TMT-Based Quantitative Proteomics Analysis Reveals Airborne PM2.5-Induced Pulmonary Fibrosis

Low Dose of Nickel and Benzo [a] Anthracene in Rat-Diet, Induce Apoptosis, Fibrosis, and Initiate Carcinogenesis in Liver via NF-Ƙβ Pathway

Environmental contaminants such as polycyclic aromatic hydrocarbon (PAH) and heavy metals are major contaminants of food such as fish thus serving as source of exposure to human. This study was designed to evaluate the carcinogenic risk and other risks associated with long-term consumption of environmentally relevant dose of nickel and benzo [a] anthracene in rats. Thirty-six (36) male rats weighing between 80 and 100 g were assigned into 6 groups of 6 animals each; normal, nickel-, and benzo [a] anthracene-exposed groups for 12 and 24 weeks, respectively. Micronucleus and comet analyses were done in the blood, liver, and bone marrow. Liver function, redox, and inflammatory markers (AST, ALT, GGT, SOD, GSH, MDA, protein carbonyl, protein thiol, total protein, IL-10, 1L-1β, TNF-α, TGF-β NF-Ƙβ, and 8-oxodeoxyguansine) were analysed by standard methods. Immuno-histochemical quantification of Bax, Bcl2, and Erk 1/2 as well as mRNA expression of cyclin D1 was done in liver. From the results, weight gain was observed in varying degrees throughout the exposure period. The polychromatic erythrocytes/normochromatic erythrocytes ratio > 0.2 indicates no cytotoxic effects on the bone marrow. Percentage-MnPCE in blood significantly (p < 0.05) increased throughout exposure duration. Percentage tail DNA in blood was significantly (< 0.05) increased at weeks 20 and 24 in the exposed groups and in liver at weeks 12 (16.22 ± 0.47) and 24 (17.00 ± 0.36) of nickel-exposed rats. The aspartate amino transferase (AST):alanine amino transferase (ALT) ratio indicated fatty liver disease in the benzo [a] anthracene (0.90) and acute liver injury in the nickel (> 10 times greater than the upper limits of the reference group) exposed groups during the first 12 weeks. Observation from the histological and cytological data of the liver revealed the presence of inflammation, fibrosis, and high nuclear/cytoplasmic ratio, respectively, in the nickel and benzo [a] anthracene groups. Only benzo [a] anthracene induced liver oxidative stress with significant (p < 0.05) decrease in SOD (0.64 ± 0.02) activity and increase in protein carbonyl (7.60 ± 0.80 × 10-5) and MDA (57.10 ± 6.64) concentration after 24 weeks. Benzo [a] anthracene up-regulated the cyclin D1 expression and significantly (p < 0.05) increased the levels of the cytokines. Nickel and benzo [a] anthracene significantly (p < 0.05) increased the Bax (183.45 ± 6.50 and 199.76 ± 10.04) and Erk 1/2 (108.25 ± 6.41 and 136.74 ± 4.22) levels when compared with the control (37.43 ± 22.22 and 60.37 ± 17.86), respectively. Overall result showed that the toxic effects of nickel and benzo [a] anthracene might involve fibrosis, cirrhosis, apoptosis, and inflammation of the liver. As clearly demonstrated in this study, benzo [a] anthracene after the 24 weeks of exposure stimulates carcinogenic process by suppressing the liver antioxidant capacity, altering apoptotic, cell proliferation, and differentiation pathways.

Berberine hydrochloride ameliorates PM2.5-induced pulmonary fibrosis in mice through inhibiting oxidative stress and inflammatory

Elevated levels of respirable particulate matter (PM) have been strongly linked to disease incidence and mortality in population-based epidemiological studies. Berberine hydrochloride (BBR), an isoquinoline alkaloid found in Coptis chinensis, exhibits antipyretic, anti-inflammatory, and antioxidant properties. However, the protective effects and underlying mechanism of BBR against pulmonary fibrosis remain unclear. This study aimed to investigate the protective effect of BBR on lung tissue damage using a mouse model of PM2.5-induced pulmonary fibrosis. SPF grade C57BL/6 mice were randomly assigned to four groups, each consisting of 10 mice. The mice were pretreated with BBR (50 mg/kg) by gavage for 45 consecutive days. A tracheal drip of PM2.5 suspension (8 mg/kg) was administered once every three days for a total of 15 times to induce lung fibrosis. Moreover, the results demonstrated that PM2.5 was found to inhibit the PPARγ signaling pathway, increase ROS expression, upregulate protein levels of IL-6, IL-1β, TNF-α, as well as regulation of gene expression of STAT3 and SOCS3. Importantly, PM2.5 induced lung fibrosis by promoting collagen deposition, upregulating gene expression of fibrosis markers (TGF-β1, FN, α-SMA, COL-1, and COL-3), and downregulating E-cadherin expression. Remarkably, our findings suggest that these injuries could be reversed by BBR pretreatment. BBR acts as a PPARγ agonist in PM2.5-induced pulmonary fibrosis, activating the PPARγ signaling pathway to mitigate oxidative and inflammatory factor-mediated lung injury. This study provides valuable insights for the future prevention and treatment of pulmonary fibrosis.

Codium fragile Suppressed Chronic PM2.5-Exposed Pulmonary Dysfunction via TLR/TGF-β Pathway in BALB/c Mice

This study investigated the ameliorating effect of the aqueous extract of Codium fragile on PM2.5-induced pulmonary dysfunction. The major compounds of Codium fragile were identified as palmitic acid, stearic acid, and oleamide using GC/MS2 and hexadecanamide, oleamide, and 13-docosenamide using UPLC-Q-TOF/MSE. Codium fragile improved pulmonary antioxidant system deficit by regulating SOD activities and reducing GSH levels and MDA contents. It suppressed pulmonary mitochondrial dysfunction by regulating ROS contents and mitochondrial membrane potential levels. It regulated the inflammatory protein levels of TLR4, MyD88, p-JNK, p-NF-κB, iNOS, Caspase-1, TNF-α, and IL-1β. In addition, it improved the apoptotic protein expression of BCl-2, BAX, and Caspase-3 and attenuated the fibrous protein expression of TGF-β1, p-Smad-2, p-Smad-3, MMP-1, and MMP-2. In conclusion, this study suggests that Codium fragile might be a potential material for functional food or pharmaceuticals to improve lung damage by regulating oxidative stress inflammation, cytotoxicity, and fibrosis via the TLR/TGF-β1 signaling pathway.

