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Query: UMLS:C0043167 (
pertussis
)
19,595
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Human immunodeficiency virus (HIV) dementia (HIVD) is associated with an increase in the number of activated monocytes within the central nervous system (CNS), a pathological feature that may be more remarkable in the setting of superimposed substance abuse. Monocytes may transport HIV to the brain, and, moreover, activated and/or infected monocytes have been shown to release a number of potent neurotoxins. Although the mechanisms responsible for the increase in the CNS ingress of monocytes are multiple, blood-brain barrier (BBB)-degrading matrix metalloproteinases (MMPs) are likely to play an important role. The current study investigates the effects of the HIV-1-encoded protein Tat, and the drug of abuse methamphetamine, on MMP release from brain derived cells. The release of urokinase plasminogen activator (uPA), an activator of MMPs, was also investigated. Mixed human neuron/astrocyte cultures were stimulated with Tat or methamphetamine, and supernatants were analyzed by enzyme-linked immunosorbent assay (ELISA) and/or gelatin substrate zymography. Results showed that Tat and methamphetamine increased the release of MMP-1 from these cultures. Tat also increased supernatant levels of active
MMP-2
. In addition, both Tat and methamphetamine stimulated the release of the MMP activator uPA, and in a manner that was sensitive to inhibition with
pertussis
toxin. Together, these results suggest that in HIVD, Tat and methamphetamine may contribute to CNS inflammation by stimulating increased release and/or activation of matrix-degrading proteinases through mechanisms that include Gi/Go-coupled signaling. These results also suggest a potential mechanism for acceleration of HIVD with methamphetamine use.
...
PMID:Human immunodeficiency virus type 1 Tat and methamphetamine affect the release and activation of matrix-degrading proteinases. 1498 25
The homeopathic compound of resonance FMS*Calciumfluor (FMS*) reportedly promotes osteogenic differentiation of rat pre-osteoblasts in vitro. Here, we show that the continuous exposure of differentiating rat osteogenic cells (ROB) to FMS* modulates the level of expression of mRNAs for 7 of the 8 osteogenic markers tested. Alkaline phosphatase (AP), osteocalcin (OC), metalloproteinases (
MMP-2
and -14), procollagenase C (BMP-1), biglycan (BG) and integrin 1 are expressed at higher levels in FMS*-treated osteoblasts than in control cultures.
MMP-2
and -14 mRNA are not down-modulated at mineralization. Also, the pattern of expression induced by FMS* for some of these genes (BMP-1, BG and integrin 1) is changed, but collagen type I (Coll I) mRNA levels are not affected by treatment with FMS*. This suggests that FMS* modulates mRNA levels and that this is not generalized, but gene(s) specific. We also report that exposure to FMS* rapidly and transiently induces activation of mitogen-activated protein kinases (MAPKs) 42,44 in populations of early osteoblasts, but not in pre-osteoblasts, with a cell differentiation stage-dependent and
pertussis
toxin (PTX)-sensitive response. Subsequent to FMS* MAPK signaling activation, an increase in AP and MMP-14 mRNA is detected, which is also inhibited by PTX, suggesting that FMS* activation of MAPK signaling could be an early event required for the induction of these genes. Exposure to FMS* does not cause changes in the activity of p125 (FAK)-mediated signaling.
...
PMID:FMS*Calciumfluor specifically increases mRNA levels and induces signaling via MAPK 42,44 and not FAK in differentiating rat osteoblasts. 1602 62
Overexpression of cAMP-response element (CRE)-binding protein (CREB) and activating transcription factor (ATF) 1 contributes to melanoma progression and metastasis at least in part by promoting tumor cell survival and stimulating matrix metalloproteinase (MMP) 2 expression. However, little is known about the regulation of CREB and ATF-1 activities and their phosphorylation within the tumor microenvironment. We analyzed the effect of platelet-activating factor (PAF), a potent phospholipid mediator of inflammation, for its ability to activate CREB and ATF-1 in eight cultured human melanoma cell lines, and we found that PAF receptor (PAFR) was expressed in all eight lines. In metastatic melanoma cell lines, PAF induced CREB and ATF-1 phosphorylation via a PAFR-mediated signal transduction mechanism that required
pertussis
toxin-insensitive Galphaq protein and adenylate cyclase activity and was antagonized by a cAMP-dependent protein kinase A and p38 MAPK inhibitors. Addition of PAF to metastatic A375SM cells stimulated CRE-dependent transcription, as observed in a luciferase reporter assay, without increasing the CRE DNA binding capacity of CREB. Furthermore, PAF stimulated the gelatinase activity of
MMP-2
by activating transcription and
MMP-2
expression.
