scholarly journals Phosphoinositide 3-kinase inhibition restores neutrophil accuracy in the elderly: toward targeted treatments for immunosenescence

Blood ◽  
2014 ◽  
Vol 123 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Elizabeth Sapey ◽  
Hannah Greenwood ◽  
Georgia Walton ◽  
Elizabeth Mann ◽  
Alexander Love ◽  
...  
Keyword(s):  
Neutrophil Elastase ◽  
Neutrophil Migration ◽  
The Elderly ◽  
Elastase Activity ◽  
Pi3k Activity ◽  
Targeted Treatments ◽  
Key Points ◽  
Phosphoinositide 3 Kinase ◽  
Primary Granule ◽  
Granule Release

Key Points Constitutive PI3K activity is associated with less accurate neutrophil migration in healthy aged adults. This is associated with increased primary granule release and neutrophil elastase activity and may contribute to inflammation and infection.

scholarly journals WS02.2 Role of soluble and membrane-associated neutrophil elastase activity in cystic fibrosis sputum

2017 ◽  
Vol 16 ◽  
pp. S3
Author(s):  
A.S. Dittrich ◽  
I. Kühbandner ◽  
S. Gehrig ◽  
V. Rickert-Zacharias ◽  
C.C. Taggart ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Neutrophil Elastase ◽  
Elastase Activity ◽  
Cystic Fibrosis Sputum

scholarly journals Impaired platelet responses to thrombin and collagen in AKT-1–deficient mice

Blood ◽  
2004 ◽  
Vol 104 (6) ◽  
pp. 1703-1710 ◽  
Author(s):  
Juhua Chen ◽  
Sarmishtha De ◽  
Derek S. Damron ◽  
William S. Chen ◽  
Nissim Hay ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Ex Vivo ◽  
Dense Granules ◽  
Fibrinogen Binding ◽  
Downstream Effectors ◽  
Low Concentrations ◽  
Phosphoinositide 3 Kinase ◽  
Deficient Mice ◽  
Granule Release

Abstract We investigated the role of Akt-1, one of the major downstream effectors of phosphoinositide 3-kinase (PI3K), in platelet function using mice in which the gene for Akt-1 had been inactivated. Using ex vivo techniques, we showed that Akt-1-deficient mice exhibited impaired platelet aggregation and spreading in response to various agonists. These differences were most apparent in platelets activated with low concentrations of thrombin. Although Akt-1 is not the predominant Akt isoform in mouse platelets, its absence diminished the amount of total phospho-Akt and inhibited increases in intracellular Ca2+ concentration in response to thrombin. Moreover, thrombin-induced platelet α-granule release as well as release of adenosine triphosphate from dense granules was also defective in Akt-1-null platelets. Although the absence of Akt-1 did not influence expression of the major platelet receptors for thrombin and collagen, fibrinogen binding in response to these agonists was significantly reduced. As a consequence of impaired αIIbβ3 activation and platelet aggregation, Akt-1 null mice showed significantly longer bleeding times than wild-type mice. (Blood. 2004;104:1703-1710)

Abstract 16292: Selective Platelet Protease-Activated-Receptor (PAR)1 and PAR4 Mediated Thrombin Desensitisation in the Elderly is Correlated With Inflammation and Chronic Thrombin Receptor Stimulation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sonali R Gnanenthiran ◽  
Gabrielle Pennings ◽  
Caroline Reddel ◽  
Heather Campbell ◽  
Justin Hamilton ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Platelet Activation ◽  
The Elderly ◽  
Elderly Subjects ◽  
Thrombin Receptor ◽  
Receptor Stimulation ◽  
Activation Markers ◽  
Tnf Α ◽  
D Dimer ◽  
Granule Release

