The hydroalcoholic extract of Nasturtium officinale protectively inhibits apoptotic and inflammatory pathways in hepato- and nephrotoxicity: An in vivo study

Objective

Nasturtium officinale (N. officinale (NO)) has been widely used in traditional medicine. This study investigates the protective effects of NO against hepatic and renal damage induced by CCl4 and gentamicin, respectively, in rats.

Materials and Methods

Male Wistar rats were divided into two arms: A (CCl4-induced hepatotoxicity) and B (gentamicin-induced nephrotoxicity). Seventeen groups were formed by dividing arms A and B, with nine groups in arm A and eight groups in arm B (n=5). Rats were daily treated with various doses (50, 100, and 200 mg/kg BW) of N. officinale extract (NOE) (Total extract; Oral gavage) for 14 and 28 days in arm A and B, respectively. Biochemical and histopathological evaluations and gene expression analyses were conducted on blood, liver, and kidney tissues.

Results

NOE treatment significantly modulated B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) and B-cell lymphoma protein 2 (Bcl-2) expression in kidney tissue, reducing Bax (p<0.01) and increasing Bcl-2 (p<0.05). In liver tissue, NOE inhibited tumor necrosis factor alpha (TNF-α) (p<0.01) and Interleukin-1 beta (IL-1β) (p<0.001), while reducing AST and ALT activity (p<0.001). Additionally, blood urea nitrogen (BUN) levels significantly decreased (p<0.05) in nephrotoxic rats.

Conclusion

Our findings highlight the capability of NOE as a promising therapeutic against liver and kidney damage induced by CCl4 and gentamicin, respectively, in animal models.

Galangin prevents gentamicin-induced nephrotoxicity by modulating oxidative damage, inflammation and apoptosis in rats

The well-known antibiotic gentamicin (GEN) works well against a variety of pathogenic bacteria, nevertheless its therapeutic use might be limited by the possibility of nephrotoxicity. The naturally occurring flavonoid galangin (GAL) has several interesting anti-inflammatory and antioxidant properties. The present study evaluated the nephroprotective effect of GAL on GEN-induced renal injury. Rats received GAL for 14 days and GEN from day 8 to day 14. There was a significant increase in serum urea and creatinine along with several histopathological changes in the kidney following GEN administration. GEN-treated rats also showed increased levels of kidney MDA and NO, and decreased GSH content and activities of antioxidant enzymes. Rats received GEN also demonstrated increased NF-κB p65, iNOS, TNF-α, IL-1β and IL-6 levels in the kidney. GAL remarkably prevented tissue injury, attenuated MDA and NO levels, improved antioxidants, and decreased levels of inflammatory mediators in the kidney of GEN-treated rats. Furthermore, GEN-administrated rats exhibited increased Bax and caspase-3 with concomitant decline in Bcl-2 levels in the kidney, an effect that GAL attenuated. In conclusion, GAL prevents GEN-induced nephrotoxicity by attenuating oxidative stress, inflammation, and apoptosis and augmenting antioxidant defense, suggesting its therapeutic potential against drug nephrotoxicity.

Metabolic engineering approaches for the biosynthesis of antibiotics

BACKGROUND

Antibiotics have been saving countless lives from deadly infectious diseases, which we now often take for granted. However, we are currently witnessing a significant rise in the emergence of multidrug-resistant (MDR) bacteria, making these infections increasingly difficult to treat in hospitals.

MAIN TEXT

The discovery and development of new antibiotic has slowed, largely due to reduced profitability, as antibiotics often lose effectiveness quickly as pathogenic bacteria evolve into MDR strains. To address this challenge, metabolic engineering has recently become crucial in developing efficient enzymes and cell factories capable of producing both existing antibiotics and a wide range of new derivatives and analogs. In this paper, we review recent tools and strategies in metabolic engineering and synthetic biology for antibiotic discovery and the efficient production of antibiotics, their derivatives, and analogs, along with representative examples.

CONCLUSION

These metabolic engineering and synthetic biology strategies offer promising potential to revitalize the discovery and development of new antibiotics, providing renewed hope in humanity's fight against MDR pathogenic bacteria.

Enriched human embryonic stem cells-derived CD133+, CD24+ renal progenitors engraft and restore function in a gentamicin-induced kidney injury in mice

Introduction

Acute kidney injury (AKI) is a common health problem that leads to high morbidity and potential mortality. The failure of conventional treatments to improve forms of this condition highlights the need for innovative and effective treatment approaches. Regenerative therapies with Renal Progenitor Cells (RPCs) have been proposed as a promising new strategy. A growing body of evidence suggests that progenitor cells differentiated from different sources, including human embryonic stem cells (hESCs), can effectively treat AKI.

Methods

Here, we describe a method for generating RPCs and directed human Embryoid Bodies (EBs) towards CD133+CD24+ renal progenitor cells and evaluate their functional activity in alleviating AKI.

Results

The obtained results show that hESCs-derived CD133+CD24+ RPCs can engraft into damaged renal tubules and restore renal function and structure in mice with gentamicin-induced kidney injury, and significantly decrease blood urea nitrogen levels, suppress oxidative stress and inflammation, and attenuate histopathological disturbances, including tubular necrosis, tubular dilation, urinary casts, and interstitial fibrosis.

Conclusion

The results suggest that RPCs have a promising regenerative potential in improving renal disease and can lay the foundation for future cell therapy and disease modeling.

Lactoferrin alleviates gentamicin-induced acute kidney injury in rats by suppressing ferroptosis: Highlight on ACSL4, SLC7A11, NCOA4, FSP1 pathways and miR-378a-3p, LINC00618 expression

The use of gentamicin (GNT) is associated with acute kidney injury (AKI). Ferroptosis is a newly recognized iron-dependent, non-apoptotic cell death that can lead to AKI. Lactoferrin (LF), an iron-binding glycoprotein, was previously reported to be renoprotective. Nonetheless, LF's impact on GNT-induced AKI and ferroptosis has not yet been investigated. Accordingly, we assessed the dose-dependent effect of LF on GNT-induced AKI and its influence on ferroptosis. Thirty-six male rats were allocated as control, LF, GNT (100 mg/kg/day, i.p.), and groups given LF (100, 200, and 300 mg/kg, p.o.) for 14 days prior concurrently with GNT (Day 8-14). The high dose of LF (300 mg/kg) showed better histopathological picture, higher creatinine clearance, reduced serum and urine levels of kidney injury markers when compared to the GNT group and the lower two doses. These nephroprotective effects of LF can be attributed to the observed reduction in renal ferrous iron, 4-HNE, and MDA, miR-378a-3p and ALOX15 expression, TFR1, NCOA4, and ACSL4 protein expression and the increased LINC00618 expression, GSH levels, GPX4, SLC7A11, and FSP1 protein expression. In conclusion, LF high dose was the most renoprotective against GNT-induced AKI, in which suppression of ferroptosis pathways was a likely contributor to its protective mechanism.

Effect of alpha-linolenic acid on aminoglycoside nephrotoxicity and RhoA/Rho-kinase pathway in kidney

Aminoglycoside nephrotoxicity stands as a primary contributor to the development of acute intrinsic renal failure. Distinctive characteristic associated with this nephrotoxicity is the occurrence of tubular necrosis, which is why it is commonly referred to as acute tubular necrosis. Studies have demonstrated that inhibiting rhoA/rho-kinase pathway is beneficial for kidney damage induced by diabetes and renal ischemia. Comparable pathological conditions can be observed in aminoglycoside nephrotoxicity, like those found in diabetes and renal ischemia. Gentamicin, an aminoglycoside, is known to activate Rho/Rho-kinase pathway. The primary goal of this study is to explore influence of oxidative stress on this pathway by concurrently administering gentamicin and alpha-linolenic acid (ALA) possessing known antioxidant properties. To achieve this, gentamicin (100 mg kg-1) and ALA (70 mg kg-1) were administered to mice for a period of 9 days, and Rho/Rho-kinase pathway was examined by using ELISA. Administration of gentamicin to mice led to an elevation in RhoA and rho-kinase II levels, along with the activity of rho-kinase in kidneys. However, ALA effectively reversed this heightened response. ALA, known for its antioxidant properties, inhibited activation of Rho/Rho-kinase pathway induced by gentamicin. This finding suggests that gentamicin induces nephrotoxicity through oxidative stress.

Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles as Natural Nanocarriers in the Treatment of Nephrotoxic Injury In Vitro

Umbilical cord mesenchymal stem cell-derived extracellular vesicles (UC-EVs) are valuable in nanomedicine as natural nanocarriers, carrying information molecules from their parent cells and fusing with targeted cells. miRNA-126, specific to endothelial cells and derived from these vesicles, supports vascular integrity and angiogenesis and has protective effects in kidney diseases.

