Exercise ameliorates fine particulate matter-induced metabolic damage through the SIRT1/AMPKα/PGC1-α/NRF1 signaling pathway.

Air pollution, particularly fine particulate matter (PM2.5), poses a major threat to human health. Exercise has long been recognized as a beneficial way to maintain physical health. However, there is limited research on whether exercise can mitigate the damage caused by PM2.5 exposure. In this study, the mice were exercised on the IITC treadmill for 1 h per day, then exposed to concentrated PM2.5 for 8 h. After 2, 4 and 6-month exercise and PM2.5 exposure, the glucose tolerance and insulin tolerance were determined. Meanwhile, the corresponding indicators in epididymal white adipose tissue (eWAT), brown adipose tissue (BAT) and skeletal muscle were detected. The results indicated that PM2.5 exposure significantly increased insulin resistance (IR), while exercise effectively attenuated this response. The observations of muscle, BAT and eWAT by transmission electron microscopy (TEM) showed that PM2.5 significantly reduced the number of mitochondria in all of the three tissues mentioned above, and decreased the mitochondrial area in skeletal muscle and BAT. Exercise reversed the changes in mitochondrial area in all of the three tissues, but had no effect on the reduction of mitochondrial number in skeletal muscle. At 2 months, the expressions of Mfn2, Mfn1, OPA1, Drp1 and Fis1 in eWAT of the PM mice showed no significant changes when compared with the corresponding FA mice. However, at 4 months and 6 months, the expression levels of these genes in PM mice were higher than those in the FA mice in skeletal muscle. Exercise intervention significantly reduced the upregulation of these genes induced by PM exposure. The study indicated that PM2.5 may impact mitochondrial biogenesis and dynamics by inhibiting the SIRT1/AMPKα/PGC1-α/NRF1 pathway, which further lead to IR, glucose and lipid disorders. However, exercise might alleviate the damages caused by PM2.5 exposure.

Chronic PM2.5 exposure disrupts intestinal barrier integrity via microbial dysbiosis-triggered TLR2/5-MyD88-NLRP3 inflammasome activation.

BACKGROUND: PM2.5, a known public health risk, is increasingly linked to intestinal disorders, however, the mechanisms of its impact are not fully understood. PURPOSE: This study aimed to explore the impact of chronic PM2.5 exposure on intestinal barrier integrity and to uncover the underlying molecular mechanisms. METHODS: C57BL/6 J mice were exposed to either concentrated ambient PM2.5 (CPM) or filtered air (FA) for six months to simulate urban pollution conditions. We evaluated intestinal barrier damage, microbial shifts, and metabolic changes through histopathology, metagenomics, and metabolomics. Analysis of the TLR signaling pathway was also conducted. RESULTS: The mean concentration of PM2.5 in the CPM exposure chamber was consistently measured at 70.9 ± 26.8 µg/m³ throughout the study period. Our findings show that chronic CPM exposure significantly compromises intestinal barrier integrity, as indicated by reduced expression of the key tight junction proteins Occludin and Tjp1/Zo-1. Metagenomic sequencing revealed significant shifts in the microbial landscape, identifying 35 differentially abundant species. Notably, there was an increase in pro-inflammatory nongastric Helicobacter species and a decrease in beneficial bacteria, such as Lactobacillus intestinalis, Lactobacillus sp. ASF360, and Eubacterium rectale. Metabolomic analysis further identified 26 significantly altered metabolites commonly associated with intestinal diseases. A strong correlation between altered bacterial species and metabolites was also observed. For example, 4 Helicobacter species all showed positive correlations with 13 metabolites, including Lactate, Bile acids, Pyruvate and Glutamate. Additionally, increased expression levels of TLR2, TLR5, Myd88, and NLRP3 proteins were noted, and their expression patterns showed a strong correlation, suggesting a possible involvement of the TLR2/5-MyD88-NLRP3 signaling pathway. CONCLUSIONS: Chronic CPM exposure induces intestinal barrier dysfunction, microbial dysbiosis, metabolic imbalance, and activation of the TLR2/5-MyD88-NLRP3 inflammasome. These findings highlight the urgent need for intervention strategies to mitigate the detrimental effects of air pollution on intestinal health and identify potential therapeutic targets.

Label-free detection and quantification of ultrafine particulate matter in lung and heart of mouse and evaluation of tissue injury.