Introduction: Platelet activation, by adenosine diphosphate (ADP) via P2Y 12 receptors and thrombin via PAR1 and PAR4, is a key therapeutic target in cardiovascular disease (CVD). The efficacy of antiplatelet agents diminishes in the elderly, but it is unknown whether these pathways change with aging. Hypothesis: Platelet activation pathways change with aging. Methods: Platelet activity was evaluated in young (20-30yrs), middle-aged (40-55yrs) and elderly (≥70yrs) healthy volunteers (n=174). Whole blood aggregometry and flow cytometry (P-selectin: α-granule release; CD63: dense granule release; PAC1 binding: activated GPIIb/IIIa) were performed under basal conditions and post ex vivo stimulation with ADP, thrombin, PAR1 agonist or PAR4 agonist. EC 50 and E max values were derived for each agonist. Receptor cleavage and quantification (P2Y 12 ; PAR1; PAR4; GPIbα) were assessed with flow cytometry. Thrombin generation (D-Dimer) and inflammation (interleukin [IL]-1β; tumour necrosis factor [TNF]-α) were assessed via ELISA. Results: The elderly had higher basal platelet activation markers (P-selectin, CD63, activated GPIIb/IIIa) than the young, with higher basal activity correlating with increasing IL-1β. P2Y 12 receptor density was higher in the elderly and associated with greater ADP-induced platelet aggregation and activation. Elderly subjects had less platelet activation in response to thrombin (higher EC 50 ), demonstrating hyporeactivity to selective stimulation of PAR1 or PAR4, more basal PAR1/PAR4 cleavage, and less inducible PAR1/PAR4 cleavage. This was associated with reduced thrombin binding receptor GPIbα and reduced secondary ADP contribution to thrombin-mediated activation. D-Dimer and TNF-α levels were elevated in the elderly, and inversely correlated with platelet thrombin sensitivity, implying a role of desensitization from chronic thrombin receptor stimulation. Conclusion: Aging is associated with increased basal platelet activation and hyperreactivity to ADP, but selective desensitization to thrombin. The latter appears mediated by chronic thrombin receptor stimulation and inflammation. Age-specific antiplatelet strategies may require selective targeting of these pathways to treat CVD in the elderly.

scholarly journals A point-of-care neutrophil elastase activity assay identifies bronchiectasis severity, airway infection and risk of exacerbation

2019 ◽  
Vol 53 (6) ◽  
pp. 1900303 ◽  
Author(s):  
Amelia Shoemark ◽  
Erin Cant ◽  
Luis Carreto ◽  
Alexandria Smith ◽  
Martina Oriano ◽  
...  
Keyword(s):  
Neutrophil Elastase ◽  
Point Of Care ◽  
Severity Index ◽  
Forced Expiratory Volume ◽  
Lateral Flow ◽  
Elastase Activity ◽  
Lateral Flow Device ◽  
Airway Infection ◽  
Independent Validation ◽  
Flow Device

IntroductionNeutrophil elastase activity in sputum can identify patients at high risk of airway infection and exacerbations in bronchiectasis. Application of this biomarker in clinical practice is limited, because no point-of-care test is available. We tested whether a novel semi-quantitative lateral flow device (neutrophil elastase airway test stick – NEATstik®) can stratify bronchiectasis patients according to severity, airway infection and exacerbation risk.MethodsSputum samples from 124 patients with stable bronchiectasis enrolled in the UK and Spain were tested using the NEATstik®, which scores neutrophil elastase concentration from 0 (<8 µg·mL−1 elastase activity) to 10 (maximum detectable neutrophil elastase activity). High neutrophil elastase activity was regarded as a NEATstik® grade >6. Severity of disease, airway infection from sputum culture and exacerbations over the 12 months were recorded. An independent validation was conducted in 50 patients from Milan, Italy.Measurements and main resultsPatients had a median age of 69 years and forced expiratory volume in 1 s (FEV1) 69%. High neutrophil elastase activity was associated with worse bronchiectasis severity using the bronchiectasis severity index (p=0.0007) and FEV1 (p=0.02). A high NEATstik® grade was associated with a significant increase in exacerbation frequency, incident rate ratio 2.75 (95% CI 1.63–4.64, p<0.001). The median time to next exacerbation for patients with a NEATstik® grade >6 was 103 days compared to 278 days. The hazard ratio was 2.59 (95% CI 1.71–3.94, p<0.001). Results were confirmed in the independent validation cohort.ConclusionsA novel lateral flow device provides assessment of neutrophil elastase activity from sputum in minutes and identifies patients at increasing risk of airway infection and future exacerbations.

