Health literacy and long-term health outcomes following myocardial infarction: protocol for a multicentre, prospective cohort study (ENHEARTEN study).

INTRODUCTION: Low health literacy is common in people with cardiovascular disease and may be one factor that affects an individual's ability to maintain secondary prevention health behaviours following myocardial infarction (MI). However, little is known about the association between health literacy and longer-term health outcomes in people with MI. The ENhancing HEAlth literacy in secondary pRevenTion of cardiac evENts (ENHEARTEN) study aims to examine the relationship between health literacy and a number of health outcomes (including healthcare costs) in a cohort of patients following their first MI. Findings may provide evidence for the significance of health literacy as a predictor of long-term cardiac outcomes. METHODS AND ANALYSIS: ENHEARTEN is a multicentre, prospective observational study in a convenience sample of adults (aged >18 years) with their first MI. A total of 450 patients will be recruited over 2 years across two metropolitan health services and one rural/regional health service in Victoria, Australia. The primary outcome of this study will be all-cause, unplanned hospital admissions within 6 months of index admission. Secondary outcomes include cardiac-related hospital admissions up to 24 months post-MI, emergency department presentations, health-related quality of life, mortality, cardiac rehabilitation attendance and healthcare costs. Health literacy will be observed as a predictor variable and will be determined using the 12-item version of the European Health Literacy Survey (HLS-Q12). ETHICS AND DISSEMINATION: Ethics approval for this study has been received from the relevant human research ethics committee (HREC) at each of the participating health services (lead site Monash Health HREC; approval number: RES-21-0000-242A) and Services Australia HREC (reference number: RMS1672). Informed written consent will be sought from all participants. Study results will be published in peer-reviewed journals and collated in reports for participating health services and participants. TRIAL REGISTRATION NUMBER: ACTRN12621001224819.

An exported kinase (FIKK4.2) that mediates virulence-associated changes in Plasmodium falciparum-infected red blood cells.

Alteration of the adhesive and mechanical properties of red blood cells caused by infection with the malaria parasite Plasmodium falciparum underpin both its survival and extreme pathogenicity. A unique family of parasite putative exported kinases, collectively called FIKK (Phenylalanine (F) - Isoleucine (I) - Lysine (K) - Lysine (K)), has recently been implicated in these pathophysiological processes, however, their precise function in P. falciparum-infected red blood cells or their likely role in malaria pathogenesis remain unknown. Here, for the first time, we demonstrate that one member of the FIKK family, FIKK4.2, can function as an active kinase and is localised in a novel and distinct compartment of the parasite-infected red blood cell which we have called K-dots. Notably, targeted disruption of the gene encoding FIKK4.2 (fikk4.2) dramatically alters the parasite's ability to modify and remodel the red blood cells in which it multiplies. Specifically, red blood cells infected with fikk4.2 knockout parasites were significantly less rigid and less adhesive when compared with red blood cells infected with normal parasites from which the transgenic clones had been derived, despite expressing similar levels of the major cytoadhesion ligand, PfEMP1, on the red blood cell surface. Notably, these changes were accompanied by dramatically altered knob-structures on infected red blood cells that play a key role in cytoadhesion which is responsible for much of the pathogenesis associated with falciparum malaria. Taken together, our data identifies FIKK4.2 as an important kinase in the pathogenesis of P. falciparum malaria and strengthens the attractiveness of FIKK kinases as targets for the development of novel next-generation anti-malaria drugs.

A novel, rapid method to detect infectious HIV-1 from plasma of persons infected with HIV-1.

Efficient isolation of replication-competent virus from plasma of patients infected with HIV-1 is needed to characterize important clinical parameters of virus. However, addition of plasma to in vitro cultures results in clot formation. Blood from HIV-1 infected patients was collected in the presence of three commonly used anticoagulants (ACD, heparin and EDTA) and plasma was isolated. Plasma was then used to infect HIV-1 indicator cell lines (TZM-bl and GHOST) with spinoculation in the presence or absence of additional heparin and positively charged polymers. The presence of additional heparin during inoculation significantly reduced clot formation without affecting the sensitivity of HIV-1 infection in the GHOST cell line. However, heparin reduced the frequency of HIV-1 infection of the TZM-bl cell line. Using plasma from patients with HIV RNA>1000 copies/ml (n=58), the frequency of HIV-1 isolation was 92% in GHOST (n=51) and 54% in TZM-bl (n=26) cell lines. A sensitive method was developed for rapid isolation of infectious HIV-1 from plasma of patients with HIV RNA>1000 copies/ml that includes spinoculation and the addition of heparin during infection of GHOST cells. This technique could be used for rapid evaluation of viral fitness, co-receptor usage or drug resistance without the need for viral amplification.

The cytoplasmic domain of tissue factor in macrophages augments cutaneous delayed-type hypersensitivity.

