Bombesin receptor subtype-3(BRS-3) is an orphan receptor in the bombesin receptor family. Its signal transduction mechanism and biological function have attracted much attention. Seeking the ligand for BRS-3 is of great significance for exploring its function. Considering the fact that the activation of BRS-3 receptor can induce the change in intracellular Ca~(2+) concentration, the fluo-rometric imaging plate reader(FLIPR) was utilized for ligand screening at the cellular level. Among more than 400 monomeric compounds isolated from Chinese herbs, yuanhunine from Corydalis Rhizoma and sophoraisoflavanone A and licoriphenone from Glycyrrhizae Radix et Rhizoma antagonized BRS-3 to varying degrees. It was confirmed in HEK293 cells expressing BRS-3 that yuanhunine, sophoraisoflavanone A, and licoriphenone inhibited the calcium current response after the activation of BRS-3 by [D-Phe~6,β-Ala~(11),Phe~(13),Nle~(14)]bombesin-(6-14) in a dose-dependent manner with the IC_(50) values being 8.58, 4.10, and 2.04 μmol·L~(-1), respectively. Further study indicated that yuanhunine and sophoraisoflavanone A exhibited good selectivity for BRS-3. In this study, it was found for the first time that monomers derived from Chinese herbs had antagonistic activity against orphan receptor BRS-3, which has provided a tool for further study of BRS-3 and also the potential lead compounds for new drug discovery. At the same time, it provides reference for the research and development of innovative drugs based on the active ingredients of Chinese herbs.
Drugs, Chinese Herbal/chemistry* ; HEK293 Cells ; Humans ; Ligands ; Receptors, Bombesin

Neuromedin B (NMB) acts as a growth factor or a morphogen and plays a role in cancer progression. Indeed, the NMB receptor (NMB-R) is overexpressed in different types of tumors. In our current study, we investigated the involvement of NMB-R in the proliferation of oral cancer cells. Human oral squamous cell carcinoma (SCC) and human oral cancer cells, SCC-25 cells were found to be NMB-R-positive. The NMB-R antagonist PD168368 inhibited the proliferation of SCC-25 cells and reduced their colony formation capacity. We also found that PD168368 induced the cell cycle arrest and apoptosis of SCC-25 cells in a dose-/time-dependent manner. Overall, this antitumor activity of PD168368 in human oral cancer cells suggests that NMB-R is a potential target for the future prevention and treatment of human cancers.
Apoptosis ; Carcinoma, Squamous Cell ; Cell Cycle Checkpoints ; Humans ; Mouth Neoplasms* ; Receptors, Bombesin*

Recently various peptide receptors which displayed the highest binding affinity and specificity with their peptide ligands by ligand-receptor have been exploited to develop drug delivery system which can directionally deliver drug to targeted cell. It is significant to study and applicate, including targeted drug delivery system mediated by bombesin receptor, somatostatin receptor, SynB3 receptor, LH-RH receptor and other peptide receptor, et al. Several small peptide fragments were selected as carriers radicals combining doxorubicin, 2-pyrrolino-DOX, methotrexate, cis-platinum, and camptothecin to form hybrid cytotoxic analogs. These highly potent cytotoxic analogs have been designed as targeted anti-tumor agents for the treatment and study of various cancers that possess receptors for the carrier peptide.
Animals ; Antineoplastic Agents ; therapeutic use ; Doxorubicin ; analogs & derivatives ; therapeutic use ; Drug Delivery Systems ; Humans ; Neoplasms ; drug therapy ; metabolism ; Oligopeptides ; metabolism ; Pyrroles ; therapeutic use ; Receptors, Bombesin ; metabolism ; Receptors, LHRH ; metabolism ; Receptors, Somatostatin ; metabolism

OBJECTIVETo study the effect of Jiaweisinisan (JWSNS), a traditional Chinese herbal medicinal recipe, on gastric mucosal ultrastructure and brain-gut axis in rat models of chronic psychological stress and elucidate the mechanism of JWSNS for ameliorating stress-induced gastrointestinal dysfunction.