Monocyte inflammation augments acrolein-induced Muc5ac expression in mouse lung

1999 ◽  
Vol 277 (3) ◽  
pp. L489-L497 ◽  
Author(s):  
Michael T. Borchers ◽  
Scott Wesselkamper ◽  
Susan E. Wert ◽  
Steven D. Shapiro ◽  
George D. Leikauf
Keyword(s):  
Gene Expression ◽  
Neutrophil Elastase ◽  
Airway Hyperreactivity ◽  
Mouse Lung ◽  
Mrna Levels ◽  
Elastase Activity ◽  
Mucus Hypersecretion ◽  
Mucin Gene ◽  
Cell Counts ◽  
Macrophage Accumulation

Acrolein, an unsaturated aldehyde found in smog and tobacco smoke, can induce airway hyperreactivity, inflammation, and mucus hypersecretion. To determine whether changes in steady-state mucin gene expression ( Muc2 and Muc5ac) are associated with inflammatory cell accumulation and neutrophil elastase activity, FVB/N mice were exposed to acrolein (3.0 parts/million; 6 h/day, 5 days/wk for 3 wk). The levels of Muc2 and Muc5ac mRNA were determined by RT-PCR, and the presence of Muc5ac protein was detected by immunohistochemistry. Total and differential cell counts were determined from bronchoalveolar lavage (BAL) fluid, and neutrophil elastase activity was measured in the BAL fluid supernatant. Lung Muc5ac mRNA was increased on days 12and 19, and Muc5ac protein was detected in mucous granules and on the surface of the epithelium on day 19. Lung Muc2 mRNA was not detected at measurable levels in either control or exposed mice. Acrolein exposure caused a significant and persistent increase in macrophages and a rapid but transient increase in neutrophils in BAL fluid. Recoverable neutrophil elastase activity was not significantly altered at any time after acrolein exposure. To further examine the role of macrophage accumulation in mucin gene expression, additional strains of mice (including a strain genetically deficient in macrophage metalloelastase) were exposed to acrolein for 3 wk, and Muc5ac mRNA levels and macrophage accumulation were measured. The magnitude of macrophage accumulation coincided with increased Muc5ac mRNA levels, indicating that excessive macrophage accumulation augments acrolein-induced Muc5ac synthesis and secretion after repeated exposure. These findings support a role for chronic monocytic inflammation in the pathogenesis of mucus hypersecretion observed in chronic bronchitis.

scholarly journals Inhibition of Neutrophil Primary Granule Release during Yersinia pestis Pulmonary Infection

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Kara R. Eichelberger ◽  
Grant S. Jones ◽  
William E. Goldman
Keyword(s):  
Yersinia Pestis ◽  
Critical Role ◽  
Immune Defense ◽  
Calcium Flux ◽  
Human Neutrophils ◽  
Pneumonic Plague ◽  
Content Type ◽  
Neutrophil Degranulation ◽  
Primary Granule ◽  
Granule Release

