Su1879 SIRT1 Antagonizes Distinct Effects of TNF-α on Intestinal Epithelial Barrier
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AGA Abstracts with siRNA os-9 obviously decreased the TER (806.6±49.9V/cm2). Consistently, os-9 knock- down in hypoxia significantly reduced the TER (333.3±31.5V/cm2) compared to in hypoxia only (736.6±39.8V/cm2). Conclusion: Os-9 knockdown significantly aggratated hypoxia- induced intestinal epithelium injury. These findings indicate that os-9 may play an important role in maintaining the epithelial barrier function through occludin and claudin-1. Su1879 SIRT1 Antagonizes Distinct Effects of TNF-α on Intestinal Epithelial Barrier Yuanhang Ma, Guoqing Chen, Weidong Xiao, Lihua Sun, Songwei Yang, Min Yu, Yuan Qiu, Chao Xu, Ke Peng, Ligang Sun, Hua Yang Background: It has been shown that TNF-α increase in intestinal permeability, a contributing factor in the loss of intestinal barrie function in Crohn's disease (CD). SIRT1 has been shown to alleviate TNF-α induced inflammation. The purpose of this study was to determine whether SIRT1 was involved in TNF-α modulation of intestinal epithelial permeability by using an in vitro intestinal epithelial system consisting of filter-grown Caco-2 monolayers. Methods: Caco-2 cells were randomly divided into three groups: Control group, TNF-α group (TNF-α, 50 ng/ml for 24 h) and 40 μM Resveratrol (agonist of SIRT1) plus TNF-α group (Res+TNF-α). Epithelial barrier function was evaluated by transepithelial resistance (TER). SIRT1, ZO-1 expressions were examined by using Western blotting and immunofluo- rescence confocal microscopy. Results: SIRT1 expression was significantly increased by 43% in Res+ TNF-α group when compared with TNF-α group (p<0.05). TERs of the control group, TNF-α group and Res+TNF-α group were (153±5) Ohm/cm3, (98±4) Ohm/cm3 and (122±7) Ohm/cm3. Compare with the control group, the TER of the TNF-α group was decreased by 40% (p<0.05); TER in Res+TNF-α group were increased by 24% when compare with the TNF-α group, but it was still significantly lower than the control group (p<0.05). ZO- 1 expression was significantly decreased after treated with TNF-α (0.67±0.4 vs. 0.27±0.03, p<0.05), and resveratrol administration increased ZO-1 expression (0.38±0.04) compared with TNF-α group. Assessed by immunofluorescent localization of ZO-1 proteins, ZO-1 proteins were localized at the apical cellular junctions and appeared as continuous belt-like structures encircling the cells at the cellular borders in the control Caco-2 monolayers. TNF- α (50 ng/ml) caused a zig-zagging appearance and discrete punctate or gaplike appearance of ZO-1 localization at the cellular borders. Resveratrol prevented the TNF-α-induced disturb- ance of ZO-1 localization at cellular junctions. Conclusion: SIRT1 could reduce the damage caused by TNF-α on intestinal epithelial barrier through up- regulation of ZO-1 expression. Su1880 Effects on CaCO-2 Gastrointestinal Epithelial Barrier Properties of the Nutraceuticals Zinc, Berberine, Butyrate, Indole and Quercetin James M. Mullin, Mary Carmen Valenzano, Katherine DiGuilio, Mimi Teter, Joanna Mercado, Julie To, Brittany Mixson, Brendan Ferraro, Isabel Manley, Valerissa Baker Zinc, Berberine, Quercetin, Indole and Butyrate all improved CACO-2 barrier function but did so with patterns unique to each nutraceutical compound. All five increased transepithelial electrical resistance but only berberine induced a decrease in transepithelial permeability to 14C-D-mannitol. The pattern of changes induced in the protein composition of tight junc- tional complexes was also unique to each compound. Claudin-2 was decreased dramatically by butyrate and berberine but increased dramatically by quercetin. Quercetin also increased claudins -4 and -5 dramatically. Butyrate induced over 300% increases in claudin-7. These unique patterns suggest that combinations of compounds may prove superior over individual compounds in terms of barrier enhancement. Zinc and indole was one such combination that evidenced additive effects on transepithelial electrical resistance. The action of these compounds on tight junctional proteins is partially dependent on the degreee of differentiation of the CACO-2 cell layer, as evidenced by dramatically different effects of quercetin on the claudin composition of 1-day vs 7-day postconfluent cell layers. The effects of zinc on electrical resistance and transepithelial mannitol flux were similarly dependent on the degree of differentiation. The substratum to which the epithelia adhere also