Objective: To analyze the developmental trajectories of clustered health risk behaviors and their association with self-esteem and lonelinesss among junior high school students, so as to provide a reference for formulating comprehensive prevention and control measures of health risk behaviors among adolescents. Methods: In October 2023, 1 165 first year junior high school students from two schools of Jishou City in Hunan Province were selected by convenient sampling method for three follow up surveys (T1:October 2023; T2:April 2024; T3:October 2024). The Adolescent Health Risk Behavior Questionnaire, Rosenberg Self esteem Scale and Loneliness Scale were used to assess health risk behaviors, self esteem and loneliness, respectively. Latent growth curve modeling and latent growth mixture modeling were applied to analyze the developmental trajectories of clustered health risk behaviors among junior high school students. Logistic regression was used to analyze the association of the developmental trajectories of clustered health risk behaviors with self esteem and loneliness among junior high school students. Results: The overall developmental trajectories among junior high school students showed a declining trend (intercept=0.15, slope=-1.65, both P <0.05), with three heterogeneous categories:low risk improvement group ( n =862, 74.0%), moderate risk stable group ( n =260, 22.3%), and high risk deterioration group ( n =43, 3.7%). After adjusting the status of the left behind individuals，using the low risk improvement group as the reference category in multinomial Logistic regression analysis, results indicated that higher loneliness scores among junior high school students increased the risks of belonging to the moderate risk stable group ( OR=1.02, 95%CI =1.00- 1.04 ) and the high risk deterioration group ( OR=1.04, 95%CI =1.00-1.08), while higher self esteem scores reduced the risks of belonging to the moderate risk stable group ( OR=0.93, 95%CI =0.91-0.96) and the high risk deterioration group ( OR=0.88, 95%CI =0.83-0.94) (all P <0.05). Conclusions The overall trend of clustered health risk behaviors among junior high school students gradually improves, and the self esteem and loneliness are significant correlative factors. Targeted intervention measures should be developed for the junior high school students, with a focus on enhancing their self esteem and alleviating loneliness.

Objective: To investigate the relationship between 24 hour activity behaviors and fine motor development in preschool children, and to simulate the effects of reallocating time among different activity behaviors on fine motor development using isotemporal substitution analysis. Methods: From March to July 2022, a stratified cluster random sampling method was used to recruit 447 preschool children aged 3-6 years (254 boys and 193 girls) from Pingxiang City, Jiangxi Province. The 24 hour activity behaviors in preschool children were measured using ActiGraph wGT3-BT accelerometers and subjective sleep reports. Fine motor development was assessed using the Gesell Developmental Schedules. A component linear regression model was employed to analyze the impact of 24 hour activity behaviors on the development of fine motor activities, and the potential effects of adjusting activity behaviors were simulated through an isochoric substitution model. Results: The daily durations of sedentary behavior (SB) was ( 572.92 ±102.96) min (accounting for 39.79% of 24 h), the duration of light physical activity (LPA) was (131.21± 38.11 ) min ( 9.11% ), the duration of moderate to vigorous physical activity (MVPA) was (65.61±22.21) min (4.56%), and sleep duration was (670.65±57.58) min (46.82%). Sleep composition was positively associated with fine motor development ( β =2.74), while MVPA ( β =-0.84) and SB ( β =-1.93) compositions were negatively associated with fine motor development (all P <0.01). Isochoric substitution analysis showed that sleep had positive effects on the development of fine motor skills when replacing other activity behaviors (all P < 0.05), with the substitution effect for MVPA being the most significant and gradually increasing with the duration of substitution (60 min: β =28.66); sleep replacement of SB and LPA also showed positive effects (60 min: β =4.25, 2.00) (all P < 0.05). On the contrary, the substitution of sleep with MVPA showed negative effects (60 min: β =-7.86), and the substitution of LPA and SB with MVPA also showed negative effects (60 min: β =-5.65, -3.40) (all P <0.05). Conclusions The overall composition of 24 hour activity behaviors is associated with fine motor development in preschool children, with sleep playing a crucial role. Ensuring adequate sleep and optimizing the structure of activity behaviors may effectively promote the development of fine motor skills in preschool children.

