Involvement of ERK1/2 and p38 MAPK in up-regulation of 14-3-3 protein induced by hydrogen peroxide preconditioning in PC12 cells

Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 4′,6′-diamidino-2-phenylindole （DAPI） staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase （MAPK） were determined by Western blot. Enzyme-linked immunosorbent assay （ELISA） was used to measure the activity of extracellular signal-regulated protein kinase 1/2 （ERK1/2）. Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^＋ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^＋- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP＋ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.

The involvement of p38 MAPK in transforming growth factor β1-induced apoptosis in murine hepatocytes

We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly inhibited the TGF-beta1-induced apoptosis and PAI-1 promoter activity. Treatment of cells with TGF-beta1 activates p38. Furthermore, over-expression of dominant negative mutant p38 also reduced the TGF-beta1-induced apoptosis. The data indicate that the activation of p38 is involved in TGF-beta1-mediated gene expression and apoptosis.

Differential activation of mitogen-activated protein kinases by γ-irradi-ation in IEC-6 cells: Role of intracellular Ca^(2+)

Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.

IL-36 Cytokine Expression and Its Relationship with p38 MAPK and NF-κB Pathways in Psoriasis Vulgaris Skin Lesions

Summary： This study examined the correlation of the expression of interleukin-36 （IL-36）, a novel member of interleukin-1 （IL-1） family, with p38 mitogen-activated protein kinase （p38 MAPK） and nu clear factor-kappa B （NF-kB） pathways in psoriasis vulgaris skin lesions. The expression levels of IL-36a, IL-3613, IL-367, phosphorylated p38 MAPK, and NF-id3p65 were detected in the skin tissues of 38 psoriasis patients and 17 healthy control subjects by real-time quantitative reverse transcription po lymerase chain reaction （qRT-PCR） and Western blotting. The cytokine expression levels were com pared between the psoriasis group and the control group. A correlation analysis between cytokine pro teins was performed in the psoriasis group. Results showed that the expression levels of IL-36a, IL-3613, IL-36y, phosphorylated p38 MAPK and NF-rh3p65 in the psoriasis group were Significantly higher than those in the control group （P〈0.001）. In the psoriasis group, the IL-36 cytokine expression was positively correlated with phosphorylated p38 MAPK and NF-kBp65 expression （P〈0.05）. A significant positive correlation was also found between the phosphorylated p38 MAPK and NF-v,.Bp65 expression （P〈0.01）. It was concluded that the increased IL-36 expression is correlated with p38 MAPK and NF-kB pathways in psoriasis vulgaris skin lesions. All the three factors may be jointly involved in the pathogenesis and local inflammatory response of psoriasis.

Downregulation of p38 MAPK Involved in Inhibition of LDL-induced Proliferation of Mesangial Cells and Matrix by Curcumin

Curcumin, as a main pharmacological component in the traditional Chinese medicine-- tttrmeric, has shown anti-inflammatory, anti-oxidation, anti-tumor and anti-fibrotic effects. This study aimed to investigate the possible underlying signaling pathway which was involved in the inhibition of LDL-induced proliferation of mesangial cells and matrix by curcumin. Rat mesangial cells in vitro were incubated with low-density lipoprotein （LDL） and different concentrations of curcumin （0, 6.25, 12.5, 25.0 9mol/L） or p38 MAPK inhibitor, SB203580 （10 μmol/L）. Under LDL incubation, mesangial cells proliferated, the expression of MMP-2 mRNA and protein was decreased, the expression of COX-2 mRNA and protein was increased, reactive oxygen species （ROS） generation was increased and p38 MAPK was activated significantly （P〈0.05）. When LDL-induced cells were treated with curcumin in the concentration of 12.5 or 25.0 μmol/L, LDL-induced proliferation ofmesangial cells was suppressed, the expression of MMP-2 mRNA and protein increased, the expression of COX-2 mRNA and protein downregulated, the production of ROS inhibited and p38 MAPK inactivated （P〈0.05）. In conclusion, curcumin can inhibit the LDL-induced proliferation of mesangial cells and up-regulate the expression of MMP-2, which may be related with the inhibitory effect of curcumin on COX-2 expression, ROS pro- duction and p38 MAPK.

