HIV-1 induces in vivo platelet activation by enhancing platelet NOX2 activity.

OBJECTIVES: HIV-1 patients show increased platelet activation, but the mechanisms involved are not completely clarified. We speculated that HIV-1 might induce in vivo platelet activation by enhancing platelet NOX2-related oxidative stress. METHODS: We measured soluble CD40 Ligand (sCD40L), a systemic marker of platelet activation, in 36 HIV-1 patients under effective combined antiretroviral therapy (cART) and in 10 naïve HIV-1 subjects. As control, 20 healthy subjects (HS) were included. Platelet oxidative stress was measured by platelet NOX2-derived peptide (sNOX2-dp), p47(phox) translocation to platelet membrane and platelet prostaglandin F2α (8-iso-PGF2α). RESULTS: sCD40L was increased both in HIV-1 naïve and cART patients compared to HS (p < 0.001). Platelet sNOX2-dp and 8-iso-PGF2α were significantly higher in HIV-1 naïve subjects compared to those on cART and to HS, and both were mutually correlated (R = 0.734, p < 0.001). A stepwise multivariable linear regression analysis showed that platelet sNOX2-dp (β: 0.803, p < 0.001), HIV-1 infection (β: 0.146, p = 0.014) and age (β: 0.166, p = 0.001) were independently associated to sCD40L levels. CONCLUSIONS: HIV-1 infection is associated with increased platelet oxidative stress, which was related to the activation of NOX2. The independent association between platelet NOX2 activation and plasma levels of sCD40L suggest that in vivo platelet activation may be dependent upon platelet oxidative stress

High-Mobility Group Box 1 Protein in Human and Murine Skin: Involvement in Wound Healing

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Function and dysfunction of the PI system in membrane trafficking

The phosphoinositides (PIs) function as efficient and finely tuned switches that control the assembly–disassembly cycles of complex molecular machineries with key roles in membrane trafficking. This important role of the PIs is mainly due to their versatile nature, which is in turn determined by their fast metabolic interconversions. PIs can be tightly regulated both spatially and temporally through the many PI kinases (PIKs) and phosphatases that are distributed throughout the different intracellular compartments. In spite of the enormous progress made in the past 20 years towards the definition of the molecular details of PI–protein interactions and of the regulatory mechanisms of the individual PIKs and phosphatases, important issues concerning the general principles of the organisation of the PI system and the coordination of the different PI-metabolising enzymes remain to be addressed. The answers should come from applying a systems biology approach to the study of the PI system, through the integration of analyses of the protein interaction data of the PI enzymes and the PI targets with those of the ‘phenomes' of the genetic diseases that involve these PI-metabolising enzymes

Secreted Gal-3BP is a novel promising target for non-internalizing Antibody–Drug Conjugates

Abstract Galectin-3-binding protein (Gal-3BP) has been identified as a cancer and metastasis-associated, secreted protein that is expressed by the large majority of cancers. The present study describes a special type of non-internalizing antibody-drug-conjugates that specifically target Gal-3BP. Here, we show that the humanized 1959 antibody, which specifically recognizes secreted Gal-3BP, selectively localized around tumor but not normal cells. A site specific disulfide linkage with thiol-maytansinoids to unpaired cysteine residues of 1959, resulting in a drug-antibody ratio of 2, yielded an ADC product, which cured A375m melanoma bearing mice. ADC products based on the non-internalizing 1959 antibody may be useful for the treatment of several human malignancies, as the cognate antigen is abundantly expressed and secreted by several cancers, while being present at low levels in most normal adult tissues

Association Between Preexisting Versus Newly Identified Atrial Fibrillation and Outcomes of Patients With Acute Pulmonary Embolism

