Activation of G-protein-coupled receptor 39 reduces neuropathic pain in a rat model

Activated G-protein-coupled receptor 39(GPR39)has been shown to attenuate inflammation by interacting with sirtuin 1(SIRT1)and peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α).However,whether GPR39 attenuates neuropathic pain remains unclear.In this study,we established a Sprague-Dawley rat model of spared nerve injury-induced neuropathic pain and found that GPR39 expression was significantly decreased in neurons and microglia in the spinal dorsal horn compared with sham-operated rats.Intrathecal injection of TC-G 1008,a specific agonist of GPR39,significantly alleviated mechanical allodynia in the rats with spared nerve injury,improved spinal cord mitochondrial biogenesis,and alleviated neuroinflammation.These changes were abolished by GPR39 small interfering RNA(siRNA),Ex-527(SIRT1 inhibitor),and PGC-1αsiRNA.Taken together,these findings show that GPR39 activation ameliorates mechanical allodynia by activating the SIRT1/PGC-1αpathway in rats with spared nerve injury.

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.

G-protein-coupled estrogen receptor as a new therapeutic target for treating coronary artery disease

Coronary heart disease(CHD) continues to be the greatest mortality risk factor in the developed world. Estrogens are recognized to have great therapeutic potential to treat CHD and other cardiovascular diseases; however,a significant array of potentially debilitating side effects continues to limit their use. Moreover,recent clinical trials have indicated that long-term postmenopausal estrogen therapy may actually be detrimental to cardiovascular health. An exciting new development is the finding that the more recently discovered G-protein-coupled estrogen receptor(GPER) is expressed in coronary arteries-both in coronary endothelium and in smooth muscle within the vascular wall. Accumulating evidence indicates that GPER activation dilates coronary arteries and can also inhibit the prolif-eration and migration of coronary smooth muscle cells. Thus,selective GPER activation has the potential to increase coronary blood flow and possibly limit the debilitating consequences of coronary atherosclerotic disease. This review will highlight what is currently known regarding the impact of GPER activation on coronary arteries and the potential signaling mechanisms stimulated by GPER agonists in these vessels. A thorough understanding of GPER function in coronary arteries may promote the development of new therapies that would help alleviate CHD,while limiting the potentially dangerous side effects of estrogen therapy.

Mechanisms of regulation and function of G-protein-coupled receptor kinases

G-protein-coupled receptor kinases (GRKs) interact with the agonist-activated form of G-protein-coupled receptor (GPCR) to affect receptor phosphorylation and to initiate profound impairment of receptor signaling, or desensitization. GPCR forms the largest family of cell surface receptors, and defects in GRK function have the potential consequence to affect GPCR-stimulated biological responses in many pathological situations.

Desensitization of G-protein-coupled receptors induces vascular hypocontractility in response to norepinephrine in the mesenteric arteries of cirrhotic patients and rats

BACKGROUND: The increased β-arrestin-2 and its combination with G-protein-coupled receptors (GPCRs) lead to GPCRs desensitization. The latter may be responsible for decreased contractile reactivity in the mesenteric arteries of cirrhotic patients and rats. The present study is to investigate the machinery changes of α-adrenergic receptors and G proteins and their roles in the contractility of mesenteric arteries of cirrhotic patients and animal models. METHODS: Patients with cirrhosis due to hepatitis B and cirrhotic rats induced by CCl 4 were studied. Mesenteric artery contractility in response to norepinephrine was determined by a vessel perfusion system. The contractile effect of G protein-coupled receptor kinase-2 (GRK-2) inhibitor on the mesenteric artery was evaluated. The protein expression of the α 1 adrenergic receptor, G proteins, β-arrestin-2, GRK-2 as well as the activity of Rho associated coiled-coil forming protein kinase-1 (ROCK-1) were measured by Western blot. In addition, the interaction of α 1 adrenergic receptor with β-arrestin-2 was assessed by co-immunoprecipitation. RESULTS: The portal vein pressure of cirrhotic patients and rats was significantly higher than that of controls. The doseresponse curve to norepinephrine in mesenteric arteriole was shifted to the right, and EC 50 was significantly increased in cirrhotic patients and rats. There were no significant differences in the expressions of the α 1 adrenergic receptor and G proteins in the cirrhotic group compared with the controls. However, the protein expressions of GRK-2 and β-arrestin-2 were significantly elevated in cirrhotic patients and rats compared with those of the controls. The interaction of the α 1 adrenergic receptor and β-arrestin-2 was significantly aggravated. This interaction was significantly reversed by GRK-2 inhibitor. Both the protein expression and activity of ROCK-1 were significantly decreased in the mesenteric artery in patients with cirrhosis compared with those of the controls, and this phenomenon was not shown in the cirrhotic rats. Norepinephrine significantly increased the activity of ROCK-1 in normal rats but not in cirrhotic ones. Norepinephrine significantly increased ROCK-1 activity in cirrhotic rats when GRK-2 inhibitor was used. CONCLUSIONS: β-arrestin-2 expression and its interaction with GPCRs are significantly upregulated in the mesenteric arteries in patients and rats with cirrhosis. These upregulations result in GPCR desensitization, G-protein dysfunction and ROCK inhibition. These may explain the decreased contractility of the mesenteric artery in response to vasoconstrictors.

