Search

Much excitement has been generated by recent work showing that a variety of myelin-forming cell types can elicit remyelination and facilitate axonal regeneration in animal models of demyelination and axonal transection. These cells include peripheral-myelin-forming cells, such as Schwann cells and olfactory ensheathing cells. In addition, progenitor cells derived from the subventricular zone of the brain and from bone marrow (BM) can form myelin when transplanted into demyelinated lesions in rodents. Here, we discuss recent findings that examine the remyelination potential of transplantation of peripheral-myelin-forming cells and progenitor cells derived from brain and bone marrow. Better understanding of the repair potential of these cells in animal models may offer exciting opportunities to develop cells that may be used in future clinical studies. [ABSTRACT FROM AUTHOR]

Background: Experimental animal models of ischemic spinal cord injury (iSCI) are essential for studying its pathogenesis and for developing new therapeutic strategies to improve functional recovery in humans. Many existing models, however, exhibit high variability or early lethality. A reliable experimental iSCI model would significantly advance novel treatment approaches for these severe neurological disorders. To this end, we have established a rat model of persistent iSCI with an extended lifespan., Methods: We have developed a novel iSCI model that induces localized ischemic lesions in the spinal cord of male Sprague-Dawley rats. This is achieved by cross clamping the descending aorta just rostral the azygos vein using an atraumatic bulldog clamp., Results: The experimental iSCI model consistently demonstrated symptoms specific to spinal cord ischemia at the lumbar level. The procedure takes approximately 50 min and does not require specialized surgical equipment. It has a survival rate of 84%, a recovery rate of 40%, and a complication rate of 16%., Conclusions: We have successfully developed a rat model of persistent iSCI. This protocol proves to be highly reliable and holds promise for evaluating new therapeutic strategies aimed at promoting functional recovery in patients suffering from spinal cord ischemia., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The primary objective of this study was to investigate the potential facilitating effects of daily rehabilitation for chronic cerebral ischemia following the intravenous infusion of mesenchymal stem cells (MSC) in rats. The middle cerebral artery (MCA) was occluded by intraluminal occlusion using a microfilament (MCAO). Eight weeks after MCAO induction, the rats were used as a chronic cerebral ischemia model. Four experimental groups were studied: Vehicle group (medium only, no cells); Rehab group (vehicle + rehabilitation), MSC group (MSC only); and Combined group (MSC + rehabilitation). Rat MSCs were intravenously infused eight weeks after MCAO induction, and the rats received daily rehabilitation through treadmill exercise for 20 min. Behavioral testing, lesion volume assessment using magnetic resonance imaging (MRI), and histological analysis were performed during the observation period until 16 weeks after MCAO induction. All treated animals showed functional improvement compared with the Vehicle group; however, the therapeutic efficacy was greatest in the Combined group. The combination therapy is associated with enhanced neural plasticity shown with histological analysis and MRI diffusion tensor imaging. These findings provide behavioral evidence for enhanced recovery by combined therapy with rehabilitation and intravenous infusion of MSCs, and may form the basis for the development of clinical protocols in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Perinatal brain injury is multifactorial and primarily associated with brain prematurity, inflammation, and hypoxia-ischemia. Although recent advances in perinatal medicine　have improved the survival rates of preterm infants, neurodevelopmental disorders remain a significant complication. We tested whether the intravenous infusion of mesenchymal stem cells (MSCs) had therapeutic efficacy against perinatal brain injury in rats., Methods: Pregnant rats at embryonic day (E) 18 received lipopolysaccharide and the pups were born at E21. On postnatal day (PND) 7, the left common carotid artery of each pup was ligated, and they were exposed to 8% oxygen for 2 h. They were randomized on PND10, and MSCs or vehicle were intravenously infused. We performed behavioral assessments, measured brain volume using MRI, and performed histological analyses on PND49., Results: Infused MSCs showed functional improvements in our model. In vivo MRI revealed that MSC infusion increased non-ischemic brain volume compared to the vehicle group. Histological analyses showed that cortical thickness, the number of NeuN + and GAD67 + cells, and synaptophysin density in the non-ischemic hemisphere in the MSC group were greater than the vehicle group, but less than the control group., Conclusions: Infused MSCs improve sensorimotor and cognitive functions in perinatal brain injury and enhance neuronal growth., Impact: Intravenous infusion of MSCs improved neurological function in rats with perinatal brain injury, including motor, sensorimotor, cognitive, spatial, and learning memory. Infused MSCs increased residual (non-ischemic) tissue volume, number of neuronal cells, GABAergic cells, and cortical synapses in the contralesional (right) hemisphere. Intravenous administration of MSC might be suitable for the treatment of perinatal brain injury., (© 2023. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)