OBJECTIVE

This study investigates the delivery of miRNA-126 and anti-miRNA-126 via UC-EVs as natural nanocarriers for treating nephrotoxic injury in vitro.

METHOD

The umbilical cord-derived mesenchymal stem cell and UC-EVs were characterized according to specific guidelines. Rat kidney proximal tubular epithelial cells (tubular cells) were exposed to nephrotoxic injury through of gentamicin and simultaneously treated with UC-EVs carrying miRNA-126 or anti-miRNA-126. Specific molecules that manage cell cycle progression, proliferation cell assays, and newly synthesized DNA and DNA damage markers were evaluated.

RESULTS

We observed significant increases in the expression of cell cycle markers, including PCNA, p53, and p21, indicating a positive cell cycle regulation with newly synthesized DNA via BrDU. The treatments reduced the expression of DNA damage marker, such as H2Ax, suggesting a lower rate of cellular damage.

CONCLUSIONS

The UC-EVs, acting as natural nanocarriers of miRNA-126 and anti-miRNA-126, offer nephroprotective effects in vitro. Additionally, other components in UC-EVs, such as proteins, lipids, and various RNAs, might also contribute to these effects.

Protective effects of the secondary metabolites from Quercus salicina Blume against gentamicin-induced nephrotoxicity in zebrafish (Danio rerio) model

To reveal the protective effect on the nephrotoxicity of Quercus salicina Blume(QS), a traditional medicine for the treatment of urolithiasis, the 50 % ethanol extract from the branches and leaves of QS was chemically studied by systematic solvent extraction and HPLC chromatography. Two phenolic acids and three flavonoids were identified by nuclear magnetic resonance spectroscopy, namely Ferulic acid (1), p-Hydroxycinnamic acid (2), Hesperidin (3), Formononetin (4), and Quercetin (5). At the same time, the gentamicin-induced nephrotoxicity of zebrafish was used as a model for the first time. The antioxidant activity of these derivatives with good antioxidant activity screened from free radical scavenging experiments in vitro (DPPH and ABTS) was evaluated in vivo, including protein levels (LPO, NO, GSH, and SOD), kidney injury factor (KIM-1), zebrafish kidney pathology and real-time PCR. The results showed that metabolites 1, 3, and 5 had strong antioxidant activity, and oxidative stress in renal tissue was significantly reduced; KIM-1, TNF-α, and IL-6 mRNA expression in a dose-dependent manner, which preliminarily revealed the protective effect of the secondary metabolites of QS on nephrotoxicity, and preliminarily discussed the structure-activity relationship. This study provides an experimental basis for further exploring the mechanism of QS in the kidney.

Fluid shear stress-induced changes in megalin trafficking enhance endocytic capacity in proximal tubule cells

Proximal tubule (PT) cells maintain a high-capacity apical endocytic pathway to recover essentially all proteins that escape the glomerular filtration barrier. The multi ligand receptors megalin and cubilin play pivotal roles in the endocytic uptake of normally filtered proteins in PT cells but also contribute to the uptake of nephrotoxic drugs, including aminoglycosides. We previously demonstrated that opossum kidney (OK) cells cultured under continuous fluid shear stress (FSS) are superior to cells cultured under static conditions in recapitulating essential functional properties of PT cells in vivo. To identify drivers of the high-capacity, efficient endocytic pathway in the PT, we compared FSS-cultured OK cells with less endocytically active static-cultured OK cells. Megalin and cubilin expression are increased, and endocytic uptake of albumin in FSS-cultured cells is > 5-fold higher compared with cells cultured under static conditions. To understand how differences in receptor expression, distribution, and trafficking rates contribute to increased uptake, we used biochemical, morphological, and mathematical modeling approaches to compare megalin traffic in FSS- versus static-cultured OK cells. Our model predicts that culturing cells under FSS increases the rates of all steps in megalin trafficking. Importantly, the model explains why, despite seemingly counterintuitive observations (a reduced fraction of megalin at the cell surface, higher colocalization with lysosomes, and a shorter half-life of surface-tagged megalin in FSS-cultured cells), uptake of albumin is dramatically increased compared with static-grown cells. We also show that FSS-cultured OK cells more accurately exhibit the mechanisms that mediate uptake of nephrotoxic drugs in vivo compared with static-grown cells. This culture model thus provides a useful platform to understand drug uptake mechanisms, with implications for developing interventions in nephrotoxic injury prevention.

Renoprotective mechanisms of exercise training against acute and chronic renal diseases - A perspective based on experimental studies

Regular exercise training can lead to several health benefits, reduce mortality risk, and increase life expectancy. On the other hand, a sedentary lifestyle is a known risk factor for chronic diseases and increased mortality. Acute kidney injury (AKI) and chronic kidney disease (CKD) represent a significant global health problem, affecting millions of people worldwide. The progression from AKI to CKD is well-recognized in the literature, and exercise training has emerged as a potential renoprotective strategy. Thus, this article aims to review the main molecular mechanisms underlying the renoprotective actions of exercise training in the context of AKI and CKD, focusing on its antioxidative, anti-inflammatory, anti-apoptotic, anti-fibrotic, and autophagy regulatory effects. For that, bibliographical research was carried out in Medline/PubMed and Scielo databases. Although the pathophysiological mechanisms involved in renal diseases are not fully understood, experimental studies demonstrate that oxidative stress, inflammation, apoptosis, and dysregulation of fibrotic and autophagic processes play central roles in the development of tissue damage. Increasing evidence has suggested that exercise can beneficially modulate these mechanisms, potentially becoming a safe and effective non-pharmacological strategy for kidney health protection and promotion. Thus, the evidence base discussed in this review suggests that an adequate training program emerges as a valuable tool for preserving renal function in experimental animals, mainly through the production of antioxidant enzymes, nitric oxide (NO), irisin, IL-10, and IL-11. Future research can continue to explore these mechanisms to develop specific guidelines for the prescription of exercise training in different populations of patients with kidney diseases.

The renoprotective potential of montelukast: a scoping review

Introduction

Kidney damage can result from various factors, leading to structural and functional changes in the kidney. Acute kidney injury (AKI) refers to a sudden decline in kidney function, while chronic kidney disease involves a gradual deterioration lasting more than 3 months. Mechanisms of renal injury include impaired microcirculation, inflammation, and oxidative stress. Cysteinyl-leukotrienes (CysLTs) are inflammatory substances contributing to tissue damage. Montelukast, a leukotriene receptor antagonist, has shown potential renoprotective effects in experimental models of kidney injury.

Methods

The authors conducted a scoping review using PubMed, Scopus, and Web of Science databases to identify relevant studies investigating the impact of montelukast on renal diseases. Articles published until 2022 were included and evaluated for quality. Data extraction and analysis were performed based on predetermined inclusion criteria.

Results

The scoping review included 30 studies from 8 countries. Montelukast demonstrated therapeutic effects in various experimental models of nephrotoxicity and AKI induced by agents such as cisplatin, lipopolysaccharide, diclofenac, amikacin, Escherichia coli, cyclosporine, methotrexate, cobalt-60 gamma radiation, doxorubicin, and cadmium. Studies involving human subjects with nephrotic syndrome, pyelonephritis, and other renal diseases also reported positive outcomes with montelukast treatment. Montelukast exhibited anti-inflammatory, anti-apoptotic, antioxidant, and neutrophil-inhibiting properties, leading to improved kidney function and histopathological changes.

Conclusions

Montelukast shows promise as a renoprotective medication, particularly in early-stage kidney injury. Its ability to mitigate inflammation, oxidative stress, and neutrophil infiltration contributes to its therapeutic effects. Further research is needed to explore the clinical applications and mechanisms underlying the renoprotective action of montelukast.

