CD40-CD40 ligand interactions in oxidative stress, inflammation and vascular disease

Impact of cardiac surgery on the expression of CD40, CD80, CD86 and HLA-DR on B cells and monocytes

OBJECTIVE

We measured and compared changes in the percentage of cells expressing CD80, CD86, CD40, HLA-DR and the expression of these molecules on B cells and monocytes of patients who underwent either on-pump, mini on-pump or off-pump cardiac surgery.

METHODS

Blood samples from patients who underwent either on-pump, mini on-pump or off-pump cardiac surgery were collected before surgery, instantly after surgery and on the 1(st), 3(rd) and 7(th) days after surgery. Surface expression of CD80, CD86, CD40 and HLA-DR molecules was determined by flow cytometry.

RESULTS

Our results show that all three surgical techniques altered the expression of these molecules, as well as the percentage relative number of specific cell populations. We identified statistically significant differences when comparing different surgical techniques. On-pump surgery revealed a more pronounced impact on the phenotype of immune system cells than the other techniques. Therefore, it is likely that the function of immune cells is changed the most by on-pump surgery. We found a lower decrease in the number of CD80(+) monocytes and a lower drop in the CD40 expression on monocytes in off-pump patients in comparison with on-pump patients.

CONCLUSION

All the types of cardiac surgical techniques, off-pump, on-pump and modified mini-invasive on-pump, are associated with changes in CD80, CD86, CD40 and HLA-DR expression. We found several significant differences in the expression of the selected molecules when we compared all three groups of patients.

Multitargeting of selected prostanoid receptors provides agents with enhanced anti-inflammatory activity in macrophages

A polypharmacologic approach to prostanoid based anti-inflammatory therapeutics was undertaken in order to exploit both the anti- and proinflammatory properties attributed to the various prostanoid receptors. Multitargeting of selected prostanoid receptors yielded a prototype compound, compound 1 (AGN 211377), that antagonizes prostaglandin D2 receptors (DPs) DP1 (49) and DP2 (558), prostaglandin E2 receptors (EPs) EP1 (266) and EP4 (117), prostaglandin F2α receptor (FP) (61), and thromboxane A2 receptor (TP) (11) while sparing EP2, EP3, and prostaglandin I2 receptors (IPs); Kb values (in nanomoles) are given in parentheses. Compound 1 evoked a pronounced inhibition of cytokine/chemokine secretion from lipopolysaccharide or TNF-α stimulated primary human macrophages. These cytokine/chemokines included cluster of designation 40 receptor (CD40), epithelial-derived neutrophil-activating protein 78 (ENA-78), granulocyte colony stimulating factor (G-CSF), granulocyte macrophage colony stimulating factor (GM-CSF), IL-8, IL-18, monocyte chemotactic protein-1 (CCL2) (MCP-1), tissue plasminogen activator inhibitor (PAI-1), and regulated on activation, normal T cell expressed and secreted (RANTES). In contrast, the inhibitory effects of most antagonists selective for a single receptor were modest or absent, and selective EP2 receptor blockade increased cytokine release in some instances. Compound 1 also showed clear superiority to the cyclooxygenase inhibitors diclofenac and rofecoxib. These findings reveal that blockade of multiple prostanoid receptors, with absent antagonism of EP2 and IP, may provide more effective anti-inflammatory activity than global suppression of prostanoid synthesis or highly selective prostanoid receptor blockade. These investigations demonstrate the first working example of prostanoid receptor polypharmacology for potentially safer and more effective anti-inflammatory therapeutics by blocking multiple proinflammatory receptors while sparing those with anti-inflammatory activity.

Characterization of Innate Immunity in an Extended Whole Blood Model of Human Islet Allotransplantation

The instant blood-mediated inflammatory reaction (IBMIR) has been studied in whole blood models of human allo-islet transplantation for short periods (<6 h). Beyond this time frame the innate response to intraportally transplanted islets is less well described. A novel whole blood model was applied to study blood-islet-graft interactions up to 48 h. Heparinized polyvinyl chloride tubing was sealed into small bags containing venous blood together with allogeneic human islets and exocrine tissue, respectively. The bags were attached to a rotating wheel (37°C). Concentrated glucose and sodium hydrogen carbonate were added every 12 h to maintain physiological limits for sustained immune cell functions. Plasma was collected at repeated time points for analyses of coagulation/complement activation and chemokine/cytokine production. Immune cell infiltration was analyzed using immunohistochemistry. Coagulation and platelet activation markers, thrombin-antithrombin complex (TAT) and soluble CD40 ligand (sCD40L) showed early high concentrations (at 6-12 h). sC5b-9 steadily increased over 48 h. At 6 h neutrophils and monocytes surrounded the clotted cellular grafts with a following massive infiltration of neutrophils. High and increasing concentrations of CXCR1/2 ligands [IL-8 and growth-regulated oncogene α/β/γ (Gro-α/β/γ)] and IL-6 were produced in response to human islets and exocrine tissue. The CCR2 ligand monocyte chemoattractant protein 1 (MCP-1) exhibited increasing concentrations in response to exocrine tissue. The CXCR3 ligand interferon-inducible T cell α chemoattractant (I-TAC) was produced in response to both human islets and exocrine tissue from 6 h. Monokine induced by γ interferon (Mig) and interferon γ-induced protein 10 (IP-10) showed a later response, preferentially to exocrine tissue and with larger variations among preparations. An extended blood model of clinical islet transplantation allowed characterization of early immune activation in response to human islets and exocrine tissue. Increased production of chemokines targeting CXCR1/2, CCR2, and CXCR3 was observed, accompanied by massive intraislet neutrophil infiltration over 48 h. The model proved to be useful in exploring early blood-mediated reactions to cellular transplants and has relevance for evaluation of pharmacological interventions to prevent graft loss.

Mechanisms of Nifedipine-Downregulated CD40L/sCD40L Signaling in Collagen Stimulated Human Platelets

The platelet-derived soluble CD40L (sCD40L) release plays a critical role in the development of atherosclerosis. Nifedipine, a dihydropyridine-based L-type calcium channel blocker (CCB), has been reported to have an anti-atherosclerotic effect beyond its blood pressure-lowering effect, but the molecular mechanisms remain unclear. The present study was designed to investigate whether nifedipine affects sCD40L release from collagen-stimulated human platelets and to determine the potential role of peroxisome proliferator-activated receptor-β/-γ (PPAR-β/-γ). We found that treatment with nifedipine significantly inhibited the platelet surface CD40L expression and sCD40L release in response to collagen, while the inhibition was markedly reversed by blocking PPAR-β/-γ activity with specific antagonist such as GSK0660 and GW9662. Meanwhile, nifedipine also enhanced nitric oxide (NO) and cyclic GMP formation in a PPAR-β/-γ-dependent manner. When the NO/cyclic GMP pathway was suppressed, nifedipine-mediated inhibition of sCD40L release was abolished significantly. Collagen-induced phosphorylation of p38MAPK, ERK1/2 and HSP27, matrix metalloproteinase-2 (MMP-2) expression/activity and reactive oxygen species (ROS) formation were significantly inhibited by nifedipine, whereas these alterations were all attenuated by co-treatment with PPAR-β/-γ antagonists. Collectively, these results demonstrate that PPAR-β/-γ-dependent pathways contribute to nifedipine-mediated downregulation of CD40L/sCD40L signaling in activated platelets through regulation of NO/ p38MAPK/ERK1/2/HSP27/MMP-2 signalings and provide a novel mechanism regarding the anti-atherosclerotic effect of nifedipine.

Associations between the functional CD40 rs4810485 G/T polymorphism and susceptibility to rheumatoid arthritis and systemic lupus erythematosus: a meta-analysis

Objective

The aim of this study was to determine whether the functional CD40 rs4810485 G/T polymorphism is associated with susceptibility to rheumatoid arthritis (RA) or with susceptibility to systemic lupus erythematosus (SLE).

Methods

A series of meta-analyses were conducted to test for association between the CD40 rs4810485 G/T polymorphism and RA or SLE.

