Gene Expression Profiling Confirms the Dosage-Dependent Additive Neuroprotective Effects of Jasminoidin in a Mouse Model of Ischemia-Reperfusion Injury

Abstract

Recent evidence demonstrates that a double dose of Jasminoidin (2·JA) is more effective than Jasminoidin (JA) in cerebral ischemia therapy, but its dosage-effect mechanisms are unclear. In this study, the software GeneGo MetaCore was used to perform pathway analysis of the differentially expressed genes obtained in microarrays of mice belonging to four groups (Sham, Vehicle, JA, and 2·JA), aiming to elucidate differences in JA and 2·JA's dose-dependent pharmacological mechanism from a system's perspective. The top 10 enriched pathways in the 2·JA condition were mainly involved in neuroprotection (70% of the pathways), apoptosis and survival (40%), and anti-inflammation (20%), while JA induced pathways were mainly involved in apoptosis and survival (60%), anti-inflammation (20%), and lipid metabolism (20%). Regarding shared pathways and processes, 3, 1, and 3 pathways overlapped between the Vehicle and JA, Vehicle and 2·JA, and JA and 2·JA conditions, respectively; for the top ten overlapped processes these numbers were 3, 0, and 4, respectively. The common pathways and processes in the 2·JA condition included differentially expressed genes significantly different from those in JA. Seven representative pathways were only activated by 2·JA, such as Gamma-Secretase regulation of neuronal cell development. Process network comparison indicated that significant nodes, such as alpha-MSH, ACTH, PKR1, and WNT, were involved in the pharmacological mechanism of 2·JA. Function distribution was different between JA and 2·JA groups, indicating a dosage additive mechanism in cerebral ischemia treatment. Such systemic approach based on whole-genome multiple pathways and networks may provide an effective and alternative approach to identify alterations underlining dosage-dependent therapeutic benefits of pharmacological compounds on complex disease processes.

Figure 1

Variation of infarction volume among different groups. Both 2·JA and JA were effective in reducing the ischemic infarction volume.

Figure 2

Pathway profiles in different groups analyzed with GeneGo. (a–c) The top 10 GeneGo pathways of each group are shown; the overlapping cascades between Vehicle and JA (2, in green) and JA and 2·JA (2, in blue) and among the three groups (1, in red) are marked; no overlapping pathways were shared between Vehicle and 2·JA groups. (d) Overlapping and specific pathways of each group are presented in a Venn diagram.

Figure 3

Process networks annotated by GeneGo for the Vehicle, JA, and 2·JA groups. (a–c) The top 10 GeneGo process networks of each group are shown; the overlapping cascades between Vehicle and JA (3, in green) and JA and 2·JA (4, in blue) are marked; no overlapping networks were shared between Vehicle and 2·JA. (d) Overlapping and specific process networks of each group are presented in a Venn diagram.

Figure 4

Two pathways of genes altered in the 2·JA group. Gamma-Secretase proteolytic targets (a) and Gamma-Secretase regulation of neuronal cell development and function (b). The map legend can be viewed at http://lsresearch.thomsonreuters.com/static/uploads/files/2014-05/MetaCoreQuickReferenceGuide.pdf.

Figure 5

Signal transduction-neuropeptides signaling pathways. They contain 28 target genes, with 23 and 17 in JA and 2·JA, respectively. Among them, 12 target molecules were activated by both dosages (in black); 2 were only activated in the JA (in blue) group, while 5 were specific to 2·JA (in red) treatment.

Figure 6

JNK1 and NIK pathways were upregulated and contributed to cell death in brain ischemia in the Vehicle group.

Figure 7

Altered genes representing 2·JA (in blue), JA (in green), and Vehicle (in red) that target pathways involved in cerebral ischemia. Lipid metabolism, apoptosis and survival, inflammation pathways, and others were affected.