Diabetes and high-glucose could upregulate the expression of receptor for activated C kinase 1 in retina

BACKGROUND Diabetic retinopathy(DR)is a major ocular complication of diabetes mellitus,leading to visual impairment.Retinal pigment epithelium(RPE)injury is a key component of the outer blood retinal barrier,and its damage is an important indicator of DR.Receptor for activated C kinase 1(RACK1)activates protein kinase C-ε(PKC-ε)to promote the generation of reactive oxygen species(ROS)in RPE cells,leading to apoptosis.Therefore,we hypothesize that the activation of RACK1 under hypoxic/high-glucose conditions may promote RPE cell apoptosis by modulating PKC-ε/ROS,thereby disrupting the barrier effect of the outer blood retinal barrier and contributing to the progression of DR.AIM To investigate the role and associated underlying mechanisms of RACK1 in the development of early DR.METHODS In this study,Sprague-Dawley rats and adult RPE cell line-19(ARPE-19)cells were used as in vivo and in vitro models,respectively,to explore the role of RACK1 in mediating PKC-εin early DR.Furthermore,the impact of RACK1 on apoptosis and barrier function of RPE cells was also investigated in the former model.RESULTS Streptozotocin-induced diabetic rats showed increased apoptosis and upregulated expression of RACK1 and PKC-εproteins in RPE cells following a prolonged modeling.Similarly,ARPE-19 cells exposed to high glucose and hypoxia displayed elevated mRNA and protein levels of RACK1 and PKC-ε,accompanied by an increases in ROS production,apoptosis rate,and monolayer permeability.However,silencing RACK1 significantly downregulated the expression of PKC-εand ROS,reduced cell apoptosis and permeability,and protected barrier function.CONCLUSION RACK1 plays a significant role in the development of early DR and might serve as a potential therapeutic target for DR by regulating RPE apoptosis and barrier function.

Pan-TRK positive uterine sarcoma in immunohistochemistry without neurotrophic tyrosine receptor kinase gene fusions:A case report

BACKGROUND The classification of uterine sarcomas is based on distinctive morphological and immunophenotypic characteristics,increasingly supported by molecular genetic diagnostics.Data on neurotrophic tyrosine receptor kinase(NTRK)gene fusionpositive uterine sarcoma,potentially aggressive and morphologically similar to fibrosarcoma,are limited due to its recent recognition.Pan-TRK immunohistochemistry(IHC)analysis serves as an effective screening tool with high sensitivity and specificity for NTRK-fusion malignancies.CASE SUMMARY We report a case of a malignant mesenchymal tumor originating from the uterine cervix,which was pan-TRK IHC-positive but lacked NTRK gene fusions,accompanied by a brief literature review.A 55-year-old woman presented to the emergency department with abdominal pain and distension,exhibiting significant ascites and multiple solid pelvic masses.Pelvic examination revealed a tumor encompassing the uterine cervix,extending to the vagina and uterine corpus.A punch biopsy of the cervix indicated NTRK sarcoma with positive immunochemical pan-TRK stain.However,subsequent next generation sequencing revealed no NTRK gene fusion,leading to a diagnosis of poorly differentiated,advanced-stage sarcoma.CONCLUSION The clinical significance of NTRK gene fusion lies in potential treatment with TRK inhibitors for positive sarcomas.Identifying such rare tumors is crucial due to the potential applicability of tropomyosin receptor kinase inhibitor treatment.

Characterization of a S-locus-related Receptor-like Kinase Cluster in Rice Chromosome 4

We have identified 14 S _locus glycoprotein (SLG)_related protein kinase genes in a 323 kb contig of rice (Oryza sativa L.) chromosome 4 and we detected the transcription pattern of this gene cluster by reverse transcription_polymerase reaction (RT_PCR). RT_PCR results revealed that nine putative genes were transcribed in rice and these genes had the different expression patterns: two genes are expressed predominantly in reproductive tissues while the other seven genes are expressed in both reproductive and vegetative tissues. Analysis of the predicted amino acid sequences demonstrated that the extracellular receptor domains are highly homologous to SLG of Brassica, whereas the cytoplasmic kinase domains contain conserved amino acids present in serine/threonine kinases.

