MiRNA-122 Promotes Ischemia-Reperfusion Injury after Lung Transplantation via the Toll-like Receptor Signaling Pathway

Objective:MiRNAs have been recently implicated in the pathogenesis of ischemia-reperfusion(IR)injury.This study aimed to investigate the miRNA expression profiles,in the early stages after lung transplantation(LT)and to study the involvement of the Toll-like receptor(TLR)signaling pathway in lung IR injury following LT.Methods:We established the left LT model in mice and selected the miRNA-122 as a research target.The mice were injected with a miRNA-122-specific inhibitor,following which pathological changes in the lung tissue were studied using different lung injury indicators.In addition,we performed deep sequencing of transplanted lung tissues to identify differentially expressed(DE)miRNAs and their target genes.These target genes were used to further perform gene ontology(GO)enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis.Results:A total of 12 DE miRNAs were selected,and 2476 target genes were identified.The GO enrichment analysis predicted 6063 terms,and the KEGG analysis predicted 1554 biological pathways.Compared with the control group,inhibiting the expression of miRNA-122 significantly reduced the lung injury and lung wet/dry ratio(P<0.05).In addition,the activity of myeloperoxidase and the expression levels of tumor necrosis factor-alpha and TLR2/4 were decreased(P<0.05);whereas the expression of interleukin-10 was increased(P<0.05).Furthermore,the inhibition of miRNA-122 suppressed the IR injury-induced activation of the TLR signaling pathway.Conclusion:Our findings showed the differential expression of several miRNAs in the early inflammatory response following LT.Of these,miRNA-122 promoted IR injury following LT,whereas its inhibition prevented IR injury in a TLR-dependent manner.

Metabotropic glutamate receptors(mGluRs)in epileptogenesis:an update on abnormal mGluRs signaling and its therapeutic implications

Epilepsy is a neurological disorder characterized by high morbidity,high recurrence,and drug resistance.Enhanced signaling through the excitatory neurotransmitter glutamate is intricately associated with epilepsy.Metabotropic glutamate receptors(mGluRs)are G protein-coupled receptors activated by glutamate and are key regulators of neuronal and synaptic plasticity.Dysregulated mGluR signaling has been associated with various neurological disorders,and numerous studies have shown a close relationship between mGluRs expression/activity and the development of epilepsy.In this review,we first introduce the three groups of mGluRs and their associated signaling pathways.Then,we detail how these receptors influence epilepsy by describing the signaling cascades triggered by their activation and their neuroprotective or detrimental roles in epileptogenesis.In addition,strategies for pharmacological manipulation of these receptors during the treatment of epilepsy in experimental studies is also summarized.We hope that this review will provide a foundation for future studies on the development of mGluR-targeted antiepileptic drugs.

Netrin-1 signaling pathway mechanisms in neurodegenerative diseases

Netrin-1 and its receptors play crucial roles in inducing axonal growth and neuronal migration during neuronal development.Their profound impacts then extend into adulthood to encompass the maintenance of neuronal survival and synaptic function.Increasing amounts of evidence highlight several key points:(1)Diminished Netrin-1 levels exacerbate pathological progression in animal models of Alzheimer’s disease and Parkinson’s disease,and potentially,similar alterations occur in humans.(2)Genetic mutations of Netrin-1 receptors increase an individuals’susceptibility to neurodegenerative disorders.(3)Therapeutic approaches targeting Netrin-1 and its receptors offer the benefits of enhancing memory and motor function.(4)Netrin-1 and its receptors show genetic and epigenetic alterations in a variety of cancers.These findings provide compelling evidence that Netrin-1 and its receptors are crucial targets in neurodegenerative diseases.Through a comprehensive review of Netrin-1 signaling pathways,our objective is to uncover potential therapeutic avenues for neurodegenerative disorders.

