Expression and functional analyses of the mitogen-activated protein kinase (MPK) cascade genes in response to phytohormones in wheat ( Triticum aestivum L.)

Mitogen-activated protein kinase （MPK） cascades consist of a set of kinase types （MPKKKs, MPKKs, MPKs） to establish conserved signal-transducing modules mediating plant growth, development as well as responses to internal and external cues. In this study, the expression patterns of six MPKKK, two MPKK, and 11 MPK genes in wheat in responses to external treatments of phytohormones, including naphthylacetic acid （NAA）, abscisic acid （ABA）, 6-benzyladenine （6-BA）, gibber- ellin （GA3）, salisylic acid （SA）, jasmonic acid （JA）, and ethylene （ETH）, were investigated. Expression analysis revealed that several of the MPK cascade genes are responses to the external phytohormone signaling. Of which, TaMPKKKA;3 is induced by 6-BA and NAA while TaMPK4 repressed by ETH, GA3, SA, and JA; TaMPKKKA, TaMPKKKA;3 and TaMPK1 are down-regulated by ETH and GA3whereas TaMPK9 and TaMPK12 repressed by ETH and JA in addition that TaMPK12 also repressed by GA3; TaMPK12;1 is down-regulated by ABA, GA3 and SA while TaMPK17 repressed by all exogenous phytonormones examined. TaMPK4, a MPK type gene previously characterized to mediate tolerance to phosphate （Pi） deprivation, was functionally evaluated for its role in mediation of responses of plants to exogenous GA3, ETH, SA, and JA. Results indicated that overexpression and antisense expression of TaMPK4 in tobacco dramatically modify the growth of seedlings upon treatments of GA3, SA and JA, in which the overexpressors behaved deteriorated growth feature whereas the seedlings with antisense expression of TaMPK4 exhibited improved seedling phenotype. The growth behaviors in lines overexpressing or antisensely expressing TaMPK4 are closely associated with the biomass and the corresponding hormone-associated parameters. These results demonstrated that TaMPK4 acts as a critical player in mediating the phyto- hormone signaling. Our findings have identified the phytohormone-responsive MPK cascade genes in wheat and provided a connection between the phytohormone-mediated responses and the MPK cascade pathways.

Jiawei Wendan decoction affects mitogen-activated protein kinase signal pathway in the hippocampus of depression rats

A previous study from our group showed that Jiawei Wendan decoction inhibits protein expression of interleukin-1β, 2, and 6, as well as plasma neuropeptide Y, P substance and somatostatin in the hippocampus of depression rat models. The present study analyzed the influence of Jiawei Wendan decoction on the mitogen-activated protein kinase signal transduction pathway in the hippocampus. Results demonstrated that Jiawei Wendan decoction effectively upregulated expression of small molecular G proteins, extracellular regulated kinase 1/2, and activated ribosomal S6 kinase protein in the rat hippocampus. In addition, Jiawei Wendan decoction exhibits antidepressant effects similar to fluoxetine. The underlying mechanisms were shown to be dependent on increased mitogen-activated protein kinase signal transduction pathway activity.

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.

Influence of electroacupuncture on mitogen-activated protein kinase signal transduction in a rat model of cerebral ischemia/reperfusion

Following electroacupuncture at Baihui （DU 20） and Dazhui （DU 14） in a rat model of cerebral ischemia/reperfusion, extracellular-signal-regulated kinase expression in cerebral cortex and corpus striatum, serum glutathione reductase, glutathione peroxidase activity, and serum glutathione content were elevated, and neurobehavioral scores improved. However, these effects were antagonized by mitogen-activated protein kinase inhibitor PD98059. Results indicated that electroacupuncture reversed free radical chain reactions and oxidative stress injury caused by cerebral ischemia/reperfusion, thereby providing neuroprotection. This process could correlate with the mitogen-activated protein kinase signal transduction pathway.

