Neuropilin-1 mediates lung tissue-specific control of ILC2 function in type 2 immunity.

Group 2 innate lymphoid cells (ILC2s) are highly heterogeneous tissue-resident lymphocytes that regulate inflammation and tissue homeostasis in health and disease. However, how these cells integrate into the tissue microenvironment to perform tissue-specific functions is unclear. Here, we show neuropilin-1 (Nrp1), which is induced postnatally and sustained by lung-derived transforming growth factor beta-1 (TGFß1), is a tissue-specific marker of lung ILC2s. Genetic ablation or pharmacological inhibition of Nrp1 suppresses IL-5 and IL-13 production by ILC2s and protects mice from the development of pulmonary fibrosis. Mechanistically, TGFß1-Nrp1 signaling enhances ILC2 function and type 2 immunity by upregulating IL-33 receptor ST2 expression. These findings identify Nrp1 as a tissue-specific regulator of lung-resident ILC2s and highlight Nrp1 as a potential therapeutic target for pulmonary fibrosis.

CDK inhibitor Palbociclib targets STING to alleviate autoinflammation.

Aberrant activation of stimulator of interferon genes (STING) is tightly associated with multiple types of disease, including cancer, infection, and autoimmune diseases. However, the development of STING modulators for the therapy of STING-related diseases is still an unmet clinical need. We employed a high-throughput screening approach based on the interaction of small-molecule chemical compounds with recombinant STING protein to identify functional STING modulators. Intriguingly, the cyclin-dependent protein kinase (CDK) inhibitor Palbociclib was found to directly bind STING and inhibit its activation in both mouse and human cells. Mechanistically, Palbociclib targets Y167 of STING to block its dimerization, its binding with cyclic dinucleotides, and its trafficking. Importantly, Palbociclib alleviates autoimmune disease features induced by dextran sulphate sodium or genetic ablation of three prime repair exonuclease 1 (Trex1) in mice in a STING-dependent manner. Our work identifies Palbociclib as a novel pharmacological inhibitor of STING that abrogates its homodimerization and provides a basis for the fast repurposing of this Food and Drug Administration-approved drug for the therapy of autoinflammatory diseases.

The non-telomeric evolutionary trajectory of TRF2 in zebrafish reveals its specific roles in neurodevelopment and aging.

The shelterin protein complex is required for telomere protection in various eukaryotic organisms. In mammals, the shelterin subunit TRF2 is specialized in preventing ATM activation at telomeres and chromosome end fusion in somatic cells. Here, we demonstrate that the zebrafish ortholog of TRF2 (encoded by the terfa gene) is protecting against unwanted ATM activation genome-wide. The terfa-compromised fish develop a prominent and specific embryonic neurodevelopmental failure. The heterozygous fish survive to adulthood but exhibit a premature aging phenotype. The recovery from embryonic neurodevelopmental failure requires both ATM inhibition and transcriptional complementation of neural genes. Furthermore, restoring the expression of TRF2 in glial cells rescues the embryonic neurodevelopment phenotype. These results indicate that the shelterin subunit TRF2 evolved in zebrafish as a general factor of genome maintenance and transcriptional regulation that is required for proper neurodevelopment and normal aging. These findings uncover how TRF2 links development to aging by separate functions in gene expression regulation and genome stability control.

Limited resection is comparable to lobectomy for tumor size ≤ 2 cm pulmonary invasive mucinous adenocarcinoma.

