1.Mechanism of tissue-engineered bone recruiting endogenous mesenchymal stem cells towards bone regeneration
Xiaolong YIN ; Tianyong HOU ; Yanzhu LU ; Zhilin LI ; Junchao XING ; Aijun YANG ; Jianzhong XU
Chinese Journal of Trauma 2018;34(4):362-369
Objective To investigate the mechanism of implanted tissue-engineered bone (TEB)recruiting endogenous mesenchymal stem cells (BMSCs) towards bone regeneration after traumatic bone defect.Methods In vivo experiments:2 mm of diaphysis and periosteum were removed from the middle of the femoral shaft in 8 week old FVB/N mice to form a large segment of bone defect.Demineralized bone matrix (DBM) and TEB were implanted into the defect area and fixated.All mice were randomly divided into DBM group (n =18) and TEB group (n =18).The results were observed 24 hours after implantation:(1) flow cytometry was used to evaluate the number of mobilized host BMSCs into the blood;(2) non-invasive bioluminescent imaging was used to observe the ability of two groups in recruiting mouse bone marrow derived mesenchymal stem cells (mBMSCs) in peripheral blood to the defect area;(3) ELISA was used to evaluate the stromal cell-derived factor 1 (SDF-1) content in peripheral blood of two groups.In vitro experiments:(1) transwell assay was conducted to evaluate the ability of SDF-1 (100 ng/ml) in promoting the migration of human bone marrow derived mesenchymal stem cells (hBMSCs).SDF-1/C-X-C motif chemokine receptor-4 (CXCR4) pathway was blocked by the selective CXCR4 antagonist Plerixafor (AMD3100).The experimental groups were divided into control group,SDF-1 group,and SDF-1 + AMD3100 group.(2) The co-culture system of human umbilical vein endothelial cells (hUVECs) and hBMSCs was established,and cells were stimulated by SDF-1.The experimental groups were divided into hBMSCs group,hBMSCs + hUVECs group,and hBMSCs + hUVECs (AMD3100 pretreatment) group.Transwell assays were used to compare the migration of hBMSCs in each group.ELISA was used to detect the concentration of hepatocyte growth factor (HGF) in the co-culture supernatant.(3) In vitro cultured hUVECs were stimulated by SDF-1 and SDF-1/CXCR4 pathway was antagonized by AMD3100.The experimental groups were divided into control group,SDF-1 group,and SDF-1 + AMD3100 group.Quantitative real-time polymerase chain reaction (qRT PCR) was used to evaluate the expression of HGF in each group.Results In vivo experiments:24 h after transplantation,the number of BMSCs and SDF-1 concentration in the TEB group were significantly highcr than those in the DBM group (P < 0.05).The number of recruited mBMSCs into the circulation in the TEB group was larger than that in the DBM group (P< 0.01).In vitro experiments:(1) compared with the control group and the SDF-1 + AMD3100 group,the SDF-1 group significantly enhanced the migration ability of hBMSCs in Transwell migration experiments (P < 0.01);(2) compared with the hBMSCs group and the hBMSCs + hUVECs (AMD3100 pretreatment) group,the number of migrated cells and HGF concentration in the hBMSCs + hUVEC group significantly increased (P < 0.01),but there were no significant differences between the hBMSCs group and the hBMSCs + hUVECs (AMD3100 Pretreatment) group (P >0.05);(3) qRT-PCR showed that the expression of HGF was significantly increased in the SDF-1 group compared with the control group (P < 0.05).After antagonizing SDF-1/CXCR4,HGF expression in the SDF-1 + AMD3100 group was significantly lower than that in the SDF-1 group.Conclusions TEB transplantation in traumatic bone defect can significantly increase the concentration of chemokine SDF-1 in vivo and effectively promote the mobilization of endogenous MSCs and recruitment of circulating MSCs.SDF-1 not only directly promotes the migration of hBMSCs through SDF-1/CXCR4 pathway,but also up-regulates the expression and secretion of HGF in vascular cells to further amplify the chemotactic effect of SDF-1 on hBMSCs.
