Endothelial cells, tissue factor and infectious diseases

Mitochondrial DAMPs: Key mediators in neuroinflammation and neurodegenerative disease pathogenesis

Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) are increasingly linked to mitochondrial dysfunction and neuroinflammation. Central to this link are mitochondrial damage-associated molecular patterns (mtDAMPs), including mitochondrial DNA, ATP, and reactive oxygen species, released during mitochondrial stress or damage. These mtDAMPs activate inflammatory pathways, such as the NLRP3 inflammasome and cGAS-STING, contributing to the progression of neurodegenerative diseases. This review delves into the mechanisms by which mtDAMPs drive neuroinflammation and discusses potential therapeutic strategies targeting these pathways to mitigate neurodegeneration. Additionally, it explores the cross-talk between mitochondria and the immune system, highlighting the complex interplay that exacerbates neuronal damage. Understanding the role of mtDAMPs could pave the way for novel treatments aimed at modulating neuroinflammation and slowing disease progression, ultimately improving patient outcome.

Network pharmacology analysis and clinical verification of Panax notoginseng saponins in deep venous thrombosis prevention

In the present study, the mechanism of Panax notoginseng saponins (PNS), the extract of Panax notoginseng, against deep vein thrombosis (DVT) was explored by networks pharmacology and its effect was demonstrated through clinical data. PNS includes 5 main active components, which have 101 targets. A total of 1,342 DVT-related targets were obtained, 55 of which were the common targets of PNS and DVT. AKT1, TNF, IL1B, EGFR, VEGFA and MAPK3 were selected as hub genes from the protein-protein interaction network. The potential anti-DVT mechanism of PNS may involve the AGE-RAGE signaling pathway and the PI3K-Akt signaling pathway. Molecular docking presented a total of 10 binding interactions, with all molecules showing good binding ability with PNS-DVT common hub target genes (all binding energy <-6 kcal/mol). Analysis of clinical data showed that the combined use of PNS significantly reduced the incidence of postoperative DVT in patients undergoing orthopedic surgery compared with the use of low-molecular-weight heparin alone, which is the most commonly used clinical anticoagulant.

The Role of Tissue Factor In Signaling Pathways of Pathological Conditions and Angiogenesis

Tissue factor (TF) is an integral transmembrane protein associated with the extrinsic coagulation pathway. TF gene expression is regulated in response to inflammatory cytokines, bacterial lipopolysaccharides, and mechanical injuries. TF activity may be affected by phosphorylation of its cytoplasmic domain and alternative splicing. TF acts as the primary initiator of physiological hemostasis, which prevents local bleeding at the injury site. However, aberrant expression of TF, accompanied by the severity of diseases and infections under various pathological conditions, triggers multiple signaling pathways that support thrombosis, angiogenesis, inflammation, and metastasis. Protease-activated receptors (PARs) are central in the downstream signaling pathways of TF. In this study, we have reviewed the TF signaling pathways in different pathological conditions, such as wound injury, asthma, cardiovascular diseases (CVDs), viral infections, cancer and pathological angiogenesis. Angiogenic activities of TF are critical in the repair of wound injuries and aggressive behavior of tumors, which are mainly performed by the actions of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF1-α). Pro-inflammatory effects of TF have been reported in asthma, CVDs and viral infections, including COVID-19, which result in tissue hypertrophy, inflammation, and thrombosis. TF-FVII induces angiogenesis via clotting-dependent and -independent mechanisms. Clottingdependent angiogenesis is induced via the generation of thrombin and cross-linked fibrin network, which facilitate vessel infiltration and also act as a reservoir for endothelial cells (ECs) growth factors. Expression of TF in tumor cells and ECs triggers clotting-independent angiogenesis through induction of VEGF, urokinase-type plasminogen activator (uPAR), early growth response 1 (EGR1), IL8, and cysteine-rich angiogenic inducer 61 (Cyr61).

