Transcutaneous Electrical Nerve Stimulation (TENS) Alleviates Brain Ischemic Injury by Regulating Neuronal Oxidative Stress, Pyroptosis, and Mitophagy

Shen-fu Injection Modulates HIF- 1α/BNIP3-Mediated Mitophagy to Alleviate Myocardial Ischemia-Reperfusion Injury

Coronary reperfusion therapy is the most common surgical treatment for myocardial infarction, but it can further induce myocardial ischemia-reperfusion injury (MIRI). Therefore, MIRI following coronary intervention is a challenging clinical issue. This study aims to investigate the involvement of HIF- 1α/BNIP3-mediated mitophagy in the protective effects of Shen-fu Injection (SFI) on MIRI in rats. Key targets and signaling pathways of myocardial MIRI were analyzed using high-throughput transcriptome data from the GSE240842 dataset in the GEO database.To establish the MIRI rat model, the left anterior descending coronary artery was ligated for 30 min, followed by reperfusion for 120 min. Hypoxia/reoxygenation (H/R) in neonatal rat primary cardiomyocytes was induced by oxygen-glucose deprivation for 4 h, followed by reoxygenation for 2 h. Two hours after reperfusion, assessments included myocardial infarction area, CK-MB, CTnI, HE staining, TUNEL, mitochondrial ultrastructure and autophagosomes, HIF- 1α, BNIP3, LC3B-II, LC3B-I protein expression, immunofluorescence, and qRT-PCR. Cardiac function was also evaluated using M-mode ultrasound 2 h after reperfusion. In cardiomyocytes, CCK- 8, EdU cell proliferation levels, scratch assay, mitochondrial membrane potential, ROS levels, cardiomyocyte apoptosis, protein expression levels, and immunofluorescence were assessed 2 h after reoxygenation. Our results indicate that HIF- 1α and BNIP3 are key targets in MIRI. SFI upregulates HIF- 1α expression, promoting moderate mitophagy. This process clears excessively damaged mitochondria, reduces cardiomyocyte apoptosis, and decreases myocardial injury. Additionally, SFI reduces autophagosome accumulation, lowers ROS production, and stabilizes membrane potential. Consequently, the area of myocardial infarction is reduced, and cardiac function is improved. SFI activates the HIF- 1α/BNIP3 pathway to mediate moderate mitophagy, effectively reducing cardiomyocyte apoptosis and alleviating myocardial ischemia-reperfusion injury, thereby protecting cardiomyocytes.

The association between basal metabolic rate and ischemic stroke: a Mendelian randomization study

Objective

This study aims to elucidate the potential impact of basal metabolic rate on ischemic stroke at the genetic prediction level through a two-sample Mendelian randomization analysis.

Methods

Using summary data from genome-wide association studies, we obtained information on basal metabolic rate and ischemic stroke from a large-scale genome-wide association study. MR analysis used inverse variance weighting, weighted median, MR-Egger, simple mode, and weighted estimation. Sensitivity analyses, including the MR-Egger method, MR-PRESSO, Cochran's Q-test, and leave-one-out assessment, were performed to assess the reliability of the results.

Results

Genetic susceptibility to basal metabolic rate was significantly associated with ischemic stroke in multiple models, including the inverse variance weighting model (OR, 1.108 [95% CI: 1.005-1.221]; p = 0.0392), the weighted median method (OR, 1.179 [95% CI: 1.020-1.363]; p = 0.0263), and MR-Egger (OR, 1.291 [95% CI: 1.002-1.663]; p = 0.0491). These results indicate a positive causal relationship between basal metabolic rate and ischemic stroke. The MR-Egger intercept and Cochran's Q-test indicated the absence of heterogeneity and horizontal pleiotropy in the analyses of basal metabolic rate and ischemic stroke.

Conclusion

The MR analysis suggests a positive correlation between basal metabolic rate and ischemic stroke.

