Intestinal-type Fatty Acid Binding Protein Research Articles

Intestinal barrier biomarkers in clinical evaluation of patients with inflammatory bowel disease.

Inflammatory bowel disease (IBD) is associated with chronic intestinal barrier dysfunction, though its non-invasive assessment remains challenging. This study aimed to determine how four putative circulating markers vary across differing states of intestinal inflammation and with therapy in patients with IBD. Plasma samples from one prospective cross-sectional and four longitudinal studies, including healthy controls, were analysed for markers of lipopolysaccharide translocation, lipopolysaccharide-binding protein (LBP) and soluble-CD14 (sCD14), and markers of epithelial injury, syndecan-1 and intestinal-type fatty acid-binding protein (IFABP). Inflammatory activity was determined using objective measures. Compared with healthy subjects, concentrations of LBP and sCD14 were higher in patients with active (P < 0.001) and severe ulcerative colitis (UC) (P < 0.0001) and active Crohn's disease (CD) (P < 0.001). In UC in remission, LBP was less than in active disease (P = 0.011) LBP levels decreased longitudinally before and after induction of medical therapy in patients with IBD (P = 0.030) and as severe UC was brought into remission at weeks 2 and 12 (P ≤ 0.022). Response to treatment was associated with higher baseline levels of LBP (P = 0.019) and soluble-CD14 (P = 0.014). Concentrations of syndecan-1 and IFABP were or tended to be lower in UC and CD in active disease and did not change with successful therapy. While markers of epithelial injury were subnormal with active disease and did not change with therapy, markers of lipopolysaccharide translocation directly reflected intestinal inflammation, reduced with successful therapy and predicted treatment response.

Effect of STING signaling on intestinal barrier damage in severe acute pancreatitis

BackgroundPatients with severe acute pancreatitis (SAP) have a compromised intestinal barrier with decreased barrier function and increased cell death. Intestinal epithelial cells (IECs) create a physicochemical barrier that anchors bacteria in the intestine. Recent studies have shown that the stimulator of interferons genes (STING) signaling pathway plays an important function in a number of inflammatory conditions. MethodsThe rat SAP model was established by retrograde injection of freshly prepared sodium taurocholate into the biliopancreatic duct. Serum amylase (AMY), lipase (LIPA), interleukin (IL)-6, interferon (IFN)-β, tumor necrosis factor (TNF)-α, intestinal-type fatty acid binding protein (FABP2), diamine oxidase (DAO) and endotoxin (ET) levels were measured in rats. H&E staining was used to assess histological changes in the intestine and pancreas. The expression of intestinal epithelial cell tight junction (TJ) proteins and STING signaling pathway proteins and genes were measured by RT- PCR, Western blot and immunofluorescence staining were used to analyze. The expression of STING signaling pathway proteins in pancreas were measured by Western blot were used to analyze. TUNEL was used to detect IECs death. ResultsUpregulation of STING pathway-related proteins and genes occurred after sap-induced IECs. In addition, C-176 reduced serum AMY, LIPA, TNF-α, IL-6, INF-β, FABP2, DAO and endotoxin levels and decreased pancreatic and intestinal histopathological injury in SAP rats; DMXAA aggravated serum AMY, LIPA, TNF-α, IL-6, INF-β, FABP2, DAO and endotoxin levels and increased pancreatic and intestinal histopathological injury in SAP rats. ConlusionsThe results suggest that inhibition of STING signaling can alleviate IECs after SAP, and activation of STING signaling can aggravate IECs after SAP.

Dose-Dependent Effects of Histamine on Growth, Immunity and Intestinal Health in Juvenile Grouper (Epinephelus coioides)