Role of doublecortin-like kinase 1 and leucine-rich repeat-containing G-protein-coupled receptor 5 in patients with stage Ⅱ/Ⅲ colorectal cancer:Cancer progression and prognosis

BACKGROUND Cancer stem cells(CSCs)are a subpopulation of cancer cells with the potential of self-renewal and differentiation.CSCs play critical roles in tumorigenesis,recurrence,metastasis,radiation tolerance and chemoresistance.AIM To assess the expression patterns and clinical potential of doublecortin-like kinase 1(DCLK1)and leucine-rich repeat-containing G-protein-coupled receptor 5(Lgr5),as prognostic CSC markers of colorectal cancer(CRC).METHODS The expression of DCLK1 and Lgr5 in CRC tissue sections from 92 patients was determined by immunohistochemistry.Each case was evaluated using a combined scoring method based on signal intensity staining(scored 0-3)and the proportion of positively stained cancer cells(scored 0-3).The final staining score was calculated as the intensity score multiplied by the proportion score.Low expression of DCLK1 and Lgr5 was defined as a score of 0-3;high expression of DCLK1 and Lgr5 was defined as a score of≥4.Specimens were categorized as either high or low expression,and the correlation between the expression of DCLK1 or Lgr5 and clinicopathological factors was investigated.RESULTS DCLK1 and Lgr5 expression levels were significantly positively correlated.CRC patients with high DCLK1,Lgr5 and DCLK1/Lgr5 expressions had poorer progression-free survival and overall survival.Moreover,high expression of DCLK1 was an independent prognostic factor for recurrence and overall survival in patients with CRC by multivariate analysis(P=0.026 and P=0.049,respectively).CONCLUSION DCLK1 may be a potential CSC marker for the recurrence and survival of CRC patients.

Effects of ω-3 fatty acids on toll-like receptor 4 and nuclear factor-κB p56 in lungs of rats with severe acute pancreatitis

AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.

Cloning of rat sp56,the homologue of mouse sperm ZP3 receptor-sp56

Mouse sp56 is considered as one of the candidates for mouse zona pellucida 3 (mZP3) receptor. Up to date, its homologue has only been cloned from guinea pig. namely AM67. Based on the cDNA sequence of mouse sp56, we designed a pair of primer to amplify its homologue from rat testis cDNA. Using RT-PCR, two fragments of 743 bp and 938 bp were amplified. The PCR products show very high homology to mouse sp56. However, the 743 bp product completely lacks one of the seven Sushi domains of mouse sp56. Using the 743 bp product as the probe to detect the expression profile of sp56 in rat tissues, Northern blot shows that a -2.0 kb mRNA expresses specifically in testis. Employed the RACE method, two full cDNA sequences of rat sp56 were obtained. A Mr -42 KD band was detected in denatured and non-reducing protein sample of rat testis and sperm with anti-mouse sp56 monoclonal antibody by Western blot method. Rat sp56 was localized on rat sperm head by the indirect immunofluorescence method. Rat sp56 immunoreactivity was detected from the early pachytene spermatocytes and throughout the spermatogenesis. Its cloning will further our understanding of the mechanism of the sperrn-egg recognition and binding.

