Comparative effectiveness of adipose-derived mesenchymal stromal cells in the management of knee osteoarthritis:A meta-analysis

BACKGROUND Osteoarthritis(OA)is the most common joint disorder,is associated with an increasing socioeconomic impact owing to the ageing population.AIM To analyze and compare the efficacy and safety of bone-marrow-derived mesenchymal stromal cells(BM-MSCs)and adipose tissue-derived MSCs(AD-MSCs)in knee OA management from published randomized controlled trials(RCTs).METHODS Independent and duplicate electronic database searches were performed,including PubMed,EMBASE,Web of Science,and Cochrane Library,until August 2021 for RCTs that analyzed the efficacy and safety of AD-MSCs and BM-MSCs in the management of knee OA.The visual analog scale(VAS)score for pain,Western Ontario McMaster Universities Osteoarthritis Index(WOMAC),Lysholm score,Tegner score,magnetic resonance observation of cartilage repair tissue score,knee osteoarthritis outcome score(KOOS),and adverse events were analyzed.Analysis was performed on the R-platform using OpenMeta(Analyst)software.Twenty-one studies,involving 936 patients,were included.Only one study compared the two MSC sources without patient randomization;hence,the results of all included studies from both sources were pooled,and a comparative critical analysis was performed.RESULTS At six months,both AD-MSCs and BM-MSCs showed significant VAS improvement(P=0.015,P=0.012);this was inconsistent at 1 year for BM-MSCs(P<0.001,P=0.539),and AD-MSCs outperformed BM-MSCs compared to controls in measures such as WOMAC(P<0.001,P=0.541),Lysholm scores(P=0.006;P=0.933),and KOOS(P=0.002;P=0.012).BM-MSC-related procedures caused significant adverse events(P=0.003)compared to AD-MSCs(P=0.673).CONCLUSION Adipose tissue is superior to bone marrow because of its safety and consistent efficacy in improving pain and functional outcomes.Future trials are urgently warranted to validate our findings and reach a consensus on the ideal source of MSCs for managing knee OA.

The Origin of Neointimal Smooth Muscle Cells in Transplant Arteriosclerosis from Recipient Bone-marrow Cells in Rat Aortic Allograft

In order to investigate the origin of neointimal smooth muscle cells in transplant arterio- sclerosis in rat aortic allograft, sex-mismatched bone marrow transplantation was performed from male Wistar rats to female Wistar rats. Four weeks after transplantation, the aortic transplant model was established by means of micro-surgery in rats. The recipients were divided into 4 groups: female Wistar-female Wistar aortic isografts, female SD-female Wistar aortic allografts, male SD-male Wis- tar aortic allografts, female SD-chimera Wistar aortic allografts. Eight weeks after transplantation, aortic grafts were removed at autopsy and processed for histological evaluation and immunohisto- chemistry. The results indicated that excessive accumulation of α-SMA-positive smooth muscle cells resulted in significant neointima formation and vascular lumen stricture in rat aortic allografts. Neointima assay revealed that the neointimal area and NIA/MA ratio of transplanted artery were sig- nificantly increased in all of aortic allograft groups as compared with those in aortic isograft group (P<0.01). Neointimal smooth muscle cells were harvested from cryostat sections of aortic allograft by microdissection method. The Sry gene-specific PCR was performed, and the result showed that a dis- tinct DNA band of 225 bp emerged in the male-male aortic allograft group and chimera aortic al- lograft group respectively, but not in the female-female aortic allograft group. It was suggested that recipient bone-marrow cells, as the origin of neointimal smooth muscle cells, contributed to the pathological neointimal hyperplasia of aortic allograft and transplant arteriosclerosis.

