Alleviation of the doxorubicin-induced nephrotoxicity by fasudil in vivo and in vitro

Agomelatine ameliorates doxorubicin-induced cortical and hippocampal brain injury via inhibition of TNF-alpha/NF-kB pathway

Side effects of doxorubicin (DOX) are mainly due to oxidative stress, with the involvement of inflammatory and apoptotic mechanisms. Agomelatine (AGO) is a melatonin receptor agonist with antioxidant, anti-inflammatory, and anti-apoptotic features. This study aimed to evaluate the effects of AGO with different doses on DOX-induced neurotoxicity. Rats were divided into four groups as control, DOX (40 mg/kg, intraperitoneal single dose), DOX + AGO20 (20 mg/kg AGO oral gavage for 14 days), and DOX + AGO40 (40 mg/kg AGO oral gavage for 14 days). On day 14, brain tissues were collected for biochemical, histopathological, and genetic examinations. DOX significantly increased malondialdehyde and decreased superoxide dismutase and catalase (CAT) levels. CAT levels were significantly increased only in the DOX + AGO40 group compared to the DOX group (p = 0.040) while other changes in oxidant and antioxidant indicators were insignificant. DOX-induced significant increases in TNF-alpha and NF-κB were reversed following both low and high-dose AGO administration in a dose-dependent manner (p < 0.001 for both doses). Cellular shrinkage, pycnotic change, and vacuolization in apoptotic bodies were apparent in the cortical and hippocampal areas of DOX-treated samples. Both doses of AGO alleviated these histopathological changes (p = 0.01 for AGO20 and p = 0.05 for AGO40). Significantly increased apoptosis shown with caspase-3 immunostaining in the DOX group was alleviated following AGO administration, with additional improvement after high-dose treatment (p < 0.01 for DOX compared to both AGO groups and p < 0.05 for AGO40 compared to AGO20). AGO can be protective against DOX-induced neurotoxicity by antioxidant, anti-inflammatory, and anti-apoptotic mechanisms in a dose-dependent manner.

RhoA/rho kinase pathway activation in age-associated endothelial cell dysfunction and thrombosis

The small GTPase RhoA and the downstream Rho kinase (ROCK) regulate several cell functions and pathological processes in the vascular system that contribute to the age-dependent risk of cardiovascular disease, including endothelial dysfunction, excessive permeability, inflammation, impaired angiogenesis, abnormal vasoconstriction, decreased nitric oxide production and apoptosis. Frailty is a loss of physiological reserve and adaptive capacity with advanced age and is accompanied by a pro-inflammatory and pro-oxidative state that promotes vascular dysfunction and thrombosis. This review summarises the role of the RhoA/Rho kinase signalling pathway in endothelial dysfunction, the acquisition of the pro-thrombotic state and vascular ageing. We also discuss the possible role of RhoA/Rho kinase signalling as a promising therapeutic target for the prevention and treatment of age-related cardiovascular disease.

Cellular senescence promotes meibomian gland dysfunction in a chronic graft-versus-host disease mouse model

PURPOSE

Aging is a well-established risk factor for meibomian gland dysfunction (MGD). We previously reported an accelerated cellular senescence phenomenon in the lacrimal glands of a murine model of chronic graft-versus-host disease (cGVHD). Herein, we aimed to elucidate the relationship between cellular senescence and MGD in cGVHD mice, utilizing the senolytic agent ABT-263.

METHODS

A cGVHD mouse model was established through allogeneic bone marrow transplantation (BMT) from B10.D2 to BALB/c mice. Subsequently, cGVHD mice were treated with either ABT-263 or vehicle. The eyelids of recipients were analyzed at 4-week intervals post-BMT in both groups.

RESULTS

Meibomian gland (MG) area was significantly smaller in cGVHD mice than in syngeneic control mice. ABT-263-treated mice retained a significantly larger MG area than their vehicle-treated counterparts. Pathological and immunohistochemical examinations revealed significant reductions in eyelid tissue inflammation and pathological fibrosis in the ABT-263 group compared to that in the vehicle-treated group. Additionally, expression of DNA damage markers, senescent cell markers, and senescence-associated secretory phenotype (SASP) factors was elevated in the eyelids of cGVHD mice compared with that in syngeneic mice. The expression of these cellular senescence-associated molecules was considerably suppressed in ABT-263-treated eyelids compared to that in vehicle-treated ones.

