In comparison to mature platelets, reticulated platelets (RPs) are newly released from the bone marrow and exhibit a larger size, higher reactivity, and a greater quantity of RNA, and can be an agile indicator of platelet turnover. The transcriptome associated with platelet function is significantly upregulated in RPs, which is a possible explanation for RPs intrinsic hyper-reactivity. We presented a comprehensive overview of the detection techniques for RPs. Current methods to quantify RPs in clinical routine are flow cytometry and fully automated hematology analyzers (Sysmex-XE/XN, Abbott, ADVIA, Mindray), which make the detection of RPs simpler, faster and more affordable. The proportion of RPs increased in the circulation has potential diagnostic and prognostic values in multiple clinical settings (risk stratification in cardiovascular diseases, the effect on antiplatelet drugs, differential diagnosis of thrombocytopenia, monitor platelet recovery after bone marrow or stem cell transplantation, and other diseases). There have been several studies focusing on RPs in recent years, particularly in cardiovascular disease and thrombocytopenia. In this review we summarizes the current study with regard to RPs and discuss their likely contribution in clinical routine.

Intravital microscopy has enabled the study of immune dynamics in the pulmonary microvasculature, but many key events remain unseen because they occur in deeper lung regions. We therefore developed a technique for stabilized intravital imaging of bronchovascular cuffs and collecting lymphatics surrounding pulmonary veins in mice. Intravital imaging of pulmonary lymphatics revealed ventilation dependence of steady-state lung lymph flow and ventilation-independent lymph flow during inflammation. We imaged the rapid exodus of migratory dendritic cells through lung lymphatics following inflammation and measured effects of pharmacologic and genetic interventions targeting chemokine signaling. Intravital imaging also captured lymphatic immune surveillance of lung-metastatic cancers and lymphatic metastasis of cancer cells. To our knowledge, this is the first imaging of lymph flow and leukocyte migration through intact pulmonary lymphatics. This approach will enable studies of protective and maladaptive processes unfolding within the lungs and in other previously inaccessible locations.

Despite approximately 40% of all patients with cancer developing pulmonary metastases in the course of their disease, it remains a diagnostic challenge in clinical practice. Herein, we propose a fluorogenic probe (CPRG) with gamma-glutamyl transferase (GGT)-triggered signal turn-on for near-infrared fluorescence imaging (NIRF) and urinalysis of orthotopic pulmonary metastatic tumors in living mice. CPRG comprised four key moieties: a GGT-reactive moiety, a hemicyanine-based signal unit, a polyethylene glycol linker, and an active tumor targeting moiety. Such a tailored probe is intrinsically nonfluorescent and only activates its NIRF signals in the presence of GGT. After intratracheal administration into the lungs of living tumor-bearing mice, CPRG can efficiently accumulate in the pulmonary tumors and sensitively turn-on the NIRF signal for real-time imaging. Relying on the high renal clearance efficiency (∼70% ID), it can be rapidly excreted through kidneys for urinalysis and assessed by the chemotherapeutic efficacy of cisplatin. This study not only reports fluorogenic tracers for imaging of pulmonary metastatic tumors but also provides guidelines for the development of molecular probes for companion diagnosis of metastatic cancer.

Megakaryocytes are large, polyploid cells that produce platelets and originate from hematopoietic stem cells (HSCs) in the bone marrow. While in the classical paradigm, megakaryocytes are generated in a stepwise fashion through increasingly committed progenitor stages, studies using in-vivo barcoding, transplantation, and in-vitro culture have suggested that, in addition, a more direct pathway existed. The relevance of this direct pathway and its functional and phenotypic characteristics were unclear, however.

Recent publications using fate-mapping and single-cell transplantation now unequivocally demonstrate the existence of a direct megakaryocyte differentiation pathway, provide molecular characterization, and indicate distinct roles and regulation of both pathways. The direct pathway originates from a separate subset of 'top' HSCs, is enhanced by hematopoietic stress, inflammation and aging, bypasses multipotential progenitors, may be more active in myeloproliferative neoplasms, and generates phenotypically distinct megakaryocyte progenitors and more reactive platelets.

Novel insights into the direct megakaryocyte differentiation pathway provide a deeper understanding of HSC biology, hematological recovery after myeloablation, and aging of the hematopoietic system, and suggest that this pathway may contribute to the increase in thrombotic incidents with age and in myeloproliferative neoplasms.

Platelets are crucial players in hemostasis and thrombosis but also contribute to immune regulation and host defense, using different receptors, signaling pathways, and effector functions, respectively. Whether distinct subsets of platelets specialize in these diverse tasks is insufficiently understood. Here, we used a pulse-labeling method in Mus musculus models for tracking in vivo platelet aging and its functional implications. Using in vitro and in vivo assays, we reveal that young, reticulated platelets show heightened responses in the setting of clot formation, with corresponding, increased responses to agonists, adhesion, and retractile function. Unexpectedly, aged platelets lose their hemostatic proficiency but are more prone to react to inflammatory challenge: compared with reticulated platelets, this cohort was more likely to form platelet-leukocyte aggregates and showed increased adhesion to neutrophils in vitro, as well as enhanced bactericidal function. In vivo, this was reflected in increased pulmonary recruitment of aged platelets in an acute lung injury model. Proteomic analyses confirmed the upregulation of immune pathways in this cohort, including enhanced procoagulant function. In mouse models of prolonged platelet half-life, this resulted in increased pulmonary leukocyte infiltration and inflammation upon acute lung injury. Similarly, human platelet concentrates decreased their hemostatic function and elevated their putative immunomodulatory potential in vitro over time, and in a mouse model of platelet transfusion, aged platelet concentrates resulted in augmented inflammation. In summary, we show that platelets exhibit age-dependent phenotypic shifts, allowing them to fulfill their diverse tasks in the vasculature. Because functional alterations of aging platelets extend to platelet concentrates, this may hold important implications for transfusion medicine.