人脐带间充质干细胞治疗早发性卵巢功能不全的研究进展

早发性卵巢功能不全(POI)是一种复杂的内分泌疾病,具体发病机制尚不明确,目前研究表明,遗传、免疫、环境、手术及放化疗等因素与之相关;同时,氧化应激、血管损伤、卵巢颗粒细胞(OGC)和膜间质细胞(TIC)的凋亡会伴随疾病发生。近年来POI的发病率逐渐上升且出现年轻化趋势,临床上常用的激素替代疗法、免疫疗法及辅助生殖技术皆无法从根本上改善卵巢功能。人脐带间充质干细胞(hUCMSC)属于多能干细胞,具有多向分化和自我更新能力,能够减少体内活性氧(ROS)的堆积、调节自噬、减少TIC凋亡及抑制卵巢纤维化、促进卵泡发育和OGC增殖。可见,hUCMSC具有“一对多”的生物学效应,本文就hUCMSC治疗POI的研究进展进行综述,或许能为hUCMSC恢复受损卵巢组织功能的机制提供理论依据。

Stem cell transplantation for spinal cord injury： a meta-analysis of treatment effectiveness and safety

OBJECTIVE： The aim of this study was to evaluate the effectiveness and safety of stem cell transplantation for spinal cord injury（SCI）.DATA SOURCES： PubM ed, EMBASE, Cochrane, China National Knowledge Infrastructure, China Science and Technology Journal, Wanfang, and Sino Med databases were systematically searched by computer to select clinical randomized controlled trials using stem cell transplantation to treat SCI, published between each database initiation and July 2016. DATA SELECTION： Randomized controlled trials comparing stem cell transplantation with rehabilitation treatment for patients with SCI. Inclusion criteria：（1） Patients with SCI diagnosed according to the American Spinal Injury Association（ASIA） International standards for neurological classification of SCI;（2） patients with SCI who received only stem cell transplantation therapy or stem cell transplantation combined with rehabilitation therapy;（3） one or more of the following outcomes reported： outcomes concerning neurological function including sensory function and locomotor function, activities of daily living, urination functions, and severity of SCI or adverse effects. Studies comprising patients with complications, without full-text, and preclinical animal models were excluded. Quality of the included studies was evaluated using the Cochrane risk of bias assessment tool and Rev Man V5.3 software, provided by the Cochrane Collaboration, was used to perform statistical analysis. OUTCOME MEASURES： ASIA motor score, ASIA light touch score, ASIA pinprick score, ASIA impairment scale grading improvement rate, activities of daily living score, residual urine volume, and adverse events.RESULTS： Ten studies comprising 377 patients were included in the analysis and the overall risk of bias was relatively low level. Four studies did not detail how random sequences were generated, two studies did not clearly state the blinding outcome assessment, two studies lacked blinding outcome assessment, one study lacked follow-up information, and four studies carried out selective reporting. Compared with rehabilitation therapy, stem cell transplantation significantly increased the lower limb light touch score（odds ratio（OR） = 3.43, 95% confidence interval（CI）： 0.01 – 6.86, P = 0.05）, lower limb pinprick score（OR = 3.93, 95%CI： 0.74 – 7.12, P = 0.02）, ASI grading rate（relative risk（RR） = 2.95, 95%CI： 1.64 – 5.29, P = 0.0003）, and notably reduced residual urine volume（OR = –8.10, 95%CI： –15.09 to –1.10, P = 0.02）. However, stem cell transplantation did not significantly improve motor score（OR = 1.89, 95%CI： –0.25 to 4.03, P = 0.08） or activities of daily living score（OR = 1.12, 95%CI： –1.17 to 4.04, P = 0.45）. Furthermore, stem cell transplantation caused a high rate of mild adverse effects（RR = 14.49, 95%CI： 5.34 – 34.08, P 〈 0.00001）; however, these were alleviated in a short time. CONCLUSION： Stem cell transplantation was determined to be an efficient and safe treatment for SCI and simultaneously improved sensory and bladder functions. Although associated minor and temporary adverse effects were observed with transplanted stem cells, spinal cord repair and axon remyelination were apparent. More randomized controlled trials with larger sample sizes and longer follow-up times are needed to further validate the effectiveness of stem cell transplantation in the treatment of SCI.

Chitosan-collagen porous scaffold and bone marrow mesenchymal stem cell transplantation for ischemic stroke

In this study, we successfully constructed a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold in vitro, transplanted either the composite or bone marrow mesenchymal stem cells alone into the ischemic area in animal models, and compared their effects. At 14 days after co-transplantation of bone marrow mesenchymal stem cells and the hi- tosan-collagen scaffold, neurological function recovered noticeably. Vascular endothelial growth factor expression and nestin-labeled neural precursor cells were detected in the iscbemic area, surrounding tissue, hippocampal dentate gyrus and subventricular zone. Simultaneously, a high level of expression of glial fibrillary acidic protein and a low level of expression of neuron-spe- cific enolase were visible in BrdU-labeled bone marrow mesenchymal stem cells. These findings suggest that transplantation of a composite of bone marrow mesenchymal stem cells and a chi- tosan-collagen scaffold has a neuroprotective effect following ischemic stroke.

