Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracel...Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracellular signal regulated kinase （ERK） expression in it. Methods： Rat＇s HSC-T6 were cultured and treated by SAB or curcumin. The inhibitory effect on cell proliferation was determined by 3-（4,5-dimthyl-2- 2thiazoly）-2,5-diphenyl-2H-tetrazolium bromide （MTT） colorimetry, and the expression levels of a smooth actin （a-SMA）, collagen type Ⅰ , and ERK were determined by Western blot. Results： SAB and curcumin inhibited the proliferation and activation of rat＇s HSC-T6 in dose-dependent fashion and significantly reduced the expression level of a-SMA （ P〈0.01 ）. Curcumin significantly reduced the expression of collagen type Ⅰ （P〈0.05）. Both SAB and curcumin showed insignificant effect on the ERK expression level, but they could significantly reduce the level of phosphorylated-ERK expression, showing significant difference as compared with that in the control group （ P〈0.01 and P〈0.05 respectively）. Conclusion： SAB and curcumin could significantly inhibit the proliferation, activation of HSC, and the production of type Ⅰ collagen in HSC, the mechanism may be associated with their inhibition on ERK phosphorylation.展开更多
Objective： To investigate the relationship between the proliferation of sensitized human airway smooth muscle cells （HASMCs） and the expression of extracellular signal regulated kinase （ERK） and the effect of She...Objective： To investigate the relationship between the proliferation of sensitized human airway smooth muscle cells （HASMCs） and the expression of extracellular signal regulated kinase （ERK） and the effect of Shenmai Injection （参麦注射液, SMI） on HASMCs. Methods： The HASMCs cultured in vitro were divided into three groups： （1） control group; （2） sensitized group： containing 10% asthmatic serum; （3） SMI group： further divided into three different concentration subgroups interferred with 10 μL/mL, 50 μL/mL, and 100 μL/mL SMI, respectively. The proliferation of HASMCs was detected using MTT method, the expression of proliferating cell nucleus antigen （PCNA） in HASMCs was detected using immunocytochemical staining, and the expression of phosphoration-ERK1/2 （p-ERK1/2） protein was detected using Western-blot. Results： After passive sensitization, the optical density value （A49o value） of HASMCs was significantly increased from 0.366± 0.086 to 0.839 ± 0.168 （P〈0.05）. In addition, the expression of PCNA was significantly increased from 28.7% ± 5.9% in the control group to 69.8% ±7.5% in the sensitized group （P〈0.05）. At the same time, the expression of p-ERK1/2 in passively sensitized HASMCs was significantly increased compared with the control group （all P〈0.05）. Affer application of 10 μL/mL, 50 μL/mL, and 100 μL/mL SMI to the cultured media of passively sensitized group, the A570 value was significantly decreased from 0.839 ±0.168 to 0.612 ±0.100, 0.412 ± 0.092, and 0.339 ± 0.077, respectively （P〈0.05）. Moreover, the expression of PCNA was significantly decreased from 69.8% ±7.5% to 57.8% ± 6.2%, 40.7%±5.4%, and 26.1% ± 5.2%, respectively. At the same time, the expression of p-ERK1/2 in each SMI group was significantly decreased compared with the sensitized group （all ,P〈0.05）. Conclusion： ERK signal transduction pathway may be involved in the airway remodeling in asthma. The expression of ERK can be inhibited by SMI in a dose-dependent manner, thus preventing the proliferation of HASMCs.展开更多
In the recent two decades, it has been well elucidated that receptor activator of nuclear factor-κB ligand （RANKL; also known as TNFSF11） binding to its receptor RANK （also known as TNFRSF11A） drives osteoclast d...In the recent two decades, it has been well elucidated that receptor activator of nuclear factor-κB ligand （RANKL; also known as TNFSF11） binding to its receptor RANK （also known as TNFRSF11A） drives osteoclast development as the crucial signaling pathway.;However, accumulating evidence also implies that展开更多
RANKL signaling is essential for osteoclastogenesis. Its role in osteoblastic differentiation and bone formation is unknown. Here we demonstrate that RANK is expressed at an early stage of bone marrow mesenchymal stem...RANKL signaling is essential for osteoclastogenesis. Its role in osteoblastic differentiation and bone formation is unknown. Here we demonstrate that RANK is expressed at an early stage of bone marrow mesenchymal stem cells(BMSCs) during osteogenic differentiation in both mice and human and decreased rapidly. RANKL signaling inhibits osteogenesis by promoting β-catenin degradation and inhibiting its synthesis. In contrast, RANKL signaling has no significant effects on adipogenesis of BMSCs.Interestingly, conditional knockout of rank in BMSCs with Prx1-Cre mice leads to a higher bone mass and increased trabecular bone formation independent of osteoclasts. In addition, rank: Prx1-Cre mice show resistance to ovariectomy-(OVX) induced bone loss. Thus, our results reveal that RANKL signaling regulates both osteoclasts and osteoblasts by inhibition of osteogenic differentiation of BMSCs and promotion of osteoclastogenesis.展开更多
In order to investigate the changes in the expression of extracellular signal regulated kinase (ERK1/ERK2) and angiotensin converting enzyme (ACE) in the patients with atrial fibrillation (AF), 52 patients with rheu...In order to investigate the changes in the expression of extracellular signal regulated kinase (ERK1/ERK2) and angiotensin converting enzyme (ACE) in the patients with atrial fibrillation (AF), 52 patients with rheumatic heart diseases were examined. Nineteen patients had chronic persistent AF (AF≥6 months, CAF), 12 patients had paroxymal AF (PAF) and 21 patients had no history of AF. The ERK expression was detected at the mRNA level by reverse transcription polymerase chain reaction, at the protein level by Western blotting and at atrial tissue level by immunohistochemistry. ERK activating kinases (MEK1/2) and ACE were determined by Western blotting techniques. The expression of ERK2 mRNA was increased in the patients with CAF (74±19 U vs sinus rhythm: 32±24 U, P <0.05). Activated ERK1/ERK2 and MEK1/2 were increased to more than 150 % in the patients with AF compared to those with sinus rhythm. No significant difference between CAF and PAF was found. The expression of ACE was three fold increased in the patients with CAF compared to those with sinus rhythm. Patients with AF showed an increased expression of ERK1/ERK2 in atrial interstitial cells and marked atrial fibrosis. An ACE dependent increase in the amounts of activated ERK1/ERK2 in atrial interstitial cells may be one of molecular mechanisms for the development of atrial fibrosis in the patients with AF. These findings may have important impact on the treatment of AF.展开更多
