Alleviation of renal mitochondrial dysfunction and apoptosis underlies the protective effect of sitagliptin in gentamicin-induced nephrotoxicity

Effect of mitochondrial coenzyme-Q10 precursor solanesol in gentamicin-induced experimental nephrotoxicity: Evidence from restoration of ETC-complexes and histopathological alterations

Nephrotoxicity occurs when the body is exposed to certain drugs or toxins. When kidney damage occurs, the kidney fails to eliminate excess urine and waste. Solanesol (C45H74O) is a tri-sesquiterpenoid alcohol first isolated from tobacco, and it is widely distributed in plants of the Solanaceae family. Solanesol (SNL) is an intermediate in the synthesis of coenzyme Q10 (CoQ10), an antioxidant which protects nerve cells. This study investigated the protective effect of SNL at doses of 30 and 60 mg/kg in gentamicin-induced nephrotoxicity in Wistar albino rats. Animals were distributed into six groups and administered 100 mg/kg gentamicin-intraperitoneal injection for 14 days. Biochemical assessments were performed on kidney homogenate, blood, and serum. Treatment with SNL was shown as lower serum levels of creatinine, blood urea nitrogen (BUN), thiobarbituric acid reactive substances (TBARS), and Tumor necrosis factor alpha)TNF-α ((p < .001). It also restored reduced glutathione (GSH) and mitochondrial complex enzymatic activity as protective measures against gentamicin-induced nephrotoxicity. SNL were shown to reduce inflammation and oxidative stress markers (p < .001). Histological findings furtherly augmented the protective effects of SNL. Long-term SNL therapy also restored mitochondrial electron transport chain complex enzymes, such as complex-I (p < .001). In conclusion, these findings suggest that SNL can represent a protective therapeutic option for drug-induced nephrotoxicity, a long-term adverse effect of aminoglycoside antibiotics such as gentamicin.

Targeting SIRT1/AMPK/Nrf2/NF-кB by sitagliptin protects against oxidative stress-mediated ER stress and inflammation during ANIT-induced cholestatic liver injury

Intrahepatic cholestasis is a common clinical form of hepatobiliary injury characterized by the intrahepatic accumulation of toxic bile acids. Besides its antidiabetic activity, the dipeptidyl peptidase IV inhibitor sitagliptin (SG) has been recently assigned diverse pharmacological activities and therapeutic potential against different disorders owing to its emerging antioxidant and anti-inflammatory properties. The current study explored the potential hepatoprotective effect of SG on α-naphthyl isothiocyanate (ANIT)-induced cholestatic liver injury (CLI) in mice and investigate its possible targeted signaling pathways. Mice received SG (10 and 20 mg/kg) for four consecutive days, two days before and after a single oral administration of ANIT (75 mg/kg). Our results revealed that SG administration remarkably prevented ANIT-induced histopathological lesions in the liver and maintained hepatic functions and oxidative/antioxidant balance. Ultimately, SG counteracted the inflammatory response in the liver, as indicated by the marked suppression of hepatic expression of NF-κB, TNF-α, and IL-6. Moreover, it inhibited the endoplasmic reticulum (ER) stress response in the liver. These beneficial effects of SG were accompanied by upregulation of SIRT1, p-AMPK, and Nrf2 expressions while downregulating keap1 expression in the liver. In conclusion, this study is the first to demonstrate the ability of SG to protect against ANIT-induced CLI through modulating multiple signaling cascades, including SIRT1/AMPK, Nrf2/keap1, and NF-кB, which resulted in enhanced antioxidant capacity and repressed inflammatory and ER stress responses in the liver.

