BACKGROUND:LncRNA-TNFRSF13C,an important factor in B cell development and function,is expressed in periodontal tissues of patients with periodontitis,but the specific mechanism is still unclear. OBJECTIVE:To investigate the mechanism of lncRNA-TNFRSF13C regulating miR-1246 on hypoxia-inducible factor 1α in periodontal cells. METHODS:Human periodontal ligament cells(hPDLCs)were treated with lipopolysaccharide and divided into group A(hPDLCs cell lines without transfection),group B(hPDLCs cell lines transfected with TNFRSF13C NC-siRNA),group C(hPDLCs cell lines transfected with TNFRSF13C-siRNA),group D(hPDLCs cell line transfected with miR-1246 mimics),group E(hPDLCs cell line transfected with miR-1246 siRNA),group F(hPDLCs cell line transfected with TNFRSF13C-siRNA+miR-1246 mimics),and group G(hPDLCs cell line transfected with TNFRSF13C-siRNA+miR-1246 siRNA).The relative expression of lncRNA-TNFRSF13C and miR-1246 in each group was detected by qRT-PCR.Cell counting kit-8 assay was used to detect cell viability.Apoptosis was detected by flow cytometry.Expression of hypoxia-inducible factor 1α and vascular endothelial growth factor proteins was detected by western blot.The correlation between lncRNA-TNFRSF13C and miR-1246 was analyzed by Pearson,and the targeting relationship was analyzed by dual-luciferase reporter assay. RESULTS AND CONCLUSION:There was no significant difference in human periodontal ligament cell activity,apoptosis rate and protein indexes between groups A and B(P>0.05).Compared with group B,hPDLCS cell activity in group C was increased,and apoptosis rate and the expression of hypoxia-inducible factor 1α and vascular endothelial growth factor proteins were decreased(P<0.05).Compared with group C,hPDLCS cell activity in group D was decreased,and apoptosis rate and the expression of hypoxia-inducible factor 1α and vascular endothelial growth factor proteins were increased(P<0.05).Compared with group D,the cell activity of group E was increased(P<0.05).The cell activity in group F was lower than that in group E,and the apoptosis rate was reduced in both groups E and F(P<0.05).Compared with group F,the cell activity of group G was increased,and the apoptosis rate and the expression of hypoxia-inducible factor 1α and vascular endothelial growth factor were decreased(P<0.05).LncRNA-TNFRSF13C was positively correlated with miR-1246(P<0.05).Compared with the TNFRSF13C-siRNA group,the fluorescence activity of miR-1246-wt in the TNFRSF13C-NC group was reduced(P>0.05);compared with the miR-1246-NC group,the fluorescence activities of hypoxia-inducible factor 1α-wt and vascular endothelial growth factor-wt in the miR-1246 mimics group were increased(P<0.05).To conclude,down-regulation of lncRNA-TNFRSF13C can promote the activity of periodontal cells treated with lipopolysaccharide,reduce apoptosis,and inhibit hypoxia-inducible factor 1α and vascular endothelial growth factor.The mechanism is related to the regulation of miR-1246 activity.

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:In recent years,there has been an explosion of research in the field of physical activity and cognition of older adults,and the research hotspots and topics in this field are constantly evolving.However,a comprehensive review of the literature in this field is lacking. OBJECTIVE:To explore the current international research hotspots and contents in the field of physical activity and cognition of older adults using bibliometrics. METHODS:The Web of Science Core Collection Database,including SCI-EXPANDED,SSCI,A&HCI,CPCI-S,CPCI-SSH,BKCI-S,BKCI-SSH,ESCI,CCR-EXPANDED,IC,etc.,was searched for relevant literature in English.CiteSpace software was used to visualize and analyze 2593 documents collected in the Web of Science database. RESULTS AND CONCLUSION:The evolution of the topics of physical activity and cognition of older adults includes five stages:research on companion robots for older adults,research on the risk of diseases such as dementia,research on cognitive ability and its related ability,research on the relationship between physical activity level and cognitive ability in older adults,and research on different intervention methods and their mechanisms.The research in this field tends to be diversified.On the basis of the research on diseases and cognitive risk reduction,more attention has been paid to the effects of different physical activity modalities on cognition and the related mechanisms,which is the current research hotspot and will be the main research trend in the future.

