Increased endothelin receptor B and G protein coupled kinase-2 in the mesentery of portal hypertensive rats

AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP) was measured directly via catheters placed in the portal vein tract. The level of endothelin-1 (ET-1) in the mesenteric circulation was determined by radioimmunoassay, and the expression of the endothelin A receptor (ETAR) and endothelin B receptor (ETBR) was assessed by immunofluorescence and Western blot. Additionally, expression of G protein coupled kinase-2 (GRK2) and β-arrestin 2, which influence endothelin receptor sensitivity, were also studied by Western blot. RESULTS: PP of CBDL rats increased significantly (11.89 ± 1.38 mmHg vs 16.34 ± 1.63 mmHg). ET-1 expression decreased in the mesenteric circulation 2 and 4 wk after CBDL. ET-1 levels in the systemic circulation of CBDL rats were increased at 2 wk and decreased at 4 wk. There was no change in ETAR expression in response to CBDL; however, increased expression of ETBR in the endothelial cells of mesenteric arterioles and capillaries was observed. In sham-operated rats, ETBR was mainly expressed in the CD31+ endothelial cells of the arterioles. With development of PHT, in addition to the endothelial cells, ETBR expression was noticeably detectable in the SMA+ smooth muscle cells of arterioles and in the CD31+ capillaries. Following CBDL, increased expression of GRK2 was also found in mesenteric tissue, though there was no change in the level of β-arrestin 2. CONCLUSION: Decreased levels of ET-1 and increased ETBR expression in the mesenteric circulation following CBDL in rats may underlie mesenteric vasodilation in individuals with PHT. Mechanistically, increased GRK2 expression may lead to desensitization of ETAR, as well as other vasoconstrictors, promoting this vasodilatory effect.

Adrenal G protein-coupled receptor kinase-2 in regulation of sympathetic nervous system activity in heart failure

Heart failure(HF), the number one cause of death in the western world, is caused by the insufficient performance of the heart leading to tissue underperfusion in response to an injury or insult. It comprises complex interactions between important neurohormonal mechanisms that try but ultimately fail to sustain cardiac output. The most prominent such mechanism is the sympathetic(adrenergic) nervous system(SNS), whose activity and outflow are greatly elevated in HF. SNS hyperactivity confers significant toxicity to the failing heart and markedly increases HF morbidity and mortality via excessive activation of adrenergic receptors, which are G protein-coupled receptors. Thus, ligand binding induces their coupling to heterotrimeric G proteins that transduce intracellular signals. G protein signaling is turned-off by the agonist-bound receptor phosphorylation courtesy of G protein-coupled receptor kinases(GRKs), followed by βarrestin binding, which prevents the GRK-phosphorylated receptor from further interaction with the G proteins and simultaneously leads it inside the cell(receptor sequestration). Recent evidence indicates that adrenal GRK2 and βarrestins can regulate adrenal catecholamine secretion, thereby modulating SNS activity in HF. The present review gives an account of all these studies on adrenal GRKs and βarrestins in HF and discusses the exciting new therapeutic possibilities for chronic HF offered by targeting these proteins pharmacologically.

Roles of G protein-coupled receptors in inflammatory bowel disease

Inflammatory bowel disease(IBD)is a complex disease with multiple pathogenic factors.Although the pathogenesis of IBD is still unclear,a current hypothesis suggests that genetic susceptibility,environmental factors,a dysfunctional immune system,the microbiome,and the interactions of these factors substantially contribute to the occurrence and development of IBD.Although existing and emerging drugs have been proven to be effective in treating IBD,none can cure IBD permanently.G protein-coupled receptors(GPCRs)are critical signaling molecules implicated in the immune response,cell proliferation,inflammation regulation and intestinal barrier maintenance.Breakthroughs in the understanding of the structures and functions of GPCRs have provided a driving force for exploring the roles of GPCRs in the pathogenesis of diseases,thereby leading to the development of GPCR-targeted medication.To date,a number of GPCRs have been shown to be associated with IBD,significantly advancing the drug discovery process for IBD.The associations between GPCRs and disease activity,disease severity,and disease phenotypes have also paved new avenues for the precise management of patients with IBD.In this review,we mainly focus on the roles of the most studied proton-sensing GPCRs,cannabinoid receptors,and estrogen-related GPCRs in the pathogenesis of IBD and their potential clinical values in IBD and some other diseases.