In the tumor context, platelets play a significant role in primary tumor progression, dissemination and metastasis. Analysis of this interaction in various cancers, such as non-small cell lung cancer (NSCLC), demonstrate that platelets can both transfer and receive biomolecules (e.g. RNA and proteins) to and from the tumor at different stages, becoming tumor-educated platelets. To investigate how platelets are able to transfer oncogenic material, we developed in vitro platelet-like particles (PLPs), from a differentiated MEG-01 cell line, that stably carry RNA and protein of the KRASG12D oncogene in fusion with GFP. We co-cultured these PLPs with NSCLC H1975 tumor cells to assess their ability to transfer this material. We observed that the generated platelets were capable of stably expressing the oncogene and transferring both its RNA and protein forms to tumor cells using qPCR and imaging techniques. Additionally, we found that coculturing PLPs loaded with GFP-KRASG12D with tumor cells increased their proliferative capacity at specific PLP concentrations. In conclusion, our study successfully engineered an MEG-01 cell line to produce PLPs carrying oncogenic GFP-KRASG12D simulating the tumor microenvironment, demonstrating the efficient transfer of this oncogene to tumor cells and its significant impact on enhancing proliferation.

Intrahepatic cholangiocarcinoma (ICC), an aggressive liver cancer, lacks simple and accurate clinical tests, which poses challenges to postoperative diagnosis and treatment. Recent studies have indicated that platelet levels might be relevant to the postoperative prognosis of ICC. However, their prognostic significance in ICC remains unclarified. This study included 218 ICC patients who underwent hepatic resection. Comprehensive analyses of patients' postoperative prognosis were conducted primarily focusing on their platelet levels associated with prognostic traits. To further investigate the underlying mechanism between platelet levels and patients' postoperative prognosis, we elucidated the association between platelets and tumor metastasis using HCCC-9810 and HUCC-T1 cells as well as mouse models. In the retrospective cohort study, elevated serum platelet levels (≥300 × 109/L) or tumoral platelet levels (≥0.23) individually indicated an unfavorable postoperative prognosis in individuals with ICC. Multivariate analysis showed that tumoral platelet levels can be an independent prognostic factor, while the loss of prognostic superiority of serum platelet levels in the analysis may be attributed to the influence of confounding inclusion variables. Epithelial/mesenchymal transition (EMT) marker expression changes in HCCC-9810 and HUCC-T1 cells with platelet treatment were analyzed to understand how platelets contribute to ICC malignant recurring progression. The significant role of the TGF-β/Smad2 pathway in ICC metastasis was identified. In addition, aspirin was found to have the potential to reduce ICC metastasis by inhibiting platelet function. In conclusion, this study indicated that ICC patients with postoperative serum platelet levels ≥300 × 109/L or tumoral platelet levels ≥0.23 have significantly higher risk of poor postoperative prognosis. This is due to platelet-derived TGFβ1 leading to EMT in ICC cells, thus promoting tumor metastasis.

Platelet-Rich Plasma (PRP) is a plasma product obtained by centrifuging autologous blood, containing a high concentration of platelets, white blood cells, and fibrin. PRP is enriched with various growth factors, such as Transforming Growth Factor-beta (TGF-β), Platelet-Derived Growth Factor (PDGF), Epidermal Growth Factor (EGF), Insulin-Like Growth Factor (IGF), and Vascular Endothelial Growth Factor (VEGF), all of which promote tissue growth and repair. Currently, PRP has been widely applied in the clinical field of wound repair and has achieved certain therapeutic effects. Biomaterials, as an important direction in the treatment of wounds, combined with PRP, provide new possibilities to enhance the regenerative repair of wounds by PRP. This article reviews the latest research progress of biomaterials combined with PRP in the treatment of wounds, aiming to provide references for PRP wound treatment, as well as to provide ideas for the development of subsequent medical materials.

Non-small cell lung cancer (NSCLC) accounts for 80% of lung cancers, the leading cause of cancer mortality. microRNAs (miRNA, miR) have emerged as important components of carcinogenesis and promising biomarkers. We aimed to analyse global plasma miRs in NSCLC patients before and at least one year after tumour resection.

Plasma was collected from the peripheral blood of 24 donors without cancer and of NSCLC patients before surgery (n=36) and at least 1 year after surgery (n=12). Next-generation sequencing (NGS)-based miR profiling was performed. Patients were followed-up for 4 to 12 years after surgery to assess disease recurrence.

Untreated NSCLC patients exhibited significant changes in plasma miR levels compared to cancer-free donors (48 up- and 17 down-regulated miRs). miR profiles in patients with adenocarcinoma (ADC) (n=18) and squamous cell carcinoma (SCC) significantly differed (16 and 86 miRs up-, and 15 and 16 miRs down-regulated, respectively). A subset of pre-surgery deregulated miRs was found to be associated with recurrence (49 miRs). Six miRs were shown to have independent prognostic value. After tumour resection, some pre-surgery miR alterations returned to control levels (18 miRs), some others persisted (27 miRs), while also novel plasma miR changes emerged (75 miRs) in patients with no clinical evidence of recurrence.

Untreated NSCLC patients present deregulated plasma miRs, some of which may have a potential of prognostic markers. After tumour excision plasma miR profiles change, some miR levels normalise, some changes persist and novel miR changes are observed despite no clinical symptoms of recurrence. Plasma miR profiles in NSCLC patients may suggest systemic abnormalities predisposing to lung cancer and/or reflect a systemic response to pre-cancer/dormant cancer cells.

