Effect of charge at an amino acid of basic fibroblast growth factor on its mitogenic activity

The amino acid at the 119th position of human basic fibroblast growth factor(hbFGF),lysine(K119),is a critical component for its mitogenic activity.However,little is known about the effects of the characteristics of this residue including charge on the mitogenic activity of hbFGF.Herein,this basic residue was replaced with neutral glutamine residue and acidic glutamic acid residue to construct mutants hbFGF^(K119Q) and hbFGF^(K119E),respectively.The mutants were produced by BL21(DE3)/pET3c expression system...

Genome-wide characterization of mapk gene family in black rockfish Sebastes schlegelii and their expression patterns against Edwardsiella piscicida infection

Mitogen-activated protein kinases(MAPKs)play pivotal roles in response to environmental stresses and bacterial infections.Compared with those in the higher vertebrates,studies of mapk gene family are still limited in teleost.Identification,characterization,classification,and expression profiling of totally 15 mapk genes in black rockfish(Sebastes schlegelii)were conducted.Phylogenetic relationships show that these mapk genes could be divided into extracellular signal-regulated kinase(ERK),c-Jun N-terminal kinase(JNK),and p38 sub-families.In addition,gene structures,syntenic analysis,and selective pressure analysis are performed to confirm their annotations.Results of selective pressure analysis indicate that mapk1,mapk3,mapk7,mapk10,mapk11,and mapk12 underwent significantly-positive selections,while the others genes such as mapk4,mapk6,mapk15,mapk8a,mapk8b,mapk9,mapk13,mapk14a,and mapk14b were under purifying selections.Moreover,results of qRT-PCR indicate that mapk genes in 8 healthy tissues displayed different expression patterns.The expression patterns of several mapk genes including mapk12,mapk13,mapk14a,mapk14b,and mapk15 were significantly changed in mucosal tissues after Edwardsiella piscicida infection.This study demonstrates that mapk genes in black rockfish play vital prevention roles against bacterial infection,which not only helps us understand the structure and function of mapk genes in black rockfish,but also provides a reference to understand the role of mapk genes in teleost immune responses.

有氧运动与饮食干预对肥胖小鼠睾丸氧化应激的影响

目的:通过对肥胖小鼠施加有氧运动与饮食干预,探索运动与饮食干预对肥胖小鼠睾丸氧化应激和p38MAPK-NF-κB通路中的作用。方法:随机将17只C57BL/6J小鼠分为正常饮食组(ND),37只分为高脂饮食组(HFD),高脂饮食脂肪占比40%,喂养12周后,HFD组剔除3只肥胖抵抗小鼠,其余34只肥胖造模成功;随后将ND组分为正常饮食对照组(NC,n=8),正常饮食运动组(NE,n=9),肥胖高脂饮食对照组(OC,n=8),肥胖高脂饮食运动组(OE,n=9),肥胖正常饮食组(ONC,n=8),肥胖正常饮食运动组(ONE,n=9),各组继续饲养8周,其中NE、OE和ONE组以速度20 m/min,60 min/d,6 d/week,进行8周跑台运动,末次运动后36~40 h取血和睾丸组织,ELISA检测血清睾酮和睾丸氧化应激(MDA、T-SOD、T-AOC)水平,RT-PCR和Western blot检测睾丸p38MAPK-NF-κB水平。结果:与NC组比较,OC组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显升高(P<0.01),睾丸SOD、睾丸系数和血睾酮明显降低(P<0.01);NE组小鼠体脂参数明显降低(P<0.05),血清睾酮明显升高(P<0.01)。与OC组比较,OE组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.05或0.01),睾丸SOD和血睾酮水平明显升高(P<0.01);ONC组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.01),睾丸SOD水平和睾丸系数明显升高(P<0.05);ONE组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.01),睾丸SOD、睾丸系数和血睾酮水平明显升高(P<0.01)。结论:肥胖引起小鼠睾丸发生氧化应激,上调睾丸p38MAPK-NF-κB水平,并降低血睾酮水平;运动、饮食和运动×饮食干预均能通过降低体脂,改善睾丸氧化应激,下调睾丸p38MAPK-NF-κB水平。

Neuroprotective mechanisms of rutin for spinal cord injury through anti-oxidation and anti-inflammation and inhibition of p38 mitogen activated protein kinase pathway

Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase （p38 MAPK） pathway is the most important member of the MAPK family that controls inflammation. We assumed that the mechanism of rutin in the repair of spinal cord injury is associated with the inhibition of p38 MAPK pathway. Allen’s method was used to establish a rat model of spinal cord injury. The rat model was intraperitoneally injected with rutin （30 mg/kg） for 3 days. After treatment with rutin, Basso, Beattie and Bresnahan locomotor function scores increased. Water content, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 levels, p38 MAPK protein expression and caspase-3 and -9 activities in T8–9 spinal cord decreased. Oxidative stress related markers superoxide dismutase and glutathione peroxidase levels increased in peripheral blood. Rutin exerts neuroprotective effect through anti-oxidation, anti-inflammation, anti-apoptosis and inhibition of p38 MAPK pathway.

Prosaposin ablation inactivates the MAPK and Akt signaling pathways and interferes with the development of the prostate gland

<abstract>The recent development of a prosaposin -/- mouse model has allowed the investigation of the role of prosaposin in the development of the male reproductive organs. A morphometric analysis of the male reproductive system of 37 days old mice revealed that prosaposin ablation produced a 30 % reduction in size and weight of the testes, 37 % of the epididymis, 75 % of the seminal vesicles and 60 % of the prostate glands. Light microscopy (LM) showed that smaller testis size from homozygous mutant mice was associated with reduced spermiogenesis. Both, dorsal and ventral lobules of the prostate glands were underdeveloped in the homozygous mutant. LM analysis also showed that prostatic alveoli were considerably smaller and lined by shorter epithelial cells in the homozygous mutant. Smaller tubular diameter and shorter undifferentiated epithelial cells were also observed in seminal vesicles and epididymis. In the efferent ducts of the homozygous mutant mice, the epithelium was composed exclusively of ciliated cells in contrast to the heterozygotes, which showed the presence of nonciliated cells. Radioimmunoassays demonstrated that testosterone levels were normal or higher in mice with the inactivated prosaposin gene. Immunostaining of prostate sections with an anti-androgen receptor antibody showed that the epithelial cells lining the alveoli express androgen receptor in both the heterozygous and homozygous tissue. Similarly, sections immunostained with antibodies to the phosphorylated MAPKs and Akts strongly reacted with tall prostatic secretory cells in prostate from heterozygous mouse. On the other hand, the epithelial cells in the homozygous prostate remained unstained or weakly stained. These findings demonstrate that inactivation of the prosaposin gene affected the development of the prostate gland and some components of the MAPK pathway. 63 )

Vasopressin decreases neuronal apoptosis during cardiopulmonary resuscitation

The American Heart Association and the European Resuscitation Council recently recommend- ed that vasopressin can be used for cardiopulmonary resuscitation, instead of epinephrine. However, the guidelines do not discuss the effects of vasopressin during cerebral resuscitation. In this study, we intraperitoneally injected epinephrine and/or vasopressin during cardiopul- monary resuscitation in a rat model of asphyxial cardiac arrest. The results demonstrated that, compared with epinephrine alone, the pathological damage to nerve cells was lessened, and the levels of c-Iun N-terminal kinase and p38 expression were significantly decreased in the hippo- campus after treatment with vasopressin alone or the vasopressin and epinephrine combination. No significant difference in resuscitation effects was detected between vasopressin alone and the vasopressin and epinephrine combination. These results suggest that vasopressin alone or the vasopressin and epinephrine combination suppress the activation of mitogen-activated protein kinase and c-Iun N-terminal kinase signaling pathways and reduce neuronal apoptosis during cardiopulmonary resuscitation.

Xuebijing alters tumor necrosis factor-alpha, interleukin-1beta and p38 mitogen activated protein kinase content in a rat model of cardiac arrest following cardiopulmonary resuscitation

We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase content were increased. Rats injected with Xuebijing, a Chinese herb compound preparation, exhibited normal cellular structure and morphology, dense neuronal cytoplasm, and decreased tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase expression at 24 hours following cardiopulmonary resuscitation. These data suggest that Xuebijing can attenuate neuronal injury induced by hypoxia and reperfusion during cardiopulmonary resuscitation.

