Myocardial fibrosis in type 2 diabetes is associated with functional and metabolomic parameters

Systemic proinflammatory-profibrotic response in aortic stenosis patients with diabetes and its relationship with myocardial remodeling and clinical outcome

BACKGROUND

Previous studies have mainly focused more on how diabetes affects the valve than the myocardium in aortic stenosis (AS). In the pressure-overloaded heart, myocardial fibrosis is an important driver of the progression from compensated hypertrophy to heart failure. Using comprehensive noninvasive imaging and plasma proteomics, we investigated whether and how diabetes aggravates the remodeling of the myocardium and its relation with prognosis in AS patients.

METHODS

Severe AS patients were enrolled in two prospective cohorts for imaging and biomarker analysis. The imaging cohort (n = 253) underwent echocardiography and cardiac magnetic resonance, and the biomarker cohort (n = 100) blood sampling with multiplex proximity extension assay for 92 proteomic biomarkers. The composite outcome of hospitalization for heart failure admissions and death was assessed in the imaging cohort.

RESULTS

Diabetic patients were older (70.4 ± 6.8 versus 66.7 ± 10.1 years) with more advanced ventricular diastolic dysfunction and increased replacement and diffuse interstitial fibrosis (late gadolinium enhancement % 0.3 [0.0-1.6] versus 0.0 [0.0-0.5], p = 0.009; extracellular volume fraction % 27.9 [25.7-30.1] versus 26.7 [24.9-28.5], p = 0.025) in the imaging cohort. Plasma proteomics analysis of the biomarker cohort revealed that 9 proteins (E-selectin, interleukin-1 receptor type 1, interleukin-1 receptor type 2, galectin-4, intercellular adhesion molecule 2, integrin beta-2, galectin-3, growth differentiation factor 15, and cathepsin D) were significantly elevated and that pathways related to inflammatory response and extracellular matrix components were enriched in diabetic AS patients. During follow-up (median 6.3 years), there were 53 unexpected heart failure admissions or death in the imaging cohort. Diabetes was a significant predictor of heart failure and death, independent of clinical covariates and aortic valve replacement (HR 1.88, 95% CI 1.06-3.31, p = 0.030).

CONCLUSIONS

Plasma proteomic analyses indicate that diabetes potentiates the systemic proinflammatory-profibrotic milieu in AS patients. These systemic biological changes underlie the increase of myocardial fibrosis, diastolic dysfunction, and worse clinical outcomes in severe AS patients with concomitant diabetes.

Mesenchymal Stem Cell Transplantation Increases Antioxidant Protein Expression and Ameliorates GP91/ROS/Inflammasome Signals in Diabetic Cardiomyopathy

Background: Cardiomyopathy is one of the complications associated with diabetes. Due to its high prevalence, diabetic cardiomyopathy has become an urgent issue for diabetic patients. Various pathological signals are related to diabetic cardiomyopathy progress, including inflammasome. Mesenchymal stem cell transplantation is full of potential for the treatment of diabetic cardiomyopathy because of stem cell cardiac regenerative capability. This study investigates whether mesenchymal stem cell transplantation shows therapeutic effects on diabetic cardiomyopathy through inflammasome signaling regulation. Methods: Wistar male rats were divided into three groups including Sham, T1DM (rats with type 1 diabetes) and T1DM + WJSC (T1DM rats receiving 1 × 106 stem cells per rat). Results: Compared to the Sham, experimental results indicated that several pathological conditions can be observed in heart tissues with T1DM, including structural change, fibrosis, oxidative stress elevation and inflammasome related protein expression. All of these pathological conditions were significantly improved in T1DM rats receiving mesenchymal stem cell transplantation (T1DM + WJSC). Furthermore, the experimental findings suggest that mesenchymal stem cell transplantation exerted antioxidant protein expression in diabetic heart tissues, resulting in a decrease in oxidative stress and inflammasome signaling blockage. Conclusion: These findings imply that mesenchymal stem cell transplantation shows therapeutic effects on diabetic cardiomyopathy through inflammasome regulation induced by oxidative stress.