BACKGROUND:Transcranial magneto-acoustic-electrical stimulation is a novel non-invasive neural regulation technique that utilizes the induced electric field generated by the coupling effect of ultrasound and static magnetic field to regulate the discharge activity of the nervous system.However,the mechanism by which it affects synaptic plasticity in the brain is still not enough. OBJECTIVE:To explore the effect of transcranial magneto-acoustic-electrical stimulation intensity on synaptic plasticity of the prefrontal cortex neural network in mice. METHODS:(1)Animal experiment:Twenty-four C57 mice were equally and randomly divided into four groups:the control group receiving pseudo-stimulation,the 6.35 W/cm2 stimulation group receiving coupled stimulation of 0.3 T,6.35 W/cm2,the 17.36 W/cm2 stimulation group receiving coupled stimulation of 0.3 T,17.36 W/cm2,and the 56.25 W/cm2 stimulation group receiving coupled stimulation of 0.3 T,56.25 W/cm2.The local field potential signals and behavioral correctness were recorded during the execution of T-maze in mice.(2)Modeling and simulation experiments:A neural network model of the prefrontal cortex in mice stimulated by transcranial magneto-acoustic-electrical stimulation was constructed to compare the structural connectivity characteristics of the neural network under different stimulation intensities. RESULTS AND CONCLUSION:Transcranial magneto-acoustic-electrical stimulation could effectively shorten the behavior learning time,improve the working memory ability of mice(P＜0.05),and continue to stimulate the frontal lobe of mice after learning behavior.There was no significant difference in the accuracy of the T-maze behavioral experiment among the experimental groups(P＞0.1).Analysis of local field potential signals in the frontal lobe of mice revealed that transcranial magneto-acoustic-electrical stimulation promoted energy enhancement of β and γ rhythms.As the stimulation intensity increased,there was an asynchronous decrease in β and γ rhythms.Through β-γ phase amplitude coupling,it was found that stimuli could enhance the neural network's ability to adapt to new information and task requirements.Modeling and simulation experiments found that stimulation could enhance the discharge level of the neural network,increase the long-term synaptic weight level,and decrease the short-term synaptic weight level only when the stimulation intensity was high.To conclude,there is a complex nonlinear relationship between different stimulus intensities and the functional structure of neural networks.This neural regulation technique may provide new possibilities for the treatment of related neurological diseases such as synaptic dysfunction and neural network abnormalities.

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:Troxerutin has been found to have a significant ameliorative effect on brain disorders,but there are fewer studies on the effects of troxerutin on the treatment of cerebral infarction and on neuronal cells. OBJECTIVE:To investigate the mechanism by which troxerutin regulates nuclear factor-κB signaling pathway to reduce brain injury and neuronal apoptosis in cerebral infarction rats. METHODS:Fifty clean grade rats were randomized into healthy group,model group,and troxerutin+nuclear factor-κB agonist group,troxerutin group,and nuclear factor-κB inhibitor group.Except for the healthy group,all other groups were used to establish a rat model of cerebral infarction by arterial ligation.The healthy and model groups were treated once a day with an equal amount of physiological saline by gavage.The troxerutin+nuclear factor-κB agonist group was intervened with 72 mg/kg troxerutin by gavage+20 mg/kg RANK intraperitoneally.The troxerutin group was treated with 72 mg/kg troxerutin by gavage.The nuclear factor κB inhibitor group was intervened intraperitoneally with 120 mg/kg nuclear factor κB inhibitor pyrrolidine disulfiram.Administration in each group was given once a day for 30 continuous days.Zea-longa was used to detect neurological damage in rats,hematoxylin-eosin staining was used to observe pathological changes,TUNEL was used to detect neuronal apoptosis,and immunoblotting and PCR were used to detect the expression of nuclear factor-κB p65 and nuclear factor-κB p50 at protein and mRNA levels,respectively. RESULTS AND CONCLUSION:Compared with the healthy group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65,nuclear factor-κB p50 mRNA and protein expression levels were elevated in the model group(P＜0.05).Compared with the model group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65 