1.USP29 alleviates the progression of MASLD by stabilizing ACSL5 through K48 deubiquitination
Sha HU ; Zhouxiang WANG ; Kun ZHU ; Hongjie SHI ; Fang QIN ; Tuo ZHANG ; Song TIAN ; Yanxiao JI ; Jianqing ZHANG ; Juanjuan QIN ; Zhigang SHE ; Xiaojing ZHANG ; Peng ZHANG ; Hongliang LI
Clinical and Molecular Hepatology 2025;31(1):147-165
Background/Aims:
Metabolic dysfunction–associated steatotic liver disease (MASLD) is a chronic liver disease characterized by hepatic steatosis. Ubiquitin-specific protease 29 (USP29) plays pivotal roles in hepatic ischemiareperfusion injury and hepatocellular carcinoma, but its role in MASLD remains unexplored. Therefore, the aim of this study was to reveal the effects and underlying mechanisms of USP29 in MASLD progression.
Methods:
USP29 expression was assessed in liver samples from MASLD patients and mice. The role and molecular mechanism of USP29 in MASLD were assessed in high-fat diet-fed and high-fat/high-cholesterol diet-fed mice and palmitic acid and oleic acid treated hepatocytes.
Results:
USP29 protein levels were significantly reduced in mice and humans with MASLD. Hepatic steatosis, inflammation and fibrosis were significantly exacerbated by USP29 deletion and relieved by USP29 overexpression. Mechanistically, USP29 significantly activated the expression of genes related to fatty acid β-oxidation (FAO) under metabolic stimulation, directly interacted with long-chain acyl-CoA synthase 5 (ACSL5) and repressed ACSL5 degradation by increasing ACSL5 K48-linked deubiquitination. Moreover, the effect of USP29 on hepatocyte lipid accumulation and MASLD was dependent on ACSL5.
Conclusions
USP29 functions as a novel negative regulator of MASLD by stabilizing ACSL5 to promote FAO. The activation of the USP29-ACSL5 axis may represent a potential therapeutic strategy for MASLD.
2.USP29 alleviates the progression of MASLD by stabilizing ACSL5 through K48 deubiquitination
Sha HU ; Zhouxiang WANG ; Kun ZHU ; Hongjie SHI ; Fang QIN ; Tuo ZHANG ; Song TIAN ; Yanxiao JI ; Jianqing ZHANG ; Juanjuan QIN ; Zhigang SHE ; Xiaojing ZHANG ; Peng ZHANG ; Hongliang LI
Clinical and Molecular Hepatology 2025;31(1):147-165
Background/Aims:
Metabolic dysfunction–associated steatotic liver disease (MASLD) is a chronic liver disease characterized by hepatic steatosis. Ubiquitin-specific protease 29 (USP29) plays pivotal roles in hepatic ischemiareperfusion injury and hepatocellular carcinoma, but its role in MASLD remains unexplored. Therefore, the aim of this study was to reveal the effects and underlying mechanisms of USP29 in MASLD progression.
Methods:
USP29 expression was assessed in liver samples from MASLD patients and mice. The role and molecular mechanism of USP29 in MASLD were assessed in high-fat diet-fed and high-fat/high-cholesterol diet-fed mice and palmitic acid and oleic acid treated hepatocytes.
Results:
USP29 protein levels were significantly reduced in mice and humans with MASLD. Hepatic steatosis, inflammation and fibrosis were significantly exacerbated by USP29 deletion and relieved by USP29 overexpression. Mechanistically, USP29 significantly activated the expression of genes related to fatty acid β-oxidation (FAO) under metabolic stimulation, directly interacted with long-chain acyl-CoA synthase 5 (ACSL5) and repressed ACSL5 degradation by increasing ACSL5 K48-linked deubiquitination. Moreover, the effect of USP29 on hepatocyte lipid accumulation and MASLD was dependent on ACSL5.
Conclusions
USP29 functions as a novel negative regulator of MASLD by stabilizing ACSL5 to promote FAO. The activation of the USP29-ACSL5 axis may represent a potential therapeutic strategy for MASLD.