In addition to its procoagulant role, tissue factor (TF) has important coagulation-independent roles, including in inflammation. The cytoplasmic domain of TF has been implicated in some of these coagulation-independent roles, particularly cell signaling. To assess the contribution of the cytoplasmic domain of TF to cell-mediated adaptive immunity, the development of cutaneous delayed-type hypersensitivity (DTH) was studied in mice lacking the cytoplasmic domain of TF (TF(deltaCT/deltaCT) mice). DTH responses in sensitized mice were significantly attenuated in TF(deltaCT/deltaCT) mice, and leukocyte-endothelial cell interactions, assessed by intravital microscopy, were impaired significantly. Studies in chimeric mice, created by bone marrow transplantation, showed that the absence of the cytoplasmic domain of TF in leukocytes rather than endothelial cells was responsible for reduced DTH and leukocyte recruitment. DTH responses to OVA could be induced in wild-type mice but not in TF(deltaCT/deltaCT) mice by transfer of activated CD4(+) OVA-specific TCR transgenic T cells, demonstrating that the defective DTH response in TF(deltaCT/deltaCT) mice was independent of any defect in T cell activation. Macrophage and neutrophil accumulation and expression of TNF-alpha mRNA and phospho-p38-MAPK were reduced significantly in TF(deltaCT/deltaCT) mice, and their macrophages had reduced P-selectin-binding capacity and reduced in vivo emigration in response to MCP-1. These results indicate that leukocyte expression of the cytoplasmic domain of TF contributes to antigen-specific cellular adaptive immune responses via effects on leukocyte recruitment and activation.

Annexin 1 negatively regulates IL-6 expression via effects on p38 MAPK and MAPK phosphatase-1.

Annexin 1 (Anx-1) is a mediator of the anti-inflammatory actions of glucocorticoids, but the mechanism of its anti-inflammatory effects is not known. We investigated the role of Anx-1 in the regulation of the proinflammatory cytokine, IL-6. Lung fibroblast cell lines derived from Anx-1(-/-) and wild-type (WT) mice were treated with dexamethasone and/or IL-1. IL-6 mRNA and protein were measured using real-time PCR and ELISA, and MAPK pathway activation was studied. Compared with WT cells, unstimulated Anx-1(-/-) cells exhibited dramatically increased basal IL-6 mRNA and protein expression. In concert with this result, Anx-1 deficiency was associated with increased basal phosphorylated p38, JNK, and ERK1/2 MAPKs. IL-1-inducible phosphorylated p38 was also increased in Anx-1(-/-) cells. The increase in IL-6 release in Anx-1(-/-) cells was inhibited by inhibition of p38 MAPK. Anx-1(-/-) cells were less sensitive to dexamethasone inhibition of IL-6 mRNA expression than WT cells, although inhibition by dexamethasone of IL-6 protein was similar. MAPK phosphatase-1 (MKP-1), a glucocorticoid-induced negative regulator of MAPK activation, was up-regulated by dexamethasone in WT cells, but this effect of dexamethasone was significantly impaired in Anx-1(-/-) cells. Treatment of Anx-1(-/-) cells with Anx-1 N-terminal peptide restored MKP-1 expression and inhibited p38 MAPK activity. These data demonstrate that Anx-1 is an endogenous inhibitory regulator of MAPK activation and IL-6 expression, and that Anx-1 is required for glucocorticoid up-regulation of MKP-1. Therapeutic manipulation of Anx-1 could provide glucocorticoid-mimicking effects in inflammatory disease.

Regulation of IL-1 and TNF receptor expression and function by endogenous macrophage migration inhibitory factor.

Macrophage migration inhibitory factor (MIF) has a key role in regulation of innate and adaptive immunity and is implicated in sepsis, tumorigenesis, and autoimmune disease. MIF deficiency or immunoneutralization leads to protection against fatal endotoxic, exotoxic, and infective shock, and anti-inflammatory effects in other experimental models of inflammatory disease. We report a novel regulatory role of MIF in type 1 IL-1R and p55 TNFR expression and function. Compared with wild-type cells, MIF-deficient cells were hyporesponsive to IL-1- and TNF-induced MAPK activity, AP-1 activity, and cellular proliferation, while NF-kappaB function was preserved. Hyporesponsiveness of MIF-deficient cells was associated with down-regulation of cytokine receptor expression, which was restored by reconstitution of either an upstream kinase of MAPK, MAPK/ERK kinase, or MIF. These data suggest that endogenous MIF is required for cytokine activation of MAPK/AP-1 and cytokine receptor expression. This autocrine regulatory pathway defines an important amplifying role of endogenous MIF in cytokine-mediated immune and inflammatory diseases and provides further molecular evidence for the critical role of MIF in cellular activation.

