BACKGROUND:The mesenchymal stem cell secretome contains bioactive substances,cytokines,and growth factors.Three-dimensional cell culture can regulate the secretion of these components,potentially enhancing the ability to promote injury repair.OBJECTIVE:To investigate the repair effect of three-dimensional cultured human umbilical cord mesenchymal stem cell secretome on skin injuries in mice.METHODS:Human umbilical cord mesenchymal stem cells were cultured in conventional two-dimensional culture dishes and 96-well U-bottom cell culture plates,from which their secretory components were subsequently collected.The expression of skin damage repair related secretory factors in umbilical cord mesenchymal stem cells was analyzed using RT-qPCR.The protein expression level of skin damage repair related factors in umbilical cord mesenchymal stem cell secretome was detected using enzyme-linked immunosorbent assay.The potential of human umbilical cord mesenchymal stem cell secretome to repair vascular injuries was evaluated using an immortalized human umbilical vein endothelial cell migration model.A mouse skin injury model was established,and the human umbilical cord mesenchymal stem cell secretome was injected subcutaneously.Repair effects on skin injury were assessed through wound healing rates and histopathological analysis.RESULTS AND CONCLUSION:(1)After three days of cultivation,human umbilical cord mesenchymal stem cells cultured in two dimensions exhibited a fibroblast-like,swirling growth pattern,whereas three-dimensional culture led to the formation of uniform microspheres.(2)Compared with two-dimensional culture,three-dimensional culture significantly increased the mRNA expression of transforming growth factor β and basic fibroblast growth factor in human umbilical cord mesenchymal stem cells.(3)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly enhanced the protein expression of vascular endothelial growth factor,interleukin-10,and granulocyte-macrophage colony-stimulating factor in the human umbilical cord mesenchymal stem cell secretome.(4)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly promoted the migration of immortalized human umbilical cord mesenchymal stem cells.(5)Compared with the untreated control group and the two-dimensional cultured human umbilical cord mesenchymal stem cell secretome,the three-dimensional cultured human umbilical cord mesenchymal stem cell secretome can significantly accelerate the skin wound healing rate and wound skin structure remodeling in mice.These results indicate that three-dimensional culture can enhance the expression of paracrine factors of human umbilical cord mesenchymal stem cells,and their secretome can significantly promote the repair of mouse skin damage.

BACKGROUND:The mesenchymal stem cell secretome contains bioactive substances,cytokines,and growth factors.Three-dimensional cell culture can regulate the secretion of these components,potentially enhancing the ability to promote injury repair.OBJECTIVE:To investigate the repair effect of three-dimensional cultured human umbilical cord mesenchymal stem cell secretome on skin injuries in mice.METHODS:Human umbilical cord mesenchymal stem cells were cultured in conventional two-dimensional culture dishes and 96-well U-bottom cell culture plates,from which their secretory components were subsequently collected.The expression of skin damage repair related secretory factors in umbilical cord mesenchymal stem cells was analyzed using RT-qPCR.The protein expression level of skin damage repair related factors in umbilical cord mesenchymal stem cell secretome was detected using enzyme-linked immunosorbent assay.The potential of human umbilical cord mesenchymal stem cell secretome to repair vascular injuries was evaluated using an immortalized human umbilical vein endothelial cell migration model.A mouse skin injury model was established,and the human umbilical cord mesenchymal stem cell secretome was injected subcutaneously.Repair effects on skin injury were assessed through wound healing rates and histopathological analysis.RESULTS AND CONCLUSION:(1)After three days of cultivation,human umbilical cord mesenchymal stem cells cultured in two dimensions exhibited a fibroblast-like,swirling growth pattern,whereas three-dimensional culture led to the formation of uniform microspheres.(2)Compared with two-dimensional culture,three-dimensional culture significantly increased the mRNA expression of transforming growth factor β and basic fibroblast growth factor in human umbilical cord mesenchymal stem cells.(3)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly enhanced the protein expression of vascular endothelial growth factor,interleukin-10,and granulocyte-macrophage colony-stimulating factor in the human umbilical cord mesenchymal stem cell secretome.(4)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly promoted the migration of immortalized human umbilical cord mesenchymal stem cells.(5)Compared with the untreated control group and the two-dimensional cultured human umbilical cord mesenchymal stem cell secretome,the three-dimensional cultured human umbilical cord mesenchymal stem cell secretome can significantly accelerate the skin wound healing rate and wound skin structure remodeling in mice.These results indicate that three-dimensional culture can enhance the expression of paracrine factors of human umbilical cord mesenchymal stem cells,and their secretome can significantly promote the repair of mouse skin damage.

