Probing Multiple Transplant Delivery Routes of CD+34 Stem Cells for Promoting Behavioral and Histological Benefits in Experimental Ischemic Stroke.

Stroke is a leading cause of death in the US and around the world but with limited treatment options. Survivors often present with long-term cognitive and neurological deficits. Stem cell-based therapy has emerged as a potential treatment for stroke. While stem cell transplantation in stroke has reached clinical trials, mostly safety outcomes have been reported with efficacy readouts warranting more studies. In an effort to optimize the stem cell regimen for stroke, here we conducted vis-a-vis comparison of different routes of transplantation, namely, intracerebral, intraarterial, and intranasal delivery of expanded human CD34 + stem cells, called ProtheraCytes, in the established stroke model of transient middle cerebral artery occlusion (MCAO) using adult Sprague-Dawley rats. After adjusting for the dose and subacute timing of cell delivery, animals were randomly assigned to receive either ProtheraCytes or vehicle. Motor and neurological assays from days 7 to 28 post-stroke revealed significant functional recovery across all 3 delivery routes of ProtheraCytes compared to vehicle-treated stroke rats. Additionally, ProtheraCytes-transplanted stroke rats displayed significantly reduced infarct size and cell loss in the peri-infarct area coupled with enhanced neurogenesis and angiogenesis compared to vehicle-treated stroke rats. These results highlight the safety and efficacy of transplanting ProtheraCytes, including via the minimally invasive intranasal route, in conferring robust and stable behavioral and histological positive outcomes in experimental stroke.

Endogenous Extracellular Vesicles Participate in Brain Remodeling after Ischemic Stroke.

Brain remodeling after an ischemic stroke represents a promising avenue for exploring the cellular mechanisms of endogenous brain repair. A deeper understanding of these mechanisms is crucial for optimizing the safety and efficacy of neuroprotective treatments for stroke patients. Here, we interrogated the role of extracellular vesicles, particularly exosomes, as potential mediators of endogenous repair within the neurovascular unit (NVU). We hypothesized that these extracellular vesicles may play a role in achieving transient stroke neuroprotection. Using the established ischemic stroke model of middle cerebral artery occlusion in adult rats, we detected a surged in the extracellular vesicle marker CD63 in the peri-infarct area that either juxtaposed or co-localized with GFAP-positive glial cells, MAP2-labeled young neurons, and VEGF-marked angiogenic cells. This novel observation that CD63 exosomes spatially and temporally approximated glial activation, neurogenesis, and angiogenesis suggests that extracellular vesicles, especially exosomes, contribute to the endogenous repair of the NVU, warranting exploration of extracellular vesicle-based stroke therapeutics.

Identifying the Target Traumatic Brain Injury Population for Hyperbaric Oxygen Therapy.

Traumatic brain injury (TBI) results from direct penetrating and indirect non-penetrating forces that alters brain functions, affecting millions of individuals annually. Primary injury following TBI is exacerbated by secondary brain injury; foremost is the deleterious inflammatory response. One therapeutic intervention being increasingly explored for TBI is hyperbaric oxygen therapy (HBOT), which is already approved clinically for treating open wounds. HBOT consists of 100% oxygen administration, usually between 1.5 and 3 atm and has been found to increase brain oxygenation levels after hypoxia in addition to decreasing levels of inflammation, apoptosis, intracranial pressure, and edema, reducing subsequent secondary injury. The following review examines recent preclinical and clinical studies on HBOT in the context of TBI with a focus on contributing mechanisms and clinical potential. Several preclinical studies have identified pathways, such as TLR4/NF-kB, that are affected by HBOT and contribute to its therapeutic effect. Thus far, the mechanisms mediating HBOT treatment have yet to be fully elucidated and are of interest to researchers. Nonetheless, multiple clinical studies presented in this review have examined the safety of HBOT and demonstrated the improved neurological function of TBI patients after HBOT, deeming it a promising avenue for treatment.

Probing Gut Participation in Parkinson's Disease Pathology and Treatment via Stem Cell Therapy.