Cyclosporine-induced kidney damage was halted by sitagliptin and hesperidin via increasing Nrf2 and suppressing TNF-α, NF-κB, and Bax

Cyclosporine A (CsA) is employed for organ transplantation and autoimmune disorders. Nephrotoxicity is a serious side effect that hampers the therapeutic use of CsA. Hesperidin and sitagliptin were investigated for their antioxidant, anti-inflammatory, and tissue-protective properties. We aimed to investigate and compare the possible nephroprotective effects of hesperidin and sitagliptin. Male Wistar rats were utilized for induction of CsA nephrotoxicity (20 mg/kg/day, intraperitoneally for 7 days). Animals were treated with sitagliptin (10 mg/kg/day, orally for 14 days) or hesperidin (200 mg/kg/day, orally for 14 days). Blood urea, serum creatinine, albumin, cystatin-C (CYS-C), myeloperoxidase (MPO), and glucose were measured. The renal malondialdehyde (MDA), glutathione (GSH), catalase, and SOD were estimated. Renal TNF-α protein expression was evaluated. Histopathological examination and immunostaining study of Bax, Nrf-2, and NF-κB were performed. Sitagliptin or hesperidin attenuated CsA-mediated elevations of blood urea, serum creatinine, CYS-C, glucose, renal MDA, and MPO, and preserved the serum albumin, renal catalase, SOD, and GSH. They reduced the expressions of TNF-α, Bax, NF-κB, and pathological kidney damage. Nrf2 expression in the kidney was raised. Hesperidin or sitagliptin could protect the kidney against CsA through the mitigation of oxidative stress, apoptosis, and inflammation. Sitagliptin proved to be more beneficial than hesperidin.

Renoprotective Effect of Fucoidan from Seaweed Sargassum angustifolium C. Agardh 1820 on Gentamicin-Induced Nephrotoxicity: From Marine Resources to Therapeutic Uses

Background: Nephrotoxicity is a major side effect of aminoglycoside antibiotics, caused by oxidative damage and inflammation. Fucoidan, a group of sulfated polysaccharides derived from different species of brown algae, are well recognized for their antioxidant and anti-inflammatory activities. Objectives: In the present study, we aimed to investigate, for the first time, the efficacy of fucoidan extracted from Sargassum angustifolium C. Agardh 1820 against gentamicin-induced nephrotoxicity in rats. Methods: Twenty-eight male Wistar rats were divided into 4 groups of control, gentamicin (100 mg/kg), and gentamicin plus 50- and 100-mg/kg/day fucoidan pretreatment. In the end, all rats were killed, and then urine, blood, and tissue samples were prepared. Kidney weight (KW), body weight (BW), and 24-hour urine volume, as well as serum creatinine (Cr), blood urea nitrogen (BUN), Cr clearance, and malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity, were measured. Kidney samples were also evaluated for histopathological changes. Results: Gentamicin significantly increased KW, KW/BW ratio, 24-hour urine volume, serum Cr, MDA, and BUN levels; however, fucoidan pretreatment, especially at a dose of 50 mg/kg, significantly returned these variables near to the control group values. Gentamicin also decreased BW gain, Cr clearance, SOD activity, and the degree of renal tissue damage compared to the control group, while treatment with fucoidan significantly reversed these alterations. Conclusions: The results show that fucoidan from S. angustifolium C. Agardh 1820 ameliorates gentamicin-induced nephrotoxicity by alleviating oxidative stress and augmenting antioxidant enzymes activity in renal tissue, suggesting the potential use of this fucoidan in a clinical setting.

A molecular link between diabetes and breast cancer: Therapeutic potential of repurposing incretin-based therapies for breast cancer

Female breast cancer recently surpassed lung cancer and became the most commonly diagnosed cancer worldwide. As per the recent data from WHO, breast cancer accounts for one out of every 8 cancer cases diagnosed among an estimated 2.3 million new cancer cases. Breast cancer is the most prevailing cancer type among women causing the highest number of cancer-related mortality. It has been estimated that in 2020, 68,5000 women died due to this disease. Breast cancers have varying degrees of molecular heterogeneity; therefore, they are divided into various molecular clinical sub types. Recent reports suggest that type 2 diabetes (one of the common chronic diseases worldwide) is linked to the higher incidence, accelerated progression, and aggressiveness of different cancers; especially breast cancer. Breast cancer is hormone-dependent in nature and has a cross-talk with metabolism. A number of antidiabetic therapies are known to exert beneficial effects on various types of cancers, including breast cancer. However, only a few reports are available on the role of incretin-based antidiabetic therapies in cancer as a whole and in breast cancer in particular. The present review sheds light on the potential of incretin based therapies on breast cancer and explores the plausible underlying mechanisms. Additionally, we have also discussed the sub types of breast cancer as well as the intricate relationship between diabetes and breast cancer.