Advanced Lung Adenocarcinoma with EGFR 19-del Mutation Transformed into SCC after EGFR-tyrosine Kinase inhibitors Treatment:A Case report

BACKGROUND Epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs)significantly improve the survival of patients with Epidermal growth factor receptor(EGFR)sensitive mutations in non-small cell lung cancer(NSCLC).CASE SUMMARY A 67-year-old female patient in advanced lung adenocarcinoma suffered from drug resistance after EGFR-TKIs treatment.Secondary pathological tissue biopsy confirmed squamous cell carcinoma(SCC)transformation.Patients inevitably encountered drug resistance issues after receiving EGFR-TKIs treatment for a certain period of time,while EGFR-TKIs can significantly improve the survival of patients with EGFR-sensitive mutations in NSCLC.Notably,EGFR-TKIs resistance includes primary and acquired.Pathological transformation is one of the mechanisms of acquired resistance in EGFR-TKIs,with SCC transformation being relatively rare.Our results provide more detailed results of the patient’s diagnosis and treatment process on SCC transformation after EGFR-TKIs treatment for lung adenocarcinoma.CONCLUSION Squamous cell carcinoma transformation is one of the acquired resistance mechanisms of EGFR-TKIs in advanced lung adenocarcinoma with EGFR mutations.

Primary anaplastic lymphoma kinase-positive large B-cell lymphoma of the left bulbar conjunctiva: A case report

BACKGROUND Anaplastic lymphoma kinase(ALK)-positive large B-cell lymphoma(LBCL)is an aggressive and rare variant of diffuse LBCL.Herein,we report an uncommon case of stage IE extranodal ALK-positive LBCL initially originating in the bulbar con-junctiva.CASE SUMMARY A 63-year-old woman presented with a mass in the left bulbar conjunctiva that had persisted for six months,accompanied by swelling and pain that had per-sisted for 3 d.Eye examination revealed an 8 mm slightly elevated pink mass in the lower conjunctival sac of the left eye.Microscopically,the tumor was com-posed of large immunoblastic and plasmablastic large lymphoid cells with scattered anaplastic or multinucleated large cells.Immunophenotypically,the neoplastic cells were positive for ALK,CD10,CD138,Kappa,MUM1,BOB.1,OCT-2,CD4,CD45,EMA,CD79a,CD38,and AE1/AE3,and negative for CD20,PAX5,Lambda,BCL6,CD30 and all other T-cell antigens.The results of gene rearrangement tests showed monoclonal IGH/IGK/IGL and TCRD rearran-gements.Fluorescence in situ hybridization studies did not reveal any BCL2,BCL6 or MYC rearrangements.Furthermore,Epstein-Barr virus was not detected by in situ hybridization in the lesions.Based on the histopathological and imaging examinations,the neoplasm was classified as stage IE ALK-positive LBCL.No further treatments were administered.At the 6,15,and 21 mo postoperative follow-up visits,the patient was in good condition,without obvious discomfort.This case represents the first example of primary extranodal ALK-positive LBCL presenting as a bulbar conjunctival mass,which is extremely rare and shares morphological and immunohistochemical features with a variety of other neo-plasms that can result in misdiagnosis.CONCLUSION Awareness of the condition presented in this case report is necessary for early and accurate diagnosis and appropriate treatment.

Advanced lung adenocarcinoma with EGFR 19-del mutation transforms into squamous cell carcinoma after EGFR tyrosine kinase inhibitor treatment

In this editorial we comment on the article by Ji et al.We focus specifically on the EGFR tyrosine kinase inhibitor(EGFR-TKI)treatment and the development of drug resistance to EGFR-TKIs.

