Bile-pancreatic juice exclusion increases cholinergic M3 and CCK-A receptor expression and interleukin-6 production in ligation-induced acute pancreatitis

BACKGROUND: Using an original model, the Donor Rat Model, we showed that bile-pancreatic juice (BPJ) exclusion from gut exacerbates ligation-induced acute pancreatitis in rats. We also showed that muscarinic cholinergic M3 and CCK-A receptor expression is induced following duct ligation. Increased receptor number potentially could exacerbate cytokine production. We hypothesize that BPJ exclusion is responsible for M3 and CCK-A receptor induction and increased interleukin-6 (IL-6) production. METHODS: M3 and CCK-A receptor expression and IL-6 production were compared in rat pancreata 1 to 3 hours after duct ligation with or without BPJ replacement. RESULTS: Our studies showed that BPJ replacement attenuates duct ligation-induced increases in M3 and CCK-A receptor expression and IL-6 production. CONCLUSIONS: In this model, BPJ exclusion from gut induces M3 and CCK-A receptor expression and increases IL-6 production. In this experimental corollary of gallstone pancreatitis, BPJ exclusion from gut may play a key role in the mechanism of disease pathogenesis.     

Bile and pancreatic juice exclusion activates acinar stress kinases and exacerbates gallstone pancreatitis

HYPOTHESIS: Bile and pancreatic juice exclusion from gut activates acinar stress kinases and exacerbates gallstone pancreatitis as evidenced by the ameliorating effects of replacement therapy in an experimental model of duct ligation-induced acute pancreatitis. In the early stages of gallstone pancreatitis, bile-pancreatic juice cannot enter the gut. Enteral exclusion worsens pancreatitis by causing feedback hyperstimulation of the exocrine pancreas that activates acinar cell stress kinases. Investigations using a unique surgical model, the Donor Rat Model, showed that duodenal replacement of bile-pancreatic juice in rats with duct ligation attenuates pancreatic stress kinase activation, reduces pancreatic cytokine production, and ameliorates pancreatic morphologic changes. These findings suggest that exclusion-induced acinar hyperstimulation, in the presence of duct obstruction, exacerbates acute pancreatitis via stress kinase activation. Although acinar hyperstimulation has often been implicated in the pathogenesis of acute pancreatitis, the lack of supporting evidence remains a conspicuous void. The proposed hypothesis draws on fresh evidence to present a new paradigm that reexamines the role of exocrine pancreatic hyperstimulation in gallstone pancreatitis pathogenesis.     

Bile-pancreatic juice exclusion promotes Akt/NF-kB activation and chemokine production in ligation-induced acute pancreatitis

Using a unique surgical model (the donor rat model), we showed previously that duodenal replacement of bile-pancreatic juice, obtained fresh from a donor rat, ameliorates ligation-induced acute pancreatitis. We hypothesize that bile-pancreatic juice exclusion from gut exacerbates Akt/nuclear factor-kB (NF-kB) pathway activation and induces chemokine production in ligation-induced acute pancreatitis. We compared rats with bile-pancreatic duct ligation to those with duodenal bile-pancreatic juice replacement fresh from a donor rat beginning immediately before duct ligation. Sham control rats had ducts dissected but not ligated. Rats were killed 1 or 3 hours after operation (n=7/group). Akt activation (immunoblotting, immune-complex kinase assay, and ELISA), inhibitory protein I-kB (I-kB) activation (immunoblotting), and production of chemokines MCP-1 and RANTES (ELISA) were measured in pancreatic homogenates. NF-kB was quantitated in nuclear fractions using electrophoretic mobility shift assay. Duct ligation produced significant increases in pancreatic Akt, IkB, and NF-kB activation and production of MCP-1 and RANTES. Activation of the Akt/NF-kB pathway and increased MCP-1 and RANTES production in response to duct ligation were significantly reduced by bile-pancreatic juice replacement (ANOVA, P<0.05). Bile-pancreatic juice exclusion stimulates Akt/NF-kB pathway activation and increases chemokine production in ligation-induced acute pancreatitis. Presented at the annual meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 16, 2005 (poster).     