Mitogen activated protein kinase signaling pathways participate in the active principle region of Buyang Huanwu decoction-induced differentiation of bone marrow mesenchymal stem cells

Our preliminary studies confirmed that an active principle region of Buyang Huanwu decoction, comprising alkaloid, polysaccharide, aglycon, glucoside and volatile oil, can induce bone marrow mesenchymal stem cell differentiation into neurons. Mitogen-activated protein kinase signaling was identified as one of the key pathways underlying this differentiation process. The present study shows phosphorylated extracellular signal-regulated protein kinase and phosphorylated p38 protein expression was increased after differentiation. Cellular signaling pathway blocking agents, PD98059 and SB203580, inhibited extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways respectively, mRNA and protein expression of the neuronal marker, neuron specific enolase, and neural stem cell marker, nestin, were decreased in bone marrow mesenchymal stem cells after treatment with the active principle region of Buyang Huanwu decoction. Experimental findings indicate that, extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways participate in bone marrow mesenchymal stem cell differentiation into neuron-like cells, induced by the active principle region of Buyang Huanwu decoction.

γ-Aminobutyric acid alleviates litchi thaumatin-like protein-induced inflammation and reduces gut microbial translocation

Previous research reported litchi thaumatin-like protein(LcTLP)could lead to inflammation,which is a factor causing the adverse reactions after excessive intake of litchi.As a main amino acid in litchi pulp,γ-aminobutyric acid(GABA)was found with anti-inflammatory effect.Therefore,this study aimed to investigate the effects of GABA on LcTLP-induced inflammation through RAW264.7 macrophages and C57BL mice models.In vitro study showed GABA could effectively regulate the level of inflammatory cytokines(interleukin(IL)-1β,IL-6,IL-10,and prostaglandin E2)and Ca2+in cells,and inhibit the phosphorylation of p65,IκB,p38,c-Jun N-terminal kinase(JNK)and extracellular signal-regulated kinase(ERK).These results indicate GABA alleviated inflammation through nuclear factor-κB and mitogen-activated protein kinase pathway signaling pathways.In vivo experiment was performed to verify the anti-inflammatory effect of GABA,and the results demonstrated that GABA reduced the inflammation and oxidative stress in the liver of LcTLP-treated mice,as it down-regulated the pro-inflammatory cytokines,malondialdehyde,aspartate transferase,and alanine transaminase.The relative expression of phosphorylated p38,JNK and ERK in mice liver with GABA treatment were reduced to 65%,39%and 80%of the control group,respectively.Furthermore,GABA treatment enriched probiotic bacteria and decreased pathogenic bacteria in mice gut,which reveals GABA could effectively reduce the translocation of gut microbiota.

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.

Marsdenia tenacissima extract induces G_0/G_1 cell cycle arrest in human esophageal carcinoma cells by inhibiting mitogen-activated protein kinase(MAPK) signaling pathway

Marsdenia tenacissima extract(MTE, trade name: Xiao-Ai-Ping injection) is an extract of a single Chinese plant medicine. It has been used for the treatment of cancer in China for decades, especially for esophageal cancer and other cancers in the digestive tract. In the present study, the potential mechanism for MTE's activity in esophageal cancer was explored. The effects of MTE on the proliferation of human esophageal cancer cells(KYSE150 and Eca-109) were investigated by the MTT assay, the Brd U(bromodeoxyuridine) incorporation immunofluorescence assay, and flow cytometric analysis. MTE inhibited cell proliferation through inducing G0/G1 cell cycle arrest in KYSE150 and Eca-109. Western blot analysis was employed to determine protein levels in the MTE treated cells. Compared with the control cells, the expression levels of the cell cycle regulatory proteins cyclin D1/D2/D3, cyclin E1, CDK2/4/6(CDK: cyclin dependent kinase), and p-Rb were decreased significantly in the cells treated with MTE at 40 mg·m L-1. In addition, MTE had an inhibitory effect on the MAPK(mitogen-activated protein kinase) signal transduction pathway, including ERK(extracellular signal-regulated kinase), JNK(c-Jun N-terminal kinase), and p38 MAPK. Moreover, MTE showed little additional effects on the regulation of cyclin D1/D3, CDK4/6, and p-Rb when the ERK pathway was already inhibited by the specific ERK inhibitor U0126. In conclusion, these data suggest that MTE inhibits human esophageal cancer cell proliferation through regulation of cell cycle regulatory proteins and the MAPK signaling pathways, which is probably mediated by the inhibition of ERK activation.

