1.Therapeutic effect and mechanism by which Trichosanthis Fructus-Allii Macrostemonis Bulbus regulates gut microbiota in a rat model of coronary heart disease
Guanghan SUN ; Zhencong XIE ; Mi SUN ; Yang XU ; Dong GUO
Chinese Journal of Tissue Engineering Research 2025;29(5):917-927
BACKGROUND:A network-based pharmacological approach has identified multifunctional effects of the main bioactive compounds in the Trichosanthis Fructus-Allii Macrostemonis Bulbus on coronary heart disease;however,the mechanism of its therapeutic effect on coronary heart disease has not been fully elucidated. OBJECTIVE:To investigate the role and mechanism of Trichosanthis Fructus-Allii Macrostemonis Bulbus in improving coronary heart disease by regulating the composition of gut microbiota. METHODS:Forty Sprague-Dawley rats were randomly divided into four groups:blank control group(n=10),model group(n=10),positive drug group(n=10),and medicine pair group(n=10).A rat model of coronary heart disease was established by continuous gastric perfusion of fat emulsion and injection of pituitrin.After modeling,rats in the model group were gavaged with distilled water(10 mL/kg)for control,rats in the positive drug group were gavaged with simvastatin 4 mg/kg per day,and rats in the medicine pair group were gavaged with Trichosanthis Fructus-Allii Macrostemonis Bulbus pairs 7.56 g/kg per day.All interventions lasted for 14 days.Electrocardiograms and myocardial pathology were observed,and blood lipid levels were measured.The structure of gut microbiota was analyzed using 16S rDNA sequencing technology. RESULTS AND CONCLUSION:Electrocardiogram results showed ST segment elevation in the model group.There were no significant abnormalities in the electrocardiograms of the positive drug group and medicine pair group.Compared with the blank control group,the levels of total cholesterol,triacylglycerol,and low-density lipoprotein cholesterol were significantly higher in the model group(P<0.05).Compared with the model group,the levels of total cholesterol,triacylglycerol,and low-density lipoprotein cholesterol were significantly lower in the positive drug group and medicine pair group(P<0.05).Compared with the blank control group,focal myocardial cell necrosis was observed in the model group,while partial myocardial cell disarray was observed in the positive drug group and medicine pair group.Compared with the blank control group,the Ace,Shannon,and Chao indices were increased(P<0.05)and the Simpson index was decreased(P<0.05)in the model group,positive drug group and medicine pair group.Compared with the model group,the Ace and Chao indices were decreased(P<0.05),while the Shannon index showed no significant difference(P>0.05)and the Simpson index was also decreased(P<0.05)in the positive drug group and medicine pair group.Compared with the blank control group,the relative abundances of Desulfovibrionia,Muribaculaceae_norank,etc.were increased in the model group,while those of Clostridia,[Eubacterium]_coprostanoligenes_group_norank,etc.were decreased.Compared with the model group,the relative abundances of WPS-2_norank,Muribaculaceae_norank,etc.were increased in the medicine pair group,while those of Clostridia,[Eubacterium]_coprostanoligenes_group_norank,etc.were decreased;the relative abundances of Desulfobacterota,[Eubacterium]_coprostanoligenes_group_norank,etc.were increased in the positive drug group,while those of Firmicutes,Muribaculaceae_norank,etc.were decreased.Compared with the positive drug group,the relative abundances of Desulfobacterota,Bacteroides,etc.were increased in the medicine pair group,while those of Firmicutes,[Eubacterium]_coprostanoligenes_group_norank,etc.were decreased.The LEfSe results showed that the medicine pair group had the highest microbial enrichment,followed by the blank control group and positive drug group,with the model group having the lowest microbial enrichment.To conclude,Trichosanthis Fructus-Allii Macrostemonis Bulbus pairs can improve the development of coronary heart disease by regulating gut microbiota composition,providing new insights for further research and development of Trichosanthis Fructus-Allii Macrostemonis Bulbus pairs.