OBJECTIVES: Invasive mucinous adenocarcinoma (IMA) has a rare incidence with better prognosis than nonmucinous adenocarcinoma. We aimed to investigate the prognosis between limited resection and lobectomy for patients with clinical stage IA IMA ≤ 2 cm. METHODS: Data were taken from two cohorts: In Shanghai Pulmonary Hospital (SPH) corhort, we identified 403 patients with clinical stage IA IMA who underwent surgery. In the SEER corhort, 480 patients with stage T1 IMA who after surgery were included. Recurrence-free survival (RFS) for SPH corhort, lung cancer-specific survival (LCSS) for the SEER corhort and overall survival (OS) for both corhort were compared between patients undergoing lobectomy and limited resection by Log-rank and Cox proportional hazard regression model. RESULTS: In SPH corhort, patients who underwent limited resection had equivalent prognosis than those underwent lobectomy (5-year RFS: 79.3% versus. 82.6%, p = 0.116; 5-year OS: 86.2% versus. 88.3%, p = 0.235). However, patients with IMA > 2 to 3 cm had worse prognosis than those with IMA ≤ 2 cm (5-year RFS: 73.7% versus. 86.1%, p = 0.007). In the analysis of IMA > 2 to 3 cm subgroup, multivariate analysis showed that limited resection was an independent risk factor of RFS (hazard ratio, 2.417; 95% confidence interval, 1.157-5.049; p = 0.019), while OS (p = 0.122) was not significantly different between two groups. For IMA ≤ 2 cm, limited resection was not a risk factor of RFS (p = 0. 953) and OS (p = 0.552). In the SEER corhort, IMA ≤ 2 cm subgroup, limited resection was equivalent prognosis in LCSS (p = 0.703) and OS (p = 0.830). CONCLUSIONS: Limited resection could be a potential surgical option which comparable to lobectomy in patients with clinical stage IA IMA ≤ 2 cm.

Subcellular Expression Patterns of FKBP Prolyl Isomerase 10 (FKBP10) in Colorectal Cancer and Its Clinical Significance.

FKBP10, a member of the FK506-binding protein (FKBP) family, has been implicated in cancer development, although its prognostic function remains controversial. In this study, we analyzed the expression of FKBP10 in tumor tissues using online databases (TCGA) as well as our CRC cohort, and investigated the relationship between its subcellular expression pattern and patient outcomes. Cox regression analysis was used to determine the associations between different subcellular expression patterns of FKBP10 and clinical features of patients. We also discussed the expression level of FKBP10 based on different subcellular expression patterns. Our results showed that FKBP10 was significantly elevated in CRC tissues and exhibited three different subcellular expression patterns which were defined as 'FKBP10-C' (concentrated), 'FKBP10-T' (transitional) and 'FKBP10-D' (dispersive). The FKBP10-D expression pattern was only found in tumor tissues and was associated with unfavorable disease-free survival in CRC patients. High expression levels of FKBP10-C predicted an unfavorable prognosis of recurrence of CRC, while FKBP10-D did not. Our findings suggest that the subcellular expression patterns and expression level of FKBP10 play crucial prognostic roles in CRC, which revealed that FKBP10 may be a viable prognostic and therapeutic target for the diagnosis and treatment of CRC.

Identification of filigree pattern increases the diagnostic accuracy of micropapillary pattern on frozen section for lung adenocarcinoma.

AIMS: The presence of micropapillary (MIP) in early-stage lung adenocarcinoma is associated with a poorer prognosis, especially in patients undergoing sublobectomy. However, data on the sensitivity of frozen section (FS) evaluation of MIP is still limited. We included the concept of a filigree pattern on FS to assess its effect on the diagnostic sensitivity and specificity of MIP, and to verify its prognostic value in stage T1 lung adenocarcinoma. METHODS: A panel of five pathologists evaluated 125 patients with T1 lung adenocarcinoma from January to February 2014 as a study cohort, and 151 patients from January to February 2020 as a validation cohort. The diagnostic accuracy of the filigree and classical micropapillary (cMIP) pattern on FS was investigated. RESULTS: The diagnostic sensitivity of the MIP pattern on FS increased from 43.2% to 65.3% and 56.8% to 81.1% in the study cohort and validation cohort, respectively, and both with good specificity. Filigree not only increased the sensitivity of identifying MIP when there was an absence of cMIP, but also increased the sensitivity when the presence of a minor amount of cMIP. The almost perfect agreement among five pathologists was reached on cMIP and substantial agreement was reached on the filigree in the two cohorts. Moreover, the cMIP and filigree were both correlated with poorer recurrence-free survival (pcMIP = 0.003; pfiligree = 0.032) and overall survival (pcMIP = 0.004; pfiligree = 0.005). CONCLUSIONS: The identification of a filigree may improve the diagnostic sensitivity of the MIP pattern on FS. FS was feasible for the detection of filigree and cMIP patterns in stage T1 lung adenocarcinomas.

Physical exercise rescues cocaine-evoked synaptic deficits in motor cortex.

