Search Results (78)

Hypoglycemia is associated with cardiovascular events reflected by platelet abnormalities. We hypothesized that sequential endothelial changes may occur during hypoglycemia that may enhance cardiovascular risk. In type 2 diabetes (T2D) (n = 23) and controls (n = 23), blood SOMAscan proteomic analysis of endothelial proteins at baseline, insulin-induced hypoglycemia and post hypoglycemia to 24 h were examined using repeated-measures linear mixed modeling with a prospective parallel study design. Most endothelial proteins that changed over time did not differ between groups. Baseline levels of P-selectin, plasminogen activator inhibitor-1 (PAI-1; serpine-1), E-selectin and angiopoietin-1 (ANGPT1) were significantly higher, whilst cadherin-5 was lower in T2D. Several proteins exhibited changes versus baseline in both T2D and controls. Under hypoglycemia, decreases in cadherin-5 and soluble angiopoietin-1 receptor (sTie-2) were observed, with increased P-selectin, intercellular adhesion molecule-3 (ICAM3), ANGPT1 and PAI-1. Post hypoglycemia, decreased cadherin-5 and ICAM5 were observed at 2 h and PAI-1 at 4 h, as well as increases in P-selectin at 30 min, 1 h and 24 h and ICAM3 at 24 h. Post hypoglycemia, E-selectin, P-selectin and ICAM3 were significantly lower in T2D patients at 2 h, while PAI-1 was significantly lower at 4 h and ICAM3 was significantly lower at 24 h. Baseline endothelial proteins differed between T2D and controls, which may suggest local endothelial inflammatory activation leading to a pro-thrombotic, destabilized vascular phenotype characteristic of diabetic vasculopathy. Hypoglycemia may exacerbate this towards a pro-adhesive and pro-thrombotic phenotype, worsening endothelial dysfunction. Full article

Background: Biomarker analysis in neurodegeneration with brain iron accumulation (NBIA) can offer valuable insights into the disease’s pathology and natural history. Methods: Twenty-five patients with C19orf12 mutations causing mitochondrial membrane protein-associated neurodegeneration (MPAN), 12 patients with PANK2 mutations causing pantothenate kinase-associated neurodegeneration (PKAN), and 30 age- and gender-matched controls were studied. Serum levels of MMP-9, S100B, ICAM-1, E- and P-selectins, total α-synuclein, neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), Tau, ubiquitin-C-terminal hydrolase-L1 (UCH-L1), and brain-derived neurotrophic factor (BDNF) were measured. Clinical status was evaluated with dedicated rating scales. Results: Compared to the control group, MPAN patients had significantly higher serum levels of nearly all biomarkers, except BDNF. NfL, GFAP, and UCH-L1, were elevated by 5, 2, and 3.5 times, respectively. PKAN patients showed no significant differences in GFAP, UCH-L1, and S100B levels compared to controls. However, NfL and Tau levels were increased by 3 and 1.8 times, respectively. A correlation was observed between disease severity and levels of NfL, Tau, and UCH-L1 in MPAN, and GFAP, Tau, and UCH-L1 in PKAN. Conclusions: Patients with MPAN and PKAN showed increased levels of neurodegeneration biomarkers. Elevated inflammation and blood–brain barrier dysfunction biomarkers were specific to MPAN patients. Full article