Animals can sense many environment stimuli simultaneously and integrate these signals within the nervous system.However,the neural system and molecular mechanisms underlying are largely unknown.The insulin-like signal...Animals can sense many environment stimuli simultaneously and integrate these signals within the nervous system.However,the neural system and molecular mechanisms underlying are largely unknown.The insulin-like signaling pathway is known to regulate dauer formation,longevity and fat metabolism C.elegans.Here,we report that this pathway is also involved in interaction assay which is to observe the interaction between chemotaxis toward diacetyl and avoidance of cu2+ion.展开更多
Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rode...Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.展开更多
Arabidopsis seedlings undergo photomorphogenesis in the light and etiolation in the dark. HFR1, a bHLH transcription factor, is required for both phytochrome A (phyA)-mediated far-red and cryptochrome 1 (cry1)-mediate...Arabidopsis seedlings undergo photomorphogenesis in the light and etiolation in the dark. HFR1, a bHLH transcription factor, is required for both phytochrome A (phyA)-mediated far-red and cryptochrome 1 (cry1)-mediated blue light signaling. We report that HFR1 is a short-lived protein in darkness and is degraded through a 26S proteasome-dependent pathway. Light, irrespective of its quality, enhances HFR1 protein accumulation via promoting its stabilization. We demonstrate that HFR1 physically interacts with COP1 and that COP1 exhibits ubiquitin ligase activity toward HFR1 in vitro. In addition, we show that COP1 is required for degradation of HFR1 in vivo. Furthermore, plants overexpressing a C-terminal 161 amino acid fragment of HFR1 (CT161) display enhanced photomorphogenesis, suggesting an autonomous function of CT161 in promoting light signaling. This truncated HFR1 gene product is more stable than the full-length HFR1 protein in darkness, indicating that the COP1-interacting N-terminal portion of HFR1 is essential for COP1-mediated destabilization of HFR1. These results suggest that light enhances HFR1 protein accumulation by abrogating COP1-mediated degradation of HFR1, which is necessary and sufficient for promoting light signaling. Additionally, our results substantiate the E3 ligase activity of COP1 and its critical role in desensitizing light signaling.展开更多
Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for sign...Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.展开更多
YAP（yes-associated protein） is a transcriptional factor that is negatively regulated by Hippo pathway, a conserved pathway for the development and size control of multiple organs. The exact function of YAP in bone h...YAP（yes-associated protein） is a transcriptional factor that is negatively regulated by Hippo pathway, a conserved pathway for the development and size control of multiple organs. The exact function of YAP in bone homeostasis remains controversial. Here we provide evidence for YAP＇s function in promoting osteogenesis, suppressing adipogenesis, and thus maintaining bone homeostasis.YAP is selectively expressed in osteoblast（OB）-lineage cells. Conditionally knocking out Yap in the OB lineage in mice reduces cell proliferation and OB differentiation and increases adipocyte formation, resulting in a trabecular bone loss. Mechanistically, YAP interacts with β-catenin and is necessary for maintenance of nuclear β-catenin level and Wnt/β-catenin signaling. Expression of β-catenin in YAP-deficient BMSCs（bone marrow stromal cells） diminishes the osteogenesis deficit. These results thus identify YAP-β-catenin as an important pathway for osteogenesis during adult bone remodeling and uncover a mechanism underlying YAP regulation of bone homeostasis.展开更多
Bone morphogenetic proteins （Bmp） are well-known to induce bone formation following chondrogenesis, but the direct role of Bmp signaling in the osteoblast lineage is not completely understood. We have recently shown...Bone morphogenetic proteins （Bmp） are well-known to induce bone formation following chondrogenesis, but the direct role of Bmp signaling in the osteoblast lineage is not completely understood. We have recently shown that deletion of the receptor Bmprla in the osteoblast lineage with Dmpl-Cre reduces osteoblast activity in general but stimulates proliferation of preosteoblasts specifically in the cancellous bone region, resulting in diminished periosteal bone growth juxtaposed with excessive cancellous bone formation. Because expression of sclerostin （SOST）, a secreted Wnt antagonist, is notably reduced in the Bmprla- deficient osteocytes, we have genetically tested the hypothesis that increased Wnt signaling might mediate the increase in cancellous bone formation in response to Bmprla deletion. Forced expression of human SOST from a Dmpl promoter fragment partially rescues preosteoblast hyperproliferation and cancellous bone overgrowth in the Bmprla mutant mice, demonstrating functional interaction between Bmp and Wnt signaling in the cancellous bone compat^a-tent. To test whether increased Wnt signaling can compensate for the defect in periosteal growth caused by Bmprla deletion, we have generated compound mutants harboring a hyperactive mutation （A214V） in the Wnt receptor Lrp5. However, the mutant Lrp5 does not restore periosteal bone growth in the Bmprla-deficient mice. Thus, Bmp signaling restricts cancellous bone accrual partly through induction of SOST that limits preosteoblast proliferation, but promotes periosteal bone growth apparently independently of Wnt activation.展开更多