CONCLUSIONS

Cellular senescence, along with expression of SASP factors, exhibited increased activity in the eyelids, particularly in the MGs of cGVHD mice. ABT-263 mitigated the severity of MGD. These findings highlight the potential of targeting cellular senescence as an effective approach for MGD treatment in cGVHD.

The Protective Effects of Vitamin B Complex on Diclofenac Sodium-Induced Nephrotoxicity: The Role of NOX4/RhoA/ROCK

Diclofenac sodium (DIC) is a widely used non-steroidal anti-inflammatory drug. Unfortunately, its prolonged use is associated with nephrotoxicity due to oxidative stress, inflammation, and fibrosis. We aimed to investigate the nephroprotective effects of vitamin B complex (B1, B6, B12) against DIC-induced nephrotoxicity and its impact on NOX4/RhoA/ROCK, a pathway that plays a vital role in renal pathophysiology. Thirty-two Wistar rats were divided into four groups: (1) normal control; (2) vitamin B complex (16 mg/kg B1, 16 mg/kg B6, 0.16 mg/kg B12, intraperitoneal); (3) DIC (10 mg/kg, intramuscular); and (4) DIC plus vitamin B complex group. After 14 days, the following were assayed: serum renal biomarkers (creatinine, blood urea nitrogen, kidney injury molecule-1), oxidative stress, inflammatory (tumor necrosis factor-α, interleukin-6), and fibrotic (transforming growth factor-β) markers as well as the protein levels of NOX4, RhoA, and ROCK. Structural changes, inflammatory cell infiltration, and fibrosis were detected using hematoxylin and eosin and Masson trichrome stains. Compared to DIC, vitamin B complex significantly decreased the renal function biomarkers, markers of oxidative stress and inflammation, and fibrotic cytokines. Glomerular and tubular damage, inflammatory infiltration, and excessive collagen accumulation were also reduced. Protein levels of NOX4, RhoA, and ROCK were significantly elevated by DIC, and this elevation was ameliorated by vitamin B complex. In conclusion, vitamin B complex administration could be a renoprotective approach during treatment with DIC via, at least in part, suppressing the NOX4/RhoA/ROCK pathway.

Podocyte injury at young age causes premature senescence and worsens glomerular aging

As life expectancy continues to rise, age-related diseases are becoming more prevalent. For example, proteinuric glomerular diseases typified by podocyte injury have worse outcomes in the elderly compared with young patients. However, the reasons are not well understood. We hypothesized that injury to nonaged podocytes induces senescence, which in turn augments their aging processes. In primary cultured human podocytes, injury induced by a cytopathic antipodocyte antibody, adriamycin, or puromycin aminonucleoside increased the senescence-related genes CDKN2A (p16INK4a/p14ARF), CDKN2D (p19INK4d), and CDKN1A (p21). Podocyte injury in human kidney organoids was accompanied by increased expression of CDKN2A, CDKN2D, and CDKN1A. In young mice, experimental focal segmental glomerulosclerosis (FSGS) induced by adriamycin and antipodocyte antibody increased the glomerular expression of p16, p21, and senescence-associated β-galactosidase (SA-β-gal). To assess the long-term effects of early podocyte injury-induced senescence, we temporally followed young mice with experimental FSGS through adulthood (12 m of age) and middle age (18 m of age). p16 and Sudan black staining were higher at middle age in mice with earlier FSGS compared with age-matched mice that did not get FSGS when young. This was accompanied by lower podocyte density, reduced canonical podocyte protein expression, and increased glomerular scarring. These results are consistent with injury-induced senescence in young podocytes, leading to increased senescence of podocytes by middle age accompanied by lower podocyte lifespan and health span.NEW & NOTEWORTHY Glomerular function is decreased by aging. However, little is known about the molecular mechanisms involved in age-related glomerular changes and which factors could contribute to a worse glomerular aging process. Here, we reported that podocyte injury in young mice and culture podocytes induced senescence, a marker of aging, and accelerates glomerular aging when compared with healthy aging mice.