The role of HIF-1α/BNIP3/mitophagy in acrylonitrile-induced neuronal death in HT22 cells and mice: A potential neuroprotection target

Acrylonitrile (AN) is a widely utilized organic compound in the production of diverse industrial synthetic materials. While acute exposure to AN can cause neurotoxicity, the precise mechanism remains unclear. Hypoxia-inducible factor 1 alpha (HIF-1α) is a pivotal transcription factor that coordinates and orchestrates multiple physiological processes to adapt to hypoxic conditions, ensuring cellular survival and homeostasis. In this study, we used in vitro (cultured mouse hippocampal neuronal cell line, HT22) and in vivo (AN exposed mice) approaches to investigate the potential modulator effects of HIF-1α in AN-induced neurotoxicity. In vitro, AN exposure caused concentration-dependent toxicity in HT22 cells, which was paralleled by increased Bax levels while decreasing Bcl-2. Exposure to AN resulted in reduced protein levels of HIF-1α, Bcl-2 19-kDa interacting protein 3 (BNIP3), microtubule-associated protein 1 light chain 3 beta (LC3B) and Beclin1, while increased the protein levels of the translocase of outer mitochondrial membrane 20 (TOM20). Furthermore, mitochondrial morphology and function were compromised, suggesting that AN impaired HIF-1α/BNIP3-mediated mitochondrial autophagy and promoted apoptosis. Treatment with a HIF-1α activator, cobalt chloride (CoCl2), reversed these effects, while pretreatment with a HIF-1α inhibitor, 2-methoxyestradiol (2-MeOE2), augmented them. In BNIP3 overexpressing HT22 cells, enhanced cell viability and reduced apoptosis rates were observed. Furthermore, the HIF-1α/BNIP3 pathway was activated by the prolyl hydroxylase (PHD2) inhibitor, deferoxamine (DFO), which increased HT22 cell viability. Similarly, the activation of HIF-1α by administering 20 mg/kg of CoCl2 was found to alleviate neurotoxicity in mice. This treatment enhanced elevations of autophagy protein expression and co-localization of BNIP3 and LC3B. In summary, under normoxia, AN induced neurotoxicity by promoting PHD2-mediated HIF-1α degradation, disrupted the BNIP3-mediated mitophagy pathway, and enhanced apoptosis. Our findings underscore the effect of the HIF-1α/BNIP3-mediated mitochondrial autophagy in AN-induced neurotoxicity and suggest potential therapeutic strategies involving HIF-1α activation or BNIP3 overexpression for AN poisoning treatment.

The therapeutic effects of salvianolic acids on ischemic stroke: From molecular mechanisms to clinical applications

Ischemic stroke (IS), primarily caused by cerebrovascular occlusion, poses a significant public health challenge with limited effective therapeutic options. Evidence suggests that salvianolic acids (SAs), mainly from Salvia miltiorrhiza Bunge, have been formulated into injections and are widely used in clinical treatments for cardiovascular and cerebrovascular diseases, including stroke. The pharmacological properties of SAs include reducing neuroinflammation, alleviating oxidative stress injury, inhibiting cellular apoptosis, preserving endothelial function, maintaining blood-brain barrier integrity, and promoting angiogenesis. Salvianolic acids for injection (SAFI) serve as a safe and effective treatment option for cardiovascular and cerebrovascular conditions by influencing various signaling pathways and molecular targets associated with these diseases. In this review, we first discuss the pathogenesis of IS, then summarize the classification of SAs, elaborate detailed molecular mechanisms of their efficacy, and the related clinical applications of SAFI. We also emphasize the recent pharmacological advancements and therapeutic possibilities of this promising drug preparation derived from herbs for cerebrovascular conditions.

Endothelin-1-Induced Persistent Ischemia in a Chicken Embryo Model

Current ischemic models strive to replicate ischemia-mediated injury. However, they face challenges such as inadequate reproducibility, difficulties in translating rodent findings to humans, and ethical, financial, and practical constraints that limit the accuracy of extensive research. This study introduces a novel approach to inducing persistent ischemia in 3-day-old chicken embryos using endothelin-1. The protocol targets the right vitelline arteries, validated with Doppler blood flow imaging and molecular biology experiments. This innovative approach facilitates the exploration of oxidative stress, inflammatory responses, cellular death, and potential drug screening suitability utilizing a 3-day-old chicken embryo. Key features • This model enables the evaluation and investigation of the pathology related to persistent ischemia • This model allows for the assessment of parameters like oxidative stress, inflammation, and cellular death • This model enables quantification of molecular changes at the nucleic acid and protein levels • This model allows for the efficient screening of drugs and their targets Graphical overview.