MMP-2
activation correlated with the PAF-induced increase in the expression of an
MMP-2
activator, membrane type 1 MMP. PAF-induced expression of pro-
MMP-2
was causally related to PAF-induced CREB and ATF-1 phosphorylation; it was prevented by PAFR antagonist and inhibitors of p38 MAPK and protein kinase A and was abrogated upon quenching of CREB and ATF-1 activities by forced overexpression of a dominant-negative form of CREB. PAF-induced
MMP-2
activation was also down-regulated by p38 MAPK and protein kinase A inhibitors. Finally, PAFR antagonist PCA4248 inhibited the development of A375SM lung metastasis in nude mice. This result indicated that PAF acts as a promoter of melanoma metastasis in vivo. We proposed that metastatic melanoma cells overexpressing CREB/ATF-1 are better equipped than nonmetastatic cells to respond to PAF within the tumor microenvironment.
...
PMID:Platelet-activating factor mediates MMP-2 expression and activation via phosphorylation of cAMP-response element-binding protein and contributes to melanoma metastasis. 1630 50
Treatment of bovine pulmonary artery smooth muscle with the O2 *- generating system hypoxanthine plus xanthine oxidase stimulated
MMP-2
activity and PKC activity; and inhibited Na+ dependent Ca2+ uptake in the microsomes. Pretreatment of the smooth muscle with SOD (the O2 *- scavenger) and TIMP-2 (
MMP-2
inhibitor) prevented the increase in
MMP-2
activity and PKC activity, and reversed the inhibition of Na+ dependent Ca2+ uptake in the microsomes. Pretreatment with calphostin C (a general PKC inhibitor) and rottlerin (a PKCdelta inhibitor) prevented the increase in PKC activity and reversed O2 *- caused inhibition of Na+ dependent Ca2+ uptake without causing any change in
MMP-2
activity in the microsomes of the smooth muscle. Treatment of the smooth muscle with the O2 *- generating system revealed, respectively, 36 kDa RACK-1 and 78 kDa PKCdelta immunoreactive protein profile along with an additional 38 kDa immunoreactive fragment in the microsomes. The 38 kDa band appeared to be the proteolytic fragment of the 78 kDa PKCdelta since pretreatment with TIMP-2 abolished the increase in the 38 kDa immunoreactive fragment. Co-immunoprecipitation of PKCdelta and RACK-1 demonstrated O2 *- dependent increase in PKCdelta-RACK-1 interaction in the microsomes. Immunoblot assay elicited an immunoreactive band of 41 kDa G(i)alpha in the microsomes. Treatment of the smooth muscle tissue with the O2 *- generating system causes phosphorylation of G(i)alpha in the microsomes and pretreatment with TIMP-2 and rottlerin prevented the phosphorylation. Pretreatment of the smooth muscle tissue with
pertussis
toxin reversed O2 *- caused inhibition of Na+ dependent Ca2+ uptake without affecting the protease activity and PKC activity in the microsomes. We suggest the existence of a
pertussis
toxin sensitive G protein mediated mechanism for inhibition of Na+ dependent Ca2+ uptake in microsomes of bovine pulmonary artery smooth muscle under O2 *- triggered condition, which is regulated by PKCdelta dependent phosphorylation and sensitive to TIMP-2 for its inhibition.
...
