Nephroprotective effects of nebivolol in 2K1C rats through regulation of the kidney ROS-ADMA-NO pathway

Protein arginine methyltransferases in renal development, injury, repair, and fibrosis

Protein arginine methyltransferases (PRMTs) methylate a range of histone and non-histone substrates and participate in multiple biological processes by regulating gene transcription and post-translational modifications. To date, most studies on PRMTs have focused on their roles in tumors and in the physiological and pathological conditions of other organs. Emerging evidence indicates that PRMTs are expressed in the kidney and contribute to renal development, injury, repair, and fibrosis. In this review, we summarize the role and the mechanisms of PRMTs in regulating these renal processes and provide a perspective for future clinical applications.

Treatment with β-blocker nebivolol ameliorates oxidative stress and endothelial dysfunction in tenofovir-induced nephrotoxicity in rats

Background

Tenofovir disoproxil fumarate (TDF), a widely prescribed component in antiretroviral regimens, has been associated with nephrotoxicity. Nebivolol is a third generation selective β-1 adrenergic receptor blocker and may protect renal structure and function through the suppression of oxidative stress and enhancement of nitric oxide (NO) synthesis. We aimed to investigate whether nebivolol could be an effective therapeutic strategy to mitigate tenofovir-induced nephrotoxicity.

Methods

We allocated Wistar rats to four groups: control (C), received a standard diet for 30 days; NBV, received a standard diet for 30 days added with nebivolol (100 mg/kg food) in the last 15 days; TDF, received a standard diet added with tenofovir (300 mg/kg food) for 30 days; and TDF+NBV, received a standard diet added with tenofovir for 30 days and nebivolol in the last 15 days.

Results

Long-term exposure to tenofovir led to impaired renal function, induced hypertension, endothelial dysfunction and oxidative stress. Nebivolol treatment partially recovered glomerular filtration rate, improved renal injury, normalized blood pressure and attenuated renal vasoconstriction. Administration of nebivolol contributed to reductions in asymmetric dimethylarginine (ADMA) levels as well as increases in endothelial nitric oxide sintase (eNOS) accompanied by renin-angiotensin-aldosterone system downregulation and decreases in macrophage and T-cells infiltrate. Furthermore, nebivolol was responsible for the maintenance of the adequate balance of thiobarbituric acid reactive substances (TBARS) and glutathione (GSH) levels and it was associated with reductions in NADPH oxidase (NOX) subunits.

Conclusion

Nebivolol holds multifaceted actions that promote an advantageous option to slow the progression of kidney injury in tenofovir-induced nephrotoxicity.

Nobiletin resolves left ventricular and renal changes in 2K-1C hypertensive rats

This study investigated the effects of nobiletin on cardiorenal changes and the underlying mechanisms involved in two-kidney, one-clip (2K-1C) hypertension. 2K-1C rats were treated with nobiletin (15 or 30 mg/kg/day) or losartan (10 mg/kg/day) for 4 weeks (n = 8/group). Nobiletin (30 mg/kg) reduced high levels of blood pressure and circulating angiotensin II and angiotensin-converting enzyme activity in 2K-1C rats. Left ventricular (LV) dysfunction and remodelling in 2K-1C rats were alleviated in the nobiletin-treated group (P < 0.05). Nobiletin reduced the upregulation of Ang II type I receptor (AT₁R)/JAK (Janus kinase)/STAT (signal transducer and activator of transcription) protein expression in cardiac tissue of 2K-1C rats (P < 0.05). The reduction in kidney function, and accumulation of renal fibrosis in 2K-1C rats were alleviated by nobiletin (P < 0.05). Overexpression of AT₁R and NADPH oxidase 4 (Nox4) protein in nonclipped kidney tissue was suppressed in the nobiletin-treated group (P < 0.05). The elevations in oxidative stress parameters and the reductions in antioxidant enzymes were attenuated in 2K-1C rats treated with nobiletin (P < 0.05). In summary, nobiletin had renin-angiotensin system inhibitory and antioxidant effects and attenuated LV dysfunction and remodelling via restoration of the AT₁R/JAK/STAT pathway. Nobiletin also resolved renal damage that was related to modulation of the AT₁R/Nox4 cascade in 2K-1C hypertension.

Effect of a Low Dose of Carvedilol on Cyclophosphamide-Induced Urinary Toxicity in Rats—A Comparison with Mesna

One of the major side effects of cyclophosphamide (CPX)—an alkylating anticancer drug that is still clinically used—is urotoxicity with hemorrhagic cystitis. The present study was designed to evaluate the ability of carvedilol to protect rats from cyclophosphamide-induced urotoxicity. Rats were injected intraperitoneally (i.p.) with CPX (200 mg/kg) and administered carvedilol (2 mg/kg) intragastrically a day before, at the day and a day after a single i.p. injection of CPX, with or without mesna (40, 80, and 80 mg/kg i.p. 20 min before, 4 h and 8 h after CPX administration, respectively). Pretreatment with carvedilol partly prevented the CPX-induced increase in urinary bladder and kidney index, and completely protects from CPX-evoked alterations in serum potassium and creatinine level, but did not prevent histological alterations in the urinary bladder and hematuria. However, carvedilol administration resulted in significant restoration of kidney glutathione (GSH) level and a decrease in kidney interleukin 1β (IL-1β) and plasma asymmetric dimethylarginine (ADMA) concentrations. Not only did mesna improve kidney function, but it also completely reversed histological abnormalities in bladders and prevented hematuria. In most cases, no significant interaction of carvedilol with mesna was observed, although the effect of both drugs together was better than mesna given alone regarding plasma ADMA level and kidney IL-1β concentration. In conclusion, carvedilol did not counteract the injury caused in the urinary bladders but restored kidney function, presumably via its antioxidant and anti-inflammatory properties.

