Seasonal effects of fish, seaweed and abalone cultures on dissolved organic matter and carbon sequestration potential in Sansha Bay, China.

Coastal bays serve as undeniable dissolved organic matter (DOM) reactors and the role of prevalent mariculture in DOM cycling deserves investigation. This study, based on four seasonal field samplings and a laboratory incubation experiment, examined the source and seasonal dynamics of DOM and fluorescent dissolved organic matter (FDOM) in the seawater of fish (Larimichthys crocea, LC), seaweed (Gracilaria lemaneiformis, GL) and abalone (Haliotis sp., HA) culturing zones in Sansha Bay, China. Using three-dimensional fluorescence spectroscopy coupled with parallel factor analysis (EEMs-PARAFAC), three fluorescent components were identified, i.e. protein-like C1, protein-like C2, and humic-like C3. Our results showed that mariculture activities dominated the DOM pool by seasonal generating abundant DOM with lower aromaticity and humification degrees. Accounting for 40-95 % of total fluorescent components, C1 (Ex/Em = 300/340 nm) was regarded the same as D1 (Ex/Em = 300/335 nm) identified in a 180-day degradation experiments of G. lemaneiformis detritus, indicating that the cultured seaweed modulated DOM through the seasonal production of C1. In addition, the incubation experiment revealed that 0.7 % of the total carbon content of seaweed detritus could be preserved as recalcitrant dissolved organic carbon (RDOC). However, fish culture appeared to contribute to liable DOC and protein-like C2, exerting a substantial impact on DOM during winter but making a negligible contribution to carbon sequestration, while abalone culture might promote the potential export and sequestration of seaweed-derived carbon to the ocean. Our results highlight the influences of mariculture activities, especially seaweed culture, in shaping DOM pool in coastal bays. These findings can provide reference for future studies on the carbon accounting of mariculture.

Emerging Chemodynamic Nanotherapeutics for Cancer Treatment.

Chemodynamic therapy (CDT) has emerged as a transformative paradigm in the realm of reactive oxygen species -mediated cancer therapies, exhibiting its potential as a sophisticated strategy for precise and effective tumor treatment. CDT primarily relies on metal ions and hydrogen peroxide to initiate Fenton or Fenton-like reactions, generating cytotoxic hydroxyl radicals. Its notable advantages in cancer treatment are demonstrated, including tumor specificity, autonomy from external triggers, and a favorable side-effect profile. Recent advancements in nanomedicine are devoted to enhancing CDT, promising a comprehensive optimization of CDT efficacy. This review systematically elucidates cutting-edge achievements in chemodynamic nanotherapeutics, exploring strategies for enhanced Fenton or Fenton-like reactions, improved tumor microenvironment modulation, and precise regulation in energy metabolism. Moreover, a detailed analysis of diverse CDT-mediated combination therapies is provided. Finally, the review concludes with a comprehensive discussion of the prospects and intrinsic challenges to the application of chemodynamic nanotherapeutics in the domain of cancer treatment.

Colonization characteristics and dynamic transition of archaea communities on polyethylene and polypropylene microplastics in the sediments of mangrove ecosystems.

Microplastics are a growing concern in mangrove ecosystems; however, their effects on archaeal communities and related ecological processes remain unclear. We conducted in situ biofilm-enrichment experiments to investigate the ecological influence of polyethylene (PE) and polypropylene microplastics on archaeal communities in the sediments of mangrove ecosystems. The archaeal community present on microplastics was distinct from that of the surrounding sediments at an early stage but became increasingly similar over time. Bathyarchaeota, Thaumarchaeota, Euryarchaeota, and Asgardaeota were the most abundant phyla. Methanolobus, an archaeal biomarker, was enriched in PE biofilms, and significantly controlled by homogeneous selection in the plastisphere, indicating an increased potential risk of methane emission. The dominant archaeal assembly process in the sediments was deterministic (58.85%-70.47%), while that of the PE biofilm changed from stochastic to deterministic during the experiment. The network of PE plastispheres showed less complexity and competitive links, and higher modularity and stability than that of sediments. Functional prediction showed an increase in aerobic ammonia oxidation during the experiment, whereas methanogenesis and chemoheterotrophy were significantly higher in the plastisphere. This study provides novel insights into the impact of microplastic pollution on archaeal communities and their mediating ecological functions in mangrove ecosystems.

