Transmembrane-4-superfamily proteins CD151 and CD81 associate with alpha 3 beta 1 integrin, and selectively contribute to alpha 3 beta 1-dependent neurite outgrowth

2000 ◽  
Vol 113 (11) ◽  
pp. 1871-1882 ◽  
Author(s):  
C.S. Stipp ◽  
M.E. Hemler
Keyword(s):  
Neurite Outgrowth ◽  
Inhibitory Effect ◽  
Positive Contribution ◽  
Laminin 5 ◽  
Dependent Inhibition ◽  
Beta 1 Integrin ◽  
Alpha3beta1 Integrin ◽  
Integrin Family ◽  
Laminin 1 ◽  
Transmembrane 4 Superfamily

Proteins in the transmembrane-4-superfamily (TM4SF) form many different complexes with proteins in the integrin family, but the functional utility of these complexes has not yet been demonstrated. Here we show that TM4SF proteins CD151, CD81, and CD63 co-distribute with alpha3beta1 integrin on neurites and growth cones of human NT2N cells. Also, stable CD151-alpha3beta1 and CD81-alpha3beta1 complexes were recovered in NT2N detergent lysates. Total NT2N neurite outgrowth on laminin-5 (a ligand for alpha3beta1 integrin) was strongly inhibited by anti-CD151 and -CD81 antibodies either together (approximately 85% inhibition) or alone (approximately 45% inhibition). Notably, these antibodies had no inhibitory effect on NT2N neurites formed on laminin-1 or fibronectin, when alpha3beta1integrin was not engaged. Neurite number, length, and rate of extension were all affected by anti-TM4SF antibodies. In summary: (1) these substrate-dependent inhibition results strongly suggest that CD151 and CD81 associations with alpha3beta1 are functionally relevant, (2) TM4SF proteins CD151 and CD81 make a strong positive contribution toward neurite number, length, and rate of outgrowth, and (3) NT2N cells, a well-established model of immature central nervous system neurons, can be a powerful system for studies of integrin function in neurite outgrowth and growth cone motility.

Cell adhesion to laminin 1 or 5 induces isoform-specific clustering of integrins and other focal adhesion components

1998 ◽  
Vol 111 (6) ◽  
pp. 793-802 ◽  
Author(s):  
D. Dogic ◽  
P. Rousselle ◽  
M. Aumailley
Keyword(s):  
Cell Adhesion ◽  
Focal Adhesion ◽  
Adhesion Formation ◽  
Focal Adhesions ◽  
Specific Expression ◽  
Normal Human Skin ◽  
Laminin 5 ◽  
Cell Shapes ◽  
Alpha3beta1 Integrin ◽  
Laminin 1

Laminin 1 (alpha1beta1gamma1) and laminin 5 (alpha3beta3gamma2) induce cell adhesion with different involvement of integrins: both are ligands for the alpha6beta1 integrin, while alpha3beta1 integrin has affinity for laminin 5 only. These two laminin isoforms therefore provide good models to investigate whether alpha3beta1 and alpha6beta1 integrins play different roles in signal transduction and in focal adhesion formation. Laminin 1 or 5 induced adhesion of normal human skin fibroblasts to a similar extent but promoted different overall cell shapes. On laminin 1 the fibroblasts formed mainly filopodia-like structures, while on laminin 5 they developed lamellipodias. Staining of fibrillar actin with fluorescein-phalloidin revealed a similar organisation of the actin cytoskeleton on both substrates. However, integrin subunits and several cytoskeletal linker proteins, including vinculin, talin, and paxillin, showed an isoform-specific arrangement into focal adhesions. On laminin 1 they were recruited into thick and short aggregates localized at the termini of actin stress fibers, while on laminin 5 they appeared as dots or streaks clustered on a long portion of actin microfilaments. To test whether the differing affinity of laminin 1 or 5 for alpha3beta1 integrin would explain the formation of morphologically different focal adhesions, cells were seeded on laminin 1 under conditions in which alpha3beta1 integrins were occupied by a function-blocking antibody. This resulted in the formation of focal adhesions similar to that observed on laminin 5, where the integrin is occupied by its natural ligand. These results provide the first evidence for a cross-talk between alpha3beta1 and alpha6beta1 integrins and indicate that occupancy of alpha3beta1 integrins results in a trans-dominant regulation of alpha6beta1 integrin clustering and of focal adhesions. It suggests that recruitment of integrins and cytoskeletal linker proteins are laminin isoform-specific and that tissue specific expression of laminin isoforms might modulate cell behavior by the activation of distinct sets of integrins and by the induction of distinct molecular assemblies within the cell adhesion signaling complexes.

Inhibition of the Activities of α2-Plasmin inhibitor (PI) and CI inhibitor (CI-Inh) by the Synthetic Fibrinolytic Agent, 3-Hydroxypropyl Flufenamide (Flu-HPA)

1979 ◽  
Author(s):  
L Miles ◽  
J Burnier ◽  
M Verlander ◽  
M Goodman ◽  
A Kleiss ◽  
...  
Keyword(s):  
Plasminogen Activators ◽  
Inhibitory Effect ◽  
Mechanisms Of Action ◽  
Flufenamic Acid ◽  
Clot Lysis ◽  
Factor Xiia ◽  
Dependent Inhibition ◽  
Normal Human ◽  
Plasmin Inhibitor

Flu-HPA is one of a series of flufenamic acid derivations that enhances plasminogen-dependent clot lysis in vitro. Studies of possible mechanisms of action of Flu-HPA were undertaken. The influence of Flu-HPA on the inhibition of purified plasmin by purified PI was studied. PI activity was assessed by its inhibition of the clevage of the tripeptide S-2251 (H-D-Val-Leu-Lys-pNA) by plasmin. Flu-HPA was dissolved in DMF or in methonol and preincubated with PI before addition of plasmin. At Flu-HPA concentrations greater than 1mM and up to 60mM, the inhibitory activity of PI was totally lost. The inhibitory effect of normal human plasma on plasmin was also completely abolished at concentrations of Flu-HPA between 2.5 and 40mM. The effect of Flu-HPA on the inhibition of purified plasma kallikrein by purified CI-Inh was also studied. CI-Inh activity was measured by its inhibition of cleavage of the tripeptide Bz-Pro-Phe-Arg-pNA by kallikrein. When Flu-HPA, dissolved in DMF or in methonol, was preincubated with CI-Inh, a concentration dependent inhibition of CI-Inh activity was observed. CI-Inh activity was abolished by concentrations of Flu-HPA greater than 1mM. Flu-HPA also inhibited the activity of CI-Inh on purified Factor XIIa. These observations suggest that this flufenamic acid derivative may enhance fibrinolysis not only by inhibiting PI activity but also by decreasing the inactivation of plasminogen activators by CI-Inh.

scholarly journals Characterization of the inositol 1,4,5-trisphosphate-induced calcium release from permeabilized endocrine cells and its inhibition by decavanadate and p-hydroxymercuribenzoate

1989 ◽  
Vol 262 (1) ◽  
pp. 83-89 ◽  
Author(s):  
K J Föhr ◽  
J Scott ◽  
G Ahnert-Hilger ◽  
M Gratzl
Keyword(s):  
Endocrine Cells ◽  
Calcium Release ◽  
Cell Types ◽  
Inhibitory Effect ◽  
Maximal Effect ◽  
Thiol Compounds ◽  
Inositol 1,4,5 Trisphosphate ◽  
Dependent Inhibition ◽  
Pheochromocytoma Pc12 ◽  
First Time

The inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ compartment of endocrine cells was studied with alpha-toxin- and digitonin-permeabilized rat insulinoma (RINA2) and rat pheochromocytoma (PC12) cells. The Ca2+ uptake was ATP-dependent, and submicromolar concentrations of IP3 specifically released the stored Ca2+. Half-maximal Ca2+ release was observed with 0.25-0.5 mumol of IP3/l, and the amount of Ca2+ released due to IP3 could be enhanced by additional loading of the Ca2+ compartment. Consecutive additions of the same concentration of IP3 for 1-2 h always released the same amount of Ca2+ without desensitization, providing an ideal basis to further characterize the IP3-induced Ca2+ release. Here we describe for the first time a reversible inhibitory effect of decavanadate on the IP3-induced Ca2+ release. Among the vanadium species tested (decavanadate, oligovanadate and monovanadate), only decavanadate was inhibitory, with a half-maximal effect at 5 mumol/l in both cell types. The effect of decavanadate could be overcome by increasing the amount of sequestered Ca2+ or added IP3. Decavanadate did not affect the ATP-driven Ca2+ uptake but oligovanadate was inhibitory on Ca2+ uptake. p-Hydroxymercuribenzoate (pHMB) at concentrations between 10 and 30 mumol/l also inhibited the Ca2+ release due to IP3. Thiol compounds such as dithiothreitol (DTT; 1 mmol/l) added before pHMB removed all its inhibitory effect on the IP3-induced Ca2+ release, whereas the inhibition caused by decavanadate was unaffected by DTT. Thus, the decavanadate-dependent inhibition functions by a distinctly different mechanism than pHMB and could serve as a specific tool to analyse various aspects of the IP3-induced Ca2+ release within endocrine cells.

