Research progress on biologic repair of rotator cuff injury / 天津医药

Rotator cuff injury is a common shoulder disease,which often results in pain and limited motion of shoulder and reduces the quality of life.There are some limitations for current treatments,which often lead to repair failure or reinjury of rotator cuff.Therefore,a novel repair technique is needed.Biologic repair represents a novel technique in the management of rotator cuff injury,and has the potential to restore the normal histological structure of rotator cuff.Biologic repair involves the application of growth factors and/or cells to promote the regeneration of rotator cuff tendons. This study reviewed the literatures on biologic repair of rotator cuff injury,and presented the research progress.

Differentiation of human umbilical cord-derived mesenchymal stem cells into annulus fibrosus-like cells by co-culture / 临床与实验病理学杂志

Purpose To induce the differentiation of hu-man umbilical cord mesenchymal stem cells ( HUCMSCs) into annulus fibrosus (AF) cells by in vitro co-culture technique and to investigate the morphological and histological changes of HUCMSCs after co-culture. Methods HUCMSCs and AF cells were isolated from the normal neonatal umbilical cord and New Zealand white rabbit. Transwell six-well plates were used for co-culture with the cells seeded at the ratio of 1 ∶ 1, HUCMSCs cultured alone served as controls. After two weeks of co-culture, morphological changes were observed by inverted microscope. Real-time PCR was used to detect the expression of typeⅠcolla-gen, aggrecan and SOX-9 gene in HUCMSCs. Immunocyto-chemical staining and toluidine blue staining were used to detect the synthesis of cell matrix such as type Ⅰ collagen and aggre- can. Results The morphology of HUCMSCs in control group was long-fusiform, the morphology of HUCMSCs in co-culture gradually became short-fusiform or polygonal, and began to ap-pear synapse, showing the morphological features of AF-like cells. Real-time PCR results showed that typeⅠcollagen, aggre-can and SOX-9 mRNA were significantly increased in the co-cul-ture group (P＜0. 05). Immunocytochemical staining and tolui-dine blue staining showed that type I collagen and aggrecan were positive, respectively. Conclusion In vitro co-culture technol-ogy can induce HUCMSCs to differentiate into AF-like cells, which is expected to provide a new kind of seed cells for the bio-logical treatment of degenerative disc disease.

Effects of different decellularization methods on biomechanical properties and histological structure of annulus fibrosus in pigtail / 医用生物力学

Objective To investigate effects of different de-cellularization methods on biomechanical properties and histological structure of annulus fibrosus in pigtails and provide experimental evidence for the construction of tissue engineering annulus fibrosus. Methods Sixty Fresh annulus fibrosus were dissected from caudal disks of pigs and randomly assigned to 4 groups with 15 in each group. Triton X-100 group(Group A): annulus fibrosus were treated with hypotonic Tris-HCl buffer for 48 hours and de-cellularized with Triton X-100, DNase Ⅰ and RNase A. SDS group (Group B): annulus fibrosus were subjected to 3 cycles of freeze-thaw and subsequently de-cellularized with SDS, DNaseⅠ and RNase A. Trypsin group (Group C): annulus fibrosus were de-cellularized with Tris buffer containing trypsin, DNase Ⅰ and RNase A. Control group: fresh annulus fibrosus underwent no treatment. After the de-cellularization process was completed, hematoxylin-eosin (HE) staining was carried out to examine the efficacy on cell removal, and the ultrastructure of annulus fibrosus were observed by scanning electron microscopy. The collagen content, glycosaminoglycan (GAG) content and biomechanical parameters in each group were also detected. Results HE staining and scanning electron microscopy showed that no residual cells were found in Group A, B and C. The structure of annulus fibrosus in Group A was not disturbed, while that in Group B and C was damaged severely and slightly, respectively. There was no statistical difference in collagen content among Group A, B and C, as compared to the control group (P>0.05). But the GAG content was significantly more lower in Group A, B and C than in the control group (P0.05), while these parameters of Group B were lower than those in the control group (P<0.05). Conclusions The Triton X-100-treated annulus fibrosus retained the major extracellular matrix composition after cell removal and preserved the major structure and mechanical strength, which is preferable for the construction of tissue engineering annulus fibrosus.

