右美托咪啶对神经病理性痛大鼠脊髓背角pERK、c－fos表达的影响

目的：评价右美托咪啶对神经病理性痛大鼠脊髓背角神经元磷酸化胞外反应激酶（ phosphoryltion of extracellular reg-ulated protein kinases, pERK ）、c－fos蛋白表达的影响。方法：健康成年雄性Wistar大鼠54只,6～8周龄,体重180～220 g,采用随机数字表法,将其分为3组（n＝18）：假手术组（S组）、慢性神经病理性痛组（C组）和右美托咪啶组（D组）。 S组仅分离坐骨神经但不结扎,C组和D组采用结扎坐骨神经的方法制备大鼠坐骨神经慢性压迫性损伤（ chronic constriction injury, CCI）的神经病理性痛模型,D组于术后即刻开始至处死前1天腹腔注射右美托咪啶50μg／kg,1次／d,S组和C组注射等容量生理盐水。于术前1天、术后3、7、14天时以缩足阈值（ paw withdrawal threshold, PWT）测定大鼠机械痛阈和辐射热的缩足潜伏期（ paw withdrawl latency, PWL）测定大鼠的热痛阈,并于术后测定痛阈后灌注处死大鼠,取L4～6脊髓组织,采用免疫组织化学法检测脊髓背角神经元pERK、c－fos的表达水平。结果：与S组比较,C组和D组术后3、7、14天时MWT降低,TWL缩短,脊髓背角pERK、c－fos表达上调（P＜0．05）;与C组比较,D组术后3、7、14天时MWT升高,TWL延长,脊髓背角pERK、c－fos表达下调（P＜0．05）。与术前1天比较,C组和D组术后3、7、14天时MWT降低,TWL缩短;与术后3天时比较,C组和D组7、14天时MWT降低,TWL缩短,脊髓背角pERK、c－fos表达上调（ P＜0．05）。结论：右美托咪啶可减轻大鼠慢性神经病理性痛,抑制pERK、c－fos的表达可能是其作用机制之一。     

Anatomical evidence that the uninjured adjacent L4 nerve plays a significant role in the development of peripheral neuropathic pain after L5 spinal nerve ligation in rats

Rats develop hyperalgesia and allodynia in the hind paw after L5 spinal nerve ligation. Phosphorylated extracellular regulated kinase (pERK) was used as a pain marker to investigate the potential role of adjacent uninjured L4 nerve in the development of heat hyperalgesia after L5 nerve injury. Left L5 nerve was ligated and sectioned in rats. Three days later, rats were randomly assigned to five groups; each had both hind paws immersed in water at different temperatures (no heat, 37, 42, 47, and 52°C) under sevoflurane anesthesia for 2 minutes. Five minutes after stimulation the rats were sacrificed and sections of L3–L6 spinal segments were stained immunocytochemically with pERK antibody. pERK immunoreactivity, which is not detectable in the normal spinal cord, was discernible in neurons (not glia) of the superficial dorsal horn after noxious heat stimuli. pERK‐positive neurons clearly overlapped in laminae I–II with normal unmyelinated and thin myelinated afferents labeled with calcitonin gene‐related peptide and isolectin B4, and injured unmyelinated afferents labeled with vasoactive intestinal polypeptide. There was a linear increase in pERK immunoreactivity on both sides with an increase in temperature. Importantly, the number of positive pERK neurons was significantly higher in the ipsilateral side of L4 spinal segment, which receives innervation from uninjured L4 nerve, compared with the contralateral control side, which receives both uninjured L4 and L5 spinal nerves. The data demonstrate that the uninjured L4 nerve plays an important role in the development of heat hyperalgesia at the spinal cord level after L5 nerve injury. J. Comp. Neurol. 523:1731–1747, 2015. © 2015 Wiley Periodicals, Inc.     

Proteomic identification of 14‐3‐3ϵ as a linker protein between pERK1/2 inhibition and BIM upregulation in human osteosarcoma cells

Despite advancements in multimodality chemotherapy, conventional cytotoxic treatments still remain ineffective for a subset of patients with aggressive metastatic or multifocal osteosarcoma. It has been shown that pERK1/2 inhibition enhances chemosensitivity to doxorubicin and promotes osteosarcoma cell death in vivo and in vitro. One of the pro‐apoptotic mechanisms is upregulation of Bim by pERK1/2 inhibitors. To this end, we examined proteomic changes of 143B human osteosarcoma cells with and without treatment of PD98059, pERK1/2 inhibitor. Specifically, we identified 14‐3‐3? protein as a potential mediator of Bim expression in response to inhibition of pERK1/2. We hypothesized that 14‐3‐3? mediates upregulation of Bim expression after pERK1/2 inhibition. We examined the expression of Bim after silencing 14‐3‐3? using siRNA. The 14‐3‐3? gene silencing resulted in downregulation of Bim expression after PD98059 treatment. These data indicate that 14‐3‐3? is required for Bim expression and that it has an anti‐cancer effect under pERK1/2 inhibition in 143B cells. By playing an essential role upstream of Bim, 14‐3‐3? may potentially be a coadjuvant factor synergizing the effect of pERK1/2 inhibitors in addition to conventional cytotoxic agents for more effective osteosarcoma treatments. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:848–854, 2014.

