Objective: To study the protective effect of CDDO-imidazolide (CDDO-Im) on CCl4-induced hepatic fibrosis and its mechanism. Methods: 24 C57 mice were randomly divided into 4 groups, each group has 6 mice, including blank group, CCl4 model group, CDDO-Im+CCl4 group and CDDO-Im control group. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in different groups were observed and analyzed. The liver tissues were examined using HE staining, Sirius red staining, Masson staining, alpha smooth muscle movement protein(α-SMA) immunohistochemistry; hydroxyproline (HYP) content was measured along with liver malonaldehyde (MDA) levels and liver glutathione (GSH). mRNA expression levels of IL-6 and TGF-β were analyzed by reverse transcriptional quantitative PCR. The expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and the associated proteins heme oxygenase-1 (HO-1) and quinone oxidoreductase 1 (NQO1) in liver tissues of different groups was detected and analyzed by Western blot assay. Results: Compared with the CCl4 model group, the serum ALT and AST levels significantly decreased in the CDDO-Im+CCl4 group (P<0.05), while HYP content and MDA levels in liver tissue significantly decreased (P<0.05), accompanied by an increase in GSH content (P<0.05). Molecular and cellular changes revealed that treatment with CDDO-Im reduced IL-6 and TGF-β mRNA expression while increasing Nrf2 expression level along with its related proteins' expressions(P<0.05), thereby alleviating hepatocyte inflammation induced by CC14 exposure while reducing collagen fiber deposition.The degree of liver cell degeneration, necrosis, and fibrosis was also reduced. Conclusion: CDDO-imidazolide improves CC14-induced liver fibrosis, and this improvement may be attributed to activation of the Nrf2 signaling pathway.
Programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1), as key immune checkpoints, play a crucial role in the field of tumor immunotherapy. Currently, treatment options for advanced digestive system cancers, such as gastric cancer, colorectal cancer, and liver cancer, are limited. As a new treatment option for advanced stages, PD-1/PD-L1 immune checkpoint inhibitors still face significant patient dissatisfaction with their efficacy. Non-coding RNA (ncRNA), including microRNA (miRNA), long non-coding RNA (lncRNA) and circular RNA (circRNA), have been shown to influence the expression and function of PD-1/PD-L1. Further research into the effects of ncRNA on PD-1/PD-L1 could provide new insights into the application of immune checkpoint inhibitors in cancer, thereby enhancing the effectiveness of clinical immunotherapy. This article reviews the research progress on ncRNA intervening in PD-1/PD-L1 regulation in digestive system cancers.
Copper is an essential trace element in the human body, and an imbalance in its homeostasis can cause cellular damage, including but not limited to oxidative damage, inhibition of the ubiquitin-proteasome system, promotion of ferroptosis and cuproptosis. Recent studies have revealed the mechanisms of cuproptosis and shown that it is involved in the development of nonalcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC). This review focuses on the functions and regulation of copper death-related genes (CRGs) in NAFLD and HCC. The pyruvate dehydrogenase E1 subunit β (PDHB), ATPase copper transporting β (ATP7B), and nuclear factor-erythroid 2-related factor 2 (Nrf2) genes are crucial in the progression of NAFLD, while the lipoyltransferase 1 (LIPT1), metal regulatory transcription factor 1 (MTF1), and pyridoxal kinase (PDXK) genes are closely associated with the development of HCC. The dihydrolipoamide dehydrogenase (DLD), dihydrolipoamide S-acetyltransferase (DLAT), and ferredoxin 1 (FDX1) genes are related to both conditions. Therefore, cuproptosis provides new insights into the pathogenesis of NAFLD and HCC, which may aid in the discovery of novel therapeutic targets.