Chronic high-altitude hypoxia is associated with reduced platelet count, but it is unclear whether the decrease in platelet count is due to impaired production or increased clearance. This study examines how hypoxia affects platelet production and apoptosis and elucidates the impact of glycoprotein Ibα-von Willebrand factor interaction on platelets in rats using a hypobaric hypoxia chamber. The results showed that the number of megakaryocytes increased under hypoxia; however, the levels of differentiation and polyploidy decreased, while those of apoptosis increased. Platelet production did not reduce according to the reticulated platelet percentage, while platelet apoptosis enhanced; these results suggest that increased platelet clearance was the main reason behind platelet reduction. Our previous microarray results indicated that glycoprotein Ibα (GPIbα) expression increased under hypoxia, which was a protein involved in platelet clearance; therefore, we examined the interaction of platelet GPIbα with the von Willebrand factor (vWF) both in vivo and in vitro to explore the effect of this process on platelets and whether it is related to platelet apoptosis. Under hypoxia, the stronger interaction between GPIbα and vWF promoted platelet apoptosis; inhibiting this interaction reduced platelet apoptosis and increased platelet counts. Platelet reduction is associated with apoptosis induced by the interaction between GPIbα and vWF.

Platelets, known for maintaining blood balance, also participate in antimicrobial defense. Upon severeacute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, platelets become hyperactivated, releasing molecules such as cytokines, granule contents, and bioactive lipids. The key effector biolipids produced by platelets include 12-hydroxyeicosatetraenoic acid (12-HETE) and 12-hydroxyeicosatrienoic acid (12-HETrE), produced by 12-lipoxygenase (12-LOX), and prostaglandins and thromboxane, produced by cyclooxygenase-1. While prostaglandin E2 and thromboxane B2 were previously associated with lung inflammation in severe COVID-19, the role of platelet 12-LOX in SARS-CoV-2 infection remains unclear. Using mice deficient for platelets' 12-LOX, we report that SARS-CoV-2 infection resulted in higher lung inflammation characterized by histopathological tissue analysis, increased leukocyte infiltrates, and cytokine production relative to wild-type mice. In addition, distinct platelet and lung transcriptomic changes, including alterations in NOD-like receptor (NLR) family pyrin domain-containing 1 (NLRP1) inflammasome-related gene expression, were observed. Mass spectrometry lipidomic analysis in 12-LOX-deficient-infected mice revealed significant changes in bioactive lipid content, including reduced levels of 12-HETrE that inversely correlated with disease severity. Finally, platelet 12-LOX deficiency was associated with increased morbidity and lower survival rates relative to wild type (WT) mice. Overall, this study highlights the complex interplay between 12-LOX-related lipid metabolism and inflammatory responses during SARS-CoV-2 infection. The findings provide valuable insights into potential therapeutic targets aimed at mitigating severe outcomes, emphasizing the pivotal role of platelet enzymes in the host response to viral infections.

Cytoskeletal remodeling and mitochondrial bioenergetics play important roles in thrombocytopoiesis and platelet function. Recently, α-actinin-1 mutations have been reported in patients with congenital macrothrombocytopenia. However, the role and underlying mechanism of α-actinin-1 in thrombocytopoiesis and platelet function remain elusive. Using megakaryocyte (MK)-specific α-actinin-1 knockout (KO; PF4-Actn1-/-) mice, we demonstrated that PF4-Actn1-/- mice exhibited reduced platelet counts. The decreased platelet number in PF4-Actn1-/- mice was due to defects in thrombocytopoiesis. Hematoxylin and eosin staining and flow cytometry revealed a decrease in the number of MKs in the bone marrow of PF4-Actn1-/- mice. The absence of α-actinin-1 increased the proportion of 2 N-4 N MKs and decreased the proportion of 8 N-32 N MKs. Colony-forming unit-MK colony formation, the ratio of proplatelet formation-bearing MKs, and MK migration in response to stromal cell-derived factor-1 signaling were inhibited in PF4-Actn1-/- mice. Platelet spreading, clot retraction, aggregation, integrin αIIbβ3 activation, and CD62P exposure in response to various agonists were decreased in PF4-Actn1-/- platelets. Notably, PF4-Actn1-/- platelets inhibited calcium mobilization, reactive oxygen species (ROS) generation, and actin polymerization in response to collagen and thrombin. Furthermore, the PF4-Actn1-/- mice exhibited impaired hemostasis and thrombosis. Mechanistically, proteomic analysis of low-ploidy (2-4 N) and high-ploidy (≥8 N) PF4-Actn1-/- MKs revealed that α-actinin-1 deletion reduced platelet activation and mitochondrial function. PF4-Actn1-/- platelets and Actn1 KO 293T cells exhibited reduced mitochondrial membrane potential, mitochondrial ROS generation, mitochondrial calcium mobilization, and mitochondrial bioenergetics. Overall, in this study, we report that mice with α-actinin-1 deficiency in MKs exhibit low platelet count and impaired platelet function, thrombosis, and mitochondrial bioenergetics.

The lung undergoes continuous remodeling throughout normal development and aging, including changes to alveolar and capillary structure and function. While histological methods allow static analysis of these age-related changes, characterizing the changes that occur in response to mechanical stimuli remains difficult, particularly over a dynamic, physiologically relevant range in a functioning lung. Alveolar and capillary distension - the change in diameter of alveoli and capillaries, respectively, in response to pressure changes - is one such process, where dynamically controlling and monitoring the diameter of the same capillary or alveolus is essential to infer its mechanical properties. We overcome these limitations by utilizing the recently developed crystal ribcage to image the alveoli and vasculature of a functional mouse lung across the lifespan in postnatal (6-7 days), young adult (12-18 weeks), and aged (20+ months) mice. Using a range of biologically relevant vascular (0-15 cmH2O) and transpulmonary (3-12 cmH2O) pressures, we directly quantify vascular and alveolar distention in the functional lung as we precisely adjust pulmonary pressures. Our results show differences in age-related alveolar and vascular distensibility: when we increase transpulmonary alveolar or vascular pressure, vessels in postnatal lungs expand less and undergo less radial and axial strain, under each respective pressure type, suggesting stiffer capillaries than in older lungs. However, while vessels in young adult and aged lungs respond similarly to variations in vascular pressure, differences in elasticity start to emerge at the alveolar scale in response to transpulmonary alveolar pressure changes. Our results further indicate that differing effects of ventilation mode (i.e., positive vs negative) present themselves at the capillary level, with vessels under positive pressure undergoing more compression than when under negative-pressure conditions. These findings contribute both to the understanding of the functional changes that occur within the lung across the lifespan, as well as to the debate of ventilation effects on lung microphysiology.