Adenosine 2A receptor contributes to the facilitation of postinfectious irritable bowel syndrome by γδ T cells via the PKA/CREB/NF-κB signaling pathway

BACKGROUND Immunological dysfunction-induced low-grade inflammation is regarded as one of the predominant pathogenetic mechanisms in post-infectious irritable bowel syndrome(PI-IBS).γδT cells play a crucial role in innate and adaptive immunity.Adenosine receptors expressed on the surface ofγδT cells participate in intestinal inflammation and immunity regulation.AIM To investigate the role ofγδT cell regulated by adenosine 2A receptor(A2AR)in PI-IBS.METHODS The PI-IBS mouse model has been established with Trichinella spiralis(T.spiralis)infection.The intestinal A2AR and A2AR inγδT cells were detected by immunohistochemistry,and the inflammatory cytokines were measured by western blot.The role of A2AR on the isolatedγδT cells,including proliferation,apoptosis,and cytokine production,were evaluated in vitro.Their A2AR expression was measured by western blot and reverse transcription polymerase chain reaction(RT-PCR).The animals were administered with A2AR agonist,or A2AR antagonist.Besides,γδT cells were also injected back into the animals,and the parameters described above were examined,as well as the clinical features.Furthermore,the A2AR-associated signaling pathway molecules were assessed by western blot and RT-PCR.RESULTS PI-IBS mice exhibited elevated ATP content and A2AR expression(P<0.05),and suppression of A2AR enhanced PI-IBS clinical characteristics,indicated by the abdominal withdrawal reflex and colon transportation test.PI-IBS was associated with an increase in intestinal T cells,and cytokine levels of interleukin-1(IL-1),IL-6,IL-17A,and interferon-α(IFN-α).Also,γδT cells expressed A2AR in vitro and generated IL-1,IL-6,IL-17A,and IFN-α,which can be controlled by A2AR agonist and antagonist.Mechanistic studies demonstrated that the A2AR antagonist improved the function ofγδT cells through the PKA/CREB/NF-κB signaling pathway.CONCLUSION Our results revealed that A2AR contributes to the facilitation of PI-IBS by regulating the function ofγδT cells via the PKA/CREB/NF-κB signaling pathway.

Role of Toll-like receptor 4 and Janus kinase and signal transducer and activator of transcription signal transduction pathway in sepsis-induced brain damage

The Janus kinase and signal transducer and activator of transcription （JAK/STAT） signal transduction pathway is involved in sepsis-induced functional damage to the heart, liver, kidney, and other organs. However, the cellular and molecular mechanisms underlying sepsis-induced brain damage remain elusive. In the present study, we found severe loss of neurons in the hippocampal CA1 region in rats with sepsis-induced brain damage following intraperitoneal injection of endotoxin, The expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 was significantly increased in brain tissues following lipopolysaccharide exposure. AG490 （JAK2 antagonist） and rapamycin （STAT3 antagonist） significantly reduced neuronal loss and suppressed the increased expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 in the hippocampal CA1 region in sepsis-induced brain damaged rats. Overall, these data suggest that blockade of the JAK/STAT signal transduction pathway is neuroprotective in sepsis-induced brain damage via the inhibition of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 exoression.

Efficacy of Jiangzhi Xiaoban tablet(降脂消斑片)on toll-like receptor 4/nuclear factor-kappa B/nod-like receptor protein 3 signaling pathway in mice with atherosclerosis induced by high-fat diet

