Interleukin-10 regulates hepcidin in Plasmodium falciparum malaria

BACKGROUND: Acute malarial anemia remains a major public health problem. Hepcidin, the major hormone controlling the availability of iron, is raised during acute and asymptomatic parasitemia. Understanding the role and mechanism of raised hepcidin and so reduced iron availability during infection is critical to establish evidence-based guidelines for management of malaria anemia. Our recent clinical evidence suggests a potential role of IL-10 in the regulation of hepcidin in patients with acute P. falciparum malaria. METHODS: We have measured secretion of hepcidin by primary macrophages and the hepatoma cell line HepG2 stimulated with IL-10, IL-6 and Plasmodium falciparum-infected erythrocytes. FINDINGS: We have observed that IL-10 and IL-6 production increased in primary macrophages when these cells were co-cultured with Plasmodium falciparum-infected erythrocytes. We found that IL-10 induced hepcidin secretion in primary macrophages in a dose-dependent manner but not in HepG2 cells. These effects were mediated through signal transducer and activator of transcription (STAT) 3-phosphorylation and completely abrogated by a specific STAT3 inhibitor. CONCLUSION: IL-10 can directly regulate hepcidin in primary macrophages but not in HepG2 cells. This effect can be modulated by Plasmodium falciparum. The results are consistent with a role for IL-10 in modulating iron metabolism during acute phase of infection

Proteomic identification of host and parasite biomarkers in saliva from patients with uncomplicated Plasmodium falciparum malaria.

BACKGROUND: Malaria cases attributed to Plasmodium falciparum account for approximately 600,000 deaths yearly, mainly in African children. The gold standard method to diagnose malaria requires the visualization of the parasite in blood. The role of non-invasive diagnostic methods to diagnose malaria remains unclear. METHODS: A protocol was optimized to deplete highly abundant proteins from saliva to improve the dynamic range of the proteins identified and assess their suitability as candidate biomarkers of malaria infection. A starch-based amylase depletion strategy was used in combination with four different lectins to deplete glycoproteins (Concanavalin A and Aleuria aurantia for N-linked glycoproteins; jacalin and peanut agglutinin for O-linked glycoproteins). A proteomic analysis of depleted saliva samples was performed in 17 children with fever and a positive-malaria slide and compared with that of 17 malaria-negative children with fever. RESULTS: The proteomic signature of malaria-positive patients revealed a strong up-regulation of erythrocyte-derived and inflammatory proteins. Three P. falciparum proteins, PFL0480w, PF08_0054 and PFI0875w, were identified in malaria patients and not in controls. Aleuria aurantia and jacalin showed the best results for parasite protein identification. CONCLUSIONS: This study shows that saliva is a suitable clinical specimen for biomarker discovery. Parasite proteins and several potential biomarkers were identified in patients with malaria but not in patients with other causes of fever. The diagnostic performance of these markers should be addressed prospectively

Identification of a novel clinical phenotype of severe Malaria using a network-based clustering approach

The parasite Plasmodium falciparum is the main cause of severe malaria (SM). Despite treatment with antimalarial drugs, more than 400,000 deaths are reported every year, mainly in African children. The diversity of clinical presentations associated with SM highlights important differences in disease pathogenesis that often require specific therapeutic options. The clinical heterogeneity of SM is largely unresolved. Here we report a network-based analysis of clinical phenotypes associated with SM in 2,915 Gambian children admitted to hospital with Plasmodium falciparum malaria. We used a network-based clustering method which revealed a strong correlation between disease heterogeneity and mortality. The analysis identified four distinct clusters of SM and respiratory distress that departed from the WHO definition. Patients in these clusters characteristically presented with liver enlargement and high concentrations of brain natriuretic peptide (BNP), giving support to the potential role of circulatory overload and/or right-sided heart failure as a mechanism of disease. The role of heart failure is controversial in SM and our work suggests that standard clinical management may not be appropriate. We find that our clustering can be a powerful data exploration tool to identify novel disease phenotypes and therapeutic options to reduce malaria-associated mortality

