Analysis of rat intestinal apolipoprotein (apo) AIV and HNF-4 gene expression in the early adaptive...
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A762 AGA ABSTRACTS GASTROENTEROLOGY, Vol. 108, No. 4
• ADDITIVE EFFECT OF BASIC FIBROBLAST GROWTH FACTOR (bFGF) AND LANSOPRAZOLE ON CHRONIC DUODENAL ULCER HEALING IN RATS..~. Vincz~. S. KusstatschcL H. Satoh" and S. Szabo. Bfigh,m & W ~ ' s Hosp., Harvard Mod. Sck, Boston, MA, USA and "Takeda Cheanical Ind., LtcL, Osaka, Japan.
We described previously tim potent ulc~ healing properties of the angiogcnic polyp~tidc bFGF without decreasing gastric acid or pepsin secretion. On molar basis, the antiulcc* effest of bFGF (100 ng/100 g) was about 7 million times more potent than that of H2-bluekers, was additive or synergistic with that Of cimctidin¢. Aim of this study was to investigate the ¢ffc~'t of combinabun of bFGF and a new proton-pump inhibitor lensoprazole un uteer healing. Sprague-Dawlay female rats (160-240 g) were maintain~ on Purina laboratory chow and tap water ad libitum throughout the study and rcc~ved cystcamiue-HCl (25 rag/100 g) intragastrieally (i.g.) 3 times on th* first day. On the third day laparotomy was lx~formed under ether anasthesia and rats were randomized to create 6 animal groaps (11 = 7-12) bomogeueously severe ulcers (perforat~ or penetrated into the liver or pancreas) and treated x2/day i.g. for 3 weeks with a) comrols, vehicle citrate buffer (0.05 M pH 7.0); b) lansoprazole (Takeda Chem. Ind., Japan) 1 mg/i00 g; c) the acid- resistant mutton bFGF-CS23 (Takoda Chem. Ind., Japan)" 2 rig/100 g; d) bFGF- CS23 50 ng/100 g; c) lansoprazole + bFGF-CS23 2 n,g/100 g; f) lansoprazole + bFGF-CS23 50 ng/100 g. Autopsy was ixa'form~ on the 21st day end the ulcer size was calculated by the allips¢ formula. The results were confirmed by computerized stereomicroscopie planiiuetry and ulcer healing was evaluated by fight microscopy and histochemistly. The ulcer sizes were: a) 12.0 ± 3.0; b) 4.9± 2.1 (p = 0.05); c) 6.8 ± 2.6 (9 = 0.11); d) 4.1 ± 1.3 (p = 0.02); 0) 2.0 q- 0.8 (p = 0.02); f) 2.7 ± 1.1 (p = 0.03). Histologic e~aml,ation revealed slightly or markedly enhanced angiogeuesis in the remaining ulcer crater in rats treated with bFGF-CS23 at 2 or 50 ng/100 g, respectively. This was associated with dense granulation tissue and virtually complete restoration of duodensl architecture. ~ 1. Lansoprazole combined with bFGF-CS23 at 50 but not 2 ng/100 g significantly improved the ulcer healing. 2. The combined administration of lansoprazole and both doses of bFGF was more effective than the monotherapy and enhanced the quality of ulcer healing; 3) bFGF and lausoprazole may thus exert an additive or potentiating interaction in dundenal ulcer healing.
OREGULATION OF JEJUNAL APOLIPOPROTEIN EXPRESSION IN THE NEWBORN PIGLET BY DIETARY LIPID. H. Wano, R. Zhan, F. Hunter, D. Black. Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, AR
We have previously shown that dietary lipid absorption acutely regulates jejunal apolipoProtein (apoLp) expression in the newborn piglet, compared to the absence of dietary lipid (J Lipid Res 31:497, 1990, Pediatr Res 29:32, 1991, Gene 123:173, 1993). Ape A-IV an d C-Ill are regulated at the pre-translational level, ape A-I at the translational level, and ape B-48 at the post-translational level by lipid absorption. Purpose: To determine the effects of dietary fatty acids of varying chain lengths and degrees of saturation on jejunal apoLp expression in the newborn piglet. Methods: Tw0-day-old female piglets were prepared with duodenal infusion catheters. After a glucose- saline infusion during a 24 hr recovery period, three groups of animals each received one of three isocaloric formulas, containing 47% of total Calories (120 keal/kg/24 hr) as medium-chain triglycerides (MCT) from MCT oil, intermediate-chain saturated triglyeerides (ICST) from coconut oil, or long-chain polyunsaturated triglycerides (LCPUT) from safflower oil by continuous intraduodena( infusion for 24 hrs. Segments of proximal jejunum were pulse-radiolabeled in vivo with 3Hdeucine. Mucosal ape A-I and B-48 were immunoprecipitated, and synthesis expressed as a percentage of total protein synthesis. Total jejunal RNA was extracted, and ape A-IV and C-Ill mRNA abundance was determined by slot blot hybridization with ~-actin as a control. Reaulta: Although ape B-48 synthesis was not different in the three groups, 2-fold higher ape A-I synthesis was found in the LCPUT group compared to the MCT and ICST groups (14.18 4-1.69%, 7.56 4- 2.63%, and 6.36 4- 0.58%, respectively, mean + SEM, p<0.05 by ANOVA). Ape A-IV and C-Ill mRNA abundance, expressed as apoLp to ~-actin absorbance ratios, was 0.81 + 0.09 and 1.06 +- 0.14, respectively, in the LCPUT group, as compared to 0.44 + 0.08 and 0.50 + 0.09 in the MCT group (p<0.05), and 0.42 + 0.06 and 0.53 + 0.23 in the ICST group (p<0.05). Conclusions;. The short-term '(24 hrs) feeding Of formula containing LCPUT up-regulates ape A-I expression at the translational level, and ape A-IV and C-Ill at the pre-translational level, as compared to MCT and ICST, in the newborn piglet proximal small intestine.
