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

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*

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*

OBJECTIVE: To investigate the effect of G protein-coupled receptor 17 (GPR17) on hypoxia injury in retinal ganglion cells . METHODS: CoCl (400 μmol/L) was used to induce hypoxic injury in RGC-5 cells. The expression of GPR17 and the effect of GPR17 ligands were investigated, and the role of GPR17 in hypoxia injury was further studied by transfection of RGC-5 cells with GPR17 small interfering RNA (siRNA). The cell viability was determined by MTT and the cell apoptosis rate was detected by flow cytometry analysis. The expression of GPR17 mRNA was determined with RT-PCR. RESULTS: mRNA expressions of GPR17 in RGC-5 cells with and without CoCl treatment were 0.36±0.05 and 0.26±0.08(<0.01). Compared with hypoxia without any treatment, pretreatment with GPR17 agonists (LTD, UDP, UDP-G) significantly reduced cell viability (the survival rates of cells decreased by 29.6%, 31.8% and 33.9%, all <0.01), while the effect of GPR17 antagonist (cangrelor) was the opposite (the survival rates of cells increased by 33.2%, <0.01). Transfection with GPR17 SiRNA inhibited hypoxia-induced up-expression of GPR17 mRNA (<0.01)and reduced cell apoptosis[rates of cell apoptosis were(39.73±2.06)%,(42.50±3.64)% and (24.98±2.16)% for blank control, NC siRNA and GPR17 siRNA groups, <0.01]. CONCLUSIONS GPR17 may mediate hypoxia injury in RGC-5 cells, while the knockdown of GPR17 can reduce the hypoxia injury.
Apoptosis ; Cell Hypoxia ; genetics ; Cell Line ; Cell Survival ; Cobalt ; Gene Expression Regulation ; drug effects ; Gene Knockdown Techniques ; Humans ; Hypoxia ; chemically induced ; genetics ; Receptors, G-Protein-Coupled ; genetics ; metabolism ; Retinal Ganglion Cells ; drug effects

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

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

OBJECTIVETo investigate the effects of different concentrations of lipopolysaccharide (LPS), tumor necrosis factor α (TNFα), interleukin-6 (IL-6), dexamethasone (Dex), and insulin on the mRNA and protein expressions of GPR54 in the MCF7 cell line in vitro.

METHODSMCF7 breasr cancer cells were cultured and treated with different concentrations of LPS (10 and 20 µg/ml), TNFα (20 and 100 ng/ml), IL-6 (10 and 20 ng/ml), Dex (10(-6) and 10(-7) mol/L), and insulin (0.01 and 0.1 IU/L). Those treated with culture fluid only served as controls. The mRNA and protein expressions of GPR54 were measured by real-time PCR and Western blot, respectively, after 6, 24, 48, and 72 hours of treatment.

RESULTSCompared with the blank con- trol, LPS (10 and 20 µg/ml), TNFα (20 and 100 ng/ml), IL-6 (10 and 20 ng/ml), Dex (10(-6) and 10(-7) mol/L), and insulin (0.01 and 0.1 IU/L) significantly increased the expressions of GPR54 mRNA (P < 0.05) and protein (P < 0.05).

CONCLUSIONLPS, TNFα, IL-6, Dex, and insulin evidently increase the expression of GPR54 in the MCF7 cell line, indicating their influence on the function of gonads by regulating the GPR54 level.

Blotting, Western ; Dexamethasone ; administration & dosage ; pharmacology ; Glucocorticoids ; administration & dosage ; pharmacology ; Gonads ; drug effects ; metabolism ; Humans ; Hypoglycemic Agents ; administration & dosage ; pharmacology ; Insulin ; administration & dosage ; pharmacology ; Interleukin-6 ; administration & dosage ; pharmacology ; Lipopolysaccharides ; administration & dosage ; pharmacology ; MCF-7 Cells ; RNA, Messenger ; metabolism ; Real-Time Polymerase Chain Reaction ; Receptors, G-Protein-Coupled ; drug effects ; genetics ; metabolism ; Receptors, Kisspeptin-1 ; Time Factors ; Tumor Necrosis Factor-alpha ; administration & dosage ; pharmacology

OBJECTIVETo investigate whether ginsenoside-Rb1 (Gs-Rb1) inhibits the apoptosis of hypoxia cardiomyocytes by up-regulating apelin-APJ system and whether the system is affected by hypoxia-induced factor 1α (Hif-1α).

METHODSNeonatal rat cardiomyocytes were randomly divided into 6 groups: a control group, a simple CoCl group, a simple Gs-Rb1 group, a CoCl and Gs-Rb1 hypoxia group, a CoCl and 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) group, a CoCl and YC-1 group and a Gs-Rb1 group, in which YC-1 inhibits the synthesis and accelerates the degradation of Hif-1a. The concentration of CoCl, Gs-Rb1 and YC-1 was 500 μmol/L, 200 μmol/L and 5 μmol/L, respectively; the apoptosis ratio was analyzed with a flow cytometer; and apelin, APJ and Hif-1α were assayed with immunocytochemistry, Western blot assays and reverse transcription polymerase chain reaction (RT-PCR).

RESULTS(1) The anti-apoptosis effect of Gs-Rb1 on hypoxia cardiomyocytes was significantly inhibited by YC-1; (2) Hypoxia significantly up-graded the expression of mRNA and protein of apelin; this effect was further reinforced by Gs-Rb1 and significantly inhibited by YC-1; (3) Gs-Rb1 further strengthened the expression of APJ mRNA and APJ proteins once hypoxia occurred, which was significantly inhibited by YC-1; (4) Gs-Rb1 significantly increased the expression of Hif-1α, which was completely abolished by YC-1; (5) There was a negative relationship between AR and apelin (or APJ, including mRNA and protein), a positive correlation between apelin (or APJ) protein and Hif-1a protein, in hypoxia cardiomyocytes.