Eucalyptol regulates Nrf2 and NF-kB signaling and alleviates gentamicin-induced kidney injury in rats by downregulating oxidative stress, oxidative DNA damage, inflammation, and apoptosis

Gentamicin, an aminoglycoside antibiotic, is nowadays widely used in the treatment of gram-negative microorganisms. The antimicrobial, anti-inflammatory, and antioxidant activities of eucalyptol, a type of saturated monoterpene, have been reported in many studies. The aim of this study was to examine the possible effects of eucalyptol on gentamicin-induced renal toxicity. A total of 32 rats were divided into 4 groups; Control (C), Eucalyptol (EUC), Gentamicin (GEN), and Gentamicin + Eucalyptol (GEN + EUC). In order to induce renal toxicity, 100 mg/kg gentamicin was administered intraperitoneally (i.p.) for 10 consecutive days in the GEN and GEN + EUC groups. EUC and GEN + EUC groups were given 100 mg/kg orally of eucalyptol for 10 consecutive days. Afterwards, rats were euthanized and samples were taken and subjected to histopathological, biochemical, immunohistochemical, and real-time PCR examinations. The blood urea nitrogen (BUN) and creatinine (CRE) levels were significantly decreased in the GEN + EUC group (0.76 and 0.69-fold, respectively) compared to the GEN group. The glutathione peroxidase (GPx) and catalase (CAT) activities were significantly increased in the GEN + EUC group (1.35 and 2.67-fold, respectively) compared to the GEN group. In GEN group, Nuclear factor kappa B (NF-kB), Interleukin 1-beta (IL-1β), Inducible nitric oxide synthase (iNOS), Tumor necrosis factor-α (TNF-α), Caspase-3, 8-Hydroxy-2'-deoxyguanosine (8-OHdG) and Nuclear factor erythroid 2-related factor (Nrf2) expression levels were found to be quite irregular. GEN + EUC group decreased the expressions of NF-kB, IL-1β, iNOS, TNF-α, Caspase-3, and 8-OHdG (0.55, 0.67, 0.54, 0.54, 0.63 and 0.67-fold, respectively), while it caused increased expression of Nrf2 (3.1 fold). In addition, eucalyptol treatment ameliorated the histopathological changes that occurred with gentamicin. The results of our study show that eucalyptol has anti-inflammatory, antioxidative, antiapoptotic, nephroprotective, and curative effects on gentamicin-induced nephrotoxicity.

Fluid Shear Stress-Induced Changes in Megalin Trafficking Enhance Endocytic Capacity in Proximal Tubule Cells

Proximal tubule (PT) cells maintain a high-capacity apical endocytic pathway to recover essentially all proteins that escape the glomerular filtration barrier. The multiligand receptors megalin and cubilin play pivotal roles in the endocytic uptake of normally filtered proteins in PT cells but also contribute to the uptake of nephrotoxic drugs, including aminoglycosides. We previously demonstrated that opossum kidney (OK) cells cultured under continuous fluid shear stress (FSS) are superior to cells cultured under static conditions in recapitulating essential functional properties of PT cells in vivo. To identify drivers of the high-capacity, efficient endocytic pathway in the PT, we compared FSS-cultured OK cells with less endocytically active static-cultured OK cells. Megalin and cubilin expression are increased, and endocytic uptake of albumin in FSS-cultured cells is >5-fold higher compared with cells cultured under static conditions. To understand how differences in receptor expression, distribution, and trafficking rates contribute to increased uptake, we used biochemical, morphological, and mathematical modeling approaches to compare megalin traffic in FSS- versus static-cultured OK cells. Our model predicts that culturing cells under FSS increases the rates of all steps in megalin trafficking. Importantly, the model explains why, despite seemingly counterintuitive observations (a reduced fraction of megalin at the cell surface, higher colocalization with lysosomes, and a shorter half-life of surface-tagged megalin in FSS-cultured cells), uptake of albumin is dramatically increased compared with static-grown cells. We also show that FSS-cultured OK cells more accurately exhibit the mechanisms that mediate uptake of nephrotoxic drugs in vivo compared with static-grown cells. This culture model thus provides a useful platform to understand drug uptake mechanisms, with implications for developing interventions in nephrotoxic injury prevention.

Baicalin-2-ethoxyethyl ester alleviates gentamicin-induced acute kidney injury via NF-κB signaling pathway

Drug nephrotoxicity has high fatality rates and complications. To study this conditional, traditionally, Gentamicin (GM) is used to induce acute injury and establish a nephrotic syndrome model. Baicalin, a flavonoid derived from baicalin with potent anti-inflammatory and antioxidant activity, has been used to treat various inflammatory diseases. This study aims to investigate the process of baicalin-2-ethoxyethyl ester (BAE) synthesis and its therapeutic effect on GM-induced acute kidney injury (AKI). Briefly, baicalin was processed by various reactions to yield BAE. A GM-induced AKI model was established for in vivo evaluation of the protective effect and mechanism of BAE. The results indicated that BAE reduced serum creatinine and urea nitrogen levels and improved pathological alterations, inflammatory responses, and oxidative stress in renal tissues. Furthermore, it was revealed that BAE might exert anti-inflammatory and anti-oxidative responses during AKI via the NF-κB signaling pathway regulation. The findings imply that BAE has a protective impact on the kidneys and might serve as a potent medicine for treating renal damage.

The Antioxidant, Antibacterial and Cell-Protective Properties of Bioactive Compounds Extracted from Rowanberry (Sorbus aucuparia L.) Fruits In Vitro

Considering that Sorbus aucuparia fruits have been underutilized despite their tremendous potential, this study aimed to correlate the in vitro antioxidant, antibacterial and cell-protective abilities of fruit extracts derived from Sorbus aucuparia Romanian cultivars with their phytochemical composition. Therefore, following the preparation of ethanolic and carotenoid extracts, phytochemical screening was performed using UV-Vis and HPLC-DAD-ESI-MS methods. The antioxidant activity was analyzed using DPPH and FRAP tests. As the results revealed high contents of bioactive compounds (polyphenols 1.11 mg GAE/g DM, flavonoids 430.06 µg QE/g DM and carotenoids 95.68 µg/g DM) and an important antiradical action (DPPH 24.51 mg/mL and FRAP 0.016 µM TE/mL), we chose to further examine the fruits' biological properties. The antibacterial capacity was assessed employing agar well diffusion and broth microdilution techniques, with fruits displaying an intense activity against MSSA, MRSA and Enterococcus faecalis, but also E. coli and Pseudomonas aeruginosa. The cell-protective activity was analyzed on gentamicin-stressed renal cells, through MTT and Annexin V-FITC assays. Importantly, a significant increase in viability was registered on stressed cells following extract administration in low doses; nevertheless, viability was noticed to decline when exposed to elevated concentrations, potentially due to the cumulative actions of the extract and gentamicin. These findings offer novel light on the antibacterial activity of Sorbus aucuparia Romanian cultivars, as well as their cell-protective ability in renal cell injury.

Protective role of pyrroloquinoline quinone against gentamicin induced cochlear hair cell ototoxicity

Gentamicin (GM) is one of the commonly used antibiotics in the aminoglycoside class but is ototoxic, which constantly impacts the quality of human life. Pyrroloquinoline quinone (PQQ) as a redox cofactor produced by bacteria was found in soil and foods that exert an antioxidant and redox modulator. It is well documented that the PQQ can alleviate inflammatory responses and cytotoxicity. However, our understanding of PQQ in ototoxicity remains unclear. We reported that PQQ could protect against GM-induced ototoxicity in House Ear Institute-Organ of Corti 1 (HEI-OC1) cells in vitro. To evaluate reactive oxygen species (ROS) production and mitochondrial function, ROS and JC-1 staining, oxygen consumption rate (OCR), and extracellular acidification rate (ECAR) measurements in living cells, mitochondrial dynamics analysis was performed. GM-mediated damage was performed by reducing the production of ROS and inhibiting mitochondria biogenesis and dynamics. PQQ ameliorated the cellular oxidative stress and recovered mitochondrial membrane potential, facilitating the recovery of mitochondrial biogenesis and dynamics. Our in vitro findings improve our understanding of the GM-induced ototoxicity with therapeutic implications for PQQ.

Lysosomal membrane stabilization by imipramine attenuates gentamicin-induced renal injury: Enhanced LAMP2 expression, down-regulation of cytoplasmic cathepsin D and tBid/cytochrome c/cleaved caspase-3 apoptotic signaling

Nephrotoxicity is a serious complication commonly encountered with gentamicin (GTM) treatment. Permeabilization of lysosomes with subsequent cytoplasmic release of GTM and cathepsins is considered a crucial issue in progression of GTM toxicity. This study was designed to evaluate the prospective defensive effect of lysosomal membrane stabilization by imipramine (IMP) against GTM nephrotoxicity in rats. GTM (30 mg/kg/h) was intraperitoneally administered over 4 h daily (120 mg/kg/day) for 7 days. IMP (30 mg/kg/day) was orally administered for 14 days; starting 7 days before and then concurrently with GTM. On 15th day, samples (urine, blood, kidney) were collected to estimate biomarkers of kidney function, lysosomal stability, apoptosis, and inflammation. IMP administration to GTM-treated rats ameliorated the disruption in lysosomal membrane stability induced by GTM. That was evidenced by enhanced renal protein expressions of LAMP2 and PI3K, but reduced cathepsin D cytoplasmic expression in kidney sections. Besides, IMP guarded against apoptosis in GTM-treated rats by down-regulation of the pro-apoptotic (tBid, Bax, cytochrome c) and the effector cleaved caspase-3 expressions, while the anti-apoptotic Bcl-2 expression was enhanced. Additionally, the inflammatory cascade p38 MAPK/NF-κB/TNF-α was attenuated in GTM + IMP group along with marked improvement in kidney function biomarkers, compared to GTM group. These findings were supported by the obvious improvement in histological architecture. Furthermore, in vitro enhancement of the antibacterial activity of GTM by IMP confers an additional benefit to their combination. Conclusively, lysosomal membrane stabilization by IMP with subsequent suppression of tBid/cytochrome c/cleaved caspase-3 apoptotic signaling could be a promising protective strategy against GTM nephrotoxicity.