Results

A total of 21 comparisons involving 15,095 patients and 27,050 controls for RA, and 1353 patients and 2342 controls for SLE were considered. Meta-analysis showed a significant association between the CD40 rs4810485 T allele and RA in all subjects (odds ratio (OR) 0.890, 95% confidence interval (CI) 0.846–0.936, p = 5.5 × 10−7). After stratification by ethnicity, the CD40 T allele was found to be significantly associated with RA in Europeans (OR 0.879, 95% CI 0.848–0.901, p = 3.0 × 10−9). A similar pattern of association was observed between the CD40 T allele and RA when the analysis was performed using the recessive, dominant, and additive models. Meta-analysis also showed a significant association between the CD40 polymorphism and SLE in Europeans (OR for the T allele 0.715, 95% CI 0.641–0.832, p = 1.4 × 10−6).

Conclusions

Our meta-analyses confirm that the CD40 rs4810485 G/T polymorphism is associated with susceptibility to RA and SLE in Europeans.

Increased plasma soluble CD40 ligand concentration in pelvic inflammatory disease

BACKGROUND

The role of soluble CD40 ligand (sCD40L) in pelvic inflammatory disease (PID) remains unclear. We sought to determine whether sCD40L was an efficient serum marker as with WBC and CRP in PID patients.

METHODS

Enzyme-linked immunosorbent assay was used to measure the plasma levels of sCD40L before and after routine protocol treatments in sixty-four PID patients and seventy healthy controls.

RESULTS

The level of plasma sCD40L (pg/ml) was significantly elevated in PID patients (1632.83±270.91) compared to that in normal controls (700.33±58.77; p=0.001) and decreased significantly as compared to that in the same patients (928.77±177.25; p=0.0001) after they received treatment. The concentration of sCD40L was significantly correlated with the level of plasma C-reactive protein (CRP) in the blood (r=0.202, p=0.01, n=134). When the cutoff level of plasma sCD40L levels was determined to be 1612.26pg/ml based on ROC, the sensitivity, specificity, and the area under the curve of plasma sCD40L level for predicting PID were 0.26, 0.97, and 0.58 (95% confidence interval: 0.48-0.68), respectively, while the adjusted odds ratio (AOR) with their 95% CI of plasma sCD40L for PID risk was 7.09 (95% CI=1.14-43.87, p=0.03).

CONCLUSIONS

The expression of plasma sCD40L was increased in patients with PID and detection of plasma sCD40L could be useful for the diagnosis of PID.

Prognosis of ulcerative colitis differs between patients with complete and partial mucosal healing, which can be predicted from the platelet count

AIM: To determine the difference in clinical outcome between ulcerative colitis (UC) patients with Mayo endoscopic subscore (MES) 0 and those with MES 1.

METHODS: UC patients with sustained clinical remission of 6 mo or more at the time of colonoscopy were examined for clinical outcomes and the hazard ratios of clinical relapse according to MES. Parameters, including blood tests, to identify predictive factors for MES 0 and slight endoscopic recurrence in clinically stable patients were assessed. Moreover, a receiver operating characteristic curve was generated, and the area under the curve was calculated to indicate the utility of the parameters for the division between complete and partial mucosal healing. All P values were two-sided and considered significant when less than 0.05.

RESULTS: A total of 183 patients with clinical remission were examined. Patients with MES 0 (complete mucosal healing: n = 80, 44%) were much less likely to relapse than those with MES 1 (partial mucosal healing: n = 89, 48%) (P < 0.0001, log-rank test), and the hazard ratio of risk of relapse in patients with MES 1 vs MES 0 was 8.17 (95%CI: 4.19-17.96, P < 0.0001). The platelet count (PLT) < 26 × 10⁴/μL was an independent predictive factor for complete mucosal healing (OR = 4.1, 95%CI: 2.15-7.99). Among patients with MES 0 at the initial colonoscopy, patients of whom colonoscopy findings shifted to MES 1 showed significant increases in PLT compared to those who maintained MES 0 (3.8 × 10⁴/μL vs -0.6 × 10⁴/μL, P < 0.0001).

CONCLUSION: The relapse rate differed greatly between patients with complete and partial mucosal healing. A shift from complete to partial healing in clinically stable UC patients can be predicted by monitoring PLT.

The protective effect of fenofibrate against TNF-α-induced CD40 expression through SIRT1-mediated deacetylation of NF-κB in endothelial cells

Fenofibrate, as a lipid-lowering drug in clinic, participates in the regulation of inflammatory response. Recently, increasing studies have indicated that sirtuin1 (SIRT1), a NAD+-dependent deacetylase, has potential anti-inflammatory effect in endothelial cells. However, whether the regulatory effect of fenofibrate on inflammation response is mediated by SIRT1 remains unclear. The aim of this study was to investigate the effect of fenofibrate on the expressions of SIRT1 and pro-inflammatory cytokine CD40 in endothelial cells and explore the underlying mechanisms. The results showed that fenofibrate upregulated SIRT1 expression and inhibited CD40 expression in TNF-α-stimulated endothelial cells, but these effects were reversed by peroxisome proliferator-activated receptor-α (PPARα) antagonist GW6471. Furthermore, SIRT1 inhibitors sirtinol/nicotinamide (NAM) or SIRT1 knockdown could attenuate the effect of fenofibrate on CD40 expression in endothelial cells. Importantly, NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) augmented the effect of fenofibrate on CD40 expression. Further study found that fenofibrate decreased the expression of acetylated-NF-κB p65 (Ac-NF-κB p65) in TNF-α-stimulated endothelial cells, which was abolished by SIRT1 knockdown. These results indicate that fenofibrate has protective effect against TNF-α-induced CD40 expression through SIRT1-mediated deacetylation of the p65 subunit of NF-κB.

Micronutrients and superoxide dismutase in postmenopausal women with chronic periodontitis: a pilot interventional study

Purpose

The study was aimed at investigating changes in periodontal parameters and superoxide dismutase activity triggered by root surface debridement with and without micronutrient supplementation in postmenopausal women.

Methods

Forty-three postmenopausal chronic periodontitis patients were divided into two groups: group 1 (n=22) were provided periodontal treatment in the form of scaling and root planing (SRP) and group 2 (n=21) patients received SRP along with systemic administration of micronutrient antioxidants. Patients in both groups were subjected to root surface debridement. Group 2 patients also received adjunctive micronutrient antioxidant supplementation. Serum and salivary superoxide dismutase (SOD) activity along with periodontal parameters were recorded at baseline and 3 months after therapy.

Results

Salivary and serum SOD values significantly (P<0.05) improved with periodontal treatment. Improvement in systemic enzymatic antioxidant status along with reduction in gingival inflammation and bleeding on probing (%) sites was significantly greater in group 2 as compared to group 1.

Conclusions

Adjunctive micronutrient supplements reduce periodontal inflammation and improve the status of systemic enzymatic antioxidants in postmenopausal women.

Graphical Abstract

Critical role for bone marrow stromal antigen 2 in acute Chikungunya virus infection

Bone marrow stromal antigen 2 (BST-2; also known as tetherin or CD317) is an IFN-inducible gene that functions to block the release of a range of nascent enveloped virions from infected host cells. However, the role of BST-2 in viral pathogenesis remains poorly understood. BST-2 plays a multifaceted role in innate immunity, as it hinders retroviral infection and possibly promotes infection with some rhabdo- and orthomyxoviruses. This paradoxical role has probably hindered exploration of BST-2 antiviral function in vivo. We reported previously that BST-2 tethers Chikungunya virus (CHIKV)-like particles on the cell plasma membrane. To explore the role of BST-2 in CHIKV replication and host protection, we utilized CHIKV strain 181/25 to examine early events during CHIKV infection in a BST-2(-/-) mouse model. We observed an interesting dichotomy between WT and BST-2(-/-) mice. BST-2 deficiency increased inoculation site viral load, culminating in higher systemic viraemia and increased lymphoid tissues tropism. A suppressed inflammatory innate response demonstrated by impaired expression of IFN-α, IFN-γ and CD40 ligand was observed in BST-2(-/-) mice compared with the WT controls. These findings suggested that, in part, BST-2 protects lymphoid tissues from CHIKV infection and regulates CHIKV-induced inflammatory response by the host.