OBJECTIVE:To study the effect of Jiangzhi Xiaoban tablet(降脂消斑片,JZXB)on toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB)/Nod-like receptor protein 3(NLRP3)signaling pathway expression in atherosclerosis(AS)mice by establishing a mouse model of AS,and to explore its mechanism of prevention and treatment of AS.METHODS:Sixty-four male C57BL/6J mice were randomly divided into two groups,12 in the normal control group and 52 in the model group(MOD).Seven weeks later,two mice in each of the above two groups were randomly sacrificed,and the whole aortic tissue of the mice was taken out for hematoxylin-eosin staining.After successful modeling,50 mice in the modeling group were randomly divided into 5 groups:MOD,atorvastatin group(ATO),low-dose group of JZXB(JZXB-L),middle-dose group of JZXB(JZXB-M),and high-dose group of JZXB(JZXB-H),10 mice in each group.The mice in each group were killed after 6 weeks of preventive administration.HE staining was used to observe the pathological changes of aorta in AS mice.The levels of serum triglyceride(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C)and high-density lipoprotein cholesterol(HDL-C)were detected by automatic biochemical analyzer.The levels of inflammatory factor interleukin-1β(IL-1β)were detected by enzyme linked immunosorbent assay.The expression of TLR4,NF-κB and NLRP3 proteins in aortic tissue was detected by immunohistochemistry.RESULTS:Compared with the MOD,the levels of serum TC,TG and LDL-C in the JZXB-H and ATO were significantly decreased,while the level of HDL-C was significantly increased.The levels of serum TG,LDL-C in the JZXB-M were significantly decreased,and the level of HDL-C was significantly increased.Compared with the MOD,the levels of IL-1βwere significantly decreased,aortic lesions were significantly improved,and the expression of TLR4,NF-κB,and NLRP3 proteins in the aortic tissue was significantly decreased in the JZXB-H,JZXB-M,and ATO.CONCLUSION:JZXB has inhibitory effect on atherosclerosis in mice,and its mechanism may be through regulating the TLR4/NF-κB/NLRP3 signaling pathway and reducing the inflammatory response,so as to play a role in inhibiting atherosclerosis.

Protective effect of modified Huangqi Chifeng decoction(加味黄芪赤风汤)on immunoglobulin A nephropathy through toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-kappa B signaling pathway

OBJECTIVE:To examine the nephroprotective mechanism of modified Huangqi Chifeng decoction(加味黄芪赤风汤,MHCD)in immunoglobulin A nephropathy(IgAN)rats.METHODS:To establish the IgAN rat model,the bovine serum albumin,lipopolysaccharide,and carbon tetrachloride 4 method was employed.The rats were then randomly assigned to the control,model,telmisartan,and high-,medium-,and low-dose MHCD groups,and were administered the respective treatments via intragastric administration for 8 weeks.The levels of 24-h urinary protein,serum creatinine(CRE),and blood urea nitrogen(BUN)were measured in each group.Pathological alterations were detected.IgA deposition was visualized through the use of immunofluorescence staining.The ultrastructure of the kidney was observed using a transmission electron microscope.The expression levels of interleukin-6(IL-6),monocyte chemoattractant protein-1(MCP-1),and transforming growth factor-β1(TGF-β1)were examined by immunohistochemistry and quantitative polymerase chain reaction.Levels of toll-like receptor 4(TLR4),myeloid differentiation factor 88(MyD88),and nuclear factor-kappa B(NF-κB)P65,were examined by immunohistochemistry,Western blotting,and quantitative polymerase chain reaction.RESULTS:The 24-h urine protein level in each group increased significantly at week 6,and worsen from then on.But this process can be reversed by treatments of telmisartan,and high-,medium-,and low-dose of MHCD,and these treatments did not affect renal function.Telmisartan,and high-,and medium-dose of MHCD reduced IgA deposition.Renal histopathology demonstrated the protective effect of high-,medium-,and low-dose of MHCD against kidney injury.The expression levels of MCP-1,IL-6,and TGF-β1 in kidney tissues were downregulated by low,medium and high doses of MHCD treatment.Additionally,treatment of low,medium and high doses of MHCD decreased the protein and mRNA levels of TLR4,MyD88,and NF-κB.CONCLUSIONS:MHCD exerted nephroprotective effects on IgAN rats,and MHCD regulated the expressions of key targets in TLR4/MyD88/NF-κB signaling pathway,thereby alleviating renal inflammation by inhibiting MCP-1,IL-6 expressions,and ameliorating renal fibrosis by inhibiting TGF-β1 expression.

