Human Milk Fortification Increases Bnip3 Expression Associated With Intestinal Cell Death In Vitro.
OBJECTIVE
The aim of the present study was to determine the in vitro effect(s) of a bovine-based human breast milk fortifier (HMF) on human intestinal cells. HMF increases the expression of BCL2/adenovirus E1B 19 kDa protein-interacting protein (Bnip3) and cell death; the prostaglandin analogue misoprostol will rescue this effect.


METHODS
Cultured intestinal cells were exposed to in vitro-digested human breast milk (BM) ± HMF. Intracellular oxidation, cell damage/cell death, and BNIP3 expression were measured after exposure.


RESULTS
In vitro-digested BM + HMF significantly increased intracellular oxidation, cell damage, and cell death in enterocyte cell cultures compared with either saline or BM controls, an effect that was rescued by the prostaglandin analogue, misoprostol. Bnip3 transcript and Bnip3 protein levels were significantly increased in vitro after treatment with BM + HMF. We also provide evidence that transfection of enterocytes with Bnip3 increases cell death, an effect that is rescued by a nonfunctional Bnip3 splice variant.


CONCLUSIONS
Our data support the hypothesis that HMF increases intestinal Bnip3 in vitro, and that the gene product triggers cell death. We suggest that misoprostol is a promising therapy, which may reduce intestinal cell death.
*Faculty of Health Disciplines, Athabasca University, Athabasca, Alberta †Department of Biological Sciences, University of Manitoba ‡Department of Human Anatomy and Cell Science §Faculty of Nursing ||Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada.
William
W
Diehl-Jones
Alyssa
A
Archibald
Joseph W
JW
Gordon
Wajihah
W
Mughal
Zakir
Z
Hossain
James K
JK
Friel
D000818:Animals; D002417:Cattle; D016923:Cell Death; D002460:Cell Line; D004032:Diet; D019587:Dietary Supplements / Q000009:adverse effects*; D020345:Enterocolitis, Necrotizing / Q000209:etiology / Q000517:prevention & control; D020895:Enterocytes / Q000378:metabolism; D005260:Female; D005527:Food, Fortified / Q000009:adverse effects*; D006801:Humans; D066298:In Vitro Techniques; D007223:Infant; D041943:Infant Formula / Q000737:chemistry*; D007234:Infant, Premature; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology / Q000187:drug effects*; D008565:Membrane Proteins / Q000378:metabolism*; D008895:Milk, Human; D024101:Mitochondrial Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D014162:Transfection
C090121:BNIP3 protein, human; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D011518:Proto-Oncogene Proteins