     

Dynamic distribution of ERK,p38 and JNK during the development of pancreatic ductal adenocarcinoma

We recently discovered that oncogenic c-kit is highly expressed concomitantly with the development of pancreatic ductal adenocarcinoma (PDAC). Since oncogenic c-kit may activate major pathways of protein tyrosine phosphorylation, we decided to investigate this issue in the major protein phosphorylation cascades. In normal pancreas labeling with antiphosphorylated ERK1/2 (pERK1/2) antibody was mainly confined to islets of Langerhans in close overlapping with insulin containing cells. Phosphorylated p38 (pp38) showed a similar pattern of distribution, while only weak labeling was evident for pJNK and no labeling of pMEK was observed. As expected, general ERK1/2 (gERK1/2), general p38 (gp38), general JNK (gJNK) as well as general MEK (gMEK) were all evident in islets of Langerhans and in the exocrine tissue. In early development of PDAC, pERK1/2 and pp38 retained their localization in islets of Langerhans. Intensive staining of pERK1/2 was also evident in the cancerous ducts, while the labeling with antibodies to pp38 was more moderate. While pJNK staining in islets of Langerhans was weak, with no labeling in the cancerous ducts, antibodies to gJNK revealed intensive staining suggesting the weak staining of pJNK is not due to the lack of the enzyme. In a more advanced stage of PDAC the carcinomas were clearly stained with pERK1/2 and pp38, while moderate staining with pJNK was also evident. In liver metastases, the cancer cells were heavily labeled with all three phospho-MAPKs. It should be noted that the localization of all three kinases was mainly in the cell nuclei. In the more advanced stage of PDAC, heavy labeling was evident using antibodies to gERK1/2, gp38, gJNK and gMEK. However, no labeling to pMEK was evident in parallel sections. Our data suggest that both in normal and cancerous pancreas, most of the MAPK activities are located in islets of Langerhans and cancerous ducts. It is suggested that using inhibitors to protein kinases may attenuate the progression of the disease.     

Upregulation of fatty acid synthase in MYC and BCL-2 double-expressor lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common and heterogeneous lymphoid malignancy. The subtype with MYC and BCL-2 double-expressor lymphoma (DEL) was defined by its aggressive nature and poor survival outcome. Therefore, the development of effective therapies for the DEL subtype is imperative. Fatty acid synthase (FASN) activity is associated with altered lipid metabolism and aberrant protein translation in DLBCL. However, the inter-regulation of these key processes is not fully determined in DEL. In the present study, the clinical and biological impact of FASN was investigated in the DEL subtype. Initially, FASN expression levels were analyzed from a patient cohort and the data indicated that the highest FASN expression was noted in DEL tissues compared with that noted in the DLBCL and reactive lymphoid hyperplasia tissues. Patients with DEL with combined high-FASN expression indicated poorer EFS outcomes than the rest of the patients. In vitro data indicated that FASN was overexpressed in SU-DHL-2 and U2932 cells. Silencing FASN decreased cell growth and promoted cell apoptosis by modulating the pERK/BCL-2 signaling pathway. In conclusion, the present study indicated that FASN was overexpressed in DEL and that its expression was associated with poor survival outcomes. Furthermore, the data demonstrated that FASN regulated the biological function via the pERK/BCL-2 signaling pathway. FASN serves a critical role in the progression of DEL and its expression may be associated with the development to a more aggressive phenotype of DLBCL. Therefore, it may be considered a potential therapeutic target for DLBCL.     