Background Atrial fibrillation (AF) may exist before or occur early in the course of pulmonary embolism (PE). We determined the PE outcomes based on the presence and timing of AF. Methods and Results Using the data from a multicenter PE registry, we identified 3 groups: (1) those with preexisting AF, (2) patients with new AF within 2 days from acute PE (incident AF), and (3) patients without AF. We assessed the 90-day and 1-year risk of mortality and stroke in patients with AF, compared with those without AF (reference group). Among 16 497 patients with PE, 792 had preexisting AF. These patients had increased odds of 90-day all-cause (odds ratio [OR], 2.81; 95% CI, 2.33-3.38) and PE-related mortality (OR, 2.38; 95% CI, 1.37-4.14) and increased 1-year hazard for ischemic stroke (hazard ratio, 5.48; 95% CI, 3.10-9.69) compared with those without AF. After multivariable adjustment, preexisting AF was associated with significantly increased odds of all-cause mortality (OR, 1.91; 95% CI, 1.57-2.32) but not PE-related mortality (OR, 1.50; 95% CI, 0.85-2.66). Among 16 497 patients with PE, 445 developed new incident AF within 2 days of acute PE. Incident AF was associated with increased odds of 90-day all-cause (OR, 2.28; 95% CI, 1.75-2.97) and PE-related (OR, 3.64; 95% CI, 2.01-6.59) mortality but not stroke. Findings were similar in multivariable analyses. Conclusions In patients with acute symptomatic PE, both preexisting AF and incident AF predict adverse clinical outcomes. The type of adverse outcomes may differ depending on the timing of AF onset.info:eu-repo/semantics/publishedVersio

Lipid-transfer proteins in membrane trafficking at the Golgi complex

The Golgi complex (GC) represents the central junction for membrane trafficking. Protein and lipid cargoes continuously move through the GC in both anterograde and retrograde directions, departing to and arriving from diverse destinations within the cell. Nevertheless, the GC is able to maintain its identity and strict compartmentalisation, having a different composition in terms of protein and lipid content compared to other organelles. The discovery of coat protein complexes and the elucidation of their role in sorting cargo proteins into specific transport carriers have provided a partial answer to this phenomenon. However, it is more difficult to understand how relatively small and diffusible molecules like lipids can be concentrated in or excluded from specific subcellular compartments. The discovery of lipid-transfer proteins operating in the secretory pathway and specifically at the GC has shed light on one possible way in which this lipid compartmentalisation can be accomplished. The correct lipid distribution along the secretory pathway is of crucial importance for cargo protein sorting and secretion. This review focuses on what is now known about the putative and effective lipid-transfer proteins at the GC, and on how they affect the function and structure of the GC itself

Lipid-transfer proteins in membrane trafficking at the Golgi complex

The Golgi complex (GC) represents the central junction for membrane trafficking. Protein and lipid cargoes continuously move through the GC in both anterograde and retrograde directions, departing to and arriving from diverse destinations within the cell. Nevertheless, the GC is able to maintain its identity and strict compartmentalisation, having a different composition in terms of protein and lipid content compared to other organelles. The discovery of coat protein complexes and the elucidation of their role in sorting cargo proteins into specific transport carriers have provided a partial answer to this phenomenon. However, it is more difficult to understand how relatively small and diffusible molecules like lipids can be concentrated in or excluded from specific subcellular compartments. The discovery of lipid-transfer proteins operating in the secretory pathway and specifically at the GC has shed light on one possible way in which this lipid compartmentalisation can be accomplished. The correct lipid distribution along the secretory pathway is of crucial importance for cargo protein sorting and secretion. This review focuses on what is now known about the putative and effective lipid-transfer proteins at the GC, and on how they affect the function and structure of the GC itself

The multiple roles of PtdIns(4)P - Not just the precursor of PtdIns(4,5)P2

The phosphoinositides (PIs) are membrane phospholipids that actively operate at membrane-cytosol interfaces through the recruitment of a number of effector proteins. In this context, each of the seven different PI species represents a topological determinant that can establish the nature and the function of the membrane where it is located. Phosphatidylinositol 4-phosphate (PtdIns(4)P) is the most abundant of the monophosphorylated inositol phospholipids in mammalian cells, and it is produced by D-4 phosphorylation of the inositol ring of PtdIns. PtdIns(4)P can be further phosphorylated to PtdIns(4,5)P(2) by PtdIns(4)P 5-kinases and, indeed, PtdIns(4)P has for many years been considered to be just the precursor of PtdIns(4,5)P(2). Over the last decade, however, a large body of evidence has accumulated that shows that PtdIns(4)P is, in its own right, a direct regulator of important cell functions. The subcellular localisation of the PtdIns(4)P effectors initially led to the assumption that the bulk of this lipid is present in the membranes of the Golgi complex. However, the existence and physiological relevance of ;non-Golgi pools' of PtdIns(4)P have now begun to be addressed. The aim of this Commentary is to describe our present knowledge of PtdIns(4)P metabolism and the molecular machineries that are directly regulated by PtdIns(4)P within and outside of the Golgi complex