Effect of protein tyrosine phosphatase σ on the reactivation of ocular dominance plasticity in the visual cortex of adult rats / 中华实验眼科杂志

Background Chondroitin sulphate proteoglycans (CSPGs) can cause the termination of ocular dominance plasticity in the visual cortex.Recently,protein tyrosine phosphatase σ (PTPσ) has been identified as a receptor that inhibits CSPGs.However,whether PTPσ and its downstream molecules participate in the reactivation of ocular dominance plasticity in adult visual cortex has not been studied.Objective The present study was to investigate the changes in the expression of the PTPσ,probabilistic neural networks (PNNs),and molecules downstream of PNN,such as N-cadherin/β-catenin,after the reactivation of adult visual cortical plasticity.Methods Fifty-four SPF Long Evans rats were grouped according to different postnatal week (PW) as the PW1 (6 rats),PW3 (6 rats),PW5 (6 rats),PW7 (24 rats),and PW9 (12 rats) groups,and the upper and lower eyelids were sutured in the 12 rats from the PW7 group for 14 days to establish the binocular plasticity reactivation models.Expression of PTPσ and PNNs in the rat visual cortex was detected using immunochemistry,and changes of PTPσ mRNA,N-cadherin mRNA and β-catenin mRNA expression in the rat visual cortex with plasticity reactivation were assessed by real-time fluorescence quantitative PCR (RT Q-PCR).The use of animals followed the Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results The expression level of PTPσ mRNA was significantly higher in the PW9 group than that of the binocular plasticity reactivation models and the PW7 group (t =1.965,3.526,P＜0.01).The staining of the rat visual cortex for PTPσwas localized to the cellular membrane,cytoplasm and axon.Cell densities of the PW9 group in the Ⅱ-Ⅲ layer,Ⅳ layer and Ⅴ-Ⅵ layer of the visual cortex were elevated in the PW9 rats compared with the PW7 rats (t =24.593,23.444,13.556,P＜0.01) and rats from the binocular plasticity reactivation model (t =44.111,43.000,16.556,P＜0.01).Cell densities for PNNs in the Ⅳ and Ⅴ-Ⅵ layers were significantly increased in the PW9 rats in comparison with the PW7 rats (t=1.926,P＜0.01 ;t=1.370,P＜0.05),but the cell density in the Ⅱ-Ⅱ layer has no statistical significance (t=0.889,P＞0.05).However,cell densities for PNNs in the Ⅱ-Ⅲ and Ⅳ layers in the binocular plasticity reactivation models were lower than those of the PW9 rats (t =2.556,4.585,P＜0.01).Compared with PW1 rats,the expression levels of the N-cadherin mRNA in the PW3,PW5,PW7,PW9 rats were lower (t =28.932,28.988,27.083,28.908,P＜0.01),but those in the PW7 rats were enhanced in comparison with the PW3 rats,PW5 rats and PW9 rats (t =1.848,1.904,1.825,P＜0.01).No significant difference was seen in the expression of the N-cadherin mRNA between the PW9 rats and rats from the binocular plasticity reactivation model (t =0.072,P＞0.05).A statistically significant increase was found in the β-catenin mRNA expression in the PW1 rats compared with the PW3,PW5,PW7 and PW9 rats (t =3.918,3.534,2.645,4.652,P＜ 0.0 1),as well as between rats from the binocular plasticity reactivation model and the PW9 rats (t =0.570,P＜0.01).Conclusions PTPr,PNNs and β-catenin are involved in the reactivation of ocular dominance plasticity in the adult visual cortex.

Epidemiological characteristics and clinical phenotype of sporadic retinitis pigmentosa / 中华实验眼科杂志