傅宗懋著『清代軍機処組織及職掌之研究』

Objective: The neurodegenerative disease amyotrophic lateral sclerosis (ALS) is a heterogeneous clinical syndrome involving multiple molecular pathways. The development of biomarkers for use in therapeutic trials is a priority. We sought to use a high-throughput proteomic method to identify novel biomarkers in individual cerebrospinal fluid samples. Methods: Liquid chromatography-tandem mass spectrometry with label-free quantification was used to identify cerebrospinal fluid proteins using samples from a well-characterised longitudinal cohort comprising patients with ALS (n=43), the upper motor neuron variant primary lateral sclerosis (PLS, n=6), cross-sectional healthy (n=20) and disease controls (Parkinsons’s n=20, ALS mimic disorders n=12). Results: Three macrophage-derived chitinases showed increased abundance in ALS: chitotriosidase (CHIT1), chitinase-3-like protein 1 (CHI3L1) and chitinase-3-like protein 2 (CHI3L2). Elevated CHI3L1 was common to ALS and PLS, whereas CHIT1 and CHI3L2 levels differed. Chitinase levels correlated with disease progression rate (CHIT1 r=0.56, p&lt;0.001; CHI3L1 r=0.31, p=0.028; CHI3L2 r=0.29, p=0.044). CHIT1, CHI3L1 and CHI3L2 levels correlated with phosphorylated neurofilament heavy chain (pNFH; r=0.62, p&lt;0.001; r=0.49, p&lt;0.001; r=0.41, p&lt;0.001). CHI3L1 levels, but not CHIT1 or CHI3L2, increased over time in those with low initial levels (gradient=0.005 log abundance units/month, p=0.001). High CHIT1 was associated with shortened survival (HR 2.84, p=0.009). Inclusion of pNFH in survival models left only an association of pNFH and survival (HR 1.26, p=0.019). Interpretation: Neuroinflammatory mechanisms have been consistently implicated through various experimental paradigms. These results support a key role for macrophage activity in ALS pathogenesis, offering novel target engagement and pharmacodynamic biomarkers for neuroinflammation-focused ALS therapy.</p

Subclinical changes in deceased donor kidney proteomes are associated with 12-month allograft function post transplantation: A preliminary study

Background: Cerebral injury during Donation after Brain Death (DBD) may induce systemic damage affecting long-term kidney function posttransplantation. Conventional evaluation of donor organ quality as a triage for transplantation is of limited utility. Methods: We compared donor kidneys yielding opposing extremes of the continuum of posttransplantation outcomes by several common kidney biopsy evaluation techniques including Kidney Donor Profile Index (KDPI) and Remuzzi scoring, and analysed tissue from a minimal sample cohort using Label-Free Quantitation (LFQ) mass spectrometry. Further assessment of the proteomic results was performed by orthogonal quantitative comparisons of selected key proteins by immunoblotting. Results: We show that common evaluation techniques of kidney biopsies were not predictive for posttransplantation outcomes. In contrast, despite the limited cohort size, the proteomic analysis was able to clearly differentiate between kidneys yielding extreme posttransplantation outcome differences. Pathway analysis of the proteomic data suggested that outcome-related variance in protein abundance associated with profibrotic, apoptosis and antioxidant proteins. Immunoblotting confirmation further supported this observation. Conclusions: We present preliminary data indicating that there is scope for existing evaluation approaches to be supplemented by the analysis of proteomic differences. Furthermore, the observed outcome-related variance in a limited cohort was supported by immunoblotting and is consistent with mechanisms previously implicated in the development of injury and cytoprotection in kidney transplantation

Subclinical changes in deceased donor kidney proteomes are associated with 12-month allograft function post transplantation: A preliminary study

