Repair impact of vibration exercise with different frequencies on articular cartilage of rats with early knee osteoarthritis and its JNK/NF-κB, SOX9 mechanisms / 中国应用生理学杂志

Objective: To investigate the repair effect and JNK/NF-κB,SOX9 mechanisms of vibration exercise with different frequencies on articular cartilage in rats with early knee osteoarthritis. Methods: Forty-eight adult male SD rats were randomly divided into six groups(n=8):model control group(MC),high frequency vibration group 1 (GP1,60 Hz),high frequency vibration 2 group (GP2,40 Hz),medium frequency vibration group (ZP,20 Hz),minor frequency group(DP,10 Hz)and normal control group(NC). Except for NC group,the rats in each group were made into early knee osteoarthritis model after six weeks of knee joint cavity injection of papain solution and 2% mixture l-cysteine on the 1st,4 th and 7th day. Each exercise group was subjected vibration to 40 minutes a day with amplitude of 2～5 mm and 5 days a week. Four weeks later, the articular cartilage of the lateral femoral condyle of the both back leg knee joints were detected by HE staining,serine O staining and Mankin scores for morphological observation. The expression levels of JNK,NF-κB p65 and Sox9 mRNA in articular cartilage of the medial femoral condyle were detected by RT-qPCR,and the protein expressions of JNK,NF-κB p65 and Sox9 were detected by Western blot. Results: Compared with the NC group,the Mankin score in other groups was significantly higher (P＜0.01). Compared with the MC group,the Mankin score of each vibration group was significantly lower(P＜0.05),the mRNA and protein expressions of JNK and NF-κB p65 in each vibration training group were significantly lower (P＜0.01),the expressions of Sox9 mRNA and protein in vibration training group were increased significantly (P＜0.01). Compared with the higher frequency group,the Mankin score,the mRNA and protein expressions of JNK and NF-κB p65 of lower frequency group were significantly lower (P＜0.05 or P＜0.01). But the expressions of Sox9 mRNA and protein were significantly higher (P＜ 0.05 or P＜0.01). Conclusion: Vibration exercise of different frequencies may present varying degrees of cartilage repair impact in rats with early knee osteoarthritis,and the cartilage repair by low-frequency vibration training is better than that by high-frequency vibration. This can be one of the mechanisms on controlling collagen synthesis by down-regulating JNK/NF-κB expression and increasing SOX9 activity of OA articular cartilage.

Mechanism of effective components of Mori Folium in alleviating insulin resistance based on JNK signaling pathway / 中国中药杂志

A stable hepatoma cell line(Hep G2 cell) insulin resistance model was established and used to analyze the effect of effective components of Mori Folium in alleviating insulin resistance,and preliminary explore the mechanism for alleviating insulin resistance. The Hep G2 insulin action concentration and the duration of action were investigated using the glucose oxidase method(GOD-POD method) to establish a stable Hep G2 insulin resistance model. Normal control group,model group,Mori Folium polysaccharide group,Mori Folium flavonoid group and rosiglitazone group were divided to determine the glucose consumption. The effect of Mori Folium effective components on Hep G2 insulin resistance was analyzed. The mRNA expressions of JNK,IRS-1 and PDX-1 in each group were detected by Real-time quantitative PCR(qRT-PCR). The protein expressions of p-JNK,IRS-1 and PDX-1 were detected by Western blot. And the mechanism of effective components of Mori Folium in alleviating insulin resistance was investigated. The results showed that the glucose consumption was significantly decreased in the insulin resistance cells after incubation with 25. 0 mg·L-1 insulin for 36 h(P<0. 01),and the model was relatively stable within 36 h. Mori Folium polysaccharides and flavonoids all alleviated insulin resistance,among which Mori Folium flavonoids had better effect in alleviating Hep G2 insulin resistance(P<0. 05). The qRT-PCR analysis showed that Mori Folium polysaccharides and flavonoids could inhibit JNK and IRS-1 mRNA expressions,while enhancing PDX-1 mRNA expression. Western blot analysis displayed that Mori Folium polysaccharides and flavonoids could inhibit p-JNK and IRS-1 protein expressions,while enhancing PDX-1 protein expression. Mori Folium polysaccharides and flavonoids can alleviate insulin resistance in Hep G2 cells,and its mechanism may be the alleviation of insulin resistance by inhibiting JNK signaling pathway.