Effects of tetrandrine on phenotypic modulation of vascular smooth muscle cells and expression of p38 MAPK as well as MKP-1 after intimal injury of rabbit carotid arteries

Objective： To study the effects of tetrandrine （Tet） on phenotypic modulation of vascular smooth muscle cells （VSMCs） and expression of p38 mitogen-activated protein kinase （p38MAPK） as well as mitogen-activated protein kinase phosphatase-1 （MKP-1） after vascular intimal injury. Methods： HE staining was used to analyze vascular morphology of sham-injured group, injured group and Tet-treated group at day 28. lmmunohistochemistry, Western blot and RT-PCR were respectively used to detect the expression change of smooth muscle a-actin （SMa-actin）, proliferation cell nuclear antigen （PCNA）, p38MAPK and MKP-1 of injured group and Tet group at days 7, 14 and 28 after balloon injury. Results： ① All layers of vascular wall in sham-injured group were intact at day 28. The neointimal area was significantly increased and the lumen area notably decreased in injured group at day 28. The neointimal proliferation in Tet treated group was less than that in injured group, and the lumen area of Tet group was significantly increased than that of injured group at day 28. ②Compared with the injured group, the expression of SMa-actin, PCNA, p38MAPK and MKP-1 of vascular wall in Tet group was no difference, and the neointimal proliferation condition was also basically as same as injured group at day 7 after injury. The expression of PCNA and p38MAKP in Tet group was obviously lower than that in injured group, and the expression of MKP-1 in Tet group was obviously higher than that in injured group at days 14 and 28 after injury. The expression of SMa-actin in Tet group was slightly higher than that in injured group at days 14 and 28 after injury. Conclusions： Tet could reduce neointimal proliferation by inhibiting VSMCs phenotypic modulation and p38MAPK signaling transduction pathway as well as its down regulation.

Effect of oxymatrine on the p38 mitogen-activated protein kinases signalling pathway in rats with CCl4 induced hepatic fibrosis

Background Recent studies have suggested that p38 mitogen-activated protein kinases （MAPK） signalling pathway plays an important role in hepatic fibrosis. This study explored the antifibrotic effect of oxymatrine on tetrachloromethane induced liver fibrosis in rats and its modulation on the p38 MAPK signalling pathway. Methods One hundred and twenty healthy male Sprague-Dawley rats were randomly assigned to six groups： normal （n=20）, induced fibrosis （n=20）, colchicine （n=20） and three treatment groups of oxymatrine （n=20x3）. We obesrved changes in deposition of collagen, hyaluronic acid （HA）, laminin （LN）, collagen type IV （CIV）, procollagen III （PCIll） and hydroxyproline （Hyp）, a-smooth muscle actin （α-SMA） and phosphor-p38 （pp38）. Results The relative indicators of changes in histopathology, HA, LN, CIV, PCIII, Hyp, a-SMA and pp38 were raised significantly in the induced fibrosis group （P〈0.01 vs normal group）. The semiquantitative hepatic fibrosis staging scores of middle dose group and high dose group were decreased （P 〈0.05 and P 〈0.01 respectively vs the induced fibrosis group）, as was the average area of collagen in rats＇ liver, the concentrations of serum HA, LN, CIV, PCIII and liver tissue homogenate Hyp. The gene expression of α-SMA mRNA was considerably decreased in the treated animals, as was the protein espression of pp38 protein. Conclusions Oxymatrine is effective in reducing the production and deposition of collagen in the liver tissue of experimental rats in ways which relate to modulating the fibrogenic signal transduction via p38 MAPK signalling pathway.