The crosstalk between megakaryocytic lineage cells and the skeletal system has just begun to be explored but remains largely elusive. Using conditional gene knockout mouse models, we demonstrated that loss of Beclin 1 (Becn1), a major regulator of mammalian autophagy, exclusively in the megakaryocytic lineage disrupted autophagy in platelets but did not compromise megakaryopoiesis or the formation and function of platelets. Unexpectedly, conditional Becn1 deletion in male mice led to a remarkable increase in bone mass with improved bone quality, in association with a decrease in sex hormone binding globulin (SHBG) and an increase in free testosterone (FT). In vivo Becn1 overexpression in megakaryocytic lineage-specific cells reduced bone mass and quality, along with an increase in SHBG and a decrease in FT. Transplantation of wild-type bone marrow cells into megakaryocytic lineage Becn1-deficient male mice restored bone mass and normalized SHBG and FT. Furthermore, bilateral orchiectomy of Becn1f/f;Pf4-iCre mice, which are crippled with the production of testosterone, resulted in a reduction in bone mass and quality, whereas in vivo overexpression of SHBG, specifically in the liver of Becn1f/f;Pf4-iCre mice, decreased FT and reduced bone mass and quality. In addition, metformin treatment, which induces SHBG expression, reduced FT and normalized bone mass in Becn1f/f;Pf4-iCre mice. We thus concluded that Becn1 of the megakaryocytic lineage is dispensable locally for platelet hemostasis but limits bone mass by increasing SHBG, which in turn reduces the FT of male mice. Our findings highlight a mechanism by which Becn1 from megakaryocytic lineage cells distally balances bone growth.

Recent research has highlighted the crucial role of immune regulation in lung function impairment due to exposure to hazardous materials. This study aimed to identify dynamic network biomarkers for lung function damage caused by hexavalent chromium inhalation exposure, using immune-related indicators in blood. An 11-year follow-up longitudinal study was conducted on a population occupationally exposed to hexavalent chromate (Cr [VI]) from 2010 to 2020, consisting of sixty-one subjects with 328 repeat measurements. Quantitative analysis of immune-related indicators, including white blood cells, cytokines, and platelet count, was performed. The concentration of urinary Cr served as an indicator of internal exposure, confirming its association with lung function impairment. Dynamic network analysis revealed that platelet count was connected to neutrophils, IL-8, IL-6, and IL-33 when the exposure time was equal to or longer than 9.2 years (the median exposure time). Notably, the association between platelet count and IL-33 was specific to long-term (≥ 9.2 years) exposure. The areas under the receiver operating characteristic (ROC) curves (AUCs) for platelet count combined with IL-33 to predict lung function impairment in the long-term and short-term Cr [VI]-exposed populations were 80.5 % and 55.4 %, respectively. These findings provide evidence that the combination of platelets and IL-33 holds significant promise as biomarkers for predicting lung function impairment. Moreover, they shed light on the potential mechanism involving immune and hematopoiesis functions in the context of environmental hazardous exposure.

While the bone marrow is the main site of blood cell production in adults, rare pools of hematopoietic stem and progenitor cells have been found in extramedullary organs. In mice, we have previously shown that the lungs contain hematopoietic progenitor cells and is a site of platelet production. Here, in the adult human lung, we show that functional hematopoietic precursors reside in the extravascular spaces with a frequency similar to the bone marrow, and are capable of proliferation and engraftment in mice. The gene signature of pulmonary and medullary CD34+ hematopoietic progenitors indicates greater baseline activation of immune, megakaryocyte/platelet and erythroid-related pathways in lung progenitors. Spatial transcriptomics mapped blood progenitors in the lung to an alveolar interstitium niche with only a few cells identified in an intravascular location. In human blood samples collected for stem cell transplantation, CD34+ cells with a lung signature enriched the mobilized pool of hematopoietic stem cells. These results identify the lung as a pool for uniquely programmed blood stem and progenitor cells with the potential to support hematopoiesis in humans.

Platelets, or thrombocytes are anucleate cell fragments of megakaryocytes (MKs) that are highly reactive to sites of vascular injury and implicated in many pathologies. However, the molecular mechanisms regulating the number and activity of platelets in the circulation remain undefined. The primary outstanding question remains what is the triggering mechanism of platelet production, or thrombopoiesis? Putative stimulatory factors and mechanical forces are thought to drive this process, but none induce physiological levels of thrombopoiesis. Intrinsic inhibitory mechanisms that maintain MKs in a refractory state in sites of thrombopoiesis are conspicuously overlooked, as well as extrinsic cues that release this brake system, allowing asymmetric platelet production to proceed toward the vascular lumen. Here we introduce the novel concept of a MK/platelet checkpoint, putative components and a working model of how it may be regulated. We postulate that the co-inhibitory receptor G6b-B and the non-transmembrane protein-tyrosine phosphatases (PTPs) Shp1 and Shp2 form an inhibitory complex that is the primary gatekeeper of this checkpoint, which is spatiotemporally regulated by the receptor-type PTP CD148 and vascular heparan sulfate proteoglycans. By advancing this alternative model of thrombopoiesis, we hope to stimulate discourse and a shift in how we conceptualize and address this fundamental question.

