Cross-talk of MLST and transcriptome unveiling antibiotic resistance mechanism of carbapenem resistance Acinetobacter baumannii clinical strains isolated in Guiyang, China.

Introduction: Acinetobacter baumannii (A. baumannii) is an important opportunistic pathogen causing nosocomial infection in the clinic. The occurrence rate of antibiotic resistance is increasing year by year, resulting in a highly serious situation of bacterial resistance. Methods: To better understand the local epidemiology of multidrug-resistant A. baumannii, an investigation was conducted on the antibiotic resistance of different types of A. baumannii and its relationship with the genes of A. baumannii. Furthermore, the molecular mechanism underlying antibiotic resistance in A. baumannii was investigated through transcriptome analysis. Results: These results showed that a total of 9 STs were detected. It was found that 99% of the strains isolated in the hospital belonged to the same STs, and the clone complex CC208 was widely distributed in various departments and all kinds of samples. Furthermore, these A. baumannii strains showed high resistance to ertapenem, biapenem, meropenem, and imipenem, among which the resistance to ertapenem was the strongest. The detection rate of bla OXA-51 gene in these carbapenem resistance A. baumannii (CRAB) reached 100%; Additionally, the transcriptome results showed that the resistance genes were up-regulated in resistance strains, and these genes involved in biofilm formation, efflux pumps, peptidoglycan biosynthesis, and chaperonin synthesis. Discussion: These results suggest that the CC208 STs were the main clonal complex, and showed high carbapenem antibiotic resistance. All these resistant strains were distributed in various departments, but most of them were distributed in intensive care units (ICU). The bla OXA-23 was the main antibiotic resistance genotype; In summary, the epidemic trend of clinical A. baumannii in Guiyang, China was analyzed from the molecular level, and the resistance mechanism of A. baumannii to carbapenem antibiotics was analyzed with transcriptome, which provided a theoretical basis for better control of A. baumannii.

FTY720 ameliorates experimental MPO-ANCA-associated vasculitis by regulating fatty acid oxidation via the neutrophil PPARα-CPT1a pathway.

OBJECTIVES: Increasing studies demonstrated the importance of C5a and anti-neutrophil cytoplasmic antibody (ANCA)-induced neutrophil activation in the pathogenesis of ANCA-associated vasculitis (AAV). Sphingosine-1-phosphate (S1P) acts as a downstream effector molecule of C5a and enhances neutrophil activation induced by C5a and ANCA. The current study investigated the role of a S1P receptor modulator FTY720 in experimental autoimmune vasculitis (EAV) and explored the immunometabolism-related mechanisms of FTY720 in modulating ANCA-induced neutrophil activation. METHODS: The effects of FTY720 in EAV were evaluated by quantifying hematuria, proteinuria, crescent formation, tubulointerstitial injury and pulmonary hemorrhage. RNA sequencing of renal cortex and gene enrichment analysis were performed. The proteins of key identified pathways were analyzed in neutrophils isolated from peripheral blood of patients with active AAV and normal controls. We assessed the effects of FTY720 on ANCA-induced neutrophil respiratory burst and neutrophil extracellular traps formation (NETosis). RESULTS: FTY720 treatment significantly attenuated renal injury and pulmonary hemorrhage in EAV. RNA sequencing analyses of renal cortex demonstrated enhanced fatty acid oxidation (FAO) and peroxisome proliferators-activated receptors (PPAR) signalling in FTY720-treated rats. Compared with normal controls, patients with active AAV showed decreased FAO in neutrophils. FTY720-treated differentiated HL-60 cells showed increased expression of carnitine palmitoyltransferase 1A (CPT1a) and PPARα. Blocking or knockdown of CPT1a or PPARα in isolated human neutrophils and HL-60 cells reversed the inhibitory effects of FTY720 on ANCA-induced neutrophil respiratory burst and NETosis. CONCLUSION: FTY720 attenuated renal injury in EAV through upregulating FAO via the PPARα-CPT1a pathway in neutrophils, offering potential immunometabolic targets in AAV treatment.

