椎间盘微环境下椎间盘源性干细胞和髓核间充质干细胞的活性

文题释义：椎间盘微环境：在正常情况下,髓核组织缺乏血液供应,其营养代谢主要依赖渗透。由于代谢产物等影响,椎间盘组织内部的pH值为6.9-7.2,被认为是人体内最恶劣的环境之一,在这种条件下细胞正常代谢能力受到很大抑制,即使是特化的髓核细胞其代谢率也仅为正常的32%。当椎间盘退变后,葡萄糖及氧浓度进一步下降,乳酸堆积,pH值降低和代谢产物进行性增加。 髓核间充质干细胞：经过前期实验发现髓核间充质干细胞经自体移植于椎间盘局部,可以分化为纤维环细胞和髓核细胞,或者通过旁分泌细胞因子来促进组织细胞的再生,但髓核间充质干细胞在椎间盘微环境中存活量级并不清楚。椎间盘源性干细胞和髓核间充质干细胞在椎间盘微环境下的生存变化差异性也还是未知。 背景：椎间盘微环境对干细胞生物学行为具有重要作用,拟通过微环境调节作用来实现不依赖种子细胞的椎间盘组织修复。 目的：探讨椎间盘微环境下椎间盘源性干细胞和髓核间充质干细胞活性的差异。 方法：健康雄性SD大鼠10只,按照解剖区分离椎间盘骨组织,用Ⅱ型胶原酶消化后进行体外培养椎间盘源性干细胞;分离髓核组织,采用酶消化法体外培养髓核间充质干细胞。将获得的椎间盘源性干细胞和髓核间充质干细胞在体外进行正常条件、椎间盘微环境条件下培养扩增,培养第1-6天采用MTT法测定细胞增殖情况,培养第1,3,6天采用流式细胞技术检测CD29阳性表达水平。 结果与结论：①在不同环境的培养条件下,椎间盘源性干细胞和髓核间充质干细胞增殖情况呈相反趋势。在正常培养条件下,椎间盘源性干细胞和髓核间充质干细胞呈增殖状态,第4-6天为对数增殖期,两者差异无显著性意义(P > 0.05);在椎间盘微环境条件下,髓核间充质干细胞的增殖活性明显低于椎间盘源性干细胞,差异有显著性意义(P < 0.05);②在椎间盘微环境条件下培养第3,6天,椎间盘源性干细胞表面CD29阳性抗原表达水平明显高于髓核间充质干细胞,差异有显著性意义(P < 0.05);③结果表明,在椎间盘微环境条件下,髓核间充质干细胞和椎间盘源性干细胞活性受到一定程度的抑制,但椎间盘源性干细胞较髓核间充质干细胞保留更多的细胞活性。 ORCID: 0000-0002-3582-5630(胡炜) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Transplantation of mesenchymal stem cells embedded in Atelocollagen gel to the intervertebral disc: a potential therapeutic model for disc degeneration

Intervertebral disc degeneration is considered to be one of the major causes of low back pain. Despite this irreversible phenomenon, attempts to decelerate disc degeneration using various techniques have been reported. However, to date there has been no proven technique effective for broad clinical application. Based on previous studies, we hypothesize that maintenance of proteoglycan content in the disc is achieved by avoiding the depletion of nucleus pulposus and preserving the structure of the annulus is a primary factor in decelerating disc degeneration.One novel approach to solve the dilemma of intervertebral disc degeneration is found at the stem cell level. Mesenchymal stem cells (MSCs) are known to possess the ability to differentiate into various kinds of cells from mesenchymal origin. Although the majority of cells that contribute to disc formation are known to obtain chondrocyte-like phenotypes, no reported study has emphasized the correlation with mesenchymal stem cells.To evaluate the possible potential of MSCs in disc cell research and treatment of degenerative disc disease, autologous MSCs embedded in Atelocollagen gel were transplanted into the discs of rabbits which had undergone a procedure proven to induce degeneration. The results suggest that MSC transplantation is effective in decelerating disc degeneration in experimental models and provided new hopes for treatment of degenerative disc disease in humans. Atelocollagen gel served as an important carrier of MSCs in transplantation, permitting proliferation, matrix synthesis and differentiation of MSCs. This study strengthens the viable efficacy of practical application of MSCs in treatment of intervertebral disc disease.     