The coagulation process and infiltration of macrophages affect the progression and prognosis of lung adenocarcinoma (LUAD) patients. This study was designed to explore novel classification methods that better guide the precise treatment of LUAD patients on the basis of coagulation and macrophages.

Weighted gene coexpression network analysis (WGCNA) was applied to identify M2 macrophage-related genes, and TAM marker genes were acquired through the analysis of scRNA-seq data. The MSigDB and KEGG databases were used to obtain coagulation-associated genes. The intersecting genes were defined as coagulation and macrophage-related (COMAR) genes. Unsupervised clustering analysis was used to evaluate distinct COMAR patterns for LUAD patients on the basis of the COMAR genes. The R package "limma" was used to identify differentially expressed genes (DEGs) between COMAR patterns. A prognostic risk score model, which was validated through external data cohorts and clinical samples, was constructed on the basis of the COMAR DEGs.

In total, 33 COMAR genes were obtained, and three COMAR LUAD subtypes were identified on the basis of the 33 COMAR genes. There were 341 DEGs identified between the three COMAR subtypes, and 60 prognostic genes were selected for constructing the COMAR risk score model. Finally, 15 prognosis-associated genes (CORO1A, EPHA4, FOXM1, HLF, IFIH1, KYNU, LY6D, MUC16, PPARG, S100A8, SPINK1, SPINK5, SPP1, VSIG4, and XIST) were included in the model, which was efficient and robust in predicting LUAD patient prognosis and clinical outcomes in patients receiving anti-PD-1/PD-L1 immunotherapy.

LUAD can be classified into three subtypes according to COMAR genes, which may provide guidance for precise treatment.

Platelets, traditionally known for their role in hemostasis, have emerged as key players in immune response and inflammation. Sepsis, a life-threatening condition characterized by systemic inflammation, often presents with thrombocytopenia, which at times, can be significant. Platelets contribute to the inflammatory response by interacting with leukocytes, endothelial cells, and the innate immune system. However, excessive platelet activation and consumption can lead to thrombocytopenia and exacerbate the severity of sepsis. Understanding the multifaceted roles of platelets in sepsis is crucial for developing effective therapeutic strategies. Targeting platelet-mediated inflammatory responses and promoting platelet production may offer potential avenues for improving outcomes in septic patients with thrombocytopenia. Future research should focus on elucidating the mechanisms underlying platelet dysfunction in sepsis and exploring novel therapeutic approaches to optimize platelet function and mitigate inflammation. This review explores the intricate relationship between platelets, inflammation, and thrombosis in the context of sepsis.

Blood platelets are anucleate cells essential for normal blood hemostasis. To maintain a normal platelet count of 150 000 to 400 000 per μL of blood, 1011 platelets must be released each day from precursor cells called megakaryocytes. In this review, we aim to provide an overview of platelet production and evaluate the proposed mechanisms of platelet generation. We will discuss novel cytoskeletal mechanisms of platelet production, including microtubule and actin-based systems. We present new evidence that supports a cytoplasmic trigger for platelet production, discuss centrosome clustering as a new mechanism to trigger proplatelet production, and review new data supporting the bone marrow as the major location of platelet production.

Trichuriasis, a well-known type of soil-transmitted helminthiasis, is a neglected gastrointestinal nematode disease predominantly affecting children in tropical regions and is caused by Trichuris trichiura. The potential zoonotic transmission of this disease is indicated by its presence in nonhuman primates. Chronic infection leads to mucosal damage, bacterial translocation, and intense inflammatory infiltration; however, the progression of these processes remains poorly understood. This study tracks the acute phase of experimental trichuriasis, providing detailed insights into nematode tissue migration stages, inflammatory infiltration, cytokine production, and 2D/3D imaging of the bacterial translocation process. We showed a mixed immune response (Th1, Th2, and Th17) initiated by larval-induced lesions in the intestine tissue and modulated by L4 larvae and adult worms in the cecum, with systemic changes observed in the mesenteric lymph nodes, peritoneal macrophages, and spleen. Despite the disruption of the intestinal mucosa within the first 10 days post-infection (d.p.i.), bacterial invasion becomes evident only after the development of the nematode into the L3 larval stage (17 d.p.i.), intensifying with lesions caused by the L4 larvae (22 d.p.i.) and adult worms (35 d.p.i.). Our multidimensional approach, which incorporates microscopy tools, micro-CT, physiological evaluations, tissue/organ assessments, and immunological parameters, demonstrates the ability of larvae to breach the intestinal mucosa, further indicating the timing of extensive bacterial infiltration. Additionally, a 3D animation illustrates how adult worm attachment mechanisms may facilitate bacterial translocation. This study provides significant insights into the immunological and pathological mechanisms of trichuriasis progression, highlighting the complex interplay among host immune responses, the gut microbiome, and parasite survival strategies, all of which are crucial aspects for future therapeutic development.

Phosphatidylinositol-3 kinases (PI3Ks) play a critical role in maintaining cardiovascular health and the development of cardiovascular diseases (CVDs). Specifically, vacuolar Protein Sorting 34 (VPS34) or PIK3C3, the only member of Class III PI3K, plays an important role in CVD progression. The main function of VPS34 is inducing the production of phosphatidylinositol 3-phosphate, which, together with other essential structural and regulatory proteins in forming VPS34 complexes, further regulates the mammalian target of rapamycin activation, autophagy, and endocytosis. VPS34 is found to have crucial functions in the cardiovascular system, including dictating the proliferation and survival of vascular smooth muscle cells and cardiomyocytes and the formation of thrombosis. This review aims to summarize our current knowledge and recent advances in understanding the function and regulation of VPS34 in cardiovascular health and disease. We also discuss the current development of VPS34 inhibitors and their potential to treat CVDs.