Objective: Bronchial asthma is a chronic airway inflammatory disease with complicated pathological mechanism. Dihydro-carvacrol is a compound extracted from Artemisia argyi essential oil, which has potential anti-inflammatory effect, but its exact molecular target is still unclear. The purpose of this study is to explore the anti-inflammatory effect of Dihydrocarvonol in bronchial asthma, and to clarify its potential mechanism and key molecular targets. Methods: CCK-8 method was used to detect the effect of Dihydrocarvonol on the proliferation of bronchial epithelial cells (BEAS-2B cells) and macrophages (RAW264.7 cells). Griess method was used to detect the elative expression of NO in RAW264.7 cells, a macrophage (Raw 264.7 cells) induced by lipopolysaccharide (LPS), and RT-qPCR was used to detect the effect of dihydrocarvacrol on tumor necrosis factor-α (tumor necrosis factor-α, TNF-α) and interleukin-1β(IL-1β) mRNA expression levels; The targets of dihydrocarvonol against bronchial asthma were screened by network pharmacological analysis, molecular docking and molecular dynamics simulation. The binding stability of Dihydrocarvacrol to target protein was evaluated by drug affinity reaction experiment, and the effects of different concentrations of dihydrocarvacrol on the expression of target protein in BEAS-2B cells induced by LPS were explored by western blot. Results: A number of key targets that may be involved in the inflammatory regulation of bronchial asthma were screened by network pharmacological analysis, among which nitric oxide synthase 2 (NOS2) showed good binding ability and stability in molecular docking and molecular dynamics simulation. Experimental results show that dihydrocarvonol can effectively inhibit the expression of TNF-α and IL-1β mRNA inflammatory factors in BEAS-2B cells induced by LPS, and inhibit the expression of NOS2 protein in BEAS-2B cells induced by LPS in a targeted and concentration-dependent manner. Conclusion: This study screened and verified that NOS2 can be used as the target of dihydrocarvacrol in the treatment of bronchial asthma, which provides a theoretical basis for its potential application in the treatment of bronchial asthma.
Objective: To compare the micro-characteristics and HPLC fingerprints of Clematidis argentilucidae Caulis and its adulterants, clarify their differences, and provide a basis for the identification and differentiation of them. Methods: A total of 13 batches of Clematidis argentilucidae Caulis and 9 batches of its adulterants, including Clematis armandii Caulis and Clematidis grandidentatae Caulis. Among them, 19 batches were wild harvested from the original habitats and processed according to relevant standards, while 3 batches were purchased from the herbal medicine market. Stem cross-sections were then prepared. Their microscopic characteristics were observed and recorded, and comparative analysis was conducted using chemometric methods. Results: For the first time, the angle of the xylem bundle was proposed as a parameter for studying the micro-characteristics of transverse section of vine-stem medicinal materials. The results showed that the depth of longitudinal ridges on the surface of stems, the number of primary rays, and the arrangement of vessel pores had relatively specific characteristics. The angle ratio between two adjacent xylem bundles of different sizes showed regularity, which could be used for variety identification and differentiation. Caffeic acid and chicoric acid were found in Clematidis argentilucidae Caulis for the first time. Using chicoric acid as the index component and reference peak, an HPLC fingerprint of Clematidis argentilucidae Caulis with 13 common peaks was established. Comparison with the fingerprints of adulterants identified 9 common peaks. Through similarity evaluation and chemometric methods, the differences in fingerprints between Clematidis argentilucidae Caulis and its adulterants were clarified, enabling accurate identification and differentiation. Conclusion: This study summarizes the micro-characteristics of Clematidis argentilucidae Caulis and highlights the differences in HPLC fingerprints between Clematidis argentilucidae Caulis and its adulterants. It provides a scientific basis for the accurate identification of Clematidis argentilucidae Caulis.
