Research progress on the role of hormones in ischemic stroke

The influence of the prolactin/vasoinhibin axis on post-stroke lesion volume, astrogliosis, and survival

Ischemic stroke is a significant global health issue, ranking fifth among all causes of death and a leading cause of serious long-term disability. Ischemic stroke leads to severe outcomes, including permanent brain damage and neuronal dysfunction. Therefore, decreasing and preventing neuronal injuries caused by stroke has been the focus of therapeutic research. In recent years, many studies have shown that fluctuations in hormonal levels influence the prognosis of ischemic stroke. Thus, it is relevant to understand the role of hormones in the pathophysiological mechanisms of ischemic stroke for preventing and treating this health issue. Here, we investigate the contribution of the prolactin/vasoinhibin axis, an endocrine system regulating blood vessel growth, immune processes, and neuronal survival, to the pathophysiology of ischemic stroke. Male mice with brain overexpression of prolactin or vasoinhibin by adeno-associated virus (AAV) intracerebroventricular injection or lacking the prolactin receptor (Prlr-/-) were exposed to transient middle cerebral artery occlusion (tMCAO) for 45 min followed by 48 h of reperfusion. Overexpression of vasoinhibin or the absence of the prolactin receptor led to an increased lesion volume and decreased survival rates in mice following tMCAO, whereas overexpression of prolactin had no effect. In addition, astrocytic distribution in the penumbra was altered, glial fibrillary acidic protein and S100b mRNA expressions were reduced, and interleukin-6 mRNA expression increased in the ischemic hemisphere of mice overexpressing vasoinhibin. Of note, prolactin receptor-null mice (Prlr-/-) showed a marked increase in serum vasoinhibin levels. Furthermore, vasoinhibin decreased astrocyte numbers in mixed hippocampal neuron-glia cultures. These observations suggest that increased vasoinhibin levels may hinder astrocytes' protective reactivity. Overall, this study suggests the involvement of the prolactin/vasoinhibin axis in the pathophysiology of ischemic stroke-induced brain injury and provides insights into the impact of its dysregulation on astrocyte reactivity and lesion size. Understanding these mechanisms could help develop therapeutic interventions in ischemic stroke and other related neurological disorders.

The role of hormones in ILC2-driven allergic airway inflammation

Group 2 innate lymphoid cells (ILC2s) are a type of innate immune cells that produce a large amount of IL-5 and IL-13 and two cytokines that are crucial for various processes such as allergic airway inflammation, tissue repair and tissue homeostasis. It is known that damaged epithelial-derived alarmins, such as IL-33, IL-25 and thymic stromal lymphopoietin (TSLP), are the predominant ILC2 activators that mediate the production of type 2 cytokines. In recent years, abundant studies have found that many factors can regulate ILC2 development and function. Hormones synthesized by the body's endocrine glands or cells play an important role in immune response. Notably, ILC2s express hormone receptors and their proliferation and function can be modulated by multiple hormones during allergic airway inflammation. Here, we summarize the effects of multiple hormones on ILC2-driven allergic airway inflammation and discuss the underlying mechanisms and potential therapeutic significance.

Exploring the causal factor effects of hypothyroidism on ischemic stroke: a two-sample Mendelian randomization study

Background

Observational studies have suggested a possible association between hypothyroidism and increased risk of ischemic stroke. However, a causal relationship remains unclear.

Methods

Data on single nucleotide polymorphisms (SNPs) associated with hypothyroidism and ischemic stroke were sourced from the FinnGens database and the UK Biobank of European descent. Both databases underwent separate two-sample Mendelian randomization (MR) analyses. A subsequent meta-analysis of MR results using a random-effects model was conducted to determine the causal relationship between hypothyroidism and ischemic stroke.

Results

All five analyses indicated a positive causal relationship between hypothyroidism and ischemic stroke. MR analysis of the association between hypothyroidism and ischemic stroke yielded a result of the inverse variance weighted (IVW) method at 4.7411 (1.3598-16.5308), p = 0.0146. The analysis of ischemic stroke (without excluding controls) yielded a result of the IVW method of 4.5713 (1.3570-15.3986), p = 0.0142. MR analysis with cerebral infarction yielded a result of the IVW method at 1.0110 (1.0006-1.0215), p = 0.0373. The MR analysis with cerebrovascular disease sequelae yielded an IVW method result of 2.4556 (1.0291-5.8595), p = 0.0429. Analysis for the sequelae of cerebrovascular disease (without excluding controls) yielded an IVW method result of 2.4217 (1.0217-5.7402), p = 0.0446. No evidence of heterogeneity or horizontal pleiotropy was found. The meta-analysis of the five MR results was 2.24 (1.18-4.26), p = 0.025.

Conclusion

Our two-sample Mendelian randomization study suggested a causal relationship between hypothyroidism and ischemic stroke, indicating that hypothyroidism could be a risk factor for ischemic stroke. However, further studies are required to elucidate the underlying biological mechanisms.