Accumulating evidence suggests the critical role of the gut-brain axis (GBA) in Parkinson's disease (PD) pathology and treatment. Recently, stem cell transplantation in transgenic PD mice further implicated the GBA's contribution to the therapeutic effects of transplanted stem cells. In particular, intravenous transplantation of human umbilical-cord-blood-derived stem/progenitor cells and plasma reduced motor deficits, improved nigral dopaminergic neuronal survival, and dampened α-synuclein and inflammatory-relevant microbiota and cytokines in both the gut and brain of mouse and rat PD models. That the gut robustly responded to intravenously transplanted stem cells and prompted us to examine in the present study whether direct cell implantation into the gut of transgenic PD mice would enhance the therapeutic effects of stem cells. Contrary to our hypothesis, results revealed that intragut transplantation of stem cells exacerbated motor and gut motility deficits that corresponded with the aggravated expression of inflammatory microbiota, cytokines, and α-synuclein in both the gut and brain of transgenic PD mice. These results suggest that, while the GBA stands as a major source of inflammation in PD, targeting the gut directly for stem cell transplantation may not improve, but may even worsen, functional outcomes, likely due to the invasive approach exacerbating the already inflamed gut. The minimally invasive intravenous transplantation, which likely avoided worsening the inflammatory response of the gut, appears to be a more optimal cell delivery route to ameliorate PD symptoms.

Metabolic Switching of Cultured Mesenchymal Stem Cells Creates Super Mitochondria in Rescuing Ischemic Neurons.

Transfer of healthy mitochondria from mesenchymal stem cells (MSCs) to ischemic neurons represents a potent stroke therapeutic. MSCs were grown under ambient conditions (nMSCs) or a metabolic switching paradigm by alternating galactose and glucose in medium (sMSCs) and then assayed for oxygen consumption rates using the Seahorse technology. Subsequently, primary neurons were subjected to oxygen glucose deprivation (OGD) and then co-cultured with either nMSCs or sMSCs. Compared to nMSCs, sMSCs displayed higher basal energy production, larger spare respiratory capacity, greater ATP production, and decreased proton leak. Co-culture of OGD-exposed neurons with sMSCs conferred greater cell viability, enhanced cell metabolism, reduced mitochondrial reactive oxidative species mRNA, and elevated mitochondria ATP mRNA than those cultured with nMSCs. Metabolic switching produces "super" mitochondria that may underlie the therapeutic benefit of using sMSCs to treat ischemic cells.

Inflammatory gut as a pathologic and therapeutic target in Parkinson's disease.

Parkinson's disease (PD) remains a significant unmet clinical need. Gut dysbiosis stands as a PD pathologic source and therapeutic target. Here, we assessed the role of the gut-brain axis in PD pathology and treatment. Adult transgenic (Tg) α-synuclein-overexpressing mice served as subjects and were randomly assigned to either transplantation of vehicle or human umbilical cord blood-derived stem cells and plasma. Behavioral and immunohistochemical assays evaluated the functional outcomes following transplantation. Tg mice displayed typical motor and gut motility deficits, elevated α-synuclein levels, and dopaminergic depletion, accompanied by gut dysbiosis characterized by upregulation of microbiota and cytokines associated with inflammation in the gut and the brain. In contrast, transplanted Tg mice displayed amelioration of motor deficits, improved sparing of nigral dopaminergic neurons, and downregulation of α-synuclein and inflammatory-relevant microbiota and cytokines in both gut and brain. Parallel in vitro studies revealed that cultured dopaminergic SH-SY5Y cells exposed to homogenates of Tg mouse-derived dysbiotic gut exhibited significantly reduced cell viability and elevated inflammatory signals compared to wild-type mouse-derived gut homogenates. Moreover, treatment with human umbilical cord blood-derived stem cells and plasma improved cell viability and decreased inflammation in dysbiotic gut-exposed SH-SY5Y cells. Intravenous transplantation of human umbilical cord blood-derived stem/progenitor cells and plasma reduced inflammatory microbiota and cytokine, and dampened α-synuclein overload in the gut and the brain of adult α-synuclein-overexpressing Tg mice. Our findings advance the gut-brain axis as a key pathological origin, as well as a robust therapeutic target for PD.

