DHCR24 gene knockout mice demonstrate lethal dermopathy with differentiation and maturation defects in the epidermis.
Desmosterolosis is an autosomal recessive disorder due to mutations in the 3beta-hydroxysterol-Delta24 reductase (DHCR24) gene that encodes an enzyme catalyzing the conversion of desmosterol to cholesterol. To date, only two patients have been reported with severe developmental defects including craniofacial abnormalities and limb malformations. We employed mice with targeted disruption of DHCR24 to understand the pathophysiology of desmosterolosis. All DHCR24-/- mice died within a few hours after birth. Their skin was wrinkleless and less pliant, leading to restricted movement and inability to suck (empty stomach). DHCR24 gene was expressed abundantly in the epidermis of control but not of DHCR24-/- mice. Accordingly, cholesterol was not detected whereas desmosterol was abundant in the epidermis of DHCR24-/- mice. Skin histology revealed thickened epidermis with few and smaller keratohyaline granules. Aberrant expression of keratins such as keratins 6 and 14 suggested hyperproliferative hyperkeratosis with undifferentiated keratinocytes throughout the epidermis. Altered expression of filaggrin, loricrin, and involcrin were also observed in the epidermis of DHCR24-/-. These findings suggested impaired skin barrier function. Indeed, increased trans-epidermal water loss and permeability of Lucifer yellow were observed in DHCR24-/- mice. DHCR24 thus plays crucial role for skin development and its proper function.
Mirza
Rusella
R
Department of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University, Chikusa-ku, Nagoya, Japan.
Hayasaka
Shizu
S
Takagishi
Yoshiko
Y
Kambe
Fukushi
F
Ohmori
Sachiko
S
Maki
Kazuko
K
Yamamoto
Michiyo
M
Murakami
Kohji
K
Kaji
Takahide
T
Zadworny
David
D
Murata
Yoshiharu
Y
Seo
Hisao
H
D000818:Animals; D017209:Apoptosis; D051242:Caveolin 1 / Q000032:analysis; D002454:Cell Differentiation; D049109:Cell Proliferation; D002518:Ceramides / Q000032:analysis; D002784:Cholesterol / Q000096:biosynthesis; D003897:Desmosterol / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000032:analysis; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000166:cytology; D007633:Keratins / Q000032:analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000235:genetics / Q000502:physiology*; D010539:Permeability; D012867:Skin / Q000378:metabolism / Q000473:pathology*; D012871:Skin Diseases / Q000209:etiology* / Q000473:pathology
D051242:Caveolin 1; D002518:Ceramides; D005230:Fatty Acids, Nonesterified; D009419:Nerve Tissue Proteins; D003897:Desmosterol; D007633:Keratins; D002784:Cholesterol; D044925:Oxidoreductases Acting on CH-CH Group Donors; C499056:Dhcr24 protein, mouse