Spinal cord injury (SCI) can cause paralysis with a high disease burden with limited treatment options. A single intravenous infusion of mesenchymal stem cells (MSCs) improves motor function in rat SCI models, possibly through the induction of axonal sprouting and remyelination. Repeated infusions (thrice at weekly intervals) of MSCs were administered to rats with chronic SCI to determine if multiple-dosing regimens enhance motor improvement. Chronic SCI rats were randomized and infused with vehicle (vehicle), single MSC injection at week 6 (MSC-1) or repeatedly injections of MSCs at 6, 7, and 8 weeks (MSC-3) after SCI induction. In addition, a single high dose of MSCs (HD-MSC) equivalent to thrice the single dose was infused at week 6. Locomotor function, light and electron microscopy, immunohistochemistry and ex vivo diffusion tensor imaging were performed. Repeated infusion of MSCs (MSC-3) provided the greatest functional recovery compared to single and single high-dose infusions. The density of remyelinated axons in the injured spinal cord was the greatest in the MSC-3 group, followed by the MSC-1, HD-MSC and vehicle groups. Increased sprouting of the corticospinal tract and serotonergic axon density was the greatest in the MSC-3 group, followed by MSC-1, HD-MSC, and vehicle groups. Repeated infusion of MSCs over three weeks resulted in greater functional improvement than single administration of MSCs, even when the number of infused cells was tripled. MSC-treated rats showed axonal sprouting and remyelination in the chronic phase of SCI., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Spinal cord injury (SCI) in young adults leads to severe sensorimotor disabilities as well as slowing of growth. Systemic pro-inflammatory cytokines are associated with growth failure and muscle wasting. Here we investigated whether intravenous (IV) delivery of small extracellular vesicles (sEVs) derived from human mesenchymal stem/stromal cells (MSC) has therapeutic effects on body growth and motor recovery and can modulate inflammatory cytokines following severe SCI in young adult rats., Methods: Contusional SCI rats were randomized into three different treatment groups (human and rat MSC-sEVs and a PBS group) on day 7 post-SCI. Functional motor recovery and body growth were assessed weekly until day 70 post-SCI. Trafficking of sEVs after IV infusions in vivo, the uptake of sEVs in vitro, macrophage phenotype at the lesion and cytokine levels at the lesion, liver and systemic circulation were also evaluated., Results: An IV delivery of both human and rat MSC-sEVs improved functional motor recovery after SCI and restored normal body growth in young adult SCI rats, indicating a broad therapeutic benefit of MSC-sEVs and a lack of species specificity for these effects. Human MSC-sEVs were selectively taken up by M2 macrophages in vivo and in vitro, consistent with our previous observations of rat MSC-sEV uptake. Furthermore, the infusion of human or rat MSC-sEVs resulted in an increase in the proportion of M2 macrophages and a decrease in the production of the pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-6 at the injury site, as well as a reduction in systemic serum levels of TNF-α and IL-6 and an increase in growth hormone receptors and IGF-1 levels in the liver., Conclusions: Both human and rat MSC-sEVs promote the recovery of body growth and motor function after SCI in young adult rats possibly via the cytokine modulation of growth-related hormonal pathways. Thus, MSC-sEVs affect both metabolic and neurological deficits in SCI., (© 2023 The Authors. Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

Schwann cells (SCs) are the primary glia of the peripheral nervous system. SCs are involved in many debilitating disorders, including diabetic peripheral neuropathy (DPN). Here, we present a strategy for deriving SCs from human pluripotent stem cells (hPSCs) that enables comprehensive studies of SC development, physiology, and disease. hPSC-derived SCs recapitulate the molecular features of primary SCs and are capable of in vitro and in vivo myelination. We established a model of DPN that revealed the selective vulnerability of SCs to high glucose. We performed a high-throughput screen and found that an antidepressant drug, bupropion, counteracts glucotoxicity in SCs. Treatment of hyperglycemic mice with bupropion prevents their sensory dysfunction, SC death, and myelin damage. Further, our retrospective analysis of health records revealed that bupropion treatment is associated with a lower incidence of neuropathy among diabetic patients. These results highlight the power of this approach for identifying therapeutic candidates for DPN., Competing Interests: Declaration of interests F.F., L.S., S.C., and Z.G. are inventors on several patent applications owned by UCSF, MSKCC, and Weill Cornell Medicine related to hPSC differentiation technologies including the technologies reported in this manuscript. L.S. is a scientific co-founder and paid consultant of BlueRock Therapeutics and DaCapo BrainScience., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Magnetic resonance angiography (MRA) is an important tool in rat models of cerebrovascular disease. Although MRA has long been used in rodents, the image quality is typically not as high as that observed in clinical practice. Moreover, studies on MRA image quality in rats are limited. This study aimed to develop a practical high-spatial-resolution MRA protocol for imaging cerebral arteries in rats., New Method: We used the "half position method" regarding coil placement and modified the imaging parameters and image reconstruction method. We applied this new imaging method to measure maturation-related signal changes on rat MRAs., Results: The new practical high-spatial-resolution MRA imaging protocol obtained a signal intensity up to 3.5 times that obtained using a basic coil system, simply by modifying the coil placement method. This method allowed the detection of a gradual decrease in the signal in cerebral vessels with maturation., Comparison With Existing Methods: A high-spatial-resolution MRA for rats was obtained with an imaging time of approximately 100 min. Comparable resolution and image quality were obtained using the new protocol with an imaging time of 30 min CONCLUSIONS: The new practical high-spatial-resolution MRA protocol can be implemented simply and successfully to achieve high image quality with an imaging time of approximately 30 min. This protocol will benefit researchers performing MRA imaging in cerebral artery studies in rats., Competing Interests: Declaration of Competing Interest None of the author has any conflict of interest to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Although limited spontaneous recovery occurs after spinal cord injury (SCI), current knowledge reveals that multiple forms of axon growth in spared axons can lead to circuit reorganization and a detour or relay pathways. This hypothesis has been derived mainly from studies of the corticospinal tract (CST), which is the primary descending motor pathway in mammals. The major CST is the dorsal CST (dCST), being the major projection from cortex to spinal cord. Two other components often called "minor" pathways are the ventral and the dorsal lateral CSTs, which may play an important role in spontaneous recovery. Intravenous infusion of mesenchymal stem cells (MSCs) provides functional improvement after SCI with an enhancement of axonal sprouting of CSTs. Detailed morphological changes of CST pathways, however, have not been fully elucidated. The primary objective was to evaluate detailed changes in descending CST projections in SCI after MSC infusion. The MSCs were infused intravenously one day after SCI. A combination of adeno-associated viral vector (AAV), which is an anterograde and non-transsynaptic axonal tracer, was injected 14 days after SCI induction. The AAV with advanced tissue clearing techniques were used to visualize the distribution pattern and high-resolution features of the individual axons coursing from above to below the lesion. The results demonstrated increased observable axonal connections between the dCST and axons in the lateral funiculus, both rostral and caudal to the lesion core, and an increase in observable axons in the dCST below the lesion. This increased axonal network could contribute to functional recovery by providing greater input to the spinal cord below the lesion.