IL-18 is redundant in T-cell responses and in joint inflammation in antigen-induced arthritis.

IL-18 is an important cofactor in Th1 immune responses and it has additional roles in inflammation. Recent reports suggest the contribution of IL-18 to immune responses may vary between mouse strains and immune contexts. We investigated the contribution of IL-18 to T-cell activation and joint inflammation in Ag-induced arthritis (AIA) in C57Bl/6 mice. AIA and cutaneous delayed-type hypersensitivity (DTH) reactions were induced in wild-type (WT) and IL-18-/- C57Bl/6 mice, and Ag-specific T-cell proliferation and IFN-gamma and IL-4 production were measured. The humoral immune response was measured as serum antibody to the disease-initiating Ag, methylated BSA (mBSA). Splenocyte production of IL-6 was measured by ELISA. To confirm the dependence of this model on Th1-cell-mediated immunity, IL-12p40-/- mice were similarly studied. WT mice developed synovitis, joint effusion, cartilage destruction and bone damage associated with induction of DTH, and in vitro Ag-specific T-cell proliferation and IFN-gamma production. Unexpectedly, IL-18-/- mice developed AIA and indices of T-cell activation were similar to those of WT mice. In contrast, IL-12p40-/- mice did not develop AIA, DTH or T-cell activation. WT and IL-18-/- mice, but not IL-12p40-/- mice, developed significantly increased serum antibody to mBSA compared with naive controls. WT and IL-18-/- splenocytes produced high levels of IL-6, whereas IL-12p40-/- cells had significantly lower IL-6 production compared with both. In conclusion, IL-18 is redundant both as a Th1 response cofactor and inflammatory cytokine, whereas IL-12p40-/- is a key cytokine, in AIA in C57Bl/6 mice.

The cytoplasmic domain of tissue factor contributes to leukocyte recruitment and death in endotoxemia.

Tissue factor (TF) is an integral membrane protein that binds factor VIIa and initiates coagulation. The extracellular domain of TF is responsible for its hemostatic function and by implication in the dysregulation of coagulation, which contributes to death in endotoxemia. The role of the cytoplasmic domain of tissue factor in endotoxemia was studied in mice, which lack the cytoplasmic domain of TF (TF(deltaCT/deltaCT)). These mice develop normally and have normal coagulant function. Following i.p injection with 0.5 mg of lipopolysaccharide (LPS), TF(deltaCT/deltaCT) mice showed significantly greater survival at 24 hours compared to the wt mice (TF(+/+)). The serum levels of TNF-alpha and IL-1beta were significantly lower at 1 hour after LPS injection and IL-6 levels were significantly lower at 24 hours in TF(deltaCT/deltaCT) mice compared to TF(+/+)mice. Neutrophil recruitment into the lung was also significantly reduced in TF(deltaCT/deltaCT) mice. Nuclear extracts from tissues of endotoxemic TF(deltaCT/deltaCT) mice also showed reduced NFkappaB activation. LPS induced leukocyte rolling, adhesion, and transmigration in post-capillary venules assessed by intravital microscopy was also significantly reduced in TF(deltaCT/deltaCT) mice. These results indicate that deletion of the cytoplasmic domain of TF impairs the recruitment and activation of leukocytes and increases survival following endotoxin challenge.

Reduction in arthritis severity and modulation of immune function in tissue factor cytoplasmic domain mutant mice.

Tissue factor (TF), a transmembrane receptor for plasma factor VII(a), is the main initiator of the coagulation cascade. It has also been implicated in noncoagulant processes, including inflammation. The function of the TF cytoplasmic domain was studied in mice in which 18 of the 20 cytoplasmic amino acids were deleted. This mutation (TF(deltaCT/deltaCT)) is not associated with alterations in blood coagulation. Arthritis was induced by intra-articular injection of methylated bovine serum albumin (mBSA) in mice preimmunized with mBSA. Arthritis severity was significantly reduced in TF(deltaCT/deltaCT) mice compared to wild-type mice, including reductions in synovitis, synovial exudate, cartilage degradation, and bone damage. A marked reduction in synovial interleukin (IL)-1beta and IL-6 mRNA was also observed. Serum anti-mBSA IgG1, but not IgG2a, was increased in mutant mice. Cutaneous delayed-type hypersensitivity and antigen-induced T-cell proliferation were reduced in TF(deltaCT/deltaCT) compared to wild-type mice. A significant down-regulation of lipopolysaccharide-induced IL-1, tumor necrosis factor, IL-6, macrophage migration inhibitory factor, and matrix metalloproteinase-13 mRNA was observed in immunized, but not in naive TF(deltaCT/deltaCT) macrophages ex vivo. These data suggest a significant role for the cytoplasmic domain of TF in the regulation of the immunoinflammatory responses, a murine arthritis model, and macrophage function.