G蛋白偶联受体56基因敲除抑制少突胶质前体细胞成熟

目的:探讨G蛋白偶联受体56(GPR56)基因敲除对小鼠脑胼胝体内轴突髓鞘化和少突胶质前体细胞(OPCs)成熟的影响。方法:筛选出GPR56基因杂合型(GPR56+/-)和敲除型(GPR56-/-)小鼠36只,分为GPR56+/-和GPR56-/-组,每组18只。每组根据小鼠出生后时间分为出生后7 d(P7)、14 d(P14)、21 d(P21)和28d(P28)4个亚组。应用FluoroMyelin染色观察P14、P21和P28 GPR56+/-和GPR56-/-小鼠脑胼胝体内髓鞘形成。用电镜观察P28 GPR56+/-和GPR56-/-小鼠胼胝体内轴突髓鞘化,比较髓鞘的厚度。用荧光免疫组化染色观察P7GPR56+/-和GPR56-/-小鼠胼胝体内血小板源性生长因子α受体阳性(PDGF-αR+)细胞(即OPCs)的数量。用原位杂交监测P28 GPR56+/-和GPR56-/-小鼠胼胝体内髓鞘蛋白脂质蛋白阳性(PLP+)细胞数。用出生后1 d的GPR56+/-和GPR56-/-小鼠脑皮质做体外OPCs培养并诱导其分化成熟,观察pro-oligodendroblast、immature oligodendrocyte和mature oligodendrocyte阶段O4+细胞百分比。结果:与GPR56+/-小鼠比较,在P14、P21和P28GPR56-/-小鼠脑胼胝体中髓鞘的形成明显减少。电镜见P28 GPR56-/-小鼠脑胼胝体内髓鞘化轴突的数量明显减少,髓鞘g-ratio值变大,髓鞘厚度变薄。荧光免疫组化和原位杂交结果显示P7 GPR56+/-和GPR56-/-小鼠胼胝体内PDGF-aR+细胞数量无差异,但P28 GPR56+/-小鼠胼胝体内PLP+细胞数明显多于P28 GPR56-/-小鼠。体外细胞培养结果显示在pro-oligodendroblast阶段GPR56-/-O4+细胞百分比明显多于GPR56+/-O4+细胞,在immature oligodendrocyte和mature oligodendrocyte阶段GPR56-/-O4+细胞百分比明显少于GPR56+/-O4+细胞。结论:GPR56蛋白可能参与了脑白质轴突髓鞘化和OPCs的成熟。

G蛋白偶联受体56对小鼠脑胼胝体轴突髓鞘化的影响

目的探讨G蛋白偶联受体56(GPR56)对小鼠脑胼胝体轴突髓鞘化的影响。方法筛选出GPR56基因杂合型(GPR56+/-)小鼠(GPR56+/-组)和敲除型(GPR56-/-)小鼠(GPR56-/-组)各38只。每组选在小鼠出生后7 d、14 d、21 d、28 d(P7d、P14d、P21d、P28d)进行研究。应用免疫组化染色和Western Blot方法监测髓鞘碱性蛋白(MBP)和2、3-环核苷酸3-磷酸二酯酶(CNPase)在P7d、P14d、P21d、P28d两组小鼠脑胼胝体白质中的表达;用电镜观察P28d小鼠胼胝体白质内轴突髓鞘化,比较轴突髓鞘的厚度。用荧光免疫组化染色观察P7d两组小鼠胼胝体内PDGF-aR阳性(PDGF-aR+)细胞的数量。用原位杂交检测P28d两组小鼠胼胝体内髓鞘蛋白脂质蛋白(PLP)阳性(PLP+)细胞数。结果与GPR56+/-小鼠比较,MBP在P14d、P21d、P28d GPR56-/-小鼠脑胼胝体白质中的表达明显下降,CNPase在P7d、P14d、P21d、P28d GPR56-/-小鼠脑胼胝体白质中的表达明显下降(均P<0.01)。电镜见P28d GPR56-/-小鼠脑胼胝体白质内髓鞘化轴突的数量明显减少,轴突髓鞘的g-ratio值升高(P<0.05),髓鞘的厚度变薄。荧光免疫组化和原位杂交结果显示P7d GPR56+/-和GPR56-/-小鼠胼胝体内PDGF-aR+细胞数量无差异,但P28d GPR56+/-小鼠胼胝体内PLP+细胞数明显多于P28d GPR56-/-小鼠(P<0.01)。结论 GPR56蛋白分子可能通过影响少突胶质前体细胞分化成熟参与了脑白质轴突髓鞘化。

Effect of organophosphorus insecticides on phosphorylation of the M_2 muscarinic acetylcholine receptor