Investigation the effects of 2-aminoethoxydiphenyl borate (2-APB) on aminoglycoside nephrotoxicity

Investigation the protective effect of transient receptor potential channel modulator 2-Aminoethoxydiphenyl Borate (2-APB) on aminoglycoside nephrotoxicity caused by reactive oxygen species, calcium-induced apoptosis and inflammation was aimed. Forty Wistar rats were divided (n=8) as follows: Control group; DMSO group; 2-APB group; Gentamicin group (injected 100 mg/kg gentamicin intramuscularly for 10 days); Gentamicin+ 2-APB group (injected 2 mg/kg 2-APB intraperitoneally, then after 30 minutes 100 mg/kg gentamicin was injected intramuscularly for 10 days). Blood samples were collected for biochemical analyses, kidney tissue samples were collected for light, electron microscopic and immunohistochemical investigations. In gentamicin group glomerular degeneration, tubular dilatation, vacuolization, desquamation of tubular cells and hyaline cast formation in luminal space and leukocyte infiltration were seen. Disorganization of microvilli of tubular cells, apical cytoplasmic blebbing, lipid accumulation, myelin figure like structure formation, increased lysosomes, mitochondrial swelling and disorganization of cristae structures, apoptotic changes and widening of intercellular space were found. TNF-α, IL-6 and caspase 3 expressions were increased. BUN and creatinine concentrations were increased. Increase in MDA levels and decrease in SOD activities were determined. Even though degeneration still continues in gentamicin+2-APB treatment group, severity and the area it occupied were decreased and the glomerular and tubule structures were generally preserved. TNF-α, IL-6, caspase 3 immunoreactivities and BUN, creatinine, MDA concentrations were reduced and SOD activities were increased markedly compared to gentamicin group. In conclusion, it has been considered that 2-APB can prevent gentamicin mediated nephrotoxicity with its anti-oxidant, anti-apoptotic and anti-inflammatory effects.

Pathophysiology of Acute Kidney Frailty

Acute kidney frailty is a premorbid condition of diminished renal functional reserve that predisposes to acute kidney injury; this condition results from subclinical wear or distortion of renal homeostatic responses that protect the renal excretory function. Knowledge of its pathophysiological basis is critical for the development of diagnostic and therapeutic strategies that allow for prophylactic intervention and disease prevention.

Physical exercise as a friend not a foe in acute kidney diseases through immune system modulation

Regular and moderate exercise is being used for therapeutic purposes in treating several diseases, including cancer, cardiovascular diseases, arthritis, and even chronic kidney diseases (CKDs). Conversely, extenuating physical exercise has long been pointed out as one of the sources of acute kidney injury (AKI) due to its severe impact on the body's physiology. AKI development is associated with increased tubular necrosis, which initiates a cascade of inflammatory responses. The latter involves cytokine production, immune cell (macrophages, lymphocytes, and neutrophils, among others) activation, and increased oxidative stress. AKI can induce prolonged fibrosis stimulation, leading to CKD development. The need for therapeutic alternative treatments for AKI is still a relevant issue. In this context arises the question as to whether moderate, not extenuating, exercise could, on some level, prevent AKI. Several studies have shown that moderate exercise can help reduce tissue damage and increase the functional recovery of the kidneys after an acute injury. In particular, the immune system can be modulated by exercise, leading to a better recovery from different pathologies. In this review, we aimed to explore the role of exercise not as a trigger of AKI, but as a modulator of the inflammatory/immune system in the prevention or recovery from AKI in different scenarios. In AKI induced by ischemia and reperfusion, sepsis, diabetes, antibiotics, or chemotherapy, regular and/or moderate exercise could modulate the immune system toward a more regulatory immune response, presenting, in general, an anti-inflammatory profile. Exercise was shown to diminish oxidative stress, inflammatory markers (caspase-3, lactate dehydrogenase, and nitric oxide), inflammatory cytokines (interleukin (IL)-1b, IL-6, IL-8, and tumor necrosis factor-α (TNF-α)), modulate lymphocytes to an immune suppressive phenotype, and decrease tumor necrosis factor-β (TGF-β), a cytokine associated with fibrosis development. Thus, it creates an AKI recovery environment with less tissue damage, hypoxia, apoptosis, or fibrosis. In conclusion, the practice of regular moderate physical exercise has an impact on the immune system, favoring a regulatory and anti-inflammatory profile that prevents the occurrence of AKI and/or assists in the recovery from AKI. Moderate exercise should be considered for patients with AKI as a complementary therapy.

The Nephroprotective Effect of Cornelian Cherry (Cornus mas L.) and Rowanberry (Sorbus aucuparia L.) in Gentamicin-Induced Nephrotoxicity on Wistar Rats with Emphasis on the Evaluation of Novel Renal Biomarkers and the Antioxidant Capacity in Correlation with Nitro-Oxidative Stress

In spite of its well-known nephrotoxicity, gentamicin is nonetheless routinely used in humans and animals. However, no adjuvant treatments have been implemented to mitigate this harmful effect. Given this concern, medicinal plants represent a significant reservoir of natural antioxidants that could potentially reduce the renal oxidative stress induced by gentamicin. Therefore, the main objective of this research was to investigate the nephroprotective properties of Cornus mas and Sorbus aucuparia fruits in an experimental model of nephrotoxicity. The 3-week study was performed on male Wistar rats, which were randomly divided into six experimental groups, being subcutaneously treated with 50 mg/kg gentamicin and orally given Cornus mas and Sorbus aucuparia extracts, in doses of 40 mg/kg and 10 mg/kg, respectively. Antioxidant therapy significantly improved the nitro-oxidative stress parameters as well as the specific renal biomarkers KIM-1 and iNAG, demonstrating a considerable renal tubular protective impact. These outcomes were reinforced by biochemical and histopathological enhancements. Nevertheless, neither of the tested extracts succeeded in substantially diminishing BUN levels. Additionally, CysC did not significantly decline following extracts treatment, suggesting that the remedies did not effectively protect renal glomeruli against gentamicin stress. Future studies are required in order to determine the underlying mechanisms of these berries.

Tools for photomotor response assay standardization in ecotoxicological studies: Example of exposure to gentamicin in the freshwater planaria Schmidtea mediterranea

Photomotor response assay (PMR) is very useful in an ecotoxicological context because it allows evaluation of behavioral response to potential toxic compounds. However, a lack of procedure standardization makes results comparison difficult between labs and organisms. Here, we aimed to propose five different tools to standardize the PMR procedure so that it may be applied to all model species, regarding: (1) the minimum total sample size, (2) the acclimation period, (3) the number and duration of light and dark phases alternation, (4) the measured behavior, and (5) the statistical analysis. As an example of procedure application, we analyzed the effect of an exposure to the antibiotic gentamicin on the locomotion behavior during PMR in an invertebrate species: the asexual freshwater planaria Schmidtea mediterranea. We encourage future studies using PMR to follow these five tools to improve data analysis and results comparability.

Phytochemical Profile, Antioxidant, Antimicrobial and Cytoprotective Effects of Cornelian Cherry (Cornus mas L.) Fruit Extracts

Cornus mas L. is characterized by an increased quantity of bioactive compounds, namely polyphenols, monoterpenes, organic acids, vitamin C and lipophilic compounds such as carotenoids, being anciently used in the treatment of various diseases. This paper’s objectives were to characterize the phytochemical profile of Cornus mas L. fruits and to evaluate the in vitro antioxidant, antimicrobial and cytoprotective effects on renal cells exposed to gentamicin. As such, two ethanolic extracts were obtained. The resulting extracts were used to assess the total polyphenols, flavonoids and carotenoids through spectral and chromatographic methods. The antioxidant capacity was assessed using DPPH and FRAP assays. Due to the high content of phenolic compounds analyzed in fruits and the results obtained regarding antioxidant capacity, we decided to further use the ethanolic extract to investigate the in vitro antimicrobial and cytoprotective effects on renal cells stressed with gentamicin. The antimicrobial activity was assessed using agar well diffusion and broth microdilution methods, with great results regarding Pseudomonas aeruginosa. The cytotoxic activity was assessed using MTT and Annexin-V assays. According to the findings, extract-treated cells had a higher cell viability. However, at high concentrations, viability was shown to decline, most likely due to the extract and gentamicin’s additive effects.