Drug exposure impairs cortical plasticity and motor learning, which underlies the reduced behavioral flexibility in drug addiction. Physical exercise has been used to prevent relapse in drug rehabilitation program. However, the potential benefits and molecular mechanisms of physical exercise on drug-evoked motor-cortical dysfunctions are unknown. Here we report that 1-week treadmill training restores cocaine-induced synaptic deficits, in the form of improved in vivo spine formation, synaptic transmission, and spontaneous activities of cortical pyramidal neurons, as well as motor-learning ability. The synaptic and behavioral benefits relied on de novo protein synthesis, which are directed by the activation of the mechanistic target of rapamycin (mTOR)-ribosomal protein S6 pathway. These findings establish synaptic functional restoration and mTOR signaling as the critical mechanism supporting physical exercise training in rehabilitating the addicted brain.

Expression of the α7 nAChR Subunit Duplicate Form (CHRFAM7A) Was Down-Regulated in Patients with Intracranial Infection and Reduced Inflammation in in vitro Model by p38 MAPK.

OBJECTIVE: In this study, we investigated that the effects and possible mechanisms of the α7 nAChR subunit duplicate form (CHRFAM7A) affected inflammation in the model of intracranial infection. METHODS: Mice of the model group were injected (intracranial injection) with Staphylococcus aureus. Mouse microglial BV2 cell was exposed with 200 ng of LPS for 4 h. RESULTS: CHRFAM7A mRNA expressions were reduced in patients with intracranial infection. CHRFAM7A mRNA and protein expressions were suppressed in mice with intracranial infection in a time-dependent manner. CHRFAM7A reduced inflammation in mice with intracranial infection. The inhibition of CHRFAM7A reduced inflammation in mice with intracranial infection. CHRFAM7A suppressed p38 MAPK in mice with intracranial infection. The inhibition of p38 MAPK shows the effects of CHRFAM7A in intracranial infection. CONCLUSION: Our data demonstrate that the expression of the CHRFAM7A was down-regulated in patients with intracranial infection and reduced inflammation in in vitro model by p38 MAPK, which suggests the potential role of CHRFAM7A as a diagnostic biomarker for intracranial infection.

Plant cadmium resistance 6 from Salix linearistipularis (SlPCR6) affects cadmium and copper uptake in roots of transgenic Populus.

Phytoextraction in phytoremediation is one of the environmentally friendly methods used for restoring soils contaminated by heavy metals (HMs). The screening and identification of HM-resistant plants and their regulatory genes associated with HM ion transport are the key research aims in this field. In this study, a plant cadmium (Cd) resistance (PCR) gene family member, SlPCR6, was identified in roots of Salix linearistipularis, which exhibits strong HM resistance. The results revealed that SlPCR6 expression was induced in S. linearistipularis roots in response to Cd stress. Furthermore, SlPCR6 was mainly localized on the plasma membrane. Compared with the wild type, SlPCR6 overexpression reduced the Cd and copper (Cu) contents in the transgenic poplar (84 K) and increased its Cd and Cu resistance. The roots of transgenic poplar seedlings had lower net Cd and Cu uptake rates than wild type roots. Further investigation revealed that the transcript levels of multiple HM ion transporters were not significantly different between the roots of the wild type and those of the transgenic poplar. These results suggest that SlPCR6 is directly involved in Cd and Cu transport in S. linearistipularis roots. Therefore, SlPCR6 can serve as a candidate gene to improve the phytoextraction of the HMs Cd and Cu through genetic engineering.

Arabidopsis cold-regulated plasma membrane protein Cor413pm1 is a regulator of ABA response.

Cold-regulated (COR) genes are considered downstream functional genes in the cold-response pathway. However, we identified a plasma membrane-type, AtCor413pm1, as a regulatory gene for the abscisic acid (ABA) response, and found that ABA induced it predominantly in Arabidopsis roots, vasculature, stipules, and guard cells. Differentially expressed genes combined with qPCR analysis revealed the expressions of three ABA-responsive genes (AtDTX50, AtABR1, and AtCIPK20) were significantly altered in the ABA-treated atcor413pm1 mutant, compared to the wild-type. Furthermore, the ABA-induced transient Ca2+ oscillation in the plasma membrane of atcor413pm1 roots was different from that observed in the wild-type. Our results revealed that AtCor413pm1 might play a role in the cross-talk between the ABA and stress response pathways.

The learning curve for uniportal video-assisted thoracoscopic anatomical segmentectomy.

