Investigation of serum proteome alterations in human glioblastoma multiforme

Serum proteome changes in dengue virus-infected patients from a dengue-endemic area of India: towards new molecular targets?

The global burden of dengue continues to worsen, specifically in tropical and subtropical countries, and has evolved as a major public health problem. We investigated the changes in serum proteome in dengue fever (DF) patients from a dengue-endemic area of India to obtain mechanistic insights about the disease pathogenesis, the host immune response, and identification of potential serum protein biomarkers of this infectious disease. In this study, serum samples from DF patients, healthy subjects, and patients with falciparum malaria (an infectious disease control) were investigated by 2D-DIGE in combination with MALDI-TOF/TOF MS. The findings were validated with Western blotting. Functional clustering of the identified proteins was performed using PANTHER and DAVID tools. Compared to the healthy controls, we found significant changes in the expression levels of 48 protein spots corresponding to 18 unique proteins (7 downregulated and 11 upregulated) in DF patients (p<0.05). Among these differentially-expressed proteins, 11 candidates exhibited different trends in dengue fever compared to falciparum malaria. Importantly, our results suggest that dengue virus infection leads to alterations in expression levels of multiple serum proteins involved in diverse and vital physiological pathways, including acute phase response signaling, complement cascades, hemostasis, and blood coagulation. For the first time we report here that the serum levels of hemopexin, haptoglobin, serum amyloid P, and kininogen precursor, are altered in DF. This study informs the pathogenesis and host immune response to dengue virus infection, as well as the current search for new diagnostic and molecular drug targets.

Proteomic investigation of falciparum and vivax malaria for identification of surrogate protein markers

This study was conducted to analyze alterations in the human serum proteome as a consequence of infection by malaria parasites Plasmodium falciparum and P. vivax to obtain mechanistic insights about disease pathogenesis, host immune response, and identification of potential protein markers. Serum samples from patients diagnosed with falciparum malaria (FM) (n = 20), vivax malaria (VM) (n = 17) and healthy controls (HC) (n = 20) were investigated using multiple proteomic techniques and results were validated by employing immunoassay-based approaches. Specificity of the identified malaria related serum markers was evaluated by means of analysis of leptospirosis as a febrile control (FC). Compared to HC, 30 and 31 differentially expressed and statistically significant (p<0.05) serum proteins were identified in FM and VM respectively, and almost half (46.2%) of these proteins were commonly modulated due to both of the plasmodial infections. 13 proteins were found to be differentially expressed in FM compared to VM. Functional pathway analysis involving the identified proteins revealed the modulation of different vital physiological pathways, including acute phase response signaling, chemokine and cytokine signaling, complement cascades and blood coagulation in malaria. A panel of identified proteins consists of six candidates; serum amyloid A, hemopexin, apolipoprotein E, haptoglobin, retinol-binding protein and apolipoprotein A-I was used to build statistical sample class prediction models. By employing PLS-DA and other classification methods the clinical phenotypic classes (FM, VM, FC and HC) were predicted with over 95% prediction accuracy. Individual performance of three classifier proteins; haptoglobin, apolipoprotein A-I and retinol-binding protein in diagnosis of malaria was analyzed using receiver operating characteristic (ROC) curves. The discrimination of FM, VM, FC and HC groups on the basis of differentially expressed serum proteins demonstrates the potential of this analytical approach for the detection of malaria as well as other human diseases.