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254 Methyl Donor Deficiency Induces Small Intestinal Crypt Hypertrophy in Mice and Murine Enteroids
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of acute pancreatitis. Methods: p62 and autophagy markers/mediators were measured in mouse pancreatitis induced by cerulein or L-arginine; alcoholic pancreatitis induced by a combination of ethanol (Lieber-DeCarli) diet and low-dose cerulein; and the ex-vivo model of CCK-hyperstimulated acinar cells. To examine the role of autophagy in regulating p62, we used lysosomal inhibitors and mice with genetic deletion of the key autophagy mediator Atg5 in acinar cells (Atg5Dacinar). We used pharmacologic inhibitors and genetically modified mice to study the regulation of p62 by mTOR, PI3K and p38 protein kinases, and by transcription factors NF-kB, STAT3 and CHOP Results: p62 is greatly up-regulated in mouse non-alcoholic and alcoholic pancreatitis models. Autophagy blockade with lysosomal inhibitors (E64d plus pepstatin) or in Atg5Dacinar mice increases basal acinar cell p62 level, indicating a role of degradation in regulating p62. However, cerulein pancreatitis causes an additional p62 increase in Atg5Dacinar mice; and cycloheximide markedly decreases p62 in acinar cells. Thus, p62 accumulation in pancreatitis is mediated by both decreased degradation and increased synthesis. We find that mTOR is activated in pancreatitis and its' inhibition with Torin or PP242 largely prevents p62 rise. Torin and PP242 also prevent p62 increase in conditions in which autophagy is blocked, indicating that mTOR mediates p62 synthesis. The results further implicate the key transcription factor STAT3, but not NF- kB, in mTOR's effect on p62 synthesis. Conclusions: p62 is up-regulated in experimental pancreatitis (as well as in human disease). mTOR is a critical regulator of acinar cell p62 in pancreatitis: mTOR both inhibits p62 autophagic degradation and stimulates its synthesis. A generally novel effect is that mTOR stimulates p62 synthesis via STAT3. The results suggest mTORSTAT3 inhibition as an approach to alleviate ER and oxidative stress in pancreatitis.
AGA Abstracts
Methyl Donor Deficiency Induces Small Intestinal Crypt Hypertrophy in Mice and Murine Enteroids Stephanie B. Oliveira, Lauren M. Dehan, Jill Pruszka, Elizabeth A. Maier, Kristina Betz, Sean R. Moore Background & Aims: Environmental enteropathy (EE) is a subclinical intestinal condition highly prevalent in low- and middle-income countries characterized, in part, by malabsorption, intestinal villous atrophy, and crypt hypertrophy. The pathogenesis of EE remains unclear, however supplementation with folate (a key source of one carbon units for DNA methylation) is an effective adjunct therapy for tropical sprue, i.e., persistent diarrhea on a background of EE. To determine the extent to which methyl donor deficiency (MDD) provokes features of EE in mice, we evaluated mechanistic links between dietary methyl donor deficiency and intestinal crypt hypertrophy in mice and in mouse small intestinal crypt cultures (enteroids). Methods: We randomized dams to a standard diet or an isocaloric MDD diet lacking folate, choline, and betaine when pups were 10-days-old. We then randomized weanlings to their dams' diet on day of life 21. Mice were sacrificed and the jejunum was harvested at 6 weeks of age for both histology (n=6/group) and generation of enteroids. Results: Histological comparisons of the jejunum revealed longer crypts in MDD versus control mice, moreso in the distal (85.6 +/- 13.7 µm vs. 69.3 +/- 7.2 µm; P<0.0001), vs. proximal (88.8 +/- 17 µm vs 80.7 +/- 10.7 µm; P=0.04) portions of the small intestine. Enteroids from control and MDD mice were both viable in standard minigut media; however, all enteroids maintained in MDD media displayed alterations in crypt morphology and decreased epithelial proliferation. Enteroid crypt neck width was 1.3-fold greater in standard vs. MDD media (P<0.001). The number of crypt buds per enteroid was 1.6-fold higher in standard media vs. MDD media (p = 0.0007). The ratio of EdU-positive, or proliferating, cells to Hoechst-positive cells was 2.2-fold higher in standard media vs. MDD media (P<0.0001). Qualitatively, enteroids in MDD media displayed longer crypt domains vs. enteroids in standard media. Conclusions: Complementary in vivo and in vitro findings of altered small intestinal crypt in the setting of methyl donor deficiency suggest that methyl donor deficiency plays a role in the pathogenesis of environmental enteropathy. Further studies are needed to determine whether prolonged methyl donor deficiency promotes epigenetic changes of intestinal stem cells and whether methyl donor supplementation prevents or reverses these changes to promote intestinal epithelial homeostasis in global settings of poverty.
