Inhibition of HIF-prolyl hydroxylases (PHD1, PHD2, and PHD3) causes the stabilization of hypoxia-inducible factor-1α and -2α (HIF-1α and HIF-2α) to regulate various cell signaling pathways. Hypoxia-inducible factor (HIF) is crucial in regulating signal responses mediated by hypoxia. HIF regulates the transcription of many genes involved in the response to hypoxia and ischemic insult. Our current work investigates the protective effects of PHD1 knockout in mice against myocardial infarction. Study Design: Myocardial infarction (MI) was induced by left anterior descending coronary artery (LAD) ligation (8–12-week-old mice) in both wild-type (WT) and PHD1 knockout (PHD1^−/−) mice. WT sham (S) and PHD1^−/−S group mice underwent surgery without LAD ligation. Thirty days post-surgery, cardiac functions were measured by echocardiogram. Mice in all the groups were euthanized at various time points for tissue collection post-MI 8 h (gel shift and microarray analysis), 4 days (Western blot analysis), 7 days (blood vessel density), or 30 days (histological analysis). For microarray analysis, WTMI and PHD1^−/−MI group mices’ heart tissue was used for RNA isolation, then hybridization to a GeneChip™ Mouse Gene 1.0 ST Array as per the manufacturer’s instructions. Bioinformatic analysis was performed using the transcriptome analysis console (TAC) to generate a list of differentially regulated genes, followed by ingenuity pathway analysis. Results: The study findings revealed a significant increase in vessel density (capillary and arteriolar density) in the PHD1^−/−MI mice compared to those with WTMI. The echocardiographic examination demonstrated that the PHD1^−/−MI mice group had an increased ejection fraction and fractional shortening than the WT mice 30 days post-MI. HIF-1α DNA binding activity was higher in PHD1^−/−MI mice than in WTMI. The Western blot analysis showed a significant increase in the expression of HSPA12B in the PHD1^−/−MI compared to WTMI mice. Bioinformatic analysis using TAC software, Version 4.0.2.15 (1.5 fold, p < 0.05) showed 174 differentially regulated genes. Conclusions: In conclusion, our study showed PHD1 knockout activates several important molecules and signaling pathways, resulting in increased angiogenesis and cardioprotection against myocardial infarction.

Background: Head and Neck Squamous Cell Carcinoma (HNSCC) causes half a million deaths each year; therefore, it is essential to understand the factors that affect patient prognosis. Many studies fail to investigate the biological drivers behind survival disparities, especially sex-specific differences within racial groups. This study serves as a foundational project to begin elucidating biological differences in the tumor microenvironment between male and female African American HNSCC patients. Methods: A total of 111 patients who were diagnosed with HNSCC and identify as African American were grouped by sex. Analyses of socioeconomic status, co-morbidities, tumor characteristics, and treatment were conducted. Spatial transcriptomic analysis was performed on four randomly selected primary HNSCC tumor tissues. Results: No sex-based differences were observed in socioeconomic measures, treatments, tumor stage, follow-up, recurrence, or cause of death (all p > 0.15), though females had higher median income than males (p = 0.035). Comorbidity profiles were also largely comparable between males and females. Evaluating tumor microenvironments, we found that male tumors were dominated by malignant cells and fibroblasts, with limited adaptive immune infiltration. By contrast, female tumors displayed markedly higher proportions of immune cells, including T cells and B cells. Male tumors harbored sparse T cells, largely skewed toward exhausted phenotypes while female tumors displayed abundant T cell infiltration consistent with immunologically active tumor microenvironment. Conclusions: Clinical and demographic factors showed minimal sex-based differences among African American HNSCC patients, spatial transcriptomic profiling revealed strikingly distinct immune microenvironments by sex. These findings suggest that biological, rather than simply clinical, differences may drive survival disparities. This project serves as a novel and foundational study promoting the use of spatial transcriptomics to evaluate possible survival disparities within HNSCC populations to alleviate survival disparities.