Effect of different therapies of Chinese medicine on the expressions of c-Fos and c-Jun proteins in hippocampus of rats with post-stroke depression

BACKGROUND ： c-fos and c-jun, the important immediate early genes （IEG）, are regarded as the markers for the location and function of neuronal activity, as well as the third signal messengers, they couple the stress stimulation and the gene expression in neuron, and hippocampus is involved in the process of signal transmission after stress stimulation induced depression. OBJECTIVE： To observe the therapeutic effects of Bushen Yiqi （tonifying kidney to benefit qi）, Huoxue Huayu （promoting blood circulation to dissipate blood stasis） and Ditan Kaiqiao （eliminating phlegm for resuscitation） on the expressions of c-Fos and c-Jun proteins in hippocampus and spontaneous behaviors of rats with post-stroke depression （PSD）, and compare the results with those of fluoxetine, which is known to have definite effect on depression. DESIGN： A randomized controlled tna SETTING ： Zhejiang College of Traditional Chinese Medicine MATERIALS ： The trial was completed in Zhejiang College of Traditional Chinese Medicine from January to July in 2003. Fifty-six healthy adult Wistar male rats of clean grade, weighing （250±50） g, were randomly divided into 7 groups with 8 rats in each group： control group, model group, forced swimming group, Bushen Yiqi group; Huoxue Huayu, Ditan Kaiqiao group and fluoxetine group. The Bushen Yiqi Tang contained Renshen, Huangqi, Heshouwu, Gouqi, Shudi, etc., crude drugs 1 800 g/L. The Huoxue Huayu Tang contained Danshen, Chuanxiong, Chishao, Yujin, etc., crude drugs 3 600 g/L. The Ditan Kaiqiao Tang contained Banxia, Danxing, Changpu, Yuanzhi, etc., crude drug 1 000 g/b METHODS： ① Except the control group and forced swimming group, rats in the other groups were made into PSD models by deligating the bilateral common carotid artedes permanently. ② Rats in the control group, model group and forced swimming group were intragastncally perfused by saline （3 mL for each time）; those in the Bushen Yiqi group, Huoxue Huayu, Ditan Kaiqiao group and fluoxetine group were intragastncally perfused with Bushen Yiqi Tang （18 g/kg）, Huoxue Huayu Tang （9 g/kg）, Ditan Kaiqiao Tang （9 g/kg） and fluoxetine （2.5 mg/kg） respectively, once a day. ③ At 55 days after model establishment, rats in the forced swimming group were managed according to the Porsolt＇s method. They were placed in water for 15 minutes, and then taken out and dned, no moving-time within 5 minutes was recorded at drying and 24 hours after drying. ④ Measurement of spontaneous behaviors： Except the forced swimming group, the spontaneous behaviors and activities （including horizontal and vertical movements） of rats were observed with the Open-Field method at 28, 42 and 56 days after administration in the other groups. ⑤ The expressions of c-Fos and coJun proteins in hippocampus were determined with the immunohistochemical method, the relative sectional area ratio and average objective gray value of c-Fos and c-Jun positive cells in hip- pocampus were measured with the computerized image analytical system. MAIN OUTCOME MEASURES： The spontaneous behaviors of rats, the relative sectional area ratio and average objective gray value of c-Fos and c-Jun positive cells in hippocampus were observed. RESULTS： Of the 56 rats, 1 died in the forced swimming group, and finally 55 rats were involved in the analysis of results. ① Results of spontaneous activities： At 28 days, the times of crossing movements were obviously fewer in the model group and fluoxetine group [（69.00±37.01）, （98.11 ±36.68） times/3 minutes] than in the control group [（128.44±16.85） times/3 minutes, P 〈 0.01, 0.05], but those in the Bushen Yiqi group, Huoxue Quyu group and Ditan Kaiqiao group had no obvious differences as compared with those in the control group （P 〉 0.05）. At 42 and 56 days, the times of crossing movements were obviously more in the Bushen Yiqi group, Huoxue Quyu group and Ditan Kaiqiao group [（106.44±31.24）, （117.20±23.95）, （134.80±28.18）, （136.36±40.95） times/3 minutes; （117.33±35.91）, （129.60 ±23.78）, （131.90 ±26.81）, （136.09±28.34） times/3 minutes] than in the model group [（64.00±17.51）, （72.86±20.68） times/3 minutes, P 〈 0.01]. The times of rearing movements had no obvious differences among the groups for the three times （P 〉 0.05）. ② The no moving-time within 5 minutes 24 hours after drying was obviously longer than that at drying in the forced swimming group. ③ The average objective gray values of c-Fos positive cells were not obviously different in the Bushen Yiqi group and Ditan Kaiqiao group from the control group （P 〉 0.05）, but lower in the model group than in the control group （69.84±9.82, 75.78±5.89, P 〈 0.01）, and higher in the forced swimming group than in the control group （85.97±10.99, P 〈 0.01）; all higher in the fluoxetine group, Bushen Yiqi group, Huoxue Quyu group and Ditan Kaiqiao group than in the model group （81.27±10.73, 74.04±8.34, 83.29±9.89, 70.14±4.92, P 〈 0.05-0.01）. The average objective gray values of c-Jun positive cells were obviously lower in the Bushen Yiqi group than in the control group （68.11 ±6.89, 79.58±5.86, P 〈 0.01）, but all higher in the other groups than in the control group （84.68±7.15, 81.34 ±8.36, 97.51±10.55, 85.68±9.25, 86.19±10.98, P 〈 0.05-0.01）; Those were obviously higher in the fluoxetine group, Huoxue Quyu group and Ditan Kaiqiao group than in the model group （P 〈 0.05-0.01 ）, lower in the Bushen Yiqi group than in the model group （P 〈 0.05）, all obviously lower in the Bushen Yiqi group, Huoxue Quyu group and Ditan Kaiqiao group than in the fluoxetine group （P 〈 0.01）. The relative sectional area ratios of c-Fos and c-Jun positive cells had no obvious differences among the groups （P 〉 0.05）. CONCLUSION ： The methods of Bushen Yiqi, Huoxue Quyu and Ditan Kaiqiao can effectively treat PSD in rats, and the results were equivalent with those of fluoxetine, the actions of the above-mentioned drugs may correlated with their regulation to c-Fos and c-Jun expressions in hippocampus. PSD animal models can be successfully established by both permanent deligation of bilateral common carotid arteries and forced swimming, and the models induced by the former has similar basic cerebrovascular lesions as human stroke in clinic.