Activation and cellular localization of the p38 and JNK MAPK pathways in rat crescentic glomerulonephritis

BACKGROUND: The p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) are intracellular signal transduction pathways involved in the production of inflammatory mediators. Little, however, is known about the contribution of these pathways to renal inflammation, nor the cell types in which these pathways are activated within normal and inflamed kidneys. The aim of this study was therefore to delineate the pattern and cellular localization of p38 and JNK activation in normal rat kidney and rat acute and chronic inflammatory renal disease. METHODS: Normal male Sprague-Dawley rats and groups of rats given accelerated anti-glomerular basement membrane (GBM) disease were killed at 3 hours, day 1, day 7, or day 28 and examined for p38 and JNK pathway activation by Western blotting and immunolocalization of the phosphorylated p38 (p-p38) and JNK (p-JNK) kinases. RESULTS: In terms of glomerular MAPK activation, Western blotting identified the presence of both p-p38 and p-JNK in normal glomeruli, localized by immunohistochemistry to podocytes and epithelial cells of Bowman's capsule. In anti-GBM disease, Western blotting showed that p38 activation peaked at 3 hours and remained elevated above normal throughout the disease time course. JNK activation (via the 54 kD isoform) likewise increased at 3 hours of anti-GBM disease and remained elevated throughout disease. At 3 hours, p-p38, but not p-JNK, was localized to neutrophils and glomerular endothelial cells. p-JNK was localized to glomerular endothelial cells at day 7. Macrophages, lymphocytes, activated podocytes, and myofibroblasts were positive for both p-p38 and p-JNK. In terms of tubular MAPK activation, Western blotting identified p38 and JNK activation in tubules of normal kidney. Immunostaining showed that most cortical tubules contained some p-p38 and p-JNK stained cells. There was a significant increase in tubular p38 activation at 3 hours of anti-GBM disease, followed by increased JNK activation of the 54 kD isoform from day 7 onward, and the 46 kD isoform at day 28. Immunostaining of diseased tissue localized p-p38 and p-JNK to virtually all cortical tubular cells. CONCLUSION: The p38 and JNK MAPK pathways are activated in glomeruli and tubules of normal kidney. In acute anti-GBM disease, there was an increase in p38 activation within glomerular endothelial cells and within infiltrating neutrophils, suggesting an important role for p38 MAPK in acute inflammation. In progressive anti-GBM disease, p38 and JNK activation in podocytes, glomerular endothelial cells, infiltrating macrophages, T cells, and myofibroblasts suggests that both the p38 and JNK MAPK pathways are important in chronic inflammation and fibrosis. Blockade of these pathways may therefore be potentially therapeutic in the treatment of acute and chronic renal inflammation.     

Murine pancreatic duct ligation induces stress kinase activation, acute pancreatitis, and acute lung injury

Background

Acute lung injury is a major determinant of outcomes in acute pancreatitis. We evaluated acute lung injury and stress kinase activation in ligation-induced acute pancreatitis in mice.

Methods

Mice with duct ligation or sham operation were killed after 24 or 48 hours.

Results

In addition to acute pancreatitis, duct ligation was associated with pulmonary morphologic changes indicative of acute lung injury (alveolar septal thickening, congestion, and neutrophil infiltration). Furthermore, immunoblotting showed stress kinase activation in the pancreas and lung after ligation. Although mortality was observed in the ligated group, that is consistent with severe lung injury, it requires further evaluation.

Conclusions

Bile and pancreatic duct ligation in the mouse is associated with pancreatic and pulmonary stress kinase activation and acute inflammatory changes consistent with early acute pancreatitis and acute lung injury. Our findings are important as acute lung injury increases mortality in clinical acute pancreatitis and stress kinases are established proinflammatory signal transducers.     

