APPROACH AND RESULTS: Human atherosclerotic plaques showed marked mitochondrial dysfunction, manifested as reduced mtDNA copy number and oxygen consumption rate in fibrous cap and core regions. Vascular smooth muscle cells derived from plaques showed impaired mitochondrial respiration, reduced complex I expression, and increased mitophagy, which was induced by oxidized low-density lipoprotein. Apolipoprotein E-deficient (ApoE-/-) mice showed decreased mtDNA integrity and mitochondrial respiration, associated with increased mitochondrial reactive oxygen species. To determine whether alleviating mtDNA damage and increasing mitochondrial respiration affects atherogenesis, we studied ApoE-/- mice overexpressing the mitochondrial helicase Twinkle (Tw+/ApoE-/-). Tw+/ApoE-/- mice showed increased mtDNA integrity, copy number, respiratory complex abundance, and respiration. Tw+/ApoE-/- mice had decreased necrotic core and increased fibrous cap areas, and Tw+/ApoE-/- bone marrow transplantation also reduced core areas. Twinkle increased vascular smooth muscle cell mtDNA integrity and respiration. Twinkle also promoted vascular smooth muscle cell proliferation and protected both vascular smooth muscle cells and macrophages from oxidative stress-induced apoptosis.
CONCLUSIONS: Endogenous mtDNA damage in mouse and human atherosclerosis is associated with significantly reduced mitochondrial respiration. Reducing mtDNA damage and increasing mitochondrial respiration decrease necrotic core and increase fibrous cap areas independently of changes in reactive oxygen species and may be a promising therapeutic strategy in atherosclerosis.
RESULTS: Mean age of the patients was 49.7 years. Male: female ratio was 1.5:1. Primary site was lymph node in 99 (71.74%) patients, out of which, 36 (26.09%) patients had B symptoms and 19 (13.77%) patients had stage IV disease. 39 (28.26%) patients had primary extra nodal involvement, 4 (2.90%) patients had B symptoms and 3 (2.17%) had stage IV disease. Extra nodal sites involved in primary extra nodal DLBCL were gastrointestinal tract (GIT) 19 (48.72%), tonsils 6 (15.38%), spine 4 (10.26%), soft tissue swelling 3 (7.69%), parotid gland 2 (5.13%), thyroid 2 (5.13%) central nervous system (CNS) 1 (2.56), breast 1 (2.56%) and bone marrow 1 (2.56%). Our study revealed increased percentage of patients with nodal DLBCL in stage IV and with B symptoms. Few patients with primary extra nodal DLBCL had B symptoms and stage IV disease at presentation. GIT was the most common site of involvement in primary extra nodal DLBCL.