In growing children, growth plate cartilage has limited self-repair ability upon fracture injury always leading to limb growth arrest. Interestingly, one type of fracture injuries within the growth plate achieve amazing self-healing, however, the mechanism is unclear. Using this type of fracture mouse model, we discovered the activation of Hedgehog (Hh) signaling in the injured growth plate, which could activate chondrocytes in growth plate and promote cartilage repair. Primary cilia are the central transduction mediator of Hh signaling. Notably, ciliary Hh-Smo-Gli signaling pathways were enriched in the growth plate during development. Moreover, chondrocytes in resting and proliferating zone were dynamically ciliated during growth plate repair. Furthermore, conditional deletion of the ciliary core gene Ift140 in cartilage disrupted cilia-mediated Hh signaling in growth plate. More importantly, activating ciliary Hh signaling by Smoothened agonist (SAG) significantly accelerated growth plate repair after injury. In sum, primary cilia mediate Hh signaling induced the activation of stem/progenitor chondrocytes and growth plate repair after fracture injury.
Mice ; Animals ; Hedgehog Proteins/genetics* ; Receptors, G-Protein-Coupled/metabolism* ; Cilia/metabolism* ; Cartilage/metabolism* ; Regeneration

Hypertension is a clinical syndrome characterized by elevated systemic arterial blood pressure, which may be accompanied by functional or organic damage of heart, brain, kidney and other organs. The pathogenesis and development of hypertension are affected by genetic, environmental, epigenetic, intestinal microbiota and other factors. They are the result of multiple factors that promote the change of blood pressure level and vascular resistance. G protein coupled receptors(GPCRs) are the largest and most diverse superfamily of transmembrane receptors that transmit signals across cell membranes and mediate a large number of cellular responses required by human physiology. A variety of GPCRs are involved in the control of blood pressure and the maintenance of normal function of cardiovascular system. Hypertension contributes to the damages of heart, brain, kidney, intestine and other organs. Many GPCRs are expressed in various organs to regulate blood pressure. Although many GPCRs have been used as therapeutic targets for hypertension, their efficacy has not been fully studied. The purpose of this paper is to elucidate the role of GPCRs in blood pressure regulation and its distribution in target organs. The relationship between GPCRs related to intestinal microorganisms and blood pressure is emphasized. It is proposed that traditional Chinese medicine may be a new way to treat hypertension by regulating the related GPCRs via intestinal microbial metabolites.
Blood Pressure ; GTP-Binding Proteins ; Gastrointestinal Microbiome ; Humans ; Hypertension/genetics* ; Receptors, G-Protein-Coupled/metabolism*

Numerous musculoskeletal disorders are caused by thickened ligament, tendon stiffness, or fibrosis of joint capsule. Relaxin, a peptide hormone, can exert collagenolytic effect on ligamentous and fibrotic tissues. We hypothesized that local injection of relaxin could be used to treat entrapment neuropathy and adhesive capsulitis. Because hormonal effect depends on the receptor of the hormone on the target cell, it is important to confirm the presence of such hormonal receptor at the target tissue before the hormone therapy is initiated. The aim of this study was to determine whether there were relaxin receptors in the ligament, tendon, and joint capsular tissues of rats and to identify the distribution of relaxin receptors in these tissues. Transverse carpal ligaments (TCLs), inguinal ligaments, anterior cruciate ligaments (ACLs), Achilles tendons, and shoulder joint capsules were obtained from male Wistar rats. Western blot analysis was used to identify relaxin receptor isoforms RXFP1 and RXFP2. The distribution of relaxin receptors was determined by immunohistochemical staining. The RXFP1 isoform was found in all tissues examined. The RXFP2 isoform was present in all tissues but the TCLs. Its expression in ACLs tissues was relatively weak compared to that in other tissues. Our results revealed that RXFP1 and RXFP2 were distributed in distinctly different patterns according to the type of tissue (vascular endothelial cells, fibroblast-like cells) they were identified.
Animals ; Blotting, Western ; *Gene Expression Regulation ; Immunohistochemistry ; Ligaments/*metabolism ; Male ; Rats ; Rats, Wistar ; Receptors, G-Protein-Coupled/*genetics/metabolism ; Receptors, Peptide/*genetics/metabolism ; Shoulder Joint/*metabolism ; Tendons/*metabolism

Astrocytoma ; genetics ; metabolism ; Brain Neoplasms ; genetics ; metabolism ; Frizzled Receptors ; genetics ; metabolism ; Glioblastoma ; genetics ; metabolism ; Glioma ; genetics ; metabolism ; Humans ; Paraffin Embedding ; RNA, Messenger ; metabolism ; Receptors, G-Protein-Coupled ; genetics ; metabolism ; Signal Transduction ; Wnt2 Protein ; genetics ; metabolism ; beta Catenin ; genetics ; metabolism

OBJECTIVETo investigate the expression of urotensin II (U II) and G-protein coupled receptor 14 (GPR14) mRNA in human pheochromocytoma tissues.