Protective effect of Cistanche deserticola on gentamicin-induced nephrotoxicity in rats

Objective

Gentamicin (GM) is a commonly used aminoglycoside antibiotic, however, renal toxicity has limited its usage. The present study was designed to evaluate the ameliorative effect of Cistanche deserticola on GM-induced nephrotoxicity in rats.

Methods

The nephrotoxicity in rats was induced by intraperitoneal administration of GM (100 mg/kg) for 10 consecutive days. Glomerular filtration rate, blood urea nitrogen, creatinine and kidney histopathology were detected to assess the GM-induced nephrotoxicity. The oxidative stress (catalase, superoxide dismutase, glutathione and malondialdehyde) was assessed. The inflammatory response (tumor necrosis factor-α, interleukin-6, myeloperoxidase and nuclear factor-kappa B) and apoptotic marker (Bax and Bcl-2) were also evaluated.

Results

The results showed that water and 75% ethanol extracts of C. deserticola (named CDW and CDE, respectively) (100, 200 and 400 mg/kg) in combination with GM could recover the reduction of glomerular filtration rate and enhance the renal endogenous antioxidant capability induced by GM. The increase in the expression of renal inflammatory cytokines (tumor necrosis factor-α and interleukin-6), nuclear protein of nuclear factor-kappa B (p65) and the activity of myeloperoxidase induced by GM was significantly decreased upon CDW or CDE treatment. In addition, CDW or CDE treatment could decrease the Bax protein expression and increase the Bcl-2 protein expression in GM-induced nephrotoxicity in rats significantly.

Conclusion

The study demonstrated that C. deserticola treatment could attenuate kidney dysfunction and structural damage in rats induced by GM through the reduction of inflammation, oxidative stress and apoptosis.

Liraglutide ameliorates gentamicin-induced acute kidney injury in rats via PGC-1α- mediated mitochondrial biogenesis: Involvement of PKA/CREB and Notch/Hes-1 signaling pathways

Acute kidney injury (AKI) is a challenging side effect which may clinically impede the use of gentamicin (GM). The present study explored the impact of liraglutide (Lir) on GM-induced kidney injury in rats. Lir (0.2 and 0.4 mg/kg, s.c) was given for 10 days (a dose/day) starting 3 days before giving GM (100 mg/kg, i.p) once daily for 7 days. Interestingly, Lir notably ameliorated GM-induced elevated levels of renal injury markers; urea and creatinine. Moreover, Lir remarkably mitigated malondialdehyde (MDA) level and elevated glutathione (GSH) level as well as superoxide dismutase (SOD) activity. Also, Lir pre-treatment notably diminished inflammatory markers levels; interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), vascular cell adhesion molecule (VCAM), monocyte chemoattractant protein 1 (MCP-1) and interferon gamma (INF-γ). In addition, Lir significantly replenished expression of Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α), Protein kinase A (PKA), cAMP response element-binding protein (CREB), nuclear Nuclear factor erythroid 2-related factor 2 (Nrf2), heme Oxygenase-1 (HO-1), B-cell lymphoma 2 (Bcl-2), and remarkably attenuated expression of Notch homolog 1 (Notch1), Hairy and enhancer of split-1 (Hes-1), Bcl-2-associated X (Bax), cleaved caspase 3 and nuclear Nuclear factor Kappa B (NF-κB (p65)). The nephroprotective activity of Lir was further confirmed by histopathological examination as well as transmission electron microscopy (TEM). In conclusion Lir achieved its nephroprotective effects through the amelioration of oxidative stress, inflammatory and apoptotic manifestations. It is worth-mentioning that the current study is the first to focus on the involvement of mitochondrial biogenesis and its upstream regulators, PKA/CREB and Notch/Hes-1 signaling pathways in the nephroprotective potentials of Lir. The attenuation of the aforementioned injurious aspects is partially attributed to the improvement of the mitochondrial status as demonstrated by elevated PGC-1α expression via acceleration of PKA/CREB and abatement of Notch/Hes-1 signaling pathways.

Mitochondrial transplantation against gentamicin-induced toxicity on rat renal proximal tubular cells: the higher activity of female rat mitochondria

Mitochondrial dysfunction is a fundamental mechanism leading to drug nephrotoxicity, such as gentamicin-induced nephrotoxicity. Mitochondrial therapy (mitotherapy) or exogenous mitochondria transplantation is a method that can be used to replace dysfunctional mitochondria with healthy mitochondria. This method can help in the treatment of diseases related to mitochondria. In this research, we studied the transplantation effect of freshly isolated mitochondria on the toxicity induced by gentamicin on renal proximal tubular cells (RPTCs). Furthermore, possible gender-related effects on supplying exogenous rat kidney mitochondria on gentamicin-induced RPTCs were investigated. At first, the normality and proper functioning of fresh mitochondria were assessed by measuring mitochondrial succinate dehydrogenase activity (SDH) and changes in mitochondrial membrane potential (MMP). Then, the protective effects of mitochondrial transplantation against gentamicin-induced mitochondrial toxicity were evaluated through parameters including lactate dehydrogenase (LDH) leakiness, reactive oxygen species (ROS) production, lipid peroxidation (LPO) content, reduced glutathione (GSH) level, extracellular oxidized glutathione (GSSG) level, ATP level, MMP collapse, and caspase-3 activity. According to the statistical analysis, transplanting the healthy mitochondria decreased the cytotoxicity, ROS production, MMP collapse, LPO content, GSSG levels, and caspase-3 activity caused by gentamicin in RPTCs. Also, it has caused an increase in the level of ATP and GSH in the RPTCs. Furthermore, higher preventive effects were observed for the female group. According to the current study, mitochondrial transplantation is a potent therapeutic method in xenobiotic-caused nephrotoxicity.

Expression of ER stress markers (GRP78 and PERK) in experimental nephrotoxicity induced by cisplatin and gentamicin: roles of inflammatory response and oxidative stress

This study aimed to establish the relationship between two endoplasmic reticulum (ER) stress proteins, glucose-regulated protein 78 (GRP78/BiP) and PKR-like endoplasmic reticulum kinase (PERK), and oxidative stress markers in cisplatin (CIS)-induced and gentamicin (GEN)-induced nephrotoxicity.The study consisted of five groups: control (saline solution only), CIS D2 (2.5 mg/kg for 2 days), CIS D7 (2.5 mg/kg for 7 days), GEN D2 (160 mg/kg for 2 days), and GEN D7 (160 mg/kg for 7 days). All rats were sacrificed 24 h after the last injection for standard clinical chemistry, and ultrastructural and histological evaluation of the kidney.CIS and GEN increased blood urea nitrogen (BUN) and serum creatinine (Cr) levels, as well as total oxidant status (TOS), while decreasing total antioxidant status (TAS) level in CIS D7 and GEN D7 groups. Histopathological and ultrastructural findings were also consistent with renal tubular damage. In addition, expression of markers of renal inflammation (tumor necrosis factor-α (TNF-α) and interleukin 1β (IL-1β)) and ER stress markers (GRP78 and PERK) was significantly increased in the kidney tissue of rats treated with CIS and GEN for 7 days.These findings suggest that CIS and GEN administration for 7 days aggravates nephrotoxicity through the enhancement of oxidative stress, inflammation, and ER stress-related markers. As a result, the recommended course of action is to utilize CIS and GEN as an immediate but brief induction therapy, stopping after 3 days and switching to other drugs instead.

Epigallocatechin Gallate Attenuates Gentamicin-Induced Nephrotoxicity by Suppressing Apoptosis and Ferroptosis

Gentamicin (GEN) is a kind of aminoglycoside antibiotic with the adverse effect of nephrotoxicity. Currently, no effective measures against the nephrotoxicity have been approved. In the present study, epigallocatechin gallate (EG), a useful ingredient in green tea, was used to attenuate its nephrotoxicity. EG was shown to largely attenuate the renal damage and the increase of malondialdehyde (MDA) and the decrease of glutathione (GSH) in GEN-injected rats. In NRK-52E cells, GEN increased the cellular ROS in the early treatment phase and ROS remained continuously high from 1.5 H to 24 H. Moreover, EG alleviated the increase of ROS and MDA and the decrease of GSH caused by GEN. Furthermore, EG activated the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). After the treatment of GEN, the protein level of cleaved-caspase-3, the flow cytometry analysis and the JC-1 staining, the protein levels of glutathione peroxidase 4 (GPX4) and SLC7A11, were greatly changed, indicating the occurrence of both apoptosis and ferroptosis, whereas EG can reduce these changes. However, when Nrf2 was knocked down by siRNA, the above protective effects of EG were weakened. In summary, EG attenuated GEN-induced nephrotoxicity by suppressing apoptosis and ferroptosis.