Downregulation of CD40 expression contributes to the accumulation of myeloid-derived suppressor cells in gastric tumors

An elevated number of myeloid-derived suppressor cells (MDSCs) in tumor-bearing hosts has been recognized as a crucial mediator of tumor progression due to the cells potent ability to suppress antitumor immunity. Cluster of differentiation (CD) 40, as a suppressive phenotype expressed in MDSCs, is essential for MDSC-mediated immune suppression and the expansion of T regulatory cells. However, whether CD40 exerts a direct effect on the accumulation of MDSCs remains unclear. In the present study, CD40 was observed to be highly expressed on the MDSCs obtained from mice bearing gastric tumors. Notably, a significant decrease in the level of CD40 expression was observed in addition to an increased number of MDSCs during tumor progression. Further analysis revealed that the MDSC levels were found to positively correlate with tumor progression and that CD40 expression levels inversely correlate with the accumulation of MDSCs. To confirm the potent correlation between CD40 expression and the accumulation of MDSCs, the apoptosis of the MDSCs was detected using agonistic anti-CD40 treatment. The results indicated that CD40 activation induces apoptosis in MDSCs and that the downregulation of CD40 expression may contribute to MDSC accumulation by facilitating MDSC resistance to apoptosis. Thus, these observations provide a novel mechanism to improve our understanding of the involvement of CD40 in MDSC accumulation during cancer development.

Costimulatory pathways in kidney transplantation: pathogenetic role, clinical significance and new therapeutic opportunities

Costimulatory pathways play a key role in immunity, providing the second signal required for a full activation of adaptive immune response. Different costimulatory families (CD28, TNF-related, adhesion and TIM molecules), characterized by structural and functional analogies, have been described. Costimulatory molecules modulate T cell activation, B cell function, Ig production, cytokine release and many other processes, including atherosclerosis. Patients suffering from renal diseases present significant alterations of the costimulatory pathways, which might make them particularly liable to infections. These alterations are further pronounced in patients undergoing kidney transplantation. In these patients, different costimulatory patterns have been related to distinct clinical features. The importance that costimulation has gained during the last years has led to development of several pharmacological approaches to modulate this critical step in the immune activation. Different drugs, mainly monoclonal antibodies targeting various costimulatory molecules (i.e. anti-CD80, CTLA-4 fusion proteins, anti-CD154, anti-CD40, etc.) were designed and tested in both experimental and clinical studies. The results of these studies highlighted some criticisms, but also some promising findings and now costimulatory blockade is considered a suitable strategy, with belatacept (a CTLA-4 fusion protein) being approved as the first costimulatory blocker for use in renal transplantation. In this review, we summarize the current knowledge on costimulatory pathways in the setting of kidney transplantation. We describe the principal costimulatory molecule families, their role and clinical significance in patients undergoing renal transplantation and the new therapeutic approaches that have been developed to modulate the costimulatory pathways.

The green tea extract epigallocatechin-3-gallate inhibits irradiation-induced pulmonary fibrosis in adult rats

The present study evaluated the effect of epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea, on irradiation-induced pulmonary fibrosis and elucidated its mechanism of action. A rat model of irradiation-induced pulmonary fibrosis was generated using a ⁶⁰Co irradiator and a dose of 22 Gy. Rats were intraperitoneally injected with EGCG (25 mg/kg) or dexamethasone (DEX; 5 mg/kg) daily for 30 days. Mortality rates and lung index values were calculated. The severity of fibrosis was evaluated by assaying the hydroxyproline (Hyp) contents of pulmonary and lung tissue sections post-irradiation. Alveolitis and fibrosis scores were obtained from semi-quantitative analyses of hematoxylin and eosin (H&E) and Masson’s trichrome lung section staining, respectively. The serum levels of transforming growth factor β1 (TGF-β1), interleukin (IL)-6, IL-10, and tumor necrosis factor-α (TNF-α) were also measured. Surfactant protein-B (SPB) and α-SMA expression patterns were evaluated using immunohistochemistry, and the protein levels of nuclear transcription factor NF-E2-related factor 2 (Nrf-2) and its associated antioxidant enzymes heme oxygenase-1 enzyme (HO-1) and NAD(P)H:quinone oxidoreductase-1 (NQO-1) were examined via western blot analysis. Treatment with EGCG, but not DEX, reduced mortality rates and lung index scores, improved histological changes in the lung, reduced collagen depositions, reduced MDA content, enhanced SOD activity, inhibited (myo)fibroblast proliferation, protected alveolar epithelial type II (AE2) cells, and regulated serum levels of TGF-β1, IL-6, IL-10, and TNF-α. Treatment with EGCG, but not DEX, activated Nrf-2 and its downstream antioxidant enzymes HO-1 and NQO-1. Taken together, these results showed that EGCG treatment significantly inhibits irradiation-induced pulmonary fibrosis. Furthermore, the results suggested promising clinical EGCG therapies to treat this disorder.

Evidence for involvement of the CD40/CD40L system in post-stroke epilepsy

Post-stroke epilepsy (PSE) has a negative effect on stroke prognosis and quality of life. The CD40/CD40L system is reported to be involved in the progression of multiple disease states. We investigated the association between functional polymorphism of CD40 and PSE susceptibility, and we also explored the role of the CD40/CD40L system in PSE. A case-control study was performed in 410 ischemic stroke (IS) patients and in 389 PSE patients. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The CD40 mRNA and protein levels were determined by real-time PCR and western blotting, respectively. The plasma sCD40L level was detected using an ELISA kit. The frequency of the T allele in PSE patients was significantly higher than in IS patients (P<0.05). The plasma sCD40L level was significantly higher in the PSE patients than in the healthy controls and IS patients (P<0.01, P<0.05, respectively). The peripheral blood mononuclear cells (PBMCs) from PSE patients showed significantly higher CD40 mRNA and protein expression than the healthy controls and IS patients (P<0.01, P<0.05, respectively). In the PSE patients, the T-allele carriers showed increased plasma sCD40L levels and increased CD40 mRNA expression. Our study suggested that the T allele of the CD40 -1C/T polymorphism may be associated with PSE susceptibility. The CD40/CD40L system is involved in the process of PSE.

Soluble ligand CD40 and uric acid as markers of atheromatosis in patients with obstructive sleep apnea

The aim of the study was to evaluate the risk of atheromatosis in patients with obstructive sleep apnea (OSA), as based on the concentration of the pro-atherogenic soluble CD40L ligand (sCD40L) in relation to the level of uric acid. The serum levels of sCD40L and uric acid were measured in 79 OSA patients (mean apnea/hypopnea index - AHI 34.4 ± 20.9) and in 40 healthy controls. We found that sCD40L was higher in the OSA patients with hyperuricemia than that in the patients with uric acid in the normal range (sCD40L: 9.0 ng/ml vs. 8.0 ng/ml, respectively, p < 0.05). There was a positive association of sCD40L with AHI (p = 0.01) and a negative one with the mean minimal nocturnal SaO₂(p < 0.05). Uric acid correlated negatively with the mean and minimal SaO₂and positively with the oxygen desaturation index (p < 0.05). OSA patients with hyperuricemia also had a higher prevalence of hypertension and ischemic heart disease. We conclude that OSA patients with increased uric acid concentration have increased risk of atheromatosis, as indicated by a higher level of soluble pro-atherogenic ligand CD40, and a higher prevalence of cardiovascular adverse events.

Targeting platelet-derived soluble CD40 ligand: a new treatment strategy for HIV-associated neuroinflammation?

Human immunodeficiency virus type 1 (HIV) continues to be one of the most prevalent global health afflictions to date. The advent and introduction of combined antiretroviral therapy (cART) has made a significant impact on the course of infection. However, as patients are living longer, many HIV-associated illnesses are becoming prevalent among the infected population, especially those associated with chronic inflammation. Consistently, HIV-associated neuroinflammation is believed to be a major catalyst in the development of HIV-associated neurocognitive disorders (HAND), which are estimated to persist in approximately 50% of infected individuals regardless of cART. This dramatically underscores the need to develop effective adjunctive therapies capable of controlling this aspect of the disease, which are currently lacking.