Specific effects of c-Jun NH2-terminal kinaseinteracting protein 1 in neuronal axons

c-Jun NH2-terminal kinase（JNK）-interacting protein 3 plays an important role in brain-derived neurotrophic factor/tropomyosin-related kinase B（Trk B） anterograde axonal transport. It remains unclear whether JNK-interacting protein 1 mediates similar effects, or whether JNK-interacting protein 1 affects the regulation of Trk B anterograde axonal transport. In this study, we isolated rat embryonic hippocampus and cultured hippocampal neurons in vitro. Coimmunoprecipitation results demonstrated that JNK-interacting protein 1 formed Trk B complexes in vitro and in vivo. Immunocytochemistry results showed that when JNK-interacting protein 1 was highly expressed, the distribution of Trk B gradually increased in axon terminals. However, the distribution of Trk B reduced in axon terminals after knocking out JNK-interacting protein 1. In addition, there were differences in distribution of Trk B after JNK-interacting protein 1 was knocked out compared with not. However, knockout of JNK-interacting protein 1 did not affect the distribution of Trk B in dendrites. These findings confirm that JNK-interacting protein 1 can interact with Trk B in neuronal cells, and can regulate the transport of Trk B in axons, but not in dendrites.

运动对c-Jun氨基末端激酶影响研究进展

c-Jun氨基末端激酶（c-Jun N-terminal kinase,JNK）家族是1990年被发现的丝裂原活化蛋白激酶（mito-gen-activated protein kinase,MAPK）超家族成员之一,涉及多种生理过程,在细胞分化、细胞凋亡、应激反应中起着至关重要的作用。JNK也参与了许多病理过程，可能介导了病理性心脏肥大反应、高血糖引起的血管内皮细胞凋亡、胰岛素抵抗、胰岛β细胞凋亡、神经萎缩和多种人类肿瘤的发生发展。JNK信号通路已成为近年来研究的热点。

JNK1,JNK2,and JNK3 are involved in P-glycoprotein-mediated multidrug resistance of hepatocellular carcinoma cells

BACKGROUND:Multidrug resistance(MDR)is extremely common in hepatocellular carcinoma(HCC)and is a major problem in cancer eradication by limiting the efficacy of chemotherapy.Modulation of c-Jun NH2-terminal kinase(JNK)activation could be a new method to reverse MDR.However,the relationship between JNK activity and MDR in HCC cells is unknown.This study aimed to explore the relationship between MDR and JNK in HCC cell lines with different degrees of MDR.METHODS:A MDR human HCC cell line,SMMC-7721/ ADM,was developed by exposing parental cells to gradually increasing concentrations of adriamycin.The MTT assay was used to determine drug sensitivity.Flow cytometry was used to analyze the cell cycle distribution and to measure the expression levels of P-glycoprotein(P-gp)and MDR-related protein(MRP)-1 in these cells.JNK1,JNK2 and JNK3 mRNA expression levels were quantified by real-time PCR.Expression and phosphorylation of JNK1,JNK2,and JNK3 were analyzed by Western blotting.RESULTS:The MDR of SMMC-7721/ADM cells resistant to 0.05 mg/L adriamycin was mainly attributed to the overexpression of P-gp but not MRP1.In addition,these cells had a significant increase in percentage in the S phase,accompanied by a decrease in percentage in the G0/G1 phase,which is likely associated with a reduced ability for cell proliferation and MDR generation.We found that JNK1,JNK2,and JNK3 activities were negatively correlated with the degree of MDR in HCC cells.CONCLUSION:This study suggests that JNK1,JNK2,and JNK3 activities are negatively correlated with the degree of MDR in HCC cells.

Ceramide from sphingomyelin hydrolysis differentially mediates mitogen-activated protein kinases (MAPKs) activation following cerebral ischemia in rat hippocampal CA1 subregion

Objective： To explore the role that ceramide plays in the activation of mitogen-activated protein kinases （MAPKs） during cerebral ischemia and reperfusion. Methods： Rats were subjected to ischemia by the fourvessel occlusion （4-VO） method. The sphingomyelinase inhibitor TPCK was administered to the CA1 subregion of the rat hippocampus before inducing ischemia. Western blot was used to examine the activity of extracellular- signal regulated kinase （ERK） and c-Jun N-terminal protein kinase （JNK） using antibodies against ERK, JNK and diphosphorylated ERK and JNK. Results： At lh reperfusion post-ischemia, JNK reached its peak activity while ERK was undergoing a sharp inactivation （P 〈 0.05）. The level of diphosphorylated JNK was significantly reduced but the sharp inactivation of ERK was visibly reversed （P 〈 0.05） by the sphingomyelinase inhibitor. Conclusion： The ceramide signaling pathway is up-regulated through sphingomyelin hydrolysis in brain ischemia, promoting JNK activation and suppressing ERK activation, culminating in the ischemic lesion.

Mitogen-activated protein kinase phosphatase 1 protects PC12 cells from amyloid beta-induced neurotoxicity

