1H NMR based serum metabolic profiling reveals differentiating biomarkers in patients with diabetes and diabetes-related complication.

BACKGROUND: Diabetes is among the most prevalent diseases worldwide, of all the affected individuals a significant proportion of the population remains undiagnosed due to lack of specific symptoms early in this disorder and inadequate diagnostics. Diabetes and its associated sequela, i.e., comorbidity are associated with microvascular and macrovascular complications. As diabetes is characterized by an altered metabolism of key metabolites and regulatory pathways. Metabolic phenotyping can provide us with a better understanding of the unique set of regulatory perturbations that predispose to diabetes and its associated complication/comorbidities. METHODOLOGY: The present study utilizes the analytical platform NMR spectroscopy coupled with Random Forest statistical analysis to identify the discriminatory metabolites in diabetes (DB = 38) vs. diabetes-related complication (DC = 35) along with the healthy control (HC = 50) subjects. A combined and pairwise analysis was performed to identify the discriminatory metabolites responsible for class separation. The perturbed metabolites were further rigorously validated using t-test, AUROC analysis to examine the statistical significance of the identified metabolites. RESULTS: The DB and DC patients were well discriminated from HC. However, 15 metabolites were found to be significantly perturbed in DC patients compared to DB, the identified panel of metabolites are TCA cycle (succinate, citrate), methylamine metabolism (trimethylamine, methylamine, betaine), -intermediates; energy metabolites (glucose, lactate, pyruvate); and amino acids (valine, arginine, glutamate, methionine, proline, and threonine). CONCLUSION: The 1H NMR metabolomics may prove a promising technique to differentiate and predict diabetes and its complication on their onset or progression by determining the altered levels of the metabolites in serum.

Differential Histone Acetylation in Sub-Regions of Bed Nucleus of the Stria Terminalis Underlies Fear Consolidation and Extinction.

OBJECTIVE: The hallmark of anxiety disorders is excessive fear. Previous studies have suggested that selective neural projections from Basal nucleus of stria terminalis (BNST) to amygdala and vice-versa precisely control the fear learning process. However the exact mechanism how the BNST controls fear consolidation and its extinction is largely unknown. In the present study we observed the changes in the BNST sub-regions following fear conditioning and its extinction. METHODS: The change in the number of positive neurons was determined by immunohistochemistry for Acetyl H3 (Histone 3), Acetyl H4 (Histone 4), cAMP response element binding Protein (CBP) and c-fos in three sub-regions of the BNST namely the anterio-lateral BNST (STLP) and anterio-medial BNST (STMA), and lateral-ventral BNST (STLV) of rats subjected to auditory fear conditioning and extinction. RESULTS: We found significant increase in the number of CBP, acetyl H3 and acetyl H4 positive neurons in the STMA and STLV but not in the STLP after fear conditioning. However, following fear extinction the number of CBP, acetyl H3 and acetyl H4 positive neurons increased significantly in the STLP but not in the STMA and STLV. Similar changes were observed in the number of c-fos positive neurons after fear consolidation and extinction. CONCLUSION: The results from this study suggest that the differential histone acetylation in the different sub-regions of the BNST following fear learning and its extinction may be responsible for changes in the neuronal activation patterns resulting in either fear or less fear.