Neuronal-like cell differentiation of non-adherent bone marrow cell-derived mesenchymal stem cells

Non-adherent bone marrow cell-derived mesenchymal stem cells from C57BL/6J mice were sepa- rated and cultured using the ＂pour-off＂ method. Non-adherent bone marrow cell-derived mesen- chymal stem ceils developed colony-forming unit-fibroblasts, and could be expanded by supple- mentation with epidermal growth factor. Immunocytochemistry showed that the non-adherent bone marrow cell-derived mesenchymal stem cells exposed to basic fibroblast growth factor/epidermal growth factor/nerve growth factor expressed the neuron specific markers, neurofilament-200 and NeuN, in vitro. Non-adherent bone marrow cell-derived mesenchymal stem cells from 13-galactosidase transgenic mice were also transplanted into focal ischemic brain （right corpus striatum） of C57BL/6J mice. At 8 weeks, cells positive for LacZ and 13-galactosidase staining were observed in the ischemic tissues, and cells co-labeled with both 13-galactosidase and NeuN were seen by double immunohistochemical staining. These findings suggest that the non-adherent bone marrow cell-derived mesenchymal stem cells could differentiate into neuronal-like cells in vitro and in vivo.

Human dental pulp stem cells: Applications in future regenerative medicine

Stem cells are pluripotent cells, having a property of differentiating into various types of cells of human body. Several studies have developed mesenchymal stem cells(MSCs) from various human tissues,peripheral blood and body fluids. These cells are then characterized by cellular and molecular markers to understand their specific phenotypes. Dental pulp stem cells(DPSCs) are having a MSCs phenotype and they are differentiated into neuron, cardiomyocytes, chondrocytes, osteoblasts, liver cells and β cells of islet of pancreas. Thus, DPSCs have shown great potentiality to use in regenerative medicine for treatment of various human diseases including dental related problems. These cells can also be developed into induced pluripotent stem cells by incorporation of pluripotency markers and use for regenerative therapies of various diseases. The DPSCs are derived from various dental tissues such as human exfoliated deciduous teeth, apical papilla, periodontal ligament and dental follicle tissue. This review will overview the information about isolation, cellular and molecular characterization and differentiation of DPSCs into various types of human cells and thus these cells have important applications in regenerative therapies for various diseases. This review will be most useful for postgraduate dental students as well as scientists working in the field of oral pathology and oral medicine.

Human umbilical cord Wharton's jelly-derived oligodendrocyte precursor-like cells for axon and myelin sheath regeneration

Human umbilical mesenchymal stem cells from Wharton＇s jelly of the umbilical cord were induced to differentiate into oligodendrocyte precursor-like cells in vitro. Oligodendrocyte precursor cells were transplanted into contused rat spinal cords. Immunofluorescence double staining indicated that transplanted cells survived in injured spinal cord, and differentiated into mature and immature oligodendrocyte precursor cells. Biotinylated dextran amine tracing results showed that cell transplantation promoted a higher density of the corticospinal tract in the central and caudal parts of the injured spinal cord. Luxol fast blue and toluidine blue staining showed that the volume of residual myelin was significantly increased at 1 and 2 mm rostral and caudal to the lesion epicenter after cell transplantation. Furthermore, immunofluorescence staining verified that the newly regenerated myelin sheath was derived from the central nervous system. Basso, Beattie and Bresnahan testing showed an evident behavioral recovery. These results suggest that human umbilical mesenchymal stem cell-derived oligodendrocyte precursor cells promote the regeneration of spinal axons and myelin sheaths.