Diabetic Nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) globally, representing a major global health burden with limited disease-modifying therapies. Podocyte injury serves as the core pathological hallmark of DN, and conventional treatments targeting metabolic disorders or hemodynamic abnormalities fail to reverse the progressive decline of renal function. Accumulating evidence over the past decade has established that high glucose-induced podocyte pyroptosis—a pro-inflammatory form of programmed cell death—is a key driving force in DN progression. Its core molecular mechanism hinges on the activation of the TXNIP-NLRP3 inflammasome axis. Under sustained hyperglycemic conditions, excessive reactive oxygen species (ROS) are generated via pathways including the polyol pathway, advanced glycation end products (AGEs) accumulation, and mitochondrial dysfunction. Concurrently, methylglyoxal (a glucose metabolite) mediates post-translational modification of thioredoxin-interacting protein (TXNIP). These events collectively trigger the dissociation of TXNIP from thioredoxin (TRX), a redox-regulating protein. The free TXNIP then translocates to the mitochondria, where it binds to The NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) and promotes inflammasome assembly. This assembly activates cysteine-aspartic acid protease 1 (caspase-1), which cleaves Gasdermin D (GSDMD) to generate its N-terminal fragment (GSDMD-NT). GSDMD-NT oligomerizes to form membrane pores, leading to podocyte swelling, rupture, and the release of pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18). These cytokines amplify local inflammatory responses, induce mesangial cell proliferation, and accelerate extracellular matrix deposition, ultimately exacerbating glomerulosclerosis. MCC950, a highly selective NLRP3 inhibitor, exerts its therapeutic effects through a multi-layered mechanism: it binds to the NACHT domain (NAIP, CIITA, HET-E and TP1 domain) of NLRP3 with nanomolar affinity, forming hydrogen bonds with key residues (Lys-42 and Asp-166) within the ATP-hydrolysis pocket to block ATP hydrolysis, thereby locking NLRP3 in an inactive conformational state. Additionally, MCC950 interferes with the protein-protein interaction between TXNIP and NLRP3 and regulates mitochondrial homeostasis to reduce ROS production. Preclinical studies have demonstrated that MCC950 dose-dependently reduces proteinuria, restores the expression of podocyte-specific markers (nephrin and Wilms tumor 1 protein, WT1), and alleviates podocyte foot process fusion and glomerulosclerosis in both streptozotocin (STZ)-induced type 1 diabetic models (characterized by absolute insulin deficiency) and db/db type 2 diabetic models (driven by insulin resistance). However, discrepancies in therapeutic outcomes exist across different models—some studies report exacerbated renal inflammation and fibrosis in STZ-induced models—which may stem from differences in disease pathogenesis, intervention timing (early vs. mid-stage disease), and dosing duration. Despite its promising preclinical efficacy, MCC950 faces significant translational challenges, including low oral bioavailability, insufficient podocyte targeting, potential hepatotoxicity, and drug-drug interactions with statins (commonly prescribed to diabetic patients for cardiovascular risk management). Furthermore, off-target effects such as the inhibition of carbonic anhydrase 2 have been identified, raising concerns about its safety profile. Nevertheless, its unique mechanism of action—directly blocking podocyte pyroptosis by targeting the TXNIP-NLRP3 axis—endows it with substantial translational value. In the future, strategies to overcome these barriers are expected to advance its clinical application: targeted delivery via nanocarriers (e.g., PLGA-PEG nanoparticles or nephrin antibody-conjugated systems) to enhance renal accumulation and podocyte specificity; precise patient stratification based on biomarkers such as serum IL-18 and renal TXNIP/NLRP3 expression to identify “inflammatory-phenotype” DN patients most likely to benefit; and combination therapy with sodium-glucose cotransporter 2 (SGLT2) inhibitors—whose metabolic benefits synergize with MCC950’s anti-inflammatory effects. These approaches hold great potential to break through clinical translation bottlenecks, offering a novel, precise anti-inflammatory treatment option for DN and addressing an unmet clinical need for therapies targeting the inflammatory underpinnings of the disease.