and nuclear factor-κB p50 mRNA and protein expression levels were decreased in the troxerutin+nuclear factor-κB agonist group(P＜0.05).Compared with the troxerutin+nuclear factor-κB agonist group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65 and nuclear factor-κB p50 mRNA and protein expression levels were reduced in the troxerutin group and nuclear factor-κB inhibitor group(P＜0.05).In addition,there was no difference between the troxerutin group and the nuclear factor-κB inhibitor group(P＞0.05).In the model group,there was a large number of cytoplasmic vacuolation,obvious edema and necrosis,and a large number of inflammatory cell infiltrations.In the troxerutin+nuclear factor-κB agonist,the swelling of brain tissue was reduced,and reticulate structures and condensed cells were reduced,still with some edema.In the troxerutin group and nuclear factor-κB inhibitor group,brain tissue swelling,neuronal edema degeneration,cytoplasmic vacuolation and neuronal nucleus consolidation were reduced,and the inflammatory cell infiltration was significantly decreased.To conclude,troxrutin can reduce the expression of neurological impairment,inhibit neuronal apoptosis and improve the pathological injury of brain tissue in rats with cerebral infarction,and its mechanism of action may be related to the modulation of nuclear factor-κB expression and related signaling pathways.

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:It has been proved clinically that adhesion of fibrous scar with the dura mater or nerve root after lumbar operation is an important factor for postoperative symptoms,such as postoperative pain and numbness. OBJECTIVE:To verify the inhibitory effect of autologous ligamentum flavum on the formation of epidural fibrous scar after lumbar surgery and explore the possible molecular biological mechanism. METHODS:Forty-eight Japanese white rabbits(6-8 months old)were randomly divided into three groups:a ligamentum flavum preservation group,a ligamentum flavum non-preservation group,and an autologous fat reposition group.A lumbar laminectomy model was established in all the three groups of rabbits,and rabbit epidural tissues were collected at 3 and 6 weeks after modeling.Hematoxylin-eosin staining was used to observe histological changes and the number and density of fibroblasts,VG staining was used to observe the percentage of collagen fiber area,and immunohistochemistry was used to observe the expression of transforming growth factor β1 and Smad3 proteins. RESULTS AND CONCLUSION:Hematoxylin-eosin staining results revealed that fibroblasts in the ligamentum flavum preservation group were few and loosely arranged,while the cells in the ligamentum flavum non-preservation and autologous fat reposition groups were more numerous and closely arranged.The number density of fibroblasts in the ligamentum flavum preservation group was lower than that in the ligamentum flavum non-preservation and autologous fat reposition groups at 3 and 6 weeks after surgery(P＜0.05);however,there was no significant difference between the latter two groups.VG staining results showed that the collagen fibers in the ligamentum flavum preservation group were sparse and distributed unevenly,while a lot of red collagen fibers were gathered in the ligamentum flavum non-preservation and autologous fat reposition groups.The area percentage of collagen fibers in the ligamentum flavum preservation group was lower than that in the ligamentum flavum non-preservation and autologous fat reposition groups at 3 and 6 weeks after surgery(P＜0.05),but there was no significant difference between the latter two groups.The results of immunohistochemistry showed that the degree of positive staining of retained histone the ligamentum flavum preservation group was significantly lower than that of the other two groups.The absorbance value of transforming growth factor β1 and Smad3 in the ligamentum flavum preservation group was significantly lower than that in the other two groups at 3 and 6 weeks after surgery(P＜0.05),but there was no significant difference between the latter two groups.To conclude,there are different degrees of epidural fibrous scar formation after lumbar surgery.If the ligamentum flavum is preserved,it can help to reduce the number of epidural fibroblasts as well as the formation of collagen fibers,thus reducing the adhesion of the fibrous scar tissue to the dural sac and nerve root.The mechanism is not only a purely mechanical blockade,but also to reduce the formation of epidural fibrous scar by interfering with the transforming growth factor β1/Smad3 signaling pathway.