Yemazhui(Herba Eupatorii Lindleyani)ameliorates lipopolysaccharide-induced acute lung injury via modulation of the toll-like receptor 4/nuclear factor kappa-B/nod-like receptor family pyrin domain-containing 3 protein signaling pathway and intestinal flor

OBJECTIVE:To investigate the impact of Yemazhui(Herba Eupatorii Lindleyani,HEL)against lipopolysaccharide(LPS)-induced acute lung injury(ALI)and explore its underlying mechanism in vivo.METHODS:The chemical constituents of HEL were analyzed by ultra-high performance liquid chromatographyquadrupole time-of-flight mass spectrometry method.Then,HEL was found to suppress LPS-induced ALI in vivo.Six-week-old male Sprague-Dawley rats were randomly divided into 6 groups:control,LPS,Dexamethasone(Dex),HEL low dose 6 g/kg(HEL-L),HEL medium dose 18 g/kg(HEL-M)and HEL high dose 54 g/kg(HEL-H)groups.The model rats were intratracheally injected with 3 mg/kg LPS to establish an ALI model.Leukocyte counts,lung wet/dry weight ratio,as well as myeloperoxidase(MPO)activity were determined followed by the detection with hematoxylin and eosin staining,enzyme linked immunosorbent assay,quantitative real time polymerase chain reaction,western blotting,immunohistochemistry,and immunofluorescence.Besides,to explore the effect of HEL on ALI-mediated intestinal flora,we performed 16s rRNA sequencing analysis of intestinal contents.RESULTS:HEL attenuated LPS-induced inflammation in lung tissue and intestinal flora disturbance.Mechanism study indicated that HEL suppressed the lung coefficient and wet/dry weight ratio of LPS-induced ALI in rats,inhibited leukocytes exudation and MPO activity,and improved the pathological injury of lung tissue.In addition,HEL reduced the expression of tumor necrosis factoralpha,interleukin-1beta(IL-1β)and interleukin-6(IL-6)in bronchoalveolar lavage fluid and serum,and inhibited nuclear displacement of nuclear factor kappa-B p65(NF-κBp65).And 18 g/kg HEL also reduced the expression levels of toll-like receptor 4(TLR4),myeloid differentiation factor 88,NF-κBp65,phosphorylated inhibitor kappa B alpha(phospho-IκBα),nod-like receptor family pyrin domain-containing 3 protein(NLRP3),IL-1β,and interleukin-18(IL-18)in lung tissue,and regulated intestinal flora disturbance.CONCLUSIONS:In summary,our findings revealed that HEL has a protective effect on LPS-induced ALI in rats,and its mechanism may be related to inhibiting TLR4/NF-κB/NLRP3 signaling pathway and improving intestinal flora disturbance.

Microwave Exposure Impairs Synaptic Plasticity in the Rat Hippocampus and PC12 Cells through Over-activation of the NMDA Receptor Signaling Pathway

Objective The aim of this study is to investigate whether microwave exposure would affect the N-methyI-D-aspartate receptor （NMDAR） signaling pathway to establish whether this plays a role in synaptic plasticity impairment. Methods 48 male Wistar rats were exposed to 30 mW/cm^2 microwave for 10 min every other day for three times. Hippocampal structure was observed through H＆E staining and transmission electron microscope. PC12 cells were exposed to 30 mW/cm^2 microwave for 5 min and the synapse morphology was visualized with scanning electron microscope and atomic force microscope. The release of amino acid neurotransmitters and calcium influx were detected. The expressions of several key NMDAR signaling molecules were evaluated. Results Microwave exposure caused injury in rat hippocampal structure and PC12 cells, especially the structure and quantity of synapses. The ratio of glutamic acid and gamma-aminobutyric acid neurotransmitters was increased and the intracellular calcium level was elevated in PC12 cells. A significant change in NMDAR subunits （NR1, NR2A, and NR2B） and related signaling molecules （CaZ＋/calmodulin-dependent kinase II gamma and phosphorylated cAMP-response element binding protein） were examined. Conclusion 30 mW/cm^2 microwave exposure resulted in alterations of synaptic structure, amino acid neurotransmitter release and calcium influx. NMDAR signaling molecules were closely associated with impaired synaptic plasticity.