Enhancing oxidative phosphorylation over glycolysis for energy production in cultured mesenchymal stem cells.

OBJECTIVE: Strokes represent as one of the leading causes of death and disability in the USA, however, there is no optimal treatment to reduce the occurrence or improve prognosis. Preconditioning of tissues triggers ischemic tolerance, a physiological state that may involve a metabolic switch (i.e. from glycolysis to oxidative phosphorylation or OxPhos) to preserve tissue viability under an ischemic insult. Here, we hypothesized that metabolic switching of energy source from glucose to galactose in cultured mesenchymal stem cells (MSCs) stands as an effective OxPhos-enhancing strategy. METHODS: MSCs were grown under ambient condition (normal MSCs) or metabolic switching paradigm (switched MSCs) and then assayed for oxygen consumption rates (OCR) and extracellular acidification rate (ECAR) using the Seahorse technology to assess mitochondrial respiration. RESULTS: Normal MSCs showed a lower OCR/ECAR ratio than switched MSCs at baseline (P < 0.0001), signifying that there were greater levels of OxPhos compared to glycolysis in switched MSCs. By modulating the mitochondrial metabolism with oligomycin (time points 4-6), carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (7-9), and rotenone and antimycin (time points 10-12), switched MSCs greater reliance on OxPhos was further elucidated (time points 5-12; P < 0.0001; time point 4; P < 0.001). CONCLUSION: The metabolic switch from glycolytic to oxidative metabolism amplifies the OxPhos potential of MSCs, which may allow these cells to afford more robust therapeutic effects against neurological disorders that benefit from ischemic tolerance.

Contraceptive drug, Nestorone, enhances stem cell-mediated remodeling of the stroke brain by dampening inflammation and rescuing mitochondria.

Ischemic stroke remains a significant unmet need causing massive mortality and morbidity due to few treatment options with limited therapeutic window. The progestin Nestorone® (segesterone acetate) displays high affinity for the progesterone receptor in exerting its potent birth control and hormone replacement therapy. Accumulating evidence implicates a new utility of Nestorone in affording neuroprotection in a variety of central nervous system diseases, including stroke. However, the mechanism of action mediating Nestorone's neuroprotection in stroke remains unknown. Here, we showed that stand-alone treatments of Nestorone or human amniotic fluid-derived stem cells (hAFSc), but more pronounced with their combined treatment, led to significant improvements in behavioral function and reductions in infarction and peri-infarct cell loss in adult rats with ischemic stroke. We detected significantly lower levels of pro-inflammatory signals (OX6 and IBA1) coupled with enhanced levels of stem cell proliferation (Ki67) and differentiation (DCX and MAP2) in both brain and spleen of stroke rats that received stand-alone or combined treatments of Nestorone and hAFSc. In concert, the in vitro oxygen-glucose deprivation stroke model revealed that neural stem cells treated with Nestorone exhibited increased stem cell proliferation and differentiation that was accompanied by rescue of the mitochondrial respiratory activity characterized by reduced mitochondrial reactive oxygen species, increased ATP, elevated mitochondrial deacetylase Sirtuin 3 (SIRT3), and a normalized ratio of acetyl-superoxide dismutase 2 (Ac-SOD2)/SOD2, suggesting the key role of mitochondrial metabolism and oxidative protection in Nestorone's therapeutic effects in stroke.

Building a Nomogram for Metabolic Syndrome Using Logistic Regression with a Complex Sample-A Study with 39,991,680 Cases.

Metabolic syndrome can cause complications, such as stroke and cardiovascular disease. We aimed to propose a nomogram that visualizes and predicts the probability of metabolic syndrome occurrence after identifying risk factors related to metabolic syndrome for prevention and recognition. We created a nomogram related to metabolic syndrome in this paper for the first time. We analyzed data from the Korea National Health and Nutrition Examination Survey VII. Total 17,584 participants were included in this study, and the weighted sample population was 39,991,680, which was 98.1% of the actual Korean population in 2018. We identified 14 risk factors affecting metabolic syndrome using the Rao-Scott chi-squared test. Next, logistic regression analysis was performed to build a model for metabolic syndrome and 11 risk factors were finally obtained, including BMI, marriage, employment, education, age, stroke, sex, income, smoking, family history and age* sex. A nomogram was constructed to predict the occurrence of metabolic syndrome using these risk factors. Finally, the nomogram was verified using a receiver operating characteristic curve (ROC) and a calibration plot.