Cisplatin-resistance induces lung squamous carcinoma cell growth by nicotine-mediated α7nAchR/HDAC1/Cyclin D1/pRb cell cycle activation.

The majority of adenocarcinoma lung cancer is found in nonsmokers. A history of tobacco use is more common in squamous cell carcinoma of the lung. The aim of this study is to identify the cisplatin (CDDP)-resistance that promotes lung squamous carcinoma cell growth through nicotine-mediated HDAC1/7nAchR/E2F/pRb cell cycle activation. Squamous cell carcinoma (NCI-H520 and NCI-H157) cells were examined after cisplatin and nicotine treatment by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, cell migration assay, immunofluorescence staining, western blot analysis, and immunoprecipitation analysis. Consequently, CDDP is released from DNA and Rb phosphorylated pRb as a result of nicotine-induced cancer cell proliferation through 7nAchR, which then triggers the opening of the HDAC1 cell cycle. The cell cycle is stopped when CDDP adducts are present. Nicotine exerts cancer cytoprotective effects by allowing HDAC1 repair mechanisms to re-establish E2F promoting DNA stimulation cell cycle integrity in the cytosol and preventing potential CDDP and HDAC1 suppressed in the nuclear. Concentration expression of nicotine causes squamous carcinoma cell carcinogens to emerge from inflammation. COX2, NF-KB, and NOS2 increase as a result of nicotine-induced squamous carcinoma cell inflammation. Nicotine enhanced the cell growth-related proteins such as α7nAchR, EGFR, HDAC1, Cyclin D, Cyclin E, E2F, Rb, and pRb by western blot analysis. It also induced cancer cell inflammation and growth. As a result, we suggest that nicotine will increase the therapeutic resistance effects of CDDP. This has the potential to interact with nicotine through α7nAchR receptors and HDAC1/Cyclin D/E2F/pRb potentially resulting in CDDP therapy resistance, as well as cell cycle-induced cancer cell growth.

Accurate carbon storage estimation for the salt marsh ecosystem based on Bayesian maximum entropy approach - A case study for the Spartina alterniflora ecosystem.

The blue carbon ecosystem, including the salt marsh ecosystem, possesses a significant carbon sequestration potential. Therefore, accurately quantifying the carbon storage within such ecosystems is crucial for the adequate accounting of carbon sequestration. The present work chose a Spartina alterniflora ecosystem in the Xiaogan Island (China) as the study area (approximately 11 ha), and employed the Bayesian maximum entropy (BME) approach to assimilate both hard organic carbon (OC) data and soft OC data measured from 2 cm and 10 cm stratified samples. A 3-dimensional model was developed for space-time OC estimation purposes based on the sediment chronology results. The 10-fold BME cross validation results demonstrated a high estimation accuracy, with the R2, RMSE and MAE values equal to 0.8564, 0.1026 % and 0.0748 %, respectively. A noteworthy outcome was the BME-generated carbon storage density maps with 1 m spatial resolution. These maps revealed that the carbon storage density at the top 30 cm sediment depth in the stable zone (with elder stand age of S. alterniflora) was higher than that in the rapid expansion zone, i.e., 71.79 t/ha vs. 69.82 t/ha, respectively. Additionally, the study found that the averaged carbon burial rate and the total carbon storage at the top 30 cm sediment depth across the study area were 266 g C/m2/yr and 781.50 t, respectively. Lastly, the proposed BME-based framework of carbon storage estimation was found to be versatile and applicable to other blue carbon ecosystems. This approach can foster the development of a standardized carbon sink metrological methodology for diverse blue carbon ecosystems.

Rh(III)-catalyzed selective C2 C-H acyloxylation of indoles.

Herein, we present the first highly regio- and chemoselective C2 C-H acyloxylation of indole under rhodium catalysis and an N-quinolinyl auxiliary. This strategy accommodates a wide range of indoles and structurally diverse carboxylic acids with good reaction efficiencies to yield functionalized indoles. The utility of this logic was demonstrated by the concise synthesis of the functionalized 2-oxindole derivatives. Preliminary mechanistic studies indicate that catalyst turnover of RhIII-RhIV/V-RhII/III-RhIII might be involved in this catalytic C-H transformation.

Carbon sequestration potential of transplanted mangroves and exotic saltmarsh plants in the sediments of subtropical wetlands.