Diabetic Nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) globally, representing a major global health burden with limited disease-modifying therapies. Podocyte injury serves as the core pathological hallmark of DN, and conventional treatments targeting metabolic disorders or hemodynamic abnormalities fail to reverse the progressive decline of renal function. Accumulating evidence over the past decade has established that high glucose-induced podocyte pyroptosis—a pro-inflammatory form of programmed cell death—is a key driving force in DN progression. Its core molecular mechanism hinges on the activation of the TXNIP-NLRP3 inflammasome axis. Under sustained hyperglycemic conditions, excessive reactive oxygen species (ROS) are generated via pathways including the polyol pathway, advanced glycation end products (AGEs) accumulation, and mitochondrial dysfunction. Concurrently, methylglyoxal (a glucose metabolite) mediates post-translational modification of thioredoxin-interacting protein (TXNIP). These events collectively trigger the dissociation of TXNIP from thioredoxin (TRX), a redox-regulating protein. The free TXNIP then translocates to the mitochondria, where it binds to The NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) and promotes inflammasome assembly. This assembly activates cysteine-aspartic acid protease 1 (caspase-1), which cleaves Gasdermin D (GSDMD) to generate its N-terminal fragment (GSDMD-NT). GSDMD-NT oligomerizes to form membrane pores, leading to podocyte swelling, rupture, and the release of pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18). These cytokines amplify local inflammatory responses, induce mesangial cell proliferation, and accelerate extracellular matrix deposition, ultimately exacerbating glomerulosclerosis. MCC950, a highly selective NLRP3 inhibitor, exerts its therapeutic effects through a multi-layered mechanism: it binds to the NACHT domain (NAIP, CIITA, HET-E and TP1 domain) of NLRP3 with nanomolar affinity, forming hydrogen bonds with key residues (Lys-42 and Asp-166) within the ATP-hydrolysis pocket to block ATP hydrolysis, thereby locking NLRP3 in an inactive conformational state. Additionally, MCC950 interferes with the protein-protein interaction between TXNIP and NLRP3 and regulates mitochondrial homeostasis to reduce ROS production. Preclinical studies have demonstrated that MCC950 dose-dependently reduces proteinuria, restores the expression of podocyte-specific markers (nephrin and Wilms tumor 1 protein, WT1), and alleviates podocyte foot process fusion and glomerulosclerosis in both streptozotocin (STZ)-induced type 1 diabetic models (characterized by absolute insulin deficiency) and db/db type 2 diabetic models (driven by insulin resistance). However, discrepancies in therapeutic outcomes exist across different models—some studies report exacerbated renal inflammation and fibrosis in STZ-induced models—which may stem from differences in disease pathogenesis, intervention timing (early vs. mid-stage disease), and dosing duration. Despite its promising preclinical efficacy, MCC950 faces significant translational challenges, including low oral bioavailability, insufficient podocyte targeting, potential hepatotoxicity, and drug-drug interactions with statins (commonly prescribed to diabetic patients for cardiovascular risk management). Furthermore, off-target effects such as the inhibition of carbonic anhydrase 2 have been identified, raising concerns about its safety profile. Nevertheless, its unique mechanism of action—directly blocking podocyte pyroptosis by targeting the TXNIP-NLRP3 axis—endows it with substantial translational value. In the future, strategies to overcome these barriers are expected to advance its clinical application: targeted delivery via nanocarriers (e.g., PLGA-PEG nanoparticles or nephrin antibody-conjugated systems) to enhance renal accumulation and podocyte specificity; precise patient stratification based on biomarkers such as serum IL-18 and renal TXNIP/NLRP3 expression to identify “inflammatory-phenotype” DN patients most likely to benefit; and combination therapy with sodium-glucose cotransporter 2 (SGLT2) inhibitors—whose metabolic benefits synergize with MCC950’s anti-inflammatory effects. These approaches hold great potential to break through clinical translation bottlenecks, offering a novel, precise anti-inflammatory treatment option for DN and addressing an unmet clinical need for therapies targeting the inflammatory underpinnings of the disease.

The recombinant human thyroid-stimulating hormone (rhTSH) can be used for differentiated thyroid cancer (DTC) preparation before ¹³¹I therapy, and follow-up. Since its approval by the American Food and Drug Administration (FDA) in 1998, rhTSH has been clinically used in European countries, the United States, and other countries for nearly 30 years. In April 2024, China’s first independently developed rhTSH agent was approved. Based on clinical experience and evidence from domestic and international studies, an expert consensus on the application of rhTSH has been developed following thorough consultations among experts. The consensus offers evidence-based recommendations to guide the appropriate use of rhTSH in clinical practice.

