Horeya E Korayem, Mohamed Abdo, Magda M Naim, Soha E Yones and Somaya Hosny
Background: Research evidence has indicated that monosodium glutamate (MSG) consumption produces
certain deleterious effects on the cerebellum of adult rats at high doses which can consequently affect cerebellar
function. The use of stem cells in nervous system disorders is a growing field, which in numerous reports has shown
promising results in the restoration of neurological function.
Aim: To compare the effect of injection of human umbilical cord blood CD34+ stem cells versus CD34- fraction in
a rat model of cerebellar damage induced by monosodium glutamate.
Methods: Forty adult female albino rats were equally randomized into 4 groups: group I served as control,
group II received MSG, group III received MSG followed by CD34+ stem cell separated from umbilical cord blood
of human male fetuses, group IV received MSG followed by the CD34- fraction. At the end of the experiment, all
rats were subjected to assessment of motor function, histological and immunohistochemical techniques as well as a
polymerase chain reaction analysis of male-specific Sry gene.
Results: Group II showed a significant decrease in the mean number of Purkinje cells and cells of the molecular
layer. Nissl’s granules and length of dendrites of Purkinje cells were markedly decreased. Marked increase of GFAP
immunoexpression in astrocytes was also detected. Group III stem cells showed improvement in motor function after
4 weeks of treatment. The CD34- group (IV) showed more increase in the number of cells in the molecular, granular
and Purkinje cell layers as well as an increase in Nissl’s granules and Purkinje cell dendrite length compared to
CD34+ stem cell group (III). There was also a significant decrease in optical density of GFAP immunoexpression of
the CD 34- group compared to both MSG and CD34+ groups. The Sry gene was not detected in either of the CD34+
and CD34- groups implying that the improvement happened without homing of stem cells in the cerebellum.
Conclusion: Both CD34 -ve and CD34+ve stem cells improved cerebellar structure and function against damage
induced by monosodium glutamate; however CD34- stem cells showed more improvement than CD34+ stem cells.