Different approaches are being developed to efficiently produce in vitro platelets from cultured megakaryocytes to meet the constant demand of platelet transfusion and serve for research purposes. Recent works have shown that turbulence and periodic stress can significantly enhance platelet yield. Here we have developed and characterized a platelet production device that takes in account these properties. This device is based on the Taylor-Couette reactor in which a suspension is confined and sheared between two concentric cylinders. We have demonstrated that such a system allows obtaining high number of in vitro platelets per megakaryocyte with native-like morphology and functional properties. Using the combination of in silico and in vitro techniques, we claimed that overall turbulent conditions are not sufficient for efficient platelet release, and highlighted the importance of the uniform impact of flow on each megakaryocyte, a property that must be taken into account along with general flow characteristics when designing platelet release bioreactors. In addition, we have demonstrated that our system can be scaled up to large volumes without loss of efficiency, a significant advantage for the industrialization of platelet culture. In conclusion, we have developed a platelet production device with a predictable and highly precise effect on each megakaryocyte.

The modification of endothelial cells (ECs) biological function under pathogenic conditions leads to the expression of mesenchymal stromal cells (MSCs) markers, defined as endothelial-to-mesenchymal transition (EndMT). Invisible in onset and slow in progression, atherosclerosis (AS) is a potential contributor to various atherosclerotic cardiovascular diseases (ASCVD). By triggering AS, EndMT, the "initiator" of AS, induces the progression of ASCVD such as coronary atherosclerotic heart disease (CHD) and ischemic cerebrovascular disease (ICD), with serious clinical complications such as myocardial infarction (MI) and stroke. In-depth research of the pathomechanisms of EndMT and identification of potential targeted therapeutic strategies hold considerable research value for the prevention and treatment of ASCVD-associated with delayed EndMT. Although previous studies have progressively unraveled the complexity of EndMT and its pathogenicity triggered by alterations in vascular microenvironmental factors, systematic descriptions of the most recent pathogenic roles of EndMT in the progression of AS, targeted therapeutic strategies, and their future research directions are scarce.

We aim to provide new researchers with comprehensive knowledge of EndMT in AS. We exhaustively review the latest research advancements in the field and provide a theoretical basis for investigating EndMT, a biological process with sophisticated mechanisms.

This review summarized that altered hemodynamics with microenvironmental crosstalk consisting of inflammatory responses or glycolysis, oxidative stress, lactate or acetyl-CoA (Ac-CoA), fatty acid oxidation (FAO), intracellular iron overload, and transcription factors, including ELK1 and STAT3, modulate the EndMT and affect AS progression. In addition, we provide new paradigms for the development of promising therapeutic agents against these disease-causing processes and indicate promising directions and challenges that need to be addressed to elucidate the EndMT process.

Germline RUNX1 haplodeficiency (RHD) is associated with thrombocytopenia, platelet dysfunction, and predisposition to myeloid malignancies. Platelet expression profiling of an RHD patient showed decreased F13A1, encoding for the A subunit of factor (F)XIII, a transglutaminase that cross-links fibrin and induces clot stabilization. FXIII-A is synthesized by hematopoietic cells, megakaryocytes, and monocytes.

To understand RUNX1 regulation of F13A1 expression in platelets/megakaryocytes and the mechanisms and consequences of decreased F13A1 in RHD.

We performed studies in platelets, human erythroleukemia (HEL) cells, and human CD34+ cell-derived megakaryocytes including on clot contraction in cells following small inhibitor RNA knockdown (KD) of RUNX1 or F13A1.

Platelet F13A1 mRNA and protein were decreased in our index patient and in 2 siblings from an unrelated family with RHD. Platelet-driven clot contraction was decreased in the patient and affected daughter. Promoter studies in HEL cells showed that RUNX1 regulates F13A1 transcription; RUNX1 overexpression increased, and small inhibitor RNA RUNX1 KD reduced F13A1 promoter activity and protein. Following RUNX1 or F13A1 KD, clot contraction by HEL cells was decreased, as were FXIII-A surface expression, myosin light chain phosphorylation, and PAC1 antibody binding upon activation. F13A1 expression and clot contraction were impaired in RUNX1 downregulation in human megakaryocytes.

RUNX1 regulates platelet-megakaryocyte F13A1 expression, which is decreased in RHD, reflecting regulation of a coagulation protein by a hematopoietic transcription factor. Platelet and megakaryocyte clot contraction is decreased in RHD, related to multiple impaired mechanisms including F13A1 expression, myosin phosphorylation, and αIIbβ3 activation.

Hematopoiesis is the process that generates the cells of the blood and immune system from hematopoietic stem and progenitor cells (HSPCs) and represents the system with the most rapid cell turnover in a mammalian organism. HSPC differentiation trajectories, their underlying molecular mechanisms, and their dysfunctions in hematologic disorders are the focal research questions of experimental hematology. While HSPC transplantations in murine models are the traditional tool in this research field, recent advances in genome editing and next generation sequencing resulted in the development of many fundamentally new approaches for the analyses of mammalian hematopoiesis in situ and at single cell resolution. The current review will cover many recent developments in this field in murine models, from the bulk lineage tracing studies of HSPC differentiation to the barcoding of individual HSPCs with Cre-recombinase, Sleeping Beauty transposase, or CRISPR/Cas9 tools, to map hematopoietic cell fates, together with their transcriptional and epigenetic states. We also address studies of the clonal dynamics of human hematopoiesis, from the tracing of HSPC clonal behaviours based on viral integration sites in gene therapy patients to the recent analyses of unperturbed human hematopoiesis based on naturally accrued mutations in either nuclear or mitochondrial genomes. Such studies are revolutionizing our understanding of HSPC biology and hematopoiesis both under homeostatic conditions and in the response to various forms of physiological stress, reveal the mechanisms responsible for the decline of hematopoietic function with age, and in the future may advance the understanding and management of the diverse disorders of hematopoiesis.