Coastal blue carbon ecosystems offer promising benefits for both climate change mitigation and adaptation. While there have been widespread efforts to transplant mangroves from the tropics to the subtropics and to introduce exotic saltmarsh plants like Spartina alterniflora in China, few studies have thoroughly quantified the chronological records of carbon sequestration with different organic carbon (OC) sources. To understand how variations in OC sources can affect the carbon sequestration potential of coastal wetland environment over time, we conducted a study on typical islands with two scenarios: S. alterniflora invasion and mangrove transplantation. Our study determined chronological records of carbon sequestration and storage from five sediment profiles and traced changes in the OC sources using carbon stable isotope (δ13C) and C:N ratios in response to these scenarios. The S. alterniflora invasion resulted in an 84 ± 19 % increase in the OC burial rate compared to unvegetated mudflats, while mangrove transplantation resulted in a 167 ± 74 % increase in the OC burial rate compared to unvegetated mudflats. S. alterniflora and mangroves showed greater carbon sequestration potential in areas with high supplies of suspended particulate matter, while mangroves needed to grow to a certain scale to display obvious carbon sequestration benefits. In the mangrove saltmarsh ecotone, mature mangrove habitats exhibited resistance to the S. alterniflora invasion, while mangrove transplantation in the environment invaded by S. alterniflora had a significant effect on OC contribution. Besides, plant-derived OC can be exported to the surrounding environment due to the rapid turnover of sediments. The blue carbon chronosequence-based estimation of OC sources and burial rates provides a useful reference for establishing carbon accounting policies.

The emerging roles of MAPK-AMPK in ferroptosis regulatory network.

Ferroptosis, a newform of programmed cell death, driven by peroxidative damages of polyunsaturated-fatty-acid-containing phospholipids in cellular membranes and is extremely dependent on iron ions, which is differs characteristics from traditional cell death has attracted greater attention. Based on the curiosity of this new form of regulated cell death, there has a tremendous progress in the field of mechanistic understanding of ferroptosis recent years. Ferroptosis is closely associated with the development of many diseases and involved in many diseases related signaling pathways. Not only a variety of oncoproteins and tumor suppressors can regulate ferroptosis, but multiple oncogenic signaling pathways can also have a regulatory effect on ferroptosis. Ferroptosis results in the accumulation of large amounts of lipid peroxides thus involving the onset of oxidative stress and energy stress responses. The MAPK pathway plays a critical role in oxidative stress and AMPK acts as a sensor of cellular energy and is involved in the regulation of the energy stress response. Moreover, activation of AMPK can induce the occurrence of autophagy-dependent ferroptosis and p53-activated ferroptosis. In recent years, there have been new advances in the study of molecular mechanisms related to the regulation of ferroptosis by both pathways. In this review, we will summarize the molecular mechanisms by which the MAPK-AMPK signaling pathway regulates ferroptosis. Meanwhile, we sorted out the mysterious relationship between MAPK and AMPK, described the crosstalk among ferroptosis and MAPK-AMPK signaling pathways, and summarized the relevant ferroptosis inducers targeting this regulatory network. This will provide a new field for future research on ferroptosis mechanisms and provide a new vision for cancer treatment strategies. Video Abstract.

Spatiotemporal variation of phytoplankton communities and water quality among seaweed, shellfish and cage fish culture systems.

Various marine aquaculture systems have different impacts on the environment, but few assessments were focused on the environmental impact by different systems in the same region. To study the effects of various aquaculture systems on phytoplankton community structure and water properties, 5 surveys were carried out in seaweed (Gracilaria lemaneiformis, GL), shellfish (Mytilus coruscus, MC) and cage fish (Larimichthys crocea, LC) mariculture areas in Dongji island, Zhejiang, China from June to September 2020. Significant differences were observed in some environmental parameters and phytoplankton communities among three aquaculture systems. The dissolved oxygen concentrations and Secchi depth in the surface waters in GL area were relatively higher than in the blank and other areas. As for nutrients concentration, LC and MC areas had higher concentrations than blank area, while GL area was the lowest. Though Chlorophyll-a concentration displayed fluctuations, relatively lower concentrations were found in GL area. Shannon diversity index was found to be relatively constant and higher in GL area. The Non-metric multidimensional scaling results revealed that phytoplankton composition had a distinct pattern among sampling times. The correlations and Redundancy analysis showed that total nitrogen, salinity and transparency were primary environmental factors associated with phytoplankton composition. Our study confirmed that different marine aquaculture systems can cause environmental fluctuations. Among the three systems, seaweed cultivation can bring multiple positive effects by improving surrounding water quality and increasing the phytoplankton composition. G. lemaneiformis culture in summer has great positive impact on seawater environment as it can maintain the ecological balance and reduce the risk of harmful algal blooms (HABs), and therefore, it is strongly recommended more G. lemaneiformis cultivation in this region in summer.

