Pluripotential hemopoietic stem cells in adult mouse brain.

Abstract

Single cell suspensions ofadult mouse brain were shown to contain large numbers of pluripotential hemopoietic stem cells as detected by the ability to form hemopoietic colonies in the spleens of irradiated hosts. These colony forming unit, spleen (CFU-s) cells derived from brain gave rise to colonies identical in morphology and histology to those ofbone marrow-derived CFU-s. The average number of CFU-s obtained per 105 dissociated adult brain cells was 14, whereas other adult tissues such as lung, kidney, liver, heart, and thymus contained insignificant CFU-s levels when tested. As the level of CFU-s in adult blood is <1 per 106 nucleated cells, blood contamination does not contribute to the high levels found in adult brain. Individual spleen colonies isolated from irradiated CBA (H-2k) recipients injected with (BALB/c x CBA)F1 (H-2d x H-2k) brain cells were shown by immunofluorescence to contain cells bearing surface H-2d molecules, thus indicating that the colonies arose from the brain cell inoculum and were not endogenously derived. The surface phenotype of brainand bone marrow-derived CFU-s was found to differ in that brain CFU-s could be inhibited by prior incubation with a monoclonal antibrain antibody B2A2, whereas bone marrow CFU-s were not. Further differences were found between brain and bone marrow CFU-s in the congenitally anemic Wf/lW mice. These mice were shown to have very few CFU-s in the adult bone marrow, whereas the brain contained normal adult levels. The large number of hemopoietic stem cells in the brain may indicate an essential requirement for the continual generation of cells such as microglia or phagocytic cells, without the disruption of the blood-brain barrier.

Tumor Necrosis Factor Alpha, Interleukin 1 and Related Cytokines in Brain Development: Normal and Pathological

“…Indeed, these cells cross an intact blood-brain barrier. Studies using chimaeric ani mals [21,22], immunological methods [23,24], and histochemical techniques [15,25,26] have allowed tracking of bone marrow derived mononuclear phagocytes to the brain where they become microglia. Such studies have added to phenotypic and functional evidence which would seem to substantiate del Rio H ortega's [27] origi nal proposal of mesodermal and not neuroectodermal origin of these cells [28],…”

Hematopoietic and nonhematopoietic potentials of Hoechstlow/side population cells isolated from adult rat kidney

“…Although it is a general concept that stem cells regenerate only a subset of differentiated cell types in a given tissue, the overall developmental potentials of a stem cell seem to be much wider than expected; different environmental cues determine different repertoires of potential stem cell fates. For example, muscle-derived cells can generate blood cells [7,8] and brain-derived cells can generate blood cells [9,10] or muscle [11,12].…”

Toward Transgene-Free Induced Pluripotent Stem Cells: Lessons from Transdifferentiation Studies

“…The confounding results of the following studies and the ensuing debate illustrate some of the problems facing the field of transdifferentiation and argues that in vitro cell culture could account for some of the observations. Several groups had reported that neural stem cells (NSCs) can differentiate into blood cells (Bartlett, 1982;Bjornson et al, 1999;Clarke et al, 2000;Shih et al, 2001). Bjornson et al (1999) reported that NSCs can differentiate into myeloid and lymphoid cells as well as early hematopoietic cells after injection of LacZ expressing NSC isolated from the brain or clonally derived NSC into sublethally irradiated mice resulted in LacZpositive hematopoetic cells in the BM as assessed by colony forming unit assays and by flow cytometry.…”