Autophagy Ameliorates Reactive Oxygen Species-Induced Platelet Storage Lesions.

Platelet transfusion is a life-saving therapy to prevent bleeding; however, the availability of platelets for transfusion is limited by the markedly short shelf life owing to the development of platelet storage lesions (PSLs). The mechanism of PSLs remains obscure. Dissection of the intracellular biological changes in stored platelets may help to reduce PSLs and improve platelet transfusion efficiency. In the present study, we explore the changes of stored platelets at room temperature under constant agitation. We found that platelets during storage showed an increased reactive oxygen species (ROS) generation accompanied with receptor shedding, apoptosis, and diminished platelet aggregation. ROS scavenger reduced platelet shedding but also impaired platelet aggregation. Autophagy is a conserved catabolic process that sequesters protein aggregates and damaged organelles into lysosomes for degradation and platelets' own intact autophagic system. We revealed that there exist a stable autophagic flux in platelets at the early stage of storage, and the autophagic flux in platelets perished after long-term storage. Treatment stored platelets with rapamycin, which stimulates autophagy in eukaryotic cells, markedly ameliorated PSLs, and improved platelet aggregation in response to extracellular stimuli.

Role and Clinical Application of Metagenomic Next-Generation Sequencing in Immunocompromised Patients With Acute Respiratory Failure During Veno-Venous Extracorporeal Membrane Oxygenation.

Objectives: There are few studies of metagenomic next-generation sequencing (mNGS) in immunocompromised patients assisted by veno-venous extracorporeal membrane oxygenation (vv-ECMO). The present study is aimed to investigate the pathogen-detected effect and clinical therapy value of mNGS technologies in immunocompromised patients assisted by vv-ECMO. Methods: Our study retrospectively enrolled 46 immunocompromised patients supported by vv-ECMO from Jan 2017 to June 2021 at the First Affiliated Hospital of Zhengzhou University, respectively. Patients were divided into the deterioration group (Group D) (n = 31) and improvement group (Group I) (n = 15) according to their outcomes. Baseline characteristics and etiological data of patients during hospitalization of 2 groups were compared. The pathogens detected by mNGS and antibiotic regimens guided by mNGS in immunocompromised patients assisted by vv-ECMO were analyzed. Results: Compared with Group I, the deterioration patients showed a higher percentage of chronic obstructive pulmonary disease (COPD) (32.3% vs. 6.7%, p < 0.01) and were significantly older (47.77 ± 16.72 years vs. 32 ± 15.05 years, p < 0.01). Within 48 h of being ECMO assisted, the consistency of the samples detected by traditional culture and mNGS at the same time was good (traditional culture vs. mNGS detection, the positive rate of bronchoalveolar lavage fluid (BALF) culture: 26.1% vs. 30.4%; the positive rate of blood sample culture: 12.2% vs. 12.2%, p > 0.05). However, mNGS detected far more pathogen species and strains than conventional culture (30 strains vs. 78 strains, p < 0.01); the most popular pathogen was Klebsiella pneumoniae. Parts of patients had their antibiotic treatment adjustments, and the improvement patients showed less usage of broad-spectrum antibiotics. Conclusions: mNGS may play a relatively important role in detecting mixed pathogens and personalized antibiotic treatment in immunocompromised patients assisted by vv-ECMO.

Saccharides from Arctium lappa L. root reduce platelet activation and thrombus formation in a laser injury thrombosis mouse model.

Arctium lappa L., also known as burdock, is a popular medicinal plant in traditional Chinese medicine due to its potential therapeutic properties. Saccharides from Arctium lappa L. root (ALR-S) have been extensively studied for their anti-inflammatory and anti-diabetes effects. Platelets play a pivotal role in thrombosis. The present study describes the effects of ALR-S on platelet activation and thrombosis using a laser injury thrombosis in vivo model. The study also measured the effects of ALR-S on platelet activation by analysing aggregation, ATP release, platelet spreading, adhesion and clot retraction in vitro. Specifically, the effects were ALR-S concentration-dependent inhibition of platelet aggregation and ATP release. Activated platelets pretreated with ALR-S showed diminished CD62P expression levels and fibrinogen binding, as measured by flow cytometry. ALR-S inhibited platelet spreading on fibrinogen and adhesion on collagen under shear. ALR-S attenuated platelet activation by decreasing oxidative stress and thrombus formation. These results demonstrated the antiplatelet effects of ALR-S, suggesting the antithrombotic and cardiovascular protective activities of ALR-S as a functional food.