ObjectiveTo investigate whether intestinal deficiency of lanosterol synthase （LSS）， a key enzyme in cholesterol synthesis， influences the progression of metabolic dysfunction-associated steatotic liver disease （MASLD） by regulating intestinal cholesterol absorption and immune response. MethodsLSS heterozygous knockout （LSS^+/-） mice and wild-type （WT） controls were generated using CRISPR/Cas9 technology and fed either a high-fat diet （HFD） or regular chow （CHOW）. The model was validated by genotyping. Hepatic steatosis was assessed by HE and oil red O staining. Immunohistochemistry was used to detect the localization and expression of NPC1L1 and CD36 proteins in the intestine. Western blot analysis was performed to measure JNK phosphorylation and TLR4 protein levels in intestinal tissues. Real-time quantitative polymerase chain reaction （qPCR） was employed to examine the mRNA expression of TLR4 and IL-6. ResultsLSS^+/- mice were successfully validated by genotyping and reduced intestinal LSS protein expression. HE and oil red O staining of liver sections showed that， compared with WT mice fed a CHOW diet， WT mice fed a HFD exhibited a marked increase in hepatic lipid vacuoles. In contrast， compared with HFD-fed WT mice， HFD-fed LSS^+/- mice displayed significantly attenuated hepatic lipid deposition and reduced serum ALT levels （P<0.05）. Immunohistochemical analysis revealed that， compared with WT mice， the expression of the cholesterol absorption protein NPC1L1 in the intestinal villi of LSS^+/- mice was downregulated under both CHOW and HFD conditions （P_HFD<0.001）. Conversely， the expression of the fatty acid transporter CD36 was upregulated in the intestines of LSS^+/- mice （P_CHOW<0.05， P_HFD<0.01）. Western blot analysis demonstrated that， compared with WT mice， TLR4 protein expression in the intestines of LSS^+/- mice significantly increased under both CHOW and HFD conditions （both P<0.05）. JNK phosphorylation level was significantly elevated in LSS^+/- mice under CHOW condition （both P<0.05）. Under HFD condition， total JNK protein expression increased， but its phosphorylation level showed no significant change. qPCR analysis showed that， compared with WT mice， the mRNA levels of TLR4 （P_CHOW<0.01， P_HFD<0.000 1） and IL-6 （P_CHOW<0.001， P_HFD<0.01） were significantly upregulated in the intestines of LSS^+/-mice. ConclusionLSS deficiency counteracts hepatic lipid deposition by orchestrating a synergistic reprogramming involving restricted intestinal cholesterol absorption， enhanced fatty acid utilization， and activation of immune pathways， suggesting intestinal LSS as a potential therapeutic target of MASLD.