Gut-Brain Axis as a Pathological and Therapeutic Target for Neurodegenerative Disorders.

Human lifestyle and dietary behaviors contribute to disease onset and progression. Neurodegenerative diseases (NDDs), considered multifactorial disorders, have been associated with changes in the gut microbiome. NDDs display pathologies that alter brain functions with a tendency to worsen over time. NDDs are a worldwide health problem; in the US alone, 12 million Americans will suffer from NDDs by 2030. While etiology may vary, the gut microbiome serves as a key element underlying NDD development and prognosis. In particular, an inflammation-associated microbiome plagues NDDs. Conversely, sequestration of this inflammatory microbiome by a correction in the dysbiotic state of the gut may render therapeutic effects on NDDs. To this end, treatment with short-chain fatty acid-producing bacteria, the main metabolites responsible for maintaining gut homeostasis, ameliorates the inflammatory microbiome. This intimate pathological link between the gut and NDDs suggests that the gut-brain axis (GBA) acts as an underexplored area for developing therapies for NDDs. Traditionally, the classification of NDDs depends on their clinical presentation, mostly manifesting as extrapyramidal and pyramidal movement disorders, with neuropathological evaluation at autopsy as the gold standard for diagnosis. In this review, we highlight the evolving notion that GBA stands as an equally sensitive pathological marker of NDDs, particularly in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and chronic stroke. Additionally, GBA represents a potent therapeutic target for treating NDDs.

Extended Ischemic Recovery After Implantation of Human Mesenchymal Stem Cell Aggregates Indicated by Sodium MRI at 21.1 T.

Extended therapeutic application remains a significant issue in the use of stem cell therapies to treat ischemic stroke. Along these lines, neurological recovery in a rodent model of ischemic stroke was evaluated following implantation of human mesenchymal stem cell aggregates (hMSC-agg), labeled with micron-sized particles of iron oxide, directly into the lateral ventricle contralateral to the ischemic lesion hemisphere. Longitudinally, disease progression and response to hMSC-agg therapy were assessed by 1H and 23Na magnetic resonance imaging (MRI) at 21.1 T to investigate cellular localization, migration, and recovery over an extended timeframe. MRI provides quantifiable metrics of tissue status through sodium distributions in addition to traditional proton imaging. Quantitative 23Na MRI revealed a significant decrease of sodium concentrations following hMSC aggregate implantation, indicating recovery of homeostasis. This result correlates positively with extended neurological recovery assessed by behavioral analysis and immunohistochemistry. These findings demonstrate the potential of implanted hMSC aggregate therapy to provide extended treatment for ischemic stroke, as well as the robustness of MRI for monitoring such approaches. This method potentially can be translated to a clinical setting for the assessment of extended cell therapy efficacy.

Treating Metastatic Brain Cancers With Stem Cells.

Stem cell therapy may present an effective treatment for metastatic brain cancer and glioblastoma. Here we posit the critical role of a leaky blood-brain barrier (BBB) as a key element for the development of brain metastases, specifically melanoma. By reviewing the immunological and inflammatory responses associated with BBB damage secondary to tumoral activity, we identify the involvement of this pathological process in the growth and formation of metastatic brain cancers. Likewise, we evaluate the hypothesis of regenerating impaired endothelial cells of the BBB and alleviating the damaged neurovascular unit to attenuate brain metastasis, using the endothelial progenitor cell (EPC) phenotype of bone marrow-derived mesenchymal stem cells. Specifically, there is a need to evaluate the efficacy for stem cell therapy to repair disruptions in the BBB and reduce inflammation in the brain, thereby causing attenuation of metastatic brain cancers. To establish the viability of stem cell therapy for the prevention and treatment of metastatic brain tumors, it is crucial to demonstrate BBB repair through augmentation of vasculogenesis and angiogenesis. BBB disruption is strongly linked to metastatic melanoma, worsens neuroinflammation during metastasis, and negatively influences the prognosis of metastatic brain cancer. Using stem cell therapy to interrupt inflammation secondary to this leaky BBB represents a paradigm-shifting approach for brain cancer treatment. In this review article, we critically assess the advantages and disadvantages of using stem cell therapy for brain metastases and glioblastoma.

