ObjectiveTo investigate the potential mechanism of Danggui Shaoyaosan （DSS） in ameliorating renal injury in db/db mice. MethodsThirty 8-week-old specific pathogen-free （SPF）-grade male db/db mice and six db/m mice were acclimated for one week. Urinary microalbumin and blood glucose levels were measured weekly in both db/db and db/m mice. Successful modeling was determined by significantly higher microalbuminuria in db/db mice compared to db/m mice and a fasting blood glucose ≥16.7 mmol·L^-1. The 30 db/db mice were randomly divided into five groups： the model group， the irbesartan （IBN） group， and three DSS dose groups （low-， medium-， and high-dose DSS groups， administered at 16.77， 33.54， 67.08 g·kg^-1·d^-1， respectively）. Additionally， the six db/m mice served as the normal control group. The IBN group received irbesartan at 0.025 g·kg^-1·d^-1 by gavage， while the three DSS groups received DSS at 16.77， 33.54， and 67.08 g·kg^-1·d^-1 by gavage， respectively. The normal and model groups were administered with an equivalent volume of normal saline by gavage. All interventions lasted for 8 consecutive weeks. After intervention， serum creatinine （SCr）， blood urea nitrogen （BUN）， urinary total protein （UTP）， triglyceride （TG）， and low-density lipoprotein cholesterol （LDL-C） were measured to evaluate the therapeutic efficacy of the treatments. Renal histopathological changes were observed with hematoxylin-eosin （HE） staining. Western blot was used to detect the protein expression of silencing information regulator 1 （SIRT1）， hypoxia-inducible factor-1α （HIF-1α）， very low-density lipoprotein receptor （VLDLr）， and cluster of differentiation 31 （CD31）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA levels of HIF-1α and VLDLr. Immunohistochemistry was used to observe the expression and distribution of HIF-1α and Caspase-3. ResultsCompared to the normal group， the model group showed significantly increased SCr， BUN， UTP， TG， and LDL-C. HE staining revealed glomerulosclerosis， mesangial matrix hyperplasia， capillary loop distortion and thickening， with extensive inflammatory cell infiltration. Protein expression of SIRT1 and CD31 significantly decreased （P<0.05）， while HIF-1α and VLDLr protein and mRNA levels increased （P<0.05）. Immunohistochemistry showed increased expression of HIF-1α and Caspase-3 （P<0.05）， indicating hypoxia and apoptosis in renal cells. In all treatment groups， SCr， BUN， TG， and LDL-C were significantly reduced compared to the model group （P<0.05）， and UTP was significantly improved in the medium-dose DSS group （P<0.05）. Renal tissue structure and morphology were improved， inflammatory cells were reduced， and no vascular hyaline degeneration was observed. SIRT1 and CD31 protein expression was elevated to varying degrees compared to the model group （P<0.05）， while HIF-1α and VLDLr protein and mRNA levels decreased （P<0.05）. Immunohistochemistry showed reduced expression of HIF-1α and Caspase-3 in all treatment groups （P<0.05）， with the most significant improvement observed in the IBN group and medium-dose DSS group （P<0.05）. ConclusionDSS can effectively ameliorate glomerulosclerosis and lipid deposition in db/db mice， and its mechanism may involve the SIRT1/HIF-1α/VLDLr signaling pathway.

