Identification of androgen receptor protein and 5alpha-reductase mRNA in human ocular tissues.
OBJECTIVE
Androgens have been reported to influence the structural organisation, functional activity, and/or pathological features of many ocular tissues. In addition, these hormones have been proposed as a topical therapy for such conditions as dry eye syndromes, corneal wound healing, and high intraocular pressure. To advance our understanding of androgen action in the eye, the purpose of the present study was twofold: firstly, to determine whether tissues of the anterior and posterior segments contain androgen receptor protein, which might make them susceptible to hormone effects following topical application; and, secondly, to examine whether these tissues contain the mRNA for types 1 and/or 2 5alpha-reductase, an enzyme that converts testosterone to the very potent metabolite, dihydrotestosterone.


METHODS
Human ocular tissues and cells were obtained and processed for histochemical and molecular biological procedures. Androgen receptor protein was identified by utilising specific immunoperoxidase techniques. The analysis of type 1 and type 2 5alpha-reductase mRNAs was performed by the use of RT-PCR, agarose gel electrophoresis, and DNA sequence analysis. All immunohistochemical evaluations and PCR amplifications included positive and negative controls.


RESULTS
These findings show that androgen receptor protein exists in the human lacrimal gland, meibomian gland, cornea, bulbar and forniceal conjunctivae, lens epithelial cells, and retinal pigment epithelial cells. In addition, our results demonstrate that the mRNAs for types 1 and 2 5alpha-reductase occur in the human lacrimal gland, meibomian gland, bulbar conjunctiva, cornea, and RPE cells.


CONCLUSIONS
These combined results indicate that multiple ocular tissues may be target sites for androgen action.
Rocha
E M
EM
Schepens Eye Research Institute and Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
Wickham
L A
LA
da Silveira
L A
LA
Krenzer
K L
KL
Yu
F S
FS
Toda
I
I
Sullivan
B D
BD
Sullivan
D A
DA
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000032:analysis* / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D003228:Conjunctiva / Q000737:chemistry; D003315:Cornea / Q000737:chemistry; D004587:Electrophoresis, Agar Gel; D005123:Eye / Q000737:chemistry* / Q000201:enzymology; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis / Q000235:genetics; D007765:Lacrimal Apparatus / Q000737:chemistry; D007908:Lens, Crystalline / Q000737:chemistry; D008297:Male; D008537:Meibomian Glands / Q000737:chemistry; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011944:Receptors, Androgen / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
D007527:Isoenzymes; D012333:RNA, Messenger; D011944:Receptors, Androgen; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase