scholarly journals Role of microtubules in granulocyte adherence

Blood ◽  
1978 ◽  
Vol 51 (6) ◽  
pp. 1045-1050 ◽  
Author(s):  
LA Boxer ◽  
JM Allen ◽  
AM Watanabe ◽  
HR Jr Besch ◽  
RL Baehner
Keyword(s):  
Ascorbic Acid ◽  
Cyclic Nucleotides ◽  
Polymorphonuclear Leukocytes ◽  
Microtubule Assembly ◽  
Dose Dependent Fashion ◽  
Chediak Higashi Syndrome ◽  
Human Polymorphonuclear Leukocytes ◽  
Dose Dependent

Abstract The adherence of human polymorphonuclear leukocytes (PMN) to nylon fibers is inhibited in a dose-dependent fashion by exposure in vitro of these cells to either colchicine or VM-26, both of which agents prevent microtubule assembly. Mean adherence of human PMN was 48% +/- 2%, following treatment with 10(-5) M colchicine or 10(-4) M VM-26 it was reduced to 31% +/- 2% and 7%, respectively. Peritoneal PMN obtained from mice and mink with Chediak-Higashi syndrome (CHS) thought to have a microtubule-membrane disorder affecting the PMN had a mean adherence of 29% +/- 3% and 40% +/- 8% compared to control values of 46% +/- 5% and 73% +/- 8%, respectively, from the mice and mink. Both ascorbic acid and bethanechol, shown previously to enhance microtubule assembly in humans with CHS, normalized granulocyte adherence in PMN obtained from mice with CHS. Cyclic nucleotide levels were not altered by treatment of human PMN with colchicine, nor did they differ between normal and CHS animals. Thus it appears that the state of microtubule assembly may directly affect the properties of the PMN plasma membrane without requiring alterations of cyclic nucleotides as an intermediary.

scholarly journals Role of microtubules in granulocyte adherence

Blood ◽  
1978 ◽  
Vol 51 (6) ◽  
pp. 1045-1050
Author(s):  
LA Boxer ◽  
JM Allen ◽  
AM Watanabe ◽  
HR Jr Besch ◽  
RL Baehner
Keyword(s):  
Ascorbic Acid ◽  
Cyclic Nucleotides ◽  
Polymorphonuclear Leukocytes ◽  
Microtubule Assembly ◽  
Dose Dependent Fashion ◽  
Chediak Higashi Syndrome ◽  
Human Polymorphonuclear Leukocytes ◽  
Dose Dependent

The adherence of human polymorphonuclear leukocytes (PMN) to nylon fibers is inhibited in a dose-dependent fashion by exposure in vitro of these cells to either colchicine or VM-26, both of which agents prevent microtubule assembly. Mean adherence of human PMN was 48% +/- 2%, following treatment with 10(-5) M colchicine or 10(-4) M VM-26 it was reduced to 31% +/- 2% and 7%, respectively. Peritoneal PMN obtained from mice and mink with Chediak-Higashi syndrome (CHS) thought to have a microtubule-membrane disorder affecting the PMN had a mean adherence of 29% +/- 3% and 40% +/- 8% compared to control values of 46% +/- 5% and 73% +/- 8%, respectively, from the mice and mink. Both ascorbic acid and bethanechol, shown previously to enhance microtubule assembly in humans with CHS, normalized granulocyte adherence in PMN obtained from mice with CHS. Cyclic nucleotide levels were not altered by treatment of human PMN with colchicine, nor did they differ between normal and CHS animals. Thus it appears that the state of microtubule assembly may directly affect the properties of the PMN plasma membrane without requiring alterations of cyclic nucleotides as an intermediary.

scholarly journals Relation of the CD11/CD18 family of leukocyte antigens to the transient neutropenia caused by chemoattractants

Blood ◽  
1990 ◽  
Vol 76 (6) ◽  
pp. 1240-1245 ◽  
Author(s):  
C Lundberg ◽  
SD Wright
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Dose Dependence ◽  
Blood Stream ◽  
Leukocyte Antigens ◽  
Similar Dose ◽  
Inflammatory Site ◽  
Dose Dependent Fashion ◽  
Plasma Leakage ◽  
Dose Dependent