affects the barrier response to nutraceuticals, as evidenced by dramatically different responses to zinc by CACO- 2 cell layers grown on Millicell PCFs vs Millicell HAs. In summary, these data suggest that diseases characterized by barrier defects may show improvement by nutraceutical administra- tion, especially in unique combinations, and that responses to these compounds may vary not only along the length of the GI tract but also along the crypt-villus axis. Su1881 The Effect of High-Fat Diet, High-Fructose Diet and Soft Drink on Intestinal Integrity and Inflammation Eunyoung Doo, Oh Young Lee, Hang Lak Lee, Dae Won Jun, Byung Chul Yoon, Ho Soon Choi, Kang Nyeong Lee, Joon Soo Hahm Objectives Nonalcoholic fatty liver disease (NAFLD) is associated with food composition including fat and fructose. Recently, it was also suggested that intestinal permeability and inflammation was increased in NAFLD. However, whether high-fat and high-fructose diets are associated with increased intestinal permeability and inflammation in NAFLD is not determined. Therefore, we investigated the effect of high-fat diet, high-fructose diet and soft drink on intestinal integrity and inflammation. Methods Thirty-seven male Sprague-Dawley rats (300-350 g) were divided into 4 groups, which were fed with a high-fat, high-fructose, cola, and control diet, respectively, for 20 weeks. To determine the effects of high-fat, high- fructose, and cola on intestinal integrity and inflammation, we assessed the integrity of epithelial tight junctions within the small intestine by immunohistochemical analysis of ZO- 1 and occludin expression. We also performed immunohistochemical stain of inflammatory markers, TLR-4 and NOX-4. Results Expression of occluding in the high-fat diet group was lower than that in the control group (2.14 vs. 2.89; p=0.042) and expression of TLR-4 in the high-fat diet group was higher than that in the control group (1.17 vs. 0.78; p=0.016). Expression of ZO-1 in the high-fructose diet group was lower than that in the control group (1.56 vs. 2.56; p=0.024). Expression of occludin in the cola diet group was lower than that S-492 AGA Abstracts in the control group (2.08 vs. 2.89; p=0.003). Conclusions High-fat diet, high-fructose diet and cola may be related to disruption of tight junction integrity. Su1882 Amino Acid and Fatty Acid Sensing Mechanisms in the Human Colon Madusha Peiris, Harween Dogra, Adam D. Robinow, Amanda J. Page, Richard L. Young, Ashley Blackshaw Background: Gastric bypass surgery normalizes appetite and glucose homeostasis in obese patients by shunting nutrients away from the stomach and small intestine directly to the distal gut. This is linked to increased release of Peptide YY (PYY) and glucagon-like peptide (GLP-1) from L-cells, which reduces appetite, implying a novel role for nutrient receptors in the proximal colon. Studies in rodents have also demonstrated that 5-HT regulates vagal afferent activity and regulates appetite. However, the pathways leading to activation of L- cells and enterochromaffin (EC) cells in the distal gut are unknown. We show that the human ascending colon expresses receptors for fatty acids and amino acids, and their activation can induce release of PYY and 5-HT. Methods: Human ascending colon samples were obtained from surgical resection specimens for GPCR immunohistochemistry (IHC). Mucosal biopsies obtained from patients with normal, non-inflamed ascending colons were used for RNA extraction or stimulated with lauric acid. Release of gut hormones was measured using a MAGPIX assay (Merck Millipore). 5-HT was measured by ELISA. Results are shown as means ± SEM. Results: Amino acid and fatty acid receptors were expressed in the proximal colon (N=4) in the following order GPR120 (long chain fatty acid receptor; 1.15 ± 0.09 cells/crypt) > GPR92 (amino acid receptor; 1.08 ± 0.09 cells/crypt) > GPR84 (medium chain fatty acid receptor; 0.89 ± 0.05 cells/crypt) > GPR43 (short chain fatty acid receptor; 0.85 ± 0.07 cells/crypt). mRNA results matched protein expression levels. Specific analysis of cell types, found GPR84 immunoreactivity in 73% of EC & 24% of L-cells, GPR92 in 70% of EC & 18% of L-cells, GPR120 in 70% of EC & 11% of L-cells, and GPR43 in 66% EC & 15% of L-cells. As GPR84 had the highest level of expression on EC and L-cells, we stimulated cells with lauric acid (GPR84 agonist). Lauric acid induced expression of activation marker pERK in both populations. Therefore we stimulated biopsies with lauric acid to induce mediator release. Lauric acid (25mM) significantly increased 5-HT (control: 0.57 ± 0.12 ng/ mL vs. treated: 1.05 ± 0.14 ng/mL, N = 3) and PYY release (control: 27.6 ± 14.6 pg/mL vs. treated: 605.5 ± 218.3 pg/mL, N = 5). Preliminary data also indicate release of GLP-1, but not ghrelin or GIP. Conclusions: Most nutrient receptors sensing amino acids and medium/long chain fatty acids in the human ascending colon are found on 5-HT containing EC. L-cells containing both PYY and GLP-1 also express these receptors albeit to a lesser degree. GPR84 is functionally active in normal human colon since both 5-HT and PYY are released upon receptor stimulation. Overall, these results demonstrate the proximal colon is capable of releasing appetite regulating hormone, suggesting it may be the source of anorexigenic mediator release following bariatric surgery. Su1883 Genetic Inactivation of the Bile Salt Export Pump in Mice Profoundly Increases Fecal Cholesterol Excretion Mariette Y. van der Wulp, Theo H. van Dijk, Vincent Bloks, Albert K. Groen, Henkjan J. Verkade Introduction The bile salt export pump (Bsep) is the major hepatic bile salt (BS) transporter, facilitating BS transfer from liver hepatocytes into the bile canaliculi. Bsep -/- mice were previously shown to escape severe cholestasis by increasing biliary BS hydrophilicity, resulting in activation of alternative transporters. Bsep -/- mice surprisingly showed increased biliary cholesterol secretion. The consequence of strongly increased biliary cholesterol secretion for intestinal handling is not known. To determine these downstream effects of Bsep deficiency we determined biliary BS and whole body cholesterol fluxes. Methods Mice were fed either a low or a high fat diet (LFD or HFD, respectively), since it was previously shown that a HFD can induce cholesterol excretion. We determined cholesterol intake, biliary secretion, absorption and synthesis, cholesterol ouput (in feces), and the origin of fecal sterols (by gas chromatography and stable isotope methodology) in Bsep -/- and Bsep +/+ mice. In addition, we determined biliary BS composition and secretion. Results Results were essentially the same in Bsep -/- mice fed a LFD and HFD versus control mice. Here we present the data of the LFD fed mice. Biliary BS secretion was decreased in Bsep -/- compared with Bsep +/+ mice (-40%; p<0.01). Biliary cholate secretion was decreased (-85%; p<0.001), whereas beta- muricholate secretion was increased (+55%; p<0.01) in Bsep -/- mice. Cholesterol intake (+25%; p<0.001), biliary secretion (4 fold; p<0.001) and synthesis (11 fold; p<0.001) were increased, whereas cholesterol absorption was decreased (-90%; p<0.01) in Bsep -/- mice. Fecal cholesterol excretion was increased 8 fold (p<0.001) in Bsep -/- mice, mostly facilitated by the transintestinal cholesterol excretion pathway. Conclusion Bsep -/- mice show increased (transintestinal) cholesterol excretion, which appears to be induced by severely impaired cholesterol absorption in the presence of a hydrophilic BS pool. Potential health benefits of an increasingly hydrophilic BS pool in terms of cholesterol elimination form the body require further research. Su1884 Lyso-Phosphatidylcholine Is Important for Intestinal Fat Absorption Shahzad Siddiqi, Charles M. Mansbach PKCζ is an atypical protein kinase which does not require calcium or diacylglycerol (DAG) for activation. It is involved in controlling the function of other proteins by the phosphorylation of serine and /or threonine. We have shown that liver fatty acid binding protein (FABP1) can generate pre-chylomicron transport vesicle (PCTV) without the addition of ATP whereas ATP is required when whole intestinal cytosol are utilized, suggesting the requirement of active kinase. The amount of PCTV generation is directly dependent on the amount of FABP1 bound to the endoplasmic reticulum (ER). We have established that PKCζ is the kinase and on activation phosphorylate Sar1b. This phosphorylation releases FABP1 from
Transcript of Su1879 SIRT1 Antagonizes Distinct Effects of TNF-α on Intestinal Epithelial Barrier
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swith siRNA os-9 obviously decreased the TER (806.6±49.9V/cm2). Consistently, os-9 knock-down in hypoxia significantly reduced the TER (333.3±31.5V/cm2) compared to in hypoxiaonly (736.6±39.8V/cm2). Conclusion: Os-9 knockdown significantly aggratated hypoxia-induced intestinal epithelium injury. These findings indicate that os-9 may play an importantrole in maintaining the epithelial barrier function through occludin and claudin-1.