Background/Objectives: Endothelial activation by lipopolysaccharides (LPS) contributes to inflammation and the development of cardiovascular disease, making n-3 polyunsaturated fatty acids (PUFAs) potential modulators capable of mitigating endothelial dysfunction. The current study examines the effects of long-chain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), along with their precursor, α-linolenic acid (ALA), on oxidative stress, adhesion molecule expression, and cytokine milieu in LPS-stimulated human aortic endothelial cells (HAECs). Methods: HAECs (fifth passage) were cultured in control medium under standard conditions: ~37 °C, 5% CO₂, ≥80% humidity. Cells were incubated in control basal cell medium or medium supplemented with ALA, EPA, DHA, and their combination (50 µM; n = 5 per group). After 48 h, cells were treated overnight (~16 h) with LPS from E. coli (0.75 and 1 µg/mL). HAECs and supernatants were collected for flow cytometry, Luminex, and ELISA assays. Significance was assessed using two-way analysis of variance ANOVA, followed by post hoc analyses (p < 0.05). Spearman’s correlation analysis was performed between markers, and p-values were adjusted using the Benjamini–Hochberg (BH) correction. Results: PUFA supplementation, particularly with DHA and ALA, significantly reduced intracellular reactive oxygen species (ROS) production and the expression of adhesion molecules (ICAM-1, E-selectin) in HAECs under both basal and LPS-stimulated inflammatory conditions. All PUFAs reduced pro-inflammatory cytokine levels (IFNγ, TNFα, IL-6), while ALA increased IL-1α and endoglin expression, indicating differential immunomodulatory effects. EPA exhibited antioxidant and anti-inflammatory effects primarily at higher LPS concentrations. Correlation analysis demonstrated strong interdependence between oxidative stress, inflammatory markers, and vascular activation, further confirming PUFA-mediated endothelial protection. Conclusions: PUFA supplementation produced molecule-specific effects on endothelial inflammation. DHA and ALA consistently showed anti-inflammatory and antioxidative effects, while EPA’s beneficial effect was more pronounced under inflammatory conditions, emphasising the importance of PUFA type and context in managing vascular inflammation. Full article

Calafate berry, an ancient perennial shrub of South America (Chile and Argentina), produces a high antioxidant capacity berry with a high polyphenol (1344.2–6553 mg GAE/100 g d.w.) and anthocyanin (26.5–80 mg C-3-G/100 g d.w.) content. The beneficial effects of calafate berries on human health are related to the anti-inflammatory, hypoglycemic, anticancer, and antioxidant properties that the berries possess, which have been confirmed through evidence to date, primarily from in vitro, ex vivo, and animal studies. Several investigations have shown a relationship between the consumption of calafate and a reduction in the risk of contracting cardiovascular diseases (CVD). This was evident in changes in plasma level biomarkers related to CVD, such as thrombomodulin (−24%), adiponectin (+68%), sE-selectin (−34%), sICAM-1 (−24%) and proMMP-9 (−31%), and changes in the production of OH radicals in plasma (−17%) after calafate intake. Calafate may have an antithrombotic role that supports cardiovascular health by lowering the Atherogenic and Cardiovascular Risk Indices. Various authors indicate delphinidin-3-glucoside (384–386 mg/100 g) as the primary bioactive compound responsible for the beneficial properties of Calafate. Although some studies report calafate’s health benefits, scientific evidence, especially in humans, remains limited. Meanwhile, Chile is working to domesticate and cultivate calafate, aiming to turn it from a wild native berry into a sustainable crop for use in the antioxidants and nutraceuticals industry. The lack of human clinical trials emphasizes the need for future research to validate calafate’s health benefits berry. Full article

Obesity is a risk factor for numerous complications, including atherosclerosis, the pathogenesis of which is complex. The aim of our study is to evaluate serum levels of E-selectin and hs-CRP and pulse wave velocity (PWV) as atherosclerosis risk factors and to explore their relationship with advanced glycation end products (AGEs), methylgioxal (MG) and skin autofluorescence (sAF). We evaluated 125 children aged 8–18 years with simple obesity, stratified into two subgroups based on SDS BMI (Group I: 2–4; Group II: >4), and compared them with 33 age-matched peers of normal weight. Children with obesity exhibited significantly elevated serum concentrations of AGEs, MG, E-selectin, and hs-CRP relative to the control group. Additionally, both height-normalized pulse wave velocity (SDS PWV) and sAF values were significantly higher in the children with obesity compared to their normal-weight counterparts. Except for sAF, which was elevated in children with obesity with a higher SDS BMI, no significant differences were observed among the subgroups of children. Positive correlations were observed between E-selectin and AGEs, MG and SDS PWV, as well as sAF and SDS BMI. Our findings indicate that children with obesity exhibit early signs of atherosclerotic changes, regardless of the degree of obesity. Moreover, circulating AGEs may represent a more reliable biomarker of atherosclerosis risk than sAF, as suggested by the strong positive correlation between AGEs and E-selectin. Further studies are warranted to validate these findings. Full article