Mesenchymal stem cells in the treatment of inflammatory and autoimmune diseases in experimental animal models

Multipotent mesenchymal stromal cells [also known as mesenchymal stem cells(MSCs)] are currently being studied as a cell-based treatment for inflammatory disorders. Experimental animal models of human immune-mediated diseases have been instrumental in establishing their immunosuppressive properties. In this review, we summarize recent studies examining the effectiveness of MSCs as immunotherapy in several widely-studied animal models, including type 1 diabetes, experimental autoimmune arthritis, experimental autoimmune encephalomyelitis, inflammatory bowel disease, graft-vs-host disease, and systemic lupus erythematosus. In addition, we discuss mechanisms identified by which MSCs mediate immune suppression in specific disease models, and potential sources of functional variability of MSCs between studies.

Electro-acupuncture at Conception and Governor vessels and transplantation of umbilical cord bloodderived mesenchymal stem cells for treating cerebral ischemia/reperfusion injury

Mesenchymal stem cell transplantation is a novel means of treating cerebral ischemia/reper- fusion, and can promote angiogenesis and neurological functional recovery. Acupuncture at Conception and Governor vessels also has positive effects as a treatment for cerebral ischemia/ reperfusion. Therefore, we hypothesized that electro-acupuncture at Conception and Governor vessels plus mesenchymal stem cell transplantation may have better therapeutic effects on the promotion of angiogenesis and recovery of neurological function than either treatment alone. In the present study, human umbilical cord blood-derived mesenchymal stem cells were isolated, cultured, identified and intracranially transplanted into the striatum and subcortex of rats at 24 hours following cerebral ischemia/reperfusion. Subsequently, rats were electro-acupunctured at Conception and Governor vessels at 24 hours after transplantation. Modified neurological severity scores and immunohistochemistry findings revealed that the combined interventions of electro-acupuncture and mesenchymal stem cell transplantation clearly improved neurological impairment and up-regulated vascular endothelial growth factor expression around the isch- emic focus. The combined intervention provided a better outcome than mesenchymal stem cell transplantation alone. These findings demonstrate that electro-acupuncture at Conception and Governor vessels and mesenchymal stem cell transplantation have synergetic effects on promot- ing neurological function recovery and angiogenesis in rats after cerebral ischemia/reperfusion.

Endothelial precursor cells promote angiogenesis in hepatocellular carcinoma

AIM:To investigate the role of bone marrow-derived endothelial progenitor cells(EPCs) in the angiogenesis of hepatocellular carcinoma(HCC).METHODS:The bone marrow of HCC mice was reconstructed by transplanting green fluorescent protein(GFP) + bone marrow cells.The concentration of circulating EPCs was determined by colony-forming assays and fluorescence-activated cell sorting.Serum and tissue levels of vascular endothelial growth factor(VEGF) and colony-stimulating factor(CSF) were quantified by enzyme-linked immunosorbent assay.The distribution of EPCs in tumor and tumor-free tissues was detected by immunohistochemistry and real-time polymerase chain reaction.The incorporation of EPCs into hepatic vessels was examined by immunofluorescence and immunohistochemistry.The proportion of EPCs in vessels was then calculated.RESULTS:The HCC model was successful established.The flow cytometry analysis showed the mean percentage of CD133CD34 and CD133VEGFR2 double positive cells in HCC mice was 0.45% ± 0.16% and 0.20% ± 0.09% respectively.These values are much higher than in the sham-operation group(0.11% ± 0.13%,0.05% ± 0.11%,n = 9) at 14 d after modeling.At 21 d,the mean percentage of circulating CD133CD34 and CD133VEGFR2 cells is 0.23% ± 0.19%,0.25% ± 0.15% in HCC model vs 0.05% ± 0.04%,0.12% ± 0.11% in control.Compared to the transient increase observed in controls,the higher level of circulating EPCs were induced by HCC.In addition,the level of serum VEGF and CSF increased gradually in HCC,reaching its peak 14 d after modeling,then slowly decreased.Consecutive sections stained for the CD133 and CD34 antigens showed that the CD133+ and CD34+ VEGFR2 cells were mostly recruited to HCC tissue and concentrated in tumor microvessels.Under fluorescence microscopy,the bone-marrow(BM)-derived cells labeled with GFP were concentrated in the same area.The relative levels of CD133 and CD34 gene expression were elevated in tumors,around 5.0 and 3.8 times that of the tumor free area.In frozen liver sections from HCC mice,cells co-expressing CD133 and VEGFR2 were identified by immunohistochemical staining using anti-CD133 and VEGFR2 antibodies.In tumor tissue,the double-positive cells were incorporated into vessel walls.In immunofluorescent staining.These CD31 and GFP double positive cells are direct evidence that tumor vascular endothelial cells(VECs) come partly from BM-derived EPCs.The proportion of GFP CD31 double positive VECs(out of all VECs) on day 21 was around 35.3% ± 21.2%.This is much higher than the value recorded on day 7 group(17.1% ± 8.9%).The expression of intercellular adhesion molecule 1,vascular adhesion molecule 1,and VEGF was higher in tumor areas than in tumor-free tissues.CONCLUSION:Mobilized EPCs were found to participate in tumor vasculogenesis of HCC.Inhibiting EPC mobilization or recruitment to tumor tissue may be an efficient strategy for treating HCC.