Human kidney 11β-hydroxysteroid dehydrogenase: regulation by adrenocorticotropin?

1996 ◽  
Vol 134 (3) ◽  
pp. 301-307 ◽  
Author(s):  
S Diederich ◽  
M Quinkler ◽  
K Miller ◽  
P Heilmann ◽  
M Schöneshöfer ◽  
...  
Keyword(s):  
Human Kidney ◽  
Kinetic Studies ◽  
Hydroxysteroid Dehydrogenase ◽  
Inhibitory Effect ◽  
Benjamin Franklin ◽  
Dependent Inhibition ◽  
Direct Inhibitory Effect ◽  
Dose Dependent Inhibition ◽  
Endogenous Substrates ◽  
Radioactive Detection

Diederich S, Quinkler M, Miller K, Heilmann P, Schöneshöfer M, Oelkers W. Human kidney 11βhydroxysteroid dehydrogenase: regulation by adrenocorticotropin? Eur J Endocrinol 1996;134:301–7. ISSN 0804–4643 In ectopic adrenocorticotropin (ACTH) syndrome (EAS) with higher ACTH levels than in pituitary Cushing's syndrome and during ACTH infusion, the ratio of cortisol to cortisone in plasma and urine is increased, suggesting inhibition of renal 11β-hydroxysteroid dehydrogenase (11β-HSD) by ACTH or by ACTH-dependent steroids. Measuring the conversion of cortisol to cortisone by human kidney slices under different conditions, we tested the possibility of 11β-HSD regulation by ACTH and corticosteroids. Slices prepared from unaffected parts of kidneys removed because of renal cell carcinoma were incubated with unlabeled or labeled cortisol, and cortisol and cortisone were quantitated after HPLC separation by UV or radioactive detection. The 11β-HSD activity was not influenced by incubation with increasing concentrations (10−12–10−9 mol/l) of ACTH (1–24 or 1–39) for 1 h. Among 12 ACTH-dependent steroids tested (10−9–10−6 mol/l), only corticosterone (IC50 = 2 × 10−7 mol/l), 18-OH-corticosterone and 11βOH-androstenedione showed a significant dose-dependent inhibition of 11β-HSD activity. The percentage conversion rate of cortisol to cortisone was concentration dependent over the whole range of cortisol concentrations tested (10−8–10−5 mol/l). A direct inhibitory effect of ACTH on 11β-HSD is, therefore, unlikely. The only steroids inhibiting the conversion of cortisol to cortisone are natural substrates for 11β-HSD Kinetic studies show a saturation of the enzyme at high cortisol concentrations. Thus, the reduced percentage renal cortisol inactivation in EAS seems to be due mainly to overload of the enzyme with endogenous substrates (cortisol, corticosterone and others) rather than to direct inhibition of 11β-HSD by ACTH or ACTHdependent steroids, not being substrates of 11β-HSD. S Diederich, Department of Endocrinology, Klinikum Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 30, 12200 Berlin, Germany

Regulation of renal CYP4A expression and 20-HETE synthesis by nitric oxide in pregnant rats

2003 ◽  
Vol 285 (2) ◽  
pp. F295-F302 ◽  
Author(s):  
Mong-Heng Wang ◽  
Jishi Wang ◽  
Hsin-Hsin Chang ◽  
Barbara A. Zand ◽  
Miao Jiang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Rat Kidney ◽  
Late Pregnancy ◽  
Inhibitory Effect ◽  
Female Rats ◽  
Male Rats ◽  
Pregnant Rats ◽  
Renal Vasoconstriction ◽  
Dependent Inhibition