Protective Effect of Lonicera japonica on PM2.5-Induced Pulmonary Damage in BALB/c Mice via the TGF-β and NF-κB Pathway

This study aimed to assess the protective effect of an extract of Lonicera japonica against particulate-matter (PM)_2.5-induced pulmonary inflammation and fibrosis. The compounds with physiological activity were identified as shanzhiside, secologanoside, loganic acid, chlorogenic acid, secologanic acid, secoxyloganin, quercetin pentoside, and dicaffeoyl quinic acids (DCQA), including 3,4-DCQA, 3,5-DCQA, 4,5-DCQA, and 1,4-DCQA using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS^E). The extract of Lonicera japonica reduced cell death, reactive oxygen species (ROS) production, and inflammation in A549 cells. The extract of Lonicera japonica decreased serum T cells, including CD4⁺ T cells, CD8⁺ T cells, and total T helper 2 (Th2) cells, and immunoglobulins, including immunoglobulin G (IgG) and immunoglobulin E (IgE), in PM_2.5-induced BALB/c mice. The extract of Lonicera japonica protected the pulmonary antioxidant system by regulating superoxide dismutase (SOD) activity, reduced glutathione (GSH) contents, and malondialdehyde (MDA) levels. In addition, it ameliorated mitochondrial function by regulating the production of ROS, mitochondrial membrane potential (MMP), and ATP contents. Moreover, the extract of Lonicera japonica exhibited a protective activity of apoptosis, fibrosis, and matrix metalloproteinases (MMPs) via TGF-β and NF-κB signaling pathways in lung tissues. This study suggests that the extract of Lonicera japonica might be a potential material to improve PM_2.5-induced pulmonary inflammation, apoptosis, and fibrosis.

N6-methyladenosine mediates Nrf2 protein expression involved in PM2.5-induced pulmonary fibrosis

It has been reported that particulate matter with an aerodynamic diameter of <2.5 µm (PM2.5) could induce epithelial-mesenchymal transition (EMT)- and extracellular matrix (ECM)-related pulmonary fibrosis (PF). The transcription factor Nrf2 alleviated PM2.5-induced PF by antagonizing oxidative stress. The N⁶-methyladenosine (m⁶A) modification plays a significant role in the stress response. However, the effect of m⁶A modification on the mechanisms of Nrf2-mediated defense against PM2.5-induced PF remained unknown. Here, we explored the role and the underlying molecular mechanisms of m⁶A methylation of Nrf2 mRNA in PM2.5-induced PF. We established filtered air (FA), unfiltered air (UA), and concentrated PM2.5 air (CA) group mice model and 0, 50, and 100 μg/mL PM2.5-treated 16HBE cell models. The extent of lung fibrosis in mice and fibrosis indicators were detected by histopathological analysis, immunohistochemical staining and western blotting. The molecular mechanism of m⁶A-modified Nrf2 was demonstrated by m⁶A-methylated RNA immunoprecipitation (MeRIP), RNA immunoprecipitation (RIP), qRT-PCR and T3 ligase-based PCR. Our data showed that PM2.5 exposure for 16 weeks could induce pulmonary fibrosis and activate Nrf2 signaling pathway. m⁶A methyltransferase METTL3 was upregulated after PM2.5 treatment in vivo and in vitro. Moreover, METTL3 mediated m⁶A modification of Nrf2 mRNA and promoted Nrf2 translation in mice and 16HBE cells after PM2.5 exposure. Mechanistically, three m⁶A-modified sites (1317, 1376 and 935; numbered relative to the first nucleotide of 3'UTR) of Nrf2 mRNA were identified in PM2.5-treatment 16HBE cells. Furthermore, the m⁶A binding proteins YTHDF1/IGF2BP1 promoted Nrf2 translation by binding to m⁶A residues of Nrf2 mRNA. Our results revealed the mechanism of m⁶A mediated Nrf2 signaling pathway against oxidative stress, which affected the development of PM2.5-induced PF.

Curcumin Ameliorates Particulate Matter-Induced Pulmonary Injury through Bimodal Regulation of Macrophage Inflammation via NF-κB and Nrf2

The direct effects of particulate matter (PM) on lung injury and its specific molecular mechanisms are unclear. However, experimental evidence has shown that oxidative stress-mediated inflammation in macrophages is the main pathological outcome of PM exposure. Curcumin has been reported to protect organs against the disturbance of homeostasis caused by various toxic agents through anti-inflammatory and antioxidative effects. However, the protective action of curcumin against PM-induced pulmonary inflammation and the underlying mechanism have not been thoroughly investigated. In this study, we established a PM-induced pulmonary inflammation mouse model using the intratracheal instillation method to investigate the protective ability of curcumin against PM-induced pulmonary inflammation. Compared to the mice treated with PM only, the curcumin-treated mice showed alleviated alveolar damage, decreased immune cell infiltration, and reduced proinflammatory cytokine production in both lung tissue and BALF. To evaluate the underlying mechanism, the mouse macrophage cell line RAW264.7 was used. Pretreatment with curcumin prevented the production of PM-induced proinflammatory cytokines by deactivating NF-κB through the suppression of MAPK signaling pathways. Furthermore, curcumin appears to attenuate PM-induced oxidative stress through the activation of Nrf2 and downstream antioxidant signaling. Our findings demonstrate that curcumin protects against PM-induced lung injury by suppressing oxidative stress and inflammatory activation in macrophages.

Sex-specific metabolic risk factors and their trajectories towards the non-alcoholic fatty liver disease incidence

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease. This study examined sex-specific associations between NAFLD and metabolic factors and investigated the trajectory of risk factors.

METHODS

We retrospectively investigated 16,140 individuals from Beijing Health Management Cohort. Univariate and multivariate time-dependent Cox regression analyses were performed to identify independent risk factors for new-onset NAFLD. The trajectory of risk factors was investigated using the latent growth curve model and growth mixture model.

