BACKGROUND:Parkinson's disease is a multifactorial neurological disorder characterized by progressive loss of dopaminergic neurons,and dimethyl fumarate(DMF)has potent neuroprotective and immunomodulatory effects in neurodegenerative diseases. OBJECTIVE:To explore the neuroprotective mechanism of DMF in a mouse model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson's disease. METHODS:Twenty-four C57BL/6 mice were selected and randomly divided into control group,model group,low-dose DMF,and high-dose DMF groups.An animal model of Parkinson's disease was established in the latter three groups by intraperitoneal injection of 30 mg/kg MPTP,once a day for 5 consecutive days.Intragastric administration was given 30 minutes after each injection of MPTP.Mice in the low-dose DMF group(30 mg/kg)and high-dose DMF group(50 mg/kg)were intragastrically administered once a day for 7 consecutive days.The control and model groups were initially administered the same dose of normal saline.Behavioral testing,western blot,oxidative stress marker detection,and immunohistochemical staining were used to analyze the regulatory effects of DMF on oxidative stress and Keap1/Nrf2 signaling pathway in MPTP-induced Parkinson's disease mice,as well as the protective mechanism of DMF on degeneration of dopamine neurons. RESULTS AND CONCLUSION:Compared with the model group,mice in the low-dose DMF group exhibited significant improvements in motor retardation and postural imbalance(P<0.01),with even more remarkable improvements observed in the high-dose DMF group(P<0.01).Compared with the control group,the model group showed a significant increase in the oxidative stress marker malondialdehyde and a decrease in superoxide dismutase expression(P<0.01).Compared with the model group,the low-dose DMF group reduced malondialdehyde production and increased superoxide dismutase expression(P<0.01),and similar improvements were observed in the high-dose DMF group(P<0.01).Immunohistochemical and western blot assays demonstrated a significant decrease in the number of dopaminergic neurons and tyrosine hydroxylase protein expression in the substantia nigra of mice in the model group compared with the control group(P<0.01).However,in the low-dose DMF group,there was an increase in the number of dopaminergic neurons and tyrosine hydroxylase protein expression in the substantia nigra(P<0.01),with even more significant improvements in the high-dose DMF group(P<0.01).Western blot results revealed that the model group exhibited elevated Keap1 protein expression and decreased Nrf2 protein expression.In contrast,the DMF groups showed reduced Keap1 protein expression and increased Nrf2 protein expression compared to the model group(P<0.01).To conclude,DMF regulates the Keap1/Nrf2 pathway in the substantia nigra of mice with Parkinson's disease,and this regulatory effect is positively correlated with the dose of DMF(P<0.01).Therefore,we infer that DMF exerts neuroprotective effects through the Keap1/Nrf2 signaling pathway.

BACKGROUND:Rheumatoid arthritis is an inflammatory disease.Many studies have shown that wogonin has a good anti-inflammatory effect on rheumatoid arthritis,but its exact efficacy and specific mechanism of action remain to be clarified. OBJECTIVE:To investigate the mechanism of wogonin ameliorating joint inflammation by regulating endoplasmic reticulum stress pathway in rats with collagen-induced arthritis. METHODS:(1)At the animal level:Female Wistar rats were divided into healthy control group,arthritis model group and wogonin treatment group.Rat models of arthritis in the latter two groups were established by subcutaneous injection of bovine type Ⅱ collagen and adjuvant.In the wogonin group,wogonin was given by gavage for 28 consecutive days after modeling.During this period,the rats in each group were weighed,and arthritis score and ankle swelling were measured every 7 days.After the experiment,the pathological changes of the joint were observed,the mRNA and protein levels of endoplasmic reticulum stress pathway GRP78 and CHOP were detected by qRT-PCR,western blot,and immunohistochemistry.