Circulating Extracellular Vesicles in Subarachnoid Hemorrhage Patients: Characterization and Cellular Effects

Circulating extracellular vesicles (EVs) may play a pathophysiological role in the onset of complications of subarachnoid hemorrhage (SAH), potentially contributing to the development of vasospasm (VP). In this study, we aimed to characterize circulating EVs in SAH patients and examine their effects on endothelial and smooth muscle cells (SMCs). In a total of 18 SAH patients, 10 with VP (VP), 8 without VP (NVP), and 5 healthy controls (HC), clinical variables were recorded at different time points. EVs isolated from plasma samples were characterized and used to stimulate human vascular endothelial cells (HUVECs) and SMCs. We found that EVs from SAH patients expressed markers of T-lymphocytes and platelets and had a larger size and a higher concentration compared to those from HC. Moreover, EVs from VP patients reduced cell viability and mitochondrial membrane potential in HUVECs and increased oxidants and nitric oxide (NO) release. Furthermore, EVs from SAH patients increased intracellular calcium levels in SMCs. Altogether, our findings reveal an altered pattern of circulating EVs in SAH patients, suggesting their pathogenic role in promoting endothelial damage and enhancing smooth muscle reactivity. These results have significant implications for the use of EVs as potential diagnostic/prognostic markers and therapeutic tools in SAH management.

New insights in ferroptosis: Potential therapeutic targets for the treatment of ischemic stroke

Stroke is a common disease in clinical practice, which seriously endangers people's physical and mental health. The neurovascular unit (NVU) plays a key role in the occurrence and development of ischemic stroke. Different from other classical types of cell death such as apoptosis, necrosis, autophagy, and pyroptosis, ferroptosis is an iron-dependent lipid peroxidation-driven new form of cell death. Interestingly, the function of NVU and stroke development can be regulated by activating or inhibiting ferroptosis. This review systematically describes the NVU in ischemic stroke, provides a comprehensive overview of the regulatory mechanisms and key regulators of ferroptosis, and uncovers the role of ferroptosis in the NVU and the progression of ischemic stroke. We further discuss the latest progress in the intervention of ferroptosis as a therapeutic target for ischemic stroke and summarize the research progress and regulatory mechanism of ferroptosis inhibitors on stroke. In conclusion, ferroptosis, as a new form of cell death, plays a key role in ischemic stroke and is expected to become a new therapeutic target for this disease.

MARTX toxin of Vibrio vulnificus induces RBC phosphatidylserine exposure that can contribute to thrombosis

V. vulnificus-infected patients suffer from hemolytic anemia and circulatory lesions, often accompanied by venous thrombosis. However, the pathophysiological mechanism of venous thrombosis associated with V. vulnificus infection remains largely unknown. Herein, V. vulnificus infection at the sub-hemolytic level induced shape change of human red blood cells (RBCs) accompanied by phosphatidylserine exposure, and microvesicle generation, leading to the procoagulant activation of RBCs and ultimately, acquisition of prothrombotic activity. Of note, V. vulnificus exposed to RBCs substantially upregulated the rtxA gene encoding multifunctional autoprocessing repeats-in-toxin (MARTX) toxin. Mutant studies showed that V. vulnificus-induced RBC procoagulant activity was due to the pore forming region of the MARTX toxin causing intracellular Ca²⁺ influx in RBCs. In a rat venous thrombosis model triggered by tissue factor and stasis, the V. vulnificus wild type increased thrombosis while the ΔrtxA mutant failed to increase thrombosis, confirming that V. vulnificus induces thrombosis through the procoagulant activation of RBCs via the mediation of the MARTX toxin.

The pathophysiological mechanism of venous thrombosis associated with Vibrio vulnificus infection remains largely unknown. In this work, the authors investigate this association, focusing on effects of the pore-forming MARTX toxin of V. vulnificus on red blood cells, and the utilisation of a rat venous thrombosis model.

miR-19a-3p downregulates tissue factor and functions as a potential therapeutic target for sepsis-induced disseminated intravascular coagulation