N-methyl-D-aspartate receptors mediate diphosphorylation of extracellular signal-regulated kinases through Src family tyrosine kinases and Ca^2＋/calmodulin-dependent protein kinase Ⅱ in rat hippocampus after cerebral ischemia

Objective： Extracellular signal-regulated kinases （ERKs） can be activated by calcium signals. In this study, we investigated whether calcium-dependent kinases were involved in ERKs cascade activation after global cerebral ischemia. Methods Cerebral ischemia was induced by four-vessel occlusion, and the calcium-dependent proteins were detected by immunoblot. Results Lethal-simulated ischemia significantly resulted in ERKs activation in N-methyl-D-aspartate （NMDA） receptor-dependent manner, accompanying with differential upregulation of Src kinase and Ca^2＋/calmodulin-dependent protein kinase Ⅱ （CaMKⅡ） activities. With the inhibition of Src family tyrosine kinases or CaMKⅡ by administration of PP2 or KN62, the phosphorylation of ERKs was impaired dramatically during post-ischemia recovery. However, ischemic challenge also repressed ERKs activity when Src kinase was excessively activated. Conclusions Src family tyrosine kinases and CaMKⅡ might be involved in the activation of ERKs mediated by NMDA receptor in response to acute ischemic stimuli in vivo, but the intense activation of Src kinase resulted from ischemia may play a reverse role in the ERKs cascade.

百子莲体细胞发育受体激酶APSERK1(Somatic Embryogenesis Receptor Kinase1)基因全长克隆及表达分析

根据前期百子莲(Agapanthus praecox ssp.orientalis)转录组测序分析的结果,获得了1个与胚性能力相关的关键基因Somatic Embryogenesis Receptor Kinase1(SERK1)同源性较高的核心片段。采用cDNA末端快速扩增(rapid amplification of cDNA ends,RACE)方法得到了百子莲SERK基因cDNA全长序列,命名为ApSERK1。序列分析表明,百子莲ApSERK1基因开放阅读框(ORF)为1800bp,编码1个含有600个氨基酸的蛋白质。氨基酸同源性比对发现,百子莲ApSERK1蛋白序列与水稻、小兰屿蝴蝶兰、铁皮石斛、椰子树和菠萝等植物蛋白序列的相似性可达到90%以上。实时荧光定量qRT-PCR结果表明,ApSERK1基因有一定时空表达差异,在百子莲的种子、小花梗中表达含量最高,且随着外源生长素浓度的增加,胚性愈伤组织的胚性能力呈现下降趋势。推测ApSERK1基因是衡量植物细胞胚性能力的重要指标。

Are TrkB receptor agonists the right tool to fulfill the promises for a therapeutic value of the brain-derived neurotrophic factor?

Brain-derived neurotrophic factor signaling via its receptor tro pomyosin receptor kinase B regulates several crucial physiological processes.It has been shown to act in the brain,promoting neuronal survival,growth,and plasticity as well as in the rest of the body where it is involved in regulating for instance aspects of the metabolism.Due to its crucial and very pleiotro pic activity,reduction of brain-derived neurotrophic factor levels and alterations in the brain-derived neurotrophic factor/tropomyosin receptor kinase B signaling have been found to be associated with a wide spectrum of neurological diseases.Howeve r,because of its poor bioavailability and pharmacological properties,brain-derived neurotrophic factor itself has a very low therapeutic value.Moreover,the concomitant binding of exogenous brain-derived neurotrophic factor to the p75 neurotrophin receptor has the potential to elicit several unwanted and deleterious side effects.Therefo re,developing tools and approaches to specifically promote tropomyosin receptor kinase B signaling has become an important goal of translational research.Among the newly developed tools are different categories of tropomyosin receptor kinase B receptor agonist molecules.In this review,we give a comprehensive description of the diffe rent tro pomyosin receptor kinase B receptor agonist drugs developed so far and of the res ults of their application in animal models of several neurological diseases.Moreover,we discuss the main benefits of tropomyosin receptor kinase B receptor agonists,concentrating especially on the new tropomyosin receptor kinase B agonist antibodies.The benefits observed both in vitro and in vivo upon application of tropomyosin receptor kinase B receptor agonist drugs seem to predominantly depend on their general neuroprotective activity and their ability to promote neuronal plasticity.Moreover,tro pomyosin receptor kinase B agonist antibodies have been shown to specifically bind the tropomyosin receptor kinase B receptor and not p75 neurotrophin receptor.Therefore,while,based on the current knowledge,the tropomyosin receptor kinase B receptor agonists do not seem to have the potential to reve rse the disease pathology per se,promoting brainderived neurotrophic factor/tro pomyosin receptor kinase B signaling still has a very high therapeutic relevance.