BackgroundRetinitis pigmentosa (RP)is a group of progressive monogenic inheritance disease.Seldom epidemiology is performed to summarize the varied clinical phenotypes,especially some sporadic cases with untypical genetic history.ObjectiveThe aim of this survey was to investigate the clinical epidemiological characteristics and phenotype of sporadic RP.MethodsA prospective cohort study was designed.A survey of a series of clinically diagnosed sporadic primary RP patients was conducted at the Southwest Eye Hospital from July 2010 to November 2011.A total of 130 patients that matched the inclusion criteria were enrolled in this survey.Clinical ocular examinations and questionnaire surveys were given,including ophthalmoscopic examination,best corrective visual acuity( BCVA ),perimetry and Ganzfield electroretinogram (ERG)and color fundus photo.RP with different phenotypes were classified. ResultsA total of 130 sporadic RP patients were collected in this survey.Of them,66 were male and 64 were female with a mean age of (36.9±14.4) years.The average onset age of these subjects was (21.2±18.4) years.Seven (5.38％) patients had consanguineous marriage history,and 13 ( 10.00％ )patients had systemic disease.Forty-four (33.85％) patients had outdoor jobs,and 86 (66.15％ ) worked indoor.Eighty-nine patients had typical RP ( 68.5％ ),and the number of patients that developed central RP and sine pigmento RP were 16 ( 12.3％ ) and 16( 12.3％ ),respectively.An absence of a- and b-waves in full-field ERG wasdetected in 99 (76.15％ ) cases.The longest duration of night blindness was identified in typical RP patients and the lowest BCVA in central RP patients.ConclusionsThe age at first onset is early in sporadic RP.There are wide variations in different types of RP,but the ERG outcome is specific for all RP types.

Targeted migration and differentiation of engrafted neural precursor cells in amyloid beta-treated hippocampus in rats / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To observe the migration and differentiation of the neural precursor cells (NPCs) that derived from murine embryonic stem cells (ESCs) when they were transplanted into amyloid beta (A beta)-treated rat hippocampus.</p><p><b>METHODS</b>MESPU35, a murine ESC cell line that express the enhanced green fluorescent protein (EGFP), was induced differentiation into nestin-positive NPCs by modified serum-free methods. The A beta plaques and the differentiation of the grafted cells were observed by immunofluorescent staining.</p><p><b>RESULTS</b>Comparing 16 weeks with 4 weeks post-transplantation, the migration distance increased about 5 times; the rate of migratory NPCs differentiating into glial fibrillary acidic protein (GFAP)-positive cells kept rising from (30.41+/-1.45) % to (49.25+/-1.23) %, and the rate of NPCs differentiating into neurofilament 200 (NF200) positive cells increased from (16.68+/-0.95) % to (27.94+/-1.21) %. Meanwhile, the GFAP-positive cells targeting to the ipsilateral side of A beta plaques increased from 60.2% to 81.3%, while the NF200-positive cells increased from 61.3% to 84.1%. The migration distance had significant positive linear correlations to the neuronal differentiation rate (r = 0.991) and to the astrocytic differentiation rate (r = 0.953).</p><p><b>CONCLUSION</b>Engrafted NPCs migrate targetedly to the A beta injection site and differentiate into neurons and astrocytes.</p>

Comparative study of histopathology changes between the PS1/APP double transgenic mouse model and Abeta1-40 -injected rat model of Alzheimer disease / 神经科学通报·英文版

Objective To identify the genetype of the PS1/APP double transgenic mouse model, then to analyse the histopathological changes in the brain and compare the differences between the transgenic mice models and Abeta1-40-injected rats models of Alzheimer disease. Methods The modified congo red staining, Nissl's staining and immunohistology staimouse extensively displayed Abeta deposits, activation of astrocyte respectively. Results (1) The PS1/APP transgenic mouse extensively displayed Abeta deposits in the cortex and hippocampal structures, and GFAP positive cells were aggregated in mass and surrounded the congo red-positive plaque. (2) The Abeta1-40-intrahippocampal-injected rat model showed the Abeta plaque deposits in the dentate gyrus of the hippocampus, with the astrocyte surrounded. The neurons loss was significant in the injection point and pin hole of injection with Nissl's staining methods. GFAP-positive cells increased significantly compared with the uninjected lateral of the hippocampus. Conclusion Although Abeta1-40-injected rat models could simulate some characteristic pathological features of human Alzheimer diseases, Abeta deposits and neurons loss in partial hippocampal, it would not simulate the progressive degenenration in the brain of AD. The double transgenic PS1/APP mice could simulate the specific pathogenesis and progressive changes of AD, mainly is Abeta deposits and the spongiocyte response, while no neurons loss were observed in this model.