20-Hydroxyeicosatetraenoic acid (20-HETE), which promotes renal vasoconstriction, is formed in the rat kidney primarily by cytochrome P-450 (CYP) 4A isoforms (4A1, 4A2, 4A3, 4A8). Nitric oxide (NO) has been shown to bind to the heme moiety of the CYP4A2 protein and to inhibit 20-HETE synthesis in renal arterioles of male rats. However, it is not known whether NO interacts with and affects the activity of CYP4A1 and CYP4A3, the major renal CYP4A isoforms in female rats. Incubation of recombinant CYP4A1 and 4A3 proteins with sodium nitroprusside (SNP) shifted the absorbance at 440 nm, indicating the formation of a ferric-nitrosyl-CYP4A complex. The absorbance for CYP4A3 was about twofold higher than that of CYP4A1. Incubation of SNP or peroxynitrite (PN; 0.01–1 mM) with CYP4A recombinant membranes caused a concentration-dependent inhibition of 20-HETE synthesis, with both chemicals having a greater inhibitory effect on CYP4A3-catalyzed activity. Moreover, incubation of CYP4A1 and 4A3 proteins with PN (1 mM) resulted in nitration of tyrosine residues in both proteins. In addition, PN and SNP inhibited 20-HETE synthesis in renal microvessels from female rats by 65 and 59%, respectively. We previously showed that microvessel CYP4A1/CYP4A3 expression and 20-HETE synthesis are decreased in late pregnancy. Therefore, we investigated whether such a decrease is dependent on NO, the synthesis of which has been shown to increase in late pregnancy. Administration of NG-nitro-l-arginine methyl ester (l-NAME) to pregnant rats for 6 days ( days 15- 20 of pregnancy) caused a significant increase in systolic blood pressure, which was prevented by concurrent treatment with the CYP4A inhibitor 1-aminobenzotriazole (ABT). Urinary NO2/NO3 excretion decreased by 40 and 52% in l-NAME- and l-NAME + ABT-treated groups, respectively. Interestingly, renal microvessel 20-HETE synthesis showed a marked increase following l-NAME treatment, and this increase was diminished with coadministration of ABT. These results demonstrate that NO interacts with CYP4A proteins in a distinct manner and it interferes with renal microvessel 20-HETE synthesis, which may play an important role in the regulation of blood pressure and renal function during pregnancy.

scholarly journals The inhibitory effect on neurite outgrowth of motoneurons exerted by the ligands ELF-1 and RAGS

1997 ◽  
Vol 64 (1-2) ◽  
pp. 127-135 ◽  
Author(s):  
Kunimasa Ohta ◽  
Hiroko Iwamasa ◽  
Uwe Drescher ◽  
Hidenori Terasaki ◽  
Hideaki Tanaka
Keyword(s):  
Neurite Outgrowth ◽  
Inhibitory Effect

Selective increase in the binding of the alpha 1 beta 1 integrin for collagen type IV during neurite outgrowth of human neuroblastoma TR 14 cells

1994 ◽  
Vol 107 (12) ◽  
pp. 3379-3392
Author(s):  
G. Carmeliet ◽  
B. Himpens ◽  
J.J. Cassiman
Keyword(s):  
Neurite Outgrowth ◽  
Collagen Type ◽  
Collagen Type I ◽  
Collagen Type Iv ◽  
Type I ◽  
Human Neuroblastoma ◽  
Specific Antibodies ◽  
Type Iv ◽  
Beta 1 Integrin ◽  
In Cells

Regulation of beta 1 integrins in neurite outgrowth following N6,2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate (dBcAMP) treatment was investigated using the human neuroblastoma cell line TR 14. Three beta 1 integrins were identified: the alpha 1 beta 1 receptor bound collagen type I, collagen type IV and probably laminin; the alpha 2 beta 1 integrin bound collagen type I; and the alpha v beta i receptor bound fibronectin. Neurite extension was detectable as early as 30 minutes following dBcAMP treatment, was maximal after 24 hours and remained constant during treatment for 4 days. Adhesion-perturbing beta 1 subunit-specific antibodies, added together with dBcAMP, prevented the outgrowth of new neurites. During the first 24 hours of neurite outgrowth, no change was observed in the amount of beta 1 integrins nor in their topographic distribution. However, dBcAMP treatment increased the binding of alpha 1 beta 1 receptors to collagen type IV-Sepharose by a factor 2.3 +/- 0.6 (P < 0.02), while no alteration in the binding to collagen type I was detected. Moreover, neurites and growth cones were immunoreactive for collagen type IV but not for collagen type I. Consistently dBcAMP-induced neurite outgrowth was inhibited by adhesion-perturbing alpha 1 subunit-specific antibodies. Following maximal neurite outgrowth, the amount of beta 1 integrins determined by immunoprecipitation and by confocal microscopy decreased to 58.3 +/- 11.2% (P < 0.001) and to 55.4 +/- 17.5% (P < 0.001) of untreated levels, respectively, without any change in the level of beta 1 mRNA or de novo synthesized beta 1 precursor. However, pulse-chase experiments showed an increased turnover of the beta 1 subunit: the amount of beta 1 precursor that was degraded after 1 hour chase was 50.5 +/- 8.4% in cells treated for 4 days and 34.2 +/- 3.9% in untreated cells (P < 0.02); the amount of mature beta 1 after 24 hours chase was smaller in cells treated for 4 days compared to untreated cells. In conclusion, during neurite outgrowth, alpha 1 beta 1 integrins are required and acquire an enhanced binding activity for collagen type IV; but following maximal neurite outgrowth, expression of beta 1 integrins is reduced.