The mitogen-activated protein kinase（MAPK） signaling pathway plays an important role in the regulation of cell growth, proliferation, differentiation, transformation and death. Mitogen-activated protein kinase phosphatase 1（MKP1） has an inhibitory effect on the p38 MAPK and JNK pathways, but it is unknown whether it plays a role in Aβ-induced oxidative stress and neuronal inflammation. In this study, PC12 cells were infected with MKP1 sh RNA, MKP1 lentivirus or control lentivirus for 12 hours, and then treated with 0.1, 1, 10 or 100 μM amyloid beta 42（Aβ42）. The cell survival rate was measured using the cell counting kit-8 assay. MKP1, tumor necrosis factor-alpha（TNF-α） and interleukin-1β（IL-1β） m RNA expression levels were analyzed using quantitative real time-polymerase chain reaction. MKP1 and phospho-c-Jun N-terminal kinase（JNK） expression levels were assessed using western blot assay. Reactive oxygen species（ROS） levels were detected using 2′,7′-dichlorofluorescein diacetate. Mitochondrial membrane potential was measured using flow cytometry. Superoxide dismutase activity and malondialdehyde levels were evaluated using the colorimetric method. Lactate dehydrogenase activity was measured using a microplate reader. Caspase-3 expression levels were assessed by enzyme-linked immunosorbent assay. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase d UTP nick end labeling method. MKP1 overexpression inhibited Aβ-induced JNK phosphorylation and the increase in ROS levels. It also suppressed the Aβ-induced increase in TNF-α and IL-1β levels as well as apoptosis in PC12 cells. In contrast, MKP1 knockdown by RNA interference aggravated Aβ-induced oxidative stress, inflammation and cell damage in PC12 cells. Furthermore, the JNK-specific inhibitor SP600125 abolished this effect of MKP1 knockdown on Aβ-induced neurotoxicity. Collectively, these results show that MKP1 mitigates Aβ-induced apoptosis, oxidative stress and neuroinflammation by inhibiting the JNK signaling pathway, thereby playing a neuroprotective role.

Serine-threonine protein kinase activation may be an effective target for reducing neuronal apoptosis after spinal cord injury

The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, including extracellular signal-regulated kinase（ERK）, serine-threonine protein kinase（Akt） and c-Jun N-terminal kinase（JNK） signaling pathways. We established a rat model of acute spinal cord injury by inserting a catheter balloon in the left subclavian artery for 25 minutes. Rat models exhibited notable hindlimb dysfunction. Apoptotic cells were abundant in the anterior horn and central canal of the spinal cord. The number of apoptotic neurons was highest 48 hours post injury. The expression of phosphorylated Akt（pAkt） and phosphorylated ERK（p-ERK） increased immediately after reperfusion, peaked at 4 hours（p-Akt） or 2 hours（p-ERK）, decreased at 12 hours, and then increased at 24 hours. Phosphorylated JNK expression reduced after reperfusion, increased at 12 hours to near normal levels, and then showed a downward trend at 24 hours. Pearson linear correlation analysis also demonstrated that the number of apoptotic cells negatively correlated with p-Akt expression. These findings suggest that activation of Akt may be a key contributing factor in the delay of neuronal apoptosis after spinal cord ischemia, particularly at the stage of reperfusion, and thus may be a target for neuronal protection and reduction of neuronal apoptosis after spinal cord injury.

Potential roles of vitamin D binding protein in attenuating liver injury in sepsis

Background:In sepsis,vitamin D binding protein(VDBP)has been shown to be low-expressed.The current study examined the relationship between serum VDBP level and liver injury in sepsis patients,as well as in a mouse model for sepsis and in cultured liver epithelial cell line exposed to lipopolysaccharide(LPS).Methods:The human study included 78 sepsis patients and 50 healthy volunteers.Sepsis patients were categorized into sepsis survivor group(n=43)and sepsis non-survivor group(n=35)based on 28-day mortality for data analysis.Adult male C57BL/6 mice were subjected to cecal ligation and puncture(CLP).Serum samples were collected on day 1,3,5 and 7 to determine the levels of VDBP,25-hydroxyvitamin D[25(OH)D_(3)],1,25-dihydroxyvitamin D[1,25(OH)_(2)D_(3)],interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-α).Potential protective effects of VDBP overexpression against LPS-induced liver damage were examined in cultured THLE2 cells.Results:Serum levels of VDBP,25(OH)D_(3),and 1,25(OH)_(2)D_(3)were significantly lower in sepsis patients vs.the healthy control(P<0.001),as well as in the sepsis non-survivor group vs.the sepsis survivor group(P<0.001,P=0.0338,or P=0.0013,respectively).Lower serum VDBP level was associated with higher Acute Physiology and Chronic Health Evaluation(APACHE)II score(r=−0.2565,P=0.0234)and Sequential Organ Failure Assessment score(r=−0.3522,P=0.0016),but lower serum albumin(ALB,r=0.4628,P<0.001)and total protein(TP,r=0.263,P=0.02).In CLP mice,there was a 5-day period of serum VDBP reduction,followed by return towards the baseline on day 7.VDBP was also decreased in LPS-treated THLE2 cells(P<0.001).VDBP overexpression reduced LPS-induced THLE2 damage.Reduced damage was associated with decreased oxidative stress and inactivation of the c-Jun N-terminal kinase signaling pathway.Conclusion:VDBP may be protective against sepsis-induced liver injury.