While it is known that air borne ultrafine particulate matter (PM) may pass through the pulmonary circulation of blood at the alveolar level between lung and heart and cross the air-blood barrier, the mechanism and effects are not completely clear. In this study the imaging method fluorescence lifetime imaging microscopy is adopted for visualization with high spatial resolution and quantification of ultrafine PM particles in mouse lung and heart tissues. The results showed that the median numbers of particles in lung of mice exposed to ultrafine particulate matter of diameter less than 2.5 µm was about 2.0 times more than that in the filtered air (FA)-treated mice, and about 1.3 times more in heart of ultrafine PM-treated mice than in FA-treated mice. Interestingly, ultrafine PM particles were more abundant in heart than lung, likely due to how ultrafine PM particles are cleared by phagocytosis and transport via circulation from lungs. Moreover, heart tissues showed inflammation and amyloid deposition. The component analysis of concentrated airborne ultrafine PM particles suggested traffic exhausts and industrial emissions as predominant sources. Our results suggest association of ultrafine PM exposure to chronic lung and heart tissue injuries. The current study supports the contention that industrial air pollution is one of the causative factors for rising levels of chronic pulmonary and cardiac diseases.

NLRP3 inflammasome is involved in ambient PM2.5-related metabolic disorders in diabetic model mice but not in wild-type mice.

AIMS: To explore the role of nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) inflammasome in ambient fine particulate matter (PM2.5)-related metabolic disorders. METHODS: In this study, the C57BL/6 and db/db mice were exposed to concentrated PM2.5 or filtered air (FA) using Shanghai Meteorological and Environmental Animal Exposure System (Shanghai-METAS) for 12 weeks. Indices of lipid metabolism, glucose metabolism, insulin sensitivity, and protein expression of NLRP3 inflammasome in visceral adipose tissue (VAT) were measured, respectively. RESULTS: The results showed that PM2.5 exposure increased circulatory insulin, triglycerides (TG), and total cholesterol (TC), and decreased high-density lipoprotein (HDL) in both C57BL/6 and db/db mice. The levels of NLRP3-related circulatory inflammatory cytokines including both interleukin (IL)-18 and IL-1ß in serum were increased in the PM2.5-exposed mice and accompanied by the elevation in fasting blood glucose and insulin. The results also showed that exposure to PM2.5 promoted the activation of NLRP3, pro-caspase-1, caspase-1, and apoptosis-associated speck-like protein containing CARD (ASC), simultaneously accompanied by the increase of IL-18 and IL-1ß expression in VAT, but the statistically significant difference only found in the db/db mice, not in C57BL/6 mice. CONCLUSION: The activation of NLRP3 inflammasome might be not the main mechanism of PM2.5-related metabolic disorders in wide type mice but it partly mediated the exacerbation of metabolic disorders in diabetic model mice.

Childhood co-exposure of cold stress and PM2.5 aggravates the susceptibility and severity of asthma in adulthood of mice.

Both cold stress and ambient fine particle particulate matter (PM2.5 ) has been reported to aggravate and induce respiratory problems like asthma, but the mechanism involved in that has not been fully understood. Therefore, the present study is to explore the mechanism involved in the increased susceptibility and severity of asthma caused by cold stress and PM2.5 exposure. Urban PM2.5 of Shanghai was concentrated to simulate a PM2.5 -polluted environment with an average concentration of 400 µg/m3 , where 1-month young C57BL/6J mice were exposed for 2 months under cold stress (2°C). Co-exposure of cold stress and PM2.5 in childhood of mice led to significant infiltration of inflammatory cells in the peribronchial region or airspaces and the thickening or fibrosis of alveolar septum, increased OVA-specific IgE in serum and total cells, eosinophil cells, and the levels of inflammatory cytokines including IL-4, IL-8, IL-1ß, IL-5, IL-13, and IFN-γ in bronchoalveolar lavage fluid (BALF) of asthma mice. Moreover, mice in co-exposure group presented a significantly high cough feature, reduced catalase (CAT), glutathione (GSH), superoxide dismutase (SOD), and elevated malonaldehyde (MDA) elevated in BALF; increased ratio of Th2/Th1 and the markable inhibition of Th17 differentiation toward Treg cells in the adulthood of asthma mice. Cold stress and PM2.5 co-exposure in childhood may promote the deterioration of asthma symptoms in adulthood of mice by increasing inflammatory cytokines, ROS formation, Th2/Th1 imbalance, and suppressing the differentiation of Th17 toward Treg cells, which will help to provide experimental references when making some therapeutic strategies in allergic diseases through focusing on some natural solutions.