BACKGROUND： Organophosphorus insecticides may promote the accumulation of acetylcholine at synapses and the neuromuscular junction by inhibiting acetylcholinesterase activity to cause disturbance of neural signal conduction and induce a toxic reaction. Organophosphorus insecticides may act on M2 muscarinic acetylcholine receptors, whose combination with G proteins is regulated by phosphorylation of G protein-coupled receptor kinase 2. OBJECTIVE： To investigate the effects of organophosphorus insecticides on the phosphorylation of G protein-coupled receptor kinase 2-mediated M2 muscarinic acetylcholine receptors and to reveal other possible actions of organophosphorus insecticides. DESIGN, TIME AND SETTING： An observational study, which was performed in the Central Laboratory of Shenyang Medical College, and Department of Physiological Sciences, College of Veterinary Medicine, Oklahoma State University from June 2002 to December 2004. MATERIALS： Paraoxon, parathion, chlorpyrifos, and chlorpyrifos oxon were provided by Chem Service Company, USA, [γ -p^32] ATP and [^35S]GTP γ S by New England Nuclear Life Science Products, and recombinant β 2-adrenergic receptor membrane protein by Sigma Company, USA. METHODS： The M2 muscarinic acetylcholine receptor was extracted and purified from pig brain using affinity chromatography. Subsequently, the purified M2 muscarinic acetylcholine receptor, G protein-coupled receptor kinase 2, and [γ -p^32] ATP were incubated with different concentrations of paraoxon and chlorpyrifos oxon together. The mixture then underwent polyacrylamide gel electrophoresis, and the gel film was dried and radioactively autographed to detect phosphorylation of the M2 muscarinic acetylcholine receptor. Finally, the radio-labeled phosphorylated M2 receptor protein band was excised for counting with an isotope liquid scintillation counter. MAIN OUTCOME MEASURES： Effects of chlorpyrifos oxon, paraoxon, chlorpyrifos, and parathion in different concentrations on the phosphorylation of the M2 muscarinic acetylcholine receptor; effects of chlorpyrifos oxon on the phosphorylation of the β -adrenergic receptor. RESULTS： Chlorpyrifos oxon could completely inhibit the phosphorylation of the M2 muscarinic acetylcholine receptor, and its IC50 was 70 μ mol/L. Chlorpyrifos could also inhibit the phosphorylation of the M2 muscarinic acetylcholine receptor. However, paraoxon and parathion could not inhibit the phosphorylation of the M2 muscarinic acetylcholine receptor. Chlorpyrifos oxon in different concentrations could also not inhibit the phosphorylation of the β 2-adrenergic receptor catalyzed by G protein-coupled receptor kinase 2. CONCLUSION： Different kinds of organophosphorus insecticides have different effects on the phosphorylation of the G protein-coupled receptor kinase 2-mediated M2 muscarinic acetylcholine receptor. Organophosphorus insecticides possibly have different toxic effects.

Molecular regulation of calcium-sensing receptor(CaSR)-mediated signaling

Calcium-sensing receptor(CaSR),a family C G-protein-coupled receptor,plays a crucial role in regulating calcium homeostasis by sensing small concentration changes of extracellular Ca^(2+),Mg^(2+),amino acids(e.g.,L-Trp and L-Phe),small peptides,anions(e.g.,HCO_(3)^(-)and PO_(4)^(3-)),and pH.CaSR-mediated intracellular Ca^(2+)signaling regulates a diverse set of cellular processes including gene transcription,cell proliferation,differentiation,apoptosis,muscle contraction,and neuronal transmission.Dysfunction of CaSR with mutations results in diseases such as autosomal dominant hypocalcemia,familial hypocalciuric hypercalcemia,and neonatal severe hyperparathyroidism.CaSR also influences calciotropic disorders,such as osteoporosis,and noncalciotropic disorders,such as cancer,Alzheimer's disease,and pulmonary arterial hypertension.This study first reviews recent advances in biochemical and structural determination of the framework of CaSR and its interaction sites with natural ligands,as well as exogenous positive allosteric modulators and negative allosteric modulators.The establishment of the first CaSR protein-protein interactome network revealed 94 novel players involved in protein processing in endoplasmic reticulum,trafficking,cell surface expression,endocytosis,degradation,and signaling pathways.The roles of these proteins in Ca^(2+)-dependent cellular physiological processes and in CaSR-dependent cellular signaling provide new insights into the molecular basis of diseases caused by CaSR mutations and dysregulated CaSR activity caused by its protein interactors and facilitate the design of therapeutic agents that target CaSR and other family C G-protein-coupled receptors.

