Acute Kidney Injury In Rats Research Articles

Acute kidney injury causes subclinical renal and endothelial injury in female rats which predisposes to adverse outcomes of pregnancy

Clinical data report a 3-5-fold increase in adverse pregnancy outcomes, including preeclampsia and small for gestational age neonates, among women with a history of acute kidney injury (AKI) despite clinical recovery of renal function. We developed a rat model of pregnancy post-AKI: Sprague-Dawley (SD) rats undergo a bilateral renal-ischemia reperfusion and fully recover renal function as measured by creatinine clearance 30 days post-AKI. Rats are then mated and during pregnancy recovered AKI rats exhibit decreased creatinine clearance, increased uterine artery resistance, reduced plasma volume expansion, and decreased fetal growth compared to pregnant rats that received sham surgery. Healthy pregnancy demands robust renal and vascular adaptations. Whether subclinical renal and vascular injury persists following AKI in females, and whether this is exacerbated in pregnancy to drive the adverse pregnancy outcomes remains unknown. We tested the hypothesis that AKI results in subclinical renal and vascular injury that lingers into pregnancy. Female SD rats were randomized to 45-minute warm bilateral renal ischemia reperfusion or sham (N=6-8/grp) and renal and vascular injury assessments were made 30 days post-AKI/Sham (pre-pregnancy) or during pregnancy on gestational day 20 (GD20). Pre-pregnancy urine volume measured via metabolic cage was greater in post-AKI rats compared to sham (10±1 vs 21±2 ml/daily urine, p<0.05). Urinary kidney injury marker-1 (KIM-1) measured via ELISA 30 days post-AKI/Sham was greater in pre-pregnant AKI rats compared to sham (9685±871 vs. 6399±198 pg/24 hrs urine, p<0.05). Vascular function, measured via wire myography on 3rd order mesenteric arteries 30 days post-AKI/Sham, revealed decreased endothelial-dependent relaxation to acetylcholine (ACh) (concentration-response, 1 nM-10 μM, 2-way ANOVA, RM, *p<0.05). GD20 urine volume (31±5 vs 19±2 ml/daily urine, p<0.05) and KIM-1 levels (9125±673 vs 6380±297 pg/daily urine, p<0.05) were elevated in post-AKI pregnant rats compared to sham pregnant rats. Mason Trichrome renal staining revealed greater glomerular fibrosis (0.93±0.08 vs 0.04±0.04, *p<0.05) and tubular fibrosis (1.7±0.19 vs 0.0±0.0, *p<0.05) in post-AKI pregnant rats vs. sham pregnant. Ultrastructural changes to the kidneys were evaluated via electron microscopy and further revealed extensive brush border loss, loss of mitochondrial structure and mitochondrial swelling in post-AKI pregnant rats compared to sham pregnant. Endothelial-dependent relaxation to ACh was also lower (2-way ANOVA, *p<0.05), suggesting enhanced endothelial dysfunction in post-AKI pregnant rats vs. sham pregnant. Taken together, these data suggest that with a history of AKI, subclinical renal and vascular injury is present despite “recovery” of renal function using clinical definitions and may predispose to adverse pregnancy outcomes in pregnant women with a history of AKI. 1R01HL169576 4R00HL146948 1RO1DK134695 AHA967662. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Salutary Effects of Diminazene, Lisinopril or Valsartan on Cisplatin – Induced Acute Kidney Injury in Rats: A Comparative Study

Nephrotoxicity as a cause of acute kidney injury (AKI) induced by cisplatin (CP), limits its usefulness as an anticancer agent. Diminazene, an angiotensin converting enzyme 2 activator, exhibited renoprotective properties on rat models of kidney diseases. This research aims to investigate the salutary effect of diminazene in comparison with lisinopril or valsartan in CP-induced AKI. The first and second groups of rats received oral vehicle (distilled water) for 9 days, and saline injection or intraperitoneal CP (6 mg/kg) on day 6, respectively. Third, fourth, and fifth groups received intraperitoneal injections of CP on day 6 and diminazene (15 mg/kg/day, orally), lisinopril (10 mg/kg/day, orally), or valsartan (30 mg/kg/day, orally), for 9 days, respectively. 24h after the last day of treatment, blood and kidneys were removed under anesthesia for biochemical and histopathological examination. Urine during the last 24 h before sacrificing the rats was also collected. CP significantly increased plasma urea, creatinine, neutrophil gelatinase-associated lipocalin, calcium, phosphorus, and uric acid. It also increased urinary albumin/creatinine ratio, N-Acetyl-β-D-Glucosaminidase/creatinine ratio, and reduced creatinine clearance, as well the plasma concentrations of inflammatory cytokines [plasma tumor necrosis factor–alpha, and interleukin-1beta], and significantly reduced antioxidant indices [catalase, glutathione reductase , and superoxide dismutase]. Histopathologically, CP treatment caused necrosis of renal tubules, tubular casts, shrunken glomeruli, and increased renal fibrosis. Diminazine, lisinopril, and valsartan ameliorated CP-induced biochemical and histopathological changes to a similar extent. The salutary effect of the three drugs used is, at least partially, due to their anti-inflammatory and antioxidant effects. Keywords: Cisplatin • Diminazene • ACE2 activator • Lisinopril • Valsartan • Acute kidney injury

