Rac1 is crucial for hair follicle integrity but is not essential for maintenance of the epidermis.

TY - JOUR

T1 - Rac1 is crucial for hair follicle integrity but is not essential for maintenance of the epidermis.

AU - Chrostek, Anna

AU - Wu, Xunwei

AU - Quondamatteo, Fabio

AU - Hu, Rong

AU - Sanecka, Anna

AU - Niemann, Catherin

AU - Langbein, Lutz

AU - Haase, Ingo

AU - Brakebusch, Cord

N1 - Keywords: Animals; Cell Differentiation; Cell Movement; Enzyme Activation; Gene Deletion; Hair Follicle; JNK Mitogen-Activated Protein Kinases; Keratinocytes; Macrophages; Mice; Morphogenesis; NF-kappa B; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; Tamoxifen; p38 Mitogen-Activated Protein Kinases; rac1 GTP-Binding Protein; rho GTP-Binding Proteins

PY - 2006

Y1 - 2006

N2 - Rac1 is a small GTPase that regulates the actin cytoskeleton but also other cellular processes. To investigate the function of Rac1 in skin, we generated mice with a keratinocyte-restricted deletion of the rac1 gene. Rac1-deficient mice lost nearly all of their hair within a few weeks after birth. The nonpermanent part of mutant hair follicles developed constrictions; lost expression of hair follicle-specific keratins, E-cadherin, and alpha6 integrin; and was eventually removed by macrophages. The permanent part of hair follicles and the sebaceous glands were maintained, but no regrowth of full-length hair follicles was observed. In the skin of mutant mice, epidermal keratinocytes showed normal differentiation, proliferation, cell-cell contacts, and basement membrane deposition, demonstrating no obvious defects of Rac1-deficient epidermis in vivo. In vitro, Rac1-null keratinocytes displayed a strong spreading defect and slightly impaired adhesion. These data show that Rac1 plays an important role in sustaining the integrity of the lower part of hair follicles but not in maintenance of the epidermis.

AB - Rac1 is a small GTPase that regulates the actin cytoskeleton but also other cellular processes. To investigate the function of Rac1 in skin, we generated mice with a keratinocyte-restricted deletion of the rac1 gene. Rac1-deficient mice lost nearly all of their hair within a few weeks after birth. The nonpermanent part of mutant hair follicles developed constrictions; lost expression of hair follicle-specific keratins, E-cadherin, and alpha6 integrin; and was eventually removed by macrophages. The permanent part of hair follicles and the sebaceous glands were maintained, but no regrowth of full-length hair follicles was observed. In the skin of mutant mice, epidermal keratinocytes showed normal differentiation, proliferation, cell-cell contacts, and basement membrane deposition, demonstrating no obvious defects of Rac1-deficient epidermis in vivo. In vitro, Rac1-null keratinocytes displayed a strong spreading defect and slightly impaired adhesion. These data show that Rac1 plays an important role in sustaining the integrity of the lower part of hair follicles but not in maintenance of the epidermis.

U2 - 10.1128/MCB.00075-06

DO - 10.1128/MCB.00075-06

M3 - Journal article

C2 - 16943436

SN - 0270-7306

VL - 26

SP - 6957

EP - 6970

JO - Molecular and Cellular Biology

JF - Molecular and Cellular Biology

IS - 18

ER -