RESULTS

Over a median follow-up of 3.15 years, 2,450 (15.18%) participants developed NAFLD. The risk factors for NAFLD in men were increased body mass index (BMI); waist circumference (WC); triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), haemoglobin (Hb), and serum uric acid (SUA) levels; and platelet (PLT) count and decreased serum creatinine-to-body weight (sCr/bw) and high-density lipoprotein cholesterol (HDL-C) levels. In women, the risk factors were increased BMI, WC, and fasting plasma glucose (FPG), TG, LDL-C, SUA, white blood cell (WBC), and PLT and decreased sCr/bw and HDL-C levels. In addition, BMI, LDL-C, sCr/bw and PLT changing trajectories were associated with NAFLD in men; BMI, WC, TG, LDL-C, SUA and sCr/bw trends was associated with NAFLD risk in women.

CONCLUSIONS

Development of NAFLD is associated with BMI, LDL-C, sCr/bw and PLT changing trajectories in men; BMI, WC, TG, LDL-C, SUA and sCr/bw trends are associated an increased risk of NAFLD in women. Deterioration of metabolic risk factors status can be a predictor of NAFLD many years before its occurrence.

The role of PP2A /NLRP3 signaling pathway in ambient particulate matter 2.5 induced lung injury

Ambient particulate matter 2.5 (PM_2.5) exposure has been linked to pulmonary fibrosis. However, the key signaling pathways remained unclear. In the present study, we applied a mouse model with myeloid-specific deletion of Ppp2r1a gene (encoding protein phosphatase 2 A (PP2A) A subunit) to identify the key signaling pathways involved in PM_2.5-induced pulmonary fibrosis. PP2A Aα^-/- homozygote mice and matched wild-type (WT) littermates were exposed to filtered air (FA), unfiltered air (UA), and concentrated PM_2.5 (CA) in a real-ambient PM exposure system for 8 weeks and 16 weeks, respectively. The mice exposed to PM_2.5 displayed a progressive inflammation and pulmonary fibrosis. Moreover, the expressions of NLRP3, pro-caspase-1, caspase-1, ASC and IL-1β were increased in mice lung following PM_2.5 exposure, indicating PM_2.5 exposure caused pulmonary inflammation by the NLRP3 pathways activation. Furthermore, the effects of PM exposure on pulmonary inflammation, pulmonary fibrosis, oxidative stress, and pulmonary function damage were significantly enhanced in PP2A^-/- mice compared to WT mice, indicating the role of PP2A in the regulation of pulmonary injury induced by PM exposure. In vitro study confirmed that PP2A was involved in the PM_2.5-induced inflammation response and NLRP3 inflammasome activation. Importantly, we identified PP2A regulated the activation of NLRP3 pathways by direct dephosphorylating IRE1α in response to PM_2.5 exposure. Taken together, our results demonstrated that PP2A-IRE1α-NLRP3 signaling pathway played a crucial role in regulating the inflammation response, triggering the lung fibrogenesis upon PM_2.5 exposure. Our findings provide new insights into regulatory role of PP2A in human diseases upon the PM exposure.

Effects of Different Concentrations of Oil Mist Particulate Matter on Pulmonary Fibrosis In Vivo and In Vitro

Oil-mist particulate matter (OMPM) refers to oily particles with a small aerodynamic equivalent diameter in ambient air. Since the pathogenesis of pulmonary fibrosis (PF) has not been fully elucidated, this study aims to explore the potential molecular mechanisms of the adverse effects of exposure to OMPM at different concentrations in vivo and in vitro on PF. In this study, rats and cell lines were treated with different concentrations of OMPM in vivo and in vitro. Sirius Red staining analysis shows that OMPM exposure could cause pulmonary lesions and fibrosis symptoms. The expression of TGF-β1, α-SMA, and collagen I was increased in the lung tissue of rats. The activities of MMP2 and TIMP1 were unbalanced, and increased N-Cadherin and decreased E-Cadherin upon OMPM exposure in a dose-dependent manner. In addition, OMPM exposure could activate the TGF-β1/Smad3 and TGF-β1/MAPK p38 signaling pathways, and the differentiation of human lung fibroblast HFL-1 cells. Therefore, OMPM exposure could induce PF by targeting the lung epithelium and fibroblasts, and activating the TGF-β1/Smad3 and TGF-β1/MAPK p38 signaling pathways.

Dimethylarginine dimethylaminohydrolase 1 protects PM2.5 exposure-induced lung injury in mice by repressing inflammation and oxidative stress

BACKGROUND

Airborne fine particulate matter with aerodynamic diameter ≤ 2.5 μm (PM_2.5) pollution is associated with the prevalence of respiratory diseases, including asthma, bronchitis and chronic obstructive pulmonary disease. In patients with those diseases, circulating asymmetric dimethylarginine (ADMA) levels are increased, which contributes to airway nitric oxide deficiency, oxidative stress and inflammation. Overexpression of dimethylarginine dimethylaminohydrolase 1 (DDAH1), an enzyme degrading ADMA, exerts protective effects in animal models. However, the impact of DDAH1/ADMA on PM_2.5-induced lung injury has not been investigated.

METHODS

Ddah1^-/- and DDAH1-transgenic mice, as well as their respective wild-type (WT) littermates, were exposed to either filtered air or airborne PM_2.5 (mean daily concentration ~ 50 µg/m³) for 6 months through a whole-body exposure system. Mice were also acutely exposed to 10 mg/kg PM_2.5 and/or exogenous ADMA (2 mg/kg) via intratracheal instillation every other day for 2 weeks. Inflammatory response, oxidative stress and related gene expressions in the lungs were examined. In addition, RAW264.7 cells were exposed to PM_2.5 and/or ADMA and the changes in intracellular oxidative stress and inflammatory response were determined.

RESULTS

Ddah1^-/- mice developed more severe lung injury than WT mice after long-term PM_2.5 exposure, which was associated with greater induction of pulmonary oxidative stress and inflammation. In the lungs of PM_2.5-exposed mice, Ddah1 deficiency increased protein expression of p-p65, iNOS and Bax, and decreased protein expression of Bcl-2, SOD1 and peroxiredoxin 4. Conversely, DDAH1 overexpression significantly alleviated lung injury, attenuated pulmonary oxidative stress and inflammation, and exerted opposite effects on those proteins in PM_2.5-exposed mice. In addition, exogenous ADMA administration could mimic the effect of Ddah1 deficiency on PM_2.5-induced lung injury, oxidative stress and inflammation. In PM_2.5-exposed macrophages, ADMA aggravated the inflammatory response and oxidative stress in an iNOS-dependent manner.