PMID:Role of MMP-2 in PKCdelta-mediated inhibition of Na+ dependent Ca2+ uptake in microsomes of pulmonary smooth muscle: involvement of a pertussis toxin sensitive protein. 1631 11
This study was designed to evaluate the signaling pathways coupling adenosine A1 receptors and extracellular signal-regulated kinase (ERK) 1 and 2 in human trabecular meshwork (HTM) cells. Studies were conducted using cultures of primary HTM cells and the HTM-3 cell line. Activation of ERK1/2, location of protein kinase C (PKC) isoforms, and matrix metalloproteinase (MMP) secretion were determined by Western blotting. In primary HTM cells and the HTM-3 cell line, administration of the A1 agonist N6-cyclohexyladenosine (CHA) produced a concentration-dependent increase in ERK1/2 activation. This CHA-induced ERK activation was blocked by pretreatment with the A1 receptor antagonist 8-cyclopentyl-1,3-dimethylxanthine or
pertussis
toxin. Transfection with dominant negative N17 Ras produced only a small (31%) decline in CHA-induced ERK activation, and the response was not altered by pretreatment with the Src tyrosine kinase inhibitor, PP2 [3-(4-chlorophenyl)1-(1,1-dimethylethyl)-1H-pyrazolo[3,4-D] pyrimidin-4-amine], the phosphoinositide kinase-3 inhibitor, LY-294002 [2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one], or the A3 receptor antagonist, MRS-1191 [3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(+/-)-dihydropyridine-3,5-dicarboxylate]. Administration of CHA also induced the translocation of PKCalpha from the cytosol to the membrane, and pretreatment with the phospholipase C (PLC) inhibitor, U73122 [1-[6-[[(17beta)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]-hexyl]-1H-pyrrole-2,5-dione], blocked ERK1/2 activation induced by CHA. Transfection of short interfering RNA targeting PKCalpha blocked the CHA-induced ERK1/2 activation and the secretion of
MMP-2
. These results confirm the existence of functional adenosine A1 receptors in the trabecular meshwork cells. These receptors are coupled to the activation of ERK1/2 through G(i/o) proteins and dependent upon the upstream activation of PLC and PKCalpha. These studies provide evidence that adenosine A1 receptor agonists increase outflow facility through sequential activation of G(i/o) > PLC > PKCalpha > c-Raf > mitogen-activated protein kinase kinase > ERK1/2, leading to secretion of
MMP-2
.
...
PMID:Mechanisms linking adenosine A1 receptors and extracellular signal-regulated kinase 1/2 activation in human trabecular meshwork cells. 1701 37
Cell migration is a complex biological function involved in both physiologic and pathologic processes. Although this is a subject of intense investigation, the mechanisms by which cell migration is regulated are not completely understood. In this study we show that the bioactive sphingolipid ceramide 1-phosphate (C1P), which is involved in inflammatory responses, causes upregulation of metalloproteinases (MMP) -2 and -9 in J774A.1 macrophages. This effect was shown to be dependent on stimulation of phosphatidylinositol 3-kinase (PI3K) and extracellularly regulated kinases 1-2 (ERK1-2) as demonstrated by treating the cells with specific siRNA to knockdown the p85 regulatory subunit of PI3K, or ERK1-2. Inhibition of
MMP-2
or MMP-9 pharmacologically or with specific siRNA to silence the genes encoding these MMPs abrogated C1P-stimulated macrophage migration. Also, C1P induced actin polymerization and potently increased phosphorylation of the focal adhesion protein paxillin, which are essential factors in the regulation of cell migration. As expected, blockade of paxillin activation with specific siRNA significantly reduced actin polymerization. In addition, inhibition of actin polymerization with cytochalasin D completely blocked C1P-induced
MMP-2
and -9 expression as well as C1P-stimulated macrophage migration. It was also observed that
pertussis
toxin (Ptx) inhibited Akt, ERK1-2, and paxillin phosphorylation, and completely blocked cell migration. The latter findings support the notion that C1P-stimulated macrophage migration is a receptor mediated effect, and point to
MMP-2
and -9 as possible therapeutic targets to control inflammation.
...
PMID:Implication of matrix metalloproteinases 2 and 9 in ceramide 1-phosphate-stimulated macrophage migration. 2716 14