Effects of ELK-1/JNK/c-Fos on apoptosis of rat hippocampal neurons cultured in vitro with Zuogui Jiangtang Jieyu Formula in simulated diabetes mellitus complicated with depression / 中国应用生理学杂志

OBJECTIVE@#To study the effects of Zuogui Jiangtang Jieyu Formula (ZGJTJYF, the Chinese Medicine) on hippocampal neuron apoptosis in diabetes mellitus complicated with depression (DD).@*METHODS@#The primary cultured hippocampal neurons were treated with high glucose (150 mmol/L) and corticosterone (200 micromol/L) to establish the cell model of DD in vitro. The cultured hippocampal neurons were randomly divided into five groups: blank serum group, normal group, Zuogui Jiangtang Jieyu recipe drug-containing serum group, positive drug (metformin + fluoxetine) drug-containing serum group and model group (three compound holes in each group). The model group and the normal group were given the same amount of culture medium, and the other groups were given the corresponding serum with 10% volume fraction for 18 hours. Hoechst staining, high content cell imaging and RT-PCR were used to detect the apoptosis of hippocampal neurons and the expressions of apoptosis-related ETS-like 1 transcription factor(ELK-1), C-Jun N-terminal kinase(JNK) and c-Fos proteins and genes.@*RESULTS@#Compared with the blank group, the apoptotic number of hippocampal neurons in the model group was increased significantly, and the expression levels of ELK-1, JNK and c-Fos were increased significantly (P＜0.05). Compared with the model group, the local bright spots of hippocampal neurons in the Zuogui Jiangtang Jieyu recipe-containing serum group and the positive drug-containing serum group were decreased significantly, and the number of apoptotic cells was decreased significantly. The expressions of JNK, c-fos protein and mRNA were down-regulated significantly (P＜ 0.05), and the neural network and dendritic junction were improved significantly.@*CONCLUSION@#Zuo Gui Jiang Tang Jie Yu Formula can reverse the expressions of ELK-1, JNK and c-Fos signals in hippocampal neurons under DD environment and play an anti-apoptotic effect.

Notum attenuates HBV-related liver fibrosis through inhibiting Wnt 5a mediated non-canonical pathways

BACKGROUND: Non-canonical Wnt pathways play important roles in liver fibrosis. Notum is a newly discovered inhibitor to Wnt proteins. This study was to investigate anti-fibrotic effects of Notum. METHODS: 53 patients with hepatitis B virus (HBV) infection as well as a cell co-culture system of LX-2 and Hep AD38 cells were engaged in this study. Clinical, biological and virological data of each patient were analyzed. Cell viability was detected at different time points. mRNA and protein levels of NFATc1 (Nuclear factor of activated T-cells), Jnk, α-SMA, Col1A1 and TIMP-1 were detected both in LX-2 and liver tissue. Protein levels of NFATc1 and Jnk in liver tissue and their correlations with fibrosis score were analyzed. RESULTS: Hepatitis B virus replication up-regulated Wnt5a induced NFATc1 and Jnk activity in Hep AD38. Notum suppressed NFATc1, Jnk and fibrosis genes expression, reduced cell viability in co-cultured LX-2 cells induced by HBV. Interestingly, Patients with HBV DNA > 5log copies/ml had higher mRNA levels of NFATc1 and fibrosis genes than patients with HBV DNA < 5log copies/ml. Most importantly, protein expressions of NFATc1 and pJnk have positive correlations with liver fibrosis scores in HBV-infected patients. CONCLUSIONS: Our data showed that Notum inhibited HBV-induced liver fibrosis through down-regulating Wnt 5a mediated non-canonical pathways. This study shed light on anti-fibrotic treatment.

Effects of excessive endoplasmic reticulum stress on lung ischemia/reperfusion induced myocardial injury in mice / 中国应用生理学杂志