The future of artificial hibernation medicine: protection of nerves and organs after spinal cord injury

Spinal cord injury is a serious disease of the central nervous system involving irreversible nerve injury and various organ system injuries. At present, no effective clinical treatment exists. As one of the artificial hibernation techniques, mild hypothermia has preliminarily confirmed its clinical effect on spinal cord injury. However, its technical defects and barriers, along with serious clinical side effects, restrict its clinical application for spinal cord injury. Artificial hibernation is a future-oriented disruptive technology for human life support. It involves endogenous hibernation inducers and hibernation-related central neuromodulation that activate particular neurons, reduce the central constant temperature setting point, disrupt the normal constant body temperature, make the body "adapt" to the external cold environment, and reduce the physiological resistance to cold stimulation. Thus, studying the artificial hibernation mechanism may help develop new treatment strategies more suitable for clinical use than the cooling method of mild hypothermia technology. This review introduces artificial hibernation technologies, including mild hypothermia technology, hibernation inducers, and hibernation-related central neuromodulation technology. It summarizes the relevant research on hypothermia and hibernation for organ and nerve protection. These studies show that artificial hibernation technologies have therapeutic significance on nerve injury after spinal cord injury through inflammatory inhibition, immunosuppression, oxidative defense, and possible central protection. It also promotes the repair and protection of respiratory and digestive, cardiovascular, locomotor, urinary, and endocrine systems. This review provides new insights for the clinical treatment of nerve and multiple organ protection after spinal cord injury thanks to artificial hibernation. At present, artificial hibernation technology is not mature, and research faces various challenges. Nevertheless, the effort is worthwhile for the future development of medicine.

Exploring the in vitro anti-inflammatory activity of gross saponins of Tribulus terrestris L. fruit by using liquid chromatography-mass spectrometry-based cell metabolomics approach

Our previous studies confirmed the efficacy of gross saponins of Tribulus terrestris L. fruit in treating cerebral ischemia. This study aimed to investigate the related mechanisms in vitro. The lipopolysaccharide-induced BV2 cells model was constructed and treated with gross saponins at different concentrations to explore its anti-inflammatory activity. The cell metabolite changes were tracked by liquid chromatography-mass spectrometry (LC-MS)-based metabolomics, and the metabolic biomarkers and related metabolic pathways were analyzed. Molecular biochemistry analysis was further used to verify the relevant inflammatory pathways. The results showed that the saponins reduced nitric oxide release and the secretion of tumor necrosis factor-alpha, interleukin-1β, and interleukin-6 from lipopolysaccharide-induced BV2 cells. Metabolic perturbations occurred in lipopolysaccharide-treated BV2 cells, which could be reversed by drug treatment via mainly regulating glycerophospholipid metabolism, tryptophan metabolism, purine metabolism pathways, etc. The western blot analysis demonstrated that saponin could suppress the activation of the inflammatory-related signaling pathway. The present study explored the in vitro anti-inflammatory mechanism of gross saponins of Tribulus terrestris L. fruit using an LC-MS-based cell metabolomics approach, which confirms the great potential of LC-MS for drug efficacy evaluation and can be applied in other herbal medicine-related analyses.

Multi-target mechanism of Naoshuantong capsule for treatment of Ischemic stroke based on network pharmacology and molecular docking

BACKGROUND

Naoshuantong capsule (NST capsule) is a classic Chinese patent medicine, which can treat ischemic stroke (IS) and has good clinical efficacy. However, its pharmacological mechanism remains to be further explored in the treatment of IS.

METHODS

The bio-active components and potential targets of NST Capsules were obtained by ETCM and TCMSP databases. In addition, the related targets of IS were collected by Genecard, OMIM, DrugBank, TTD and DisGeNET databases. NST-IS common target was obtained by Venn platform. PPI network of NST-IS common target and the composition - target network diagram of NST Capsule were constructed by Cytoscape3.8.1. Finally, AutoDock was used for molecular docking.

RESULTS

265 targets were predicted from 32 active compounds in NST Capsule, 109 common targets were identified between NST Capsule and IS. The top 10 key targets of PPI network were ALB, TNF, TP53, VEGFA, CASP3, MYC, etc. Enrichment analysis showed that NST capsules treated IS mainly through lipid and atherosclerosis, fluid shear stress and atherosclerosis signaling pathways.

CONCLUSION

Through the methods of network pharmacology and molecular docking, this study clarified that NST capsules play a role in the treatment of IS, which is multi-target, multi-channel and multi-component regulation. This study further explored the pharmacological mechanism of NST capsule in the treatment of IS, which can provide some references for the subsequent research in the pharmacological mechanism of NST capsule.

The role of plasma cortisol in dementia, epilepsy, and multiple sclerosis: A Mendelian randomization study

BACKGROUND

Many clinical studies have shown a correlation between plasma cortisol and neurological disorders. This study explored the causal relationship between plasma cortisol and dementia, epilepsy and multiple sclerosis based on Mendelian randomization (MR) method.

METHODS

Data were taken from the summary statistics of a genome-wide association study, FinnGen consortium and United Kingdom Biobank. Dementia, epilepsy, and multiple sclerosis were used as outcomes, and genetic variants associated with plasma cortisol were used as instrumental variables. The main analysis was performed using the inverse variance weighted method, and the results were assessed according to the odds ratio (OR) and 95% confidence interval. Heterogeneity tests, pleiotropy tests, and leave-one-out method were conducted to evaluate the stability and accuracy of the results.

RESULTS

In two-sample MR analysis, the inverse variance weighted method showed that plasma cortisol was associated with Alzheimer's disease (AD) [odds ratio (95% confidence interval) = 0.99 (0.98-1.00), P = 0.025], vascular dementia (VaD) [odds ratio (95% confidence interval) = 2.02 (1.00-4.05), P = 0.049)], Parkinson's disease with dementia (PDD) [odds ratio (95% confidence interval) = 0.24 (0.07-0.82), P = 0.023] and epilepsy [odds ratio (95% confidence interval) = 2.00 (1.03-3.91), P = 0.042]. There were no statistically significant associations between plasma cortisol and dementia with Lewy bodies (DLB), frontotemporal dementia (FTD) and multiple sclerosis.

CONCLUSION

This study demonstrates that plasma cortisol increase the incidence rates of epilepsy and VaD and decrease the incidence rates of AD and PDD. Monitoring plasma cortisol concentrations in clinical practice can help prevent diseases, such as AD, PDD, VaD and epilepsy.