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.

Albumin resuscitation protects against traumatic/hemorrhagic shock-induced lung apoptosis in rats

Objective: To determine the effects of albumin administration on lung injury and apoptosis in traumatic/hemorrhagic shock (T/HS) rats. Methods: Studies were performed on an in vivo model of spontaneously breathing rats with induced T/HS; the rats were subjected to femur fracture, ischemia for 30 min, and reperfusion for 20 min with Ringer's lactate solution (RS) or 5% (w/v) albumin (ALB), and the left lower lobes of the lungs were resected. Results: Albumin administered during reperfusion markedly attenuated injury of the lung and decreased the concentration of lactic acid and the number of in situ TdT-mediated dUTP nick-end labelling (TUNEL)-positive cells. Moreover, immunohistochemistry performed 24 h after reperfusion revealed increases in the level of nuclear factor κB (NF-κB), and phosphorylated p38 mitogen-activated protein kinase (MAPK) in the albumin-untreated group was down-regulated by albumin treatment when compared with the sham rats. Conclusion: Resuscitation with albumin attenuates tissue injury and inhibits T/HS-induced apoptosis in the lung via the p38 MAPK signal transduction pathway that functions to stimulate the activation of NF-κB.

Scutellarein Ameliorated Chondrocyte Inflammation and Osteoarthritis in Rats

Objective:Osteoarthritis(OA)is a degenerative joint disorder characterized by the gradual degradation of joint cartilage and local inflammation.This study aimed to investigate the anti-OA effect of scutellarein(SCU),a single-unit flavonoid compound obtained from Scutellaria barbata D.Don,in rats.Methods:The extracted rat chondrocytes were treated with SCU and IL-1β.The chondrocytes were divided into control group,IL-1βgroup,IL-1β+SCU 50µmol/L group,and IL-1β+SCU 100µmol/L group.Morphology of rat chondrocytes was observed by toluidine blue and safranin O staining.CCK-8 method was used to detect the cytotoxicity of SCU.ELISA,qRT-PCR,Western blotting,immunofluorescence,SAβ-gal staining,flow cytometry,and bioinformatics analysis were applied to evaluate the effect of SCU on rat chondrocytes under IL-1βintervention.Additionally,anterior cruciate ligament transection(ACL-T)was used to establish a rat OA model.Histological changes were detected by safranin O/fast green,hematoxylin-eosin(HE)staining,and immunohistochemistry.Results:SCU protected cartilage and exhibited anti-inflammatory effects via multiple mechanisms.Specifically,it could enhance the synthesis of extracellular matrix in cartilage cells and inhibit its degradation.In addition,SCU partially inhibited the nuclear factor kappa-B/mitogen-activated protein kinase(NF-κB/MAPK)pathway,thereby reducing inflammatory cytokine production in the joint cartilage.Furthermore,SCU significantly reduced IL-1β-induced apoptosis and senescence in rat chondrocytes,further highlighting its potential role in OA treatment.In vivo experiments revealed that SCU(at a dose of 50 mg/kg)administered for 2 months could significantly delay the progression of cartilage damage,which was reflected in a lower Osteoarthritis Research Society International(OARSI)score,and reduced expression of matrix metalloproteinase 13(MMP13)in cartilage.Conclusion:SCU is effective in the therapeutic management of OA and could serve as a potential candidate for future clinical drug therapy for OA.

Regulation of CD137 expression through K-Ras signaling in pancreatic cancer cells

Background:The interaction between CD137 and its ligand(CD137L)plays a major role in the regulation of immune functions and affects cancer immunotherapy.CD137 is a cell surface protein mainly located on activated T cells,and its regulation and functions in immune cells are well established.However,the expression of CD137 and its regulation in cancer cells remain poorly understood.The main purposes of this study were to examine the expression of CD137 in pancreatic cancer cells and to investigate its underlying mechanisms.Methods:Cells containing inducible K-RasG12V expression vector or with different K-Ras mutational statuses were used as in vitro models to examine the regulation of CD137 expression by K-Ras.Various molecular assays were employed to explore the regulatory mechanisms.Tumor specimens from 15 pancreatic cancer patients and serum samples from 10 patients and 10 healthy donors were used to test if the expression of CD137 could be validated in clinical samples.Results:We found that the CD137 protein was expressed on the cell surface in pancreatic cancer tissues and cancer cell lines.Enzyme-linked immunosorbent assay revealed no difference in the levels of secreted CD137 in the sera of patients and healthy donors.By using the K-Ras inducible cell system,we further showed that oncogenic K-Ras up-regulated CD137 through the activation of MAPK(mitogen-activated protein kinases)and NF-κB(nuclear factor kappa-light-chain-enhancer of activated B cells)pathways,as evidenced by significantly reduced CD137 mRNA expression led by genetic silencing of MAPK1 and p65,the key proteins involved in the respective pathways.Further-more,we also found that the NF-κB pathway was mainly stimulated by the K-Ras-induced secretion of interleukin-1α(IL-1α)which promoted the transcription of the CD137 gene in pancreatic cancer cell lines.Analysis of the TCGA(the cancer genome atlas)database also revealed a significant correlation between IL-1αand CD137 expression(r=0.274)in tumor samples from pancreatic cancer patients(P<0.001).Conclusions:The present study has demonstrated that the CD137 protein was expressed on pancreatic cancer cell surface,and has identified a novel mechanism by which K-Ras regulates CD137 in pancreatic cancer cells through MAPK and NF-κB pathways stimulated by IL-1α.

Assessing the therapeutic impact of Qianjinba polysaccharide in a rheumatoid arthritis murine model

Qianjinba is primarily cultivated in the southern regions of China and finds extensive use in traditional Chinese medicine(TCM)for conditions such as rheumatism,arthralgia,and gynecological ailments.It has been officially recognized as a protected variety of TCM by the state.The aim of this study was to investigate the therapeutic potential of Qianjinba polysaccharide(QJBDT)in treating rheumatoid arthritis(RA)in mice,along with a preliminary exploration of its mechanisms for inhibiting RA in these animals.Kunming mice(KM)were randomly divided into several groups,including a normal group,a model group(LPS group),low-dose,medium-dose,and high-dose QJBDT groups,as well as a positive control group(TGP group),each consisting of 10 mice.To induce inflammation and create an RA model,type II collagen was injected into the right hind foot joint.Following a 7-day modeling period,various concentrations of QJBDT and the positive control drug total glycoside of peony were administered via gavage once a day for 21 consecutive days.Throughout the study,we monitored and recorded the mice's weight,measured foot swelling,and assessed the arthritis index on a weekly basis.We also conducted pathological examinations of joint tissues and analyzed the signal pathway of p38 mitogen-activated protein kinase(MAPK)as well as the protein expression of nuclear factor NF-κB in the mice’s right foot joint tissues.Additionally,we employed ELISA to detect the levels of interleukin-β(IL-β),IL-17,and tumor necrosis factor-α(TNF-α)in the mice’s serum.The results of this study revealed that QJBDT effectively reduced the degree of foot swelling and the arthritis index in collagen-induced arthritis mice while improving their weight loss(P<0.05).Furthermore,it alleviated the pathological damage observed in the mice’s joints.Notably,the expression of transcription factors p38 and NF-κB proteins was down-regulated(P<0.05),and the levels of inflammatory cytokines IL-β,IL-17,and TNF-αin the mice’s serum were decreased(P<0.05).In conclusion,this study demonstrated that polysaccharides could inhibit the expression of transcription factors p38 and NF-κB,reduce the production of inflammatory factors,and alleviate the progression of RA to a certain extent.