A Protein Microarray-Based Investigation of Cerebrospinal Fluid Reveals Distinct Autoantibody Signature in Low and High-Grade Gliomas

Gliomas are one of the most aggressive primary brain tumors arising from neural progenitor cells. Delayed diagnosis, invasive biopsy, and diagnostic challenges stems the need for specific, minimally-invasive, and early diagnostic biomarkers. Tumor-associated (TA) autoantibodies are measurable in the biofluids long before the onset of the symptoms, suggesting their role in early diagnosis and clinical management of the patients. In the current study, cerebrospinal fluid (CSF) samples from patients with low-grade glioma (LGG) and the Glioblastoma multiforme (GBM) that characterizes advanced disease were compared with healthy control samples to identify putative TA autoantibodies, using protein microarrays. The CSF samples from LGGs (n = 10), GBM (n = 7) were compared with the control CSF samples (n = 6). Proteins showing significant antigenic response were cross-verified. Proteins NOL4 (a cancer-testis antigen) and KALRN showed an antigenic response in the CSF of GBM patients, whereas, UTP4 and CCDC28A showed an antigenic response in low grade gliomas when compared with the control samples. TA autoantibodies identified in this study from the CSF of the patients could supplement current screening modalities. Further validation of these TA autoantibodies on a larger clinical cohort could provide cues towards relevance of these proteins in early diagnosis of the disease.

Multi-pronged proteomic analysis to study the glioma pathobiology using cerebrospinal fluid samples

PURPOSE

Gliomas are one of the most aggressive and lethal brain tumors arising from neoplastic transformation of astrocytes and oligodendrocytes. A comprehensive quantitative analysis of proteome level differences in cerebrospinal fluid (CSF) across different grades of gliomas for a better understanding of glioma pathobiology is carried out.

EXPERIMENTAL DESIGN

Glioma patients are diagnosed by radiology and histochemistry-based analyses. Differential proteomic analysis of high (n = 12) and low (n = 5) grade gliomas, and control (n = 3) samples is performed by using two complementary quantitative proteomic approaches; 2D-DIGE and iTRAQ. Further, comparative analysis of three IDH wild-type and five IDH mutants is performed to identify the proteome level differences between these two sub-classes.

RESULTS

Level of several proteins including haptoglobin, transthyretin, osteopontin, vitronectin, complement factor H and different classes of immunoglobulins are found to be considerably increased in CSF of higher grades of gliomas. Subsequent bioinformatics analysis indicated that many of the dysregulated CSF proteins are associated with metabolism of lipids and lipoproteins, complement and coagulation cascades and extracellular matrix remodeling in gliomas. Intriguingly, CSF of glioma patients with IDH mutations exhibite increased levels of multiple proteins involved in response to oxidative stress.

CONCLUSION AND CLINICAL RELEVANCE

To the best of our knowledge, this is the foremost proteome level investigation describing comprehensive proteome profiles of different grades of gliomas using proximal fluid (CSF); and thereby providing insights into disease pathobiology, which aided in identification of grade and sub-type specific alterations. Moreover, if validated in larger clinical cohorts, a panel of differentially abundant CSF proteins may serve as potential disease monitoring and prognostic markers for gliomas.

Real-time iTRAQ-based proteome profiling revealed the central metabolism involved in nitrogen starvation induced lipid accumulation in microalgae

To understand the post-transcriptional molecular mechanisms attributing to oleaginousness in microalgae challenged with nitrogen starvation (N-starvation), the longitudinal proteome dynamics of Chlorella sp. FC2 IITG was investigated using multipronged quantitative proteomics and multiple reaction monitoring assays. Physiological data suggested a remarkably enhanced lipid accumulation with concomitant reduction in carbon flux towards carbohydrate, protein and chlorophyll biosynthesis. The proteomics-based investigations identified the down-regulation of enzymes involved in chlorophyll biosynthesis (porphobilinogen deaminase) and photosynthetic carbon fixation (sedoheptulose-1,7 bisphosphate and phosphoribulokinase). Profound up-regulation of hydroxyacyl-ACP dehydrogenase and enoyl-ACP reductase ascertained lipid accumulation. The carbon skeletons to be integrated into lipid precursors were regenerated by glycolysis, β-oxidation and TCA cycle. The enhanced expression of glycolysis and pentose phosphate pathway enzymes indicates heightened energy needs of FC2 cells for the sustenance of N-starvation. FC2 cells strategically reserved nitrogen by incorporating it into the TCA-cycle intermediates to form amino acids; particularly the enzymes involved in the biosynthesis of glutamate, aspartate and arginine were up-regulated. Regulation of arginine, superoxide dismutase, thioredoxin-peroxiredoxin, lipocalin, serine-hydroxymethyltransferase, cysteine synthase, and octanoyltransferase play a critical role in maintaining cellular homeostasis during N-starvation. These findings may provide a rationale for genetic engineering of microalgae, which may enable synchronized biomass and lipid synthesis.

Defect-rich ZnO quantum dots as a potential multifunctional sunscreen and cosmetic active ingredient

In sunscreens, ZnO nanoparticles (NPs) are used as inorganic UV filter which have a prominent band edge emission in the UVA region (~385 nm). When applied to biological surface, this highly penetrating UVA emission from ZnO NPs would enhance the generation of reactive oxygen species resulting in oxidative stress. Therefore, the elimination of this harmful UVA emission from ZnO NPs are much sought after for the development of safer sunscreens. In this paper we introduce the use of defect-rich ZnO (D-ZnO) quantum dots (QDs) as a multifunctional active ingredient in sunscreen/cosmetic application. These D-ZnO QDs make use of their defect energy levels to emit in visible region by bypassing their harmful band edge emission at UVA region. The D-ZnO QDs also showed prominent visible luminescence which matches well with the autofluorescence of in vivo human skin. Hence, this visible luminescence could be useful for camouflaging, thereby enabling its potential as a biologically safe active ingredient for both cosmetic and UV screening applications.

Surface defect rich ZnO quantum dots as antioxidants inhibiting α-amylase and α-glucosidase: a potential anti-diabetic nanomedicine

The antioxidant and enzyme inhibitory activity of defect rich ZnO quantum dots is reported, which shows potential for developing anti-diabetic nanomedicine.

Enhanced visible photoluminescence in ZnO quantum dots by promotion of oxygen vacancy formation

We report on the synthesis of ZnO quantum dots (QDs) rich in oxygen vacancies by inducing an oxygen deficient environment. The precise tunability of particle size is achieved by counter ion capping of the precursor used for synthesis. The prepared QDs show size tunable visible emission with high quantum yield.

Severe acute maternal morbidity in rural South Africa

OBJECTIVE

Our objective was to identify the frequency, causes, and avoidable factors of severe acute maternal morbidity (SAMM) in four non-specialist hospitals in rural South Africa.

METHOD

We conducted a prospective audit using criteria for SAMM suited to the diagnostic and treatment facilities available in the primary hospital setting. For each case of SAMM, a local audit team assessed the standard of care against local management guidelines and examined avoidable factors. An external specialist also retrospectively examined avoidable factors.

RESULT

The facility-based incidence of SAMM was 541 cases per 100,000 births (95% CI 368-767). The commonest organ systems involved were cerebral (42%), coagulation (19%), and vascular dysfunctions (16%). The commonest obstetric diagnoses were eclampsia (39%) and obstetric haemorrhage (32%). Approximately 65% of cases were avoidable.

CONCLUSION

A qualitative case review audit of SAMM in a non-specialist rural setting appears feasible and sustainable, and provides valuable information towards improving deficiencies in maternal care.