We previously demonstrated that the inflammatory mediator soluble CD40 ligand (sCD40L) is elevated in both the plasma and cerebrospinal fluid of cognitively impaired infected individuals compared to their non-impaired infected counterparts. Our group, and others have recently demonstrated that there is an increasing role for this inflammatory mediator in the pathogenesis of HIV-associated neuroinflammation, thereby identifying this molecule as a potential therapeutic target for the management of HAND. Platelets are the major source of circulating sCD40L, and these small cells are increasingly implicated in a multitude of inflammatory disorders, including those common during HIV infection. Thus, antiplatelet therapies that minimize the release of platelet-derived inflammatory mediators such as sCD40L are an innovative, non-traditional approach for the treatment of HIV-associated neuroinflammation, with the potential to benefit other HIV-associated illnesses.

CD40 signal regulates CXCR4 mediating ovarian carcinoma cell migration: implications for extrapelvic metastastic factors

Ovarian carcinomas are highly invasive, especially in the peritoneal cavity. SDF-1α and its receptor, CXCR4, play a crucial role in migration of cancer cells. Here, SDF-1α directed HO8910 cell migration, but not SKOV3 cells. After being educated to express CXCR4 in vivo or by treating with sCD40L, SDF-1α reexhibited the ability of directing SKOV3 cell migration, which could be antagonized by CXCR4-neutralizing antibody. Furthermore, concomitant expression of CXCR4/CD40 in ovarian carcinoma tissues had stronger correlation with pelvic metastasis than did each alone. It is suggest that SDF-1α acts through CXCR4 to induce ovarian cancer cell migration, which could be facilitated by CD40 activation. Simultaneously examining the expression of CXCR4 and CD40 will provide valuable diagnosis of pelvic metastasis for ovarian carcinomas.

Native high density lipoproteins (HDL) interfere with platelet activation induced by oxidized low density lipoproteins (OxLDL)

Platelets and lipoproteins play a crucial role in atherogenesis, in part by their ability to modulate inflammation and oxidative stress. While oxidized low density lipoproteins (OxLDL) play a central role in the development of this disease, high density lipoproteins (HDL) represent an atheroprotective factor of utmost importance. As platelet function is remarkably sensitive to the influence of plasma lipoproteins, it was the aim of this study to clarify if HDL are able to counteract the stimulating effects of OxLDL with special emphasis on aspects of platelet function that are relevant to inflammation. Therefore, HDL were tested for their ability to interfere with pro-thrombotic and pro-inflammatory aspects of platelet function. We are able to show that HDL significantly impaired OxLDL-induced platelet aggregation and adhesion. In gel-filtered platelets, HDL decreased both the formation of reactive oxygen species and CD40L expression. Furthermore, HDL strongly interfered with OxLDL-induced formation of platelet-neutrophil aggregates in whole blood, suggesting that platelets represent a relevant and sensitive target for HDL. The finding that HDL effectively competed with the binding of OxLDL to the platelet surface might contribute to their atheroprotective and antithrombotic properties.

Soluble CD40 ligand impairs the anti-platelet function of peripheral blood angiogenic outgrowth cells via increased production of reactive oxygen species

Adult peripheral blood angiogenic early outgrowth cells (EOCs), also known as early endothelial progenitor cells, interact with other blood and vascular cells and may regulate atherothrombosis. We have previously shown that endothelial progenitor cells inhibit platelet function and thrombus formation. The CD40L/CD40 axis is a thrombo- inflammatory mediator that affects platelet and endothelial functions. It has been shown that EOCs express CD40, whereas platelets represent the major source of its soluble ligand (sCD40L), which impairs EOC function.We aimed to test the hypothesis that the sCD40L/CD40 axis affects the anti-platelet function of EOCs. Human peripheral blood mononuclear cell-derived EOCs in culture inhibited platelet aggregation. Pre-treatment of EOCs with sCD40L reduced their inhibitory effect on platelet aggregation in a CD40-dependent manner. EOCs viability and release of the anti-aggregating agents, prostacyclin and nitric oxide, were not affected by sCD40L. However, production of reactive oxygen species (ROS) was increased in sCD40L-treated EOCs. Blockade of ROS reversed the effects of sCD40L-treated EOCs on platelet aggregation. This study reveals that the sCD40L/CD40 axis impairs the anti-platelet properties of EOCs through increased production of ROS. These data may explain the link between elevated levels of sCD40L, impaired activity of EOCs and enhanced platelet reactivity, and consequently the occurrence of atherothrombotic disease.

Excess soluble CD40L contributes to blood brain barrier permeability in vivo: implications for HIV-associated neurocognitive disorders

Despite the use of anti-retroviral therapies, a majority of HIV-infected individuals still develop HIV-Associated Neurocognitive Disorders (HAND), indicating that host inflammatory mediators, in addition to viral proteins, may be contributing to these disorders. Consistently, we have previously shown that levels of the inflammatory mediator soluble CD40L (sCD40L) are elevated in the circulation of HIV-infected, cognitively impaired individuals as compared to their infected, non-impaired counterparts. Recent studies from our group suggest a role for the CD40/CD40L dyad in blood brain barrier (BBB) permeability and interestingly, sCD40L is thought to regulate BBB permeability in other inflammatory disorders of the CNS. Using complementary multiphoton microscopy and quantitative analyses in wild-type and CD40L deficient mice, we now reveal that the HIV transactivator of transcription (Tat) can induce BBB permeability in a CD40L-dependent manner. This permeability of the BBB was found to be the result of aberrant platelet activation induced by Tat, since depletion of platelets prior to treatment reversed Tat-induced BBB permeability. Furthermore, Tat treatment led to an increase in granulocyte antigen 1 (Gr1) positive monocytes, indicating an expansion of the inflammatory subset of cells in these mice, which were found to adhere more readily to the brain microvasculature in Tat treated animals. Exploring the mechanisms by which the BBB becomes compromised during HIV infection has the potential to reveal novel therapeutic targets, thereby aiding in the development of adjunct therapies for the management of HAND, which are currently lacking.

Study of association of CD40-CD154 gene polymorphisms with disease susceptibility and cardiovascular risk in Spanish rheumatoid arthritis patients

Objective

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with increased cardiovascular (CV) mortality. Since CD40-CD154 binding has direct consequences on inflammation process initiation, we aimed to replicate previous findings related to disease susceptibility in Spanish RA population. Furthermore, as the major complication in RA disease patients is the development of CV events due to accelerated atherosclerosis, and elevated levels of CD40L/CD154 are present in patients with acute myocardial infarction, we assessed the potential association of CD40 and CD154/CD40L gene variants with CV risk in Spanish RA patients.

Methods

One thousand five hundred and seventy-five patients fulfilling the 1987 ACR classification criteria for RA and 1600 matched controls were genotyped for the CD40 rs1883832, rs4810485 and rs1535045 and CD154 rs3092952 and rs3092920 gene polymorphisms, using predesigned TaqMan single nucleotide polymorphism genotyping assays. Afterwards, we investigated the influence of CD40-CD154 gene variants in the development of CV events. Also, in a subgroup of 273 patients without history of CV events, we assessed the influence of these polymorphisms in the risk of subclinical atherosclerosis determined by carotid ultrasonography.

Results

Nominally significant differences in the allele frequencies for the rs1883832 CD40 gene polymorphism between RA patients and controls were found (p = 0.038). Although we did not observe a significant association of CD40-CD154 gene variants with the development of CV events, an ANCOVA model adjusted for sex, age at the time of the ultrasonography assessment, follow-up time, traditional CV risk factors and anti-cyclic citrullinated peptide antibodies disclosed a significant association (p = 0.0047) between CD40 rs1535045 polymorphism and carotid intima media thickness, a surrogate marker of atherosclerosis.