METHODSSixty rats were randomly assigned into normal control group, model group, 3 JWSNS groups (high, moderate, and small doses), and omeprazole group (n=10). Rat models of chronic psychological stress were established by random stressful stimulations, and following the corresponding interventions, plasma adrenocorticotropic hormone (ACTH) and cortisol (CORT) levels were detected using radioimmunoassay, and the mRNA expressions of gastrin receptor in the gastric tissue (GASR) and vasoactive intestinal peptide II receptor (VIPR2) in the jejunal tissue were examined using RT-PCR. Transmission electron microscopy was employed to examine the ultrastructural changes in the gastric mucosa tissue cells of the glandular stomach area and alterations in the intercellular junctions.

RESULTSElectron microscopy revealed obvious damages in gastric mucosal epithelial cell organelles and nuclei in the model rats. These damages were ameliorated after treatments with JWSNS and omeprazole. Compared with the model group, the 3 JWSNS groups and omeprazole group all showed significantly lowered plasma ACTH and CORT levels, increased gastrin receptor mRNA expression and decreased jejunal VIPR2 mRNA expression (P<0.05 or 0.01).

CONCLUSIONJWSNS can obviously ameliorate the pathologies of the gastric mucosa cells, regulate the state of brain-gut axis, and modulate the gastric gastrin receptor and jejunal VIPR2 mRNA expressions in rats with chronic psychological stress.

Adrenal Cortex Hormones ; blood ; Adrenocorticotropic Hormone ; blood ; Animals ; Drugs, Chinese Herbal ; pharmacology ; Gastric Mucosa ; metabolism ; pathology ; ultrastructure ; Hydrocortisone ; blood ; Jejunum ; metabolism ; Male ; Rats ; Rats, Wistar ; Receptors, Bombesin ; metabolism ; Receptors, Vasoactive Intestinal Peptide, Type II ; metabolism ; Stress, Psychological ; pathology

OBJECTIVE: To investigate the spatiotemporal expression of neuromedin B receptor (NMBR) in mice myometrium at different pregnant stages, as well as its mechanism and relation with parturition. METHODS: The pregnant mice were divided into no-pregnancy (NP), early pregnancy (EP), mid-pregnancy (MP), late-pregnancy (LP), parturition (PT) and postpartum (PP) groups (12 mice in each group), according to pregnant stage. The mRNA and protein expression of NMBR, HSP70 and IL-6 were detected in myometrium in pregnant mice by semi-quantitative RT-PCR and Western blot, while NF-kappaB-P65 DNA binding activity was determined by NoShift transcription factor assay kits, respectively. Their relation with parturition was analyzed. RESULTS: The mRNA expression level of NMBR in the PT group was significantly higher than that in the NP, EP, LP and PP groups (P<0.05), but this difference was not observed in the MP group (P>0.05). The NMBR protein in PT group was significantly higher than that in the other 5 groups (P<0.01). NF-kappaB-P65 DNA binding activity at PT group was remarkably higher than that in the NP, LP and PP groups (P<0.05). The expression of IL-6 mRNA was significantly higher than that in the NP, LP and PP groups (P<0.05), its protein expression in PT and LP groups was significantly higher than that in the NP and PP groups (P<0.05). The expression of HSP70 mRNA in the PT group was significantly higher than that in the NP and PP groups (P<0.05), and the protein of HSP70 was significantly up-regulated in PT and PP groups compared with in NP and LP groups (P<0.05). The DNA-binding activity of P65 was positively correlated to the mRNA expression of NMBR and IL-6 (r=0.40, P<0.01; r=0.30, P<0.05), so were positively correlated to DNA-binding activity of P65, mRNA expression of HSP70 and NMBR ( r=0.40, P<0.01; r=0.49, P<0.01). DNA-binding activity of P65 did not correlate with the mRNA expression of HSP70. CONCLUSION The mRNA and protein expressions of NMBR reach a peak at the onset of labor. NMBR may play an important role in the parturition via NF-kappaB P65-IL-6 signal transduction pathway. It may also influence the onset of labor by regulating HSP70, but this role does not rely on P65 pathway.
Animals ; Female ; Gestational Age ; HSP70 Heat-Shock Proteins ; metabolism ; Interleukin-6 ; metabolism ; Male ; Mice ; Myometrium ; metabolism ; Parturition ; metabolism ; Pregnancy ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Receptors, Bombesin ; genetics ; metabolism ; Signal Transduction ; Transcription Factor RelA ; metabolism

