Therapeutic Potential of a Combination of Electroacupuncture and Human iPSC-Derived Small Extracellular Vesicles for Ischemic Stroke

Astrocyte modulation in cerebral ischemia-reperfusion injury: A promising therapeutic strategy

Cerebral ischemia-reperfusion injury (CIRI) poses significant challenges for drug development due to its complex pathogenesis. Astrocyte involvement in CIRI pathogenesis has led to the development of novel astrocyte-targeting drug strategies. To comprehensively review the current literature, we conducted a thorough analysis from January 2012 to December 2023, identifying 82 drugs aimed at preventing and treating CIRI. These drugs target astrocytes to exert potential benefits in CIRI, and their primary actions include modulation of relevant signaling pathways to inhibit neuroinflammation and oxidative stress, reduce cerebral edema, restore blood-brain barrier integrity, suppress excitotoxicity, and regulate autophagy. Notably, active components from traditional Chinese medicines (TCM) such as Salvia miltiorrhiza, Ginkgo, and Ginseng exhibit these important pharmacological properties and show promise in the treatment of CIRI. This review highlights the potential of astrocyte-targeted drugs to ameliorate CIRI and categorizes them based on their mechanisms of action, underscoring their therapeutic potential in targeting astrocytes.

Cell-Specific Impacts of Surface Coating Composition on Extracellular Vesicle Secretion

Biomaterial properties have recently been shown to modulate extracellular vesicle (EV) secretion and cargo; however, the effects of substrate composition on EV production remain underexplored. This study investigates the impacts of surface coatings composed of collagen I (COLI), fibronectin (FN), and poly l-lysine (PLL) on EV secretion for applications in therapeutic EV production and to further understanding of how changes in the extracellular matrix microenvironment affect EVs. EV secretion from primary bone marrow-derived mesenchymal stromal cells (BMSCs), primary adipose-derived stem cells (ASCs), HEK293 cells, NIH3T3 cells, and RAW264.7 cells was characterized on the different coatings. Expression of EV biogenesis genes and cellular adhesion genes was also analyzed. COLI coatings significantly decreased EV secretion in RAW264.7 cells, with associated decreases in cell viability and changes in EV biogenesis-related and cell adhesion genes at day 4. FN coatings increased EV secretion in NIH3T3 cells, while PLL coatings increased EV secretion in ASCs. Surface coatings had significant effects on the capacity of EVs derived from RAW264.7 and NIH3T3 cells to impact in vitro macrophage proliferation. Overall, surface coatings had different cell-specific effects on EV secretion and in vitro functional capacity, thus highlighting the potential of substrate coatings to further the development of clinical EV production systems.

MiR-24-3p enhances the Treg/Th17 balance to improve cerebral ischemic injury by suppressing acetyl-CoA carboxylase 1 expression

BACKGROUND

Targeting ACC1 (acetyl coenzyme A carboxylase 1) to restore the balance between T-helper 17 (Th17) cells and regulatory T cells (Tregs) through metabolic reprogramming has emerged as a promising strategy for reducing neuroinflammation following stroke. We examined the roles of potential miRNAs in regulating ACC1 expression in Tregs and treating ischemic stroke.

METHODS

The expression of miR-24-3p in CD4+T cells of mice was confirmed. Then the protective effects of Ago-24-3p in a mouse model of prolonged occlusion of the distal middle cerebral artery (dMCAO) were examined. We analyzed the infiltration of Tregs and CD3+T cells into the brain and evaluated the improvement of neurological deficits induced by Ago-24-3p using the Modified Garcia Score and foot fault testing.

RESULTS

Our investigation revealed that miR-24-3p specifically targets ACC1. Elevated levels of miR-24-3p have been demonstrated to increase the population of Tregs and enhance their proliferation and suppressive capabilities. Conversely, targeted reduction of ACC1 in CD4+T cells has been shown to counteract the improved functionality of Tregs induced by miR-24-3p. In a murine model of dMCAO, administration of Ago-24-3p resulted in a substantial reduction in the size of the infarct within the ischemic brain area. This effect was accompanied by an upregulation of Tregs and a downregulation of CD3+T cells in the ischemic brain region. In ACC1 conditional knockout mice, the ability of Ago-24-3p to enhance infiltrating Treg cells and diminish CD3+T cells in the ischemic brain area has been negated. Furthermore, its capacity to reduce infarct volume has been reversed. Furthermore, we demonstrated that Ago-24-3p sustained improvement in post-stroke neurological deficits for up to 4 weeks after the MCAO procedure.