Su1879
SIRT1 Antagonizes Distinct Effects of TNF-α on Intestinal Epithelial BarrierYuanhang Ma, Guoqing Chen, Weidong Xiao, Lihua Sun, Songwei Yang, Min Yu, YuanQiu, Chao Xu, Ke Peng, Ligang Sun, Hua Yang
Background: It has been shown that TNF-α increase in intestinal permeability, a contributingfactor in the loss of intestinal barrie function in Crohn's disease (CD). SIRT1 has been shownto alleviate TNF-α induced inflammation. The purpose of this study was to determinewhether SIRT1 was involved in TNF-α modulation of intestinal epithelial permeability byusing an in vitro intestinal epithelial system consisting of filter-grown Caco-2 monolayers.Methods: Caco-2 cells were randomly divided into three groups: Control group, TNF-αgroup (TNF-α, 50 ng/ml for 24 h) and 40 μM Resveratrol (agonist of SIRT1) plus TNF-αgroup (Res+TNF-α). Epithelial barrier function was evaluated by transepithelial resistance(TER). SIRT1, ZO-1 expressions were examined by using Western blotting and immunofluo-rescence confocal microscopy. Results: SIRT1 expression was significantly increased by 43%in Res+ TNF-α group when compared with TNF-α group (p<0.05). TERs of the controlgroup, TNF-α group and Res+TNF-α group were (153±5) Ohm/cm3, (98±4) Ohm/cm3and (122±7) Ohm/cm3. Compare with the control group, the TER of the TNF-α group wasdecreased by 40% (p<0.05); TER in Res+TNF-α group were increased by 24% when comparewith the TNF-α group, but it was still significantly lower than the control group (p<0.05). ZO-1 expression was significantly decreased after treated with TNF-α (0.67±0.4 vs. 0.27±0.03,p<0.05), and resveratrol administration increased ZO-1 expression (0.38±0.04) comparedwith TNF-α group. Assessed by immunofluorescent localization of ZO-1 proteins, ZO-1proteins were localized at the apical cellular junctions and appeared as continuous belt-likestructures encircling the cells at the cellular borders in the control Caco-2 monolayers. TNF-α (50 ng/ml) caused a zig-zagging appearance and discrete punctate or gaplike appearanceof ZO-1 localization at the cellular borders. Resveratrol prevented the TNF-α-induced disturb-ance of ZO-1 localization at cellular junctions. Conclusion: SIRT1 could reduce the damagecaused by TNF-α on intestinal epithelial barrier through up- regulation of ZO-1 expression.
Su1880
Effects on CaCO-2 Gastrointestinal Epithelial Barrier Properties of theNutraceuticals Zinc, Berberine, Butyrate, Indole and QuercetinJames M. Mullin, Mary Carmen Valenzano, Katherine DiGuilio, Mimi Teter, JoannaMercado, Julie To, Brittany Mixson, Brendan Ferraro, Isabel Manley, Valerissa Baker
Zinc, Berberine, Quercetin, Indole and Butyrate all improved CACO-2 barrier function butdid so with patterns unique to each nutraceutical compound. All five increased transepithelialelectrical resistance but only berberine induced a decrease in transepithelial permeability to14C-D-mannitol. The pattern of changes induced in the protein composition of tight junc-tional complexes was also unique to each compound. Claudin-2 was decreased dramaticallyby butyrate and berberine but increased dramatically by quercetin. Quercetin also increasedclaudins -4 and -5 dramatically. Butyrate induced over 300% increases in claudin-7. Theseunique patterns suggest that combinations of compounds may prove superior over individualcompounds in terms of barrier enhancement. Zinc and indole was one such combinationthat evidenced additive effects on transepithelial electrical resistance. The action of thesecompounds on tight junctional proteins is partially dependent on the degreee of differentiationof the CACO-2 cell layer, as evidenced by dramatically different effects of quercetin on theclaudin composition of 1-day vs 7-day postconfluent cell layers. The effects of zinc onelectrical resistance and transepithelial mannitol flux were similarly dependent on the degreeof differentiation. The substratum to which the epithelia adhere also affects the barrierresponse to nutraceuticals, as evidenced by dramatically different responses to zinc by CACO-2 cell layers grown on Millicell PCFs vs Millicell HAs. In summary, these data suggest thatdiseases characterized by barrier defects may show improvement by nutraceutical administra-tion, especially in unique combinations, and that responses to these compounds may varynot only along the length of the GI tract but also along the crypt-villus axis.