Objective: To investigate the clinical significance of anti-neutrophil cytoplasmic antibodies (ANCA), particularly perinuclear ANCA (pANCA), in systemic lupus erythematosus (SLE) through a cross-sectional study. Methods: A retrospective analysis was conducted on 106 SLE patients treated at the Department of Rheumatology and Immunology, the Second Affiliated Hospital of Xinjiang Medical University (January 2013-January 2023). Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). ANCA seropositivity was determined by enzyme-linked immunosorbent assay (ELISA), with pANCA-positive (n=64) and pANCA-negative (n=42) groups defined based on ANCA test results.Statistical methods, including independent samples t-tests, chi-square tests, and Fisher's exact tests, were used to compare various indicators between SLE patients with positive and negative pANCA, supplemented by a review of relevant literature. Results: ① A total of 106 SLE patients were enrolled, including 78 females and 28 males, with a mean age of (47.43±17.53) years. Among them, 65 patients (61.3%) tested positive for ANCA, of whom 64 were pANCA-positive and 1 was cytoplasmic ANCA (cANCA)-positive. ②Compared with the pANCA-negative group, the pANCA-positive group exhibited significantly higher seropositivity rates (P<0.05) for multiple autoantibodies, including anti-nuclear antibody (ANA), anti-double-stranded DNA (dsDNA) antibody, anti-histone antibody (AHA), anti-nucleosome antibody (AnuA), and anti-Smith D1 (SmD1) antibody. ③The pANCA-positive group demonstrated significantly higher ANA titers (P=0.030) and a higher prevalence of lupus nephritis (LN) (P<0.001) than the pANCA-negative group. ④However, among LN patients, no statistically significant differences (P>0.05) were observed between pANCA-negative and pANCA-positive subgroups in white blood cell count, inflammatory markers, immunoglobulin levels, 24-hour urinary protein quantification (24h UTP), or SLEDAI scores. Conclusion: pANCA seropositivity in SLE patients demonstrates significant associations with autoantibody profiles and LN incidence, suggesting its potential clinical relevance for disease characterization and therapeutic decision-making.
Objective: The 16S rRNA high throughput sequencing technology was used to study the difference of microbial flora in the gingival crevicular fluid of the implant under screw retention and adhesive retention, and to find the characteristic biomarkers related to the peri-implant. Methods: Illumina HiSeq high-throughput sequencing technology was used to perform 16S rRNA sequencing and bioinformatics analysis of the bacterial flora in the bacterial V3-V4 region of gingival crevicular fluid under two groups of retention methods. Results: Microbiota analysis showed that at the genus level, the dominant flora of the screw-retained group mainly included Haemophilus and Neisseria spp. The dominant flora of the adhesive retention group mainly included Fusobacterium spp., Neisseria spp., etc. The analysis of microbial metabolism showed that the abundance of energy metabolism and amino acid metabolism was higher in the screw-retention group. Conclusion: The results indicate that there are differences in the structure and composition of subgingival bacterial microbiota between screw-retained and cement-retained group, and the dominant microbiota varies under different retained methods.
Objective: To explore the influencing factors of severe sepsis in children, and to build the early warning model of nomogram. Methods: A total of 203 children with sepsis diagnosed and treated in our hospital from January 2020 to December 2022 were retrospectively selected as the study objects. According to the severity of sepsis, the children were divided into severe sepsis group (n=55) and non-severe sepsis group (n=148), and the clinical data of the two groups were compared differently. The risk factors of severe sepsis in children were analyzed by univariate and binary Logistic regression, and a columbaric early warning model was constructed based on the analysis. The prediction efficiency of the model was analyzed, and the columbaric early warning model was internally verified by Bootstrap method (B=1 000). The area under receiver operating characteristic (ROC) curve (AUC) and clinical calibration chart were used for fit testing and calibration, and the clinical utility of the clinical decision curve analysis model was plotted. Results: Univariate analysis showed that there were significant differences in respiratory pattern, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), procalcitonin (PCT) and lactic acid (LA) levels between two groups (all P<0.05). Further binary Logistic regression analysis showed that NLR, CRP, PCT and LA were independent risk factors for severe sepsis in children (all P<0.05). The AUC of NLR, CRP, PCT, LA level and histogram warning models were 0.786, 0.766, 0.755, 0.833 and 0.962, respectively. When cut-off was taken, the respective sensitivity was 0.855, 0.600, 0.727, 0.782 and 0.891, respectively. The specificity was 0.642, 0.811, 0.716, 0.770 and 0.939, respectively. The internal consistency index (C-index) of the Bootstrap method is 0.924, indicating that the prediction of this model is relatively stable. Decision analysis indicates that this model has a positive net yield.Conclusion:NLR, CRP, PCT and LA are independent risk factors for severe sepsis in children. The nomogram early warning model based on risk factors has high predictive value.