Background: Brain injuries resulting from motor vehicle accidents and falls, as well as hypoxic insults and other conditions, are one of the leading causes of disability and death in the world. Current treatments are limited but include continuous rehabilitation, especially for chronic brain injury. Recent studies have demonstrated that the intravenous infusion of mesenchymal stem cells (MSCs) has therapeutic efficacy for several neurological diseases, including stroke and spinal cord injury., Objective: The objective of our investigator-initiated clinical trial is to assess the safety and potential efficacy of the intravenous infusion of autoserum-expanded autologous MSCs for patients with chronic brain injury., Methods: The (phase 2) trial will be a single-arm, open-label trial with the primary objective of confirming the safety and efficacy of autoserum-expanded autologous MSCs (STR-01; produced under good manufacturing practices) when administered to patients with chronic brain injury. The estimated number of enrolled participants is 6 to 20 patients with a modified Rankin Scale grade of 3 to 5. The assessment of safety and the proportion of cases in which the modified Rankin Scale grade improves by 1 point or more at 180 days after the injection of STR-01 will be performed after MSC infusion., Results: We received approval for our clinical trial from the Japanese Pharmaceuticals and Medical Devices Agency on December 12, 2017. The trial will be completed on June 11, 2023. The registration term is 5 years. The recruitment of the patients for this trial started on April 20, 2018, at Sapporo Medical University Hospital in Japan., Conclusions: Our phase 2 study will aim to address the safety and efficacy of the intravenous infusion of MSCs for patients with chronic brain injury. The use of STR-01 has been performed for patients with cerebral infarction and spinal cord injury, providing encouraging results. The potential therapeutic efficacy of the systemic administration of autoserum-expanded autologous MSCs for chronic brain injury should be evaluated, given its safety and promising results for stroke and spinal cord injury., Trial Registration: Japan Medical Association Center for Clinical Trials JMA-IIA00333; https://tinyurl.com/nzkdfnbc., International Registered Report Identifier (irrid): DERR1-10.2196/37898., (©Shinichi Oka, Tomohiro Yamaki, Masanori Sasaki, Ryo Ukai, Mitsuhiro Takemura, Takahiro Yokoyama, Yuko Kataoka-Sasaki, Rie Onodera, Yoichi M Ito, Shigeki Kobayashi, Jeffery D Kocsis, Yasuo Iwadate, Osamu Honmou. Originally published in JMIR Research Protocols (https://www.researchprotocols.org), 06.07.2022.)

Objective: Stroke is a major cause of long-term disability, and there are few effective treatments that improve function in patients during the chronic phase of stroke. Previous research has shown that single systemic infusion of mesenchymal stem cells (MSCs) improves motor function in acute and chronic cerebral ischemia models in rats. A possible mechanism that could explain such an event includes the enhanced neural connections between cerebral hemispheres that contribute to therapeutic effects. In the present study, repeated infusions (3 times at weekly intervals) of MSCs were administered in a rat model of chronic stroke to determine if multiple dosing facilitated plasticity in neural connections., Methods: The authors induced middle cerebral artery occlusion (MCAO) in rats and, 8 weeks thereafter, used them as a chronic stroke model. The rats with MCAO were randomized and intravenously infused with vehicle only (vehicle group); with MSCs at week 8 (single administration: MSC-1 group); or with MSCs at weeks 8, 9, and 10 (3 times, repeated administration: MSC-3 group) via femoral veins. Ischemic lesion volume and behavioral performance were examined. Fifteen weeks after induction of MCAO, the thickness of the corpus callosum (CC) was determined using Nissl staining. Immunohistochemical analysis of the CC was performed using anti-neurofilament antibody. Interhemispheric connections through the CC were assessed ex vivo by diffusion tensor imaging., Results: Motor recovery was better in the MSC-3 group than in the MSC-1 group. In each group, there was no change in the ischemic volume before and after infusion. However, both thickness and optical density of neurofilament staining in the CC were greater in the MSC-3 group, followed by the MSC-1 group, and then the vehicle group. The increased thickness and optical density of neurofilament in the CC correlated with motor function at 15 weeks following induction of MCAO. Preserved neural tracts that ran through interhemispheric connections via the CC were also more extensive in the MSC-3 group, followed by the MSC-1 group and then the vehicle group, as observed ex vivo using diffusion tensor imaging., Conclusions: These results indicate that repeated systemic administration of MSCs over 3 weeks resulted in greater functional improvement as compared to single administration and/or vehicle infusion. In addition, administration of MSCs is associated with promotion of interhemispheric connectivity through the CC in the chronic phase of cerebral infarction.

Background: Interstitial cystitis/bladder pain syndrome (IC/BPS) categorized with and without Hunner lesions is a condition that displays chronic pelvic pain related to the bladder with no efficacious treatment options. There are strong associations suggested between Hunner-type IC and autoimmune diseases. Recently, we established an animal model of Hunner-type IC using a Toll-like receptor-7 (TLR7) agonist. Intravenous infusion of mesenchymal stem cells (MSCs) can be used to treat injury via multimodal and orchestrated therapeutic mechanisms including anti-inflammatory effects. Here, we investigated whether infused MSCs elicit therapeutic efficacy associated with the TLR7-related anti-inflammatory pathway in our Hunner-type IC model., Methods: Voiding behaviors were monitored 24 h prior to the Loxoribine (LX), which is a TLR7 agonist instillation in order to establish a Hunner-type IC model (from - 24 to 0 h) in female Sprague-Dawley rats. LX was instilled transurethrally into the bladder. At 0 h, the initial freezing behavior test confirmed that no freezing behavior was observed in any of the animals. The LX-instilled animals were randomized. Randomized LX-instilled rats were intravenously infused with MSCs or with vehicle through the right external jugular vein. Sampling tissue for green fluorescent protein (GFP)-positive MSCs were carried out at 48 h. Second voiding behavior tests were monitored from 72 to 96 h. After the final evaluation of the freezing behavior test at 96 h after LX instillation (72 h after MSC or vehicle infusion), histological evaluation with H&E staining and quantitative real-time polymerase chain reaction (RT-PCR) to analyze the mRNA expression levels of inflammatory cytokines were performed., Results: Freezing behavior was reduced in the MSC group, and voiding behavior in the MSC group did not deteriorate. Hematoxylin-eosin staining showed that mucosal edema, leukocyte infiltration, and hemorrhage were suppressed in the MSC group. The relative expression of interferon-β mRNA in the bladder of the MSC group was inhibited. Numerous GFP-positive MSCs were distributed mainly in the submucosal and mucosal layers of the inflammatory bladder wall., Conclusion: Intravenous infusion of MSCs may have therapeutic efficacy in a LX-instilled Hunner-type IC rat model via a TLR7-related anti-inflammatory pathway., (© 2021. The Author(s).)

