Upon metabolomics data is quite different from the process for proteomics

Upon metabolomics data is quite different from the process for proteomics, transcriptomics or genomics datasets. This is because concept or text-based associations (for example GO categories or MESH headings) are not associated with small molecule compounds as they are for proteins or genes. While pathway databases such as KEGG can be used to deduce some 25033180 mechanisms, the available data are extremely limited. For example, only a fraction of the known human metabolome is linked to pathways, and secondary processes such as gut microbiome-generated effects [27] and much of lipid metabolism are not included. For this reason, less direct methods using existing tools must be used for pathway and network analysis for complex studies. The approach used MetaMAPP [28], a network modeling tool that uses KEGG reaction pairs (e.g. standard metabolic pathways) and then adds compounds, which are not on these pathways, by chemical similarity (Tanimoto) index [29].ResultsBaseline characteristics according to race for the PEAR participants included in this metabolomics study are described in Table 1. GC-TOF data from plasma samples collected before and after 9 weeks of atenolol treatment were analyzed; a total of 544 samples from 272 patients were analyzed. Analysis of plasma on the GC-TOF platform resulted in a total of 157 identified compounds after processing in BinBase. These included amino acids, sugars and sugar alcohols, fatty acids and cholesterol, organic anions, including TCA cycle intermediates, and many other compounds. There were 171 additional compounds in the dataset that were observed and annotated but not identified.Metabolomic Signature of Atenolol TreatmentStudy participants on average had expected physiological and metabolic changes over a course of atenolol therapy (Table 2). Systolic and diastolic blood pressure decreased, along with LDL,HDL and plasma renin activity in both Caucasians and African American patients. Glucose, triglycerides and uric acid increased significantly over the course of the 9 weeks. As expected, there were significant difference between Caucasians and African Americans in blood pressure and plasma renin activity change in response to atenolol monotherapy (Table 2). Seventeen metabolites had a nominally significant change in plasma levels upon atenolol treatment; nine changed significantly in the complete dataset after considering false discovery rate (Table 3) seven of which were fatty acids. Four of these fatty acids, myristic, methylhexadecanoic, palmitic and stearic acids are saturated, whereas palmitoleic and oleic are monounsaturated; arachidonic acid and SR-3029 site linoleic are polyunsaturated. These structurally diverse fatty acids decreased in concentration significantly over the treatment period. Many free fatty acids, such as arachidonic acid, oleic, linoleic and palmitic, are non-covalently bound in large quantities to human serum albumin [30]. Fatty acid changes correlated strongly with each other in the total population (Figure 1). Some fatty acids, including the saturated fatty acids lauric (12:0) and capric (10:0), caprylic acid (8:0), pentadecanoic acid (15:0), and azelaic acid, a saturated dicarboxylic acid, remained unchanged by atenolol treatment across categories. Elaidic acid (18:1 trans-9), the trans isomer of oleic acid, was not changed. The ketone body 3-hydroxybutyrate was significantly reduced upon atenolol treatment in the complete dataset. Two other ketone bodies, 166518-60-1 site acetone and acetoacetate, wer.Upon metabolomics data is quite different from the process for proteomics, transcriptomics or genomics datasets. This is because concept or text-based associations (for example GO categories or MESH headings) are not associated with small molecule compounds as they are for proteins or genes. While pathway databases such as KEGG can be used to deduce some 25033180 mechanisms, the available data are extremely limited. For example, only a fraction of the known human metabolome is linked to pathways, and secondary processes such as gut microbiome-generated effects [27] and much of lipid metabolism are not included. For this reason, less direct methods using existing tools must be used for pathway and network analysis for complex studies. The approach used MetaMAPP [28], a network modeling tool that uses KEGG reaction pairs (e.g. standard metabolic pathways) and then adds compounds, which are not on these pathways, by chemical similarity (Tanimoto) index [29].ResultsBaseline characteristics according to race for the PEAR participants included in this metabolomics study are described in Table 1. GC-TOF data from plasma samples collected before and after 9 weeks of atenolol treatment were analyzed; a total of 544 samples from 272 patients were analyzed. Analysis of plasma on the GC-TOF platform resulted in a total of 157 identified compounds after processing in BinBase. These included amino acids, sugars and sugar alcohols, fatty acids and cholesterol, organic anions, including TCA cycle intermediates, and many other compounds. There were 171 additional compounds in the dataset that were observed and annotated but not identified.Metabolomic Signature of Atenolol TreatmentStudy participants on average had expected physiological and metabolic changes over a course of atenolol therapy (Table 2). Systolic and diastolic blood pressure decreased, along with LDL,HDL and plasma renin activity in both Caucasians and African American patients. Glucose, triglycerides and uric acid increased significantly over the course of the 9 weeks. As expected, there were significant difference between Caucasians and African Americans in blood pressure and plasma renin activity change in response to atenolol monotherapy (Table 2). Seventeen metabolites had a nominally significant change in plasma levels upon atenolol treatment; nine changed significantly in the complete dataset after considering false discovery rate (Table 3) seven of which were fatty acids. Four of these fatty acids, myristic, methylhexadecanoic, palmitic and stearic acids are saturated, whereas palmitoleic and oleic are monounsaturated; arachidonic acid and linoleic are polyunsaturated. These structurally diverse fatty acids decreased in concentration significantly over the treatment period. Many free fatty acids, such as arachidonic acid, oleic, linoleic and palmitic, are non-covalently bound in large quantities to human serum albumin [30]. Fatty acid changes correlated strongly with each other in the total population (Figure 1). Some fatty acids, including the saturated fatty acids lauric (12:0) and capric (10:0), caprylic acid (8:0), pentadecanoic acid (15:0), and azelaic acid, a saturated dicarboxylic acid, remained unchanged by atenolol treatment across categories. Elaidic acid (18:1 trans-9), the trans isomer of oleic acid, was not changed. The ketone body 3-hydroxybutyrate was significantly reduced upon atenolol treatment in the complete dataset. Two other ketone bodies, acetone and acetoacetate, wer.