257 Basal Autophagy Plays an Important Role in Maintaining the Integrity of Pancreatic Acinar Cells in Mice Kiyoshi Iwahashi, Hayato Hikita, Minoru Shigekawa, Kenji Ikezawa, Nawa Takatoshi, Ryotaro Sakamori, Takuya Miyagi, Tomohide Tatsumi, Tetsuo Takehara Background and Aim: Basal autophagy plays an important role in many organs. However, the role of autophagy in pancreatic acinar cells in a physiological condition still remains unclear. We examined the effect of autophagy impairment on acinar cell in a physiological condition using pancreas-specific ATG7 knockout (KO) mice. Method: We generated pancreas-specific ATG7 KO mice by crossing Atg7fl/fl mice with Pdx1-Cre transgenic mice. We examined KO mice and their wild-type (WT) littermates from 2 to 30 weeks of age. Result: ATG7 KO mice were born and grew up at the expected Mendelian ratio. The ablation of ATG7 protein was confirmed by Western blotting analysis. Autophagy was impaired in ATG7 KO pancreases, evidenced by decreased expression levels of LC3-II and increased expression levels of P62. Body weights of KO mice did not differ from those of WT mice. At 2 weeks of age, KO mice did not show elevation of serum pancreatic enzyme nor abnormal histological findings with H&E stain and Sirius Red stain. At 1 month of age, KO mice showed elevation of serum lipase. Pancreas/body weight ratios of KO mice were significantly higher than those of WT mice. Histological sections of KO mouse pancreases showed vacuolization and apoptosis in acinar cells, pseudotubular complex, and fibrosis. Electron microscopy revealed marked increase of zymogen granules in acinar cells. In accordance with zymogen granule accumulation, trypsin and trypsinogen, which are stored in zymogen granules, were increased in pancreas of KO mice. After 2 months of age, pancreas/body weight ratios of KO mice decreased with atrophic change, and were significantly lower than those of WT mice. Histological sections of KO pancreases showed glandular atrophy, pseudotubular complex, and fibrosis, which suggested chronic pancreatitis continuously occurred in KO mouse pancreases. Pancreases in KO mice contained smaller amount of amylase, evidenced by Western blotting analysis. Trypsin activity in pancreas tissue of KO mice was weaker than that of WT mice. Conclusion: Basal autophagy plays an important role in maintaining the integrity of pancreatic acinar cells. Autophagy impairment in pancreatic acinar cell in mice induces accumulation of zymogen granules and apoptosis in acinar cell followed by severe atrophic change in pancreas similarly with chronic pancreatitis.