Exacerbation of acute pancreatitis by combined cholinergic stimulation and duct obstruction

BACKGROUND: The role of cholinergic pathways in the pathogenesis of bile-pancreatic duct ligation (BPDL)-induced acute pancreatitis in rats remains controversial. We hypothesized that cholinergic stimulation exacerbates acute pancreatic inflammation in the presence of duct obstruction. METHODS: We studied 34 rats divided into 5 groups as follows: (1) sham operation; (2) BPDL; (3) BPDL with duodenal bile-pancreatic juice (BPJ) replacement fresh from a donor rat; (4) BPDL with BPJ replacement as in 3 above, and carbachol (CCh) 5 ug/h subcutaneously; or (5) CCh 5 ug/h subcutaneously only. Rats were killed after 6 hours. RESULTS: The P value was less than .05 by analysis of variance. Pancreatic morphologic changes and zymogen fraction hyperamylasemia seen with duct ligation (2 vs. 1) were ameliorated significantly by duodenal BPJ replacement (3 vs. 2), but not when exogenous CCh was administered (4 vs. 3), whereas CCh alone showed no significant changes compared with sham (5 vs. 1). CONCLUSIONS: Cholinergic stimulation and duct obstruction synergistically amplify acinar hyperstimulation and exacerbate acute pancreatitis.     

大鼠重症急性胰腺炎肺泡巨噬细胞的活化和调控作用

目的 观察巨噬细胞中p38蛋白活化激酶对大鼠重症急性胰腺炎肺损伤的影响.方法 假手术组仅胆胰管注射生理盐水0.1 ml/100 g;5%的牛黄胆酸(0.1 ml/100 g)逆行注射到SD大鼠的胆胰管内,造成重症急性胰腺炎(SAP)分为SAP组和SB03580组(SB203580,0.5 mg/kg,静注).在6 h剖杀大鼠,查腹水,抽血检测血清淀粉酶(AMS)和肿瘤坏死因子(TNF)-α和白细胞介素(IL)-6[酶联免疫吸附试验(ELISA)法];同时分别离心收集全肺肺泡巨噬细胞,免疫组织化学检测肺组织及其巨噬细胞中p38 MAPK的表达,同时检测肺组织中的TNF-α和IL-6;光镜下检测胰腺组织损害.结果 SAP组及SB组中AMS在6 h分别为(4865.12±890.35)IU/L和(2918.24±614.58)IU/L,差异有统计学意义.血清TNF-α分别为(106.59±43.71)ng/L和(76.43±38.43)ng/L;IL-6是(2203.76±640.85)ng/L和(1254.76±459.35)ng/L,差异有统计学意义(P<0.01).肺组织中的TNF-α和IL-6的升高与血中的一致.光镜下,胰腺组织内可见炎细胞浸润、充血、水肿和坏死;在SAP组中肺组织及其巨噬细胞中p38 MAPK强烈表达,TNF-α和IL-6的表达一致,SB治疗组表达下降.结论 TNF-α和IL-6在重症急性胰腺炎肺损伤起着重要作用;肺泡巨噬细胞中p38 MAPK表达对TNF-α和IL-6的转录和合成起重要作用.     

In vitro evidence for role of ERK, p38, and JNK in exocrine pancreatic cytokine production

