The potential role of endothelial dysfunction and platelet activation in the development of thrombotic risk in COPD patients

Effects of Panax notoginseng saponins on alleviating low shear induced endothelial inflammation and thrombosis via Piezo1 signalling

ETHNOPHARMACOLOGICAL RELEVANCE

Panax notoginseng saponins (PNS) are the major effective components of Panax notoginseng (burk) F.H.Chen which is one of the classic promoting blood circulation herbs in traditional Chinese medicine. PNS is widely used in China for the treatment of cerebral ischemic stroke. Pathological low shear stress is a causal factor in endothelial inflammation and thrombosis. However, the mechanism of PNS against low shear related endothelial inflammation is still unclear.

AIM TO THE STUDY

This study aims to investigate the effects of PNS against endothelial inflammation induced by low shear stress and to explore the underlying mechanical and biological mechanisms.

MATERIALS AND METHODS

Mouse model of carotid partial ligation for inducing low endothelial shear stress was established, the pharmacodynamic effect and mechanism of PNS against endothelial inflammation induced by low shear stress through Piezo1 were explored. Yoda1-evoked Piezo1 activation and expression in human umbilical vein endothelial cells (HUVECs) were determined at static condition. Microfluidic channel systems were used to apply shear stress on HUVECs and Piezo1 siRNA HUVECs to determine PECAM-1, p-YAP and VCAM-1 expression. And platelet rich plasma (PRP) was introduced to low shear treated endothelial cells surface to observe the adhesion and activation by fluorescence imaging and flowcytometry.

RESULTS

PNS attenuated endothelial inflammation and improved blood flow in a reasonable dose response pattern in carotid partial ligation mouse model by influencing Piezo1 and PECAM-1 expression, while suppressing yes-associated protein (YAP) nuclear translocation. We found Piezo1 sensed abnormal shear stress and transduced these mechanical signals by different pathways in HUVECs, and PNS relieved endothelial inflammation induced by low shear stress through Piezo1. We also found Piezo1 signalling has interaction with PECAM-1 under low shear stress, which were involved in platelets adhesion to endothelial cells. Low shear stress increased YAP nuclear translocation and increased VCAM-1 expression in HUVECs which might activate platelets. PNS inhibited low shear induced Piezo1 and PECAM-1 expression and YAP nuclear translocation in HUVECs, furthermore inhibited platelet adhesion and activation on dysfunctional endothelial cells induced by low shear stress.

CONCLUSION

PNS ameliorated endothelial inflammation and thrombosis induced by low shear stress through modulation of the Piezo1 channel, PECAM-1 expression, and YAP nuclear translocation. PNS might serve as a potential therapeutic candidate for ameliorating endothelial inflammation induced by abnormal blood shear stress.

Key role of activated platelets in the enhanced adhesion of circulating leucocyte-platelet aggregates to the dysfunctional endothelium in early-stage COPD

Background

Chronic obstructive pulmonary disease (COPD), usually caused by long-term tobacco smoking, is independently associated with systemic inflammation. However, little is known about the systemic inflammatory status of patients with early-stage COPD (classified as GOLD 1) and long-term smokers with normal lung function (LF). Here, we characterised the early changes in the associated inflammatory state in patients with GOLD 1 and in long-term smokers with normal LF.

Methods

Fresh blood samples from 27 patients with GOLD 1, 27 long-term smokers and 14 non-smokers were analysed.

Results

Ex vivo blood analysis revealed greater leucocyte-platelet adhesion to TNFα-stimulated pulmonary endothelium in patients with GOLD 1 than in smokers and non-smokers. In addition, platelet reactivity (platelet count and activation, and fibrinogen levels) and the frequency of leucocyte-platelet aggregates were higher in the GOLD 1 group than in the other groups. Some of these findings correlated with the severity of lung dysfunction, while platelet hyperactivity correlated positively with leucocyte-platelet adhesion. The GOLD 1 group also had a higher Th17/Treg ratio and higher circulating levels of IL-17C and C-reactive protein than the other groups. However, long-term smokers also had higher leucocyte counts and activation, and higher plasma levels of TNFα and IL-6 than non-smokers.