Emodin disrupts the Notch1/Nrf2/GPX4 antioxidant system and promotes renal cell ferroptosis

Emodin has been demonstrated to possess multiple pharmacological activities. However, emodin has also been reported to induce nephrotoxicity at high doses and with long-term use, and the underlying mechanism has not been fully disclosed. The current study aimed to investigate the roles of oxidative stress and ferroptosis in emodin-induced kidney toxicity. Mice were intraperitoneally treated with emodin, and NRK-52E cells were exposed to emodin in the presence or absence of treatment with Jagged1, SC79, or t-BHQ. Emodin significantly upregulated the levels of blood urea nitrogen, serum creatinine, malondialdehyde, and Fe2+ , reduced the levels of superoxide dismutase and glutathione, and induced pathological changes in the kidneys in vivo. Moreover, the viability of NRK-52E cells treated with emodin was reduced, and emodin induced iron accumulation, excessive reactive oxygen species production, and lipid peroxidation and depolarized the mitochondrial membrane potential (ΔΨm). In addition, emodin treatment downregulated the activity of neurogenic locus notch homolog protein 1 (Notch1), reduced the nuclear translocation of nuclear factor erythroid-2 related factor 2 (Nrf2), and decreased glutathione peroxidase 4 protein levels. However, Notch1 activation by Jagged1 pretreatment, Akt activation by SC79 pretreatment, or Nrf2 activation by t-BHQ pretreatment attenuated the toxic effects of emodin in NRK-52E cells. Taken together, these results revealed that emodin-induced ferroptosis triggered kidney toxicity through inhibition of the Notch1/Nrf2/glutathione peroxidase 4 axis.

Dapagliflozin protects against doxorubicin-induced nephrotoxicity associated with nitric oxide pathway-A translational study

Doxorubicin (Dox) is a potent anticancer agent, but its associated organ toxicity, including nephrotoxicity, restricts clinical applications. Dapagliflozin (DAPA), a sodium-glucose cotransporter-2 inhibitor, has been shown to slow the progression of kidney disease in patients with and without diabetes. However, the effect of DAPA to counteract Dox-induced nephrotoxicity remains uncertain. Therefore, in this study, we aimed to elucidate the effects of DAPA in mitigating Dox-induced nephrotoxicity. We analyzed the Taiwan National Health Insurance Database to evaluate the incidence of renal failure among breast cancer patients receiving Dox treatment compared to those without. After adjusting for age and comorbidities, we found that the risk of renal failure was significantly higher in Dox-treated patients (incidence rate ratio, 2.45; confidence interval, 1.41-4.26; p = 0.0014). In a parallel study, we orally administered DAPA to Sprague-Dawley rats for 6 weeks, followed by Dox for 4 weeks. DAPA ameliorated Dox-induced glomerular atrophy, renal fibrosis, and dysfunction. Furthermore, DAPA effectively suppressed Dox-induced apoptosis and reactive oxygen species production. On a cellular level, DAPA in HK-2 cells mitigated Dox-mediated suppression of the endothelial NOS pathway and reduced Dox-induced activities of reactive oxygen species and apoptosis-associated proteins. DAPA improved Dox-induced apoptosis and renal dysfunction, suggesting its potential utility in preventing nephrotoxicity in patients with cancer undergoing Dox treatment.

miR-16-5p Regulates Ferroptosis by Targeting SLC7A11 in Adriamycin-Induced Ferroptosis in Cardiomyocytes

Introduction

Adriamycin (ADR) is commonly used in tumor chemotherapy, but its nonreversible cardiotoxicity severely hampers its clinical application. Ferroptosis is an implicated cause of ADR-induced injury. However, the underlying molecular mechanisms remain poorly understood. This study explored whether ferroptosis is a pivotal pathogenic pathway underlying ADR-induced cardiotoxicity and the possible molecular mechanisms involved.

Methods

In vivo and in vitro experimental models were used to study the mechanism of ADR-mediated ferroptosis. Ferroptosis levels were examined in mice and human/rat cardiomyocytes. Mechanistically, the expression levels of SLC7A11 and related miRNAs were examined. Bioinformatics prediction and luciferase reporter assays were used to verify the potential interaction between miR-16-5p and SLC7A11. The biological functions and interaction of SLC7A11 and miR-16-5p were investigated in vivo and in vitro.

