Tempol Preserves Endothelial Progenitor Cells in Male Mice with Ambient Fine Particulate Matter Exposure

Gender Medicine and Pharmacology

Gender-specific medicine consists of a transversal methodological approach that aims to study the influence of sex and gender on diseases [...].

CARD9 deficiency improves the recovery of limb ischemia in mice with ambient fine particulate matter exposure

Background

Exposure to fine particulate matter (PM) is a significant risk for cardiovascular diseases largely due to increased reactive oxygen species (ROS) production and inflammation. Caspase recruitment domain (CARD)9 is critically involved in innate immunity and inflammation. The present study was designed to test the hypothesis that CARD9 signaling is critically involved in PM exposure-induced oxidative stress and impaired recovery of limb ischemia.

Methods and results

Critical limb ischemia (CLI) was created in male wildtype C57BL/6 and age matched CARD9 deficient mice with or without PM (average diameter 2.8 μm) exposure. Mice received intranasal PM exposure for 1 month prior to creation of CLI and continued for the duration of the experiment. Blood flow and mechanical function were evaluated in vivo at baseline and days 3, 7, 14, and 21 post CLI. PM exposure significantly increased ROS production, macrophage infiltration, and CARD9 protein expression in ischemic limbs of C57BL/6 mice in association with decreased recovery of blood flow and mechanical function. CARD9 deficiency effectively prevented PM exposure-induced ROS production and macrophage infiltration and preserved the recovery of ischemic limb with increased capillary density. CARD9 deficiency also significantly attenuated PM exposure-induced increase of circulating CD11b⁺/F4/80⁺ macrophages.

Conclusion

The data indicate that CARD9 signaling plays an important role in PM exposure-induced ROS production and impaired limb recovery following ischemia in mice.

Air Pollution Exposure Induces Vascular Injury and Hampers Endothelial Repair by Altering Progenitor and Stem Cells Functionality

Extensive evidence indicates an association of air pollution exposure with an increased risk of cardiovascular disease (CVD) development. Fine particulate matter (PM) represents one of the main components of urban pollution, but the mechanisms by which it exerts adverse effects on cardiovascular system remain partially unknown and under investigation. The alteration of endothelial functions and inflammation are among the earliest pathophysiological impacts of environmental exposure on the cardiovascular system and represent critical mediators of PM-induced injury. In this context, endothelial stem/progenitor cells (EPCs) play an important role in vascular homeostasis, endothelial reparative capacity, and vasomotor functionality modulation. Several studies indicate the impairment of EPCs' vascular reparative capacity due to PM exposure. Since a central source of EPCs is bone marrow (BM), their number and function could be related to the population and functional status of stem cells (SCs) of this district. In this review, we provide an overview of the potential mechanisms by which PM exposure hinders vascular repair by the alteration of progenitor and stem cells' functionality.

N‑acetyl cysteine prevents ambient fine particulate matter‑potentiated atherosclerosis via inhibition of reactive oxygen species‑induced oxidized low density lipoprotein elevation and decreased circulating endothelial progenitor cell

Ambient fine particulate matter (PM) serves an important role in the development of cardiovascular disease, including atherosclerosis. Antioxidant N‑acetyl cysteine (NAC) has protective effects in the cardiovascular system. However, it is unknown if NAC prevents PM‑potentiated atherosclerosis in hyperlipidemia. Low‑density lipoprotein (LDL) receptor knockout mice were pretreated with 1 mg/ml NAC in drinking water for 1 week and continued to receive NAC, high‑fat diet and intranasal instillation of PM for 1 week or 6 months. Blood plasma was collected for lipid profile, oxidized (ox‑)LDL, blood reactive oxygen species (ROS) and inflammatory cytokine (TNF‑α, IL‑1β and IL‑6) measurement. Blood cells were harvested for endothelial progenitor cell (EPC) population and intracellular ROS analysis. Murine aorta was isolated for atherosclerotic plaque ratio calculation. NAC treatment maintained circulating EPC level and significantly decreased blood ox‑LDL and ROS, inflammatory cytokines, mononuclear and EPC intracellular ROS levels as well as aortic plaque ratio. NAC prevented PM‑potentiated atherosclerosis by inhibiting plasma ROS‑induced ox‑LDL elevation, mononuclear cell and EPC intracellular ROS‑induced circulating EPC reduction and inflammatory cytokine production.