Conclusion

Our data suggest that the altered inflammatory parameters in long-term smokers may represent early biomarkers of COPD. Accordingly, peripheral immune monitoring based on the above parameters may be useful to prevent disease progression in long-term smokers with normal LF and early COPD.

Interrelationship between COVID-19 and Coagulopathy: Pathophysiological and Clinical Evidence

Since the first description of COVID-19 infection, among clinical manifestations of the disease, including fever, dyspnea, cough, and fatigue, it was observed a high incidence of thromboembolic events potentially evolving towards acute respiratory distress syndrome (ARDS) and COVID-19-associated-coagulopathy (CAC). The hypercoagulation state is based on an interaction between thrombosis and inflammation. The so-called CAC represents a key aspect in the genesis of organ damage from SARS-CoV-2. The prothrombotic status of COVID-19 can be explained by the increase in coagulation levels of D-dimer, lymphocytes, fibrinogen, interleukin 6 (IL-6), and prothrombin time. Several mechanisms have been hypothesized to explain this hypercoagulable process such as inflammatory cytokine storm, platelet activation, endothelial dysfunction, and stasis for a long time. The purpose of this narrative review is to provide an overview of the current knowledge on the pathogenic mechanisms of coagulopathy that may characterize COVID-19 infection and inform on new areas of research. New vascular therapeutic strategies are also reviewed.

Endogenous humoral determinants of vascular endothelial dysfunction as triggers of acute poisoning complications

The vascular endothelium is not only the semipermeable membrane that separates tissue from blood but also an organ that regulates inflammation, vascular tone, blood clotting, angiogenesis and synthesis of connective tissue proteins. It is susceptible to the direct cytotoxic action of numerous xenobiotics and to the acute hypoxia that accompanies acute poisoning. This damage is superimposed on the preformed state of the vascular endothelium, which, in turn, depends on many humoral factors. The probability that an exogenous toxicant will cause life-threatening dysfunction of the vascular endothelium, thereby complicating the course of acute poisoning, increases with an increase in the content of endogenous substances in the blood that disrupt endothelial function. These include ammonia, bacterial endotoxin, indoxyl sulfate, para-cresyl sulfate, trimethylamine N-oxide, asymmetric dimethylarginine, glucose, homocysteine, low-density and very-low-density lipoproteins, free fatty acids and products of intravascular haemolysis. Some other endogenous substances (albumin, haptoglobin, haemopexin, biliverdin, bilirubin, tetrahydrobiopterin) or food-derived compounds (ascorbic acid, rutin, omega-3 polyunsaturated fatty acids, etc.) reduce the risk of lethal vascular endothelial dysfunction. The individual variability of the content of these substances in the blood contributes to the stochasticity of the complications of acute poisoning and is a promising target for the risk reduction measures. Another feasible option may be the repositioning of drugs that affect the function of the vascular endothelium while being currently used for other indications.

Sleep Deprivation, Immune Suppression and SARS-CoV-2 Infection

Sleep health and its adaptation to individual and environmental factors are crucial to promote physical and mental well-being across animal species. In recent years, increasing evidence has been reported regarding the relationship between sleep and the immune system and how sleep disturbances may perturb the delicate balance with severe repercussions on health outcomes. For instance, experimental sleep deprivation studies in vivo have reported several major detrimental effects on immune health, including induced failure of host defense in rats and increased risk for metabolic syndrome (MetS) and immune suppression in humans. In addition, two novel risk factors for dysregulated metabolic physiology have recently been identified: sleep disruption and circadian misalignment. In light of these recent findings about the interplay between sleep and the immune system, in this review, we focus on the relationship between sleep deprivation and immunity against viruses, with a special interest in SARS-CoV-2 infection.

Association of baseline parameters with year 0 and year 1 acute exacerbations in male patients with chronic obstructive pulmonary disease

Objectives

Acute exacerbations (AEs) of chronic obstructive pulmonary disease (COPD) can affect health status, hospitalization and readmission rates, and disease progression. This study aimed to identify independent markers associated with COPD AEs.

Methods

This study included male patients with COPD and collected data regarding their AEs and baseline clinical parameters.