Background: Cerebral injury during Donation after Brain Death (DBD) may induce systemic damage affecting long-term kidney function posttransplantation. Conventional evaluation of donor organ quality as a triage for transplantation is of limited utility. Methods: We compared donor kidneys yielding opposing extremes of the continuum of posttransplantation outcomes by several common kidney biopsy evaluation techniques including Kidney Donor Profile Index (KDPI) and Remuzzi scoring, and analysed tissue from a minimal sample cohort using Label-Free Quantitation (LFQ) mass spectrometry. Further assessment of the proteomic results was performed by orthogonal quantitative comparisons of selected key proteins by immunoblotting. Results: We show that common evaluation techniques of kidney biopsies were not predictive for posttransplantation outcomes. In contrast, despite the limited cohort size, the proteomic analysis was able to clearly differentiate between kidneys yielding extreme posttransplantation outcome differences. Pathway analysis of the proteomic data suggested that outcome-related variance in protein abundance associated with profibrotic, apoptosis and antioxidant proteins. Immunoblotting confirmation further supported this observation. Conclusions: We present preliminary data indicating that there is scope for existing evaluation approaches to be supplemented by the analysis of proteomic differences. Furthermore, the observed outcome-related variance in a limited cohort was supported by immunoblotting and is consistent with mechanisms previously implicated in the development of injury and cytoprotection in kidney transplantation

Cytoskeletal protein degradation in brain death donor kidneys associates with adverse post-transplant outcomes

In brain death, cerebral injury contributes to systemic biological dysregulation, causing significant cellular stress in donor kidneys adversely impacting the quality of grafts. Here, we hypothesized that DBD kidneys undergo proteolytic processes that may deem grafts susceptible to post-transplant dysfunction. Using mass spectrometry and immunoblotting, we mapped degradation profiles of cytoskeletal proteins in deceased and living donor kidney biopsies. We found that key cytoskeletal proteins in DBD kidneys were proteolytically cleaved, generating peptide fragments, predominantly in grafts with suboptimal posttransplant function. Interestingly, α-actinin-4 and Talin-1 proteolytic fragments were detected in brain-death but not in circulatory-death or living-donor kidneys with similar donor characteristics. As Talin-1 is a specific proteolytic target of Calpain-1, we investigated a potential trigger of Calpain activation and Talin-1 degradation using human ex-vivo precision-cut kidney slices and in-vitro podocytes. Notably, we showed that activation of Calpain-1 by Transforming-Growth Factor-β generated proteolytic fragments of Talin-1 that matched the degradation fragments detected in DBD preimplantation kidneys, also causing dysregulation of the actin cytoskeleton in human podocytes; events that were reversed by Calpain-1 inhibition. Our data provide initial evidence that brain death donor kidneys are more susceptible to cytoskeletal protein degradation. Correlation to posttransplant outcomes may be established by future studies.</p

Proteomic profiling of the plasma of Gambian children with cerebral malaria

BackgroundCerebral malaria (CM) is a severe neurological complication of Plasmodium falciparum infection. A number of pathological findings have been correlated with pediatric CM including sequestration, platelet accumulation, petechial haemorrhage and retinopathy. However, the molecular mechanisms leading to death in CM are not yet fully understood. MethodsA shotgun plasma proteomic study was conducted using samples form 52 Gambian children with CM admitted to hospital. Based on clinical outcome, children were assigned to two groups: reversible and fatal CM. Label-free liquid chromatography–tandem mass spectrometry was used to identify and compare plasma proteins that were differentially regulated in children who recovered from CM and those who died. Candidate biomarkers were validated using enzyme immunoassays. ResultsThe plasma proteomic signature of children with CM identified 266 proteins differentially regulated in children with fatal CM. Proteins from the coagulation cascade were consistently decreased in fatal CM, whereas the plasma proteomic signature associated with fatal CM underscored the importance of endothelial activation, tissue damage, inflammation, haemolysis and glucose metabolism. The concentration of circulating proteasomes or PSMB9 in plasma was not significantly different in fatal CM when compared with survivors. Plasma PSMB9 concentration was higher in patients who presented with seizures and was significantly correlated with the number of seizures observed in patients with CM during admission. ConclusionsThe results indicate that increased tissue damage and hypercoagulability may play an important role in fatal CM. The diagnostic value of this molecular signature to identify children at high risk of dying to optimize patient referral practices should be validated prospectively.</p