Living kidney transplantation offers the best results for end-stage renal disease patients, but concerns about cardiovascular risk after nephrectomy for kidney donors have been raised. We aimed to estimate the contribution of renal function to endothelial dysfunction (ED) and subclinical inflammation in a non-interventional, prospective, multicenter, longitudinal study with two cohorts: living kidney donors and their transplant recipients (registered clinical trial NCT02515643). The measured glomerular filtration rate (mGFR) by iohexol clearance, estimated GFR according to the CKD-EPI and MDRD-4 formulas, and levels of endothelial dysfunction (sVCAM-1, sICAM-1, E-selectin, von Willebrand Factor, pentraxin, and urinary albumin-to-creatinine ratio) and subclinical inflammation biomarkers (sIL-6, sTNF-R1, sTNF-R2, sTWEAK, and high-sensitivity C-reactive protein) were determined at baseline and 1-year follow-up. Fifty pairs of donors and recipients were recruited between 2015 and 2018. Among the endothelial dysfunction biomarkers, sVCAM-1 increased in donors and decreased in recipients (p < 0.01) while, among the inflammation biomarkers, sTNFR1 and sTNFR2 significantly increased in donors and decreased in recipients (p < 0.001). After transplantation, parallel increases and decreases in ED and subclinical inflammation biomarkers were observed in the donor and recipient cohorts, respectively. Long-term follow-up is needed to characterize the cardiovascular risk associated with these changes. Full article

Atherosclerosis as a multifactorial disease remains the first cause of death worldwide. Current oral lipid-lowering drugs (especially statins) reduce low-density lipoprotein cholesterol (LDLC) levels in the blood, but their clinical efficacy seems to be partially attributed to pleiotropic effects on different pathophysiologic factors of atherosclerosis extending beyond lipid-lowering properties such as anti-inflammatory, antithrombotic and antioxidative features. Novel drugs that interfere with proprotein convertase subtilisin/kexin type 9 (PCSK9) axis of LDL-C receptors (LDLRs) degradation, from the group of monoclonal antibodies (e.g., alirocumab, evolocumab) or small interfering RNA (siRNA), e.g., inclisiran, are effective in reducing LDLC as well. However, data depicting their antithrombotic and antiplatelet activity are scarce, whereas prothrombotic properties of PCSK9 are widely described. Thus, we performed a study to assess the effects of inclisiran on subclinical prothrombotic [fibrinogen, coagulation factor VIII (FVIII), plasminogen activator inhibitor-1 (PAI-1)] and platelet activation markers (platelet factor-4 (PF-4), soluble p-selectin (sCD62P)). Ten patients at high cardiovascular risk with concomitant heterozygous familial hypercholesterolemia (HeFH)—study group 1, and fourteen patients at very high cardiovascular risk without concomitant HeFH—study group 2, were recruited for the study. Lipid profile, subclinical prothrombotic and platelet activation markers were assessed at the beginning and after 3 months of therapy with inclisiran. During therapy, statistically significant reductions in both study groups were seen in total cholesterol levels (study group 1: from 287.6 ± 94.2 to 215.2 ± 89.1 (mg/dL), p = 0.022; study group 2: from 211.7 ± 52.7 to 147.6 ± 55.4 (mg/dL), p < 0.001) and LDL-c (study group 1: from 180.8 ± 73.3 to 114.7 ± 71.5 (mg/dL), p = 0.031; study group 2: from 129.6 ± 46.8 to 63.4 ± 43.6 (mg/dL), p < 0.001). Lipid profile changes were associated with significant decrease in the concentration of FVIII in both groups (study group 1: from 33.3 ± 22 to 22 ± 14.5 (ng/mL), p = 0.006; study group 2: from 37 ±16.9 to 29.3 ±16.4 (ng/mL), p = 0.002) and fibrinogen, but only in study group 2 (from 51.4 (33.2–72.7) to 42.6 (31.3–57.2) (µg/mL), p = 0.035). Among platelet activation markers, a significant decrease in PF-4 in study group 2 was noted (from 286 (272–295.5) to 272 (268–281.5) (ng/mL), p = 0.047). However, there were no statistically significant changes in PAI-1 and sCD62P throughout the study. In our study, inclisiran appeared to be an effective lipid-lowering drug in patients at high cardiovascular risk. Moreover, it was shown that beyond lipid-lowering properties, the drug may also partially affect thrombogenesis and platelet activation. Full article