ObjectiveTo investigate the protective effect of liver-targeted fibroblast growth factor 21 （FGF21） overexpression against CCl₄-induced acute liver injury （ALI） and its association with silent information regulator 1/glutathione peroxidase 4 （SIRT1/GPX4） expression and ferroptosis-related markers. MethodsFemale ICR mice （8 weeks old） were randomly divided into Control， CCl₄， adeno-associated virus （AAV）-FGF21， and AAV-FGF21 + CCl₄ groups. Liver-targeted FGF21 overexpression was achieved via tail vein injection of AAV8-FGF21 virus with green fluorescent protein （GFP） labeling. ALI was induced by intraperitoneal injection of CCl₄ （0.3 mL/kg）， with sample collection at 12 hours. Body weight and liver weight were recorded to calculate the liver weight/body weight. Alanine aminotransferase （ALT） and aspartate aminotransferase （AST） levels were measured using a biochemical analyzer. FGF21 expression in liver tissues was detected by immunofluorescence. Hepatic histopathology was evaluated by HE staining. RT-qPCR was performed to assess mRNA expression of ferroptosis and iron metabolism-related genes （ACSL4， PTGS2， HJV， FPN， GPX4）， FGF21， and SIRT1. Protein expression of FGF21， SIRT1， and GPX4 were determined by Western blot. Iron content， malondialdehyde （MDA）， glutathione （GSH）， and superoxide dismutase （SOD） activity in liver homogenate were quantified using assay kits. ResultsCompared with the Control group， the FGF21 mRNA and protein expression elevated in CCl₄ group； serum ALT/AST levels and liver weight/body weigh increased. The HE staining results showed that the liver cell membranes were ruptured. The mRNA levels of ACSL4 and PTGS2， the iron content and MDA levels all increased （P<0.01）. The mRNA levels of SIRT1， GPX4， HJV， and FPN， the GSH level and SOD activity all decreased （P<0.05）， and the protein levels of SIRT1 and GPX4 both decreased （P<0.05）. Compared with the CCl₄ group， the serum levels of ALT and AST in the AAV-FGF21 + CCl4 group were decreased （P<0.01）， and the liver/body ratio of mice decreased （P<0.01）. The results of HE staining showed that the degree of liver injury was alleviated. The mRNA levels of ACSL4 and PTGS2， iron content and MDA level all decreased （P<0.01）， while the mRNA levels of SIRT1， GPX4， HJV， FPN， GSH level and SOD activity all increased （P<0.05）. The protein levels of SIRT1 and GPX4 both increased （P<0.05）. ConclusionFGF21 overexpression is associated with enhanced SIRT1/GPX4 expression and suppression of ferroptosis features， thereby contributing to the alleviation of CCl₄-induced ALI.

Objective : To investigate the effect of laminarin(LAM) on nonproliferative diabetes retinopathy by high throughput sequencing(RNA-seq). Methods : The diabetes model was established by intraperitoneal injection of streptozotocin(STZ), and the effect of LAM on diabetic mice was observed.C57BL/6 mice were randomly divided into three groups: Control group, Model group, and LAM group, with 8 mice in each group. After 8 weeks of modeling, the LAM group received a 4-week intraperitoneal injection of LAM treatment. Changes in blood glucose and body weight of the three groups of mice were recorded, HE staining was performed to examine retinal lesions, and RNA-seq was used to identify differentially expressed genes(DEGs) in diabetic retinopathy(DR) under the action of STZ and LAM. Results : STZ successfully established the model of DR, and LAM reduced the blood sugar in diabetic mice to a certain extent and improved the pathological morphology of retinal structural looseness in diabetic mice. After RNA-seq analysis of DEGs, it was found that there were a total of 214 DEGs in the retina of the Model group mice compared to the Control group. Enrichment analysis revealed that DR could exacerbate the lesions through the PI3K Akt signaling pathway. There were a total of 42 DEGs in the retina of the Model group and LAM group mice, and enrichment showed that LAM improved the lesions through the neutrophil extracellular trap pathway. Early growth response factor 1(Egr1), FBJ osteosarcoma oncogene(Fos), nuclear receptor subfamily 4A member 1(Nr4a1), and salt-induced kinase 1(Sik1) were regulated by STZ, and LAM significantly regulated their expression, which might be closely related to LAM′s treatment of diabetic retinopathy. Conclusion DEGs can exacerbate the severity of diabetic retinopathyviathe PI3K-Akt signaling pathway. LAM can mitigate diabetic retinopathyviathe neutrophil extracellular trap pathway. Egr1, Fos, Nr4a1, and Sik1 are key genes involved in LAM treatment of STZ-induced DR.