Suppressing high mobility group box-1 release alleviates morphine tolerance via the adenosine5'-monophosphate-activated protein kinase/heme oxygenase-1 pathway

Opioids,such as morphine,are the most potent drugs used to treat pain.Long-term use results in high tolerance to morphine.High mobility group box-1(HMGB1) has been shown to participate in neuropathic or inflammatory pain,but its role in morphine tolerance is unclear.In this study,we established rat and mouse models of morphine tolerance by intrathecal injection of morphine for 7 consecutive days.We found that morphine induced rat spinal cord neurons to release a large amount of HMGB1.HMGB1 regulated nuclear factor κB p65 phosphorylation and interleukin-1β production by increasing Toll-like receptor 4receptor expression in microglia,thereby inducing morphine tolerance.Glycyrrhizin,an HMGB1 inhibito r,markedly attenuated chronic morphine tole rance in the mouse model.Finally,compound C(adenosine 5’-monophosphate-activated protein kinase inhibitor) and zinc protoporphyrin(heme oxygenase-1 inhibitor)alleviated the morphine-induced release of HMGB1 and reduced nuclear factor κB p65 phosphorylation and interleukin-1β production in a mouse model of morphine tolerance and an SH-SY5Y cell model of morphine tole rance,and alleviated morphine tolerance in the mouse model.These findings suggest that morphine induces HMGB1 release via the adenosine 5’-monophosphate-activated protein kinase/heme oxygenase-1 signaling pathway,and that inhibiting this signaling pathway can effectively reduce morphine tole rance.

Targeting receptor tyrosine kinases in gastric cancer

Molecularly targeted therapeutic agents are constantly being developed and have been shown to be effective in various clinical trials. One group of representative targeted oncogenic kinases, the receptor tyrosine kinases (RTKs), has been associated with gastric cancer development. Trastuzumab, an inhibitor of ERBB2, has been approved for the treatment of gastric cancer, although other receptor tyrosine kinases, such as epidermal growth factor receptor, vascular endothelial growth factor, platelet-derived growth factor receptor, c-Met, IGF-1R and fibroblast growth factor receptor 2, are also activated in gastric cancer. The promising results of the trastuzumab clinical trial for gastric cancer resulted in the approval of trastuzumab-based therapy as a first-line treatment for human epidermal growth factor receptor 2-positive patients. On the other hand, the trial examining bevacizumab in combination with conventional chemotherapy did not meet its primary goal of increasing the overall survival time of gastric cancer patients; however, a significantly higher response rate and a longer progression-free survival were observed in the bevacizumab arm of the trial. Other clinical trials, especially phase III trials that have tested drugs targeting RTKs, such as cetuximab, panitumumab, gefitinib, erlotinib, figitumumab, sorafenib, sunitinib and lapatinib, have shown that these drugs have modest effects against gastric cancer. This review summarizes the recent results from the clinical trials of molecularly targeted drugs and suggests that further improvements in the treatment of advanced gastric cancer can be achieved through the combination of conventional drugs with the new molecularly targeted therapies.