Endothelial activation and cell adhesion molecules (CAMs) are exacerbated in the interaction of HIV infection and pre-eclampsia. This study compares the levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1), and E-selectin (sE-selectin) in HIV-infected normotensive pregnant versus pre-eclamptic women. We investigated the plasma concentration of sVCAM-1, sICAM-1, and sE-selectin in normotensive pregnant women (n = 40) and pre-eclamptic women (n = 40) using an immunoassay procedure. The concentrations of both sVCAM-1 (p < 0.0083) and sE-selectin (p < 0.0260) were significantly different from sICAM-1 in pre-eclampsia compared to normotensive pregnant groups, irrespective of HIV status. In contrast to sVCAM-1, sICAM-1 (p = 0.0349) and sE-selectin (p < 0.0445) concentrations were significantly elevated in HIV-positive compared to HIV-negative groups, regardless of pregnancy type. In pregnancies complicated by HIV, statistically significant differences in ICAM-1 concentration were observed between pre-eclamptic HIV-positive versus pre-eclamptic HIV-negative groups (p < 0.0010). Similarly, sVCAM-1 levels differed significantly between pre-eclamptic HIV-negative and normotensive HIV-positive groups (p < 0.0139). In contrast, sE-selectin levels varied significantly between pre-eclamptic HIV-positive versus normotensive HIV-negative groups (p < 0.0485). We report a dysregulation of sICAM-1, sVCAM-1, and SE-selectin in the co-morbidity of pre-eclampsia in pregnant women living with HIV. This differential expression may be attributed to oxidative stress emanating from the hypoxic endothelial activation in both pre-eclampsia and HIV infection and exacerbated by the immune restorative action of antiretroviral therapy. Full article

Background: TGF-β is an immunosuppressive cytokine. Its signaling pathway plays a role in anti-inflammatory responses. Coronary artery disease (CAD) is a clinical consequence of atherosclerosis, which manifests as chronic inflammation and involves platelet mediators, including TGF-β. The aim of this study is to validate the diagnostic utility of TGF-β levels in relation to classical and molecular risk factors for CAD. Methods: The study group included 25 women and 75 men, all aged up to 55 and 50 years, respectively, who had been diagnosed with early-onset CAD. Fasting blood samples were taken to measure plasma levels of TGF-β, sCD36, PCSK9, TNF, VEGF, IL-6, and E-selectin using the ELISA method. Furthermore, a full lipid profile, apolipoproteins (Lp(a), ApoA1, and ApoB), C-reactive protein (hsCRP), and blood morphology were analyzed at the Central Hospital Laboratory. A physical examination was also performed. Results: Positive associations were observed between TGF-β concentration and TNF, platelet count, PTC, and triglyceride levels. TNF and platelet concentration were significant independent predictors of increased plasma TGF-β levels. None of the clinical parameters showed statistically significant associations with plasma TGF-β concentration. Conclusions: Our research has demonstrated that TGF-β levels, including circulating TNF, triglycerides, and platelets, are linked to specific biochemical risk factors in early-onset CAD cases. Full article