A 56 day feeding trial was conducted to examine the effects of different levels of dietary histamine on growth performance, immune response, and intestinal health of grouper (Epinephelus coioides). Seven isonitrogenous (46%), isolipidic (10%) diets were prepared with histamine supplement levels of 0 (T0), 0.05% (T1), 0.1% (T2), 0.15% (T3), 0.2% (T4), 0.25% (T5), and 0.3% (T6), respectively. The results showed that histamine supplementation had no significant effects on weight gain rate (WGR), specific growth rate (SGR), feed conversion rate (FCR), hepatosomatic index (HSI), and survival rate (SR) at the initial feeding period (day 0–28), but WGR and SGR had negative linear responses to the dietary histamine level at the whole feeding period (day 0–56), and a significant decrease was observed in groups T5 and T6 compared with T0 (P &amp;lt; 0.05). Supplementation of histamine decreased antioxidant capacity, immune response, the contents of serum interleukin-1 beta (IL-1β), intestinal-type fatty acid-binding protein (FABP2) and intestinal trefoil factor (ITF), and caused serious damage of intestine with significantly decreased VH and MFH of grouper, especially in fish fed with diets supplemented with high doses of histamine (0.25 and 0.3%). The intestinal microbial communities in treatments were different clearly with the control (T0), in terms of beta (β)-diversity boxplots and UPGMA phylogenetic tree based on unweighted unifrac distance. At the phylum level, the relative abundance of Fusobacteria was lower in group T0, while the abundance of Firmicutes was significantly lower in groups T5 and T6 (P &amp;lt; 0.05). At the genus level, the relative abundance of uncultured_bacterium_f_Bacteroidales_S24-7_group, uncultured_bacterium_f_Lachnospiraceae, and Ruminiclostridium were significantly higher in the control, while the abundance of Cetobacterium was significantly higher in groups T5 and T6 (P &amp;lt; 0.05). In conclusion, the present study suggested that up to 0.2% of dietary histamine did not result in a remarkable reduction in growth, immune response, and intestinal health; however, 0.25% or more dietary histamine could cause significant negative effects on growth performance, immune response, and intestinal health in E. coioides.

Bioinformatics analysis and tissue-specific expression of intestinal-type fatty acid binding protein in domestic pigeons (Columba livia)

ABSTRACT Intestinal fatty-acid binding protein (I-FABP, also called FABP2) is involved in the uptake of dietary fatty acids in the intestine, and its binding specificity is only with long-chain fatty acid. In this study, sequences of 4 exons in pigeon FABP2 were successfully amplified. The encoded protein had a molecular weight of 15.13 kDa and the theoretical pI was 6.75. Bioinformatics analysis indicated that the protein was predicted to contain 10 potential phosphorylation sites and did not contain signal peptide structure. The evolutionary analysis suggested the amino acid sequence of pigeon FABP2 was closest to the mallard (Nippoia nippon) homologs. Meanwhile the expression of FABP2 mRNA in different ages and tissues we conducted. It showed that the expression of the FABP2 gene was the highest in the liver, followed by the small intestine and adipose tissue, while lowest in the breast muscle. Also, the expression level in the gizzard was gradually increased with aging. Our results may serve as reference to better studies of the functional characterization and structure of the FABP2 in pigeon.

The effects of dietary sulfur amino acids on growth performance, intestinal morphology, enzyme activity, and nutrient transporters in weaning piglets.

Early weaning results in intestinal dysfunction in piglets, while sulfur amino acids (SAA) are involved in improving intestinal functions. We tested a hypothesis that dietary supplementation with SAA can improve intestinal functions of weaning piglets and analyzed the effects of different dietary SAA levels on intestinal functions. A total of 80 piglets (Duroc × Landrace × Yorkshire) were weaned at 21 d of age and randomly assigned to one of the five diets that contained 0.53%, 0.63%, 0.74%, 0.85%, or 0.96% SAA, which corresponded to 70%, 85%, 100%, 115%, or 130% of the SAA:Lys ratio recommended by the National Research Council (2012). The 14 d feeding experiment involved 16 pens per diet and one piglet per pen. Eight randomly selected piglets from each treatment were euthanized for tissue sampling on day 7 and 14 post weaning. Supplementation with SAA led to a rise over time in G:F (linear, P = 0.001; quadratic, P = 0.001). Between day 0 and 14 of treatment, the jejunal crypt depth decreased (linear, P = 0.018; quadratic, P = 0.015), while that of the duodenal villus (linear, P = 0.049) and ileal villus width (linear, P = 0.029; quadratic, P = 0.034) increased. The activities of jejunal alkaline phosphatase (ALP) were quadratically increased (P = 0.040) from day 0 to 14 due to dietary SAA. Dietary SAA also elevated the activities of jejunal lactase (linear, P = 0.003; quadratic, P = 0.004), jejunal sucrase (linear, P = 0.032; quadratic, P = 0.027), and jejunal contents of glutathione (GSH) from day 0 to 7, as well as the activity of jejunal maltase (linear, P = 0.014; quadratic, P = 0.001) between day 0 and 14. During the first wk, dietary SAA linearly increased the amounts of intestinal-type fatty acid-binding protein (I-FABP) (P = 0.048) and SGLT-1 (P = 0.021) and linearly decreased the amount of GLUT2 (P = 0.029) proteins in the jejunum. The abundance of jejunal I-FABP (P = 0.044) and PEPT1 (P = 0.049) protein linearly increased from day 0 to 14 in response to this supplementation. These findings indicate that there is a dose-dependent response to dietary SAA on feed efficiency and intestinal parameters of weanling pigs.