Unlocking renal Restoration: Mesaconine from Aconitum plants restore mitochondrial function to halt cell apoptosis in acute kidney injury

Acute kidney injury (AKI) is characterized by a sudden decline in renal function. Traditional Chinese medicine has employed Fuzi for kidney diseases; however, concerns about neurotoxicity and cardiotoxicity have constrained its clinical use. This study explored mesaconine, derived from processed Fuzi, as a promising low-toxicity alternative for AKI treatment. In this study, we assessed the protective effects of mesaconine in gentamicin (GM)-induced NRK-52E cells and AKI rat models in vitro and in vivo, respectively. Mesaconine promotes the proliferation of damaged NRK-52E cells and down-regulates intracellular transforming growth factor β1 (TGF-β1) and kidney injury molecule 1 (KIM-1) to promote renal cell repair. Concurrently, mesaconine restored mitochondrial morphology and permeability transition pores, reversed the decrease in mitochondrial membrane potential, mitigated mitochondrial dysfunction, decreased ATP production, inhibited inflammatory factor release, and reduced early apoptosis rates. In vivo, GM-induced AKI rat models exhibited elevated AKI biomarkers, in which mesaconine was effectively reduced, indicating improved renal function. Mesaconine enhanced superoxide dismutase activity, reduced malondialdehyde content, alleviated inflammatory infiltrate, mitigated tubular and glomerular lesions, and downregulated NF-κB (nuclear factor-κb) p65 expression, leading to decreased tumor necrosis factor-α (TNF-α) and IL-1β (interleukin-1β) levels in GM-induced AKI animals. Furthermore, mesaconine inhibited the expression of renal pro-apoptotic proteins (Bax, cytochrome c, cleaved-caspase 9, and cleaved-caspase 3) and induced the release of the anti-apoptotic protein bcl-2, further suppressing apoptosis. This study highlighted the therapeutic potential of mesaconine in GM-induced AKI. Its multifaceted mechanisms, including the restoration of mitochondrial dysfunction, anti-inflammatory and antioxidant effects, and apoptosis mitigation, make mesaconine a promising candidate for further exploration in AKI management.

TAG-FREE GLYCOSYLATED RHMFG-E8 AS A THERAPY FOR ACUTE KIDNEY INJURY.

Background: Acute kidney injury (AKI) can result from renal ischemia and reperfusion (I/R) and often occurs during surgical procedures in cardiac, liver, kidney transplantation, and trauma-hemorrhage. Milk fat globule epidermal growth factor-factor VIII (MFG-E8) functions as a bridging molecule to promote the removal of dying cells by professional phagocytes. Because MFG-E8 promotes clearance of apoptotic cells, we have explored its therapeutic potential in various organ injury conditions. To develop human MFG-E8 as a potential therapy, we have generated a human cell-expressed, and thus glycosylated, tag-free recombinant human (rh) MFG-E8 and tested its safety and biological activity in vitro . We hypothesize that the tag-free glycosylated rhMFG-E8 is protective in I/R-induced AKI and it can be developed as an effective therapy for AKI. Methods: To assess the pharmacokinetic properties of the tag-free rhMFG-E8, Sprague-Dawley rats were either untreated or treated with a bolus dose of the tag-free rhMFG-E8, blood collected at various time points and the recovery of human MFG-E8 in the blood were measured by ELISA. Adult male C57BL6 mice underwent bilateral renal ischemia for 30 min, and immediately upon reperfusion, mice were treated intraperitoneally with either normal saline (vehicle) or 20 μg/kg human cell expressed, glycosylated tag-free rhMFG-E8. At either 24 h or 48 h after I/R, blood and kidneys were harvested for further analysis. In separate cohorts of mice after I/R and treatment, mice were observed for 10 days, and survival recorded. Results: AKI rats treated with the tag-free rhMFG-E8 had similar half-life as those in the treated control rats. At 48 h after I/R-induced AKI, renal function markers, blood urea nitrogen, and creatinine were increased and treatment with the tag-free rhMFG-E8 significantly decreased these markers. At both 24 h and 48 h after AKI, inflammatory cytokines, TNF-α, IL-6, and IL-1β were increased and treatment decreased these levels. The kidney mRNA expressions of these cytokines were also increased at 24 h after AKI and treatment significantly decreased those mRNA expressions. Histologically, at 48 h after AKI, tubular damage, and the number of TUNEL staining cells were increased and treatment markedly decreased these measurements. Administration of tag-free rhMFG-E8 at the time of reperfusion improved survival in a 10-day survival study. Conclusion: Our new human cell-expressed tag-free rhMFG-E8 is protective in I/R-induced AKI and it may have the potential to be further developed as a safe and effective therapy for AKI.