B cell receptor signaling pathway involved in benign lymphoepithelial lesions of the lacrimal gland

AIM：To detect the expression of B cell receptor signaling pathway（BCRSP） in lacrimal gland benign lymphoepithelial lesions（LGBLEL）.METHODS：Gene microarray was used to compare whole-genome expression in lacrimal gland tissues from LGBLEL patients to tissues from orbital cavernous hemangioma（control tissues）. Expression of BCRSP was confirmed by polymerase chain reaction（PCR） and immunohistochemistry. RESULTS：The expression of 22 genes of the BCRSP increased significantly in LGBLEL patients. PCR analysis showed that CD22, CR2, and BTK were all highly expressed in LGBLEL tissues. Immunohistochemical analysis showed that CR2 protein was present in LGBLEL, but CD22 and BTK proteins were negative. CR2, CD22, and BTK were not observed in the orbital cavernous hemangiomas with either PCR or immunohistochemistry. CONCLUSION：BCRSP might be involved in the pathogenesis of LGBLEL.

Expression of Chicken Toll-Like Receptors and Signal Adaptors in Spleen and Cecum of Young Chickens Infected with Eimeria tenella

Toll-like receptors （TLRs） are a group of highly conserved molecules which initiate the innate immune response to pathogens by recognizing structural motifs of microbes. Understanding the changes in chicken Toll-like receptors （ChTLRs） and signal adaptors expression that occur with Eimeria tenella infection will help to elucidate the molecular basis of immune control of coccidiosis caused by Eimeria. The present study detected the dynamic changes in the expression of ChTLRs and associated signal adaptors in the spleen and cecum ofE. tenella-infected chickens during the early stage of infection. The results showed that the expression peak for ChTLRs, MyD88 and TRIF occurred at 12 h post-infection （hpi）, ChTLR3, ChTLRI 5 and MyD88 mRNA expression in the spleen ofE. tenella infected chickens were significantly higher （P〈0.05） than that of negative control chickens, and there were similar tendencies of these molecules expression in the cecum and spleen of E. tenella-infected chickens. The expression of MyD88 was upregnlated at four time points in the cecum of E. tenella-infected chickens. The results of this study indicate that ChTLR3, ChTLR15 and MyD88 play a role in young chickens infected with E. tenella.

Gamma-aminobutyric acid A receptors in Alzheimer＇s disease： highly localized remodeling of a complex and diverse signaling pathway

Alzheimer＇s disease （AD）, the predominant form of dementia, is a chronic, incurable neurodegenerative disorder presenting with symptoms includ- ing progressive memory loss and disturbed emotional state. It has been estimated that dementia affects over 47 million people worldwide （Prince et al., 2015）, and with 60-80% of cases attributable to AD.

Function of the CaMKII-ryanodine receptor signaling pathway in rabbits with left ventricular hypertrophy and triggered ventricular arrhythmia

BACKGROUND:Calcium calmodulin-dependent kinase II(CaMKII) can be more active in patients with left ventricular hypertrophy(LVH),which in turn causes phosphorylation of ryanodine receptors,resulting in inactivation and the instability of intracellular calcium homeostasis.The present study aimed to determine the effect of CaMKII-ryanodine receptor pathway signaling in rabbits with left ventricular hypertrophy and triggered ventricular arrhythmia.METHODS:Forty New Zealand rabbits were randomized into four groups(10 per group):sham group,LVH group,KN-93 group(LVH+KN-93),and ryanodine group(LVH+ryanodine).Rabbits in the LVH,KN-93,and ryanodine groups were used to establish a left ventricular hypertrophy model by the coarctation of the abdominal aorta,while those in the sham group did not undergo the coarctation.After eight weeks,action potentials(APs) were recorded simultaneously in the endocardium and epicardium,and a transmural electrocardiogram(ECG) was also recorded in the rabbit left ventricular wedge model.Drugs were administered to the animals in the KN-93 and ryanodine groups,and the frequency of triggered APs and ventricular tachycardia was recorded after the rabbits were given isoprenaline(1 μmol/L) and high-frequency stimulation.RESULTS:The frequency(animals/group) of triggered APs was 0/10 in the sham group,10/10 in the LVH group,4/10 in the KN-93 group,and 1/10 in the ryanodine group.The frequencies of ventricular tachycardia were 0/10,9/10,3/10,and 1/10,respectively.The frequencies of polymorphic ventricular tachycardia or ventricular fibrillation were 0/10,7/10,2/10,and 1/10,respectively.The frequencies of triggered ventricular arrhythmias in the KN-93 and ryanodine groups were much lower than those in the LVH group(P<0.05).CONCLUSIONS:KN-93 and ryanodine can effectively reduce the occurrence of triggered ventricular arrhythmia in rabbits with LVH.The CaMKII-ryanodine signaling pathway can be used as a new means of treating ventricular arrhythmia.