Sepsis-induced disseminated intravascular coagulation (DIC) is a common life-threatening terminal-stage disease with high mortality. This study aimed to identify effective miRNAs as therapeutic targets for DIC. Bioinformatics and luciferase reporter gene analyses were performed to predict miR-19a-3p and validate that it targets tissue factor (TF). Quantitative real-time PCR was used to detect the expression of miR-19a-3p and TF, and TF procoagulant activity was determined using the chromogenic substrate method. Western blotting was used to detect the protein levels of TF, AKT serine/threonine kinase (AKT), extracellular regulated protein kinases (ERK), nuclear factor kappa B (NF-κB) P65, NFKB inhibitor alpha (IκB-a) and their phosphorylated counterparts in cell experiments. Furthermore, a rat model was established to explore the potential of miR-19a-3p in DIC treatment. As a result, a human clinical study revealed that miR-19a-3p was downregulated and that TF was upregulated in neonates with sepsis-induced DIC compared with those in the control group. The luciferase reporter assay showed that TF was a direct target of miR-19a-3p. Cell experiments verified that the mRNA and protein levels of TF, and the p-AKT/AKT, p-Erk/Erk, p-P65/P65, p-IκB-a/IκB-a ratios, and TF procoagulant activity were significantly decreased in lipopolysaccharide (LPS) -induced human peripheral blood mononuclear cells (PBMCs) and human umbilical vein endothelial cells (HUVECs) inhibited by overexpression of miR-19a-3p, and that miR-19a-3p regulating TF was dependent on the NF-kB and AKT pathways. In vivo, miR-19a-3p injection into DIC rats suppressed the mRNA expression of TF; more importantly, significant improvements in coagulation function indicators and in histopathologies of lung and kidney were observed. In conclusion, miR-19a-3p may suppress DIC by targeting TF and might be a potential therapeutic target in treating sepsis-induced DIC.

Anti-thrombotic activity of phenolic acids obtained from Salvia miltiorrhiza f. alba in TNF-α-stimulated endothelial cells via the NF-κB/JNK/p38 MAPK signaling pathway

Over the past 100 years, Salvia miltiorrhiza f. alba (Lamiaceae) (RSMA) roots have been used to cure thromboangiitis obliterans (TAO) in local clinics. This study aimed to confirm the anti-thrombotic efficacy of 12 phenolic acids obtained from RSMA and to clarify the possible underlying mechanisms. The results of quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) experiments demonstrated that most of the phenolic acids markedly inhibited PAI-1 protein and mRNA levels but increased t-PA protein and mRNA levels in TNF-α-induced EA.hy926 cells (P < 0.05 or 0.001), with lithospermic acid displaying the strongest effect. In vitro anticoagulation and antiplatelet aggregation assays showed that lithospermic acid and salvianolic acid B significantly prolonged prothrombin time (PT), activated partial thromboplastin time (APTT), decreased fibrinogen concentration (FIB), and inhibited platelet aggregation induced by adenosine diphosphate (ADP) in rat blood. Both lithospermic acid and salvianolic acid B markedly down-regulated the expression of factor Xa and factor IIa on the external surface of EA.hy926 cells and demonstrated significant anti-factor IIa and anti-factor Xa activity using chromogenic substrates in vitro. Western blot results revealed that both lithospermic acid and salvianolic acid B also significantly inhibited the expression of TF, p-p65, p-p38, and pJNK proteins induced by TNF-α. These results indicated that all of the phenolic acids appeared to have some anti-thrombotic activity, with salvianolic acid B and lithospermic acid markedly decreasing the chance of thrombosis by regulating the NF-κB/JNK/p38 MAPK signaling pathway in response to TNF-α.

Host Pathways of Hemostasis that Regulate Group A Streptococcus pyogenes Pathogenicity

A hallmark feature of severe Group A Streptococcus pyogenes (GAS) infection is dysregulated hemostasis. Hemostasis is the primary pathway for regulating blood flow through events that contribute towards clot formation and its dissolution. However, a number of studies have identified components of hemostasis in regulating survival and dissemination of GAS. Several proteins have been identified on the surface of GAS and they serve to either facilitate invasion to host distal sites or regulate inflammatory responses to the pathogen. GAS M-protein, a surface-exposed virulence factor, appears to be a major target for interactions with host hemostasis proteins. These interactions mediate biochemical events both on the surface of GAS and in the solution when M-protein is released into the surrounding environment through shedding or regulated proteolytic processes that dictate the fate of this pathogen. A thorough understanding of the mechanisms associated with these interactions could lead to novel approaches for altering the course of GAS pathogenicity.