Lewis Acid-Mediated Electrophilic Thiolative Difunctionalization of Enimides: Rapid Access to ß-Amino Sulfides.

An efficient and practical route for the synthesis of ß-amino sulfides by Lewis acid-mediated electrophilic thiolative difunctionalization of enimides is disclosed. A series of free phenols, electron-rich arene, alcohol, azide, and hydride, are successfully incorporated into the substrates in high regio- and stereoselectivities under mild conditions. The obtained products possess multiple functional groups and can be easily transformed to other valuable molecules.

Spatiotemporal variation analysis of global XCO2 concentration during 2010-2020 based on DINEOF-BME framework and wavelet function.

Combining with Carbon dioxide column concentration (XCO2) remote sensing data, it is of great scientific significance to obtain XCO2 long time series data with high precision and high spatio-temporal coverage. In this study, the combination framework of DINEOF and BME were employed to integrate the XCO2 data of GOSAT, OCO-2 and OCO-3 satellites for generating global XCO2 data from January 2010 to December 2020, with the average monthly space coverage rate of more than 96 %. Through cross-validation and comparison of The Total Carbon Column Observing Network (TCCON) XCO2 data and DINEOF-BME interpolation XCO2 products, it is verified that DINEOF-BME method has better interpolation accuracy, and the coefficient of determination of interpolated XCO2 products and TCCON data is 0.920. The long time series of global XCO2 products showed a wave rising trend, with a total increase of ~23 ppm; obviously seasonal characteristics were also detected with the highest XCO2 value in spring and the lowest in autumn. According to the zonal integration analysis, the values of XCO2 in the northern hemisphere is higher than the southern hemisphere during January-May and October-December, while the values of XCO2 in the southern hemisphere is higher than the northern hemisphere during June-September, which accords with the seasonal law. Through EOF mapping, the first mode accounted for 88.93 % of the total variability, and its variation trend is consistent with that of XCO2 concentration, which verifies the variation rule of XCO2 from the time and space pattern. Through wavelet analysis, the time scale corresponding to the first main cycle of XCO2 change is 59-month, which has obvious regularity on the time scale. DINEOF-BME technology framework has good generality, while XCO2 long time series data products and the spatio-temporal variation of XCO2 revealed by the research provide a solid theoretical basis and data support for related research.

Impact of bentonite on greenhouse gas emissions during pig manure composting and its subsequent application.

Additives were widely investigated to retain the nutrients and mitigate the greenhouse gas emissions (GHGs) during manure composting. However, the sustained effects of additives on the GHGs emissions following incorporation of composts to soil were scarcely explored. This study evaluated the effects of bentonite added at the beginning of pig manure composting on the GHGs emissions during two successive processes, i.e., composting and soil incubation amended with composting products. Addition of bentonite did not hinder the composting process and alter the total CO2 emission. On the other hand, reduction by about 17% and 29% for CH4 and N2O emission, respectively, was achieved in the presence of bentonite during composting. Incorporation of the final composting products to soil enhanced significantly the soil C and N of various forms, and gas emissions of CO2 and N2O. However, no significant differences were observed between bentonite-manure co-compost and manure-only compost application except for the N2O emission. Compared to the manure-only compost, compost amended with bentonite reduced N2O loss by around 6.8%, but not statistically significant. This study confirmed that addition of bentonite at the composting stage can mitigate the GHGs emission considering both composting and compost application stages, with all reductions occurring at the composting stage.

Palladium-catalyzed interannular C-H amination of biaryl amines.

A palladium-catalyzed interannular C-H amination of biaryl amines with O-benzoylhydroxylamines is reported. This reaction undergoes smoothly with operational practicality and good tolerance of functional groups, thereby providing a concise synthesis of 2,2'-diaminobiaryls. Moreover, the readily accessible scale-up synthesis and the ability to transform the products into structurally diverse N-containing heterocycles demonstrate the synthetic potential of this catalytic protocol.

Pd-Catalyzed Atroposelective C-H Acyloxylation Enabling Access to an Axially Chiral Biaryl Phenol Organocatalyst.

