Decreased expression of Intestinal I- and L-FABP levels in rare human genetic lipid malabsorption syndromes.
We investigated, for the first time, the expression of I- and L-FABP in two very rare hereditary lipid malabsorption syndromes as compared with normal subjects. Abetalipoproteinemia (ABL) and Anderson's disease (AD) are characterized by an inability to export alimentary lipids as chylomicrons that result in fat loading of enterocytes. Duodeno-jejunal biopsies were obtained from 14 fasted normal subjects, and from four patients with ABL and from six with AD. Intestinal FABP expression was investigated by immuno-histochemistry, western blot, ELISA and Northern blot analysis. In contrast to normal subjects, the cellular immunostaining for both FABPs was clearly decreased in patients, as the enterocytes became fat-laden. In patients with ABL, the intestinal contents of I- (60.7 +/- 13.38 ng/mg protein) and L-FABP (750.3 +/- 121.3 ng/mg protein) are significantly reduced (50 and 35%, P < 0.05, respectively) as compared to normal subjects (I-135.3 +/- 11.1 ng, L-1211 +/- 110 ng/mg protein). In AD, the patients also exhibited decreased expression (50%, P < 0.05; I-59 +/- 11.88 ng, L-618.2 +/- 104.6 ng/mg protein). Decreased FABP expression was not associated with decreased mRNA levels. The results suggest that enterocytes might regulate intracellular FABP content in response to intracellular fatty acids, which we speculate may act as lipid sensors to prevent their intracellular transport.
Guilmeau
S
S
Institut National de la Santé et de la Recherche Médicale (INSERM), U773, Centre de Recherche Bichat Beaujon CRB3, Université Paris 7 Denis Diderot, site Bichat, BP 416, 75018, Paris, France.
Niot
I
I
Laigneau
J P
JP
Devaud
H
H
Petit
V
V
Brousse
N
N
Bouvier
R
R
Ferkdadji
L
L
Besmond
C
C
Aggerbeck
L P
LP
Bado
A
A
Samson-Bouma
M E
ME
D000012:Abetalipoproteinemia / Q000235:genetics / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D002648:Child; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism*; D008052:Lipid Metabolism, Inborn Errors / Q000235:genetics / Q000378:metabolism*; D008286:Malabsorption Syndromes / Q000235:genetics / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism
C493319:FABP1 protein, human; C493404:FABP2 protein, human; D050556:Fatty Acid-Binding Proteins; D012333:RNA, Messenger