Bone morphogenetic protein 2-induced human dental pulp cell differentiation involves p38 mitogen-activated protein kinase-activated canonical WNT pathway

Both bone morphogenetic protein 2（BMP2） and the wingless-type MMTV integration site（WNT）/p-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis.Cross-talk between BMP2 and WNT/p-catenin in osteoblast differentiation and bone formation has been identified.However,the roles and mechanisms of the canonical WNT pathway in the regulation of BMP2 in dental pulp injury and repair remain largely unknown.Here,we demonstrate that BMP2 promotes the differentiation of human dental pulp cells（HDPCs） by activating WNT/p-catenin signalling,which is further mediated by p38mitogen-activated protein kinase（MAPK） in vitro.BMP2 stimulation upregulated the expression of p-catenin in HDPCs,which was abolished by SB203580 but not by Noggin or LDN193189.Furthermore,BMP2 enhanced cell differentiation,which was not fully inhibited by Noggin or LDN193189.Instead,SB203580 partially blocked BMP2-induced p-catenin expression and cell differentiation.Taken together,these data suggest a possible mechanism by which the elevation of p-catenin resulting from BMP2 stimulation is mediated by the p38 MAPK pathway,which sheds light on the molecular mechanisms of BMP2-mediated pulp reparative dentin formation.

Inhibition of MAPK Hog1 Results in Increased Hsp104 Aggregate Formation Probably through Elevated Arsenite Influx into the Cells, an Approach with Numerous Potential Applications

Arsenic is a highly toxic and carcinogenic metalloid widely dispersed in the environment, contaminating water and soil and accumulating in crops. Paradoxically, arsenic is also part of modern therapy and employed in treating numerous ailments and diseases. Hence, inventing strategies to tune cellular arsenic uptake based on purpose is striking. Here, we describe an approach in which the arsenite uptake can be increased using a MAPK inhibitor. Employing microfluidic flow chambers in combination with optical tweezers and fluorescent microscopy, we elevated the influx of arsenite into the yeast Saccharomyces cerevisiae cells following short-term treatment with a Hog1 kinase inhibitor. The increase in arsenite uptake was followed on arsenite triggered redistribution of a reporter protein, Hsp104-GFP, which was imaged over time. The effect was even more pronounced when the yeast mother and daughter cells were analyzed disjointedly, an opportunity provided owing to single-cell analysis. Our data firstly provide a strategy to increase arsenite uptake and secondly show that arsenite triggered aggregates, previously shown to be sites of damaged proteins, are distributed asymmetrically and less accumulated in daughter cells. Inventing approaches to tune arsenite uptake has a great value for its use in environmental as well as medical applications.

Research progress of traditional Chinese medicine monomers in intervening colorectal cancer by regulating MAPK signaling pathway

The incidence rate and mortality rate of colorectal cancer in China are increasing year by year.Finding effective therapeutic strategies and interventions,especially exploring“highly effective and low toxic”drugs to prevent“inflammation-cancer”transformation,treat primary tumors,prevent tumor metastasis and reduce the toxicity and increase efficiency of existing therapies has become a hot topic of domestic and foreign scholars.The advantage of traditional Chinese medicine in the treatment of colorectal cancer is to reduce the postoperative recurrence rate,improve patients’symptoms and the quality of life of“tumor survivors”and prolong the survival time.This paper summarizes the tumor treatment strategies and research prospects of traditional Chinese medicine targeting mitogen activated protein kinase by sorting out the mechanism of traditional Chinese medicine extracts or effective components intervening colorectal cancer by regulating mitogen activated protein kinase signal pathway in tumor cells in recent years.

Association between delayed cardioprotection of aged rat myocytes and activation of mitogenactivated protein kinase

Objective To study the cardioprotective effects of hypoxic preconditioning (HPC) on aged rat ventricular myocytes and the cellular mechanism of protection Methods In the model of hypoxia/reoxygenation (H/R) of isolated ventricular myocytes of aged rat, the effects of HPC on aged rat ventricular myocytes against lethal H/R stimulated ischemia/reperfusion (I/R) injury 24 hours later and the changes of mitogen activated protein kinase (MAPK) system were observed in the present study Results HPC attenuated the lactate dehydrogenase (LDH) release and ATP depletion in myocytes and increased the viability of myocytes It was also found that MAPK and its down stream kinase—S6 kinase were also activated after HPC Conclusion There is delayed cardioprotection in cardiac myocytes of aged rat and the cellular mechanism underlying might involve the activation of MAPK system

Role of protein tyrosine kinase in IL-1β induced activation of mitogen- activated protein kinase in fibroblast-like synoviocytes of rheumatoid arthritis