Effect of cigarette smoke extract on lipopolysaccharide-activated mitogen-activated protein kinase signal transduction pathway in cultured cells

Background Lipopolysaccharide （LPS） forms outer membrane of the wall of Gram-negative cells. LPS can directly cause damage to epithelia of respiratory tract and is the major factor responsible for the chronic inflammation of respiratory passage. The mitogen-activated protein kinase （MAPK） signal transduction pathway of the airway epithelia is intimately associated with the action of LPS. The chronic inflammation of respiratory tract and smoking are interrelated and entwined in the development and progression of chronic lung diseases. This study was designed to examine the effects of cigarette smoke extract （CSE） and LPS on MAPK signal transduction pathway in order to further understand the roles CSE and LPS play in chronic lung inflammation. Methods Cultured primary human epithelial cells of airway were divided into four groups according to the stimulants used： blank control group, LPS-stimulation group, CSE-stimulation group and CSE plus LPS group. Western blotting was employed for the detection of phosphorylation level of extracellular-signal-regulated-kinase （ERK1/2）, p38 MAPK and c-Jun N-terminal kinase （JNK）. The expression of cytokines of MAPK transduction pathway （granulocyte-macrophage colony stimulating factor （GM-CSF） and mRNA of IL-8） in the primary epithelial cells of respiratory tract was also determined. Results Western blotting revealed that the phosphorylation levels of ERK1/2, p38 MAPK and JNK were low and 2 hours after the LPS stimulation, the phosphorylation of ERK1/2, p38 MAPK and JNK were all increased. There was a significant difference in the phosphorylation between the LPS-stimulation group and blank control group （P〈0.05）; no significant difference was found between CSE-stimulation group and blank control group （P〉0.05）; there was a significant difference between CSE ＋ LPS group and blank control group and between CSE ＋ LPS group and LPS group （P〈0.05）. The phosphorylation of CSE-LPS group was higher than that of blank control group but lower than that of LPS group. In blank control group, the expression of IL-8 and GM-CSF mRNA was low in the epithelial cells of airway and the release of IL-8 and GM-CSF was also at a low level. One hour after LPS stimulation, the level of IL-8 mRNA increased （P〈0.05） and reached a peak after 2 hours. On the other hand, GM-CSF mRNA level increased 2 hours after the stimulation （P〈0.05） and reached the highest level 4 hours after the stimulation. Two hours after LPS stimulation, IL-8 and GM-CSF protein level began to rise （P〈0.05）, and the level was the highest 8 hours after the stimulation （P〈0.01）. Stimulation with CSE alone had no effect on the release of IL-8 and GM-CSF and expression of IL-8 mRNA （P〉0.05）, but pre-treatment with CSE could delay the LPS-induced release of IL-8 and GM-CSF and the expression of IL-8 mRNA and its peak was lower. Conclusions LPS stimulation can significantly increase the phosphorylation of ERK1/2, p38 MAPK and JNK in the epithelial cells of airway and activate the MAPK transduction pathway, thereby can activate the downstream signal transduction pathway, and can ultimately result in the release of cytokines by the epithelial cells of airway. CSE can partially abolish the LPS-induced activation of MAPK signal transduction pathway and the expression of cytokines of the pathway, which might contribute to the development and progression of the inflammatory reactions in COPD patients.

Mitogen-activated protein kinase signal pathways play an important role in right ventricular hypertrophy of tetralogy of Fallot

Background Tetralogy of Fallot （TOF） is the most common malformation of children with an incidence of approximately 10% of congenital heart disease patients. There can be a wide spectrum to the severity of the anatomic defects, which include ventricular septal defect, aortic override, right ventricular outflow tract obstruction, and right ventricular hypertrophy. We examined the relationship between right ventricular hypertrophy in patients with TOF and the gene expression of factors in the mitogen-activated protein kinase （MAPK） signal pathway. Methods To gain insight into the characteristic gene（s） involved in molecular mechanisms of right ventricular hypertrophy in TOF, differential mRNA and micro RNA expression profiles were assessed using expression-based micro array technology on right ventricular biopsies from young TOF patients who underwent primary correction and on normal heart tissue. We then analyzed the gene expression of the MAPK signal pathway using reverse transcription-polymerase chain reaction （RT-PCR） in normals and TOF patients. Results Using the micro RNA chip V3.0 and human whole genome oligonucleotide microarray VI.0 to detect the gene expression, we found 1068 genes showing altered expression of at least two-fold in TOF patients compared to the normal hearts, and 47 micro RNAs that showed a significant difference of at least two-fold in TOF patients. We then analyzed these mRNAs and micro RNAs by target gene predicting software Microcosm Targets version 5.0, and determined those mRNA highly relevant to the right ventricular hypertrophy by RT-PCR method. There were obvious differences in the gene expression of factors in the MAPK signal pathway when using RT-PCR, which was consistent to the results of the cDNA microarray.Conclusion The upregulation of genes in the MAPK signal pathway may be the key events that contribute to right ventricular hypertrophy and stunted angiogenesis in patients with TOF.