Elucidation of mechanisms of acinar cell cytokine production is essential for a better understanding of acute pancreatitis pathogenesis. We hypothesize that the stress kinases ERK, p38, and JNK play an important role in acinar cell cytokine production. Rat pancreatic fragments were incubated with 100 nM concentration of the cholecystokinin analog caerulein or 100 nM caerulein and specific ERK inhibitor (100 μM PD98059), specific p38 inhibitor (10 μM SB203580), or specific JNK inhibitor (20 μM SP600125). After 3 hours of caerulein treatment, pancreatic fragments were homogenized and assayed for total and phosphorylated ERK, p38, and JNK, and for tumor necrosis factor-α or interleukin-1β concentrations (ELISA). Pancreatic fragments stimulated with caerulein showed activation of ERK, p38, and JNK and increased cytokine concentrations (ANOVA, P<0.05). Specific stress kinase inhibitors significantly attenuated caerulein-induced activation of the corresponding stress kinase and cytokine production; however, the effect of the JNK inhibitor was comparatively less convincing. Increased activation of ERK, p38, and JNK in pancreatic fragments was not associated with significant increases in total ERK, total p38, or total JNK concentrations. The stress kinases ERK and p38 play an important role in caerulein-stimulated exocrine pancreatic overproduction of cytokines. The role of JNK needs further evaluation in this experimental model. This work was presented at the Forty-Seventh Annual Meeting of The Society for Surgery of the Alimentary Tract, Los Angeles, CA, May 22, 2006. Dr. Samuel was supported for this research by an American College of Surgeons Faculty Research Fellowship (2003–2005) and a National Institutes of Health NIDDK Career Development Award (grant K08-DK062805).     

Effect of simultaneous inhibition of TNF-alpha production and xanthine oxidase in experimental acute pancreatitis: the role of mitogen activated protein kinases

OBJECTIVE: To assess the effects of inhibiting both tumor necrosis factor (TNF)-alpha production and xanthine oxidase activity on the inflammatory response, mitogen-activated protein kinase (MAPK) activation and mortality in necrotizing acute pancreatitis in rats. SUMMARY BACKGROUND DATA: Pancreatic injury triggers 2 major pathways involved in the systemic effects of severe acute pancreatitis: pro-inflammatory cytokines and oxidative stress. METHODS: Pancreatitis was induced by intraductal infusion of 3.5% sodium taurocholate. We examined whether treatment with oxypurinol, a specific inhibitor of xanthine oxidase, and/or pentoxifylline, an inhibitor of TNF-alpha production, affects pancreatic damage, ascites, lung inflammation, and MAPK phosphorylation. RESULTS: Oxypurinol prevented p38 phosphorylation in the pancreas and partially avoided the rise in lung myeloperoxidase activity. Pentoxifylline prevented erk 1/2 and JNK phosphorylation in the pancreas, and it partially reduced ascites and the rise in lung myeloperoxidase activity. Combined treatment with oxypurinol and pentoxifylline almost completely abolished ascites, MAPK phosphorylation in the pancreas, and the increase in lung myeloperoxidase activity. Histology revealed a reduction in pancreatic and lung damage. These changes were associated with a significant improvement of survival. CONCLUSIONS:: Simultaneous inhibition of TNF-alpha production and xanthine oxidase activity greatly reduced local and systemic inflammatory response in acute pancreatitis and decreased mortality rate. These effects were associated with blockade of the 3 major MAPKs.     

Stimulation of MAPK cascades by insulin and osmotic shock: lack of an involvement of p38 mitogen-activated protein kinase in glucose transport in 3T3-L1 adipocytes