Evaluation of Novel Urinary Biomarkers in Beagle Dogs With Amphotericin B-Induced Kidney Injury

Next-generation urinary protein biomarkers have been qualified to enable monitoring for drug-induced kidney injury in toxicology studies conducted in rats. However, there is limited literature on the utility of these biomarkers in dogs. To add to the existing body of knowledge on the utility of the next-generation drug-induced kidney injury (DIKI) biomarkers, we evaluated the value of these biomarkers for the early detection of DIKI in Beagle dogs using a differentiated nephrotoxicant, Amphotericin B (AmpB). In dogs with AmpB-induced kidney injury, we monitored the response of urinary albumin, total protein, clusterin, kidney injury molecule 1, neutrophil gelatinase-associated lipocalin and N-acetyl-beta-D-glucosaminidase. We also measured blood urea nitrogen, serum creatinine and cystatin C. The results showed that urinary clusterin (up to ∼ 112x) was much more sensitive to AmpB-induced kidney injury relative to other biomarkers. Moreover, other than urinary clusterin and to a much lesser extent urinary albumin and total protein, none of the other biomarkers analyzed in this study were more sensitive than blood urea nitrogen and serum creatinine. The AmpB related tubular alterations were characterized by minimal to mild, multifocal necrosis, degeneration, regeneration, dilatation and mineralization. The mild nature of these histopathologic findings further attested to the sensitivity of urinary clusterin to AmpB-induced kidney injury in dogs. These results will help drug developers make informed decisions when selecting urinary biomarkers for monitoring DIKI in dogs for toxicology studies.

The Credible Role of Curcumin in Oxidative Stress-Mediated Mitochondrial Dysfunction in Mammals

Oxidative stress and mitochondrial dysfunction are associated with the pathogenesis of several human diseases. The excessive generation of reactive oxygen species (ROS) and/or lack of adequate antioxidant defenses causes DNA mutations in mitochondria, damages the mitochondrial respiratory chain, and alters membrane permeability and mitochondrial defense mechanisms. All these alterations are linked to the development of numerous diseases. Curcumin, an active ingredient of turmeric plant rhizomes, exhibits numerous biological activities (i.e., antioxidant, anti-inflammatory, anticancer, and antimicrobial). In recent years, many researchers have shown evidence that curcumin has the ability to reduce the oxidative stress- and mitochondrial dysfunction-associated diseases. In this review, we discuss curcumin’s antioxidant mechanism and significance in oxidative stress reduction and suppression of mitochondrial dysfunction in mammals. We also discuss the research gaps and give our opinion on how curcumin research in mammals should proceed moving forward.

Oxymatrine Alleviates Gentamicin-Induced Renal Injury in Rats

Gentamicin is an aminoglycoside antibiotic commonly used to treat Gram-negative bacterial infections that possesses considerable nephrotoxicity. Oxymatrine is a phytochemical with the ability to counter gentamicin toxicity. We investigated the effects and protective mechanism of oxymatrine in rats. The experimental groups were as follows: Control, Oxymatrine only group (100 mg/kg/d), Gentamicin only group (100 mg/kg/d), Gentamicin (100 mg/kg/d) plus Oxymatrine (100 mg/kg/d) group (n = 10). All rats were treated for seven continuous days. The results indicated that oxymatrine alleviated gentamicin-induced kidney injury, and decreased rats’ kidney indices and NAG (N-acetyl-beta-d-glucosaminidase), BUN (blood urea nitrogen) and CRE (creatine) serum levels. The oxymatrine-treated group sustained less histological damage. Oxymatrine also relived gentamicin-induced oxidative and nitrative stress, indicated by the increased SOD (superoxidase dismutase), GSH (glutathione) and CAT (catalase) activities and decreased MDA (malondialdehyde), iNOS (inducible nitric oxide synthase) and NO (nitric oxide) levels. Caspase-9 and -3 activities were also decreased in the oxymatrine-treated group. Oxymatrine exhibited a potent anti-inflammatory effect on gentamicin-induced kidney injury, down-regulated the Bcl-2ax and NF-κB mRNAs, and upregulated Bcl-2, HO-1 and Nrf2 mRNAs in the kidney tissue. Our investigation revealed the renal protective effect of oxymatrine in gentamicin-induced kidney injury for the first time. The effect was achieved through activation of the Nrf2/HO-1 pathways. The study underlines the potential clinical application of oxymatrine as a renal protectant agent for gentamicin therapy.

Protective effect of inhibiting necroptosis on gentamicin-induced nephrotoxicity

Necroptosis is defined as a novel programmed cell necrosis that is mediated by receptor interacting serine-threonine protein kinase 1 (RIPK1) and other related signals. Necrosis, apoptosis and inflammation are commonly considered as the leading mechanism in acute kidney injury (AKI) induced by gentamicin (GEN), which is a useful antibiotic for treating the infection of Gram-negative bacterial. However, the necroptosis in the pathogenesis of GEN-induced AKI is unknown. In this study, to investigate the process and function of necroptosis in GEN-induced AKI, NRK-52E and HK-2 cells and SD rats were used as the models. The necroptosis-related proteins, including RIPK1, RIPK3, mixed lineage kinase domain-like (MLKL) and phosphorylated MLKL (p-MLKL), were all increasing time-dependently when GEN was continuously given. By using the RIPK1 inhibitor necrostatin-1 (NEC-1) and RIPK3 inhibitor (CPD42), the GEN-induced toxicity of tubular cells was alleviated. Moreover, it was validated that GEN-induced cell apoptosis and inflammation were attenuated after treating with NEC-1 or CPD42, both in vivo and in vitro. When MLKL was knocked down by siRNA, NEC-1 and CPD42 can not further protect the damage of tubular cells by GEN. Although the using of pan-caspase inhibitor Z-VAD significantly decreased GEN-induced apoptosis, it enhanced necroptosis and slightly promoted the decreased cell viability in GEN-treated cells, with the protective effects weaker than NEC-1 or CPD42. Finally, in vitro minimum inhibitory concentration (MIC) tests and bacteriostatic ring studies showed that NEC-1 did not interfere with the antibiotic effects of GEN. Thus, suppressing necroptosis can serve as a promising strategy for the prevention of GEN-induced nephrotoxicity.

Ataluren suppresses a premature termination codon in an MPS I-H mouse

Abstarct

Suppressing translation termination at premature termination codons (PTCs), termed readthrough, is a potential therapy for genetic diseases caused by nonsense mutations. Ataluren is a compound that has shown promise for clinical use as a readthrough agent. However, some reports suggest that ataluren is ineffective at suppressing PTCs. To further evaluate the effectiveness of ataluren as a readthrough agent, we examined its ability to suppress PTCs in a variety of previously untested models. Using NanoLuc readthrough reporters expressed in two different cell types, we found that ataluren stimulated a significant level of readthrough. We also explored the ability of ataluren to suppress a nonsense mutation associated with Mucopolysaccharidosis I-Hurler (MPS I-H), a genetic disease that is caused by a deficiency of α-L-iduronidase that leads to lysosomal accumulation of glycosaminoglycans (GAGs). Using mouse embryonic fibroblasts (MEFs) derived from Idua-W402X mice, we found that ataluren partially rescued α-L-iduronidase function and significantly reduced GAG accumulation relative to controls. Two-week oral administration of ataluren to Idua-W402X mice led to significant GAG reductions in most tissues compared to controls. Together, these data reveal important details concerning the efficiency of ataluren as a readthrough agent and the mechanisms that govern its ability to suppress PTCs.

Key messages

Ataluren promotes readthrough of PTCs in a wide variety of contexts.

Ataluren reduces glycosaminoglyan storage in MPS I-H cell and mouse models.

Ataluren has a bell-shaped dose–response curve and a narrow effective range.