RBPjk-dependent Notch signaling regulates both the onset of chondrocyte hypertrophy and the progression to terminal chondrocyte maturation during endochondral ossification. It has been suggested that Notch signaling c...RBPjk-dependent Notch signaling regulates both the onset of chondrocyte hypertrophy and the progression to terminal chondrocyte maturation during endochondral ossification. It has been suggested that Notch signaling can regulate Sox9 transcription, although how this occurs at the molecular level in chondrocytes and whether this transcriptional regulation mediates Notch control of chondrocyte hypertrophy and cartilage development is unknown or controversial. Here we have provided conclusive genetic evidence linking RBPjk-dependent Notch signaling to the regulation of Sox9 expression and chondrocyte hypertrophy by examining tissuespecific Rbpjk mutant（Prx1Cre;Rbpjkf/f）, Rbpjk mutant/Sox9 haploinsufficient（Prx1Cre;Rbpjkf/f;Sox9f/1）,and control embryos for alterations in SOX9 expression and chondrocyte hypertrophy during cartilage development. These studies demonstrate that Notch signaling regulates the onset of chondrocyte maturation in a SOX9-dependent manner, while Notch-mediated regulation of terminal chondrocyte maturation likely functions independently of SOX9. Furthermore, our in vitro molecular analyses of the Sox9 promoter and Notch-mediated regulation of Sox9 gene expression in chondrogenic cells identified the ability of Notch to induce Sox9 expression directly in the acute setting, but suppresses Sox9 transcription with prolonged Notch signaling that requires protein synthesis of secondary effectors.展开更多
Spinal cord injury （SCI） elicits a robust inflammatory response that is a hallmark of the secondary injury mechanisms. Neuroinflammation is orchestrated initially by the response of resident astrocytes and microglia...Spinal cord injury （SCI） elicits a robust inflammatory response that is a hallmark of the secondary injury mechanisms. Neuroinflammation is orchestrated initially by the response of resident astrocytes and microglia to injury, which subsequently facilitates the recruitment of peripheral immune cells into the SCI lesion （Orr and Gensel, 2018）. This inflammatory response contributes to cell death and tissue degeneration through the production of pro-inflammatory cytokines and chemokines, free radicals and proteolytic enzymes. However, neuroinflammatory cells also play beneficial regulatory role in repair mechanisms after SCI by adopting a reparative and wound healing phenotype （Orr and Gensel, 2018; Tran et al., 2018）. Hence, understanding the underlying mechanisms by which immune cells are reg- ulated within the microenvironment of injury would aid in harnessing the reparative potential of inflammation following SCI.展开更多
Objective The rostral anterior cingulate cortex （rACC） is implicated in processing the emotional component of pain. N-methyl-D-aspartate receptors （NMDARs） are highly expressed in the rACC and mediate painrelated ...Objective The rostral anterior cingulate cortex （rACC） is implicated in processing the emotional component of pain. N-methyl-D-aspartate receptors （NMDARs） are highly expressed in the rACC and mediate painrelated affect by activating a signaling pathway that involves cyclic adenosine monophosphate （cAMP）/protein ki- nase A （PKA） and/or extracellular regulated kinase （ERK）/cAMP-response element-binding protein （CREB）. The present study investigated the contributions of the NMDAR glycine site and GluN2B subunit to the activation of ERK and CREB both in vitro and in vivo in rat rACC. Methods Immunohistochemistry and Western blot analy- sis were used to separately assess the expression of phospho-ERK （pERK） and phospho-CREB （pCREB） in vitro and in vivo. Double immunostaining was also used to determine the colocalization of pERK and pCREB. Results Both bath application of NMDA in brain slices in vitro and intraplantar injection of formalin into the rat hindpaw in vivo induced significant up-regulation of pERK and pCREB in the rACC, which was inhibited by the NMDAR antago- nist DL-2-amino-5-phospho-novaleric acid. Selective blockade of the NMDAR GluN2B subunit and the glycine- binding site, or degradation of endogenous D-serine, a co-agonist for the glycine site, significantly decreased the up- regulation of pERK and pCREB expression in the rACC. Further, the activated ERK predominantly colocalized with CREB. Conclusion Either the glycine site or the GluN2B subunit of NMDARs participates in the phosphorylation of ERK and CREB induced by bath application of NMDA in brain slices or hindpaw injection of 5% formalin in rats, and these might be fundamental molecular mechanisms underlying pain affect.展开更多
How osteoblast cells are induced is a central question for understanding skeletal formation. Abnormal osteoblast differentiation leads to a broad range of devastating craniofacial diseases. Here we have investigated i...How osteoblast cells are induced is a central question for understanding skeletal formation. Abnormal osteoblast differentiation leads to a broad range of devastating craniofacial diseases. Here we have investigated intramembranous ossification during cranial bone development in mouse models of skeletal genetic diseases that exhibit craniofacial bone defects. The GNAS gene encodes Gαs that transduces GPCR signaling. GNAS activation or loss-of-function mutations in humans cause fibrous dysplasia(FD) or progressive osseous heteroplasia(POH) that shows craniofacial hyperostosis or craniosynostosis, respectively. We find here that, while Hh ligand-dependent Hh signaling is essential for endochondral ossification, it is dispensable for intramembranous ossification, where Gαsregulates Hh signaling in a ligand-independent manner. We further show that Gαscontrols intramembranous ossification by regulating both Hh and Wnt/β-catenin signaling. In addition, Gαsactivation in the developing cranial bone leads to reduced ossification but increased cartilage presence due to reduced cartilage dissolution, not cell fate switch. Small molecule inhibitors of Hh and Wnt signaling can effectively ameliorate cranial bone phenotypes in mice caused by loss or gain of Gnas function mutations, respectively. Our work shows that studies of genetic diseases provide invaluable insights in both pathological bone defects and normal bone development, understanding both leads to better diagnosis and therapeutic treatment of bone diseases.展开更多
Humans have been using Cannabis and its extracts for a few thousand years as a medicinal and recreational drug. How- ever, the chemical component in Cannabis sativa, △9-tet- rahydrocannabinol （△9-THC）, an exogenou...Humans have been using Cannabis and its extracts for a few thousand years as a medicinal and recreational drug. How- ever, the chemical component in Cannabis sativa, △9-tet- rahydrocannabinol （△9-THC）, an exogenous cannabinoid, remained unknown until it was isolated and identified as the main psychoactive ingredient （Gaoni and Mechoulam, 1964）.展开更多