OBJECTIVES: The aim of this study is to evaluate the time course and caseload required to achieve proficiency by plotting the learning curve of uniportal thoracoscopic segmentectomy. METHODS: We retrospectively analyzed the first 238 and 159 cases of uniportal thoracoscopic segmentectomy performed by two surgeons (A and B). The learning curves were assessed using cumulative sum analysis. Perioperative outcomes were evaluated as the learning curve developed. Two subtypes of this surgical approach, simple and complex segmentectomy, were separately analyzed. RESULTS: Based on the learning curve, the inflection points occurred at 64 and 90 cases for surgeon A, 71 and 100 cases for surgeon B. Significantly longer operative time (p = .013), length of stay (p = .002), and drainage duration (p = .039) were observed between phase I and phase II compared to phase III for surgeon A. Operative times (p = .001) were significantly reduced for surgeon B. Furthermore, 26-28 and 52-56 cases were necessary to master the simple and complex segmentectomy, respectively. CONCLUSIONS: A total 64-71 cases were required to master uniportal thoracoscopic segmentectomy and 90-100 cases were necessary to achieve proficiency.

GNAS-AS1/miR-4319/NECAB3 axis promotes migration and invasion of non-small cell lung cancer cells by altering macrophage polarization.

Non-small cell lung cancer (NSCLC) represents for approximately 85% of all lung cancers, which is the most common cancer worldwide. Tumor-associated macrophages (TAM) are crucial for tumor progression, which was widely believed to be mediated by long non-coding RNAs (LncRNAs). We aimed to explore the effect of one LncRNA, GNAS-AS1, in TAM-associated NSCLC progression. Relative mRNA levels were determined by qRT-PCR. Western blot and ELISA were used to detect protein levels. Proliferation in vitro was assessed by MTT and clone formation assays. Migration and invasion of cell lines were evaluated by transwell-based assays. Interaction between molecules was detected by luciferase report assay. GNAS-AS1 expression was dramatically enhanced in TAM, NSCLC cell lines, and clinical tumor tissues, and negatively correlated with overall survival of NSCLC patients. GNAS-AS1 promoted macrophage M2 polarization and NSCLC cell progression via directly inhibiting miR-4319, which could target N-terminal EF-hand calcium binding protein 3 (NECAB3) to inhibit its expression. GNAS-AS1/miR-4319/NECAB3 axis promotes tumor progression of NSCLC by altering macrophage polarization. This novel mechanism may provide potential strategy for NSCLC treatment.

AMPK activation attenuates inflammatory pain through inhibiting NF-κB activation and IL-1ß expression.

BACKGROUND: Chronic pain is a major clinical problem with limited treatment options. Previous studies have demonstrated that activation of adenosine monophosphate-activated protein kinase (AMPK) can attenuate neuropathic pain. Inflammation/immune response at the site of complete Freund's adjuvant (CFA) injection is known to be a critical trigger of the pathological changes that produce inflammatory pain. However, whether activation of AMPK produces an analgesic effect through inhibiting the proinflammatory cytokines, including interleukin-1ß (IL-1ß), in inflammatory pain remains unknown. METHODS: Inflammatory pain was induced in mice injected with CFA. The effects of AICAR (5-aminoimidazole-4-carboxyamide ribonucleoside, an AMPK activator), Compound C (an AMPK inhibitor), and IL-1ra (an IL-1 receptor antagonist) were tested at day 4 after CFA injection. Inflammatory pain was assessed with von Frey filaments and hot plate. Immunoblotting, hematoxylin and eosin (H&E) staining, and immunofluorescence were used to assess inflammation-induced biochemical changes. RESULTS: The AMPK activator AICAR produced an analgesic effect and inhibited the level of proinflammatory cytokine IL-1ß in the inflamed skin in mice. Moreover, activation of AMPK suppressed CFA-induced NF-κB p65 translocation from the cytosol to the nucleus in activated macrophages (CD68+ and CX3CR1+) of inflamed skin tissues. Subcutaneous injection of IL-1ra attenuated CFA-induced inflammatory pain. The AMPK inhibitor Compound C and AMPKα shRNA reversed the analgesic effect of AICAR and the effects of AICAR on IL-1ß and NF-κB activation in inflamed skin tissues. CONCLUSIONS: Our study provides new information that AMPK activation produces the analgesic effect by inhibiting NF-κB activation and reducing the expression of IL-1ß in inflammatory pain.

Anti-inflammatory activity of extensively hydrolyzed casein is mediated by granzyme B.

