Stroke activates neural stem cells in the ventricular-subventricular zone (V/SVZ) of the lateral ventricle, which increases neuroblasts and oligodendrocyte progenitor cells (OPCs). Within the ischemic brain, neural stem cells, neuroblasts and OPCs appear to actively communicate with cerebral endothelial cells and other brain parenchymal cells to mediate ischemic brain repair; however, stroke-induced neurogenesis unlikely plays any significant roles in neuronal replacement. In this mini-review, we will discuss recent findings how intercellular communications between stroke-induced neurogenesis and oligodendrogenesis and brain parenchymal cells could potentially facilitate brain repair processes.
Brain* ; Endothelial Cells ; Lateral Ventricles ; Neural Stem Cells* ; Neurogenesis ; Neurons ; Oligodendroglia ; Stem Cells ; Stroke

BACKGROUND AND OBJECTIVES: The transplantation of human umbilical cord blood cells (hUCBCs) has been shown to attenuate the unregulated activation of microglia in a rat model of cerebral palsy (CP). To investigate whether hUCBCs transplantation is also anti-inflammatory in humans, we performed a clinical trial in patients with CP. METHODS AND RESULTS: Allogeneic or autologous hUCBCs and erythropoietin (EPO) were intravenously injected into human patients with CP (mean age of approximately 38 weeks), and patients were analyzed for their motor function and social behavior. Blood samples were tested for cytokine levels. The most surprising finding in the study was that the cytokine levels were dependent on the donor cell source (allogeneic or autologous). Interestingly, the allogeneic treatment group demonstrated significantly decreased levels of pro-inflammatory factors, such as IL-1alpha, IL-6, TNF-beta, and RANTES, and showed a statistically significant improvement in motor and social behavior compared to the autologous treatment group. CONCLUSIONS: Given that inflammation plays a pivotal role in CP, our results suggest that allogeneic hUCBCs therapy may be an appropriate strategy for CP treatment. In addition, prior to transplantation, a detailed analysis of the amount of proinflammatory cytokines in cord blood may be needed to avoid exacerbating inflammatory responses.
Animals ; Cerebral Palsy ; Chemokine CCL5 ; Cytokines ; Erythropoietin ; Fetal Blood ; Humans ; Inflammation ; Interleukin-6 ; Lymphotoxin-alpha ; Microglia ; Rats ; Social Behavior ; Tissue Donors ; Transplants ; Umbilical Cord

Traumatic brain injury (TBI) remains a major cause of death and disability worldwide. Increasing evidence indicates that TBI is an important risk factor for neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and chronic traumatic encephalopathy. Despite improved supportive and rehabilitative care of TBI patients, unfortunately, all late phase clinical trials in TBI have yet to yield a safe and effective neuroprotective treatment. The disappointing clinical trials may be attributed to variability in treatment approaches and heterogeneity of the population of TBI patients as well as a race against time to prevent or reduce inexorable cell death. TBI is not just an acute event but a chronic disease. Among many mechanisms involved in secondary injury after TBI, emerging preclinical studies indicate that posttraumatic prolonged and progressive neuroinflammation is associated with neurodegeneration which may be treatable long after the initiating brain injury. This review provides an overview of recent understanding of neuroinflammation in TBI and preclinical cell-based therapies that target neuroinflammation and promote functional recovery after TBI.
Age Factors ; Animals ; Brain ; immunology ; Brain Injuries, Traumatic ; complications ; therapy ; Cell- and Tissue-Based Therapy ; methods ; Exosomes ; Extracellular Vesicles ; physiology ; Female ; Humans ; Inflammation ; etiology ; Lymphatic System ; physiology ; Male ; Neuroprotective Agents ; Sex Characteristics