Characterization of a glycosyltransferase from Paris polyphylla for application in biosynthesis of rare ophiopogonins and ginsenosides.

Saponins are bioactive components of many medicinal plants, possessing complicated chemical structures and extensive pharmacological activities, but the production of high-value saponins remains challenging. In this study, a 6'-O-glucosyltransferase PpUGT7 (PpUGT91AH7) was functionally characterized from Paris polyphylla Smith var. yunnanensis (Franch.) Hand. -Mazz., which can transfer a glucosyl group to the C-6' position of diosgenin-3-O-rhamnosyl-(1 â†’ 2)-glucoside (1), pennogenin-3-O-rhamnosyl-(1 â†’ 2)-glucoside (2), and diosgenin-3-O-glucoside (5). The KM and Kcat values of PpUGT7 towards the substrate 2 were 8.4 µM and 2 × 10-3 s-1, respectively. Through molecular docking and site-directed mutagenesis, eight residues were identified to interact with the sugar acceptor 2 and be crucial for enzyme activity. Moreover, four rare ophiopogonins and ginsenosides were obtained by combinatorial biosynthesis, including an undescribed compound ruscogenin-3-O-glucosyl-(1 â†’ 6)-glucoside (10). Firstly, two monoglycosides 9 and 11 were generated using a known sterol 3-O-ß-glucosyltransferase PpUGT80A40 with ruscogenin (7) and 20(S)-protopanaxadiol (8) as substrates, which were further glycosylated to the corresponding diglycosides 10 and 12 under the catalysis of PpUGT7. In addition, compounds 7-11 were found to show inhibitory effects on the secretion of TNF-α and IL-6 in macrophages RAW264.7. The findings provide valuable insights into the enzymatic glycosylation processes in the biosynthesis of bioactive saponins in P. polyphylla var. yunnanensis, and also serve as a reference for utilizing UDP-glycosyltransferases to construct high-value or rare saponins for development of new therapeutic agents.

Exploration of the profiles of steroidal saponins from Rhizoma Paridis and their metabolites in rats by UPLC-Q-TOF-MS/MS.

INTRODUCTION: Steroidal saponins characterised by intricate chemical structures are the main active components of a well-known traditional Chinese medicine (TCM) Rhizoma Paridis. The metabolic profiles of steroidal saponins in vivo remain largely unexplored, despite their renowned antitumor, immunostimulating, and haemostatic activity. OBJECTIVE: To perform a comprehensive analysis of the chemical constituents of Rhizoma Paridis total saponins (RPTS) and their metabolites in rats after oral administration. METHOD: The chemical constituents of RPTS and their metabolites were analysed using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS). RESULTS: A reliable UPLC-Q-TOF-MS/MS method was established, and a total of 142 compounds were identified in RPTS. Specifically, diosgenin-type saponins showed the diagnostic ions at m/z 415.32, 397.31, 283.25, 271.21, and 253.20, whereas pennogenin-type saponins exhibited the diagnostic ions at m/z 413.31, 395.30, and 251.20. Based on the characteristic fragments and standard substances, 15 specific metabolites were further identified in the faeces, urine, plasma, and bile of rats. The metabolic pathways of RPTS, including phase I reactions (de-glycosylation and oxidation) and phase II reactions (glucuronidation), were explored and summarised, and the enrichment of metabolites was characterised by multivariate statistical analysis. CONCLUSION: The intricate RPTS could be transformed into relatively simple metabolites in rats through de-glycosylation, which provides a reference for further metabolic studies and screening of active ingredients for TCM.

Structure-switching aptasensors for sensitive detection of ochratoxin A.

Ochratoxin A (OTA) is a toxic metabolite commonly found in various foods and feedstuffs. Accurate and sensitive detection of OTA is needed for food safety and human health. Based on a common OTA-binding aptamer (OTABA), two structure-switching OTABAs, namely OTABA4 and OTABA3, were designed by configuring a split G-quadruplex and a split G-triplex, respectively, at the two ends of OTABA to construct aptasensors for the detection of OTA. The OTABA, G-quadruplex, and G-triplex all can capture the thioflavin T (ThT) probe, thereby enhancing the fluorescence intensity of ThT. Bonding with OTA could change the conformations of OTABA and G-quadruplex or G-triplex regions, resulting in the release of the captured ThT and diminution of its fluorescence intensity. Dual conformation changes in structure-switching OTABA synergistically amplified the fluorescence signal and improved the sensitivity of the aptasensor, especially for that with OTABA3. The detection limits of the OTABA4-ThT and OTABA3-ThT systems for OTA were 0.28 and 0.059 ng ml-1 , with a 1.4-fold and 6.7-fold higher sensitivity than that of the original OTABA-ThT system, respectively. They performed well in corn and peanut samples and met the requirements of the food safety inspections.