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 in colon function, immune regulation and carcinogenesis

Estrogens play important roles in the development and progression of multiple tumor types.Accumulating evidence points to the significance of estrogen action not only in tumors of hormonally regulated tissues such as the breast,endometrium and ovary,but also in the development of colorectal cancer(CRC).The effects of estrogens in physiological and pathophysiological conditions are mediated by the nuclear estrogen receptorsαandβ,as well as the membranebound G protein-coupled estrogen receptor(GPER).The roles of GPER in CRC development and progression,however,remain poorly understood.Studies on the functions of GPER in the colon have shown that this estrogen receptor regulates colonic motility as well as immune responses in CRC-associated diseases,such as Crohn’s disease and ulcerative colitis.GPER is also involved in cell cycle regulation,endoplasmic reticulum stress,proliferation,apoptosis,vascularization,cell migration,and the regulation of fatty acid and estrogen metabolism in CRC cells.Thus,multiple lines of evidence suggest that GPER may play an important role in colorectal carcinogenesis.In this review,we present the current state of knowledge regarding the contribution of GPER to colon function and CRC.

New insights into sodium transport regulation in the distal nephron:Role of G-protein coupled receptors

The renal handling of Na^+ balance is a major determinant of the blood pressure(BP) level. The inability of the kidney to excrete the daily load of Na+ represents the primary cause of chronic hypertension. Among the different segments that constitute the nephron, those present in the distal part(i.e., the cortical thick ascending limb, the distal convoluted tubule, the connecting and collecting tubules) play a central role in the fine-tuning of renal Na^+ excretion and are the target of many different regulatory processes that modulate Na^+ retention more or less efficiently. G-protein coupled receptors(GPCRs) are crucially involved in this regulation and could represent efficient pharmacological targets to control BP levels. In this review, we describe both classical and novel GPCR-dependent regulatory systems that have been shown to modulate renal Na^+ absorption in the distal nephron. In addition to the multiplicity of the GPCR that regulate Na^+ excretion, this review also highlights the complexity of these different pathways, and the connections between them.

Isoleucine, an Essential Amino Acid, Induces the Expression of Human <i>β</i>Defensin 2 through the Activation of the G-Protein Coupled Receptor-ERK Pathway in the Intestinal Epithelia

Anti-microbial peptides are essential for the intestinal innate immunity that protects the intestinal epithelia from attacks by foreign pathogens. Human β-defensin (HBD) is one of the pivotal anti-microbial peptides that are expressed in the colonic epithelia. This study investigated the effect and the signaling mechanism of inducible β-defensin HBD2 by an essential amino acid, isoleucine (Ile) in colonic epithelial cells. Here we examined the expression level of HBD2 on induction of Ile in epithelial cells, and checked this pathway. HBD2 mRNA was induced by co-incubation with IL-1α and Ile in Caco2 cells, but not by Ile alone. An inhibitor of either ERK or Gi, a subunit of G-proteins, reduced the induction of HBD2 mRNA by Ile. The treatment with Ile also increased the intracellular calcium ion concentration, thus suggesting that the GPCR and ERK signaling pathway mediate the effects of Ile. These results indicate that an essential amino acid, Ile, enhances the expression of an inducible β-defensin, namely HBD2, by IL-1α through the activation of GPCRs and ERK signaling pathway. The administration of Ile may therefore represent a possible option to safely treat intestinal inflammation.

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.