Levels of circulating microparticles in septic shock and sepsis-related complications: a case-control study

BACKGROUND

Microparticles (MP) have been largely studied as potential biomarkers in septic shock (SS) though their biological and clinical relevance is still unclear. This case-control study describes the trend of various MP subtypes during SS to evaluate their possible association with severity of illness and sepsis-related complications (disseminated intravascular coagulation [DIC] and acute kidney injury [AKI]).

METHODS

Forty patients admitted to the Intensive Care Unit with SS and 40 matched healthy volunteers were recruited. AnnexinV+, E-selectin+, thrombomodulin (TM+), leukocyte-derived (CD45+, CD36+) and platelet-derived MP (PMP-expressed as PMP/platelets ratio) were measured by flow-cytometry at baseline, on day 1, 3 and 7 after diagnosis. Severity of illness was assessed by Sequential Organ Failure Assessment Score, duration of vasoactive support and mechanical ventilation. Sepsis-related complications were considered.

RESULTS

Overall, septic patients showed higher levels of all MP considered compared to controls. TM+MP were significantly lower in more severe sepsis, while CD36+MP and PMP/platelets ratio were significantly increased in patients requiring longer vasoactive support and mechanical ventilation. As for sepsis-related complications, a higher PMP/platelets ratio in patients who developed DIC and increased E-selectin+MP in subjects who developed AKI were observed. PMP/platelets ratio at baseline was significantly associated with longer vasoactive support (OR=1.59 [1.05-2.42]), longer mechanical ventilation (OR=1.6 [1.06-2.42]) and DIC occurrence (OR=1.45 [1.08-1.96]).

CONCLUSIONS

A global response through extra-vesiculation of endothelial cells, leukocytes and platelets during the early stages of SS was confirmed. The cellular activation was detected until day 3 after diagnosis. PMP/platelets ratio at diagnosis may be useful to evaluate SS severity and DIC occurrence.

Replicative senescence promotes prothrombotic responses in endothelial cells: Role of NADPH oxidase- and cyclooxygenase-derived oxidative stress

Endothelial senescence has been suggested to promote endothelial dysfunction in age-related vascular disorders. This study evaluated the prothrombotic properties of senescent endothelial cells (ECs) and the underlying mechanism. Serial passaging from passage (P)1 to P4 (replicative senescence) of porcine coronary artery ECs, or treatment of P1 ECs with the endothelial nitric oxide synthase (eNOS) inhibitor L-NAME (premature senescence) induced acquisition of markers of senescence including increased senescence-associated-β-galactosidase (SA-β-gal) activity and p53, p21, p16 expression. Approximately 55% of P3 cells were senescent with a high level oxidative stress, and decreased eNOS-derived nitric oxide (NO) formation associated with increased expression of NADPH oxidase subunits (gp91phox, p47phox), cyclooxygenase (COX)-2 but not COX-1, and a decreased eNOS expression leading to a reduced ability of ECs to inhibit platelet aggregation. P3 cells also presented increased expression and activity of tissue factor (TF), a key initiator of the coagulation cascade. Treatment of senesecent cells with a NADPH oxidase inhibitor (VAS-2870) or by a COX inhibitor (indomethacin) reduced oxidative stress, decreased TF activity and expression, and reduced the expression of gp91phox, p47phox and COX-2 and restored the ability of ECs to inhibit effectively platelet aggregation. Thus, replicative endothelial senescence promotes a prothrombotic response involving the down-regulation of the protective NO pathway and the upregulation of the NADPH oxidase- and COXs-dependent oxidative stress pathway promoting TF expression and activity.