A G-triplex and G-quadruplex concatemer-enhanced fluorescence probe coupled with hybridization chain reaction for ultrasensitive aptasensing of ochratoxin A.

Ochratoxin A (OTA), a typical mycotoxin contaminant found in various agricultural products and foods, poses a serious threat to human health. In this study, an aptasensor based on a novel fluorescence probe comprising a G-rich DNA sequence (G43) and thioflavin T (ThT) was designed via hybridization chain reaction (HCR) for the ultrasensitive detection of OTA. G43 is a concatemer of G-quadruplex and G-triplex (a G-quadruplex-like structure with one G-quartet removed), which can drastically enhance the fluorescence intensity of ThT. For this strategy to work, the OTA aptamer is pro-locked in a hairpin structure, denoted "hairpin-locked aptamer" (HL-Apt). OTA binds to HL-Apt, opens the hairpin structure, releases the trigger sequence, and initiates the HCR reaction to form a long DNA duplex and numerous side chains. The side chains combine entirely with the complementary DNA and liberate the pro-locked G43 DNA, dramatically enhancing the intensity of the ThT fluorescence signal. The fluorescence intensity correlates linearly with the OTA concentration between 0.02 and 2.00 ng mL-1, and the method has a detection limit of 0.008 ng mL-1. The developed aptasensor was used to detect OTA in foodstuffs with satisfactory results.

A DMD case caused by X chromosome rearrangement.

Duchenne/Becker muscular dystrophy (DMD/BMD) is one of the most common progressive muscular dystrophy diseases with X-linked recessive inheritance. It is mainly caused by the deletion, duplication and point mutation of DMD gene. In rare cases, it is also caused by the destruction of DMD gene by chromosomal structural rearrangement. Here, we report a case of Duchenne/Becker Muscular dystrophy (DMD/BMD) with typical symptoms but unknown genetic defects after MLPA and next generation sequencing tests in other hospitals. Interestingly, we find a pericentric inversion of X chromosome (Chr.X: g. [31939463-31939465del; 31939466-131765063 inv; 131765064-131765067del]) in this patient. We then use the karyotyping, FISH, long-read sequencing and Sanger sequencing technologies to characterize the chromosome rearrangement. We find that this chromosomal aberration disrupt both the DMD gene and the HS6ST2 gene. The patient present with typical DMD symptoms such as muscle weakness, but no obvious symptoms of Paganini-Miozzo syndrome. Our results suggest that the destruction of DMD gene by structural rearrangement is also one of the important causes of DMD. Therefore, we suggest to provide further genetic testing for those DMD patients with unknown genetic defects through routine genetic testing. Cost-effective karyotyping and FISH should be considered firstly to identify chromosome rearrangements. Long-read sequencing followed by Sanger sequencing could be useful to locate the precise breakpoints. The genetic diagnosis of this case made it possible for reproductive intervention in the patient's family.

Fluorinated magnetic porous carbons for dispersive solid-phase extraction of perfluorinated compounds.

Novel magnetic and fluorinated porous carbons (M-FPCs) with high fluorine content, large pore volume and specific surface area were first prepared by carbonizing and further fluorinating Fe-Zr bimetal-organic frameworks. The M-FPCs exhibit excellent adsorption performance toward perfluorinated compounds (PFCs), and the maximal adsorption capacity ranges from 518.1 to 919.3 mg g-1 for various PFCs. Based on this property, an environmental analytical method of dispersive solid-phase extraction (DSPE) using M-FPCs as adsorbents coupled with ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS) was developed for the detection of trace PFCs. The linear range was as wide as 10-200 ng L-1, and low limit of detection (0.02-0.16 ng L-1) and good precision (relative standard deviation less than 6.11% for intra-day and inter-day) were achieved. This method was applied to the detection of trace PFCs in environmental water and soil samples with satisfactory results.

MutS functions as a clamp loader by positioning MutL on the DNA during mismatch repair.