2.Role of Arpin protein in bone repair by mediating migration of mesenchymal stem cells to bone defect area
Wei PENG ; Zhongxue LI ; Yanzhu LU ; Qiuchi AI ; Jiangling ZHOU ; Tianyong HOU
Chinese Journal of Trauma 2020;36(3):275-282
Objective:]To investigate the role of Arpin protein in bone repair by mediating migration of host bone marrow mesenchymal stem cells (BMSCs) to the bone defect area after transplantation of tissue engineering bone (TEB).Methods:Immunofluorescence was used to observe the expression and relative localization of Arpin and Arp2/3 proteins in BMSCs. Lentiviruses that ware designed to interfere with Arpin expression were constructed to transfect BMSCs for knockdown Arpin expression. Knockdown efficiency was verified by real-time quantitative reverse transcription PCR ( qRT-PCR) and Western blot. According to different levels of Arpin protein expression, experiments were divided into empty vector control group and an Arpin expression inhibition group in vitro and in vivo. In vitro experiments: the cell migration model was established with a migration chamber, then the cells from both groups were seeded on the up chamber, and the number of migrated cells were detected by fluorescence microscopy. Cells from both groups were seeded on six-well plates. Model of wound healing experiment was established and wound healing ratio was examined by microscopy. In vivo experiments: 8-week-old C57BL/6 mice were selected and assigned to empty vector control group and Arpin expression inhibition group according to the random number table, with 6 rats per group. Diaphysis of 2 mm and periosteum in the middle femur were excised to make a large segment of bone defects. Then, TEB was transplanted into the defect area and fixed.Green fluorescein-labeled BMSCs (1 million cells per mouse) from empty vector control group and Arpin expression inhibition group were injected through the tail vein. Number of BMSCs homing to the bone defect area was detected by immunofluorescence staining at day 2 and 7 after operation. At 4 weeks after operation, the femur was taken for a Micro-CT scan to analyze bone mass density(BMD), bone volume density (BV/TV), trabecular spacing (Tb.Sp) and trabecular thickness (Tb.Th). Then, the specimens were stained with pathological HE and MASSON staining to observe the quality of bone formation. Results:Mouse BMSCs expressed Arpin protein, which was located at the cell edge relative to Arp2/3. After transfection of lentivirus, BMSCs expressed green fluorescent protein, and the expression of Arpin gene and protein in Arpin expression inhibition group were decreased compared to empty vector control group ( P<0. 01). BMSCs migration was enhanced in Arpin expression inhibition group compared to empty vector control group [(76.6±6.6) vs. (105.7±6.5)] ( P<0. 01). Wound healing was accelerated in Arpin expression inhibition group compared to empty vector control group [(43.8±0.19)% vs. (62.6±3.2)%]( P<0.01). At day 2 after operation, immunofluorescence results showed no significant difference in cell migration between the two groups and almost no labeled cells migrated. At day 7 after operation, more cells migrated to the transplanted area in Arpin expression inhibition group compared to empty vector control group [(5.7±1.5) vs. (11.3±1.5)] ( P<0.01). At 4 weeks after operation, Micro-CT results showed that Arpin expression inhibition group had better bone formation quality than empty vector control group [BMD: (172.7±6.0)mg/cm 3vs. (140.0±6.0)mg/cm 3, BV/TV: (28.8±1.3)% vs. (23.4±0.9)%, Tb.Sp: (0.33±0.01)μm vs. (0.28±0.01)μm, Tb.Th: (0.11±0.01)μm vs.(0.15±0. 01)μm]( P<0.05). Pathological staining showed there were more new bone tissue in Arpin expression inhibition group ( P<0.01). Conclusion:Silencing Arpin protein expression promotes BMSCs to migrate to the bone defect area and improves bone repair effect.