255 High Unsaturated Fat Diets and Unsaturated Visceral Fat Worsen Acute Pancreatitis (AP) Outcomes At Lower Body Mass Index (BMI) Krutika Patel, Pawan Noel, Ram Trivedi, Cristiane de Oliveira, Vijay P. Singh BACKGROUND:Previous studies show dietary fat composition affects body fat composition. BMIs associated with severe acute pancreatitis(SAP) differ in various reports from different countries. We have reported that unsaturated fatty acids(UFA), enriched in human pancreatic necrosis collections worsen acute pancreatitis. Dairy and red meat are the major sources of saturated fat such as palmitate while fish and vegetable oil are the major sources of unsaturated fat such as linoleate. We therefore compared the fat consumption patterns from various countries and the studies from these countries reporting the association of BMIs with AP outcomes. We also compared the effect of the unsaturated triglyceride glyceryl trilinoleate(GTL) to the saturated triglyceride glyceryl tri-palmitate(GTP) on exocrine pancreatic acinar injury in vitro, and compared the impact of increasing these triglycerides in visceral fat on AP outcomes. METHODS:22 Studies from 1991 to 2014 analyzing BMI and AP outcomes were reviewed. These were superimposed on world maps quantifying dairy, fish and vegetable consumption. Pancreatic acinar cells were incubated in a medium containing GTL or GTP(0.3 to 3mM) and lipolysis(glycerol generation), cell injury(LDH leakage), ATP levels and Cytochrome C leakage were measured. GTL or GTP(0.8% bodyweight) were administered into the peritoneal cavity of CD-1 mice to increase visceral unsaturated or saturated triglycerides respectively, and a classically mild model of caerulein pancreatitis was initiated in these. RESULTS: 4/4 studies showing BMI was unrelated to SAP, and 10/ 12 studies saying a BMI > 30 kg/m2 was associated with SAP were from countries with >119 kg/capita/year dairy intake. 3 of the former and 8 of the latter group also consumed <10% animal protein from fish. 6/7 studies with a BMI >23-25 kg/m2 associated with SAP were from countries with <119 kg/capita/year dairy intake, with 5 of these studies from countries with >10% animal protein being from fish and high vegetable consumption. Pancreatic lipase mediated hydrolysis of GTL but not GTP caused acinar necrosis. Mice with caerulein pancreatitis, co-administered GTL had 100% mortality(vs.10% in the GTP group, p<0.01) and had multisystem organ failure with systemic complications including renal failure(Sr.BUN 74±15 vs. 12±1.6 mg/dl in GTP group, p<0.01) and hypocalcemia(Sr.Calcium 6.5±0.8 vs. 9.4±0.3 mg/dl in GTP group, p<0.01). CONCLUSIONS: Dietary composition of fat relates to the BMIs associated with SAP. Countries with higher UFA consumption in diet report SAP associated with lower BMIs and those with higher saturated fat intake report SAP to be unrelated to BMI or occurring at BMI's >30 kg/ m2. Increasing unsaturated visceral triglyceride converted mild AP to SAP. Thus high unsaturated fat diets may have a more deleterious effect on SAP outcomes than diets enriched in saturated fat.
258 Exosomes Derived From Pancreatic Stellate Cells: microRNA Signature and Effects on Pancreatic Cancer Cells Atsushi Masamune, Tetsuya Takikawa, Shin Hamada, Takayuki Kogure, Eriko Nakano, Tooru Shimosegawa Background: Pancreatic stellate cells (PSCs) play a pivotal role in the development of pancreatic fibrosis in chronic pancreatitis and pancreatic cancer. Although it is still controversial, PSCs might promote the progression of pancreatic cancer by affecting cell functions in pancreatic cancer cells. Many cell constituents, including messenger RNAs, microRNAs (miRNAs) and proteins, may be exported from cells within membranous nanovesicles (approximately 50-150 nm in diameter) termed "exosomes". The roles of exosomes in the interaction between PSCs and pancreatic cancer cells remain unknown. Aim: To clarify the miRNA signature of the exoxomes derived from PSCs and their effects on the cell functions in pancreatic cancer cells. Methods: Conditioned medium was prepared from human PSCs immortalized by the introduction of SV40 large T antigen and human telomerase. Exosomes were prepared from the conditioned medium by ultracentrifugation, and characterized by electron microscopy and CD63 expression. Total RNAs including miRNAs were prepared from the exosomes and their parental PSCs, and the miRNA expression profiles were analyzed using Agilent's microarray. Human pancreatic cancer cells (Panc-1 and SUIT-2 cells) were treated with the exosomes derived from PSCs. The effects of the exosomes on the mRNA expression profiles in pancreatic cancer cells were assessed using Agilent's microarray. The proliferation of pancreatic cancer cells was examined by a BrdU assay. Results: Exosomes derived from human PSCs contained a variety of miRNAs including miR-21-5p, miR-1246 and miR-1290. Comparison of the miRNA signatures between the exosomes and the parental PSCs revealed that that several miRNAs such as miR-451a and miR-630 were selectively enriched in exosomes. Exosomes derived from PSCs induced the expression of mRNAs for chemokines (CXCL1, CXCL2, and CCL20) and serum amyloid A in pancreatic cancer cells. the proliferation of pancreatic cancer cells was stimulated by exosomes derived from PSCs. Conclusions: We clarified the miRNA expression profile in exosomes derived from PSCs.