Highly conserved MutS and MutL homologs operate as protein dimers in mismatch repair (MMR). MutS recognizes mismatched nucleotides forming ATP-bound sliding clamps, which subsequently load MutL sliding clamps that coordinate MMR excision. Several MMR models envision static MutS-MutL complexes bound to mismatched DNA via a positively charged cleft (PCC) located on the MutL N-terminal domains (NTD). We show MutL-DNA binding is undetectable in physiological conditions. Instead, MutS sliding clamps exploit the PCC to position a MutL NTD on the DNA backbone, likely enabling diffusion-mediated wrapping of the remaining MutL domains around the DNA. The resulting MutL sliding clamp enhances MutH endonuclease and UvrD helicase activities on the DNA, which also engage the PCC during strand-specific incision/excision. These MutS clamp-loader progressions are significantly different from the replication clamp-loaders that attach the polymerase processivity factors ß-clamp/PCNA to DNA, highlighting the breadth of mechanisms for stably linking crucial genome maintenance proteins onto DNA.

Observing Protein One-Dimensional Sliding: Methodology and Biological Significance.

One-dimensional (1D) sliding of DNA-binding proteins has been observed by numerous kinetic studies. It appears that many of these sliding events play important roles in a wide range of biological processes. However, one challenge is to determine the physiological relevance of these motions in the context of the protein's biological function. Here, we discuss methods of measuring protein 1D sliding by highlighting the single-molecule approaches that are capable of visualizing particle movement in real time. We also present recent findings that show how protein sliding contributes to function.

Fluorescence polarization assay improves the rapid detection of human brucellosis in China.

BACKGROUND: Brucellosis is an infectious-allergic zoonotic disease caused by bacteria of the genus Brucella. Early diagnosis is the key to preventing, treating, and controlling brucellosis. Fluorescence polarization immunoassay (FPA) is a new immunoassay for relatively rapid and accurate detection of antibodies or antigens based on antigen-antibody interaction. However, there is no report on FPA-based detection of human brucellosis in China. Therefore, this study is to evaluate the value of FPA for the diagnosis of human brucellosis in China. METHODS: We recruited 320 suspected brucellosis cases who had the clinical symptoms and epidemiological risk factors between January and December, 2019. According to China Guideline for Human Brucellosis Diagnosis, the Rose Bengal test (RBT) was used for the screening test, and the serum agglutination test (SAT) was used as the confirmatory test. Brucellosis was confirmed only if the results of both tests were positive. Additionally, FPA and enzyme linked immune sorbent assay (ELISA) were compared with SAT, and their sensitivity, specificity, coincidence rate and consistency coefficient (Kappa value) as diagnostic tests were analyzed individually and in combination. The optimal cut-off value of FPA was also determined using the receiver operator characteristic (ROC) curve. RESULTS: The optimum cut-off value of FPA was determined to be 88.5 millipolarization (mP) units, with a sensitivity of 94.5% and specificity of 100.0%. Additionally, the coincidence rate with the SAT test was 96.6%, and the Kappa value (0.9) showed excellent consistency. The sensitivity and specificity of FPA and ELISA combined were higher at 98.0% and 100.0% respectively. CONCLUSIONS: When the cut-off value of FPA test is set at 88.5 mP, it has high value for the diagnosis of brucellosis. Additionally, when FPA and ELISA are combined, the sensitivity of diagnosis is significantly improved. Thus, FPA may have potential in the future as a diagnostic method for human brucellosis in China.

Molecular characteristics of Brucella melitensis isolates from humans in Qinghai Province, China.

BACKGROUND: The prevalence of human brucellosis in Qinghai Province of China has been increasing rapidly, with confirmed cases distributed across 31 counties. However, the epidemiology of brucellosis transmission has not been fully elucidated. To characterize the infecting strains isolated from humans, multiple-locus variable-number tandem repeats analysis (MLVA) and whole-genome single-nucleotide polymorphism (SNP)-based approaches were employed. METHODS: Strains were isolated from two males blood cultures that were confirmed Brucella melitensis positive following biotyping and MLVA. Genomic DNA was extracted from these two strains, and whole-genome sequencing was performed. Next, SNP-based phylogenetic analysis was performed to compare the two strains to 94 B. melitensis strains (complete genome and draft genome) retrieved from online databases. RESULTS: The two Brucella isolates were identified as B. melitensis biovar 3 (QH2019001 and QH2019005) following conventional biotyping and were found to have differences in their variable number tandem repeats (VNTRs) using MLVA-16. Phylogenetic examination assigned the 96 strains to five genotype groups, with QH2019001 and QH2019005 assigned to the same group, but different subgroups. Moreover, the QH2019005 strain was assigned to a new subgenotype, IIj, within genotype II. These findings were then combined to determine the geographic origin of the two Brucella strains. CONCLUSIONS: Utilizing a whole-genome SNP-based approach enabled differences between the two B. melitensis strains to be more clearly resolved, and facilitated the elucidation of their different evolutionary histories. This approach also revealed that QH2019005 is a member of a new subgenotype (IIj) with an ancient origin in the eastern Mediterranean Sea.