Altered profiles of fecal bile acids correlate with gut microbiota and inflammatory responses in patients with ulcerative colitis

BACKGROUND Gut microbiota and its metabolites may be involved in the pathogenesis of inflammatory bowel disease.Several clinical studies have recently shown that patients with ulcerative colitis(UC)have altered profiles of fecal bile acids(BAs).It was observed that BA receptors Takeda G-protein-coupled receptor 5(TGR5)and vitamin D receptor(VDR)participate in intestinal inflammatory responses by regulating NF-ĸB signaling.We hypothesized that altered profiles of fecal BAs might be correlated with gut microbiota and inflammatory responses in patients with UC.AIM To investigate the changes in fecal BAs and analyze the relationship of BAs with gut microbiota and inflammation in patients with UC.METHODS The present study used 16S rDNA sequencing technology to detect the differences in the intestinal flora between UC patients and healthy controls(HCs).Fecal BAs were measured by targeted metabolomics approaches.Mucosal TGR5 and VDR expression was analyzed using immunohistochemistry,and serum inflammatory cytokine levels were detected by ELISA.RESULTS Thirty-two UC patients and twenty-three HCs were enrolled in this study.It was found that the diversity of gut microbiota in UC patients was reduced compared with that in HCs.Firmicutes,Clostridium IV,Butyricicoccus,Clostridium XlVa,Faecalibacterium,and Roseburia were significantly decreased in patients with UC(P=3.75E-05,P=8.28E-07,P=0.0002,P=0.003,P=0.0003,and P=0.0004,respectively).Proteobacteria,Escherichia,Enterococcus,Klebsiella,and Streptococcus were significantly enriched in the UC group(P=2.99E-09,P=3.63E-05,P=8.59E-05,P=0.003,and P=0.016,respectively).The concentrations of fecal secondary BAs,such as lithocholic acid,deoxycholic acid,glycodeoxycholic acid,glycolithocholic acid,and taurolithocholate,in UC patients were significantly lower than those in HCs(P=8.1E-08,P=1.2E-07,P=3.5E-04,P=1.9E-03,and P=1.8E-02,respectively)and were positively correlated with Butyricicoccus,Roseburia,Clostridium IV,Faecalibacterium,and Clostridium XlVb(P<0.01).The concentrations of primary BAs,such as taurocholic acid,cholic acid,taurochenodeoxycholate,and glycochenodeoxycholate,in UC patients were significantly higher than those in HCs(P=5.3E-03,P=4E-02,P=0.042,and P=0.045,respectively)and were positively related to Enterococcus,Klebsiella,Streptococcus,Lactobacillus,and pro-inflammatory cytokines(P<0.01).The expression of TGR5 was significantly elevated in UC patients(0.019±0.013 vs 0.006±0.003,P=0.0003).VDR expression in colonic mucosal specimens was significantly decreased in UC patients(0.011±0.007 vs 0.016±0.004,P=0.033).CONCLUSION Fecal BA profiles are closely related to the gut microbiota and serum inflammatory cytokines.Dysregulation of the gut microbiota and altered constitution of fecal BAs may participate in regulating inflammatory responses via the BA receptors TGR5 and VDR.

Sphingosine-1-phosphate signaling in vasculogenesis and angiogenesis

Blood vessels either form de novo through the process of vasculogenesis or through angiogenesis that involves the sprouting and proliferation of endothelial cells in pre-existing blood vessels. A complex interactive network of signaling cascades downstream from at least three of the nine known G-protein-coupled sphingosine-1-phosphate (S1P) receptors act as a prime effector of neovascularization that occurs in embryonic development and in association with various pathologies. This review focuses on the current knowledge of the roles of S1P signaling in vasculogenesis and angiogenesis, with particular emphasis on vascular cell adhesion and motility responses.

Conformational dynamics in GPCR signaling by NMR

G-protein-coupled receptors(GPCRs)mediate a wide range of cellular responses to various ligands or stimuli,and are the most important drug targets associated with human diseases.While major advances in GPCR structural biology have greatly deepened our understanding of its activation mechanism,the highly complex changes in the structural dynamics of GPCRs during activation remain underdetermined and their links to physiological functions largely unknown.Solution nuclear magnetic resonance(NMR)spectroscopy is an essential technique that allows the characterization of protein structural dynamics at atomic level,and has been applied in the studies of GPCR structural-function relationship in the past decade.Herein,we summarize a few specific studies in which solution NMR methods were employed and provided novel insights into questions difficult to be addressed by other methods.

Deletion of Gpr128 results in weight loss and increased intestinal contraction frequency

AIM: To generate a Gpr128 gene knockout mouse model and to investigate its phenotypes and the biological function of the Gpr128 gene.

