Induced Pluripotent Stem Cells from Human Hair Follicle Mesenchymal Stem Cells

Reprogramming of somatic cells into inducible pluripotent stem cells (iPSCs) provides an alternative to using embryonic stem cells (ESCs). Mesenchymal stem cells derived from human hair follicles (hHF-MSCs) are easily accessible, reproducible by direct plucking of human hairs. Whether these hHF-MSCs can be reprogrammed has not been previously reported. Here we report the generation of iPSCs from hHF-MSCs obtained by plucking several hairs. hHF-MSCs were isolated from hair follicle tissues and their mesenchymal nature confirmed by detecting cell surface antigens and multilineage differentiation potential towards adipocytes and osteoblasts. They were then reprogrammed into iPSCs by lentiviral transduction with Oct4, Sox2, c-Myc and Klf4. hHF-MSC-derived iPSCs appeared indistinguishable from human embryonic stem cells (hESCs) in colony morphology, expression of alkaline phosphotase, and expression of specific hESCs surface markers, SSEA-3, SSEA-4, Tra-1-60, Tra-1-81, Nanog, Oct4, E-Cadherin and endogenous pluripotent genes. When injected into immunocompromised mice, hHF-MSC-derived iPSCs formed teratomas containing representatives of all three germ layers. This is the first study to report reprogramming of hHF-MSCs into iPSCs.     

Unveiling Hair Follicle Stem Cells

Adult mammalian skin consists of the epidermis, hair follicles (HFs), and sebaceous glands (SGs). Each of these three epithelial lineages contains its own stem cell (SC) population for normal tissue homeostasis, HF cycling, and repair of the epidermis following injury. Here, we provide an overview of the current knowledge on follicle SCs of the adult skin, including their essential features and, most importantly, the control of follicle SC fate. Wnt/β-catenin is required for follicle SC maintenance and niche biology, and β-catenin activation is essential for promoting quiescent follicle SCs to proliferate and terminally differentiate along the hair cell lineage. Further, β-catenin stabilization promotes de novo HF morphogenesis, and constitutively active β-catenin expression results in pilomatricoma. Both bone morphogenetic protein (BMP) and transforming growth factor-β (TGF-β) signals are required for quiescent niche maintenance: BMP deletion results in SC activation, whereas TGF-β may play a role in SC identity maintenance.     

Behavior of Human Mesenchymal Stem Cells in Fibrin-Based Vascular Tissue Engineering Constructs

A limitation of current tissue engineering vascular graft technology is the provision of an expandable, autologous cell source. By harnessing the multipotency of mesenchymal stem cells (MSC), it is hoped that functional vascular cells can be produced. To date, a range of 2D and 3D environments have been investigated for the manipulation of MSC differentiation pathways. To this end, this study aims to test the hypothesis that MSC seeded in various fibrin gel environments will exhibit evidence of a smooth muscle cell (SMC) phenotype. Initially, a range of cell-seeding densities were screened for 2D and 3D fibrin constructs, where it was observed that a seeding densities of 500,000 cells/mL facilitated gel compaction without degradation or loss in cell viability. Additionally, positive expression of CD49, CD73, CD105 markers and negative expression of hemopoietic stem cell-associated CD34 and CD45 indicated that MSC phenotype was retained within the fibrin gel. Nonetheless, a decrease in the gene expression of α-smooth cell actin and calponin was observed for MSC cultured in static 3D fibrin gels. Although a slight recovery was observed after 24 h mechanical stimulation, the fold-change remained significantly lower than that observed for cells cultured on 2D tissue culture plastic. While MSC differentiation toward a SMC appears possible in both 2D and 3D environments, scaffold architecture and mechanical stimulation undoubtedly play an important role in the creation of a functional SMC phenotype.     

