Getting to the Heart of the Matter: Lysosomal Storage Diseases That Manifest a Cardiac Phenotype

Cardioprotective effects of CoQ10 in pediatric patients with lysosomal storage disorders

BACKGROUND

Lysosomal storage disorders (LSDs) result from an accumulation of specific substrates, due to the inability to break them down leading to cellular dysfunction in multiple organs, including the heart constituting an important and treatable cause of cardiomyopathy. Given the role of oxidative stress in many inborn errors of metabolism, many studies are evaluating oxidative stress and hence the role of antioxidants in patients with LSDs.

THE AIM OF THIS STUDY

was to study the possible effects of Coenzyme Q10 as a cardioprotective and an antioxidant drug in patients with LSDs.

METHODS

This study was a prospective case-control study conducted on 30 patients with LSDs and an equal number of healthy subjects of matched age and sex served as a control group at the unit of Medical Genetics and inborn errors of metabolism at the Pediatric Department of Tanta University Hospital. All subjects included were subjected to full history taking, complete physical examination, assessing serum level of N-terminal pro-brain natriuretic peptide (NT-proBNP) & serum malondialdehyde (MDA), along with comprehensive cardiac evaluation that was done using tissue doppler imaging and speckling tracking echo. Then the patient group was subdivided into two subgroups, half of the patients received Co enzyme Q10 (CoQ10) while the other half received a placebo for 24 weeks followed by cardiac evaluation and reassessment of serum MDA and NT-proBNP for both patient subgroups.

RESULTS

Patients with LSDs had significantly higher levels of serum MDA than controls denoting higher oxidative stress, P-value < 0.001. CoQ10 resulted in significant beneficial reduction of serum MDA (15%) &NT-proBNP (30%) in the group of patients who received CoQ10, P-value < 0.001 and improvement of cardiac functional parameters in patients with LSDs.

CONCLUSION

These findings suggest that CoQ10 may have a role in reducing oxidative stress and so may prevent the development of cardiomyopathy in patients with LSDs.

TRIAL REGISTRATION

This study was performed after approval from the Ethical Committee, Faculty of Medicine, Tanta University, Egypt (approval code 33255/07/19) and after obtaining written informed consent from children guardians. Also, this trial was registered on Pan African clinical trials registry with the number PACTR, 'PACTR202107466690046'. Registered 04 July 2021.

Lysosome (Dys)function in Atherosclerosis-A Big Weight on the Shoulders of a Small Organelle

Atherosclerosis is a progressive insidious chronic disease that underlies most of the cardiovascular pathologies, including myocardial infarction and ischemic stroke. The malfunctioning of the lysosomal compartment has a central role in the etiology and pathogenesis of atherosclerosis. Lysosomes are the degradative organelles of mammalian cells and process endogenous and exogenous substrates in a very efficient manner. Dysfunction of these organelles and consequent inefficient degradation of modified low-density lipoproteins (LDL) and apoptotic cells in atherosclerotic lesions have, therefore, numerous deleterious consequences for cellular homeostasis and disease progression. Lysosome dysfunction has been mostly studied in the context of the inherited lysosomal storage disorders (LSDs). However, over the last years it has become increasingly evident that the consequences of this phenomenon are more far-reaching, also influencing the progression of multiple acquired human pathologies, such as neurodegenerative diseases, cancer, and cardiovascular diseases (CVDs). During the formation of atherosclerotic plaques, the lysosomal compartment of the various cells constituting the arterial wall is under severe stress, due to the tremendous amounts of lipoproteins being processed by these cells. The uncontrolled uptake of modified lipoproteins by arterial phagocytic cells, namely macrophages and vascular smooth muscle cells (VSMCs), is the initial step that triggers the pathogenic cascade culminating in the formation of atheroma. These cells become pathogenic "foam cells," which are characterized by dysfunctional lipid-laden lysosomes. Here, we summarize the current knowledge regarding the origin and impact of the malfunctioning of the lysosomal compartment in plaque cells. We further analyze how the field of LSD research may contribute with some insights to the study of CVDs, particularly how therapeutic approaches that target the lysosomes in LSDs could be applied to hamper atherosclerosis progression and associated mortality.