Parental PM2 .5 exposure changes Th17/Treg cells in offspring, is associated with the elevation of blood pressure.

Epidemiological evidences have indicated that fine particulate matter (PM2.5 ) exposure is associated with the occurrence and development of hypertension. The present study aims to explore the effects of parental PM2.5 exposure on blood pressure in offspring and elucidate the potential mechanism. The parental male and female C57BL/6 mice were exposed to concentrated PM2.5 or filtered air (FA) using Shanghai Meteorological and Environmental Animal Exposure System (Shanghai-METAS) for 16 weeks. At week 12, the mice were assigned to breed offspring. The male offspring mice were further exposed to PM2.5 or FA as above method. During the parental exposure, the average PM2.5 concentration was 133.7 ± 53.32 µg/m3 in PM chamber, whereas the average concentration in FA chamber was 9.4 ± 0.23 µg/m3 . Similarly, during the offspring exposure, the average concentration in PM and FA chamber were 100.76 ± 26.97 µg/m3 and 9.15 ± 0.15 µg/m3 , respectively. The PM2.5 -exposed offspring mice displayed the elevation of blood pressure, the increase of angiotensin II (Ang II), the decrease of angiotensin converting enzyme 2 (ACE2) and Ang (1-7) in serum when compared with the FA-exposed offspring mice. The similar results displayed in the proteins expression of ACE2, AT1R, and Ang (1-7) in vessel and kidney. More importantly, parental PM exposure further induced the increase in serous Ang II and the protein expression of AT1R in vessel, but decrease in ACE2 and Ang (1-7). The serous Ang II was positively associated with splenic T helper type 17 (Th17) cell population and serous IL (interleukin)-17A, but negatively associated with T regular (Treg) cell population and serous IL-10. The results suggested that parental air pollution exposure might induce the elevation of offspring blood pressure via mediate Th17- and Treg-related immune microenvironment.

Fine Particulate Matter (PM2.5) upregulates expression of Inflammasome NLRP1 via ROS/NF-κB signaling in HaCaT Cells.

Skin, as the major organ of a human body, is constantly exposed to PM2.5 stimulation, which may exert specific toxic influences on the physiology of skin. This study aims to investigate the effect of PM2.5 on the formation of inflammasomes in skin cells and to explore the potential mechanism linking PM2.5 and skin inflammation. Changes in mRNA and protein levels of inflammasome-related genes were detected by real-time PCR and western blot in human immortalized epidermal cells (HaCaT) treated with PM2.5 at multiple concentrations for 24 hours. The expression of NLRP1 was increased significantly both in mRNA and protein levels after PM2.5 exposure while the elevated secretory protein level of IL-1ß in cell culture was detected by ELISA, which is one of the main downstream factors of NLRP1. In addition, the upregulation of NLRP1 and IL-1ß could be reversed by NF-κB inhibitor indicating that PM2.5 may promote NLRP1 expression through activating NF-κB pathway. Furthermore, high ROS level was also found in cells treated with PM2.5 and inhibition of ROS could also reverse NK-κB production stimulated by PM2.5 that means ROS is involved in this skin inflammation process.

Ambient fine particulate matter induced the elevation of blood pressure through ACE2/Ang(1-7) pathway: The evidence from urine metabolites.

BACKGROUND: Exposure to ambient fine particulate matter (PM2.5) is associated with various adverse health outcomes. Although several mechanisms have been proposed including oxidative stress and inflammatory responses, the exact mechanism is still unknown. Few studies have investigated the mechanism linking PM2.5 and blood pressure (BP). In this study, we measured urinary metabolites and BP -related renin-angiotensin-aldosterone system (RAAS) to investigate the associations between ambient PM2.5 exposure and BP in healthy C57BL/6 mice. METHODS: The C57BL/6 mice were exposed to ambient concentrated PM2.5 or filtered air (FA) for 16 weeks. Systolic BP and diastolic BP were measured by noninvasive BP system. The urine metabolites were quantified using the untargeted metabolomics approach. The expression of RAAS-related proteins angiotensin-converting enzyme (ACE)2, angiotensin (Ang) II, Ang (1-7) and aldosterone (ALD) were measured using Western blot and ELISA kits. RESULTS: The metabolomics analysis demonstrated that PM2.5 exposure induced significant changes of some metabolites in urine, including stress hormones, amino acids, fatty acids, and lipids. Furthermore, there was an elevation of BP, increase of serous Ang II and ALD, along with the decrease of ACE2 and Ang (1-7) in kidney in the PM2.5-exposed mice compared with FA-exposed mice. CONCLUSIONS: The results demonstrated that PM2.5 exposure-induced BP elevation might be associated with RAAS activation. Meanwhile, PM2.5 exposure-induced changes of stress hormone and lipid metabolism might mediate the activation of RAAS. The results suggested that the systemic stress hormone and lipid metabolism was associated with the development of hypertension.