Results

Our study observed that ADR treatment significantly increased ferroptosis levels in vivo and in vitro. Ferroptosis-related pharmacological interventions further confirmed these results. Our data displayed that the SLC7A11 level was significantly decreased in cardiac tissues and cells, while an increased expression level of miR-16-5p was observed. Moreover, upregulation of SLC7A1 and inhibition of miR-16-5p attenuated ADR-induced cardiomyocyte ferroptosis injury. Interactive rescue experiments showed that the protective effects of miR-16-5p inhibition on ADR-induced cardiomyocyte injury were blocked by SLC7A11 knockdown.

Discussion

Based on these findings, targeting miR-16-5p could partially reverse the ADR-induced cardiotoxicity by rescuing the SLC7A11 to attenuate ferroptosis. This study presents a pre-clinical basis to identify miR-16-5p/SLC7A11 as a potential treatment target for ADR-induced cardiotoxicity.

The role of BMI1 in endometrial cancer and other cancers

Endometrial cancer (EC) is the third leading gynecological malignancy, and its treatment remains challenging. B cell-specific Moloney murine leukemia virus integration site-1 (BMI1) is one of the core members of the polycomb group (PcG) family, which plays a promoting role in the occurrence and development of various tumors. Notably, BMI1 has been found to be frequently upregulated in endometrial cancer (EC) and promote the occurrence of EC through promoting epithelial-mesenchymal transition (EMT) and AKT/PI3K pathways. This review summarizes the structure and upstream regulatory mechanisms of BMI1 and its role in EC. In addition, we focused on the role of BMI1 in chemoradiotherapy resistance and summarized the current drugs that target BMI1.

Fluvastatin alleviates doxorubicin-induced cardiac and renal toxicity in rats via regulation of oxidative stress, inflammation, and apoptosis associated genes expressions

Doxorubicin (DOXO) is a cytostatic agent used in the chemotherapy protocol of several cancers for more than 40 years, but usage of this drug in cancer treatment has been limited due to severe renal and cardiac tissue toxicities that may result in death in patients. Fluvastatin (FV) is a fully synthetic hydroxymethyl glutaryl coenzyme A (HMG-CoA) reductase inhibitor used as a cholesterol-lowering agent in patients with hypercholesterolemia. Previous studies revealed that FV also exhibits antioxidant, anti-inflammatory, and antitumor activity. Additionally, our previous study indicated that FV exerts a prophylactic effect on DOXO-induced testicular toxicity by preventing lipid peroxidation, supporting the antioxidant system, and regulating the blood-testis barrier-associated genes expression. Herein, we purposed to evaluate the possible therapeutic and the protective effects of FV on the DOXO-induced cardiac and renal toxicitiy model by histochemical, immunohistochemical, biochemical, and real-time polymerase chain reaction (real-time PCR) analyses. Results point out protective use of FV exerts a beneficial effect by repressing lipid peroxidation and by regulating the inducible nitric oxide synthase (iNOS), nitric oxide synthase endothelial (eNOS), nuclear factor kappa-B (NF-κB), and Caspase-3 (Casp3) protein and mRNA expressions, which play an important role in mediating DOXO-induced renal and cardiac toxicity mechanisms. In conclusion, FV may be a candidate agent for the prevention of renal and cardiac toxicities in cancer patients receiving DOXO chemotherapy.

King Oyster Mushroom, Pleurotus eryngii (Agaricomycetes), Extract Can Attenuate Doxorubicin-Induced Lung Damage by Inhibiting Oxidative Stress in Rats

Doxorubicin (DOX), a broad spectrum chemotherapeutic, has toxic effects on healthy tissues. Mitochondrial processes and oxidative stress act in the DOX-induced toxicity, therefore antioxidant therapies are widely used. The study was aimed to evaluate the therapeutic potential of Pleurotus eryngii extract (PEE), an extract of a fungus with antioxidant properties, against DOX-induced lung damage. Rats were divided into Control, DOX, DOX + PEE, and PEE groups (n = 6). DOX was administered intraperitoneally in a single dose (10 mg/kg BW) and PE (200 mg/kg BW) was administered by oral gavage every other day for 21 days. Histopathological evaluations, immunohistochemical analyses, total oxidant status (TOS)/total antioxidant status (TAS) method, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis were performed. DOX led to severe histopathological disruptions in rat lungs. Also, DOX remarkably increased the expression of dynamin 1 like (DRP1) and decreased the expression of mitofusin 1 (MFN1) and mitofusin 2 (MFN2) genes, which are related to mitochondrial dynamics. Moreover, DOX caused an increase in TOS/ TAS and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. On the other hand, PEE treatment remarkably normalized the histopathological findings, mitochondrial dynamics-related gene expressions, markers of oxidative stress, and DNA damage. The present study signs out that PEE can ameliorate the DOX-mediated lung toxicity and the antioxidant mechanism associated with mitochondrial dynamics can have a role in this potent therapeutic effect.