OBJECTIVE: Nutritional factors such as extensively hydrolyzed casein (eHC) have been proposed to exert anti-inflammatory activity and affect clinical outcomes such as tolerance development in cow's milk allergy. Granzyme B (GrB) induces apoptosis in target cells and also controls the inflammatory response. Whether eHC could affect the activity of granzyme B and play a role in GrB-mediated inflammatory responses in vitro was unknown. METHODS: The activity of GrB was measured using the substrate Ac-IEPD-pNA. Inflammatory responses were induced with GrB in HCT-8 and THP-1 cells, and pro-inflammatory cytokines were determined at the transcriptional and protein level. RESULTS: GrB could induce the expression of IL-1ß in HCT-8 cells, and IL-8 and MCP-1 in THP-1 cells, respectively. Interestingly, GrB acted synergistically on LPS-induced inflammation in HCT-8 cells and eHC reduced pro-inflammatory responses in both GrB and LPS-mediated inflammation. Further analyses revealed that eHC could inhibit the biological activities and cytotoxic activities of GrB and then could reduce GrB-mediated inflammatory response. CONCLUSION: The results from the current study suggest that anti-inflammatory activity of extensively hydrolyzed casein is, to a certain extent, mediated through modulation of granzyme B activity and responses.

Electroacupuncture inhibits visceral pain via adenosine receptors in mice with inflammatory bowel disease.

To investigate the involvement of peripheral adenosine receptors in the effect of electroacupuncture (EA) on visceral pain in mice with inflammatory bowel disease (IBD). 2,4,6-Trinitrobenzene sulfonic acid (TNBS) was used to induce the visceral pain model. EA (1 mA, 2 Hz, 30 min) treatment was applied to bilateral acupoints "Dachangshu" (BL25) 1 day after TNBS injection once daily for 7 consecutive days. Von Frey filaments were used to measure the mechanical pain threshold. Western blot was used to detect the protein expression levels of adenosine 1 receptor (A1R), adenosine 2a receptor (A2aR), adenosine 2b receptor (A2bR), adenosine 3 receptor (A3R), substance P (SP), and interleukin 1 beta (IL-1ß) in colon tissue. EA significantly ameliorated the disease-related indices and reduced the expression of SP and IL-1ß in the colon tissues of mice with IBD. EA increased the expression of A1R, A2aR, and A3R and decreased the expression of A2bR in the colon tissue. Furthermore, the administration of adenosine receptor antagonists influenced the effect of EA. EA can inhibit the expression of the inflammatory factors SP and IL-1ß by regulating peripheral A1, A2a, A2b, and A3 receptors, thus inhibiting visceral pain in IBD mice.

Prevalence and Risk Factors of Acute Pulmonary Embolism in Patients with Lung Cancer Surgery.

Acute pulmonary embolism (PE) is one of the serious complications with high mortality after thoracic surgery. The authors aimed to determine the prevalence of PE events and evaluate additional risk factors for PE in patients with lung cancer surgery. Patients underwent lung cancer resections during January 2012 to July 2015 and had 30-day postoperative follow-up were included. Those with incomplete or miscoded data were excluded. The number of postoperative PE events was recorded retrospectively. Analyses were used to evaluate risk factors of PE during the hospitalization. The authors reviewed 11,474 patients who underwent surgery for lung cancer. The overall 30-day incidence of PE after thoracic surgery at their institution was 0.53%. The 30-day PE incidence without chemical prophylaxis was 0.57% (55/9,726) and the mortality rate was 10%. Multivariate analyses revealed that age over 66 (odds ratio [OR]: 1.09, 95% confidence interval [CI]: 1.05-1.12, p < 0.001), more extensive surgery than lobectomy (OR: 2.34, 95% CI: 1.28-4.25, p = 0.006) and stage IV of lung cancer (OR: 4.22, 95% CI: 1.50-11.9, p = 0.007) were associated with an increased risk of PE. Using these additional risk factors, based on readily available clinical characteristics, can help to risk-stratify patients and warrant extended chemical prophylaxis for patients to reduce the incidence of acute PE.

Early-life exposure to PM2.5 and risk of acute asthma clinical encounters among children in Massachusetts: a case-crossover analysis.