Mechanism of dexmedetomidine protection against cisplatin induced acute kidney injury in rats

Objective This study explored the molecular mechanisms by which dexmedetomidine (Dex) alleviates cisplatin (CP)-induced acute kidney injury (AKI) in rats. Methods CP-induced AKI models were established, and Dex was intraperitoneally injected at different concentrations into rats in the model groups. Subsequently, rats were assigned to the control, CP, CP + Dex 10 μg/kg, and CP + Dex 25 μg/kg groups. After weighing the kidneys of the rats, the kidney arterial resistive index was calculated, and CP-induced AKI was evaluated. In addition, four serum biochemical indices were measured: histopathological damage in rat kidneys was detected; levels of inflammatory factors, interleukin (IL)-1β, IL-18, IL-6, and tumor necrosis factor alpha, in kidney tissue homogenate of rats were assessed through enzyme-linked immunosorbent assay (ELISA); and levels of NLRP-3, caspase-1, cleaved caspase-1, gasdermin D (GSDMD), and GSDMD-N in kidney tissues of rats were determined via western blotting. Results Dex treatment reduced nephromegaly and serum clinical marker upregulation caused by CP-induced AKI. In addition, hematoxylin and eosin staining revealed that Dex treatment relieved CP-induced kidney tissue injury in AKI rats. ELISA analyses demonstrated that Dex treatment reduced the upregulated levels of proinflammatory cytokines in the kidney tissue of AKI rats induced by CP, thereby alleviating kidney tissue injury. Western blotting indicated that Dex alleviated CP-induced AKI by inhibiting pyroptosis mediated by NLRP-3 and caspase-1. Conclusion Dex protected rats from CP-induced AKI, and the mechanism may be related to NLRP-3/Caspase-1-mediated pyroptosis.

Indoxyl sulphate-TNFα axis mediates uremic encephalopathy in rodent acute kidney injury.

Acute kidney injury (AKI) is often accompanied by uremic encephalopathy resulting from accumulation of uremic toxins in brain possibly due to impaired blood-brain barrier (BBB) function. Anionic uremic toxins are substrates or inhibitors of organic anionic transporters (OATs). In this study we investigated the CNS behaviors and expression/function of BBB OAT3 in AKI rats and mice, which received intraperitoneal injection of cisplatin 8 and 20 mg/kg, respectively. We showed that cisplatin treatment significantly inhibited the expressions of OAT3, synaptophysin and microtubule-associated protein 2 (MAP2), impaired locomotor and exploration activities, and increased accumulation of uremic toxins in the brain of AKI rats and mice. In vitro studies showed that uremic toxins neither alter OAT3 expression in human cerebral microvascular endothelial cells, nor synaptophysin and MAP2 expressions in human neuroblastoma (SH-SY5Y) cells. In contrast, tumour necrosis factor alpha (TNFα) and the conditioned medium (CM) from RAW264.7 cells treated with indoxyl sulfate (IS) significantly impaired OAT3 expression. TNFα and CM from IS-treated BV-2 cells also inhibited synaptophysin and MAP2 expressions in SH-SY5Y cells. The alterations caused by TNFα and CMs in vitro, and by AKI and TNFα in vivo were abolished by infliximab, a monoclonal antibody designed to intercept and neutralize TNFα, suggesting that AKI impaired the expressions of OAT3, synaptophysin and MAP2 in the brain via IS-induced TNFα release from macrophages or microglia (termed as IS-TNFα axis). Treatment of mice with TNFα (0.5 mg·kg-1·d-1, i.p. for 3 days) significantly increased p-p65 expression and reduced the expressions of Nrf2 and HO-1. Inhibiting NF-κB pathway, silencing p65, or activating Nrf2 and HO-1 obviously attenuated TNFα-induced downregulation of OAT3, synaptophysin and MAP2 expressions. Significantly increased p-p65 and decreased Nrf2 and HO-1 protein levels were also detected in brain of AKI mice and rats. We conclude that AKI inhibits the expressions of OAT3, synaptophysin and MAP2 due to IS-induced TNFα release from macrophages or microglia. TNFα impairs the expressions of OAT3, synaptophysin and MAP2 partly via activating NF-κB pathway and inhibiting Nrf2-HO-1 pathway.

