Dengue-2 Structural Proteins Associate with Human Proteins to Produce a Coagulation and Innate Immune Response Biased Interactome

<p>Abstract</p> <p>Background</p> <p>Dengue virus infection is a public health threat to hundreds of millions of individuals in the tropical regions of the globe. Although Dengue infection usually manifests itself in its mildest, though often debilitating clinical form, dengue fever, life-threatening complications commonly arise in the form of hemorrhagic shock and encephalitis. The etiological basis for the virus-induced pathology in general, and the different clinical manifestations in particular, are not well understood. We reasoned that a detailed knowledge of the global biological processes affected by virus entry into a cell might help shed new light on this long-standing problem.</p> <p>Methods</p> <p>A bacterial two-hybrid screen using DENV2 structural proteins as bait was performed, and the results were used to feed a manually curated, global dengue-human protein interaction network. Gene ontology and pathway enrichment, along with network topology and microarray meta-analysis, were used to generate hypothesis regarding dengue disease biology.</p> <p>Results</p> <p>Combining bioinformatic tools with two-hybrid technology, we screened human cDNA libraries to catalogue proteins physically interacting with the DENV2 virus structural proteins, Env, cap and PrM. We identified 31 interacting human proteins representing distinct biological processes that are closely related to the major clinical diagnostic feature of dengue infection: haemostatic imbalance. In addition, we found dengue-binding human proteins involved with additional key aspects, previously described as fundamental for virus entry into cells and the innate immune response to infection. Construction of a DENV2-human global protein interaction network revealed interesting biological properties suggested by simple network topology analysis.</p> <p>Conclusions</p> <p>Our experimental strategy revealed that dengue structural proteins interact with human protein targets involved in the maintenance of blood coagulation and innate anti-viral response processes, and predicts that the interaction of dengue proteins with a proposed human protein interaction network produces a modified biological outcome that may be behind the hallmark pathologies of dengue infection.</p

Gene Expression Profiling during Early Acute Febrile Stage of Dengue Infection Can Predict the Disease Outcome

Background: We report the detailed development of biomarkers to predict the clinical outcome under dengue infection. Transcriptional signatures from purified peripheral blood mononuclear cells were derived from whole-genome gene-expression microarray data, validated by quantitative PCR and tested in independent samples. Methodology/Principal Findings: The study was performed on patients of a well-characterized dengue cohort from Recife, Brazil. The samples analyzed were collected prospectively from acute febrile dengue patients who evolved with different degrees of disease severity: classic dengue fever or dengue hemorrhagic fever (DHF) samples were compared with similar samples from other non-dengue febrile illnesses. The DHF samples were collected 2-3 days before the presentation of the plasma leakage symptoms. Differentially-expressed genes were selected by univariate statistical tests as well as multivariate classification techniques. The results showed that at early stages of dengue infection, the genes involved in effector mechanisms of innate immune response presented a weaker activation on patients who later developed hemorrhagic fever, whereas the genes involved in apoptosis were expressed in higher levels. Conclusions/Significance: Some of the gene expression signatures displayed estimated accuracy rates of more than 95%, indicating that expression profiling with these signatures may provide a useful means of DHF prognosis at early stages of infection. © 2009 Nascimento et al

Association of Angiotensin-Converting Enzyme Gene Polymorphisms and Nephropathy in Diabetic Patients at a Tertiary Care Centre in South India

Background: Genetic polymorphisms of the angiotensin-renin pathway have been thought to influence the development of diabetic nephropathy. However, there are conflicting results regarding this association in previous studies on populations with varying ethnicity. Aims: Primary aim was to compare the frequency of distribution of angiotensin-converting enzyme ( ACE ) gene (insertion/deletion [I/D]) polymorphism in Tamilian Indian type 2 diabetic individuals with and without microalbuminuria. Secondary objective was to compare the frequency of distribution of the 3 genotypes in diabetic patients with urinary albumin/creatinine ratio (ACR)  300 mg/dL. Methods: A total of 179 consecutive diabetic individuals between 40 and 70 years, from Puducherry and Tamilnadu of Dravidian descent participated in the study conducted from 2012 to 2014. Inclusion criteria were as follows: age ≥ 40 years and duration of type 2 diabetes mellitus for ≥5 years. Patients were divided into 2 groups based on ACR values. Group 1 consisted of 50 individuals with urinary ACR  30 mg/g. Angiotensin I–converting enzyme ( ACE ) gene polymorphism was determined by allele-specific polymerase chain reaction method using a primer pair flanking the polymorphic region of its intron 16. Furthermore, group 2 patients were subdivided into those with urinary ACR = 30 to 300 mg/g of creatinine and those with urinary ACR > 300 mg/g of creatinine, and distribution of ACE gene polymorphism was compared in the three groups. Statistics: Statistical analysis was done using SPSS version 17.0. Independent Student t test was used to compare mean values between the 2 groups. Odds ratio was calculated for testing association between ACE gene (I/D) polymorphism and presence of microalbuminuria. P   300 mg/g) was done using 1-way analysis of variance with Bonferroni multiple comparison test as post hoc analysis. Conclusions: Heterozygous I/D genotype was more frequent in the study population (45.8%) than the other genotypes. There was no difference in the genotype distribution in patients with varying levels of albuminuria