KRÜPPEL-LIKE FACTOR 4 GENE EXPRESSION IN DEVELOPING HUMAN FETAL SKIN
JaNiece Walker1, Suzanne McConaghy2, Robin Ohls2.
1Xavier University of Louisiana, New Orleans, LA, 2The University of New Mexico, Albuquerque, NM.
Preterm delivery abruptly alters the natural course of gene expression, forcing extremely low-birth-weight (ELBW) infants to continue development in a nonuterine, postnatal environment which is abundant in oxygen. In ELBW infants, the skin is not yet fully established as the primary barrier to prevent evaporation, nor as a critical component of the immune system resulting in susceptibility to bacterial infections and dehydration. Krüppel-like factor 4 (KLF4) is a transcription factor that regulates proteins such as keratohyalin and small proline-rich protein 2A, which are responsible for maturation in developing skin. We sought to determine changes in the KLF4 gene expression following ex utero exposure of fetal skin to a postnatal environment. We hypothesized that gene expression of KLF4 in human fetal skin would increase with exposure to ambient oxygen. Fetal skin samples (10.4 to 19.2 weeks gestation) were collected. Samples were triturated and incubated in DMEM with 10% fetal bovine serum and 1% antimicrobials at 21% oxygen, 5% CO2 in a humidified incubator for 0, 24, 48, and 72 hours. RNA was extracted and reverse transcription polymerase chain reaction (RT- PCR) performed with primers and a probe specific for KLF4. β-actin was used as a control in duplex PCR reactions. An increase in KLF4 expression occurred between baseline and 24 hours, and between baseline and 48 hours of incubation (p < 0.05). KLF4 gene expression increased with increasing exposure to air. We speculate that postpartum conditions up regulate gene expression of KLF4 and promote skin maturation.