Particulate matter exposure aggravates osteoarthritis severity

Abstract

Several diseases have been linked to particulate matter (PM) exposure. Outdoor activities, such as road running or jogging, are popular aerobic exercises due to few participatory limitations. Osteoarthritis (OA) is a progressive degenerative joint disease, usually observed at age 40, and not noticed before pain or diagnosis. Although exercise has health benefits, it is unclear whether outdoor jogging in higher PM (standard reference material 1649b, SRM 1649b) concentration environments could affect OA development or severity. Hence, a PM exposure monosodium iodoacetate (MIA)-induced OA animal jogged model was established for investigation. Results showed that high doses of PM (5 mg) significantly increased pro-inflammatory factors such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6, and M1 macrophages in the lung region, also obtained in systemic IL-6 and TNF-α expressions in this MIA-OA rat model. Moreover, levels of osteocalcin, cartilage oligomeric matrix protein (COMP), and N‐telopeptides of type I collagen were especially influenced in MIA+PM groups. Morphological and structural changes of the knee joint were detected by micro-computed tomography images (micro-CT) and immunohistochemistry. MIA + PM rats exhibited severe bone density decrease, cartilage wear, and structure damages, accompanied by lower levels of physical activity, than the sham group and groups receiving MIA or PM alone. The findings suggest that the severity of OA could be promoted by PM exposure with a PM concentration effect via systemic inflammatory mechanisms. To the best of our knowledge, this is the first study to provide direct effects of PM exposure on OA severity.

Impact of Exposure to Ambient Fine Particulate Matter Pollution on Adults with Knee Osteoarthritis

“…In particular, IL-1β and TNF-α can stimulate IL-6 expression, and IL-6 is a biomarker reflecting the severity of osteoarthritis [ 44 , 45 ]. Furthermore, an animal experiment on a rat model showed that exposure to particulate matter affects osteocalcin, cartilage oligomeric matrix protein, and N-telopeptides of type I collagen, resulting in decreased bone density, cartilage wear and structural damage, and development of osteoarthritis [ 14 ]. Unfortunately, no study has specifically examined the mechanisms by which PM 2.5 increases the risk of or exacerbates osteoarthritis.…”

“…The 2015 Global Burden of Diseases, Injuries, and Risk Factors Study (GBD 2015) identified air pollution as one of the main causes of the increase in global disease burden, especially in low- and middle-income countries [ 9 ]. Accordingly, in the last few years, mounting evidence has linked indoor/outdoor air pollution to musculoskeletal disease [ 10 , 11 , 12 , 13 ], and previous epidemiological studies have shown that environmental factors, especially environmental pollution, may be specifically associated with an increased risk of knee osteoarthritis [ 14 , 15 ]. With regard to the underlying mechanism, air pollutants may cause oxidative stress in the lung, and this may lead to the production of a large number of antibodies and pro-inflammatory cytokines.…”

“…With regard to the underlying mechanism, air pollutants may cause oxidative stress in the lung, and this may lead to the production of a large number of antibodies and pro-inflammatory cytokines. Alternatively, air pollutants could also be genotoxic and induce epigenetic changes that may lead to cartilage erosion and synovial inflammation [ 16 ] and eventually cause the development of musculoskeletal disease [ 14 ]. In particular, fine particulate matter or PM 2.5 , which is defined as particulate matter that has an aerodynamic diameter of ≤2.5 μm, is the most harmful to human health, and it ranks fifth in the list of mortality risk factors [ 17 ].…”

Running and Physical Activity in an Air-Polluted Environment: The Biomechanical and Musculoskeletal Protocol for a Prospective Cohort Study 4HAIE (Healthy Aging in Industrial Environment—Program 4)

“…However, active travel may increase the intake of air pollution leading to negative health consequences [5]. A recent study found that the severity of osteoarthritis could be promoted by air pollution via systemic inflammatory mechanisms [6]. In addition, pollution from traffic may be an environmental risk factor for rheumatoid arthritis [7].…”

Ac-SDKP Attenuates Activation of Lung Macrophages and Bone Osteoclasts in Rats Exposed to Silica by Inhibition of TLR4 and RANKL Signaling Pathways

“…These results partially and presumably explain why air particulate matter is associated with bone loss and fracture risk and aggravates the severity of osteoarthritis. 36,37 Increased levels of RANKL have been documented in cystic fibrosis-related bone disease, 38 adjuvant arthritisinterstitial lung disease, 39 and metastasis of lung cancer to bone. 40 The increased levels of RANKL in these studies suggest osteoclast activation with lung disease.…”