METHODSTotal RNA from normal adrenal and pheochromocytoma tissues was extracted. The reverse transcription-polymerase chain reaction method was used to evaluate the levels of U II and GPR14 mRNA expression in human pheochromocytoma tissues.

RESULTSThere was no significant difference of U II and GPR14 mRNA expression between normal adrenal cortex and medulla. The expression of U II and GPR14 mRNA in pheochromocytoma was significantly lower than that in normal adrenal cortex and medulla (P < 0.05). The expression of GPR14 mRNA in adrenal pheochromocytomas was significantly lower than that of extra-adrenal pheochromocytomas (P < 0.05).

CONCLUSIONU II and GPR14 may play a role in the pathogenesis and hypertension regulating of pheochromocytoma.

Adrenal Cortex ; metabolism ; Adrenal Gland Neoplasms ; metabolism ; Adrenal Medulla ; metabolism ; Humans ; Pheochromocytoma ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, G-Protein-Coupled ; biosynthesis ; genetics ; Urotensins ; biosynthesis ; genetics

OBJECTIVETo investigate the expression and its significance of melatonin receptor in human hypertrophic scarring.

METHODSThe expression of melatonin receptor GPR50 was detected with immunohistochemistry and the melatonin receptors (MT1, MT2) mRNA were assessed with RT-PCR method in 10 cases of human hypertrophic scar and normal skin. The positive production was sequenced with auto sequencing instrument.

RESULTSPositive signals of melatonin receptor could be found in the cell membrane and cytoplasm. The melatonin receptor GPR50 was located in the epithelial basal cells,sweat gland cells and hair follicle in both hypertrophic scar and normal skin. The melatonin receptor GPR50 was extensively expressed in fibroblasts of hypertrophic scar, but not in fibroblasts in normal skin. RT-PCR showed that the expression of melatonin receptor (MT1, MT2) mRNA in hypertrophic scar was significantly higher than that in normal skin (P < 0.05). In normal skin and hypertrophic scar group, the expression of MT1 mRNA was higher than MT2 mRNA (P < 0.05). In normal skin and hypertrophic scar group, the expression of MT1 mRNA was 0.99081 +/- 0.26485 and 1.16584 +/- 0.21829 copy number/microl cDNA, respectively; the expression of MT2 mRNA was 0.77083 +/- 0.15927 and 0.99550 +/- 0.14624 copy number/ microl cDNA, respectively. Sequencing results indicated that the positive product coincided with cDNA of human melatonin receptor in GeneBank.

CONCLUSIONSPositive expression of melatonin receptor can be found in human hypertrophic scar and normal skin, but it is higher in scar. The over expression of melatonin receptor in hypertrophic scar may be related to the development of hypertrophic scar.

Adult ; Cicatrix, Hypertrophic ; metabolism ; Female ; Humans ; Male ; Nerve Tissue Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; Receptors, G-Protein-Coupled ; genetics ; metabolism

GPCR proteins represent the largest family of signaling membrane proteins in eukaryotic cells. Their importance to basic cell biology, human diseases, and pharmaceutical interventions is well established. Many crystal structures of GPCR proteins have been reported in both active and inactive conformations. These data indicate that agonist binding alone is not sufficient to trigger the conformational change of GPCRs necessary for binding of downstream G-proteins, yet other essential factors remain elusive. Based on analysis of available GPCR crystal structures, we identified a potential conformational switch around the conserved Asp2.50, which consistently shows distinct conformations between inactive and active states. Combining the structural information with the current literature, we propose an energy-coupling mechanism, in which the interaction between a charge change of the GPCR protein and the membrane potential of the living cell plays a key role for GPCR activation.
Binding Sites ; GTP-Binding Proteins ; chemistry ; genetics ; metabolism ; Humans ; Hydrogen Bonding ; Membrane Potentials ; Models, Molecular ; Protein Conformation ; Receptors, G-Protein-Coupled ; chemistry ; genetics ; metabolism ; Signal Transduction