Q ANALYSIS OF RAT INTESTINAL APOLIPOPROTEIN (apo) AIV AND HNF-4 GENE EXPRESSION IN THE EARLY ADAPTIVE PERIOD FOLLOWING MASSIVE SMALL BOWEL RESECTION.
E. Swietlicki, tL Tudos, D.C. Rubin, M.S. Levin. Department of Medteine, Washington University School of Medicine, St. Louis, Me.
Loss of functional small bowel surface area results in an adaptive response with increased villus height, crypt depth and enhanced absorptionl We have been studying the molecular and cellular mechanisms regulating this process. Previously, we reported that rat apoAIV and liver fatty acid binding protein (L- FABP) mRNA levels are induced in adaptive intestine at 4 8 h and 1 week following 70% intestinal resection (Gastrb 104:4 A276, 1993.) ApoAIV is involved in intestinal lipid synthesis and reverse cholesterol transport, and may function as a satiety factor; It !s primarily synthesized in the intestine. Recent studies suggest that apoAIV gene expression is enhanced by the transcription factor HNF-4 and suppressed by Ear3. The aim of this study was to extend our previous observations by determining the temporal pattern of expression of apoAIV, HNF-4 and L-FABP at earlier times postreseetion. Methods Adult male rats were subjected to 70% sroximal small bowel resection or to intestinal transection with reenastomos~'(enntrol). They were harvested at 2, 4, 8, 16, 24, or 48 h or 1 week post-op (n=3 to 10 rats per group) and the expression of apoAIV, L-FABP and HNF-4 were assessed by RNA dot and Northern blotting end/or immunghistochemicai analysis. Results AFoAIV protein levels were dramatically increased in ileal segments between 8 and 2 4 h following resection. RNA blot analyses showed that remnant ileal apoAIV mRNA levels were induced beginning at 8 h following resection. Peak induction (9-fold) occurred at ~16 h. L-FABP mRNA induction also peaked at 16 h (2-fold). HNF-4 mRNA levels were also induced at 16 end 24 h (peak induction 1.7 fold). Conclusions Intestinal apoAIV mRNA and protein levels are significantly induced early in the course of the adaptive response following 70% proximal resection. The magnitude of this induction is significantly greater than that of other genes with roles in intestinal lipid trafficking ~,e.g., L-FABP and cellular retinol binding protein ID. The increase in apoAIV expression is concomitant with the induction of HNF-4 mRNA. These data do not directly address the role of apoAIV in the early postresection period or the role of HNF-4 in modulating the intestinal expression of apoAIV. Nevertheless, they suggest that further exploration of the role of HNF-4 and apoAIV in adaptation is warranted.
OVITAMIN A DEFICIENCY POTENTIATES METHOTREXATE (MTX) ENTEROPATHY IN RATS. R Warden, L Francis, p Dunkley and E O'Louahlin. Faculty of Medicine, University of Newcastle, NSW Australia. Vitamin A deficiency increases childhood morbidity andmortality from infectious diarrheal diseases but the role of vitamin A in the intestine is poorly understood. Aims: To determine if vitamin A deficiency alters intestinal response to injury. Methods: Male wistar rats were fed a vitamin A deficient diet for 45 days (VA-) and compared to pair fed controls (C). Groups of C and VA- were administered MTX 7mg/kg/day D40-D43 and studied D45 (CMTX and VAMTX). Diarrhea, body weight change over last 5 days (Awgt), serum vitamin A levels (vita, ~M/L), jejunal histology and mucosal wet weight (mww, mg/cm), protein (P,mg/cm), DNA (mg/gm P) and Maltase (U/gm P) were measured. Results: Diarrhea occurred in 3/14 CMTX and 10/15 VAMTX (p<0.05) but not VA- or C. Results are depicted as X±SE n Z 8.
4.7±o.3 3'6+-0.2 81~3 8,3+-3
l, 5+_0 1 o
28+_2" 22±3" 2.3+--0,26 1 • 9+--0.4"
Maltase 428+53 424+43 248±52" 41+15 ='b a,p<0.05 compared to C and VA-; b, p<0.05 MTX vs VAMTX; c, p<0.05 compared to C only. Morphology was unaltered in C and VA-, demonstrated mild inflammatory changes in CMTX but severe villous atrophy in VAMTX. conclusions: Vitamin A deficiency did not alter any intestinal parameter compared to controls but did potentiate the MTX induced' enteropathy. Vitamin A may play a role in normal epithelial barrier function and/o~ epithelial repair after acute injury.