Polycystic ovary syndrome (PCOS) represents a prevalent endocrine and metabolic disorder among women of reproductive age, with its pathogenesis remaining largely unclear and manifesting in a wide array of clinical presentations across the population. Current research has established a significant correlation between PCOS and abnormalities in hormone secretion, follicular development, as well as chronic inflammatory stimulation of ovarian tissue. Insulin-like growth factor (IGF), particularly IGF-1, is a natural growth hormone that exhibits a high degree of amino acid sequence homology to insulin. This homology allows IGF-1 to bind to either the insulin-like growth factor 1 receptor (IGF-1R) or the insulin receptor, thereby initiating downstream signaling pathways such as PI3K/AKT/mTOR. These activated pathways influence the secretion of various crucial hormones, including insulin, androgen, and growth hormone.Furthermore, IGF-1 promotes cellular glucose uptake by cells, facilitates the conversion of glucose into glycogen, and regulates lipid and amino acid metabolism, thereby playing a crucial role in maintaining metabolic homeostasis in PCOS patients. Furthermore, the binding of IGF-1 to IGF-1R stimulates the growth of follicular granulosa cells while effectively inhibiting their apoptosis. IGF-1 is also closely associated with the regulation of oxidative stress and microenvironmental inflammatory factors in tissues. By maintaining an appropriatelevel of IGF-1, it is possible to ameliorate the chronic inflammatory state observed in PCOS patients’ tissues. This review focuses on elucidating the various potential modes of action and molecular mechanisms of IGF-1 and its receptor in the pathogenesis and progression of PCOS. By providing insights into these complexities, the review aims to offer valuable guidance for future research and clinical treatment of PCOS.
Objective: To investigate the clinical value and innovation of karyotyping and copy number variation sequencing (CNV-seq) in fetuses with increased nuchal translucency (NT) in prenatal diagnosis during first and second trimester pregnancy. Methods: A retrospective analysis of 185 fetuses who were diagnosed with increased nuchal translucency (NT≥2.5 mm) by ultrasound screening in Jiangxi Maternal and Child Health Hospital were enrolled, including 95 fetuses of first trimester prenatal diagnosis and 90 fetuses of second trimester prenatal diagnosis. Villi and amniotic fluid samples were extracted for performing karyotype analysis and CNV-seq. The correlation between the distribution of NT and chromosome abnormalities was compared by X2 test and regression analysis. Results: Chromosome abnormalities were discovered in 48 fetuses (25.95%,48/185) with increased NT. The abnormality rate detected by karyotyping in first-trimester pregnancy group was significantly higher than that in second-trimester pregnancy group(31.58% vs 14.13%, P<0.05). There was no significant difference in the detection rate by CNV-seq between the two groups (31.58% vs 20.00%, P>0.05). In fetuses with 2.5<NT<4 mm, CNV-seq provided an additional detection yield of 4.85% compared to karyotyping(17.48% vs 12.62%, P<0.05). There was no significantly increased anomaly rate in NT≥4 group produced by CNV-seq compared karyotyping(36.59% vs 36.59%, P>0.05). Conclusion: Increased NT play an important role in predicting fetal chromosomal abnormalities. we recommend that the NT of 2.5~4 mm should be considered as a critical risk range of chromosome abnormality, and combinations of karyotyping and CNV-seq facilitate genetic diagnosis of fetal structural anomalies in prenatal diagnosis.