BACKGROUND Colon adenocarcinoma(COAD)is a malignant tumor of the digestive system.The mechanisms underlying COAD development and progression are still largely unknown.AIM To identify the role of canopy FGF signaling r...BACKGROUND Colon adenocarcinoma(COAD)is a malignant tumor of the digestive system.The mechanisms underlying COAD development and progression are still largely unknown.AIM To identify the role of canopy FGF signaling regulator 3(CNPY3)in the development and progression of COAD by using bioinformatic tools and functional experiments.METHODS Bioinformatic data were downloaded from public databases.The associations of clinicopathological features,survival,and immune function with the expression of CNPY3 were analyzed.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses and Gene Set Enrichment Analysis were used to explore the related pathways.Then,quantitative real-time PCR and immunohistochemistry were used for validation of CNPY3 expression in clinical samples and tumor cell lines.Cell lines with CNPY3 knockdown were constructed to further analyze gene functions.The functional experiments included proliferation,invasion,migration and apoptosis assays.RESULTS In both the TCGA cohort and the merged dataset,elevated CNPY3 expression was observed in tumor tissues.High CNPY3 expression correlated with adverse survival and compromised immune functions.Functional enrichment analysis suggested that the pro-oncogenic properties of CNPY3 might be linked to the PI3K-AKT signaling pathway.CNPY3 expression was validated at both the RNA and protein levels.Functional assays indicated that cell proliferation,invasion,and migration were inhibited and cell apoptosis was promoted after CNPY3 knockdown.Additionally,Western blot results revealed the downregulation of key proteins in the PI3K/AKT pathway following CNPY3 knockdown.PI3K/AKT pathway activator reversed the decrease in proliferation,invasion,and migration and the increase in apoptosis.Notably,CNPY3 knockdown still affected the cells when the pathway was inhibited.CONCLUSION This study showed that CNPY3 is upregulated in COAD and might regulate COAD development and progression by the PI3K/AKT pathway.Thus,CNPY3 might be a promising therapeutic target.展开更多
Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets an...Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.展开更多
BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progr...BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progression of gastric cancer(GC)is not yet clear.AIM To explore the role and underlying mechanisms of action of RGS4 in GC develop-ment.METHODS The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC.Function assays were employed to assess the carcinogenic impact of RGS4,and the mechanism of its possible influence was detected by western blot analysis.A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.RESULTS RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues.Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage,increased tumor grade as well as poorer overall survival in patients with GC.Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation,migration and invasion.Similarly,xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth.Moreover,RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase,phosphatidyl-inositol-3-kinase,and protein kinase B,decreased vimentin and N-cadherin,and elevated E-cadherin.CONCLUSION High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker.RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.展开更多
AIM:To investigate the inhibitory role and the underlying mechanisms of sorafenib on signal transducer and activator of transcription 3(STAT3)activity in hepatocellular carcinoma(HCC).METHODS:Human and rat HCC cell li...AIM:To investigate the inhibitory role and the underlying mechanisms of sorafenib on signal transducer and activator of transcription 3(STAT3)activity in hepatocellular carcinoma(HCC).METHODS:Human and rat HCC cell lines were treated with sorafenib.Proliferation and STAT3 dephosphorylation were assessed.Potential molecular mechanisms of STAT3 pathway inhibition by sorafenib were evaluated.In vivo antitumor action and STAT3 inhibition were investigated in an immunocompetent orthotopic rat HCC model.RESULTS:Sorafenib decreased STAT3 phosphorylationat the tyrosine and serine residues(Y705 and S727),but did not affect Janus kinase 2(JAK2)and phosphatase shatterproof 2(SHP2),which is associated with growth inhibition in HCC cells.Dephosphorylation of S727 was associated with attenuated extracellular signal-regulated kinase(ERK)phosphorylation,similar to the effects of a mitogen-activated protein kinase(MEK)inhibitor U0126,suggesting that sorafenib induced S727 dephosphorylation by inhibiting MEK/ERK signaling.Meanwhile,sorafenib could also inhibit Akt phosphorylation,and both the phosphatidylinositol-3-kinase(PI3K)inhibitor LY294002 and Akt knockdown resulted in Y705 dephosphorylation,indicating that Y705 dephosphorylation by sorafenib was mediated by inhibiting the PI3K/Akt pathway.Finally,in the rat HCC model,sorafenib signifi cantly inhibited STAT3 activity,reducing tumor growth and metastasis.CONCLUSION:Sorafenib inhibits growth and metastasis of HCC in part by blocking the MEK/ERK/STAT3 and PI3K/Akt/STAT3 signaling pathways,but independent of JAK2 and SHP2 activation.展开更多
基金Supported by the National Natural Science Foundation of China (No. 30300458)
文摘Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracellular signal regulated kinase （ERK） expression in it. Methods： Rat＇s HSC-T6 were cultured and treated by SAB or curcumin. The inhibitory effect on cell proliferation was determined by 3-（4,5-dimthyl-2- 2thiazoly）-2,5-diphenyl-2H-tetrazolium bromide （MTT） colorimetry, and the expression levels of a smooth actin （a-SMA）, collagen type Ⅰ , and ERK were determined by Western blot. Results： SAB and curcumin inhibited the proliferation and activation of rat＇s HSC-T6 in dose-dependent fashion and significantly reduced the expression level of a-SMA （ P〈0.01 ）. Curcumin significantly reduced the expression of collagen type Ⅰ （P〈0.05）. Both SAB and curcumin showed insignificant effect on the ERK expression level, but they could significantly reduce the level of phosphorylated-ERK expression, showing significant difference as compared with that in the control group （ P〈0.01 and P〈0.05 respectively）. Conclusion： SAB and curcumin could significantly inhibit the proliferation, activation of HSC, and the production of type Ⅰ collagen in HSC, the mechanism may be associated with their inhibition on ERK phosphorylation.