Results

We included 149 male patients. Among them, 58 were included in the year 0 high-AE group and 91 in the low-AE group. Multivariate analysis revealed that the high-AE group had higher white blood cell count, lower serum albumin level, and post-bronchodilator (BD) forced expiratory volume in one second (FEV₁) (%) with a combined receiver operating characteristic curve (ROC) of 0.721 (p < 0.001). Additionally, 34 patients were included in the year 1 high-AE group and 70 in the low-AE group (p < 0.001). Multivariate analysis revealed that the high-AE group had higher platelet count, positive asthma history, and lower pre-BD FEV₁ (%) with a combined ROC of 0.782 (p < 0.001).

Conclusion

In male patients with COPD, baseline white blood cell count, albumin level, and post-BD FEV₁ (%) were correlated with year 0 AE; on the other hand, baseline platelet count, positive asthma history, and pre-BD FEV₁ (%) were associated with year 1 AE.

Hypercoagulation in COPD: the clot thickens

There is a growing body of evidence that hypercoagulability is present in stable COPD, involves changes in multiple coagulation factors, and is not simply associated with major causes of inflammation and thrombosis https://bit.ly/3F5NnfN.

Effect of urban air pollution on CRP and coagulation: a study on inpatients with acute exacerbation of chronic obstructive pulmonary disease

PURPOSE

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an important event in the course of chronic obstructive pulmonary disease that negatively affects patients' quality of life and leads to higher socioeconomic costs. While previous studies have demonstrated a significant association between urban air pollution and hospitalization for AECOPD, there is a lack of research on the impact of particulate matter (PM) on inflammation and coagulation in AECOPD inpatients. Therefore, this study investigated the association of changes in coagulation function and C-reactive protein (CRP) with PM levels in the days preceding hospitalization.

PATIENTS AND METHODS

We reviewed the medical records of AECOPD patients admitted to Putuo Hospital, Shanghai University of Traditional Chinese Medicine, between March 2017 and September 2019. We analyzed the association of coagulation function and CRP level in AECOPD patients with PM levels in the days before hospitalization. Multivariate unconditional logistic regression analyses were used to evaluate the adjusted odds ratio (OR) and 95% confidence interval (CI) for the association of CRP data with hospitalization day. Kruskal-Wallis tests were used to evaluate mean aerodynamic diameter of ≥ 2.5 μm (PM2.5) exposure on the day before hospitalization; we assessed its association with changes in prothrombin time (PT) in AECOPD inpatients with different Global Initiative for Chronic Obstructive Lung Disease (GOLD) classes.

RESULTS

The peripheral blood PT of AECOPD patients with PM2.5 ≥ 25 mg/L on the day before hospitalization were lower than those of patients with PM2.5 < 25 mg/L (t = 2.052, p = 0.041). Patients with severe GOLD class exposed to greater than 25 mg/L of PM2.5on the day before hospitalization showed significant differences in PT (F = 9.683, p = 0.008). Peripheral blood CRP levels of AECOPD patients exposed to PM2.5 ≥ 25 mg/L and PM10 ≥ 50 mg/L on the day before hospitalization were higher than those of patients exposed to PM2.5 < 25 mg/L and PM10 < 50 mg/L (t = 2.008, p = 0.046; t = 2.637, p = 0.009). Exposure to < 25 mg/L of PM2.5 on the day before hospitalization was significantly associated with CRP levels (adjusted OR 1.91; 95% CI 1.101, 3.315; p = 0.024).

CONCLUSION

Exposure of patients with AECOPD to high PM levels on the day before hospitalization was associated with an increased CRP level and shortened PT. Moreover, PM2.5 had a greater effect on CRP level and PT than mean aerodynamic diameter of ≥ 10 μm (PM10). AECOPD patients with severe GOLD class were more sensitive to PM2.5-induced shortening of PT than those with other GOLD classes.