人脐血间充质干细胞的培养条件比较

目的摸索人脐血间充质干细胞（mesenchymal stem cell,MSC）的培养条件。方法根据不同采血量、首次换液时间、胎龄、不同培养基对样本分组，比较不同培养条件对脐血中的间充质干细胞原代生长的影响，以流式细胞仪对培养出的间充质干细胞进行细胞表面标志检测。结果在相同条件下，取10ml的脐血能较大程度培养出间充质干细胞；观察首次换液时间在培养后96h较为合适，延长换液时间有利于数量不占优势的单核细胞充分贴壁：早产胎儿的脐血培养出的间充质干细胞成功率较高；胎牛血清的质和量决定了培养成功与否。培养出的间充质干细胞不表达造血细胞系的标志（CD34、CD45、CD14）及内皮细胞的标志（CD106），强表达CD29、CD44、CD13。结论样本量、首次换液时间、胎龄、培养基的质和量对MSCs的成活、生长有关键作用。     

Mesenchymal Stem Cells versus Mesenchymal Stem Cells Combined with Cord Blood for Engraftment Failure after Autologous Hematopoietic Stem Cell Transplantation: A Pilot Prospective,Open-Label,Randomized Trial

Engraftment failure (EF) after autologous hematopoietic stem cell transplantation is a serious complication. We prospectively evaluated the effects and safeties of mesenchymal stem cells (MSCs) alone and MSCs combined with cord blood (CB) for EF. Twenty-two patients were randomized to receive MSCs (MSC group; n = 11) or MSCs plus CB (CB group; n = 11). Patients with no response (NR) to MSCs received the therapeutic schedule in the CB group, and those patients with partial response (PR) in the MSC group and patients without complete remission (CR) in the CB group received another cycle of MSC treatment. Patients who did not achieve CR after 2 cycles of treatments received other treatments, including allogeneic HSCT. After the first treatment cycle, response was seen in 7 of 11 patients in the MSC group and in 9 of 11 in the CB group (P = .635), with a significant difference in neutrophil reconstruction between the 2 groups (P = .030). After 2 treatment cycles, 16 patients achieved CR, 3 achieved PR, and 3 had NR. No patient experienced graft-versus-host disease (GVHD). With a median follow-up of 345 d (range, 129 to 784 d) post-transplantation, 18 patients remained alive and 4 had died (3 from primary disease relapse and 1 from cytomegalovirus pneumonia). The 2-year overall survival, disease-free survival, and cumulative incidence of tumor relapse post-transplantation were 75.2% ± 12.0%, 79.5% ± 9.4%, and 20.5% ± 9.4%, respectively. Our data indicate that the 2 strategies are effective for EF and do not result in GVHD or increase the risk of tumor relapse, but the MSC plus CB regimen has a superior effect on neutrophil reconstruction.     

Phenotypic and Functional Characterization of Mesenchymal Stem Cells from Chorionic Villi of Human Term Placenta

Background

Bone marrow derived mesenchymal stem cells (BM-MSCs) are used extensively in transplantation but their use is associated with many problems including low abundance in BM, low overall number, decreased differentiation potential with age and the invasive isolation procedures needed to obtain BM. We report a novel method of isolating placental MSCs (pMSCs) from chorionic villi, which exhibit the phenotypic and functional characteristics that will make them an attractive source of MSCs for cell-based therapy.

Methods

A novel explant approach was used to isolate pMSCs from chorionic villi of human placentae. These pMSCs were characterized by flow cytometry and were differentiated into adipocytes, osteocytes and chondrocytes using differentiation medium as demonstrated by cytochemical staining. The gene and protein expression profiles of pMSCs were also characterized using real time polymerase chain reaction (PCR) and flow cytometry, respectively. In addition, cytokine secretion by pMSCs was also analysed using sandwich enzyme-linked immunosorbent assay (ELISA) technique. Moreover, the migration and proliferation potentials of pMSCs were also determined.