Effects of (-)-Epigallocatechin gallate on some protein factors involved in the epidermal growth factor receptor signaling pathway

（-）-Epigallocatechin gallate （EGCG）, a major polyphenolic constituent of green tea, can inhibit activity of specific receptor tyrosine kinases （RTKs） and related downstream signal transduction pathways, resulting in the control of unwanted cell proliferation. The epidermal growth factor receptor （EGFR） signaling pathway is one of the most important pathways that regulates growth, survival,proliferation and differentiation in mammalian cells. This review addresses the effects of EGCG on some protein factors involved in the EGFR signaling pathway in a direct or indirect manner. Based on our understanding of the interaction between EGCG and these factors, and based on their structures, EGCG could be used as a lead compound for designing and synthesizing novel drugs with significant biological activity.

Research progress on the regulation of androgen receptor signaling pathway in the treatment of prostate cancer by traditional Chinese medicine monomers

The prevalence of prostate cancer in males worldwide is increasing every year.Androgen and androgen receptor drive the development of prostate cancer and are important targets for the treatment of prostate cancer.A growing number of reports indicate that the traditional Chinese medicine has a clear advantage in the prevention and treatment of prostate cancer.This article provides an overview of the in vitro and in vivo studies of different traditional Chinese medicine monomers acting on the androgen receptor-signaling pathway in prostate cancer.

Toll-like receptors in pathophysiology of liver diseases

Toll-like receptors(TLRs) are pattern recognition receptors that participate in host defense by recognizing pathogen-associated molecular patterns alongside inflammatory processes by recognizing damage associated molecular patterns. Given constant exposure to pathogens from gut, strict control of TLR-associated signaling pathways is essential in the liver, which otherwise may lead to inappropriate production of pro-inflammatory cytokines and interferons and may generate a predisposition to several autoimmune and chronic inflammatory diseases. The liver is considered to be a site of tolerance induction rather than immunity induction, with specificity in hepatic cell functions and distribution of TLR. Recent data emphasize significant contribution of TLR signaling in chronic liver diseases via complex immune responses mediating hepatocyte(i.e., hepatocellular injury and regeneration) or hepatic stellate cell(i.e., fibrosis and cirrhosis) inflammatory or immune pathologies. Herein, we review the available data on TLR signaling, hepatic expression of TLRs and associated ligands, as well as the contribution of TLRs to the pathophysiology of hepatic diseases.