G protein-coupled receptors (GPCRs) are involved in all human physiological systems where they are responsible for transducing extracellular signals into cells. GPCRs signal in response to a diverse array of stimuli including light, hormones, and lipids, where these signals affect downstream cascades to impact both health and disease states. Yet, despite their importance as therapeutic targets, detailed molecular structures of only 30 GPCRs have been determined to date. A key challenge to their structure determination is adequate protein expression. Here we report the quantification of protein expression in an insect cell expression system for all 826 human GPCRs using two different fusion constructs. Expression characteristics are analyzed in aggregate and among each of the five distinct subfamilies. These data can be used to identify trends related to GPCR expression between different fusion constructs and between different GPCR families, and to prioritize lead candidates for future structure determination feasibility.
Animals ; Computational Biology ; Crystallography, X-Ray ; Gene Expression ; Humans ; Plasmids ; genetics ; metabolism ; Protein Domains ; Receptors, Adrenergic, beta-1 ; Receptors, G-Protein-Coupled ; classification ; genetics ; metabolism ; Receptors, Odorant ; metabolism ; Receptors, Purinergic P1 ; genetics ; metabolism ; Sf9 Cells ; Spodoptera

BACKGROUNDOGR1 was found as a G-protein coupled receptor (GPCR) and proton sensor. Our previous studies have found that OGR1 has inhibitory effect on the metastasis of prostate cancer. In order to investigate the roles of OGR1 gene in the biological activities of ovarian cancer, we studied the OGR1 effects on ovarian cancer cells, HEY cells.

METHODSOGR1 gene was transfected into HEY cell, in which endogenous expression is low. OGR1-overxepressed cells and vector-transfected cells were compared in different assays. Western blotting was employed to confirm the high expression level of OGR1. Cell proliferation was determined by MTT assay and cell doubling time assay. Cell migration assay (transwell assay) and cell adhesion assay were performed to determine the migration and adhesion potential of cells. Student's t test was employed for statistical analysis.

RESULTSProliferation of OGR1-overexpressed cells was significantly reduced (P < 0.01); cell migration was significantly inhibited in the OGR1-transfected cells (P < 0.01); cell adhesion to extracellular matrix including fibronectin, vitronectin, collagen I/IV was significantly increased (P < 0.01).

CONCLUSIONSOGR1 expression in human ovarian cancer cells significantly inhibited the cell proliferation and migration, but significantly enhanced cell adhesion to the extracellular matrix. It indicated that OGR1 may be a tumor suppressor gene for ovarian cancer.

Blotting, Western ; Cell Adhesion ; genetics ; physiology ; Cell Line, Tumor ; Cell Movement ; genetics ; physiology ; Cell Proliferation ; Humans ; Receptors, G-Protein-Coupled ; genetics ; metabolism ; Transfection

Orthodontically induced tooth root resorption (OIRR) is a serious complication during orthodontic treatment. Stimulating cementum repair is the fundamental approach for the treatment of OIRR. Parathyroid hormone (PTH) might be a potential therapeutic agent for OIRR, but its effects still lack direct evidence, and the underlying mechanisms remain unclear. This study aims to explore the potential involvement of long noncoding RNAs (lncRNAs) in mediating the anabolic effects of intermittent PTH and contributing to cementum repair, as identifying lncRNA-disease associations can provide valuable insights for disease diagnosis and treatment. Here, we showed that intermittent PTH regulates cell proliferation and mineralization in immortalized murine cementoblast OCCM-30 via the regulation of the Wnt pathway. In vivo, daily administration of PTH is sufficient to accelerate root regeneration by locally inhibiting Wnt/β-catenin signaling. Through RNA microarray analysis, lncRNA LITTIP (LGR6 intergenic transcript under intermittent PTH) is identified as a key regulator of cementogenesis under intermittent PTH. Chromatin isolation by RNA purification (ChIRP) and RNA immunoprecipitation (RIP) assays revealed that LITTIP binds to mRNA of leucine-rich repeat-containing G-protein coupled receptor 6 (LGR6) and heterogeneous nuclear ribonucleoprotein K (HnRNPK) protein. Further co-transfection experiments confirmed that LITTIP plays a structural role in the formation of the LITTIP/Lgr6/HnRNPK complex. Moreover, LITTIP is able to promote the expression of LGR6 via the RNA-binding protein HnRNPK. Collectively, our results indicate that the intermittent PTH administration accelerates root regeneration via inhibiting Wnt pathway. The lncRNA LITTIP is identified to negatively regulate cementogenesis, which activates Wnt/β-catenin signaling via high expression of LGR6 promoted by HnRNPK.
Mice ; Animals ; Cementogenesis ; Wnt Signaling Pathway ; beta Catenin/metabolism* ; Heterogeneous-Nuclear Ribonucleoprotein K/metabolism* ; RNA, Long Noncoding/genetics* ; Parathyroid Hormone ; Receptors, G-Protein-Coupled/metabolism*