Developmental expression of glial cell-line derived neurotrophic factor, neurturin, and their receptor mRNA in the rat urinary bladder.
OBJECTIVE
Glial cell-line derived neurotrophic factor (GDNF) and related factors neurturin (NRTN), artemin, and persephin are members of the GDNF family of neurotrophic factors. GDNF and NRTN bind to the tyrosine kinase receptor Ret and the receptors GFRalpha1 and GFRalpha2. The objective was to examine the developmental expression of GDNF, NRTN, and their receptors within the rat urinary bladder.


METHODS
Rat bladders dissected from embryonic day (E) 15, postnatal day (P) 0, P14, P28, and adult rats (P60) were investigated by semiquantitative reverse transcriptase polymerase chain reaction. Embryos (E15, E16, and E17) were immunohistochemically stained for neurofilament.


RESULTS
GDNF and Ret mRNA levels at E15 were the highest of all the stages we examined and then immediately decreased. In contrast, NRTN mRNA levels did not change between E15 and postnatal day 14; thereafter, they gradually but insignificantly increased. GFRalpha1 and GFRalpha2 mRNA levels were high at E15, after which their signal intensities decreased. In whole-mounted specimens, neurofilament-positive axons were first detected in the bladder at E16.


CONCLUSIONS
Our results suggest that GDNF and NRTN may act as trophic factors for neural in-growth to the bladder and/or for the maintenance of mature neurons innervating the bladder. These factors might also be involved in bladder morphogenesis.
Kawakami
Takahiro
T
Department of Urology, Shiga University of Medical Science, Otsu, Japan.
Wakabayashi
Yoshihiko
Y
Aimi
Yoshinari
Y
Isono
Takahiro
T
Okada
Yusaku
Y
D000375:Aging / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D029721:Drosophila Proteins; D005314:Embryonic and Fetal Development; D005333:Fetus / Q000378:metabolism; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism*; D051101:Neurturin; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051096:Proto-Oncogene Proteins c-ret; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D001743:Urinary Bladder / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism*
D029721:Drosophila Proteins; C495041:Gdnf protein, rat; C494992:Gfra2 protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009414:Nerve Growth Factors; D051101:Neurturin; C495057:Nrtn protein, rat; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; C495001:Ret protein, rat