ObjectiveTo investigate the therapeutic efficacy of Danggui Shaoyaosan （DSS） on renal injury in db/db mice and its impact on endoplasmic reticulum stress （ERS） in renal tissues. MethodsThirty 8-week-old male db/db mice and six db/m mice were acclimated for one week， after which urinary microalbumin and blood glucose levels were monitored to establish a diabetic kidney disease （DKD） model. The model mice were randomly divided into a model group， an irbesartan group， and three DSS treatment groups with different doses （16.77， 33.54， and 67.08 g·kg^-1·d^-1）. A normal group was set as control. Each group was intragastrically administered with the corresponding drugs or saline for 8 weeks. After the intervention， general conditions were observed. Serum cystatin C （Cys-C）， 24-hour urinary total protein （24 h-UTP）， 24-hour urinary microalbumin （24 h-UMA）， urinary creatinine （Ucr）， and urea nitrogen （UUN） were measured. Transmission electron microscopy （TEM） was used to observe glomerular basement membrane （GBM） and ultrastructural changes of the endoplasmic reticulum （ER） in glomerular endothelial cells. Western blot， real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and immunohistochemistry were used to analyze renal tissue structure and the expression of GRP78， CHOP， and related markers. ResultsCompared with the normal group， the mice in the model group showed curled posture， sluggish response， poor fur condition， increased levels of Cys-C， 24 h-UTP， 24 h-UMA， and UUN （P<0.05）， while Ucr decreased （P<0.05）. The GBM was significantly thickened， with podocyte and foot process fusion. The protein expressions of GRP78， CHOP， and ATF6 were significantly upregulated （P<0.05）， the mRNA levels of GRP78 and CHOP increased （P<0.05）， and immunohistochemistry showed an enhanced GRP78 signal （P<0.05）. After treatment， the mice exhibited improved behavior， normalized GBM and podocyte structure， improved ER morphology and markedly better biochemical indicators. Western blot， Real-time PCR， and immunohistochemistry indicated that the ERS-related markers were downregulated in the DSS treatment groups （P<0.05）， suggesting alleviated ERS and improved renal function. ConclusionDSS can effectively ameliorate renal pathological damage in db/db mice， possibly by regulating ERS in glomerular endothelial cells， although the underlying signaling mechanisms require further investigation.

ObjectiveTo investigate whether Huanglian Jiedutang can inhibit neutrophil infiltration in the brains of middle cerebral artery occlusion （MCAO） mice by regulating the expression of neutrophil-related chemokines in exosomes， thereby achieving therapeutic effects. MethodsA total of 130 male specific pathogen-free （SPF） C57BL/6J mice were randomly divided into four groups： Sham-operated group， MCAO model group， Huanglian Jiedutang group （6 g·kg^-1）， and Ginaton group （21.6 mg·kg^-1）， with 10 mice in the Ginaton group and 40 mice in each of the remaining three groups. Mice in the Huanglian Jiedutang group and the Ginaton group were administered the corresponding drugs by oral gavage once daily at a volume of 0.15 mL·（10 g）^-1 for 7 consecutive days， while the sham-operated and model groups received an equal volume of saline via the same route. After 7 days， MCAO surgery was performed. The distal and proximal ends of the right common carotid artery （CCA） were ligated， a small incision was made between the two ligatures， and a silicone rubber-coated monofilament with a rounded tip was inserted into the lumen to occlude the CCA. The filament was left in place for 1 h to establish a focal cerebral ischemia model. At 24 h after modeling， mice were evaluated. Neurological function was assessed using the Longa score. Cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Cerebral blood flow was observed by laser speckle imaging. Hematoxylin and eosin （HE） staining and Nissl staining were used to observe pathological changes in brain tissues. Exosomes were isolated from mouse plasma and brain tissues by ultracentrifugation and molecular size exclusion and identified by electron microscopy， particle size analysis， and protein blotting. Long-chain RNA libraries of exosomes were constructed and sequenced. Real-time quantitative reverse transcription polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of inflammatory factors and neutrophil-related chemokines in exosomes from plasma and brain tissues of each group. Enzyme-linked immunosorbent assay （ELISA） was used to detect the protein expression of inflammatory factors and neutrophil-related chemokines in exosomes from brain tissues of each group. Immunohistochemistry was used to detect the expression of the neutrophil-specific protein myeloperoxidase （MPO） in the brains of mice in each group. ResultsCompared with the sham-operated group， the model group showed decreased neurological function scores （P<0.01）， obvious cerebral infarction （P<0.01）， reduced cerebral blood flow （P<0.01）， neuronal necrosis in the brain， and decreased numbers of Nissl bodies （P<0.01）. The mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were significantly increased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were increased （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were elevated （P<0.01）. Compared with the model group， the Huanglian Jiedutang group and the Ginaton group showed increased neurological function scores （P<0.05）， reduced cerebral infarct volume （P<0.01）， restored cerebral blood flow （P<0.01）， reduced necrotic cells in the brain， and increased numbers of Nissl bodies （P<0.01）. In the Huanglian Jiedutang group， the mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were decreased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were reduced （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were decreased （P<0.01）. ConclusionHuanglian Jiedutang can effectively regulate the expression of neutrophil-related chemokines in exosomes from plasma and brain tissues of MCAO mice， thereby reducing neutrophil infiltration in the brain and achieving therapeutic effects.

