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C M Terry

Publications and source records attributed to C M Terry.

8 recordsLinked to original sources
PubMed1999

TNF-alpha and IL-1alpha induce heme oxygenase-1 via protein kinase C, Ca2+, and phospholipase A2 in endothelial cells.

Heme oxygenase-1 (HO-1), an enzyme important in protection against oxidant stress, is induced in human vascular endothelial cells by the cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1alpha (IL-1alpha). However, the signaling mediators that regulate the induction are not known. This study examined the involvement of protein kinase C (PKC), phospholipase A2 (PLA2), calcium, and oxidants in cytokine induction of HO-1. Acute exposure to the PKC activator phorbol 12-myristate 13-acetate (PMA) stimulated HO-1 mRNA. However, prolonged exposure, which downregulates most PKC isoforms, blocked induction of HO-1 mRNA by IL-1alpha and TNF-alpha. Additionally, the phosphatase inhibitors okadaic acid and calyculin enhanced cytokine induction of HO-1. Mepacrine, a PLA2 inhibitor, prevented HO-1 induction by cytokine, suggesting a role for arachidonate, the product of PLA2 hydrolysis of phospholipids, in HO-1 expression. The intracellular calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM) blocked cytokine induction of HO-1. Paradoxically, the calcium ionophore A-23187 prevented HO-1 induction by cytokine but not by PMA. Finally, the oxidant scavenger N-acetylcysteine inhibited HO-1 induction by cytokines. These results demonstrate that TNF-alpha and IL-1alpha induction of HO-1 requires PKC-mediated phosphorylation and PLA2 activation as well as oxidant generation.

Acetylcysteine↗
PubMed1998

Effect of tumor necrosis factor-alpha and interleukin-1 alpha on heme oxygenase-1 expression in human endothelial cells.

Heme iron exacerbates oxidant damage by catalyzing the production of free radicals. Heme oxygenase is the rate-limiting enzyme involved in heme catabolism. An inducible form of heme oxygenase, heme oxygenase-1 (HO-1), is upregulated in oxidant and inflammatory settings, and recent work suggests that HO-1 induction may serve a protective function against oxidant injury. The ability of the endogenous inflammatory mediators, interleukin (IL)-1 alpha, tumor necrosis factor-alpha (TNF-alpha), and IL-6, to enhance HO-1 expression in cultured human endothelial cells was examined in this study. HO-1 mRNA and protein expression were upregulated by IL-1 alpha and TNF-alpha exposure but not by IL-6. Induction of HO-1 mRNA by IL-1 alpha and TNF-alpha occurred in a concentration- and time-dependent fashion, with maximal expression occurring by 4 h for both cytokines. Induction depended on protein synthesis and occurred at the transcriptional level. Inhibition of the AP-1 transcription factor with curcumin decreased the cytokine induction of HO-1 mRNA, suggesting the involvement of this transcription factor in cytokine signaling of HO-1. The results of this study indicate that the endogenous inflammatory cytokines IL-1 alpha and TNF-alpha induce HO-1 in endothelial cells, providing further evidence that HO-1 may be an important cellular response to inflammatory stress.

Blotting, Western↗
PubMed1998

Major depression.

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Adolescent↗
PubMed1996

Protein kinase C regulates cytokine-induced tissue factor transcription and procoagulant activity in human endothelial cells.

Interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha) induce tissue factor in endothelium, which results in activation of the coagulation cascade. Despite extensive investigation, in which various stimuli that induce tissue factor have been defined, the intracellular processes that control tissue factor expression are not well understood. It has been proposed that protein kinase C regulates tissue factor expression primarily because phorbol myristate acetate, the protein kinase C activator, induces tissue factor expression. In this study we examined whether IL-1 alpha- or TNF-alpha-stimulated tissue factor production is regulated through a protein kinase C-dependent mechanism. Northern blot analysis showed that cytokine-induced tissue factor mRNA was significantly reduced in human umbilical vein endothelial cells treated with calphostin C, a specific protein kinase C inhibitor. Tissue factor functional activity was decreased in the presence of calphostin C as well. Calphostin C also inhibited phorbol myristate acetate-induced tissue factor expression. In contrast, calphostin C did not alter cytokine induction of E-selectin or prostacyclin release. Because calcium stimulates protein kinase C binding to the membrane and its resulting catalytic activity, human umbilical vein endothelial cells were exposed to IL-1 alpha or TNF-alpha in the presence of calcium ionophore A23187. A23187 had little effect alone but significantly augmented cytokine stimulation of tissue factor mRNA. Okadaic acid, a phosphatase inhibitor, increased cytokine-induced tissue factor mRNA compared with cytokine alone, which suggests that a phosphorylation event is important in tissue factor expression. These results indicate that protein kinase C is involved in cytokine activation of endothelial cell tissue factor expression.

Blood Coagulation↗
PubMed1995

Oxidation at C-1 controls the cytotoxicity of 1,1-dichloro-2,2- bis(p-chlorophenyl)ethane by rabbit and human lung cells.

Isolated rabbit Clara cells and a transformed human bronchial epithelial cell line, BEAS-2B, were used to investigate the mechanism of cytotoxicity of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), a persistent insecticide and stable metabolite of 1,1,1-trichloro-2,2- bis(p-chlorophenyl)ethane. Both BEAS-2B cells and rabbit Clara cells were highly susceptible to DDD toxicity and were partially protected by 1-aminobenzotriazole, a suicide substrate inhibitor of cytochrome P450 enzymes. DDD (0.05 mM) killed 47 +/- 1.8% of rabbit Clara cells and 42 +/- 7.9% of BEAS-2B cells after 3 hr and 84 +/- 3.0% of rabbit Clara cells and 80 +/- 14% of BEAS-2B cells after 6 hr. Consequently, DDD is the most potent Clara cell toxicant recognized to date. The cytotoxicity of DDD to these cells was decreased by deuterium substitution at the C-1 position. Rabbit Clara cells and pulmonary microsomes incubated with 14C-DDD produced the fully oxidized acetic acid metabolite 2,2'-bis(p- chlorophenyl)acetic acid (DDA), but DDA was not formed by Clara cells when DDD was coincubated with 1-aminobenzotriazole. These results support the hypothesis that the cytotoxicity of DDD to susceptible subpopulations of rabbit and human lung cells is, at least in part, caused by cytochrome P450-mediated oxidation of DDD at C-1. A required step for the production of the cytotoxic intermediate is proposed to be the formation of a highly reactive acyl halide intermediate that is readily hydrolyzed to a stable, nontoxic metabolite, DDA.

Animals↗
PubMed1989

Clinical measurement of glare effect in cataract patients.

Glare complaints are common for patients with good visual acuity. Spot glare sensitivity is a sensitive measure of intraocular scattering caused by cataracts. The TVA functional vision tester was used to measure contrast sensitivity with and without spot glare. The case studies presented compare relative spot glare disability for cataractous and normal patients with the same visual acuity. The glare measurements show distinct attenuation of contrast sensitivity for cataract patients over patients with no ocular pathology.

Aged↗