Mesenchymal stem cells and collagen patches for anterior cruciate ligament repair

AIM: To investigate collagen patches seeded with mesenchymal stem cells(MSCs) and/or tenocytes(TCs) with regards to their suitability for anterior cruciate ligament(ACL) repair. METHODS: Dynamic intraligamentary stabilization utilizes a dynamic screw system to keep ACL remnants in place and promote biological healing, supplemented by collagen patches. How these scaffolds interact with cells and what type of benefit they provide has not yet been investigated in detail. Primary ACL-derived TCs and human bone marrow derived MSCs were seeded onto two different types of 3D collagen scaffolds, Chondro-Gide?(CG) and Novocart?(NC). Cells were seeded onto the scaffolds and cultured for 7 d either as a pure populations or as "premix" containing a 1:1 ratio of TCs to MSCs. Additionally, as controls, cells were seeded in monolayers and in co-cultures on both sides of porous high-density membrane inserts(0.4 μm). We analyzed the patches by real time polymerase chain reaction, glycosaminoglycan(GAG), DNA and hydroxyproline(HYP) content. To determine cell spreading and adherence in the scaffolds microscopic imaging techniques, i.e., confocal laser scanning microscopy(c LSM) and scanning electron microscopy(SEM), were applied.RESULTS: CLSM and SEM imaging analysis confirmed cell adherence onto scaffolds. The metabolic cell activity revealed that patches promote adherence and proliferation of cells. The most dramatic increase in absolute metabolic cell activity was measured for CG samples seeded with tenocytes or a 1:1 cell premix. Analysis of DNA content and c LSM imaging also indicated MSCs were not proliferating as nicely as tenocytes on CG. The HYP to GAG ratio significantly changed for the premix group, resulting from a slightly lower GAG content, demonstrating that the cells are modifying the underlying matrix. Real-time quantitativepolymerase chain reaction data indicated that MSCs showed a trend of differentiation towards a more tenogenic-like phenotype after 7 d.CONCLUSION: CG and NC are both cyto-compatible with primary MSCs and TCs; TCs seemed to perform better on these collagen patches than MSCs.

Is cellular therapy beneficial in management of rotator cuff tears?Meta-analysis of comparative clinical studies