(2)At the cellular level,cell counting kit-8 was used to detect the cytotoxic effect of wogonin on fibroblast-like synoviocytes from rats with collagen-induced arthritis.The fibroblast-like synoviocytes induced by thapsigargin were treated with different concentrations of wogonin.The levels of interleukin-1β and tumor necrosis factor-α in the cell supernatant were detected by ELISA,and the intracellular reactive oxygen species in each group were determined by DCFH-DA probe method.The mRNA and protein levels of GRP78,IRE1α,XBP1s and CHOP were detected by qRT-PCR and western blot,respectively. RESULTS AND CONCLUSION:Compared with the healthy control group,arthritis index score and ankle swelling degree in the arthritis model group were increased(P<0.01),synovial hyperplasia,inflammatory cell infiltration,cartilage destruction and bone erosion were observed in pathological sections,and the mRNA and protein expressions of GRP78 and CHOP in the ankle were significantly increased(P<0.01),which were mainly located in synovial tissue and articular surface.Compared with the arthritis model group,the arthritis index score and ankle swelling degree in the wogonin treatment group were decreased(P<0.05),synovial hyperplasia and the number of inflammatory cells were decreased,cartilage destruction and bone erosion were alleviated,the mRNA and protein expression levels of GRP78 and CHOP in the ankle were decreased(P<0.05),particularly in synovial tissue and on the articular surface.There was no significant difference in body mass among the three groups(P>0.05).In the cell experiment,200 μmol/L wogonin significantly reduced the survival rate of fibroblast-like synoviocytes(P<0.01).Compared with the blank control group,the levels of interleukin-1β,tumor necrosis factor-α,content of reactive oxygen species,and mRNA and protein expression of GRP78,IRE1α,XBP1s,and CHOP in the thapsigargin group were significantly increased(P<0.05);compared with the thapsigargin group,50 and 100 μmol/L wogonin significantly reduced the levels of interleukin-1β and tumor necrosis factor-α in the cell supernatant(P<0.05,P<0.01),and 100 μmol/L wogonin significantly reduced the content of reactive oxygen species(P<0.01)and down-regulated the mRNA and protein expression levels of GRP78,IRE1α,XBP1s and CHOP(all P<0.05).These results suggest that wogonin can effectively alleviate joint inflammatory responses in rats with collagen-induced arthritis,and the endoplasmic reticulum stress pathway may be the key target of its intervention.

BACKGROUND:Streptococcus mutans is an important pathogen of dental caries,and timely detection of its levels is of great significance for early detection and treatment of dental caries. OBJECTIVE:To evaluate the effect of loop-mediated isothermal amplification(FTA-LAMP)direct extraction of Streptococcus mutans DNA. METHODS:(1)Bacterial suspensions containing ATCC standard strains(Streptococcus mutans)were prepared and inoculated into the brain-heart leachate medium.After mixed thoroughly,the mixture was then diluted in a 10-fold gradient into seven concentrations(4.2×107,4.2×106,4.2×105,4.2×104,4.2×103,4.2×102,4.2×10 CFU/mL),two parallel controls were made for each dilution level,and sterile water was used as a blank control.(2)The DNA of Streptococcus mutans was extracted using FTA Elute card,boiling method,kit extraction and lysate extraction methods separately and then amplified using LAMP technology was amplified.A specificity test was also performed to compare the differences between the four DNA extraction methods.RESULTS AND CONCLUSION:The DNA extracted by all four methods met the requirements for LAMP amplification.Specificity test results showed that only Streptococcus mutans could specifically amplify the target gene.The detection limit value of the DNA concentration was 4.2×103 CFU/mL for the lysate method,4.2×104 CFU/mL for the FTA Elute card extraction method,4.2×106 CFU/mL for the kit extraction method,and 4.2×107 CFU/mL for the boiling method.In the other aspects of the four extraction methods,the kit extraction method had the highest experimental cost,number of steps and time;the other three methods had the same number of steps,with the FTA Elute card method requiring the least amount of instruments,the boiling method having the lowest single cost,and the lysate extraction method taking the least amount of time.Only a small amount of bacteria were needed for successful extraction using both the FTA Elute card and lysate extraction methods.Compared with the FTA Elute card method,the lysate extraction method was superior in terms of time,but it had a high single cost and required more equipment.To conclude,the FTA-LAMP technology established in this study has the advantages of ease of operation,high specificity,high sensitivity,and visualization,which is expected to be a new way for efficient extraction and detection of Streptococcus mutans.