3.USP29 alleviates the progression of MASLD by stabilizing ACSL5 through K48 deubiquitination
Sha HU ; Zhouxiang WANG ; Kun ZHU ; Hongjie SHI ; Fang QIN ; Tuo ZHANG ; Song TIAN ; Yanxiao JI ; Jianqing ZHANG ; Juanjuan QIN ; Zhigang SHE ; Xiaojing ZHANG ; Peng ZHANG ; Hongliang LI
Clinical and Molecular Hepatology 2025;31(1):147-165
Background/Aims:
Metabolic dysfunction–associated steatotic liver disease (MASLD) is a chronic liver disease characterized by hepatic steatosis. Ubiquitin-specific protease 29 (USP29) plays pivotal roles in hepatic ischemiareperfusion injury and hepatocellular carcinoma, but its role in MASLD remains unexplored. Therefore, the aim of this study was to reveal the effects and underlying mechanisms of USP29 in MASLD progression.
Methods:
USP29 expression was assessed in liver samples from MASLD patients and mice. The role and molecular mechanism of USP29 in MASLD were assessed in high-fat diet-fed and high-fat/high-cholesterol diet-fed mice and palmitic acid and oleic acid treated hepatocytes.
Results:
USP29 protein levels were significantly reduced in mice and humans with MASLD. Hepatic steatosis, inflammation and fibrosis were significantly exacerbated by USP29 deletion and relieved by USP29 overexpression. Mechanistically, USP29 significantly activated the expression of genes related to fatty acid β-oxidation (FAO) under metabolic stimulation, directly interacted with long-chain acyl-CoA synthase 5 (ACSL5) and repressed ACSL5 degradation by increasing ACSL5 K48-linked deubiquitination. Moreover, the effect of USP29 on hepatocyte lipid accumulation and MASLD was dependent on ACSL5.
Conclusions
USP29 functions as a novel negative regulator of MASLD by stabilizing ACSL5 to promote FAO. The activation of the USP29-ACSL5 axis may represent a potential therapeutic strategy for MASLD.
4.Salvianolic Acid B and Ginsenoside Rg1 Combination Attenuates Cerebral Edema Accompanying Glymphatic Modulation.
Lingxiao ZHANG ; Yanan SHAO ; Zhao FANG ; Siqi CHEN ; Yixuan WANG ; Han SHA ; Yuhan ZHANG ; Linlin WANG ; Yi JIN ; Hao CHEN ; Baohong JIANG
Neuroscience Bulletin 2025;41(11):1909-1923
Cerebral edema is characterized by fluid accumulation, and the glymphatic system (GS) plays a pivotal role in regulating fluid transport. Using the Tenecteplase system, magnesium salt of salvianolic acid B/ginsenoside Rg1 (SalB/Rg1) was injected intravenously into mice 4.5 h after middle cerebral artery occlusion and once every 24 h for the following 72 h. GS function was assessed by Evans blue imaging, near-infrared fluorescence region II (NIR-II) imaging, and magnetic resonance imaging (MRI). SalB/Rg1 had significant effects on reducing the infarct volume and hemorrhagic transformation score, improving neurobehavioral function, and protecting tissue structure, especially inhibiting cerebral edema. Meanwhile, the influx/efflux drainage of GS was enhanced by SalB/Rg1 according to NIR-II imaging and MRI. SalB/Rg1 inhibited matrix metalloproteinase-9 (MMP-9) activity, reduced cleaved β-dystroglycan (β-DG), and stabilized aquaporin-4 (AQP4) polarity, which was verified by colocalization with CD31. Our findings indicated that SalB/Rg1 treatment enhances GS function and attenuates cerebral edema, accompanying the regulation of the MMP9/β-DG/AQP4 pathway.