Formononetin Ameliorates Renal Dysfunction, Oxidative Stress, Inflammation, and Apoptosis and Upregulates Nrf2/HO-1 Signaling in a Rat Model of Gentamicin-Induced Nephrotoxicity

Gentamicin (GEN) is a bactericidal aminoglycoside known to cause nephrotoxicity. Formononetin (FN) is a potent flavonoid that exhibits numerous promising pharmacological activities. In this study, we have assessed the nephroprotective efficacy of FN against GEN-induced renal injury in rats. Rats were orally administered with FN (60 mg/kg/day, for 2 weeks) and were co-treated with intraperitoneal (i.p.) injection of GEN (100 mg/kg/day) during the days 8–14. GEN-treated rats demonstrated increased urea and creatinine levels in serum associated with marked histopathological changes in the kidney. Malondialdehyde (MDA) and protein carbonyl contents were elevated, whereas glutathione concentration and catalase and superoxide dismutase activities were lowered in GEN-administered rats. The FN largely prevented tissue damage, attenuated renal function, reduced MDA and protein carbonyl, and enhanced antioxidant capacity in the kidney of GEN-administrated animals. The kidney of GEN-treated rats demonstrated elevated Bax and caspase-3 protein expression, accompanied by lowered Bcl-2 protein expression, an effect that FN attenuated. Moreover, FN treatment caused upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) expression in renal tissue of GEN-intoxicated animals. Collectively, FN protects against GEN-caused renal damage via exhibiting antioxidant, anti-inflammatory, and antiapoptotic activities and augmenting Nrf2 signaling, suggesting FN as a promising agent for preventing drug-induced organ damage.

Nephroprotective Effect of Asparagus africanus Lam. Root Extract against Gentamicin-Induced Nephrotoxicity in Swiss Albino Mice

The kidney is the organ most vulnerable to nephrotoxic drugs such as gentamicin. Nephrotoxicity is a rapid deterioration of kidney function due to various factors. Gentamicin causes nephrotoxicity, which was manifested by an increase in serum kidney biomarkers. Asparagus africanus is one of the ethnomedicinal plants used as traditional medicine for treating various ailments, including kidney disease in Ethiopian society. Thus, the aim of this study is to evaluate the nephroprotective effect of A. africanus root extract on gentamicin-induced nephrotoxicity. Using maceration techniques, 100 g of dried plant powder was extracted in 1 L of ethanol. The physicochemical screening of plant extracts revealed the presence of flavonoids, phenols, tannins, saponins, and steroids. The nephroprotective activity of A. africanus crude extract was evaluated on male Swiss albino mice. The crude ethanolic extract at 200 and 400 mg/kg doses showed strong nephroprotective effects by restoring biomarkers such as creatinine, uric acid, and blood urea nitrogen, which were damaged by gentamicin (p < 0.05) in a dose-dependent manner. The mice treated with higher doses (400 mg/kg) had a comparable nephroprotective effect compared to the positive control group (200 mg/kg silymarin; p > 0.05). The histopathology of the control group showed normal glomeruli, normal parenchyma, distal convoluted, and no tubular damage. The toxicant-induced group showed damage to glomeruli and inflammatory infiltration. Therefore, A. africanus root extract has a nephroprotective activity by retarding the gentamicin toxicity in male Swiss albino mice.

Application of the Adverse Outcome Pathway Concept to In Vitro Nephrotoxicity Assessment: Kidney Injury due to Receptor-Mediated Endocytosis and Lysosomal Overload as a Case Study

Application of adverse outcome pathways (AOP) and integration of quantitative in vitro to in vivo extrapolation (QIVIVE) may support the paradigm shift in toxicity testing to move from apical endpoints in test animals to more mechanism-based in vitro assays. Here, we developed an AOP of proximal tubule injury linking a molecular initiating event (MIE) to a cascade of key events (KEs) leading to lysosomal overload and ultimately to cell death. This AOP was used as a case study to adopt the AOP concept for systemic toxicity testing and risk assessment based on in vitro data. In this AOP, nephrotoxicity is thought to result from receptor-mediated endocytosis (MIE) of the chemical stressor, disturbance of lysosomal function (KE1), and lysosomal disruption (KE2) associated with release of reactive oxygen species and cytotoxic lysosomal enzymes that induce cell death (KE3). Based on this mechanistic framework, in vitro readouts reflecting each KE were identified. Utilizing polymyxin antibiotics as chemical stressors for this AOP, the dose-response for each in vitro endpoint was recorded in proximal tubule cells from rat (NRK-52E) and human (RPTEC/TERT1) in order to (1) experimentally support the sequence of key events (KEs), to (2) establish quantitative relationships between KEs as a basis for prediction of downstream KEs based on in vitro data reflecting early KEs and to (3) derive suitable in vitro points of departure for human risk assessment. Time-resolved analysis was used to support the temporal sequence of events within this AOP. Quantitative response-response relationships between KEs established from in vitro data on polymyxin B were successfully used to predict in vitro toxicity of other polymyxin derivatives. Finally, a physiologically based kinetic (PBK) model was utilized to transform in vitro effect concentrations to a human equivalent dose for polymyxin B. The predicted in vivo effective doses were in the range of therapeutic doses known to be associated with a risk for nephrotoxicity. Taken together, these data provide proof-of-concept for the feasibility of in vitro based risk assessment through integration of mechanistic endpoints and reverse toxicokinetic modelling.

Celecoxib has Preventive and Therapeutic Benefits against Nephrotoxicity Caused by Gentamicin in Mice

It's crucial to comprehend the impact of oxidative stress and pro-inflammatory cytokines in the gentamicin-induced kidney injury mechanism. Celecoxib was administered orally either before or after intraperitoneal therapy with gentamicin in mice. The serum levels of creatinine (SCr), blood urea nitrogen (BUN), IL-6, and TNF-α were measured by ELISA test, as well as the levels of the kidney tissue malondialdehyde (MDA), and glutathione (GSH) were also estimated spectrophotometrically. The renal expression of nuclear factor-κB (NF-κB), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and cyclooxygenase 2 (COX-2) mRNAs were evaluated by qPCR. Histopathological evaluation and Immunohistochemical examination of kidney NF-κB, IL-6, and COX-2 were also, performed. Celecoxib successfully prevented gentamicin-induced kidney damage as indicated by reducing blood BUN, SCr, and tissue MDA levels and increasing renal tissue GSH levels as well as lowering the blood IL-6 and TNF-α in comparison to mice received gentamicin. Furthermore, celecoxib has inhibited COX-2, NF-κB, IL-6, and TNF-α expression in the renal tissue. It is noteworthy that celecoxib therapy after gentamicin administration brought about substantially the same results as celecoxib treatment before gentamicin injection in mice. Our results showed the role of celecoxib as a therapeutic tool for gentamicin-induced nephrotoxicity as well as raised its beneficial prophylactic role in this medical challenge by attenuating oxidative stress and inflammation.

Effect of Hydroaloholic Extract of Rotula Aquatica Lour on Gentamicin-Induced Nephrotoxicity in Wistar Albino Rats: An In Vitro and In Vivo Approach

One-third of the world population suffer from kidney complications such as acute and chronic renal failure, renal calculi, kidney stones, Fanconi's syndrome and urethritis which doesn't have a proper effective treatment regimen. The current study explores the nephroprotective effect of herbal drug Rotula Aquatica by both In Vitro and In Vivo methods. MTT assay was applied In Vitro to evaluate the nephroprotective effect of R. aquatica leaves extract on HEK 293 cell line. The acute toxicity of the extract was evaluated as per the limit test under the protocol of OECD 423 at a concentration of 2000 mg/kg using 6 female rats. Further, an In Vivo study using the Gentamicin-instigated nephrotoxicity model was carried out for a period of 8 days. Biochemical markers of renal damage, endogenous antioxidants and histopathology were determined to assess the effect of treatment. The In Vitro study using HEK 293 cell line resulted in an EC50 value of 51.50 μg/ml for the extract in comparison to the standard drug Cytsone (12.26 μg/ml). Based on the limit test of OECD 423, doses of 200 and 400 mg/kg were chosen for the study. The results revealed a strong nephroprotective activity at 400 mg/kg in Gentamicin-induced nephrotoxicity against standard drug cystone by restoring the decrement in body weight, renal enzymatic and non-enzymatic antioxidants, creatinine and urea levels in urine and plasma. This indicated that hydroalcoholic extract of Rotula aquatica (HAERA) can prevent the Gentamicin toxicity due to the high content of antioxidant and anti-inflammatory secondary metabolites.

Reducing the Toxicity of Designer Aminoglycosides as Nonsense Mutation Readthrough Agents for Therapeutic Targets

A significant proportion of genetic disease cases arise from truncation of proteins caused by premature termination codons. In eukaryotic cells some aminoglycosides cause readthrough of premature termination codons during protein translation. Inducing readthrough of these codons can potentially be of therapeutic value in the treatment of numerous genetic diseases. A significant drawback to the repeated use of aminoglycosides as treatments is the lack of balance between their readthrough efficacy and toxicity. The synthesis and biological testing of designer aminoglycoside compounds is documented herein. We disclose the implementation of a strategy to reduce cellular toxicity and maintain readthrough activity of a library of compounds by modification of the overall cationic charge of the aminoglycoside scaffold through ring I modifications.