Objective: By solving the image problems of low contrast, blurry details, and high noise in the original medical imaging process, the aim is to improve the quality and application performance of medical images. Methods: By analyzing the technical principles of the time-delay neural network model, a four-dimensional time-delay neural network model is constructed, and the optimal parameter setting method is explored. Based on this, an enhancement method for low-quality images based on the time-delay neural network is proposed, and it is verified that the model can achieve the amplification of small signals. Results: Image enhancement performance was verified on two datasets, and experimental comparisons with mainstream enhancement algorithms were conducted. The results showed that the mean information entropy value was approximately 38% higher than that of other methods, which was confirmed in ultrasound and magnetic resonance imaging images. Conclusion: The enhancement method for low-quality images based on time-delay neural networks can significantly improve the quality of low-quality medical images. It can not only significantly enhance image contrast but also better preserve image detail information.
Objective: Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive stage of metabolic dysfunction-associated fatty liver disease (MAFLD). Currently, diagnosis primarily relies on liver biopsy, which is invasive and has issues with poor compliance. Therefore, the diagnosis of which relies on invasive liver biopsy, and there is an urgent need to develop non-invasive biomarkers to aid diagnosis. In this study, we aimed to screen key diagnostic genes for MASH by integrating machine learning algorithms and liver transcriptome data, and to investigate the regulatory mechanism and diagnostic value of secreted phosphoprotein 1 (SPP1) in MASH. Methods: The liver transcriptome dataset of MAFLD patients was obtained from the gene expression omnibus (GEO), and the differential expression analysis differentially expressed genes (DEGs) were screened. Random forest, artificial neural network, Lasso regression and support vector machine recursive feature elimination algorithm were used to screen key genes, construct a Neural-MASH diagnostic model, and evaluate the performance by receiver operating characteristic (ROC) curve. Subsequently, correlation analysis between candidate key genes and immune cell infiltration/clinical indicators was performed, along with functional enrichment analysis. Results: A total of 85 DEGs were selected, and functional enrichment showed that they were closely related to the p53 signaling pathway and extra cellular matrix (ECM)-receptor interaction. Through multi-algorithm cross-validation, SPP1, fc alpha and mu receptor (FCAMR) and flavin-containing monooxygenase 1 (FMO1) were identified as key genes, and the expression of SPP1 was up-regulated in MASH, and was positively correlated with M0 infiltration of B cells and macrophages and clinical indicators (all P<0.05). The area under curve (AUC) of the Neural-MASH model in the training set and the validation set were 1.000 and 0.811, respectively. Functional analysis revealed that SPP1 was mainly involved in biological processes such as extracellular matrix organization, cell migration regulation, lipid localization and IL-18 signaling pathway. Conclusion: SPP1 can be used as a potential diagnostic marker for MASH, and its interaction with the immune microenvironment may play a key regulatory role in disease progression. The Neural-MASH model constructed based on machine learning has high diagnostic performance and can provide a reference for non-invasive diagnosis of MASH.
Hepatocellular carcinoma (HCC) accounts for 75%~85% of primary liver cancers. Due to its rapid progression, high invasiveness, and lack of effective therapeutic targets, HCC has an extremely poor prognosis. Pyruvate kinase M2 (PKM2), a key rate-limiting enzyme in glycolysis, not only sustains the malignant phenotype of HCC cells by enhancing aerobic glycolysis but also promotes HCC progression through non-glycolytic pathways, such as inducing an immunosuppressive tumor microenvironment. Currently, various PKM2-targeting agents (including natural products, nucleotide-based drugs, etc.) have demonstrated promising anti-HCC effects in both in vitro and in vivo studies. Although PKM2 presents excellent translational value as a therapeutic target for HCC in preclinical research, no PKM2-related clinical trials for HCC have been initiated to date. Worldwide, only 10 clinical trials directly related to PKM2 exist, most of which are either recruiting or terminated. This status is incongruent with the significant therapeutic potential demonstrated for PKM2 in basic research. This review systematically summarizes the latest research progress on PKM2 in HCC, preliminarily explores the potential reasons for the discrepancy between basic and clinical findings regarding PKM2 in HCC, and aims to provide new research perspectives for the targeted intervention in HCC.