The preventive effect of Gastrodia elata Blume extract on vancomycin-induced acute kidney injury in rats.

Gastrodia elata Blume (GEB), a traditional medicinal herb, has been reported to have pharmacological effect including protection against liver, neuron and kidney toxicity. However, explanation of its underlying mechanisms remains a great challenge. This study investigated the protective effects of GEB extract on vancomycin (VAN)-induced nephrotoxicity in rats and underlying mechanisms with emphasis on the anti-oxidative stress, anti-inflammation and anti-apoptosis. The male Sprague-Dawley rats were randomly divided three groups: control (CON) group, VAN group and GEB group with duration of 14 days. The kidney weight and the serum levels of blood urea nitrogen and creatinine in the GEB group were lower than the VAN group. Histological analysis using hematoxylin & eosin and periodic acid Schiff staining revealed pathological changes of the VAN group. Immunohistochemical analysis revealed that the expression levels of N-acetyl-D-glucosaminidase, myeloperoxidase and tumor necrosis factor-alpha in the GEB group were decreased when compared with the VAN group. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells, phosphohistone and malondialdehyde levels were lower in the GEB group than VAN group. The levels of total glutathione in the GEB group were higher than the VAN group. The findings of this study suggested that GEB extract prevents VAN-induced renal tissue damage through anti-oxidation, anti-inflammation and anti-apoptosis.

Renoprotective effect of diacetylrhein on diclofenac-induced acute kidney injury in rats via modulating Nrf2/NF-κB/NLRP3/GSDMD signaling pathways

Diclofenac (DF)-induced acute kidney injury (AKI) is characterized by glomerular dysfunction and acute tubular necrosis. Due to limited treatment approaches, effective and safe drug therapy to protect against such AKI is still needed. Diacetylrhein (DAR), an anthraquinone derivative, has different antioxidant and anti-inflammatory properties. Therefore, the aim of the current study was to investigate the renoprotective effect of DAR on DF-induced AKI while elucidating the potential underlying mechanism. Our results showed that DAR (50 and 100 mg/kg) markedly abrogated DF-induced kidney dysfunction decreasing SCr, BUN, serum NGAL, and serum KIM1 levels. Moreover, DAR treatment remarkably maintained renal redox balance and reduced the levels of pro-inflammatory biomarkers in the kidney. Mechanistically, DAR boosted Nrf2/HO-1 antioxidant and anti-inflammatory response in the kidney while suppressing renal TLR4/NF-κB and NLRP3/caspase-1 inflammatory signaling pathways. In addition, DAR markedly inhibited renal pyroptosis via targeting of GSDMD activation. Collectively, this study confirmed that the interplay between Nrf2/HO-1 and TLR4/NF-κB/NLRP3/Caspase-1 signaling pathways and pyroptotic cell death mediates DF-induced AKI and reported that DAR has a dose-dependent renoprotective effect on DF-induced AKI in rats. This effect is due to powerful antioxidant, anti-inflammatory, and anti-pyroptotic activities that could provide a promising treatment approach to protect against DF-induced AKI.

Valsartan Mitigates the Progression of Methotrexate-Induced Acute Kidney Injury in Rats via the Attenuation of Renal Inflammation and Oxidative Stress.