CONCLUSIONS

MiR-24-3p shows promise in the potential to reduce ACC1 expression, enhance the immunosuppressive activity of Tregs, and alleviate injuries caused by ischemic stroke. These discoveries imply that miR-24-3p could be a valuable therapeutic option for treating ischemic stroke.

The immunomodulatory mechanism of acupuncture treatment for ischemic stroke: research progress, prospects, and future direction

Ischemic stroke (IS) is one of the leading causes of death and disability. Complicated mechanisms are involved in the pathogenesis of IS. Immunomodulatory mechanisms are crucial to IS. Acupuncture is a traditional non-drug treatment that has been extensively used to treat IS. The exploration of neuroimmune modulation will broaden the understanding of the mechanisms underlying acupuncture treatment. This review summarizes the immune response of immune cells, immune cytokines, and immune organs after an IS. The immunomodulatory mechanisms of acupuncture treatment on the central nervous system and peripheral immunity, as well as the factors that influence the effects of acupuncture treatment, were summarized. We suggest prospects and future directions for research on immunomodulatory mechanisms of acupuncture treatment for IS based on current progress, and we hope that these will provide inspiration for researchers. Additionally, acupuncture has shown favorable outcomes in the treatment of immune-based nervous system diseases, generating new directions for research on possible targets and treatments for immune-based nervous system diseases.

Induced Pluripotent Stem Cells and Organoids in Advancing Neuropathology Research and Therapies

This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant potential for regenerative therapy and drug discovery. The adaptability of iPSCs, along with associated methodologies, enables the generation of various types of neural cell differentiations and their integration into three-dimensional organoid models, effectively replicating complex tissue structures in vitro. Key advancements in organoid and iPSC generation protocols, alongside the careful selection of donor cell types, are emphasized as critical steps in harnessing these technologies to mitigate tumorigenic risks and other hurdles. Encouragingly, iPSCs show promising outcomes in regenerative therapies, as evidenced by their successful application in animal models.

Acupuncture modulates the gut microbiota in Alzheimer's disease: current evidence, challenges, and future opportunities

Alzheimer's disease, one of the most severe and common neurodegenerative diseases, has no effective cure. Therefore it is crucial to explore novel and effective therapeutic targets. The gut microbiota - brain axis has been found to play a role in Alzheimer's disease by regulating the neuro-immune and endocrine systems. At the same time, acupuncture can modulate the gut microbiota and may impact the course of Alzheimer's disease. In this Review, we discuss recent studies on the role of acupuncture on the gut microbiota as well current challenges and future opportunities of acupuncture as potential treatment for the prevention and treatment of Alzheimer's disease.

Exosome-based regenerative rehabilitation: A novel ice breaker for neurological disorders

Neurological disorders affect a large population, often leading to different levels of disability and resulting in decreased quality of life. Due to the limited recovery obtained from surgical procedures and other medical approaches, a large number of patients with prolonged dysfunction receive neurorehabilitation protocols to improve their neural plasticity and regeneration. However, the poor neural regeneration ability cannot effectively rebuild the tissue integrity and neural functional networks; consequently, the prognoses of neurorehabilitation remain undetermined. To increase the chances of neural regeneration and functional recovery for patients with neurological disorders, regenerative rehabilitation was introduced with combined regenerative medicine and neurorehabilitation protocols to repair neural tissue damage and create an optimized biophysical microenvironment for neural regeneration potential. With the deepening of exosome research, an increasing number of studies have found that the systemic therapeutic effects of neurorehabilitation approaches are mediated by exosomes released by physically stimulated cells, which provides new insight into rehabilitative mechanisms. Meanwhile, exosome therapy also serves as an alternative cell-free therapy of regenerative medicine that is applied in partnership with neurorehabilitation approaches and formulates exosome-based neurological regenerative rehabilitation. In this study, we review the current state of exosome-associated neurorehabilitation. On the one hand, we focus on presenting the varied mediating effects of exosomes in neurorehabilitation protocols of specific neurological pathologies; on the other hand, we discuss the diverse combinations of exosome therapies and neurorehabilitation approaches in the field of neurological regenerative rehabilitation, aiming to increase the awareness of exosome research and applications in the rehabilitation of neurological disorders.

