Keratinocyte growth factor decreases total parenteral nutrition-induced apoptosis in mouse intestinal epithelium via Bcl-2.
OBJECTIVE
Total parenteral nutrition (TPN) induces epithelial cell (EC) apoptosis. Keratinocyte Growth Factor (KGF) increases EC-growth; however, little is known of its effect on apoptosis. This study aims to determine if mRNA expression of Bcl-2 proteins (major mediators of epithelial cell apoptosis) is altered with TPN, and if KGF-administration influences Bcl-2 family expression.


METHODS
C57BL/6J mice (n = 6 per group) received oral feeding (control), TPN (TPN), or TPN plus intravenous KGF daily (TPN + KGF). After 7 days, intestine was harvested and EC isolated. Apoptosis was identified using flow cytometry. EC mRNA expression of Bcl-2 family members was measured by reverse transcriptase polymerase chain reaction; Bcl-2 protein level was measured by immunoblot analysis.


RESULTS
EC apoptotic rates were: control, 14.4% +/- 5.1%; TPN, 29.4% +/- 11.3%; KGF, 17.2% +/- 5.6%. Pro-apoptotic Bcl-2 proteins changed minimally with TPN or KGF; however, the antiapoptotic protein Bcl-2 changed significantly: control, 0.78 +/- 0.24; TPN, 0.10 +/- 0.13; KGF, 0.76 +/- 0.36. EC Bcl-2 protein levels were: control, 0.16 +/- 0.13; TPN 0.18 +/- 0.16; and TPN + KGF 0.47 +/- 0.19.


CONCLUSIONS
TPN-induced apoptosis decreased Bcl-2 mRNA expression. KGF decreased EC apoptosis and increased Bcl-2 expression. Modalities to increase endogenous KGF, or KGF-administration may have benefit in patients on TPN.
Wildhaber
Barbara E
BE
University of Michigan, Department of Pediatric Surgery, C.S. Mott Children's Hospital, Ann Arbor, MI, USA.
Yang
Hua
H
Teitelbaum
Daniel H
DH
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015536:Down-Regulation; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors / Q000502:physiology*; D015151:Immunoblotting; D007413:Intestinal Mucosa / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010289:Parenteral Nutrition, Total; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis
C496454:Fgf7 protein, mouse; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors