Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The cytochrome P450 (CYP) mixed-function oxidase system is widely distributed in body tissues and plays a key role in the metabolism of endogenous and exogenous compounds. Little attention has been paid to the expression of the system in the islets of Langerhans. The current study has examined the expression and potential role of the CYP1A family within the islets of Langerhans of control and 3-methylcholanthrene (3-MC)-induced Wistar rats. 2. CYP1A expression within pancreatic slices and islets from 3-MC-induced and control rats demonstrated that CYP1A-like protein levels were induced by 3-MC pretreatment (25 mg kg-1 day-1; i.p. for 3 days). 3. Effects of 3-MC-induction on beta-cell secretory responsiveness were investigated by use of rat collagenase-isolated islets. Insulin release from control islets incubated with 3 mM glucose (basal) was 1.4 +/- 0.2 ng/islet h-1 (mean +/- s.e.mean, n = 7). Incubation with 16.7 mM glucose, 25 mM KCl, 100 microM arachidonic acid, or 100 microM carbachol caused a 4.4, 7.0, 4.0 and 4.2 fold, respectively, increase in insulin release (P < 0.001). Forskolin (2 microM), or phorbol 12-myristic 13-acetate (10 nM) potentiated glucose-stimulated insulin release 1.2 and 1.6 fold (P < 0.01) whereas adenalin (1 microM) caused a 76% inhibition (P < 0.01). 4. Islets from 3-MC pretreated animals displayed similar responsiveness to all agents tested except arachidonic acid, carbachol and forskolin. Insulin release in response to arachidonic acid and carbachol was enhanced 5.2 and 5.0 fold, respectively, by 3-MC pretreatment (P < 0.001 compared to control islets incubated with 3 mM glucose); the effect of forskolin on insulin output was significantly decreased (20%; P < 0.01) compared to control islets. 5. 3-MC pretreatment did not cause any significant differences in food intake, plasma glucose or total islet insulin content. Incubation of islets with 3-MC in vitro (1 microM - 10 mM) did not affect basal or glucose-stimulated insulin release. 6. These data suggest that CYP1A-like protein expression within the pancreatic islets of Langerhans is inducible and may have a role in the alteration of pancreatic beta-cell secretory responsiveness.
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PMID:Cytochrome P450 1A-like proteins expressed in the islets of Langerhans and altered pancreatic beta-cell secretory responsiveness. 917 78

Rat testicular cells dispersed by 0.03% collagenase digestion were seperated by discontinuous/continuous of Percoll, yielding highly pure Leydig cell fraction. 0.52 nmol/L hCG 0.1 mumol/L cholera toxin and 10 mumol/L forskolin signifcantly stimulated production of cAMP (Cholera toxin > Forskolin > hCG) and testosterone (no signifcient differences among cholera toxin, Forskolin and hCG). Ovalbumin glycopeptides prepared by extensive pronase digestion significantly inhibited production of cAMP and testosterone of rat testis Leydig cells stimulated by hCG, cholera toxin and forskolin. These results suggest that the carbohydrate moiety of hCG participate in the signal transduction among receptor, G-protein and adenylatecyclase which is inhibited by Asn-linked oligosaccharide chains from ovalbumin glycopeptides.
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PMID:[Inhibition of ovalbumin glycopeptides on the hCG signal transduction system]. 938 90

Ets-1 is a transcription factor that activates expression of matrix-degrading proteinases such as collagenase and stromelysin. To study the control of ets-1 gene expression in rat vascular smooth muscle cells (VSMC), cells were exposed to factors known to regulate VSMC migration and proliferation. Platelet-derived growth factor-BB (PDGF-BB), endothelin-1 (ET-1), and phorbol 12-myristate 13-acetate (PMA) induced a dose-dependent expression of ets-1 mRNA. These effects were abrogated by inhibition of protein kinase C (PKC) by H-7 or chronic PMA treatment. Ets-1 mRNA was superinduced by PDGF-BB and ET-1 in the presence of cycloheximide. The chelation of intracellular Ca2+ by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester and the depletion of endoplasmic reticulum intracellular Ca2+ concentration ([Ca2+]i) by thapsigargin inhibited PDGF-BB- and ET-1-induced ets-1 mRNA, whereas ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid had no effect. However, [Ca2+]i release alone was not sufficient to increase ets-1 mRNA. Forskolin blocked ET-1-, PDGF-BB-, and PMA-induced ets-1 mRNA, as well as inositol phosphate formation, consistent with an effect through impairment of PKC activation. Inhibitors of ets-1 gene expression, such as H-7 and herbimycin A, inhibited the ET-1 induction of collagenase I mRNA. We propose that ets-1 may be an important element in the orchestration of matrix proteinase expression and of vascular remodeling after arterial injury.
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PMID:Ets-1 is an early response gene activated by ET-1 and PDGF-BB in vascular smooth muscle cells. 948 38

A cellular suspension from rat submandibular glands was prepared with collagenase. The intracellular pH (pHi) was estimated with 2',7'-bis-(2-carboxy-ethyl)-5(6)-carboxyfluorescein (BCECF). After exposure to NH4Cl, the pHi transiently increased (diffusion of NH3) and then dropped (influx of NH4+). Isoproterenol increased 2.5-fold the rate of NH4+ influx; bumetanide, an inhibitor of the Na+-K+-2Cl(-)-cotransporter blocked the response to isoproterenol, confirming that the beta-adrenergic agonist stimulated the cotransporter. Forskolin (1 micromol/L) mimicked the response to isoproterenol. VIP (1 nmol/L(-1) micromol/L) also increased the activity of the cotransporter. Cyclic AMP rather than calcium was the mediator of this activation since 1) carbachol which increased the [Ca2+]i fivefold increased the uptake of NH4+ by only 50%; 2) only high concentrations of VIP significantly increased the [Ca2+]i; 3) incubation in the presence of EGTA had no effect on the response to VIP; 4) low concentrations (nmol/L) of the neuropeptide increased the intracellular level of cAMP; and 5) the stimulation of the cotransporter by VIP, forskolin, and isoproterenol was inhibited by H8, an inhibitor of cAMP-dependent protein kinase. It is concluded that the Na+-K+-2Cl(-)-cotransporter of rat submandibular glands is activated by isoproterenol, forskolin, and neuropeptides of the VIP family by a mechanism involving cAMP-dependent processes. The activation of the cotransporter by VIP could partly explain the potentiating effect of VIP on the response to sialagogues like substance P or muscarinic agonists.
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PMID:Activation of the Na+-K+(NH4+)-2Cl(-)- cotransporter from rat submandibular glands in response to VIP. 988 83

Prostaglandin E2 (PGE2), an abundant eicosanoid in bone, has been implicated in a number of pathological states associated with bone loss and is also known to stimulate matrix metalloproteinase-1 synthesis and secretion in rat and human osteoblast cells, although the intracellular reactions responsible for this remain unclear. Interleukin-1beta (IL-1beta) is a cytokine that plays a critical role in bone remodeling and appears to act as a downstream effector of most bone-resorbing agents. However, the issue of whether PGE2 regulates the expression of IL-1beta in mouse osteoblasts has not been resolved. In this work, we demonstrate that PGE2 is a potent inducer of IL-1beta production by fetal osteoblasts and show that PGE2 stimulates the activity of the IL-1beta promoter in osteoblasts, suggesting that PGE2 controls IL-1beta gene expression at least at the transcriptional level. PGE2 was found to induce IL-1beta mRNA expression in the cells within 4 h and the level of expression was maintained for 36 h. A dose-related increase in IL-1beta production was found with 0.1-2.0 microM PGE2. The induction of IL-1beta protein in the medium paralleled the induction of IL-1beta mRNA levels. The role of cAMP activation in PGE2-mediated IL-1beta production was examined by the effects of forskolin, an adenylyl cyclase (AC) activator and dideoxyadenosine (DDA), an AC inhibitor. Forskolin enhanced and DDA blocked the production of IL-1beta by PGE2. In addition, PGE2-mediated IL-1beta induction was completely inhibited by the cAMP antagonist, Rp-cAMP, and protein kinase A (PKA) inhibitors of KT5720 and H89. The PGE2-induced production of IL-1beta was also blocked by the PKA inhibitor PKI14-22. However, a specific inhibitor of protein kinase C, calphostin C, had no affect on PGE2-induced IL-1beta gene expression. Among the potential agonists, forskolin was a potent inducer of IL-1beta expression, while phorbol myristate acetate and serum had little effect. These findings indicate that PGE2 involves the cAMP-PKA signaling pathway in regulating IL-1beta gene expression in osteoblasts.
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PMID:PGE2 induces IL-1beta gene expression in mouse osteoblasts through a cAMP-PKA signaling pathway. 1513 19

Although the enterochromaffin (EC) cell is one of the primary neuroendocrine regulatory cells of the small intestine, the lack of a purified cell system has precluded characterization of the cell and limited precise physiological evaluation. We developed methodology to obtain a pure population of Mastomys ileal EC cells, evaluated their functional regulation, and defined the transcriptome. Mastomys ilea were everted, end ligated, pronase-collagenase digested, and Nycodenz gradient centrifuged, and EC cells were collected by fluorescence-activated cell sorting (FACS) of acridine orange-labeled cells. Enrichment was confirmed by immunostaining of tryptophan hydroxylase and chromogranin A, specific EC cell markers, serotonin content, EC cell marker gene expression, and electron microscopy. Pituitary adenylate cyclase-activating polypeptide (PACAP), somatostatin, and gastrin receptor expression was determined by real-time RT-PCR. Live post-FACS-sorted cells were cultured, and the effects of forskolin, isoproterenol, acetylcholine, GABAA, PACAP-38, and gastrin on serotonin secretion were measured by ELISA. GeneChip Affymetrix profiling of FACS-sorted cells was undertaken to obtain the EC cell transcriptome. FACS produced a >70-fold enrichment of EC cells with a serotonin content of 240 +/- 22 ng/mg protein. Preparations were 99 +/- 0.7% pure by immunostaining for tryptophan hydroxylase. Vasoactive intestinal peptide/PACAP receptor 1 (VPAC1) and somatostatin receptor 2 were present, whereas PACAP receptor 1 (PAC1) and CCK2 receptors were undetectable. Forskolin, isoproterenol, and PACAP-38 stimulated serotonin secretion at EC50 values of 5 x 10(-10), 4.5 x 10(-10), and 1.2 x 10(-9) M, respectively. Isoproterenol stimulated cAMP levels by approximately 3.5 +/- 0.62-fold vs. unstimulated cells (EC50 of approximately 10(-9) M). Octreotide, acetylcholine, and GABAA inhibited serotonin secretion with IC50 values of 3 x 10(-11), 3 x 10(-10), and 2.9 x 10(-10) M, respectively. Gastrin had no effect on serotonin secretion. The naive EC cell transcriptome revealed highly expressed EC cell marker genes, the absence of marker genes for other small intestinal cell types, and a receptor profile that included cholinergic, adrenergic, dopaminergic, serotoninergic, GABAergic, and prostaglandin receptors. We were able to isolate homogeneous preparations (>99%) of live ileal EC cells and demonstrated regulation of serotonin secretion as well as established the normal EC cell transcriptome. Application of this methodology to normal and diseased human ileum will facilitate the elucidation of the pathophysiology of EC cells.
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PMID:Isolation, functional characterization, and transcriptome of Mastomys ileal enterochromaffin cells. 1645 86

We investigated whether the signal mechanism for relaxation may be affected by inflammation of the cat esophagus. Acute esophagitis was induced by perfusion with 0.1N HCI at a rate of 1 mL/min for 45 min over three consecutive days. We then isolated esophageal smooth muscle cells by enzymatic digestion with collagenase. We pre-contracted the isolated smooth cells with acetylcholine (ACh) (10(-5) M) and compared the agonist-induced relaxation of pre-con tracted normal cells with those of esophagitic cells. Vasoactive intestinal polypeptide (VIP) caused a dose-dependent relaxation in normal cells, and this curve was down shifted in esophagitic cells. Sodium nitroprusside (SNP) or SIN-1 (NO donor) produced dose-dependent relaxation in normal cells, which was not affected by esophagitis. 8-Br-cGMP (a cGMP ana log) also induced dose-dependent relaxation to a similar extent in both normal and esoph agitic cells. Forskolin (a cAMP activator) or db-cAMP (a cAMP analog) produced dose-dependent relaxation in normal cells, and this relaxation curve was down shifted in esoph agitic cells. Western blotting was used to determine what subtype of adenylyl cyclase was involved in the cAMP pathway. Western blot analysis of homogenates derived from esophageal smooth muscle using antibodies against adenylyl cyclase types II, III, IV and V/VI revealed the presence of type V and/or type VI only. This result suggests that relaxation via a cAMP-dependent pathway rather than a cGMP dependent-pathway is down regulated in cat acute esophagitis. This subsensitivity of the cAMP related pathway may be related to the activ ity of adenylyl cyclase V/VI.
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PMID:Cyclic AMP dependent down regulation in the relaxation of smooth muscle cells of cat esophagitis. 1767 49


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