Stem cells adaptive network: mechanism and implications for evolution and disease development.
During development, different cells and tissues acquire different programmes of gene expression, so that cells are related to each other through a somatic cells tree or cluster and adult pluripotential stem cells (PSC) may be defined as progenitors that we distinguish in four types according to their biological behaviour. This clustering may segregate specific pathways establishing spatial patterns of cell-cell communications. Thus, we suggest that normal somatic cells renewal is tributary of multipotential stem cells (MSC), while renewal of cells undergoing stress or abnormal death is tributary of PSC through specific pathway(s) from cluster, thus, defining the cell repertoire that will be produced. We also assume that PSC play a pivotal role in evolutionary and propose the theory of "internal clusters competition". According to the functional duality of stem cells (SC) we define a stem cells adaptive network (SCAN) which we believe is linked to the central clock and display two pathways. The diurnal pathway includes SC-somatic cells communications, while the nocturnal pathway includes inter-SC network. These alternate pathways could be activated or repressed as a consequence of change in the biological chirality. This new approach of SC may contribute to our understanding on how some diseases may develop including cancer which could be linked to "cluster illness", while demyelinating and systemic diseases could be related to "PSC locus illness" or "focalised SCAN disturbances" and it explains how any environment stress may act on organism evolution.
Hamlat
Abderrahmane
A
Department of Neurosurgery, CHRU Pontchaillou, Rue Henry Le Guilloux, 35000 Rennes, Cedex 2, France. abdhamlat@yahoo.fr
Pasqualini
Eduardo
E
D053687:Adult Stem Cells / Q000166:cytology; D000818:Animals; D005075:Biological Evolution; D002454:Cell Differentiation; D019070:Cell Lineage; D030342:Genetic Diseases, Inborn / Q000473:pathology*; D006801:Humans; D008954:Models, Biological; D008957:Models, Genetic; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*