Neuronal effects of SP600125 pretreatment in a rat model of cerebral ischemia/reperfusion injury Inhibited down-regulation of DNA repair protein

BACKGROUND： Recent studies have shown that the selective inhibitor of c-Jun N-terminal kinases （JNKs） signaling pathway, SP600125, exhibits neuronal protective effects in a rat model of brain ischemia/reperfusion. OBJECTIVE： To determine the mechanisms of neuroprotective effects of SP600125 in a rat model of brain ischemia/reperfusion, and determine the role of the JNK signaling pathway in SP600125-induced effects. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Animal Experiment Center, Medical School of Xi＇an Jiaotong University from June 2007 to September 2008. MATERIALS： SP600125 was provided by Biosource, USA; rabbit anti-phospho-JNK （Thr183/Tyr185） polyclonal antibody from Cell Signaling Technology, USA; rabbit anti-X-ray repair cross-complementing protein 1 （XRCC1） and anti-Ku70 polyclonal antibodies from Santa Cruz Biotechnology, USA; and TUNEL kit from Beijing Huamei Biology, China. METHODS： A total of 108 male, 4-month-old, Sprague Dawley rats were randomly assigned to three groups, with 36 rats per group. The sham operation group and ischemia/reperfusion group （I/R group） were intracerebroventricularly injected with 10 μL 1% DMSO. The SP600125-treated group （pre-SP group） was given 10 μL SP600125 （3 μg/μL）. Thirty minutes later, brain ischemia was induced in the I/R and pre-SP groups using the four-vessel occlusion method. Specifically, whole brain ischemia was induced for 6 minutes, and the clips were released to restore carotid artery blood flow. Rats from each group were observed at 2, 6, 12, 24, 48, and 72 hours, with 6 rats for each time point. The sham operation group was treated with the same surgical exposure procedures, with exception of occlusion of the carotid artery. MAIN OUTCOME MEASURES： Hematoxylin-eosin staining was used to observe neuronal survival in the hippocampal CA1 region, TUNEL was used to detect apoptosis in the hippocampal CA1 region, and immunohistochemistry was used to detect expression of phospho-JNK, XRCC1, and Ku70. RESULTS： Following brain ischemia/reperfusion, neuronal survival significantly decreased, and the number of apoptotic cells significantly increased （P 〈 0.01）. Compared with the I/R group, neuronal survival significantly increased in the pre-SP group, and the number of apoptotic cells significantly decreased （P 〈 0.01）. Expression of phospho-JNK increased, and XRCC1 and Ku70 significantly decreased （P 〈 0.05） following ischemia/reperfusion. Compared with the I/R group, expression of phospho-JNK decreased, and XRCC1 and Ku70 significantly increased in the pre-SP group （P 〈 0.05）. Correlation analysis revealed an inverse correlation between phospho-JNK gray value and XRCC1 and Ku70 gray values in the hippocampal CA1 region （r = -0.983, -0.953, P 〈 0.01）. CONCLUSION： SP600125 treatment decreased apoptosis induced by global brain ischemia/reperfusion in the rat hippocampal CA1 region. Results suggested that the neuroprotective effects were due to inhibited phosphorylation of JNK and reduced down-regulation of XRCC1 and Ku70.