Osmotic shock and insulin stimulate GLUT4 translocation and glucose transport via mechanisms that are for the most part distinct yet convergent. In this article, we investigated the effect of osmotic shock and insulin on the activation of the mitogen-activated protein kinase (MAPK) cascades in differentiated 3T3-L1 adipocytes. The MAPKs are activated by phosphorylation on conserved tyrosine and threonine residues. Both sorbitol and insulin strongly stimulated extracellular regulated kinase (ERK) 1 and 2 phosphorylation (8- and 18-fold, respectively). In contrast, c-jun-NH2-terminal kinase (JNK)/stress-activated protein kinase (SAPK) phosphorylation was stimulated only by sorbitol (sevenfold) and not by insulin. Phosphorylation of p38 MAPK was stimulated strongly by sorbitol (22-fold) but weakly by insulin (2.7-fold). Measurement of intrinsic JNK and p38 MAPK activity confirmed the phosphorylation studies. JNK and p38 MAPK were activated only significantly by sorbitol. The MAPKs are phosphorylated by dual-specificity kinases (mitogen-activated ERK-activating kinase [MEK] or MAPK kinase [MKK]). As expected, sorbitol and insulin both stimulated MEK phosphorylation. MKK4 was phosphorylated only in response to sorbitol, and neither of the stimuli caused phosphorylation of MKK3 or 6. To determine the functional significance of the observed activation of p38 MAPK in response to insulin and osmotic shock, we used three pyridinyl imidazole p38 MAPK inhibitors, SB203580, SB202190, and PD169316. Insulin and osmotic shock-stimulated glucose transport was not inhibited by any inhibitor at concentrations that were shown to block p38 MAPK activity. Furthermore, activation of the p38 MAPK pathway by treatment of cells with anisomycin did not stimulate glucose transport. These results suggest that activation of the p38 MAPK pathway is not involved in the stimulation of glucose transport.     

清胰颗粒减轻急性出血坏死性胰腺炎大鼠早期肺损伤

目的：探讨复方中药提取物清胰颗粒对急性出血坏死性胰腺炎（AHNP）大鼠早期肺损伤的影响和可能作用机制。方法：72只健康雄性Wistar大鼠随机分为假手术组、AHNP组、清胰颗粒组。采用胆胰管逆行注射3.5%牛磺胆酸钠建立AHNP动物模型。清胰颗粒组于制模前2 h给予清胰颗粒水溶液灌胃,以后每12 h灌胃1次。各组大鼠分别于制模后6 h、12 h和24 h取肺组织观察病理改变并进行病理评分,检测髓过氧化物酶（MPO）活性,并用荧光定量PCR检测Toll样受体4（TRL-4）和p38MAPK mRNA表达。结果：与同时点AHNP组比较,清胰颗粒组于造模后12 h和24 h肺组织病理评分、MPO活性降低（P〈0.05）,于造模后6 h、12 h和24 h TRL-4和p38MAPK mRNA表达显著降低（P〈0.05）。结论：清胰颗粒能够减轻AHNP大鼠病理损伤和炎症反应,其作用机制可能与抑制p38MAPK信号通路有关。     

P38 mitogen-activated protein kinase inhibition attenuates ischemia-reperfusion injury of the rat liver

BACKGROUND: Several studies have implicated the mitogen-activated protein kinase (MAPK) signal pathway in non-hepatic organ ischemia-reperfusion injury. However, the role of p38 MAPK in hepatic ischemia-reperfusion injury remains unclear. This study investigated the role of p38 MAPK in hepatic ischemia-reperfusion injury. METHODS: Male Sprague-Dawley rats were divided into 4 groups (sham, FR-only, control, and FR-treated groups). The animals in the control and FR-treated groups were subjected to 30 minutes of warm ischemia with congestion of the gut. The FR-only and FR-treated groups received FR167653 (FR), which is a novel p38 MAPK inhibitor. The serum levels of aspartate transaminase, alanine transaminase, lactate dehydrogenase, tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) were measured (each, n = 6). Liver tissue blood flow was measured at pre-ischemia, end-ischemia, and 30, 60, 90, and 120 minutes after reperfusion (each, n = 4). The liver tissues in the control and FR-treated groups were excised for p38 MAPK and c-Jun N-terminal kinase (JNK) analyses and histopathology (each, n = 4). RESULTS: Serum levels of aspartate transaminase, alanine transaminase, lactate dehydrogenase, TNF-alpha, and IL-1beta were significantly lower in the FR-treated group than in the control group, and liver tissue blood flow was significantly higher in the FR-treated group than in the control group. Histopathologically, tissue damage was milder in the FR-treated group than in the control group. Both p38 MAPK and JNK were markedly phosphorylated after 30 minutes of reperfusion, and FR inhibited the phosphorylation of p38 MAPK without affecting the JNK. CONCLUSIONS: FR decreased serum TNF-alpha and IL-1beta levels and liver injury associated with the inhibition of p38 MAPK activation. These results suggest that inhibiting the activation of p38 MAPK may attenuate warm ischemia-reperfusion injury of the liver.     

