Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.1 (adenylate cyclase)
 19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human c-kit receptor ligand, rhSCF, is the only cytokine known to be active on human mast cells, but its intracellular signal transduction pathway is still unknown. We compared the effect of rhSCF on intracellular Ca2+ levels in purified (> 70% pure) adult skin mast cells with two other immunologic stimuli, namely, anti-IgE and substance P. Both rhSCF (1 microgram/mL) and anti-IgE (3 micrograms/mL) induced a rapid (< 20 sec) and sustained (T1/2 for decay > 10 min) increase in free cytosolic Ca2+ concentration. In contrast, substance P (5 microM) elicited a very rapid (< 1 sec) and transient (T1/2 for decay congruent to 5 sec) rise in intracellular Ca2+ levels. Intracellular cAMP levels were then increased by pharmacologic means to examine the role of the cyclic nucleotide in controlling the Ca2+ response in skin mast cells. A combination of the general phosphodiesterase inhibitor, isobutylmethylxanthine (IBMX) (200 microM) and the adenylate cyclase activator, forskolin (30 microM) was effective in inhibiting the Ca2+ response induced by rhSCF or anti-IgE (82 and 68% inhibition, respectively), while IBMX and forskolin alone were much less effective. The phosphodiesterase isozyme IV inhibitor, rolipram (10 microM), variably affected the increase in Ca2+ levels induced by anti-IgE, but it exerted a significant inhibitory activity on anti-IgE- or rhSCF-induced response in the presence of forskolin (30 micrograms/mL) (33 and 67%, respectively). Two different protein kinase C (PKC) activators TPA (200 nM) and bryostatin 1 (200 nM) similarly inhibited rhSCF- (22 and 32%, respectively) and anti-IgE-induced (24 and 32%) Ca2+ response. Finally, the kinase inhibitor genistein (30 micrograms/mL) was a somewhat more effective inhibitor of the rise in intracellular Ca2+ induced by rhSCF (100%) than that activated by anti-IgE (54%) (P < 0.05). These data indicate that rhSCF and anti-IgE may act on human mast cells through a common pathway to increase free cytosolic Ca2+ levels and this effect is similarly modulated by various drugs.
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PMID:Studies of the intracellular Ca2+ levels in human adult skin mast cells activated by the ligand for the human c-kit receptor and anti-IgE. 751 34

In previous in vitro studies we found that contact between mouse primordial germ cells and other cell types (neighbouring somatic cells or established TM4 or STO cell lines) is crucial for supporting primordial germ cell survival and proliferation and for activating their motility. We have studied primordial germ cell adhesion to different cell monolayers (STO, TM4, COS and F9 cells) as an in vitro model for interactions between primordial germ cells and cellular substrates. The results suggest that these cell interactions are mediated by multiple mechanisms involving Steel factor and its receptor encoded by c-kit, carbohydrates and possibly other unknown factors. We find that Steel factor and leukaemia inhibitory factor are survival rather than proliferation factors for primordial germ cells. Both molecules prevent primordial germ cell death in culture by suppressing apoptosis. Morphological and molecular features of primordial germ cell apoptosis in vitro are reported. Activation of protein kinase C does not promote primordial germ cell proliferation, but compounds known to enhance intracellular levels of cAMP (i.e. dibutyryl cAMP and forskolin) markedly stimulate primordial germ cells to proliferate in culture. We have preliminary results indicating that neuropeptides PACAP-27 and PACAP-28 are possible physiological activators of adenylate cyclase in primordial germ cells.
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PMID:Interactions between migratory primordial germ cells and cellular substrates in the mouse. 753 Jun 18

To avoid mutilating surgery in the treatment of distal aganglionosis, transplantation of autologous nervous elements to the affected intestine would be an attractive option. This treatment modality has emerged as a possible alternative for different brain disorders, mostly using fetal nervous tissue. Our objective was to evaluate whether myenteric ganglia (MG) and interstitial cells of Cajal (ICC) could survive a transplantation procedure and to evaluate possible differences between animals with distal colonic aganglionosis (lethal spotted mice) and their healthy littermates. Autologous transplantation of MG with adherent smooth muscle from small intestine to the subcapsular space of the kidney was performed in mice 3-12 weeks of age. The transplants were evaluated 5 to 9 days postoperatively. The presence of myenteric neurons in the transplants was registered using immunohistochemical detection of different neurotransmitters and markers. For identification of ICC antibodies against c-kit, a cell surface tyrosine-kinase receptor, were used. The transplants showed overall good survival. Neurons containing the general neuronal marker protein gene-related product, the neuronal nitric oxide synthesizing enzyme, and the neuropeptides vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide, calcitonin gene-related peptide, galanin, substance P, and neuropeptide Y could be shown throughout the transplants. ICC were consistently seen in the grafted tissue among the smooth muscle cells, particularly in the deep muscular plexus, and within the MG. No obvious differences in ICC or enteric neuronal tissue survival, or in the frequency of the various neuronal populations displayed could be detected between the two groups of animals. These findings support the use of autologous MG for further research on transplantation of enteric ganglia as a possible alternative treatment for colonic aganglionosis.
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PMID:Survival of neurons and interstitial cells of Cajal after autotransplantation of myenteric ganglia from small intestine in the lethal spotted mouse. 1089 28