Lingual Linear Lesions: A Clinical Sign Strongly Suggestive of Severe Vitamin B12 Deficiency.

BACKGROUND: Lingual linear lesions (LLLs) are the oral linear lesions located on the dorsum, lateral borders, and/or ventral surface of tongue. It has been suggested that LLLs might be an early clinical sign of vitamin B12 deficiency. Here, a retrospective study was conducted to further investigate and validate the association between LLL and vitamin B12 deficiency. METHODS: Based on the clinical examination, patients with LLLs were enrolled and analyzed retrospectively. Data regarding clinical and laboratory features were obtained. Follow-up was done at least 6 months following appropriate supplementation therapy. RESULTS: A total of 57 patients, consisting of 20 males and 37 females with a mean age of 59.12 years (range, 18-80), were enrolled in this study. The hematological examination revealed that 56 (98.25%) of the 57 patients had severe serum vitamin B12 deficiency, and the other 1 patient had a borderline low level of vitamin B12 . All the enrolled patients responded well to cobalamin replacement therapy. CONCLUSION: LLLs might be a clinical sign strongly suggestive of severe vitamin B12 deficiency.

The profile of hematinic deficiencies in patients with oral lichen planus: a case-control study.

BACKGROUND: Oral lichen planus (OLP) is a relatively common mucocutaneous disorder, and its causative factors and pathogenesis are not fully understood. Existing studies on the association between hematinic deficiencies and OLP are limited and inconsistent. The aim of this study was to assess the hematinic deficiencies in a cohort of OLP patients and evaluate the correlation between hematinic deficiencies and OLP. METHODS: A total of 236 OLP patients and 226 age-and-gender-matched healthy controls were enrolled in this study. The levels of hemoglobin (Hb), serum folate, vitamin B12 and ferritin were measured and compared between OLP patients and healthy controls. An REU (reticular/hyperkeratotic, erosive/erythematous, ulcerative) scoring system was adopted and compared between the OLP patients with and without hematinic deficiencies. The correlation between hematinic deficiencies and OLP was analyzed. RESULTS: The frequencies of serum ferritin and vitamin B12 deficiency in OLP patients were both significantly higher than those of the healthy controls. According to gender and age, the profiles of hematinic deficiencies in OLP patients were significantly different. As for the REU score, no significant difference existed between OLP patients with and without hematinic deficiencies. Both serum ferritin deficiency and serum vitamin B12 deficiency were significantly correlated with OLP. CONCLUSIONS: The present study suggested a significant association between hematinic deficiencies and OLP. Iron, folate, and vitamin B12 levels in OLP patients should be monitored routinely. Further studies are warranted to explore the interactions between OLP and hematinic deficiencies.

[Downregulation of SND1 Expression Accelerates Cell Senescence of Human Diploid Fibroblasts 2BS via Modulating the SASP].

OBJECTIVE: To investigate the effect of down-regulation of SND1 expression on senescence of human diploid fibroblasts. METHODS: Western blot and immunohistochemistry were used to detect the expression of SND1 in young or senescent 2BS cells and aged tissues. Immunofluorescence was conducted to detect the localization of SND1 in young 2BS cells. CCK8 and EDU were performed to detect the proliferation of 2BS. Colony formation analysis was used to evaluate the capacity of colony formation of 2BS. Expression chip and RT-qPCR analysis were performed to detect the change of SASP expression level. ß-galactosidase staining was employed to indicate the senescent 2BS cells. RESULTS: The expression of SND1 in the senescent 2BS cells was significantly down-regulated compared with in the younger 2BS cells, and in human colon adenomas, its expression was also significantly down-regulated compared with in non-lesion colon tissues. In young 2BS, knockdown of SND1 inhibited the proliferation and colony formation of 2BS, and led to stronger senescence-associated beta-galactosidase staining (SA-ß-gal). Expression chip and RT-qPCR analysis indicated that knockdown of SND1 up-regulated the expression of senescence-associated secretory phenotype components (SASP). CONCLUSIONS: Our data indicated that down-regulation of SND1 regulated human diploid cell senescence by up-regulating the expression of SASP components.