Cardiovascular Disease in Patients with Chronic Obstructive Pulmonary Disease, Obstructive Sleep Apnoea Syndrome and Overlap Syndrome

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea syndrome (OSAS) are among the most prevalent chronic respiratory disorders. Accumulating data suggest that there is a significant burden of cardiovascular disease (CVD) in patients with COPD and OSAS, affecting negatively patients' quality of life and survival. Overlap syndrome (OS), i.e. the co-existence of both COPD and OSAS in the same patient, has an additional impact on the cardiovascular system multiplying the risk of morbidity and mortality. The underlying mechanisms for the development of CVD in patients with either OSAS or COPD and OS are not entirely elucidated. Several mechanisms, in addition to smoking and obesity, may be implicated, including systemic inflammation, increased sympathetic activity, oxidative stress and endothelial dysfunction. Early diagnosis and proper management of these patients might reduce cardiovascular risk and improve patients' survival. In this review, we summarize the current knowledge regarding epidemiological aspects, pathophysiological mechanisms and present point-to-point specific associations between COPD, OSAS, OS and components of CVD, namely, pulmonary hypertension, coronary artery disease, peripheral arterial disease and stroke.

Platelet Count and Platelet Indices in Patients with Stable and Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Platelets play an important role in the pathophysiology of chronic obstructive pulmonary disease (COPD) by mediating thrombotic, inflammatory, and immune processes in the lung. We conducted a systematic review and meta-analysis of studies investigating the platelet count and three platelet indices, mean platelet volume (MPV), platelet distribution width (PDW), and platelet to lymphocyte ratio (PLR) in stable COPD vs. non-COPD patients and in stable COPD vs. acute exacerbation of COPD (AECOPD) patients (PROSPERO registration number: CRD42021228263). PubMed, Web of Science, Scopus and Google Scholar were searched from inception to December 2020. Twenty-seven studies were included in the meta-analysis, 26 comparing 4,455 stable COPD patients with 7,128 non-COPD controls and 14 comparing 1,251 stable COPD with 904 AECOPD patients. Stable COPD patients had significantly higher platelet counts (weighted mean difference, WMD = 13.39 x10⁹/L, 95% CI 4.68 to 22.11 x10⁹/L; p < 0.001) and PLR (WMD = 59.52, 95% CI 29.59 to 89.44; p < 0.001) than non-COPD subjects. AECOPD patients had significantly higher PLR values than stable COPD patients (WMD = 46.03, 95% CI 7.70 to 84.35; p = 0.02). No significant differences were observed in MPV and PDW. Between-study heterogeneity was extreme. In sensitivity analysis, the effect size was not modified when each study was sequentially removed. The was no evidence of publication bias. In our meta-analysis, specific platelet biomarkers were associated with stable COPD (platelet count and PLR) and AECOPD (PLR). However, the observed heterogeneity limits the generalizability of the findings. Further studies are required to determine their prognostic utility and the effects of targeted interventions in COPD.

Coagulation dysfunction in patients with AECOPD and its relation to infection and hypercapnia

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) often have coagulation abnormalities. However, the factors that lead to coagulation dysfunction in acute exacerbation of COPD (AECOPD) remain insufficiently explored. This study aimed to investigate the factors affecting coagulation status in patients with COPD and their influence on thrombosis.

METHODS

Data of COPD patients, including 135 cases in acute exacerbation stage and 44 cases in stable stage from Nov 2016 to Nov 2019 in our hospital, were collected. Healthy people (n = 135) were enrolled as the controls. The coagulation parameters, blood gas indexes and blood routine examination results were collected and analyzed.

RESULTS

White blood count (WBC), neutrophil count, neutrophil percentage (N%), platelet (PLT), prothrombin time (PT), international normalized ratio (INR), fibrinogen (FIB), and activated partial thromboplastin time (APTT) increased, plasma thrombin time (TT) decreased in AECOPD group compared with the control group. In AECOPD group, PT, APTT, and FIB were positively correlated with neutrophils and C-reaction protein levels. PT was positively correlated with PCO2 and negatively with pH. Thrombosis was observed in five acute exacerbation and three stable stage COPD patients.

CONCLUSIONS

Patients with AECOPD presented abnormal coagulation status, which was correlated to infection and hypercapnia and might be potentially the risk factor of thrombosis.