GRP78和pERK在胃癌及非胃癌组织中的表达及临床意义

背景与目的：在胃癌的发生、发展过程中,内质网应激、细胞的修复及凋亡是重要的病理生理过程,而GRP78与pERK在其中发挥了重要的作用。研究葡萄糖调节蛋白78(glucose-regulatedproteins 78,GRP78)和磷酸化细胞外信号调节激酶(pERK)在胃腺癌、慢性萎缩性胃炎及浅表性胃炎组织中的表达,研究它们与胃癌发生、发展的关系。方法：RT-PCR法检测各25例胃腺癌、慢性萎缩性胃炎和浅表性胃炎新鲜组织中GRP78、pERK基因表达;免疫组化法分别检测各60例胃腺癌、慢性萎缩性胃炎和浅表性胃炎组织中GRP78、pERK蛋白表达,并分析其蛋白表达与临床病理参数间的相关性。结果：RTPCR半定量结果显示,胃癌组织中GRP78及pERK mRNA的相对表达水平(1.26±0.18、2.35±0.36)均明显高于慢性萎缩性胃炎组织(0.89±0.25、1.18±0.25)及浅表性胃炎组织(0.29±0.09、0.68±0.10),差异有统计学意义(P＜0.01)。免疫组织化学结果显示,GRP78及pERK蛋白在胃癌组织中的表达率(78.3%、88.3%)亦均高于慢性萎缩性胃炎(46.6%、43.3%)及浅表性胃炎组织(6.7%、5.0%),差异有统计学意义(P＜0.01)。胃癌组织中GRP78及pERK蛋白表达与胃癌分化程度、分期、淋巴结转移等有明显相关性。GRP78及pERK基因及蛋白表达水平在胃癌中均呈正相关(基因：r=0.307,P=0.000;蛋白：r=0.368,P=0.000)。单因素分析结果显示：组织学分级、浸润深度、TNM分期、淋巴结转移、GRP78高表达及pERK高表达与胃癌预后有关(P均＜0.05)。浸润全层、低分化、TNM分期晚、有淋巴结转移、GRP78高表达及pERK高表达患者生存时间短。多因素生存分析结果结果显示：GRP78高表达与GRP78低表达相比生存时间差异有统计学意义(P＜0.001)。GRP78高表达的胃癌患者生存时间短,提示GRP78是负性的预后因子。结论：GRP78和pERK在胃癌中高表达,GRP78和pERK在正常细胞向恶性细胞转化的过程中可能扮演了重要角色,检测pERK和GRP78的表达可能有助于对胃腺癌的预防、早期诊断及预后判断,同时为胃癌治疗寻找新的靶点。     

Role of hydrogen sulfide in portal hypertension and esophagogastric junction vascular disease

AIM:To investigate the association between endogenous hydrogen sulfide(H2S)and portal hypertension as well as its effect on vascular smooth muscle cells.METHODS:Portal hypertension patients were categorized by Child-Pugh score based on bilirubin and albumin levels,prothrombin time,ascites and hepatic encephalopathy.Plasma H2S concentrations and portal vein diameters(PVDs)were compared between portal hypertension patients and control participants,as well as between portal hypertension patients with varying degrees of severity.In addition,we established a rabbit hepatic schistosomiasis portal hypertension(SPH)model and analyzed liver morphology,fibrosis grade,plasma and liver tissue H2S concentrations,as well as cystathionineγ-lyase(CSE)activity and phosphorylated extracellular signal-regulated kinase(pERK)1/2,B cell lymphoma(Bcl)-2 and Bcl-XL expression in portal vein smooth muscle cells,in addition to their H2S-induced apoptosis rates.RESULTS:In portal hypertension patients,endogenous H2S levels were significantly lower than those in healthy controls.The more severe the disease was,the lower were the H2S plasma levels,which were inversely correlated with PVD and Child-Pugh score.Liver tissue H2S concentrations and CSE expression were significantly lower in the SPH rabbit livers compared with the control animals,starting at 3 wk,whereas pERK 1/2expressions gradually increased 12-20 wk after SPH model establishment.In portal vein smooth muscle cells,increasing H2S levels led to increased apoptosis,while Bcl-2 and Bcl-XL expression decreased.CONCLUSION:H2S prevents vascular restructuring caused by excessive proliferation of smooth muscle cells via apoptosis induction,which helps to maintain normal vascular structures.     

N-Ras、pERK1/2在非霍奇金淋巴瘤中的表达及临床意义

本研究检测了非霍奇金淋巴瘤(non-Hodgkin lymphoma,NHL)N-Ras和pERK1/2(extracellular signal regulated kinase,ERK)表达水平,探讨其临床意义.     

Expression of phosphorylated ERK1/2 and homeodomain protein CDX2 in cholangiocarcinoma

Purpose The extracellular signal-regulated kinase (ERK) 1/2 pathway plays important roles in the regulation of cell proliferation, differentiation and cell survival. The caudal-related homeobox protein CDX2 is essential for the development of the intestine, and is related to gastric and gallbladder cancers with the intestinal phenotype. However, the roles of ERK1/2 phosphorylation (pERK1/2) and CDX2 in cholangiocarcinogenesis remain unknown.Methods We investigated the expression of pERK1/2, CDX2 and MUC2 in Thai cholangiocarcinoma (CCA) specimens by means of immunohistochemical staining, and compared the expression of these proteins with clinicopathological factors.Results The pERK1/2 protein was expressed in 29 of 59 (49.2%) CCA cases. Interestingly, in tubular-type CCA, the frequency of pERK1/2 expression was associated with a higher grade of differentiation (P = 0.001). CDX2 expression was observed in 22 of the 59 (37.3%) CCA cases, showed a relationship with MUC2 expression (P = 0.001), and was much higher in papillary-type than tubular-type CCA (P = 0.002).Conclusion These results imply that pERK1/2 may be important for the differentiation of tubular-type CCA, while CDX2 is related to the intestinal phenotype of papillary-type CCA.