Objective: To examine the impact of exclusive and concurrent use of tobacco and e-cigarettes (dual use) on long-term illness, short-term illness, and mental distress compared to conventional cigarette smoking. Methods: Participants were 851 urban residents, who were identified through a multistage survey sampling process that included seven administrative districts of Guangzhou, China. E-cigarette use and conventional cigarette smoking was measured by the suggested questions from Global Adult Tobacco Survey (GATS). Short-term and long-term illness was evaluated by community short self-reported items. Mental distress were measured using a 12-item Chinese version of the General Health Questionnaire (CHQ) with a cut-off score of >3 to measure elevated sever mental distress. Both unadjusted and adjusted logistic regression model were used to examine the relationships between dependent and independent variables. Results: The rates of exclusive and dual e-cigarette use were 2.00% and 12.34%, respectively. Adjusted logistic regression analyses showed that, compared to those who had never used e-cigarettes or conventional cigarettes, dual users had a significantly higher likelihood of experiencing short-term illness (OR=5.49, 95% CI: 3.36~8.96) and long-term illness (OR=4.58, 95% CI: 2.76~7.61). These odd ratios were greater than those for exclusive conventional cigarette smokers (short-term illness: OR=2.43, 95% CI: 1.47~4.01; long-term illness: OR=2.81, 95% CI: 1.71~4.63). Mental distress was strongly associated with dual use (OR=3.42, 95% CI: 2.16~5.40) and exclusive e-cigarette use (OR=2.82, 95% CI: 1.04~7.65). Compared to conventional cigarette smokers, dual users were more likely to experience short-term illness (OR=2.17, 95% CI: 1.18~4.00) and mental distress (OR=2.34, 95% CI: 1.26~4.33). No significant difference was found for long-term illness (OR=1.53, 95% CI: 0.81~2.91). Conclusion: Dual use of e-cigarettes and conventional cigarettes is associated with a higher likelihood of short-term illness and mental distress compared to exclusive use of either product. Tobacco control policies and smoking cessation programs should address the concurrent use of both conventional cigarettes and e-cigarettes.
Objective: To observe and evaluate the application of the medical consortium model in improving the quality of acute ischemic stroke treatment. Methods: Acute ischemic stroke patients admitted to the Department of Neurology at the Third People's Hospital of Shunde District of Foshan City, from 2016 to 2020 were selected. Patients admitted from July 2016 to December 2017 were classified as the pre-intervention group (before receiving assistance measures from the First Affiliated Hospital of Jinan University via the “medical consortium model”). Patients admitted from January 2018 to June 2019 were classified as the early-intervention group (receiving initial assistance measures via the medical consortium model), and those admitted from July 2019 to December 2020 were classified as the mature-intervention group (receiving optimized assistance measures via the medical consortium model). The medical quality control indicators were compared among the three groups. Results: The proportion of patients undergoing neurological deficit assessment increased from 0.6% in the pre-intervention group to 90.3% in the mature-intervention group. The thrombolysis rate for ischemic stroke patients within 4.5 hours of onset rose from 45.5% in the early-intervention group to 75.9% in the mature-intervention group. The proportion of patients with a door-to-needle time (DNT) ≤60 minutes increased from 45% in the early-intervention group to 95.2% in the mature-intervention group, while the proportion with DNT ≤45 minutes rose from 5% to 85.7%, and DNT ≤30 minutes increased from 5% to 55.6%. All differences were statistically significant (P<0.001). The rates of dual antiplatelet therapy within 24 hours for non-disabling ischemic stroke were 20.5% (23/112), 57.6% (68/118), and 77.1% (111/144) in the three groups, respectively. The screening rates for swallowing function in ischemic stroke patients were 0.0% (0/159), 31.2% (54/173), and 73.8% (183/248), respectively. The rehabilitation assessment rates were 12.0% (19/159), 16.8% (29/173), and 37.1% (92/248), respectively. All intergroup differences were statistically significant (P<0.05). Conclusion: The medical consortium model significantly improves the level of standardized diagnosis and treatment, as well as the medical quality, for acute ischemic stroke in primary hospitals.