ObjectiveTo investigate whether Huanglian Jiedutang can inhibit neutrophil infiltration in the brains of middle cerebral artery occlusion （MCAO） mice by regulating the expression of neutrophil-related chemokines in exosomes， thereby achieving therapeutic effects. MethodsA total of 130 male specific pathogen-free （SPF） C57BL/6J mice were randomly divided into four groups： Sham-operated group， MCAO model group， Huanglian Jiedutang group （6 g·kg^-1）， and Ginaton group （21.6 mg·kg^-1）， with 10 mice in the Ginaton group and 40 mice in each of the remaining three groups. Mice in the Huanglian Jiedutang group and the Ginaton group were administered the corresponding drugs by oral gavage once daily at a volume of 0.15 mL·（10 g）^-1 for 7 consecutive days， while the sham-operated and model groups received an equal volume of saline via the same route. After 7 days， MCAO surgery was performed. The distal and proximal ends of the right common carotid artery （CCA） were ligated， a small incision was made between the two ligatures， and a silicone rubber-coated monofilament with a rounded tip was inserted into the lumen to occlude the CCA. The filament was left in place for 1 h to establish a focal cerebral ischemia model. At 24 h after modeling， mice were evaluated. Neurological function was assessed using the Longa score. Cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Cerebral blood flow was observed by laser speckle imaging. Hematoxylin and eosin （HE） staining and Nissl staining were used to observe pathological changes in brain tissues. Exosomes were isolated from mouse plasma and brain tissues by ultracentrifugation and molecular size exclusion and identified by electron microscopy， particle size analysis， and protein blotting. Long-chain RNA libraries of exosomes were constructed and sequenced. Real-time quantitative reverse transcription polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of inflammatory factors and neutrophil-related chemokines in exosomes from plasma and brain tissues of each group. Enzyme-linked immunosorbent assay （ELISA） was used to detect the protein expression of inflammatory factors and neutrophil-related chemokines in exosomes from brain tissues of each group. Immunohistochemistry was used to detect the expression of the neutrophil-specific protein myeloperoxidase （MPO） in the brains of mice in each group. ResultsCompared with the sham-operated group， the model group showed decreased neurological function scores （P<0.01）， obvious cerebral infarction （P<0.01）， reduced cerebral blood flow （P<0.01）， neuronal necrosis in the brain， and decreased numbers of Nissl bodies （P<0.01）. The mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were significantly increased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were increased （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were elevated （P<0.01）. Compared with the model group， the Huanglian Jiedutang group and the Ginaton group showed increased neurological function scores （P<0.05）， reduced cerebral infarct volume （P<0.01）， restored cerebral blood flow （P<0.01）， reduced necrotic cells in the brain， and increased numbers of Nissl bodies （P<0.01）. In the Huanglian Jiedutang group， the mRNA expression levels of IL-1β， MPO， CXCL1， CXCL2， CXCL3， CXCL10， CCL2， and CCL3 in exosomes from plasma and brain tissues were decreased （P<0.05， P<0.01）. The protein expression levels of IL-1β， MPO， CXCL2， and CXCL10 in exosomes from brain tissues were reduced （P<0.05， P<0.01）， and MPO-positive rates and mean optical density values in brain tissues were decreased （P<0.01）. ConclusionHuanglian Jiedutang can effectively regulate the expression of neutrophil-related chemokines in exosomes from plasma and brain tissues of MCAO mice， thereby reducing neutrophil infiltration in the brain and achieving therapeutic effects.