Combined Plasma Elevation of CRP, Intestinal-Type Fatty Acid-Binding Protein (I-FABP), and sCD14 Identify Older Patients at High Risk for Health Care-Associated Infections.

We hypothesized that low-grade inflammation was driven by microbial translocation and associated with an increased risk of health care-associated infections (HAIs). We included 121 patients aged 75 years or over in this prospective cohort study. High-sensitivity C-reactive protein (hs-CRP), I-FABP, and sCD14-as markers for low-grade inflammation, intestinal epithelial barrier integrity, and monocyte activation, respectively-were measured at admission. HAIs occurred during hospitalization in 62 (51%) patients. Elevated hs-CRP (≥6.02 mg/L, ie, the median) was associated with a significantly higher HAI risk when I-FABP was in the highest quartile (odds ratio [OR], 4; 95% confidence interval [95% CI], 1.39-11.49; p = .010). In patients with hs-CRP elevation and highest-quartile I-FABP, sCD14 elevation (≥0.65 µg/mL, ie, the median) was associated with an 11-fold higher HAI risk (OR, 10.8; 95% CI, 2.28-51.1; p = .003). Multivariate analyses adjusted for invasive procedures and comorbidities did not change the associations linking the three markers to the HAI risk. Increased levels of hs-CRP, I-FABP, and sCD14 may reflect loss of intestinal epithelial barrier integrity with microbial translocation leading to monocyte activation and low-grade inflammation. In our cohort, these markers identified patients at high risk for HAIs.

Pro-Inflammatory Cytokines but Not Endotoxin-Related Parameters Associate with Disease Severity in Patients with NAFLD.

Intestinal dysbiosis and elevated lipopolysaccharides (LPS) levels have been implicated in the development of obesity, insulin resistance and non-alcoholic steatohepatitis (NASH). In order to determine if LPS levels are elevated in patients with NASH compared to patients with non-alcoholic fatty liver (NAFL) and, if elevated LPS levels correlated with histological severity of non-alcoholic fatty liver disease (NAFLD) we compared LPS, markers of LPS bioactivity and pro-inflammatory cytokines/chemokines in patients undergoing bariatric surgery. At the time of surgery a liver biopsy was taken allowing the stratification into well-delineated subgroups including: No NAFL/NAFL; NASH; NASH with fibrosis and NASH cirrhotics, using the NAFLD Activity Score (NAS). Anthropometric data and plasma were collected for assessment of LPS, lipopolysaccharide binding protein (LBP), soluble CD14 (sCD14), intestinal-type fatty acid binding protein (iFABP), Toll-like receptors 2 and 4 (TLR2, 4) and a panel of cytokines/chemokines. Similar analysis was performed on plasma from a cohort of healthy controls. Our data indicate elevated levels of LPS, LBP, sCD14, iFABP and TLR2,4 in obese patients compared to healthy controls, however, these parameters remained unaltered within patients with limited liver disease (NAFL) compared to NASH/NASH with fibrosis subgroups. Hierarchic cluster analysis using endotoxin-related parameters failed to discriminate between lean controls, NAFLD. While similar cluster analysis implementing inflammation-related parameters clearly distinguished lean controls, NALFD subgroups and NASH cirrhotics. In addition, LPS levels was not associated with disease severity while TNFα, IL8, and CCL3 featured a clear correlation with transaminase levels and the histological severity of NALFD. In conclusion our data indicate a stronger correlation for circulating inflammatory- rather than endotoxin-related parameters in progression of NAFLD and highlights the need for additional larger studies in unravelling further mechanistic insights.