Abstract Adherence of leukocytes to the endothelium is a prerequisite for infiltration and accumulation of cells at an inflammatory site. Recent studies suggest that the CD11/CD18 family of adhesion-promoting receptors plays a crucial role in the initial adherence of polymorphonuclear leukocytes (PMNs) to endothelium. We have studied the effect of the anti-CD18 monoclonal antibody (MoAb) IB4, on movement of PMN in rabbits. Accumulation of PMNs in the skin induced by a local injection of the chemoattractant, zymosan-activated serum (ZAS), was strongly inhibited, in a dose-dependent fashion, by intravenous injection of IB4. A greater than 95% reduction in PMN accumulation was seen with 1 mg IB4/kg body weight, the highest dose used. PMN-dependent plasma leakage in the ZAS-injected skin sites was also inhibited by pretreatment with MoAb IB4, with a similar dose dependence. Histamine- induced plasma leakage, which is PMN independent, was not affected by this treatment. F(ab)2 fragments of IB4 were as effective as the whole immunoglobulin G molecule in reducing PMN accumulation. The half-life of circulating IB4 in rabbits was found to be 11.5 hours. These results are consistent with in vitro studies that show that binding of PMNs to endothelium requires both expression of CD11/CD18 molecules and activation of the PMNs by agonists, and confirm that sites on CD11/CD18 that recognize endothelial cells are blocked by IB4. Other investigators have shown that injection of chemoattractants into the blood stream causes a rapid neutropenia associated with accumulation of PMNs in the lung. We find that intravenous treatment of animals with IB4 did not block the transient accumulation of PMNs in the lung induced by formyl-methionyl-leucyl-phenylalanine, suggesting that this accumulation occurs by a mechanism that does not require CD11/CD18 molecules.

cAMP-stimulated rise of [Ca2+]i in rabbit connecting tubules: role of peritubular Ca

1990 ◽  
Vol 258 (3) ◽  
pp. F751-F755 ◽  
Author(s):  
J. E. Bourdeau ◽  
B. K. Eby
Keyword(s):  
Parathyroid Hormone ◽  
Ethylene Glycol ◽  
Cell Activation ◽  
Proximal Tubules ◽  
Tetraacetic Acid ◽  
Luminal Membrane ◽  
Dose Dependent Fashion ◽  
Dose Dependent

Parathyroid hormone (PTH) increases cytosolic free Ca concentration ([ Ca2+]i) by mechanisms that depend on extracellular Ca in both cultured renal proximal tubules and isolated rabbit connecting tubules (CNTs). In CNTs 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP) mimics this action, implicating cAMP as a second messenger, and part of the rise, due to increased luminal membrane Ca entry, is likely related to Ca absorption. In cultured proximal tubules the rise in [Ca2+]i, presumably mediated by increased Ca entry across the basolateral plasmalemma, activates gluconeogenesis and shortens microvilli. In the present study we examined cAMP-mediated Ca entry across the basolateral membranes of CNT cells, an effect potentially related to cell activation. Single CNTs were dissected from rabbit kidneys and loaded with fura-2. [Ca2+]i was measured by dual-wavelength excitation during perfusion of isolated segments in vitro. With 1.8 or 2.0 mM Ca in the lumen and the bath, suffusate 8-BrcAMP increased [Ca2+]i within minutes in a dose-dependent fashion. The increase persisted as long as 8-BrcAMP was present and reversed on its withdrawal. With 0.1 microM Ca in the lumen and the bath, 8-BrcAMP, but not ionomycin, failed to increase [Ca2+]i, implying that extracellular Ca is the major source. In tubules perfused with 2 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to eliminate luminal Ca, but suffused with 1.8 or 2.0 mM Ca, 8-BrcAMP increased [Ca2+]i (though less so than with Ca in the lumen), implying Ca entry across basolateral cell membranes. This rise in [Ca2+]i was attenuated markedly by the presence of 50 microM LaCl3 in the bath.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Tubulin tyrosinolation in human polymorphonuclear leukocytes: studies in normal subjects and in patients with the Chediak-Higashi syndrome.

1982 ◽  
Vol 95 (2) ◽  
pp. 519-526 ◽  
Author(s):  
J Nath ◽  
M Flavin ◽  
J I Gallin
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Specific Activity ◽  
Normal Subjects ◽  
In Vivo Experiments ◽  
Peritoneal Leukocytes ◽  
Chediak Higashi Syndrome ◽  
Human Polymorphonuclear Leukocytes ◽  
Stimulation Of