Neuroprotective Effects of Raloxifene on Aβ_(25-35)-induced Damages in PC12 Cells via Mitogen-activated Protein Kinase Signaling Pathway

Objective To investigate the neuroprotective effects and the mechanism of this protection of raloxifene （RLX）, a selective estrogen receptor modulator.Methods MTT assay and flow cytometry with annexin V-FITC/PI staining were performed to evaluate the neuroprotective effects of RLX on Aβ25-35-induced toxicity. The potential mechanisms were studied by Western blotting in cultured rat pheochromocytoma cells （PC12 cells）.Results RLX（1 000 nmol/L）, in combination with Aβ25-35 （30 llmol/L）, increased the cell viability （P 〈0.001）, and reduced the number of apoptotic cells （P 〈0.05）. RLX attenuated Aβ25-35-induced loss of △ψm （P 〈0.01）. The changing of △ψm was similar to the variation of apoptosis. PD98059 （inhibitor of ERK1/2） inhibited the effects of RLX on cell viability and phosphorylation of cleaved caspase-9. No significant difference of cell viability or phosphorylation of cleaved caspase-9 had been found when PC12 cells were incubated with SB203580 （inhibitor of p38MAPK） or SP600125 （inhibitor of JNK）. Afl25.35 induced a time-dependent phosphorylation of p38MAPK and JNK. In PC12 cells treated solely with RLX, ERK1/2 was activated （P〈0.01）. In PC12 cells treated with Aβ25-35 and RLX, Aβ2545-induced phosphorylation of p38MAPK and JNK were inhibited （P〈0.01 and P〈0.001, respectively）.Conclusion RLX inhibited Af125.35-induced cell apoptosis by activating the ERK1/2 pathway in PC12 cells. RLX also attenuated Aβ25-35-induced activation of p38MAPK and JNK. The mitochondria pathway Was involved in this inhibitory effect.

Regulation of TMEM100 expression by epigenetic modification,effects on proliferation and invasion of esophageal squamous carcinoma

BACKGROUND Esophageal squamous cell carcinoma(ESCC)is a prevalent malignancy with a high morbidity and mortality rate.TMEM100 has been shown to be suppressor gene in a variety of tumors,but there are no reports on the role of TMEM100 in esophageal cancer(EC).AIM To investigate epigenetic regulation of TMEM100 expression in ESCC and the effect of TMEM100 on ESCC proliferation and invasion.METHODS Firstly,we found the expression of TMEM100 in EC through The Cancer Genome Atlas database.The correlation between TMEM100 gene expression and the survival of patients with EC was further confirmed through Kaplan-Meier analysis.We then added the demethylating agent 5-AZA to ESCC cell lines to explore the regulation of TMEM100 expression by epigenetic modification.To observe the effect of TMEM100 expression on tumor proliferation and invasion by overexpressing TMEM100.Finally,we performed gene set enrichment analysis using the Kyoto Encyclopaedia of Genes and Genomes Orthology-Based Annotation System database to look for pathways that might be affected by TMEM100 and verified the effect of TMEM100 expression on the mitogen-activated protein kinases(MAPK)pathway.RESULTS In the present study,by bioinformatic analysis we found that TMEM100 was lowly expressed in EC patients compared to normal subjects.Kaplan-meier survival analysis showed that low expression of TMEM100 was associated with poor prognosis in patients with EC.Then,we found that the demethylating agent 5-AZA resulted in increased expression of TMEM100 in ESCC cells[quantitative real-time PCR(qRT-PCR)and western blotting].Subsequently,we confirmed that overexpression of TMEM100 leads to its increased expression in ESCC cells(qRT-PCR and western blotting).Overexpression of TMEM100 also inhibited proliferation,invasion and migration of ESCC cells(cell counting kit-8 and clone formation assays).Next,by enrichment analysis,we found that the gene set was significantly enriched in the MAPK signaling pathway.The involvement of TMEM100 in the regulation of MAPK signaling pathway in ESCC cell was subsequently verified by western blotting.CONCLUSION TMEM100 is a suppressor gene in ESCC,and its low expression may lead to aberrant activation of the MAPK pathway.Promoter methylation may play a key role in regulating TMEM100 expression.

