Glimepiride ameliorates renal toxicity induced by cadmium in mice: Modulation of Jun N terminal kinase (JNK)/nuclear factor kappa B (NF-κB) and phosphatidylinositol 3-kinases (PI3K)/protein kinase (AKT) pathways.

AIMS: Nephrotoxicity is one of the most serious health consequences of cadmium (Cd) toxic exposure. Cd was associated with nephrotoxicity through different mechanisms including apoptosis, inflammation, and oxidative stress. This study investigated the effects of glimepiride on renal inflammatory reactions and oxidative stress in response to Cd in mice animal model, pointing to the possible role of JNK/NF-кB and PI3K/AKT signaling. MATERIALS AND METHODS: Four groups of animals were created; the control group, the glimepiride group (4 mg/kg; i.p.), CdCl2 nephrotoxic group (6.5 mg/kg; i.p.), and the CdCl2/glimepiride group. On the other hand, molecular docking studies were used to investigate the affinity of glimepiride towards JNK, AKT, and PI3K targets. KEY FINDINGS: The CdCl2 group's serum creatinine and urea levels were found to have a significant increase when compared to the normal group. High expression of 8-OHDG, JNK, AKT, and NGAL was also detected in the CdCl2 group. In addition, coagulative necrosis of the renal tubules and increased immunostaining of NF-κB and PI3K. Furthermore, glimepiride significantly decreased the serum creatinine and urea level and alleviated the degenerative and necrotic changes within the renal tubules. Moreover, the renal NGAL and JNK were suppressed, and oxidants/antioxidants hemostasis was observed. SIGNIFICANCE: The available data show that glimepiride is an attractive strategy for improving the nephrotoxicity associated with CdCl2 through inhibition of JNK/NF-κB, PI3K/AKT inflammatory pathways. From the abovementioned results, glimepiride treatment might be a potential therapeutic approach to treat renal tissue against severe acute renal damage induced by the toxic effects of CdCl2.

Glimepiride mitigates tauopathy and neuroinflammation in P301S transgenic mice: role of AKT/GSK3ß signaling.

BACKGROUND AND OBJECTIVE: Tauopathy is a group of neurodegenerative diseases in which the pathogenesis processes are related to tau protein. The imbalances between the activities of kinases and phosphatases of tau protein lead to tau hyperphosphorylation and subsequent neurodegeneration. Numerous studies suggest a strong linkage between type 2 diabetes mellitus (T2D) and neurodegenerative diseases. Therefore, finding a drug with a dual therapeutic activity against T2D and neuroprotective will be a promising idea. Hence, the potential neuroprotective effect of Glimepiride (GPD) against tauopathy was evaluated in the current study. METHODS: P301S mice model was employed for tauopathy and C57BL/6 wild type mice (WT) was used as control. Phosphorylated and acetylated tau protein levels was assessed in cortex and hippocampus by western blot. Effect of GPD on tauopathy related enzymes, neuroinflammation, apoptotic markers were evaluated. Furthermore, the neuroprotective effects against anxiety like behavior and motor impairment was analyzed using Parallel rod floor and Open field tests. RESULTS: GPD significantly ameliorates motor impairment, anxiety like behavior and neurodegeneration in P301S mice. Phosphorylated tau and acetylated tau were significantly decreased in both cortex and hippocampus of P301S mice via decreasing GSK3ß, increasing ratio of phosphorylated-AKT to total-AKT, increasing PP2A and normalization of CDK5 levels. Furthermore, GPD treatment also decreased neuroinflammation and apoptosis by reducing NF-kB, TNF-α and caspase 3 levels. CONCLUSION: The current data suggests that GPD exerts a protective effect against tauopathy, behavioural consequences, neurodegeneration, neuroinflammation and apoptosis. GPD is therefore a promising agent for the treatment of neurodegenerative diseases associated with tauopathy.

Potential role of Drug Repositioning Strategy (DRS) for management of tauopathy.

Tauopathy is a term that has been used to represent a pathological condition in which hyperphosphorylated tau protein aggregates in neurons and glia which results in neurodegeneration, synapse loss and dysfunction and cognitive impairments. Recently, drug repositioning strategy (DRS) becomes a promising field and an alternative approach to advancing new treatments from actually developed and FDA approved drugs for an indication other than the indication it was originally intended for. This paradigm provides an advantage because the safety of the candidate compound has already been established, which abolishes the need for further preclinical safety testing and thus substantially reduces the time and cost involved in progressing of clinical trials. In the present review, we focused on correlation between tauopathy and common diseases as type 2 diabetes mellitus and the global virus COVID-19 and how tau pathology can aggravate development of these diseases in addition to how these diseases can be a risk factor for development of tauopathy. Moreover, correlation between COVID-19 and type 2 diabetes mellitus was also discussed. Therefore, repositioning of a drug in the daily clinical practice of patients to manage or prevent two or more diseases at the same time with lower side effects and drug-drug interactions is a promising idea. This review concluded the results of pre-clinical and clinical studies applied on antidiabetics, COVID-19 medications, antihypertensives, antidepressants and cholesterol lowering drugs for possible drug repositioning for management of tauopathy.