Exploring Research Trend and Hotspots on Oxidative Stress in Ischemic Stroke (2001-2022): Insights from Bibliometric

Oxidative stress is widely involved in the pathological process of ischemic stroke and ischemia-reperfusion. Several research have demonstrated that eliminating or reducing oxidative stress can alleviate the pathological changes of ischemic stroke. However, current clinical antioxidant treatment did not always perform as expected. This bibliometric research aims to identify research trends, topics, hotspots, and evolution on oxidative stress in the field of ischemic stroke, and to find potentially antioxidant strategies in future clinical treatment. Relevant publications were searched from the Web of Science (WOS) Core Collection databases (2001-2022). VOSviewer was used to visualize and analyze the development trends and hotspots. In the field of oxidative stress and ischemic stroke, the number of publications increased significantly from 2001 to 2022. China and the USA were the leading countries for publication output. The most prolific institutions were Stanford University. Journal of Cerebral Blood Flow and Metabolism and Stroke were the most cited journals. The research topics in this field include inflammation with oxidative stress, mitochondrial damage with oxidative stress, oxidative stress in reperfusion injury, oxidative stress in cognitive impairment and basic research and clinical translation of oxidative stress. Moreover, "NLRP3 inflammasome," "autophagy," "mitophagy," "miRNA," "ferroptosis," and "signaling pathway" are the emerging research hotspots in recent years. At present, multi-target regulation focusing on multi-mechanism crosstalk has progressed across this period, while challenges come from the transformation of basic research to clinical application. New detection technology and new nanomaterials are expected to integrate oxidative stress into the clinical treatment of ischemic stroke better.

Transcutaneous Electrical Nerve Stimulation Integrated into Pants for the Relief of Postoperative Pain in Hip Surgery Patients: A Randomized Trial

Background

The effect of transcutaneous electrical nerve stimulation (TENS) on pain and impression of change was assessed during a 2.5-hour intervention on the first postoperative days following hip surgery in a randomized, single-blinded, placebo-controlled trial involving 30 patients.

Methods

Mixed-frequency TENS (2 Hz/80 Hz) was administered using specially designed pants integrating modular textile electrodes to facilitate stimulation both at rest and during activity. The treatment outcome was assessed by self-reported pain Numerical Rating Scale (NRS) and Patient Global Impression of Change (PGIC) scores at four time points. The ability to perform a 3-meter walk test and the use of analgesics were also evaluated. Group comparison and repeated-measure analysis were carried out using nonparametric statistics.

Results

The active TENS group exhibited significantly higher PGIC scores after 30 minutes, which persisted throughout the intervention (all p ≤ 0.001). A reduction in NRS appeared after one hour of active TENS, persisting throughout the intervention (all p ≤ 0.05). The median group differences in pain ratings were greater than the minimum clinically important difference, and the analysis of pain trajectories confirmed clinical significance at the individual level. Moreover, patients in the active TENS group were more likely able to perform a 3-meter walk test by the end of the intervention (p = 0.04). Analysis of the opioid-sparing effect of TENS was inconclusive (p = 0.066). No postoperative surgical complications or TENS-related side effects were observed during the study.

Conclusion

Mixed-frequency TENS integrated in pants could potentially be an interesting addition to the arsenal of treatments for multimodal analgesia following hip surgery. This trial is registered with NCT05678101.