Hypoxia enhances anti-fibrotic properties of extracellular vesicles derived from hiPSCs via the miR302b-3p/TGFβ/SMAD2 axis

BACKGROUND

Cardiac fibrosis is one of the top killers among fibrotic diseases and continues to be a global unaddressed health problem. The lack of effective treatment combined with the considerable socioeconomic burden highlights the urgent need for innovative therapeutic options. Here, we evaluated the anti-fibrotic properties of extracellular vesicles (EVs) derived from human induced pluripotent stem cells (hiPSCs) that were cultured under various oxygen concentrations.

METHODS

EVs were isolated from three hiPSC lines cultured under normoxia (21% O2; EV-N) or reduced oxygen concentration (hypoxia): 3% O2 (EV-H3) or 5% O2 (EV-H5). The anti-fibrotic activity of EVs was tested in an in vitro model of cardiac fibrosis, followed by a detailed investigation of the underlying molecular mechanisms. Sequencing of EV miRNAs combined with bioinformatics analysis was conducted and a selected miRNA was validated using a miRNA mimic and inhibitor. Finally, EVs were tested in a mouse model of angiotensin II-induced cardiac fibrosis.

RESULTS

We provide evidence that an oxygen concentration of 5% enhances the anti-fibrotic effects of hiPS-EVs. These EVs were more effective in reducing pro-fibrotic markers in activated human cardiac fibroblasts, when compared to EV-N or EV-H3. We show that EV-H5 act through the canonical TGFβ/SMAD pathway, primarily via miR-302b-3p, which is the most abundant miRNA in EV-H5. Our results show that EV-H5 not only target transcripts of several profibrotic genes, including SMAD2 and TGFBR2, but also reduce the stiffness of activated fibroblasts. In a mouse model of heart fibrosis, EV-H5 outperformed EV-N in suppressing the inflammatory response in the host and by attenuating collagen deposition and reducing pro-fibrotic markers in cardiac tissue.

CONCLUSIONS

In this work, we provide evidence of superior anti-fibrotic properties of EV-H5 over EV-N or EV-H3. Our study uncovers that fine regulation of oxygen concentration in the cellular environment may enhance the anti-fibrotic effects of hiPS-EVs, which has great potential to be applied for heart regeneration.

Modulation of Neuroinflammation: Advances in Roles and Mechanisms of the IL-33/ST2 Axis Involved in Ischemic Stroke

Interleukin (IL)-33 was initially recognized as a constituent of the IL-1 cytokine family in 2005. It exerts pleiotropic effects by regulating immune responses via its binding to the receptor ST2 (IL-33R). The IL-33/ST2 pathway has been linked to several inflammatory disorders. In human and rodents, the broad expression of IL-33 in spinal cord tissues and brain indicates its central nervous system-specific functions. Growing evidence supports the protective effects of the IL-33/ST2 pathway in ischemic stroke, along with a better understanding of the underlying mechanisms. IL-33 plays a crucial role in the regulation of the release of inflammatory molecules from glial cells in response to neuropathological lesions. Moreover, IL-33/ST2-mediated neuroprotection following cerebral ischemia may be linked to T-cell function, specifically regulatory T cells. Soluble ST2 (sST2) acts as a decoy receptor in the IL-33/ST2 axis, blocking IL-33 signaling through the membrane ST2 receptor. sST2 has also been identified as a potential inflammatory biomarker of ischemic stroke. Targeting sST2 specifically to eliminate its inhibition of the protective IL-33/ST2 pathway in ischemic brain tissues is a promising approach for the treatment of ischemic stroke.

The role of exosomes in central nervous system tissue regeneration and repair

Exosomes are membrane-bound vesicles secreted by various cell types into the extracellular environment and contain kinds of bioactive molecules. These molecules can mediate various biological processes such as cell differentiation, proliferation, and survival, making them attractive for tissue regeneration and repair. Owing to their nanoscale size, bilayer membrane structure, and receptor-mediated transcytosis, exosomes can cross the blood-brain barrier (BBB) and reach the central nervous system (CNS) tissue. Additionally, exosomes can be loaded with exogenous substances after isolation. It has been suggested that exosomes could be used as natural drug carriers to transport therapeutic agents across the BBB and have great potential for CNS disease therapy by promoting tissue regeneration and repair. Herein, we discuss perspectives on therapeutic strategies to treat neurodegenerative disease or spinal cord injury using a variety of cell types-derived exosomes with kinds of exosomal contents, as well as engineering strategies of specific functional and exosome administration routes.

