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Biomedical subjects

David L Stocum

Publications and source records attributed to David L Stocum.

6 recordsLinked to original sources

Stem cells in CNS and cardiac regeneration.

The central nervous system (CNS) and the heart muscle regenerate poorly after injury, yet evidence is mounting that both harbor cells capable of rebuilding neural and cardiac tissue. The reason for the poor regenerative response of CNS tissue and myocardium must therefore lie in the nature of the injury environment, which promotes fibrosis over regeneration. Strategies for regenerating these tissues thus rely on overcoming the fibrotic response by filling lesions with tissue-specific regeneration-competent cells that replace or rescue dying cells, or by activating endogenous regeneration-competent cells that do likewise. There has also been considerable excitement about the possibility of transplanting bone marrow cells into CNS or cardiac lesions to repair them, because bone marrow cells have been reported to be pluripotent. In this chapter, contemporary evidence for the existence of regeneration-competent cells in the CNS and heart is discussed, as well as attempts to use these cells and bone marrow cells to reconstitute new tissue.

Cardiac Surgical Procedures↗

Regeneration of the urodele limb: a review.

Urodele amphibians have been widely used for studies of limb regeneration. In this article, we review studies on blastema cell proliferation and propose a model of blastemal self-organization and patterning. The model is based on local cell interactions that intercalate positional identities within circumferential and proximodistal boundaries that outline the regenerate. The positional identities created by the intercalation process appear to be reflected in the molecular composition of the cell surface. Transcription factors and signaling molecules involved in patterning are discussed within the context of the boundary/intercalation model.

Animals↗

Urodele spinal cord regeneration and related processes.

Urodele amphibians, newts and salamanders, can regenerate lesioned spinal cord at any stage of the life cycle and are the only tetrapod vertebrates that regenerate spinal cord completely as adults. The ependymal cells play a key role in this process in both gap replacement and caudal regeneration. The ependymal response helps to produce a different response to neural injury compared with mammalian neural injury. The regenerating urodele cord produces new neurons as well as supporting axonal regrowth. It is not yet clear to what extent urodele spinal cord regeneration recapitulates embryonic anteroposterior and dorsoventral patterning gene expression to achieve functional reconstruction. The source of axial patterning signals in regeneration would be substantially different from those in developing tissue, perhaps with signals propagated from the stump tissue. Examination of the effects of fibroblast growth factor and epidermal growth factor on ependymal cells in vivo and in vitro suggest a connection with neural stem cell behavior as described in developing and mature mammalian central nervous system. This review coordinates the urodele regeneration literature with axial patterning, stem cell, and neural injury literature from other systems to describe our current understanding and assess the gaps in our knowledge about urodele spinal cord regeneration.

Animals↗