Su1881
The Effect of High-Fat Diet, High-Fructose Diet and Soft Drink on IntestinalIntegrity and InflammationEunyoung Doo, Oh Young Lee, Hang Lak Lee, Dae Won Jun, Byung Chul Yoon, Ho SoonChoi, Kang Nyeong Lee, Joon Soo Hahm
Objectives Nonalcoholic fatty liver disease (NAFLD) is associated with food compositionincluding fat and fructose. Recently, it was also suggested that intestinal permeability andinflammation was increased in NAFLD. However, whether high-fat and high-fructose dietsare associated with increased intestinal permeability and inflammation in NAFLD is notdetermined. Therefore, we investigated the effect of high-fat diet, high-fructose diet and softdrink on intestinal integrity and inflammation. Methods Thirty-seven male Sprague-Dawleyrats (300-350 g) were divided into 4 groups, which were fed with a high-fat, high-fructose,cola, and control diet, respectively, for 20 weeks. To determine the effects of high-fat, high-fructose, and cola on intestinal integrity and inflammation, we assessed the integrity ofepithelial tight junctions within the small intestine by immunohistochemical analysis of ZO-1 and occludin expression. We also performed immunohistochemical stain of inflammatorymarkers, TLR-4 and NOX-4. Results Expression of occluding in the high-fat diet group waslower than that in the control group (2.14 vs. 2.89; p=0.042) and expression of TLR-4 inthe high-fat diet group was higher than that in the control group (1.17 vs. 0.78; p=0.016).Expression of ZO-1 in the high-fructose diet group was lower than that in the control group(1.56 vs. 2.56; p=0.024). Expression of occludin in the cola diet group was lower than that
S-492AGA Abstracts
in the control group (2.08 vs. 2.89; p=0.003). Conclusions High-fat diet, high-fructose dietand cola may be related to disruption of tight junction integrity.
Su1882
Amino Acid and Fatty Acid Sensing Mechanisms in the Human ColonMadusha Peiris, Harween Dogra, Adam D. Robinow, Amanda J. Page, Richard L. Young,Ashley Blackshaw
Background: Gastric bypass surgery normalizes appetite and glucose homeostasis in obesepatients by shunting nutrients away from the stomach and small intestine directly to thedistal gut. This is linked to increased release of Peptide YY (PYY) and glucagon-like peptide(GLP-1) from L-cells, which reduces appetite, implying a novel role for nutrient receptorsin the proximal colon. Studies in rodents have also demonstrated that 5-HT regulates vagalafferent activity and regulates appetite. However, the pathways leading to activation of L-cells and enterochromaffin (EC) cells in the distal gut are unknown. We show that thehuman ascending colon expresses receptors for fatty acids and amino acids, and theiractivation can induce release of PYY and 5-HT. Methods: Human ascending colon sampleswere obtained from surgical resection specimens for GPCR immunohistochemistry (IHC).Mucosal biopsies obtained from patients with normal, non-inflamed ascending colons wereused for RNA extraction or stimulated with lauric acid. Release of gut hormones was measuredusing a MAGPIX assay (Merck Millipore). 5-HT was measured by ELISA. Results are shownas means ± SEM. Results: Amino acid and fatty acid receptors were expressed in the proximalcolon (N=4) in the following order GPR120 (long chain fatty acid receptor; 1.15 ± 0.09cells/crypt) > GPR92 (amino acid receptor; 1.08 ± 0.09 cells/crypt) > GPR84 (medium chainfatty acid receptor; 0.89 ± 0.05 cells/crypt) > GPR43 (short chain fatty acid receptor; 0.85± 0.07 cells/crypt). mRNA results matched protein expression levels. Specific analysis of celltypes, found GPR84 immunoreactivity in 73% of EC & 24% of L-cells, GPR92 in 70% ofEC & 18% of L-cells, GPR120 in 70% of EC & 11% of L-cells, and GPR43 in 66% EC &15% of L-cells. As GPR84 had the highest level of expression on EC and L-cells, we stimulatedcells with lauric acid (GPR84 agonist). Lauric acid induced expression of activation markerpERK in both populations. Therefore we stimulated biopsies with lauric acid to inducemediator release. Lauric acid (25mM) significantly increased 5-HT (control: 0.57 ± 0.12 ng/mL vs. treated: 1.05 ± 0.14 ng/mL, N = 3) and PYY release (control: 27.6 ± 14.6 pg/mLvs. treated: 605.5 ± 218.3 pg/mL, N = 5). Preliminary data also indicate release of GLP-1,but not ghrelin or GIP. Conclusions: Most nutrient receptors sensing amino acids andmedium/long chain fatty acids in the human ascending colon are found on 5-HT containingEC. L-cells containing both PYY and GLP-1 also express these receptors albeit to a lesserdegree. GPR84 is functionally active in normal human colon since both 5-HT and PYY arereleased upon receptor stimulation. Overall, these results demonstrate the proximal colonis capable of releasing appetite regulating hormone, suggesting it may be the source ofanorexigenic mediator release following bariatric surgery.