Objective: Prepare a sulfhydrylated hyaluronic acid hydrogel loaded with Interleukin-13 (IL-13) to regulate the inflammatory and proliferative phases during wound repair by mediating macrophage polarization. Methods: Thiolated hyaluronic acid hydrogel (HA-SH) was prepared with Sulfhydryl-modified hyaluronic acid (HA) and the gel was characterized for its injectability, mechanical properties, adhesion and water absorption. IL-13/HA-SH hydrogels were prepared by adding IL-13, and the ability of IL-13/HA-SH hydrogels to mediate macrophage polarization was investigated. Results: Physicochemical characterization showed that 6% HA-SH had the best performance, short gel formation time, uniform and tight pore distribution, good mechanical properties and water absorption capacity. IL-13/HA-SH hydrogel had the highest M2∶M1 ratio of cultured macrophage, promoted the secretion of inflammation-suppressing factors IL-10 and TGF-β, and up-regulated the secretion of Arg-1 and TGF-β, while decreasing the secretion of pro-inflammatory factors TNF-α and IL-1β, and down-regulating the gene expression levels of TNF-α and CD80. Conclusion: IL-13/HA-SH hydrogel can mediate macrophage polarization to M2 type and reduce inflammatory response, which has a good prospect for application in the field of wound dressing.
Objective: To Explore the physiological responses of three moss plants to Cd stress and provide a useful reference for ecological restoration in Cd-contaminated areas. Methods: Thuidium cymbifolium, Dicranum nipponense and Racomitrium japonicum were used as materials in a laboratory Cd stress experiment. Through physiological and biochemical measurements, the response differences of chlorophyll mass fraction, osmoregulatory substances mass fraction, membrane damage degree, antioxidant enzyme activity, and enrichment characteristics of three moss plants to five different concentrations of Cd stress were compared to explore their sensitivity and tolerance to Cd stress. Results: Low mass concentration Cd stress(5 mg·L-1) activated the adaptive regulation of mosses, significantly enhancing the antioxidant enzyme(SOD, GPX) activity of Thuidium cymbifolium and Dicranum nipponense. The Chl mass fraction increased by 6.81% and 7.06% respectively compared to the control, and the SP mass fraction increased by 41.69% and 31.91%. High mass concentration of Cd stress(100 mg·L-1) resulted in a significant decrease in Chla, Chlb, and Chl mass fraction of three mosses(37.73%~44.55%, 28.50%~32.86%, 34.77%~40.74%, respectively), a significant increase in RC(34.73%~51.16%), a significant decrease in SP mass fraction(40.41%~66.67%), a significant decrease in GPX and SOD activities(10.66%~14.91%, 17.74%~25.00%, respectively). And the MDA mass fraction were 2.36, 2.79 and 3.77 times higher than the control, respectively. Interspecies comparisons revealed that Racomitrium japonicum was the most sensitive to Cd, showing a linear increase in Pro content with Cd concentration, the weakest antioxidant enzyme activity(GPX decreased by 14.9%), and the lowest tolerance indices(BCF=0.02, Ti=0.30) under high mass concentration Cd stress. In contrast, Thuidium cymbifolium exhibited the strongest tolerance, with the highest bioconcentration factor(BCF=0.03) and tolerance index(Ti=0.43), along with minimal declines in antioxidant enzyme activity. Conclusion: Thuidium cymbifolium is a potential candidate for ecological restoration in Cd-contaminated areas, while the low tolerance of Racomitrium japonicum could be used as a biomarker for monitoring early-stage Cd pollution.
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