Conclusion

Data from our pilot study indicate a potential association of rs1883832 CD40 gene polymorphism with susceptibility to RA. Also, the CD40 rs1535045 gene variant may influence development of subclinical atherosclerosis in RA patients.

Revascularization of pancreatic islet allografts is enhanced by α-1-antitrypsin under anti-inflammatory conditions

Pancreatic islets are a highly vascularized entity, and their transplantation into diabetic individuals requires optimal revascularization. In addition, β-cells in islets are extremely sensitive to inflammation. α-1-Antitrypsin (AAT), a circulating serine-protease inhibitor that is available for clinical use as an affinity-purified human product, has been shown to protect islets from graft failure in mouse transplantation models and to achieve readily vascularized islet grafts. AAT is known to induce vascular endothelial growth factor (VEGF) expression and release, as well as protect from proteolytic cleavage of VEGF by elastase, promote viability of endothelial cells, and enhance migration of myocytes. Our aim was to examine whether AAT enhances vasculogenesis toward islet grafts. We employed Matrigel-islet plugs as means to introduce islets in an explantable isolated compartment and examined vessel formation, vessel maturation, and inflammatory profile of explants 9 days after implantation. Also, we examined primary epithelial cell grafts that were prepared from lungs of mice that are transgenic for human AAT. In addition, aortic ring sprouting assay was performed, and HUVEC tube formation assays were studied in the presence of AAT. Our findings indicate that islet grafts exhibit mature vessels in the presence of AAT, as demonstrated by morphology, as well as expression of endothelial CD31, smooth muscle actin (SMA), and von Willebrand factor (vWF). Epithelial cells that express human AAT achieved a similar positive outcome. Aortic ring sprouting was enhanced in AAT-treated cultures and also in cultures that contained primary epithelial cells from human AAT transgenic animals in the absence of added AAT. According to the tube formation assay, HUVECs exhibited superior responses in the presence of AAT. We conclude that vasculogenesis toward islet grafts is enhanced in the presence of AAT. Together with the remarkable safety profile of AAT, the study supports its use in the relevant clinical setups.

Differential modulation by delta9-tetrahydrocannabinol (∆9)-THC) of CD40 ligand (CD40L) expression in activated mouse splenic CD4+ T cells

The anti-inflammatory activity of cannabinoids has been widely demonstrated in experimental animal models and in humans. CD40-CD40-ligand (L) interactions are among the most crucial initiators of inflammation. This study investigated the effects of ∆(9)-THC on CD40L expression in mouse splenic T cells after activation with various stimuli. Time course studies demonstrated that peak surface expression of CD40L by CD4(+) T cells after anti-CD3/CD28 or phorbol ester plus calcium ionophore (PMA/Io) occurred 8 h post activation. Peak CD40L mRNA levels were observed at 2 h post PMA/Io treatment and at 4 h post anti-CD3/CD28 treatment. Pretreatment with ∆(9)-THC significantly impaired the upregulation of CD40L induced by anti-CD3/CD28 at both the protein and mRNA level. By contrast, ∆(9)-THC did not affect PMA/Io-induced surface CD40L expression on CD4(+) T cells. Additionally, ∆(9)-THC also attenuated anti-CD3/CD28-induced CD40L expression on CD4(+) T cells derived from CB1(-/-)/CB2(-/-) mice. We investigated whether the mechanism by which ∆(9)-THC suppressed CD40L expression involved putative cannabinoid activation of the glucocorticoid receptor (GR). Although activation of GR resulted in suppression of CD40L induction by anti-CD3/CD28, no interaction between ∆(9)-THC and GR was observed by a glucocorticoid response element (GRE) luciferase reporter assay in HEK293T cells. Collectively, these results suggest that ∆(9)-THC targets proximal T cell receptor-associated signaling in a cannabinoid receptor- and glucocorticoid receptor-independent manner. These findings identify suppression of CD40L expression as a novel part of the mechanism by which ∆(9)-THC exerts anti-inflammatory activity.

Effects of sensor-augmented pump therapy on glycemic variability in well-controlled type 1 diabetes in the STAR 3 study

BACKGROUND

Compared with multiple daily injections (MDI), sensor-augmented pump (SAP) insulin therapy may reduce glycemic variability and oxidative stress in type 1 diabetes in a glycosylated hemoglobin (A1C)-independent manner.

SUBJECTS AND METHODS

The STAR 3 study compared SAP with MDI therapy for 1 year. Week-long continuous glucose monitoring studies were conducted at baseline and 1 year for assessment of glycemic variability in both groups. Soluble CD40 ligand (CD40L), a biomarker of inflammation and thrombocyte function, was measured at baseline and 1 year. Subjects were classified according to treatment group and 1-year A1C levels (<6.5%, 6.5-6.9%, 7-7.9%, ≥8%). Glycemic parameters were compared between SAP and MDI subjects in each A1C cohort.

RESULTS

At 1 year, sensor glucose values at A1C levels ≥6.5% were similar in the SAP and MDI groups. However, sensor glucose SD and coefficient of variation (CV) values were lower at A1C levels <8% among SAP than among MDI subjects; the overall between-group difference was significant for both SD (P<0.01) and CV (P=0.01). The overall mean amplitude of glycemic excursion was similar in MDI and SAP groups (P=0.23). CD40L levels fell over the course of the study in both groups, but the between-group difference was not significant (P=0.18). CD40L concentrations were unrelated to A1C, change in A1C from baseline, or glycemic variability.

CONCLUSIONS

At comparable A1C levels of <8%, SAP reduced glycemic variability as measured by SD and CV compared with MDI. SAP may provide beneficial reductions in the number and severity of glycemic excursions.

Mechanisms underlying sCD40 production in hemodialysis patients

CD40 and its ligand (CD40L) regulate several cellular functions, including T and B-cell activation. The soluble form of CD40 (sCD40) antagonizes CD40/CD40L interaction. Patients undergoing hemodialysis (HD) present elevated sCD40 serum levels, which underlying molecular mechanisms are unknown. We studied sCD40 serum and urinary levels, CD40 membrane and gene expression and membrane shedding in HD, uremic not-HD patients (UR) and healthy subjects (N). We found that in HD sCD40 serum levels were higher than UR and N, being significantly elevated in anuric patients, and that sCD40 correlated to renal function in UR subjects, who presented also a reduced sCD40 urinary excretion rate. HD and UR presented reduced CD40 membrane and gene expression. The concentration of TNF-α converting enzyme (TACE), responsible for CD40 cleavage was not different between HD and N. Therefore the reduced renal clearance is the main cause of elevated sCD40 levels in HD. This finding could have relevant clinical implications.

CD40 ligand (CD154) involvement in platelet transfusion reactions

Platelet transfusions are commonly used treatments that occasionally lead to adverse reactions. Clinical trials, in vitro and animal studies have been performed to try to understand the causes of such reactions. Multiple studies have shown that the supernatant fraction of platelet concentrates contain prothrombotic and pro-inflammatory mediators. The origin of these mediators was first ascribed to white blood cells contaminating the platelet preparation. However, the accumulation of bioactive mediators after leukoreduction focused attention on platelets themselves during storage. Numerous cytokines, chemokines and prostaglandins are released in stored platelet concentrates. We have focused on a powerful mediator called soluble CD40 ligand (sCD40L, formally known as CD154) as a seminal contributor to adverse reactions. sCD40L can bind and signal the surface receptor, CD40, which is present on various types of human cells including white blood cells, vascular cells and fibroblasts. Downstream results of sCD40L/CD40 signaling include pro-inflammatory cytokine and chemokine production, prothrombotic mediator release, adherence and transmigration of leukocytes to endothelium and other undesirable vascular inflammatory events. Increased plasma levels of sCD40L can be detected in conditions such as myocardial infarction, stroke, unstable angina, high cholesterol, or other cardiovascular conditions. In retrospective studies, correlations were made between increased sCD40L levels of platelet concentrates and adverse transfusion reactions. We hypothesize that transfusion of partially activated, CD40L-expressing platelets along with sCD40L into a recipient with damaged or dysfunctional vascular tissue results in a "double-hit", thus inciting inflammation and vascular damage in the recipient.