256 p62/SQSTM1 in Pancreatitis Is Regulated Through Both Synthesis and Degradation: Role of mTOR Michael Pimienta, Sudarshan Malla, Ethan M. Lotshaw, Jason M. Elperin, Masaki Ohmuraya, Olga A. Mareninova, Anna S. Gukovskaya, Ilya Gukovsky Background & Aims: p62/SQSTM1 is a multifunctional signaling protein that plays a key role in autophagy. p62 mediates autophagic clearance of protein aggregates; is specifically degraded via autophagy; and was recently shown to mediate ER and oxidative stress in a genetic pancreatitis model caused by IKKa deficiency. However, the regulation of p62 in pancreas is largely unknown. Here, we investigate the role and mechanisms of p62 degradation and synthesis in regulating pancreatic acinar cell p62 level, both basal and in models
AGA Abstracts
X : 55624$1AGA 03-28-15 04:55:56 PDFd : 55624B : e
S-58
Page 58
of acute pancreatitis. Methods: p62 and autophagy markers/mediators were measured in mouse pancreatitis induced by cerulein or L-arginine; alcoholic pancreatitis induced by a combination of ethanol (Lieber-DeCarli) diet and low-dose cerulein; and the ex-vivo model of CCK-hyperstimulated acinar cells. To examine the role of autophagy in regulating p62, we used lysosomal inhibitors and mice with genetic deletion of the key autophagy mediator Atg5 in acinar cells (Atg5Dacinar). We used pharmacologic inhibitors and genetically modified mice to study the regulation of p62 by mTOR, PI3K and p38 protein kinases, and by transcription factors NF-kB, STAT3 and CHOP Results: p62 is greatly up-regulated in mouse non-alcoholic and alcoholic pancreatitis models. Autophagy blockade with lysosomal inhibitors (E64d plus pepstatin) or in Atg5Dacinar mice increases basal acinar cell p62 level, indicating a role of degradation in regulating p62. However, cerulein pancreatitis causes an additional p62 increase in Atg5Dacinar mice; and cycloheximide markedly decreases p62 in acinar cells. Thus, p62 accumulation in pancreatitis is mediated by both decreased degradation and increased synthesis. We find that mTOR is activated in pancreatitis and its' inhibition with Torin or PP242 largely prevents p62 rise. Torin and PP242 also prevent p62 increase in conditions in which autophagy is blocked, indicating that mTOR mediates p62 synthesis. The results further implicate the key transcription factor STAT3, but not NF- kB, in mTOR's effect on p62 synthesis. Conclusions: p62 is up-regulated in experimental pancreatitis (as well as in human disease). mTOR is a critical regulator of acinar cell p62 in pancreatitis: mTOR both inhibits p62 autophagic degradation and stimulates its synthesis. A generally novel effect is that mTOR stimulates p62 synthesis via STAT3. The results suggest mTORSTAT3 inhibition as an approach to alleviate ER and oxidative stress in pancreatitis.