Animals
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Ginsenosides/administration & dosage*
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Brain Edema/etiology*
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Male
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Benzofurans/administration & dosage*
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Glymphatic System/diagnostic imaging*
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Mice
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Infarction, Middle Cerebral Artery/drug therapy*
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Aquaporin 4/metabolism*
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Disease Models, Animal
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Mice, Inbred C57BL
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Matrix Metalloproteinase 9/metabolism*
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Neuroprotective Agents/pharmacology*
;
Depsides
5.Short-term results of a multicenter study based on a modified N7 induction regimen combined with arsenic trioxide in the treatment of children with high-risk neuroblastoma
Shu YANG ; Kailan CHEN ; Yunyan HE ; Xiaomin PENG ; Hao XIONG ; Wenguang JIA ; Sha WU ; Xunqi JI ; Yuwen CHEN ; Chuan TIAN ; Zhonglü YE ; Zhen YANG ; Jianjun ZHU ; Aiguo LIU ; Xiaohua TIAN ; Fengjuan PAN ; Ke HUANG ; Dunhua ZHOU ; Jianpei FANG ; Yang LI
Chinese Journal of Pediatrics 2024;62(10):949-955
Objective:To analyze the short-term clinical efficacy and safety of arsenic trioxide (ATO) combined with a modified N7 induction regimen in the treatment of children with high-risk neuroblastoma (NB).Methods:This study was a prospective, single-arm, multicenter phase Ⅱ clinical study. Sixty-seven high-risk NB children from eight units of Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Wuhan Children′s Hospital of Tongji Medical College of Huazhong University of Science and Technology, First Affiliated Hospital of Guangxi Medical University, Hainan General Hospital, Affiliated Hospital of Guangdong Medical University, Kunming Children′s Hospital, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, and Guangdong Provincial Agricultural Reclamation Center Hospital were enrolled from January 2019 to August 2023 and were treated with ATO combined with a modified N7 induction regimen. The efficacy and adverse effects at the end of induction chemotherapy were assessed and analyzed, and the differences in the clinical characteristics were further compared between the treatment-responsive and treatment-unresponsive groups by using the Fisher′s exact test.Results:Among 67 high-risk NB children, there were 40 males (60%) and 27 females (40%), with the age of disease onset of 3.5 (2.6, 4.8) years. Primary NB sites were mostly in retroperitoneum (including adrenal gland) (56/67, 84%) and the common metastases sites at initial diagnosis were distant lymph node in 25 cases (37%),bone in 48 cases (72%),bone marrow in 56 cases (84%) and intracalvarium in 3 cases (4%). MYCN gene amplification were detected in 28 cases (42%). At the end of induction, 33 cases (49%) achieved complete remission, 29 cases (43%) achieved partial remission, 1 case (1%) with stable disease, and 4 cases (6%) were assessed as progressive disease (PD). The objective remission rate was 93% (62/67) and the disease control rate was 94% (63/67). The percentage of central system metastases at the initial diagnosis was higher in the treatment-unresponsive group than in the treatment-responsive group (2/5 vs. 2% (1/62), P=0.013), whereas the difference in MYCN gene amplification was not statistically significant between two groups (3/5 vs.40% (25/62), P=0.786). Grade Ⅲ or higher adverse reactions during the induction chemotherapy period were myelosuppression occurred in 60 cases (90%), gastrointestinal symptoms occurred in 33 cases (49%), infections occurred in 20 cases (30%), hepatotoxicity occurred in 4 cases (6%), and cardiovascular toxicity occurred in 1 case (2%). There were no chemotherapy-related deaths. Conclusion:ATO combined with N7-modified induction regimen had a superiority in efficacy and safety, which deserved further promotion in clinical practice.