Flacourtia indica fruit extract modulated antioxidant gene expression, prevented oxidative stress and ameliorated kidney dysfunction in isoprenaline administered rats

This study evaluated the effect of Flacourtia indica fruit extract against isoprenaline (ISO) induced renal damage in rats. This investigation showed that ISO administration in rats increased the level oxidative stress biomarkers such as malondialdehyde (MDA), nitric oxide (NO), advanced protein oxidation product (APOP) in kidneys followed by a decrease in antioxidant enzymes functions. Flacourtia indica fruit extract, which is rich in strong antioxidants, also reduced the MDA, NO and APOP level in kidney of ISO administered rats. Inflammation and necrosis was also visible in kidney section of ISO administered rats which was significantly prevented by atenolol and Flacourtia indica fruit extract. Moreover, atenolol and Flacourtia indica fruit extract also modulated the genes expressions related to inflammation and oxidative stress in kidneys. The beneficial effects could be attributed to the presence of a number of phenolic antioxidants. This study suggests that Flacourtia indica fruit extract may prevent kidney dysfunction in ISO administered rats, probably by preventing oxidative stress and inflammation.

Does nebivolol have renoprotective action in patients with chronic kidney disease conditions? An integrative review

Systemic arterial hypertension (SAH) is a chronic disease of multifactorial origin and one of the main risk factors for major adverse cardiovascular events (MACE), which are the leading causes of morbidity and mortality worldwide. The pharmacological treatment of SAH involves five main classes of drugs, and Nebivolol (NEB) is one of those drugs, belonging to the class of third generation β1-adrenoceptors selective blockers. NEB is composed of a racemic mixture of two enantiomers: d-nebivolol, which exerts antagonist effects on β₁-adrenoceptors, and l-nebivolol, a vascular β₃ receptor agonist. There are several studies that report different actions of NEB, not only for the treatment of SAH, but also as an antioxidant agent or even as a protector of renal damage. The aim of this systematic review was to investigate the available evidence regarding the effects of NEB on kidney diseases, evaluating its possible renoprotective action.

Nephroprotective Effect of the Herbal Composition BNO 2103 in Rats with Renal Failure

(1) Background: this research aims at studying the nephroprotective properties of BNO 2103 in a model of chromate-induced renal failure in rats and at proving the possibility of using BNO 2103 in clinical practice for the complex treatment of chronic kidney disease (CKD). (2) Methods: fifty rats divided into five groups were studied. The drugs BNO 2103, Prednisolone and Lespephril were administered within 20 days. The excretory function and the functional state of kidneys, blood biochemical parameters and indicators of nitrogen metabolism were determined. (3) Results: under the influence of BNO 2103, there was a significant improvement in renal excretory function, in nitrogen metabolism and blood biochemical parameters compared with the control pathology group. BNO 2103 also outperformed the comparators in most indicators. (4) Conclusions: BNO 2103 has demonstrated nephroprotective, hypoazotemic and diuretic effects; and can be used to implement to the combined therapy of CKD.

Endothelial Dysfunction in Chronic Kidney Disease, from Biology to Clinical Outcomes: A 2020 Update

The vascular endothelium is a dynamic, functionally complex organ, modulating multiple biological processes, including vascular tone and permeability, inflammatory responses, thrombosis, and angiogenesis. Endothelial dysfunction is a threat to the integrity of the vascular system, and it is pivotal in the pathogenesis of atherosclerosis and cardiovascular disease. Reduced nitric oxide (NO) bioavailability is a hallmark of chronic kidney disease (CKD), with this disturbance being almost universal in patients who reach the most advanced phase of CKD, end-stage kidney disease (ESKD). Low NO bioavailability in CKD depends on several mechanisms affecting the expression and the activity of endothelial NO synthase (eNOS). Accumulation of endogenous inhibitors of eNOS, inflammation and oxidative stress, advanced glycosylation products (AGEs), bone mineral balance disorders encompassing hyperphosphatemia, high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23), and low levels of the active form of vitamin D (1,25 vitamin D) and the anti-ageing vasculoprotective factor Klotho all impinge upon NO bioavailability and are critical to endothelial dysfunction in CKD. Wide-ranging multivariate interventions are needed to counter endothelial dysfunction in CKD, an alteration triggering arterial disease and cardiovascular complications in this high-risk population.

The Biological Axis of Protein Arginine Methylation and Asymmetric Dimethylarginine

Protein post-translational modifications (PTMs) in eukaryotic cells play important roles in the regulation of functionalities of the proteome and in the tempo-spatial control of cellular processes. Most PTMs enact their regulatory functions by affecting the biochemical properties of substrate proteins such as altering structural conformation, protein-protein interaction, and protein-nucleic acid interaction. Amid various PTMs, arginine methylation is widespread in all eukaryotic organisms, from yeasts to humans. Arginine methylation in many situations can drastically or subtly affect the interactions of substrate proteins with their partnering proteins or nucleic acids, thus impacting major cellular programs. Recently, arginine methylation has become an important regulator of the formation of membrane-less organelles inside cells, a phenomenon of liquid-liquid phase separation (LLPS), through altering π-cation interactions. Another unique feature of arginine methylation lies in its impact on cellular physiology through its downstream amino acid product, asymmetric dimethylarginine (ADMA). Accumulation of ADMA in cells and in the circulating bloodstream is connected with endothelial dysfunction and a variety of syndromes of cardiovascular diseases. Herein, we review the current knowledge and understanding of protein arginine methylation in regards to its canonical function in direct protein regulation, as well as the biological axis of protein arginine methylation and ADMA biology.