Engineering considerations of iPSC-based personalized medicine

Personalized medicine aims to provide tailored medical treatment that considers the clinical, genetic, and environmental characteristics of patients. iPSCs have attracted considerable attention in the field of personalized medicine; however, the inherent limitations of iPSCs prevent their widespread use in clinical applications. That is, it would be important to develop notable engineering strategies to overcome the current limitations of iPSCs. Such engineering approaches could lead to significant advances in iPSC-based personalized therapy by offering innovative solutions to existing challenges, from iPSC preparation to clinical applications. In this review, we summarize how engineering strategies have been used to advance iPSC-based personalized medicine by categorizing the development process into three distinctive steps: 1) the production of therapeutic iPSCs; 2) engineering of therapeutic iPSCs; and 3) clinical applications of engineered iPSCs. Specifically, we focus on engineering strategies and their implications for each step in the development of iPSC-based personalized medicine.

Electroacupuncture and human iPSC-derived small extracellular vesicles regulate the gut microbiota in ischemic stroke via the brain-gut axis

Electroacupuncture (EA) and induced pluripotent stem cell (iPSC)-derived small extracellular vesicles (iPSC-EVs) have substantial beneficial effects on ischemic stroke. However, the detailed mechanisms remain unclear. Here, we explored the mechanisms underlying the regulation of EA and iPSC-EVs in the microbiome-gut-brain axis (MGBA) after ischemic stroke. Ischemic stroke mice (C57BL/6) were subjected to middle cerebral artery occlusion (MCAO) or Sham surgery. EA and iPSC-EVs treatments significantly improved neurological function and neuronal and intestinal tract injury, downregulated the levels of IL-17 expression and upregulated IL-10 levels in brain and colon tissue after cerebral ischemia-reperfusion. EA and iPSC-EVs treatments also modulated the microbiota composition and diversity as well as the differential distribution of species in the intestines of the mice after cerebral ischemia-reperfusion. Our results demonstrated that EA and iPSC-EVs treatments regulated intestinal immunity through MGBA regulation of intestinal microbes, reducing brain and colon damage following cerebral ischemia and positively impacting the outcomes of ischemic stroke. Our findings provide new insights into the application of EA combined with iPSC-EVs as a treatment for ischemic stroke.

Regulatory Effect of Electroacupuncture on Hypothalamic Serotonin and its Receptor in Rats with Cerebral Ischemia

BACKGROUND

Previous studies have shown that the neurological damage caused by middle cerebral artery occlusion (MCAO) is not only limited to local infarction but can also cause secondary damage in distant sites, such as the hypothalamus. 5-hydroxytryptamine (5-HT)/ 5-HT transporter (5-HTT) and 5-HT receptor 2A (5-HT2A) are important in the treatment of cerebrovascular diseases.

OBJECTIVE

This study aimed to study the effect of electroacupuncture (EA) on the expression of 5- HT, 5-HTT, and 5-HT2A in the hypothalamus of rats with ischemic brain injury and to explore the protective effect and potential mechanism of EA on the secondary injury of cerebral ischemia.

METHODS

Sprague-Dawley (SD) rats were randomly divided into three groups: sham group, model group, and EA group. The permanent middle cerebral artery occlusion (pMCAO) method was used to induce ischemic stroke in rats. In the EA group, the Baihui (GV20) and Zusanli (ST36) points were selected for treatment, which was administered once per day for two consecutive weeks. The neuroprotective effect of EA was evaluated by nerve defect function scores and Nissl staining. The content of 5-HT in hypothalamus was detected by enzyme linked immunosorbent assay (ELISA), and the expression of 5-HTT and 5-HT2A were detected by Western blot.

RESULTS

Compared with that in the sham group, the nerve defect function score in the model group rats was significantly increased, the hypothalamus tissue showed obvious nerve damage, the levels of 5-HT and the expression of 5-HTT were significantly reduced, and the expression of 5-HT2A was significantly increased. After 2 weeks of EA treatment, the nerve defect function scores of pMCAO rats were significantly reduced, the hypothalamic nerve injury was significantly reduced, the levels of 5-HT and the expression of 5-HTT were significantly increased, and the expression of 5-HT2A was significantly decreased.

CONCLUSION

EA has a certain therapeutic effect on hypothalamic injury secondary to permanent cerebral ischemia, and its potential mechanism may be closely related to the upregulation of 5-HT and 5-HTT expression and the downregulation of 5-HT2A expression.