In Vitro and In Vivo Evidence on the Role of Mitochondrial Impairment as a Mechanism of Lithium-Induced Nephrotoxicity

Lithium is abundantly administered against bipolar disorder. On the other hand, the lithium-induced renal injury is a clinical complication which commonly reveals as drug-induced diabetes insipidus. However, lithium-induced cytotoxicity might also play a role in the adverse effects of this drug on the kidney. There is no clear cellular and molecular mechanism(s) for lithium-induced nephrotoxicity. The current study was designed to assess the effect of lithium on kidney tissue oxidative stress biomarkers and mitochondrial function and its relevance to drug-induced nephrotoxicity and electrolyte imbalance. Rats were treated with lithium (lithium carbonate, 25 and 50 mg/kg/day, i.p., for 28 consecutive days). Kidney mitochondria were also isolated from rats and exposed to increasing concentrations of lithium (0.01-10 mM). Serum and urine biomarkers of kidney injury, kidney tissue markers of oxidative stress, and renal histopathological changes were assessed. Moreover, several mitochondrial indices were monitored. Lithium-induced renal injury revealed a significant increase in urine and serum biomarkers of renal impairment. Lithium caused an increase in the kidney reactive oxygen species (ROS) level and lipid peroxidation (LPO). Renal glutathione (GSH) reservoirs were also depleted, and tissue antioxidant capacity decreased in lithium-treated animals. Significant tissue histopathological changes, including necrosis, Bowman capsule dilation, and interstitial inflammation, were evident in lithium-treated animals. On the other hand, significant alterations in kidney mitochondrial function were detected in lithium-treated groups. These data mention oxidative stress, mitochondrial dysfunction, and cellular energy crisis as the potential primary mechanisms for lithium-induced renal injury.

Thymoquinone, but Not Metformin, Protects against Gentamicin-Induced Nephrotoxicity and Renal Dysfunction in Rats

Background: Gentamicin (GM) is an antibiotic that is widely used to treat many Gram-negative bacteria, such as those involved in urinary tract infections. However, being nephrotoxic, GM dose adjustment and reno-protective elements must be concurrently administered with GM to minimize kidney damage. Oxidative stress plays a pivotal role in the pathogenesis of GM-induced nephrotoxicity. Thymoquinone (TQ) is a promising therapeutic substance, that is being extensively studied in many diseases, such as diabetes mellitus, cancer, hypertension, and others. The powerful antioxidant properties of TQ may greatly help in minimizing GM nephrotoxicity. Metformin (MF) is a well-known, clinically approved oral hypoglycaemic drug that has many other actions, including antioxidant properties. The aim of this work was to evaluate the possible antioxidant and reno-protective effects of TQ and metformin in GM-induced nephrotoxicity in the same model (rats) at the same time. In addition, we aimed to further understand the effects underlying GM-induced nephrotoxicity. Methods: Twenty male rats were randomly divided into four equal groups: the first group (control) received distilled water; the second group received GM only; the third group received concurrent oral TQ and GM; and the fourth group received concurrent oral MF and GM. After 4 weeks, renal function and histopathology, as well as levels of the oxidative markers glutathione peroxidase-1 (GLPX1), superoxide dismutase (SOD), and malondialdehyde (MDA) in the kidney tissues, were assessed. Results: Compared with the control group, and as expected, the GM-injected rats showed significant biochemical and histological changes denoting renal damage. Compared with GM-injected rats, the concurrent administration of TQ with GM significantly reduced the levels of serum creatinine, serum urea, and tissue MDA and significantly increased the levels of GLPX1 and SOD. Concurrent metformin administration with GM significantly increased the levels of both GLPX1 and SOD and significantly decreased the levels of tissue MDA but had no significant effect on serum creatinine and urea levels. Compared with GM-injected rats, the addition of either TQ or MF resulted in a reduction in endothelial proliferation and mesangial hypercellularity. Conclusions: Both TQ and MF effectively alleviated the oxidative stress in GM-induced nephrotoxicity in rats, with TQ but not MF producing a complete reno-protective effect. Further studies for evaluation of different reno-protective mechanisms of TQ should be conducted.

HPLC-ESI/MS profiling, phytoconstituent isolation and evaluation of renal function, oxidative stress and inflammation in gentamicin-induced nephrotoxicity in rats of Ficus spragueana Mildbr. & Burret

Ficus spragueana Mildbr. & Burret (family Moraceae) was reported to have various biological activities. However, its activity in treatment of renal injury has not been investigated yet. The current study aimed to evaluate the effects of F. spragueana leaf extract on nephrotoxicity caused by gentamicin. Gentamicin is an important broad-spectrum antibiotic; nevertheless, it exhibits serious nephrotoxic adverse effects. HPLC-ESI/MS spectrometric analysis of the extract revealed the presence of 37 phenolic compounds. Moreover, five compounds were isolated from the leaf extract, and identified on the basis of spectroscopic analysis. The isolated compounds were syringic acid (1), p-coumaric acid (2), 3',5' O-dicaffeoylquinic acid (3), luteolin-8-C-β-D glucopyranoside (orientin) (4) and 8-methoxy kaempferol-3-O-[α-L-rhamnopyranosyl (1→2) β-D-glucopyranoside] (5). The gentamicin-induced nephrotoxicity model was used to evaluate the protective effect of F. spragueana on renal toxicity biomarkers throughout the development of acute kidney injury. Administration of extract led to improvement in kidney function through inhibition of kidney injury molecule-1, creatinine, blood urea nitrogen and total bilirubin, as well as decreasing the inflammatory markers interlukin1-beta and myeloperoxidase. Furthermore, it reduced the oxidative stress by increasing reduced glutathione and total antioxidant capacity levels while decreasing malondialdehyde and nitric oxide content, and improved renal histopathological injuries.

Identification of urinary microRNA biomarkers for in vivo gentamicin-induced nephrotoxicity models

BACKGROUND

Although previous in vivo studies explored urinary microRNA (miRNA), there is no agreement on nephrotoxicity-specific miRNA biomarkers.

OBJECTIVES

In this study, we assessed whether urinary miRNAs could be employed as biomarkers for nephrotoxicity.

METHODS

For this, literature-based candidate miRNAs were identified by reviewing the previous studies. Female Sprague-Dawley rats received subcutaneous injections of a single dose or repeated doses (3 consecutive days) of gentamicin (GEN; 137 or 412 mg/kg). The expression of miRNAs was analyzed by real-time reverse transcription-polymerase chain reaction in 16 h pooled urine from GEN-treated rats.

RESULTS

GEN-induced acute kidney injury was confirmed by the presence of tubular necrosis. We identified let-7g-5p, miR-21-3p, 26b-3p, 192-5p, and 378a-3p significantly upregulated in the urine of GEN-treated rats with the appearance of the necrosis in proximal tubules. Specifically, miR-26-3p, 192-5p, and 378a-3p with highly expressed levels in urine of rats with GEN-induced acute tubular injury were considered to have sensitivities comparable to clinical biomarkers, such as blood urea nitrogen, serum creatinine, and urinary kidney injury molecule protein.

CONCLUSIONS

These results indicated the potential involvement of urinary miRNAs in chemical-induced nephrotoxicity, suggesting that certain miRNAs could serve as biomarkers for acute nephrotoxicity.

Pathophysiological mechanisms underlying a rat model of triple whammy acute kidney injury

Simultaneous administration of certain antihypertensive (renin-angiotensin system inhibitors and diuretics) and nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a renal toxicity syndrome known as "triple whammy" acute kidney injury (TW-AKI), yet poorly characterized at the pathophysiological level, as no specific experimental model exists on which to conduct preclinical research. Herein, we generated and characterized a rat model of TW-AKI (0.7 mg/kg/day trandolapril +400 mg/kg/day ibuprofen +20 mg/kg/day furosemide). Double treatments involving the NSAID caused a subclinical acute kidney injury, as they reduced glomerular filtration rate to a significant but not sufficient extent to increase Cr_pl concentration. Only the triple treatment generated an overt AKI with increased Cr_pl provided that animals were under partial water ingestion restriction. Histological examination revealed no evidence of tissue renal injury, and no proteinuria or makers of renal damage were detected in the urine. These findings, along with a normal fractional excretion of sodium and glucose, indicated that these drug combinations produce a prerenal type of AKI. In fact, blood pressure and renal blood flow were also reduced (most markedly following the triple combination), although renal dysfunction was more pronounced than expected for the corresponding pressure drop, supporting a key pathological role of the interference with renal autoregulation mechanisms. In summary, prerenal TW-AKI only occurs when volemia is challenged (i.e., by furosemide in partially water-deprived animals) under the effects of renin-angiotensin system inhibitors and NSAIDs. This model will facilitate further pathophysiological knowledge for a better diagnosis and clinical handling of this syndrome.