Objective: To explore the bidirectional associations among body mass index Z scores (BMI Z scores) and weight stigma with depressive symptoms in adolescents, thereby providing evidence for targeted intervention strategies. Methods: A stratified cluster random sampling method was employed to select 18 301 adolescents aged 12-18 years from all 12 prefectures (103 counties) in the Inner Mongolia Autonomous Region, and two waves of longitudinal surveys were conducted in September 2023 (T1) and September 2024 (T2) among the adolescents. Weight stigma was assessed by using a self developed questionnaire, depressive symptom was measured with the Center for Epidemiologic Studies Depression Scale (CES-D), and BMI Z scores were calculated according to the World Health Organization standards. Pearson correlation analysis was used to examine associations among variables, and cross lagged panel models were constructed to investigate the dynamic bidirectional relationships among the three variables. Results: Adolescents BMI Z scores and weight stigma with depressive symptoms all exhibited autoregressive stability across the two time points (autoregressive paths, all P <0.01). Cross lagged model comparisons indicated that the bidirectional path model achieved the best fit ( χ 2=12.65, RMSEA =0.017, CFI =1.000; △ χ 2=193.39, P <0.01), supporting dynamic bidirectional associations among the three variables. After adjusting for gender, age, subjective social status and only child status, T1 BMI Z scores among adolescents positively predicted T2 weight stigma ( β =0.061), and T1 weight stigma positively predicted T2 depressive symptoms ( β =0.608); in the reverse direction, T1 depressive symptoms predicted T2 weight stigma ( β =0.003), and T1 weight stigma predicted T2 BMI Z scores ( β =0.081) (all P <0.01). Conclusions There is a bidirectional cross lagged relationship among adolescents BMI Z scores and weight stigma with depressive symptoms, suggesting that weight stigma may serve as a key psychological variable linking obesity and depressive symptoms. Greater attention should be paid to the potential threat of weight stigma to adolescents mental health, with intervention strategies expanded from a solely physiological focus to encompass psychosocial dimensions.

This study aimed to investigate the inhibitory effect of tubuloside B (Tub B) on amyloid β-protein (Aβ), and analyse the potential mechanism. A model of amyloid fibril was established by incubation of Aβ_1-42 in vitro. Thioflavin-T (ThT), Congo red (CR), 8-anilino-1-naphthene sulfonic acid (ANS) staining and transmission electron microscopy (TEM) were applied to detect the suppression of Tub B on the formation of Aβ_1-42 fibril. Circular dichroism (CD) was used to analyse the regulatory effect of Tub B on the secondary structure of Aβ_1-42. 3-(4,5-Dimethyl-2-thiazole) -2,5-diphenyltetrazolium bromide (MTT) and red blood cell hemolysis experiments were used to investigate the attenuation of Tub B on Aβ_1-42 induced cytotoxicity. 2',7'-Dichlorofluorescin diacetate (DCFH-DA) staining was used to assess the expression of intracellular reactive oxygen species (ROS) induced by Aβ_1-42. And molecular docking experiment was used to explore the interaction between Tub B and Aβ_1-42. The results indicated that Tub B could inhibit Aβ_1-42 fibrillization in a certain extent, which retarded the structural transition of α-helix to β-sheet of Aβ_1-42, hampered the exposure of hydrophobic regions, and attenuated amyloid-induced cytotoxicity and hemolysis. In summary, Tub B can prevent the formation of Aβ_1-42 amyloid fibril, which may be related to its antioxidant activity and hydrogen bonding and hydrophobic interactions with protein molecules. All animal experiments were approved by the Experimental Animal Research Center of Air Force Medical University (No. 20190051).