Objective: To investigate the effect of loss of function of lanosterol synthase( LSS) gene on intestinal function in a mouse model of non-alcoholic fatty liver disease( NAFLD) induced by a high-fat diet． Methods: LSS gene heterozygous knockout C57 mice ( LSS + / －) were established using the CRISRP / Cas9 system．After being fed a high-fat diet with 60% fat content for 6 months，the fat deposition in liver tissues was detected by HE and Oil red O staining，the morphological changes of small intestine tissue were detected by HE staining．The changes in total cholesterol content in intestinal tissue were detected by kits．The gastrointestinal motility function of mice was detected by phenol red paste．The intestinal permeability was detected by Evans blue staining，and the expression of LSS，tight junction protein ( Claudin) -1，Claudin-5，cluster of differentiation 36 ( CD36) ，and Niemann-Pick type C1-like 1 protein ( NPC1L1) proteins in small intestinal tissues were detected by Western blot． Results : The results of HE and Oil red O staining of liver tissues showed that liver fat deposition in LSS gene heterozygous knockout mice was lower than that in wild-type mice in the high-fat diet group．The total cholesterol content in intestinal tis- sue of LSS gene heterozygous knockout mice decreased ( P ＜0. 01) ，but no morphological differences were ob- served between the two groups of mice by HE staining of intestinal tissues．The gastrointestinal motility function of LSS gene heterozygous knockout mice did not show significant changes．The intestinal permeability of LSS gene het- erozygous knockout mice in the high-fat diet group decreased as detected by Evans blue ( P＜0. 05) ．The expres- sion levels of Claudin-5 protein in the intestinal tissue of LSS gene heterozygous knockout mice in the high-fat diet group increased ( P ＜0. 05 ) ，while the expression of LSS protein in the intestinal tissues of LSS heterozygous knockout mice decreased ( P ＜0. 05) ． Conclusion In the NAFLD model induced by a high-fat diet，LSS gene heterozygous knockout reduces liver fat deposition induced by a high-fat diet and improves intestinal barrier function by regulating cholesterol metabolism in intestinal tissues and up-regulating the expression of Claudin-5．

Objective : To explore the changes in behavior and spatial memory of C57BL/6J female mice of different ages (youth , middle-aged , and elderly) . Methods: C57BL/6J female mice were divided into female youth group (YG group) , female middle-aged group ( MG group) and female elderly group ( OG group) according to age. The Morris water maze test measured spatial memory ability , and the open field and elevated cross maze test observed activity level and anxiety level. Western blot was used to determine the protein expressions of CREB , CaMKⅡ(pan) and CaMKⅡ(p) in the hippocampus of the brain tissues of female mice in each group. Results: Compared with the YG group , the weight of the MG group and the OG group significantly increased (P < 0. 01 , P < 0. 001) . Compared with the OG group , the third quadrant escape latency and the number of crossings in the YG group and MG group were shortened , and the difference was not statistically significant. Compared with the OG group , there was a statistically significant difference in the exercise speed in the open field of the YG group (P < 0. 01) , there was no significant difference in the movement speed in the open field of the MG group , the number of entries into the central zone significantly increased in the MG group ( P < 0. 05 ) , and there was no significant difference in the number of entries in the YG group (P > 0. 05) . Compared with the OG group , the YG group had a statistically significant difference in the elevated cross maze (P < 0. 05) , the MG group had no statistically signif- icant difference in the elevated cross maze , and the number of closed arm entries in the YG group and MG group significantly increased (P < 0. 001 , P < 0. 01) . Compared with the YG group , the relative expression level of CaMKⅡ(pan) in the OG group was statistically significant ( P < 0. 05 ) , while the relative expression level of CaMKⅡ(pan) in the MG group was not statistically significant ( P > 0. 05) . Conclusion With the increase of age , the weight of C57BL/6J female mice gradually increased , the activity level and desire to explore gradually de- creased , the spatial memory ability also declined , and the anxiety level and anxiety-like behavior increased. This study helps to reveal the effect of age on the activity level and cognitive function of females , and provides a refer- ence for studying cognitive and memory decline in older females.

Objective:To construct a medical quality evaluation index system for inpatients in public hospitals based on the life cycle theory,starting from the entire process of medical treatment.Method:A comprehensive study was conducted on the screening of medical quality evaluation indicators for hospitalized patients using literature analysis,key informant interviews,and expert inquiry methods.Results:The effective recovery rate of the two rounds of expert consultation was 100%,with high enthusiasm from the experts.The authority coefficient was above 0.7,and Kendall's W coordination coefficient was 0.267(P＜0.05).The evaluation indicators for medical quality of hospitalized patients,including 3 primary indicators,10 secondary indicators,and 51 tertiary indicators,were determined.Conclusions:The medical quality evaluation index system for inpatients in public hospitals based on the life cycle theory has certain scientificity and reliability.However,the weight analysis of the index system has not been carried out and is still in the theoretical exploration stage.Further empirical research is needed for verification and improvement.

