Cardiovascular Prognosis in Patients with Peripheral Artery Disease and Approach to Therapy

Relationships of Leg Ischemia Symptoms and Carotid Artery Atherosclerosis with Hypertensive-Disorders-of-Pregnancy-Associated Peptides in Patients with Lower Extremity Arterial Disease

Objectives: We have proposed seven peptides with low molecular weights in blood as biomarkers for the diagnosis of hypertensive disorders of pregnancy (HDP). The purpose of this cross-sectional study was to investigate the relationships of the HDP-associated peptides with symptoms of leg ischemia and degree of atherosclerosis in patients with lower extremity arterial disease (LEAD). Methods: The subjects were 165 outpatients with LEAD (145 men and 20 women aged 74.3 ± 8.1 years [47-93 years]). Their symptoms of leg ischemia, leg arterial flow, and degree of atherosclerosis were evaluated using the Rutherford classification of Clinical Ischemia Category, ankle-brachial index (ABI) and the intima-media thickness (IMT) of carotid arteries, respectively. Serum concentrations of the HDP-related peptides were measured by mass spectrometry. Results: The grade of the Rutherford classification was positively associated with levels of the peptides with m/z 2091 and 2378 and was inversely associated with levels of the peptide with m/z 2081. The category of the Rutherford classification was inversely associated with ABI. There were no HDP-associated peptides that showed significant relationships with IMT. Conclusions: The peptides with m/z 2081, 2091, and 2378 are possible biomarkers of leg ischemia but are not associated with carotid atherosclerosis in LEAD patients.

Targeting Mitochondrial Dynamics during Lower-Limb Ischemia Reperfusion in Young and Old Mice: Effect of Mitochondrial Fission Inhibitor-1 (mDivi-1)

Peripheral arterial disease (PAD) strikes more than 200 million people worldwide and has a severe prognosis by potentially leading to limb amputation and/or death, particularly in older patients. Skeletal muscle mitochondrial dysfunctions and oxidative stress play major roles in this disease in relation with ischemia-reperfusion (IR) cycles. Mitochondrial dynamics through impairment of fission-fusion balance may contribute to skeletal muscle pathophysiology, but no data were reported in the setting of lower-limb IR despite the need for new therapeutic options. We, therefore, investigated the potential protective effect of mitochondrial division inhibitor-1 (mDivi-1; 50 mg/kg) in young (23 weeks) and old (83 weeks) mice submitted to two-hour ischemia followed by two-hour reperfusion on systemic lactate, muscle mitochondrial respiration and calcium retention capacity, and on transcripts specific for oxidative stress and mitochondrial dynamics. At the systemic levels, an IR-related increase in circulating lactate was still major despite mDivi-1 use (+305.9% p < 0.0001, and +269.4% p < 0.0001 in young and old mice, respectively). Further, IR-induced skeletal muscle mitochondrial dysfunctions (more severely impaired mitochondrial respiration in old mice (OXPHOS CI state, -68.2% p < 0.0001 and -84.9% p < 0.0001 in 23- and 83-week mice) and reduced calcium retention capacity (-46.1% p < 0.001 and -48.2% p = 0.09, respectively) were not corrected by mDivi-1 preconditioning, whatever the age. Further, mDivi-1 treatment did not oppose superoxide anion production (+71.4% p < 0.0001 and +37.5% p < 0.05, respectively). At the transcript level, markers of antioxidant enzymes (SOD 1, SOD 2, catalase, and GPx) and fission markers (Drp1, Fis) remained unchanged or tended to be decreased in the ischemic leg. Fusion markers such as mitofusin 1 or 2 decreased significantly after IR in both groups. In conclusion, aging enhanced the deleterious effects or IR on muscle mitochondrial respiration, and in this setting of lower-limb IR, mDivi-1 failed to protect the skeletal muscle both in young and old mice.