AGA Abstracts
Methyl Donor Deficiency Induces Small Intestinal Crypt Hypertrophy in Mice and Murine Enteroids Stephanie B. Oliveira, Lauren M. Dehan, Jill Pruszka, Elizabeth A. Maier, Kristina Betz, Sean R. Moore Background & Aims: Environmental enteropathy (EE) is a subclinical intestinal condition highly prevalent in low- and middle-income countries characterized, in part, by malabsorption, intestinal villous atrophy, and crypt hypertrophy. The pathogenesis of EE remains unclear, however supplementation with folate (a key source of one carbon units for DNA methylation) is an effective adjunct therapy for tropical sprue, i.e., persistent diarrhea on a background of EE. To determine the extent to which methyl donor deficiency (MDD) provokes features of EE in mice, we evaluated mechanistic links between dietary methyl donor deficiency and intestinal crypt hypertrophy in mice and in mouse small intestinal crypt cultures (enteroids). Methods: We randomized dams to a standard diet or an isocaloric MDD diet lacking folate, choline, and betaine when pups were 10-days-old. We then randomized weanlings to their dams' diet on day of life 21. Mice were sacrificed and the jejunum was harvested at 6 weeks of age for both histology (n=6/group) and generation of enteroids. Results: Histological comparisons of the jejunum revealed longer crypts in MDD versus control mice, moreso in the distal (85.6 +/- 13.7 µm vs. 69.3 +/- 7.2 µm; P<0.0001), vs. proximal (88.8 +/- 17 µm vs 80.7 +/- 10.7 µm; P=0.04) portions of the small intestine. Enteroids from control and MDD mice were both viable in standard minigut media; however, all enteroids maintained in MDD media displayed alterations in crypt morphology and decreased epithelial proliferation. Enteroid crypt neck width was 1.3-fold greater in standard vs. MDD media (P<0.001). The number of crypt buds per enteroid was 1.6-fold higher in standard media vs. MDD media (p = 0.0007). The ratio of EdU-positive, or proliferating, cells to Hoechst-positive cells was 2.2-fold higher in standard media vs. MDD media (P<0.0001). Qualitatively, enteroids in MDD media displayed longer crypt domains vs. enteroids in standard media. Conclusions: Complementary in vivo and in vitro findings of altered small intestinal crypt in the setting of methyl donor deficiency suggest that methyl donor deficiency plays a role in the pathogenesis of environmental enteropathy. Further studies are needed to determine whether prolonged methyl donor deficiency promotes epigenetic changes of intestinal stem cells and whether methyl donor supplementation prevents or reverses these changes to promote intestinal epithelial homeostasis in global settings of poverty.