Reno-protective effect of linagliptin against gentamycin nephrotoxicity in rats

BACKGROUND

Recent studies demonstrated the reno-protective effects of two dipeptidyl peptidase-4 (DPP-4) inhibitors, saxagliptin and sitagliptin, against gentamycin-induced renal injury. However, none of these studies investigated whether renal DPP-4 contributes to the pathogenesis of this nephrotoxicity or not. This prompted us to test this hypothesis and to assess, for the first time, the potential reno-protective effect of linagliptin and whether this action is related or not to DPP-4 inhibition. Lingliptin was chosen since it is mainly excreted through a non-renal pathway and can therefore be used safely in individuals with renal injury.

METHODS

Male Sprague-Dawley rats were administered gentamycin (100 mg/kg/day, ip for 10 days) alone or combined with linagliptin (3 mg/kg/day, orally for 14 days). Gentamycin was administered once daily during the last ten days of the linagliptin treatment.

RESULTS

Linagliptin administration ameliorated gentamycin-induced renal injury and restored renal functional, oxidative, inflammatory, apoptotic and histopathological changes. Furthermore, the current study highlighted the role of increased plasma and renal DPP-4 in the pathogenesis of gentamycin renal insults and showed that the potential reno-protective effect of linagliptin is partly, mediated via inhibition of DPP-4, in addition to other antioxidant, anti-inflammatory and anti-apoptotic actions.

CONCLUSION

Linagliptin may serve as a beneficial adjutant to reduce gentamycin-induced renal injury.

Gentamicin Affects the Bioenergetics of Isolated Mitochondria and Collapses the Mitochondrial Membrane Potential in Cochlear Sensory Hair Cells

Aminoglycoside antibiotics are widely prescribed to treat a variety of serious bacterial infections. They are extremely useful clinical tools, but have adverse side effects such as oto- and nephrotoxicity. Once inside a cell they are thought to cause mitochondrial dysfunction, subsequently leading to apoptotic cell death due to an increase in reactive oxygen species (ROS) production. Here we present evidence of a direct effect of gentamicin (the most commonly prescribed aminoglycoside) on the respiratory activities of isolated rat liver and kidney mitochondria. We show that gentamicin stimulates state 4 and inhibits state 3u respiratory rates, thereby reducing the respiratory control ratio (RCR) whilst simultaneously causing a collapse of the mitochondrial membrane potential (MtMP). We propose that gentamicin behaves as an uncoupler of the electron transport chain (ETC) - a hypothesis supported by our evidence that it reduces the production of mitochondrial ROS (MtROS). We also show that gentamicin collapses the MtMP in the sensory hair cells (HCs) of organotypic mouse cochlear cultures.

Cell Death in the Kidney

Apoptotic cell death is usually a response to the cell's microenvironment. In the kidney, apoptosis contributes to parenchymal cell loss in the course of acute and chronic renal injury, but does not trigger an inflammatory response. What distinguishes necrosis from apoptosis is the rupture of the plasma membrane, so necrotic cell death is accompanied by the release of unprocessed intracellular content, including cellular organelles, which are highly immunogenic proteins. The relative contribution of apoptosis and necrosis to injury varies, depending on the severity of the insult. Regulated cell death may result from immunologically silent apoptosis or from immunogenic necrosis. Recent advances have enhanced the most revolutionary concept of regulated necrosis. Several modalities of regulated necrosis have been described, such as necroptosis, ferroptosis, pyroptosis, and mitochondrial permeability transition-dependent regulated necrosis. We review the different modalities of apoptosis, necrosis, and regulated necrosis in kidney injury, focusing particularly on evidence implicating cell death in ectopic renal calcification. We also review the evidence for the role of cell death in kidney injury, which may pave the way for new therapeutic opportunities.