OBJECTIVE: To determine the prevalence of lumbar spondylolysis (LS) and the proportion of spondylolytic spondylolisthesis (SS) in China, and to evaluate the musculoskeletal status of patients with LS and SS. METHODS: Spine Computed Tomography (CT) images were collected from community populations aged 40 and above in a nationwide multi-center project. LS was diagnosed, and SS was graded by an experienced radiologist. Bone mineral density (BMD) and paraspinal muscle parameters were quantified based on CT images. RESULTS: One hundred and seventeen patients of a total of 3,317 individuals were diagnosed with LS, corresponding to a prevalence rate of 3.53%. 63 of the 1,214 males (5.18%) and 54 of the 2,103 females (2.57%) were diagnosed with LS. SS occurred in 64/121 vertebrae (52.89%). BMD was not associated with LS ( P = 0.341). The L5 extensor paraspinal muscle density was higher in the LS group than in the non-LS group. In the LS group, patients with SS had a smaller L5 paraspinal extensor muscle cross-sectional area than those without SS ( P = 0.003). CONCLUSION The prevalence of LS in Chinese adults was 3.53%, with prevalence rates of 5.18% in males and 2.57% in females. Patients with LS have higher muscle density, whereas those with SS have smaller muscle cross-sectional areas at the L5 level.
Humans ; Male ; Female ; Middle Aged ; China/epidemiology* ; Prevalence ; Adult ; Lumbar Vertebrae/diagnostic imaging* ; Spondylolysis/diagnostic imaging* ; Aged ; Bone Density ; Tomography, X-Ray Computed ; Aged, 80 and over ; Spondylolisthesis/epidemiology* ; East Asian People

OBJECTIVE: To investigate the relationship between physical activity and genetic risk and their combined effects on the risk of developing chronic obstructive pulmonary disease. METHODS: This prospective cohort study included 318,085 biobank participants from the UK. Physical activity was assessed using the short form of the International Physical Activity Questionnaire. The participants were stratified into low-, intermediate-, and high-genetic-risk groups based on their polygenic risk scores. Multivariate Cox regression models and multiplicative interaction analyses were used. RESULTS: During a median follow-up period of 13 years, 9,209 participants were diagnosed with chronic obstructive pulmonary disease. For low genetic risk, compared to low physical activity, the hazard ratios ( HRs) for moderate and high physical activity were 0.853 (95% confidence interval [ CI]: 0.748-0.972) and 0.831 (95% CI: 0.727-0.950), respectively. For intermediate genetic risk, the HRs were 0.829 (95% CI: 0.758-0.905) and 0.835 (95% CI: 0.764-0.914), respectively. For participants with high genetic risk, the HRs were 0.809 (95% CI: 0.746-0.877) and 0.818 (95% CI: 0.754-0.888), respectively. A significant interaction was observed between genetic risk and physical activity. CONCLUSION Moderate or high levels of physical activity were associated with a lower risk of developing chronic obstructive pulmonary disease across all genetic risk groups, highlighting the need to tailor activity interventions for genetically susceptible individuals.
