Melatonin mitigates type 1 diabetes-aggravated cerebral ischemia-reperfusion injury through anti-inflammatory and anti-apoptotic effects

Calpain: The regulatory point of cardiovascular and cerebrovascular diseases

Calpain, a key member of the Calpain cysteine protease superfamily, performs limited protein hydrolysis in a calcium-dependent manner. Its activity is tightly regulated due to the potential for non-specific cleavage of various intracellular proteins upon aberrant activation. A thorough review of the literature from 2010 to 2023 reveals 121 references discussing cardiovascular and cerebrovascular diseases. Dysregulation of the Calpain system is associated with various pathological phenomena, including lipid metabolism disorders, inflammation, apoptosis, and excitotoxicity. Although recent studies have revealed the significant role of Calpain in cardiovascular and cerebrovascular diseases, the precise mechanisms remain incompletely understood. Exploring the potential of Calpain inhibition as a therapeutic approach for the treatment of cardiovascular and cerebrovascular diseases may emerge as a compelling area of interest for future calpain research.

Melatonin and resveratrol alleviate molecular and metabolic toxicity induced by Bisphenol A in endometrial organoids

Bisphenol A (BPA), a widespread environmental contaminant, poses concerns due to its disruptive effects on physiological functions of the uterine endometrium. In contrast, melatonin (MT) and Resveratrol (RSV) are under scrutiny for their potential protective roles against BPA-induced damage. For the efficacy and ethical concerns in the animal test, endometrial organoids, three-dimensional models mimicking endometrium, serve as crucial tools for unraveling the impact of environmental factors on reproductive health. This study aimed to comprehensively characterize the morphological, molecular and metabolic responses of porcine endometrial organoids to BPA and assess the potential protective effects of MT and RSV. Porcine uteri were prepared, digested with collagenase, mixed with Matrigel, and incubated at 38°C with 5 % CO2. Passaging involved dissociation through trypsin-EDTA treatment and subculturing. The culture medium was refreshed every 2-3 days. To investigate the environmental impact on reproductive health, endometrial organoids were treated with BPA (0.5 µM), MT (with/without BPA at 0.1 µM), and/or RSV (10 µM). Various molecular screening using gene expression, western blotting, immunofluorescence staining, and metabolites profiling were assessed the effects of BPA, MT, and RSV in terms of cell viability, morphology, reproductivity, and metabolism alteration in the endometrial organoids. As expected, BPA induced structural and molecular disruptions in organoids, affecting cytoskeletal proteins, Wnt/β-catenin signaling, and epithelial/mesenchymal markers. It triggered oxidative stress and apoptotic pathways, altered miRNA expression, and disrupted the endocannabinoid system. The level of glucose, galactose, and essential amino acids were increased or decreased by approximately 1.5-3 times in BPA-treated groups compared to the control groups (p-value < 0.05), indicating metabolic changes. Moreover, MT and RSV treated groups exhibited protective effects, mitigating BPA-induced disruptions across multiple pathways. For the first time, our study models endometrial organoids, advancing understanding of environmental impacts on reproductive health.

SMAD1 Regulates the Hippocampal Neuronal Death and Ferroptosis via Affecting the Transcription of PDCD4 in Cerebral Ischemia

Results of previous studies suggested that programmed cell death 4 (PDCD4) was overexpressed in cerebral ischemia (CI), and mothers against decapentaplegic homolog 1 (SMAD1) is a transcription factor of PDCD4, and it is also elevated in CI; however, the regulatory mechanism of SMAD1/PDCD4 axis in CI remains unclear. The current work has been designed to explore the role and associated mechanisms of SMAD1/PDCD4 in CI. PDCD4 and SMAD1 expressions have been examined by real-time reverse transcription-polymerase chain reaction (RT-qPCR) method, and receiver operating characteristic (ROC) curve analysis has been performed to determine the potential diagnostic value of PDCD4 and SMAD1. An oxygen-glucose deprivation (OGD) model has been used to investigate the effects of PDCD4 and SMAD1 on CI in vitro. Cell apoptosis was evaluated using TdT-mediated dUTP nick end labeling (TUNEL) assays. The interaction between SMAD1 and PDCD4 axis has been confirmed by using dual-luciferase reporter as well as chromatin immunoprecipitation (Ch-IP) assays. Finally, the effects of SMAD1/PDCD4 axis on the ferroptosis of neuron cells have been examined. PDCD4 was overexpressed in blood samples of CI patients. ROC analysis showed the AUC for PDCD4 was 0.7478, and NIHSS and MRS scores were positively correlated with PDCD4 expression. Moreover, the cellular OGD model was established and knockdown of PDCD4 suppressed the apoptosis of neurons. Besides, knockdown of PDCD4 also inhibited ferroptosis of OGD-treated neuron cells in vitro. Additionally, SMAD1 was upregulated in blood samples of CI patients, NIHSS and MRS scores were positively correlated with SMAD1 expression, and SMAD1 is a transcriptional factor of PDCD4, and SMAD1 could transcriptionally regulate the expression of PDCD4. Finally, SMAD1 could regulate the ferroptosis of neuron cells through regulating the transcription of PDCD4. The SMAD1/PDCD4 axis regulates the growth, apoptosis, and ferroptosis of neuron cells, suggesting that targeting the SMAD1/PDCD4 axis may be a potential therapeutic method.