Protective Effect of Cimicifuga racemosa (L.) Nutt Extract on Oocyte and Follicle Toxicity Induced by Doxorubicin during In Vitro Culture of Mice Ovaries

This study evaluated the potential of Cimicifuga racemosa (L.) Nutt extract (CIMI) to reduce the deleterious effects of doxorubicin (DOXO) in oocytes, follicles and stromal cells in mice ovaries cultured in vitro. In experiment 1, mice ovaries were cultured in DMEM⁺ alone or supplemented with 5, 50 or 500 ng/mL CIMI, while in experiment 2, mice ovaries were cultured in DMEM⁺ alone or supplemented with 5 ng/mL CIMI (better concentration), 0.3 μg/mL DOXO or both. Thereafter, the ovaries were processed for histological (morphology, growth, activation, extracellular matrix configuration and stromal cell density), immunohistochemical (caspase-3) analyses. Follicle viability was evaluated by fluorescence microscopy (ethidium homodimer-1 and calcein) while real-time PCR was performed to analyses the levels of (mRNA for SOD, CAT and nuclear factor erythroid 2-related factor 2 (NRF2) analyses. The results showed that DOXO reduces the percentage of normal follicles and the density of stromal cells in cultured ovaries, but these harmful effects were blocked by CIMI. The DOXO reduced the percentage of primordial follicles, while the presence of CIMI alone did not influence percentage of primordial follicles. A higher staining for caspase-3 was seen in ovaries cultured in control medium alone or with DOXO when compared with those cultured with CIMI alone or both CIMI and DOXO. In addition, follicles from ovaries cultured with both CIMI and DOXO were stained by calcein, while those follicles cultured with only DOXO were stained with ethidium homodimer-1. Furthermore, ovaries cultured with CIMI or both CIMI and DOXO had higher levels of mRNA for SOD and CAT, respectively, than those cultured with only DOXO. In conclusion, the extract of CIMI protects the ovaries against deleterious effects of DOXO on follicular survival and ovarian stromal cells.

Fasudil Ameliorates Osteoporosis Following Myocardial Infarction by Regulating Cardiac Calcitonin Secretion

We hypothesis that Rho kinase inhibitor fasudil ameliorates osteoporosis following myocardial infarction (MI) by regulating cardiac calcitonin secretion. A mice model of MI and cultured neonatal cardiomyocytes exposed to hypoxia and serum deprivation (H/SD), and fibroblasts exposed to TGF-β were used, respectively. Cardiac function in vivo was assessed with echocardiography. Osteoporosis in vivo was assessed with X-ray and micro-CT. In vivo and in vitro studies used histological and immunohistochemical techniques, along with western blots. In mice post-MI, fasudil ameliorates the microstructure and bone metabolism of the lumbar, improved cardiac function, and attenuated myocardial fibrosis. In vitro, fasudil or αCGRP could effectively inhibit the proliferation of primary fibroblasts treated with TGF-β. Moreover, fasudil ameliorates the cardiac calcitonin secretion induced by MI in vivo or by H/SD in vitro. Our findings suggest that fasudil improved MI-induced osteoporosis by promoting cardiac secreting calcitonin.

Fasudil Ameliorates Methotrexate-Induced Hepatotoxicity by Modulation of Redox-Sensitive Signals