2.Effect of fibroblast growth factor receptor 1 inhibitor on bone destruction in rats with collagen-induced arthritis
Haihui HAN ; Xiaohui MENG ; Bo XU ; Lei RAN ; Qi SHI ; Lianbo XIAO
Chinese Journal of Tissue Engineering Research 2025;29(5):968-977
BACKGROUND:Preliminary research by our group suggests that targeting fibroblast growth factor receptor 1(FGFR1)may be an effective strategy for treating RA. OBJECTIVE:To investigate the effects of an FGFR1 inhibitor(PD173074)on bone destruction in rats with collagen-induced arthritis. METHODS:Twenty-five female Sprague-Dawley rats were randomly divided into five groups:normal control group,model group,methotrexate group,low-dose PD173074 group,and high-dose PD173074 group.Except for the normal control group,rat models of type Ⅱ collagen-induced arthritis were made in each group.After successful modeling,rats were injected intraperitoneally with sterile PBS in the normal and model groups,1.04 mg/kg methotrexate in the methotrexate group,and 5 and 20 mg/kg in the low-dose group and high-dose PD173074 groups,once a week.After 4 weeks of drug administration,clinical symptoms and joint swelling in rats were observed.Micro-CT was used for three-dimensional reconstruction and analysis of the ankle joints.Pathological changes in the ankle joints were observed.Periarticular angiogenesis and the expression of receptor activator of nuclear factor-Κb ligand were detected.The expression levels of p-FGFR1,vascular endothelial growth factor A,and tartrate-resistant acid phosphatase in the synovial membrane were measured.Pathological changes in the liver,spleen,and kidney were observed and liver,spleen,and kidney indices were calculated. RESULTS AND CONCLUSION:PD173074 could alleviate clinical symptoms and joint swelling,delay bone loss,improve bone structure,reduce synovial invasion and cartilage bone erosion,reduce the number of periarticular osteoclasts,inhibit angiogenesis in synovial tissues,reduce the expression of receptor activator of nuclear factor-Κb ligand,and inhibit the expression of FGFR1 phosphorylated protein,tartrate-resistant acid phosphatase and vascular endothelial growth factor A.Pathologic observation of the liver,spleen and kidney in rats showed no obvious toxic side effects after PD173074 treatment.To conclude,the FGFR1 inhibitor can delay the progression of joint inflammation and bone destruction and inhibit angiogenesis in the rat model of type Ⅱ collagen-induced arthritis.The therapeutic effect of PD173074 has been preliminarily validated in the type Ⅱ collagen-induced arthritis model and may act by inhibiting FGFR1 phosphorylation,which provides a direction for the search of new therapeutic targets for rheumatoid arthritis.
3.Dimethyl fumarate alleviates nerve damage in a mouse model of Parkinson's disease
Ranran LU ; Xu ZHOU ; Lijie ZHANG ; Xinling YANG
Chinese Journal of Tissue Engineering Research 2025;29(5):989-994
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.
4.Metformin exerts a protective effect on articular cartilage in osteoarthritis rats by inhibiting the PI3K/AKT/mTOR pathway
Tianjie XU ; Jiaxin FAN ; Xiaoling GUO ; Xiang JIA ; Xingwang ZHAO ; Kainan LIU ; Qian WANG
Chinese Journal of Tissue Engineering Research 2025;29(5):1003-1012
BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.
5.Effects of wogonin on joint inflammation in collagen-induced arthritis rats via the endoplasmic reticulum stress pathway
Yuru WANG ; Siyuan LI ; Ye XU ; Yumeng ZHANG ; Yang LIU ; Huiqin HAO
Chinese Journal of Tissue Engineering Research 2025;29(5):1026-1035
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.
6.Treating acute type Ⅲ-Ⅴ acromioclavicular joint dislocation with single tunnel fixation versus tunnel-free suspension fixation of the coracoid process under shoulder arthroscopy
Yongtao ZENG ; Hongcheng ZHENG ; Nacikedaoerji ; Refati·Nijiati ; Li SHU ; Xu LIU ; Hongtao CHEN
Chinese Journal of Tissue Engineering Research 2025;29(5):1036-1042
BACKGROUND:At present,there are few reports on the postoperative efficacy of arthroscopic coracoid tunnel-free suspension fixation and coracoid single tunnel fixation in the treatment of acromioclavicular joint dislocation at home and abroad.The specific clinical efficacy of the two procedures and whether there are other risks need to be explored. OBJECTIVE:To compare the short-term postoperative clinical efficacy of arthroscopic TightRope band plate fixation with single tunnel fixation of the coracoid process and tunnel-free suspension fixation of the coracoid process in the treatment of acute type Ⅲ-Ⅴ acromioclavicular joint dislocation. METHODS:A retrospective analysis was performed in 45 patients with acromioclavicular joint dislocation who met the inclusion criteria admitted to the Sixth Affiliated Hospital of Xinjiang Medical University from June 2019 to September 2022,and were divided into coracoid single tunnel fixation group(20 cases)and coracoid tunnel-free suspension fixation group(25 cases)according to the surgical treatment plan.Operation time,incision length,blood loss,Constant-Murley score,visual analogue scale score,the American Shoulder and Elbow Surgeons(ASES)score and intraoperative and postoperative complications of the shoulder joint before operation,3 