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@#Receptor activity-modifying proteins(RAMPs) are type I transmembrane proteins,which are activity-modifying proteins of a variety of G-protein-coupled receptors(GPCRs).RAMPs are related to physiological and pathological phenomena such as neurological diseases,cardiovascular diseases,renal function,skeletal development and obesity,and of great significance for disease prevention,which are potential targets for the treatment of various diseases and also closely related to the prognosis of diseases.At present,there are few studies on proteins that may regulate the expression of RAMPs.This paper focuses on the sterol regulatory element-binding factor-2(SREBF-2) that may regulate the transcription and expression of RAMP3, and reviews the research progress of RAMPs in biology,pathology and pharmacology,providing a reference for the further research on RAMPs and the prevention and detection of related diseases.
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@#Free fatty acid receptors(FFARs)are a series of orphan G protein-coupled receptors(GPCRs)activated by free fatty acids(FFAs)and their derivatives. As transmembrane receptors,GPCRs are involved in the occurrence and development of many diseases and provide a wide range of therapeutic targets for these diseases. FFARs combined with FFAs are mainly involved in the secretion of endocrine hormones such as insulin,adipocyte differentiation,inflammatory response,autoimmune response and other processes,which was a potential therapeutic target for energy metabolism disorders and immune diseases. However,recent studies have shown that FFAs and its receptor FFARs are widely involved in neuroinflammation and neuroimmunity directly or through the brain-intestinal axis,and are expected to be a therapeutic target for multiple sclerosis,Alzheimer′s disease(AD),Parkinson′s disease(PD),depression and other diseases. This paper reviews the research progress of the role of FFARs in nervous system diseases.
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G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors in mammals that contain seven transmembrane helices. The human genome encodes about 800 different types of GPCRs, which are widely involved in the pathological processes underlying different diseases, e.g. metabolic diseases and tumors, rendering them popular therapeutic targets. Peptides are organic substances consisted of two to dozens of amino acids linked by peptide bonds. They are bioactive substances involved in various cellular activities. To date, over 7 000 natural peptides have been identified as hormones, neurotransmitters, growth factors, ion channel ligands and antibiotics. Peptide drugs are valued for being selective and efficacious, and at the same time relatively safe and with low costs of production. In recent years, based on the increased understanding of GPCR structures, the development of GPCR-targeting peptide drugs has made great progress. Up to now, there have been nearly 50 peptide drugs targeting GPCRs approved by FDA for the treatment of metabolic diseases, nervous system diseases, cancer or other diseases. The research and development of peptide drugs have gone through three stages: development based on human peptides, on natural peptides and by modern biotechnology. At present, most of the marketed GPCR-targeting peptide drugs are derivatives of human natural peptides. In this review, we sum up the recent marketed GPCR-targeting peptide drugs, and also summarize the current strategies and further directions of peptide drug development.
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Clinical pharmacology/research has a very interesting history. It started in the 40's of the 20th century through the pioneering work of Harry Gold at Cornell University, New York. Clinical research is an integral part of drug development. Drug development can be hastened by a number of new techniques with reduction in cost. In addition reverse pharmacology approaches for drug discovery have come to occupy a special place. 85% of the neutral antagonists act as inverse agonists. Inverse agonists have a distinct effect on receptor regulation as opposed to neutral antagonists. Orphan receptors constitute about 50% of the GPCRs. It is estimated that now there are nearly 175 orphan receptors after 125 having been deorphanised. Targeting these orphan receptors can lead to about the same number of ligands and antagonists thereof. Polymorphism of cytochrome P450 provides the basis for the use of predictive pharmacogenomics to yield drug therapies that are more efficient and safer. It is estimated that such personalized P450 gene-based treatment would be relevant for 10- 20% of all drug therapy.
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Objective To explore the mechanisms of trafficking and signaling of serotonin 1A receptor(5-HT_(1A))and its spatiotemporal distribution in living cells.Methods The mouse 5-HT_(1A) gene amplified by RT-PCR was recombined into pEGFP-N1 vector and the EGFP coding sequence was located in-frame at the C-terminal end of the 5-HT_(1A) receptor.The 5-HT_(1A)-EGFP was transfected into neuron-like PC12 cells as well as HEK293.The transfected cells were visualized using confocal microscopy,the mobility of 5-HT_(1A)-EGFP was monitored by live measurements and fluorescence recovery after photobleaching.Results The 5-HT_(1A) gene was identitical with the published gene sequence NM_008308.4 and a 5-HT_(1A)-EGFP fusion construct was created.After stable transfection of the plasimd into a PC12 cell line and analysis with a confocal laser scanning microscopy,the EGFP-tagged 5-HT_(1A) was predominantly associated with the plasma membrane,but some intracellular vesicles in the perinuclear region also contained the fusion protein.The predominant localization of 5-HT_(1A)-EGFP at the plasma membrane was confirmed in transiently transfected HEK293 cells.Bleached fluorescence was partialy recovered in 100 seconds,indicating that the 5-HT_(1A)-EGFP was mobiled on the membrane.Conclusion Spatiotemporal distribution and mobility of 5-HT_(1A) tagged with EGFP can be monitored in the 5-HT_(1A)-EGFP stable PC12 cell line,which could be an excellent neuron-like experimental cell model for research of 5-HT_(1A) trafficking and signaling.
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OBJECTIVE: To analyze the aberrant expression of the GIPR and LHCGR in different forms of adrenocortical hyperplasia: ACTH-independent macronodular adrenal hyperplasia (AIMAH), primary pigmented nodular adrenocortical disease (PPNAD) and diffuse adrenal hyperplasia secondary to Cushing's disease (DAHCD). METHODS: We quantified GIPR and LHCGR expressions using real time PCR in 20 patients with adrenocortical hyperplasia (seven with AIMAH, five with PPNAD, and eight with DAHCD). Normal adrenals tissues were used as control and the relative expression was compared with β-actin. RESULTS: GIPR and LHCGR expressions were demonstrated in all tissues studied. Median GIPR and LHCGR mRNA levels were 1.6; 0.4; 0.5 and 1.3; 0.9; 1.0 in adrenocortical tissues from AIMAH, PPNAD and DAHCD respectively. There were no differences between GIPR and LHCGR expressions in all tissues studied. CONCLUSIONS: GIPR and LHCGR overexpression were not identified in the studied cases, thus suggesting that this molecular mechanism is not involved in adrenocortical hyperplasia in our patients.
OBJETIVO: Analisar a expressão aberrante do GIPR e do LHCGR em diferentes formas de hiperplasias adrenocorticais: hiperplasia adrenal macronodular independente de ACTH (AIMAH), doença adrenocortical nodular pigmentada primária (PPNAD) e hiperplasia adrenal difusa secundária à doença de Cushing (DAHCD). MÉTODOS: Quantificou-se por PCR em tempo real a expressão desses receptores em 20 pacientes: sete com AIMAH, cinco com PPNAD e oito com DAHCD. Adrenais normais foram utilizadas como controle e a expressão relativa desses receptores foi comparada à expressão da β-actina. RESULTADOS: A expressão desses receptores foi demonstrada em todos os tecidos estudados. A mediana da expressão do GIPR e do LHCGR foi de 1,6; 0,4; 0,5 e de 1,3; 0,9; 1,0 nos tecidos dos pacientes com AIMAH, PPNAD e DAHCD, respectivamente. Não houve diferença significativa na expressão desses receptores nos tecidos estudados. CONCLUSÕES: Hiperexpressão do GIPR e do LHCGR não foi observada, sugerindo que esse mecanismo não está envolvido na patogênese molecular da hiperplasia adrenal nesses pacientes.