Background: Surgical reconstruction options of soft-tissue defects often include random pattern skin flaps. Flap survival depends on flap size and rotation arc and can be challenging regarding flap perfusion, leading to wound healing complications, insufficient wound coverage, and even flap loss. Therefore, novel approaches that promote skin flap survival are required. Bone marrow-derived mesenchymal stem cells intravenous infusion is therapeutically effective in various experimental disease models by means of multimodal and orchestrated mechanisms including anti-inflammatory and immunomodulatory effects, and by means of microvasculature reestablishment., Methods: A modified McFarlane-type rodent skin flap model was used. After skin flap surgery, intravenous infusion of mesenchymal stem cells or vehicle was performed. In vivo optical near-infrared imaging using indocyanine green was performed, followed by histologic analysis, including hematoxylin and eosin and Masson trichrome staining, and gene expression analysis., Results: The flap survival area was greater in the mesenchymal stem cell group. In vivo optical near-infrared perfusion imaging analysis suggested that skin blood perfusion was greater in the mesenchymal stem cell group. Ex vivo histologic analysis demonstrated that the skin structure was more clearly observed in the mesenchymal stem cell group. The dermal thickness was greater in the mesenchymal stem cell group, according to the Masson trichrome staining results. The authors observed a higher expression of fibroblast growth factor 2 mRNA in the tissues of the mesenchymal stem cell group using quantitative reverse-transcription polymerase chain reaction., Conclusion: These results suggest that intravenous infusion of bone marrow-derived mesenchymal stem cells promotes skin survival of random pattern flaps, which is associated with increased blood perfusion and higher expression of fibroblast growth factor 2., (Copyright © 2021 by the American Society of Plastic Surgeons.)

Intravenous (IV) infusion of bone marrow-derived mesenchymal stem/stromal cells (MSCs) stabilizes the blood-spinal cord barrier (BSCB) and improves functional recovery in experimental models of spinal cord injury (SCI). Although IV delivered MSCs do not traffic to the injury site, IV delivered small extracellular vesicles (sEVs) derived from MSCs (MSC-sEVs) do and are taken up by a subset of M2 macrophages. To test whether sEVs released by MSCs are responsible for the therapeutic effects of MSCs, we tracked sEVs produced by IV delivered DiR-labelled MSCs (DiR-MSCs) after transplantation into SCI rats. We found that sEVs were released by MSCs in vivo, trafficked to the injury site, associated specifically with M2 macrophages and co-localized with exosome markers. Furthermore, while a single MSC injection was sufficient to improve locomotor recovery, fractionated dosing of MSC-sEVs over 3 days (F-sEVs) was required to achieve similar therapeutic effects. Infusion of F-sEVs mimicked the effects of single dose MSC infusion on multiple parameters including: increased expression of M2 macrophage markers, upregulation of transforming growth factor-beta (TGF-β), TGF-β receptors and tight junction proteins, and reduction in BSCB permeability. These data suggest that release of sEVs by MSCs over time induces a cascade of cellular responses leading to improved functional recovery., (© 2021 The Authors. Journal of Extracellular Vesicles published by Wiley Periodicals, LLC on behalf of the International Society for Extracellular Vesicles.)

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative fatal disorder in which motor neurons within the brain and spinal cord degenerate. A single infusion of mesenchymal stem cells (MSCs) delays disease progression by protecting motor neurons and restoring the blood-spinal cord barrier in the SOD1G93A transgenic ALS rat model. However, the therapeutic effect of a single infusion of MSCs is transient and does not block disease progression. In this study, we demonstrated that repeated administration of MSCs (weekly, four times) increased the survival period, protected motor functions, and reduced deterioration of locomotor activity compared to a single infusion and vehicle infusion, after which rats displayed progressive deterioration of hind limb function. We also compared the days until gait ability was lost in rats and found that the repeated-infused group maintained gait ability compared to the single-infusion and vehicle-infusion groups. These results suggest that repeated administration of MSCs may prevent the deterioration of motor function and extend the lifespan in ALS.