257 Basal Autophagy Plays an Important Role in Maintaining the Integrity of Pancreatic Acinar Cells in Mice Kiyoshi Iwahashi, Hayato Hikita, Minoru Shigekawa, Kenji Ikezawa, Nawa Takatoshi, Ryotaro Sakamori, Takuya Miyagi, Tomohide Tatsumi, Tetsuo Takehara Background and Aim: Basal autophagy plays an important role in many organs. However, the role of autophagy in pancreatic acinar cells in a physiological condition still remains unclear. We examined the effect of autophagy impairment on acinar cell in a physiological condition using pancreas-specific ATG7 knockout (KO) mice. Method: We generated pancreas-specific ATG7 KO mice by crossing Atg7fl/fl mice with Pdx1-Cre transgenic mice. We examined KO mice and their wild-type (WT) littermates from 2 to 30 weeks of age. Result: ATG7 KO mice were born and grew up at the expected Mendelian ratio. The ablation of ATG7 protein was confirmed by Western blotting analysis. Autophagy was impaired in ATG7 KO pancreases, evidenced by decreased expression levels of LC3-II and increased expression levels of P62. Body weights of KO mice did not differ from those of WT mice. At 2 weeks of age, KO mice did not show elevation of serum pancreatic enzyme nor abnormal histological findings with H&E stain and Sirius Red stain. At 1 month of age, KO mice showed elevation of serum lipase. Pancreas/body weight ratios of KO mice were significantly higher than those of WT mice. Histological sections of KO mouse pancreases showed vacuolization and apoptosis in acinar cells, pseudotubular complex, and fibrosis. Electron microscopy revealed marked increase of zymogen granules in acinar cells. In accordance with zymogen granule accumulation, trypsin and trypsinogen, which are stored in zymogen granules, were increased in pancreas of KO mice. After 2 months of age, pancreas/body weight ratios of KO mice decreased with atrophic change, and were significantly lower than those of WT mice. Histological sections of KO pancreases showed glandular atrophy, pseudotubular complex, and fibrosis, which suggested chronic pancreatitis continuously occurred in KO mouse pancreases. Pancreases in KO mice contained smaller amount of amylase, evidenced by Western blotting analysis. Trypsin activity in pancreas tissue of KO mice was weaker than that of WT mice. Conclusion: Basal autophagy plays an important role in maintaining the integrity of pancreatic acinar cells. Autophagy impairment in pancreatic acinar cell in mice induces accumulation of zymogen granules and apoptosis in acinar cell followed by severe atrophic change in pancreas similarly with chronic pancreatitis.
255 High Unsaturated Fat Diets and Unsaturated Visceral Fat Worsen Acute Pancreatitis (AP) Outcomes At Lower Body Mass Index (BMI) Krutika Patel, Pawan Noel, Ram Trivedi, Cristiane de Oliveira, Vijay P. Singh BACKGROUND:Previous studies show dietary fat composition affects body fat composition. BMIs associated with severe acute pancreatitis(SAP) differ in various reports from different countries. We have reported that unsaturated fatty acids(UFA), enriched in human pancreatic necrosis collections worsen acute pancreatitis. Dairy and red meat are the major sources of saturated fat such as palmitate while fish and vegetable oil are the major sources of unsaturated fat such as linoleate. We therefore compared the fat consumption patterns from various countries and the studies from these countries reporting the association of BMIs with AP outcomes. We also compared the effect of the unsaturated triglyceride glyceryl trilinoleate(GTL) to the saturated triglyceride glyceryl tri-palmitate(GTP) on exocrine pancreatic acinar injury in vitro, and compared the impact of increasing these triglycerides in visceral fat on AP outcomes. METHODS:22 Studies from 1991 to 2014 analyzing BMI and AP outcomes were reviewed. These were superimposed on world maps quantifying dairy, fish and vegetable consumption. Pancreatic acinar cells were incubated in a medium containing GTL or GTP(0.3 to 3mM) and lipolysis(glycerol generation), cell injury(LDH leakage), ATP levels and Cytochrome C leakage were measured. GTL or GTP(0.8% bodyweight) were administered into the peritoneal cavity of CD-1 mice to increase visceral unsaturated or saturated triglycerides respectively, and a classically mild model of caerulein pancreatitis was initiated in these. RESULTS: 4/4 studies showing BMI was unrelated to SAP, and 10/ 12 studies saying a BMI > 30 kg/m2 was associated with SAP were from countries with >119 kg/capita/year dairy intake. 3 of the former and 8 of the latter group also consumed <10% animal protein from fish. 6/7 studies with a BMI >23-25 kg/m2 associated with SAP were from countries with <119 kg/capita/year dairy intake, with 5 of these studies from countries with >10% animal protein being from fish and high vegetable consumption. Pancreatic lipase mediated hydrolysis of GTL but not GTP caused acinar necrosis. Mice with caerulein pancreatitis, co-administered GTL had 100% mortality(vs.10% in the GTP group, p<0.01) and had multisystem organ failure with systemic complications including renal failure(Sr.BUN 74±15 vs. 12±1.6 mg/dl in GTP group, p<0.01) and hypocalcemia(Sr.Calcium 6.5±0.8 vs. 9.4±0.3 mg/dl in GTP group, p<0.01). CONCLUSIONS: Dietary composition of fat relates to the BMIs associated with SAP. Countries with higher UFA consumption in diet report SAP associated with lower BMIs and those with higher saturated fat intake report SAP to be unrelated to BMI or occurring at BMI's >30 kg/ m2. Increasing unsaturated visceral triglyceride converted mild AP to SAP. Thus high unsaturated fat diets may have a more deleterious effect on SAP outcomes than diets enriched in saturated fat.