Modifications to the composition of the hyphal outer layer of Aspergillus fumigatus modulates HUVEC proteins related to inflammatory and stress responses

Aspergillus fumigatus, the main etiologic agent causing invasive aspergillosis, can induce an inflammatory response and a prothrombotic phenotype upon contact with human umbilical vein endothelial cells (HUVECs). However, the fungal molecules involved in this endothelial response remain unknown. A. fumigatus hyphae produce an extracellular matrix composed of galactomannan, galactosaminogalactan and α-(1,3)-glucan. In this study, we investigated the consequences of UGM1 gene deletion in A. fumigatus, which produces a mutant with increased galactosaminogalactan production. The ∆ugm1 mutant exhibited an HUVEC-hyperadhesive phenotype and induced increased endothelial TNF-α secretion and tissue factor mRNA overexpression in this "semi-professional" immune host cell. Using a shotgun proteomics approach, we show that the A. fumigatus ∆ugm1 strain can modulate the levels of proteins in important endothelial pathways related to the inflammatory response mediated by TNF-α and to stress response pathways. Furthermore, a purified galactosaminogalactan fraction was also able to induce TNF-α secretion and the coincident HUVEC pathways regulated by the ∆ugm1 mutant, which overexpresses this component, as demonstrated by fluorescence microscopy. This work contributes new data regarding endothelial mechanisms in response to A. fumigatus infection.

SIGNIFICANCE

Invasive aspergillosis is the main opportunistic fungal infection described in neutropenic hematologic patients. One important clinical aspect of this invasive fungal infection is vascular thrombosis, which could be related, at least in part, to the activation of endothelial cells, as shown in previous reports from our group. It is known that direct contact between the A. fumigatus hyphal cell wall and the HUVEC cell surface is necessary to induce an endothelial prothrombotic phenotype and secretion of pro-inflammatory cytokines, though the cell surface components of this angioinvasive fungus that trigger this endothelial response are unknown. The present work employs a discovery-driven proteomics approach to reveal the role of one important cell wall polysaccharide of A. fumigatus, galactosaminogalactan, in the HUVEC interaction and the consequent mechanisms of endothelial activation. This is the first report of the overall panel of proteins related to the HUVEC response to a specific and purified cell wall component of the angioinvasive fungus A. fumigatus.

Tissue factor expression by myeloid cells contributes to protective immune response against Mycobacterium tuberculosis infection

Tissue factor (TF) is a transmembrane glycoprotein that plays an essential role in hemostasis by activating coagulation. TF is also expressed by monocytes/macrophages as part of the innate immune response to infections. In the current study, we determined the role of TF expressed by myeloid cells during Mycobacterium tuberculosis (M. tb) infection by using mice lacking the TF gene in myeloid cells (TF(Δ) ) and human monocyte derived macrophages (MDMs). We found that during M. tb infection, a deficiency of TF in myeloid cells was associated with reduced inducible nitric oxide synthase (iNOS) expression, enhanced arginase 1 (Arg1) expression, enhanced IL-10 production and reduced apoptosis in infected macrophages, which augmented M. tb growth. Our results demonstrate that a deficiency of TF in myeloid cells promotes M2-like phenotype in M .tb infected macrophages. A deficiency in TF expression by myeloid cells was also associated with reduced fibrin deposition and increased matrix metalloproteases (MMP)-2 and MMP-9 mediated inflammation in M. tb infected lungs. Our studies demonstrate that TF expressed by myeloid cells has newly recognized abilities to polarize macrophages and to regulate M. tb growth.

In vitro endothelial cell damage is positively correlated with enhanced virulence and poor vancomycin responsiveness in experimental endocarditis due to methicillin-resistant Staphylococcus aureus

The pathogenesis of Staphylococcus aureus infective endocarditis (IE) is postulated to involve invasion and damage of endothelial cells (ECs). However, the precise relationships between S. aureus-EC interactions in vitro and IE virulence and treatment outcomes in vivo are poorly defined. Ten methicillin-resistant S. aureus (MRSA) clinical isolates previously tested for their virulence and vancomycin responsiveness in an experimental IE model were assessed in vitro for their haemolytic activity, protease production, and capacity to invade and damage ECs. There was a significant positive correlation between the in vitro EC damage caused by these MRSA strains and their virulence during experimental IE (in terms of bacterial densities in target tissues; P < 0.02). Importantly, higher EC damage was also significantly correlated with poor microbiological response to vancomycin in the IE model (P < 0.001). Interestingly, the extent of EC damage was unrelated to a strain's ability to invade ECs, haemolytic activity and protease production, or β-toxin gene transcription. Inactivation of the agr locus in two MRSA strains caused ∼20% less damage as compared with the corresponding parental strains, indicating that a functional agr is required for maximal EC damage induction. Thus, MRSA-induced EC damage in vitro is a unique virulence phenotype that is independent of many other prototypical MRSA virulence factors, and may be a key biomarker for predicting MRSA virulence potential and antibiotic outcomes during endovascular infections.