Herein, we present the Pd(II)-catalyzed atroposelective C-H acyloxylation strategy for the assembly of biaryl aldehyde atropoisomers using readily available amino acids as the catalytic auxiliary and chiral pool. This strategy exhibits a broad substrate scope with a good yield (≤90%) and excellent enantioselectivity (≤99%), furnishing functionalized aldehydes through direct asymmetric C-H oxidation. The application utility of this method was demonstrated by the concise synthesis of a kind of atropoisomeric amino-phenol organocatalyst, which enables good enantiocontrol in catalyzing asymmetric addition of diethylzinc to aldehydes.

Microplastics distribution in different habitats of Ximen Island and the trapping effect of blue carbon habitats on microplastics.

Sediments are considered to be important sinks of microplastics, but the enrichment process of microplastics by blue carbon ecosystems is poorly studied. This study analyzed the spatial distribution and temporal changes, assessed the polymer types and morphological characteristics of microplastics in sediments of five ecosystems, i.e. forests, paddy fields, mangroves, saltmarshes and bare beaches on Ximen Island, Yueqing Bay, China. The trapping effect of blue carbon (mangrove and saltmarsh) sediments on microplastic was further explored. Temporal trends in microplastic abundance showed a significant increase over the last 20 years, with the enrichment of microplastics in mangrove and saltmarsh sediments being 1.7 times as high as that in bare beach, exhibiting blue carbon vegetations have strong enrichment effect on microplastics. The dominant color, shape, size, and polymer type of microplastics in sediments were transparent, fibers and fragments, <1 mm, and polyethylene, respectively. Significant differences in the abundance and characteristics of microplastics between intertidal sediments and terrestrial soils reveal that runoff input is the main source of microplastics. This study provided the evidence of blue carbon habitats as traps of microplastics.

Periodicity and global order parameter of hexagonally packed cylinders in a periodic box.

In all molecular simulations of periodic ordered morphologies (such as those formed by block copolymers), the periodic boundary conditions (PBCs) of the simulation box usually do not match the bulk periodicity L0 of the morphology, thus changing the structure and even the stability of the morphologies obtained in the simulations. To address this problem for hexagonally packed cylinders, we first proposed a general method of calculating the periodicity of such cylinders in a cuboid simulation box with the PBCs applied in all directions, which further allows one to enumerate all possible orientations and periodicities of such cylinders within an estimated range that can fit into a cuboid box of given lengths. We then showed how to choose the lengths of a cuboid box such that regular-hexagonally packed (RHP) cylinders with given intercylinder distance and orientation can fit into the box. Next, taking as an example the dissipative particle dynamics (DPD) simulations of a cylinder-forming diblock copolymer melt, we showed that L0 of RHP cylinders oriented along the body diagonal of a cubic box is found when all the off-diagonal elements of the pressure tensor vanish. Finally, based on our general method of calculating the periodicity of hexagonally packed cylinders, we designed a global order parameter for such cylinders, which takes into account their ordering only for the orientations that can fit into the simulation box. Using again the DPD simulations, we showed that our global order parameter can be used to quantify the formation of hexagonally packed cylinders in each collected configuration and to monitor their orientation (thus periodicity) during the simulation run.

Underestimated PAH accumulation potential of blue carbon vegetation: Evidence from sedimentary records of saltmarsh and mangrove in Yueqing Bay, China.

Sediments of blue carbon vegetation are becoming a sink of natural and anthropogenic pollutants, such as polycyclic aromatic hydrocarbons (PAHs). However, the extent to which PAHs are accumulated and varied in blue carbon sediments, and the impact of blue carbon vegetation on the accumulation and retention capacity of PAHs, have been poorly explored. This study examines the sedimentary records of PAHs in profiles from mangrove plantation, saltmarsh, and mudflat in Ximen Island and Maoyan Island of Yueqing Bay, China. The existence of blue carbon vegetation provides a sheltered environment for the accelerated burial of sediment and OC. Decadal PAH sedimentation records show staged changes characterized by the emission of PAHs and colonization of blue carbon vegetation, reflecting the accelerated burial of PAHs in sediments by blue carbon vegetation colonization. In addition, the colonization of blue carbon vegetation contributes to the shift of PAH compositions in sediments. This study provides new insights into the underestimated PAH accumulation potential and retention capacity of blue carbon vegetation and the corresponding underlying sediments, supporting the environmental benefits of blue carbon vegetation.