Aspects extrapulmonaires des exacerbations de bronchopneumopathie chronique obstructive

La bronchopneumopathie chronique obstructive (BPCO) est une maladie systémique aux multiples atteintes, émaillée d’exacerbations. L’inflammation, l’hypoxémie, les troubles de la coagulation et les perturbations des interactions coeur–poumon expliquent en partie les atteintes non pulmonaires observées notamment lors d’exacerbations aiguës. Les événements cardiovasculaires sont la première cause de mortalité des patients BPCO, et leur recrudescence est observée pendant plusieurs semaines après une exacerbation. Aux urgences, la prise en charge des patients en exacerbation de BPCO repose donc en plus du support ventilatoire sur une bonne évaluation des potentielles pathologies associées telles que l’insuffisance cardiaque, l’ischémie myocardique, l’insuffisance rénale ou encore la maladie thromboembolique. Cette évaluation globale permet d’adapter les thérapeutiques parfois délétères sur la fonction cardiaque ou l’équilibre acide−base et de prendre en compte le risque extrapulmonaire dans le choix du parcours de soins du patient. Dans cette mise au point, nous abordons quelques explications physiologiques des multiples perturbations observées au cours de l’exacerbation de BPCO, et proposons une vision globale de l’évaluation de ces patients admis pour une dyspnée ou un autre motif pouvant être en rapport avec la BPCO.

Platelet Biogenesis in the Lung Circulation

Megakaryocytes are normal cellular components of the blood returning to the heart and entering the lungs, and historical data has pointed to a role of the lungs in platelet production. Recent studies using intravital microscopy have demonstrated that platelet release occurs in the lung from bone marrow megakaryocytes that embolize into the lung circulation.

Dose-response relationships between polycyclic aromatic hydrocarbons exposure and platelet indices

The relations of polycyclic aromatic hydrocarbons (PAHs) exposure with platelet indices remain unclear. Based on the baseline data from the Wuhan-Zhuhai Cohort Study, we used generalized linear model, multivariate logistic regression analysis and restricted cubic splines (RCS) to assess linear and nonlinear relationship of PAHs exposure with platelet indices. The results showed that among Wuhan individuals, there were the non-linear relations between total hydroxynaphthalene (ΣOHNa) and mean platelet volume (MPV) or ratio of mean platelet volume to platelet count (MPVP), total hydrophenanthrene (ΣOHPh) and MPV or platelet distribution width (PDW), the sum concentration of urinary monohydroxylated metabolites of PAHs (ΣOH-PAHs) and ratio of platelet count to lymphocyte count (PLR) or MPVP, 1-hydropyrene (1-OHP) and PLR or PDW. But among Zhuhai individuals, neither linear nor non-linear relations were found between each of OH-PAHs or ΣOH-PAHs and platelet indices. The findings indicate that serum MPV and MPVP may be independent biomarkers of effects of exposing to environmental PAHs on human bodies.

Shared Features of Endothelial Dysfunction between Sepsis and Its Preceding Risk Factors (Aging and Chronic Disease)

Acute vascular endothelial dysfunction is a central event in the pathogenesis of sepsis, increasing vascular permeability, promoting activation of the coagulation cascade, tissue edema and compromising perfusion of vital organs. Aging and chronic diseases (hypertension, dyslipidaemia, diabetes mellitus, chronic kidney disease, cardiovascular disease, cerebrovascular disease, chronic pulmonary disease, liver disease, or cancer) are recognized risk factors for sepsis. In this article we review the features of endothelial dysfunction shared by sepsis, aging and the chronic conditions preceding this disease. Clinical studies and review articles on endothelial dysfunction in sepsis, aging and chronic diseases available in PubMed were considered. The main features of endothelial dysfunction shared by sepsis, aging and chronic diseases were: (1) increased oxidative stress and systemic inflammation, (2) glycocalyx degradation and shedding, (3) disassembly of intercellular junctions, endothelial cell death, blood-tissue barrier disruption, (4) enhanced leukocyte adhesion and extravasation, (5) induction of a pro-coagulant and anti-fibrinolytic state. In addition, chronic diseases impair the mechanisms of endothelial reparation. In conclusion, sepsis, aging and chronic diseases induce similar features of endothelial dysfunction. The potential contribution of pre-existent endothelial dysfunction to sepsis pathogenesis deserves to be further investigated.