BACKGROUND:Recent studies have found that Nrf2/ARE signaling pathway activators have the characteristics of low toxicity and control,and have a protective effect against radiation tissue damage.OBJECTIVE:To investigate whether nitrooleic acid can protect submandibular gland epithelial cells from radiation injury by regulating the Nrf2/ARE signaling pathway.METHODS:Rat submandibular gland epithelial cells were cultured in vitro and CCK-8 assay was used to screen the optimal concentration and time of nitrooleic acid administration.Submandibular gland epithelial cells were divided into non-radiation group,radiation control group,nitrooleic acid group,nitrooleic acid+ML385(Nrf2/ARE signaling pathway specific inhibitor)group,and ML385 group.Submandibular gland cells were pretreated with nitrooleic acid and ML385 for 24 hous according to the experimental groups,and then irradiated with 5 Gy radiation to establish the models.At 48 hours after irradiation,CCK-8 assay was used to detect the cell proliferation rate.Real-time quantitative PCR was used to detect the expression of Nrf2,HO-1,and NQO1 mRNA in the cells.Real-time quantitative PCR and enzyme-linked immunosorbent assay were used to detect the cell secretion function and the expression of inflammatory factors.DCFH-DA fluorescent probe kit was used to detect the level of intracellular reactive oxygen species.RESULTS AND CONCLUSION:(1)Compared with the radiation control group,the proliferation rate of submandibular gland epithelial cells and the expression levels of secretion function related factors aquaporin 5 and α-amylase in the nitrooleic acid group of rats increased(P＜0.05),and the expression levels of Nrf2,HO-1,and NQO1 mRNA increased(P＜0.05),while the expression levels of inflammatory factors interleukin-1β,interleukin-6,and tumor necrosis factor-αdecreased(P＜0.05),and reactive oxygen species generation reduced(P＜0.01).(2)Compared with the nitrooleic acid group,the addition of nitrooleic acid and ML385 group resulted in a decrease in cell proliferation rate and expression levels of secretion function related factors aquaporin 5 and α-amylase(P＜0.05),and mRNA expressions of Nrf2,HO-1,and NQO1 were all decreased(P＜0.05),while the expression levels of inflammatory factors interleukin-1β,interleukin-6,and tumor necrosis factor-α increased(P＜0.05),and generation of reactive oxygen species increased(P＜0.05).(3)Results indicated that in the radiation environment,nitrooleic acid has a certain protective effect on the proliferation ability and secretion function of rat submandibular gland epithelial cells,reduces the expression of inflammatory factors,lowers intracellular reactive oxygen species levels,and alleviates the damage of rat submandibular gland epithelial cells caused by radiation.This function may be related to the activation of Nrf2/ARE signaling pathway.

BACKGROUND:Radiotherapy for head and neck tumors can easily cause xerostomia,seriously affecting the quality of life of patients.In recent years,engineered stem cells and their paracrine factors have shown therapeutic potential in the repair of salivary gland injury.However,there is currently no experimental study on the application of amniotic mesenchymal stem cell-derived exosome in radiation-induced salivary gland injury.OBJECTIVE:To preliminarily explore the repair effect of exosome derived from human amniotic mesenchymal stem cells on radiation-induced submandibular gland injury.METHODS:H uman amniotic mesenchymal stem cell exosomes were extracted and identified by ultrafiltration and ultracentrifugation.SD rats were randomly divided into a control group,a radiation injury group,and a radiation injury+exosome group.An in vitro model of radiation-induced submandibular gland injury was constructed using the submandibular gland tissue of SD rats irradiated with 18 Gy of radiation.One day after radiation modeling,exosome derived from human amniotic mesenchymal stem cells was injected into the submandibular gland in situ.Samples are taken at 1,3,7,and 14 days to detect the resting salivary flow rate.The structure of the submandibular gland tissue was observed by hematoxylin-eosin staining.The expression of glycogen particles in the submandibular gland tissue was observed by Periodic Acid-Schiff staining.Fibrosis in the submandibular gland tissue was observed by Masson staining.The secretion of salivary amylase was detected by enzyme-linked immunosorbent assay.The expression of aquaporin and tight junction proteins in submandibular gland tissue was observed by immunofluorescence staining.Real-time fluorescence quantitative PCR was used to detect the relative expression levels of aquaporins and salivary amylase mRNA in submandibular gland tissue.TUNEL assay was used to detect the apoptosis rate of submandibular gland tissues in each group.RESULTS AND CONCLUSION:After radiomodeling,compared with the radiation injury group,(1)hematoxylin-eosin staining observed that the submandibular gland tissue structure in the radiation injury+exosome group was restored,the nucleoli increased,the number of acinus increased,and the acinar atrophy improved.(2)Glycogen staining observed that the number and density of positive zymogen granules in the acinar cytoplasm of the radiation injury+exosome group gradually increased.(3)Masson staining results observed that the number and density of positive collagen fibers in the interstitium and around the ducts in the radiation injury+exosome group gradually decreased,the degree of fibrosis decreased,and the collagen deposition decreased.(4)The salivary flow rate in the radiation injury+exosome group increased(P＜0.05).The fluorescence intensity of aquaporin-5 was enhanced(P＜0.05)and the gene expression was significantly enhanced(P＜0.01).The fluorescence distribution of tight junction protein 4 was weakened and the fluorescence intensity decreased(P＜0.05,P＜0.01).The content of salivary amylase increased(P＜0.05)and gene expression were significantly increased(P＜0.01).The number of positive apoptotic cells decreased(P＜0.05,P＜0.01).It is indicated that local injection of exosome derived from human amniotic mesenchymal stem cells could improve the pathological morphology of submandibular gland tissue,promote saliva flow rate and amylase expression,and may play a functional repair role in radioactive submandibular gland injury by inhibiting acinar apoptosis.