Melatonin at repeated doses alleviates hyperglycemia-exacerbated cerebral ischemia-reperfusion injury at 72 h via anti-inflammation and anti-apoptosis

Objective

We aimed to investigate how hyperglycemia would exacerbate cerebral ischemia-reperfusion injury (CIRI) in a rat model of type 1 diabetes mellitus (T1DM) and explore the beneficial effects of multiple doses of melatonin in T1DM induced CIRI.

Method

The T1DM rat model was induced with streptozocin, and melatonin (10 mg/kg) was injected at 0.5 h before ischemia as well as at 24 and 48 h after reperfusion.

Results

When compared to normoglycemic (NG) rats, T1DM rats had hyperglycemia with weight loss before CIRI. Despite comparable degrees of ischemia and initial reperfusion, T1DM rats tended to have greater weight loss and had worse neurological deficits and larger infarct volume than NG rats up to 72 h after CIRI. Persistent activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway but not of apoptosis or calpains was a crucial factor in T1DM-mediated exacerbation of CIRI at 72 h. Despite lacking effects on baseline hyperglycemia, ischemia and initial reperfusion, melatonin at multiple doses lessened post-CIRI weight loss, neurological deficits and infarct volume in T1DM rats at 72 h. when compared to vehicle-treated T1DM rats with CIRI. Beneficial effects of melatonin treatment included decreased activation of NF-κB pathway, apoptosis and calpains, leading to reduced expression of inducible nitric oxide synthase and enhanced neuronal density.

Conclusion

Melatonin at multiple doses can alleviate T1DM-mediated exacerbation of CIRI at 72 h through anti-inflammation and anti-apoptosis.

Systematic review of melatonin in cerebral ischemia-reperfusion injury: critical role and therapeutic opportunities

Cerebral ischemia-reperfusion (I/R) injury is the predominant causes for the poor prognosis of ischemic stroke patients after reperfusion therapy. Currently, potent therapeutic interventions for cerebral I/R injury are still very limited. Melatonin, an endogenous hormone, was found to be valid in preventing I/R injury in a variety of organs. However, a systematic review covering all neuroprotective effects of melatonin in cerebral I/R injury has not been reported yet. Thus, we perform a comprehensive overview of the influence of melatonin on cerebral I/R injury by collecting all available literature exploring the latent effect of melatonin on cerebral I/R injury as well as ischemic stroke. In this systematic review, we outline the extensive scientific studies and summarize the beneficial functions of melatonin, including reducing infarct volume, decreasing brain edema, improving neurological functions and attenuating blood-brain barrier breakdown, as well as its key protective mechanisms on almost every aspect of cerebral I/R injury, including inhibiting oxidative stress, neuroinflammation, apoptosis, excessive autophagy, glutamate excitotoxicity and mitochondrial dysfunction. Subsequently, we also review the predictive and therapeutic implications of melatonin on ischemic stroke reported in clinical studies. We hope that our systematic review can provide the most comprehensive introduction of current advancements on melatonin in cerebral I/R injury and new insights into personalized diagnosis and treatment of ischemic stroke.

Melatonin alleviates renal injury in diabetic rats by regulating autophagy

Melatonin (MLT) is a biologically active indoleamine involved in regulating various biological rhythms, which is deficient in individuals with Type 2 diabetes. The present study examined the effects of MLT on diabetic neuropathy (DN). Diabetic rats received MLT treatment for 12 weeks, after which changes in kidney histology, oxidative damage, mitochondrial morphology and autophagy were measured. The glucose tolerance‑ and isoflurane tolerance‑area under the curve (AUC) values and the relative renal weight index (RI) in the diabetes mellitus (DM) group of rats were significantly higher compared with those in the control group. A significant increase in malondialdehyde (MDA) content, and decreases in the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH‑Px) and GSH were demonstrated in the kidneys of DM rats compared with those in the control rats. Histological staining of DM rat kidney tissue with hematoxylin and eosin, Masson's trichome and Periodic acid‑Schiff demonstrated glomerular and tubule lesions, and an increase in collagen compared with control rats. Protein expression levels of LC3II, P62, collagen IV (COL‑IV) and α‑SMA were increased in DM rats and HG‑induced NRK‑52E cells compared with those in the control groups. Phosphorylation of AMPK was reduced, whereas phosphorylation of PI3K, Akt and mTOR were increased in vivo and in vitro. Notably, MLT treatment significantly reduced glucose tolerance‑AUC and RI, decreased MDA content, and increased SOD, CAT, GSH‑Px and GSH activity. Glomerular and tubule lesions improved, collagen was decreased and mitochondrial damage was alleviated by MLT treatment. MLT treatment also decreased the protein expression levels of LC3II, P62 and COL‑IV, whereas the phosphorylation of AMPK was significantly increased, which inhibited the phosphorylation of PI3K, AKT and mTOR in vivo and in vitro. These results demonstrated that MLT protects against DN and NRK‑52E cell injury through inhibiting oxidative damage and regulating autophagy via the PI3K/AKT/mTOR signaling pathway.