ABSTRACT Inhalation of Yersinia pestis causes primary pneumonic plague, the most severe manifestation of plague that is characterized by a dramatic neutrophil influx to the lungs. Neutrophils are ineffective during primary pneumonic plague, failing to control Y. pestis growth in the airways. However, the mechanisms by which Y. pestis resists neutrophil killing are incompletely understood. Here, we show that Y. pestis inhibits neutrophil degranulation, an important line of host innate immune defense. We observed that neutrophils from the lungs of mice infected intranasally with Y. pestis fail to release primary granules throughout the course of disease. Using a type III secretion system (T3SS) injection reporter strain, we determined that Y. pestis directly inhibits neutrophil granule release by a T3SS-dependent mechanism. Combinatorial mutant analysis revealed that a Y. pestis strain lacking both effectors YopE and YopH did not inhibit primary granule release and is killed by neutrophils both in vivo and in vitro. Similarly, Y. pestis strains injecting only YopE or YopH are able to inhibit the majority of primary granule release from human neutrophils. We determined that YopE and YopH block Rac2 activation and calcium flux, respectively, to inhibit neutrophil primary granule release in isolated human neutrophils. These results demonstrate that Y. pestis coordinates the inhibition of neutrophil primary granule release through the activities of two distinct effectors, and this inhibition promotes Y. pestis survival during primary pneumonic plague. IMPORTANCE Yersinia pestis is the causative agent of plague and is one of the deadliest human pathogens. The pneumonic form of Y. pestis infection has played a critical role in the severity of both historical and modern plague outbreaks, yet the host-pathogen interactions that govern the lethality of Yersinia pestis pulmonary infections are incompletely understood. Here, we report that Yersinia pestis inhibits neutrophil degranulation during infection, rendering neutrophils ineffective and allowing unrestricted growth of Y. pestis in the lungs. This coordinated inhibition of granule release not only demonstrates the pathogenic benefit of “silencing” lung neutrophils but also reveals specific host processes and pathways that could be manipulated to reduce the severity of primary pneumonic plague.

scholarly journals Propolis Suppresses UV-Induced Photoaging in Human Skin through Directly Targeting Phosphoinositide 3-Kinase

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3790
Author(s):  
Da Hyun Kim ◽  
Joong-Hyuck Auh ◽  
Jeongyeon Oh ◽  
Seungpyo Hong ◽  
Sungbin Choi ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Human Skin ◽  
Therapeutic Potential ◽  
Skin Aging ◽  
Dermal Fibroblasts ◽  
Kinase Assay ◽  
Aging Effects ◽  
Propolis Extract ◽  
Pi3k Activity ◽  
Phosphoinositide 3 Kinase

Propolis is a resinous substance generated by bees using materials from various plant sources. It has been known to exhibit diverse bioactivities including anti-oxidative, anti-microbial, anti-inflammatory, and anti-cancer effects. However, the direct molecular target of propolis and its therapeutic potential against skin aging in humans is not fully understood. Herein, we investigated the effect of propolis on ultraviolet (UV)-mediated skin aging and its underlying molecular mechanism. Propolis suppressed UV-induced matrix metalloproteinase (MMP)-1 production in human dermal fibroblasts. More importantly, propolis treatment reduced UV-induced MMP-1 expression and blocked collagen degradation in human skin tissues, suggesting that the anti-skin-aging activity of propolis can be recapitulated in clinically relevant conditions. While propolis treatment did not display any noticeable effects against extracellular signal-regulated kinase (ERK), p38, and c-jun N-terminal kinase (JNK) pathways, propolis exerted significant inhibitory activity specifically against phosphorylations of phosphoinositide-dependent protein kinase-1 (PDK1) and protein kinase B (Akt). Kinase assay results demonstrated that propolis can directly suppress phosphoinositide 3-kinase (PI3K) activity, with preferential selectivity towards PI3K with p110α and p110δ catalytic subunits over other kinases. The content of active compounds was quantified, and among the compounds identified from the propolis extract, caffeic acid phenethyl ester, quercetin, and apigenin were shown to attenuate PI3K activity. These results demonstrate that propolis shows anti-skin-aging effects through direct inhibition of PI3K activity.

scholarly journals Phosphoinositide 3-Kinase Activity Controls the Chemoattractant-mediated Activation and Adaptation of Adenylyl Cyclase

