Epidemiologic studies have reported the association between fine particles (aerodynamic diameter ≤ 2.5 μm; PM2.5) and health effects, but the immunological mechanisms are not clear. To investigate the dose and time-dependent role of toll-like receptor (TLR) and Th1/Th2 shift in local and systemic inflammation induced by PM2.5, mice were subjected to intratracheal instillation of 2.5, 5, or 10 mg/kg PM2.5 in this study. After 24 h, 72 h, 7 days, and 14 days, mice were sacrificed to measure TLR2 and TLR4 expressions and Th1/Th2 related cytokines in bronchoalveolar lavage fluid (BALF) and peripheral blood. Histopathological changes in lung were also examined. Inflammatory infiltration and macrophages with engulfed particles were found by lung histopathology after PM2.5 exposure. TLR4 positive cells decreased in BALF but increased in blood at 24 h after the exposure. The low percentage of TLR4 positive cells continued to day 14 in BALF, but recovered at day 7 and decreased further to lower than the control value at day 14 in blood. TLR2 positive cell changed similar to TLR4 in BALF on the dose effects. In BALF at 24 h after the exposure, the Th2 related cytokines IL-5 and IL-10 increased dose-dependently; and in blood, the Th2 related cytokines IL-4, IL-5, and IL-10 also increased. These results suggest that acute exposure of PM2.5 leads to acute inflammatory responses locally and systemically in mice. TLR2 and TLR4 are involved in this process and PM2.5 can drive a Th2-biased immune response.
Background:Fibrosing mediastinitis (FM) is a rare disease. FM is thought to be related to prior granulomatous mediastinal infection, such as histoplasmosis or tuberculosis. The majority of cases have been reported in endemic regions for histoplasmosis. The characteristics of cases of FM in China, where the prevalence of tuberculosis is high, have not been reported. We analyzed the clinical, imaging, and bronchoscopic features of Chinese patients with FM to promote awareness of this disease.Methods:Between January 2005 and June 2015, twenty patients were diagnosed with FM in our hospital. Medical records and follow-up data were collected. Imaging and biopsy findings were reviewed by radiologists and pathologists.Results:A total of 20 patients were analyzed (8 males and 12 females). The age ranged from 43 to 88 years with a mean age of 69.5 years. Previous or latent tuberculosis was found in 12 cases. Clinical symptoms included dyspnea (18/20), cough (17/20), expectoration (7/20), and recurrent pneumonia (3/20). Chest computed tomography scans showed a diffuse, homogeneous, soft tissue process throughout the mediastinum and hila with compression of bronchial and pulmonary vessels. Calcification was common (15/20). Pulmonary hypertension was present in 9 of 20 cases. Diffuse black pigmentation in the bronchial mucosa was frequently seen on bronchoscopy (12/13). The patients’ response to antituberculosis treatment was inconsistent.Conclusions:FM in Chinese patients is most likely associated with tuberculosis. Some characteristics of FM are different from cases caused by histoplasmosis.
With the increasingly serious problem of environmental pollution, the health problems caused by PM2.5 are gradually coming into our line of sight. Previous researches have indicated that air pollution is nearly related to various diseases, but few studies have focused on the exact function mediated by particulate matter less than 2.5 (PM2.5) in these diseases. PM2.5 is known to induce multiple ways of cell death, including autophagy, necrosis, apoptosis, pyroptosis and ferroptosis. Therefore, it is of much importance to understand the different ways of cell death caused by PM2.5 in the pathogenesis and treatment of PM2.5-related diseases. This present review is an insight of multiple ways of PM2.5-induced cell death in different diseases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.