Objective: Reperfusion therapy is a standard therapeutic strategy for acute stroke. Non-favorable outcomes are thought to partially result from impaired microcirculatory flow in ischemic tissue. Intravenous infusion of mesenchymal stem cells (MSCs) reduces stroke volume and improves behavioral function in stroke. One suggested therapeutic mechanism is the restoration of the microvasculature. The goal of this study was to determine whether infused MSCs enhance the therapeutic efficacy of reperfusion therapy following stroke in rats., Methods: First, to establish a transient middle cerebral artery occlusion (MCAO) model displaying approximately identical neurologic function and lesion volume as seen in permanent MCAO (pMCAO) at day 7 after stroke induction, we transiently occluded the MCA for 90, 110, and 120 minutes. We found that the 110-minute occlusion met these criteria and was used as the transient MCAO (tMCAO) model. Next, 4 MCAO groups were used to compare the therapeutic efficacy of infused MSCs: (1) pMCAO+vehicle, (2) tMCAO+vehicle, (3) pMCAO+MSC, and (4) tMCAO+MSC. Our ischemic model was a unique ischemic model system in which both pMCAO and tMCAO provided similar outcomes during the study period in the groups without MSC infusion groups. Behavioral performance, ischemic volume, and regional cerebral blood flow (rCBF) using arterial spin labeling-magnetic resonance imaging and histologic evaluation of microvasculature was performed., Results: The behavioral function, rCBF, and restoration of microvasculature were greater in group 4 than in group 3. Thus, infused MSCs facilitated the therapeutic efficacy of MCA reperfusion in this rat model system., Conclusions: Intravenous infusion of MSCs may enhance therapeutic efficacy of reperfusion therapy., (Copyright © 2021 Elsevier Inc. All rights reserved.)

ALS is a devastating neurodegenerative disease with few curative strategies. Both sporadic and familial ALS display common clinical features that show progressive paralysis. The pathogenesis remains unclear, but disruption of the blood-spinal cord barrier (BSCB) may contribute to the degeneration of motor neurons. Thus, restoration of the disrupted BSCB and neuroprotection for degenerating motor neurons could be therapeutic targets. We tested the hypothesis that an intravenous infusion of MSCs would delay disease progression through the preservation of BSCB function and increased expression of a neurotrophic factor, neurturin, in SOD1 G93A ALS rats. When the open-field locomotor function was under 16 on the Basso, Beattie, and Bresnahan (BBB) scoring scale, the rats were randomized into two groups; one received an intravenous infusion of MSCs, while the other received vehicle alone. Locomotor function was recorded using BBB scoring and rotarod testing. Histological analyses, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), were performed. The MSC group exhibited reduced deterioration of locomotor activity compared to the vehicle group, which displayed progressive deterioration of hind limb function. We observed the protection of motor neuron loss and preservation of microvasculature using Evans blue leakage and immunohistochemical analyses in the MSC group. Confocal microscopy revealed infused green fluorescent protein + (GFP + ) MSCs in the spinal cord, and the GFP gene was detected by nested PCR. Neurturin expression levels were significantly higher in the MSC group. Thus, restoration of the BSCB and the protection of motor neurons might be contributing mechanisms to delay disease progression in SOD1 G93A ALS rats., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Animal models are required to study the pathogenesis of brainstem ischemia and to develop new therapeutic approaches to promote functional recovery after ischemia in humans. Few models of brainstem ischemia are available, and they show great variability or cause early lethality. New, reliable animal models are therefore needed. By selectively ligating four points of the lower basilar artery, we developed a new focal basilar artery occlusion model that causes a localized brainstem ischemic lesion in female Sprague-Dawley rats. Analysis of ischemic lesion volume and neurological deficits over a period of 28 d showed that the rats present symptoms specific to this type of stroke while the ischemic lesion remains relatively unchanged over time. This procedure allows higher survival rates and extended observation periods compared with other models of brainstem ischemia. The procedure takes ~40 min, can be performed by researchers with basic surgical skills and does not require specialized surgical equipment. This protocol is highly reliable and will be useful to evaluate new therapeutic approaches to promote functional recovery in patients with brainstem ischemia.

Background: Although spinal cord injury (SCI) is a major cause of disability, current therapeutic options remain limited. Recent progress in cellular therapy with mesenchymal stem cells (MSCs) has provided improved function in animal models of SCI. We investigated the safety and feasibility of intravenous infusion of MSCs for SCI patients and assessed functional status after MSC infusion., Methods: In this phase 2 study of intravenous infusion of autologous MSCs cultured in auto-serum, a single infusion of MSCs under Good Manufacturing Practice (GMP) production was delivered in 13 SCI patients. In addition to assessing feasibility and safety, neurological function was assessed using the American Spinal Injury Association Impairment Scale (ASIA), International Standards for Neurological and Functional Classification of Spinal Cord (ISCSCI-92). Ability of daily living was assessed using Spinal Cord Independence Measure (SCIM-III). The study protocol was based on advice provided by the Pharmaceuticals and Medical Devices Agency in Japan. The trial was registered with the Japan Medical Association (JMA-IIA00154)., Results: No serious adverse events were associated with MSC injection. There was neurologic improvement based on ASIA grade in 12 of the 13 patients at six months post-MSC infusion. Five of six patients classified as ASIA A prior to MSC infusion improved to ASIA B (3/6) or ASIA C (2/6), two ASIA B patients improved to ASIA C (1/2) or ASIA D (1/2), five ASIA C patients improved and reached a functional status of ASIA D (5/5). Notably, improvement from ASIA C to ASIA D was observed one day following MSC infusion for all five patients. Assessment of both ISCSCI-92, SCIM-III also demonstrated functional improvements at six months after MSC infusion, compared to the scores prior to MSC infusion in all patients., Conclusion: While we emphasize that this study was unblinded, and does not exclude placebo effects or a contribution of endogenous recovery or observer bias, our observations provide evidence supporting the feasibility, safety and functional improvements of infused MSCs into patients with SCI., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Intravenous infusion of mesenchymal stem cells (MSCs) has been reported to provide therapeutic efficacy via microvascular remodeling in a spontaneously hypertensive rat. In this study, we demonstrate that intravenous infusion of MSCs increased the survival rate in a spontaneously hypertensive (stroke prone) rat model in which organs including kidney, brain, heart and liver are damaged during aging due to spontaneous hypertension. Gene expression analysis indicated that infused MSCs activates transforming growth factor-β1-smad3/forkhead box O1 signaling pathway. Renal dysfunction was recovered after MSC infusion. Collectively, intravenous infusion of MSC may extend lifespan in this model system., Competing Interests: The authors declare no conflict of interest., (© 2020 The Author(s).)

