Preconditioning with Trehalose Protects the Bone Marrow-Derived Mesenchymal Stem Cells Under Oxidative Stress and Enhances the Stem Cell-Based Therapy for Cerebral Ischemic Stroke

Mesenchymal stem cells and their extracellular vesicles as emerging therapeutic tools in the treatment of ischemic stroke

Ischemic stroke (IS) is a neurological condition characterized by severe long-term consequences and an unfavorable prognosis for numerous patients. Despite advancements in stroke treatment, existing therapeutic approaches possess certain limitations. However, accumulating evidence suggests that mesenchymal stem/stromal cells (MSCs) hold promise as a potential therapy for various neurological disorders, including IS, owing to their advantageous properties, such as immunomodulation and tissue regeneration. Additionally, MSCs primarily exert their therapeutic effects through the release of extracellular vesicles (EVs), highlighting the significance of their paracrine activities. These EVs are small double-layered phospholipid membrane vesicles, carrying a diverse cargo of proteins, lipids, and miRNAs that enable effective cell-to-cell communication. Notably, EVs have emerged as attractive substitutes for stem cell therapy due to their reduced immunogenicity, lower tumorigenic potential, and ease of administration and handling. Hence, this review summarizes the current preclinical and clinical studies performed to investigate the safety and therapeutic potential of MSCs and their EVs derived from different sources, including bone marrow, adipose tissue, umbilical cord blood, and Wharton's jelly in IS.

Therapeutic gene delivery by mesenchymal stem cell for brain ischemia damage: Focus on molecular mechanisms in ischemic stroke

Cerebral ischemic damage is prevalent and the second highest cause of death globally across patient populations; it is as a substantial reason of morbidity and mortality. Mesenchymal stromal cells (MSCs) have garnered significant interest as a potential treatment for cerebral ischemic damage, as shown in ischemic stroke, because of their potent intrinsic features, which include self-regeneration, immunomodulation, and multi-potency. Additionally, MSCs are easily obtained, isolated, and cultured. Despite this, there are a number of obstacles that hinder the effectiveness of MSC-based treatment, such as adverse microenvironmental conditions both in vivo and in vitro. To overcome these obstacles, the naïve MSC has undergone a number of modification processes to enhance its innate therapeutic qualities. Genetic modification and preconditioning modification (with medications, growth factors, and other substances) are the two main categories into which these modification techniques can be separated. This field has advanced significantly and is still attracting attention and innovation. We examine these cutting-edge methods for preserving and even improving the natural biological functions and therapeutic potential of MSCs in relation to adhesion, migration, homing to the target site, survival, and delayed premature senescence. We address the use of genetically altered MSC in stroke-induced damage. Future strategies for improving the therapeutic result and addressing the difficulties associated with MSC modification are also discussed.

Priming and Combined Strategies for the Application of Mesenchymal Stem Cells in Ischemic Stroke: A Promising Approach

Ischemic stroke (IS) is a leading cause of death and disability worldwide. Tissue plasminogen activator (tPA) administration and mechanical thrombectomy are the main treatments but have a narrow time window. Mesenchymal stem cells (MSCs), which are easily scalable in vitro and lack ethical concerns, possess the potential to differentiate into various types of cells and secrete a great number of growth factors for neuroprotection and regeneration. Moreover, MSCs have low immunogenicity and tumorigenic properties, showing safety and preliminary efficacy both in preclinical studies and clinical trials of IS. However, it is unlikely that MSC treatment alone will be sufficient to maximize recovery due to the low survival rate of transplanted cells and various mechanisms of ischemic brain damage in the different stages of IS. Preconditioning was used to facilitate the homing, survival, and secretion ability of the grafted MSCs in the ischemic region, while combination therapies are alternatives that can maximize the treatment effects, focusing on multiple therapeutic targets to promote stroke recovery. In this case, the combination therapy can yield a synergistic effect. In this review, we summarize the type of MSCs, preconditioning methods, and combined strategies as well as their therapeutic mechanism in the treatment of IS to accelerate the transformation from basic research to clinical application.