BACKGROUND:Previous studies have confirmed that Wen-Shen-Tong-Du Decoction can promote the recovery of spinal cord injury by inhibiting pyroptosis of splenic B cells,promoting the phagocytosis of myelin debris by microvascular endothelial cells,affecting the migration and infiltration of microglia,promoting the recovery of damaged neurons,and decreasing neuronal apoptosis after spinal cord injury,but the mechanism of this is still not clear. OBJECTIVE:To investigate the effect of Wen-Shen-Tong-Du Decoction on the triggering receptor expressed on myeloid cells 2(TREM2)and PI3K/Akt signaling pathways in mice following spinal cord injury. METHODS:Thirty-six C57BL/6 mice were selected and randomly divided into a sham-operation group,a model group and a Wen-Shen-Tong-Du Decoction group,with 12 mice in each group.In the model and Wen-Shen-Tong-Du Decoction groups,mouse models of T10 spinal cord injury were prepared by the modified Allen's method.On the 1st day after modeling,the Wen-Shen-Tong-Du Decoction group was given Wen-Shen-Tong-Du Decoction by gavage,and the sham-operation group and the model group were given saline by gavage once a day for 28 days.During the drug administration period,mouse motor function was evaluated by Basso Mouse Scale score and inclined plane test.On the 7th and 28th days after modeling,hematoxylin-eosin staining was used to observe the histopathological changes in the spinal cord tissue of the mice;immunofluorescence double staining was used to detect the protein expression of ionized calcium binding adaptor molecule 1(IBA1)and TREM2;and western blot assay was used to detect the expression of TREM2,PI3K,p-PI3K,Akt,p-Akt,Bcl2,Bax and Caspase3 in spinal cord tissue. RESULTS AND CONCLUSION:Basso Mouse Scale scores and inclined plane test results indicated that the motor function of the mouse hindlimbs was declined after spinal cord injury,and Wen-Shen-Tong-Du Decoction significantly improved motor function in mice with spinal cord injury.Hematoxylin-eosin staining results revealed that Wen-Shen-Tong-Du Decoction significantly ameliorated the pathological structure of spinal cord tissue compared with the model group,manifesting as reduced degrees of dorsal white matter and neuronal atrophy,decreased cytoplasmic vacuolization,and reduced inflammatory cell infiltration.Immunofluorescence double staining results showed that on the 7th day after modeling,the protein expression of IBA1 and TREM2 in the model group was lower than that in the sham-operation group(P＜0.05),and the protein expression of IBA1 and TREM2 in the Wen-Shen-Tong-Du Decoction group was higher than that in the model group(P＜0.05);on the 28th day after modeling,the protein expression of TREM2 in the model group was lower than that in the sham-operation group(P＜0.05),and the protein expression of TREM2 in the spinal cord tissue of the mice in the Wen-Shen-Tong-Du Decoction group was higher than that in the model group(P＜0.05).Western blot results analysis demonstrated that on the 7th day after modeling,compared with the sham-operation group,the model group exhibited a significant reduction in TREM2,PI3K,and Bcl2/Bax(P＜0.05),as well as a significant increase in p-Akt,Bax and p-Akt/Aktp-PI3K(P＜0.05);compared with the model group,the Wen-Shen-Tong-Du Decoction group showed a significant increase in TREM2,PI3K,p-PI3K,Akt,p-Akt,Bcl2,p-PI3K/PI3K,p-Akt/Ak,and Bcl2/Bax(P＜0.05),as well as a significant decrease in Bax and Caspase3 protein expression(P＜0.05).On the 28th day after modeling,compared with the sham-operation group,the model group exhibited a significant reduction in TREM2,PI3K,p-PI3K,Akt,p-Akt,Bcl2 and Bcl2/Bax(P＜0.05),as well as a significant increase in Bax protein expression(P＜0.05);compared with the model group,the Wen-Shen-Tong-Du Decoction group showed a significant increase in TREM2,PI3K,Akt,p-Akt,Bcl2,and Bcl2/Bax(P＜0.05),as well as a significant decrease in Bax protein expression(P＜0.05).To conclude,Wen-Shen-Tong-Du Decoction may activate the PI3K/Akt signaling pathway by up-regulating the expression of TREM2 protein in microglia,and then inhibit neuronal apoptosis,thus exerting neuroprotective effects and promoting the repair of spinal cord injury.