CONCLUSIONThe apelin-APJ system plays an important role in the anti-apoptosis effect of Gs-Rb1 on hypoxia neonatal cardiomyocytes, which was partly adjusted by Hif-1α.

Animals ; Animals, Newborn ; Apelin ; Apelin Receptors ; Cell Hypoxia ; drug effects ; Ginsenosides ; pharmacology ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Immunohistochemistry ; Intercellular Signaling Peptides and Proteins ; genetics ; metabolism ; Myocytes, Cardiac ; cytology ; drug effects ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats, Wistar ; Receptors, G-Protein-Coupled ; metabolism

To study the expression of angiotensin converting enzyme 2 (ACE2) and angiotensin (Ang) 1-7 specific receptor Mas protain in renal blood vessels of metabolic syndrome ( MS) rats and its anti-oxidative effect. A total of 80 male SD rats were divided into four groups: the normal control group (NC, the same volume of normal saline), the MS group (high fat diet), the MS + Astragali Radix group (MS + HQ, 6 g x kg(-1) x d(-1) in gavage) and the MS + Valsartan group (MS + XST, 30 mg x kg(-1) x d(-1) in gavage). After four weeks of intervention, their general indexes, biochemical indexes and blood pressure were measured; plasma and renal tissue Ang II, malondialdehyde (MDA) and superoxide demutase (SOD) levels were measured with radioimmunoassay. The protein expressions of Mas receptor, AT1R, ACE and ACE2 were detected by western blot analysis. According to the result, compared with the NC group, the MS group and the MS + HQ group showed significant increases in systolic and diastolic pressures, body weight, fasting glucose, fasting insulin, triglycerides, free fatty acid and Ang II level of MS rats (P < 0.05). The MS + XST group showed notable decreases in systolic and diastolic pressures than that of the MS group. The MS group showed significant increases in the SOD activity and NO level and decrease in the MDA level after being intervened with Astragali Radix. ACE and AT1R protein expressions in renal tissues of the MS group were higher than that in the NC group, but with lower ACE2 and -Mas receptor expressions (all P < 0.05). Compared with the MS group, the MS + HQ group showed significant increase in Mas receptor expression in renal tissues, whereas the MS + XST group showed notable decrease in AT1R (all P < 0.05). In conclusion, Astragali Radix can increase the Mas receptor expressions in renal tissues, decrease ACE expression and change local Ang II, MDA, NO and SOD in kidneys, so as to protect early damages in renal tissues.
Angiotensin I ; metabolism ; Animals ; Astragalus Plant ; chemistry ; Blood Glucose ; metabolism ; Blood Pressure ; drug effects ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Kidney ; drug effects ; injuries ; metabolism ; Male ; Malondialdehyde ; metabolism ; Metabolic Syndrome ; drug therapy ; genetics ; metabolism ; physiopathology ; Peptide Fragments ; metabolism ; Peptidyl-Dipeptidase A ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; genetics ; metabolism ; Signal Transduction ; drug effects

OBJECTIVETo study the therapeutic effect of Dabuyin Wan on true precocious puberty of female rats and its possible mechanism.

METHODTwenty-two-day-old female SD rats were subcutaneously injected with 40 mg x kg(-1) N-methyl-DL-aspartic acid (NMA) at 14:00 and 16:00 every day; meanwhile, the rats were given Dabuyin Wan for intervention. Visual inspection was conducted for the time of vaginal opening. The first estrus was observed by yaginal smear test. Their ovaries and uterus were weighed to calculate organ coefficients. Conventional pathological slices were made to observe morphological changes in ovaries and uterus and calculate the thickness of uterine walls and the number of corpus luteums. The level of E2 in serum was detected to assess the therapeutic effect of Dabuyin Wan on NMA precocious puberty in rats. expressions of GnRH, GPR54 and Kiss-1 mRNA in hypothalamus were measured by semi-quantitative RT-PCR to investigate the possible mechanism of Dabuyin Wan.

RESULTDabuyin Wan at 3.24 g x kg(-1) and 1.62 g x kg(-1) significantly decreased the organ coefficients in rats with precocious puberty (P < 0.05), decrease the number of vaginal openings in rats (P < 0.01) and the thickness of uterine walls and the number of corpus luteums (P < 0.05), and notably down-regulated expressions of GnRH, GPR54 and Kiss-1 mRNA in hypothalamus (P < 0.05), without significant impact on E2 in serum.

CONCLUSIONDabuyin Wan may inhibit GnRH synthesis and release as well as startup of hypothalamic-pituitary-gonadal axis by down-regulating Kiss-1/GPR54 mRNA expression in hypothalamus, in order to realize the therapeutic effect on true precocious puberty.

Animals ; Drugs, Chinese Herbal ; pharmacology ; Estrus ; drug effects ; Female ; Gene Expression ; drug effects ; Gonadotropin-Releasing Hormone ; genetics ; Hypothalamus ; drug effects ; metabolism ; Kisspeptins ; genetics ; Ovary ; drug effects ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; genetics ; Receptors, Kisspeptin-1 ; Reverse Transcriptase Polymerase Chain Reaction ; Sexual Maturation ; drug effects ; genetics ; Time Factors ; Uterus ; drug effects ; Vagina ; drug effects