c-Jun N-terminal kinase is required for thermotherapyinduced apoptosis in human gastric cancer cells

AIM:To investigate the role of c-Jun N-terminal kinase(JNK) in thermotherapy-induced apoptosis in human gastric cancer SGC-7901 cells.METHODS:Human gastric cancer SGC-7901 cells were cultured in vitro.Following thermotherapy at 43 ℃ for 0,0.5,1,2 or 3 h,the cells were cultured for a further 24 h with or without the JNK specific inhibitor,SP600125 for 2 h.Apoptosis was evaluated by immunohistochemistry [terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)] and flow cytometry(Annexin vs propidium iodide).Cell proliferation was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.The production of p-JNK,Bcl-2,Bax and caspase-3 proteins was evaluated by Western blotting.The expression of JNK at mRNA level was determined by reverse transcription polymerase chain reaction.RESULTS:The proliferation of gastric carcinoma SGC-7901 cells was significantly inhibited following thermotherapy,and was 32.7%,30.6%,43.8% and 52.9% at 0.5,1,2 and 3 h post-thermotherapy,respectively.Flow cytometry analysis revealed an increased population of SGC790l cells in G0/G1 phase,but a reduced population in S phase following thermotherapy for 1 or 2 h,compared to untreated cells(P < 0.05).The increased number of SGC-790l cells in G0/G1 phase was consistent with induced apoptosis(flow cytometry) following thermotherapy for 0.5,1,2 or 3 h,compared to the untreated group(46.5% ± 0.23%,39.9% ± 0.53%,56.6% ± 0.35% and 50.4% ± 0.29% vs 7.3% ± 0.10%,P < 0.01),respectively.This was supported by the TUNEL assay(48.2% ± 0.4%,40.1% ± 0.2%,61.2% ± 0.29% and 52.0% ± 0.42% vs 12.2% ± 0.22%,P < 0.01) respectively.More importantly,the expression of p-JNK protein and JNK mRNA levels were significantly higher at 0.5 h than at 0 h post-treatment(P < 0.01),and peaked at 2 h.A similar pattern was detected for Bax and caspase-3 proteins.Bcl-2 increased at 0.5 h,peaked at 1 h,and then decreased.Furthermore,the JNK specific inhibitor,SP600125,suppressed p-JNK,Bax and caspase-3 at the protein level in SGC790l cells following thermotherapy,compared to mock-inhibitor treatment,which was in line with the decreased rate of apoptosis.The expression of Bcl-2 was consistent with thermotherapy alone.CONCLUSION:Thermotherapy induced apoptosis in gastric cancer cells by promoting p-JNK at the mRNA and protein levels,and up-regulated the expression of Bax and caspase-3 proteins.Bcl-2 may play a protective role during thermotherapy.Activation of JNK via the Bax-caspase-3 pathway may be important in thermotherapy-induced apoptosis in gastric cancer cells.

Correlation between spina bifida manifesta in fetal rats and c-Jun N-terminal kinase signaling

Fetal rat models with neural tube defects were established by injection with retinoic acid at 10 days after conception. The immunofluorescence assay and western blot analysis showed that the number of caspase-3 positive cells in myeloid tissues for spina bifida manifesta was increased. There was also increased phosphorylation of c-Jun N-terminal kinase, a member of the mitogen activated protein kinase family. The c-Jun N-terminal kinase phosphorylation level was positively correlated with caspase-3 expression in myeloid tissues for spina bifida manifesta. Experimental findings indicate that abnormal apoptosis is involved in retinoic acid-induced dominant spina bifida formation in fetal rats, and may be associated with the c-Jun N-terminal kinase signal transduction pathway.

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.