Differential proteome analysis along jejunal crypt-villus axis in piglets

The brush-border membrane (BBM) of enterocytes is responsible for the digestion and absorption of nutrients and ions in the small intestine. To identify the BBM proteins involved in epithelial cell maturation along the crypt-villus axis, enterocytes were sequentially isolated from the villus tip to the crypt of the jejunum from 21-day-old suckling piglets. After preparation of BBM vesicles, we detected 194 proteins in the jejunal epithelial cells by isobaric tags using relative and absolute quantification (iTRAQ) techniques. Of these, 56 BBM proteins were differentially expressed along the crypt-villus axis. During differentiation, the expression of proteins related to digestion and absorption of nutrients was primarily downregulated at the upper, middle villus, or crypt compared to the villus tip, while expression of proteins related to structural and enzyme regulator proteins was largely upregulated. We verified the differences in Na(+)/K(+) -transporting ATPase, galectin-3, and an intestinal-type fatty acid binding protein by western blot or immunochemical analysis. Identification of BBM-associated proteins helps enhance our understanding of digestion and absorption in piglets and other mammals, including humans.

Lipoxin A4 Preconditioning Attenuates Intestinal Ischemia Reperfusion Injury through Keap1/Nrf2 Pathway in a Lipoxin A4 Receptor Independent Manner

Oxidative stress plays a critical role in the pathogenesis of intestinal ischemia reperfusion (IIR) injury. Enhancement in endogenous Lipoxin A4 (LXA4), a potent antioxidant and mediator, is associated with attenuation of IIR. However, the effects of LXA4 on IIR injury and the potential mechanisms are unknown. In a rat IIR (ischemia 45 minutes and subsequent reperfusion 6 hours) model, IIR caused intestinal injury, evidenced by increased serum diamine oxidase, D-lactic acid, intestinal-type fatty acid-binding protein, and the oxidative stress marker 15-F2t-Isoprostane. LXA4 treatment significantly attenuated IIR injury by reducing mucosal 15-F2t-Isoprostane and elevating endogenous antioxidant superoxide dismutase activity, accompanied with Keap1/Nrf2 pathway activation. Meanwhile, LXA4 receptor antagonist Boc-2 reversed the protective effects of LXA4 on intestinal injury but failed to affect the oxidative stress and the related Nrf2 pathway. Furthermore, Nrf2 antagonist brusatol reversed the antioxidant effects conferred by LXA4 and led to exacerbation of intestinal epithelium cells oxidative stress and apoptosis, finally resulting in a decrease of survival rate of rat. Meanwhile, LXA4 pretreatment upregulated nuclear Nrf2 level and reduced hypoxia/reoxygenation-induced IEC-6 cell damage and Nrf2 siRNA reversed this protective effect of LXA4 in vitro. In conclusion, these findings suggest that LXA4 ameliorates IIR injury by activating Keap1/Nrf2 pathway in a LXA4 receptor independent manner.

Immunosuppressive Tryptophan Catabolism and Gut Mucosal Dysfunction Following Early HIV Infection.

Tryptophan (Trp) catabolism into kynurenine (Kyn) contributes to immune dysfunction in chronic human immunodeficiency virus (HIV) infection. To better define the relationship between Trp catabolism, inflammation, gut mucosal dysfunction, and the role of early antiretroviral therapy (ART), we prospectively assessed patients early after they acquired HIV. Forty patients in the early phase of infection were longitudinally followed for 12 months after receiving a diagnosis of HIV infection; 24 were untreated, and 16 were receiving ART. Kyn/Trp ratio, regulatory T-cells (Tregs) frequency, T-cell activation, dendritic cell counts, and plasma levels of gut mucosal dysfunction markers intestinal-type fatty acid-binding protein, soluble suppression of tumorigenicity 2, and lipopolysaccharide were assessed. Compared with healthy subjects, patients in the early phase of infection presented with elevated Kyn/Trp ratios, which further increased in untreated patients but normalized in ART recipients. Accordingly, in untreated subjects, the elevated Treg frequency observed at baseline continued to increase over time. The highest CD8(+) T-cell activation was observed during the early phase of infection and decreased in untreated patients, whereas activation normalized in ART recipients. The Kyn/Trp ratio was positively associated with CD8(+) T-cell activation and levels of inflammatory cytokines (interleukin 6, interferon γ-inducible protein 10, interleukin 18, and tumor necrosis factor α) and negatively associated with dendritic cell frequencies at baseline and in untreated patients. However, ART did not normalize plasma levels of gut mucosal dysfunction markers. Early initiation of ART normalized enhanced Trp catabolism and immune activation but did not improve plasma levels of gut mucosal dysfunction markers.