Preeclampsia serum upregulates CD40/CD40L expression and induces apoptosis in human umbilical cord endothelial cells

BACKGROUND

The endothelial cell dysfunction observed in preeclampsia (PE) may be induced by CD40/CD40L signaling. This study investigated the role of CD40/CD40L in the pathogenesis of PE by comparing the effect of maternal serum obtained from healthy pregnant women and PE patients on HUVEC cell growth, apoptosis and CD40/CD40L expression.

METHODS

Maternal serum was obtained from 20 patients with PE (PE group) as well as 20 healthy pregnant women (control group). The human umbilical endothelial cell line, CRL1730, was cultured in the presence of maternal serum for 24, 48, and 72 h after which cell growth and apoptosis were assessed by MTT and flow cytometry analysis, respectively. CD40/CD40L expression was determined using flow cytometry and RT-PCR analyses.

RESULTS

As compared to CRL1730 cells treated with control sera, those treated with PE sera had altered morphology, decreased cell growth, increased apoptosis and greater CD40/CD40L protein and mRNA expression. Stimulation of CD40/CD40L protein and mRNA expression by PE sera was greatest at 24 h.

CONCLUSIONS

PE sera may induce endothelial cell damage possibly through increased CD40/CD40L expression in early-onset PE. Further studies are necessary to determine the factor(s) in PE sera responsible for the observed changes in endothelial cell viability.

Platelet-associated CD40/CD154 mediates remote tissue damage after mesenteric ischemia/reperfusion injury

Several innate and adaptive immune cell types participate in ischemia/reperfusion induced tissue injury. Amongst them, platelets have received little attention as contributors in the process of tissue damage after ischemia reperfusion (I/R) injury. It is currently unknown whether platelets participate through the immunologically important molecules including, CD40 and when activated, CD154 (CD40L), in the pathogenesis of I/R injury. We hypothesized that constitutive expression of CD40 and activation-induced expression of CD154 on platelets mediate local mesenteric and remote lung tissue damage after I/R injury. Wild type (WT; C57BL/6J), CD40 and CD154 deficient mice underwent mesenteric ischemia for 30 minutes followed by reperfusion for 3 hours. WT mice subjected to mesenteric I/R injury displayed both local intestinal and remote lung damage. In contrast, there was significantly less intestinal damage and no remote lung injury in CD40 and CD154 deficient mice when compared to WT mice. Platelet-depleted WT mice transfused with platelets from CD40 or CD154 deficient mice failed to reconstitute remote lung damage. In contrast, when CD40 or CD154 deficient mice were transfused with WT platelets lung tissue damage was re-established. Together, these findings suggest that multiple mechanisms are involved in local and remote tissue injury and also identify platelet-expressed CD40 and/or CD154 as mediators of remote tissue damage.

High sCD40L levels early after trauma are associated with enhanced shock, sympathoadrenal activation, tissue and endothelial damage, coagulopathy and mortality

BACKGROUND

Severe injury activates the sympathoadrenal, hemostatic and inflammatory systems, but a maladapted response may contribute to a poor outcome. Soluble CD40L is a platelet-derived mediator that links inflammation, hemostasis and vascular dysfunction.

OBJECTIVES

To investigate the association between the sCD40L level and tissue injury, shock, coagulopathy and mortality in trauma patients.

METHODS

A prospective, observational study of 80 trauma patients admitted to a Level I Trauma Center. Data on demography, biochemistry, Injury Severity Score (ISS) and 30-day mortality were recorded and admission plasma/serum analyzed for sCD40L and biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), tissue/endothelial cell/glycocalyx damage (histone-complexed DNA fragments [hcDNA], Annexin V, thrombomodulin and syndecan-1), coagulation activation/inhibition (PF1.2, TAT-complex, antithrombin, protein C, activated protein C, sEPCR, TFPI, von Willebrand factor [VWF], fibrinogen and factor [F] XIII), fibrinolysis (D-dimer, tissue plasminogen activator [tPA] and plasminogen activator inhibitor-1 [PAI-1]) and inflammation (interleukin-6 [IL-6] and sC5b-9). We compared patients stratified by median sCD40L level and investigated predictive values of sCD40L for mortality.

RESULTS

High circulating sCD40L was associated with enhanced tissue and endothelial damage (ISS, hcDNA, Annexin V, syndecan-1 and sTM), shock (pH, standard base excess), sympathoadrenal activation (adrenaline) and coagulopathy evidenced by reduced thrombin generation (PF1.2), hyperfibrinolysis (D-dimer), increased activated partial thromboplastin time (APTT) and inflammation (IL-6) (all P < 0.05). A higher ISS (P = 0.017), adrenaline (P = 0.049) and platelet count (P = 0.012) and lower pH (P =0.002) were associated with higher sCD40L by multivariate linear regression analysis. High circulating sCD40L (odds ratio [OR] 1.84 [95% CI 1.05-3.23], P = 0.034), high age (P = 0.002) and low Glasgow Coma Score (GCS) pre-hospital (P = 0.002) were independent predictors of increased mortality.

CONCLUSIONS

High early sCD40L levels in trauma patients reflect tissue injury, shock, coagulopathy and sympathoadrenal activation and predict mortality. As sCD40L has pro-inflammatory activity and activates the endothelium, sCD40L may be involved in trauma-induced endothelial damage and coagulopathy.

Pentoxifylline decreases soluble CD40 ligand concentration and CD40 gene expression in coronary artery disease patients

CONTEXT AND OBJECTIVE

Increased level of inflammatory mediators plays a central role in the features of coronary artery diseases (CAD). As pentoxifylline could suppress the inflammatory process and has shown some promising beneficial effects in inflammatory diseases, we evaluated the effect of 2 months pentoxifylline administration in patients with CAD.

MATERIALS AND METHODS

A randomized placebo-controlled double-blind study design was used. Forty CAD patients (32 males and 8 females) were randomized into either 2 months of pentoxifylline treatment (1200 mg/day) (n = 20) or placebo treatment (n = 20). Blood samples were obtained before and after treatment. Gene expression analysis for mRNA of CD40, p65 and IκBα in peripheral blood mononuclear cells (PBMCs) were performed using real-time reverse-transcription polymerase chain reaction (RT-PCR). Plasma concentration of soluble CD40 (sCD40) ligand as well as protein concentration of p50 were measured by ELISA method.

RESULTS

Pentoxifylline decreased CD40 mRNA by 45% (p < 0.05) in PBMCs and sCD40 ligand level in plasma of CAD patients by 34% (p < 0.01).

DISCUSSION AND CONCLUSION

Pentoxifylline treatment can suppress the CD40/CD40 ligand system activation in CAD patients. As this system has a role in plaque progression and plaque rupture, pentoxifylline could be a good choice for future studies in preventing cardiovascular events.

Oxidative Stress and Inflammation in Heart Disease: Do Antioxidants Have a Role in Treatment and/or Prevention?

Inflammation triggered by oxidative stress is the cause of much, perhaps even most, chronic human disease including human aging. The oxidative stress originates mainly in mitochondria from reactive oxygen and reactive nitrogen species (ROS/RNS) and can be identified in most of the key steps in the pathophysiology of atherosclerosis and the consequential clinical manifestations of cardiovascular disease. In addition to the formation of atherosclerosis, it involves lipid metabolism, plaque rupture, thrombosis, myocardial injury, apoptosis, fibrosis and failure. The recognition of the critical importance of oxidative stress has led to the enthusiastic use of antioxidants in the treatment and prevention of heart disease, but the results of prospective, randomized clinical trials have been overall disappointing. Can this contradiction be explained and what are its implications for the discovery/development of future antioxidant therapeutics?