Role of p38 mitogen-activated protein kinases in cardioprotection of morphine preconditioning

Background p38 mitogen-activated protein kinases （MAPK） in ischemic preconditioning （IPC） may be essential to cardioprotection. We assessed whether protective effect of morphine-induced preconditioning （MPC） on myocardial ischemia and reperfusion injury in rat hearts involved p38 MAPK activation.Methods Male Spargue-Dawley rats （weighing 300--350 g） were randomly assigned to 1 of the following 8 groups： control （CON, saline vehicle, n=9）, SB 203580 （SB, a p38 MAPK inhibitor, n=6）, MPC （n=6）, IPC （n=9）, SB＋MPC, SB＋IPC, MPC＋SB, and IPC＋SB （n=6）. Infarct sizes （IS）, a percentage of the area at risk （AAR）, were determined by triphenyltetrazolium （TTC） staining. Hssue samples were processed from the entire AAR of left ventricle for the determination of p38 MAPK protein expression （5 hearts/group）. The bands representing the proteins were visualized using an enhanced chemiluminescence detection system. Results The IS/AAR was significantly reduced by I PC （12.9±1.6）% or MPC （25.3±2.9）% compared to the control （52.7±5.5）%. SB 203580 administered prior to preconditioning abolished the effect of IPC （SB＋IPC： （43.8±2.6）%, P〉0.05 vs CON, P〈0.01 vs IPC）, but not MPC （SB＋MPC： （30.7±0.9）%, P〈0.01 vs CON, P〉0.05 vs MPC）. Treatment with SB 203580 prior to sustained ischemia diminished the protective effect of both MPC （MPC＋SB： （42.4±2.9）%, P〉0.05 vs CON） and IPC （IPC＋SB： （52.0±2.5）%, P〉0.05 vs CON） on IS/AAR. In the IPC group, phospho-p38 MAPK protein increased significantly within 5 minutes into ischemia and remained elevated at 30 minutes into reperfusion, while phospho-p38 MAPK protein in the MPC group only increased significantly at 30 minutes into reperfusion.Conclusion The activation of p38 MAPK just acts as a mediator of MPC,whereas it acts as both a trigger and a mediator in IPC.

Interleukin-1 beta up-regulates tissue inhibitor of matrix metalloproteinase-1 mRNA and phosphorylation of c-jun N-terminal kinase and p38 in hepatic stellate cells

AIM： To study the relationship between interleukin-lbeta （IL-1β） up-regulating tissue inhibitor of matrix metalloproteinase-1 （TIMMP-1） mRNA expression and phosphorylation of both c-jun N-terminal kinase （INK） and p38 in rat heffatic stellate cells （HSC）. METHODS： RT-PCR was performed to measure the expression of TIMMP-1 mRNA in rat HSC. Western blot was performed to measure IL-1β-induced JNK and p38 activities in rat HSC. RESULTS： TIMMP-1 mRNA expression （1.191± 0.079） was much higher after treatment with IL-1β （10 ng/mL） for 24 h than in control group （0.545±0.091） （P〈0.01）. IL-1β activated INK and p38 in a time-dependent manner. After stimulation with IL-1β for 0, 5, 15, 30, 60 and 120 min, the INK activity was 0.982±0.299, 1.501±0.720, 2.133±0.882, 3.360±0.452, 2.181±0.789, and 1.385 ± 0.368, respectively. There was a significant difference in JNK activity at 15 min （P〈 0.01）, 30 min （P〈 0.01） and 60 min （P〈0.01） in comparison to that at 0 min. The p38 activity was 1.061±0.310, 2.050±0.863, 2.380±0.573, 2.973±0.953, 2.421±0.793, and 1.755 ± 0.433 at the 6 time points （0, 5, 15, 30, 60 and 120 min） respectively. There was a significant difference in p38 activity at 5 min （P〈0.05）, 15 min （P〈0.01）, 30 min （P〈0.01） and 60 min （P〈0.01） compared to that at 0 min. TIMMP-1 mRNA expression trended to decrease in 3 groups pretreated with different concentrations of SP600125 （10 μmol/L, 1.022±0.113; 20 μmol/L, 0.869±0.070; 40 μmol/L, 0.666±0.123）. Their decreases were all significant （P〈0.05, P〈0.01, P〈0.01） in comparison to control group （without SP600125 treatment, 1.163±0.107）. In the other 3 groups pretreated with different concentrations of SB203580 （10 μmol/L, 1.507±0.099; 20 μmol/L, 1.698±0.107; 40 μmol/L, 1.857±0.054）, the expression of TIMMP-1 mRNA increased. Their levels were higher than those in the control group （without SB203580 treatment, 1.027 ± 0.061） with a significant statistical significance （P〈 0.01）. CONCLUSION： IL-1β has a direct action on hepatic fibrosis by up-regulating TIMMP-1 mRNA expression in ratessionin in rate HSC.JNK and p38 mitogen-activated protein kinases （MAPKs） are involved in IL-1β-induced TIMMP-1 gene expression, and play a distinct role in this process, indicating that p38 and .INK pathways cooperatively mediate TIMP-1 mRNA expression in rat HSC.