AMPK activation attenuates inflammatory response to reduce ambient PM2.5-induced metabolic disorders in healthy and diabetic mice.

Epidemiological and experimental studies have indicated that ambient fine particulate matter (PM2.5) exposure is associated with the occurrence and development of metabolic disorders such as obesity and type 2 diabetes mellitus (T2DM). However, the mechanism is not clear yet, and there are few studies to explore the possible prevention measure. In this study, C57BL/6 and db/db mice were exposed to concentrated PM2.5 or filtered air using Shanghai Meteorological and Environmental Animal Exposure System (Shanghai-METAS) for 12 weeks. From week 11, some of the mice were assigned to receive a subcutaneous injection of AMPK activator (AICAR). Lipid metabolism, glucose tolerance, insulin sensitivity and energy homeostasis were measured. Meanwhile, the respiratory, systemic and visceral fat inflammatory response was detected. The results showed that PM2.5 exposure induced the impairments of glucose tolerance, insulin resistance, lipid metabolism disorders and disturbances of energy metabolism in both C57BL/6 and db/db mice. These impairments might be consistent with the increased respiratory, circulating and visceral adipose tissue (VAT) inflammatory response, which was characterized by the release of IL-6 and TNF-α in lung, serum and VAT. More importantly, AICAR administration led to the significant enhancement of energy metabolism, elevation of AMPK as well as the decreased IL-6 and TNF-α in VAT of PM2.5-exposed mice, which suggesting that AMPK activation might attenuate the inflammatory responses in VAT via the inhibition of MAPKs and NFκB. The study indicated that exposure to ambient PM2.5 under the concentration which is often seen in some developing countries could induce the occurrence of metabolic disorders in normal healthy mice and exacerbate metabolic disorders in diabetic mice. The adverse impacts of PM2.5 on insulin sensitivity, energy homeostasis, lipid metabolism and inflammatory response were associated with AMPK inhibition. AMPK activation might inhibit PM2.5-induced metabolic disorders via inhibition of inflammatory cytokines release. These findings suggested that AMPK activation is a potential therapy to prevent some of the metabolic disorders attributable to air pollution exposure.

Fine particulate matter-induced cardiovascular injury is associated with NLRP3 inflammasome activation in Apo E-/- mice.

Epidemiological evidences have indicated that fine particulate matter (PM2.5) is associated with the increased risk of cardiovascular morbidity and mortality. Although several mechanisms linking PM2.5 and inflammatory responses have been widely implicated, the detailed mechanisms involving the occurrence of inflammation in PM2.5-induced adverse effects are lacking. This study aims to investigate whether PM2.5 exposure-induced cardiovascular injury is associated with NLRP3 inflammasome activation in apolipoprotein E-/- (Apo E-/-) mice. Thirty-two Apo E-/- mice were randomly divided into four groups. The mice were fed with normal chow (NC) or high-fat chow (HFC) for 10 weeks, respectively. From week 11, the mice were exposed to concentrated PM2.5 (PM) or filter air (FA) using Shanghai Meteorological and Environmental Animal Exposure System for 16 weeks. The cardiac function and myocardial injury were evaluated by echocardiography and histopathological examination. Meanwhile, the expression of NLRP3-related signaling pathway in myocardium was detected. Compared with the FA mice, the PM mice showed the underlying cardiac dysfunction and injury in both NC and HFC groups. Mononuclear macrophages (CD11c+) were significant higher in bone marrow of the PM mice than that in the FA mice, whilst CD206+ macrophages were lower. Accordingly, PM2.5 exposure induced the increase of circulating inflammatory cytokine TNF-α and decrease of anti-inflammatory cytokine IL-10. PM2.5 exposure was also associated with the activation of NLRP3 inflammasome, which characterized by elevated protein expression of NLRP3, ASC, caspase-1, IL-1ß and IL-18 in myocardium. All these results demonstrated PM2.5-related cardiac injury is mediated by macrophages polarization and NLRP3 inflammasome activation.

The essential function of CARD9 in diet-induced inflammation and metabolic disorders in mice.