Inactivating mutations of the FSH receptor have been described in rare cases of premature ovarian failure. Only one mutation was associated with a complete phenotype, including delayed puberty, primary amenorrhea, and small ovaries. We describe here a new patient presenting a similar complete phenotype of premature ovarian failure, with high plasma FSH levels associated with very low estrogen and inhibin B levels. No biological response to high doses of recombinant FSH was detected. A novel homozygous Pro(519)Thr mutation was found in this patient. This mutation is located in the second extracellular loop of the FSH receptor, within a motif highly conserved in gonadotropin and TSH receptors. The mutation totally impairs adenylate cyclase stimulation in vitro. FSH binding experiments and confocal microscopy showed that this mutation alters the cell surface targeting of the mutated receptor, which remains trapped intracellularly. Histological studies of the ovaries of the patient showed an increase in the density of small follicles compared with age-matched normal women. A complete block in follicular maturation after the primary stage was also observed. Immunocytochemical studies allowed detection of the expression of c-Kit and proliferation cellular nuclear antigen, whereas no apoptosis was shown by the 3'-end-labeling method. This observation supports the concept that in humans FSH seems mandatory for the initiation of follicular growth only after the primary stage. In our patient complete FSH resistance yields infertility, which is remarkably associated with the persistence of a high number of small follicles.
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PMID:Delayed puberty and primary amenorrhea associated with a novel mutation of the human follicle-stimulating hormone receptor: clinical, histological, and molecular studies. 1291 23

Many growth factors or cytokines regulate cell proliferation via different intracellular signaling pathways. The mechanisms remained quite unclear in avian primordial germ cells (PGCs). In the present study, two major protein kinases, PKA and PKC, were investigated to be involved in signal transduction of PGC proliferation. PGCs were isolated from genital ridge of 3.5-day chicken embryos and primary culture was performed with 5% fetal calf serum (FCS)-supplemented medium 199. After culture for 24 h, PGCs were subcultured on chicken embryonic fibroblast feeder (CEF) and the cells were characterized by histochemical stainings of alkaline phosphatase (ALP) and periodic acid-Schiff (PAS) reagent as well as immunocytochemical stainings of c-kit and stage-specific embryonic antigen-1 (SSEA-I). In addition, cells were challenged with adenylate cyclase activator forskolin (FRSK) and PKC activator phorbol-12-myristate-13-acetate (PMA) alone or in combinations with PKA inhibitor H(89) and PKC inhibitor H(7), respectively. Results showed that subcultured PGCs on CEF displayed positive histochemical and immunocytochemical stainings for ALP, PAS, c-kit and SSEA-I and manifested intensive proliferating activity by colony formation. Downstream activation of PKA by FRSK (10(-7) to 10(-5)M) significantly promoted the proliferation of PGCs by increasing colony number (ALP-stained) in a dose-dependant manner. PMA (10(-8)M) also increased PGC colony number (P<0.05). However, the proliferating effects elicited by FRSK or PMA could be inhibited by the respective protein kinase inhibitor H(89) or H(7). Therefore, the above results suggest that activation of intracellular protein kinases A and C by external factors may promote proliferation of cultured PGCs and PKA represents the most likely mediator of PGC proliferation in embryonic chickens.
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PMID:Activation of protein kinases A and C promoted proliferation of chicken primordial germ cells. 1705 97

Olfactory receptor (OR)-associated events are mediated by well-conserved components in the olfactory epithelium, including olfactory G-protein (Golf), adenylate cyclase III (ACIII), and olfactory marker protein (OMP). The expression of ORs has recently been observed in non-olfactory tissues where they are involved in monitoring extracellular chemical cues. The large number of OR genes and their sequence similarities illustrate the need to find an effective and simple way to detect non-olfactory OR-associated events. In addition, expression profiles and physiological functions of ORs in non-olfactory tissues are largely unknown. To overcome limitations associated with using OR as a target protein, this study used OMP with Golf and ACIII as targets to screen for potential OR-mediated sensing systems in non-olfactory tissues. Here, we show using western blotting, real-time PCR, and single as well as double immunoassays that ORs and OR-associated proteins are co-expressed in diverse tissues. The results of immunohistochemical analyses showed OMP (+) cells in mouse heart and in the following cells using the corresponding marker proteins c-kit, keratin 14, calcitonin, and GFAP in mouse tissues: interstitial cells of Cajal of the bladder, medullary thymic epithelial cells of the thymus, parafollicular cells of the thyroid, and Leydig cells of the testis. The expression of ORs in OMP (+) tissues was analyzed using a refined microarray analysis and validated with RT-PCR and real-time PCR. Three ORs (olfr544, olfr558, and olfr1386) were expressed in the OMP (+) cells of the bladder and thyroid as shown using a co-immunostaining method. Together, these results suggest that OMP is involved in the OR-mediated signal transduction cascade with olfactory canonical signaling components between the nervous and endocrine systems. The results further demonstrate that OMP immunohistochemical analysis is a useful tool for identifying expression of ORs, suggesting OMP expression is an indicator of potential OR-mediated chemoreception in non-olfactory systems.
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PMID:Olfactory marker protein expression is an indicator of olfactory receptor-associated events in non-olfactory tissues. 2563 59