Mean Platelet Volume and Platelet Distribution Width in Patients With Obstructive Sleep Apnea Syndrome and Concurrent Chronic Obstructive Pulmonary Disease

Evidence suggests that there is platelet activation in obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD). Our objective is to evaluate mean platelet volume (MPV) and platelet distribution width (PDW) in patients with overlap syndrome (OS), that is, concurrent COPD with OSAS. Mean platelet volume and PDW were assessed in consecutive patients who had undergone polysomnography and pulmonary function testing. They were divided into the following groups: controls (apnea-hypopnea index [AHI] <5/hour, and forced expiratory volume in 1st second [FEV₁]/forced vital capacity [FVC] >70%), OSAS group (AHI ≥5/hour and FEV₁/FVC >70%), and OS group (AHI ≥5/hour and FEV₁/FVC <70%). A total of 485 patients (360 males and 125 females) were included. Mean platelet volume in controls was lower compared with the other groups: 10 ± 0.9 fL for controls versus 10.3 ± 1.2 fL for OSAS ( P = .006), versus 10.7 ± 1 fL for OS ( P < .001). Additionally, MPV was higher in OS group than OSAS: 10.7 ± 1 fL versus 10.3 ± 1.2 fL, respectively ( P = .002). Platelet distribution width was lower in controls compared with the other groups: 12.9 ± 2 fL for controls versus 13.6 ± 1.9 fL for OSAS ( P = .007), versus 13.8 ± 2.3 fL for OS ( P = .008), while there was no difference between OS and OSAS groups. Mean platelet volume and PDW are increased in patients with OS compared with healthy controls, with respiratory function being the major contributor in platelet activation in this series.

Stanniocalcin 2 Regulates Non-capacitative Ca2+ Entry and Aggregation in Mouse Platelets

Stanniocalcin 2 (STC2) is a fish protein that controls body Ca²⁺ and phosphate metabolism. STC2 has also been described in mammals, and as platelet function highly depends on both extracellular and intracellular Ca²⁺, we have explored its expression and function in these cells. STC2^−/− mice exhibit shorter tail bleeding time than WT mice. Platelets from STC2-deficient mice showed enhanced aggregation, as well as enhanced Ca²⁺ mobilization in response to the physiological agonist thrombin (Thr) and the diacylglycerol analog, OAG, a selective activator of the non-capacitative Ca²⁺ entry channels. Interestingly, platelets from STC2^−/− mice exhibit attenuated interaction between STIM1 and Orai1 in response to Thr, thus suggesting that STC2 is required for Thr-evoked STIM1-Orai1 interaction and the subsequent store-operated Ca²⁺ entry (SOCE). We have further assessed possible changes in the expression of the most relevant channels involved in non-capacitative Ca²⁺ entry in platelets. Then, protein expression of Orai3, TRPC3 and TRPC6 were evaluated by Western blotting, and the results revealed that while the expression of Orai3 was enhanced in the STC2-deficient mice, others like TRPC3 and TRPC6 remains almost unaltered. Summarizing, our results provide for the first time evidence for a role of STC2 in platelet physiology through the regulation of agonist-induced Ca²⁺ entry, which might be mediated by the regulation of Orai3 channel expression.

Prioritizing chronic obstructive pulmonary disease (COPD) candidate genes in COPD-related networks

Chronic obstructive pulmonary disease (COPD) is a multi-factor disease, which could be caused by many factors, including disturbances of metabolism and protein-protein interactions (PPIs). In this paper, a weighted COPD-related metabolic network and a weighted COPD-related PPI network were constructed base on COPD disease genes and functional information. Candidate genes in these weighted COPD-related networks were prioritized by making use of a gene prioritization method, respectively. Literature review and functional enrichment analysis of the top 100 genes in these two networks suggested the correlation of COPD and these genes. The performance of our gene prioritization method was superior to that of ToppGene and ToppNet for genes from the COPD-related metabolic network or the COPD-related PPI network after assessing using leave-one-out cross-validation, literature validation and functional enrichment analysis. The top-ranked genes prioritized from COPD-related metabolic and PPI networks could promote the better understanding about the molecular mechanism of this disease from different perspectives. The top 100 genes in COPD-related metabolic network or COPD-related PPI network might be potential markers for the diagnosis and treatment of COPD.