OBJECTIVE@#To investigate the effects of excessive endoplasmic reticulum stress on lung ischemia/reperfusion (I/R) induced myocardial injury in mice.@*METHODS@#Forty healthy SPF male C57BL/6J mice were divided into 4 groups randomly (=10):sham operation group (Sham group), lung I/R group (I/R group), endoplasmic reticulum stress (ERS) pathway agonist Tunicamycin group (TM) and ERS inhibitor 4-phenyl butyric acid group (4-PBA). The model of lung I/R injury was established by clamping the left hilum of lung for 30 min followed by 180 min of reperfusion. In sham group, only sternotomy was performed, the hilum of lung was not clamped, and the mice were mechanically ventilated for 210 min. In TM and 4-PBA groups, TM 1mg/kg and 4-PBA 400 mg/kg were injected intraperitoneally, respectively, at 30 min before establishment of the model. At 180 min of reperfusion, blood samples were collected from the orbit for determination of myocardial enzyme. The animals were then sacrificed, and hearts were removed for determination of light microscope, TUNEL, Caspase 3 enzymatic activity, real-time polymerase chain reaction and Western blot.@*RESULTS@#Compared with sham group, the cardiomyocytes had obvious damage under light microscope, and the serum creatine kinase-MB (CK-MB) and lactic dehydrogenase (LDH) activities, apoptosis index and Caspase 3 enzymatic activity were increased significantly, the expressions of p-Jun N-terminalkinase(p-JNK), Caspase 12, CCAAT/enhancer-binding protein homologous protein (CHOP) and glucose regulated protein 78(GRP78) protein and mRNA were up-regulated in I/R, TM and 4-PBA groups (<0.01). Compared with I/R group, the cardiomyocytes damage was obvious under light microscope, and the serum CK-MB and LDH activities, apoptosis index and Caspase 3 enzymatic activity were increased significantly, the expressions of p-JNK, Caspase 12, CHOP and GRP78 protein and mRNA were up-regulated in group TM; while all above changes were relieved in group 4-PBA (<0.01). Compared with TM group, the cardiomyocytes damage was relieved under light microscope, and the serum CK-MB and LDH activities, apoptosis index and Caspase 3 enzymatic activity were decreased significantly, the expressions of p-JNK, Caspase 12,CHOP and GRP78 protein and mRNA were down-regulated in group 4-PBA.@*CONCLUSIONS@#The excessive endoplasmic reticulum stress participates in myocardial injury induced by lung ischemia/reperfusion (I/R) and inhibit excessive endoplasmic reticulum stress response can relieved myocardial injury.

Role of Jun amino-terminal kinase (JNK) in apoptosis of cavernosal tissue during acute phase after cavernosal nerve injury / 亚洲男科学杂志(英文版)

The present study aimed to identify which mitogen-activated protein kinase (p38 or Jun amino-terminal kinase [JNK]) was involved in cavernosal apoptosis during the acute phase after cavernosal nerve crush injury (CNCI) in rats to ameliorate apoptosis of cavernosal tissue, such as smooth muscle (SM). A total of twenty 10-week-old male Sprague-Dawley rats were divided equally into two groups: sham surgery (S) and CNCI (I). The I group approximated the clinical situation of men undergoing radical prostatectomy using two 60-second compressions of both CNs with a microsurgical vascular clamp. At 2-week postinjury, erectile response was assessed using electrostimulation. Penile tissues were harvested for immunohistochemistry analysis of alpha-SM actin (α-SMA), western blot analysis, and double immunofluorescence analysis of α-SMA and phosphorylated p38 or JNK, as well as double immunofluorescent of TUNEL and phosphorylated p38 or JNK. At 2-week postinjury, the I group had a significantly lower intracavernous pressure (ICP)/mean arterial pressure (MAP) and a lower area under the curve (AUC)/MAP than the S group. The I group also exhibited decreased immunohistochemical staining of α-SMA, an increase in the number of SM cells positive for phosphorylated JNK, an increased number of apoptotic cells positive for phosphorylated JNK, and increased JNK phosphorylation compared with the S group. However, there was no significant difference in p38 phosphorylation expression or the number of SM cells positive for phosphorylated p38 between the two groups. In conclusion, our data suggest that JNK, not p38, is involved in cavernosal apoptosis during the acute phase after partial CN damage.

Analyses of exercise-induced muscle damage-specific microRNA expression and molecular target of sarcolemmal damage in rats / 生理学报

In the present study, we were to screen the specific microRNA (miRNA) of exercise-induced muscle damage (EIMD) and assess the EIMD-specific miRNAs-regulated target of sarcolemmal damage in rats. Twenty-four male Sprague-Dawley (SD) rats were randomly divided into 3 groups, which included sedentary (C), 24 h post-exercise (E24) and 48 h post-exercise (E48) groups. Rat EIMD model was established by an acute eccentric exercise, i.e., a downhill running treatment at -16º gradient. EIMD characteristics were verified by Evans blue dye staining, differentially expressed miRNAs were detected by microarray assay, EIMD-specific miRNAs expressions were further validated by real-time quantitative RT-PCR (RT-qPCR), and targets of the miRNAs were predicted based on mRNA expressions of associated proteins and related pathway core molecules of sarcolemmal damage. Two EIMD-specific expressed miRNAs, including miR-206-3p and miR-139-3p, were found in the study. There was a significantly negative correlation (P < 0.05) between miR-206-3p expression and dystrophin (r = -0.68), utrophin (r = -0.64), JNK (r = -0.62) or ERK1 (r = -0.68) respectively, but no correlation was found between miR-139-3p and these biomolecules. The results suggest that: i) the expression profile of miRNAs in rat is significantly affected by EIMD, ii) miR-206-3p and miR-139-3p are the EIMD-specific miRNAs, and iii) miR-206-3p may control sarcolemmal damage by regulating dystrophin, utrophin, JNK and ERK1.