基金Supported by the Key Project in Science and Technology of Henan Province(No.072300450100)Project of High and New Technology Development of Health Department in Henan Province(No.20060140)
文摘Objective： To investigate the relationship between the proliferation of sensitized human airway smooth muscle cells （HASMCs） and the expression of extracellular signal regulated kinase （ERK） and the effect of Shenmai Injection （参麦注射液, SMI） on HASMCs. Methods： The HASMCs cultured in vitro were divided into three groups： （1） control group; （2） sensitized group： containing 10% asthmatic serum; （3） SMI group： further divided into three different concentration subgroups interferred with 10 μL/mL, 50 μL/mL, and 100 μL/mL SMI, respectively. The proliferation of HASMCs was detected using MTT method, the expression of proliferating cell nucleus antigen （PCNA） in HASMCs was detected using immunocytochemical staining, and the expression of phosphoration-ERK1/2 （p-ERK1/2） protein was detected using Western-blot. Results： After passive sensitization, the optical density value （A49o value） of HASMCs was significantly increased from 0.366± 0.086 to 0.839 ± 0.168 （P〈0.05）. In addition, the expression of PCNA was significantly increased from 28.7% ± 5.9% in the control group to 69.8% ±7.5% in the sensitized group （P〈0.05）. At the same time, the expression of p-ERK1/2 in passively sensitized HASMCs was significantly increased compared with the control group （all P〈0.05）. Affer application of 10 μL/mL, 50 μL/mL, and 100 μL/mL SMI to the cultured media of passively sensitized group, the A570 value was significantly decreased from 0.839 ±0.168 to 0.612 ±0.100, 0.412 ± 0.092, and 0.339 ± 0.077, respectively （P〈0.05）. Moreover, the expression of PCNA was significantly decreased from 69.8% ±7.5% to 57.8% ± 6.2%, 40.7%±5.4%, and 26.1% ± 5.2%, respectively. At the same time, the expression of p-ERK1/2 in each SMI group was significantly decreased compared with the sensitized group （all ,P〈0.05）. Conclusion： ERK signal transduction pathway may be involved in the airway remodeling in asthma. The expression of ERK can be inhibited by SMI in a dose-dependent manner, thus preventing the proliferation of HASMCs.
文摘In the recent two decades, it has been well elucidated that receptor activator of nuclear factor-κB ligand （RANKL; also known as TNFSF11） binding to its receptor RANK （also known as TNFRSF11A） drives osteoclast development as the crucial signaling pathway.;However, accumulating evidence also implies that
基金supported by the National Natural Science Foundation (NNSF) Key Research Program in Aging (91749204)National Natural Science Foundation of China (81871099, 31370958, 81701364, 81771491, 81501052)+1 种基金Shanghai Municipal Science and Technology Commission Key Program (15411950600, 18431902300)Municipal Human Resources Development Program for Outstanding Leaders in Medical Disciplines in Shanghai (2017BR011)
文摘RANKL signaling is essential for osteoclastogenesis. Its role in osteoblastic differentiation and bone formation is unknown. Here we demonstrate that RANK is expressed at an early stage of bone marrow mesenchymal stem cells(BMSCs) during osteogenic differentiation in both mice and human and decreased rapidly. RANKL signaling inhibits osteogenesis by promoting β-catenin degradation and inhibiting its synthesis. In contrast, RANKL signaling has no significant effects on adipogenesis of BMSCs.Interestingly, conditional knockout of rank in BMSCs with Prx1-Cre mice leads to a higher bone mass and increased trabecular bone formation independent of osteoclasts. In addition, rank: Prx1-Cre mice show resistance to ovariectomy-(OVX) induced bone loss. Thus, our results reveal that RANKL signaling regulates both osteoclasts and osteoblasts by inhibition of osteogenic differentiation of BMSCs and promotion of osteoclastogenesis.