Effect of Batroxobin on Expression of C-Jun in Left Temporal Ischemic Rats with Spatial Learning and Memory Disorder

The effect of Batroxobin on expression of c-Jun in left temporal ischemic rats with spatial memory disorder was investigated by means of Morri's water maze and immunohistochemistry methods. The results showed that the mean reaction time and distance of temporal ischemic rats for searching a goal were significantly longer than those of sham-operated rats, and at the same time c-Jun expression of left temporal ischemic region was significantly increased. However, the mean reaction time and distance of Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of c-Jun immune reactive cells of Batroxobin-treated rats was also less than that of ischemic group. In conclusion, Batroxobin can improve spatial memory disorder in temporal ischemic rats, and the down-regulation of the expression of c-Jun is probably related to the neuroprotective mechanism.

Heterodimer formation between c-Jun and Jun B proteins mediated by Epstein Barr virus encoded latent membrane protein 1

Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) may trigger the transcription factor AP-1 including c-Jun and c-fos. In this report, using a Tet-on LMP1 HNE2 cell line which is a dual-stable LMP1 integrated nasopharyngeal carcinoma (NPC) cell line and the expression of LMP1 in which could be regulated by the Tet-on system, we show that Jun B can efficiently form a new heterodimeric complex with the c-Jun protein under the regulation of LMP1, phosphorylation of c-Jun (ser 63, ser 73) and Jun B is involved in the process of the new heterodimeric formation. We also find that this heterodimeric form can bind to the AP-1 consensus sequence. Transfection studies suggest that JNK interaction protein (JIP) could inhibit the heterodimer formation of c-Jun and Jun B through blocking the AP-1 signaling pathway triggered by LMP1. The interaction and function between c-Jun protein and Jun B protein increase the repertoire of possible regulatory complexes by LMP1 that could play an important role in the regulation of transcription of specific cellular genes in the process of genesis of nasopharyngeal carcinoma.

内质网应激介导的细胞凋亡途径及新靶点药物

目的综述内质网应激介导的细胞凋亡信号转导途径,以及以各条途径中所涉及的关键酶为新靶点开发研制药物的进展情况。方法着重以近几年国外该领域有代表性的文献为依据,进行分析、归纳、总结。结果与结论Caspase,C/EBP homologous prote in(CHOP),Bc l-2,凋亡信号调节激酶(ASK1)等酶在内质网应激介导的细胞凋亡的信号转导途径中发挥着非常重要的作用,针对这些酶所设计的抑制剂或激活剂,可以抑制或促进细胞的凋亡,从而达到治疗相关疾病的目的。

程序性细胞死亡因子4在肿瘤及炎症中的交叉作用研究进展

肿瘤与炎症关系肿瘤与炎性关系密切，癌症的发生大约20％与慢性炎症有关［1］。感染引起的炎症反应作为宿主正常保护的一部分，主要目的是清除病原体，但是它也同时促进肿瘤的发生。致瘤性的病原体能够损坏宿主免疫使得低度而慢性的炎症持续存在。持续存在的慢性炎症能导致机体处于免疫失调及自身免疫性状态，最终促进肿瘤的发生。然而，肿瘤发生后也可引起炎症的产生。研究表明，有些肿瘤可以通过分泌一些急性分子来促进炎症的发生，这些肿瘤相关的炎症反应能被加入到肿瘤治疗行列。Michael Karin等做了大量癌症与炎症关系的研究，他们发现两者之间关系非常密切。在吸烟对肺肿瘤发生的研究中，他们发现，吸烟引起的肺部炎症导致细胞增殖增加是引起肺肿瘤发生的原因，在髓样细胞内IκB激酶β（IKKβ）的降低以及c-Jun N末端蛋白激酶1（c-Jun n-Terminal protein kinase 1，JNK1）的灭活都可降低肿瘤的发生［2］。同样，在饮食性和遗传性的肥胖引起肝癌的研究中，他们发现肥胖引起的肝癌是依赖于促肿瘤发生因子白介素6（IL-6）及肿瘤坏死因子（TNF）的大量产生，而这两种因子可以导致肝炎发生及促癌转录因子STAT 3的激活，由肥胖引起的慢性炎症反应以及IL-6及TNF的大量产生可能也增加其他癌症的发生危险［3］。多次研究发现，肿瘤微环境中存在的免疫细胞是肿瘤相关的巨噬细胞（TAMs ）和T细胞，这种肿瘤相关的巨噬细胞能促进肿瘤的增长，而且很可能是肿瘤血管生成、肿瘤浸润、转移所必需的［4］。而且，TAMs是细胞因子的重要来源［5］，因此，TAMs在肿瘤及炎症中发挥着重要作用。目前，对细胞因子信号进行药理学干预可以降低肿瘤的发生及增长［6］。因此，寻找肿瘤与炎症相关的分子进行干预很可能作为肿瘤预防和治疗的基本方法。