Association between MKK4 promoter-1304T/G polymorphism and genetic susceptibility in sporadic nasopharyngeal carcinoma / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the association between-1304T/G polymorphism in the promoter of MKK4 gene and the susceptibility in sporadic nasopharyngeal carcinoma.@*METHOD@#MKK4-1304T/G genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 90 NPC cases and 30 healthy controls.@*RESULT@#The number of nasopharyngeal carcinoma patients carrying with TG+GG genotype was much higher than those of controls (82.2% vs 66.7%, χ² =10.076, P < 0.05). Analysis showed that compared with the-1304TT genotype, -1304TG heterozygous reduced risk of nasopharyngeal carcinoma 0.56 fold (95% CI = 0.164-1.178, P < 0.01) and-1304GG lower 0.58 fold (95% CI = 0.126-1.381, P < 0.01), TG+ GG genotype variation risk of nasopharyngeal carcinoma decreased 0.72 fold (95% CI = 0.105-0.753, P < 0.01).@*CONCLUSION@#MKK4 gene-1304TG genotype can reduce risk of nasopharyngeal carcinoma, and it may be an independent protection factor in sporadic nasopharyngeal carcinoma.

Coexpression of MAP2K4 and vimentin proteins in human endometrial carcinoma and its clinicopathological significance / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the expression of MAP2K4 and vimentin in human endometrial carcinoma (EC) and their association with the clinicopathological features and prognosis of the patients.</p><p><b>METHODS</b>MAP2K4 and vimentin expressions were detected immunohistochemically in paraffin-embedded tissue sections from 128 patients with EC, and the correlation of MAP2K4 and vimentin expressions with the clinicopathological factors of the patients was analyzed.</p><p><b>RESULTS</b>MAP2K4 and vimentin proteins were positively expressed in 49 (38.3%) and 83 (64.8%) of the patients, respectively. A positive expression of MAP2K4 was negatively correlated with FIGO stage of the tumor (P=0.010) and lymph node status (P=0.016); a positive expression of vimentin was positively correlated with FIGO stage of the tumor (P=0.025), histological grades (P=0.017), depth of myometrial invasion (P=0.044) and lymph node status (P=0.032). MAP2K4 was inversely associated with vimentin expression in EC(r=-0.598, P<0.001). Patients positive for MAP2K4 tended to have a higher overall survival rate (P=0.002), and those positive for vimentin tended to have a lower overall survival rate (P=0.007); patients positive for MAP2K4 but negative for vimentin had the longest survival time, while those negative for MAP2K4 and positive for vimentin had lowest survival rate (P=0.004).</p><p><b>CONCLUSION</b>Detection of MAP2K4 and vimentin might help in early diagnosis and prognostic evaluation of patients with EC.</p>

Expressions of MAP2K4 and estrogen receptor and their clinical significance in invasive breast cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the association of mitogen-activated protein kinase kinase-4 (MAP2K4) with the pathological features, prognosis and expression of estrogen receptor (ER) in patients with breast cancer.</p><p><b>METHODS</b>The expression of MAP2K4 was detected immunohistochemically in 102 breast cancer tissues. Chi square test was used to analyze the correlation of MAP2K4 expression with the clinicopathological features of the patients. Kaplan-Meier and log rank test were used for survival analysis of the patients. Multivariate survival analysis was performed using Cox proportional hazard regression model. The correlation between the expressionsof MAP2K4 and ER was investigated using Spearman rank correlation test.</p><p><b>RESULTS</b>Immunohistochemical analysis revealed low MAP2K4 expression in 55.9%(57/102) and high MAP2K4 expression in 44.1%(45/102) of the breast cancer tissues. The expression of MAP2K4 was significantly correlated with the pathological grades of breast cancer (P=0.011). Kaplan-Meier survival analysis showed that patients with a high expression of MAP2K4 had a shorter overall survival rate than those with low MAP2K4 expressions (P=0.009). Multivariate analysis identified high expression of MAP2K4 as the independent predictor of a poor outcome of patients with breast cancer. The expressions of MAP2K4 and ER were not significantly correlated, but ER-negative patients with a high MAP2K4 expressionshowed the shortest overall survival time.</p><p><b>CONCLUSION</b>Overexpression of MAP2K4 promotes the progression in breast cancer and is associated with a poor outcome of the patients. TheER-negativepatients with a high MAP2K4 expression have the shortest overall survival time, suggestingthe value of combined examination of MAP2K4 and ER in accurate estimation of the prognosis of breast cancer patients.</p>