SPIO标记脂肪干细胞移植退变椎间盘内的MRI活体示踪

背景：国内外动物实验多是荧光标记骨髓间充质干细胞的移植,以SPIO标记脂肪干细胞移植后活体示踪对退变椎间盘修复作用的研究较少。 目的：活体监测SPIO标记的脂肪干细胞在退变椎间盘内的存活、迁移和转归,以及脂肪干细胞对退变椎间盘的修复及延缓退变作用。 方法：新西兰大白兔20只,兔椎间盘被分为4组,即正常对照组(L1/2),脂肪干细胞组(L2/3),PBS组(L3/4),SPIO-脂肪干细胞组(L4/5)。透视引导下用18G穿刺制作退变模型后2周行SPIO标记的脂肪干细胞移植。 结果与结论：SPIO-脂肪干细胞移植后即刻T2WI/FFE序列上可见椎间盘内明显低信号,8周后仍可检测到低信号。脂肪干细胞移植组与同时间点PBS组比较,椎间盘退变程度轻。提示SPIO-脂肪干细胞移植至椎间盘后,可通过MRI进行监测;脂肪干细胞椎间盘内移植有助于修复退变椎间盘和延缓椎间盘退变。     

Porcine intervertebral disc repair using allogeneic juvenile articular chondrocytes or mesenchymal stem cells

Tissue engineering strategies for intervertebral disc repair have focused on the use of autologous disc-derived chondrocytes. Difficulties with graft procurement, harvest site morbidity, and functionality, however, may limit the utility of this cell source. We used an in vivo porcine model to investigate allogeneic non-disc-derived chondrocytes and allogeneic mesenchymal stem cells (MSCs) for disc repair. After denucleation, lumbar discs were injected with either fibrin carrier alone, allogeneic juvenile chondrocytes (JCs), or allogeneic MSCs. Discs were harvested at 3, 6, and 12 months, and cell viability and functionality were assessed qualitatively and quantitatively. JC-treated discs demonstrated abundant cartilage formation at 3 months, and to a lesser extent at 6 and 12 months. For the carrier and MSC-treated groups, however, there was little evidence of proteoglycan matrix or residual notochordal/chondrocyte cells, but rather a type I/II collagen-enriched scar tissue. By contrast, JCs produced a type II collagen-rich matrix that was largely absent of type I collagen. Viable JCs were observed at all time points, whereas no evidence of viable MSCs was found. These data support the premise that committed chondrocytes are more appropriate for use in disc repair, as they are uniquely suited for survival in the ischemic disc microenvironment.     

脂肪间充质干细胞复合血小板凝胶修复兔椎间盘退变

背景：富含血小板的血浆凝胶作为三维支架使其中干细胞可以呈立体生长,同时富含血小板的血浆凝胶又释放大量生长因子,促进脂肪间充质干细胞增殖及分化。 目的：探讨脂肪间充质干细胞-富含血小板的血浆凝胶复合体注入兔椎间盘退变模型后的修复作用。 方法：取兔动脉血采用二次离心法制备自体富血小板血浆,取兔肩胛间区脂肪分离培养脂肪间充质干细胞,制备脂肪间充质干细胞-富含血小板的血浆凝胶复合体。新西兰大白兔随机分为对照组、模型组、富含血小板的血浆凝胶组和脂肪间充质干细胞-富含血小板的血浆凝胶复合体组,后3组以穿刺法制备椎间盘退变模型,退变模型制备完成2周后,富含血小板的血浆凝胶组和脂肪间充质干细胞-富含血小板的血浆凝胶复合体组分别对退变间盘中注射相应材料。 结果与结论：兔椎间盘退变后,间隙明显降低,髓核信号明显降低,髓核内基质高,密度染色较深;而经富含血小板的血浆凝胶和脂肪间充质干细胞-富含血小板的血浆凝胶复合体治疗后,上述症状明显改善,且脂肪间充质干细胞-富含血小板的血浆凝胶复合体的治疗效果更好。提示对退变椎间盘内注射富含血小板的血浆凝胶支架及脂肪间充质干细胞-富含血小板的血浆凝胶复合体均有利于减少退变对椎间盘的影响,其中脂肪间充质干细胞-富含血小板的血浆凝胶复合体注射效果更为突出。     

间充质干细胞来源外泌体在椎间盘退变修复中的研究进展

间充质干细胞来源外泌体(MSC-Exos)是一类直径30 ～ 100 nm的细胞外囊泡,其携带有核酸、蛋白及脂质等生物活性物质,在细胞间通讯和物质交换中发挥重要作用.在椎间盘髓核细胞的体内及体外实验中,MSC-Exos可以通过发挥抗细胞焦亡、抗氧化应激、抗细胞凋亡、促进细胞外基质(ECM)合成等作用,延缓甚至逆转椎间退...     