胎儿和出生后机体皮肤内p38MAPK及MAPKKs基因表达变化的比较性研究

目的 探讨p38丝裂素活化蛋白激酶(p38mitogen- activated protein kinase,p38MAPK)及其上游信号分子MAPKKs(mkk3和mkk6 )基因,在不同胎龄胎儿皮肤和出生后机体皮肤组织中表达的变化,及其可能的生物学意义。 方法 用病理学技术检测不同发育时期皮肤的结构特征后,提取18例不同胎龄(13～32周)的胎儿皮肤和6例出生后机体皮肤组织(作为对照)的总RNA,分离m RNA,用逆转录-聚合酶链反应(reverse transcription- polymerasechain reaction,RT- PCR)方法检测3种基因在不同组织中的表达规律。 结果 p38MAPK,m kk3和mkk6基因在不同发育阶段的皮肤组织中都有表达。在早期妊娠胎儿的皮肤组织中,这三种基因表达较强,随着胎儿的生长发育,皮肤组织内这三种基因表达逐渐减弱。在出生后机体的皮肤细胞中,p38MAPK、mkk3和mkk6基因的表达量分别为妊娠早期皮肤的39.6 %、6 3.5 %和5 4 .5 % ,明显减弱(P<0 .0 1)。 结论 p38MAPK、mkk3和mkk6基因在不同发育阶段人皮肤组织内都有表达,显示细胞外信号引起的p38MAPK信号通路可能对皮肤的发生、结构功能的维持以及伤后修复十分重要。在早期妊娠胎儿皮肤中p38MAPK及其上游信号分子MAPKKs基因的高表达可能是胎儿皮肤组织细胞快速增殖、皮肤创面无瘢痕愈合的机制之一。

P38MAPK在慢性阻塞性肺疾病中的作用

慢性阻塞性肺疾病是一种慢性气道炎症性疾病,是肺部对有害颗粒或气体的所产生的异常炎症反应,这种气道炎症常导致持续性的气流受限和肺功能的进行性下降。此外,由肺内炎症反应等所导致的氧化应激反应也参与了COPD的发病。p38丝裂原活化蛋白激酶（p38 mitogen-activated protein kinase,p38MAPK）是细胞内重要的信号传递者,

Electroacupuncture reduces apoptotic index and inhibits p38 mitogen-activated protein kinase signaling pathway in the hippocampus of rats with cerebral ischemia/reperfusion injury

Electroacupuncture attenuates cerebral hypoxia and neuronal apoptosis induced by cerebral ischemia/reperfusion injury.To further identify the involved mechanisms,we assumed that electroacupuncture used to treat cerebral ischemia/reperfusion injury was associated with the p38 mitogen-activated protein kinase（MAPK） signaling pathway.We established rat models of cerebral ischemia/reperfusion injury using the modified Zea-Longa＇s method.At 30 minutes before model establishment,p38 MAPK blocker SB20358 was injected into the left lateral ventricles.At 1.5 hours after model establishment,electroacupuncture was administered at acupoints of Chize（LU5）,Hegu（LI4）,Zusanli（ST36）,and Sanyinjiao（SP6） for 20 minutes in the affected side.Results showed that the combination of EA and SB20358 injection significantly decreased neurologic impairment scores,but no significant differences were determined among different interventional groups.Hematoxylin-eosin staining also showed reduced brain tissue injuries.Compared with the SB20358 group,the cells were regularly arranged,the structures were complete,and the number of viable neurons was higher in the SB20358 ＋ electroacupuncture group.Terminal deoxynucleotidyl transferase（Td T）-mediated d UTP nick-end labeling assay showed a decreased apoptotic index in each group,with a significant decrease in the SB20358 ＋ electroacupuncture group.Immunohistochemistry revealed reduced phosphorylated p38 expression at 3 days in the electroacupuncture group and SB20358 ＋ electroacupuncture group compared with the ischemia/reperfusion group.There was no significant difference in phosphorylated p38 expression between the ischemia/reperfusion group and SB20358 group.These findings confirmed that the electroacupuncture effects on mitigating cerebral ischemia/reperfusion injury are possibly associated with the p38 MAPK signaling pathway.A time period of 3 days could promote the repair of ischemic cerebral nerves.