CONCLUSION

Our data revealed that DDAH1 has a marked protective effect on long-term PM_2.5 exposure-induced lung injury.

Quantitative Proteomic Analysis of Zearalenone Exposure on Uterine Development in Weaned Gilts

The aim of this study was to explore the effect of zearalenone (ZEA) exposure on uterine development in weaned gilts by quantitative proteome analysis with tandem mass spectrometry tags (TMT). A total of 16 healthy weaned gilts were randomly divided into control (basal diet) and ZEA3.0 treatments groups (basal diet supplemented with 3.0 mg/kg ZEA). Results showed that vulva size and uterine development index were increased (p < 0.05), whereas serum follicle stimulation hormone, luteinizing hormone and gonadotropin-releasing hormone were decreased in gilts fed the ZEA diet (p < 0.05). ZEA, α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL) were detected in the uteri of gilts fed a 3.0 mg/kg ZEA diet (p < 0.05). The relative protein expression levels of creatine kinase M-type (CKM), atriopeptidase (MME) and myeloperoxidase (MPO) were up-regulated (p < 0.05), whereas aldehyde dehydrogenase 1 family member (ALDH1A2), secretogranin-1 (CHGB) and SURP and G-patch domain containing 1 (SUGP1) were down-regulated (p < 0.05) in the ZEA3.0 group by western blot, which indicated that the proteomics data were dependable. In addition, the functions of differentially expressed proteins (DEPs) mainly involved the cellular process, biological regulation and metabolic process in the biological process category. Some important signaling pathways were changed in the ZEA3.0 group, such as extracellular matrix (ECM)-receptor interaction, focal adhesion and the phosphoinositide 3-kinase−protein kinase B (PI3K-AKT) signaling pathway (p < 0.01). This study sheds new light on the molecular mechanism of ZEA in the uterine development of gilts.

Combined multi-omics analysis reveals oil mist particulate matter-induced lung injury in rats: Pathological damage, proteomics, metabolic disturbances, and lung dysbiosis

Oil mist particulate matter (OMPM) causes acute and chronic diseases and exacerbations. Owing to the characteristics of poor ventilation, high oil mist concentration, and a relatively closed working environment, the existence of OMPM in the cabin is inevitable, and its impact on the health of occupations on ships cannot be ignored. However, compared with several studies that summarized the health effects of OMPM from traditional sources, few studies have focused on the occupational exposure risk of OMPM from oil pollution sources in ships. In this study, we collected OMPM from oil pollution in cabins and assessed the exposure to OMPM from oil pollution and the corresponding health risks through acute exposure experiments in rats. OMPM exposure induces protein regulation in the extracellular matrix and immune responses, leading to severe inflammatory responses. The abundance and composition of the lung microbial community changed significantly. It interferes with the lung metabolite levels. However, more research is needed to fully understand the extent of health risks associated with OMPM exposure. Further research on vulnerable groups exposed to OMPM from ships is needed to inform public health interventions.

Molecular mechanism of Pulmonary diseases caused by exposure to urban PM2.5 in Chengdu-Chongqing Economic Circle, China

Chengdu-Chongqing Economic Circle (CD-CQ Economic Circle) is one of China's four major economic circles and five major urban agglomerations located in Southwest China's Sichuan Basin. The CD-CQ Economic Circle, with its strong economic development and dense population, suffers from severe PM_2.5 pollution, which is known to cause chronic and acute respiratory ailments. This study examined the lung disease-related hub genes, functions, and pathways that are affected by PM_2.5 in summer and winter in the two central megacities of Chengdu and Chongqing. PM_2.5 frequently activates lung disease-associated hub genes, most notably the transcription factor TP53. TP53 interacts with the majority of lung disease-related genes and regulates important and commonly occurring biological functions and pathways, including gland development, aging, reactive oxygen species metabolic process, the response to oxygen levels, and fluid shear stress, among others. Thus, PM_2.5 has been shown to target TP53 for regulating lung disease genes/functions/pathways, thereby influencing the occurrence and progression of lung illnesses. Notably, PM_2.5 may be associated with small cell carcinoma of the lung due to the high number of lung disease genes, hub genes, critical functions, and pathways enriched in this kind of cancer. These findings shed fresh light on the molecular pathophysiology of PM_2.5 pollution on the respiratory system in the CD-CQ Economic Circle and aid in the development of novel techniques for mitigating PM_2.5 pollution-associated respiratory illness.

The proteasome-dependent degradation of ALKBH5 regulates ECM deposition in PM2.5 exposure-induced pulmonary fibrosis of mice

Long-term inhalation of fine particulate matter (PM_2.5) can cause serious effects on the respiratory system. It might be attributed to the fact that PM_2.5 could directly enter and deposit in lung tissues. We established models of PM_2.5 exposure in vivo and in vitro to explore the adverse effects of ambient PM_2.5 on pulmonary and its potential pathogenic mechanisms. Our results showed that PM_2.5 exposure promoted the deposition of ECM and the increased stiffness of the lungs, and then led to pulmonary fibrosis in time- and dose- dependent manners. Pulmonary function test showed restrictive ventilation function in mice after PM_2.5 exposure. After PM_2.5 exposure, ALKBH5 was recognized by TRIM11 and then degraded through the proteasome pathway. ALKBH5 deficiency (ALKBH5^-/-) aggravated restrictive ventilatory disorder and promoted ECM deposition in lungs of mice induced by PM2.5. And the YAP1 signaling pathway was more activated in ALKBH5^-/- than WT mice after PM_2.5 exposure. In consequence, decreased ALKBH5 protein levels regulated miRNAs and then the miRNAs-targeted YAP1 signaling was activated to promote pulmonary fibrosis induced by PM_2.5.

