Franny Jongbloed

87 4 A PROTEIN-FREE DIET PROTECTS AGAINST RENAL IRI Pathway analyses and transcription factor analyses To explore the biological value of these transcriptomic responses, we used an individual approximation to identify significantly enriched pathways. The highest enriched pathways after the different dietary interventions were ranked by their –log P- value and summarized in Table S2. No clear pattern in overlapping pathways between all diets, or between the protective diets and the non-protective CHO-free diet, was observed. One pathway that emerged was the NRF2-mediated oxidative stress response pathway , since this pathway was activated by four out of five dietary interventions (Table S2). Figure 3. Venn diagram of multiple dietary interventions combined. (A) Venn diagram showing the number of DEPS after three days of fasting, two weeks 30% DR, three days of protein-free diet, three days of CHO-free diet, and their overlap with each diet. Thirty DEPS are differentially regulated in all four diets including the non-protective CHO-free (centre). The protective diets have 70 DEPS in common, of which 40 of those in common with the CHO-free diet are excluded (lower right). (B) Venn diagram showing the number of DEPS after three days of fasting, three days of a protein-free diet, two weeks and three days of 30% DR with their overlap. Forty-seven DEPS are differentially regulated in all fours diets (centre). A total of 15 DEPS were overlapping between the three protective diets. To further identify a common protective response and dissect it from the response of the non-protective CHO-free diet, a more comprehensive meta-analytic approximation was used. A combining rank orders methodology was implemented to prevent bias of the results based on outliers as well as the stronger transcriptomic response after three days of fasting 20 . By eliminating all significant probe sets induced by the CHO-free diet in this meta-analysis, only 140 DEPS remained. Pathway analysis revealed no significant pathways (data not shown). Theorizing that the protective response might be partially overlapping