Ischemic spinal cord injury (iSCI) is a devastating complication of aortic surgery, with few strategies for prevention. Intravenous infusion of mesenchymal stem cells (MSCs) for iSCI has been shown to provide functional improvement through protection of gray matter. The purpose of this study was to investigate additional mechanisms which may exert therapeutic efficacy in iSCI. Severe iSCI was created to occlude the descending aorta, which was cross-clamped 5 mm distal to the left subclavian artery for 16 min. One day after iSCI induction, iSCI rats were randomized into two groups: one received intravenous infusion of MSCs (MSC-group), the other received vehicle (no cells; vehicle-group). Locomotor function and in vivo MRI were recorded. H&E, Nissl and toluidine blue stainings, immunohistochemical analysis, diffusion tensor imaging (DTI), and the assessment of blood-spinal cord barrier (BSCB) stability were performed. MSC treated animals exhibited gradual improvement in hind-limb locomotor function during the 4-week study period; however the vehicle-treated group displayed persistent motor deficits. In the MSC-treated group we observed the protection of white and gray matter volume reduction of axonal and neuronal loss or degeneration and preservation of microvasculature including BSCB function. Intravenous infusion of MSCs may provide therapeutic efficacy to improve functional outcomes in a rat model of severe iSCI via protection of white and gray matter., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Vincristine, a widely used chemotherapeutic agent, produces painful peripheral neuropathy. The underlying mechanisms are not well understood. In this study, we investigated whether voltage-gated sodium channels are involved in the development of vincristine-induced neuropathy. We established a mouse model in which repeated systemic vincristine treatment results in the development of significant mechanical allodynia. Histological examinations did not reveal major structural changes at proximal sciatic nerve branches or distal toe nerve fascicles at the vincristine dose used in this study. Immunohistochemical studies and in vivo two-photon imaging confirmed that there is no significant change in density or morphology of intra-epidermal nerve terminals throughout the course of vincristine treatment. These observations suggest that nerve degeneration is not a prerequisite of vincristine-induced mechanical allodynia in this model. We also provided the first detailed characterization of tetrodotoxin-sensitive (TTX-S) and resistant (TTX-R) sodium currents in dorsal root ganglion neurons following vincristine treatment. Accompanying the behavioural hyperalgesia phenotype, voltage-clamp recordings of small and medium dorsal root ganglion neurons from vincristine-treated animals revealed a significant upregulation of TTX-S Na+ current in medium but not small neurons. The increase in TTX-S Na+ current density is likely mediated by Nav1.6, because in the absence of Nav1.6 channels, vincristine failed to alter TTX-S Na+ current density in medium dorsal root ganglion neurons and, importantly, mechanical allodynia was significantly attenuated in conditional Nav1.6 knockout mice. Our data show that TTX-S sodium channel Nav1.6 is involved in the functional changes of dorsal root ganglion neurons following vincristine treatment and it contributes to the maintenance of vincristine-induced mechanical allodynia., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

After CNS trauma such as spinal cord injury, the ability of surviving neural elements to sprout axons, reorganize neural networks and support recovery of function is severely restricted, contributing to chronic neurological deficits. Among limitations on neural recovery are myelin-associated inhibitors functioning as ligands for neuronal Nogo receptor 1 (NgR1). A soluble decoy (NgR1-Fc, AXER-204) blocks these ligands and provides a means to promote recovery of function in multiple preclinical rodent models of spinal cord injury. However, the safety and efficacy of this reagent in non-human primate spinal cord injury and its toxicological profile have not been described. Here, we provide evidence that chronic intrathecal and intravenous administration of NgR1-Fc to cynomolgus monkey and to rat are without evident toxicity at doses of 20 mg and greater every other day (≥2.0 mg/kg/day), and far greater than the projected human dose. Adult female African green monkeys underwent right C5/6 lateral hemisection with evidence of persistent disuse of the right forelimb during feeding and right hindlimb during locomotion. At 1 month post-injury, the animals were randomized to treatment with vehicle (n = 6) or 0.10-0.17 mg/kg/day of NgR1-Fc (n = 8) delivered via intrathecal lumbar catheter and osmotic minipump for 4 months. One animal was removed from the study because of surgical complications of the catheter, but no treatment-related adverse events were noted in either group. Animal behaviour was evaluated at 6-7 months post-injury, i.e. 1-2 months after treatment cessation. The use of the impaired forelimb during spontaneous feeding and the impaired hindlimb during locomotion were both significantly greater in the treatment group. Tissue collected at 7-12 months post-injury showed no significant differences in lesion size, fibrotic scar, gliosis or neuroinflammation between groups. Serotoninergic raphespinal fibres below the lesion showed no deficit, with equal density on the lesioned and intact side below the level of the injury in both groups. Corticospinal axons traced from biotin-dextran-amine injections in the left motor cortex were equally labelled across groups and reduced caudal to the injury. The NgR1-Fc group tissue exhibited a significant 2-3-fold increased corticospinal axon density in the cervical cord below the level of the injury relative to the vehicle group. The data show that NgR1-Fc does not have preclinical toxicological issues in healthy animals or safety concerns in spinal cord injury animals. Thus, it presents as a potential therapeutic for spinal cord injury with evidence for behavioural improvement and growth of injured pathways in non-human primate spinal cord injury., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: After traumatic nerve injury, neuromuscular junction remodeling plays a key role in determining functional outcomes. Immunohistochemical analyses of denervated muscle biopsies may provide valuable prognostic data regarding clinical outcomes to supplement electrodiagnostic studies., Methods: We performed biopsies on nonfunctioning deltoid muscles in two patients after gunshot wounds and visualized the neuromuscular junctions using two-photon microscopy with immunohistochemistry., Results: Although the nerves in both patients showed evidence of acute Wallerian degeneration, some of the motor endplates were intact but exhibited significantly decreased surface area and volume. Both patients exhibited substantial recovery of motor function over several weeks postinjury., Discussion: Two-photon microscopic assessment of neuromuscular junction integrity and motor endplate morphometry in muscle biopsies provided evidence of partial sparing of muscle innervation. This finding supported the clinical judgment that eventual recovery would occur. With further study, this technique may help to guide operative decisionmaking after traumatic nerve injuries., (© 2019 Wiley Periodicals, Inc.)