p38蛋白激酶(p38 MAPK)在癫大鼠脑内的表达

目的观察p38蛋白激酶(p38mitogen-activated protein kinase,p38MAPK)在癫大鼠脑内的表达情况。方法健康雄性SD大鼠随机分成正常对照组(n=8)和癫组(n=8)。采用戊四氮腹腔注射建立癫模型,大鼠点燃后的惊厥行为按照Racine的标准进行观察评分,采用Western blot和免疫荧光法比较两组大鼠脑内p38MAPK的表达情况。结果癫组大鼠脑内p38MAPK在皮层和海马的表达均显著高于正常对照组(P<0.01)。结论 p38MAPK在癫大鼠脑内表达上调。

N-methyl-D-aspartate receptor effects on p38 mitogen activated protein kinase and its role in a rat model of diabetic neuropathic pain

BACKGROUND： Activated N-methyl-D-aspartate （NMDA） receptor is involved in the formation of chronic neuropathic pain, and its antagonist, ketamine, exhibits effective amelioration of diabetic neuropathic pain （DNP）. However, the mechanisms of NMDA receptor participation in the formation and maintenance of DNP remain poorly understood. OBJECTIVE： To evaluate the role NMDA receptor plays in DNP and effects on p38 mitogen activated protein kinase （p38 MAPK） in a rat model of DNP. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Human Embryonic Stem Cell Research Institute of Yunyang Medical College Affiliated Taihe Hospital between July 2005 and September 2007. MATERIALS： Streptozotocin was provided by Sigma, USA; p38 MAPK inhibitor （SB203580） was provided by Shanghai KangChen Biotech, China; NMDA receptor antagonist （MK-801） was purchased from Shanghai Yope Biotech, China. METHODS： A total of 128 healthy, Wistar rats of clean grade, aged 3 months and weighing 180- 220 g, were randomly assigned to 4 groups： control, DNP model, p38 MAPK, and NMDA receptor. Each group contained 32 rats. DNP was established in all groups except for the control group by intraperitoneal injection of streptozocin （65 mg/kg）. Subsequently, 1 mg/kg SB203580 and 1 mg/kg MK-801 were injected once each week via intraperitoneal injection in the p38 MAPK and NMDA receptor groups, respectively. MAIN OUTCOME MEASURES： At the end of 2, 4, 6, and 8 weeks following streptozotocin injection, mechanical withdrawal threshold was measured in 8 animals from each group following von Frey filament stimulation. The rats were anesthetized and nerve conduction velocity of the left sciatic nerve was measured. Subsequently, the right sciatic nerve, the lumbar segment of the spinal cord, and dorsal root ganglia were removed from the L3-6 segment for microscopic examination, p38 MAPK expression was determined using immunohistochemistry and Western blot analysis. Expression of NMDA receptor 1 mRNA in dorsal root ganglion and spinal cord neurons was detected using RT-PCR. RESULTS： Mechanical withdrawal threshold and nerve conduction velocity were significantly reduced, and p38 MAPK and NMDA receptor 1 mRNA expression in the spinal cord and dorsal root ganglia were significantly increased, in the model, p38 MAPK, and NMDA receptor groups compared with the control group at all time points （P 〈 0.05）. At 4-8 weeks following successful DNP model establishment, SB203580 and MK-801 increased mechanical withdrawal threshold, accelerated nerve conduction velocity, and attenuated p38 MAPK expression, compared with the model group. The NMDA receptor group exhibited downregulated mRNA expression of NMDA receptor 1 compared with the model and p38 MAPK groups （P 〈 0.05）. CONCLUSION： NMDA receptor was highly expressed in the brains of DNP rats and was involved in DNP development via activation of the p38 MAPK signal pathway.