We have recently reported a specific dose-dependent stimulation of posttranslational incorporation of tyrosine into tubulin alpha-chains of rabbit peritoneal leukocytes as induced by the synthetic peptide chemoattractant formyl-methionyl-leucyl-phenylalanine (FMLP). The present study reports a similar, specific stimulation of tubulin tyrosinolation in human polymorphonuclear leukocytes (PMN). When compared to normal PMN, both the resting and FMLP-stimulated levels of posttranslational tyrosine incorporation were two- to threefold higher in PMN of three patients with the Chediak-Higashi syndrome (CHS). The concentration of cellular tubulin and the specific activity of tubulin tyrosine ligase were similar in PMN of CHS patients and normal donors and resembled that of other non-neuronal cells. The high levels of tyrosine incorporation in PMN of CHS patients were normalized by the administration of ascorbate, both in vitro and in in vivo experiments. In vitro addition of ascorbate also inhibited the FMLP-induced stimulation of tyrosine incorporation in both normal and CHS cells. Normalization of higher levels of tyrosine incorporation in PMN of CHS patients and the inhibition of FMLP-induced stimulation of tubulin tyrosinolation in normal and CHS cells as observed with ascorbate could also be affected by other reducing agents such as reduced glutathione, cysteine, or dithiothreitol. These results suggest a possible relationship between cellular redox and tubulin tyrosinolation in PMN.

scholarly journals Relation of the CD11/CD18 family of leukocyte antigens to the transient neutropenia caused by chemoattractants

Blood ◽  
1990 ◽  
Vol 76 (6) ◽  
pp. 1240-1245 ◽  
Author(s):  
C Lundberg ◽  
SD Wright
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Dose Dependence ◽  
Blood Stream ◽  
Leukocyte Antigens ◽  
Similar Dose ◽  
Inflammatory Site ◽  
Dose Dependent Fashion ◽  
Plasma Leakage ◽  
Dose Dependent

Adherence of leukocytes to the endothelium is a prerequisite for infiltration and accumulation of cells at an inflammatory site. Recent studies suggest that the CD11/CD18 family of adhesion-promoting receptors plays a crucial role in the initial adherence of polymorphonuclear leukocytes (PMNs) to endothelium. We have studied the effect of the anti-CD18 monoclonal antibody (MoAb) IB4, on movement of PMN in rabbits. Accumulation of PMNs in the skin induced by a local injection of the chemoattractant, zymosan-activated serum (ZAS), was strongly inhibited, in a dose-dependent fashion, by intravenous injection of IB4. A greater than 95% reduction in PMN accumulation was seen with 1 mg IB4/kg body weight, the highest dose used. PMN-dependent plasma leakage in the ZAS-injected skin sites was also inhibited by pretreatment with MoAb IB4, with a similar dose dependence. Histamine- induced plasma leakage, which is PMN independent, was not affected by this treatment. F(ab)2 fragments of IB4 were as effective as the whole immunoglobulin G molecule in reducing PMN accumulation. The half-life of circulating IB4 in rabbits was found to be 11.5 hours. These results are consistent with in vitro studies that show that binding of PMNs to endothelium requires both expression of CD11/CD18 molecules and activation of the PMNs by agonists, and confirm that sites on CD11/CD18 that recognize endothelial cells are blocked by IB4. Other investigators have shown that injection of chemoattractants into the blood stream causes a rapid neutropenia associated with accumulation of PMNs in the lung. We find that intravenous treatment of animals with IB4 did not block the transient accumulation of PMNs in the lung induced by formyl-methionyl-leucyl-phenylalanine, suggesting that this accumulation occurs by a mechanism that does not require CD11/CD18 molecules.

Neutrophil transendothelial migration in vitro toStreptococcus pneumoniaeis pneumolysin dependent

2006 ◽  
Vol 290 (5) ◽  
pp. L833-L840 ◽  
Author(s):  
Jessica G. Moreland ◽  
Gail Bailey
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Early Event ◽  
Wild Type ◽  
Pulmonary Endothelium ◽  
Vascular Space ◽  
Endothelial Adhesion Molecules ◽  
Dose Dependent ◽  
Transwell System

The recruitment of polymorphonuclear leukocytes (PMN) from the vascular space to the alveolar air space is an early event in host defense against pneumococcal pneumonia. Pneumolysin is a virulence factor for Streptococcus pneumoniae, but a specific role for pneumolysin in neutrophil-endothelial cell interactions has not been investigated. Using a Transwell system, we studied in vitro migration of PMNs across a monolayer of human pulmonary microvascular endothelial cells in response to wild-type S. pneumoniae (D39) and a pneumolysin-deficient mutant ( plnA−) incubated on the abluminal surface of the monolayer. S. pneumoniae induction of PMN migration was dose dependent and elicited by ≥105D39. Mutants lacking pneumolysin had dramatically reduced potency for eliciting PMN migration compared with the parent strain (5 × 106plnA−elicits 18.6% PMN migration vs. 55.5% for 5 × 106D39). The disparity between D39 and plnA−persisted in ethanol-fixed bacteria, consistent with the properties of pneumolysin. Neither conditioned medium from D39 nor purified pneumolysin elicited PMN migration to the same extent as the intact D39, suggesting that the role of pneumolysin in eliciting PMN migration requires a more complex interaction between the organism, the endothelium, and the PMN. Both D39 and plnA−adhered to, and translocated across, the endothelium in the abluminal to luminal direction and elicited similar levels of IL-8 production. Neither strain elicited upregulation of the endothelial adhesion molecules ICAM-1, VCAM-1, or E-selectin, and they did not cause translocation of NF-κB to the nucleus. These findings demonstrate a novel role for pneumolysin in pneumococcus-induced PMN recruitment across the pulmonary endothelium.