D-dimer as an early marker of severity in patients with acute superior mesenteric venous thrombosis.

No early serum marker of disease severity contributes to the treatment decision-making process of acute superior mesenteric venous thrombosis (ASMVT). This study aims to assess the value of serum D-dimer level in the first 3 days after admission as a severity marker of ASMVT patients.From May 2010 to June 2014, 50 consecutive patients of ASMVT were enrolled in this observational study. The serum D-dimer level was measured on a daily basis during the first 3 days after admission as well as other laboratory-testing parameters, clinical score, and outcome variables recorded during the same period. The maximum and mean D-dimer values were analyzed and compared with other potential markers for prediction of multiple-organ dysfunction syndrome (MODS) and short-bowel syndrome (SBS). The correlation of D-dimer level with other potential severity markers and inflammation parameters were also studied.Both maximum and mean D-dimer level during the first 3 days of admission were significantly higher in patients with several clinical variables such as death within 30 days, bowel resection, sepsis, abdominal compartment syndrome, MODS, and SBS. In addition, serum D-dimer level showed precise prediction for MODS and SBS, greater than l-lactate and intestinal-type fatty acid-binding protein (I-FABP). The D-dimer level was correlated well with l-lactate, I-FABP, and APACHE II score on the first 3 days of admission. Poor correlation of D-dimer level and inflammation parameters, white blood cell count, and C-reactive protein level, was detected.D-dimer level could be an effective, early, and specific serum marker indicating the clinical evolution and outcome of ASMVT.

Effect of Haemodynamic Changes on Epithelium-related Intestinal Injury in Off-pump Coronary Surgery

Intestinal injury is thought to play a central role in the occurrence of multiorgan dysfunction after on-pump coronary surgery. Clinical benefits of off-pump revascularisation remain, however, controversial. Hepatic enzymes and plasmatic IL-6, IL-8 and intestinal-type fatty acid binding protein (I-FABP) were determined in 20 patients (age 65-75) undergoing either on-pump (n = 10) or off-pump (n = 10) coronary surgery. Haemodynamic and biochemical parameters, catecholamine and volume therapy were monitored. Central venous pressure (CVP) was significantly higher in the off-pump group during and 12h after operation (9.5 ± 1.35 vs. 6.21 ± 0.63 mmH2O, p = 0.012). Higher GGT and GLDH levels occurred in the off-pump group and correlated with the elevated I-FABP levels at 24h (935.8 ± 83.7 vs. 370.4 ± 67.7 pg/mL, p<0.001). CVP correlated with I-FABP peak values (Pearson's coefficient 0.852). IL-6 and IL-8 were released to a lower extent in the off-pump group compared to on pump (p<0.05) at 24h (139.3 ± 27.7 vs. 279.4 ± 56.2 and 15.3 ± 7.4 vs. 38.5 ± 13.8 pg/mL) and at 72 h post-operatively (4.5 ± 2.1 vs. 30.1 ± 12.1 and 7.8 ± 1.2 vs. 17.1 ± 5.2 pg/mL). While inflammatory activation is reduced with CPB avoidance, elevated CVP during off-pump surgery is followed by temporary postoperative enterocyte damage that may threaten the normal function of the gastrointestinal system and lead - in certain groups of high risk patients--to irrecoverable injury.