Objective: In-stent restenosis after percutaneous transluminal angioplasty and stenting (PTAS) due to neointimal hyperplasia is a potential cause of clinical complications, including repeated revascularization and ischemic events. Neointimal hyperplasia induced by an inflammatory response to the stent strut may be a possible mechanism of in-stent restenosis. Intravenous infusion of bone marrow-derived mesenchymal stem cells (MSCs) has been reported to show therapeutic efficacy for cerebral stroke, presumably by an antiinflammatory effect. This study aimed to determine whether MSCs can reduce or prevent neointimal hyperplasia induced by an endovascular stent., Methods: In this study, two types of bare metal stents were deployed using a porcine (mini-pig) model. One stent was implanted in the common carotid artery (CCA), which is considered quite similar to the human CCA, and the other was inserted in the superficial cervical artery (SCA), which is similar in size to the human middle cerebral artery. Angiographic images, intravascular ultrasound (IVUS) imaging, and microscopic images were used for analysis., Results: Angiographic images and IVUS studies revealed that intravenous infusion of MSCs immediately after deployment of stents prevented in-stent stenosis of the CCA and SCA. Histological analysis also confirmed that inflammatory responses around the stent struts were reduced in both the stented CCA and SCA in the mini-pig., Conclusions: Intravenous infusion of MSCs inhibited the inflammatory reaction to an implanted stent strut, and prevented progressive neointimal hyperplasia in the stented CCA and SCA in a porcine model. Thus, MSC treatment could attenuate the recurrence of cerebral ischemic events after stenting.

Cerebral small vessel disease (CSVD) is not only a cause of vascular dementia (VD) but also a contributing factor to Alzheimer's disease (AD). The essential pathological feature of CSVD is the disruption of blood-brain barrier (BBB). Dysfunction of BBB due to degeneration of both endothelial cells and pericytes in capillaries leads to neuronal damage and progressive brain atrophy. Moreover, deterioration of amyloid-β (Aβ) clearance due to the failure of the transvascular BBB transport system results in accumulation of Aβ in the brain. Intravenous infusion of mesenchymal stem cells (MSCs) elicits functional recovery in experimental models including stroke and spinal cord injury. One effect of MSCs is to restore disrupted BBB through remodeling of microvasculature. Using spontaneously hypertensive rats (stroke-prone) with impaired cognitive function as a CSVD model, we have shown that infused MSCs has a therapeutic effect for cognitive function. Restoration of BBB function via remodeling of microvasculature and inhibition of Aβ accumulation could inhibit progressive brain atrophy and lead to restore cognitive dysfunction. Gene expression analysis indicated that infused MSCs activates both transforming growth factor-β and angiopoietin 1 signaling pathways and promotes the remodeling of microvasculature. Thus, infused MSCs may represent a novel therapy for both VD and AD., (Copyright © 2019 IBRO. Published by Elsevier Ltd. All rights reserved.)

Background: Intravenous infusion of mesenchymal stem cells (MSCs) derived from adult bone marrow elicits functional recovery in rat stroke models and clinical studies in patients are ongoing. Brain derived neurotrophic factor (BDNF) is a neurotrophic factor produced by MSCs and may contribute to their therapeutic efficacy. The purpose of the current study was to determine if BDNF is elevated in infarcted brain and in which compartment of blood (plasma or serum) after intravenous MSC infusion in a middle cerebral artery occlusion (MCAO) model in the rat., Methods: In rats, a permanent middle cerebral artery occlusion (MCAO) was induced by intraluminal vascular occlusion with a microfilament and MSCs were intravenously administered 6 h after right MCAO induction. Enzyme-linked immunosorbent assay (ELISA) analysis of brain, serum and plasma BDNF were performed after the MSC infusion following the MCAO induction. Lesion volume was assessed using magnetic resonance imaging. Functional outcome was assessed using the Limb Placement Test., Results: Infused MSCs reduced lesion volume and elicited functional improvement compared to the vehicle infused group. ELISA analysis of the MSC treated group revealed an increase BDNF levels in the infarcted hemisphere of the brain and plasma, but not in serum. The MSC group showed a greater increase in BDNF levels than sham control. In the MSC group, the expression of increased plasma BDNF levels correlated with increased brain BDNF levels., Conclusions: These results support the hypothesis that BDNF levels in plasma, but not serum, may be more appropriate to detect circulating BDNF in vivo following MSC infusion in a cerebral infarction rat model of ischemic stroke. Further, plasma BDNF might reflect in vivo functional viability of infused MSCs after stroke.

Spinal cord and peripheral nerve injury results in extensive damage to the locally injured cells as well as distant cells that are functionally connected to them. Both primary and secondary damage can cause a broad range of clinical abnormalities, including neuropathic pain and cognitive and memory dysfunction. However, the mechanisms underlying these abnormalities remain unclear, awaiting new methods to identify affected cells to enable examination of their molecular, cellular and physiological characteristics. Here, we report that both primary and secondary damage to cells in mouse models of spinal cord and peripheral nerve injury can be detected in vivo using a novel fluorescent reporter system based on the immediate stress response via activation of Heat Shock Factor 1. We also provide evidence for altered electrophysiological properties of reporter-positive secondarily-injured neurons. The comprehensive identification of injured, but surviving cells located both close and at distant locations from the injury site in vivo will provide a way to study their pathophysiology and possibly prevention of their further deterioration.