p38丝裂原活化蛋白激酶在应激性溃疡发病中的作用

目的探讨p38丝裂原活化蛋白激酶(MAPK)在应激性溃疡发生中的作用。方法80只SD大鼠分成正常对照组(10只)、浸水-束缚(WIR)应激模型组(0.5、1、2、4和6h时间点各10只)和p38特异性抑制剂CNI1493处理组(低剂量和高剂量组各10只)。CNI1493处理组于应激前2h尾静脉注射1或10mg/kg的CNI1493。胃黏膜病变程度采用溃疡指数计分评价,磷酸化和总p38MAPK表达采用蛋白印迹法(Westernblot)检测,肿瘤坏死因子α(TNFα)和白细胞介素1β(IL1β)基因表达采用Northernblot方法检测。结果WIR应激后大鼠胃黏膜p38MAPK发生持续活化,其最大活化发生于应激后1h,为正常水平的(6.8±3.2)倍(P<0.01)。使用CNI1493阻断p38MAPK活化后,胃黏膜损伤程度显著减轻,同时促炎性细胞因子TNFα和IL1β基因表达也明显下调。结论p38MAPK活化在实验性应激性溃疡的发生中发挥了重要作用。     

Modulation of vascular smooth muscle cell alignment by cyclic strain is dependent on reactive oxygen species and P38 mitogen-activated protein kinase

PURPOSE: The aim of this study was to investigate the molecular targets of reactive oxygen species (ROS) and to determine whether cyclic strain induces smooth muscle cell (SMC) alignment via the ROS system. We assessed stretch-induced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase activation and the redox sensitivity of cyclic strain-stimulated activation of the mitogen-activated protein kinase (MAPK) family. METHODS: SMCs were seeded on flexible collagen I-coated plates and exposed to cyclic strain. NAD(P)H oxidase activation was measured with lucigenin-enhanced chemiluminescent detection of superoxide. Activation of MAPK was detected by determining phosphorylation of extracellular signal-regulated protein kinase (ERK1/2), c-jun N-terminal kinase (JNK1/2), and p38 MAPK with immunoblotting. In other experiments, SMCs were exposed to diphenylene iodonium (DPI), an NAD(P)H inhibitor, 30 minutes before stretch. MAPK activation and cell orientation were then assessed. RESULTS: Cyclic strain elicits a rapid increase in intracellular NADH/NADPH oxidase in SMCs. There was also a rapid and robust phosphorylation of ERK1/2, JNK1/2, and p38 MAPK. Cyclic strain-induced intracellular NAD(P)H generation was almost completely blocked with DPI. DPI also inhibited the strain-induced phosphorylation of ERK1/2, JNK1/2, and p38 MAPK. Both the p38 MAPK specific inhibitor, SB 202190, and DPI blocked cyclic strain-induced cell alignment, but PD98059, an ERK1/2-specific inhibitor, and SP600125, an anthrazolone inhibitor of JNK, did not. CONCLUSION: Our results provide evidence that p38 MAPK is a critical component of the oxidant stress ROS-sensitive signaling pathway and plays a crucial role in vascular alignment induced by cyclic stain.     