Accumulated oxidative stress risk in HUVECs by chronic exposure to non-observable acute effect levels of PM2.5

Few studies have reported the accumulation of non-observable acute effect (NOAE) of PM_2.5, especially exposure to the NOAE doses (NOAEDs) of PM_2.5 in chronic way. To address this issue, HUVECs were cultured from the 1st to 30th generations (G1 to G30) and treated by the NOAED PM_2.5 once every three passages. The generational changes of oxidative damage markers, inflammatory factors, and cell adhesion molecules (CAMs) were monitored in HUVECs at G6, G12, G18, G24, and G30, and proteomes at G18 and G30, respectively. The oxidative damages monotonically accumulated with exposure time elongation and PM_2.5 dose increases. Similar to the oxidative trends, VCAM1 and ICAM1 significantly and dose-dependently increased at G30. However, many inflammatory factors altered with complex patterns to respond the NOAEDs' PM_2.5. Proteomic results demonstrated most proteins expressed stably, and the generational proteome alterations were more apparent than the NOAEDs' PM_2.5 induced ones. The PM_2.5-related proteins varied much, but only few can cross the doses and generations. These observations suggested that the proteins changed holistically rather than individually. In summary, SOD1, SUMO2, and H3F3A may initiate HUVESs responses to PM_2.5, and then broadcast and accumulate the NOAE via DNA repair, immune response, and glycolysis.

Study on Lung Injury Caused by Fine Particulate Matter and Intervention Effect of Rhodiola wallichiana

Objective

The objective of this study was to observe the protective effect of Rhodiola wallichiana drops in a rat model of fine particulate matter (PM2.5) lung injury.

Methods

Forty male Wistar rats were randomly divided into blank control (NC), normal saline (NS), PM2.5-infected (PM), and Rhodiola wallichiana (RW) groups. Rats in the NC group were not provided any interventions, whereas those in the NS and PM groups were administered normal saline and PM2.5 suspension by trachea drip once a week for four weeks. Rats in the RW group were intraperitoneally administered Rhodiola wallichiana for 14 days and then administered PM2.5 suspension by trachea drip 7 days after drug delivery. The levels of inflammatory factors such as interleukin-6, interleukin-1β, and tumor necrosis factor-alpha and oxidative stress biomarkers such as 8-hydroxy-2′-deoxyguanosine, 4-hydroxynonenal, and protein carbonyl content were determined in the serum and bronchoalveolar lavage fluid by ELISA. The level of 4-hydroxynonenal in the lung was also determined using Western blotting and immunohistochemical staining.

Results

Levels of inflammatory factors and oxidative stress biomarkers were all increased in the PM group but decreased in the RW group. Western blotting revealed increased 4-hydroxynonenal levels in the PM group but decreased levels in the RW group. Immunohistochemical staining also provided similar results.

Conclusion

Rhodiola wallichiana could protect rats from inflammation and oxidative stress injury caused by PM2.5.

Association of visceral adiposity index with incident nephropathy and retinopathy: a cohort study in the diabetic population

Background

The association between visceral adiposity index (VAI) and diabetic complications has been reported in cross-sectional studies, while the effect of VAI on complication development remains unclear. This study aims to evaluate the longitudinal association of VAI and Chinese VAI (CVAI) with the incidence of diabetic nephropathy and retinopathy using a Chinese cohort.

Methods

A total of 8 948 participants with type 2 diabetes from Beijing Health Management Cohort were enrolled during 2013–2014, and followed until December 31, 2019. Nephropathy was confirmed by urine albumin/creatinine ratio and estimated glomerular filtration rate; retinopathy was diagnosed using fundus photograph.

Results

The mean (SD) age was 53.35 (14.66) years, and 6 154 (68.8%) were men. During a median follow-up of 4.82 years, 467 participants developed nephropathy and 90 participants developed retinopathy. One-SD increase in VAI and CVAI levels were significantly associated with an increased risk of nephropathy, and the adjusted hazard ratios (HR) were 1.127 (95% CI 1.050–1.210) and 1.165 (95% CI 1.003–1.353), respectively. On contrary, VAI and CVAI level were not associated with retinopathy after adjusting confounding factors.

Conclusion

VAI and CVAI are independently associated with the development of nephropathy, but not retinopathy in Chinese adults with diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01464-1.

TMT-Based Quantitative Proteomics Reveals Cochlear Protein Profile Alterations in Mice with Noise-Induced Hearing Loss

Noise-induced hearing loss (NIHL) is a global occupational disease affecting health. To date, genetic polymorphism studies on NIHL have been performed extensively. However, the proteomic profiles in the cochleae of mice suffering noise damage remain unclear. The goal of this current study was to perform a comprehensive investigation on characterizing protein expression changes in the cochlea based on a mouse model of NIHL using tandem mass tag (TMT)-labeling quantitative proteomics, and to reveal the potential biomarkers and pathogenesis of NIHL. Male C57BL/6J mice were exposed to noise at 120 dB SPL for 4 h to construct the NIHL mouse model. The levels of MDA and SOD, and the production of proinflammatory cytokines including TNF-α and IL-6 in the mice cochleae, were determined using chemical colorimetrical and ELISA kits. Moreover, differentially expressed proteins (DEPs) were validated using Western blotting. The mouse model showed that the ABR thresholds at frequencies of 4, 8, 12, 16, 24 and 32 kHz were significantly increased, and outer hair cells (HCs) showed a distinct loss in the noise-exposed mice. Proteomics analysis revealed that 221 DEPs were associated with NIHL. Bioinformatics analysis showed that a set of key inflammation and autophagy-related DEPs (ITGA1, KNG1, CFI, FGF1, AKT2 and ATG5) were enriched in PI3K/AKT, ECM-receptor interaction, and focal adhesion pathways. The results revealed that the MDA level was significantly increased, but the activity of SOD decreased in noise-exposed mice compared to the control mice. Moreover, TNF-α and IL-6 were significantly increased in the noise-exposed mice. Western blotting revealed that the expression levels of ITGA1, KNG1, and CFI were upregulated, but FGF1, AKT2, and ATG5 were significantly downregulated in noise-exposed mice. This study provides new scientific clues about the future biomarkers and pathogenesis studies underlying NIHL. Furthermore, the findings suggest that the validated DEPs may be valuable biomarkers of NIHL, and inflammation and autophagy may be pivotal mechanisms that underlie NIHL.