Methotrexate (MTX) is one of the most widely used cytotoxic chemotherapeutic agents, and it is used in the treatment of different autoimmune disorders. However, the clinical applications of MTX are limited by its hepatic toxicity. Hence, the present study was conducted to evaluate the efficacy of fasudil (Rho-Kinase inhibitor) in the amelioration of MTX hepatotoxicity and the possible underlying mechanisms. Experimentally, 32 male Sprague Dawley rats were used and divided into four groups: control, MTX (20 mg/kg, i.p., single dose), fasudil (10 mg/kg/day i.p.) for one week, and fasudil plus MTX. It was found that MTX significantly induced hepatitis and hepatocellular damage, as shown by abnormal histological findings and liver dysfunction (ALT and AST), with up-regulation of the inflammatory mediators NF-κB-p65 and IL-1β. Moreover, MTX remarkably disrupted oxidant/antioxidant status, as evidenced by malondialdehyde (MDA) up-regulation associated with the depletion of superoxide dismutase (SOD), catalase, and reduced glutathione (GSH) levels. Moreover, MTX reduced the hepatic expression of B-cell lymphoma 2 (Bcl-2). On the contrary, the i.p. administration of fasudil significantly ameliorated MTX hepatotoxicity by histopathological improvement, restoring oxidant/antioxidant balance, preventing hepatic inflammation, and improving the hepatic anti-apoptotic capability. Furthermore, fasudil hepatic concentration was determined for the first time using the validated RP-HPLC method. In conclusion, the present study revealed that fasudil has a reliable hepatoprotective effect against MTX hepatotoxicity with underlying antioxidant, anti-inflammatory, and anti-apoptotic mechanisms. It also introduced a new method for the determination of fasudil hepatic tissue concentration using the RP-HPLC technique.

Prevention of Anthracycline-Induced Cardiotoxicity: The Good and Bad of Current and Alternative Therapies

Doxorubicin (Dox)-induced cardiotoxicity (DIC) remains a serious health burden, especially in developing countries. Unfortunately, the high cost of current preventative strategies has marginalized numerous cancer patients because of socio-economic factors. In addition, the efficacy of these strategies, without reducing the chemotherapeutic properties of Dox, is frequently questioned. These limitations have widened the gap and necessity for alternative medicines, like flavonoids, to be investigated. However, new therapeutics may also present their own shortcomings, ruling out the idea of “natural is safe”. The U.S. Food and Drug Administration (FDA) has stipulated that the concept of drug-safety be considered in all pre-clinical and clinical studies, to explore the pharmacokinetics and potential interactions of the drugs being investigated. As such our studies on flavonoids, as cardio-protectants against DIC, have been centered around cardiac and cancer models, to ensure that the efficacy of Dox is preserved. Our findings thus far suggest that flavonoids of Galenia africana could be suitable candidates for the prevention of DIC. However, this still requires further investigation, which would focus on drug-interactions as well as in vivo experimental models to determine the extent of cardioprotection.

Downregulation of nesfatin-1 expression in acute kidney injury in vivo in wistar rats and in vitro in cultured cells

AIMS

Acute kidney injury (AKI) is a debilitating condition followed by sudden kidney damage or failure within hours or days of its occurrence. AKI is characterized by rapid increase in serum creatinine/BUN and decrease in urine output. Nesfatin-1 is an endogenous peptide reported to possess anorexic, antioxidant and anti-apoptotic properties. Although few clinical studies have shown altered nesfatin-1 levels in hemodialysis patients, however, there are no reports investigating the distribution and expression pattern of nesfatin-1 in AKI.

MATERIALS AND METHODS

Nesfatin-1 expression was determined in different disease induced models of AKI by immunoblotting, immunofluorescence and RT-PCR. Gene markers of oxidative stress and inflammation were determined by RT-PCR. The expression of different markers of AKI was measured by assay kits and RT-PCR analysis.

KEY FINDINGS

There was a significant increase in serum levels of creatinine and BUN in AKI rats followed by significant increase in KIM-1 in the kidneys. Significant decrease in nesfatin-1 expression along with increased expression of IL-1β, TNF-α and decreased expression of SOD and catalase was observed in doxorubicin and cisplatin induced AKI rats. However, SOD and catalase expression were upregulated in glycerol induced AKI rats. Moreover, in vitro treatment of renal NRK-52E epithelial cells with nesfatin-1 reversed the changes induced by doxorubicin.

SIGNIFICANCE

Our study reports for the first time, nesfatin-1 expression is decreased in kidneys of different models of AKI induced rats as well as cultured NRK-52E renal epithelial cells. Further studies are required to understand the possible molecular mechanism and therapeutic potential of nesfatin-1 in acute kidney injury.