Stem Cells for Aging-Related Disorders.

This review captures recent advances in biological and translational research on stem cells. In particular, we discuss new discoveries and concepts regarding stem cell treatment of aging-related disorders. A myriad of stem cell sources exists, from hematopoietic to mesenchymal and neural cell lineages. We examine current applications of exogenous adult bone marrow-derived stem cells as an effective and safe transplantable cell source, as well as the use of electrical stimulation to promote endogenous neurogenesis for Parkinson's disease. We also explore the potential of transplanting exogenous umbilical cord blood cells and mobilizing host resident stem cells in vascular dementia and aging. In addition, we assess the ability of small molecules to recruit resident stem cells in Alzheimer's disease. Finally, we evaluate mechanisms of action recently implicated in stem cell therapy, such as the role of long non-coding RNAs, G-protein coupled receptor 5, and NeuroD1. Our goal is to provide a synopsis of recent milestones regarding the application of stem cells in aging.

Inflammation-relevant microbiome signature of the stroke brain, gut, spleen, and thymus and the impact of exercise.

Stroke remains a significant unmet need in the clinic with few therapeutic options. We, and others, have implicated the role of inflammatory microbiota in stroke secondary cell death. Elucidating this inflammation microbiome as a biomarker may improve stroke diagnosis and treatment. Here, adult Sprague-Dawley rats performed 30 minutes of exercise on a motorized treadmill for 3 consecutive days prior to transient middle cerebral artery occlusion (MCAO). Stroke animals that underwent exercise showed 1) robust behavioral improvements, 2) significantly smaller infarct sizes and increased peri-infarct cell survival and 3) decreasing trends of inflammatory microbiota BAC303, EREC482, and LAB158 coupled with significantly reduced levels of inflammatory markers ionized calcium binding adaptor molecule 1, tumor necrosis factor alpha, and mouse monoclonal MHC Class II RT1B in the brain, gut, spleen, and thymus compared to non-exercised stroke rats. These results suggest that a specific set of inflammatory microbiota exists in central and peripheral organs and can serve as a disease biomarker and a therapeutic target for stroke.

Vascular tortuosity in endovascular mechanical thrombectomy.

Endovascular mechanical thrombectomy effectively removes occlusive thrombi from the arterial lumen; however, there is little literature supporting the relevance of vascular geometry on surgical outcomes. Critical vessel characteristics including the degree of angulation and tortuosity influence the ability to advance stent retriever devices toward the site of occlusion. Therefore, it is crucial to evaluate the impact of carotid artery catheter pathway accessibility on the thrombectomy outcomes in acute ischemic stroke (AIS) patients. Traditional imaging modalities generate incomplete pictures of the vascular tortuosity and are prone to clinical judgment errors. Recent three-dimensional computed tomography angiography image analysis techniques circumvent these limitations to calculate accurate tortuosity and angulation measurements. These novel images facilitate classifying common anatomical variant patients into groups that may be treated with specially designed catheter devices. Importantly, this image analysis method reveals significant angulation in the common carotid artery and extracranial internal carotid artery that correlates with delays in reaching the occlusion site. Increased age, which is associated with increased risk of stroke, also increases the incidence of severe tortuosity. The semi-automated measurements technique also demonstrate that full 360° arterial loops are present in nearly 3% of catheter pathways and that the overall degree of angulation differs bilaterally. In this review, we examine the utility of this novel image analysis procedure and evaluate the recent literature relevant to neuroendovascular thrombectomy in AIS patients. Three literature databases - PubMed, Embase, and Web of Science were queried for original articles investigating both preclinical and clinical thrombectomy applications.