27-O-(E)-p-coumaric acyl ursolic acid via JNK/SAPK signal pathway regulates apoptosis of human breast cancer MDA-MB-231 cell line / 中国中药杂志

27-O-(E)-p-coumaric acyl ursolic acid( DY-17) from Ilex latifolia is a compound of the monomer. To investigate the DY-17 inducing apoptosis in the human breast cancer cell line, the MDA-MB-231 cells were used as research object in this experiment. The proliferation activity of the MDA-MB-231 cells stimulated with the different concentrations of DY-17 (20, 40 µmol · L(-1)) was detected at different time( 12, 24, 36, 48, 60,72 h) . We surveyed the DY-17 inducing apoptosis of the MDA-MB-231 cells with the fluorescent staining technology. The rate of MDA-MB-231 cells apoptosis and necrosis was determined by flow cell cytometry (FCC). Moreover, expression of JNK, phosphorylated JNK, Bax, PARP shear and caspase-3 shear related to JNK/SAPK pathways were investigated in every group ( control group, EGF group, EGF + DY-17 40 µmol · L(1) group and EGF + SP600125 group) with Western blot. The MTT results showed that, in the presence of DY-17, the proliferation activity of MDA-MB-231 cells decreased in a dose-dependent and time-dependent manner. The apoptosis and necrosis rates of MDA-MB-231 cells with DY-17(20, 40 µmol · L(-1)) groups was respectively 31.86%, 49.91% by flow cytometry and significantly increased compared with control group under Fluores- cence microscopy. Up-regulation of the JNK phosphorylation protein expression was observed in EGF group compared with control group. In addition, markedly decreased the expression of JNK phosphorylation protein were also surveyed in EGF + DY-17 40 µmol · L(-1) group compared with EGF group. The expression of Bax, shear PARP and shear caspase-3 protein in EGF + DY-17 40 µmol · L(-1) group were significantly increased in comparison with EGF group. The results showed DY-17 induced apoptosis of human breast cancer MDA-MB-231 cell line related to down-regulating JNK/SAPK signal pathways.

Common variants in PERK, JNK, BIP and XBP1 genes are associated with the risk of prediabetes or diabetes-related phenotypes in a Chinese population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Prediabetes is an early stage of β-cell dysfunction presenting as insulin resistance. Evidences suggest that endoplasmic reticulum (ER) stress is involved in the pathogenesis of type 2 diabetes mellitus and prediabetes. In a Chinese population with prediabetes, we investigated single nucleotide polymorphisms (SNPs) in the genes of PERK, JNK, XBP1, BIP and CHOP which encode molecular proteins involved in ER stress pathways.</p><p><b>METHODS</b>Nine SNPs at the PERK, JNK, XBP1, BIP and CHOP loci were genotyped by mass spectrometry in 1 448 unrelated individuals. By using a 75 g oral glucose tolerance test (OGTT), 828 subjects were diagnosed as prediabetes and 620 subjects aged 55 years and over as normal controls based on WHO diagnostic criteria (1999) for diabetes mellitus.</p><p><b>RESULTS</b>The allele C of SNP rs867529 at PERK locus was a risk factor for prediabetes, with the carriers of C allele genotype at a higher risk of prediabetes compared to non-carriers (OR = 1.279, 95% CI: 1.013-1.614, P = 0.039, after adjustment for age, sex and body mass index (BMI). The SNPs rs6750998 at PERK locus was associated with homeostasis model assessments of insulin resistance (HOMA-IR) (P = 0.019), and rs17037621 with BMI (P = 0.044). The allele G of SNP rs10986663 in BIP gene was associated with a decreased risk of prediabetes (OR = 0.699, 95% CI: 0.539-0.907, P = 0.007). The SNP rs2076431 in JNK gene was associated with fasting plasma glucose levels (P = 0.006) and waist-hip ratios (P = 0.019). The SNP rs2239815 in XBP1 gene was associated with 2-hour plasma glucose levels after 75 g oral glucose load (P = 0.048) in the observed population.</p><p><b>CONCLUSION</b>Common variants at PERK and BIP loci contributed to the risk of prediabetes, and the genetic variations in JNK and XBP1 genes are associated with diabetes-related clinical parameters in this Chinese population.</p>