Fine particulate matter (PM) 2.5 is the main component of air pollution causing pathological responses primarily in the respiratory and cardiovascular systems. Therefore, it is urgent to explore valid strategies to inhibit the adverse reactions induced by PM2.5. In our previous studies, we have revealed that intratracheal instillation of PM2.5 evoked airway remodeling, pulmonary inflammatory, and oxidative stress responses in rat lungs by upregulating VEGFA levels in bronchial epithelial cells and by activating ANGII/AT1R axis activation in vascular endothelial cells. The same results were obtained when human bronchial epithelial cells (Beas−2B) and human umbilical vein endothelial cells (HUVECs) cells were exposed to PM2.5 in vitro. Curcumin is a dietary polyphenol with protective properties, including anti−inflammatory and antioxidant effects. This study aims to determine the potential role of curcumin in protecting against PM2.5−induced adverse responses in the bronchial epithelium and vascular endothelium and the mechanism involved. To this end, we pretreated cells with curcumin (diluted 1000 times in sterile saline) for 2 h and then exposed them to PM2.5. Our results from RT−PCR, a luciferase reporter assay, and ELISA indicated that curcumin pretreatment effectively inhibited PM2.5−induced VEGFA elevation in Beas−2B cells by over 60% via blocking HIF1α accumulation and HIF1 transactivity, Moreover, curcumin also exerted a protective role in suppressing PM2.5−induced ANGII/AT1R axis components expression in HUVEC by over 90% via targeting the transcriptional factors, AP−1 and HIF1. Under the same conditions, curcumin pretreatment also blocked the downstream signaling events following ANGII/AT1R pathway activation, the increase in chemokines and cell adhesion molecules (sICAM−1, VCAM−1, E−Selectin, P−Selectin, IL−8, MCP−1) that drive monocyte−endothelial cell adhesion, as well as the elevated production of oxidative stress mediators (ROS and MDA) in HUVECs according to the data from immunofluorescence and flow cytometric assays. Most importantly, administration of curcumin resulted in an 80% reduction of the HIF1− and AP−1−dependent upregulation of VEGFA and AGT/AT1R axis components and impeding the resultant pro−inflammatory and oxidative responses in the lung of the rats exposed to PM2.5. Taking these data together, we disclosed the important role and mechanism of curcumin in protecting against PM2.5−induced adverse reactions in the bronchial epithelium and vascular endothelium. Curcumin might be used as a feasible and safe dietary agent to reduce the health risk of PM2.5. Full article

Inflammatory Bowel Disease (IBD) is a group of chronic intestinal diseases, among which Crohn’s disease (CD) and ulcerative colitis (UC) represent the two main types. The differential diagnosis of these two disorders is often a significant challenge, as there is a lack of specific and non-invasive biomarkers. In this study, we assessed the serum profile of proinflammatory mediators (E- and P-selectin, CCL2, IL-1α, IL-12p70, TNF-α) in patients with IBD to identify biomarkers helpful in the differential diagnosis of CD and UC. The conducted statistical analyses revealed a significant increase in E-selectin, P-selectin, IL-1α, and IL-12p70 levels in the serum of CD patients compared to UC. The performed ROC curve analysis identified moderate values of E-selectin (AUC 0.752), P-selectin (AUC 0.733), and IL-1α (AUC 0.731) in differentiating CD from UC, while IL-12p70 presented a satisfactory value (AUC 0.695). Simultaneous measurements of each biomarker with serum calprotectin improved the ability of E-selectin (AUC 0.752 vs. 0.829), P-selectin (AUC 0.733 vs. 0.75), IL-1α (AUC 0.731 vs. 0.778), and IL-12p70 (AUC 0.695 vs. 0.714) to differentiate CD from UC. Moreover, we identified a significant relationship between the concentration of CCL2 (r = 0.566, p < 0.005) and TNF-α (r = 0.431, p < 0.05) and the disease activity expressed as the Mayo score in the UC group. We also identified a significant relationship between the concentration of E-selectin (r = 0.372, p < 0.05), CCL-2 (r = 0.55, p < 0.05), IL-1α (r = 0.637, p < 0.005), and TNF-α in the group of patients with UC. Another significant correlation in the UC group was noted in the case of E-selectin and IL-12p70 (r = 0.542, p < 0.05), as well as between IL1-α and P-selectin (r = 0.514, p < 0.05). The results obtained in this study indicate the potential use of E-selectin, P-selectin, IL-1α, and IL-12p70 serum profiles in differentiating CD from UC. Regarding the significant relationship of CCL2 and TNF-α with the Mayo score, these two biomarkers might be useful in assessing and monitoring the disease activity during UC. Full article