Humans ; Pulmonary Disease, Chronic Obstructive/epidemiology* ; Exercise ; Male ; Female ; Middle Aged ; Prospective Studies ; Aged ; Genetic Predisposition to Disease ; Risk Factors ; United Kingdom/epidemiology* ; Incidence ; Adult

Objective To investigate the expression levels of class Ⅰ histone deacetylases(HDAC)in the serum of patients with newly diagnosed psoriatic arthritis(PsA)and screen out serological indicators that are of significance for early diagnosis and assessment of disease activity.Methods A total of 49 PsA patients newly diagnosed in Shanxi Provincial People's Hospital from August 2022 to February 2024 and 30 healthy individuals(control group)were enrolled in this study.Demographic data were collected,and disease severity was assessed.Serum samples were collected,and the expression levels of class Ⅰ HDAC(HDAC1,HDAC2,HDAC3,and HDAC8)in the serum of each group were determined by ELISA.The correlations between the expression levels of class Ⅰ HDAC and clinical assessment indicators in each group were evaluated.Multivariate Logistic regression was adopted to analyze the risk factors affecting the disease activity of PsA patients.The receiver operating characteristic curve was used to evaluate the diagnostic efficacy of the risk factors affecting the disease activity of PsA patients.Results Compared with the control group,PsA patients showed up-regulated expression levels of HDAC1(P=0.003),HDAC2(P=0.010),HDAC3(P=0.003),and HDAC8(P=0.018)in the serum.The serum HDAC1 level of PsA patients was positively correlated with erythrocyte sedimentation rate(r=0.344,P=0.028).The serum HDAC2 level was positively correlated with the overall assessment of disease activity(r=0.468,P=0.001),the disease activity index of arthritis(r=0.401,P=0.007),the number of swollen joints(r=0.308,P=0.042),hospital anxiety and depression scale(HADS)score of anxiety(r=0.360,P=0.018),and HADS score of depression(r=0.302,P=0.047).The serum HDAC3 level was correlated with erythrocyte sedimentation rate(r=0.542,P<0.001),C-reactive protein(CRP)level(r=0.440,P<0.001),HADS score of anxiety(r=0.420,P=0.005),interleukin-6 level(r=0.397,P=0.004),the overall assessment of disease activity(r=0.318,P=0.036),and the course of psoriatic arthritis(r=0.330,P=0.028).The serum HDAC8 level was positively correlated with HADS score of anxiety(r=0.477,P=0.008)and erythrocyte sedimentation rate(r=0.385,P=0.039).Compared with the patients with low disease activity,those with moderate to high disease activity presented up-regulated expression of HDAC3(P=0.041).HDAC2(P=0.028)and CRP(P=0.034)were risk factors for moderate to high disease activity in PsA patients.HDAC2(area under the curve=0.802,P=0.003)and CRP(area under the curve=0.718,P=0.033)had diagnostic value for the progression of PsA.Conclusions The expression levels of class Ⅰ HDAC in the serum of patients with newly diagnosed PsA were significantly different.The serum levels of HDAC2 and CRP are expected to become serological indicators for the early diagnosis and disease activity assessment of PsA.
Humans ; Histone Deacetylases/blood* ; Arthritis, Psoriatic/diagnosis* ; Male ; Female ; Histone Deacetylase 1/blood* ; Histone Deacetylase 2/blood* ; Adult ; Middle Aged ; Clinical Relevance ; Repressor Proteins

Objective:To discuss the role of angiopoietin-like protein 6(ANGPTL6)in liver fibrosis,and to analyze the improving effect of engineered exosome(Exo)-delivered ANGPTL6 mRNA on liver fibrosis.Methods:A total of 12 C57BL/6 mice were randomly divided into olive oil group(OIL group)(intraperitoneally injected with olive oil)and carbon tetrachloride(CCl4)group(intraperitoneally injected with a mixture of olive oil and CCl?),with 6 mice in each group;another 12 C57BL/6 mice were randomly divided into control group(fed a with methionine-choline sufficient diet)and methionine-choline deficient(MCD)group(fed a with MCD diet),and two kinds of mouse liver fibrosis models were established.Real-time fluorescence quantitative PCR(RT-qPCR)and Western blotting method were used to detect the ANGPTL6 mRNA and protein expression levels in liver tissue of the mice in various groups.A total of 30 mice were randomly divided into olive oil+phosphate buffered saline(PBS)group(OIL+PBS group)(intraperitoneally injected with olive oil twice a week for 8 weeks,then injected with PBS buffer by tail vein twice a week for 6 weeks),CCl4+Exo-green fluorescent protein(GFP)mRNA group(established liver fibrosis model by intraperitoneal injection of CCl4 mixture and were injected by tail vein with engineered Exo loaded with GFP mRNA for 6 weeks),and CCl?