Obejctives To study mitogen activated protein kinase (MAPKs) activation in fibroblast like synoviocytes (FLS) of rheumatoid arthritis (RA) under the stimulation of IL 1β, and to elucidate the role of protein tyrosine kinase (PTK) in the activation of MAPKs Methods Primary cultures of RA FLS were used Western blot was applied to examine transient changes in protein tyrosine phosphorylation status and MAPKs activation in RA FLS stimulated with IL 1β at various doses, and over different periods Genistein, the specific PTK inhibitor, was used to evaluate the inhibitory role in activation of MAPKs by IL 1β Results IL 1β transiently increased protein tyrosine phosphorylation, and activated the MAPKs cascades (mainly ERK 2, JNK 2 and P 38 ) in RA FLS There was no obvious difference in MAPKs activation among different doses of IL 1β (1?IU/ml,10?IU/ml, 100?IU/ml), but the peak activation of ERK 2, JNK 2 and P 38 took place at 5?min, 15?min and 1?min, respectively, after stimulation with IL 1β The activation of ERK 2 was inhibited by genistein, but the inhibitory role on that of JNK and P 38 was relatively weak Conclusions During signal transduction of IL 1β in RA FLS, tyrosine phosphorylation was increased transiently, the MAPKs cascade was activated in a few minutes, and there was heterogenicity in the activation among three subfamily members PTK had a role in the activation of ERK, but had weak effects on that of JNK and P 38

Study on the signalling pathway of inhibitory effect of adreno-medullin on the growth of cultured glomerular mesangial cells

Background Adrenomedullin （ADM）, a potent hypotensive small peptide, was recently found to inhibit the proliferation of glomerular mesangial cells （ MsC ） in vitro and to attenuate glomerular lesions in vivo, however the mechanisms remain poorly understood. In this study, we attempted to elucidate them using molecular signal transduetion. Methods Cultured rat MsC were treated with ADM and several inhibitors of signalling molecules. Methyl thiazoleterazolium （MTT） assay and BrdU incorporation method were employed for examining MsC proliferation. Western blot analysis was used for detecting total mitogen activated protein kinases （t-MAPKs） and phosphorylated MAPKs （p-MAPKs） proteins. Results ADM suppressed MsC proliferation in a concentration- and time-dependent fashion. This response was inhibited by ADM receptor antagonist CGRP8-37 and a potent protein kinase-A （PKA） inhibitor, H89. Forskolin, a direct adenylate cyclase activator, also significantly inhibited MsC proliferation. SB203580, a P38MAPK inhibitor, and U0126, a MEK inhibitor, both completely blocked ADM mediated responses in MsC. However, cureumin, a SAPK/JNK inhibitor, and GF109203X, a potent protein kinase-C （PKC） inhibitor, had no effect on MsC growth. Western blot analysis showed that ADM did not change the expression of t-MAPKs but increased p-SAPK/JNK and p-P38MAPK levels and decreased p-ERK level. These responses were inhibited by CGRP8-37. All these kinase phosphorylations, except for the increase in p-SAPK/JNK, could be stimulated using forskolin. In addition, only ADM mediated changes in ERK and P38MAPK phosphorylations were inhibited by H89. GF109203X did not affect ADM induced changes in three p-MAPKs expressions. Conclusions ADM inhibits MsC proliferation possibly through cAMP-PKA pathway. Both phosphorylations of ERK and P38MAPK pathways were necessary in mediating the antiproliferative response of ADM. It does not preclude the involvement of cAMP independent pathways in the ADM mediated responses.

Effects of Andrographolide on the Activation of Mitogen Activated Protein Kinases and Nuclear Factor-κ B in Mouse Peritoneal Macrophage-derived Foam Cells

