Roles of paroxetine and corticosterone on adult mammalian ciliary body cell proliferation.
BACKGROUND
The neurogenesis in retina of adult mammals is generally abolished, and this renders the retina lack of regenerative capacity. Despite this, there is a small population of nestin-positive cells in the ciliary epithelium which retains neurogenic potential. The present study aimed at investigating the effect of two drugs, corticosterone and paroxetine, on the cell proliferation of the ciliary body.


METHODS
Adult Sprague-Dawley rats were given vehicle, corticosterone, paroxetine, or both corticosterone and paroxetine treatment for 14 days. Cell proliferation in the ciliary body was quantified using 5-bromo-2-deoxyuridine (BrdU) immunohistochemistry. Co-labelling of BrdU and stem cell marker was used to phenotype the BrdU immunoreactive cells.


RESULTS
Corticosterone treatment suppressed while paroxetine treatment increased the cell proliferation of the ciliary body. Co-labelling with cell markers revealed that the BrdU positive cells also showed nestin expression but not glial fibrillary acidic protein (GFAP).


CONCLUSIONS
The results illustrate that proliferation of retinal progenitor cells situated in ciliary body are subjected to regulation by selective serotonin reuptake inhibitors (SSRI) and corticosteroid, which is similar to our previous findings in neurogenic regions in central nervous system (CNS). Paroxetine treatment could reverse the suppressive effect of corticosterone on ciliary body cell proliferation. This provides information for future investigation of retinal stem cell biology and potential treatment of retinal degenerative diseases.
Department of Anatomy, Li Ka Shing Faculty of Medicine, Neuropsychology Laboratory, the University of Hong Kong, Hong Kong Special Administrative Region, China.
Hua
H
Wang
Benson W M
BW
Lau
Suk-yu
SY
Yau
Suk-yee
SY
Li
Nelson
N
Leung
Ning-li
NL
Wang
Siu-wa
SW
Tang
Tatia M C
TM
Lee
Kwok-fai
KF
So
D000311:Adrenal Glands / Q000187:drug effects / Q000473:pathology; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002924:Ciliary Body / Q000166:cytology* / Q000187:drug effects*; D003345:Corticosterone / Q000494:pharmacology; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008297:Male; D009929:Organ Size / Q000187:drug effects; D017374:Paroxetine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D017374:Paroxetine; D003345:Corticosterone