GRK4 A486V variant contributes to ischemic injury by repressing autophagy after myocardial infarction

Background G-protein–coupled receptor kinases (GRKs) play important roles in cardiac hypertrophy and heart failure. The role of GRK4 in hypertension has been well demonstrated, but little is known in cardiac ischemic injury. In the present study, we explore if and how GRK4 regulates cardiomyocyte autophagy and influence the prognosis of myocardial infarction (MI).

Molecular mechanism of inflammatory pain

Chronic inflammatory pain resulting from arthritis, nerve injury and tumor growth is a serious public health issue. One of the major challenges in chronic inflammatory pain research is to develop new pharmacologic treatments with long-term efficacy and few side effects. The mediators released from inflamed sites induce complex changes in peripheral and central processing by directly acting on transducer receptors located on primary sensory neurons to transmit pain signals or indirectly modulating pain signals by activating receptors coupled with G-proteins and second messengers. High local proton concentration(acidosis) is thought to be a decisive factor in inflammatory pain and other mediators such as prostaglandin, bradykinin, and serotonin enhance proton-induced pain. Proton-sensing ion channels [transient receptor potential V1(TRPV1) and the acid-sensing ion channel(ASIC) family] are major receptors for direct excitation of nociceptive sensory neurons in response to acidosis or inflammation.G-protein-coupled receptors activated by prostaglandin, bradykinin, serotonin, and proton modulate functions of TRPV1, ASICs or other ion channels, thus leading to inflammation- or acidosis-linked hyperalgesia. Although detailed mechanisms remain unsolved, clearly different types of pain or hyperalgesia could be due to complex interactions between a distinct subset of inflammatory mediator receptors expressed in a subset of nociceptors. This review describes new directions for the development of novel therapeutic treatments in pain.

Relationship of GPRC6A and PKCzeta expression levels in prostate cancer lesions with cell proliferation and EMT

Objective: To study the relationship of GPRC6A and PKCzeta expression levels in prostate cancer lesions with cell proliferation and epithelial-mesenchymal transition (EMT). Methods:Patients with prostate cancer and patients with benign prostatic hyperplasia who received surgical resection in Huizhou Third People's Hospital between June 2014 and March 2017 were selected, right amount of prostate cancer tissue and tissue adjacent to carcinoma was collected from patients with prostate cancer, and the expression of GPRC6A, PKCzeta, cell proliferation genes and EMT genes in lesions were detected. Results: GPRC6A, Survivin, SRSF1, Bcl-xl, N-cadherin and Vimentin expression in prostate cancer lesions and adjacent lesions were significantly higher than those in benign prostatic hyperplasia lesions while PKCzeta, Caspase-3, Caspase-9, Apaf-1, E-cadherin and CK5/6 expression were significantly lower than those in benign prostatic hyperplasia lesions;Survivin, SRSF1 and Bcl-xl expression in prostate cancer lesions with lower PKCzeta expression were significantly higher than those in prostate cancer lesions with higher PKCzeta expression while Caspase-3, Caspase-9 and Apaf-1 expression were significantly lower than those in prostate cancer lesions with higher PKCzeta expression;E-cadherin and CK5/6 expression in prostate cancer lesions with lower GPRC6A expression were significantly higher than those in prostate cancer lesions with higher GPRC6A expression while N-cadherin and Vimentin expression were significantly lower than those in prostate cancer lesions with higher GPRC6A expression. Conclusion:Highly expressed GPRC6A and lowly expressed PKCzeta in prostate cancer lesions can promote cell EMT and proliferation respectively.

G蛋白耦联受体56在胃癌中的表达及其临床意义

目的 探讨G蛋白耦联受体56（GPR56）在人胃癌组织中的表达及其与胃癌生物学特征的关系.方法 采用免疫组织化学及Western blot方法检测GPR56蛋白在正常胃黏膜组织及胃癌组织中的表达水平,分析GPR56表达与胃癌临床病理特征的关系.结果 GPR56蛋白在胃癌组织中的表达水平（0.052 3±0.023 4）明显低于癌旁胃黏膜组织（0.063 3±0.027 0）的表达,两者差异有统计学意义（f =3.739,P＜0.01）;胃癌组织中GPR56的表达水平与胃癌分化程度、浸润深度和TNM分期密切相关（P＜0.05）,与患者性别、年龄、有无淋巴结转移、患者生存率无明显相关（P＞0.05）.结论 GPR56在人胃癌组织中表达显著下降,其表达水平与胃癌的侵袭、转移密切相关.