[Concentration Characteristics of PM2.5 and the Causes of Heavy Air Pollution Events in Beijing During Autumn and Winter].

To study the changing of characteristics and formation mechanisms of PM2.5 in Beijing during the last two years, particulate matter concentrations, weather conditions, and air-mass trajectories were analyzed during severe pollution episodes in fall and winter 2016-2017 using routine observations and the TrajStat model. Results showed that 13 heavy pollution events, each lasting at least two days, occurred in Beijing. Of these, approximately 61.5% occurred in winter, characterized by heavier pollution concentrations and longer durations than those occurring in autumn. A low-pressure gradient, high humidity, low surface wind speed, low boundary layer, and particular terrain (i. e., being surrounded by mountains on three sides) all contributed to the high occurrence frequency of severe pollution episodes in autumn and winter. During the pollution episodes, the average ratio of PM2.5 to PM10 reached 0.86. The air-masses during the accumulation stage were mainly transported from the northwest, west, southwest, and southeast of Beijing. The southwestern and southeastern transmission paths accounted for 21.6% of the total pollution load. In addition, the WRF-CAMx model was used to quantitatively analyze the contributions of local and external sources to the concentrations of PM2.5 in Beijing during 16-22 December 2016. Based on this analysis, PM2.5 contributions notably varied with different air-masses; in the case of southern air-masses, external sources dominated the PM2.5 concentrations in Beijing and local contributions decreased rapidly; in contrast, in the case of northwestern air-masses, the opposite pattern occurred. Overall, the contribution of local sources to PM2.5 concentrations in Beijing varied from 16.5% to 69.3% during the monitored pollution episodes.

Novel inactivating mutations in the FSH receptor cause premature ovarian insufficiency with resistant ovary syndrome.

RESEARCH QUESTION: What is the genetic aetiology of three resistant ovary syndrome (ROS) pedigrees from 13 Chinese Han families with non-syndromic premature ovarian insufficiency (POI). DESIGN: The proband in each family was subjected to whole-exome sequencing. Bioinformatic and in-vitro functional analyses were performed for the functional characterization of the FSHR mutations. RESULTS: Four novel mutations, two homozygous mutations (c.419delA, c.1510C>T), and a compound heterozygous mutation (c.44G>A and deletion of exons 1 and 2) of FSHR were identified in the three non-syndromic POI-with-ROS families. Bioinformatic analysis predicted that the three novel point mutations in FSHR are deleterious and associated with POI in the three families, which was confirmed by in-vitro functional analysis, in which FSH-induced adenosine 3',5'-cyclic monophosphate production was abolished for all receptors. CONCLUSIONS: The three novel point mutations in FSHR were all functional inactivating mutations, and were the genetic aetiology of the three non-syndromic POI-with-ROS families. The first FSHR frameshift mutation is reported here, and the first missense mutation in the signal peptide-encoding region of FSHR to be associated with POI. Women affected by ROS should consider undergoing mutation screening for FSHR.

Novel FOXL2 mutations cause blepharophimosis-ptosis-epicanthus inversus syndrome with premature ovarian insufficiency.

BACKGROUND: Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is a malformation of the eyelids. Forkhead Box L2 (FOXL2) is the only gene known to be associated with BPES. METHODS: We identified two Han Chinese BPES families with premature ovarian insufficiency (POI). Sanger sequencing and in vitro functional analysis were performed to identify the genetic cause. RESULTS: Sanger sequencing identified two novel mutations (c.462_468del, c.988_989insG) in FOXL2, one in each family. The in vitro functional analysis confirmed that both novel mutations were associated with impaired transactivation of downstream genes. Specifically, the single-base insertion, c.988_989insG, led to subcellular mislocalization and aggregation of the encoded protein, which validated the hypothesis that the two novel FOXL2 mutations are deleterious and associated with POI in the two BPES families. CONCLUSION: The novel mutations identified in the present study will enhance the present knowledge of the mutation spectrum of FOXL2. The in vitro experiments provide further insights into the molecular mechanism by which the two new variants mediate disease pathogenesis and may contribute to elucidating the genotype-phenotype correlation between the two novel FOXL2 mutations and POI.

Discovery of Novel Nucleotide Prodrugs with Improved Potency Against HCV Variants Carrying NS5B S282T Mutation.