Growth differentiation factor 7 pretreatment enhances the therapeutic capacity of bone marrow-derived mesenchymal stromal cells against cerebral ischemia-reperfusion injury

Bone marrow-derived mesenchymal stem cells (BMSCs) transplantation is a promising therapeutic strategy for cerebral ischemia/reperfusion (I/R) injury; however, the clinical outcome is barely satisfactory and demands further improvement. The present study aimed to investigate whether preconditioning of BMSCs by recombinant human growth differentiation factor 7 (rhGDF7) could enhance its therapeutic capacity against cerebral I/R injury. Mouse BMSCs and primary neurons were co-cultured and exposed to oxygen glucose deprivation/reperfusion (OGD/R) stimulation. To investigate the role of exosomal microRNA-369-3p (miR-369-3p), inhibitors, RNAi and the miR-369-3p antagomir were used. Meanwhile, mice were intravenously injected with rhGDF7-preconditioned BMSCs and then received cerebral I/R surgery. Markers of inflammation, oxidative stress and neural damage were evaluated. To inhibit AMP-activated protein kinase (AMPK), compound C was used in vivo and in vitro. Compared with cell-free transwell or vehicle-preconditioned BMSCs, rhGDF7-preconditioned BMSCs significantly prevented OGD/R-induced inflammation, oxidative stress and neural damage in vitro. Meanwhile, rhGDF7-preconditioned BMSCs could prevent I/R-induced cerebral inflammation and oxidative stress in vivo. Mechanistically, rhGDF7 preconditioning significantly increased exosomal miR-369-3p expression in BMSCs and then transferred exosomal miR-369-3p to primary neurons, where it bound to phosphodiesterase 4 D (Pde4d) 3'-UTR and downregulated PDE4D expression, thereby preventing I/R-induced inflammation, oxidative stress and neural damage through activating AMPK pathway. Our study identify GDF7 pretreatment as a promising adjuvant reagent to improve the therapeutic potency of BMSCs for cerebral I/R injury and ischemic stroke.

Effects of remote ischemic preconditioning in severe traumatic brain injury: A single-center randomized controlled trial

BACKGROUND

Traumatic brain injury (TBI) is a significant contributor to global mortality and impairment. Experimental data has shown the advantages of remote ischemic preconditioning (RIPC) in treating brain injury, however, there is a lack of evidence-based medicine regarding its clinical effectiveness and safety.

MATERIALS AND METHODS

In this study, we investigated whether RIPC could enhance outcomes in patients with severe TBI. Between January 2019 and December 2022, a comprehensive assessment was conducted on 392 individuals with severe TBI. Out of these, 304 patients were initially included and randomly assigned to receive either RIPC treatment (n = 153) or a control treatment (n = 151). The main measures of results included Glasgow Outcome Scale scores at 6 months, the occurrence of cerebral infarction during hospitalization, mortality rate within 30 days, levels of neuron-specific enolase and S-100β, any adverse effects, expenses incurred during hospitalization, and duration of hospital stay.

RESULTS

The 2 groups did not show any statistically significant differences in baseline clinical data. The Glasgow Outcome Scale scores at 6 months in the RIPC group showed significant improvement when compared with the control group. Additionally, the application of RIPC therapy can reduce the concentrations of neuron-specific enolase and S-100β. There was no notable distinction observed between the 2 groups regarding the adverse reactions of RIPC-induced objective indications of tissue or neurovascular harm. In the RIPC group, there was a significant reduction in both the duration of hospital stays and the expenses associated with hospitalization.

CONCLUSION

The results of this study suggest that RIPC has the potential to enhance clinical outcomes, mitigate nerve damage, and reduce both hospital expenses and length of stay in patients with severe TBI. The use of RIPC is a reliable and efficient method for managing severe TBI.

State of the Art and Future of Stem Cell Therapy in Ischemic Stroke: Why Don't We Focus on Their Administration?

Stroke is one of the leading causes of death and disability worldwide, so there is an urgent need to find a therapy for the tragic outcomes of this cerebrovascular disease. Stem cells appeared to be a good solution for many conditions, so different experiments were made to establish stem cells as a feasible therapy for stroke. The aim of this review is to analyze the state of the art of stem cell therapy for stroke and if the route of administration could represent a valid adjusting point for ameliorating the therapy's outcome. To obtain this, we searched the scientific literature of the last 10 years for relevant in vitro and in vivo evidence regarding stem cells' potential in stroke therapy. In vitro evidence points to hypoxia, among the preconditioning strategies, as the most used and probably efficient method to enhance cells qualities, while in vivo results raise the question if it is the type of cells or how they are administrated which can make the difference in terms of efficiency. Unfortunately, despite the number of clinical trials, only a few were successfully concluded, demonstrating how urgent the necessity is to translate pre-clinical results into clinics. Since any type of stem cell seems suitable for therapy, the chosen route of administration corresponds to different engraftment rates, distribution and efficiency in terms of the beneficial effects of stem cells. Intravenous administration was widely used for delivering stem cells into the human body, but recently intranasal administration has given promising results in vivo. It allows stem cells to efficiently reach the brain that was precluded to intravenous administration, so it is worth further investigation.