Sue and Bill Gross Stem Cell Center

Sue and, United States

Sue and Bill Gross Stem Cell Center

Sue and, United States
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Peterson S.L.,Sue and Bill Gross Stem Cell Center | Peterson S.L.,Institute for Memory Impairments and Neurological Disorders | Nguyen H.X.,Sue and Bill Gross Stem Cell Center | Nguyen H.X.,Institute for Memory Impairments and Neurological Disorders | And 5 more authors.
Journal of Neuroscience | Year: 2015

Traumatic injury to CNS fiber tracts is accompanied by failure of severed axons to regenerate and results in lifelong functional deficits. The inflammatory response to CNS trauma is mediated by a diverse set of cells and proteins with varied, overlapping, and opposing effects on histological and behavioral recovery. Importantly, the contribution of individual inflammatory complement proteins to spinal cord injury (SCI) pathology is not well understood. Although the presence of complement components increases after SCI in association with axons and myelin, it is unknown whether complement proteins affect axon growth or regeneration. We report a novel role for complement C1q in neurite outgrowth in vitro and axon regrowth after SCI. In culture, C1q increased neurite length on myelin. Protein and molecular assays revealed that C1q interacts directly with myelin associated glycoprotein (MAG) in myelin, resulting in reduced activation of growth inhibitory signaling in neurons. In agreement with a C1q-outgrowth-enhancing mechanism in which C1q binding to MAG reduces MAG signaling to neurons, complement C1q blocked both the growth inhibitory and repulsive turning effects of MAG in vitro. Furthermore, C1q KO mice demonstrated increased sensory axon turning within the spinal cord lesion after SCI with peripheral conditioning injury, consistent with C1q-mediated neutralization of MAG. Finally, we present data that extend the role for C1q in axon growth and guidance to include the sprouting patterns of descending corticospinal tract axons into spinal gray matter after dorsal column transection SCI. © 2015 the authors.

Liao W.,Sue and Bill Gross Stem Cell Research Center | Pham V.,Sue and Bill Gross Stem Cell Research Center | Pham V.,California State University, Fullerton | Liu L.,Sue and Bill Gross Stem Cell Research Center | And 8 more authors.
Biomaterials | Year: 2016

Systemic administration of mesenchymal stem cells (MSCs) affords the potential to ameliorate the symptoms of Multiple Sclerosis (MS) in both preclinical and clinical studies. However, the efficacy of MSC-based therapy for MS likely depends on the number of cells that home to inflamed tissues and on the controlled production of paracrine and immunomodulatory factors. Previously, we reported that engineered MSCs expressing P-selectin glycoprotein ligand-1 (PSGL-1) and Sialyl-Lewisx (SLeX) via mRNA transfection facilitated the targeted delivery of anti-inflammatory cytokine interleukin-10 (IL-10) to inflamed ear. Here, we evaluated whether targeted delivery of MSCs with triple PSGL1/SLeX/IL-10 engineering improves therapeutic outcomes in mouse experimental autoimmune encephalomyelitis (EAE), a murine model for human MS. We found PSGL-1/SLeX mRNA transfection significantly enhanced MSC homing to the inflamed spinal cord. This is consistent with results from in vitro flow chamber assays in which PSGL-1/SleX mRNA transfection significantly increased the percentage of rolling and adherent cells on activated brain microvascular endothelial cells, which mimic the inflamed endothelium of blood brain/spinal cord barrier in EAE. In addition, IL-10-transfected MSCs show significant inhibitory activity on the proliferation of CD4+ T lymphocytes from EAE mice. In vivo treatment with MSCs engineered with PSGL-1/SLeX/IL-10 in EAE mice exhibited a superior therapeutic function over native (unmodified) MSCs, evidenced by significantly improved myelination and decreased lymphocytes infiltration into the white matter of the spinal cord. Our strategy of targeted delivery of performance-enhanced MSCs could potentially be utilized to increase the effectiveness of MSC-based therapy for MS and other central nervous system (CNS) disorders. © 2015 Elsevier Ltd.