Morphologic characterization of early ligation-induced acute pancreatitis in rats

BACKGROUND: Bile-pancreatic duct ligation in rats causes acute pancreatic inflammation. We performed serial morphologic evaluation of the exocrine pancreas after duct ligation to facilitate further investigations using the model. METHODS: The pancreas was excised from 74 rats after 0, 1, 3, 5, 24 or 48 hours of duct ligation or sham surgery. A pathologist evaluated 1 hematoxylin- and eosin-stained slide from each rat. Confirmatory immunostaining was performed with markers for apoptosis (activated caspase-3), proliferation (cyclin D3), neutrophils (myeloperoxidase), and macrophages (CD68). RESULTS: Interstitial edema and white blood cell infiltration were apparent at 24 hours and increased at 48 hours. Progressive periods of duct ligation were characterized by ductular ectasia (1 to 3 hours), acinar vacuolization (5 to 48 hours), leukocytic margination and neutrophil exocytosis (5 to 48 hours), ductule epithelium hypertrophy and proliferation (24 to 48 hours), and discernible loss of zymogen granules (48 hours). CONCLUSIONS: Ligation-induced acute pancreatitis in rats is a useful model to investigate early events in disease pathogenesis.     

Dysregulation of the BMP-p38 MAPK signaling pathway in cells from patients with fibrodysplasia ossificans progressiva (FOP).

FOP is a disabling disorder in which skeletal muscle is progressively replaced with bone. Lymphocytes, our model system for examining BMP signaling, cannot signal through the canonical Smad pathway unless exogenous Smad1 is supplied, providing a unique cell type in which the BMP-p38 MAPK pathway can be examined. FOP lymphocytes exhibit defects in the BMP-p38 MAPK pathway, suggesting that altered BMP signaling underlies ectopic bone formation in this disease. INTRODUCTION: Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder characterized by progressive heterotopic ossification of connective tissues. Whereas the primary genetic defect in this condition is unknown, BMP4 mRNA and protein and BMP receptor type IA (BMPRIA) protein are overexpressed in cultured lymphocytes from FOP patients, supporting that altered BMP signaling is involved in this disease. In this study, we examined downstream signaling targets to study the BMP-Smad and BMP-p38 mitogen-activated protein kinase (MAPK) pathways in FOP. MATERIALS AND METHODS: Protein phosphorylation was assayed by immunoblots, and p38 MAPK activity was measured by kinase assays. To examine BMP target genes, the mRNA expression of ID1, ID3, and MSX2 was determined by quantitative real-time PCR. Statistical analysis was performed using Student's t-test or ANOVA. RESULTS: FOP lymphocytes exhibited increased levels of p38 phosphorylation and p38 MAPK activity in response to BMP4 stimulation. Furthermore, in response to BMP4, FOP cells overexpressed the downstream signaling targets ID1 by 5-fold and ID3 by 3-fold compared with controls. ID1 and ID3 mRNA induction was specifically blocked with a p38 MAPK inhibitor, but not extracellular signal-related kinase (ERK) or c-Jun N-terminal kinase (JNK) inhibitors. MSX2, a known Smad pathway target gene, is not upregulated in control or FOP cells in response to BMP, suggesting that lymphocytes do not use this limb of the BMP pathway. However, introduction of Smad1 into lymphocytes made the cells competent to regulate MSX2 mRNA after BMP4 treatment. CONCLUSIONS: Lymphocytes are a cell system that signals primarily through the BMP-p38 MAPK pathway rather than the BMP-Smad pathway in response to BMP4. The p38 MAPK pathway is dysregulated in FOP lymphocytes, which may play a role in the pathogenesis of FOP.     

