## 6 Discussion  
Our previous studies have demonstrated the beneficial effects of inhibiting these PHD enzyme (PHD2 and PHD3) isoforms in genetically knockout mice by simulating myocardial infarction with permanent ligation of the left anterior descending artery. With the advent of oral formulation of a novel PHD inhibitor in a phase one clinical study [28], there is a rekindled interest in the PHD knockout pathway to ameliorate the effects of ischemic insult in the setting of myocardial infarction. In this study, we focused on PHD1, one of the three isoforms of the PHD enzymes. PHD1 knockout mice exhibit a similar upregulation and stabilization of HIF1\(\alpha\) (Figure 8) following myocardial infarction as our previous studies with PHD 2 and PHD 3 knockout mice. PHD1 mice were subjected to MI, showing a remarkable preservation of cardiac function after the insult compared to wild-type mice, as evidenced by the superior  
Figure 8: (**A**) Image of gel shift analysis performed on each group of mice, showing a significant reduction in HIF-1\(\alpha\) in the WTMI group compared to the PHD1\({}^{-/-}\) MI group. ns is indicative of non-specific free probes detected in all groups (n = 2). (**B**) The immunoblotting analysis compared all four mice groups, using GAPDH as a loading control. The bar graph shows a significant increase in HSPA12B level in PHD1\({}^{-/-}\) S compared to the WTS group and PHD1\({}^{-/-}\) MI group compared to the WTMI group (n = 5-8; values are mean \(\pm\) SEM (* \(p<0.05\)). Asterisks represent the degree of significance between the two groups). (**C**) Immunoblotting analysis was performed comparing Insulin Receptor Substrate-2 IP/IB expression in all four groups of mice. Bar graph showing no significant difference in IRS2 (IP/IB) expression in PHD1\({}^{-/-}\) S mice when compared to WTS mice, but the PHD1\({}^{-/-}\) MI group shows a significant increase in the expression of IRS2 (IP/IB) when compared to the WTS group. Values are mean \(\pm\) SEM (* \(p<0.05\)). Asterisks represent the degree of significance between the two groups, ns represents not significant. ejection fraction and cardiac output post-ML. Stabilizing the HIF pathway brings about these effects and subsequent increased levels of HIF-1 expression, as demonstrated in our gel shift analysis, marking a significant advancement in our understanding of cardiac function preservation. On the tissue level, knockout of the PHD1 enzyme resulted in increased capillary and arteriolar density. Using anti-CD31 and anti-\(\alpha\)-smooth muscle actin, we illustrated the increase in vessel density at the myocardial risk area, confirming the proangiogenic effect of the knockout of PHD1. This preservation of the arteriolar and capillary network may contribute to the subsequent preservation of cardiac function (Figure 9). In our present study, our focus was to identify differentially regulated gene expression by the knockout of PHD1 in a mouse MI model. Due to advances in personalized medicine and therapies, there is a growing focus on identifying genes causing diseases for diagnosis and prognosis. In recent years, bioinformatics has played a significant role in omics techniques, particularly in gene array or RNA-sequencing (RNA-seq) technologies  
Figure 9: Flow diagram denoting that PHD1 knockout in mouse genetic model leads to increased angiogenesis and cardioprotection. In addition, GeneChipTM analysis designated 174 differentially expressed gene (Tables 1 and 2). Bio Render software (version 1.0.0.3) was used to create this figure. to identify vast amounts of data and differentially regulated gene expression levels in control and experimental groups. Our results provide a direction for further studies, with 174 differentially expressed genes identified so far, including 89 upregulated (Table 1) and 85 downregulated (Table 2) genes. A graphical summary of the IPA analysis is provided in Figure 5, which shows several important pathways and genes that have been identified due to PHD1 knockout.