Effect of severity of intervertebral disc injury on mesenchymal stem cell-based regeneration

Mesenchymal stem cell (MSC) implantation has been shown previously to arrest disc degeneration. This study aims to assess the effect of severity of disc degeneration on the ability of MSCs to arrest the degeneration. Disc degeneration was induced in New Zealand white rabbits at lumbar levels by annular puncture. The degeneration was allowed to progress for 1 month (early group) or 7 months (late group), followed by intradiscal injection of autologous MSCs. For disc levels that received MSCs treatment, 1 x 10(5) BrdU-labeled MSCs were injected per disc level. For the early group, MSC-injection had no significant effects on disc height or the progression of disc degeneration. For the late group, although the MSC-injected discs displayed lower disc heights than the control discs, they were significantly less degenerated together with near normal level of proteoglycan in localized areas. This is the first pilot study to demonstrate that severity of degeneration can influence the therapeutic effect of MSCs. Future studies of cell-based intervertebral disc regeneration should be carefully controlled in the context of stage of disc degeneration.     

Induction of intervertebral disc-like cells from adult mesenchymal stem cells

The potential of adult mesenchymal stem cells (MSCs) to differentiate towards cartilage, bone, adipose tissue, or muscle is well established. However, the capacity of MSCs to differentiate towards intervertebral disc (IVD)-like cells is unknown. The aim of this study was to compare the molecular phenotype of human IVD cells and articular chondrocytes and to analyze whether mesenchymal stem cells can differentiate towards both cell types after transforming growth factor beta (TGF beta)-mediated induction in vitro. Bone marrow-derived MSCs were differentiated in spheroid culture towards the chondrogenic lineage in the presence of TGF beta(3) dexamethasone, and ascorbate. A customized cDNA-array comprising 45 cartilage-, bone-, and stem cell-relevant genes was used to quantify gene expression profiles. After TGF beta-mediated differentiation, MSC spheroids turned positive for collagen type II protein and expressed a large panel of genes characteristic for chondrocytes, including aggrecan, decorin, fibromodulin, and cartilage oligomeric matrix protein, although at levels closer to IVD tissue than to hyaline articular cartilage. Like IVD tissue, the spheroids were strongly positive for collagen type I and osteopontin. MSC spheroids expressed more differentiation markers at higher levels than culture-expanded IVD cells and chondrocytes, which both dedifferentiated in monolayer culture. In conclusion, mesenchymal stem cells adopted a gene expression profile that resembled native IVD tissue more closely than native joint cartilage. Thus, these cells may represent an attractive source from which to obtain IVD-like cells, whereas modification of culture conditions is required to approach the molecular phenotype of chondrocytes in hyaline cartilage.     

骨髓间充质干细胞经大鼠冠状动脉内移植的可行性

目的 研究骨髓间充质干细胞经冠状动脉内移植的安全性及可行性.方法 左侧开胸结扎SD大鼠左冠状动脉,2周后取心脏建立Langerndorff模型.将CM-DiI标记的骨髓间充质干细胞悬液注入主动脉根部,同时收集右心房回流的液体,离心后通过流式细胞仪计数细胞数量.观察是否有细胞经冠状静脉回流及数量比例.并在不同时间测LVSP、LVDP、±dp/dt、心率,评价其安全性.在体实验中取心梗后2周的大鼠,经左心室-主动脉途径将细胞悬液注射到临时阻断的主动脉根部,分别在移植后1及24 h和1及4周取材观察细胞在心脏内的位置及细胞的迁移情况.结果 离体实验发现经冠状动脉内注射骨髓间充质干细胞90%以上的细胞在心肌组织内存留,移植后LVSP、LVDP、±dp/dt、心率没有明显变化.在体内实验中发现细胞移植后早期大部分细胞分布在心外膜下心肌组织内,在心内膜下组织内较少细胞分布,而且大部分细胞在正常心肌组织内,只有少量在心梗区域.而在细胞移植后1～4周存活的细胞多在心肌梗死及交界区组织内,在正常组织内很少有移植细胞存在.结论 经冠状动脉途径进行细胞移植是安全可行的.     