Withaferin A-Caused Production of Intracellular Reactive Oxygen Species Modulates Apoptosis via PI3K/Akt and JNKinase in Rabbit Articular Chondrocytes

Withaferin A (WFA) is known as a constituent of Ayurvedic medicinal plant, Withania somnifera, and has been used for thousands of years. Although WFA has been used for the treatment of osteoarthritis (OA) and has a wide range of biochemical and pharmacologic activities, there are no findings suggesting its properties on chondrocytes or cartilage. The aim of the present study is to investigate the effects of WFA on apoptosis with focus on generation of intracellular reactive oxygen species (ROS). Here we showed that WFA significantly increased the generation of intracellular ROS in a dose-dependent manner. We also determined that WFA markedly leads to apoptosis as evidenced by accumulation of p53 by Western blot analysis. N-Acetyl-L-Cystein (NAC), an antioxidant, prevented WFA-caused expression of p53 and inhibited apoptosis of chondrocytes. We also found that WFA causes the activation of PI3K/Akt and JNKinase. Inhibition of PI3K/Akt and JNKinase with LY294002 (LY)/triciribine (TB) or SP600125 (SP) in WFA-treated cells reduced accumulation of p53 and inhibited fragmented DNA. Our findings suggested that apoptosis caused by WFA-induced intracellular ROS generation is regulated through PI3K/Akt and JNKinase in rabbit articular chondrocytes.

Effect of JNK signal transduction pathway in intense noise-induced apoptosis of vestibular hair cells in guinea pigs / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of intense noise-induced apoptosis of vestibular hair cells in guinea pigs and the effect of phosphorylated c-Jun N-terminal kinase (JNK) signal transduction pathway in intense noise-induced apoptosis of vestibular hair cells.</p><p><b>METHODS</b>Thirty-two guinea pigs were randomly and equally divided into 1, 5, and 15 d experimental groups and control group. The guinea pigs in the experimental groups were exposed to 4 kHz narrow-band noise at 120 dB SPL for 4 h and then subjected to measurement of auditory brainstem response at 1, 5, or 15 d after noise exposure. In each group, four guinea pigs were used to prepare paraffin sections of vestibular hair cells, and the rest for extraction of total protein from vestibular hair cells. The apoptosis of vestibular hair cells was detected by terminal deoxynucleotidyl transferase (TdT)-mediated d-UTP nick-end labeling (TUNEL). The expression levels of p-JNK and pc-Jun were measured by immunohistochemistry and Western blot.</p><p><b>RESULTS</b>TUNEL-positive cells were found in the vestibular hair cells in the experimental groups, most in the 1 d experimental group and least in the 15 d experimental group, but no positive cells were found in the control group. The immunohistochemical results showed that p-JNK and pc-Jun were detected in the cell nuclei in the experimental groups, but no p-JNK- and pc-Jun-positive cells were found in the control group. The Western blot showed that p-JNK and pc-Jun were increased and activated quickly at 1d after noise exposure, reached the peak levels at 5 d after noise exposure, and were then decreased gradually, but they were still at relatively high levels at 15 d after noise exposure.</p><p><b>CONCLUSION</b>Intense noise can cause injury to vestibular hair cells by inducing cell apoptosis, and p-JNK marks the activation of JNK signal transduction pathway, suggesting that JNK signal transduction pathway plays an important role in intense noise-induced apoptosis of vestibular hair cells in guinea pigs.</p>