The authors intravenously infused mesenchymal stem cells (MSCs) into a rat model of neonatal hypoxia-ischemia and found improvements in functional outcome, increased brain volume, and enhanced synaptogenesis. The results of this animal study suggest that the intravenous administration of MSCs should be further explored as a potential treatment for patients suffering from cerebral palsy after hypoxic-ischemic encephalopathy.

Objective: Intravenous infusion of mesenchymal stem cells (MSCs) derived from adult bone marrow improves behavioral function in rat models of cerebral infarction. Although clinical studies are ongoing, most studies have focused on the acute or subacute phase of stroke. In the present study, MSCs derived from bone marrow of rats were intravenously infused 8 weeks after the induction of a middle cerebral artery occlusion (MCAO) to investigate whether delayed systemic injection of MSCs improves functional outcome in the chronic phase of stroke in rats., Methods: Eight weeks after induction of the MCAO, the rats were randomized and intravenously infused with either MSCs or vehicle. Ischemic volume and behavioral performance were examined. Blood-brain barrier (BBB) integrity was assessed by quantifying the leakage of Evans blue into the brain parenchyma after intravenous infusion. Immunohistochemical analysis was also performed to evaluate the stability of the BBB., Results: Motor recovery was better in the MSC-treated group than in the vehicle-treated group, with rapid improvement (evident at 1 week post-infusion). In MSC-treated rats, reduced BBB leakage and increased microvasculature/repair and neovascularization were observed., Conclusions: These results indicate that the systemic infusion of MSCs results in functional improvement, which is associated with structural changes in the chronic phase of cerebral infarction, including in the stabilization of the BBB.

Objective: Morbidity and mortality in patients with posterior circulation stroke remains an issue despite advances in acute stroke therapies. The intravenous infusion of mesenchymal stem cells (MSCs) elicits therapeutic efficacy in experimental supratentorial stroke models. However, since there are few reliable animal models of ischemia in the posterior circulation, the therapeutic approach with intravenous MSC infusion has not been tested. The objective of this study was to test the hypothesis that intravenously infused MSCs provide functional recovery in a newly developed model of brainstem infarction in rats., Methods: Basilar artery (BA) occlusion (BAO) was established in rats by selectively ligating 4 points of the proximal BA with 10-0 nylon monofilament suture. The intravenous infusion of MSCs was performed 1 day after BAO induction. MRI and histological examinations were performed to assess ischemic lesion volume, while multiple behavioral tests were performed to evaluate functional recovery., Results: The MSC-treated group exhibited a greater reduction in ischemic lesion volume, while behavioral testing indicated that the MSC-infused group had greater improvement than the vehicle group 28 days after the MSC infusion. Accumulated infused MSCs were observed in the ischemic brainstem lesion., Conclusions: Infused MSCs may provide neuroprotection to facilitate functional outcomes and reduce ischemic lesion volume as evaluated in a newly developed rat model of persistent BAO.

Background: Recurrence is inevitable in glioblastomas (GBMs) and requires multifactorial processes. One of the factors that cause recurrence is the strong migratory capacity of GBM cells. We recently reported that actin, alpha, cardiac muscle 1 (ACTC1) could serve as a marker to detect GBM migration in clinical cases., Objective: This study aimed to clarify whether the knockdown of highly expressed ACTC1 can inhibit the migratory capacity of cells in the GBM cell line., Methods: ACTC1 expression was examined using immunocytochemistry and droplet digital polymerase chain reaction. The motility of GBM cells that were either treated with siRNA to knock down ACTC1 or untreated were investigated using a time-lapse study in vitro., Results: The relatively high ACTC1 expression was confirmed in a GBM cell line, i.e., U87MG. The ACTC1 expression in U87MG cells was significantly inhibited by ACTC1-siRNA (p < 0.05). A cell movement tracking assay using time-lapse imaging demonstrated the inhibition of U87MG cell migration by ACTC1 knockdown. The quantitative cell migration analysis demonstrated that the distance traversed during 72 h was 3607 ± 458 (median ± SD) μm by untreated U87MG cells and 3570 ± 748 μm by negative control siRNA-treated cells. However, the distance migrated by ACTC1-siRNA-treated cells during 72 h was significantly shorter (1265 ± 457 μm, p < 0.01) than the controls., Conclusion: ACTC1 knockdown inhibits U87MG cell migration., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Systemic administration of mesenchymal stem cells (MSCs) following cerebral infarction exerts functional improvements. Previous research has suggested potential therapeutic mechanisms that promote neuroprotection and synaptogenesis. These include secretion of neurotrophic factors, remodeling of neural circuits, restoration of the blood brain barrier, reduction of inflammatory infiltration and demyelination, and elevation of trophic factors. In addition to these mechanisms, we hypothesized that restored interhemispheric bilateral motor cortex connectivity might be an additional mechanism of functional recovery. In the present study, we have shown, with both MRI diffusion tensor imaging (DTI) and neuroanatomical tracing techniques using an adeno-associated virus (AAV) expressing GFP, that there was anatomical restoration of cortical interhemispheric connections through the corpus callosum after intravenous infusion of MSCs in a rat middle cerebral artery occlusion (MCAO) stroke model. Moreover, the degree of connectivity was greater in the MSC-treated group than in the vehicle-infused group. In accordance, both the thickness of corpus callosum and synaptic puncta in the contralateral (non-infarcted) motor cortex connected to the corpus callosum were greater in the MSC-treated group than in the vehicle group. Together, these results suggest that distinct preservation of interhemispheric cortical connections through corpus callosum was promoted by intravenous infusion of MSCs. This anatomical preservation of the motor cortex in the contralateral hemisphere may contribute to functional improvements following MSC therapy for cerebral stroke., (Copyright © 2018 Elsevier B.V. All rights reserved.)