Effect of resveratrol on platelet activation in hypercholesterolemic rats: CD40-CD40L system as a potential target

Our aim was to investigate whether trans-resveratrol (t-resveratrol), a red wine constituent known for its cardioprotective effects, was able to influence CD40 ligand (CD40L) and its receptor CD40 in platelets of hypercholesterolemic rats. Sixty Wistar rats were divided into 5 groups: control (C), ethanol (E), t-resveratrol (R), hypercholesterolemia (HC), and hypercholesterolemia plus t-resveratrol (HCR). Rats in the C, E, and R groups were fed a normal diet for 80 days. For 20 days before sacrifice, we intraperitoneally (i.p.) administered 0.1 mL ethanol (50% v/v) to the E group, and 0.1 mL t-resveratrol (20 mg·kg(-1)·day(-1)) to the R group. Rats in the HC and HCR groups were fed a 5% cholesterol diet for 80 days. Rats in the HCR group were administered i.p. 0.1 mL t-resveratrol (20 mg·kg(-1)·day(-1)) for 20 days before sacrifice. Serum levels of total cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), very low-density lipoprotein (VLDL-C), and total triglycerides (TG) were assayed with a commercial colorimetric kit. Platelet P-selectin, CD40, and CD40L expression was determined by flow cytometry. sCD40L and IL6 levels were measured by ELISA. In the HC group, we observed a significant increase in serum TC, LDL-C, VLDL-C, TG, sCD40, and IL-6 levels and platelet activation markers compared with levels in the control group. However, t-resveratrol administration to the HC group (HCR group) attenuated the increase in lipids, sCD40, and IL-6 and down-regulated platelet P-selectin, CD40, and CD40L expressions. A positive correlation was found for serum lipids and all the platelet activation markers. Our study showed that the CD40-CD40L dyad is up-regulated in the presence of hypercholesterolemia and that t-resveratrol administration down-regulated the increase.

Gene-gene interaction between CD40 and CD40L reduces bone mineral density and increases osteoporosis risk in women

SUMMARY

We have analysed the association of single-nucleotide polymorphisms (SNPs) in CD40 and CD40L genes with bone mineral density (BMD) in our women. Results showed that women with TT genotype for rs1883832 (CD40) and for rs1126535 (CD40L) SNPs displayed reduced BMD and increased risk for osteopenia/osteoporosis. Our data notwithstanding, the results need to be replicated.

INTRODUCTION

Recent data have revealed that the CD40/CD40L system can be implicated in bone metabolism regulation. Moreover, we previously demonstrated that rs1883832 in the CD40 gene was significantly associated with BMD and osteoporosis risk. The objective of the present work was to determine whether polymorphisms in CD40 and CD40L genes are associated with BMD and osteoporosis risk.

METHODS

We conducted an association study of BMD values with SNPs in CD40 and CD40L genes in a population of 811 women of which 693 and 711 had femoral neck (FN) and lumbar spine (LS) densitometric studies, respectively.

RESULTS

Women with the TT genotype for rs1883832 (CD40) showed a reduction in FN-BMD (P = 0.005) and LS-BMD (P = 0.020) when compared with women with the CC/CT genotype. Moreover, we found that rs1126535 (CD40L) was significantly associated with LS-BMD so that women with the TT genotype displayed lower BMD (P = 0.014) than did women with the CC/CT genotype. Interestingly, we have found a strong interaction between polymorphisms in these genes. Thus, women with the TT genotype for both rs1883832 and rs1126535 SNPs (TT + TT women) showed a lower age-adjusted BMD (Z-score) for FN (P = 0.0007) and LS (0.007) after adjusting by years since menopause, body mass index, smoking and menopausal status, densitometer type, hormone replacement therapy (HRT) use and HRT duration and after making the Bonferroni adjustment for multiple comparisons than did the remaining women. Logistic regression analysis adjusted by these covariates showed that TT + TT women had increased risk for FN (odds ratio (OR) = 2.76; P = 0.006) and LS (OR = 2.39; P = 0.020) osteopenia or osteoporosis than did the other women.

CONCLUSIONS

Our results suggest that interaction between genetic variants in the CD40 and CD40L genes exerts a role on BMD regulation. Further studies, which we welcome, are needed to replicate these data in other populations.

In vivo therapeutic efficacy of intra-renal CD40 silencing in a model of humoral acute rejection

The humoral branch of the immune response has an important role in acute and chronic allograft dysfunction. The CD40/CD40L costimulatory pathway is crucial in B- and T- alloresponse. Our group has developed a new small interfering RNA (siRNA) molecule against CD40 that effectively inhibits its expression. The aim of the present study was to prevent rejection in an acute vascular rejection model of kidney transplant by intra-graft gene silencing with anti-CD40 siRNA (siCD40), associated or not with sub-therapeutic rapamycin. Four groups were designed: unspecific siRNA as control; sub-therapeutic rapamycin; siCD40; and combination therapy. Long-surviving rats were found only in both siCD40-treated groups. The CD40 mRNA was overexpressed in control grafts but treatment with siCD40 decreased its expression. Recipient spleen CD40+ B-lymphocytes were reduced in both siCD40-treated groups. Moreover, CD40 silencing reduced donor-specific antibodies, graft complement deposition and immune-inflammatory mediators. The characteristic histological features of humoral rejection were not found in siCD40-treated grafts, which showed a more cellular histological pattern. Therefore, the intra-renal effective blockade of the CD40/CD40L signal reduces the graft inflammation as well as the incidence of humoral vascular acute rejection, finally changing the type of rejection from humoral to cellular.

Signal pathways in astrocytes activated by cross-talk between of astrocytes and mast cells through CD40-CD40L

Background

Astrocytes, which play an active role in chronic inflammatory diseases like multiple sclerosis, exist close to mast cells with which they share perivascular localization. We previously demonstrated the possibility that astrocytes and mast cells interact in vitro and in vivo. This study aimed to investigate the signaling pathways and the role for astrocytes in the interaction of astrocytes and mast cells.

Methods

We co-cultured human U87 glioblastoma (U87) and human mast cell-1 (HMC-1) cell lines, and mouse cerebral cortices-derived astrocytes and mouse bone marrow-derived mast cells (BMMCs). Intracellular Ca²⁺ ([Ca²⁺]_i) was measured by confocal microscopy; CD40 siRNA by Silencer Express Kit; small GTPases by GTP-pull down assay; PKCs, MAPKs, CD40, CD40L, Jak1/2, STAT1, TNF receptor 1 (TNFR1) by Western blot; NF-κB and AP-1 by EMSA; cytokines by RT-PCR. An experimental allergic encephalomyelitis (EAE) model was induced using myelin oligodendrocyte glycoprotein (MOG) peptide and pertussis toxin in mice. Co-localization of TNFR1 and astrocytes in EAE brain tissues was determined by immunohistochemistry.

Results

Each astrocyte co-culture had increases in [Ca²⁺]_i levels, release of cytokines and chemokines; activities of Rho-family GTPases, NF-κB/AP-1/STAT1⁷²⁷, and Jack1/2, STAT1⁷⁰¹. These effects were inhibited by anti-CD40 antibody or CD40 siRNA, and signaling pathways for Jak1/2 were inhibited by anti-TNFR1 antibody. EAE score, expression of TNFR1, and co-localization of TNFR1 and astrocytes were enhanced in brain of the EAE model. Anti-CD40 antibody or 8-oxo-dG pretreatment reduced these effects in EAE model.

Conclusions

These data suggest that astrocytes activated by the CD40-CD40L interaction in co-culture induce inflammatory cytokine production via small GTPases, and the secreted cytokines re-activate astrocytes via Jak/STAT1⁷⁰¹ pathways, and then release more cytokines that contribute to exacerbating the development of EAE. These findings imply that the pro-inflammatory mediators produced by cell-to-cell cross-talk via interaction of CD40-CD40L may be as a promising therapeutic target for neurodegenerative diseases like MS.

