new insights into the pathophysiology of rheumatic valve disease based on different genetic and proteomics profiles

Abstract Introduction Rheumatic heart disease (RHD) pathogenesis is not fully understood. Purpose The protein profile in rheumatic heart disease may have a different fingerprint in the aortic and mitral valves, which results in different evolution in terms of valve damage. Methods To evaluate the genetic profile in symptomatic RHD, 4 simultaneous mitral and aortic valves were obtained during valve replacement, as well as 4 "normal" valves from cadavers (Control Group). The expression of 90 genes was evaluated using a customized RT-PCR array kit. A second experiment was carried out to evaluate proteomics. Then, 7 mitral and aortic valves, from the same patient, were also collected during valve surgery. The Control Group consisted of 6 mitral and aortic valves obtained from explanted hearts during heart transplantation due to non-valvular pathologies. Additionally, histopathological and sectoral proteomic analysis of amyloid deposits, found in some mitral and aortic valves, from the second experiment, were also reported. Results Mitral rheumatic valves exhibited higher expression of genes linked to calcification and immuno-inflammation compared to aortic rheumatic valves (Figure 1). Proteomic analysis, visualized through PCA graphs, highlighted differences in proteomic patterns. Despite having the same genetic pattern, control valves exhibited different proteomic profiles (Figure 1) Rheumatic mitral and aortic valves, even from the same individual, showed distinct proteomic fingerprint (Figure 1). A total of 49 significant proteins were identified in distinguishing healthy mitral and aortic valves from the same individual (Figure 1). The aortic valve displayed a richer extracellular matrix and higher levels of housekeeping proteins that maintain valve homeostasis compared to the mitral valve (Figure 1). The dominant proteomic pattern in valvular rheumatic disease was identified as alterations in critical mitochondrial metabolic activities related to proteostasis. (Figure 2). Particularly notable was the upregulation of pathways associated with lipid metabolism (Figure 2). Finally, amyloid deposits suggested APOA1 as a potential deposit protein in RHD (Figure 2). Conclusion The study confirms distinct constitutional differences between mitral and aortic valves affecting rheumatic disease progression. It emphasizes the role of altered proteostasis and altered proteins deposit, mitochondrial metabolic changes, and inflammatory responses in the disease's pathophysiology, highlighting the complexity of valvular rheumatic disease involvement.For the first time amyloid deposition has been reported as a likely consequence of significant disruption in valvular proteostasis and the proteins potentially comprising this deposit within a rheumatic valve.Genomic and proteomic overviewproteomic fingerprint of RHD and amyloid