Mismatched effects of receptor interacting protein kinase-3 on hepatic steatosis and inflammation in nonalcoholic fatty liver disease

AIM To validate the effects of receptor interacting protein kinase-3(RIP3) deletion in non-alcoholic fatty liver disease(NAFLD) and to clarify the mechanism of action.METHODS Wild-type(WT) and RIP3 knockout(KO) mice werefed normal chow and high fat(HF) diets for 12 wk. The body weight was assessed once weekly. After 12 wk, the liver and serum samples were extracted. The liver tissue expression levels of RIP3, microsomal triglyceride transfer protein, protein disulfide isomerase, apolipoprotein-B, X-box binding protein-1, sterol regulatory element-binding protein-1c, fatty acid synthase, cluster of differentiation-36, diglyceride acyltransferase, peroxisome proliferator-activated receptor alpha, tumor necrosis factor-alpha(TNF-α), and interleukin-6 were assessed. Oleic acid treated primary hepatocytes from WT and RIP3 KO mice were stained with Nile red. The expression of inflammatory cytokines, including chemokine(C-X-C motif) ligand(CXCL) 1, CXCL2, and TNF-α, in monocytes was evaluated.RESULTS RIP3 KO HF diet fed mice showed a significant gain in body weight, and liver weight, liver to body weight ratio, and liver triglycerides were increased in HF diet fed RIP3 KO mice compared to HF diet fed WT mice. RIP3 KO primary hepatocytes also had increased intracellular fat droplets compared to WT primary hepatocytes after oleic acid treatment. RIP3 overexpression decreased hepatic fat content. Quantitative real-time polymerase chain reaction analysis showed that the expression of very-low-density lipoproteins secretion markers(microsomal triglyceride transfer protein, protein disulfide isomerase, and apolipoprotein-B) was significantly suppressed in RIP3 KO mice. The overall NAFLD Activity Score was the same between WT and RIP3 KO mice; however, RIP3 KO mice had increased fatty change and decreased lobular inflammation compared to WT mice. Inflammatory signals(CXCL1/2, TNF-α, and interleukin-6) increased after lipopolysaccharide and pancaspase inhibitor(necroptotic condition) treatment in monocytes. Neutrophil chemokines(CXCL1, and CXCL2) were decreased, and TNF-α was increased after RIP3 inhibitor treatment in monocytes.CONCLUSION RIP3 deletion exacerbates steatosis, and partially inhibits inflammation in the HF diet induced NAFLD model.

MicroRNA-760 acts as a tumor suppressor in gastric cancer development via inhibiting G-protein-coupled receptor kinase interacting protein-1 transcription

BACKGROUND Gastric cancer(GC)has become a serious threat to people's health.Accumulative evidence reveals that dysregulation of numerous microRNAs(miRNAs)has been found during malignant formation.So far,the role of microRNA-760(miR-760)in the development of GC is largely unknown.AIM To measure the expression level of miR-760 in GC and investigate its role in gastric tumorigenesis.METHODS Real-time quantitative polymerase chain reaction and Western blot analysis were used to measure the expression of miR-760 and G-protein-coupled receptor kinase interacting protein-1(GIT1).Cell growth was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide(MTT)and cell colony formation assays.Apoptosis was assessed by flow cytometric analysis.The relationship between miR-760 and GIT1 was verified by luciferase reporter assay.RESULTS The results showed that the expression of miR-760 was decreased in GC and associated with poor clinical outcomes in GC patients.Furthermore,miR-760 restrained cell proliferation and cell colony formation and induced apoptosis in GC cells.In addition,miR-760 directly targeted GIT1 and negatively regulated its expression in GC.GIT1 was upregulated in GC and predicted a worse prognosis in GC patients.We also found that upregulation of GIT1 weakened the inhibitory CONCLUSION In conclusion,miR-760 targets GIT1 to inhibit cell growth and promote apoptosis in GC cells.Our data demonstrate that miR-760 may be a potential target for the treatment of GC.