OBJECTIVE: To investigate the role and mechanism of bombesin receptor subtype 3 (BRS-3) in the proliferation and protection against injury of human brochial epithelial cells (HBECs). METHODS: Effect of P3513 (a specific agonist of BRS-3) on the proliferation of HBECs was observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method; the release rate of 3H-Udr, and LDH activity, catalase activity, and the expression of cadherin and integrin beta1 were also analyzed under O3 stress with or without P3513 treatment. RESULTS: The proliferation of HBECs was accelerated by P3513 in a concentration-dependent manner (10(-9) approximately 10(-7) mol/L). Ozone stress could promote the release rate of 3H-Udr, and LDH activity, which could be inhibited by P3513. P3513 could promote the activity of catalase. The effect of proliferation and protection against injury caused by P3513 could be inhibited by W7 (calmodulin inhibitor), PD98059 (tyrosin kinase inhibitor) and H89 (PKA inhibitor). P3513 could stimulate the expression of caderin and integrinbeta1 of ozone-stressed HBECs. CONCLUSION Activation of BRS-3 caused by P3513 may play an important role in protecting HBECs from oxidant injury, and the signal pathway is possibly relevant to Ca2+, MEK and PKA.
Bronchi ; cytology ; Cadherins ; metabolism ; Catalase ; metabolism ; Cell Line ; Cell Proliferation ; Epithelial Cells ; cytology ; Humans ; Integrin beta1 ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Protective Agents ; Reactive Oxygen Species ; adverse effects ; Receptors, Bombesin ; physiology

OBJECTIVE: To screen the differentially expressed gene profile from the smooth muscles in the fundus uterus at the active stage of labor, and to provide candidate genes for picking out the drug targets related to uterine contraction. METHODS: Differentially expressed genes of uterine smooth muscles in the corpus from pro and post spontaneous parturition and those induced by oxytocin,as well as those from the corpus and the lower portion spontaneous parturition,were scanned respectively by human full-length genetic cDNA microarray with 8064 probe sets. Semi-quantitative RT-PCR was applied to testify the expression of voltage dependent calcium channel-L subtype (CACNA). The differentially expressed genes in the structure and function of the drug targets were picked out by bio-informatics to serve as candidate drug targets related to uterine contraction. RESULTS: The expressions of 29 genes were upregulated in fundus smooth muscles from the pro and post natural parturition, the pro and post inductive parturition of oxytocin, and the natural parturition. The expression of CACNA gene in RT-PCR was in accordance with that in the microarray. Among the 29 genes, neuromedin B receptor (NMBR) gene and neuropeptide Y (NPY) gene were the genes which not only had the targets of uterine contracted medicine, but also could contract the uterine. The differential expression ratios of NMBR in the above 3 types of uterine myometrium were 6.9,11.3, and 9.0, respectively while those of NPY were 6.0,29.8, and 2.9 respectively. CONCLUSION NMBR, whose expression in the uterine smooth muscles is always up-regulated at different parturition conditions, is likely to be an ideal candidate target of uterotonic drugs.
Calcium Channels ; genetics ; Drug Evaluation, Preclinical ; Female ; Gene Expression ; Gene Expression Profiling ; Humans ; Myometrium ; drug effects ; Neuropeptide Y ; genetics ; Oligonucleotide Array Sequence Analysis ; Pregnancy ; Receptors, Bombesin ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Uterine Contraction ; drug effects