PBX3 promotes migration and invasion of colorectal cancer cells via activation of MAPK/ERK signaling pathway

AIM: To investigate the role of pre-B-cell leukemia homeobox (PBX)3 in migration and invasion of colorectal cancer (CRC) cells.

IL-1RⅠ/MyD88-TIR mimic AS-1 inhibits the activation of MyD88-dependent signaling pathway induced by IL-1β in vitro

Objective： To test whether IL-1 RI/My088-TIR mimic AS-1 can work as a new compound that targeted at blocking MyD88- dependent signaling pathway, we investigated the physical structure and biological function of AS-1. Methods：The crystallographic structure of AS-1 was examined by 1^H nuclear magnetic resonance. The toxicity of AS-1 was measured with Methyl thiazolyl tetrazolium （MTT） assay. The effect of AS-1 on phosphorylation state of p38 MAPK and IRAK-1 was observed with Western blot. Results：The crystallographic details of AS-1 demonstrated that it was a tri-peptide sequence[（F/Y）-（V/L/I）-（P/G）] of the IL-1R I -TIR domain BBloop. No toxicity of AS-1 was shown to HEK 293A cells. The phosphorylation of p38 MAPK, induced by IL-1β significantly increased from those in the control group. AS-1 significantly reduced the phosphorylation of p38 MAPK induced by IL-1β. IL-1β increased the phosphorylation of IRAK-1 significantly, which was prevented by AS-1. Conclusion：AS-1 is a competitive mimic between IL-1R I-TIR and MyD88-TIR domain, which most likely interferes with MyD88-dependent signaling pathway.

Fangji Fuling Decoction Alleviates Sepsis by Blocking MAPK14/FOXO3A Signaling Pathway

Objective:To examine the therapeutic effect of Fangji Fuling Decoction(FFD) on sepsis through network pharmacological analysis combined with in vitro and in vivo experiments.Methods:A sepsis mouse model was constructed through intraperitoneal injection of 20 mg/kg lipopolysaccharide(LPS).RAW264.7 cells were stimulated by 250 ng/m L LPS to establish an in vitro cell model.Network pharmacology analysis identified the key molecular pathway associated with FFD in sepsis.Through ectopic expression and depletion experiments,the effect of FFD on multiple organ damage in septic mice,as well as on cell proliferation and apoptosis in relation to the mitogen-activated protein kinase 14/Forkhead Box O 3A(MAPK14/FOXO3A) signaling pathway,was analyzed.Results:FFD reduced organ damage and inflammation in LPS-induced septic mice and suppressed LPS-induced macrophage apoptosis and inflammation in vitro(P<0.05).Network pharmacology analysis showed that FFD could regulate the MAPK14/FOXO signaling pathway during sepsis.As confirmed by in vitro cell experiments,FFD inhibited the MAPK14 signaling pathway or FOXO3A expression to relieve LPS-induced macrophage apoptosis and inflammation(P<0.05).Furthermore,FFD inhibited the MAPK14/FOXO3A signaling pathway to inhibit LPS-induced macrophage apoptosis in the lung tissue of septic mice(P<0.05).Conclusion:FFD could ameliorate the LPS-induced inflammatory response in septic mice by inhibiting the MAPK14/FOXO3A signaling pathway.