文摘In order to investigate the changes in the expression of extracellular signal regulated kinase (ERK1/ERK2) and angiotensin converting enzyme (ACE) in the patients with atrial fibrillation (AF), 52 patients with rheumatic heart diseases were examined. Nineteen patients had chronic persistent AF (AF≥6 months, CAF), 12 patients had paroxymal AF (PAF) and 21 patients had no history of AF. The ERK expression was detected at the mRNA level by reverse transcription polymerase chain reaction, at the protein level by Western blotting and at atrial tissue level by immunohistochemistry. ERK activating kinases (MEK1/2) and ACE were determined by Western blotting techniques. The expression of ERK2 mRNA was increased in the patients with CAF (74±19 U vs sinus rhythm: 32±24 U, P <0.05). Activated ERK1/ERK2 and MEK1/2 were increased to more than 150 % in the patients with AF compared to those with sinus rhythm. No significant difference between CAF and PAF was found. The expression of ACE was three fold increased in the patients with CAF compared to those with sinus rhythm. Patients with AF showed an increased expression of ERK1/ERK2 in atrial interstitial cells and marked atrial fibrosis. An ACE dependent increase in the amounts of activated ERK1/ERK2 in atrial interstitial cells may be one of molecular mechanisms for the development of atrial fibrosis in the patients with AF. These findings may have important impact on the treatment of AF.
文摘Animals can sense many environment stimuli simultaneously and integrate these signals within the nervous system.However,the neural system and molecular mechanisms underlying are largely unknown.The insulin-like signaling pathway is known to regulate dauer formation,longevity and fat metabolism C.elegans.Here,we report that this pathway is also involved in interaction assay which is to observe the interaction between chemotaxis toward diacetyl and avoidance of cu2+ion.
基金supported by the National Institutes of Health,Nos.AA025919,AA025919-03S1,and AA025919-05S1(all to RAF).
文摘Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.
文摘Arabidopsis seedlings undergo photomorphogenesis in the light and etiolation in the dark. HFR1, a bHLH transcription factor, is required for both phytochrome A (phyA)-mediated far-red and cryptochrome 1 (cry1)-mediated blue light signaling. We report that HFR1 is a short-lived protein in darkness and is degraded through a 26S proteasome-dependent pathway. Light, irrespective of its quality, enhances HFR1 protein accumulation via promoting its stabilization. We demonstrate that HFR1 physically interacts with COP1 and that COP1 exhibits ubiquitin ligase activity toward HFR1 in vitro. In addition, we show that COP1 is required for degradation of HFR1 in vivo. Furthermore, plants overexpressing a C-terminal 161 amino acid fragment of HFR1 (CT161) display enhanced photomorphogenesis, suggesting an autonomous function of CT161 in promoting light signaling. This truncated HFR1 gene product is more stable than the full-length HFR1 protein in darkness, indicating that the COP1-interacting N-terminal portion of HFR1 is essential for COP1-mediated destabilization of HFR1. These results suggest that light enhances HFR1 protein accumulation by abrogating COP1-mediated degradation of HFR1, which is necessary and sufficient for promoting light signaling. Additionally, our results substantiate the E3 ligase activity of COP1 and its critical role in desensitizing light signaling.
基金supported by the National Natural Science Foundation of China(NSFC/RGC/JRF N_HKU735/21)Research Grant Council of Hong Kong,China(17102120,17108821,17103922,C1024-22GF,C7074-21G)+1 种基金Health and Medical Research Fund(HMRF 09200966)(to CSWL)FRQS Postdoctoral Fellowship(to AHKF).
文摘Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.
基金supported in part by grants from the National Institutes of Health(AG051773)and VA(BX000838)
文摘YAP（yes-associated protein） is a transcriptional factor that is negatively regulated by Hippo pathway, a conserved pathway for the development and size control of multiple organs. The exact function of YAP in bone homeostasis remains controversial. Here we provide evidence for YAP＇s function in promoting osteogenesis, suppressing adipogenesis, and thus maintaining bone homeostasis.YAP is selectively expressed in osteoblast（OB）-lineage cells. Conditionally knocking out Yap in the OB lineage in mice reduces cell proliferation and OB differentiation and increases adipocyte formation, resulting in a trabecular bone loss. Mechanistically, YAP interacts with β-catenin and is necessary for maintenance of nuclear β-catenin level and Wnt/β-catenin signaling. Expression of β-catenin in YAP-deficient BMSCs（bone marrow stromal cells） diminishes the osteogenesis deficit. These results thus identify YAP-β-catenin as an important pathway for osteogenesis during adult bone remodeling and uncover a mechanism underlying YAP regulation of bone homeostasis.
基金supported by NIH grants AR060456 and AR055923(FL)partly supported by P30 AR057235(Washington University Musculoskeletal Research Center)+1 种基金supported by the George O’Brien Center for Kidney Disease Research(P30 DK079333)Kidney translational Research Core and the Renal Division at the Washington University School of Medicine
文摘Bone morphogenetic proteins （Bmp） are well-known to induce bone formation following chondrogenesis, but the direct role of Bmp signaling in the osteoblast lineage is not completely understood. We have recently shown that deletion of the receptor Bmprla in the osteoblast lineage with Dmpl-Cre reduces osteoblast activity in general but stimulates proliferation of preosteoblasts specifically in the cancellous bone region, resulting in diminished periosteal bone growth juxtaposed with excessive cancellous bone formation. Because expression of sclerostin （SOST）, a secreted Wnt antagonist, is notably reduced in the Bmprla- deficient osteocytes, we have genetically tested the hypothesis that increased Wnt signaling might mediate the increase in cancellous bone formation in response to Bmprla deletion. Forced expression of human SOST from a Dmpl promoter fragment partially rescues preosteoblast hyperproliferation and cancellous bone overgrowth in the Bmprla mutant mice, demonstrating functional interaction between Bmp and Wnt signaling in the cancellous bone compat^a-tent. To test whether increased Wnt signaling can compensate for the defect in periosteal growth caused by Bmprla deletion, we have generated compound mutants harboring a hyperactive mutation （A214V） in the Wnt receptor Lrp5. However, the mutant Lrp5 does not restore periosteal bone growth in the Bmprla-deficient mice. Thus, Bmp signaling restricts cancellous bone accrual partly through induction of SOST that limits preosteoblast proliferation, but promotes periosteal bone growth apparently independently of Wnt activation.