6.Network pharmacological analysis and in vitro experimental verification based on anti-atherosclerosis mechanism of Xiaoban Tongmai Formula
Shan CAO ; Yijia ZHANG ; Yang BAI ; Fang CHEN ; Sha XIE ; Qianqian HAN
Journal of Jilin University(Medicine Edition) 2024;50(4):925-938
Objective:To preliminarily predict the potential pathways and targets of Xiaoban Tongmai Formula in anti-atherosclerosis(AS)by network pharmacology analysis,and to verify its possible mechanism combined with in vitro cell experiment.Method:The databases including Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP),GeneCards,Swiss Target Prediction,and Uniprot were used to collect the information on active compounds and corresponding targets of Xiaoban Tongmai Formula to construct the"compound-target-disease"network.The potential targets and pathways were predicted by protein-protein interaction(PPI)network,and the intersection targets were subjected to Gene Ontology(GO)functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis.The human aortic vascular smooth muscle cells(HA-VSMCs)were cultured and identified in vitro,and the abnormal proliferation of HA-VSMCs were induced by oxidized low-density lipoprotein(ox-LDL)and identified;MTT method was used to detect the proliferation activities of the HA-VSMCs in various groups after treated with different concentrations of Xiaoban Tongmai Formula;the safety of Xiaoban Tongmai Fang was confirmed.The HA-VSMCs were divided into blank group,model group(the abnormal proliferation of HA-VSMCs was induced),rosuvastatin group(treated with 4 μmol·L-1 rosuvastatin after inducing the abnormal proliferation of HA-VSMCs),and low,medium,and high doses of Xiaoban Tongmai Formula groups(treated with 0.025,0.050,and 0.100 mng·L-1 Xiaoban Tongmai Formula after inducing the abnormal proliferation of HA-VSMCs);enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of monocyte chemotactic protein-1(MCP-1),interleukin-6(IL-6),and interleukin-8(IL-8)in supernatant of the HA-VSMCs in various groups;real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of nuclear factor kappa-B(NF-κB)p65 mRNA and fibroblast growth factors 2(FGF2)mRNA in the HA-VSMCs in various groups;Western blotting method was used to detect the expression levels of NF-κB p65 and FGF2 proteins in the HA-VSMCs in various groups.Results:Xiaoban Tongmai Formula contained 103 active ingredients that exert anti-AS effect by acting on 189 target genes.The potential targets included IL-6,IL-8,vascular endothelial growth factor A(VEGFA),nuclear factor kappa B1(NF-κB1),and RELA(NF-κB p65).The GO functional analysis and KEGG pathway enrichment analysis results showed that Xiaoban Tongmai Formula exerted anti-AS effects by regulating lipid metabolism,hypoxia-inducible factor-1(HIF-1),epidermal growth factor(EGF),phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt),and NF-κB signaling pathways.The cell morphology and immunofluorescence staining results confirmed that the cells were HA-VSMCs.The oil red O staining results showed numerous red lipid droplets,indicating successful modeling.The MTT assay results showed that Xiaoban Tongmai Formula had no significant effect on the proliferation rate of HA-VSMCs within a certain dose range,indicating good safety.The ELISA results showed that compared with model group,the levels of MCP-1 and IL-6 in supernatant of the HA-VSMCs in rosuvastatin group and different doses of Xiaoban Tongmai Formula groups were decreased(P<0.05 or P<0.01),and the levels of IL-8 in supernatant of the HA-VSMCs in 0.050 and 0.100 mg·L-1 Xiaoban Tongmai Formula groups were decreased(P<0.01);compared with rosuvastatin group,the levels of MCP-1 in supernatant of the HA-VSMCs in different doses of Xiaoban Tongmai Formula groups were decreased(P<0.01),and the levels of IL-8 in supernatant of the HA-VSMCs in 0.050 and 0.100 mg·L-1 Xiaoban Tongmai Formula groups were decreased(P<0.01).Compared with model group,the expression levels of NF-κB p65 mRNA in the HA-VSMCs in rosuvastatin group and different doses of Xiaoban Tongmai Formula groups were decreased(P<0.01),and the expression levels of FGF2 mRNA in the HA-VSMCs in rosuvastatin group and 0.050 and 0.100 mg·L-1 Xiaoban Tongmai Formula groups were decreased(P<0.01);compared with rosuvastatin group,the expression levels of NF-κB p65 and FGF2 mRNA in the HA-VSMCs in 0.050 and 0.100 mg·L-1 Xiaoban Tongmai Formula groups were decreased(P<0.05 or P<0.01).Compared with model group,the expression levels of NF-κB p65 and FGF2 proteins in the HA-VSMCs in rosuvastatin group and different doses of Xiaoban Tongmai Formula groups were decreased(P<0.01);compared with rosuvastatin group,the expression levels of NF-κB p65 protein in the HA-VSMCs in 0.050 and 0.100 mg·L-1 Xiaoban Tongmai Formula groups were decreased(P<0.01),and the expression level of FGF2 protein in the HA-VSMCs in 0.100 mg·L-1 Xiaoban Tongmai Formula group was decreased(P<0.01).Conclusion:Xiaoban Tongmai Formula has anti-inflammatory effect,inhibitory effect on the proliferation of HA-VSMCs,and anti-AS effect,and its mechanism may be related to the inactivation of NF-κB/FGF2 pathway.