CD40 is overexpressed by HPV16/18-E6 positive cervical carcinoma and correlated with clinical parameters and vascular density

CD40 is expressed in many tumor cells, however, its role in tumor biology is yet to be demonstrated. In the present study, we investigated the role of CD40 in cervical carcinoma. In vivo, we evaluated CD40 expression in 56 cervical carcinoma tissues, 43 cervicitis and 38 normal cervix, and investigated the relationship between CD40 and HPV antigen, histopathological parameters, vascular density, and vascular endothelial growth factor (VEGF) expressions. The results clearly demonstrated that CD40 expression, including membranous and cytoplasmic staining, was significantly higher in cervical carcinoma than in the cervicitis and normal cervix. The expression of CD40 was significantly correlated with HPV and VEGF expressions and microvessel density (MVD). These observations provide evidence that CD40 may be involved in neovascularization of cervical carcinoma, they also suggest that CD40 and VEGF may be useful biomarkers for evaluating the risk of developing cervical carcinoma, and may also be used as a target for therapy.

Antiplatelet activity of valproic acid contributes to decreased soluble CD40 ligand production in HIV type 1-infected individuals

CD40L is a type II membrane glycoprotein of the TNF family that is found on activated T cells, B cells, and platelets. We previously reported that the soluble form of this inflammatory mediator (sCD40L) is elevated in the plasma and cerebrospinal fluid of HIV-1-infected, cognitively impaired individuals. In this study, we demonstrate that the mood-stabilizing drug valproic acid (VPA) reduces sCD40L levels in plasma samples of HIV-1-infected patients (n = 23) and in washed human platelets, which are the main source of circulating sCD40L. VPA also inhibited HIV-1 transactivator of transcription-induced release of sCD40L and platelet factor 4 in C57BL/6 mice. The mechanism by which VPA was able to do so was investigated, and we demonstrate that VPA, a known glycogen synthase kinase 3β inhibitor, blocks platelet activating factor-induced activation of glycogen synthase kinase 3β in platelets in a manner that alters sCD40L release from platelets. These data reveal that VPA has antiplatelet activity, and they convey important implications for the potential of VPA as an adjunct therapy not only for cognitively impaired patients with HIV-1 infection, but also numerous inflammatory diseases for which such antiplatelet therapies are currently lacking.

Perioperative platelet and monocyte activation in patients with critical limb ischemia

BACKGROUND

Patients with critical limb ischemia (CLI) have a high rate of adverse cardiovascular events, particularly when undergoing surgery. We sought to determine the effect of surgery and vascular disease on platelet and monocyte activation in vivo in patients with CLI.

METHODS

An observational, cross-sectional study was performed at a tertiary referral hospital in the southeast of Scotland. Platelet and monocyte activation were measured in whole blood in patients with CLI scheduled for infrainguinal bypass and compared with matched healthy controls, patients with chronic intermittent claudication, patients with acute myocardial infarction, and those undergoing arthroplasty (n = 30 per group). Platelet and monocyte activation were quantified using flow cytometric assessment of platelet-monocyte aggregation, platelet P-selectin expression, platelet-derived microparticles, and monocyte CD40 and CD11b expression.

RESULTS

Compared with those with intermittent claudication, subjects with CLI had increased platelet-monocyte aggregates (41.7% +/- 12.2% vs 32.6% +/- 8.5%, respectively), platelet microparticles (178.7 +/- 106.9 vs 116.9 +/- 53.4), and monocyte CD40 expression (70.0% +/- 12.2% vs 52.4% +/- 15.2%; P < .001 for all). Indeed, these levels were equivalent (P-selectin, 4.4% +/- 2.0% vs 4.9% +/- 2.2%; P > .05) or higher (platelet-monocyte aggregation, 41.7% +/- 12.2% vs 33.6% +/- 7.0%; P < .05; platelet microparticles, 178.7 +/- 106.9 vs 114.4 +/- 55.0/microL; P < .05) than in patients with acute myocardial infarction. All platelet and monocyte activation markers remained elevated throughout the perioperative period in patients with CLI (P < .01) but not those undergoing arthroplasty.

CONCLUSIONS

Patients undergoing surgery for CLI have the highest level of in vivo platelet and monocyte activation, and these persist throughout the perioperative period. Additional antiplatelet therapy may be of benefit in protecting vascular patients with more severe disease during this period of increased risk.

Biomarkers of inflammation and oxidative stress in atherosclerosis

Increasing evidence has highlighted the roles of oxidative stress and inflammation in the promotion of atherosclerotic cardiovascular disease. Recent pathological studies have elucidated specific mediators that appear to link these pathways to the progression and rupture of atherosclerotic plaque in the artery wall. The ability to measure levels of these mediators in the systemic circulation has provoked interest in their development as biomarkers for potential use in risk assessment and in evaluation of the response to the use of preventive therapies. The discovery of these pathological mediators and their potential translation to the clinical arena will be reviewed.

The pattern of inflammatory/anti-inflammatory cytokines and chemokines in type 1 diabetic patients over time

AIMS

To evaluate the profile of pro- and anti-inflammatory cytokines in type 1 diabetes mellitus (T1DM) and the way they are connected in co-regulated networks and determine whether disease duration influences their pattern.

METHODS

Plasma levels of 20 cytokines and soluble CD40 (sCD40) from 44 uncomplicated patients and 22 healthy controls (HCs) were measured using enzyme-linked immunosorbent assay (ELISA) and protein array technology.

RESULTS

Patients showed significantly higher levels of sCD40, IL-1a, IL-2, IL-4, IL-5, IL-10, granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage inflammatory protein (MIP)-1a, MIP-1b, regulated on activation normal T cell expressed and secreted (RANTES), matrix metalloproteinase (MMP)-9, and a trend to higher IL-6 than did HCs. RANTES and sCD40 discriminated significantly between diabetics and HCs. In patients with disease duration >6 months, cytokines were organized in two clusters mainly regulated by Th17 and Th1/Th2 cells respectively, while in those with disease duration <or=6 months a set of Th1-cytokines was separated apart from the second cluster. Monocyte chemotactic protein (MCP)-1 was revealed as the most discriminant factor between patients with disease duration of more than and less than 6 months.

CONCLUSIONS

A parallel elevation of both inflammatory and anti-inflammatory cytokines was observed in patients compared with HCs. In T1DM patients with disease duration <or=6 months, Th1-cytokines were organized on a separate cluster, suggesting a possible role of Th1 cells in the progress of beta-cell destruction during the first period of the disease.

Increased adipose tissue expression of proinflammatory CD40, MKK4 and JNK in patients with very severe chronic obstructive pulmonary disease

BACKGROUND

CD40, a transmembrane receptor of the tumor necrosis factor gene superfamily, is activated in response to cellular stress, including hypoxia, and orchestrates the process of inflammation via secondary messengers such as mitogen-activated protein kinase kinase 4 (MKK4) and c-Jun NH(2)-terminal kinases (JNK).

OBJECTIVES

We hypothesized that CD40, MKK4 and JNK expression is increased in the adipose tissue of patients with very severe chronic obstructive pulmonary disease (COPD).

METHODS

In 20 patients with stable COPD, lung function was assessed using body plethysmography, and samples of subcutaneous adipose tissue were analyzed using real-time PCR. Body composition, including fat mass index (FMI), was assessed by bioelectrical impedance.

RESULTS

12 patients in GOLD stage I-III (age 61.6 ± 8.6 years, 4 females, mean partial pressure of oxygen in arterial blood, PaO(2), 9.38 ± 0.21 kPa) were compared to 8 patients in GOLD stage IV (age 62.6 ± 6.3 years, all male, mean PaO(2) 7.70 ± 0.37 kPa). Compared to patients in GOLD stage I-III, patients in GOLD stage IV had lower FMI (p = 0.004), being associated with significantly higher adipose tissue expression of CD40, MKK4 and JNK [ΔΔCt: 2.55 (1.99, 4.40) vs. 1.87 (1.63, 2.23), p = 0.013; 5.19 (3.13, 5.96) vs. 2.98 (2.82, 3.86), p = 0.002; 9.01 (5.12, 11.41) vs. 4.65 (4.42, 6.26), p = 0.001, respectively]. Log-transformed CD40, MKK4 and JNK expression was significantly inversely related to PaO(2), respectively.

CONCLUSIONS

Upregulation of proinflammatory CD40, MKK4 and JNK gene expression in adipose tissue in very severe COPD raises the possibility of a role of chronic systemic hypoxia in the pathogenesis of adipose tissue inflammation in COPD.