Distribution, accumulation and health risk assessment of trace elements in Sargassum fusiforme.

This study compared the ability of Sargassum fusiforme to accumulate As, Cd, Cr, Cu, Ni, Pb and Zn in its five tissues (main branch, lateral branch, leaf, receptacles and pneumathode). The concentrations of these trace elements in seawater, surface sediments and different tissues of S. fusiforme were analyzed in different areas in Dongtong County (Wenzhou City, China). The presence of receptacle at all sites indicated that S. fusiforme had entered the mature stage. However, the proportion of each tissue in S. fusiforme in different sites was varied, indicating subtle differences in growth. S. fusiforme has a great capacity to accumulate trace elements, showing relatively high levels of As (28.2-64.2 mg kg-1) and Zn (19.9-80.8 mg kg-1). The elements are mainly stored in leaf, receptacles and pneumathode. Compared to element concentrations in the surrounding environment, the seaweed exhibited stronger bioconcentration capacity for As and Cd than for other elements. According to our health risk assessment results, the hazard index and carcinogenic risk were below the limit, suggesting that the S. fusiforme ingestion would not pose any health risk and the potential risk of intake branches was even lower than that of other tissues.

An AHP-based regional COVID-19 vulnerability model and its application in China.

Since the COVID-19 outbreak, four cities-Wuhan, Beijing, Urumqi and Dalian-have experienced the process from outbreak to stabilization. According to the China Statistical Yearbook and China Center for Disease Control records, regional, pathological, medical and response attributes were selected as regional vulnerability factors of infectious diseases. Then the Analytic Hierarchy Process (AHP) method was used to build a regional vulnerability index model for the infectious disease. The influence of the COVID-19 outbreak at a certain place was assessed computationally in terms of the number of days of epidemic duration and cumulative number of infections, and then fitted to the city data. The resulting correlation coefficient was 0.999952. The range of the regional vulnerability index for COVID-19 virus was from 0.0513 to 0.9379. The vulnerability indexes of Wuhan, Urumqi, Beijing and Dalian were 0.8733, 0.1951, 0.1566 and 0.1119, respectively. The lack of understanding of the virus became the biggest breakthrough point for the rapid spread of the virus in Wuhan. Due to inadequate prevention and control measures, the city of Urumqi was unable to trace the source of infection and close contacts, resulting in a relatively large impact. Beijing has both high population density and migration rate, which imply that the disease outbreak in this city had a great impact. Dalian has perfect prevention and good regional attributes. In addition, the regional vulnerability index model was used to analyze other Chinese cities. Accordingly, the regional vulnerability index and the prevention and control suggestions for them were discussed. Supplementary Information: The online version contains supplementary material available at 10.1007/s40808-021-01244-y.

Aristolochic Acid Induces Chronic Kidney Disease in ACE Knockout Mice.

BACKGROUND: Aristolochic acid I (AAI) is an extract from Chinese herbs that causes progressive interstitial nephritis. The aim of this research is to know whether chymases play the crucial role in AAI-induced nephropathy. METHODS: The mice were treated with AAI via intraperitoneal injection and the accumulated AAI dosages are 30 mg/kg of body weight for two, four, six, and eight weeks. The animals were sacrificed after another two or four weeks for nephropathy development. Collection of blood, urine, and kidney samples for the further biochemical analysis, hematoxylin-eosin (H and E) and Masson's trichrome stained to detected pathologic, and MMP2 and MMP9 activity assays. RESULTS: After the treatment of AAI, of the mice, their body weights were decreased (P < 0.01), and concentration of creatinine and blood urea nitrogen (BUN) in serum (P < 0.01) and urine collection were increased (P < 0.01). In the renal tissue sections, high amount of inflammatory cells were found by H and E stain, and increased fibrosis in renal interstitial tissue were observed by Masson's trichrome stain. In mice kidney tissue, significantly increased chymase activity after treatment of AAI was found (P < 0.01), but ACE activity did not show significant changes. In ACE KO mice, increased MMP2 and decreased MMP9 activity were found in the AAI-treated mice compared with AAI-untreated control (P < 0.01). CONCLUSIONS: Moreover, it was also observed that the deficiency of ACE would accelerate the disease development of AAI-induced nephropathy. These results may help to know more information about the role of AAI-induced chronic kidney disease and can be applied in developing new drug targets for nephropathy.