BACKGROUND:Cistanoside A has the effects of anti-inflammation,antioxidation,antioxidation,reducing renal damage and anti-osteoporosis,but its effect on osteoclast differentiation,function and its underlying molecular mechanisms remain unclear. OBJECTIVE:To investigate the effect of Cistanoside A on osteoclast differentiation and bone resorption induced by receptor activator of nuclear factor kappa-B ligand(RANKL)in vitro and its mechanism. METHODS:Bone marrow macrophages were obtained from the femur and tibia of 4-6-week-old C57BL/6 mice.The cytotoxic effect of Cistanoside A(5,10,20,40,80,and 160 μmol/L)on bone marrow macrophage viability was examined using the cell counting kit-8 assay kit.Tartrate-resistant acid phosphatase staining was performed to observe the effect of different concentrations of Cistanoside A on osteoblast differentiation and its effective intervention concentration was determined.There was positive control group,Cistanoside A low,medium,and high dose groups(40,80,and 160 μmol/L).After cell attachment,50 ng/mL RANKL was added to induce osteoblast differentiation,and the corresponding dose of Cistanoside A was added to the Cistanoside A low,medium,and high dose groups,respectively.F-actin ring and 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride staining were performed to detect the effects of Cistanoside A on the formation of osteoclasts.Toluidine blue staining of bone abrasion slices was used to observe the effects of Cistanoside A on bone resorption function of osteoclasts.The expression of upstream and downstream proteins of the JNK/MAPK pathway was detected by Western blot.The expression of genes related to osteoclast differentiation and bone resorption function such as tartrate-resistant acid phosphatase,DC-STAMP,Nfatc-1,Ctsk and c-Fos was detected by RT-qPCR. RESULTS AND CONCLUSION:Tartrate-resistant acid phosphatase staining,F-actin ring staining and resorption pit assay showed that Cistanoside A significantly inhibited RANKL-induced osteoclast differentiation and bone resorption in a dose-dependent manner compared with the positive control group.The results of RT-qPCR showed that compared with the positive control group,both high and low dose groups of Cistanoside A could significantly downregulate the mRNA expression of tartrate-resistant acid phosphatase,DC-STAMP,Nfatc-1,Ctsk and c-Fos in a dose-dependent manner.The results of western blot assay showed that the high dose group of Cistanoside A significantly inhibited the expression of p-JNK protein at 10,20,30 and 60 minutes of intervention;compared with the positive control group,Cistanoside A significantly inhibited the expression of Nfatc1 and c-Fos proteins in a dose-dependent manner.To conclude,Cistanoside A could inhibit the formation and bone resorption of osteoclasts by reducing the level of p-JNK protein,inhibiting the activation of MAPK pathway and the expression of key genes in osteoclasts.

BACKGROUND:The repair process of myocardial injury involves complex cellular and molecular mechanisms,especially mitochondrial calcium homeostasis,macrophage autophagy and pyroptosis pathways.Traditional Chinese medicine(TCM)has shown significant clinical efficacy in improving myocardial injury,but its mechanism of action needs to be thoroughly investigated. OBJECTIVE:To investigate the role of mitochondrial calcium homeostasis-mediated macrophage autophagy and pyroptosis pathways in myocardial injury,and to summarize the progress of TCM in this field. METHODS:A computerized search was performed for relevant literature from the database inception to March 2024 in the Web of Science,PubMed and CNKI.The search terms were"mitochondrial calcium homeostasis,macrophage autophagy,macrophage pyroptosis,traditional Chinese medicine,myocardial injury,myocardial injury reperfusion"in Chinese and English.Through literature review,we analyzed the relationship between mitochondrial calcium homeostasis and macrophage autophagy and pyroptosis,explored the mechanism of their roles in myocardial injury,and summarized the pathways of multi-targeted,multi-pathway effects of TCM. RESULTS AND CONCLUSION:The maintenance of mitochondrial calcium homeostasis has been found to be closely related to the normal function of cardiomyocytes.Macrophages can participate in the repair process of myocardial injury through autophagy and pyroptosis pathways.Autophagy contributes to cell clearance and regulation of inflammatory response,while pyroptosis affects myocardial repair by releasing inflammatory factors.TCM regulates mitochondrial calcium homeostasis and macrophage function through multiple mechanisms.For example,astragalosid regulates calcium homeostasis by lowering mitochondrial membrane potential and inhibiting cytochrome C,and epimedium glycoside plays a role in reducing β-amyloid deposition.In addition,herbal compounds and single drugs promote myocardial repair by activating or inhibiting specific signaling pathways,such as PI3K/AKT and nuclear factor-κB signaling pathways.Future studies should focus on the interactions between mitochondrial calcium homeostasis,autophagy and pyroptosis pathways,as well as how TCM can exert therapeutic effects through these pathways to provide new strategies and drugs for the treatment of myocardial injury.