Ischemic Postconditioning Attenuate Reperfusion Injury of Small Intestine

Ischemic postconditioning (IPoC) modulates the reperfusion maneuver to mitigate ischemia-reperfusion (I/R) injury. This study aims to investigate the effects and protective mechanism of IPoC on intestinal I/R injury. Intestinal I/R was induced by occluding the superior mesenteric artery for 30 min followed by reperfusion for 60 min on male Wistar rats. IPoC was elicited by three cycles of 30-sec reperfusion and reocclusion of superior mesenteric artery at the initiation of reperfusion. Carboxyatractyloside (CATR), a mitochondrial permeability transition pore (mPTP) opener, and N-methyl-4-isoleucine cyclosporine (NIM811), an mPTP inhibitor, were administered separately in selected groups. The serum and intestinal sections were collected for analysis. IPoC and the administration of NIM811 significantly diminished the expression of intestinal-type fatty acid-binding protein and lactate dehydrogenase (3427±236.8 U/L for I/R, 1190.5±36.7 U/L for IPoC, 1399.3±295.6 U/L for I/R+NIM811, and 2002±370.9 IU/L for IPoC+CATR) in portal blood, the release of cytosolic cytochrome c, and the cleaved caspase 9 expression in intestinal mucosa after intestinal I/R injury (P<0.05). Histopathologically, IPoC and NIM811 mitigated mucosal damage after I/R as well (Chiu's score, 3.8±0.4 for I/R, 0.2±0.2 for IPoC, 0.4±0.2 for I/R+NIM811, and 4.2±0.2 for IPoC+CATR; apoptotic index, 59.5%±4.6% for I/R, 15.7%±15.7% for I/R+IPoC, 3.5%±3.5% for I/R+NIM811, and 67.1%±9.3% in IPoC+CATR). CATR negated the protection conferred by IPoC. IPoC and NIM811 attenuate intestinal I/R injury. The addition of CATR negated the effects of IPoC, indicating that the protective mechanism of IPoC was associated with the modulation of mPTP opening.

Fatty acid‐binding protein expression in the gastrointestinal tract of calves and cows

Fatty acid-binding protein (FABP) has high affinity for long-chain fatty acids and appears to participate in the metabolism and intracellular transport of lipids. Liver- and intestinal-type FABP (L-FABP and I-FABP, respectively) are expressed in the small intestine. However, in the gastrointestinal tract of ruminants, expression and localization of FABPs are unknown. In this study, we investigated the expression of I-FABP and L-FABP in the gastrointestinal tract of cattle. I- and L-FABP had higher messenger RNA (mRNA) and protein expression levels in the duodenum and jejunum relatively to other gastrointestinal regions in both calves and cows. Furthermore, L-FABP mRNA and protein expression were high in the colon. Both these protein types were confirmed to be in the cytosol of jejunal epithelial cells, where they were found in the villi rather than in the crypts. We concluded that duodenal and jejunal FABPs might be involved in the metabolism of fatty acids mainly in epithelial cells in cattle.

Clinical significance of intestinal type fatty acid binding protein in patients undergoing coronary artery bypass surgery

The aim of this study was to determine whether serum levels of intestinal type fatty acid binding protein (I-FABP) are related to intestinal ischemia in patients undergoing coronary bypass surgery. The study was planned as prospective, observational. Elective coronary artery bypass candidate patients between ages of 50 and 70 were consecutively included in the study. Thirty-five patients scheduled for cardiopulmonary bypass (CPB) were identified as the CPB group and 16 patients not scheduled for CPB were identified as the off-pump coronary artery bypass surgery (OPCAB) group. The variables between and within the groups were analyzed with Student's t, Mann-Whitney U, Friedman and Wilcoxon tests respectively. In both CPB and OPCAB groups, I-FABP level at the end of the operation was significantly higher than that noted at the beginning of the operation (p<0.005). In the CPB group, there was a significant drop in I-FABP from the end of the operation to each of the postoperative time points (12(th) hour and 24(th) hour) (respectively p<0.001, p<0.001). In the OPCAB group, the I-FABP levels at both postoperative time points were lower than that at the end of the operation (p<0.001), and the level at 24-hour post-surgery was significantly lower than at both the end-of-operation I-FABP value (p<0.001) and the 12-hour post-surgery I-FABP value. Since we have not observed any intestinal ischemia through our research, slight changes of I-FABP measurements make us believe that I-FABP would be a valuable way to monitor for intestinal ischemia in patients who undergo cardiac surgery.

Dairy protein and leucine alter GLP-1 release and mRNA of genes involved in intestinal lipid metabolism in vitro