Apigenin Attenuates Mesoporous Silica Nanoparticles-Induced Nephrotoxicity by Activating FOXO3a

Mesoporous silica nanoparticles (MSNs) are widely used in many biomedical applications and clinical fields. However, the applications of MSNs are limited by their severe toxicity. Apigenin (AG) has demonstrated pharmacological effects with low toxicity. The aim of this study was to clarify the role of AG in the progression of MSNs-induced renal injury. BALB/c mice and NRK-52E cells were exposed to MSNs with or without AG. AG protected mice and NRK-52E cells from the MSNs-induced pathological variations in renal tissues and decreased cell viability. AG significantly reduced the levels of serum blood urea nitrogen (BUN) and serum creatinine (Scr), upregulated the levels of superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT), and improved the pathological changes of the kidney in MSNs-treated mice. The protective effects of AG were associated with its ability to increase the levels of antioxidants, reduce the accumulation of ROS, and inhibit the expression of the inflammatory mediators (TNF-α, IL-6). In addition, AG treatment upregulated the activity of FOXO3a, increased the level of IkBα, and reduced the nuclear translocation of NF-κB, which ultimately alleviated MSNs-induced inflammation. Nuclear FOXO3a translocation also triggered antioxidant gene transcription and protected nephrocyte from oxidative damage. However, knockdown of FOXO3a significantly blocked the protective effects of AG. These findings suggested that AG could be a promising therapeutic strategy for MSNs-induced nephrotoxicity, and this protective effect might be related to the suppression of oxidative stress and inflammation via the FOXO3a/NF-κB pathway.

Effects of Concurrent Exposure to Chronic Restraint-Induced Stress and Total-Body Iron Ion Radiation on Induction of Kidney Injury in Mice

Concurrent exposure to ionizing radiation (IR) and psychological stress (PS) may affect the development of adverse health consequences in scenarios such as space missions, radiotherapy and nuclear accidents. IR can induce DNA damage and cell apoptosis in the kidneys, thus potentially leading to renal fibrosis, which is the ultimate outcome of various chronic progressive nephropathies and the morphological manifestation of a continuous coordinated response after renal injury. However, little is known regarding the effects of concurrent IR exposure and PS on renal damage, particularly renal fibrosis. In this study, using a chronic restraint-induced PS (CRIPS) model, we exposed Trp53-heterozygous mice to total body irradiation with 0.1 or 2 Gy ⁵⁶Fe ions on the eighth day of 28 consecutive days of a restraint regimen. At the end of the restraint period, the kidneys were collected. The histopathological changes and the degree of kidney fibrosis were assessed with H&E and Masson staining, respectively. Fibronectin (FN) and alpha smooth muscle actin (α-SMA), biomarkers of fibrosis, were detected by immunohistochemistry. Analysis of 8-hydroxy-2 deoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage, was performed with immunofluorescence, and terminal deoxynucleotidyl transferase-mediated nick end labeling assays were used to detect apoptotic cells. Histopathological observations did not indicate significant structural damage induced by IR or CRIPS + IR. Western blotting revealed that the expression of α-SMA was much higher in the CRIPS + IR groups than the CRIPS groups. However, no differences in the average optical density per area were observed for FN, α-SMA and 8-OHdG between the IR and CRIPS + IR groups. No difference in the induction of apoptosis was observed between the IR and CRIPS + IR groups. These results suggested that exposure to IR (0.1 and 2 Gy ⁵⁶Fe ions), 28 consecutive days of CRIPS or both did not cause renal fibrosis. Thus, CRIPS did not alter the IR-induced effects on renal damage in Trp53-heterozygous mice in our experimental setup.

Cardiorenal Protective Effect of Costunolide against Doxorubicin-Induced Toxicity in Rats by Modulating Oxidative Stress, Inflammation and Apoptosis