Methotrexate (MTX) is a folic acid antagonist, commonly administered for the treatment of a variety of cancers. However, methotrexate toxicity including bone marrow suppression and hepatic and renal toxicity limits its use. Angiotensin AT1 receptor blockers including Valsartan (Val) possess the ability to ameliorate MTX-induced toxicity through various mechanisms. In this study, we explored the potential reno-protective effects of Val against MTX-induced acute kidney injury in rats. Twenty-four Wistar rats were randomly segregated into 3 groups. Group 1 served as the control group and received an oral dose of 1mL/kg of normal saline. Group 2 received a single dose of 20 mg/kg of MTX intraperitoneally (IP) for 5 days. Group 3 received a single IP dose of 20 mg/kg of MTX followed by an oral dose of 10 mg/kg of Valsartan for 5 days. At the end of the experiment, the levels of serum kidney biomarkers, inflammatory and oxidative stress markers were accessed. Furthermore, the effect of MTX on kidney tissue histology was examined. Our results showed that MTX treatment increased the level of serum kidney and inflammatory biomarkers and decreased the level of antioxidants SOD and GSH while increasing the lipid peroxidation contents. Furthermore, MTX treatment caused structural changes to kidney histology. However, the administration of Val significantly prevented these changes. Valsartan possesses nephroprotective potential and might serve as a potential therapeutic strategy against MTX-induced kidney injury.

LncTCONS_00058568 is involved in the pathophysiologic processes mediated by P2X7R in the lower thoracic spinal cord after acute kidney injury.

Acute kidney injury (AKI), a prevalent clinical syndrome, involves the participation of the nervous system in neuroimmune regulation. However, the intricate molecular mechanism that governs renal function regulation by the central nervous system (CNS) is complex and remains incompletely understood. In the present study, we found that the upregulated expression of lncTCONS_00058568 in lower thoracic spinal cord significantly ameliorated AKI-induced renal tissue injury, kidney morphology, inflammation and apoptosis, and suppressed renal sympathetic nerve activity. Mechanistically, the purinergic ionotropic P2X7 receptor (P2X7R) was overexpressed in AKI rats, whereas lncTCONS_00058568 was able to suppress the upregulation of P2X7R. In addition, RNA sequencing data revealed differentially expressed genes associated with nervous system inflammatory responses after lncTCONS_00058568 was overexpressed in AKI rats. Finally, the overexpression of lncTCONS_00058568 inhibited the activation of PI3K/Akt and NF-κB signaling pathways in spinal cord. Taken together, the results from the present study show that lncTCONS_00058568 overexpression prevented renal injury probably by inhibiting sympathetic nerve activity mediated by P2X7R in the lower spinal cord subsequent to I/R-AKI.

Sex-Specific Effects of Estradiol and Progesterone in Ischemic Kidney Injury.

The positive effects of female sex hormones, particularly estradiol and progesterone, have been observed in treatment of various pathologies. Acute kidney injury (AKI) is a common condition in hospitalized patients in which the molecular mechanisms of hormone action are poorly characterized. In this study, we investigated the influence of estradiol and progesterone on renal cells during ischemic injury. We performed both in vivo experiments on female and male rats and in vitro experiments on renal tubular cells (RTCs) obtained from the kidneys of intact animals of different sexes. Since mitochondria play an important role in the pathogenesis of AKI, we analyzed the properties of individual mitochondria in renal cells, including the area, roundness, mitochondrial membrane potential, and mitochondrial permeability transition pore (mPTP) opening time. We found that pre-treatment with progesterone or estradiol attenuated the severity of ischemia/reperfusion (I/R)-induced AKI in female rats, whereas in male rats, these hormones exacerbated renal dysfunction. We demonstrated that the mPTP opening time was higher in RTCs from female rats than that in those from male rats, which may be one of the reasons for the higher tolerance of females to ischemic injury. In RTCs from the kidneys of male rats, progesterone caused mitochondrial fragmentation, which can be associated with reduced cell viability. Thus, therapy with progesterone or estradiol displays quite different effects depending on sex, and could be only effective against ischemic AKI in females.

Evaluation of the Renoprotective Effects of Valsartan in Methotrexate-Induced Acute Kidney Injury in Rats

Evaluation of the Renoprotective Effects of Valsartan in Methotrexate-Induced Acute Kidney Injury in Rats

Lanthanum Hydroxide and Chronic Kidney Disease Mineral and Bone Disorder: A Rat Model.