Bench-to-bedside review: circulating microparticles--a new player in sepsis?

In sepsis, inflammation and thrombosis are both the cause and the result of interactions between circulating (for example, leukocytes and platelets), endothelial and smooth muscle cells. Microparticles are proinflammatory and procoagulant fragments originating from plasma membrane generated after cellular activation and released in body fluids. In the vessel, they constitute a pool of bioactive effectors pulled from diverse cellular origins and may act as intercellular messengers. Microparticles expose phosphatidylserine, a procoagulant phospholipid made accessible after membrane remodelling, and tissue factor, the initiator of blood coagulation at the endothelial and leukocyte surface. They constitute a secretion pathway for IL-1β and up-regulate the proinflammatory response of target cells. Microparticles circulate at low levels in healthy individuals, but undergo phenotypic and quantitative changes that could play a pathophysiological role in inflammatory diseases. Microparticles may participate in the pathogenesis of sepsis through multiple ways. They are able to regulate vascular tone and are potent vascular proinflammatory and procoagulant mediators. Microparticles' abilities are of increasing interest in deciphering the mechanisms underlying the multiple organ dysfunction of septic shock.

Lucio's phenomenon is a necrotizing panvasculitis: mostly a medium-sized granulomatous arteritis

Lucio's phenomenon (LPh) is a vasculitis clinically described in 1852 and microscopically documented in 1948 in patients with diffuse lepromatous leprosy; however, at present, there is no a clear concept about the pathogenesis of the necrosis, or about the type, size, and site of the damaged vessel. The objective of this study was to elucidate the type, size, site, and form of vessel damage in LPh in a retrospective, clinical, and histopathological study. Clinical information was obtained from the charts and records and/or from the histopathology request. Slides stained with hematoxylin and eosin, Ziehl-Neelsen, and Fite-Faraco were retrieved from our files. Direct immunofluorescence had been performed in 6 cases. Twelve cases fulfilled clinical evidence to make unequivocal diagnosis of diffuse lepromatous leprosy with LPh. All of them had necrotic, irregular, purpuric, and/or ulcerative lesions, which under the microscope showed medium-sized arteries, with their walls involved by clusters of macrophages containing large amounts of bacilli, distortion of the structure of the vessel wall, narrowing, and obliteration of their lumen. Smaller vessels showed changes of the leukocytoclastic type. LPh is a distinctive type of granulomatous and necrotizing panvasculitis; the involved vessels are mostly medium-sized arteries, located deeply in the skin, at the base, and within the hypodermis, but any other vessel is likewise involved, their occlusion leads to ischemic necrosis of the whole skin, frequently with detachment of the epidermis. These changes explain clearly and logically the clinical features observed more than 150 years ago.

Polarized response of endothelial cells to invasion by Aspergillus fumigatus

Hyphal invasion of blood vessels is a prominent feature of invasive aspergillosis. During invasive pulmonary aspergillosis, Aspergillus fumigatus hyphae invade the abluminal endothelial cell surface, whereas they invade the luminal endothelial cell surface during haematogenous dissemination. We investigated the endothelial cell response to abluminal and luminal infection with A. fumigatus hyphae in vitro. We found that these hyphae invaded the abluminal endothelial cell surface without inducing the formation of endothelial cell pseudopods. Also, the internalized hyphae were surrounded by a loose network of microfilaments. In contrast, A. fumigatus hyphae invaded the luminal endothelial cell surface by inducing by the formation of endothelial cell pseudopods. These endocytosed hyphae were surrounded by a tight network of microfilaments. Abluminal infection induced greater E-selectin, IL-8, tissue factor and TNF-alpha gene expression, but less endothelial cell damage than did luminal infection. Endothelial cell stimulation by infection of either surface was mediated by endothelial cell-derived TNF-alpha, and was not influenced by gliotoxin secreted by A. fumigatus. These differences in the endothelial cell response to abluminal versus luminal infection may contribute to differences in the pathogenesis of invasive versus haematogenously disseminated aspergillosis.