Inflammation and metabolic disorder are common pathophysiological conditions, which play a vital role in the development of obesity and type 2 diabetes. The purpose of this study was to explore the effects of caspase recruitment domain (CARD) 9 in the high fat diet (HFD)-treated mice and attempt to find a molecular therapeutic target for obesity development and treatment. Sixteen male CARD9-/- and corresponding male WT mice were fed with normal diet or high fat diet, respectively, for 12 weeks. Glucose tolerance, insulin resistance, oxygen consumption and heat production of the mice were detected. The CARD9/MAPK pathway-related gene and protein were determined in insulin-responsive organs using Western blotting and quantitative PCR. The results showed that HFD-induced insulin resistance and impairment of glucose tolerance were more severe in WT mice than that in the CARD9-/- mice. CARD9 absence significantly modified O2 consumption, CO2 production and heat production. CARD9-/- mice displayed the lower expression of p38 MAPK, JNK and ERK when compared to the WT mice in both HFD- and ND-treated groups. HFD induced the increase of p38 MAPK, JNK and ERK in WT mice but not in the CARD9-/- mice. The results indicated that CARD9 absence could be a vital protective factor in diet-induced obesity via the CARD9/MAPK pathway, which may provide new insights into the development of gene knockout to improving diet-induced obesity and metabolism disorder.

The severity of lung injury and metabolic disorders induced by ambient PM2.5 exposure is associated with cumulative dose.

Lots of epidemiological and experimental studies have found that ambient fine particulate matter (PM2.5) exposure is associated with the development of cardiopulmonary diseases, obesity and diabetes. This study focused on the effects of cumulative PM2.5 exposure on pulmonary and systemic inflammation and insulin resistance. Thirty-two 6-week-old male Balb/c mice were randomly divided into four groups (FA, PM, WEEK and DAY groups) and were continuously or intermittently exposed to concentrated PM2.5 or filtered air (FA) for four weeks using Shanghai Meteorological and Environmental Animal Exposure System ("Shanghai-METAS"). The levels of IL-6 and TNF-α in serum, bronchoalveolar lavage fluid (BALF), lung tissues and white adipose tissue (WAT) were measured. Meanwhile, the expression of NF-κB and phosphor-NF-κB in lung tissue was detected by Western blot. Glucose tolerance and insulin resistance were also determined at the end of exposure. The results found that the mice in PM group displayed moderate inflammatory cell infiltration in lung, whereas the mice in WEEK and DAY groups displayed slight inflammatory cell infiltration in lung. Compared with the mice in FA group, the mRNA expressions of IL-6 and TNF-α in lung tissue and WAT significantly increased in the mice of PM group. Importantly, IL-6 and TNF-α mRNA expressions in PM group were higher than those in WEEK and DAY groups. The protein expression of phospho-NF-κB in lung tissue showed that PM group showed the activation of NF-κB, which was higher than that in the WEEK and DAY groups. Meanwhile, the mice in PM group showed more severe glucose tolerance and insulin resistance than that in the WEEK and DAY groups. The results suggested that the reduction of PM2.5 cumulative exposure may alleviate pulmonary and adipose inflammation, insulin resistance and glucose tolerance impairment. The results provided a clue that the interruption of ambient PM2.5 exposures by systems such as indoor air purification could be of benefit to people's health.

[Intervention effects of selenium yeast on fine particulate matters-induced lung injury in rats].

OBJECTIVE: To evaluate if selenium yeast could inhibit the rat lung injury induced by ambient fine particulate matter( PM_(2. 5) ). METHODS: Fifty-six male SpragueDawley rats were randomly allocated in seven groups( n = 8 each). Saline control group, the rats were exposed to 0. 9% saline by instillation. PM_(2. 5) exposure group, rats were exposed to PM_(2. 5) by intra-tracheal instillation every other day for three times with the accumulated dose of 40 mg/kg. Selenium yeast treatment groups, three groups of rat were exposed to PM_(2. 5) . Then the rats were given low, middle and high dose of selenium yeast, and the doses were 8. 75, 17. 5 and 35 mg/kg, respectively. High dose selenium yeast control group, rats were given high dose of selenium yeast only. Solvent control group, therats were given 1% carboxymethyl cellulose. Saline and PM_(2. 5) were given in the first week. In the second week, selenium yeast and solvent were given by gavage. The rats were sacrificed 24 hours after the last gavage. The bronchoalveolar lavage fluid( BALF)was collected to count the neutrophils numbers and analyze the markers related to inflammation, oxidative stress and cell damage. The lung lobe that was not been lavaged was processed for light microscopic examination. RESULTS: The proportions of neutrophils in BALF and the pathologic scores of lung in PM_(2. 5) - exposed groups were significantly higher than control( P < 0. 05). Selenium yeast treatment caused decrease in tumor necrosis factor-α( TNF-α), interleukin-1ß( IL-1ß), lactate dehydrogenase( LDH), total protein( TP), alkaline phosphatase( AKP) and malondialdehyde( MDA) compared with the only PM_(2. 5) exposure group. Meanwhile, the dose-dependent increase in totalsuperoxide dismutase( T-SOD) and glutathione peroxidase( GSH-Px) activities were observed. There were no significant differences among the groups of saline control group, high dose selenium yeast control group and solvent control group. CONCLUSION: Selenium yeast treatment may protect against acute injury induced by PM_(2. 5) in rat lung.