Physiological and pharmacological functions of G protein coupled receptor 124:A review

G protein-coupled receptors(GPCRs)are the largest protein superfamily in the body,expressed in various tissues and organs,and are currently one of the most important clinical drug targets.Recently,a class of GPCRs without endogenous ligands(orphan GPCRs)have been discovered.They exhibit different physiological functions in the body and act extensively on the cardiovascular and cerebrovascular systems.Among them,G protein-coupled receptor 124(GPR124)is an orphaned member of the G protein coupled receptor adhesion family that has attracted much attention.It plays a key role in promoting cerebral angiogenesis and maintaining the stability of the blood-brain barrier.It also associated with cardiovascular and cerebrovascular diseases such as cerebral ischemia and atherosclerosis.However,the role of GPR124 in these diseases,the associated signaling pathways,and possible drug intervention targets are still unclear.This article summarizes the physiological effects,pharmacological effects and related signal pathways of GPR124 published in the field of cardiovascular and cerebrovascular diseases published in recent years,in order to provide a reference for the study of the role of GPR124 in the occurrence and development of diseases.

Overexpression of G protein-coupled receptor 31 as a poor prognosticator in human colorectal cancer

AIM To investigate the expression of G protein-coupled receptor 31 (GPR31) and its clinical significance in human colorectal cancer (CRC).METHODS To determine the association between the GPR31 expression and the prognosis of patients, we obtained paraffin-embedded pathological specimens from 466 CRC patients who underwent initial resection. A total of 321 patients from the First Affiliated Hospital of Sun Yat-sen University from January 1996 to December 2008 were included as a training cohort, whereas 145 patients from the Sixth Affiliated Hospital of Sun Yat-sen University from January 2007 to November 2008 were included as a validation cohort. We examined GPR31 expression levels in CRC tissues from two independent cohorts via immunohistochemical staining. All patients were categorized into either a GPR31 low expression group or a GPR31 high expression group. The clinicopathological factors and the prognosis of patients in the GPR31 low expression group and GPR31 high expression group were compared.RESULTS We compared the clinicopathological factors and the prognosis of patients in the GPR31 low expression group and GPR31 high expression group. Significant differences were observed in the number of patients in pM classification between patients in the GPR31 low expression group and GPR31 high expression group (P = 0.007). The five-year survival and tumor-free survival rates of patients were 84.3% and 82.2% in the GPR31 low expression group, respectively, and both rates were 59.7% in the GPR31 high expression group (P < 0.05). Results of the Cox proportional hazard regression model revealed that GPR31 upregulation was associated with shorter overall survival and tumor-free survival of patients with CRC (P < 0.05). Multivariate analysis identified GPR31 expression in colorectal cancer as an independent predictive factor of CRC patient survival (P < 0.05).CONCLUSION High GPR31 expression levels were found to be correlated with pM classification of CRC and to serve as an independent predictive factor of poor survival of CRC patients.

Insights into the structural biology of G-protein coupled receptors impacts drug design for central nervous system neurodegenerative processes

In the last few years, there have been important new insights into the structural biology of G-protein coupled receptors. It is now known that allosteric binding sites are involved in the affinity and selec- tivity of ligands for G-protein coupled receptors, and that signaling by these receptors involves both G-protein dependent and independent pathways. The present review outlines the physiological and pharmacological implications of this perspective for the design of new drugs to treat disorders of the central nervous system. Specifically, new possibilities are explored in relation to allosteric and or- thosteric binding sites on dopamine receptors for the treatment of Parkinson＇s disease, and on muscarinic receptors for Alzheimer＇s disease. Future research can seek to identify ligands that can bind to more than one site on the same receptor, or simultaneously bind to two receptors and form a dimer. For example, the design of bivalent drugs that can reach homo/hetero-dimers of D2 dopa- mine receptor holds promise as a relevant therapeutic strategy for Parkinson＇s disease. Regarding the treatment of Alzheimer＇s disease, the design of dualsteric ligands for mono-oligomeric mus- carinic receptors could increase therapeutic effectiveness by generating potent compounds that could activate more than one signaling pathway.