BACKGROUND: Associations between ambient particulate matter < 2.5 µm (PM2.5) and asthma morbidity have been suggested in previous epidemiologic studies but results are inconsistent for areas with lower PM2.5 levels. We estimated the associations between early-life short-term PM2.5 exposure and the risk of asthma or wheeze clinical encounters among Massachusetts children in the innovative Pregnancy to Early Life Longitudinal (PELL) cohort data linkage system. METHODS: We used a semi-bidirectional case-crossover study design with short-term exposure lags for asthma exacerbation using data from the PELL system. Cases included children up to 9 years of age who had a hospitalization, observational stay, or emergency department visit for asthma or wheeze between January 2001 and September 2009 (n = 33,387). Daily PM2.5 concentrations were estimated at a 4-km resolution using satellite remote sensing, land use, and meteorological data. We applied conditional logistic regression models to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CI). We also stratified by potential effect modifiers. RESULTS: The median PM2.5 concentration among participants was 7.8 µg/m3 with an interquartile range of 5.9 µg/m3. Overall, associations between PM2.5 exposure and asthma clinical encounters among children at lags 0, 1 and 2 were close to the null value of OR = 1.0. Evidence of effect modification was observed by birthweight for lags 0, 1 and 2 (p < 0.05), and season of clinical encounter for lags 0 and 1 (p < 0.05). Children with low birthweight (LBW) (< 2500 g) had increased odds of having an asthma clinical encounter due to higher PM2.5 exposure for lag 1 (OR: 1.08 per interquartile range (IQR) increase in PM2.5; 95% CI: 1.01, 1.15). CONCLUSION: Asthma or wheeze exacerbations among LBW children were associated with short-term increases in PM2.5 concentrations at low levels in Massachusetts.

Correction to: Early-life exposure to PM2.5 and risk of acute asthma clinical encounters among children in Massachusetts: a case-crossover analysis.

After publication of the article [1], it was brought to our attention that a number in Table 1 is incorrect.

Knockout of P2Y12 aggravates experimental autoimmune encephalomyelitis in mice via increasing of IL-23 production and Th17 cell differentiation by dendritic cells.

Experimental autoimmune encephalomyelitis (EAE), a common model of multiple sclerosis (MS), is mainly mediated by CD4+ T cells with demyelination and neurodegeneration of central nervous system (CNS). The loss of P2Y12 receptor might be associated with the pathogenesis of MS/EAE, but its potential mechanism is still not clear. In this study, more severe EAE developed in P2Y12-knockout (P2Y12-KO) mice compared to WT mice. Knockout of P2Y12 increased expression of IL-17A in the sera and proportion of Th17 cells in spleen and CNS. However, in vitro studies showed that P2Y12 did not influence cell differentiation and proliferation of CD4+ T cells. In bone marrow-derived dendritic cells (BMDCs), loss of P2Y12 significantly increased the production of IL-23 in contrast to the wild-type (WT) BMDCs. FACS analysis indicated that the culture supernatant from P2Y12-deficient DCs promoted more naïve CD4+ T cells to differentiate into Th17 cells. Our finding demonstrated that genetic deletion of P2Y12 receptor broke the balance of Th subtypes by affecting the cytokine profile of BMDCs and resulted in the aggravated EAE, which suggested that P2Y12 may be a potential target in treating MS.

Estimating PM2.5 Concentrations in the Conterminous United States Using the Random Forest Approach.

To estimate PM2.5 concentrations, many parametric regression models have been developed, while nonparametric machine learning algorithms are used less often and national-scale models are rare. In this paper, we develop a random forest model incorporating aerosol optical depth (AOD) data, meteorological fields, and land use variables to estimate daily 24 h averaged ground-level PM2.5 concentrations over the conterminous United States in 2011. Random forests are an ensemble learning method that provides predictions with high accuracy and interpretability. Our results achieve an overall cross-validation (CV) R2 value of 0.80. Mean prediction error (MPE) and root mean squared prediction error (RMSPE) for daily predictions are 1.78 and 2.83 µg/m3, respectively, indicating a good agreement between CV predictions and observations. The prediction accuracy of our model is similar to those reported in previous studies using neural networks or regression models on both national and regional scales. In addition, the incorporation of convolutional layers for land use terms and nearby PM2.5 measurements increase CV R2 by ∼0.02 and ∼0.06, respectively, indicating their significant contributions to prediction accuracy. A pair of different variable importance measures both indicate that the convolutional layer for nearby PM2.5 measurements and AOD values are among the most-important predictor variables for the training process.