Oxymatrine reduces neuroinflammation in rat brain A signaling pathway

Cerebral neuroinflammation models were established by injecting 10μg lipopolysaccharide into the hippocampus of male Sprague-Dawley rats. The rats were treated with an intraperitoneal injection of 120, 90, or 60 mg/kg oxymatrine daily for three days prior to the lipopolysaccharide injection. Twenty-four hours after model induction, the hippocampus was analyzed by real-time quantitative PCR, and the cerebral cortex was analyzed by enzyme-linked immunosorbent assay and western blot assay. The results of the enzyme-linked immunosorbent assay and the real-time quantitative PCR showed that the secretion and mRNA expression of the pro-inflammatory cytokines interleukin-113 and tumor necrosis factor-a were significantly decreased in the hippocampus and cerebral cortex of model rats treated with oxymatrine. Western blot assay and real-time quantitative PCR analysis indicated that toll-like receptor 4 mRNA and protein expression were significantly decreased in the groups receiving different doses of oxymatrine. Additionally, 120 and 90 mg/kg oxymatrine were shown to reduce protein levels of nuclear factor-KB p65 in the nucleus and of phosphorylated IKBa in the cytoplasm of brain cells, as detected by western blot assay. Experimental findings indicate that oxymatrine may inhibit neuroinflammation in rat brain via downregulating the expression of molecules in the toll-like receptor 4/nuclear factor-KB signaling Dathwav.

Fibroblast growth factor receptor signaling as therapeutic targets in gastric cancer

Fibroblast growth factor receptors(FGFRs) regulate a variety of cellular functions, from embryogenesis to adult tissue homeostasis. FGFR signaling also plays significant roles in the proliferation, invasion, and survival of several types of tumor cells. FGFR-induced alterations, including gene amplification, chromosomal translocation, and mutations, have been shown to be associated with the tumor initiation and progression of gastric cancer, especially in diffuse-type cancers. Therefore, the FGFR signaling pathway might be one of the therapeutic targets in gastric cancer. This review aims to provide an overview of the role of FGFR signaling in tumorigenesis, tumor progression, proliferation, and chemoresistance. We also discuss the accumulating evidence that demonstrates the effectiveness of using clinical therapeutic agents to inhibit FGFR signaling for the treatment of gastric cancer.

Pathogenesis of RON receptor tyrosine kinase in cancer cells: activation mechanism, functional crosstalk, and signaling addiction

The RON receptor tyrosine kinase, a member of the MET proto-oncogene family, is a pathogenic factor im- plicated in tumor malignancy. Specifically, aberrations in RON signaling result in increased cancer cell growth, survival, invasion, angiogenesis, and drug resistance. Biochemical events such as ligand binding, receptor over- expression, generation of structure-defected variants, and point mutations in the kinase domain contribute to RON signaling activation. Recently, functional crosstalk between RON and signaling proteins such as MET and EFGR has emerged as an additional mechanism for RON activation, which is critical for tumorigenic develop- ment. The RON signaling crosstalk acts either as a regulatory feedback loop that strengthens or enhances tumor- igenic phenotype of cancer cells or serves as a signaling compensatory pathway providing a growth/survival ad- vantage for cancer cells to escape targeted therapy. Moreover, viral oncoproteins derived from Friend leukemia or Epstein-Barr viruses interact with RON to drive viral oncogenesis. In cancer cells, RON signaling is integrated into cellular signaling network essential for cancer cell growth and survival. These activities provide the mo- lecular basis of targeting RON for cancer treatment. In this review, we will discuss recent data that uncover the mechanisms of RON activation in cancer cells, review evidence of RON signaling crosstalk relevant to cancer malignancy, and emphasize the significance of the RON signaling addiction by cancer cells for tumor therapy. Understanding aberrant RON signaling will not only provide insight into the mechanisms of tumor pathogenesis, but also lead to the development of novel strategies for molecularly targeted cancer treatment.

Research progress on signaling pathways in cirrhotic portal hypertension

Portal hypertension(PHT) is an important consequence of liver cirrhosis, which can lead to complications that adversely affect a patient's quality of life and survival, such as upper gastrointestinal bleeding, ascites, and portosystemic encephalopathy. In recent years, advances in molecular biology have led to major discoveries in the pathological processes of PHT, including the signaling pathways that may be involved: PI3 K-AKT-mTOR, RhoA/Rho-kinase, JAK2/STAT3, and farnesoid X receptor. However, the pathogenesis of PHT is complex and there are numerous pathways involved. Therefore, the targeting of signaling pathways for medical management is lagging. This article summarizes the progress that has been made in understanding the signaling pathways in PHT, and provides ideas for treatment of the disorder.