Objective： To observe the effect of andrographolide on the activation of mitogen-activated protein kinases （MAPKs） and expression of nuclear factor- kB （NF-kB） in macrophage foam cells. Methods： The mouse peritoneal macrophages were cultured in the media in the presence of oxidized low-density lipoprotein （ox-LDL）, ox-LDL＋andrographolide, or neither （control）. The phosphorylation of MAPK molecules （p38MAPK, JNK, ERK1/2） and the expressions of NK- kB p65 were examined by Western blot. Results： As compared with cells in the control group, the expressions of phospho-p38 and NF- kB p65 were increased in the cells cultured with either ox-LDL or ox-LDL＋andrographolide （P〈0.01）, but attenuated significantly in the presence of ox-LDL＋ andrographolide when compared with ox-LDL （P〈0.05）. The phospho-JNK increased in the presence of either ox-LDL or ox-LDL＋andrographolide when compared with control cells （P〈0.01）, but no significant difference existed between ox-LDL and ox-LDL＋andrographolide （P〉0.05）. The expression of phospho-ERK1/2 was increased in the presence of ox-LDL compared with the control cells （P〈0.01）, but no significant differences existed between the cells cultured in the presence of ox-LDL＋andrographolide and the control medium （P〉0.05）. Conclusions： Andrographolide could inhibit the activation of ERK1/2, p38MAPK and NK-kB induced by ox-LDL in macrophage foam cells, which might be one of its mechanisms in preventing atherosclerosis.

Inhibiting Self-Pollen:Self-Incompatibility in Papaver Involves Integration of Several Signaling Events

Cellular responses rely on signal perception and integration. A nice example of this is self incompatibility （SI）, which is an important mechanism to prevent inbreeding. It prevents self-fertilization by using a highly discriminatory cellular recognition and rejection mechanism. Most Sl systems are genetically specified by the S-locus, which has a pollen and a pistil S-component. A receptor-ligand interaction is used by Papaver rhoeas to control SI. S proteins encoded by the pistil part of the S-locus interact with incompatible pollen to achieve rapid inhibition of tip growth. The incompatible Sl interaction triggers a Ca^2＋-dependent signaling cascade. A number of Sl-specific events are triggered in incompatible pollen, including rapid depolymerization of the actin cytoskeleton; phosphorylation of soluble inorganic pyrophosphatases （SPPases）, Prp26.1; activation of a mitogen activated protein kinase, p56; programmed cell death （PCD） involving a caspase-3-1ike activity. These events contribute to prevent self-fertilizaUon. We are attempting to establish the functional significance of these events, and their possible involvement in integrating a coordinated signaling response. Here we describe the identification of these components shown to be involved in Sl, together with recent progress in identifying links between some of them. These data constitute the first steps in elucidating how SI signaling is integrated.

Flagellin of Pseudomonas aeruginosa induces transforming growth factor beta 1 expression in normal bronchial epithelial cells through mitogen activated protein kinase cascades

Background Acute lung infection due to Pseudomonas aeruginosa （P. Aeruginosa） is a serious problem, especially in patients with structural lung conditions or immune compromised hosts, leading to an overwhelming threat with a high risk of morbidity and mortality. As an outcome of infection, fibrosis can be linked with chronic lung diseases. But some fibrotic manifestations, such as an irreversible decrease of lung function and fibrous bands seen on chest imaging, have been found after an acute infection with P. Aeruginosa. Fibrogenesis/remodeling resulting from acute lung infection by P.aeruginosa is rarely reported. This study was designed to explore the relation between fibrogenesis/remodeling and acute infection by P. Aeruginosa in vitro. We used flagellin protein from P. Aeruginosa, a key initiator of acute P.aeruginosa lung infection, to elucidate mechanisms by which acute lung infection with P. Aeruginosa can cause fibrogenesis/remodeling.Methods We studied the effect of flagellin from P. Aeruginosa （flagellin for short） on the transforming growth factor beta 1 （TGF-β1） and interleukin-8 （IL-8） expression, and the possible involvement of the signaling pathway, tumor necrosis factor receptor-associated factor 6 （TRAF6）/mitogen activated protein kinase （MAPK） pathway. Flagellin was purified from the P. Aeruginosa standard strain, PAO1. Normal bronchial epithelial cells BEAS-2B were challenged with different concentrations of flagellin, and cell viability assessment was performed by cell counting kit-8. BEAS-2B cells were incubated with flagellin with the specific MAPK inhibitors or TRAF6 siRNA. Cell lysates and the cultured supernatant were collected. The level of TGF-β1 and IL-8 were detected by enzyme-linked immunosorbant assay （ELISA）. Western blotting was used to detect the protein levels of MAPK signal proteins p38, c-Jun NH2-terminal kinase （JNK） and extracellular regulated kinase （ERK）.Results Expression of TGF-β1 in BEAS-2B cells was elevated by flagellin vs. Control groups （（104.3±20.8） vs.（44.6±4.4） pg/ml （P 〈0.01）） and was ablated by either p38 or JNK inhibitors compared with flagellin treatment （（45.1±18.8）vs. （104.3±20.8） pg/ml and （48.1±20.8） vs. （104.3±20.8） pg/ml, respectively （P 〈0.05））. Flagellin also elevated the expression of IL-8 in BEAS-2B cells vs. The control groups （（554.9±57.7） vs. （51.4±2.2.9） pg/ml （P 〈0.01））, and p38 MAPK inhibitors weaken the expression by flagellin （（301.1 ±155.1） vs. （554.9±57.7） pg/ml （P 〈0.05））. Western blotting revealed that all three MAPK proteins, p38, JNK and ERK were activated by flagellin challenge in an early phase, respectively in 15 minutes （P 〈0.01）, 30 minutes （P 〈0.01） and 15 minutes （P 〈0.01）. TRAF6 siRNA which decreased expression of TRAF6, altered the activation of JNK, p38, and ERK following flagellin treatment, but its influence on the expression of TGF-β1 and IL-8 has no statistical significance.Conclusions Flagellin from P. Aeruginosa PAO1 induces TGF-β1 expression in normal bronchial epithelial cells,BEAS-2B, through the MAPK signal cascade in vitro. It suggests that the fibrogenesis/remodeling process may be initiated from an early stage of acute lung infection due to P. Aeruginosa.