3.18F-FDG PET/CT manifestations of primary systemic anaplastic large cell lymphoma
Lu ZHENG ; Yujing HU ; Xinchao ZHANG ; Kang LI ; Xiaoyu CAI ; Jiale LIU ; Yanzhu BIAN
Chinese Journal of Medical Imaging Technology 2023;39(12):1798-1802
Objective To observe the 18F-FDG PET/CT manifestations of primary systemic anaplastic large cell lymphoma(ALCL).Methods A total of 21 patients with primary systemic ALCL were enrolled,and PET/CT manifestations were observed.Results Among 21 cases of ALCL,there were 15 cases of ALK+and 6 cases of ALK-.Affected lymph nodes in multiple site were observed in 19 cases,mainly located in the neck(n=13),mediastinum(n=12 cases)or retroperitoneum(n=12),while single site affected lymph node was notice in 2 cases.Extranodal organs/site involvements were found in 12 cases,including 6 cases of soft tissue(such as skin,muscles,etc.),4 cases of bone,14 cases of organs,including 4 cases of lung,3 cases of liver,2 cases of pancreas,2 cases of kidney,2 cases of gastrointestinal tract and 1 case of thyroid.Among 21 cases of ALCL,19 with irregular lymph node morphology and fused into clusters,17 with uniform density,3 with necrosis and 1 with calcification.All ALCL lesions in 21 cases showed hypermetabolism,the maximum standard uptake value(SUVmax)and the mean standard uptake value(SUVmean)of the affected lymph node was 17.04±9.94 and 9.96±6.15,respectively,while the metabolic tumor volume(MTV)and total lesion glycolysis(TLG)of all lesions was 92.54(67.61,249.21)cm3 and 723.46(419.78,1 461.17)g,respectively.The maximum diameter of the affected lymph node was not significantly correlated with SUVmax nor SUVmean(both P>0.05),but positively correlated with MTV and TLG of all lesions(r=0.696,0.767,both P<0.001).Ann Arbor staging was positively correlated with the maximum diameter,SUVmax and SUVmean of the affected lymph node,also MTV and TLG of all lesions(r=0.467,0.458,0.702,0.780,0.664,all P<0.05).Conclusion 18F-FDG PET/CT manifestations of primary systemic ALCL were characteristic,with significant changed metabolic parameters,including SUVmax,SUVmean,MTV and TLG.
4.Microglia activation and temporal changes in rat model of trigeminal neuralgia.
Yanzhu LU ; Jingqi ZHANG ; Wenli LAI
West China Journal of Stomatology 2022;40(6):638-644
OBJECTIVES:
This study aimed to investigate whether the microglia in the spinal trigeminal nucleus caudal part (Sp5C) were activated in a rat model of trigeminal neuralgia and to explore whether the activation level of microglia is consistent with maxillofacial pain level.
METHODS:
Chronic constriction injury of trigeminal nerve (CCI) was induced by partial ligation of infraorbital nerve (IoN) in rats. The behavioral change of rats observed at D1, D5, D10, D15, and D30 days post-surgery and the change of pain threshold were detected with electronic Von Frey filaments served as an evaluation index of maxillofacial pain. Weight change was measured by weighing. Ionized calcium binding adaptor molecule-1 (Iba-1) expression level of Sp5C at each time point was detected, and three microglia morphological categories were analyzed by immunohistochemical staining.
RESULTS:
The changes of behavioral and pain threshold suggested the maxillofacial pain level first increased and then decreased post-surgery in the IoN-CCI group. Both the expressions of Iba-1 and proportion of ameboid morphology in ipsilateral Sp5C increased from D1 and reached their peaks in D10 and D5, respectively. Then, they recovered nearly to the same level with contralateral Sp5C on D30. This trend was consistent with the maxillofacial change.
CONCLUSIONS
The model of trigeminal neuralgia in rats constructed by partial ligation of infraorbital nerve can induce the activation of microglia in Sp5C, and the activation level is consistent with maxillofacial pain, which reached its peak at around D10 post-surgery.
Rats
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Animals
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Trigeminal Neuralgia
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Rats, Sprague-Dawley
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Microglia
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Pain Threshold/physiology*
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Pain
5.Treatment of skeletal Class Ⅲ malocclusion with mandibular lateral deviation by clear aligner therapy combined with orthognathic treatment: case report and literature review
LU Yanzhu ; ZHAO Rui ; JIAN Fan ; SUN Jie ; LAI Wenli
Journal of Prevention and Treatment for Stomatological Diseases 2023;31(2):123-130
Objective :
To investigate the clinical efficacy of clear aligner therapy combined with orthognathic surgery in the treatment of skeletal Class Ⅲ mandible deviation.