Inhibition by a stable factor derived from neutrophils of endothelium-dependent relaxation in rat aorta

1993 ◽  
Vol 265 (4) ◽  
pp. H1454-H1459 ◽  
Author(s):  
J. J. Liu ◽  
J. R. Chen ◽  
J. Wiley ◽  
C. C. Johnston ◽  
B. F. Buxton
Keyword(s):  
Sodium Nitroprusside ◽  
Inhibitory Effect ◽  
Rat Aorta ◽  
Oxygen Free Radical ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Stable Factor ◽  
Dependent Inhibition ◽  
Oxygen Free Radical Scavenger ◽  
Endothelium Dependent Relaxation

Polymorphonuclear leukocytes (PMNs) may play an important role in many pathophysiological states. The effect of a factor derived from PMNs on endothelium-dependent relaxation was studied using rat aortic rings in organ chambers. PMNs were obtained from cardiac surgical patients and healthy volunteers. After incubation in Krebs solution for 3 h, supernatants of PMN suspensions were isolated and used to pretreat the aortic rings for 30 min. The results showed that the supernatants derived from 1 x 10(4) to 5 x 10(6) cells/ml PMNs produced a concentration-dependent inhibition of endothelium-dependent relaxation to acetylcholine but not endothelium-independent relaxation to sodium nitroprusside. The effect could not be prevented by oxygen free radical scavenger superoxide dismutase (150 U/ml), catalase (1,200 U/ml), or mannitol (20 mM) used alone or in combination. Heating the supernatants at 95 degrees C for 30 min did not reduce the inhibitory effect. L-Arginine at 3 x 10(-5) to 3 x 10(-3) M did not significantly reverse the inhibitory effect of the PMN-derived factor. In conclusion, this study reveals that a heat-stable factor derived from human PMNs potently inhibits acetylcholine-induced endothelium-dependent relaxation but not sodium nitroprusside-induced endothelium-independent relaxation in rat aorta. This inhibitory effect is not caused by oxygen free radicals, a limitation of nitric oxide precursor or other unstable factors.

Nickel inhibits endothelin-induced contractions of vascular smooth muscle

1990 ◽  
Vol 258 (6) ◽  
pp. C1025-C1030 ◽  
Author(s):  
K. Blackburn ◽  
R. F. Highsmith
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Isometric Force ◽  
Inhibitory Effect ◽  
Rat Aorta ◽  
Porcine Coronary Artery ◽  
Force Development ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Endothelin (ET)-induced contractions of vascular smooth muscle (VSM) are dependent on extracellular Ca2+ yet display only partial sensitivity to L-type Ca2+ antagonists. The purpose of this study was to evaluate the effect of nickel (Ni2+), a Ca2+ channel antagonist with clearly documented differential potency toward L- vs. T-type Ca2+ currents on ET-mediated contractions in VSM. Treatment of rings of left anterior descending porcine coronary artery (LAD) with Ni2+ produced a profound dose-dependent inhibition of isometric force development in response to porcine ET (ET-1). At a concentration of 360 microM, Ni2+ exerted a significant inhibitory effect on contracture in response to doses of ET-1 ranging from 3 to 100 nM. In contrast, the same concentration of Ni2+ failed to significantly affect peak force development in response to KCl depolarization (5-77 mM) or to phenylephrine (0.3-30 mM). In addition, 360 microM Ni2+ significantly inhibited the contractile response of rat aorta to 10 nM ET-1. We conclude that ET-1 activates a Ni2(+)-sensitive process in VSM which may signal an additional Ca2+ influx pathway that appears to be functionally distinct from the L-type Ca2+ channel.

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