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Responses of reactive astrocytes containing S100β protein and fibroblast growth factor‐2 in the border and in the adjacent preserved tissue after a contusion injury of the spinal cord in rats: implications for wound repair and neuroregeneration
Author(s) -
Do Carmo Cunha Jinger,
De Freitas Azevedo Levy Beatriz,
De Luca Bianca Aparecida,
De Andrade Michele Schultz Ramos,
Gomide Vânia Canterucci,
Chadi Gerson
Publication year - 2007
Publication title -
wound repair and regeneration
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.847
H-Index - 109
eISSN - 1524-475X
pISSN - 1067-1927
DOI - 10.1111/j.1524-475x.2006.00194.x
Subject(s) - glial fibrillary acidic protein , spinal cord , gliogenesis , spinal cord injury , microglia , basic fibroblast growth factor , pathology , immunohistochemistry , glial scar , s100 protein , fibroblast growth factor , medicine , central nervous system , anatomy , growth factor , biology , neural stem cell , neuroscience , microbiology and biotechnology , immunology , inflammation , stem cell , receptor
This paper demonstrates glial reaction and changes in the S100β protein and basic fibroblast growth factor (bFGF, FGF‐2) in the border and in the adjacent preserved tissue of the rat spinal cord after a contusion. In view of the expression of FGF‐2 and S100β in reactive glial cells and their ability to promote gliogenesis and neuronal trophism, the molecules have been considered to participate in the wound repair and regenerative events after nervous tissue injury. Adult rats were submitted to a moderate spinal cord (10th thoracic level) contusion induced by a New York University Impactor by dropping a 10 g rod from a distance of 25 mm onto the dorsal surface of the exposed dura spinal cord. Impactor curves and parameters were used to monitor the severity of the trauma. Control rats were submitted to sham operation. The motor behavioral spontaneous recovery was demonstrated by means of a BBB test and the combining behavior score up to 3 weeks after injury. Animals were killed 72 hours, 2, and 3 weeks after surgery and spinal cords were processed for immunohistochemistry to show glial fibrillary acidic protein positive astrocytes and OX‐42‐positive microglia/macrophages as well as changes in the S100β and FGF‐2 in the border and in the adjacent preserved tissue of the lesioned cords. The changes in the immunoreaction products were quantified by means of morphometric/microdensitometric image analysis, and the cell type expressing S100β and FGF‐2 was analyzed by means of two‐color immunofluorescence procedures. Massive increases of S100β and FGF‐2 were found in reactive astrocytes, not in reactive microglia, in the border and in the white and gray matters of adjacent preserved tissue of the contused spinal cord in the periods studied. The results are discussed in view of possible paracrine trophic actions of the reactive astrocytes, mediated by S100β and FGF‐2, triggering wound repair events in the border of the trauma, and also leading to neurotrophism and neuronal plasticity in the adjacent regions. These cellular and molecular responses may interfere with the pattern of behavioral recovery after a contusion injury of the spinal cord.