What is the clinical evidence from this study?

Study design: Other. Population: Heart failure with preserved ejection fraction (HFpEF) (n=8). Intervention: SAUNA model (d-aldosterone, uninephrectomy, 1% sodium chloride) vs. Sham (saline infusion). Primary outcome: Differential protein and phosphoprotein expression in left ventricle tissue.

August 25, 2022Open Access

Proteomic and phosphoproteomic profiling in heart failure with preserved ejection fraction (HFpEF)

Key Result

In a murine model of HFpEF, 897 proteins were differentially expressed in the left ventricle compared to sham, characterized by marked changes in mitochondrial metabolism, sarcomeric proteins, and decreased SIRT3 expression.

Structured PICO

Does the SAUNA murine model of HFpEF exhibit specific proteomic and phosphoproteomic changes compared to Sham?

Population

Eight-week-old male C57BL/6J mice subjected to the SAUNA model (salty drinking water, unilateral nephrectomy, and chronic exposure to aldosterone) to induce HFpEF.

Intervention

HFpEF induction via SAUNA model (uninephrectomy, d-aldosterone 0.30 µg/h via osmotic minipumps, 1% sodium chloride drinking water) for 4 weeks

Comparator

Sham procedure (uninephrectomy, continuous infusion of saline via osmotic minipumps, 1% sodium chloride drinking water) for 4 weeks

Outcome

Cardiac-specific features of protein and phosphoprotein changes in the left ventricle using mass spectrometrysurrogate

In a murine model of HFpEF, marked changes in proteins related to mitochondrial metabolism and the cardiac contractile apparatus were observed, suggesting SIRT3 downregulation may play a key role in perpetuating these changes.

Limitations

Animal model may not fully replicate the heterogeneity of human HFpEF
Small sample size for proteomics analysis (N=4 per group)

Abstract

Although the prevalence of heart failure with preserved ejection fraction (HFpEF) is increasing, evidence-based therapies for HFpEF remain limited, likely due to an incomplete understanding of this disease. This study sought to identify the cardiac-specific features of protein and phosphoprotein changes in a murine model of HFpEF using mass spectrometry. HFpEF mice demonstrated moderate hypertension, left ventricle (LV) hypertrophy, lung congestion and diastolic dysfunction. Proteomics analysis of the LV tissue showed that 897 proteins were differentially expressed between HFpEF and Sham mice. We observed abundant changes in sarcomeric proteins, mitochondrial-related proteins, and NAD-dependent protein deacetylase sirtuin-3 (SIRT3). Upregulated pathways by GSEA analysis were related to immune modulation and muscle contraction, while downregulated pathways were predominantly related to mitochondrial metabolism. Western blot analysis validated SIRT3 downregulated cardiac expression in HFpEF vs. Sham (0.8 ± 0.0 vs. 1.0 ± 0.0; P 0.001). Phosphoproteomics analysis showed that 72 phosphosites were differentially regulated between HFpEF and Sham LV. Aberrant phosphorylation patterns mostly occurred in sarcomere proteins and nuclear-localized proteins associated with contractile dysfunction and cardiac hypertrophy. Seven aberrant phosphosites were observed at the z-disk binding region of titin. Additional agarose gel analysis showed that while total titin cardiac expression remained unaltered, its stiffer N2B isoform was significantly increased in HFpEF vs. Sham (0.144 ± 0.01 vs. 0.127 ± 0.01; P 0.05). In summary, this study demonstrates marked changes in proteins related to mitochondrial metabolism and the cardiac contractile apparatus in HFpEF. We propose that SIRT3 may play a role in perpetuating these changes and may be a target for drug development in HFpEF.

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