Alantolactone inhibits proliferation,metastasis and promotes apoptosis of human osteosarcoma cells by suppressing Wnt/β-catenin and MAPKs signaling pathways

Although there are many therapeutic strategies such as surgery and chemotherapy,the prognosis of osteosarcoma(OS)is still far from being satisfactory.It is urgent to develop more effective,tolerable and safe drugs for the treatment of OS.In the present study,we investigated the anti-OS activity of Alantolactone(ALT),a natural eucalyptone sesquiterpene lactone mainly exists in Inula helenium,and probed the possible mechanism involved.We demonstrated that ALT significantly inhibited cell proliferation of various human OS cell lines while had relative lower cytotoxicity against normal cells.Then,we validated that ALT reduced migration,decreased invasion possibly through reversing epithelial mesenchymal transition(EMT)process and suppressing Matrix metalloproteinases(MMPs).Moreover,we confirmed that ALT promoted apoptosis and arrested cell cycle at G2/M phase of human OS cells in vitro.In addition,we confirmed that ALT restrained tumor growth and metastasis of OS 143 cells in a xenograft model in vivo.Mechanistically,ALT inhibited the activity of Wnt/β-catenin and p38,ERK1/2 and JNK Mitogen Activated Protein Kinases(MAPKs)signal pathway.Notably,the combination of ALT and Wnt/β-catenin inhibitor,as well as the combination of ALT and MAPKs inhibitors resulted in a synergistically effect on inhibiting the proliferation,migration and invasion of OS cells.Collectively,our results validate the ALT may inhibit proliferation,metastasis and promotes apoptosis of human OS cells possibly through suppressing Wnt/β-Catenin and MAPKs signaling pathways.

Activation of mitogen activated protein kinases via complement receptor type 2

Background Complement receptor type 2 (CR2) is the receptor for C3d and C3dg and for Epstein Barr virus The aim of our study was to explore whether CR2 can independently mediate the activation of mitogen activated protein kinases (MAPKs, including ERK, JNK, and p38MAPK), and to highlight the molecular mechanism of CD 4 + cell deletion in AIDS Methods HOS cells (HOS CR2) and HOS CD4 cells (HOS CD4CR2) stably expressing CR2 were established and then identified by FACS and Western blotting Activation and blocking tests of MAPKs were assessed by Western blot Cell proliferation was determined using Cell Titer 96 Aqueous One Solution Reagent Results FACS results showed that the positive rates of HOS CR2 and HOS CD4CR2 cells were greater than 96%, and Western blot showed that the CR2 expression levels on HOS CR2 and HOS CD4CR2 cells were high Activation and blocking tests of MAPKs (ERK, JNK, and p38MAPK) were carried out in HOS CR2, HOS CD4, and HOS CD4CR2 cells The activation of MAPKs in HOS CR2 cells stimulated with PMA (100 ng/ml) and NHS (10%) was identical The activation of MAPKs increased at 5 minutes, reached a peak at 10 minutes, and decreased to baseline within 30 minutes, all in a time dependent manner; the activation of MAPKs was blocked by anti CR2 McAb, PD98059 (inhibitor of ERK), and Wortmanin (inhibitor of PI 3K), respectively In HOS CD4 cells, MAPKs were activated by HIV gp160 In HOS CD4CR2 cells, MAPK activation was induced by HIV gp160, 10% NHS, and HIV gp160+10%NHS; phosphorylation of p38MAPK was dramatically induced by HIV gp160+NHS, and lasted for 1 hour The cell proliferation results showed that HIV gp160 inhibited the proliferation of HOS CD4 and HOS CD4CR2 cells ( P <0 01) and that NHS enhanced the effect of HIV gp160 ( P <0 01) Conclusions The activation of MAPKs is independently mediated by CR2 and that anti CR2 McAb, PD98059, and Wortmanin block the activation of MAPKs, respectively The results of the signal transduction and cell proliferation assays of HOS CD4CR2 cells show that CR2 plays a role in the pathogenesis of HIV infection, especially in the inhibition of CD 4 + cell proliferation