Su1883
Genetic Inactivation of the Bile Salt Export Pump in Mice ProfoundlyIncreases Fecal Cholesterol ExcretionMariette Y. van der Wulp, Theo H. van Dijk, Vincent Bloks, Albert K. Groen, Henkjan J.Verkade
Introduction The bile salt export pump (Bsep) is the major hepatic bile salt (BS) transporter,facilitating BS transfer from liver hepatocytes into the bile canaliculi. Bsep-/- mice werepreviously shown to escape severe cholestasis by increasing biliary BS hydrophilicity, resultingin activation of alternative transporters. Bsep-/- mice surprisingly showed increased biliarycholesterol secretion. The consequence of strongly increased biliary cholesterol secretion forintestinal handling is not known. To determine these downstream effects of Bsep deficiencywe determined biliary BS and whole body cholesterol fluxes. Methods Mice were fed eithera low or a high fat diet (LFD or HFD, respectively), since it was previously shown that aHFD can induce cholesterol excretion. We determined cholesterol intake, biliary secretion,absorption and synthesis, cholesterol ouput (in feces), and the origin of fecal sterols (by gaschromatography and stable isotope methodology) in Bsep-/- and Bsep+/+ mice. In addition,we determined biliary BS composition and secretion. Results Results were essentially thesame in Bsep-/- mice fed a LFD and HFD versus control mice. Here we present the data ofthe LFD fed mice. Biliary BS secretion was decreased in Bsep-/- compared with Bsep+/+ mice(-40%; p<0.01). Biliary cholate secretion was decreased (-85%; p<0.001), whereas beta-muricholate secretion was increased (+55%; p<0.01) in Bsep-/- mice. Cholesterol intake(+25%; p<0.001), biliary secretion (4 fold; p<0.001) and synthesis (11 fold; p<0.001) wereincreased, whereas cholesterol absorption was decreased (-90%; p<0.01) in Bsep-/- mice.Fecal cholesterol excretion was increased 8 fold (p<0.001) in Bsep-/- mice, mostly facilitatedby the transintestinal cholesterol excretion pathway. Conclusion Bsep-/- mice show increased(transintestinal) cholesterol excretion, which appears to be induced by severely impairedcholesterol absorption in the presence of a hydrophilic BS pool. Potential health benefits ofan increasingly hydrophilic BS pool in terms of cholesterol elimination form the body requirefurther research.
Su1884
Lyso-Phosphatidylcholine Is Important for Intestinal Fat AbsorptionShahzad Siddiqi, Charles M. Mansbach
PKCζ is an atypical protein kinase which does not require calcium or diacylglycerol (DAG) foractivation. It is involved in controlling the function of other proteins by the phosphorylation ofserine and /or threonine. We have shown that liver fatty acid binding protein (FABP1) cangenerate pre-chylomicron transport vesicle (PCTV) without the addition of ATP whereasATP is required when whole intestinal cytosol are utilized, suggesting the requirement ofactive kinase. The amount of PCTV generation is directly dependent on the amount ofFABP1 bound to the endoplasmic reticulum (ER). We have established that PKCζ is thekinase and on activation phosphorylate Sar1b. This phosphorylation releases FABP1 from