Methods :
A case of mandibular lateral deviation treated by combined orthodontic and orthognathic surgery was reported and analyzed in combination with the related literature. Clear aligner therapy was chosen for orthodontic treatment, and bilateral sagittal split ramus osteotomy and genioplasty were adopted to address the skeletal deformity.
Results:
Eight intermaxillary fixation screws were inserted during surgery to fix the splint, and settling elastics were run to achieve better occlusion postsurgery. With good compliance of the patient, treatment was completed by the first set of aligners, Class I canine and molar relationships were obtained, normal overbite and overjet were achieved, and mandibular deviation was addressed. The stability was good 1 year after treatment. The results of the literature review showed that clear aligner therapy in conjunction with orthognathic surgery has been widely used, but there are still some challenges in front. Compared with traditional orthodontics, the digital features of clear aligner therapy makes it fit more closely with computer-aided surgery, and there is more space for exploration.
Conclusion
For patients with good compliance, clear aligner therapy combined with orthognathic surgery can effectively complete the treatment of simple cases. The advantage of digital design equips clear aligner therapy with good prospects for development.
6.Retrograde nerve growth factor signaling modulates tooth mechanical hyperalgesia induced by orthodontic tooth movement via acid-sensing ion channel 3.
Meiya GAO ; Xinyu YAN ; Yanzhu LU ; Linghuan REN ; Shizhen ZHANG ; Xiaoqi ZHANG ; Qianyun KUANG ; Lu LIU ; Jing ZHOU ; Yan WANG ; Wenli LAI ; Hu LONG
International Journal of Oral Science 2021;13(1):18-18
Orthodontic tooth movement elicits alveolar bone remodeling and orofacial pain that is manifested by tooth mechanical hyperalgesia. Nerve growth factor (NGF) is upregulated in periodontium and may modulate tooth mechanical hyperalgesia. The objectives were to examine the role of NGF in tooth mechanical hyperalgesia and to elucidate the underlying mechanisms. Tooth mechanical hyperalgesia was induced by ligating closed coil springs between incisors and molars in Sprague-Dawley rats. Retrograde labeling was performed by periodontal administration of fluor-conjugated NGF and the detection of fluorescence in trigeminal ganglia (TG). Lentivirus vectors carrying NGF shRNA were employed to knockdown the expression of NGF in TG. The administration of agonists, antagonists, and virus vectors into TG and periodontium was conducted. Tooth mechanical hyperalgesia was examined through the threshold of biting withdrawal. Our results revealed that tooth movement elicited tooth mechanical hyperalgesia that could be alleviated by NGF neutralizing antibody and that NGF was upregulated in periodontium (mainly in periodontal fibroblasts) and TG. Retrograde labeling revealed that periodontal NGF was retrogradely transported to TG after day 1. Acid-sensing ion channel 3 (ASIC3) and NGF were co-expressed in trigeminal neurons and the percentage of co-expression was significantly higher following tooth movement. The administration of NGF and NGF neutralizing antibody into TG could upregulate and downregulate the expression of ASIC3 in TG, respectively. NGF aggravated tooth mechanical hyperalgesia that could be alleviated by ASIC3 antagonist (APETx2). Moreover, NGF neutralizing antibody mitigated tooth mechanical hyperalgesia that could be recapitulated by ASIC3 agonist (GMQ). NGF-based gene therapy abolished tooth mechanical hyperalgesia and downregulated ASIC3 expression. Taken together, in response to force stimuli, periodontal fibroblasts upregulated the expressions of NGF that was retrogradely transported to TG, where NGF elicited tooth mechanical hyperalgesia through upregulating ASIC3. NGF-based gene therapy is a viable method in alleviating tooth-movement-induced mechanical hyperalgesia.