兔退变椎间盘中BNIP3的免疫组织化学研究

目的探讨兔退变椎间盘中BNIP3蛋白的表达情况。方法建立兔椎间盘穿刺退变模型,分别培养2、4、8周后对目的椎间盘进行组织HE染色、番红O染色及BNIP3免疫组织化学染色,与正常椎间盘随机对照,检测椎间盘退变程度及BNIP3蛋白表达情况。结果成功建立兔椎间盘退变模型,随椎间盘退变程度加重,BNIP3蛋白在中央髓核组织中的阳性表达逐渐增强。结论兔椎间盘退变过程中,BNIP3蛋白表达增强诱导髓核细胞死亡增加。     

Temperature-responsive hydroxybutyl chitosan for the culture of mesenchymal stem cells and intervertebral disk cells

Temperature-responsive polymers are attractive candidates for applications related to injectable delivery of biologically active therapeutics, such as stem cells. In this study, we evaluate the potential of thermosensitive hydroxybutyl chitosan (HBC) as a biomaterial for the culture of human mesenchymal stem cells (hMSC) and cells derived from the intervertebral disk, with the eventual goal of using the HBC polymer as an injectable matrix/cell therapeutic. Conjugation of hydroxybutyl groups to chitosan renders the polymer water soluble and thermally responsive. Below its lower critical solution temperature, a solution of HBC can be maintained indefinitely in its solvated state. Upon exposure to a 37 degrees C environment, within 60 s, a 3.8 wt% HBC solution rapidly forms a gel that can be maneuvered with forceps. Upon cooling, the gel once again is able to revert to its solvated state. The gel exhibits a dramatic increase in both G' and G' with increasing temperature, signifying a temperature-dependent enhancement of gel mechanical properties. Although a solid structure upon gelation, due to its physical nature of polymer interaction and gel formation, the gel exhibits a fluid-like viscoelastic behavior when exposed to shear stresses of up to 10% strain, with both G' and G' approaching zero with increasing shear stress. Formulations of HBC gels presented in this study have gelation temperatures ranging from 13.0 to 34.6 degrees C and water contents of 67-95%. Minimal cytotoxicity in MSC and disk cell cultures was observed with these polymers up to a concentration of 5 wt%. Detection of metabolic activity, genetic analysis of synthesized mRNA, and histological staining of MSC and disk cell cultures in these gels collectively indicate cell proliferation without a loss in metabolic activity and extracellular matrix production. This study suggests the potential of HBC gel as an injectable carrier for future applications of delivering therapeutics to encourage a biologically relevant reconstruction of the degenerated disk.     

退变椎间盘中护骨素水平与Schneiderman分级的关系

背景：护骨素可抑制破骨细胞活性,调节软骨重塑过程,在维持椎间盘软骨组织完整性方面具有重要作用。 目的：观察腰椎间盘退行性变患者椎间盘中护骨素的表达及其与病情严重程度的关系。 方法：选取64例腰椎间盘退行性变患者及25例椎体爆裂性骨折患者作为研究对象,收集患者术后的椎间盘组织,检测椎间盘中护骨素mRNA和蛋白的水平。以腰椎间盘MRI检查结果为依据,根据Schneiderman分级方法进行分级,并分析椎间盘中的护骨素水平与疾病分级的关系。 结果与结论：实时荧光定量PCR及ELISA检测发现腰椎间盘退行性变患者的腰椎间盘组织中护骨素mRNA和蛋白水平均明显高于椎体爆裂性骨折患者(P < 0.01)。非条件logistic回归分析表明,升高的护骨素mRNA和蛋白是腰椎间盘退行性变发病的独立危险因子。且护骨素mRNA和蛋白水平均与Schneiderman分级显著正相关(r=0.367,0.412,P < 0.01),说明高表达的护骨素参与了腰椎间盘退行性变的发生,并可反映疾病的严重程度。     

