Synapsing with NG2 cells(polydendrocytes),unappreciated barrier to axon regeneration?

Have you heard of NG2 cells or NG2 glia or polydendro- cytes~. These are new names for the precursor cells that used to be referred to as oligodendrocyte precursor cells （OPCs）, which become the oligodendrocytes that myelinate central nervous system （CNS） axons. Evidence suggests, however, that they have other functions, besides differentiating into oligodendrocytes. Most notably, the OPCs/NG2 cells are uni- formly distributed in grey matter as well as in white matter, which matches poorly with the distribution of myelinating oligodendrocytes. Furthermore, not every NG2 cell is fated to become an oligodendrocyte. Hence the term OPC can be fairly applied only when discussing the role of these cells in the oligodendrocyte lineage.

Neurogenic potential of NG2 in neurotrauma:a systematic review

Regenerative approaches towards neuronal loss following traumatic brain or spinal cord injury have long been considered a dogma in neuroscience and remain a cutting-edge area of research.This is reflected in a large disparity between the number of studies investigating primary and secondary injury as therapeutic to rgets in spinal co rd and traumatic brain injuries.Significant advances in biotechnology may have the potential to reshape the current state-of-the-art and bring focus to primary injury neurotrauma research.Recent studies using neural-glial factor/antigen 2(NG2)cells indicate that they may differentiate into neurons even in the developed brain.As these cells show great potential to play a regenerative role,studies have been conducted to test various manipulations in neurotrauma models aimed at eliciting a neurogenic response from them.In the present study,we systematically reviewed the experimental protocols and findings described in the scientific literature,which were peer-reviewed original research articles(1)describing preclinical experimental studies,(2)investigating NG2 cells,(3)associated with neurogenesis and neurotrauma,and(4)in vitro and/or in vivo,available in PubMed/MEDLINE,Web of Science or SCOPUS,from 1998 to 2022.Here,we have reviewed a total of 1504 papers,and summarized findings that ultimately suggest that NG2 cells possess an inducible neurogenic potential in animal models and in vitro.We also discriminate findings of NG2 neurogenesis promoted by different pharmacological and genetic approaches over functional and biochemical outcomes of traumatic brain injury and spinal co rd injury models,and provide mounting evidence for the potential benefits of manipulated NG2 cell ex vivo transplantation in primary injury treatment.These findings indicate the feasibility of NG2 cell neurogenesis strategies and add new players in the development of therapeutic alternatives for neurotrauma.

Roles of NG2 glial cells in diseases of the central nervous system

NG2 cells are a novel distinct class of central nervous system（CNS） glial cells,characterized by the expression of the chondroitin sulfate proteoglycan NG2.They have been detected in a variety of human CNS diseases.As morphological,physiological and biomolecular studies of NG2 cells have been conducted,their roles have been gradually revealed.Research on cellular and molecular mechanisms in the pathophysiological state was built on the preliminary findings of their physiological functions;and in turn,this helps to clarify their physiological roles and leads to the identification of novel therapeutic targets.This review summarizes recent findings regarding the potential roles of NG2 cells in traumatic brain injury,multiple sclerosis,glioma,epilepsy,Alzheimer＇s disease and electroconvulsive therapy for depression.

Polydendrocytes in development and myelin repair

Polydendrocytes （NG2 cells） are a distinct type of glia that populate the developing and adult central nervous systems （CNS）. In the adult CNS, they retain mitotic activity and represent the largest proliferating cell popula- tion. Genetic and epigenetic mechanisms regulate the fate of polydendrocytes, which give rise to both oligo- dendrocytes and astrocytes. In addition, polydendrocytes actively differentiate into myelin-forming oligodendro- cytes in response to demyelination. This review summarizes the current knowledge regarding polydendrocyte development, which provides an important basis for understanding the mechanisms that lead to the remyelina- tion of demyelinated lesions.