BACKGROUND Mesenchymal stromal cell(MSC)-based cellular therapy promotes type I collagen production,enhance mechanical strength of tissues,and enhance biology at the bone-tendon interface,which primarily explains their potential clinical utility in rotator cuff(RC)tears.AIM To analyze the efficacy and safety of cellular therapy utilizing MSCs in the management of RC tears from clinical studies available in the literature.METHODS We conducted independent and duplicate electronic database searches including PubMed,Embase,Reference Citation Anallysis,Web of Science,and Cochrane Library in August 2021 for studies analyzing the efficacy and safety of cellular therapy(CT)utilizing MSCs in the management of RC tears.Visual Analog Score(VAS)score for pain,American Shoulder and Elbow Surgeons(ASES)score,Disability of the Arm,Shoulder,and Hand score,Constant score,radiological assessment of healing,and complications such as retear rate and adverse events were the outcomes analyzed.Analysis was performed in R-platform using OpenMeta[Analyst]software.RESULTS Six studies involving 238 patients were included for analysis.We noted a significant reduction in VAS score for pain at 3 mo(weighed mean difference[WMD]=-2.234,P<0.001)and 6 mo(WMD=-3.078,P<0.001)with the use of CT,which was not maintained at long-term follow-up(WMD=-0.749,P=0.544).Concerning functional outcomes,utilization of CT produced a significant shortterm improvement in the ASES score(WMD=17.090,P<0.001)and significant benefit in functional scores such as Constant score(WMD=0.833,P=0.760)at long-term follow-up.Moreover,we also observed significantly improved radiological tendon healing during the longterm follow-up(odds ratio[OR]=3.252,P=0.059).We also noted a significant reduction in the retear rate upon utilization of CT in RC tears both at short-(OR=0.079,P=0.032)and long-term(OR=0.434,P=0.027)follow-ups.We did not observe any significant increase in the adverse events directly related to cellular therapy,as compared with the control group(OR=0.876,P=0.869).CONCLUSION Based on our comprehensive and critical review,we could observe that the utilization of CT in RC tear significantly reduced pain severity at 3 and 6 mo,improved short-term functional outcome,enhanced radiological tendon healing,and mitigated retear rates at both short-and long-term follow-ups.The literature also confirmed the relative safety of using MSC therapy in patients presenting with RC tears.

Prospects for bone marrow cell therapy in amyotrophic lateral sclerosis：how far are we from a clinical treatment？

Amyotrophic lateral sclerosis（ALS） is a fatal neurodegenerative disease that causes progressive muscular atrophy and death within 3–5 years after its onset.Despite the significant advances in knowledge of ALS pathology,no effective treatment is available.Therefore,it is imperative to search for new alternatives to treat ALS.Cell therapy,especially using bone-marrow cells,has showed to be very useful to protect the neural tissue in different brain disease or traumatic lesions.In ALS,most published results show beneficial effects of the use bone marrow cells,especially mesenchymal stromal cells.However,until now,the best outcome extends animal＇s lifespan by only a few weeks.It is essential to continue the search for a really effective therapy,testing different cells,routes and time-windows of administration.Studying the mechanisms that initiate and spread the degenerative process is also important to find out an effective therapy.Therefore,we discussed here some progresses that have been made using bone-marrow cell therapy as a therapeutic tool for ALS.

骨髓间充质干细胞对间充质样成釉细胞瘤细胞功能影响的研究

目的:研究骨髓间充质干细胞(BMSC),对间充质样成釉细胞瘤细胞(M-AMC)的增殖、侵袭、迁移以及自噬水平的影响,初步探讨BMSC对M-AMC功能影响的部分作用和机制。方法:组织块结合酶消化法分离培养M-AMC并鉴定,构建非接触M-AMC/BMSC共培养体系,通过EdU检测M-AMC增殖变化,利用结晶紫染色、Western blot等检测M-AMC迁移、侵袭功能和自噬相关蛋白的改变。结果:通过原代分离培养得到的M-AMC,主要来源于间质,并具有一定的干性和自我更新能力。共培养组3、7 d M-AMC增殖的细胞数量明显高于对照组(P<0.01),共培养组在24、48、72 h的Transwell迁移和侵袭出的细胞数量均高于对照组(P<0.01),M-AMC在和BMSC共培养后,自噬表达水平显著增强(P<0.01)。结论:BMSC的旁分泌作用可以上调M-AMC自噬水平,从而促进M-AMC增殖、迁移、侵袭能力。

rhBMP-7对小鼠骨髓间充质干细胞向成骨细胞分化的影响

目的:观察重组人骨形成蛋白-7(rhBMP-7)对小鼠骨髓间充质干细胞(BMSCs)向成骨细胞分化的影响。方法:采用密度梯度离心法分离骨髓,体外培养扩增,获得小鼠骨髓间充质干细胞,贴壁培养至第3代,向培养液中加入rhBMP-7,培养5 d后进行碱性磷酸酶(ALP)染色,ALP活性与骨钙素(OC)含量检测,并用RT-PCR法分析成骨细胞标志基因骨钙素(OC)与Ⅰ型胶原(Col-Ⅰ)表达情况,Western blot法检测Ⅰ型胶原(Col-Ⅰ)蛋白的分泌量。结果:rhBMP-7诱导组的骨髓间充质干细胞的ALP染色强度、ALP活性及OC含量明显升高,OC与Col-Ⅰ的mRNA表达水平以及Col-Ⅰ的蛋白表达水平均明显提高。结论:rhBMP-7可促进体外培养的小鼠BMSCs向成骨细胞方向分化。