While the pathology of acute hemorrhagic fever with renal syndrome (HFRS) has been widely researched, details on the chronic HFRS sequelae remain mainly unexplored. In this study, we analyzed the clinical and laboratory characteristics of 30 convalescent HFRS patients 14 years after the disease contraction, mainly emphasizing several endothelial dysfunction parameters. Convalescent HFRS patients exhibited significantly higher serum levels of erythrocyte sedimentation rate, von Willebrand factor, uric acid, C-reactive protein and immunoglobulin A when compared to healthy individuals. Furthermore, 24 h urine analyses revealed significantly lower sodium and potassium urine levels, as well as significantly higher proteinuria, microalbumin levels and β2-microglobulin levels when compared to healthy individuals. First morning urine analysis revealed significantly higher levels of hematuria in convalescent HFRS patients. None of the additional analyzed endothelium dysfunction markers were significantly different in post-HFRS patients and healthy individuals, including serum and urine P-selectin, E-selectin, soluble intercellular adhesion molecule 1, vascular intercellular adhesion molecule 1 (sVCAM-1) and vascular endothelial growth factor (VEGF). However, binary logistic regression revealed a weak association of serum sVCAM-1 and urine VEGF levels with HFRS contraction. Generally, our findings suggest mild chronic inflammation and renal dysfunction levels in convalescent HFRS patients 14 years after the disease contraction. Full article

Natural monoterpenes and their derivatives are widely considered the effective ingredients for the design and production of novel biologically active compounds. In this study, by using the molecular docking technique, we examined the effects of two series of “sulfide-sulfoxide-sulfone” thioterpenoids containing different (e.g., bornane and pinane) monoterpene skeletons on the platelet’s aggregation. Our data revealed that all the synthesized compounds exhibit inhibitory activities on platelet aggregation. For example, compound 1 effectively inhibited platelet activation and demonstrated direct binding with CD61 integrin, a well-known platelet GPIIb-IIIa receptor on platelets. We further examined the antiaggregant activity of the most active compound, 1, in vivo and compared its activity with that of acetylsalicylic acid and an oral GPIIb-IIIa blocker, orbofiban. We found that compound 1 demonstrates antiaggregant activity in rats when administered per os and its activity was comparable with that of acetylsalicylic acid and orbofiban. Moreover, similarly, tirofiban, a well-known GPIIb-IIIa blocker, compound 1, effectively decreased the expression of P-selectin to the values similar to those of the intact platelets. Collectively, here, we show, for the first time, the potent antiaggregant activity of compound 1 both in vitro and in vivo due to its ability to bind with the GPIIb-IIIa receptor on platelets. Full article

