Expression of nerve growth factor is upregulated in the rat thymic epithelial cells during thymus regeneration following acute thymic involution.
Neuroimmune networks in the thymic microenvironment are thought to be involved in the regulation of T cell development. Nerve growth factor (NGF) is increasingly recognized as a potent immunomodulator, promoting "cross-talk" between various types of immune system cells. The present study describes the expression of NGF during thymus regeneration following acute involution induced by cyclophosphamide in the rat. Immunohistochemical stain demonstrated not only the presence of NGF but also its upregulated expression mainly in the subcapsular, paraseptal, and perivascular epithelial cells, and medullary epithelial cells including Hassall's corpuscles in both the normal and regenerating thymus. Biochemical data obtained using Western blot and RT-PCR supported these results and showed that thymic extracts contain NGF protein and mRNA, at higher levels during thymus regeneration. Thus, our results suggest that NGF expressed in these thymic epithelial cells plays a role in the T lymphopoiesis associated with thymus regeneration during recovery from acute thymic involution.
Lee
Hee-Woo
HW
Department of Anatomy, Pusan National University School of Medicine, Seo-Gu, Busan, South Korea.
Kim
Sung-Min
SM
Shim
Na-Ri
NR
Bae
Soo-Kyung
SK
Jung
Il-Gun
IG
Kwak
Jong-Young
JY
Kim
Bong-Seon
BS
Kim
Jae-Bong
JB
Moon
Jeon-Ok
JO
Chung
Joo-Seop
JS
Yoon
Sik
S
D000818:Animals; D015153:Blotting, Western; D003520:Cyclophosphamide / Q000633:toxicity; D004847:Epithelial Cells / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D020932:Nerve Growth Factor / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013047:Specific Pathogen-Free Organisms; D013950:Thymus Gland / Q000166:cytology / Q000473:pathology / Q000502:physiology; D015854:Up-Regulation
D003520:Cyclophosphamide; D020932:Nerve Growth Factor