Effects of Thermal Stimulation and Transcutaneous Electrical Nerve Stimulation on Sensory and Motor Function of Upper Extremity in Acute Stroke Survivors: A Randomized Controlled Pilot Study

Objective Upper-limb coordination is crucial for daily activities, especially among stroke survivors who may encounter obstacles during upper-limb rehabilitation. This study aimed to investigate the effects of thermal stimulation (TS) and transcutaneous electrical nerve stimulation (TENS) on sensory and motor function during recovery in acute stroke patients. Design This is a parallel study with a randomized controlled design. The experiment was conducted in the E-Da Hospital Rehabilitation Department, Kaohsiung, Taiwan. Intervention Thirty participants were in-patients with acute stroke at the E-Da Hospital. Participants were randomly assigned to three groups for a one-week intervention: exercise combined with TS, exercise combined with TENS, or conventional physical therapy with exercise alone. The Fugl-Meyer upper extremity scale, Brunnstrom stage, minimal current perception (MCP), and modified Ashworth scale were collected for the assessment. Results The outcomes demonstrated considerable improvement in MCP in all the groups after treatment. Specifically, the groups receiving TS and TENS showed significant improvements in the Brunnstrom stage, suggesting that both treatments improved distal motor recovery. Conclusion The results, following a one-week intervention period, suggested that both TS and TENS contributed to the improvement of motor and sensory function, with a significant impact on the Brunnstrom stage in the upper extremity, particularly in the distal region. The inclusion of TS or TENS in rehabilitation protocols improved distal motor function compared to baseline measures, suggesting these treatments as effective components in acute stroke rehabilitation.

Bioinformatics integration reveals key genes associated with mitophagy in myocardial ischemia-reperfusion injury

BACKGROUND

Myocardial ischemia is a prevalent cardiovascular disorder associated with significant morbidity and mortality. While prompt restoration of blood flow is essential for improving patient outcomes, the subsequent reperfusion process can result in myocardial ischemia-reperfusion injury (MIRI). Mitophagy, a specialized autophagic mechanism, has consistently been implicated in various cardiovascular disorders. However, the specific connection between ischemia-reperfusion and mitophagy remains elusive. This study aims to elucidate and validate central mitophagy-related genes associated with MIRI through comprehensive bioinformatics analysis.

METHODS

We acquired the microarray expression profile dataset (GSE108940) from the Gene Expression Omnibus (GEO) and identified differentially expressed genes (DEGs) using GEO2R. Subsequently, these DEGs were cross-referenced with the mitophagy database, and differential nucleotide sequence analysis was performed through enrichment analysis. Protein-protein interaction (PPI) network analysis was employed to identify hub genes, followed by clustering of these hub genes using cytoHubba and MCODE within Cytoscape software. Gene set enrichment analysis (GSEA) was conducted on central genes. Additionally, Western blotting, immunofluorescence, and quantitative polymerase chain reaction (qPCR) analyses were conducted to validate the expression patterns of pivotal genes in MIRI rat model and H9C2 cardiomyocytes.

RESULTS

A total of 2719 DEGs and 61 mitophagy-DEGs were identified, followed by enrichment analyses and the construction of a PPI network. HSP90AA1, RPS27A, EEF2, EIF4A1, EIF2S1, HIF-1α, and BNIP3 emerged as the seven hub genes identified by cytoHubba and MCODE of Cytoscape software. Functional clustering analysis of HIF-1α and BNIP3 yielded a score of 9.647, as determined by Cytoscape (MCODE). In our MIRI rat model, Western blot and immunofluorescence analyses confirmed a significant elevation in the expression of HIF-1α and BNIP3, accompanied by a notable increase in the ratio of LC3II to LC3I. Subsequently, qPCR confirmed a significant upregulation of HIF-1α, BNIP3, and LC3 mRNA in the MIRI group. Activation of the HIF-1α/BNIP3 pathway mediates the regulation of the degree of Mitophagy, thereby effectively reducing apoptosis in rat H9C2 cardiomyocytes.

CONCLUSIONS

This study has identified seven central genes among mitophagy-related DEGs that may play a pivotal role in MIRI, suggesting a correlation between the HIF-1α/BNIP3 pathway of mitophagy and the pathogenesis of MIRI. The findings highlight the potential importance of mitophagy in MIRI and provide valuable insights into underlying mechanisms and potential therapeutic targets for further exploration in future studies.

