Sacubitril/Valsartan attenuates progression of diabetic cardiomyopathy through immunomodulation properties: an opportunity to prevent progressive disease.

BACKGROUND AND AIMS: Diabetic cardiomyopathy (DbCM) is recognised as a key mediator and determinant of heart failure (HF), particularly HF with preserved ejection fraction (HFpEF). Improved understanding of mechanisms underlying transition from early-stage DbCM to HFpEF will inform innovative evidence-based treatment approaches, which are urgently required to alleviate increasing disease burden. This study aimed to determine whether inhibition of neprilysin activity by Sacubitril/Valsartan in both experimental and clinical DbCM attenuates adverse remodelling through promotion of cardioprotective signalling.

METHODS AND

RESULTS

Sacubitril/Valsartan effectively reduced plasma neprilysin activity in both diabetic patients with pre-clinical HFpEF from the PARABLE trial (baseline (Val n = 25; Sac/Val n = 35) and 3 months after treatment (Val n = 21/25; Sac/Val n = 33/35)) and DbCM (high-fat diet and streptozotocin) mice. Plasma neprilysin activity at baseline was correlated with worsening cardiac performance at 18 months indicated by left atrial stiffness index in patients (n = 44/60), whilst diastolic dysfunction and pathological remodelling in DbCM mice were improved by Sacubitril/Valsartan, but not Valsartan. snRNA-sequencing showed that progressive experimental DbCM is characterised by chronic low-grade inflammation, reflected by increased infiltration of pro-inflammatory monocytes (Ccr2+ Ly6chi) and reduction in MHC-II macrophages, which was prevented by Sacubitril/Valsartan. Informatics analysis implicated IRF7 as a central mediator of Sacubitril/Valsartan-induced immunomodulation in DbCM, whilst treatment of M2-like pro-repair macrophages with the neprilysin inhibitor, LBQ657 and Valsartan suppressed glucose-induced IRF7 expression and paracrine activation of cardiac fibroblast differentiation in vitro.

CONCLUSION

Immune cells are significantly involved in DbCM progression, impacting myocardial homeostasis and HF progression. Neprilysin inhibition by Sacubitril/Valsartan improved adverse cardiac remodelling in experimental DbCM through direct regulation of inflammation, highlighting immunomodulation as a novel mechanism underlying established its cardioprotective actions.