BACKGROUND:The capability of repairing articular cartilage damage is very limited,and tissue engineering technology provides new therapeutic options for repairing damaged cartilage,in which the interaction and induction between chondrocytes,bone marrow mesenchymal stem cells,and synovial mesenchymal stem cells is the basis of autologous healing of cartilage damage. OBJECTIVE:To construct the chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell co-culture system to simulate the in vitro microenvironment of chondrocytes,and to explore the optimal cell inoculation ratio,meanwhile to observe the effects of icariin-containing serum on the proliferation of chondrocytes and the chondrogenic differentiation of stem cells in the system. METHODS:Rat knee chondrocytes,bone marrow mesenchymal stem cells and synovial mesenchymal stem cells were extracted,cultured and identified,and a chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell non-contact co-culture system was constructed according to different cell inoculation ratios.After 72 hours of co-culturing,the chondrocyte proliferative activity and phenotypic ability were observed,and the co-culture system with the best overall effect was selected.New Zealand white rabbits were gavaged with icariin solution(0.25 mg/mL)to prepare icariin-containing serum,and cultured in conventional complete medium(high sugar DMEM culture medium containing 10%fetal bovine serum and 1%double antibody by volume)as the control group,while the experimental group was intervened by adding 10%icariin-containing serum by volume on the basis of above.The proliferative activity of chondrocytes and the expression of collagen type II were tested for the two groups after 24 and 48 hours.The differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells into chondrocytes in the co-culture system was tested by immunofluorescence staining after 14 days. RESULTS AND CONCLUSION:(1)The three kinds of cells grew normally adherently to the wall in different ratios of co-culture,where chondrocytes showed the best proliferative activity and phenotypic ability in the co-culture system when chondrocytes:bone marrow mesenchymal stem cells:synovial mesenchymal stem cells=2:1:1.(2)Compared with the control group,the proliferative activity and type II collagen expression of chondrocytes in the experimental group were significantly increased after 24 hours(P<0.01),and the two groups still had difference after 48 hours(P<0.05).The two groups showed obvious chondrogenic differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells after 14 days(P<0.01),and some of the cells appeared round or oval,and the cytoplasmic type II collagen immunofluorescence staining was positive.The fluorescence intensity of the experimental group was significantly higher than that of the control group(P<0.01).(3)The results showed that the chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell co-culture system could be successfully established by the non-contact co-culture method,and the best chondrocyte proliferative activity and phenotypic ability could be obtained when the cell ratio was 2:1:1.Icariin-containing serum had the promoting effect on chondrocyte proliferation,and chondrogenic differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells in the system.

BACKGROUND:In recent years,more and more studies have confirmed that ferroptosis of dopaminergic neurons is involved in the pathogenesis of Parkinson's disease,and verbascoside has been confirmed to have antioxidant,anti-inflammatory and neuroprotective effects. OBJECTIVE:To investigate the protective effect of verbascoside on Erastin-induced ferroptosis of MN9D cells and its action mechanism. METHODS:MN9D cells were divided into control group,model group(20 μmol/L Erastin group),Erastin+1 μg/mL verbascoside group,Erastin+5 μg/mL verbascoside group,and Erastin+10 μg/mL verbascoside group.MN9D cells were cultured in a CO2 incubator for 24 hours,then pretreated with different mass concentrations of verbascoside for 8 hours,and induced with 20 μmol/L Erastin for 24 hours.The levels of reduced glutathione,superoxide dismutase,total iron ion,and malondialdehyde were detected by ELISA.The expression of tyrosine hydroxylase was detected by immunohistochemistry.The expressions of tyrosine hydroxylase,nuclear factor erythrocyte-2-associated factor 2,heme oxygenase-1,and glutathione peroxidase 4 were detected by western blot assay. RESULTS AND CONCLUSION:(1)Compared with the control group,the levels of reduced glutathione and superoxide dismutase were significantly decreased(P<0.05),and the levels of malondialdehyde and total iron ion were significantly increased in the model group(P<0.05).Compared with the model group,the levels of reduced glutathione and superoxide dismutase were significantly increased(P<0.05),and the levels of malondialdehyde and total iron ionized water were decreased in 1,5,10 μg/mL verbascoside groups(P<0.05).(2)Compared with the control group,the area of tyrosine hydroxylase positive cells in the model group was significantly reduced(P<0.05).Compared with the model group,the area of tyrosine hydroxylase positive cells was significantly increased in 1,5,10 μg/mL verbascoside groups(P<0.05).(3)Compared with the control group,the protein expressions of tyrosine hydroxylase,nuclear factor erythrocyte-2-associated factor 2,heme oxygenase-1 and glutathione peroxidase 4 were significantly decreased in the model group(P<0.05).Compared with the model group,the protein expression levels of tyrosine hydroxylase,nuclear factor erythrocyte-2-associated factor 2,heme oxygenase-1,and glutathione peroxidase 4 were significantly increased in 1,5,10 μg/mL verbascoside groups(P<0.05).The results suggested that verbascoside could inhibit Erastin-induced ferroptosis in MN9D cells,possibly by activating nuclear factor erythrocyte-2-associated factor 2/heme oxygenase-1/glutathione peroxidase 4 pathway.

