are associated with cell damage or tissue injury, but the mechanisms involved are not yet fully elucidated. Some potential mechanisms involved in the COVID-19-induced tissue dysfunction are proposed, such as: (a) High expression and levels of proinflammatory cytokines, including TNF-α IL-6, IL-1β, INF-α and INF-β, increasing the systemic and tissue inflammatory state; (b) Induction of oxidative stress due to redox imbalance, resulting in cell injury or death induced by elevated production of reactive oxygen species; and (c) Deregulation of the renin-angiotensin-aldosterone system, exacerbating the inflammatory and oxidative stress responses. In this review, we discuss the main metabolic disturbances observed in different target tissues of SARS-CoV-2 and the potential mechanisms involved in these changes associated with the tissue dysfunction.

The renoprotective effects of Heme Oxygenase-1 during contrast-induced acute kidney injury in preclinical diabetic models.

OBJECTIVES: Contrast-induced acute kidney injury (CI-AKI) is an important clinical problem that can be aggravated by diabetes mellitus, a major risk factor. However, heme oxygenase-1 (HO-1), a promising therapeutic target, can exert antioxidant effects against CI-AKI. Thus, we investigated the role of HO-1 in CI-AKI in the presence of diabetes mellitus. METHODS: Twenty-eight male Wistar rats weighing 250-300g were subjected to left uninephrectomy, and concomitantly, diabetes induced by streptozotocin (65 mg/kg). After 12 weeks, iodinated contrast (meglumine ioxithalamate, 6 mL/kg) and hemin (HO-1 inducer-10 mg/k) were administered 60 min before iodinated contrast treatment. The rats were randomly divided into four groups: control, diabetes mellitus (DM), DM iodinated contrast (DMIC), and DMIC hemin (DMICH). Kidney function, albuminuria, oxidative profile, and histology were assessed. All experimental data were subjected to statistical analyses. RESULTS: CI-AKI in preclinical diabetic models decreased creatinine clearance and increased urinary neutrophil gelatinase-associated lipocalin (NGAL) levels and the degree of albuminuria. Additionally, the levels of oxidative and nitrosative stress metabolites (urinary peroxides, thiobarbituric acid-reactive substances, and NO) were elevated, while thiol levels in kidney tissue were reduced. Kidney histology showed tubular cell vacuolization and edema. HO-1 inducer treatment improved kidney function and reduced urinary the NGAL levels. The oxidative profile showed an increase in the endogenous thiol-based antioxidant levels. Additionally, the tubular injury score was reduced following HO-1 treatment. CONCLUSIONS: Our findings highlight the renoprotective effects of HO-1 in CI-AKI and preclinical diabetic models. Therefore, HO-1 ameliorates kidney dysfunction, reduces oxidative stress, and prevents cell necrosis.

BM-MSC-derived small extracellular vesicles (sEV) from trained animals presented nephroprotective potential in unilateralureteral obstruction model

Background: The efficacy of bone marrow mesenchymal stromal cells (BM-MSC) and its extracellular vesicles has been demonstrated for a broad spectrum of indications, including kidney diseases. However, BM-MSC donor characteristics and their potential are not usually considered. Therefore, the present work aims to evaluate the nephroprotective capacity of sEV secreted by BM-MSC from trained rats inunilateral ureteral obstruction (UUO) model. Methods: BM-MSC was characterized by their differentiation potential and immunophenotypic markers. The sEV were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis and western blot. Its miRNA cargo was examined by quantitative PCR analysis for miR-26a, 126a, and 296. Wistar rats were submitted to UUO procedure and concomitantly treated with sEV secreted by BM-MSC from the untrained andtrained rats. The kidney tissue from all groups was evaluated for fibrosis mediators (transforming growth factor beta1 and collagen), CD34-angiogenesis marker, and hypoxia-inducible factor 1 alpha (HIF-1α). Results: Treadmill training stimulated in BM-MSC the production of sEV loaded with pro-angiogenic miR-296. The treatment with this sEVin UUO-rats was able to attenuate collagen accumulation and increase CD34 and HIF-1α in the kidney tissue when compared to untrained ones. Tubular proximal cells under hypoxia and exposed to BM-MSC sEV demonstrate accumulation in HIF-1α and NFR-2 (nuclear factor erythroid 2-related factor 2), possibly to mediate the response to hypoxia and oxidative stress, under these conditions. Conclusion: The BM-MSC sEV from trained animals presented an increased nephroprotective potential compared to untrained vesicles by carrying 296-angiomiR and contributing to angiogenesis in UUO model.(AU)