7.Morphologic analysis and measurement of the posterior superior iliac spine of the hip bone in adolescents based on CT three-dimensional reconstruction
Li-Rong SHA ; Zhi-Jie KANG ; Hai-Yan WANG ; Yuan FANG ; Xiao-He LI ; Feng JING ; Kai ZHANG ; Yun-Feng ZHANG ; Yong ZHU ; Tong-Tong YUE
Acta Anatomica Sinica 2024;55(6):721-727
Objective To establish a normal three-dimensional model of the hip bone in adolescents aged 10-19 years old,analyze the morphology and positional parameters of the posterior superior iliac spine of the hip bone among different genders,sides,and ages,which can supplement the study of the anatomical morphology of the hip bone and to provide a reference for the diagnosis of the clinically relevant diseases and for the therapeutic manipulation and localization of the hip bone.Methods Forty adolescent patients aged 10-19 years without previous spinal pelvic diseases were selected,and the pelvic CT image data were collected and imported into Mimics 21.0 software to establish the model.The relative position parameters of the posterior superior iliac spine and the surrounding anatomical landmarks included the length from the posterior superior iliac spine to the anterior superior iliac spine(ab),the length from the tip of the posterior superior iliac spine to the sciatica(ac),the length from the tip of the posterior superior iliac spine to the pubic tubercle(ae),the length from the tip of the posterior superior iliac spine to the midpoint of the posterior margin of the auricular joint surfaces(af),the length from the tip of the posterior superior iliac spine to the iliac spine turn(ag),and the length from the sciatica tubercle to the highest point of the iliac spine(cd).The local parameters of the posterior superior iliac spine included the width(W0)and the thickness(H0)at point A.The maximum width of the posterior iliac spine(WMAX),its distance from point a(D0),and the width of the iliac spine were measured at 0.5,1,and 1.5 cm from point a,and were recorded sequentially as W1,W2,and W3.The width of the iliac spine at the turn of the iliac spine(point g)was measured(W4).The relative positions and parameters of the posterior superior iliac spine to the surrounding anatomical landmarks and the localized parameters of the posterior superior iliac spine were compared sequentially for different genders,sides,and age groups.Results In the measurement result of the parameters of the posterior superior iliac spine and the surrounding anatomical landmarks,the differences in the comparisons between different genders of the ac,ae,and af indexes were statistically significant(P<0.05),and the differences in the comparisons between different genders of the ab,ag,and cd indexes were not statistically significant(P>0.05).The differences in the comparisons between the right and left sides of the ab,ac,ae,af,ag,and cd indexes were not statistically significant(P>0.05).The difference in comparison between different age groups of ab,ac,ae,af,ag,and cd indicators was statistically significant(P<0.05).In the measurement result of the local parameters of the posterior superior iliac spine,the difference in the comparison between the sexes of the W0,W1,W2,WMAX,and H0 indexes was statistically significant(P<0.05),and the difference in the comparison between the sexes of the W3,W4,and D0 indexes was not statistically significant(P>0.05);And the difference in the comparison between the left and right sides of the W0,W1,W2,and the right and left sides of the W3,W4,WMAX,D0,and H0 indexes was not statistically significant(P>0.05);The difference between W0,W1,W2,W3,W4,WMAX,D0,H0 indicators compared between different age groups was not statistically significant(P>0.05).Conclusion Adolescent females have overall greater pelvic parameters than males,with wider and thicker tips of the posterior superior iliac spine in females and narrower and thinner tips of the posterior superior iliac spine in males;Pelvic parameters show a tendency to increase with age,while the width and thickness of the posterior superior iliac spine,as well as the width of the cephalic end to the iliac spine remain essentially unchanged.