BACKGROUND:Previous studies have found that neohesperidin can delay bone loss in ovariectomized mice and has the potential to treat osteoporosis,but its specific mechanism of action remains to be explored. OBJECTIVE:To explore the key targets and possible mechanisms of neohesperidin in the treatment of osteoporosis based on bioinformatics and cell experiments in vitro. METHODS:The gene expression dataset related to osteoporosis was obtained from GEO database,and the differentially expressed genes were screened and analyzed in R language.The osteoporosis-related targets were screened from GeneCards and DisGeNET databases,and the neohesperidin-related targets were screened from ChEMBL and PubChem databases,and the common targets were obtained by intersection of the three.The String database was used to construct the PPI network of intersection genes,and the key targets were screened.The DAVID database was used for GO and KEGG enrichment analysis.The AutoDock software was used to verify the molecular docking between the neohesperidin and the target protein.The effect of neohesperidin on osteogenic differentiation of C57 mouse bone marrow mesenchymal stem cells was detected.Complete medium was used as blank control group;osteogenic induction medium was used as the control group;and osteogenic induction medium containing different concentrations of neohesperidin(25,50 μmol/L)was used as experimental group.The expression of alkaline phosphatase,the degree of mineralization,the expression of osteogenic-related genes and target genes during osteogenic differentiation of cells were measured at corresponding time points. RESULTS AND CONCLUSION:(1)9 253 differentially expressed genes,2 161 osteoporosis-related targets,and 326 neohesperidin-related targets were screened.There were 53 common targets among the three.All 53 genes were up-regulated in osteoporosis samples.The PPI network screened the target gene PRKACA of research significance.GO function and KEGG pathway enrichment analysis showed that neohesperidin's treatment of osteoporosis through PRKACA target mainly depended on biological processes such as protein phosphorylation and protein autophosphorylation,acting on endocrine resistance,proteoglycan in cancer,and estrogen signaling pathway to play a therapeutic role.Molecular docking results showed that neohesperidin had a certain binding ability to the protein corresponding to the target PRKACA.(2)The results of alkaline phosphatase staining showed that neohesperidin could promote the expression of alkaline phosphatase in the early stage of osteogenic differentiation of mesenchymal stem cells.Alizarin red staining showed that neohesperidin could promote the mineralization of osteogenic differentiation of mesenchymal stem cells.RT-qPCR results showed that neohesperidin could increase the mRNA expression of alkaline phosphatase,PRKACA,and osteocalcin.(3)These results indicate that neohesperidin may promote osteogenic differentiation through PRKACA target on the estrogen signaling pathway to prevent and treat osteoporosis.

BACKGROUND:A large number of studies have confirmed that the therapeutic effectiveness of mesenchymal stem cell secretome is comparable to that of mesenchymal stem cells,but the mechanism of its action is still unclear. OBJECTIVE:To summarize the research progress of mesenchymal stem cell secretome in recent years,to investigate the molecular mechanism of its therapeutic effect,to analyze the current problems and to look forward to the future development. METHODS:The terms"exosomes,mesenchymal stem cells secrete,extracellular vesicles,mesenchymal stem cells,mechanism"were used as English search terms in the PubMed database.Articles that were not related to the research purpose of the article and duplicated articles were excluded.At the same time,we combined the method of literature tracking.Finally,109 articles that met the criteria were incuded for the review. RESULTS AND CONCLUSION:(1)The mesenchymal stem cell secretome promotes tissue repair and regeneration through delivering genetic material,immunomodulatory factors,growth factors,etc.to target cells,by activating anti-apoptotic,regulating angiogenesis,modulating fibrosis and pro-survival pathways in target cells.(2)The potential of mesenchymal stem cell secretome in disease therapy has also been confirmed.Numerous research results have shown that mesenchymal stem cell secretome can be used as a new cell-free treatment for inflammatory and degenerative diseases.(3)Mesenchymal stem cell secretome has been engineered to have more efficient therapeutic effects in recent years.However,due to the heterogeneity of the mesenchymal stem cell secretome and the complexity of its components,the exact mechanism of its therapeutic effect is still unclear.(4)At present,further research is needed to identify the key targets of mesenchymal stem cell secretome,and innovative specific and enhanced mesenchymal stem cell secretome should be developed by combining with engineering and genetic engineering technologies in the future.