Extracellular vesicle-based therapy for amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) stands as a neurodegenerative disorder characterized by the rapid progression of motor neuron loss in the brain and spinal cord. Unfortunately, treatment options for ALS are limited, and therefore, novel therapies that prevent further motor neuron degeneration are of dire need. In ALS, the infiltration of pathological elements from the blood to the central nervous system (CNS) compartment that spur motor neuron damage may be prevented via restoration of the impaired blood-CNS-barrier. Transplantation of human bone marrow endothelial progenitor cells (hBM-EPCs) demonstrated therapeutic promise in a mouse model of ALS due to their capacity to mitigate the altered blood-CNS-barrier by restoring endothelial cell (EC) integrity. Remarkably, the hBM-EPCs can release angiogenic factors that endogenously ameliorate impaired ECs. In addition, these cells may produce extracellular vesicles (EVs) that carry a wide range of vesicular factors, which aid in alleviating EC damage. In an in vitro study, hBM-EPC-derived EVs were effectively uptaken by the mouse brain endothelial cells (mBECs) and cell damage was significantly attenuated. Interestingly, the incorporation of EVs into mBECs was inhibited via ß1 integrin hindrance. This review explores preclinical studies of the therapeutic potential of hBM-EPCs, specifically via hBM-EPC-derived EVs, for the repair of the damaged blood-CNS-barrier in ALS as a novel treatment approach.

Major histocompatibility complex Class II-based therapy for stroke.

This review discusses the potential of major histocompatibility complex (MHC) Class II constructs as stroke therapeutics. We focus on the delivery of MHC Class II construct, DRmQ, as a safe and effective treatment for ischemic stroke. DRmQ was observed to attenuate behavioral deficits and decrease microglia activation and proinflammatory cytokines, illustrating its ability to mitigate the secondary cell death following stroke. Similar anti-neuroinflammation treatments, such as transplantation of mesenchymal stem cells and mitochondrial transfers, are briefly discussed to provide further support that sequestration of inflammation stands as a robust therapeutic target for stroke.

Progress in progestin-based therapies for neurological disorders.

Hormone therapy, primarily progesterone and progestins, for central nervous system (CNS) disorders represents an emerging field of regenerative medicine. Following a failed clinical trial of progesterone for traumatic brain injury treatment, attention has shifted to the progestin Nestorone for its ability to potently and selectively transactivate progesterone receptors at relatively low doses, resulting in robust neurogenetic, remyelinating, and anti-inflammatory effects. That CNS disorders, including multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), spinal cord injury (SCI), and stroke, develop via demyelinating, cell death, and/or inflammatory pathological pathways advances Nestorone as an auspicious candidate for these disorders. Here, we assess the scientific and clinical progress over decades of research into progesterone, progestins, and Nestorone as neuroprotective agents in MS, ALS, SCI, and stroke. We also offer recommendations for optimizing timing, dosage, and route of the drug regimen, and identifying candidate patient populations, in advancing Nestorone to the clinic.

A Museum of Stem Cells Points to Muse Cells as Robust Transplantable Cells for Stroke: Review.

Stem cell-based therapy stands as a robust experimental treatment for ischemic stroke. Stem cells derived from fetal, embryonic, and adult tissues serve as potential sources for transplantable cells in the setting of ischemic stroke. However, the search continues for finding an optimal cell line for clinical use. Muse cells, a distinct subset of mesenchymal stem cells found sporadically in the connective tissue of nearly every organ, may be a suitable candidate due to its safety and accessibility. These cells have been investigated for therapeutic usage in chronic kidney disease, liver disease, acute myocardial infarction, and stroke. Muse cells display the ability to engraft and differentiate into the host neural network unlike many other cell lines which only display bystander immunomodulating effects. Taking advantage of this unique engraftment and differentiation mechanism behind Muse cells' therapeutic effects on the central nervous system, as well as other organ systems, will undoubtedly advance the cells' utility for cell-based regenerative medicine in stroke.