Stem cells
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Pulmonary arterial hypertension (PAH) remains a serious disease, and although current treatments may prolong and improve quality of life, search for novel and effective therapies is warranted. Using genetically modified mouse lines, we tested the ability of bone marrow-derived stromal cells (mesenchymal stem cells [MSCs]) to treat chronic hypoxia-induced PAH. Recipient mice were exposed for 5 weeks to normobaric hypoxia (8%-10% O(2)), MSC preparations were delivered through jugular vein injection and their effect on PAH was assessed after two additional weeks in hypoxia. ⋯ Donor MSCs isolated from a bitransgenic mouse line with doxycycline-inducible, lung-specific expression of HO-1 exhibited similar therapeutic efficacy only on doxycycline treatment of the recipients. In vitro experiments indicate that potential mechanisms of MSC action include modulation of hypoxia-induced lung inflammation and inhibition of smooth muscle cell proliferation. Cumulatively, our results demonstrate that MSCs ameliorate chronic hypoxia-induced PAH and their efficacy is highly augmented by lung-specific HO-1 expression in the transplanted cells, suggesting an interplay between HO-1-dependent and HO-1-independent protective pathways.
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Nearly 30% of patients with mesial temporal lobe epilepsy (TLE) are resistant to treatment with antiepileptic drugs. Neural stem cell (NSC) grafting into the hippocampus could offer an alternative therapy to hippocampal resection in these patients. As TLE is associated with reduced numbers of inhibitory gamma-amino butyric acid (GABA)-ergic interneurons and astrocytes expressing the anticonvulsant glial-derived neurotrophic factor (GDNF) in the hippocampus, we tested the hypothesis that grafting of NSCs that are capable of adding new GABA-ergic interneurons and GDNF-expressing astrocytes into the epileptic hippocampus restrains spontaneous recurrent motor seizures (SRMS) in chronic TLE. ⋯ Additionally, NSC grafting restored GDNF in a vast majority of the hippocampal astrocytes but had no effect on neurogenesis. Thus, MGE-NSC therapy is efficacious for diminishing SRMS in chronic TLE. Addition of new GABA-ergic neurons and GDNF+ cells, and restoration of GDNF in the hippocampal astrocytes may underlie the therapeutic effect of MGE-NSC grafts.
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Alzheimer's disease (AD) is characterized by the deposition of amyloid-beta peptide (Abeta) and the formation of neurofibrillary tangles. Transplantation of bone marrow-derived mesenchymal stem cells (BM-MSCs) has been suggested as a potential therapeutic approach to prevent various neurodegenerative disorders, including AD. However, the actual therapeutic impact of BM-MSCs and their mechanism of action in AD have not yet been ascertained. ⋯ Furthermore, APP/PS1 mice treated with BM-MSCs had decreased tau hyperphosphorylation and improved cognitive function. In conclusion, BM-MSCs can modulate immune/inflammatory responses in AD mice, ameliorate their pathophysiology, and improve the cognitive decline associated with Abeta deposits. These results demonstrate that BM-MSCs are a potential new therapeutic agent for AD.
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The stem cell niche plays an important role in the microenvironmental regulation of hematopoietic stem cells, but the integration of niche activity remains poorly understood. In this study, we show that a functional deficiency of Bis/BAG-3/CAIR-1, a protein related to apoptosis and the response to cellular stress, results in perturbation of the vascular stem cell niche, causing a series of hematopoietic derangements. Mice with a targeted disruption of bis (bis(-/-)) exhibited a loss of hematopoietic stem cells and defective B-cell development. ⋯ Subsequent analysis of bis(-/-) mice bone marrow revealed a characteristic defect in the vascular stem cell niche that included the defective growth of stromal progenitor cells in colony forming unit-fibroblasts, the defect in sinusoidal endothelium, and the loss of stromal cells expressing CXCL-12 or IL-7 in the bone marrow. In contrast, no abnormalities were observed in the growth and hematopoietic supporting activities of osteoblasts from bis(-/-) mice bone marrows. Collectively, these results indicate that Bis functions to mediate cellular regulation of the stem cell niche on the vascular compartment and suggest that the vascular and osteoblastic compartments of the stem cell niche can be independently regulated during the in vivo orchestration of hematopoiesis.
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Evidence that cell transplants can improve recovery outcomes in spinal cord injury (SCI) models substantiates treatment strategies involving cell replacement for humans with SCI. Most pre-clinical studies of cell replacement in SCI examine thoracic injury models. However, as most human injuries occur at the cervical level, it is critical to assess potential treatments in cervical injury models and examine their effectiveness using at-level histological and functional measures. ⋯ On the basis of reported benefits in thoracic SCI, we transplanted human embryonic stem cell (hESC)-derived oligodendrocyte progenitor cells (OPCs) into this cervical model. hESC-derived OPC transplants attenuated lesion pathogenesis and improved recovery of forelimb function. Histological effects of transplantation included robust white and gray matter sparing at the injury epicenter and, in particular, preservation of motor neurons that correlated with movement recovery. These findings further our understanding of the histopathology and functional outcomes of cervical SCI, define potential therapeutic targets, and support the use of these cells as a treatment for cervical SCI.