Objective A growing body of evidence supports an antiobesity effect of dairy products; however, the mechanisms remain unclear. The objective of this study was to explore possible intestinal mechanisms by which dairy delivers an antiobesity effect. The human intestinal cell line, NCI-H716, was used to test the hypothesis that branched-chain amino acids and dairy proteins regulate satiety hormone secretion and modulate genes involved in fatty acid and cholesterol metabolism. Methods In dose–response (0.5%, 1.0%, 2.0%, and 3.0%) studies, the effect of leucine, isoleucine, valine, skim milk, casein, and whey on glucagon-like peptide-1 release and the expression of selected genes were tested. Results Leucine, isoleucine, skim milk, and casein stimulated glucagon-like peptide-1 release ( P < 0.05). Isoleucine and whey downregulated the expression of intestinal-type fatty acid binding protein ( i-FABP), fatty acid transport protein 4 ( FATP4), Niemann-Pick C-1–like-1 protein ( NPC1L1), acetyl-coenzyme A carboxylase ( ACC), fatty acid synthase ( FAS), sterol regulatory element-binding protein-2 ( SREBP-2), and 3-hydroxy-3-methylglutaryl-CoA reductase ( HMGCR; P < 0.05). Leucine and valine downregulated the expression of NPC1L1, ACC, FAS, SREBP-2, and HMGCR ( P < 0.05). Casein downregulated the expression of i-FABP, FATP4, ACC, FAS, SREBP-2, and HMGCR ( P < 0.05). Skim milk downregulated the expression of ACC, FAS, and SREBP-2, but not i-FABP, FATP4, and NPC1L1. Conclusion This work suggests that the antiobesity effect of dairy may be mediated, at least in part, by integration of events that promote glucagon-like peptide-1 secretion and inhibit expression of genes involved in intestinal fatty acid and cholesterol absorption and synthesis.

Sequence characterization, tissue-specific expression and polymorphism of the porcine intestinal-type fatty acid binding protein gene

The intestinal fatty-acid-binding protein (IFABP) shows binding specificity for long-chain fatty acids and is proposed to be involved in the uptake of dietary fatty acids and their intracellular transport. In this study, the full-length cDNA of porcine I-FABP gene was obtained by the rapid amplification of cDNA ends (RACE). The nucleotide sequence and the predicted protein sequence share high sequence identity with its mammalian counterparts. Northern hybridization and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) revealed that porcine I-FABP is expressed in all 12 tissues studied (heart, brain, kidney, skeletal muscle, testis, liver, skin, small intestine, fat, stomach, lymph and pituitary), but a transcript of approximate 620 bp is more abundant in small intestine than in other tissues. The full-length genomic DNA of the porcine I-FABP gene was amplified by PCR. The coding region of the pig IFABP gene is organized in four exons and spans an approximate 3.5-kb genomic region. Comparative sequencing of four pig breeds revealed a single nucleotide polymorphism (SNP) within exon 1 of which an A→G substitution at codon 21 changes a codon for lysine into a codon for arginine. The distribution of allele and genotype frequencies differed significantly between indigenous Chinese Zang, Dahe and Yanan breeds (higher frequencies of A and AA) and Western Large White breed (higher frequencies of G and GG, P &lt; 0.01). The association analysis using five pig populations suggested that A21G polymorphism was associated with intramuscular fat content, indicating that the I-FABP gene A21G SNP can be a potential molecular marker for intramuscular fat content. Key words: Association analysis, cloning, gene expression, I-FABP gene, polymorphism, porcine

Molecular Cloning and Tissue-specific Expression of Intestinal-type Fatty Acid Binding Protein in Porcine

The intestinal fatty acid-binding protein (I-FABP) shows binding specificity for long-chain fatty acids and is proposed to be involved in the uptake of dietary fatty acids and their intracellular transport. In this study, the full-length cDNA of I-FABP was cloned from pig intestine by homology cloning approach combined with 3′ and 5′ RACE. Sequence analysis and bioinformatics study showed that this cDNA contained 614 nucleotides, with a 399 bp open reading frame (ORF) flanked by a 43 bp 5′ UTR and a 172 bp 3′ UTR. The encoded 132 amino acids of pig I-FABP with a molecular weight of approximately 15 kDa shared a high sequence identity of 68%–85% with those of other species. In addition, the phylogenetical analysis also indicated that the pig I-FABP was in the same branch with those of other species. The tissue-specific expression of pig I-FABP was measured by Northern hybridization and semi-quantitative RT-PCR. The results demonstrated that pig I-FABP mRNA was extensively present in various tissues, but I-FABP transcript of approximately 620 bp was more abundant in intestine than in other tissues.