Potential protective effects of Dapagliflozin in gentamicin induced nephrotoxicity rat model via modulation of apoptosis associated miRNAs

BACKGROUND

Drug-induced kidney injury (DIKI) can be manifested with progressive chronic kidney diseases or end-stage renal diseases. Understanding the molecular disarrangements caused by DIKI is an attractive point of interest. A class of non-coding RNA called microRNAs (miRNAs) is known to play a major role in regulation of gene expression and signaling pathways making miRNAs excellent targets for new therapeutic agents.

AIM OF THE STUDY

We aimed to investigate the role of miRNA 21 and 181a in gentamicin (GNT) induced nephrotoxicity rat model and the protective effect of Dapagliflozin (DAPA) in modulating their expression through studying its effect on renal function as well as renal histopathological changes.

MATERIALS AND METHODS

Wistar rats were used and divided into: naïve, DAPA, GNT and DAPA + GNT groups. In all studied groups, kidney function, oxidative stress, apoptosis markers and miRNAs' expression in serum and renal biopsies were investigated in addition to the histopathological studies to identify its early renoprotective effect.

RESULTS

DAPA was found to improve kidney function, oxidative stress markers, decrease apoptosis of renal tubular cells and increase miR-21 but decrease the expression of miR-181a with restoration of the renal architecture after 14 days of treatment in GNT induced nephrotoxicity rat model.

CONCLUSIONS

DAPA produced significant decrease in renal expression of miR-181a on the other hand it increased the expression of renal miR-21, this may introduce a novel early protective effect of DAPA against GNT-induced nephrotoxicity.

Drug-induced premature senescence model in human dental follicle stem cells

Aging is identified by a progressive decline of physiological integrity leading to age-related degenerative diseases, but its causes is unclear. Human dental pulp stem cells (hDPSCs) has a remarkable rejuvenated capacity that relies on its resident stem cells. However, because of the lack of proper senescence models, exploration of the underlying molecular mechanisms has been hindered. Here, we established a cellular model utilizing a hydroxyurea (HU) treatment protocol and effectively induced Human dental pulp stem cells to undergo cellular senescence. Age-related phenotypic changes were identified by augmented senescence-associated-β-galactosidase (SA-β-gal) staining, declined proliferation and differentiation capacity, elevated G0/G1 cell cycle arrest, increased apoptosis and reactive oxygen species levels. Furthermore, we tested the expression of key genes in various DNA repair pathways including nonhomologous end-joining (NHEJ) and homologous recombination (HR) pathways. In addition, our results showed that Dental pulp stem cells from young donors are more resistant to apoptosis and exhibit increased non-homologous end joining activity compared to old donors. Further transcriptome analysis demonstrate that multiple pathways are involved in the HU-induced Dental pulp stem cells ageing, including genes associated with DNA damage and repair, mitochondrial dysfunction and increased reactive oxygen species levels. Taken together, the cellular model have important implications for understanding the molecular exploration of Dental pulp stem cells senescence and aging.

Renal outcomes with dipeptidyl peptidase-4 inhibitors

Dipeptidyl peptidase-4 inhibitors (DPP-4is) are increasingly being used in the management of type 2 diabetes (T2D). The present review summarizes the current knowledge of the effects of DPP-4is on renal outcomes by analyzing the experimental preclinical data, the effects of DPP-4is on urinary albumin-creatinine ratios (UACRs) and estimated glomerular filtration rates (eGFRs) from observational studies and clinical trials, and renal events (including kidney failure requiring renal replacement therapy) in recent large prospective cardiovascular outcome trials. Renal protection has been demonstrated in various animal models that have implicated different underlying mechanisms independent of glucose control, whereas prevention of new onset microalbuminuria and/or progression of albuminuria has been reported in some clinical studies, but with no significant effects on eGFR in most of them. The long-term clinical effects of DPP-4is on renal outcomes and the development of end-stage renal disease remain largely unknown and, thus, demand further investigations in prospective trials and long-term observational studies. In conclusion, despite promising results in animal models, data on surrogate biological markers of renal function and clinical renal outcomes remain rather scanty in patients with T2D, and mostly demonstrate the safety rather than true efficacy of DPP-4is.