Proteomic Analysis of the Meniscus Cartilage in Osteoarthritis

The distribution of differential extracellular matrix (ECM) in the lateral and medial menisci can contribute to knee instability, and changes in the meniscus tissue can lead to joint disease. Thus, deep proteomic identification of the lateral and medial meniscus cartilage is expected to provide important information for treatment and diagnosis of various knee joint diseases. We investigated the proteomic profiles of 12 lateral/medial meniscus pairs obtained from excess tissue of osteoarthritis patients who underwent knee arthroscopy surgery using mass spectrometry-based techniques and measured 75 ECM protein levels in the lesions using a multiple reaction monitoring (MRM) assay we developed. A total of 906 meniscus proteins with a 1% false discovery rate (FDR) was identified through a tandem mass tag (TMT) analysis showing that the lateral and medial menisci had similar protein expression profiles. A total of 131 ECM-related proteins was included in meniscus tissues such as collagen, fibronectin, and laminin. Our data showed that 14 ECM protein levels were differentially expressed in lateral and medial lesions (p < 0.05). We present the proteomic characterization of meniscal tissue with mass spectrometry-based comparative proteomic analysis and developed an MRM-based assay of ECM proteins correlated with tissue regeneration. The mass spectrometry dataset has been deposited to the MassIVE repository with the dataset identifier MSV000087753.

Chronic lung inflammation and pulmonary fibrosis after multiple intranasal instillation of PM2 .5 in mice

Fine particulate matter (PM_2.5 ) is an important component of air pollution and can induce lung inflammation and oxidative stress. We hypothesized that PM_2.5 could play a role in the induction of pulmonary fibrosis. We examined whether multiple intranasal instillation of PM_2.5 can induce pulmonary fibrosis in the mouse, and also investigated the underlying pro-fibrotic signaling pathways. C57/BL6 mice were intranasally instilled with 50 μl of PM_2.5 suspension (7.8 μg/g body weight) or PBS three times a week over 3 weeks, 6 weeks or 9 weeks. To observe the recovery of pulmonary fibrosis after the termination of PM_2.5 exposure, 9 week-PM_2.5 instilled mice were also studied at 3 weeks after termination of instillation. There were significant decreases in total lung capacity (TLC) and compliance (Cchord) in the 9-week PM_2.5 -instilled mice, while there were increased histological fibrosis scores with enhanced type I collagen and hydroxyproline deposition, increased mitochondrial ROS levels and NOX activity, decreased total SOD and GSH levels, accompanied by decreased mitochondrial number and aberrant mitochondrial morphology (swelling, vacuolization, cristal disruption, reduced matrix density) in PM_2.5 -instilled mice. Multiple PM_2.5 instillation resulted in increased expression of TGFβ1, increases of N-Cadherin and Vimentin and a decrease of E-Cadherin. It also led to decreases in OPA1 and MFN2, and increases in Parkin, SQSTM1/p62, the ratio of light china (LC) 3B II to LC3B I, PI3k/Akt phosphorylation, and NLRP3 expression. Intranasal instillation of PM_2.5 for 9 weeks induced lung inflammation and pulmonary fibrosis, which was linked with aberrant epithelial-mesenchymal transition, oxidative stress, mitochondrial damage and mitophagy, as well as activation of TGFβ1-PI3K/Akt, TGFβ1- NOX and TGFβ1-NLRP3 pathways.

Particulates induced lung inflammation and its consequences in the development of restrictive and obstructive lung diseases: a systematic review

Particulate matters (PMs) are significant components of air pollution in the urban environment. PMs with aerodynamic diameter less than 2.5 μm (PM_2.5) can penetrate to the alveolar area and introduce numerous compounds to the pneumocystis that can initiate inflammatory response. There are several questions about this exposure as follows: does PM_2.5-induced inflammation lead to a specific disease? If yes, what is the form of the progressed disease? This systematic review was designed and conducted to respond to these questions. Four databases, including Web of Science, Scopus, PubMed, and Embase, were reviewed systematically to find the related articles. According to the included articles, the only available data on the inflammatory effects of PM_2.5 comes from either in vitro or animal studies. Both types of studies have shown that the induced inflammation is type I and includes secretion of proinflammatory cytokines. The exposure duration of longer than 28 weeks was not observed in any of the reviewed studies. However, as there is not a specific antigenic component in the urban particulate matters and based on the available evidence, the antigen-presenting is not a common process in the inflammatory responses to PM_2.5. Therefore, neither signaling to repair cells such as fibroblasts nor over-secretion of extracellular matrix (ECM) proteins can occur following PM_2.5-induced inflammation. These pieces of evidence weaken the probability of the development of fibrotic diseases. On the other hand, permanent inflammation induces the destruction of ECM and alveolar walls by over-secretion of protease enzymes and therefore results in progressive obstructive effects.

Proteomic Analysis Revealed the Characteristics of Key Proteins Involved in the Regulation of Inflammatory Response, Leukocyte Transendothelial Migration, Phagocytosis, and Immune Process during Early Lung Blast Injury

Previous studies found that blast injury caused a significant increased expression of interleukin-1, IL-6, and tumor necrosis factor, a significant decrease in the expression of IL-10, an increase in Evans blue leakage, and a significant increase in inflammatory cell infiltration in the lungs. However, the molecular characteristics of lung injury at different time points after blast exposure have not yet been reported. Therefore, in this study, tandem mass spectrometry (TMT) quantitative proteomics and bioinformatics analysis were used for the first time to gain a deeper understanding of the molecular mechanism of lung blast injury at different time points. Forty-eight male C57BL/6 mice were randomly divided into six groups: control, 12 h, 24 h, 48 h, 72 h, and 1 w after low-intensity blast exposure. TMT quantitative proteomics and bioinformatics analysis were performed to analyze protein expression profiling in the lungs from control and blast-exposed mice, and differential protein expression was verified by Western blotting. The results demonstrated that blast exposure induced severe lung injury, leukocyte infiltration, and the production of inflammatory factors in mice. After analyzing the expression changes in global proteins and inflammation-related proteomes after blast exposure, the results showed that a total of 6861 global proteins and 608 differentially expressed proteins were identified, of which 215, 128, 187, 232, and 65 proteins were identified at 12 h, 24 h, 48 h, 72 h, and 1 week after blast exposure, respectively. Moreover, blast exposure-induced 177 differentially expressed proteins were associated with inflammatory responses, which were enriched in the inflammatory response regulation, leukocyte transendothelial migration, phagocytosis, and immune response. Therefore, blast exposure may induce early inflammatory response of lung tissue by regulating the expression of key proteins in the inflammatory process, suggesting that early inflammatory response may be the initiating factor of lung blast injury. These data can provide potential therapeutic candidates or approaches for the development of future treatment of lung blast injury.