Transcutaneous electrical acupoint stimulation attenuated neuroinflammation and oxidative stress by activating SIRT1-induced signaling pathway in MCAO/R rat models

BACKGROUND

Silent information regulator 1 (SIRT1) plays a beneficial role in cerebral ischemic injury. Previous reports have demonstrated that transcutaneous electrical acupoint stimulation (TEAS) exerts a beneficial effect on ischemic stroke; however, whether SIRT1 participates in the underlying mechanism for the neuroprotective effects of TEAS against ischemic brain damage has not been confirmed.

METHODS

The rat models of middle cerebral artery occlusion/reperfusion (MCAO/R) were utilized in the current experiment. After MCAO/R surgery, rats in TEAS, EC and EX group received TEAS intervention with or without the injection of EX527, the SIRT1 inhibitor. Neurological deficit scores, infarct volume, hematoxylin eosin (HE) staining and apoptotic cell number were measured. The results of RNA sequencing were analyzed to determine the differential expression changes of genes among sham, MCAO and TEAS groups, in order to investigate the possible pathological processes involved in cerebral ischemia and explore the protective mechanisms of TEAS. Moreover, oxidative stress markers including MDA, SOD, GSH and GSH-Px were measured with assay kits. The levels of the proinflammatory cytokines, such as IL-6, IL-1β and TNF-α, were detected by ELISA assay, and Iba-1 (the microglia marker protein) positive cells was measured by immunofluorescence (IF). Western blot and IF were utilized to examine the levels of key molecules in SIRT1/FOXO3a and SIRT1/BRCC3/NLRP3 signaling pathways.

RESULTS

TEAS significantly decreased brain infarcted size and apoptotic neuronal number, and alleviated neurological deficit scores and morphological injury by activating SIRT1. The results of RNA-seq and bioinformatic analysis revealed that oxidative stress and inflammation were the key pathological mechanisms, and TEAS alleviated oxidative injury and inflammatory reactions following ischemic stroke. Then, further investigation indicated that TEAS notably attenuated neuronal apoptosis, neuroinflammation and oxidative stress damage in the hippocampus of rats with MCAO/R surgery. Moreover, TEAS intervention in the MCAO/R model significantly elevated the expressions of SIRT1, FOXO3a, CAT, BRCC3, NLRP3 in the hippocampus. Furthermore, EX527, as the inhibitor of SIRT1, obviously abolished the anti-oxidative stress and anti-neuroinflammatory roles of TEAS, as well as reversed the TEAS-mediated elevation of SIRT1, FOXO3a, CAT and reduction of BRCC3 and NLRP3 mediated by following MCAO/R surgery.

CONCLUSIONS

In summary, these findings clearly suggested that TEAS attenuated brain damage by suppressing apoptosis, oxidative stress and neuroinflammation through modulating SIRT1/FOXO3a and SIRT1/BRCC3/NLRP3 signaling pathways following ischemic stroke, which can be a promising treatment for stroke patients.

VEGF overexpression in transplanted NSCs promote recovery of neurological function in rats with cerebral ischemia by modulating the Wnt signal transduction pathway

Neural stem cell transplantation is a good method to treat stroke, but the mechanism is still unclear. Therefore, this study aims to explore the regulatory mechanism of VEGF overexpression in transplanted NSCs to promote the recovery of neural function in ischemic rats by regulating Wnt signal transduction pathways. We amplified VEGF gene fragments by PCR and transfected them into NSCs with Ad5 adenovirus. Rat brain IRI model was established by MCAO method, and VEGF transfected NSCs (VEGF-NSCs) were transplanted 24 h after successful IRI model. One week after the transplant, cognitive function was assessed using a neurological deficit score; Brain injury was assessed by histopathology; Photochemical and ELISA methods were used to detect oxidative stress markers and inflammatory factors, respectively. Western blotting has been detected in molecules of the Wnt signaling pathway. The results showed that the transduced NSCs express VEGF at least for 14 days. VEGF-NSCs transplantation (VNT) improved spatial learning and memory in rats, and inhibited oxidative stress injury, inflammatory response, and histopathological injury. VNT also resulted in significant changes in the phosphorylation levels of β-catenin and GSK-3β proteins, ultimately triggering activation of the Wnt signal transduction pathway. These results suggest that the neuroprotective effects of VNT may be related to the regulation of the Wnt signal transduction pathway.