Variations of p38 MAPK and slCAM-1 with therapeutic effect of different resuscitation fluids on severe traumatic patients

Objective: To investigate the dynamic variation and action mechanism of sICAM-1 and p38 mitogen-activated protein kinases (MAPK) signal transduction in human severe trauma and resuscitation, as well as the effect of lactated Ringer's solution ( LR), 7.5% sodium chloride solution ( HS ) and 20% albumin injection ( ALB ) on the incidence and mortality of multiple organ dysfunction syndrome (MODS).Methods: Seventy-two severe trauma patients (ISS score 16-43) were divided into ISS≤25 and ISS＞25 groups (each group was subdivided into LR, HS and ALB groups). ELISA was used to measure the concentration of sICAM-1. Western blot was used to measure the expression of p38 MAPK.Results: Compared with LR group, the transfusion volume needed for maintaining systolic blood pressure ≥ 90 mm Hg was significantly decreased in HS and ALB groups (P＜0.05). Compared with the control group, the concentration of blood sICAM-1 and the expression of p38 MAPK was elevated from 4 to 48 hours after trauma in all experimental groups (P ＜ 0.05 -0.01 ). At 4, 12, and 24 hours, there was significant correlation between the expression of p38 MAPK and sICAM-1 (P ＜ 0. 01).Compared with LR group, sICAM-1 and p38 MAPK in HS and ALB groups were decreased (P ＜ 0.05). sICAM-1 and p38 MAPK were significantly higher in the group of ISS ＞25 than that of ISS ≤ 25 (P ＜ 0.05 ). MODS incidence and mortality were significantly higher in the group of ISS ＞ 25 than that of ISS ≤ 25 ( P ＜ 0.05 ). MODS incidence and mortality were lower in HS and ALB groups than LR group (P＜0.05).Conclusions: The up-regulation of polymorphonuclear neutrophil-endotheliocytes (PMN-EC) adhesion may be due to the increased sICAM-1 expression during severe trauma. The up-regulation of sICAM-1 expression is correlated with the activation of p38 MAPK. During severe trauma, the levels of sICAM-1 and p38 MAPK, as well as the incidence and mortality of MODS are lower when HS and ALB are used than single lactated LR solution is used.

黄芪对脂多糖诱导大鼠急性肺损伤p38 MAPK表达的影响

目的探讨脂多糖(LPS)诱导急性肺损伤(ALI)大鼠肺组织磷酸化p38 MAPK表达的变化以及黄芪对其之影响。方法静脉注射LPS复制大鼠ALI模型。随机分成3组:正常对照组、ALI组和黄芪组。采用蛋白质印迹检测肺组织磷酸化p38 MAPK的表达,并观察大鼠动脉血氧分压(PaO2)、肺湿/干重比(W/D)、支气管肺泡灌洗液(BALF)白蛋白、血清TNF-α的变化以及肺组织病理学改变。结果LPS诱导大鼠ALI时肺组织磷酸化p38 MAPK的表达较正常对照组显著增加(P<0.01)。黄芪注射液可显著抑制大鼠肺组织磷酸化p38MAPK表达,降低W/D、BALF白蛋白以及血清TNF-α含量,使下降的PaO2回升,减轻肺组织病理学损伤。结论ALI时肺组织p38 MAPK磷酸化表达增加;黄芪注射液对内毒素性肺损伤有保护作用,其机制可能与抑制磷酸化p38 MAPK的表达有关。