基金supported in part by the following United States National Institute of Health grants: R01 grants (AR057022 and AR063071), R21 grant (AR059733 to MJH), a P30 Core Center grant (AR061307), and a T32 training grant that supported both AK and TPR (AR053459 to Regis J.O’Keefe and Michael J.Zuscik)
文摘RBPjk-dependent Notch signaling regulates both the onset of chondrocyte hypertrophy and the progression to terminal chondrocyte maturation during endochondral ossification. It has been suggested that Notch signaling can regulate Sox9 transcription, although how this occurs at the molecular level in chondrocytes and whether this transcriptional regulation mediates Notch control of chondrocyte hypertrophy and cartilage development is unknown or controversial. Here we have provided conclusive genetic evidence linking RBPjk-dependent Notch signaling to the regulation of Sox9 expression and chondrocyte hypertrophy by examining tissuespecific Rbpjk mutant（Prx1Cre;Rbpjkf/f）, Rbpjk mutant/Sox9 haploinsufficient（Prx1Cre;Rbpjkf/f;Sox9f/1）,and control embryos for alterations in SOX9 expression and chondrocyte hypertrophy during cartilage development. These studies demonstrate that Notch signaling regulates the onset of chondrocyte maturation in a SOX9-dependent manner, while Notch-mediated regulation of terminal chondrocyte maturation likely functions independently of SOX9. Furthermore, our in vitro molecular analyses of the Sox9 promoter and Notch-mediated regulation of Sox9 gene expression in chondrogenic cells identified the ability of Notch to induce Sox9 expression directly in the acute setting, but suppresses Sox9 transcription with prolonged Notch signaling that requires protein synthesis of secondary effectors.
基金supported by the Craig H.Neilsen Foundation awarded to SKAsupported by a joint studentship from Will-to-Win/Manitoba Paraplegic Foundationthe Children’s Hospital Research Institute of Manitoba
文摘Spinal cord injury （SCI） elicits a robust inflammatory response that is a hallmark of the secondary injury mechanisms. Neuroinflammation is orchestrated initially by the response of resident astrocytes and microglia to injury, which subsequently facilitates the recruitment of peripheral immune cells into the SCI lesion （Orr and Gensel, 2018）. This inflammatory response contributes to cell death and tissue degeneration through the production of pro-inflammatory cytokines and chemokines, free radicals and proteolytic enzymes. However, neuroinflammatory cells also play beneficial regulatory role in repair mechanisms after SCI by adopting a reparative and wound healing phenotype （Orr and Gensel, 2018; Tran et al., 2018）. Hence, understanding the underlying mechanisms by which immune cells are reg- ulated within the microenvironment of injury would aid in harnessing the reparative potential of inflammation following SCI.
基金supported by the National Natural Science Foundation of China (30900444,31070973,30870835,31121061 and 30830044)
文摘Objective The rostral anterior cingulate cortex （rACC） is implicated in processing the emotional component of pain. N-methyl-D-aspartate receptors （NMDARs） are highly expressed in the rACC and mediate painrelated affect by activating a signaling pathway that involves cyclic adenosine monophosphate （cAMP）/protein ki- nase A （PKA） and/or extracellular regulated kinase （ERK）/cAMP-response element-binding protein （CREB）. The present study investigated the contributions of the NMDAR glycine site and GluN2B subunit to the activation of ERK and CREB both in vitro and in vivo in rat rACC. Methods Immunohistochemistry and Western blot analy- sis were used to separately assess the expression of phospho-ERK （pERK） and phospho-CREB （pCREB） in vitro and in vivo. Double immunostaining was also used to determine the colocalization of pERK and pCREB. Results Both bath application of NMDA in brain slices in vitro and intraplantar injection of formalin into the rat hindpaw in vivo induced significant up-regulation of pERK and pCREB in the rACC, which was inhibited by the NMDAR antago- nist DL-2-amino-5-phospho-novaleric acid. Selective blockade of the NMDAR GluN2B subunit and the glycine- binding site, or degradation of endogenous D-serine, a co-agonist for the glycine site, significantly decreased the up- regulation of pERK and pCREB expression in the rACC. Further, the activated ERK predominantly colocalized with CREB. Conclusion Either the glycine site or the GluN2B subunit of NMDARs participates in the phosphorylation of ERK and CREB induced by bath application of NMDA in brain slices or hindpaw injection of 5% formalin in rats, and these might be fundamental molecular mechanisms underlying pain affect.
基金supported by the NIH grants R01DE025866 from NIDCRR01AR070877 from NIAMSsupported by the 111 Project, MOE (B14038), China
文摘How osteoblast cells are induced is a central question for understanding skeletal formation. Abnormal osteoblast differentiation leads to a broad range of devastating craniofacial diseases. Here we have investigated intramembranous ossification during cranial bone development in mouse models of skeletal genetic diseases that exhibit craniofacial bone defects. The GNAS gene encodes Gαs that transduces GPCR signaling. GNAS activation or loss-of-function mutations in humans cause fibrous dysplasia(FD) or progressive osseous heteroplasia(POH) that shows craniofacial hyperostosis or craniosynostosis, respectively. We find here that, while Hh ligand-dependent Hh signaling is essential for endochondral ossification, it is dispensable for intramembranous ossification, where Gαsregulates Hh signaling in a ligand-independent manner. We further show that Gαscontrols intramembranous ossification by regulating both Hh and Wnt/β-catenin signaling. In addition, Gαsactivation in the developing cranial bone leads to reduced ossification but increased cartilage presence due to reduced cartilage dissolution, not cell fate switch. Small molecule inhibitors of Hh and Wnt signaling can effectively ameliorate cranial bone phenotypes in mice caused by loss or gain of Gnas function mutations, respectively. Our work shows that studies of genetic diseases provide invaluable insights in both pathological bone defects and normal bone development, understanding both leads to better diagnosis and therapeutic treatment of bone diseases.