Cancer presents a significant public health concern, particularly in the context of metastatic disease. Surgical removal of primary tumors, while essential, can inadvertently heighten the risk of metastasis. Thus, there is a critical need for innovative neoadjuvant therapies capable of curtailing metastatic progression before or immediately following tumor resection. Addressing this imperative, the papaya mosaic virus nanoparticle (PapMV) has demonstrated potent immunostimulatory capabilities against both viruses and tumors, effectively hindering their proliferation. Our study reveals that PapMV exerts a protective effect against lung metastasis when administered systemically prior to tumor implantation or during the early stages of metastasis in various mouse models of cancer. This anti-tumor effect is initiated by the recruitment of myeloid cells in the lungs. These cells adopt a pro-inflammatory profile, secreting cytokines such as IFN-α, thus fostering a tumor microenvironment inhospitable to tumor progression. Crucially, this protective mechanism hinges on the presence of macrophages before treatment. TLR7 and IFN-I signaling pathways also play pivotal roles in this process. Furthermore, our findings demonstrate that PapMV triggers the activation of the bone marrow emergency response, which accounts for the influx of myeloid cells into the lungs. This study unveils a novel aspect of PapMV's functionality. By bolstering the immune system, PapMV confers robust protection against metastasis at an early stage of disease progression. This discovery holds promise for therapeutic intervention, particularly as a preemptive measure prior to or just after surgical intervention.

Platelets are small circulating anucleated cells mainly involved in thrombosis and hemostasis processes. Moreover, platelets play an active role in tumorigenesis and cancer progression, stimulating angiogenesis and vascular remodelling, and protecting circulating cancer cells from shear forces and immune surveillance. Several reports indicate that platelet number in the blood circulation of cancer patients is associated with prognosis and response to treatment. However, the mechanisms of platelets "education" by cancer cells and the crosstalk between platelets and tumor are still unclear, and the role of "tumor educated platelets" (TEPs) is achieving growing interest in cancer research. TEPs are a biological source of cancer-derived biomarkers, especially RNAs that are protected by platelets membrane from circulating RNases, and could serve as a non-invasive tool for tumor detection, molecular profiling and evolution during therapy in clinical practice. Moreover, short platelet lifespan offers the possibility to get a snapshot assessment of cancer molecular profile, providing a real-time tool. We review and discuss the potential and the clinical utility, in terms of cancer diagnosis and monitoring, of platelet count together with other morphological parameters and of the more recent and innovative TEP profiling.

To systematically evaluate the predictive value of platelet (PLT) parameters for bronchopulmonary dysplasia (BPD) in preterm infants.

PubMed, Embase, Cochrane Library, and Web of Science databases were searched for studies on PLT parameters predicting BPD in preterm infants from inception to December 2023. The Newcastle-Ottawa Scale was adopted to judge the article's quality. RevMan 5.4 was utilized for Meta-analysis, and Stata/SE 15.1 was applied for sensitivity analysis and Egger regression test.

Ten studies were included, including 1637 preterm infants, of which 540 were diagnosed with BPD. Meta-analysis showed that PLTs (SMD = -0.98, 95% CI [-1.57, -0.38], P = .001), mean platelet volume (MPV) (SMD = 0.67, 95% CI [0.19, 1.15], P = .006), and PMI (SMD = -0.47, 95% CI [-0.65, -0.28], P < .00001) could assist in predicting BPD in preterm infants. Subgroup analyses showed that PLT parameters 3 days after birth had better predictive performance for BPD in preterm infants. Sensitivity analysis implied no significant change in the results after excluding the studies 1 by 1, suggesting robust results of meta-analysis. There was a significant publication bias in the enrolled studies (P < .001).

PLT, MPV, and PMI have a predictive value for BPD in preterm infants.

Platelets are non-nucleated mammalian cells originating from the cytoplasmic expulsion of the megakaryocytes. Megakaryocytes develop during hematopoiesis through megakaryopoiesis, whereas platelets develop from megakaryocytes through thrombopoiesis. Since their first discovery, platelets have been studied as critical cells controlling hemostasis or blood coagulation. However, coagulation and innate immune response are evolutionarily linked processes. Therefore, it has become critical to investigate the immunological functions of platelets to maintain immune homeostasis. Advances in immunology and platelet biology research have explored different critical roles of platelets, including phagocytosis, release of different immune mediators, and controlling functions of different immune cells by direct interaction and immune mediators. The current article discusses platelet's development and their critical role as innate immune cells, which express different pattern recognition receptors (PRRs), recognizing different pathogen or microbe-associated molecular patterns (PAMPs or MAMPs) and death/damage-associated molecular patterns (DAMPs) and their direct interactions with innate and adaptive immune cells to maintain immune homeostasis.

Germline RUNX1 haplodeficiency (RHD) is associated with thrombocytopenia, platelet dysfunction and predisposition to myeloid malignancies. Platelet expression profiling of a RHD patient showed decreased F13A1, encoding for the A subunit of factor XIII, a transglutaminase that cross-links fibrin and induces clot stabilization. FXIII-A is synthesized by hematopoietic cells, megakaryocytes and monocytes.

To understand RUNX1 regulation of F13A1 expression in platelet/megakaryocyte and the mechanisms and consequences of decreased F13A1 in RHD.

We performed studies in platelets, HEL cells and human CD34+ cell-derived megakaryocytes including on clot contraction in cells following small inhibitor (si)RNA knockdown (KD) of RUNX1 or F13A1 .