Efficacy of Cigu Xiaozhi pill(慈菇消脂丸) on non-alcoholic steatohepatitis-associated lipoapoptosis through stress-activated c-Jun N-terminal kinase signalling pathway

OBJECTIVE: To investigate the efficacy of Cigu Xiaozhi pill(慈菇消脂丸, CGXZ) on non-alcoholic steatohepatitis(NASH)-associated lipoapoptosis through the stress-activated c-Jun N-terminal kinase(JNK)/stress-activated protein kinase signalling pathway.METHODS: Sixty male Sprague-Dawley rats were randomly divided into the following groups(10 rats each): blank control, model, low-dose CGXZ,medium-dose CGXZ, high-dose CGXZ, and positive control(treated with SP600125, a JNK inhibitor).The NASH model was established and the histomor-phological characteristics of haematoxylin and eosin-stained liver tissues were examined under a light microscope. Cell apoptosis in liver tissues was assessed via terminal deoxynucleotidyl transferase d UTP nick-end labelling assay. In addition, the m RNA and protein expression levels of p-JNK,p-c-Jun, caspase-8, Fas, and Fas-L were determined via fluorescence-based quantitative real-time PCR,immunohistochemical and Western blot assays.RESULTS: Histopathological examination of the liver showed that the model rats had moderate-to-severe steatosis with infiltration of inflammatory cells as well as significantly higher expression levels of the p-JNK, p-c-Jun, caspase-8, Fas, and Fas-L proteins, compared with those in the blank control group(P < 0.01). Hepatic lobules of the rats in the treatment groups showed significantly reduced vacuolar degeneration and steatosis as well as alleviated inflammatory cell infiltration. The high and medium-dose CGXZ groups exhibited significantly lower m RNA and protein expression levels of p-JNK, p-c-Jun, caspase-8, Fas, and Fas-L, compared with those in the model group(P < 0.05 or P <0.01).CONCLUSION: CGXZ pill inhibited the onset of hepatocyte apoptosis by regulating the expression of p-JNK, p-c-Jun, caspase-8, Fas, and Fas-L, thereby exerting therapeutic effects against NASH.

MicroRNA regulatory pattern in spinal cord ischemia-reperfusion injury

After spinal cord injury, dysregulated miRNAs appear and can participate in inflammatory responses, as well as the inhibition of apoptosis and axon regeneration through multiple pathways. However, the functions of miRNAs in spinal cord ischemia-reperfusion injury progression remain unclear. miRCURY LNATM Arrays were used to analyze miRNA expression profiles of rats after 90 minutes of ischemia followed by reperfusion for 24 and 48 hours. Furthermore, subsequent construction of aberrantly expressed miRNA regulatory patterns involved cell survival, proliferation, and apoptosis. Remarkably, the mitogen-activated protein kinase(MAPK) signaling pathway was the most significantly enriched pathway among 24-and 48-hour groups. Bioinformatics analysis and quantitative reverse transcription polymerase chain reaction confirmed the persistent overexpression of miR-22-3 p in both groups. These results suggest that the aberrant miRNA regulatory network is possibly regulated MAPK signaling and continuously affects the physiological and biochemical status of cells, thus participating in the regulation of spinal cord ischemia-reperfusion injury. As such, miR-22-3 p may play sustained regulatory roles in spinal cord ischemia-reperfusion injury. All experimental procedures were approved by the Animal Ethics Committee of Jilin University, China [approval No. 2020(Research) 01].

Ethylene-induced stomatal closure is mediated via MKK1/3–MPK3/6 cascade to EIN2 and EIN3

Mitogen-activated protein kinases(MPKs)play essential roles in guard cell signaling,but whether MPK cascades participate in guard cell ethylene signaling and interact with hydrogen peroxide(H2O2),nitric oxide(NO),and ethylene-signaling components remain unclear.Here,we report that ethylene activated MPK3 and MPK6 in the leaves of wild-type Arabidopsis thaliana as well as ethylene insensitive2(ein2),ein3,nitrate reductase1(nia1),and nia2 mutants,but this effect was impaired in ethylene response1(etr1),nicotinamide adenine dinucleotide phosphate oxidase AtrbohF,mpk kinase1(mkk1),and mkk3 mutants.By contrast,the constitutive triple response1(ctr1)mutant had constitutively active MPK3 and MPK6.Yeast two-hybrid,bimolecular fluorescence complementation,and pull-down assays indicated that MPK3 and MPK6 physically interacted with MKK1,MKK3,and the C-terminal region of EIN2(EIN2 CEND).mkk1,mkk3,mpk3,and mpk6 mutants had typical levels of ethylene-induced H2O2 generation but impaired ethylene-induced EIN2 CEND cleavage and nuclear translocation,EIN3 protein accumulation,NO production in guard cells,and stomatal closure.These results show that the MKK1/3–MPK3/6 cascade mediates ethylene-induced stomatal closure by functioning downstream of ETR1,CTR1,and H2O2 to interact with EIN2,thereby promoting EIN3 accumulation and EIN3-dependent NO production in guard cells.