Objective:To explore the predictive factors for extubation in the operating room after single lung transplantation without the assistance of extracorporeal membrane oxygenation (ECMO) in adult patients with end-stage interstitial lung disease (ILD), as well as their short-term (1-year postoperative) prognosis.Methods:A retrospective analysis was conducted on the clinical data of 78 adult ILD recipients who underwent single lung transplantation without ECMO assistance at the First Affiliated Hospital of Guangzhou Medical University from June 2018 to June 2023. Based on whether extubation was completed in the operating room (OR), patients were divided into the OR group (19 cases) and ICU group (59 cases). Baseline characteristics of donors and recipients, as well as intraoperative events, were compared between the two groups. Univariate logistic regression analysis was used to identify potential predictors, and variables with P<0.2 were included in multivariate logistic regression to determine independent predictors for OR extubation. Receiver operating characteristic (ROC) curves were plotted to evaluate predictive performance. The Kaplan-Meier method was used to analyze survival, and short-term prognosis between groups was compared. Results:The rate of OR extubation after single lung transplantation in ILD recipients was 24%(19/78). Compared with the ICU group, the OR group had shorter operation times, lower fluid volumes, reduced transfusions of red blood cells and plasma, less intraoperative bleeding, and lower lactate levels 15 minutes after pulmonary artery reperfusion (all P<0.05). Univariate logistic regression analysis identified the following factors as significantly associated with OR extubation: recipient age ( P=0.100), operative time ( P=0.001), fluid infusion volume ( P=0.005), red blood cell transfusion volume ( P=0.037), plasma transfusion volume ( P=0.039), blood loss ( P=0.004), oxygenation index at 15 minutes after reperfusion ( P=0.174), and blood lactate at 15 minutes after reperfusion ( P=0.041). Multivariate analysis revealed that intraoperative blood loss was an independent predictor of OR extubation ( OR=0.993, 95% CI: 0.986 - 0.999, P=0.026). ROC curve analysis showed that blood loss had an area under the curve (AUC) of 0.822 in predicting OR extubation, with a sensitivity of 64.4% and specificity of 89.5%. Postoperatively, patients in the OR group had significantly shorter durations of mechanical ventilation [0 vs 5 (3,11) days, P<0.001], ICU stay [7(4,8) vs 9(6,20) days, P=0.012], and overall postoperative hospitalization [19 (15,23) vs 25 (19,39) days, P=0.015]. Within one year after surgery, 2 patients (11%) in the OR group and 19 patients (32%) in the ICU group had died, but the difference in 1-year survival rates between the two groups was not statistically significant. Conclusions:Intraoperative blood loss is an independent predictor of extubation in the operating room. Early extubation in non-ECMO-assisted single lung transplantation for ILD patients is associated with improved short-term outcomes.

OBJECTIVE: To explore the protective effects and underlying mechanisms of H ₂S against lipid peroxidation-mediated carbonyl stress in the uranium-treated NRK-52E cells. METHODS: Cell viability was evaluated using CCK-8 assay. Apoptosis was measured using flow cytometry. Reagent kits were used to detect carbonyl stress markers malondialdehyde, 4-hydroxynonenal, thiobarbituric acid reactive substances, and protein carbonylation. Aldehyde-protein adduct formation and alcohol dehydrogenase, aldehyde dehydrogenase 2, aldo-keto reductase, nuclear factor E2-related factor 2 (Nrf2), and cystathionine β-synthase (CBS) expression were determined using western blotting or real-time PCR. Sulforaphane (SFP) was used to activate Nrf2. RNA interference was used to inhibit CBS expression. RESULTS: GYY4137 (an H ₂S donor) pretreatment significantly reversed the uranium-induced increase in carbonyl stress markers and aldehyde-protein adducts. GYY4137 effectively restored the uranium-decreased Nrf2 expression, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2, accompanied by a reversal of the uranium-decreased expression of CBS and aldehyde-metabolizing enzymes. The application of CBS siRNA efficiently abrogated the SFP-enhanced effects on the expression of CBS, Nrf2 activation, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2 and concomitantly reversed the SFP-enhanced effects of the uranium-induced mRNA expression of aldehyde-metabolizing enzymes. Simultaneously, CBS siRNA reversed the SFP-mediated alleviation of the uranium-induced increase in reactive aldehyde levels, apoptosis rates, and uranium-induced cell viability. CONCLUSION H ₂S induces Nrf2 activation and nuclear translocation, which modulates the expression of aldehyde-metabolizing enzymes and the CBS/H ₂S axis. Simultaneously, the Nrf2-controlled CBS/H ₂S axis may at least partially promote Nrf2 activation and nuclear translocation. These events form a cycle-regulating mode through which H ₂S attenuates the carbonyl stress-mediated NRK-52E cytotoxicity triggered by uranium.