[Effects of vitamin E and ω-3 fatty acids on protecting ambient PM_(2. 5)-induced cardiovascular injury].

OBJECTIVE: To observe whether vitamin E( Ve) and ω-3 polyunsaturated fatty acids( ω-3 FA) could prevent the fine particulate matter( PM_(2. 5))-induced cardiovascular injury and explore the potential mechanism. METHODS: The SD rats were assigned randomly to 8 groups, those were control group, PM_(2. 5)group, Ve treatment groups( 3, 10, 30 mg/( kg·d)) and ω-3 FA treatment groups( 10, 30 and 90 mg/( kg·d)). The rats were pretreated with different concentration of Ve and ω-3 FA separately for 14 days, then were exposed to ambient PM_(2. 5) by intratracheal instillation( 10 mg/kg BW). All the rats were sacrificed after the last PM_(2. 5) exposure, then the arterial blood, lungs and cardiac tissues were collected. The expressions of tumor necrosis factor-α( TNF-α), interleukin-1ß( IL-1ß), interleukin-6( IL-6) in serum, bronchoalveolar lavage fluid and supernatant of cardiac tissue were detected by ELISA kits. The levels of malondialdehyde( MDA), superoxide dismutase( SOD) and glutathione-peroxidase( GSH-Px) in serum and myocardium were also measured. RESULTS: Compared with the severe injury of rats in PM_(2. 5) exposure group, the rats in Ve or ω-3 FA groups had a slighter injury in lung and cardiac tissue with the increase of Ve and ω-3 FA. Similarly, the levels of IL-1ß, IL-6 in bronchoalveolar lavage fluid had a decreasing trend with the increase of Ve and ω-3 FA compared with the PM_(2. 5) exposure groups. Meanwhile, the expressions of TNF-α in Ve and ω-3 FA high dose groups were significantly reduced when compared with the PM_(2. 5) exposure group( P <0. 05). In addition, the MDA levels in serum were markedly decreased and the activities of SOD were significantly increased compared with the PM_(2. 5)exposure group( P < 0. 05 or P < 0. 01) whereas the SOD activities were elevated only in the ω-3 FA high dose groups( P < 0. 05). Meanwhile, the levels of IL-6 and TNF-α in serum had an obvious decrease compared with the PM_(2. 5) exposure group( P < 0. 01). Similarly, compared with the PM_(2. 5)exposure group, the expressions of MDA were markedly decreased and the activities of SOD and GSH-Px in myocardium were significantly increased( P < 0. 05 or P < 0. 01) in the Ve treatment group. In addition, the activities of GSH-Px was found higher only in the ω-3 FA high treatment group compared with the PM_(2. 5)exposure group( P < 0. 05). Meanwhile, the levels of IL-1ß and TNF-α in cardiac tissue had an obvious decrease trend with the increase of Ve and ω-3 FA. CONCLUSION: PM_(2. 5) exposure may increase inflammatory response and oxidative stress, supplementation with Ve and ω-3 FA could prevent the PM_(2. 5)-induced inflammatory reaction and oxidative stress damage by increasing the activities of SOD and GSH-Px.

Traffic-related air pollution is associated with cardio-metabolic biomarkers in general residents.