To investigate the pharmacological effects and molecular mechanisms of lanthanum hydroxide(LH) on ectopic mineralization of soft tissue and abnormal bone in rats with acute kidney injury(AKI). Wistar rats were modeled by 5/6 nephrectomy. After the operation, the rats were divided into different groups, the biochemical indexes of serum collected at different times. LH was administered by intragastric tube at doses of 0.4, 0.2, and 0.1g/kg, respectively. Rats were sacrificed in the 16th week after LH treatment. Observation of pathological changes in tissues were made by specific staining. Western Blot, Real-Time Quantitative PCR, and immunohistochemistry techniques were used to detect the impact on pathway-related proteins. Compared with the control group (no LH administered), the serum phosphate level of the LH group was significantly reduced (p<0.01), calcification of the thoracic aorta was reduced (p<0.05, p<0.01) (Serum biochemical tests before dosing and during drug treatment cycles), renal fibrosis was improved (p<0.01), nuclear entry of nuclear factor kappa-B (NF-κB) was reduced (p<0.01), and the expression of the smooth muscle protein 22α (SM22α) was significantly increased (p<0.01). The expression of osteogenic marker genes was decreased. In addition, compared with the controls, the receptor activator for nuclear factor-κB ligand/osteoprotegerin (RANKL/OPG) ratio of the femur in the model group was increased (p<0.05). LH can inhibit the occurrence and development of vascular calcification and bone abnormalities in AKI rats by inhibiting the NF-κB and RANKL/OPG signaling pathways.

TAK-242 improves sepsis-associated acute kidney injury in rats by inhibiting the TLR4/NF-κB signaling pathway

Objective This study was designed to observe the effect of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway activity on sepsis-associated acute kidney injury (SA-AKI), thereby providing new considerations for the prevention and treatment of SA-AKI. Methods The rats were divided into Sham, cecal ligation and puncture (CLP), CLP + vehicle, and CLP + TAK-242 groups. Except the Sham group, a model of CLP-induced sepsis was established in other groups. After 24 h, the indicators related to kidney injury in blood samples were detected. The pathological changes in the kidneys were observed by hematoxylin-eosin staining, and tubular damage was scored. Oxidative stress-related factors, mitochondrial dysfunction-related indicators in each group were measured; the levels of inflammatory factors in serum and kidney tissue of rats were examined. Finally, the expression of proteins related to the TLR4/NF-κB signaling pathway was observed by western blot. Results Compared with the CLP + vehicle and CLP + TAK-242 groups, the CLP + TAK-242 group reduced blood urea nitrogen (BUN), creatinine (Cr), cystatin-C (Cys-C), reactive oxygen species (ROS), malondialdehyde (MDA), and inflammatory factors levels (p < 0.01), as well as increased superoxide dismutase (SOD) activity of CLP rats (p < 0.01). Additionally, TAK-242 treatment improved the condition of CLP rats that had glomerular and tubular injuries and mitochondrial disorders (p < 0.01). Further mechanism research revealed that TAK-242 can inhibit the TLR4/NF-κB signaling pathway activated by CLP (p < 0.01). Above indicators after TAK-242 treatment were close to those of the Sham group. Conclusion TAK-242 can improve oxidative stress, mitochondrial dysfunction, and inflammatory response by inhibiting the activity of TLR4/NF-κB signaling pathway, thereby preventing rats from SA-AKI.

Monoterpene linalool restrains gentamicin-mediated acute kidney injury in rats by subsiding oxidative stress, apoptosis, and the NF-κB/iNOS/TNF-α/IL-1β pathway and regulating TGF-β.

The clinical use of gentamicin (GM) is restricted by its nephrotoxic effects. This study aimed for the first time to elucidate the ameliorative effects of the monoterpene linalool (Lin) against GM-mediated acute kidney injury in rats. A total of thirty-two rats were subdivided into four equal groups: control (saline), Lin (100mg/kg/day), GM (100mg/kg/day), and GM + Lin (100 and 100mg/kg/day). Lin and GM were intraperitoneally administered for 12 days. Our results illustrated that Lin ameliorated GM-mediated renal histopathological abnormalities and reduced serum urea and creatinine levels in rats exposed to GM. Lin treatment mitigated oxidative stress in nephrotoxic animals as manifested by reducing serum and renal levels of malondialdehyde and increasing the activities of serum and renal glutathione peroxidase and renal catalase. Moreover, Lin markedly inhibited GM-triggered inflammation by downregulating NF-κB, iNOS, TNF-α, and IL-1β and reducing renal myeloperoxidase activity and nitric oxide levels. Interestingly, Lin repressed GM-induced apoptosis, as reflected by a marked downregulation of Bax and caspase-3 expression, concurrent with the upregulation of Bcl2 expression. Finally, Lin administration led to a significant downregulation of TGF-β expression in nephrotoxic animals. In summary, Lin ameliorated GM-mediated nephrotoxicity in rats, at least through its antioxidant, anti-inflammatory, and anti-apoptotic activities and by modulating TGF-β.