months after surgery and the last follow-up were compared between the two groups. RESULTS AND CONCLUSION:All patients successfully completed the operation,and there was no important nerve or blood vessel damage during the operation.The operation time of the coracoid tunnel-free suspension fixation group was significantly shorter than that of the coracoid tunnel-free suspension fixation group(P<0.05).There was no significant difference in intraoperative blood loss and incision length between the two groups(P>0.05).All patients were followed up for 12 to 24 months,with an average of(15.29±2.73)months.In the coracoid single tunnel fixation group,at 3 months after operation and the final follow-up,the visual analogue scale score was significantly lower than the preoperative score(P<0.05);Constant-Murley score and ASES score were significantly increased compared with the preoperative values(P<0.05).In the coracoid tunnel-free suspension fixation group,at 3 months after operation and the final follow-up,the visual analogue scale score was significantly lower than the preoperative score(P<0.05);the Constant-Murley score and the ASES score were both significantly higher than the preoperative scores(P<0.05).At 3 months after operation,the Constant-Murley score of the coracoid tunnel-free suspension fixation group was higher than that of the coracoid single tunnel fixation group(P<0.05),while there was no significant difference in visual analogue scale and ASES scores between the two groups(P>0.05).There was also no significant difference in the visual analogue scale,Constant-Murley,and ASES scores between the two groups at the corresponding time points before surgery and at the final follow-up(P>0.05).Intraoperative and postoperative complications:In the coracoid single tunnel fixation group,there was one case of coracoid cortical rupture and fracture during the tunnel drilling during the operation,and one case of a loss of reduction at 3 months after operation,which was repositioned and fixed with hook plate transposition of the coracoacromial ligament.All patients had good acromioclavicular joint function recovery and no re-dislocation at the final follow-up.All patients in the coracoid tunnel-free suspension fixation group did not suffer from coracoid fractures,loss of reduction and other complications during surgery,postoperatively and at the last follow-up.To conclude,these two arthroscopic treatments for acute type Ⅲ-Ⅴ acromioclavicular joint dislocation have the advantages of less trauma,reliable reduction and fixation,and good recovery of shoulder joint function after operation.However,compared with the coracoid single tunnel technique,the coracoid tunnel-free suspension fixation requires shorter time,faster recovery of shoulder joint function in the short term,and avoids the establishment of bone tunnels on the coracoid process,which reduces the probability of iatrogenic fracture of the coracoid process during operation and provides a higher degree of safety.
7.Correlations between gastrocnemius morphology parameters and physical activity capacity in elderly females under high-frequency ultrasound
Zixing WEN ; Xin XU ; Shengqun ZHU
Chinese Journal of Tissue Engineering Research 2025;29(5):1058-1063
BACKGROUND:The application of high-frequency ultrasound technology provides an effective tool for the precise assessment of skeletal muscle morphology in the elderly.However,the correlation between the morphological parameters of skeletal muscle obtained and physical activity capacity remains unclear. OBJECTIVE:To explore the correlation between morphological parameters of the gastrocnemius muscle and physical activity capacity in elderly females using high-frequency ultrasound imaging technology,thereby identifying effective predictive indicators for physical activity capacity in the elderly. METHODS:Fifty-nine elderly female subjects over the age of 60 with the ability to live independently were recruited in the communities surrounding Shanghai Sanda University.High-frequency ultrasound images of the subjects'gastrocnemius muscles were collected to obtain the relevant parameters,including muscle thickness,fiber length,pennation angle,and fiber length/muscle thickness(Lf/Tm)index.Physical activity capacity tests were also conducted and relevant indicators included the 10-meter walk test,timed up-and-go test,30-second chair stand test,and grip strength test.Correlation analyses were performed between various morphological parameters and physical activity capacity test indicators. RESULTS AND CONCLUSION:Significant correlations were found between various muscle morphological parameters(P<0.05).The pennation angle showed significant correlations with the 10-meter walking speed(r=-0.35,P<0.05)and timed up-and-go test results(r=0.32,P<0.05).The Lf/Tm index was positively correlated with 10-meter walking speed and grip strength test results(r=0.39,P<0.01;r=0.30,P<0.05),but was negatively correlated with timed up-and-go test results(r=-0.32,P<0.05).All these findings indicate that the pennation angle and Lf/Tm index of the gastrocnemius muscle show a good correlation with physical activity capacity in elderly females,which can serve as effective predictive indicators for physical activity capacity.