BM-MSC-derived small extracellular vesicles (sEV) from trained animals presented nephroprotective potential in unilateralureteral obstruction model

Abstract Background: The efficacy of bone marrow mesenchymal stromal cells (BM-MSC) and its extracellular vesicles has been demonstrated for a broad spectrum of indications, including kidney diseases. However, BM-MSC donor characteristics and their potential are not usually considered. Therefore, the present work aims to evaluate the nephroprotective capacity of sEV secreted by BM-MSC from trained rats inunilateral ureteral obstruction (UUO) model. Methods: BM-MSC was characterized by their differentiation potential and immunophenotypic markers. The sEV were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis and western blot. Its miRNA cargo was examined by quantitative PCR analysis for miR-26a, 126a, and 296. Wistar rats were submitted to UUO procedure and concomitantly treated with sEV secreted by BM-MSC from the untrained andtrained rats. The kidney tissue from all groups was evaluated for fibrosis mediators (transforming growth factor beta1 and collagen), CD34-angiogenesis marker, and hypoxia-inducible factor 1 alpha (HIF-1). Results: Treadmill training stimulated in BM-MSC the production of sEV loaded with pro-angiogenic miR-296. The treatment with this sEVin UUO-rats was able to attenuate collagen accumulation and increase CD34 and HIF-1 in the kidney tissue when compared to untrained ones. Tubular proximal cells under hypoxia and exposed to BM-MSC sEV demonstrate accumulation in HIF-1 and NFR-2 (nuclear factor erythroid 2-related factor 2), possibly to mediate the response to hypoxia and oxidative stress, under these conditions. Conclusion: The BM-MSC sEV from trained animals presented an increased nephroprotective potential compared to untrained vesicles by carrying 296-angiomiR and contributing to angiogenesis in UUO model.

The renoprotective effects of Heme Oxygenase-1 during contrast-induced acute kidney injury in preclinical diabetic models

OBJECTIVES: Contrast-induced acute kidney injury (CI-AKI) is an important clinical problem that can be aggravated by diabetes mellitus, a major risk factor. However, heme oxygenase-1 (HO-1), a promising therapeutic target, can exert antioxidant effects against CI-AKI. Thus, we investigated the role of HO-1 in CI-AKI in the presence of diabetes mellitus. METHODS: Twenty-eight male Wistar rats weighing 250-300g were subjected to left uninephrectomy, and concomitantly, diabetes induced by streptozotocin (65 mg/kg). After 12 weeks, iodinated contrast (meglumine ioxithalamate, 6 mL/kg) and hemin (HO-1 inducer-10 mg/k) were administered 60 min before iodinated contrast treatment. The rats were randomly divided into four groups: control, diabetes mellitus (DM), DM iodinated contrast (DMIC), and DMIC hemin (DMICH). Kidney function, albuminuria, oxidative profile, and histology were assessed. All experimental data were subjected to statistical analyses. RESULTS: CI-AKI in preclinical diabetic models decreased creatinine clearance and increased urinary neutrophil gelatinase-associated lipocalin (NGAL) levels and the degree of albuminuria. Additionally, the levels of oxidative and nitrosative stress metabolites (urinary peroxides, thiobarbituric acid-reactive substances, and NO) were elevated, while thiol levels in kidney tissue were reduced. Kidney histology showed tubular cell vacuolization and edema. HO-1 inducer treatment improved kidney function and reduced urinary the NGAL levels. The oxidative profile showed an increase in the endogenous thiol-based antioxidant levels. Additionally, the tubular injury score was reduced following HO-1 treatment. CONCLUSIONS: Our findings highlight the renoprotective effects of HO-1 in CI-AKI and preclinical diabetic models. Therefore, HO-1 ameliorates kidney dysfunction, reduces oxidative stress, and prevents cell necrosis.