NF-E2-Related Factor 2/genetics* ; Animals ; Hydrogen Sulfide/pharmacology* ; Rats ; Signal Transduction/drug effects* ; Lipid Peroxidation/drug effects* ; Cell Line ; Uranium/toxicity* ; Antioxidant Response Elements ; Kidney/metabolism* ; Oxidative Stress/drug effects* ; Cell Survival/drug effects* ; Apoptosis/drug effects*

BACKGROUND:Radiotherapy for head and neck tumors can easily cause xerostomia,seriously affecting the quality of life of patients.In recent years,engineered stem cells and their paracrine factors have shown therapeutic potential in the repair of salivary gland injury.However,there is currently no experimental study on the application of amniotic mesenchymal stem cell-derived exosome in radiation-induced salivary gland injury.OBJECTIVE:To preliminarily explore the repair effect of exosome derived from human amniotic mesenchymal stem cells on radiation-induced submandibular gland injury.METHODS:H uman amniotic mesenchymal stem cell exosomes were extracted and identified by ultrafiltration and ultracentrifugation.SD rats were randomly divided into a control group,a radiation injury group,and a radiation injury+exosome group.An in vitro model of radiation-induced submandibular gland injury was constructed using the submandibular gland tissue of SD rats irradiated with 18 Gy of radiation.One day after radiation modeling,exosome derived from human amniotic mesenchymal stem cells was injected into the submandibular gland in situ.Samples are taken at 1,3,7,and 14 days to detect the resting salivary flow rate.The structure of the submandibular gland tissue was observed by hematoxylin-eosin staining.The expression of glycogen particles in the submandibular gland tissue was observed by Periodic Acid-Schiff staining.Fibrosis in the submandibular gland tissue was observed by Masson staining.The secretion of salivary amylase was detected by enzyme-linked immunosorbent assay.The expression of aquaporin and tight junction proteins in submandibular gland tissue was observed by immunofluorescence staining.Real-time fluorescence quantitative PCR was used to detect the relative expression levels of aquaporins and salivary amylase mRNA in submandibular gland tissue.TUNEL assay was used to detect the apoptosis rate of submandibular gland tissues in each group.RESULTS AND CONCLUSION:After radiomodeling,compared with the radiation injury group,(1)hematoxylin-eosin staining observed that the submandibular gland tissue structure in the radiation injury+exosome group was restored,the nucleoli increased,the number of acinus increased,and the acinar atrophy improved.(2)Glycogen staining observed that the number and density of positive zymogen granules in the acinar cytoplasm of the radiation injury+exosome group gradually increased.(3)Masson staining results observed that the number and density of positive collagen fibers in the interstitium and around the ducts in the radiation injury+exosome group gradually decreased,the degree of fibrosis decreased,and the collagen deposition decreased.(4)The salivary flow rate in the radiation injury+exosome group increased(P＜0.05).The fluorescence intensity of aquaporin-5 was enhanced(P＜0.05)and the gene expression was significantly enhanced(P＜0.01).The fluorescence distribution of tight junction protein 4 was weakened and the fluorescence intensity decreased(P＜0.05,P＜0.01).The content of salivary amylase increased(P＜0.05)and gene expression were significantly increased(P＜0.01).The number of positive apoptotic cells decreased(P＜0.05,P＜0.01).It is indicated that local injection of exosome derived from human amniotic mesenchymal stem cells could improve the pathological morphology of submandibular gland tissue,promote saliva flow rate and amylase expression,and may play a functional repair role in radioactive submandibular gland injury by inhibiting acinar apoptosis.