Electroacupuncture inhibits the expression of HMGB1/RAGE and alleviates injury to the primary motor cortex in rats with cerebral ischemia

Background

The high-mobility group box 1 (HMGB1)/receptor for advanced glycation end products (RAGE) signaling pathway holds promise as a potential therapeutic target for ischemic brain injury. The effects of FPS-ZM1 and electroacupuncture (EA) on activation of the HMGB1/RAGE signaling pathway after cerebral ischemia remain uncertain.

Methods

Middle cerebral artery occlusion (MCAO) model was established. Neurological function was assessed using Longa scores. Nissl staining was used to observe the morphology of neurons. The expression levels of HMGB1 and RAGE were assayed with immunofluorescence staining and western blot.

Results

The results showed that EA and FPS-ZM1 could reduce the neural function score and neurons cell injury in cerebral ischemia rats by inhibiting the expression of HMGB1 and RAGE in primary motor cortex (M1) region. In addition, EA combined with FPS-ZM1 had a better therapeutic effect.

Conclusions

The HMGB1/RAGE pathway could be activated after cerebral ischemia. Both EA and FPS-ZM1 improved neurological deficits and attenuated neuronal damage in rats. They had synergistic effects. These interventions were observed to mitigate brain damage by suppressing the activation of HMGB1/RAGE.

Gut microbiota in ischemic stroke: Where we stand and challenges ahead

Gut microbiota is increasingly recognized to affect host health and disease, including ischemic stroke (IS). Here, we systematically review the current understanding linking gut microbiota as well as the associated metabolites to the pathogenesis of IS (e.g., oxidative stress, apoptosis, and neuroinflammation). Of relevance, we highlight that the implications of gut microbiota-dependent intervention could be harnessed in orchestrating IS.

Interleukin-33 regulates the functional state of microglia

Microglia, the most prominent resident immune cells, exhibit multiple functional states beyond their immunomodulatory roles. Non-immune functions such as synaptic reorganization, removal of cellular debris, and deposition of abnormal substances are mediated by phagocytosis of normal or enhanced microglia. Activation or migration of microglia occurs when environmental cues are altered. In response to pathological factors, microglia change into various phenotypes, preventing or exacerbating tissue damage. Interleukin-33 (IL-33) is an important cytokine that regulates innate immunity, and microglia are thought to be its target cells. Here, we outline the role of IL-33 in the expression of microglial functions such as phagocytosis, migration, activation, and inflammatory responses. We focus on microglial properties and diverse functional states in health and disease, including the different effects of IL-33 perturbation on microglia in vivo and in vitro. We also highlight several well-established mechanisms of microglial function mediated by IL-33, which may be initiators and regulators of microglial function and require elucidation and expansion of the underlying mechanisms.

Acupuncture at GV20 and ST36 Improves the Recovery of Behavioral Activity in Rats Subjected to Cerebral Ischemia/Reperfusion Injury

Traditional acupuncture and electroacupuncture (EA) have been widely performed to treat ischemic stroke. To provide experimental support for the clinical application of acupuncture to ameliorate post-stroke sequelae, in this study, we investigated the therapeutic effect of acupuncture and EA on CIRI following middle cerebral artery occlusion (MCAO) in rats. The animals were randomly divided into five groups: sham-operated (S), model (M), traditional acupuncture (A) treatment, electroacupuncture (EA) treatment, and drug (D; edaravone) therapies. Neurological behavioral characteristics (neurological deficit score, forelimb muscle strength, sensorimotor function, body symmetry, sucrose consumption, and mood) were examined in all the groups on days 1, 3, 5, and 7 after reperfusion. Expressions of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) were detected by immunohistochemistry. Both acupuncture and EA significantly reduced neurological deficits and improved forelimb muscle strength, sensorimotor function, body symmetry recovery, and neurovascular regeneration in the rats after ischemia/reperfusion injury. The efficacies of both acupuncture and EA were comparable to that of edaravone, a commonly used medicine for stroke in the clinic. Thus, our data suggest that acupuncture and EA therapy at acupoints GV20 and ST36 might represent alternative or complementary treatments to the conventional management of ischemic stroke, providing additional support for the experimental evidence for acupuncture therapy in clinical settings. In summary, EA might provide alternative or complementary treatment strategies for treating patients with apoplexy in the clinic. However, potential mechanisms underlying the role of acupuncture require further investigation.