Resistant HCV variants carrying NS5B S282T mutation confer reduced sensitivity to sofosbuvir, the sole marketed NS5B polymerase inhibitor. On the basis of the finding that 2'-α-F-2'-ß-C-methylcytidine 5'-triphosphate (8) was more potent than sofosbuvir's active metabolite on inhibition of both wild-type and S282T mutant polymerase, a dual-prodrug approach has been established. Twenty-nine phosphoramidates with N4-modified cytosine were designed, synthesized, and evaluated for anti-HCV activity. The results showed that compounds 4c-4e and 4m (EC50 = 0.19-0.25 µM) exhibited comparable potency to that of sofosbuvir (EC50 = 0.15 µM) on inhibition of wild-type replicons. Notably, 4c (EC50 = 0.366 µM) was 1.5-fold more potent than sofosbuvir (EC50 = 0.589 µM) on inhibition of S282T mutant replicons. In vitro metabolic studies disclosed the possible metabolic pathways of 4c. The toxicity study results indicated a good safety profile of 4c. Together, 4c-4e and 4m hold promise for drug development for the treatment of HCV infection, especially the resistant variants with NS5B S282T mutation.

The complete mitochondrial genome of Papilio polytes (Lepidoptera Papilionidae).

The complete sequence mitochondrial genome of Papilio polytes was determined using long PCR and conserved primers walking approaches. The genome was 15,260 bp in length and contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 control region (CR). The gene composition and order of P. polytes were similar to other lepidopteran species. All protein-coding genes begin with ATG and ATT as initiation codon except COI using CGA. 8 genes (ATP8, ATP6, ND3, ND5, ND4L, ND6, Cytb and ND1) ended with TAA and TAG stop codon, the remaining five genes had incomplete stop codon T. The overall base composition of the genome in descending order was 39.51% A, 11.86% C, 40.75% T and 7.88% G, with a A + T bias of 80.26%. CR is located between the 12S rRNA and tRNA-Met genes and is 439 bp in length, with an AT content of 83.37%.

The complete mitochondrial genome of Papilio bianor (Lepidoptera: Papilionidae), and its phylogenetic position within Papilionidae.

The complete mitochondrial genome sequence of Papilio bianor was determined in the present paper. The complete mtDNA from P. bianor was 15,358 base pairs in length and contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes and a control region. The P. bianor genes were in the same order and orientation as the completely sequenced mitogenomes of other lepidopteran species. To determine the phylogentic position of P. bianor with related species within Papilionidae, the Bayesian phylogenetic tree was reconstructed with the concatenated nucleotide dataset of the 13 protein-coding genes. The phylogenetic trees confirmed that P. bianor and four species of Papilionidae clustered into a clade, and shared a close relationship with Papilio maraho. Meanwhile, the molecular phylogenetic trees also confirmed that Papilionidae is a monophyletic group, and Pieridae is closely related with Lycaenidae and Nymphalidae.

[Air Pollutant Emission Inventory and Impact of Typical Industries on PM2.5 in Chengde].

In this study, detailed activity level of typical sector in Chengde in 2013 was obtained through a full-coverage investigation. A comprehensive emission inventory with country-level resolution in 2013 was developed based on guide of atmospheric pollutant emission inventory and updated emission factors. Then, the emission inventory within 1 km×1 km grid was generated using source-based spastial surrogates including population, road network and landuse date. Furthemore, meteorology-air quality modeling system (WRF-CMAx) including Particulate Source Apportionment Technology (PSAT) module was established in order to evaluate the impact of topical sector (e. g., electric power, the production of construction materials, the metallurgical industry, etc.) on PM2.5 concentration in January, April, July and October which were considered as the representative months of winter, spring, summer and autumn. The results showed the total emission of SO2, NOx, TSP, PM10, PM2.5, CO, VOCs and NH3 in Chengde in 2013 was respectively 81134 t, 72556 t, 368750 t, 119974 t, 51152 t, 1281371 t, 170642 t and 81742 t. Industrial source was the main emission contributor of SO2, NOx, CO, VOCs, accounting for 89.5%, 51.9%, 82.5% and 45.6% of total emissions, respectively. The major emission source of NOx also included on-road and non-road mobile source, respectively accounting for 26.7% and 10.8%. The major emission source of TSP, PM10 and PM2.5 was fugitive dust, accounting for 76.7%, 65.6% and 46.54%, respectively. Ammonia emissions from animals and farm accounted for 67.1% and 15.8% of total emissions, respectively. The numerical simulation result showed that the fugitive dust, the others, the metallurgical industry and boilers industry had relatively higher contributions to PM2.5 concentration, accounting for 23.1%, 20.6%, 13.3% and 11.2%, respectively. These emission sources should be paid more attention during the decision-making with respect to control strategies.