Time- and Dose-Resolved Proteome of PM2.5-Exposure-Induced Lung Injury and Repair in Rats

In recent years, airborne fine particulate matter (PM_2.5) is drawing more public attention due to its various physicochemical features and causing pathological harm, as proven by epidemiological and clinical studies. However, the mechanism of PM_2.5-exposure-induced lung injury has not been fully characterized. Here, we established a PM_2.5-induced rat injury model for both short-term and long-term exposures at different concentrations. We employed the Fast-seq technique to profile 6316 proteins and the catTFRE approach to profile 387 transcription factors (TFs) in the lung tissue. In short-term exposure, we elucidated gradually upregulated proteins enriched in response to oxidative stress, phagosome, and the extracellular matrix (ECM)-receptor interaction pathway. Long-term exposure mainly showed the immune response pathway to be consisting of increased lymphocytes and cytokines. Intriguingly, we found that immune-related proteins were recoverable during short-term exposure. During the process of PM_2.5 exposure, upregulated proteins presented dose-dependence in the lung, including stress response at low dose, minor immune response at middle dose, and severe inflammatory response at high dose. This data set provides a rich resource to facilitate the understanding of PM_2.5-induced lung damage and repair mechanism.

Environmental contaminant ammonia triggers epithelial-to-mesenchymal transition-mediated jejunal fibrosis with the disassembly of epithelial cell-cell contacts in chicken

Ammonia (NH₃) is an environmental contaminant that is causing increasing problems with human and animal health due to the development of poultry industry. There are limited studies on the effect of NH₃ inhalation toxicity on the intestinal tract of animals, and underlying molecular mechanisms remain unclear. In the present study, we established a chicken model of NH₃ aspiration-induced injury for 42 days and observed histopathological changes of the jejunum. Tandem mass tag-based quantitative proteomic analysis was applied to investigate changes in the protein profile in the jejunum tissue of chickens that were exposed to NH₃. Overall, 48 significantly differentially expressed proteins (DEPs) were identified. GO and KEGG analyses revealed that most DEPs were closely related to epithelial-to-mesenchymal transition (EMT), cell-cell junctions, and fibrosis-related factors. Regarding fibrosis, type I collagen and fibronectin were significantly increased. With respect to EMT, epithelial marker proteins (such as E-cadherin and keratin) were repressed, while mesenchymal marker proteins (such as vimentin) were activated. Loss of epithelial cell-cell junctions (such as tight junctions, adherens junctions and desmosomes) were observed. Additionally, overexpression of transforming growth factor-beta (TGF-β) may play a key role in the EMT process and fibrosis. Taken together, these findings suggested that NH₃ triggered the EMT and disassembly of epithelial cell-cell contacts, resulting in jejunal fibrosis that was mediated by TGF-β in chickens. The results of our study will contribute to provide a technical reference regarding the research methods of intestinal toxicity of NH₃ and have largely regulatory implications for ecological risk assessment of human health.

Ma Xing Shi Gan Decoction Protects against PM2.5-Induced Lung Injury through Suppression of Epithelial-to-Mesenchymal Transition (EMT) and Epithelial Barrier Disruption

This research was designed to explore the effect of Ma Xing Shi Gan decoction (MXD) in alleviating particulate matter less than 2.5 μm in diameter (PM2.5) induced lung injury from the perspective of epithelial barrier protection and inhibition of epithelial-to-mesenchymal transition (EMT). Rats were exposed to PM2.5 to establish a lung injury model in vivo, and a PM2.5-stimulated primary cultured type II alveolar epithelial cell model was introduced in vitro. Our results indicated that MXD alleviated the weight loss and pathologic changes and improved the epithelial barrier dysfunction. MXD also significantly inhibited the TGF-β/Smad3 pathway, increased the level of ZO-1 and claudin-5, and reversed the EMT process. Notably, the protection of MXD was abolished by TGF-β in vitro. Our results indicated that MXD has a protection against PM2.5-induced lung injury. The proposed mechanism is reversing PM2.5-induced EMT through inhibiting TGF-β/Smad3 pathway and then upregulating the expression of tight-junction proteins.

Epitranscriptomic 5-Methylcytosine Profile in PM2.5-induced Mouse Pulmonary Fibrosis

Exposure of airborne particulate matter (PM) with an aerodynamic diameter less than 2.5 μm (PM2.5) is epidemiologically associated with lung dysfunction and respiratory symptoms, including pulmonary fibrosis. However, whether epigenetic mechanisms are involved in PM2.5-induced pulmonary fibrosis is currently poorly understood. Herein, using a PM2.5-induced pulmonary fibrosis mouse model, we found that PM2.5 exposure leads to aberrant mRNA 5-methylcytosine (m5C) gain and loss in fibrotic lung tissues. Moreover, we showed the m5C-mediated regulatory map of gene functions in pulmonary fibrosis after PM2.5 exposure. Several genes act as m5C gain-upregulated factors, probably critical for the development of PM2.5-induced fibrosis in mouse lungs. These genes, including Lcn2, Mmp9, Chi3l1, Adipoq, Atp5j2, Atp5l, Atpif1, Ndufb6, Fgr, Slc11a1, and Tyrobp, are highly related to oxidative stress response, inflammatory responses, and immune system processes. Our study illustrates the first epitranscriptomic RNA m5C profile in PM2.5-induced pulmonary fibrosis and will be valuable in identifying biomarkers for PM2.5 exposure-related lung pathogenesis with translational potential.