基金supported by National Institutes of Health grants NS076815
文摘Humans have been using Cannabis and its extracts for a few thousand years as a medicinal and recreational drug. How- ever, the chemical component in Cannabis sativa, △9-tet- rahydrocannabinol （△9-THC）, an exogenous cannabinoid, remained unknown until it was isolated and identified as the main psychoactive ingredient （Gaoni and Mechoulam, 1964）.
文摘BACKGROUND Colon adenocarcinoma(COAD)is a malignant tumor of the digestive system.The mechanisms underlying COAD development and progression are still largely unknown.AIM To identify the role of canopy FGF signaling regulator 3(CNPY3)in the development and progression of COAD by using bioinformatic tools and functional experiments.METHODS Bioinformatic data were downloaded from public databases.The associations of clinicopathological features,survival,and immune function with the expression of CNPY3 were analyzed.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses and Gene Set Enrichment Analysis were used to explore the related pathways.Then,quantitative real-time PCR and immunohistochemistry were used for validation of CNPY3 expression in clinical samples and tumor cell lines.Cell lines with CNPY3 knockdown were constructed to further analyze gene functions.The functional experiments included proliferation,invasion,migration and apoptosis assays.RESULTS In both the TCGA cohort and the merged dataset,elevated CNPY3 expression was observed in tumor tissues.High CNPY3 expression correlated with adverse survival and compromised immune functions.Functional enrichment analysis suggested that the pro-oncogenic properties of CNPY3 might be linked to the PI3K-AKT signaling pathway.CNPY3 expression was validated at both the RNA and protein levels.Functional assays indicated that cell proliferation,invasion,and migration were inhibited and cell apoptosis was promoted after CNPY3 knockdown.Additionally,Western blot results revealed the downregulation of key proteins in the PI3K/AKT pathway following CNPY3 knockdown.PI3K/AKT pathway activator reversed the decrease in proliferation,invasion,and migration and the increase in apoptosis.Notably,CNPY3 knockdown still affected the cells when the pathway was inhibited.CONCLUSION This study showed that CNPY3 is upregulated in COAD and might regulate COAD development and progression by the PI3K/AKT pathway.Thus,CNPY3 might be a promising therapeutic target.
基金funded by Eurostars project,grant number E!12764。
文摘Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.
基金Supported by the Fundamental Research Program of Shanxi Province,No.202203021222418Research Program of Shanxi Provincial Health Commission,No.2023061+2 种基金Fundamental Research Cooperation Program of Beijing-Tianjin-Hebei Region of Natural Science Foundation of Tianjin,No.22JCZXJC00140Tianjin Major Science and Technology Project,No.21ZXJBSY00110Tianjin Health and Science and Technology Project,No.TJWJ2024ZK001.
文摘BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progression of gastric cancer(GC)is not yet clear.AIM To explore the role and underlying mechanisms of action of RGS4 in GC develop-ment.METHODS The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC.Function assays were employed to assess the carcinogenic impact of RGS4,and the mechanism of its possible influence was detected by western blot analysis.A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.RESULTS RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues.Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage,increased tumor grade as well as poorer overall survival in patients with GC.Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation,migration and invasion.Similarly,xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth.Moreover,RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase,phosphatidyl-inositol-3-kinase,and protein kinase B,decreased vimentin and N-cadherin,and elevated E-cadherin.CONCLUSION High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker.RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.
基金Supported by Grants from the China 863 Project,No.2007A-A02Z479the National Natural Science Foundation of China,No.30972949 and 30901432+1 种基金Shanghai Rising-Star Program,No.10QA1401300Research Fund for the Doctoral Program of Higher Education of China,No.20090071120026
文摘AIM:To investigate the inhibitory role and the underlying mechanisms of sorafenib on signal transducer and activator of transcription 3(STAT3)activity in hepatocellular carcinoma(HCC).METHODS:Human and rat HCC cell lines were treated with sorafenib.Proliferation and STAT3 dephosphorylation were assessed.Potential molecular mechanisms of STAT3 pathway inhibition by sorafenib were evaluated.In vivo antitumor action and STAT3 inhibition were investigated in an immunocompetent orthotopic rat HCC model.RESULTS:Sorafenib decreased STAT3 phosphorylationat the tyrosine and serine residues(Y705 and S727),but did not affect Janus kinase 2(JAK2)and phosphatase shatterproof 2(SHP2),which is associated with growth inhibition in HCC cells.Dephosphorylation of S727 was associated with attenuated extracellular signal-regulated kinase(ERK)phosphorylation,similar to the effects of a mitogen-activated protein kinase(MEK)inhibitor U0126,suggesting that sorafenib induced S727 dephosphorylation by inhibiting MEK/ERK signaling.Meanwhile,sorafenib could also inhibit Akt phosphorylation,and both the phosphatidylinositol-3-kinase(PI3K)inhibitor LY294002 and Akt knockdown resulted in Y705 dephosphorylation,indicating that Y705 dephosphorylation by sorafenib was mediated by inhibiting the PI3K/Akt pathway.Finally,in the rat HCC model,sorafenib signifi cantly inhibited STAT3 activity,reducing tumor growth and metastasis.CONCLUSION:Sorafenib inhibits growth and metastasis of HCC in part by blocking the MEK/ERK/STAT3 and PI3K/Akt/STAT3 signaling pathways,but independent of JAK2 and SHP2 activation.