The cardiovascular risk factors, including smoking, ethanol, and oxidative stress, can induce cellular senescence. The senescent cells increase the expression and release of pro-inflammatory molecules and matrix metalloproteinase (MMPs). These pro-inflammatory molecules and MMPs promote the infiltration and accumulation of inflammatory cells in the vascular tissue, exacerbating vascular tissue inflammation. MMPs damage vascular tissue by degenerating the extracellular matrix. Consequently, these cellular and molecular events promote the initiation and progression of cardiovascular diseases. We used Rapalink-1, an mTOR inhibitor, to block ethanol-induced senescence. Rapalink-1 inhibited oxidative-stress-induced DNA damage and senescence in endothelial cells exposed to ethanol. It attenuated the relative protein expression of senescence marker P21 and improved the relative protein expression of DNA repair protein KU70 and aging marker Lamin B1. It inhibited the activation of NF-κB, MAPKs (P38 and ERK), and mTOR pathway proteins (mTOR, 4EBP-1, and S6). Moreover, Rapalink-1 suppressed ethanol-induced mRNA expression of ICAM-1, E-selectin, MCP-1, IL-8, MMP-2, and TIMP-2. Rapalink-1 also reduced the relative protein expression of MMP-2. In summary, Rapalink-1 prevented senescence, inhibited pro-inflammatory pathway activation, and ameliorated pro-inflammatory molecule expression and MMP-2. Full article

Integrins were originally identified as receptors for extracellular matrix (ECM) and cell-surface molecules (e.g., VCAM-1 and ICAM-1). Later, we discovered that many soluble growth factors/cytokines bind to integrins and play a critical role in growth factor/cytokine signaling (growth factor–integrin crosstalk). We performed a virtual screening of protein data bank (PDB) using docking simulations with the integrin headpiece as a target. We showed that several growth factors (e.g., FGF1 and IGF1) induce a integrin-growth factor-cognate receptor ternary complex on the surface. Growth factor/cytokine mutants defective in integrin binding were defective in signaling functions and act as antagonists of growth factor signaling. Unexpectedly, several growth factor/cytokines activated integrins by binding to the allosteric site (site 2) in the integrin headpiece, which is distinct from the classical ligand (RGD)-binding site (site 1). Since 25-hydroxycholesterol, a major inflammatory mediator, binds to site 2, activates integrins, and induces inflammatory signaling (e.g., IL-6 and TNFα secretion), it has been proposed that site 2 is involved in inflammatory signaling. We showed that several inflammatory factors (CX3CL1, CXCL12, CCL5, sPLA2-IIA, and P-selectin) bind to site 2 and activate integrins. We propose that site 2 is involved in the pro-inflammatory action of these proteins and a potential therapeutic target. It has been well-established that platelet integrin αIIbβ3 is activated by signals from the inside of platelets induced by platelet agonists (inside-out signaling). In addition to the canonical inside-out signaling, we showed that αIIbβ3 can be allosterically activated by inflammatory cytokines/chemokines that are stored in platelet granules (e.g., CCL5, CXCL12) in the absence of inside-out signaling (e.g., soluble integrins in cell-free conditions). Thus, the allosteric activation may be involved in αIIbβ3 activation, platelet aggregation, and thrombosis. Inhibitory chemokine PF4 (CXCL4) binds to site 2 but did not activate integrins, Unexpectedly, we found that PF4/anti-PF4 complex was able to activate integrins, indicating that the anti-PF4 antibody changed the phenotype of PF4 from inhibitory to inflammatory. Since autoantibodies to PF4 are detected in vaccine-induced thrombocytopenic thrombosis (VIPP) and autoimmune diseases (e.g., SLE, and rheumatoid arthritis), we propose that this phenomenon is related to the pathogenesis of these diseases. P-selectin is known to bind exclusively to glycans (e.g., sLex) and involved in cell–cell interaction by binding to PSGL-1 (CD62P glycoprotein ligand-1). Unexpectedly, through docking simulation, we discovered that the P-selectin C-type lectin domain functions as an integrin ligand. It is interesting that no one has studied whether P-selectin binds to integrins in the last few decades. The integrin-binding site and glycan-binding site were close but distinct. Also, P-selectin lectin domain bound to site 2 and allosterically activated integrins. Full article