8.Study of the prevention effect of Ankle-length or Knee-length elastic pants on deep vein thrombosis in patients with thigh liposuction
Rong GUO ; Mosheng YU ; Yueqiang ZHAO ; Zhanyong ZHU ; Sha LUO ; Zhixiang TAN ; Rui TAO ; Fang WANG
Journal of Clinical Surgery 2024;32(5):541-544
Objective To investigate the effect of elastic pants on coagulation function and deep vein thrombosis by examining blood coagulation function and deep vein thrombosis in patients with liposuction in the thigh before and after operation.Methods 80 patients with liposuction were randomly divided into Ankle-length elastic pants(Ankle group,A group,n=40)and Knee-length elastic pants(Knee group,K group,n=40)from October 2021 to October 2022.After liposuction surgery,the two groups of patients used elastic bandage to initially compress and bind the thigh.According to the length of the patients'thigh,the patients in A group wore appropriate ankle-length elastic pants and the patients in K group wore appropriate knee-length elastic pants.The index were recorded including the popliteal vein flow rate,the common femoral vein flow rate,the instep temperature,the incidence of deep vein thrombosis(DVT),the incidence of intramuscular vein thrombosis of leg and the coagulation indexes(APTT,PT,Fib,D-dimer).Results Compared with pre-operation,the blood flow rate of popliteal vein and common femoral vein in A group was significantly faster,while the blood flow rate of popliteal vein in K group was significantly slower(P<0.05).There was no significant change in APTT and PT in the two groups after operation(P>0.05),but the Fib and D-Dimer increased significantly on the first day after operation,and then decreased gradually(P<0.05).Compared with K group,the blood flow of popliteal vein and common femoral vein in A group was significantly faster at each time point after operation(P<0.05).The Fib and D-Dimer of patients in A group were significantly lower than those in K group on the 1st,3rd and 7th day after operation(P<0.05),and the blood coagulation index between the two groups returned to normal around the 14th day.There was no statistically significant difference in the instep temperature between groups and within groups(P>0.05).No deep venous thrombosis was found in A group after surgery,while there were 3 cases of deep venous thrombosis without clinical symptoms in K group on the 3rd and 7th day,with no statistical difference(P>0.05).After surgery,patients in A group and K group had intramuscular venous thrombosis of the leg on the 1st,3rd and 7th day after surgery,and there was statistically significant difference on the 3rd and 7th day between the two groups(P<0.05).Conclusion Thigh liposuction can lead to deep vein thrombosis without obvious clinical symptoms and intramuscular vein thrombosis of leg.Ankle-length elastic pants are more conducive to blood circulation of patients'legs,improve blood hypercoagulability,and reduce the risk of deep vein thrombosis after operation.
9.Finite element model establishment and stress analysis of lumbar-sacral intervertebral disc in ankylosing spondylitis
Zhijie KANG ; Zhenhua CAO ; Yangyang XU ; Yunfeng ZHANG ; Feng JIN ; Baoke SU ; Lidong WANG ; Ling TONG ; Qinghua LIU ; Yuan FANG ; Lirong SHA ; Liang LIANG ; Mengmeng LI ; Yifei DU ; Lin LIN ; Haiyan WANG ; Xiaohe LI ; Zhijun LI
Chinese Journal of Tissue Engineering Research 2024;28(6):840-846
BACKGROUND:Ankylosing spondylitis is a chronic inflammatory disease with chronic rheumatic immunity.Soft tissue ossification and fusion and spinal stiffness can cause biomechanical changes. OBJECTIVE:To reconstruct the lumbar-sacral intervertebral disc in ankylosing spondylitis patients with lumbar kyphosis by finite element analysis,and to study the range of motion of each segment of T11-S1 and the biomechanical characteristics of annulus fibrosus and nucleus pulposus. METHODS:The imaging data were obtained from an ankylosing spondylitis patient with lumbar kyphosis.The original CT image data of continuously scanned spine were imported into Mimics 21.0 in DICOM format,and T11-S1 was reconstructed respectively.The established model was imported into 3-Matic software in the format of"Stl"to reconstruct the intervertebral disc,and the fibrous intervertebral disc model was obtained.The improved model was further imported into Hypermesh software,and the vertebra,nucleus pulposus,annulus fibrosus and ligament were mesh-divided.After the material properties were given,the model was imported into ABAQUS software to observe the range of motion of each vertebral body in seven different working conditions of T11-S1,and analyze the biomechanical characteristics of each segment of annulus fibrosus and nucleus pulposus. RESULTS AND CONCLUSION:(1)The range of motion of L1 vertebrae was higher than that of other vertebrae under six different working conditions:extension,forward flexion,rotation(left and right),and lateral flexion(left and right).The maximum range of motion was 2.18° during L1 vertebral flexion,and the minimum range of motion was 0.12° during L5 vertebral extension.