2006 ◽  
Vol 17 (1) ◽  
pp. 357-366 ◽  
Author(s):  
Frank I. Comer ◽  
Carole A. Parent
Keyword(s):  
Adenylyl Cyclase ◽  
Signaling Cascades ◽  
Pi3k Activity ◽  
Temporal Cues ◽  
Signal Relay ◽  
Phosphoinositide 3 Kinase ◽  
G Protein Coupled ◽  
Kinetics Of ◽  
Initial Peak ◽  
Proper Balance

The binding of chemoattractants to cognate G protein-coupled receptors activates a variety of signaling cascades that provide spatial and temporal cues required for chemotaxis. When subjected to uniform stimulation, these responses are transient, showing an initial peak of activation followed by a period of adaptation, in which activity subsides even in the presence of stimulus. A tightly regulated balance between receptor-mediated stimulatory and inhibitory pathways controls the kinetics of activation and subsequent adaptation. In Dictyostelium, the adenylyl cyclase expressed during aggregation (ACA), which synthesizes the chemoattractant cAMP, is essential to relay the signal to neighboring cells. Here, we report that cells lacking phosphoinositide 3-kinase (PI3K) activity are deficient in signal relay. In LY294002-treated cells, this defect is because of a loss of ACA activation. In contrast, in cells lacking PI3K1 and PI3K2, the signal relay defect is because of a loss of ACA adaptation. We propose that the residual low level of 3-phosphoinositides in pi3k1-/2- cells is sufficient to generate the initial peak of ACA activity, yet is insufficient to sustain the inhibitory phase required for its adaptation. Thus, PI3K activity is poised to regulate both ACA activation and adaptation, thereby providing a link to ensure the proper balance of counteracting signals required to maintain optimal chemoresponsiveness.

Phosphoinositide-3-Kinase Inhibition Enhances Radiosensitization of Cervical Cancer In Vivo

2011 ◽  
Vol 21 (1) ◽  
pp. 100-105 ◽  
Author(s):  
Yi Liu ◽  
Baoxia Cui ◽  
Yunbo Qiao ◽  
Yan Zhang ◽  
Yongju Tian ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cancer Cells ◽  
Kinase Inhibition ◽  
Clonogenic Assays ◽  
Akt Phosphorylation ◽  
Pi3k Activity ◽  
Pi3k Inhibition ◽  
Tumor Regrowth ◽  
Phosphoinositide 3 Kinase

Background:Phosphoinositide-3-kinase (PI3K)/Akt pathway is downregulated in several human cancers, and PI3K inhibition can sensitize these cancer cells to radiation. However, no research on cervical cancer in vivo has been reported. The present study further investigated whether PI3K inhibition could sensitize cervical cancer to radiation in vivo.Methods:HeLa cells with sustained PI3K activity and Akt phosphorylation were injected subcutaneously into BALB/C nude mice to establish tumor cell xenograft, which were randomly assigned to control, PI3K inhibitor LY294002 alone, radiation alone, or combined LY294002 and radiation group. Akt phosphorylation was detected by Western blotting to evaluate the blocking efficiency on PI3K activity. The radiosensitization of PI3K inhibition was measured by clonogenic assays, apoptosis analysis, and tumor regrowth assays.Results:The combination of LY294002 and radiation resulted in significant and synergistic suppression of cervical cancer cells in a dose-dependent manner in clonogenic assays (P< 0.05), higher ratio of apoptosis cells, and more remarkable reduction of Akt phosphorylation. Tumor regrowth delay curve showed the lowest increase of tumor volume in the combined group (37 days in average) (P= 0.003). Besides, LY294002 (100 mg/kg) alone decreased cell survival and produced xenograft regrowth delay.Conclusions:Phosphoinositide-3-kinase inhibition by LY294002 can synergistically enhance radiation efficacy via dephosphorylation of Akt in cervical cancer, and PI3K inhibition alone can also suppress tumor regrowth. This may provide novel therapeutic opportunities to enhance the effect of radiotherapy against cervical cancer.

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