Altered biochemical parameters in the saliva of patients with breast cancer

Saliva plays an important role in the protection of oral cavity and alterations in either salivary flow rate or protein composition may have dramatic effects on oral health. Prevention and management of oral complications of cancer and cancer therapy will improve oral function and quality of life, and reduce morbidity and the cost of care. The aim of this study was to investigate the saliva of patients with breast cancer biochemically and cytologically and compare with healthy controls. Accordingly, lipid peroxidation (LPO), total protein, salivary flow rate, and pH levels were measured in the saliva samples obtained from 20 breast cancer patients and 11 healthy individuals. Tissue factor (TF) is a major regulator of normal hemostasis and thrombosis, and TF activity of saliva samples was evaluated. Under the conditions used, patients with breast cancer present a significant reduction in total protein, pH and LPO levels. Salivary TF activity was higher in breast cancer patients than that in control subjects, but the degree of increase was not statistically significant. In addition, the analysis of saliva samples by SDS polyacrylamide gel electrophoresis showed the retarded mobility of the 66-kDa proteins and the increased proteins of about 36 kDa in the patient group. Some patients with breast cancer had increased number of leucocytes. Importantly, dysplastic cells and yeast cells were detected only in saliva samples of cancer patients. Decreased salivary LPO may be considered as a risk factor for breast cancer.

[Microparticles during sepsis and trauma. A link between inflammation and thrombotic processes]

Sepsis and trauma lead to a sustained activation of monocytes and endothelium. In the vascular compartment, stimulated cells release microparticles. Circulating MP provide an additional procoagulant phospholipid surface enabling the assembly of the clotting enzymes complexes and thrombin generation. Their procoagulant properties rely on the exposition of phosphatidylserine, made accessible after cell stimulation and on the possible presence of tissue factor, the main cellular initiator of blood coagulation. Microparticles constitute the main reservoir of blood-borne tissue factor activity. At sites of endothelium injury, enhanced release or recruitment of procoagulant MP through P-selectin-PSGL-1 pathway could concentrate TF activity above a threshold allowing blood coagulation to be triggered. Converging evidences from experimental or clinical data highlight a role for MP harboring tissue factor in the initiation of disseminated intravascular coagulopathy. In these settings, the pharmacological modulation of MP levels or biological functions through activated protein C or factor VIIa allows challenging issues.

Cell vesiculation and immunopathology: implications in cerebral malaria

Microparticles are plasma membrane fragments that are generated and released under physiological conditions. They are also released when tissue and/or systemic homeostasis is disrupted. These microparticles display different physiological features of the cells from which they originate. They are detected in some pathological conditions, but rarely suspected of participating in the disease's pathogenesis. In the present review, we summarise data about the production of the microparticles, their biological significance and potential role during microorganism-driven processes, especially in cerebral malaria.

Role of the tissue factor pathway in the pathogenesis and management of multiple organ failure

Sepsis is caused by a dysregulated immune response to infection and, without intervention, can lead to septic shock and multiple organ failure. A leading cause of morbidity and mortality in intensive care units worldwide, severe sepsis is also associated with a considerable cost burden that places significant strain on global healthcare budgets. The development of an efficacious and cost-effective treatment strategy is therefore of vital importance to today's intensive care physicians. This paper will examine the pathophysiology of sepsis and multiple organ dysfunction before reviewing trials recently undertaken to investigate three potential anticoagulant therapies: antithrombin III, activated protein C, and tissue factor pathway inhibitor. Finally, other recent developments in the care of sepsis patients will be briefly examined.