Sphingosine kinase 1 is upregulated with lysophosphatidic acid receptor 2 in human colorectal cancer

AIM: To examine the expression of SphK1, an oncogenic kinase that produces sphingosine 1-phosphate (S1P), and its correlation with the expression of LPAR2, a major lysophosphatidic acid (LPA) receptor overexpressed in various cancers, in human colorectal cancer.METHODS: Real-time reverse-transcription polymerase chain reaction was used to measure the mRNA expression of SphK1, LPAR2, and the three major S1P receptors in 27 colorectal cancer samples and corresponding normal tissue samples. We also examined the correlation between the expression of SphK1 and LPAR2.RESULTS: Colorectal cancer tissue in 22 of 27 patients had higher levels of SphK1 mRNA than in normal tissue. In two-thirds of the samples, SphK1 mRNA expression was more than two-fold higher than in normal tissue. Consistent with previous reports, LPAR2 mRNA expression in 20 of 27 colorectal cancer tissue samples was higher compared to normal tissue samples. Expression profiles of all three major S1P receptors, S1PR1, S1PR2, and S1PR3, varied without any trend, with no significant difference in expression between cancer and normal tissues. A highly significant positive correlation was found between SphK1 and LPAR2 expression [Pearson’s correlation coefficient (r) = 0.784 and P < 0.01]. The mRNA levels of SphK1 and LPAR2 did not correlate with TNM stage.CONCLUSION: Our findings suggest that S1P and LPA may play important roles in the development of colorectal cancer via the upregulation of SphK1 and LPAR2, both of which could serve as new therapeutic targets in the treatment of colorectal cancer.

Epidermal growth factor receptor tyrosine kinase inhibitors for non-small cell lung cancer

First-generation epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs), including gefitinib and erlotinib, have proven to be highly effective agents for advanced non-small cell lung cancer(NSCLC) in patients harboring an activating EGFR mutation such as the exon 19 deletion mutation and L858 R. Although those reversible small molecular targeted agents provide a significant response and survival benefit, all responders eventually acquire resistance. Secondgeneration EGFR-targeting agents, such as irreversible EGFR/HER2 tyrosine kinase inhibitors and pan-HER TKIs, may improve survival further and be useful for patients who acquired resistance to first-generation EGFR-TKIs. This review discusses novel therapeutic strategies for EGFR-mutated advanced NSCLC using first- and second-generation EGFR-TKIs.

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.

Tyrosine kinase of insulin-like growth factor receptor as target for novel treatment and prevention strategies of colorectal cancer

AIM： To investigate the antineoplastic potency of the novel insulin-like growth factor 1 receptor （IGF-1R） tyrosine kinase inhibitor （TKI） NVP-AEW541 in cell lines and primary cell cultures of human colorectal cancer （CRC）. METHODS： Cells of primary colorectal carcinomas were from 8 patients. Immunostaining and crystal violet staining were used for analysis of growth factor receptor protein expression and detection of cell number changes, respectively. Cytotoxicity was determined by measuring the release of the cytoplasmic enzyme lactate dehydrogenase （LDH）. The proportion of apoptotic cells was determined by quantifying the percentage of sub-G1 （hypodiploid） cells. Cell cycle status reflected by the DNA content of the nuclei was detected by flow cytometry. RESULTS： NVP-AEW541 dose-dependently inhibited the proliferation of colorectal carcinoma cell lines and primary cell cultures by inducing apoptosis and cell cycle arrest. Apoptosis was characterized by caspase-3 activation and nuclear degradation. Cell cycle was arrested at the G1/S checkpoint. The NVP-AEW541-mediated cell cycle-related signaling involved the inactivation of Akt and extracellular signal-regulated kinase （ERK） 1/2, the upregulation of the cyclin-dependent kinase inhibitors p21^waf1/CIP1 and p27^kjp1, and the downregulation of the cell cycle promoter cyclin D1. Moreover, BAX was upregulated during NVP-AEW541-induced apoptosis, whereas Bcl-2 was downregulated. Measurement of LDH release showed that the antineoplastic effect of NVP-AEW541 was not due to general cytotoxicity of the compound. However, augmented antineoplastic effects were observed in combination treatments of NVP-AEW541 with either 5-FU, or the EGFR-antibody cetuximab, or the HMG-CoA-reductase inhibitor fluvastatin. CONCLUSION： IGF-1R-TK inhibition is a promising novel approach for either monoor combination treatment strategies of colorectal carcinoma and even for CRC chemoprevention.