Functionally diverse ligands modulate different activation states of the formyl peptide receptor 2,a G protein-coupled receptor

OBJECTIVE To identify the mechanisms by which the formyl peptide receptor 2(FPR2)mediates both inflammatory and anti-inflammatory signaling in an agonist-dependent manner.METHODS Cells expressing FPR2 were incubated with weak agonists,Aβ42 and Ac2-26,before stimulation with a strong agonist,WKYMVm.Calcium mobilization,c AMP inhibition and MAP kinase activation were measured.Intramolecular FRET were determined using FPR2 constructs with an ECFP attached to the C-terminus and a Fl As H binding motif embedded in the first or third intracellular loop(IL1 or IL3,respectively).RESULTS Aβ42 did not induce significant Ca^(2+) mobilization,but positively modulated WKYMVm-induced Ca^(2+) mobilization and c AMP reduction in a dose-variable manner within a narrow range of ligand concentrations.Treating FPR2-expressing cells with Ac2-26,a peptide with anti-inflammatory activity,negatively modulated WKYMVm-induced Ca^(2+) mobilization and c AMP reduction.Intramolecular FRET assay showed that stimulation of the receptor constructs with Aβ42 brought the C-terminal domain closer to IL1 but away from IL3.An opposite conformational change was induced by Ac2-26.The FPR2 conformation induced by Aβ42 corresponded to enhanced ERK phosphorylation and attenuated p38 MAPK phosphorylation,whereas Ac2-26 induced FPR2 conformational change corresponding to elevated p38 MAPK phosphorylation and reduced ERK phosphorylation.CONCLUSION Aβ42 and Ac2-26 induce different conformational changes in FPR2.These findings provide a structural basis for FPR2 mediation of inflammatory vs anti-inflammatory functions and identify a type of receptor modulation that differs from the classic positive and negative allosteric modulation.

G蛋白偶联受体(GPCR)腺苷酸环化酶(AcyA)途径介导赭曲霉群体感应现象的机制

赭曲霉(Aspergillus ochraceus)是一种代表性的产毒模式真菌,存在密度依赖性转化的高、低群体密度阈值和携带这种密度信息的群体感应(QS)信号分子--氧脂素。本研究首先基于代表高、低群体密度条件的野生型赭曲霉转录组差异,分析群体密度这一环境条件对赭曲霉行为的影响,结果发现,除了氧脂素代表的细胞通信外,还具有种内对资源的竞争现象,体现在碳代谢。进一步,基于前期实验筛选到负责响应密度信息的膜受体GprC和主要的胞内效应器腺苷酸环化酶(AcyA),构建了基因缺陷型赭曲霉(ΔgprC和ΔacyA)。对比野生型与缺陷型赭曲霉的基因表达及行为差异后发现,GprC-AcyA途径缺陷后不仅中断了密度信息的传递,还直接影响赭曲霉的生命周期。本文研究结果表明,GprC和AcyA作为G蛋白网络的重要枢纽,具有广泛的调控作用,涉及生物过程、细胞组分、分子功能中大部分行为。本研究结果对利用生物手段进行真菌毒素污染的高效、绿色防治具有指导意义。

GPCR二聚体结构及功能

G蛋白偶联受体(G-protein coupled receptor,GPCR)是最广泛表达的膜蛋白家族之一,其可接收胞外信号刺激,通过自身构象变化激活胞内G蛋白等一系列信号通路,参与众多生理调节过程,具有重要的功能,因此其也是重要的药物靶点。GPCR二聚化是调控其功能的重要形式之一,靶向GPCR二聚体开发药物是药物研发的一个新方向。越来越多的研究报道了GPCR二聚化及其结构与功能调控的机制,本文综述了GPCR二聚体结构及功能的研究进展,为了解GPCR二聚体的发现、二聚化方式、功能调控机制,及进一步靶向GPCR二聚体药物开发提供了研究基础。

利用深度迁移学习靶向GPCRs的配体活性预测

G蛋白偶联受体(GPCRs)是最重要的药物靶标之一,约占市场上药物靶标的34%。药物发现过程中,配体生物活性的准确建模和解释对于筛选苗头化合物至关重要。研究表明,同源的G蛋白偶联受体能提升配体分子生物活性的预测性能和可解释性。提出了一种新的方法GLEM,用多任务下的深度迁移学习来预测配体的生物活性,并通过组稀疏来识别相关的关键子结构。GLEM方法在9组30个具有代表性的人类GPCR数据集上进行了实验,这些GPCRs涵盖了大部分人类GPCRs的子家族,每个GPCR数据集都包含60~3000个配体。实验结果表明,GLEM方法在绝大多数数据集中都获得了最好的性能。与单任务学习方法相比,GLEM方法在r2上平均提升了31.72%;与深度学习方法相比,GLEM方法在r2上平均提升了22.45%。此外,还评估了不同数量的训练样本对模型性能的影响,实验发现GLEM方法在小样本情况下表现最好。