Objective To investigate the relationship between daily intake of monounsaturated fatty acids(MUFAs)and polyunsaturated fatty acids(PUFAs)and non-alcoholic fatty liver disease(NAFLD),and to determine the threshold values of daily MUFAs and PUFAs intake for NAFLD risk.Methods Date were collected from the Dryad database.We enrolled a total of 1 068 healthy subjects aged 18 years and older(534 in the control group and 534 with NAFLD group)who had physical check-up in the Affiliated Nanping First Hospital of Fujian Medical University from April 2015 to August 2017.Comprehensive medical histories were obtained through questionnaires;information on dietary intake was collected using a semi-quantitative food frequency questionnaire and daily MUFAs and PUFAs intake were calculated.Baseline characteristics were compared between the two groups,and Logistic regression and restricted cubic spline(RCS)analyses were used to explore the relationship between daily MUFAs or PUFAs intake and NAFLD.Results Compared with the control group,the prevalence of hypertension,tea drinking,body mass index(BMI),daily energy intake,and daily MUFAs and PUFAs intakes were significant higher in patients with NAFLD(all P＜0.05),but the proportion of physical activities was significantly lower(P＜0.05).Logistic regression analysis revealed that after adjusting other confounding factors such as age,gender and BMI,for every 10 g increase in daily MUFAs or PUFAs intake,the risk of NAFLD increased by 53％(95％ CI:1.25-1.87,P＜0.001)and 3.30 times(95％ CI:2.98-6.20,P＜0.001),respectively.RCS indicated an approximately linear relationship between daily MUFAs intake and NAFLD(P for nonlinearity=0.064)and a nonlinear relationship between daily PUFAs intake and NAFLD(P for nonlinearity＜0.05).Subgroup analysis results were generally consistent,and there was statistical evidence of interactions between MUFAs and factors such as gender,hypertension and education level,with interaction between PUFAs and BMI observed(P＜0.05).Conclusion Increased daily intake of MUFAs or PUFAs is significantly associated with an increased risk of NAFLD,and further research is needed to clarify their specific roles in hepatic lipid accumulation.

Objective To investigate the relationship between daily intake of monounsaturated fatty acids(MUFAs)and polyunsaturated fatty acids(PUFAs)and non-alcoholic fatty liver disease(NAFLD),and to determine the threshold values of daily MUFAs and PUFAs intake for NAFLD risk.Methods Date were collected from the Dryad database.We enrolled a total of 1 068 healthy subjects aged 18 years and older(534 in the control group and 534 with NAFLD group)who had physical check-up in the Affiliated Nanping First Hospital of Fujian Medical University from April 2015 to August 2017.Comprehensive medical histories were obtained through questionnaires;information on dietary intake was collected using a semi-quantitative food frequency questionnaire and daily MUFAs and PUFAs intake were calculated.Baseline characteristics were compared between the two groups,and Logistic regression and restricted cubic spline(RCS)analyses were used to explore the relationship between daily MUFAs or PUFAs intake and NAFLD.Results Compared with the control group,the prevalence of hypertension,tea drinking,body mass index(BMI),daily energy intake,and daily MUFAs and PUFAs intakes were significant higher in patients with NAFLD(all P＜0.05),but the proportion of physical activities was significantly lower(P＜0.05).Logistic regression analysis revealed that after adjusting other confounding factors such as age,gender and BMI,for every 10 g increase in daily MUFAs or PUFAs intake,the risk of NAFLD increased by 53％(95％ CI:1.25-1.87,P＜0.001)and 3.30 times(95％ CI:2.98-6.20,P＜0.001),respectively.RCS indicated an approximately linear relationship between daily MUFAs intake and NAFLD(P for nonlinearity=0.064)and a nonlinear relationship between daily PUFAs intake and NAFLD(P for nonlinearity＜0.05).Subgroup analysis results were generally consistent,and there was statistical evidence of interactions between MUFAs and factors such as gender,hypertension and education level,with interaction between PUFAs and BMI observed(P＜0.05).Conclusion Increased daily intake of MUFAs or PUFAs is significantly associated with an increased risk of NAFLD,and further research is needed to clarify their specific roles in hepatic lipid accumulation.