Effective fraction of Bletilla striata reduces the inflammatory cytokine production induced by water and organic extracts of airborne fine particulate matter (PM2.5) in vitro

BACKGROUND

Bletilla striata is a traditional Chinese medicine used to treat hemorrhage, scald, gastric ulcer, pulmonary diseases and inflammations. In this study, we investigated bioactivity of the effective fraction of B. striata (EFB) in reducing the inflammatory cytokine production induced by water or organic extracts of PM2.5.

METHODS

PM2.5 extracts were collected and analyzed by chromatographic system and inductively coupled plasma mass spectrometer. Cell viability was measured using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay, and cell supernatant was analyzed by flow cytometry, ELISA, and qRT-PCR in cultured mouse macrophage cell line RAW264.7 treated with EFB and PM2.5 extracts. Expressions of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathway were measured by Western blot.

RESULTS

PM2.5 composition is complex and the toxicity of PM2.5 extracts were not noticeable. The treatment of EFB at a wide dose-range of 0-40 μg/mL did not cause significant change of RAW264.7 cell proliferation. EFB pretreatment decreased the inflammatory cytokines in the macrophage. Further analysis showed that EFB significantly attenuated PM2.5-induced proinflammatory protein expression and downregulated the levels of phosphorylated NF-κBp65, inhibitor of kappa B (IκB)-α, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38.

CONCLUSIONS

Our study demonstrated the potential effectiveness of B. striata extracts for treating PM2.5-triggered pulmonary inflammation.

Effects of chronic PM2.5 exposure on pulmonary epithelia: Transcriptome analysis of mRNA-exosomal miRNA interactions

Epidemiological studies have established the correlations between PM_2.5 and a wide variety of pulmonary diseases. However, their underlying pathogeneses have not been clearly elucidated yet. In the present study, the epithelial-mesenchymal transition (EMT) phenotype with enhanced proliferation and migration activity of human pulmonary epithelial cell line BEAS-2B was observed after exposure to low dose PM_2.5 exposure (50 μg/ml) for 30 passages. Then, epithelial cells derived-exosomal micro-RNA (miRNA) and intracellular total RNA were extracted, and the differentially expressed exosomal miRNAs (DE-Exo-MiRs) as well as differentially expressed protein coding genes (DEGs) were identified by RNA sequencing (RNA-seq) and transcriptome analysis. We found that chronic PM_2.5 exposure stimulated the release of pulmonary epithelium derived exosomes. 45 DE-Exo-MiRs including 32 novelly predicted miRNAs and 843 DEGs between PM_2.5 exposed group and the normal control were detected. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that DEGs were significantly enriched in extracellular matrix organization, focal adhesion and cancer related terms. Besides, the enrichment analyses on 7774 mRNA targets of 27 DE-Exo-MiRs predicted by MiRanda software also revealed the potential regulatory role of exosomal miRNAs in pathways in cancer, Wingless/Integrated (Wnt) signaling pathway, focal adhesion related genes and other multiple pathogenic pathways. Moreover, the interactive exosomal miRNA-mRNA pair networks were constructed using Cytoscape software. Our results provided a novel basis for a better understanding of the mechanisms of chronic PM_2.5 exposure induced pulmonary disorders including pulmonary fibrosis and cancer, in which exosomal miRNAs (Exo-MiRs) potentially functions by dynamically regulating gene expressions.

The effect of exposure time and concentration of airborne PM2.5 on lung injury in mice: A transcriptome analysis

The association between airborne fine particulate matter (PM2.5) concentration and the risk of respiratory diseases has been well documented by epidemiological studies. However, the mechanism underlying the harmful effect of PM2.5 has not been fully understood. In this study, we exposed the C57BL/6J mice to airborne PM2.5 for 3 months (mean daily concentration ~50 or ~110 μg/m3, defined as PM2.5-3L or PM2.5-3H) or 6 months (mean daily concentration ~50 μg/m3, defined as PM2.5-6L) through a whole-body exposure system. Histological and biochemical analysis revealed that PM2.5-3H exposure caused more severe lung injury than did PM2.5-3L, and the difference was greater than that of PM2.5-6L vs PM2.5-3L exposure. With RNA-sequencing technique, we found that the lungs exposed with different concentration of PM2.5 have distinct transcriptional profiles. PM2.5-3H exposure caused more differentially expressed genes (DEGs) in lungs than did PM2.5-3L or PM2.5-6L. The DEGs induced by PM2.5-3L or PM2.5-6L exposure were mainly enriched in immune pathways, including Hematopoietic cell lineage and Cytokine-cytokine receptor interaction, while the DEGs induced by PM2.5-3H exposure were mainly enriched in cardiovascular disease pathways, including Hypertrophic cardiomyopathy and Dilated cardiomyopathy. In addition, we found that upregulation of Cd5l and reduction of Hspa1 and peroxiredoxin-4 was associated with PM2.5-induced pulmonary inflammation and oxidative stress. These results may provide new insight into the cytotoxicity mechanism of PM2.5 and help to development of new strategies to attenuate air pollution associated respiratory disease.

Walnut protein isolates attenuate particulate matter-induced lung and cardiac injury in mice and zebra fish

Air pollution is an increasingly serious problem, and the fine particles of air pollution can cause diseases of the respiratory, cardiovascular, and immune systems. Walnut protein isolates (WPIs) are peptides purified from walnut protein hydrolysates that have very high antioxidant and 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH) scavenging activities. In this study, mice and zebra fish were used to test the effect of WPIs on the acute lung injury (ALI) and heart injury induced by particulate matter (PM). The WPIs protected against ALI in the PM-induced ALI mouse model by inhibiting myeloperoxidase (MPO), nitric oxide (NO), interleukin 1β(IL-1β), and interleukin 6(IL-6) in ALI mouse bronchoalveolar lavage fluid (BALF) and pro-inflammatory cytokine production and acyl carrier protein (ACP) level. In the zebra fish model, the WPIs promoted the secretion of PM into the intestinal tract, protected against the heart injury caused by PM, and promoted the phagocytosis of zebra fish macrophages. Therefore, WPIs are potential candidates to be a health-promoting product with no toxicity.

This study supports new prospects for WPI development and shows WPIs may be potential candidates for healthy products.