PURPOSE: The study was conducted to explore the mechanisms linking traffic-related air pollution and cardio-metabolic risk. METHODS: The participants included 371 men and women aged from 45 to 75 in an urban residential area in Shanghai, China. The participants were divided into four categories (≤50, 51-100, 101-200 and >200 m) according to the residential distance to major road. Additionally, the personal fine particulate matter (PM2.5) was measured from 8:00 am to 6:00 pm to assess the PM2.5 exposure in general residents. Then, the continuous subclinical measurements and biological effects related to cardio-metabolic disorders were detected. The generalized linear regression analysis was applied for estimating the adjusted hazards ratio for cardio-metabolic disorders relative to traffic-related air pollution. RESULTS: The average personal PM2.5 is 111.1 µg/m(3) in the participants living within 50 m to major road, which is significantly higher than the personal PM2.5 (68.2 µg/m(3)) in the participants living more than 200 m away from the major road. The participants living within 50 m to major road compared with those living more than 200 m away have 1.15 times higher of heart rate (HR), 1.95 times higher of fasting insulin, 1.30 times higher of homeostasis model assessment of insulin resistance (HOMA-IR), 1.56 times higher of low-density lipoprotein cholesterol (LDL-C), 8.39 times higher of interleukin 6 (IL-6), 4.30 times higher of augmentation index (AI), 1.60 times higher of systolic blood pressure (SBP) and 1.91 times higher of diastolic blood pressure (DBP). Contrary to the increase in above biological effects, there were 1.06 times lower of low frequency (LF), 1.05 times lower of high frequency (HF), 2.54 times lower of IL-10, 4.61 times lower of nitric oxide (NO), 1.19 times lower of superoxide dismutase (SOD) and 1.85 times lower of total antioxidant capacity (T-AOC). There was no clear exposure-response relationship can be observed in the fasting glucose, LF/HF, cholesterol and high-density lipoprotein (HDL). CONCLUSION: Long-term exposure to traffic-related air pollution may contribute to the development or exacerbation of cardio-metabolic disorders. The mechanisms linking air pollution and cardio-metabolic disorders may be associated with the increased systemic inflammation and oxidative stress, reduced insulin sensitivity and elevated arterial stiffness and blood pressure.

[Effects and mechanism of inflammation and energy metabolism in mice caused by PM_(2. 5) exposure].

OBJECTIVE: The current study was conducted to observe the effects of fine particles( PM_(2. 5)) on energy metabolism and inflammation. The potential mechanism linking PM_(2. 5)and type 2 diabetes was explored. METHODS: C57 BL /6 mice were randomly assigned to 2 groups. The mice in exposure group were intratracheal instilled of 15 mg / kg BW PM_(2. 5). The mice in control were instilled with saline. The instillation were conducted three times per week for 18 weeks. Insulin resistance test( ITT) and introperitoneal glucose tolerance test( IPGTT) were determined after the last exposure. The mRNA expression of IL-6, IL-17 A, MAPK, NF-κB and TNF-α were analyzed in liver and white adipose tissue. RESULTS: The body weight of mice in PM_(2. 5)group [( 24. 976 ± 0. 571) g] showed significant decrease compared to that in control mice [( 28. 452 ± 1. 520) g]( P < 0. 05). Blood glucose significantly increased in exposure group. The mice in exposure group showed insulin resistance and glucose tolerance impairment. The expression of IL-6 mRNAexpression in liver( 0. 373 ± 0. 185) and in white adipose tissue( 0. 364 ± 0. 089)increased along with the increase of TNF-α mRNA expression( 0. 008 ± 0. 002) in white adipose tissue. CONCLUSION: The PM_(2. 5)exposure may be associated with the development of diabetes. The potential mechanism could be the impaired glucose tolerance, elevated insulin resistance and the increase of inflammatory response.

Treg responses are associated with PM2.5-induced exacerbation of viral myocarditis.

The adverse cardiovascular events induced by ambient fine particles (PM2.5) are paid more attention in the world. The current study was conducted to explore the mechanisms of T regulatory cells (Treg) responses in PM2.5-induced exacerbation of viral myocarditis. The male BALB/c mice were administered an intratracheal (i.t.) instillation of 10 mg/kg b.w. PM2.5 suspension. Twenty-four hours later, the mice were injected intraperitoneally (i.p.) with 100 µl of coxsackievirus B3 (CVB3) diluted in Eagle's minimal essential medium (EMEM). Seven days after the treatment, serum, splenetic, and cardiac tissues were examined. The results showed that pre-exposure to PM2.5 aggravated the cardiac inflammation in the CVB3-infected mice along with an increase of Treg cells in the spleen. The mRNA expressions of interleukin-6 (IL-6), TNF-α, transforming growth factor-ß (TGF-ß), and Foxp3 were up-regulated in the PM2.5-pretreated mice than that in the CVB3-treated mice. Similar results were found in the sera. In addition, compared with the CVB3-treated mice, the cardiac protein expression of TGF-ß increased in the PM2.5-pretreated mice. These results demonstrated that preexposure to PM2.5 exacerbated virus-induced myocarditis possibly through the depression of the immune response and increase of inflammation in myocardium through the Treg responses.