Soluble Thrombomodulin Purified from Human Urine Exhibits a Potent Anticoagulant Effect In Vitro and In Vivo

1995 ◽  
Vol 73 (05) ◽  
pp. 805-811 ◽  
Author(s):  
Yasuo Takahashi ◽  
Yoshitaka Hosaka ◽  
Hiromi Niina ◽  
Katsuaki Nagasawa ◽  
Masaaki Naotsuka ◽  
...  
Keyword(s):  
Human Urine ◽  
Specific Activity ◽  
Anticoagulant Activity ◽  
Rabbit Lung ◽  
Soluble Thrombomodulin ◽  
Molecular Weights ◽  
Dose Dependent Fashion ◽  
Dose Dependent

SummaryWe examined the anticoagulant activity of two major molecules of soluble thrombomodulin purified from human urine. The apparent molecular weights of these urinary thrombomodulins (UTMs) were 72,000 and 79,000, respectively. Both UTMs showed more potent cofactor activity for protein C activation [specific activity >5,000 thrombomodulin units (TMU)/mg] than human placental thrombomodulin (2,180 TMU/mg) and rabbit lung thrombomodulin (1,980 TMU/mg). The UTMs prolonged thrombin-induced fibrinogen clotting time (>1 TMU/ml), APTT (>5 TMU/ml), TT (>5 TMU/ml) and PT (>40 TMU/ml) in a dose-dependent fashion. These effects appeared in the concentration range of soluble thrombomodulins present in human plasma and urine. In the rat DIC model induced by thromboplastin, administration of UTMs by infusion (300-3,000 TMU/kg) restored the hematological abnormalities derived from DIC in a dose-dependent fashion. These results demonstrate that UTMs exhibit potent anticoagulant and antithrombotic activities, and could play a physiologically important role in microcirculation.

The Use of the Vitality and Chemotaxis of Human Polymorphonuclear Leukocytes for the In Vitro Estimation of the Acute Toxicity of the First Ten Chemicals from the MEIC List

1993 ◽  
Vol 21 (1) ◽  
pp. 73-80
Author(s):  
Matteo Valentino ◽  
Francesca Monaco ◽  
Maria Antonietta Pizzichini ◽  
Mario Governa
Keyword(s):  
Ethidium Bromide ◽  
Polymorphonuclear Leukocytes ◽  
Rank Correlation ◽  
Fluorescein Diacetate ◽  
Live Cells ◽  
In Vitro Toxicity ◽  
Ic50 Values ◽  
Acute Cytotoxicity ◽  
Human Polymorphonuclear Leukocytes

The acute cytotoxicity of the first ten MEIC chemicals has been estimated by others in various cell lines. In the present investigation, isolated human polymorphonuclear leukocytes (PMN) from ten healthy non-smoking laboratory personnel were used to assess in vitro toxicity of the same chemicals. The cells were treated with different concentrations of the respective chemicals for three hours and their vitality and chemotaxis were tested. Vitality was measured by fluorescence microscopy after the addition of fluorescein diacetate and ethidium bromide. Living cells which took up and hydrolysed fluorescein diacetate, and dead cells, stained by ethidium bromide, were counted and the percentage of live cells was calculated. Locomotion stimulated by the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (F-MLP), was measured in blind-well Boyden chambers and a chemotactic index was calculated. The results were mathematically transformed to produce a linear curve, and then fitted by the linear least squares procedure, from which LC50 and IC50 values were obtained by interpolation. All the chemicals decreased the vitality and inhibited the chemotaxis of the PMN. Obviously the chemotactic test was more sensitive than the vitality one. A correlation (r = 0.933) was found between vitality and chemotaxis inhibition. Spearman rank correlation analysis revealed significant correlations between our results and those from in vitro experiments conducted in other laboratories, as well as with data concerning mouse, rat and human lethal doses.

scholarly journals Lumican Inhibits Osteoclastogenesis and Bone Resorption by Suppressing Akt Activity

2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Map Kinases ◽  
Osteoclast Differentiation ◽  
Dependent Manner ◽  
Dual Action ◽  
Dose Dependent ◽  
Resorptive Activity

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.

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