258 Exosomes Derived From Pancreatic Stellate Cells: microRNA Signature and Effects on Pancreatic Cancer Cells Atsushi Masamune, Tetsuya Takikawa, Shin Hamada, Takayuki Kogure, Eriko Nakano, Tooru Shimosegawa Background: Pancreatic stellate cells (PSCs) play a pivotal role in the development of pancreatic fibrosis in chronic pancreatitis and pancreatic cancer. Although it is still controversial, PSCs might promote the progression of pancreatic cancer by affecting cell functions in pancreatic cancer cells. Many cell constituents, including messenger RNAs, microRNAs (miRNAs) and proteins, may be exported from cells within membranous nanovesicles (approximately 50-150 nm in diameter) termed "exosomes". The roles of exosomes in the interaction between PSCs and pancreatic cancer cells remain unknown. Aim: To clarify the miRNA signature of the exoxomes derived from PSCs and their effects on the cell functions in pancreatic cancer cells. Methods: Conditioned medium was prepared from human PSCs immortalized by the introduction of SV40 large T antigen and human telomerase. Exosomes were prepared from the conditioned medium by ultracentrifugation, and characterized by electron microscopy and CD63 expression. Total RNAs including miRNAs were prepared from the exosomes and their parental PSCs, and the miRNA expression profiles were analyzed using Agilent's microarray. Human pancreatic cancer cells (Panc-1 and SUIT-2 cells) were treated with the exosomes derived from PSCs. The effects of the exosomes on the mRNA expression profiles in pancreatic cancer cells were assessed using Agilent's microarray. The proliferation of pancreatic cancer cells was examined by a BrdU assay. Results: Exosomes derived from human PSCs contained a variety of miRNAs including miR-21-5p, miR-1246 and miR-1290. Comparison of the miRNA signatures between the exosomes and the parental PSCs revealed that that several miRNAs such as miR-451a and miR-630 were selectively enriched in exosomes. Exosomes derived from PSCs induced the expression of mRNAs for chemokines (CXCL1, CXCL2, and CCL20) and serum amyloid A in pancreatic cancer cells. the proliferation of pancreatic cancer cells was stimulated by exosomes derived from PSCs. Conclusions: We clarified the miRNA expression profile in exosomes derived from PSCs.
256 p62/SQSTM1 in Pancreatitis Is Regulated Through Both Synthesis and Degradation: Role of mTOR Michael Pimienta, Sudarshan Malla, Ethan M. Lotshaw, Jason M. Elperin, Masaki Ohmuraya, Olga A. Mareninova, Anna S. Gukovskaya, Ilya Gukovsky Background & Aims: p62/SQSTM1 is a multifunctional signaling protein that plays a key role in autophagy. p62 mediates autophagic clearance of protein aggregates; is specifically degraded via autophagy; and was recently shown to mediate ER and oxidative stress in a genetic pancreatitis model caused by IKKa deficiency. However, the regulation of p62 in pancreas is largely unknown. Here, we investigate the role and mechanisms of p62 degradation and synthesis in regulating pancreatic acinar cell p62 level, both basal and in models
AGA Abstracts
X : 55624$1AGA 03-28-15 04:55:56 PDFd : 55624B : e
S-58
Page 58