The role of JNK in apoptosis of renal tubular epithelial cells in diabetic rats with fluctuant high blood glucose / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the signal transduction mechanisms of apoptosis in renal tubular epithelial cells in diabetic rats with fluctuant high blood glucose.</p><p><b>METHODS</b>Healthy SD rats were randomly divided into 3 groups: normal control group (A), stable high blood glucose group (B) and fluctuant high blood glucose group (C). Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg), and the fluctuant high blood glucose animal model was induced by intraperitoneal injection of ordinary insulin and glucose at different time point every day. The superoxide dismutase (SOD) activity and the content of malonaldehyde (MDA) in renal tissue homogenate were detected with colorimetry. The protein expression of Nox4 and JNK were examined by immunohistochemistry and Western blot. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL).</p><p><b>RESULTS</b>After 12 experimental weeks, significantly increased cell apoptosis, up-regulation of Nox4 and P-JNK expression in renal tubular epithelial cells were observed in B and C groups compared with those in A group. The MDA content increased and SOD activity decreased in renal tissue in B and C groups. Above effects were more obviously shown in C group.</p><p><b>CONCLUSION</b>Fluctuant high blood glucose induced more apoptosis of renal tubular epithelial cell than stable high blood glucose in diabetic kidney, which might be related to the activation of JNK signal transduction pathway.</p>

The relationship between expression of mitogen-activated protein kinase kinase 4 and metastasis in oral squamous cell carcinoma / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the correlation between expression of mitogen-activated protein kinase kinase 4 (MKK4) and metastasis of oral squamous cell carcinoma (OSCC).</p><p><b>METHODS</b>Expression levels of MKK4 mRNA and protein were examined in surgically resected oral squamous cell carcinoma specimens and corresponding lymph nodes by semi-quantitative reverse Transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry.</p><p><b>RESULTS</b>The expression of MKK4 in 48 cases of metastasis of lymph node group was significantly higher than 27 cases of without metastasis of lymph node group in 75 cases of paraffin-embedded OSCC samples (P < 0.05). The expression of MKK4 in 48 cases of metastatic lymph node lesions was higher than 48 cases of primary site of OSCC (P < 0.05). There was no correlation between the expression of MKK4 and primary site, size of tumor, histological grade ( P > 0.05). The expression of MKK4 mRNA in 16 cases of metastasis of lymph node group was significantly higher than 22 cases of without metastasis of lymph node group in 38 cases of fresh OSCC samples (P < 0.01). The expression of MKK4 in 6 cases of matched metastatic lymph node lesions was higher than 16 cases of primary tumour (P < 0.05)</p><p><b>CONCLUSION</b>The up-regulation of MKK4 protein and mRNA may be related with the invasion and metastasis of OSCC. MKK4 maybe played a promoting role in the progression and metastasis of OSCC.</p>

Effect of sphingosine kinase 1 on the apoptosis, migration and invasion of colon cancer HT-29 cells and its molecular mechanisms / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect of sphingosine kinase 1 (SphK1) on the proliferation, apoptosis, migration and invasion of colon cancer TH-29 cells and to explore its molecular mechanisms.</p><p><b>METHODS</b>Phorbol 12-myristate 13-acetate (PMA) was used to induce the activity of SphK1 and N, N-dimethylsphingosine (DMS) was used to suppress the activity of SphK1. Cell prolieration and apoptosis were detected by MTT assay and flow cytometry, respectively. The migration and invasion capabilities of the cells were assessed in Transwell chambers. The activity of SphK1 was assayed by autoradiography. Western blot was used to evaluate the protein expression of SphK1, p38, phosphorylated p38 (p-p38) and SAPK/JNK.</p><p><b>RESULTS</b>PMA and DMS were able to induce and suppress the activity and protein expression of SphK1 in a time-dependent manner, respectively. PMA enhanced and DMS suppressed the cell viability in a time- and dose-dependent manner. Being treated with 100 nmol/L PMA or 50 µmol/L DMS for 0, 6, 12, 24 h, the cell apoptosis rates of PMA group were (9.35 ± 0.84)%, (7.61 ± 0.48)%, (5.53 ± 0.76)% and (0.56 ± 0.33)%, contrastly, that of DMS group were (9.18 ± 0.94)%, (12.06 ± 1.41)%, (19.80 ± 2.36)% and (31.85 ± 3.60)%, respectively. Compared with the control group, the cell migration and invasion capabilities of the PMA group were significantly enhanced, and that of the DMS group were significantly suppressed. The migration cell number of control, PMA and DMS groups were 68.75 ± 6.15, 109.33 ± 11.63 and 10.83 ± 2.48, the invasion cell number of control, PMA and DMS groups were 55.42 ± 4.50, 90.58 ± 7.06 and 9.58 ± 2.39, respectively. With the elevating activity and expression of SphK1, the protein expressions of p38, p-p38 and SAPK/JNK were strikingly suppressed. On the contrary, after treating with DMS the protein expressions of p38, p-p38 and SAPK/JNK were enhanced.</p><p><b>CONCLUSIONS</b>SphK1 potently enhances the prolieration, migration and invasion of colon cancer HT-29 cells, meanwhile suppresses the cell apoptosis. The suppressing of the p38 and SAPK/JNK signalling pathways may be one of its molecular mechanisms.</p>