Isolation and characterization of novel peptides from fermented products of Lactobacillus for ulcerative colitis prevention and treatment

Ulcerative colitis(UC)is an incurable and highly complex digestive disease affecting millions of people worldwide.Compared to the current therapeutic drugs,bioactive peptides are more promising and safe substances as functional foods or drugs for the prevention and treatment of UC.The alcohol-soluble components from fermentation broth by fresh wheat germ and apple(AC-WGAF)were found to be effective in UC prevention in dextran sulfate sodium-induced mice in vivo.Herein,4 novel peptides are identifi ed from AC-WGAF by membrane ultrafi ltration,recycling preparative high-performance liquid chromatography,and matrix-assisted laser desorption–ionization time-of-fl ight/time-of-fl ight mass spectrometry,possessing anticolitis activity via using an in vitro model.One of those peptides named T24(PVLGPVRGPFPLL)exhibited the most remarkable anti-colitis activity by preventing tight junction protein loss,maintaining epithelial barrier integrity,and promoting cell proliferation during in vitro and in vivo studies by regulating mitogen-activated protein kinase signaling pathways.Thus,T24 is a promising peptide as a functional food or novel drug for UC prevention and treatment.

Treatment time influences the effects of a low-frequency pulsed electric field on synthesis of tyrosine hydroxylase and dopamine in PC12 cells

BACKGROUND： Electromagnetic radiation can influence dopamine （DA） synthesis in brain tissues or ceils, but electromagnetic frequencies, intensities, and radiation time can produce different effects. In addition, the signal pathway by which electromagnetic radiation influences DA synthesis remains controversial. OBJECTIVE： To determine tyrosine hydroxylase （TH） expression in PC12 cells and DA levels in cell culture media after different periods of low-frequency pulsed electric field （LF-PEF） stimulation, and to determine how LF-PEF signaling stimulates TH synthesis using inhibitors. DESIGN, TIME AND SETTING： A parallel, controlled, cell experiment was performed at the Laboratory of Cell Biology, School of Life Science, East China Normal University, between January and October 2006. MATERIALS： PC12 cells were purchased from the Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China. Nerve growth factor was purchased from PeproTech, USA. The protein kinase A inhibitor, H-89, and mitogen-activated protein kinase kinase inhibitor, U0126, were purchased from Sigma, USA. METHODS： （1） Following routine culture in Dulbecco＇s modified eagle medium, primary PC12 cells were stimulated under LF-PEF （pulse frequency 50.Hz, pulse width 20 μs, peak field strength 1 V/m） for 5, 10, 15, 20, and 30 minutes. （2） Inhibitors （H-89 or U0126, 1 μmol/L） were added 30 minutes before LF-PEF stimulation for 10 minutes. MAIN OUTCOME MEASURES： （1） TH expression was determined by Western blot in PC12 cells at 0.5, 1,2, 3, and 4 days after LF-PEF stimulation. Similarly, DA was measured by high-performance liquid chromatography in media at 2, 3, 4, or 5 days after LF-PEE （2） TH expression was detected 1 day after H-89 or U0126 treatment and LF-PEE RESULTS： （1） Short-term LF-PEF stimulation （5 and 10 minutes） increased TH expression and media DA levels after short-term culture （2 days） （P 〈 0.01）, but both parameters decreased with longer culture （3 4 days） （P 〈 0.01）. Long-term LF-PEF stimulation （15, 20, or 30 minutes） decreased TH and DA synthesis, followed by a rapid increase （P 〈 0.01）. （2） H89 could completely inhibit TH expression in PC12 cells stimulated by LF-PEF for 10 minutes, while the inhibition rate of U0126 was 53.2%. CONCLUSION： Short-term LF-PEF first promotes then inhibits, while long-term LF-PEF first inhibits then promotes, TH and DA synthesis. LF-PEF stimulation regulates TH expression primarily by activating protein kinase A to regulate DA synthesis.