The development of meibomian glands in mice.
OBJECTIVE
The purpose of this study was to characterize the natural history of meibomian gland morphogenesis in the mouse.


METHODS
Embryonic (E) and post natal (P) C57Bl/6 mouse pups were obtained at E18.5, P0, P1, P3, P5, P8, P15, and P60. Eyelids were fixed and processed for en bloc staining with Phalloidin/DAPI to identify gland morphogenesis, or frozen for immunohistochemistry staining with Oil red O (ORO) to identify lipid and antibodies specific against peroxisome proliferator-activated receptor gamma (PPARgamma) to identify meibocyte differentiation. Samples were then evaluated using a Zeiss 510 Meta laser scanning confocal microscope or Nikon epi-fluorescent microscope. Tissues from adult mice (2 month-old) were also collected for western blotting.


RESULTS
Meibomian gland morphogenesis was first detected at E18.5 with the formation of an epithelial placode within the fused eyelid margin. Invagination of the epithelium into the eyelid was detected at P0. From P1 to P3 there was continued extension of the epithelium into the eyelid. ORO and PPARgamma staining was first detected at P3, localized to the central core of the epithelial cord thus forming the presumptive ductal lumen. Ductal branching was first detected at P5 associated with acinar differentiation identified by ORO and PPARgamma staining. Adult meibomian glands were observed by P15. Western blotting of meibomian gland proteins identified a 50 kDa and a 72 kDa band that stained with antibodies specific to PPARgamma.


CONCLUSIONS
We have demonstrated that meibomian gland development bears distinct similarities to hair development with the formation of an epithelial placode and expression of PPARgamma co-incident with lipid synthesis and meibocyte differentiation.
Nien
Chyong Jy
CJ
Gavin Herbert Eye Institute, University of California Irvine, Orange, CA 92868, USA.
Massei
Salina
S
Lin
Gloria
G
Liu
Hongshan
H
Paugh
Jerry R
JR
Liu
Chia-Yang
CY
Kao
Winston Whei-Yang
WW
Brown
Donald J
DJ
Jester
James V
JV
D000818:Animals; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D008055:Lipids / Q000096:biosynthesis; D008537:Meibomian Glands / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D009024:Morphogenesis; D047495:PPAR gamma / Q000378:metabolism
D008055:Lipids; D047495:PPAR gamma