Dexamethasone: Benefit and Prejudice for Patients Undergoing On-Pump Coronary Artery Bypass Grafting

Cardiac surgery with cardiopulmonary bypass (CPB) results in perioperative organ damage caused by the systemic inflammatory response syndrome (SIRS) and ischemia/reperfusion injury. Administration of corticosteroids before CPB has been demonstrated to inhibit the activation of the systemic inflammatory response. However, the clinical benefits of corticosteroid therapy are controversial. This study was designed to document the effects of dexamethasone on cytokine release and perioperative myocardial, pulmonary, renal, intestinal, and hepatic damage, as assessed by specific and sensitive biomarkers.A prospective, double-blind, placebo-controlled, randomized trial for dexamethasone was conducted in 20 patients receiving either dexamethasone (1 mg/kg before anesthesia induction and 0.5 mg/kg after 8 h; n = 10) or placebo (n = 10). Different markers were used to assess the SIRS: interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP), and tryptase; and organ damage: heart (plasma heart-type fatty acid binding protein, cardiac troponin I [cTnI], creatine kinase-MB), kidneys (N-acetyl-glucosaminidase [NAG], microalbuminuria), intestine (intestinal-type fatty acid binding protein [I-FABP]/liver-type fatty acid binding protein [L-FABP]), and liver (alpha-glutathione S-transferase).Dexamethasone modulated the SIRS with lower proinflammatory (IL-6, IL-8) and higher antiinflammatory (IL-10) IL levels. CRP and tryptase were lower in the dexamethasone group. cTnI values were lower in the dexamethasone group at 6 h in the ICU (p = 0.009). Patients in the dexamethasone group had a longer time to tracheal extubation (18.86 +/- 1.13 h vs 15.01 +/- 0.99 h, p = 0.02 [mean +/- SEM]), with a lower oxygenation index at that time: Pa(O2)/fraction of inspired oxygen ratio, 37.17 +/- 1.8 kPa vs 29.95 +/- 2.1 kPa (p = 0.009). The postoperative glucose level (10.7 +/- 0.6 mmol/L vs 7.4 +/- 0.5 mmol/L, p = 0.005) was higher in the dexamethasone group. Serum glucose was independently associated with intestinal injury (urine I-FABP peak, R2 = 42.5%, beta = 114.4 +/- 31.4, significant at p = 0.002; urine L-FABP peak, R2 = 47.3%, beta = 7,714.1 +/- 1,920.9, significant at p = 0.001) and renal injury (urine NAG, R2 = 32.1%, beta = 0.21 +/- 0.07, significant at p = 0.009). Tryptase peaks correlated negatively with peaks of intestinal and renal injury biomarkers.Even while inhibiting SIRS, dexamethasone treatment offered no protection against transient, subclinical, perioperative abdominal organ damage. Tryptase release could have a preconditioning effect, offering protection against perioperative intestinal and renal damage. Dexamethasone treatment resulted in more pronounced postoperative pulmonary dysfunction, prolonged time to tracheal extubation, and initiated postoperative hyperglycemia in patients undergoing elective on-pump coronary artery bypass graft surgery.

Sequence, linkage mapping and early developmental expression of the intestinal-type fatty acid-binding protein gene ( fabp2) from zebrafish ( Danio rerio)

The intestinal fatty acid-binding protein (I-FABP) shows binding specificity for long-chain fatty acids and is proposed to be involved in uptake of dietary fatty acids and their intracellular transport. We have determined the sequence of the gene encoding I-FABP in zebrafish. The zebrafish I-FABP gene contains four exons interrupted by three introns. Radiation hybrid mapping assigned the I-FABP gene to linkage group 1. A 924 bp sequence 5′ upstream of the initiation codon in the I-FABP gene contained several putative cis-acting regulatory elements. In adult zebrafish, reverse transcription-polymerase chain reaction (RT-PCR) detected I-FABP mRNA in intestine, brain, liver, muscle and testis. Quantitative RT-PCR demonstrated that I-FABP mRNA was most abundant in intestine, followed by brain. I-FABP mRNA levels were very low in muscle, testis, heart, liver, skin and ovary. RT-PCR using total RNA extracted from zebrafish embryos detected I-FABP mRNA as early as 12 h post-fertilization. Whole-mount in situ hybridization to zebrafish embryos detected I-FABP mRNA in the yolk syncytial layer (YSL) at early somitogenesis. Later during embryonic development the I-FABP mRNA was detected in the intestinal bulb, liver and pancreas primordium. Expression in YSL, liver or pancreas has not been previously reported for fish or mammalian I-FABP genes and may be related to specific physiological differences between fishes and mammals.