+Exo-ANGPTL6 mRNA group(established liver fibrosis model by intraperitoneal injection of CCl4 mixture and were injected by tail vein with engineered Exo loaded with ANGPTL6 mRNA for 6 weeks),with 10 mice in each group.The mice in CCl4+Exo-GFP mRNA group and CCl4+Exo-ANGPTL6 mRNA group were injected with engineered Exo twice a week,20 μg per mouse each time(volume 100 μL).ELISA method was used to detect the serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)activities in the mice in various groups;Masson staining and Sirius red staining were used to observe the collagen deposition in liver tissue of the mice in various groups;immunohistochemistry method was used to detect the α-smooth muscle actin(α-SMA)expression levels in liver tissue of the mice in various groups;RT-qPCR method was used to detect the expression levels of α-SMA,collagen type Ⅰ alpha 1 chain(Col1a1),transforming growth factor β1(TGF-β1),and tissue inhibitor of metalloproteinase 1(TIMP-1)mRNA in liver tissue of the mice in various groups.Results:The bioinformatics analysis results showed that ANGPTL6 expression was significantly down-regulated in activated hepatic stellate cell(aHSC).The ultrasound examination results showed that the liver surface of the mice in OIL group was fine and smooth;compared with OIL group,the liver section of the mice in CCl? group was rough and uneven.The RT-qPCR and Western blotting results showed that compared with OIL group,the ANGPTL6 mRNA and protein expression levels in liver tissue of the mice in CCl? group were significantly decreased(P<0.05).The engineered Exo extracted from the supernatant of HEK293T cells had intact structure and could be largely enriched in the fibrotic liver after tail vein injection,with GFP protein being largely expressed in the liver.The ELISA assay results showed that compared with OIL+PBS group,the ALT and AST activities in CCl4+Exo-GFP mRNA group were significantly increased(P<0.05);compared with CCl4+Exo-ANGPTL6 mRNA group,the serum ALT and AST activities in CCl4+Exo-GFP mRNA group were significantly decreased(P<0.05).The Masson staining and Sirius red staining results showed that compared with OIL+PBS group,the collagen deposition in liver tissue of the mice in CCl?+Exo-GFP mRNA group was significantly increased,and the relative collagen area was increased(P<0.05);compared with CCl4+Exo-GFP mRNA group,the collagen deposition in tissue liver of the mice in CCl?+Exo-ANGPTL6 mRNA group was significantly decreased,and the relative collagen area was decreased(P<0.05).The immunohistochemistry results showed that compared with OIL+PBS group,the α-SMA protein expression level in liver tissue of the mice in CCl?+Exo-GFP mRNA group was significantly increased(P<0.05);compared with CCl4+Exo-GFP mRNA group,the α-SMA protein expression level in liver tissue of the mice in CCl?+Exo-ANGPTL6 mRNA group was significantly decreased(P<0.05).The RT-qPCR results showed that compared with OIL+PBS group,the expression levels of Col1a1,α-SMA,TGF-β1,and TIMP-1 mRNA in liver tissue of the mice in CCl?+Exo-GFP mRNA group were significantly increased(P<0.05);compared with CCl4+Exo-GFP mRNA group,the expression levels of Col1a1,α-SMA,TGF-β1,and TIMP-1 mRNA in liver tissue of the mice in CCl?+Exo-ANGPTL6 mRNA group were significantly decreased(P<0.05).Conclusion:Engineered Exo-delivered ANGPTL6 mRNA injected via the tail vein in the mice is mainly enriched in the liver,and engineered Exo delivery of ANGPTL6 mRNA has an improving effect on liver fibrosis in the mice.