(2)The annular fiber flexion at L2-L3 segments was greater than the extension(P<0.05),and the annular fiber flexion at L3-L4 and L4-L5 segments was less than the extension(P<0.05).The left rotation of L1-L2 annular fibers was greater than the right rotation(P<0.05).The left flexion of the annulus was greater than the right flexion in L1-L2,L2-L3,L3-L4,L4-L5 and L5-S1 segments(P<0.05).(3)The nucleus pulposus stresses of T11-L12,L1-L2,L2-L3,L3-L4 and L4-L5 segments in forward flexion were greater than in extension(P<0.05).The left rotation of T12-L1 and L3-L4 segments was smaller than the right rotation(P<0.05),and that of T11-T12,L1-L2,and L2-L3 segments was larger than the right rotation(P<0.05).The left flexion was larger than the right flexion in the T11-S1 segment.(4)It is concluded that in ankylosing spondylitis patients with lumbar kyphosis,the minimum range of motion of the vertebral body is located at the L5 vertebral body in extension.To prevent fractures,it is recommended to avoid exercise in the extension position.During the onset of lumbar kyphosis in patients with ankylosing spondylitis,the maximum stress of the annulus fibrosus and nucleus pulposus is located in the L1-L2 segment,which is fixed and will not alter with the change of body position.The late surgical treatment and correction of deformity should focus on releasing the pressure of the annulus fibrosus and nucleus pulposus in this segment to avoid the rupture of the annulus fibrosus and the injury of the nucleus pulposus.
10.Biomechanical features of posterior"Y"osteotomy and fixation in treatment of ankylosing spondylitis based on finite element simulation analysis
Le ZHANG ; Zhenhua CAO ; Yunfeng ZHANG ; Yangyang XU ; Feng JIN ; Baoke SU ; Lidong WANG ; Xing WANG ; Ling TONG ; Qinghua LIU ; Yuan FANG ; Lirong SHA ; Haiyan WANG ; Xiaohe LI ; Zhijun LI
Chinese Journal of Tissue Engineering Research 2024;28(12):1842-1848
BACKGROUND:Ankylosing spondylitis is a progressive inflammation of spinal stiffness deformity caused by tissue ossification and fibrosis.The posture of ankylosing spondylitis patients is abnormal and their activities are limited that minor injuries can lead to thoracolumbar fractures.Traditional medical image observation limits doctors'preoperative decision planning and postoperative disease prevention for ankylosing spondylitis treatment. OBJECTIVE:Based on the spinal model of ankylosing spondylitis patients before and after posterior spinal cancellous ossification osteotomy("Y"osteotomy for short),to explore the biomechanical changes of"Y"osteotomy and fixation in the treatment of ankylosing spondylitis. METHODS:Based on the preoperative and postoperative CT images of an ankylosing spondylitis patient who went to the Second Affiliated Hospital of Inner Mongolia Medical University,a three-dimensional spine model(T11-S1)before and after"Y"osteotomy(L3 osteotomy)was reconstructed in Mimics 19.0 software.A 7.5 Nm torque was applied to the top of T11 vertebral body to simulate the movement of the spine under six conditions:flexion,extension,left bending,right bending,left rotation and right rotation.Finally,the range of motion of each vertebral body,the stress of each intervertebral disc,and the stress of the screw rod system were simulated. RESULTS AND CONCLUSION:(1)After"Y"type osteotomy and posterior fixation,the range of motion of all vertebrae in the spine decreased,and the loss rate of upper vertebrae was large(L1:77.95%).(2)The maximum stress of the spinal intervertebral disc before operation occurred at the L1-L2 segment(0.55 MPa),and the maximum stress of the spinal intervertebral disc after operation occurred at the T11-T12 segment(0.50 MPa),and the stress of intervertebral disc below T12 was far less than that before operation.(3)The maximum stress of the screw rod system(166.67 MPa)occurred in the upper and middle segments of the rod body and the root of the pedicle screw.(4)In conclusion,the"Y"type posterior fixation operation enhances the stability of the spine and reduces the range of motion of the spine.The vertebral body decompression of the fixed segment is great and the stress-shielding phenomenon of the lower vertebral body is significant.The stiffness of the rod body and the stress concentration area of the pedicle screw should be strengthened to avoid the fracture of the rod caused by stress fatigue.

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