Platelet F13A1 mRNA and protein were decreased in our index patient and in two siblings from an unrelated family with RHD. Platelet-driven clot contraction was decreased in the patient and affected daughter. Promoter studies in HEL cells showed that RUNX1 regulates F13A1 transcription; RUNX1 overexpression increased and (si)RNA RUNX1 KD reduced F13A1 promoter activity and protein. Following RUNX1 or F13A1 KD clot contraction by HEL cells was decreased as were FXIII-A surface expression, myosin light chain phosphorylation and PAC1 binding upon activation. F13A1 expression and clot contraction were impaired on RUNX1 downregulation in human megakaryocytes.

RUNX1 regulates platelet-megakaryocyte F13A1 expression, which is decreased in RHD, reflecting regulation of a coagulation protein by a hematopoietic transcription factor. Platelet and megakaryocyte clot contraction is decreased in RHD, related to multiple impaired mechanisms including F13A1 expression, myosin phosphorylation and αII b β 3 activation. Scientific category - Platelets and thrombopoiesis.

RUNX1 regulates expression of FXIII-A chain ( F13A1) in megakaryocytes (MK) and platelets. Platelet and MK F13A1 expression and clot contraction are decreased in RUNX1 deficiency. MK clot contraction, myosin phosphorylation and PAC1-binding are impaired in F13A1 deficiency. Defective clot contraction in RHD arises from defects in multiple platelet-MK mechanisms.

After prolonged adaptation to high-altitude environments, Tibetan sheep have developed a robust capacity to withstand hypobaric hypoxia. Compared to low-altitude sheep, various organs and tissues in Tibetan sheep have undergone significant adaptive remodeling, particularly in the lungs. However, whether lambs and adult Tibetan sheep exhibit similar adaptations to high-altitude hypoxia remains unclear. In this study, we selected six lambs (4 months old) and six adult (3 years old) female Tibetan sheep to assess their blood gas indicators, observe lung microstructures, and measure the expression levels of key proteins in the lungs. The results indicated that adult sheep exhibited higher hemoglobin concentrations and finer, denser pulmonary vasculature, which enhanced their oxygen-carrying capacity and increased the surface area available for blood gas exchange, resulting in improved oxygen transfer capacity. Conversely, lambs demonstrated larger lungs relative to their body weight and greater pulmonary vascular volumes, which increased relative pulmonary ventilation and blood flow, thereby enhancing oxygen uptake. These findings suggested that Tibetan sheep employ different adaptation strategies to high-altitude hypoxia at various life stages.

Platelets are important players in hemostasis. Alterations in platelet number and/or function lead to life-threatening conditions like thrombosis, myocardial infarction and stroke. During aging, changes at the cellular, organ and systemic level occur that affect platelet counts, platelet functionality, the expression of platelet surface receptors, clearance markers as well as their interactions with immune cells. Understanding how these changes influence platelets can help to prevent the alterations of hemostasis and thrombosis we observe in the elderly. In this review, we highlight the respective changes at important sites of the platelet life cycle: bone marrow, liver and spleen, but also show how alterations in immunity contribute. We point out the necessity for further research on age-related systemic alterations in these systems and their interplay with platelets to better understand the complex processes that cause alterations in the platelet life cycle during aging.

Active components of natural products, which include paclitaxel, curcumin, gambogic acid, resveratrol, triptolide and celastrol, have promising anti-inflammatory, antitumor, anti-oxidant, and other pharmacological activities. However, their clinical application is limited due to low solubility, instability, low bioavailability, rapid metabolism, short half-life, and strong off-target toxicity. To overcome these drawbacks, cell membrane-based biomimetic nanosystems have emerged that avoid clearance by the immune system, enhance targeting, and prolong drug circulation, while also improving drug solubility and bioavailability, enhancing drug efficacy, and reducing side effects. This review summarizes recent advances in the preparation and coating of cell membrane-coated biomimetic nanosystems and in their applications to disease for targeted natural products delivery. Current challenges, limitations, and prospects in this field are also discussed, providing a research basis for the development of multifunctional biomimetic nanosystems for natural products.

The current constraints associated with cancer diagnosis and molecular profiling, which rely on invasive tissue biopsies or clinical imaging, have spurred the emergence of the liquid biopsy field. Liquid biopsy involves the extraction of circulating tumor cells (CTCs), circulating free or circulating tumor DNA (cfDNA or ctDNA), circulating cell-free RNA (cfRNA), extracellular vesicles (EVs), and tumor-educated platelets (TEPs) from bodily fluid samples. Subsequently, these components undergo molecular characterization to identify biomarkers that are critical for early cancer detection, prognosis, therapeutic assessment, and post-treatment monitoring. These innovative biosources exhibit characteristics analogous to those of the primary tumor from which they originate or interact. This review comprehensively explores the diverse technologies and methodologies employed for processing these biosources, along with their principal clinical applications.

Megakaryocytes (MKs), which are traditionally known for their role in platelet production, are now emerging as unique immune cells with diverse capabilities. They express immune receptors, participate in pathogen recognition and response, phagocytose pathogens, contribute to antigen presentation, and interact with various immune cell types. When encountering inflammatory challenges, MKs exhibit intricate immune functions that can either promote or inhibit inflammation. These responses are mediated through mechanisms, such as the secretion of either anti-inflammatory or pro-inflammatory cytokines and release of immunomodulatory platelets according to specific conditions. This intricate array of responses necessitates a detailed exploration to determine whether the immune functions of MKs are carried out by the entire MK population or by a specific subpopulation. Breakthroughs in single-cell RNA sequencing have uncovered a unique "immune MK" subpopulation, revealing its distinct characteristics and immunoregulatory functions. This review provides latest insights into MKs' immune attributes and their roles in physiological and pathological contexts and emphasizes the discovery and functions of "immune MKs".