Protective role of alpha-lipoic acid against rhabdomyolysis-induced acute kidney injury in rats.

Rhabdomyolysis, a potentially life-threatening condition, occurs when myoglobin is released from damaged muscle cells, leading to acute kidney injury (AKI). Alpha lipoic acid (ALA), an organosulfur compound known for its anti-oxidant and anti-inflammatory properties, was examined in this study for its potential impact on rhabdomyolysis-induced AKI in rats. Six groups of rats were included in the study, with each group consisting of six rats (n=6): Control, rhabdomyolysis, rhabdomyolysis treated with different doses of ALA (5, 10, and 20 mg/kg), and ALA alone (20 mg/kg) groups. Rhabdomyolysis was induced by intramuscular injection of glycerol on the first day of the experiment, while ALA was administered intraperitoneally for four consecutive days. Renal function parameters, oxidative stress markers, and histological changes in the kidneys were evaluated. Western blot analysis was performed to measure the levels of neutrophil gelatinase-associated lipocalin (NGAL) and tumor necrosis factor-alpha (TNF-α) proteins. A significant increase in serum urea, creatinine, renal malondialdehyde, NGAl, and TNF-α protein levels was observed in glycerol-injected rats. In addition, a significant decrease in glutathione was recorded. Compared to the rhabdomyolysis group, treatment with ALA recovered kidney histological and biochemical abnormalities. Results suggest that rhabdomyolysis-induced AKI is associated with increased oxidative stress and inflammation. Treatment with ALA improved kidney histological abnormalities and reduced oxidative stress markers in rats. Therefore, ALA may have a potential protective effect against rhabdomyolysis-induced AKI.

Renoprotective effect of thymoquinone against rhabdomyolysis-induced acute kidney injury in the rat model.

Rhabdomyolysis leads to the release of myoglobin, sarcoplasmic proteins, and electrolytes into the blood circulation causing acute kidney injury (AKI). Thymoquinone, a natural compound found in Nigella sativa seeds, has antioxidant and anti-inflammatory effects. This investigation assessed the renoprotective effect of thymoquinone on rhabdomyolysis-induced AKI in rats. Male Wistar rats were categorized into six groups (n = 6): 1. Control: (normal saline), 2. Glycerol (50 ml/kg, single dose, IM), 3-5: Glycerol + thymoquinone (1, 2.5 and 5 mg/kg, 4 days, IP), 6. Thymoquinone (5 mg/kg). On day 5, serum and kidney tissue were isolated and the amounts of serum creatinine and blood urea nitrogen (BUN), renal malondialdehyde (MDA), glutathione (GSH.), tumor necrosis factor-alpha (TNF-α), neutrophil gelatinase-associated lipocalin (NGAL), and pathological changes were evaluated. Glycerol increased creatinine, BUN, MDA, TNF-α, and NGAL levels. It decreased GSH amounts and caused renal tubular necrosis, glomerular atrophy, and myoglobin cast in kidney tissue. Co-administration of glycerol and thymoquinone reduced creatinine, BUN, histopathological alterations, and MDA levels, and enhanced GSH amounts. Administration of glycerol and thymoquinone (5 mg/kg) had no significant effect on TNF-α amount but decreased NGAL protein levels. The administration of thymoquinone (5 mg/kg) alone did not display a significant difference from the control group. Rhabdomyolysis from glycerol injection in rats can cause kidney damage. Thymoquinone may attenuate renal dysfunction and oxidative stress. However, the TNF-α level was not significantly affected. Further studies are needed to explore the potential therapeutic effects of thymoquinone in managing AKI.

Targeted treatment of rat AKI induced by rhabdomyolysis using BMSC derived magnetic exosomes and its mechanism.