MEK inhibition activates STAT signaling to increase breast cancer immunogenicity via MHC-I expression

Aim:Immunotherapy and immune checkpoint inhibitors(ICI)have changed cancer care for many patients;however,breast cancers have exhibited minimal response to single agent ICI therapy.There is a significant need to identify novel targets capable of increasing cancer cell immunogenicity and response to ICIs in breast cancer.Mitogen activated protein kinase(MAPK)signaling is essential for many cellular processes but the relationship between MAPK signaling and cancer cell immunogenicity is less well understood.Recent reports suggest that MEK inhibition(MEKi)affects the tumor-immune microenvironment by altering the expression of interferon responsive PD-L1 and MHC-I through unknown mechanisms.Methods:Using western blotting and flow cytometry,we sought to determine whether MEKi affects JAK-STAT signaling upstream of PD-L1 and MHC-I expression in a panel of mouse mammary cancer and triple negative breast cancer cell lines.Results:The cell lines tested exhibited increased STAT activation in response to MEKi treatment.Furthermore,MEKi-induced MHC-I and PD-L1 expression are dependent upon STAT1 in MMTV-Neu cells.Interestingly,MEKiinduced STAT activation and interferon-responsive protein expression are abrogated with ErbB-family inhibitor co-treatment in MMTV-Neu cells,suggesting ErbB receptor signaling dependence,but not in basal-like cell lines.Importantly,analysis of basal-like breast cancer patient samples exhibited an inverse relationship between STAT1 and Ras/MAPK activation signatures.Conclusion:These findings suggest that MAPK signaling and STAT activation are inversely related in both mouse and human mammary tumors.This work also supports further study of MEKi to increase STAT signaling and potentially,immunotherapy responses through increased MHC-I and PD-L1 expression.

Primate Torpor: Regulation of Stress-activated Protein Kinases During Daily Torpor in the Gray Mouse Lemur, Microcebus murinus

Very few selected species of primates are known to be capable of entering torpor. This exciting discovery means that the ability to enter a natural state of dormancy is an ancestral trait among primates and, in phylogenetic terms, is very close to the human lineage. To explore the regulatory mechanisms that underlie primate torpor, we analyzed signal transduction cascades to discover those involved in coordinating tissue responses during torpor. The responses of mitogen-activated protein kinase（MAPK） family members to primate torpor were compared in six organs of control（aroused） versus torpid gray mouse lemurs, Microcebus murinus. The proteins examined include extracellular signal-regulated kinases（ERKs）, c-jun NH2-terminal kinases（JNKs）, MAPK kinase（MEK）, and p38, in addition to stress-related proteins p53 and heat shock protein 27（HSP27）. The activation of specific MAPK signal transduction pathways may provide a mechanism to regulate the expression of torpor-responsive genes or the regulation of selected downstream cellular processes. In response to torpor, each MAPK subfamily responded differently during torpor and each showed organ-specific patterns of response. For example, skeletal muscle displayed elevated relative phosphorylation of ERK1/2 during torpor. Interestingly, adipose tissues showed the highest degree of MAPK activation. Brown adipose tissue displayed an activation of ERK1/2 and p38, whereas white adipose tissue showed activation of ERK1/2, p38, MEK, and JNK during torpor. Importantly, both adipose tissues possess specialized functions that are critical for torpor, with brown adipose required for non-shivering thermogenesis and white adipose utilized as the primary source of lipid fuel for torpor. Overall, these data indicate crucial roles of MAPKs in the regulation of primate organs during torpor.