Preassembly and ligand-induced restructuring of the chains of the IFN-γ receptor complex： the roles of Jak kinases, Statl and the receptor chains

We previously demonstrated using noninvasive technologies that the interferon-gamma （IFN-γ） receptor complex is preassembled [ 1 ]. In this report we determined how the receptor complex is preassembled and how the ligand-mediated conformational changes occur. The interaction of Statl with IFN-γR1 results in a conformational change localized to IFN- γR1. Jakl but not Jak2 is required for the two chains of the IFN-γ receptor complex （IFN-γR1 and IFN-γR2） to interact; however, the presence of both Jakl and Jak2 is required to see any ligand-dependant conformational change. Two IFN- γR2 chains interact through species-specific determinants in their extracellular domains. Finally, these determinants also participate in the interaction of IFN-γR2 with IFN-γR1. These results agree with a detailed model of the IFN-γ receptor that requires the receptor chains to be pre-associated constitutively for the receptor to be active.

Auditory deprivation modifies the expression of brain-derived neurotrophic factor and tropomyosin receptor kinase B in the rat auditory cortex

The development and plasticity of central auditory system can be influenced by the change of peripheral neuronal activity. However, the molecular mechanism participating in the process remains elusive. Brain-derived neurotrophic factor(BDNF) binding with its functional receptor tropomyosin receptor kinase B(TrkB) has multiple effects on neurons. Here we used a rat model of auditory deprivation by bilateral cochlear ablation, to investigate the changes in expression of BDNF and Trk B in the auditory cortex after auditory deprivation that occurred during the critical period for the development of central auditory system. Reverse transcription-quantitative polymerase chain reaction(RTqPCR) and immunohistochemistry methods were adopted to detect the m RNA and protein expression levels of BDNF and TrkB in the auditory cortex at 2, 4, 6 and 8 weeks after surgery, respectively. The change in the expression of BDNF and TrkB mRNAs and proteins followed similar trend. In the bilateral cochlear ablation groups, the BDNF-TrkB expression level initially decreased at 2 weeks but increased at 4 weeks followed by the reduction at 6 and 8 weeks after cochlear removal, as compared to the age-matched sham control groups. In conclusion, the BDNF-TrkB signaling is involved in the plasticity of auditory cortex in an activity-dependent manner.

Imipramine protects retinal ganglion cells from oxidative stress through the tyrosine kinase receptor B signaling pathway

Retinal ganglion cell（RGC） degeneration is irreversible in glaucoma and tyrosine kinase receptor B（Trk B）-associated signaling pathways have been implicated in the process.In this study,we attempted to examine whether imipramine,a tricyclic antidepressant,may protect hydrogen peroxide（H_2O_2）-induced RGC degeneration through the activation of the Trk B pathway in RGC-5 cell lines.RGC-5 cell lines were pre-treated with imipramine 30 minutes before exposure to H_2O_2.Western blot assay showed that in H_2O_2-damaged RGC-5 cells,imipramine activated Trk B pathways through extracellular signal-regulated protein kinase/Trk B phosphorylation.TUNEL staining assay also demonstrated that imipramine ameliorated H_2O_2-induced apoptosis in RGC-5 cells.Finally,Trk B-Ig G intervention was able to reverse the protective effect of imipramine on H_2O_2-induced RGC-5 apoptosis.Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the Trk B signaling pathway.