p38α MAPK pathway:A key factor in colorectal cancer therapy and chemoresistance

Colorectal cancer (CRC) remains one of the most common malignancies in the world. Although surgical resection combined with adjuvant therapy is effective at the early stages of the disease, resistance to conventional therapies is frequently observed in advanced stages, where treatments become ineffective. Resistance to cisplatin, irinotecan and 5-fluorouracil chemotherapy has been shown to involve mitogen-activated protein kinase (MAPK) signaling and recent studies identified p38&#x003b1; MAPK as a mediator of resistance to various agents in CRC patients. Studies published in the last decade showed a dual role for the p38&#x003b1; pathway in mammals. Its role as a negative regulator of proliferation has been reported in both normal (including cardiomyocytes, hepatocytes, fibroblasts, hematopoietic and lung cells) and cancer cells (colon, prostate, breast, lung tumor cells). This function is mediated by the negative regulation of cell cycle progression and the transduction of some apoptotic stimuli. However, despite its anti-proliferative and tumor suppressor activity in some tissues, the p38&#x003b1; pathway may also acquire an oncogenic role involving cancer related-processes such as cell metabolism, invasion, inflammation and angiogenesis. In this review, we summarize current knowledge about the predominant role of the p38&#x003b1; MAPK pathway in CRC development and chemoresistance. In our view, this might help establish the therapeutic potential of the targeted manipulation of this pathway in clinical settings.

p38 MAPK inhibition alleviates experimental acute pancreatitis in mice

BACKGROUND： The mitogen-activated protein kinases （MAPKs） signaling pathway is involved in inflammatory process. However,the mechanism is not clear. The present study was to investigate the role of p38 MAPK in acute pancreatitis in mice.METHODS： Mice were divided into 4 groups： saline control; acute pancreatitis induced with repeated injections of cerulein; control plus p38 MAPK inhibitor SB203580; and acute pancreatitis plus SB203580. The pancreatic histology, pancreatic enzymes, cytokines, myeloperoxidase activity, p38 MAPK and heat shock protein （HSP） 60 and 70 were evaluated.RESULTS： Repeated injections of cerulein resulted in acute pancreatitis in mice, accompanying with the activation of p38 MAPK and overexpression of HSP60 and HSP70 in the pancreatic tissues. Treatment with SB203580 significantly inhibited the activation of p38 MAPK, and furthermore, inhibited the expression of HSP60 and HSP70 in the pancreas, the inflammatory cytokines in the serum, and myeloperoxidase activity in the lung.CONCLUSION： The p38 MAPK signaling pathway is involved in the regulation of inflammatory response and the expression of HSP60 and HSP70 in acute pancreatitis.

Inhibition of p38 mitogen-activated protein kinase may decrease intestinal epithelial cell apoptosis and improve intestinal epithelial barrier function after ischemia- reperf usion injury

AIM: To investigate the role of p38 mitogen-activated protein kinase in rat small intestine after ischemia-reperfusion (I/R)insult and the relationship between activation of p38 MAPK and apoptotic cell death of intestine.METHODS: Ninety Wistar rats were divided randomly into three groups, namely sham-operated group (C), I/R vehicle group (R) and SB203580 pre-treated group(S).In groups R and S, the superior mesenteric artery(SMA)was separated and occluded for 45 min, then released for reperfusion for0.25, 0.5, 1, 2, 6, 12 and 24 h. In group C, SMA was separated without occlusion. Plasma D-lactate levels were examined and histological changes were observed under a light microscope. The activity of p38 MAPK was determined by Western immunoblotting and apoptotic cells were detected by the terminal deoxynucleotidyl transferase (TdT)-mediated dUDP-biotin nick end labeling (TUNEL).RESULTS: Intestinal ischemia followed by reperfusion activated p38 MAPK, and the maximal level of activation (7.3-fold vs sham-operated group) was reached 30 min after I/R. Treatment with SB 203580, a p38 MAPK inhibitor,reduced intestinal apoptosis (26.72±3.39% vs62.50±3.08%in I/R vehicle, P＜0.01) and decreased plasma D-lactate level (0.78±0.15 mmol/L in I/R vehicle vs0.42±0.17 mmol/L in SB-treated group) and improved post-ischemic intestinal histological damage.CONCLUSION: p38 MAPK plays a crucial role in the signal transduction pathway mediating post-ischemic intestinal apoptosis, and inhibition of p38 MAPK may attenuate ischemia-reperfusion injury.