PM2.5 as a driver of human health disorders: insights from the regulated cell death pathways

Fine particulate matter (PM2.5) is a prevalent environmental pollutant that has been well established as a contributor to morbidity on a global scale. An increasing body of scientific evidence suggests that PM2.5 promotes various modes of regulated cell death (RCD), including apoptosis, necroptosis, pyroptosis, PANoptosis, ferroptosis, and autophagy-dependent cell death, as well as potentially cuproptosis, across a broad spectrum of human diseases. These interconnected pathways demonstrate how exposure to pollutants induces oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress (ERS), and inflammatory responses. Alterations in lysosomal permeability serve as a critical link, connecting environmental pollutants to health conditions. Importantly, dysregulation of RCD mechanisms is associated with exposure to PM2.5 and numerous health disorders, such as cardiovascular diseases (CVDs), neurological conditions, respiratory illnesses, renal and hepatic dysfunctions, reproductive health issues, and ocular diseases. Collectively, RCD functions as a central molecular framework through which PM2.5 exposure accelerates the progression of pathological conditions. This review synthesizes recent mechanistic insights, identifies promising therapeutic candidates, and highlights critical knowledge gaps. It offers a strategic framework to guide future research endeavors aimed at mitigating the impact of PM2.5-induced RCD in human diseases. Additionally, we will identify and explore the research gaps that need to be addressed to effectively translate preclinical PM2.5 studies into clinical trials. We will also provide a comprehensive overview that both highlights these gaps and offers pathways to bridge them.