Introduction: rhabdomyolysis (RM) is a serious syndrome. A large area of muscle injury and dissolution induces acute kidney injury (AKI), which results in a high incidence and mortality rate. Exosomes released by mesenchymal stem cells (MSCs) have been used to treat AKI induced by rhabdomyolysis and have shown regenerative effects. However, the most serious drawbacks of these methods are poor targeting and a low enrichment rate after systemic administration. Methods: in this study, we demonstrated that magnetic exosomes derived from bone marrow mesenchymal stem cells (BMSCs) can directly target damaged muscles rather than kidneys using an external magnetic field. Results: magnetic navigation exosomes reduced the dissolution of damaged muscles, greatly reduced the release of cellular contents, slowed the development of AKI. Discussion: in summary, our proposed method can overcome the shortcomings of poor targeting in traditional exosome therapy. Moreover, in the rhabdomyolysis-induced AKI model, we propose for the first time an exosome therapy mode that directly targets damaged muscles through magnetic navigation.

Nicorandil attenuates cisplatin-induced acute kidney injury in rats via activation of PI3K/AKT/mTOR signaling cascade and inhibition of autophagy

Cisplatin is a highly effective antitumor agent, but its clinical use is limited due to critical adverse reactions including acute kidney injury (AKI). Nicorandil is an approved antianginal agent decreasing ischemia by potassium channel opening. The aim of this study was to investigate the nephroprotective effects of nicorandil and the possible role of activating PI3K/AKT/mTOR pathway in ameliorating cisplatin-induced AKI. Forty male Wistar rats were randomly allocated in 4 groups (n = 10). Group I: rats received the vehicle and served as control. Group II: rats received a single dose of cisplatin (7 mg/kg, i.p) on the 10th day of the experiment and served as AKI group. Group III: rats received cisplatin as in group II and nicorandil (3 mg/kg/day, p.o) for 14 days. Group IV: rats received cisplatin and nicorandil as in group III as well as wortmannin (15 μg/kg, i.v) for 14 days. Nicorandil exhibited obvious nephroprotective effects via the activation of PI3K/AKT/mTOR pathway. Moreover, nicorandil succeed to reduce the expression of the autophagy markers beclin-1 and LC-3II/I. In parallel, nicorandil showed anti-inflammatory and antiapoptotic effects via inhibition of NF-κB inflammatory pathway and depression of Bax/Bcl-2 ratio. Wortmannin, the PI3K inhibitor, was used to demonstrate the proposed pathway. Our study showed the nephroprotective effects of nicorandil in cisplatin-induced AKI in rats via activation of PI3K/AKT/mTOR signaling cascade, inhibition of autophagy, anti-inflammatory, anti-apoptotic, anti-oxidant activities. Thus, nicorandil could represent a promising renoprotective agent in cancer patients treated with cisplatin.

Muscle-Derived Stem/Progenitor Cells Ameliorate Acute Kidney Injury in Rats through the Anti-Apoptotic Pathway and Demonstrate Comparable Effects to Bone Marrow Mesenchymal Stem Cells.

Background and Objectives: To date, the therapeutic potential of skeletal muscle-derived stem/progenitor cells (MDSPCs) for acute kidney injury (AKI) has only been evaluated by our research group. We aimed to compare MDSPCs with bone marrow mesenchymal stem cells (BM-MSCs) and evaluate their feasibility for the treatment of AKI. Materials and Methods: Rats were randomly assigned to four study groups: control, GM (gentamicin) group, GM+MDSPCs, and GM+BM-MSCs. AKI was induced by gentamicin (80 mg/kg/day; i.p.) for 7 consecutive days. MDSPCs and BM-MSCs were injected 24 h after the last gentamicin injection. Kidney parameters were determined on days 0, 8, 14, 21, and 35. Results: MDSPCs and BM-MSCs accelerated functional kidney recovery, as reflected by significantly lower serum creatinine levels and renal injury score, higher urinary creatinine and creatinine clearance levels (p < 0.05), lower TUNEL-positive cell number, and decreased KIM-1 and NGAL secretion in comparison to the non-treated AKI group. There was no significant difference in any parameters between the MDSPCs and BM-MSCs groups (p > 0.05). Conclusions: MDSPCs and BM-MSCs can migrate and incorporate into injured renal tissue, resulting in a beneficial impact on functional and morphological kidney recovery, which is likely mediated by the secretion of paracrine factors and an anti-apoptotic effect. MDSPCs were found to be non-inferior to BM-MSCs and therefore can be considered as a potential candidate strategy for the treatment of AKI.