The expression of lactase enzymatic activity and mRNA in human fetal jejunum Effect of organ culture and of treatment with hydrocortisone

FEBS Letters

Mantei, Ned²  Ménard, Daniel¹  Villa, Marco²  Semenza, Giorgio² 

[1] Groupe de Recherche en Biologie du Développement, Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, Qué. J1H 5N4, Canada;Department of Biochemistry, Swiss Federal Institute of Technology, ETH Zentrum, CH-8092 Zürich, Switzerland

关键词: Lactase-phlorizin hydrolase;    Intestine;    Gene regulation;    Development;    Transcription;   

DOI  :  10.1016/0014-5793(92)81248-K

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Very sensitive procedures were developed for the parallel determination of intestinal lactase (LPH) activity and the cognate mRNA. Between 14 and 20 weeks of gestation, lactase activity is low and varies only slightly; at 37 weeks, a relatively high level of activity is observed. The amounts of LPH mRNA correlates with the enzymatic activity (r = 0.64). Culture of fetal jejunal explants for 5 days induces by itself a 2-fold increase in LPH mRNA, without any significant change in lactase enzymatic activity. This increase may reflect the loss of a negative transcriptional regulation operative in vivo, and suggests all additional post-transcriptional regulatory component. The addition of hydrocortisone (50 ng/ml) during culture induces a doubling of lactase activity without variation in LHP mRNA, indicating a post-transcriptional modulation by hydrocortisone. The intestinal lysosomal acid β-galactosidase activity was shown to be unaffected by hydrocortisone treatment. This observation clearly illustrates that the two intestinal β-galactosidases are regulated differently. Our results suggests a complex developmental regulation of human intestinal lactase and that the perinatal increase in lactase activity could be modulated at a post-transcriptional level by hydrocortisone.

【 授权许可】

Unknown