Synergistic effects of HMG-CoA reductase inhibitor and angiotensin II receptor blocker on load-induced heart failure

Interactions between Angiotensin Type-1 Antagonists, Statins, and ROCK Inhibitors in a Rat Model of L-DOPA-Induced Dyskinesia

Statins have been proposed for L-DOPA-induced dyskinesia (LID) treatment. Statin anti-dyskinetic effects were related to the inhibition of the Ras-ERK pathway. However, the mechanisms responsible for the anti-LID effect are unclear. Changes in cholesterol homeostasis and oxidative stress- and inflammation-related mechanisms such as angiotensin II and Rho-kinase (ROCK) inhibition may be involved. The nigra and striatum of dyskinetic rats showed increased levels of cholesterol, ROCK, and the inflammatory marker IL-1β, which were reduced by the angiotensin type-1 receptor (AT1) antagonist candesartan, simvastatin, and the ROCK inhibitor fasudil. As observed for LID, angiotensin II-induced, via AT1, increased levels of cholesterol and ROCK in the rat nigra and striatum. In cultured dopaminergic neurons, angiotensin II increased cholesterol biosynthesis and cholesterol efflux without changes in cholesterol uptake. In astrocytes, angiotensin induced an increase in cholesterol uptake, decrease in biosynthesis, and no change in cholesterol efflux, suggesting a neuronal accumulation of cholesterol that is reduced via transfer to astrocytes. Our data suggest mutual interactions between angiotensin/AT1, cholesterol, and ROCK pathways in LID, which are attenuated by the corresponding inhibitors. Interestingly, these three drugs have also been suggested as neuroprotective treatments against Parkinson's disease. Therefore, they may reduce dyskinesia and the progression of the disease using common mechanisms.

Mitophagy: A Potential Target for Pressure Overload-Induced Cardiac Remodelling

The pathological mechanisms underlying cardiac remodelling and cardiac dysfunction caused by pressure overload are poorly understood. Mitochondrial damage and functional dysfunction, including mitochondrial bioenergetic disorder, oxidative stress, and mtDNA damage, contribute to heart injury caused by pressure overload. Mitophagy, an important regulator of mitochondrial homeostasis and function, is triggered by mitochondrial damage and participates in the pathological process of cardiovascular diseases. Recent studies indicate that mitophagy plays a critical role in the pressure overload model, but evidence on the causal relationship between mitophagy abnormality and pressure overload-induced heart injury is inconclusive. This review summarises the mechanism, role, and regulation of mitophagy in the pressure overload model. It also pays special attention to active compounds that may regulate mitophagy in pressure overload, which provide clues for possible clinical applications.

Screening for hypertrophic cardiomyopathy

ABSTRACT

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and causes changes in the cardiac muscle affecting ventricular, valvular, and cellular functions. Because HCM is an inherited disorder, all age groups are affected; however, it commonly presents in adolescents, especially athletes. Many patients are asymptomatic and undiagnosed, putting them at risk for sudden cardiac death. This article describes screening and management of patients with HCM.

Linagliptin, A Xanthine-Based Dipeptidyl Peptidase-4 Inhibitor, Ameliorates Experimental Autoimmune Myocarditis

•

Treatment with linagliptin, a DPP-4 inhibitor, alleviates not only EAM but also ICIM.

•

DPP-4 physically interacts with cathepsin G and enhances its activity.

•

Linagliptin promotes SerpinA3N activity, thereby suppressing cathepsin G activity.

•

Cathepsin G aggravates EAM through upregulating angiotensin II.

•

Linagliptin suppresses oxidative stress in EAM hearts.

This study sought to show the mechanism of how to ameliorate experimental autoimmune myocarditis (EAM) by administering dipeptidyl peptidase (DPP)-4 inhibitor linagliptin. The number of RAR-related orphan nuclear receptor gamma–positive Th17 cells infiltrated to the EAM myocardium was significantly attenuated by linagliptin treatment. Tandem mass spectrometry–based analysis demonstrated that DPP-4 binds to cathepsin G in EAM hearts, thereby protecting cathepsin G activity through inhibiting SerpinA3N activity. Linagliptin suppresses oxidative stress in EAM hearts as well. Thus, we found that DPP-4 plays a detrimental role in the progression of EAM by interacting with cathepsin G, which, in turn, suppresses SerpinA3N activity.