How caregivers of people with dementia search for dementia-specific information on the internet: Survey study

Background: During the last decade, more research has focused on web-based interventions delivered to support caregivers of people with dementia. However, little information is available in relation to internet use among caregivers in general, especially those caring for people with dementia. Objective: The aim of this study was to evaluate the dementia-related internet use and factors that may be associated with its use among caregivers of people with dementia in Greece. Methods: Secondary data from the Greek Dementia Survey of the Athens Association of Alzheimer's Disease and Related Disorders were collected from April to June 2017. A total of 580 caregivers of people with dementia participated in the study. Results: The majority of the caregivers reported that they had used the internet in the previous 3 months (84.1%, 488/580). Nearly half of the caregivers (47.5%, 276/580) reported that they had received dementia services online. Bivariate analysis showed that a dementia-specific search of information was associated with age, education, kinship, and years of care. Age (odds ratio [OR] 2.362, 95% CI 1.05-5.33) and education (OR 2.228, 95% CI 1.01-4.94) were confirmed as predictors, with younger caregivers and those with higher educational attainment being more likely to search for dementia-specific information. Use of the internet to search for dementia information was only related to hours of care. The internet use by caregivers within the previous 3 months was associated with variables such as age, education, occupation, kinship, years of care, and self-reported impact on physical and social health. Conclusions: Caregivers of people with dementia in Greece, as in the other southern European countries, are essential agents of the national health system. The existing short- and long-term respite care services are limited or nonexistent. Currently, caregivers receive mostly support and education from memory clinics and municipality consultation centers, which are mainly based in central cities in Greece. Despite the dementia awareness movement in Greece, there is still space to integrate the role of technology in the support and education of caregivers. Development of training programs for enhancing electronic health literacy skills as well as web-based services provision could support Greek caregivers in their everyday caring tasks

Discovery and validation of biomarkers to guide clinical management of pneumonia in African children

Background. Pneumonia is the leading cause of death in children globally. Clinical algorithms remain suboptimal for distinguishing between severe pneumonia from other causes of respiratory distress like malaria, and between bacterial pneumonia and pneumonia from others causes such as viruses. Molecular tools could improve diagnosis and management.Methods. We conducted a mass spectrometry-based proteomic study to identify and validate markers of severity in 390 Gambian children with pneumonia (N=204) and age, sex and neighborhood-matched controls (N=186). Independent validation was conducted on 293 Kenyan children with respiratory distress (238 with pneumonia, 41 with P. falciparum malaria and 14 with both). Predictive value was estimated by the area under the receiver operating characteristic curve (AUROC).Results. Lipocalin-2 (Lpc-2) was the best protein biomarker of severe pneumonia (AUROC: 0.71 [95% CI, 0.64-0.79]) and highly predictive of bacteremia (AUROC 78% [95% CI, 64-92%]); pneumococcal bacteremia (AUROC 84% [95% CI, 71-98%]); and ‘probable bacterial etiology’ (AUROC: 91% [95%CI 84-98]). These results were validated in Kenyan children with severe malaria and respiratory distress who also met the WHO definition of pneumonia. The combination of Lpc-2 and haptoglobin distinguished bacterial versus malaria origin of respiratory distress with high sensitivity and specificity in Gambian children (AUROC: 99% [95%CI 99-100%]) and in Kenyan children (AUROC: 82% [95% CI, 74-91%]).Conclusions. Lpc-2 and haptoglobin can help discriminate the etiology of clinically defined pneumonia, and could be used to improve clinical management. These biomarkers should be further evaluated in prospective clinical studies