基于Kisspeptin/GPR54系统探讨新加二甲地黄汤对PCOS模型大鼠卵泡发育的影响

目的探讨经新加二甲地黄汤干预后的多囊卵巢综合征(polycystic ovary syndrome,PCOS)模型大鼠的卵泡发育情况及其可能存在的效应机制。方法筛选28只拥有规律动情周期的雌性SD大鼠,随机分为正常对照组、模型组、中药组及西药组,每组7只。除正常对照组外,其余三组均连续予来曲唑-羧甲基纤维素混悬液0.1mg/(kg·d)灌胃,以构建PCOS大鼠模型。自第22天起,中药组以新加二甲地黄汤5.268g/(kg·d)灌胃,西药组以炔雌醇环丙孕酮片0.286mg/(kg·d)灌胃,正常对照组及模型组均以10ml/(kg·d)蒸馏水灌胃。3周后比较各组大鼠卵巢系数,苏木精-伊红染色观察各组大鼠卵巢组织形态学改变,对各组大鼠血清激素均采用酶联免疫吸附试验进行检测,蛋白质印迹法检测卵巢亲吻素(kisspeptin,Kp)、G蛋白偶联受体54(G-protein-coupled receptor 54,GPR54)蛋白表达水平。结果与正常对照组比较,模型组大鼠卵巢内呈现为囊状扩张和闭锁的卵泡增多,其颗粒细胞层数变少,卵巢系数增大;血清睾酮(testosterone,T)、黄体生成素(luteinizing hormone,LH)、Kp水平升高;血清卵泡刺激素(follicle stimulating hormone,FSH)、雌二醇(estradiol,E2)水平及大鼠卵巢组织中Kp、GPR54蛋白表达均显著降低(P<0.05)。予中药干预后,与模型组比较,中药组大鼠卵巢囊样扩张卵泡数量变少,颗粒细胞的层数增多,存在近成熟的卵泡,并见少量黄体存在;大鼠血清LH、T、Kp水平下降,血清FSH、E2水平及卵巢Kp、GPR54蛋白表达显著升高(P<0.05)。结论PCOS模型大鼠的卵泡发育情况经新加二甲地黄汤干预后得以改善,该治疗机制可能为通过调控Kisspeptin/GPR54系统影响FSH和LH的释放,以此影响激素含量,调整卵巢功能,使卵泡发育和排卵能力得以改善。

Kiss-1/GPR54系统在PCOS模型大鼠卵巢颗粒细胞中的表达及对卵泡发育障碍的作用机制

目的初步探讨Kiss-1/GPR54系统在多囊卵巢综合征(PCOS)模型大鼠卵巢颗粒细胞中的表达,并分析其与PCOS之间的关联。方法筛选出14只动情规律的雌性SD大鼠,按照随机数字表法分为正常对照组和模型组,每组7只。其中模型组大鼠予来曲唑-羧甲基纤维素混悬液0.1mg/(kg·d)连续灌胃21 d以构建PCOS大鼠模型。收集大鼠血清、卵巢组织、卵巢颗粒细胞。然后计算大鼠卵巢指数,对卵巢组织进行苏木精-伊红染色法,采用酶联免疫吸附测定法检测血清激素水平,免疫荧光染色检测颗粒细胞中亲吻素(Kp)、G蛋白偶联受体54(GPR54)荧光强度,实时定量反转录聚合酶链式反应检测颗粒细胞中Kiss-1、GPR54基因表达。结果与正常对照组比较,模型组大鼠卵巢囊状扩张卵泡及闭锁卵泡增加,卵泡颗粒细胞层变薄;卵巢指数增大[(1.22±0.10)mg/g比(0.82±0.13)mg/g,P<0.05];血清黄体生成素[(66.32±3.98)IU/L比(11.87±5.54)IU/L]、睾酮[(33.72±3.57)ng/mL比(8.40±2.94)ng/mL]、Kp水平[(1506.79±154.82)pg/mL比(289.57±89.20)pg/mL]均升高(P<0.05);卵巢颗粒细胞中Kp荧光强度[(1601852.67±378567.82)比(3685156.00±359825.63)]、GPR54荧光强度[(1298372.25±297701.61)比(2961456.58±309119.01)]及Kiss-1基因表达[(0.10±0.03)比(1.11±0.14)]、GPR54基因表达[(0.10±0.05)比(1.00±0.13)]均降低(P<0.05)。结论卵巢表达的Kiss-1/GPR54系统可能通过调节颗粒细胞从而影响PCOS大鼠卵泡发育。

