Human umbilical cord blood cells depress the microglia inflammatory response in vitro

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ABSTRACTS / Experimental Neurology 198 (2006) 558 – 597

Communication via gap junctions underlies early functional interactions between grafted neural stem cells and the host J. Ja¨derstad 1, L.M. Danielsson 1, V. Ourednik 2, E.Y. Snyder 3, E. Herlenius 1 1 Dept. of Women and Child Health, Astrid Lindgren’s Children’s Hospital, Karolinska Institutet, S-171 76, Stockholm, Sweden 2 College of Veterinary Medicine, Iowa State University, USA 3 The Burnham Institute for Medical Research, La Jolla, USA We used an organotypic striatal slice culture system to delineate a detailed time-course) of grafted neural stem cell (NSC) differentiation, integration, and interaction with the host via (a) ratiometric time-lapse calcium imaging (monitoring alterations in calcium dynamics, including spontaneous fluctuations and the response to chemotransmitters); (b) whole cell current clamp recordings (assaying the development of membrane properties and the ability to generate action potentials) and (c) dye-coupling studies (monitoring the intercellular transfer of large molecules). We concluded that one of the first and essential ways in which grafted NSCs integrate functionally into host neural circuitry and affect host cells – even before completely mature neuronal differentiation – is via gap-junctional coupling, permitting trans-cellular delivery of molecules as well as a direct influence on host network activity, protection of imperiled host neurons and their connections, and inhibition of a gliotic reactions. This early functional gap– junctional coupling might explain some of the recently reported supportive, protective, and rescue effects seen on host systems after NSC transplantation in vivo, particularly in animal models in which the time course and presence of fully mature graft-derived neurons are not sufficient to explain the behavioral improvements observed. doi:10.1016/j.expneurol.2006.02.050

Human umbilical cord blood cells depress the microglia inflammatory response in vitro L. Jiang 1,2,3, S. Saporta 1,2,3, N. Chen 1,2, C.D. Sanberg 4, P.R. Sanberg 1,2,3,4, A.E. Willing 1,2,3 1 Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL 2 Dept of Neurosurgery, University of South Florida College of Medicine, Tampa, FL 3 Dept of Anatomy, University of South Florida College of Medicine, Tampa, FL 4 Saneron CCEL Therapeutics, Tampa, FL Systemically, administration Human Umbilical Cord Blood Cells (HUCBc) could improve behavioral and neurological recovery in the middle cerebral artery occlusion (MCAO) model of stroke. Further, animals receiving HUCBc have a less severe inflammatory response compared to MCAO only controls. In this study, we co-cultured HUCBc with enriched primary microglia under hypoxia or normoxia condition, respectively,

and used fluorescein diacetate/propidium iodide (FDA/PI) labeling to determine cell viability. The cytokine expression was examined by ELISA assay. We also repeated the experiment with isolated subpopulations of HUCBc. FDA/PI staining showed an increase in cell death in the microglia HUCBc coculture after hypoxia compared to the microglia monoculture. In these co-cultures, hypoxia increased the expression of proinflammatory cytokines including IL-1beta, IFN gamma, and IL-6 whereas the anti-inflammatory IL-10 was inhibited. Cell sorting experiments suggested that the CD8 positive cells derived from HUCBc contributed to the microglial demise. Our data suggest that systemically delivered HUCBc can depress the inflammatory response after MCAO by directly interacting with activated microglia. This would be consistent with our in vivo observations of decreased infiltration or activation of microglial/macrophage like populations in the brains of HUCBc treated stroked rats, which may have contributed to their recovery. doi:10.1016/j.expneurol.2006.02.051

Intracellular inclusions: Differential accumulation in dopaminergic subregions of the midbrain during normal aging in the rhesus monkey N.M. Kanaan 1, T.J. Collier 2 1 Department of Neurological Sciences, Rush University Medical Center, Chicago, USA 2 Department of Neurology, University of Cincinnati, Cincinnati, USA Parkinson’s disease is an age-related neurodegenerative disorder characterized by severe loss of dopamine (DA) neurons in the ventral tier substantia nigra (vtSN) and relative sparing of DA neurons in the ventral tegmental area (VTA) and dorsal tier SN (dtSN). The factors underlying differential susceptibility to degeneration among DA subregions remain unknown. The ubiquitin – proteasome system, which breaks down intracellular proteins, and/or the lysosomal system, which breaks down organelles, may be involved with these differences in susceptibility. Ubiquitin-positive inclusions and lipofuscin are markers of these cellular processes, respectively. Tissue from young (9– 10 years), middle (14 –17 years), and old (22 – 29 years) age naive rhesus monkeys was used for immunocytochemistry and immunofluorescence. The numbers of tyrosine hydroxylaseimmunoreactive (TH-ir) neurons containing Marinesco bodies (TH + MB; intranuclear ubiquitin-ir inclusions) were stereologically quantified in the vtSN, VTA, and dtSN. The number of TH + MB neurons increased with aging in the vtSN, while few were found in other regions. In addition, a greater percentage of vtSN TH + MB neurons had multiple MBs/cell with increasing age. Similarly, the numbers of TH-ir neurons containing lipofuscin (TH + Lipo) were stereologically quantified in DA neuron subregions. The VTA had a greater number of TH + Lipo neurons compared to the dtSN and vtSN at all ages. Young animals had more TH + Lipo neurons in the VTA compared to animals of middle and old ages. Our findings suggest that with