Doxorubicin (DXB) is one of the most commonly used anticancer agents for treating solid and hematological malignancies; however, DXB-induced cardiorenal toxicity presents a limiting factor to its clinical usefulness in cancer patients. Costunolide (COST) is a naturally occurring sesquiterpene lactone with excellent anti-inflammatory, antioxidant and antiapoptotic properties. This study evaluated the effect of COST on DXB-induced cardiorenal toxicity in rats. Rats were orally treated with COST for 4 weeks and received weekly 5 mg/kg doses of DXB for three weeks. Cardiorenal biochemical biomarkers, lipid profile, oxidative stress, inflammatory cytokines, histological and immunohistochemical analyses were evaluated. DXB-treated rats displayed significantly increased levels of lipid profiles, markers of cardiorenal dysfunction (aspartate aminotransferase, creatine kinase, lactate dehydrogenase, troponin T, blood urea nitrogen, uric acid and creatinine). In addition, DXB markedly upregulated cardiorenal malondialdehyde, tumor necrosis factor-α, interleukin-1β, interleukin-6 levels and decreased glutathione, superoxide dismutase and catalase activities. COST treatment significantly attenuated the aforementioned alterations induced by DXB. Furthermore, histopathological and immunohistochemical analyses revealed that COST ameliorated the histopathological features and reduced p53 and myeloperoxidase expression in the treated rats. These results suggest that COST exhibits cardiorenal protective effects against DXB-induced injury presumably via suppression of oxidative stress, inflammation and apoptosis.

Cellular senescence and acute kidney injury

Acute kidney injury (AKI) is a common clinical complication characterized by a sudden deterioration of the kidney's excretory function, which normally occurs secondary to another serious illness. AKI is an important risk factor for chronic kidney disease (CKD) occurrence and progression to kidney failure. It is, therefore, crucial to block the development of AKI as early as possible. To date, existing animal studies have shown that senescence occurs in the early stage of AKI and is extremely critical to prognosis. Cellular senescence is an irreversible process of cell cycle arrest that is accompanied by alterations at the transcriptional, metabolic, and secretory levels along with modified cellular morphology and chromatin organization. Acute cellular senescence tends to play an active role, whereas chronic senescence plays a dominant role in the progression of AKI to CKD. The occurrence of chronic senescence is inseparable from senescence-associated secretory phenotype (SASP) and senescence-related pathways. SASP acts on normal cells to amplify the senescence signal through senescence-related pathways. Senescence can be improved by initiating reprogramming, which plays a crucial role in blocking the progression of AKI to CKD. This review integrates the existing studies on senescence in AKI from several aspects to find meaningful research directions to improve the prognosis of AKI and prevent the progression of CKD.

Kidney Response to Chemotherapy-Induced Heart Failure: mRNA Analysis in Normotensive and Ren-2 Transgenic Hypertensive Rats

The aim of the present study was to perform kidney messenger ribonucleic acid (mRNA) analysis in normotensive, Hannover Sprague-Dawley (HanSD) rats and hypertensive, Ren-2 renin transgenic rats (TGR) after doxorubicin-induced heart failure (HF) with specific focus on genes that are implicated in the pathophysiology of HF-associated cardiorenal syndrome. We found that in both strains renin and angiotensin-converting enzyme mRNA expressions were upregulated indicating that the vasoconstrictor axis of the renin-angiotensin system was activated. We found that pre-proendothelin-1, endothelin-converting enzyme type 1 and endothelin type A receptor mRNA expressions were upregulated in HanSD rats, but not in TGR, suggesting the activation of endothelin system in HanSD rats, but not in TGR. We found that mRNA expression of cytochrome P-450 subfamily 2C23 was downregulated in TGR and not in HanSD rats, suggesting the deficiency in the intrarenal cytochrome P450-dependent pathway of arachidonic acid metabolism in TGR. These results should be the basis for future studies evaluating the pathophysiology of cardiorenal syndrome secondary to chemotherapy-induced HF in order to potentially develop new therapeutic approaches.

A comprehensive review on time-tested anticancer drug doxorubicin

Doxorubicin or Adriamycin, is one of the most widely used chemotherapeutic drug for treating a myriad of cancers. It induces cell death through multiple intracellular targets: reactive oxygen species generation, DNA-adduct formation, topoisomerase II inhibition, histone eviction, Ca²⁺ and iron hemostasis regulation, and ceramide overproduction. Moreover, doxorubicin-treated dying cells undergo cellular modifications that enable neighboring dendritic cell activation and enhanced presentation of tumor antigen. In addition, doxorubicin also aids in the immune-mediated clearance of tumor cells. However, the development of chemoresistance and cardiotoxicity side effect has undermined its widespread applicability. Several formulations of doxorubicin and co-treatments with inhibitors, miRNAs, natural compounds and other chemotherapeutic drugs have been essential in reducing its dosage-dependent toxicity and combating the development of resistance. Further, more advanced research into the molecular mechanism of chemoresistance development would be vital in improving the overall survivability of clinical patients and in preventing cancer relapse.