Integrin expression in cells of the intervertebral disc

In this study, we investigated the profile of integrin expression in human and porcine intervertebral disc tissue. Differences in extracellular matrix composition between anulus fibrosus (AF) and nucleus pulposus (NP) regions of the disc, as well as differences in cellular responses to environmental stimuli, suggest a role for integrins in presenting matrix signals that may mediate these responses. Human disc tissue and porcine AF and NP tissue were stained with antibodies to alpha integrin subunits 1-6, V and IIb, and beta integrin subunits 1-6 and graded for evidence of positive staining on a scale from 0 (no staining) to 3 (high incidence of staining). Human tissue expressed alpha and beta integrin subunits shown to be present in articular cartilage, including alpha(1), alpha(5) and alpha(V). Porcine AF tissue expressed similar integrin subunits to human disc, with both expressing alpha(1), alpha(5), beta(1), beta(3) and beta(5) subunits, whereas porcine NP tissue expressed higher levels of alpha(6), beta(1) and beta(4) than AF tissue. The expressed subunits are known to interact with proteins including collagens, fibronectin and laminin; however, additional studies will be required to characterize the interactions of the integrin subunits with specific matrix constituents, as well as their specific involvement in regulating environmental stimuli.     

An atelocollagen honeycomb-shaped scaffold with a membrane seal (ACHMS-scaffold) for the culture of annulus fibrosus cells from an intervertebral disc

The aim of this study was to investigate the possibility of using the atelocollagen honeycomb-shaped scaffold with a membrane seal (ACHMS-scaffold) for the culture of annulus fibrosus (AF) cells in tissue engineering procedures of intervertebral disc repair. AF cells from the intervertebral discs of Japanese white rabbits were cultured for up to 3 weeks in the ACHMS-scaffold to allow a high density, three-dimensional culture. Although the DNA content in the scaffold increased at a lower rate than in the monolayer culture, scanning electron microscopy data showed that the scaffold was filled with the grown AF cells and produced extracellular matrix on day 21. The amount of type II collagen and its mRNA expression by the scaffold cultured cells were determined using Western blotting and Northern blotting analyses, respectively, and remained at a higher level than in the monolayer cultured cells. Furthermore, glycosaminoglycan (GAG) accumulation in the scaffold culture was at a higher level than in the monolayer culture. Western blot analysis for extracted proteoglycans from the scaffold culture also exhibited a much higher proteoglycan accumulation than the monolayer culture. These results indicate that the AF cells are able to grow and remain phenotypically stable in the scaffold.     

可注射型纤维蛋白凝胶转化生长因子β1复合骨髓间充质干细胞移植治疗椎间盘退变

背景：纤维蛋白凝胶主体胶与催化剂未混合前为液态,具有可注射的优点,注射混合后凝固成凝胶状,与髓核相似,并且凝固时间可控性强,作为间充质干细胞的载体植入到椎间盘内有诸多优点。 目的：观察可注射型纤维蛋白凝胶转化生长因子β1复合骨髓间充质干细胞移植抑制椎间盘退变的可行性。 方法：将新西兰大白兔随机分为退变模型组、纤维蛋白凝胶组,骨髓干细胞+纤维蛋白凝胶组。3组采用针刺法诱导建立退变模型后,纤维蛋白凝胶组及干细胞+纤维蛋白凝胶组分别移植入纤维蛋白凝胶转化生长因子β1复合物及骨髓间充质干细胞纤维蛋白凝胶转化生长因子β1复合物,于植入后2,6,10周行CR、MRI及病理检查。 结果与结论：退变模型组与纤维蛋白凝胶组椎间隙高度下降明显,并与时间呈正相关,干细胞+纤维蛋白凝胶组下降较缓慢(P < 0.01)。免疫组织化学及组织学检查显示,退变模型组髓核细胞的数量及Ⅱ型胶原含量进行性减少,细胞凋亡率明显增加,纤维蛋白凝胶组与退变模型组相似,干细胞+纤维蛋白凝胶组髓核细胞数量及Ⅱ型胶原含量较退变模型组及纤维蛋白凝胶组明显增多,细胞凋亡率下降。说明骨髓间充质干细胞联合纤维蛋白凝胶转化生长因子β1能很好抑制椎间盘退变,而单纯纤维蛋白凝胶转化生长因子β1移植不能抑制椎间盘退变。     

间充质干细胞移植中的旁分泌作用

间充质干细胞是细胞移植和组织工程中理想的种子细胞,然而在移植中发挥治疗作用的具体机制仍然不明确。间充质干细胞可以分泌多种细胞因子和生长因子,促进周围细胞的存活,发挥旁分泌作用。间充质干细胞可以通过调节免疫,促进周围细胞的增殖,抑制凋亡以及促血管生成作用发挥其在细胞移植治疗中的作用。