黏附性G蛋白偶联受体F1在胰腺导管腺癌中的表达及其促进癌症进展的机制研究

目的·分析黏附性G蛋白偶联受体F1(adhesion G protein-coupled receptor F1,ADGRF1)在胰腺导管腺癌(pancreatic ductal adenocarcinoma,PDAC)发生及发展过程中的表达变化,探究ADGRF1对PDAC细胞增殖的影响以及促进PDAC进展的潜在分子机制。方法·基于癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库和基因表达综合(Gene Expression Omnibus,GEO)数据库分析ADGRF1在正常胰腺组织及PDAC组织中的mRNA水平表达。利用实时荧光定量PCR(quantitative real-time PCR,qPCR)和蛋白质印迹法(Western blotting)检测ADGRF1在正常胰腺导管上皮细胞hTERT-HPNE及多种PDAC细胞中的表达情况。利用免疫组织化学染色(immunohistochemistry staining,IHC)检测PDAC患者的癌组织及癌旁组织中ADGRF1的表达差异。转染小干扰RNA(small interfering RNA,siRNA)敲低ADGRF1后,通过CCK8和平板克隆形成实验检测PDAC细胞AsPC-1、SW1990增殖能力的变化。构建稳定过表达ADGRF1的Patu8988细胞,通过CCK8实验检测过表达ADGRF1引起的PDAC细胞增殖变化。利用RNA测序(RNA-sequence,RNA-seq)、基因集富集分析(gene set enrichment analysis,GSEA)和免疫浸润分析预测与ADGRF1促进PDAC癌症进展相关的信号通路。结果·TCGA数据库和GEO数据库的分析结果显示ADGRF1 mRNA在PDAC组织中的表达高于正常胰腺组织(均P=0.000)。qPCR和Western blotting结果显示,与hTERT-HPNE细胞相比,多种PDAC细胞中ADGRF1的mRNA和蛋白水平均有所上调(均P<0.05)。IHC结果显示ADGRF1在PDAC患者癌组织中的表达也高于癌旁组织。此外,下调ADGRF1能够抑制PDAC细胞AsPC-1、SW1990的增殖能力;而过表达ADGRF1则促进Patu8988细胞的增殖能力(均P<0.05)。RNAseq、GSEA富集分析和免疫浸润的结果显示,ADGRF1的表达与干扰素α(interferon-α,IFN-α)、肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)和核因子κB(nuclear factorκB,NF-κB)等信号通路有关。结论·ADGRF1在PDAC细胞和组织中高表达,促进PDAC细胞的增殖,其机制可能与多个免疫相关信号通路有关。

GPCRs在恶性肿瘤中的研究进展

G蛋白偶联受体(GPCRs),又称为7-α螺旋跨膜蛋白受体,是目前已知的人类基因组中最大和最多样化的蛋白质家族。GPCRs通过调控下游多种信号通路,参与恶性肿瘤的增殖、凋亡、侵袭和转移等过程。此外,GPCRs的异常甲基化在肿瘤发生中也具有关键作用。近年来,GPCRs被认为是治疗许多恶性肿瘤的潜在药物靶点,然而大部分GPCRs的作用机制仍不清楚。本文就GPCRs在恶性肿瘤中的发病机制进行综述,以期为肿瘤的预防和治疗提供新的诊疗思路。