Piltti K.M.,Sue and Bill Gross Stem Cell Center | Piltti K.M.,Institute for Memory Impairments and Neurological Disorders | Piltti K.M.,University of California at Irvine | Avakian S.N.,Sue and Bill Gross Stem Cell Center | And 12 more authors.
Stem Cell Research | Year: 2015

The effect of transplantation dose on the spatiotemporal dynamics of human neural stem cell (hNSC) engraftment has not been quantitatively evaluated in the central nervous system. We investigated changes over time in engraftment/survival, proliferation, and migration of multipotent human central nervous system-derived neural stem cells (hCNS-SCns) transplanted at doses ranging from 10,000 to 500,000 cells in spinal cord injured immunodeficient mice. Transplant dose was inversely correlated with measures of donor cell proliferation at 2. weeks post-transplant (WPT) and dose-normalized engraftment at 16 WPT. Critically, mice receiving the highest cell dose exhibited an engraftment plateau, in which the total number of engrafted human cells never exceeded the initial dose. These data suggest that donor cell expansion was inversely regulated by target niche parameters and/or transplantation density. Investigation of the response of donor cells to the host microenvironment should be a key variable in defining target cell dose in pre-clinical models of CNS disease and injury. © 2015.

Thomas A.M.,Northwestern University | Seidlits S.K.,Northwestern University | Goodman A.G.,Northwestern University | Kukushliev T.V.,Northwestern University | And 8 more authors.
Integrative Biology (United Kingdom) | Year: 2014

Spinal cord injury (SCI) results in loss of sensory and motor function below the level of injury and has limited available therapies. Multiple channel bridges have been investigated as a means to create a permissive environment for regeneration, with channels supporting axonal growth through the injury. Bridges support robust axon growth and myelination. Here, we investigated the cell types that myelinate axons in the bridges and whether over-expression of trophic factors can enhance myelination. Lentivirus encoding for neurotrophin-3 (NT3), sonic hedgehog (SHH) and the combination of these factors was delivered from bridges implanted into a lateral hemisection defect at T9/T10 in mice, and the response of endogenous progenitor cells within the spinal cord was investigated. Relative to control, the localized, sustained expression of these factors significantly increased growth of regenerating axons into the bridge and enhanced axon myelination 8 weeks after injury. SHH decreased the number of Sox2+ cells and increased the number of Olig2+ cells, whereas NT3 alone or in combination with SHH enhanced the numbers of GFAP + and Olig2+ cells relative to control. For delivery of lentivirus encoding for either factor, we identified cells at various stages of differentiation along the oligodendrocyte lineage (e.g., O4+, GalC+). Expression of NT3 enhanced myelination primarily by infiltrating Schwann cells, whereas SHH over-expression substantially increased myelination by oligodendrocytes. These studies further establish biomaterial-mediated gene delivery as a promising tool to direct activation and differentiation of endogenous progenitor cells for applications in regenerative medicine. This journal is © the Partner Organisations 2014.

PubMed | Sue and Bill Gross Stem Cell Center
Type: Journal Article | Journal: Stem cells translational medicine | Year: 2013

Clinical immunosuppression protocols use calcineurin inhibitors, such as cyclosporine A (CsA) or tacrolimus (FK506), or mammalian target of rapamycin (mTOR) inhibitors, such as sirolimus (rapamycin). These compounds alter immunophilin ligand signaling pathways, which are known to interact downstream with mediators for human neural stem cell (hNSC) differentiation and proliferation, suggesting that immunosuppressants may directly alter hNSC properties. We investigated whether immunosuppressants can exert direct effects on the differentiation, proliferation, survival, and migration of human central nervous system-derived stem cells propagated as neurospheres (hCNS-SCns) in vitro and in an in vivo model of spinal cord injury. We identified unique, immunosuppressant-dependent effects on hCNS-SCns differentiation and proliferation in vitro. All immunosuppressants tested increased neuronal differentiation, and CsA and rapamycin inhibited proliferation in vitro. No immunosuppressant-mediated effects on hCNS-SCns survival or migration in vitro were detected. These data suggested that immunosuppressant administration could alter hCNS-SCns properties in vivo. We tested this hypothesis by administering immunosuppressants to constitutively immunodeficient spinal cord injured mice and assessed survival, proliferation, differentiation, and migration of hCNS-SCns after 14 weeks. In parallel, we administered immunosuppressants to immunocompetent spinal cord injury (SCI) mice and also evaluated hCNS-SCns engraftment and fate. We identified no effect of immunosuppressants on the overall hCNS-SCns fate profile in either xenotransplantation model. Despite a lower level of human cell engraftment in immunocompetent SCI mice, functional locomotor recovery was observed in animals receiving hCNS-SCns transplantation with no evidence of allodynia. These data suggest that local cues in the microenvironment could exert a stronger influence on hCNS-SCns than circulating levels of immunosuppressants; however, differences between human and rodent metabolism/pharmokinetics and xenograft versus allograft paradigms could be determining factors.

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