Rat lung response to ozone and fine particulate matter (PM2.5) exposures.

Exposure to different ambient pollutants maybe more toxic to lung than exposure to a single pollutant. In this study, we discussed the inflammation and oxidative stress responses of rat lung caused by ozone and PM2.5 versus that of rats exposed to saline, ozone, or single PM2.5 . Wistar rats inhaled 0.8 ppm ozone or air for 4 h and then placed in air for 3 h following intratracheal instillation with 0, 0.2 (low dose), 0.8 (medium dose), 3.2 (high dose) mg/rat PM2.5 dissolved in sterile saline (0.25 mL/rat), repeated twice per week for 3 weeks, the cumulative doses of PM2.5 in animals were 1.2, 4.8, and 19.2 mg. Rats were sacrificed 24 h after the last (sixth) exposure. The collected bronchoalveolar lavage fluid (BALF) was analyzed for inflammatory cells and cytokines. Lung tissues were processed for light microscopic and transmission electron microscopic (TEM) examinations. Results showed that total cell number in BALF of PM2.5 -exposed groups were higher than control (p < 0.05). PM2.5 instillation caused dose-trend increase in tumor necrosis factor alpha (TNF-α), interleukin-6, lactate dehydrogenase, and total protein of BALF. Exposure to ozone alone only caused TNF-α significant change in above-mentioned indicators of lung injury. On the other hand, ozone could enhance PM2.5-induced inflammatory changes and pathological characters in rat lungs. SOD and GSH-Px activities in lung were reduced in PM2.5-exposed rats with and without prior ozone exposure compared to control. To determine whether the PM2.5 and ozone affect endothelium system, iNOS, eNOS, and ICAM-1 mRNA levels in lung were analyzed by real-time PCR. These data demonstrated that inflammation and oxidative stress were involved in toxicology mechanisms of PM2.5 in rat lung and ozone potentiated these effects induced by PM2.5. These results have implications for understanding the pulmonary effects induced by ozone and PM2.5.

IKK inhibition prevents PM2.5-exacerbated cardiac injury in mice with type 2 diabetes.

Epidemiological studies have found that individuals with diabetes mellitus (DM) display an increased susceptibility for adverse cardiovascular outcomes when exposed to air pollution. This study was conducted to explore the potential mechanism linking ambient fine particles (PM2.5) and heart injury in a Type 2 DM (T2DM) animal model. The KKay mouse, an animal model of T2DM, was exposed to concentrated ambient PM2.5 or filtered air for 8 weeks via a versatile aerosol exposure and concentrator system. Simultaneously, an inhibitor of IκB kinase-2 (IKK-â) (IMD-0354), which is a blocker of nuclear factor κB (NF-κB) nuclear translocation, was administrated by intracerebroventricular injection (ICV) to regulate the NF-êB pathway. The results showed that ambient PM2.5 induced the increase of, NF-êB, cyclooxygenase-2 (COX-2) and mitogen activated protein kinase (MAPK) expression in cardiac tissue, and that IMD-0354 could alleviate the inflammatory injury. The results suggested that the NF-êB pathway plays an important role in mediating the PM2.5-induced cardiovascular injury in the T2DM model. Inhibiting NFκB may be a therapeutic option in air-pollution-exacerbated cardiovascular injury in diabetes mellitus.

Closed-loop recycling of sulfur-rich polymers with tunable properties spanning thermoplastics, elastomers, and vitrimers.

The development of closed-loop recycling polymers that exhibit excellent performance is of great significance. Sulfur-rich polymers possessing excellent optical, thermal, and mechanical properties are promising candidates for chemical recycling but lack efficient synthetic strategies for achieving diverse structures. Herein, we report a universal synthetic strategy for producing polytrithiocarbonates, a class of sulfur-rich polymers, via the polycondensation of dithiols and dimethyl trithiocarbonate. This strategy has excellent compatibility with a wide range of monomers, including aliphatic, heteroatomic, and aromatic dithiols enabling the synthesis of polytrithiocarbonates with diverse structures. The present synthesis strategy offers a versatile platform for the construction of thermoplastics, elastomers, and vitrimers. Notably, these polytrithiocarbonates can be easily depolymerized via solvolysis into the corresponding monomers, which can be repolymerized to virgin polymers without changing the material properties.