Landform and lithospheric development contribute to the assembly of mountain floras in China.

Although it is well documented that mountains tend to exhibit high biodiversity, how geological processes affect the assemblage of montane floras is a matter of ongoing research. Here, we explore landform-specific differences among montane floras based on a dataset comprising 17,576 angiosperm species representing 140 Chinese mountain floras, which we define as the collection of all angiosperm species growing on a specific mountain. Our results show that igneous bedrock (granitic and karst-granitic landforms) is correlated with higher species richness and phylogenetic overdispersion, while the opposite is true for sedimentary bedrock (karst, Danxia, and desert landforms), which is correlated with phylogenetic clustering. Furthermore, we show that landform type was the primary determinant of the assembly of evolutionarily older species within floras, while climate was a greater determinant for younger species. Our study indicates that landform type not only affects montane species richness, but also contributes to the composition of montane floras. To explain the assembly and differentiation of mountain floras, we propose the 'floristic geo-lithology hypothesis', which highlights the role of bedrock and landform processes in montane floristic assembly and provides insights for future research on speciation, migration, and biodiversity in montane regions.

Which contributes more to the relict flora distribution pattern in East Asia, geographical processes or climate change? New evidence from the phylogeography of Rehderodendron kwangtungense.

BACKGROUND: Relict species are important for enhancing the understanding of modern biogeographic distribution patterns. Although both geological and climatic changes since the Cenozoic have affected the relict flora in East Asia, the contributions of geographical processes remain unclear. In this study, we employed restriction-site associated DNA sequencing (RAD-seq) and shallow genome sequencing data, in conjunction with ecological niche modeling (ENM), to investigate the spatial genetic patterns and population differentiation history of the relict species Rehderodendron kwangtungense Chun. RESULTS: A total of 138 individuals from 16 populations were collected, largely covering the natural distribution of R. kwangtungense. The genetic diversity within the R. kwangtungense populations was extremely low (HO = 0.048 ± 0.019; HE = 0.033 ± 0.011). Mantel tests revealed isolation-by-distance pattern (R2 = 0.38, P < 0.001), and AMOVA analysis showed that the genetic variation of R. kwangtungense occurs mainly between populations (86.88%, K = 7). Between 23 and 21 Ma, R. kwangtungense underwent a period of rapid differentiation that coincided with the rise of the Himalayas and the establishment of the East Asian monsoon. According to ENM and population demographic history, the suitable area and effective population size of R. kwangtungense decreased sharply during the glacial period and expanded after the last glacial maximum (LGM). CONCLUSION: Our study shows that the distribution pattern of southern China mountain relict flora may have developed during the panplain stage between the middle Oligocene and the early Miocene. Then, the flora later fragmented under the force of orogenesis, including intermittent uplift during the Cenozoic Himalayan orogeny and the formation of abundant rainfall associated with the East Asian monsoon. The findings emphasized the predominant role of geographical processes in shaping relict plant distribution patterns.

Chromosome-scale genome assembly and annotation of Cotoneaster glaucophyllus.

Cotoneaster glaucophyllus is a semi-evergreen plant that blossoms in late summer, producing dense, attractive, fragrant white flowers with significant ornamental and ecological value. Here, a chromosome-scale genome assembly was obtained by integrating PacBio and Illumina sequencing data with the aid of Hi-C technology. The genome assembly was 563.3 Mb in length, with contig N50 and scaffold N50 values of ~6 Mb and ~31 Mb, respectively. Most (95.59%) of the sequences were anchored onto 17 pseudochromosomes (538.4 Mb). We predicted 35,856 protein-coding genes, 1,401 miRNAs, 655 tRNAs, 425 rRNAs, and 795 snRNAs. The functions of 34,967 genes (97.52%) were predicted. The availability of this chromosome-level genome will provide valuable resources for molecular studies of this species, facilitating future research on speciation, functional genomics, and comparative genomics within the Rosaceae family.

Autoantibodes to GP210 are a metric for UDCA responses in primary biliary cholangitis.

Objectives: Antibodies to gp210 and sp100 are specific and unique anti-nuclear autoantibodies (ANAs) associated with primary biliary cholangitis (PBC). Importantly the presence of anti-gp210 and anti-sp100 responses is indicative of poor clinical outcomes. However, the utility of measuring titers of these antibodies remains unclear. Materials and methods: Using the in-house purified gp210 (HSA108-C18) and sp100 (amino acid position 296-386), we quantitatively measured serum autoantibodies to gp210 and sp100 using chemiluminescence immunoassay (CLIA) in a very large cohort of 390 patients with PBC, including 259 cases with no prior ursodesoxycholic acid (UDCA) treatment and 131 cases with UDCA treatment. We also analyzed serial changes in anti-gp210 and anti-sp100 levels in 245 sequential samples from 88 patients. Results: In our cross-sectional analysis, we detected anti-gp210 immunoglobulin G (IgG) and anti-sp100 IgG autoantibodies in 129 out of 390 (33.1%) and 80 out of 390 (20.5%) PBC patients, respectively. Multivariate analysis revealed that serum IgG (st.ß = 0.35, P = 0.003) and gamma-glutamyltransferase (GGT) (st.ß = 0.23, P = 0.042) levels at baseline were independently associated with anti-gp210 concentrations. In serial testing, we observed significant fluctuations in anti-gp210 antibody levels. These fluctuations reflected responsiveness to UDCA therapy, particularly in anti-gp210-positive patients with initially lower concentrations in the stages of disease. Conclusions: Our study reflects that quantitative changes of anti-gp210 antibody are indicative of UDCA responses. There is a great need for newer metrics in PBC and we suggest that a more detailed and longer study of these unique ANAs is warranted.

Near-infrared light-activatable, analgesic nanocomposite delivery system for comprehensive therapy of diabetic wounds in rats.

Impaired angiogenesis, bacterial infection, persistent severe pain, exacerbated inflammation, and oxidative stress injury are intractable problems in the treatment of chronic diabetic ulcer wounds. A strategy that effectively targets all these issues has proven challenging. Herein, an in-situ sprayable nanoparticle-gel composite comprising platinum clusters (Pt) loaded-mesoporous polydopamine (MPDA) nanoparticle and QX-314-loaded fibrin gel (Pt@MPDA/QX314@Fibrin) was developed for diabetic wound analgesia and therapy. The composite shows good local analgesic effect of QX-314 mediated by near-infrared light (NIR) activation of transient receptor potential vanilloid 1 (TRPV1) channel, as well as multifunctional therapeutic effects of rapid hemostasis, anti-inflammation, antioxidation, and antibacterial properties that benefit the fast-healing of diabetic wounds. Furthermore, it demonstrates that the composite, with good biodegradability and biosafety, significantly relieved wound pain by inhibiting the expression of c-Fos in the dorsal root ganglion and the activation of glial cells in the spinal cord dorsal horn. Consequently, our designed sprayable Pt@MPDA/QX314@Fibrin composite with good biocompatibility, NIR activation of TRPV1 channel-mediated QX-314 local wound analgesia and comprehensive treatments, is promising for chronic diabetic wound therapy.

RPTOR blockade suppresses brain metastases of NSCLC by interfering the ceramide metabolism via hijacking YY1 binding.

BACKGROUND: Ceramide metabolism is crucial in the progress of brain metastasis (BM). However, it remains unexplored whether targeting ceramide metabolism may arrest BM. METHODS: RNA sequencing was applied to screen different genes in primary and metastatic foci and whole-exome sequencing (WES) to seek crucial abnormal pathway in BM + and BM-patients. Cellular arrays were applied to analyze the permeability of blood-brain barrier (BBB) and the activation or inhibition of pathway. Database and Co-Immunoprecipitation (Co-IP) assay were adopted to verify the protein-protein interaction. Xenograft and zebrafish model were further employed to verify the cellular results. RESULTS: RNA sequencing and WES reported the involvement of RPTOR and ceramide metabolism in BM progress. RPTOR was significantly upregulated in BM foci and increased the permeability of BBB, while RPTOR deficiency attenuated the cell invasiveness and protected extracellular matrix. Exogenous RPTOR boosted the SPHK2/S1P/STAT3 cascades by binding YY1, in which YY1 bound to the regions of SPHK2 promoter (at -353 ~ -365 nt), further promoting the expression of SPHK2. The latter was rescued by YY1 RNAi. Xenograft and zebrafish model showed that RPTOR blockade suppressed BM of non-small cell lung cancer (NSCLC) and impaired the SPHK2/S1P/STAT3 pathway. CONCLUSION: RPTOR is a key driver gene in the brain metastasis of lung cancer, which signifies that RPTOR blockade may serve as a promising therapeutic candidate for clinical application.

Ultrastrong and High-Tough Thermoset Epoxy Resins from Hyperbranched Topological Structure and Subnanoscaled Free Volume.

The strength and toughness of thermoset epoxy resins are generally mutually exclusive, as are the high performance and rapid recyclability. Experimentally determined mechanical strength values are usually much lower than their theoretical values. The preparation of thermoset epoxy resins with high modulus, high toughness, ultrastrong strength, and highly efficient recyclability is still a challenge. Here, novel hyperbranched epoxy resins (Bn, n = 6, 12, 24) with imide structures by a thiol-ene click reaction. Bn shows an excellent comprehensive function in simultaneously improving the strength, modulus, toughness, low-temperature resistance, and degradability of diglycidyl ether of bisphenol-A (DGEBA). All the mechanical properties first increase and then decrease with minimization of the free volume properties. The improvement is attributable to uniform molecular holes or free volume by a molecular mixture of linear and hyperbranched topological structures. The precise measurement and controllability of the molecular free volume properties of epoxy resins is first discovered, as well as the imide structure degradation of crosslinked epoxy resins. The two conflicts are successfully resolved between strength and toughness and between high performance during service and high efficiency during degradation. These findings provide a route for designing ultrastrong, tough, and recyclable thermoset epoxy resins.

Serum VEGF as a predictive marker of glycemic control and diabetic nephropathy in Chinese older adults with type 2 diabetes mellitus.

Objectives: Recent researches have demonstrated good correlation between vascular endothelial growth factor (VEGF) and diabetic nephropathy (DN); however, this relationship seems less clear-cut when VEGF was measured in blood samples. We tended to explore the possible association between serum VEGF and glycemic control and diabetic nephropathy severity in Chinese older adults with type 2 diabetes mellitus (T2DM). Materials and methods: This study retrospectively enrolled 595 older T2DM adults at random. Participants were clinically grouped across the urine albumin-to-creatinine ratio (UACR) and the HbA1c tertiles by genders. Linear regressions were performed for the correlation of VEGF with HbA1c and UACR and binary logistic regressions for the odds of DN after adjusting for confounders. The receiver operating characteristic (ROC) curves were conducted for the predictive value of VEGF for DN. Results: Both males and females with DN exhibited higher VEGF levels than non-DN (P < 0.001). Furthermore, a positive correlation of VEGF with UACR and HbA1c was presented regardless of adjusting confounding factors (P < 0.001). Serum VEGF level and fasting plasma glucose (FPG) were independent risk factors of DN in older adults of both genders (P < 0.05), while the risk prediction of DN by HbA1c only reflected in female patients (P < 0.05). The ROC curve of VEGF for DN had the area under curve (AUC) of 0.819 for males and 0.793 for females, indicating the clinical value of serum VEGF as a predictive biomarker. Conclusions: Serum VEGF was strongly associated with UACR and HbA1c in both genders, and could be regarded as a predictive biomarker for glycemic control and diabetic nephropathy in older adults with T2DM.

Population genetics of Camellia granthamiana, an endangered plant species with extremely small populations in China.

Introduction: Camellia, the largest genus of Theaceae, is well-known for having high economic values. Camellia granthamiana demonstrates large beautiful flowers with some primitive characters, such as multiple large and persistent bracteoles and sepals, was listed as Vulnerable species on the IUCN Red List. Methods: In this study, we investigated all possible records of the species, and sampled four natural populations and five cultivated individuals. By applying shallow-genome sequencing for nine individuals and RAD-seq sequencing for all the sampled 77 individuals, we investigated population genetic diversity and population structure of the species. Results and discussion: The results showed that the population sampled from Fengkai, previously identified as C. albogigias, possessed different plastid genome from other species possibly due to plastid capture; the species possesses strong population structure possibly due to the effect of isolation by distance, habitat fragmentation, and self-crossing tendency of the species, whose effective population size declined quickly in the past 4,000 years. Nevertheless, C. granthamiana maintains a medium level of genetic diversity within population, and significant differentiation was observed among the four investigated populations, it is anticipated that more populations are expected to be found and all these extant populations should be taken into instant protection.

SerpinB1 is required for Rev-erbα-mediated protection against acute lung injury induced by lipopolysaccharide-in mice.

BACKGROUND AND PURPOSE: Acute lung injury (ALI) is a serious, life-threatening inflammation of the lungs that still lacks effective treatment. We previously showed that serine protease inhibitor B1 (SerpinB1) protects against ALI induced by orthotopic autologous liver transplantation. However, the role of SerpinB1 in lipopolysaccharide (LPS)-induced ALI and its regulatory mechanisms are not known. EXPERIMENTAL APPROACH: Wild-type (WT) and SerpinB1 knockout (KO) mice were treated with intratracheal LPS stimulation to induce ALI. Some of the WT and KO mice were injected i.p. with melatonin, a rhythm-related protein Rev-erbα agonist. The circadian rhythm in WT mice was disrupted by exposing mice to 24 h of continuous dark or light conditions after intratracheal LPS. Neutrophils were isolated from alveolar lavage fluid of WT and KO mice, and from human peripheral blood. Neutrophils were treated with LPS and melatonin. KEY RESULTS: Disruption of circadian rhythm by either 24-h dark or light conditions exacerbated LPS-induced ALI and decreased expression of Rev-erbα and SerpinB1 protein in lung, whereas melatonin treatment increased SerpinB1 expression and attenuated LPS-induced ALI in WT mice, but not in KO mice. In isolated neutrophils, Rev-erbα was co-localized with SerpinB1 and bound to its promoter to trigger SerpinB1 transcription. Furthermore, LPS stimulation increased formation of neutrophil extracellular traps, which was reversed by melatonin treatment in neutrophils from WT mice, but not from KO mice. CONCLUSION AND IMPLICATIONS: In mice, SerpinB1 is rhythmically regulated by Rev-erbα, and its down-regulation exacerbates LPS-induced ALI by inducing formation of neutrophil extracellular traps.

WITHDRAWN: The Analgesic Effect of Regional Blocks for Modified Radical Mastectomy: A Network Meta-analysis.

Ahead of Print article withdrawn by publisher.

Injury Site Specific Xenon Delivered by Platelet Membrane-Mimicking Hybrid Microbubbles to Protect Against Acute Kidney Injury via Inhibition of Cellular Senescence.

Inhalation of xenon gas improves acute kidney injury (AKI). However, xenon can only be delivered through inhalation, which causes non-specific distribution and low bioavailability of xenon, thus limiting its clinical application. In this study, xenon is loaded into platelet membrane-mimicking hybrid microbubbles (Xe-Pla-MBs). In ischemia-reperfusion-induced AKI, intravenously injected Xe-Pla-MBs adhere to the endothelial injury site in the kidney. Xe-Pla-MBs are then disrupted by ultrasound, and xenon is released to the injured site. This release of xenon reduced ischemia-reperfusion-induced renal fibrosis and improved renal function, which are associated with decreased protein expression of cellular senescence markers p53 and p16, as well as reduced beta-galactosidase in renal tubular epithelial cells. Together, platelet membrane-mimicking hybrid microbubble-delivered xenon to the injred site protects against ischemia-reperfusion-induced AKI, which likely reduces renal senescence. Thus, the delivery of xenon by platelet membrane-mimicking hybrid microbubbles is a potential therapeutic approach for AKI.

A modified renal risk score for Chinese patients with antineutrophil cytoplasmic antibody-associated vasculitis.

BACKGROUND: The renal risk score (RRS) is a useful tool to predict end-stage renal disease (ESRD) in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The current study aimed to validate the predictive performance of RRS and to further modify this model in Chinese AAV patients. METHODS: Two hundred and seventy-two patients diagnosed with AAV confirmed by renal biopsies were retrospectively enrolled from a single center. The RRS was calculated based on 3 categorical variables, i.e., the proportion of normal glomeruli, the proportion of interstitial fibrosis and tubular atrophy (IF/TA), and eGFR at biopsy, classifying these patients into low-, medium-, and high-risk groups. In addition, a modified model was developed based on the RRS and was further validated in another independent cohort of 117 AAV patients. The predictive performance of each model was evaluated according to discrimination and calibration. RESULTS: Patients were classified by the RRS into low- (26.5%), medium- (46.7%), and high-risk (26.8%) groups, with 120-month renal survival rates of 93.3%, 57.2%, and 18.4%, respectively (P < 0.001). The RRS showed good discrimination but less satisfactory calibration. Therefore, a modified model with improved discrimination and calibration was developed in Chinese AAV patients, with eGFR, proportion of normal glomeruli (both as continuous variables), and IF/TA (< 25%, 25-50%, > 50%) included. Internal and external validation of the modified model were performed. Finally, an online risk prediction tool was developed based on the modified model. CONCLUSIONS: The RRS was an independent predictor of ESRD of AAV patients. The modified model could predict the probability of ESRD for AAV patients with improved performance in Chinese AAV patients.

Inhibitor of apoptosis proteins antagonist SM164 ameliorates experimental MPO-ANCA-associated vasculitis via enhancing fatty acid oxidation in neutrophils.

OBJECTIVES: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of life-threatening autoimmune diseases. Inhibitors of apoptosis proteins (IAPs) are a class of molecules engaged in cell death and inflammation, interventions of which are proven effective in a number of inflammatory diseases. Here we tested whether targeting IAPs could ameliorate AAV and explored the potential mechanism. METHODS: We collected 19 kidney specimens from patients with myeloperoxidase (MPO)-AAV to investigate the expression of IAPs. The IAP pan-inhibitor SM164 was used to treat the experimental autoimmune vasculitis (EAV) rat model of AAV. RNA sequencing of renal cortex and enrichment analysis were developed to interpret gene expression. Functional experiments were performed to investigate the role of SM164 on neutrophils and endothelial cells. RESULTS: The expression of three IAPs (cIAP1, cIAP2 and XIAP) was upregulated in kidneys of AAV patients compared with normal controls. SM164 dramatically reduced renal injury in EAV rats. Transcriptomic analysis revealed prominent alterations in fatty acid oxidation and respiratory burst following SM164 treatment. Functional studies demonstrated that SM164 inhibited neutrophil activation induced by MPO-ANCA positive IgG or serum from MPO-AAV patients, and such inhibitory effect was abolished by gene silencing or pharmacological inhibition of fatty acid oxidation. SM164 also inhibited the adhesion of neutrophils to endothelial cells with little effect on the endothelial injury induced by serum from MPO-AAV patients. CONCLUSION: Inhibition of IAPs with SM164 played a protective role in AAV through enhancing intracellular fatty acid oxidation in neutrophils.

Culture media from hypoxia conditioned mast cells aggravates hypoxia and reoxygenation injury of human intestinal cells.

Intestinal ischemia-reperfusion (II/R) injury is a common clinical and pathological change; however, its underlying mechanisms remain unclear. Previous studies have shown that the inflammatory response induced by mast cell degranulation may be involved in the mechanism underlying II/R injury in rats. In this study, we established a human intestinal epithelial adenocarcinoma cell (Caco-2) hypoxia/reoxygenation (H/R) model and transwell system to investigate the effects of culture media (CM) from hypoxia conditioned human mast cell (HMC-1) and HMC-1 H/R on hypoxia/reoxygenation injury in Caco-2 under H/R conditions. Moreover, we assessed the barrier function of Caco-2 by measuring the 4-kDa fluorescein isothiocyanate (FITC)-dextran (FD4) flux and the tight junction protein expression. The results concluded that Caco-2 exposed to H/R insult showed an increase in lactate dehydrogenase (LDH) release, cell apoptosis index, cell permeability, Bax expression, phosphorylation of c-Jun N-terminal protein kinase (JNK) and p38, and a decrease in cell viability and expression of Bcl-2, ZO1, and occludin (all P < 0.05). Notably, preincubating Caco-2 with HMC-1CM resulted in an increase in cell injury (increased LDH levels and cell permeability, decreased cell viability), apoptosis index, p-JNK, and p-38 expression and a decrease in ZO1 and occludin expression by co-culture system (all P < 0.05). In conclusion, our results show that HMC-1 hypoxic and reoxygenated CM aggravates hypoxic and reoxygenated injury in Caco-2 by increasing the phosphorylation of JNK and p38 in vitro.

Renal Expression of Annexin A1 Is Associated With the Severity of Renal Injury in Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis.

Background: Increasing studies demonstrated the importance of activation of neutrophils in the pathogenesis of antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). Previous studies showed that annexin A1 (ANXA1) inhibited the recruitment, transendothelial migration and respiratory burst of neutrophils and induced apoptosis of neutrophils. The current study aimed to investigate the plasma and renal levels of ANXA1 as well as their association with the disease severity in AAV patients. Methods: Thirty-one AAV patients in active stage and 35 AAV patients in remission stage were recruited. The expression of ANXA1 in renal specimens was assessed by immunohistochemistry. The co-localization of ANXA1 with renal intrinsic and infiltrating cells was detected by double immunofluorescence. The plasma levels of ANXA1 were determined by ELISA. The association of plasma and renal levels of ANXA1 with clinicopathological parameters was further analyzed. Results: Plasma levels of ANXA1 were significantly higher in active AAV patients than those in AAV patients in remission as well as healthy controls. The renal expression of ANXA1 was significantly higher in active AAV patients than in healthy controls and disease controls. Double immunofluorescence assay showed that ANXA1 was expressed in glomerular endothelial cells, mesangial cells, podocytes, proximal tubular epithelial cells, neutrophils, monocytes/macrophages and T cells in AAV patients. The mean optical density of ANXA1 in glomeruli was correlated with serum creatinine levels (r = -0.491, P = 0.005) and eGFR (r = 0.492, P = 0.005) at renal biopsy and the proportion of crescents (r = -0.423, P = 0.018) in renal specimens of AAV patients. The expression of ANXA1 in glomeruli of AAV patients achieving complete renal recovery was significantly higher than those achieving partial renal recovery. Conclusion: In AAV patients, the renal expression of ANXA1 was associated with the severity of renal injury.