Let-7a gene knockdown protects against cerebral ischemia/reperfusion injury

The micro RNA（mi RNA） let-7 was one of the first mi RNAs to be discovered, and is highly conserved and widely expressed among species. let-7 expression increases in brain tissue after cerebral ischemia/reperfusion injury; however, no studies have reported let-7 effects on nerve injury after cerebral ischemia/reperfusion injury. To investigate the effects of let-7 gene knockdown on cerebral ischemia/reperfusion injury, we established a rat model of cerebral ischemia/reperfusion injury. Quantitative reverse transcription-polymerase chain reaction demonstrated that 12 hours after cerebral ischemia/reperfusion injury, let-7 expression was up-regulated, peaked at 24 hours, and was still higher than that in control rats after 72 hours. Let-7 gene knockdown in rats suppressed microglial activation and inflammatory factor release, reduced neuronal apoptosis and infarct volume in brain tissue after cerebral ischemia/reperfusion injury. Western blot assays and luciferase assays revealed that mitogen-activated protein kinase phosphatase-1（MKP1） is a direct target of let-7. Let-7 enhanced phosphorylated p38 mitogen-activated protein kinase（MAPK） and c-Jun N-terminal kinase（JNK） expression by down-regulating MKP1. These findings suggest that knockdown of let-7 inhibited the activation of p38 MAPK and JNK signaling pathways by up-regulating MKP1 expression, reduced apoptosis and the inflammatory reaction, and exerted a neuroprotective effect following cerebral ischemia/reperfusion injury.

Epstein-Barr virus-encoded latent membrane protein 1 modulates cyclin D1 by c-Jun/Jun B heterodimers

In our recent studies, we found that LMP1 encoded by Epstein-Barr virus could accelerate the formation of active c-Jun/Jun B heterodimer. We studied the regulation of cyclinD1 by c-Jun/Jun B heterodimers by laser scanning confocal influorescence microscopy, Western blot, luciferase activity assay, super-EMSA and flow cytometry in the Tet-on-LMP1 HNE2 cell line, in which LMP1 expression was regulated by Tet-on system. c-Jun/Jun B heterodimers induced by LMP1 could up regulate cyclin D1 promoter activity and expression. Overexpression of cy-clinD1 accelerated the progression of cell cycle.

Anti-parkinsonian effects of octacosanol in 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-treated mice

Our previous research showed that octacosanol exerted its protective effects in 6-hydroxydopamine-induced Parkinsonian rats. The goal of this study was to investigate whether octacosanol would attenuate neurotoxicity in 1-methyl-4-phenyl-l,2,3,6 tetrahydropyridine （MPTP）-treated C57BL/6N mice and its potential mechanism. Behavioral tests, tyrosine hydroxylase immunohistochemistry and western blot were used to investigate the effects of octacosanol in a mouse model of Parkinson＇s disease. Oral administration of octacosanol （100 mg/kg） significantly improved behavioral impairments Jn mice treated by MPTP and markedly ameliorated morphological appearances of tyrosine hydroxylase-positive neuronal cells in the substantia nigra. Furthermore, octacosanol blocked MPTP-induced phosphorylation of p38MAPK and JNK, but not ERK1/2. These findings implicated that the protective effects afforded by octacosanol might be mediated by blocking the phosphorylation of p38MAPK and JNK on the signa transduction in vivo. Considering its excellent tolerability, octacosanol might be considered as a candidate agent for clinical application in treating Parkinson＇s disease.