戊乙奎醚预处理对脓毒症小鼠肺损伤时MAPK信号转导通路的影响

目的 探讨戊乙奎醚(PHC)预处理对脓毒症小鼠肺损伤时丝裂原活化蛋白激酶(MAPK)信号转导通路的影响.方法 健康雌性昆明小鼠105只,体重20～25 g,随机分为3组(n=35):假手术组(S组)、脓毒症(CLP)组和戊乙奎醚(PHC)组.采用盲肠结扎并穿孔法制备脓毒症模型.PHC组于造模前1 h腹腔注射戊乙奎醚0.45 mg/kg,s组和CLP组于造模前1 h注射等容量生理盐水.于造模后即刻测定肺微血管通透性;造模后12 h时进行动脉血气分析,观察肺组织病理结果,测定肺组织丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和磷酸化的p38丝裂原活化蛋白激酶(p38MAPK)、细胞外信号调节激酶(ERK1/ERK2)和c-jun氨基末端蛋白激酶(JNK)表达.结果 与S组比较,CLP组PaO2、PaO2/FiO2和pH值降低,肺微血管通透性和肺组织MDA含量升高,SOD活性降低,磷酸化的p38MAPK、ERK1/ERK2和JNK表达上调(P<0.05或0.01);与CLP组比较,PHC组PaO2、PaO2/FiO2和pH值升高,肺微血管通透性和肺组织MDA含量降低,SOD活性升高,磷酸化的p38MAPK和ERK1/ERK2表达下调(P<0.05或0.01).结论 戊乙奎醚预处理可通过抑制MAPK信号转导通路(p38MAPK和ERK1/ERK2)的激活,从而减轻脓毒症小鼠肺损伤.     

p38MAPK表达在大鼠重症急性胰腺炎肺损伤中的意义

目的 探讨大鼠重症急性胰腺炎(severe acute pancreatitis,SAP)时p38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38MAPK)表达的动态变化及其与肺损伤的关系.方法 72只雄性Wistar大鼠随机分为空白对照组、盐水对照组、胰腺炎组.胰管逆行注射3.5%牛磺胆酸钠诱导莺症急性胰腺炎模型,分别于造模后0.5 h、6 h、12 h、24 h取材.采用免疫组化方法检测肺组织磷酸化p38MAPK活性.利用逆转录一聚合酶链反应(RT-PCR)法检测SAP肺组织p38MAPKmRNA表达,同时观察肺组织病理改变、湿/干重比率及肺组织髓过氧化物酶(myeloperoxidase en-zyme,MPO)等.结果 正常对照组肺组织仅有少量磷酸化p38MAPK活化及p38MAPK mRNA的表达,SAP时肺组织磷酸化p38MAPK及p38MAPK mRNA高表达,MPO活力增加.造模后肺组织p38MAPK mRNA表达明显升高,6 h达高峰,24 h时活性仍高于其基础活性.肺组织p38MAPKmRNA表达与肺损伤病理评分及MPO呈正相关,相关系数分别为0.726,0.629(P<0.01).结论 肺组织p38MAPK活化及过度表达可能是SAP肺损害发生的原因之一.     

p38MAPK表达在大鼠重症急性胰腺炎肺损伤中的意义

目的 探讨大鼠重症急性胰腺炎(severe acute pancreatitis,SAP)时p38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38MAPK)表达的动态变化及其与肺损伤的关系.方法 72只雄性Wistar大鼠随机分为空白对照组、盐水对照组、胰腺炎组.胰管逆行注射3.5%牛磺胆酸钠诱导莺症急性胰腺炎模型,分别于造模后0.5 h、6 h、12 h、24 h取材.采用免疫组化方法检测肺组织磷酸化p38MAPK活性.利用逆转录一聚合酶链反应(RT-PCR)法检测SAP肺组织p38MAPKmRNA表达,同时观察肺组织病理改变、湿/干重比率及肺组织髓过氧化物酶(myeloperoxidase en-zyme,MPO)等.结果 正常对照组肺组织仅有少量磷酸化p38MAPK活化及p38MAPK mRNA的表达,SAP时肺组织磷酸化p38MAPK及p38MAPK mRNA高表达,MPO活力增加.造模后肺组织p38MAPK mRNA表达明显升高,6 h达高峰,24 h时活性仍高于其基础活性.肺组织p38MAPKmRNA表达与肺损伤病理评分及MPO呈正相关,相关系数分别为0.726,0.629(P<0.01).结论 肺组织p38MAPK活化及过度表达可能是SAP肺损害发生的原因之一.