N-乙酰半胱氨酸对过氧化氢诱导的骨髓间充质干细胞凋亡的保护及作用机制研究

目的研究N-乙酰半胱氨酸(NAC)对过氧化氢(H2O2)诱导的骨髓间充质干细胞(BMSCs)凋亡的影响,并探讨其作用机制。方法采用全骨髓贴壁培养法培养SD大鼠BMSCs,随机分成5组:正常对照组、H2O2处理组、NAC组、NAC+H2O2组和LY294002干预组。流式细胞术检测各组的细胞凋亡率及细胞内活性氧水平;RT-PCR检测各组rBMSCs中FOXO1、FOXO3、FOXO4基因水平的表达;Western blot检测各组rBMSCs中Akt、p-Akt、Bcl-2的表达。结果与正常组相比,H2O2组诱导的rBMSCs凋亡数明显增高,细胞内ROS含量明显增高,FOXO1、FOXO3、FOXO4基因水平的表达量明显下降;NAC明显抑制了rBMSCs凋亡和ROS产生,上调了FOXO1、FOXO3、FOXO4基因水平的表达,增加了细胞内p-Akt和Bcl-2的表达,但LY294002抑制剂明显抑制了NAC对氧化应激后rBMSCs的上述功能。结论 N-乙酰半胱氨酸可通过激活PI3K-Akt信号途径抑制细胞内活性氧的产生、上调FOXO1、FOXO3、FOXO4基因水平及抗凋亡Bcl-2的表达来保护BMSCs免受氧化应激引起的凋亡。

骨髓间充质干细胞移植促进糖尿病大鼠β细胞再生的机制

目的探索骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)移植促进糖尿病大鼠模型中β细胞再生的机制。方法正常SD大鼠给予单次大剂量链脲佐菌素(streptozotocin,STZ)(65 mg/kg)注射,3 d后开始监测血糖,连续3 d随机血糖>28 mmol/L者选为实验对象。所有实验对象随机分为对照组(n=15),BMSC移植组(n=15),BMSC培养上清移植组(n=15)以及BMSC示踪组(以Dil染料标记BMSCs,n=5),分别接受PBS、MSC、MSC培养上清及Dil-BMSC的移植。结果 BMSC移植后30 d左右血糖水平有明显改善[(20.4±0.98)mmol/L,n=15],胰岛素水平有明显提高[(0.99±0.23)ng/ml,n=15],β细胞质量明显增长。富含BMSC分泌因子的BMSC上清输注后,糖尿病大鼠血糖有一定程度的降低[(26.2±1.53)mmol/L,n=15],胰岛素水平有所恢复[(0.341±0.08)ng/ml,n=15],β细胞质量较对照组有所增加。在胰腺仅检测到小部分BMSC,这部分归巢于胰腺的BMSC中检测不到与胰岛素的共标。结论 BMSC的分泌效应为BMSC促进糖尿病动物模型中β细胞再生的机制。

脑源性神经营养因子基因转染骨髓间充质干细胞体外诱导分化为神经元样细胞初步观察

目的探讨骨髓间充质干细胞(bone-marrow mesenchymal stem cells,BMSCs)转染人脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)基因后在体外分化为神经元样细胞的功能。方法克隆人BDNF基因并构建其真核表达载体;分离培养5只豚鼠BMSCs,观测其形态并用流式细胞仪鉴定;将人BDNF基因电穿孔法转染BMSCs,G418筛选后用维甲酸诱导分化,免疫细胞化学法对分化细胞进行鉴定。结果分离培养的细胞具有典型的BMSCs形态和标志,转染诱导后的细胞表达神经元特异性烯醇化酶、巢蛋白(Nestin)和胶质纤维酸性蛋白,并能分泌BDNF。结论BDNF基因转染的BMSCs在体外能分化为神经元样细胞,电穿孔法能提高转染率,RA有促诱导作用。