Effect of danshensu on JNK and NF-kappaB signal transduction of rat hepatic stellate cells induced by interleukin-1beta / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of danshensu on c-Jun N-terminal kinase (JNK) and nuclear factor-kappa B (NF-kappaB) signaling in activated rat hepatic stellate cells (HSCs) and explore the mechanisms of danshensu for inhibiting hepatic fibrosis.</p><p><b>METHODS</b>MTT colorimetric assay was used to detect the proliferation of rat HSCs treated with danshensu, and the apoptosis of the cells was analyzed with Annexin- V-FITC/PI and AO/EB staining. The expressions of P-IkappaB-alpha, NF-kappaBP65 and JNK in HSCs stimulated by IL-1beta with subsequent danshensu treatment were observed by Western blotting. Type III collagen in the medium of HSCs was detected by ELISA and immunocytochemistry.</p><p><b>RESULTS AND CONCLUSIONS</b>Danshensu inhibited the activation and proliferation of HSCs, and increased the apoptotic rate of HSCs and reduced the synthesis and secretion of type III collagen. Danshensu showed obvious inhibitory effect on JNK and P-IkappaB-alpha phosphorylation and NF-kappaBP65 expression in HSCs stimulated by IL-1beta. The mechanism of the actions of dansgensu may be mediated by inhibition of JNK and NF-kappaB signal transduction.</p>

Effect of staurosporine induced apoptosis of MCF7/GFP-Bax stable cell line on Bax translocation from cytosol into mitochondria / 药学学报

To investigate Bax translocation from cytosol into mitochondria induced by staurosporine (STS) in GFP-Bax-tagged MCF7 stable cell line, the viability was measured by MTT method. Bax translocation from cytosol into mitochondria was investigated under the fluorescence microscope. The dose-effect and time-course relationships were also observed and the percentage of GFP-Bax punctuate cells were calculated. Immunofluoresence method was used to observe Bax translocation to mitochondria, Cyt-c release from mitochondria and Annexin V label. The TMRE assay was used to investigate membrane pertential (Deltapsim) and function of mitochondria. Western blotting was used to observe the mechanism of apoptosis induced by STS. The results showed that STS can induce Bax translocation from cytoplasm to mitochondria, Cyt-c release from mitochondria and Annexin V label. The Western blotting analysis presented the inhibitory effect on apoptosis induced by STS of SP600125 which is a specific JNK inhibitor. The study revealed the mechanism of STS induced apoptosis associated with JNK activated pathway.

Cytosolic accumulation of gammaH2AX is associated with tropomyosin-related kinase A-induced cell death in U2OS cells

Tropomyosin-related kinase A (TrkA) plays an important role in cell survival, differentiation, and apoptosis in various neuronal and nonneuronal cell types. Here we show that TrkA overexpression by the Tet-On system mimics NGF-mediated activation pathways in the absence of nerve growth factor (NGF) stimulation in U2OS cells. In addition, p53 upregulation upon DNA damage was inhibited by TrkA, and p21 was upregulated by TrkA in a p53-independent manner. TrkA overexpression caused cell death by interrupting cell cycle progression, and TrkA-induced cell death was diminished in the presence of its specific inhibitor GW441756. Interestingly, TrkA-mediated cell death was strongly related to gammaH2AX production and poly (ADP-ribose) polymerase cleavage in the absence of DNA damage inducer. In this study, we also reveal thatgammagammaH2AX production by TrkA is blocked by TrkA kinase inhibitors K-252a and GW441756, and it is also significantly inhibited by JNK inhibitor SP600125. Moreover, reduction of cell viability by TrkA was strongly suppressed by SP600125 treatment, suggesting a critical role of JNK in TrkA-induced cell death. We also found that gammaH2AX and TrkA were colocalized in cytosol in the absence of DNA damage, and the nuclear localization of gammaH2AX induced by DNA damage was partly altered to cytosol by TrkA overexpression. Our results suggest that the abnormal cytosolic accumulation of gammaH2AX is implicated in TrkA-induced cell death in the absence of DNA damage.