8.Mechanical stress regulates apoptosis in vascular smooth muscle cells
Fei XU ; Jinqiang YAN ; Shoudong CHAI
Chinese Journal of Tissue Engineering Research 2025;29(5):1064-1072
BACKGROUND:With the development of biomechanics,its research into cardiovascular diseases has become more and more extensive.By studying the mechanical properties of blood vessels,the pathogenesis of cardiovascular diseases such as atherosclerosis and restenosis can be effectively revealed and new ideas and methods can be developed for the treatment of cardiovascular diseases. OBJECTIVE:To review the research status of apoptosis of vascular smooth muscle cells induced by mechanical stress and search for potential target molecules and signaling pathways for clinical treatment,thereby improving the clinical treatment effect on cardiovascular diseases such as atherosclerosis and restenosis. METHODS:We searched the literature in CNKI,PubMed and ScienceDirect databases from January 1992 to May 2023.The search terms were"vascular smooth muscle cell,mechanical stress,shear stress,stretch stress,apoptosis"in Chinese and English.Finally,63 articles were included for review and analysis. RESULTS AND CONCLUSION:Physiological and pathological apoptosis of vascular smooth muscle cells is an adaptive remodeling in response to the changes in vascular mechanics.Vascular smooth muscle cells in different parts have different mechanical stimuli and their pathogenesis is also different.Low shear stress,physiological shear stress and high shear stress directly interact with surface molecules,receptors and proteins of vascular smooth muscle cells to regulate apoptosis-related signaling molecules and inhibit cell proliferation,thus regulating the apoptosis of vascular smooth muscle cells.In this part,the research on promoting proliferation is not summarized.Low stretch stress,physiological stretch stress and high stretch stress can all cause apoptosis of vascular smooth muscle cells,but it is still controversial.There are many mechanoreceptors(such as integrins and receptor tyrosine kinases)on the surface of vascular smooth muscle cells,which can transform mechanical signals into intracellular chemical signals(such as the Hippo pathway),activate the apoptosis signals of vascular smooth muscle cells and regulate the apoptosis of vascular smooth muscle cells.In short,different mechanical stimuli start a variety of signal pathways and regulate the apoptosis of vascular smooth muscle cells through various signal molecules.For example,shear stress affects Fas/FasL and Akt pathways mainly by stimulating prostaglandin secretion and transforming growth factors.Strech stress mainly regulates the YAP pathway and Notch pathway through Yes-related proteins.At different times or intensities,these molecules may play opposite two-way roles.For example,when mouse vascular smooth muscle cells are stretched at 10%physiological tension for 1 hour,cell proliferation increases.However,the proliferation of human vascular smooth muscle cells can decrease after 12 hours of stretching.Clinically,the key molecules of mechanical transduction can be disturbed by searching for key molecules that interfere with mechanical transduction at their critical time points of action.
9.Effects of artificial turf versus natural grass on biomechanical performance of the lower limbs in young females during jump-landing
Jieming LU ; Yajing LI ; Peijie DU ; Dongqing XU
Chinese Journal of Tissue Engineering Research 2025;29(6):1101-1107
BACKGROUND:It has been found that internal factors such as anatomical structure,hormone level and neuromuscular function of athletes are closely related to the risk of anterior cruciate ligament injuries,and external factors such as the material of the playing field also become one of the risk factors affecting the occurrence of non-contact anterior cruciate ligament injuries,but they are relatively under-attended in the current studies. OBJECTIVE:To explore effects of artificial turf versus natural grass on the biomechanical performance of the lower limbs in young females during jump-landing. METHODS:According to the test needs,artificial turf and natural grass in accordance with the standards of GB/T 20033.3-2006 and GB/T 19995.1-2005 were leveled and fixed on two three-dimensional force measuring platforms.Twenty-one young females were voluntarily recruited and completed the jump-landing task on the artificial turf and natural grass.Subjects stood on the steps and then jumped forward,jumped down to the force measuring platform and immediately jumped with full force to the force measuring platform again.The two landings were required to fall to the two force measuring platforms,and the whole jumping action was considered successful without any pause.The kinematic,kinetic and electromyographic data of the lower limbs during the landing process were collected synchronously to compare and analyze the differences between the two. RESULTS AND CONCLUSION:In terms of kinetics,posterior and vertical ground reaction force at the initial landing moment during jump-landing on the natural grass were significantly lower than those on the artificial turf(P<0.05,P<0.01),as well as at the peak ground reaction force moment(P<0.05,P<0.05).Additionally,the knee flexion moment when jump-landing on the natural grass was higher than that on the artificial turf(P<0.01).In terms of electromyography,within 100 ms after the initial landing moment,the electromyography activity levels of medial femoris muscle,lateral femoris muscle and anterior tibialis muscle when jump-landing on the natural grass were significantly lower than those on the artificial turf(P<0.05,P<0.01,P<0.05).To conclude,compared with the natural grass,jump-landing on the artificial turf leads to an change in biomechanical performance that will cause an increase in anterior cruciate ligament tension.
10.Effect of transcranial magneto-acousto-electrical stimulation on the plasticity of the prefrontal cortex network in mice
Shuai ZHANG ; Zichun LI ; Yihao XU ; Xiaofeng XIE ; Zhongsheng GUO ; Qingyang ZHAO
Chinese Journal of Tissue Engineering Research 2025;29(6):1108-1117
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.

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