Results

pMSCs were isolated from fetal part of the chorionic villi and these pMSCs expressed CD44, CD90, CD105, CD146, CD166 and HLA-ABC but not CD14, CD19, CD40, CD45, CD80, CD83, CD86 and HLA-DR. In addition, these pMSCs differentiated into osteocytes, chondrocytes and adipocytes and they also expressed several adhesion molecules, chemokines/receptors, growth factor receptors and cytokines/receptors. Moreover, they secreted many cytokines (IL-1Ra, IL6, IL8, IL10, IL11 and IL15) and they were able to proliferate. Furthermore, they migrated in response to chemotactic factors including stromal cell-derived factor-1 (SDF-1), platelet derived growth factor (PDGF), hepatocyte growth factor (HGF), and monocyte chemotactic protein-1 (MCP-1).

Conclusions

We devised a novel explant method of isolating pMSCs that expressed many biological factors responsible for mediating cellular processes such as migration/homing, immune modulation and angiogenesis. Therefore, we suggest that pMSCs prepared from human term placental chorionic villous explants are an attractive source of MSCs for cell therapy.     

自体血清培养人脐血间充质干细胞的实验研究

本实验采集脐血并分离脐血单核细胞与血清，分别用胎牛血清与自体脐血血清培养人脐血间充质干细胞。通过检测所培养出的成纤维细胞样细胞的表面抗原标记与细胞的成骨、成脂和成心肌细胞分化能力，鉴定所培养的细胞是否为间充质干细胞。成功采集的21例脐血中，有11例用胎牛血清和15例用自体血清培养出了间充质干细胞，表达细胞表面抗原标记CD29、CIN4、CD105，不表达CD34、CIN5，并成功地诱导成成骨细胞，脂肪细胞和心肌样细胞，说明使用自体血清培养脐血问充质干细胞较使用胎牛血清有较高的成功率，而且，自体血清培养的脐血问充质干细胞也能成功的进行多向诱导分化。     

人骨髓间充质干细胞的生物学特性

目的 建立人胚骨髓间充质干细胞(MSCs)分离及培养的方法，探讨体外培养MSCs的生物学特性．方法 通过密度梯度离心、贴壁法分离培养人胚MSCs，在倒置显微镜下连续观察细胞的形态变化．应用流式细胞术测定细胞周期和CD44、CD34、CD45表达，并研究其增殖及生长特征．结果 原代及传代培养显示，14代以前的MSCs具有活跃的增殖能力，细胞周期分析显示有82％的MSCs处于Gp／Gl期．MSCs阳性表达CD44，阴性表达CD34、CD45．结论 体外培养14代以前的的MSCs生长稳定，增殖较快，可作为组织工程的种子细胞．     

人间充质干细胞表面标志物及特征

评价人间充质干细胞表面标志,对常见的表面标志物进行总结,认识HMSCs表面标志物生物学特性,为分离和鉴定HMSCs提供参考依据.检索2010至2016年PubMed数据库和中国知网数据库收录的与HMSCs表面标志物、生物学特性相关的文献.从细胞表面标记物的本质、实验结果等进行分析总结,总结了一些常见的HMSCs表面标志物.不同组织来源的HMSCs免疫活性可能与HMSCs处于不同组织中的活化状态、组织来源和培养条件的不同有关,从而导致不同源性HMSCs免疫活性也不完全相同,其表面标志物存在差异.利用杂交瘤技术制备的抗体,可将不同来源、不同阶段、不同培养条件的HMSCs分为不同的亚群.不同来源或不同分化阶段的HMSCs表面标记物存在差异.     

人骨髓间充质干细胞的生物学特性

目的建立人胚骨髓间充质干细胞(MSCs)分离及培养的方法,探讨体外培养MSCs的生物学特性.方法通过密度梯度离心、贴壁法分离培养人胚MSCs,在倒置显微镜下连续观察细胞的形态变化.应用流式细胞术测定细胞周期和CD44、CD34、CD45表达,并研究其增殖及生长特征.结果原代及传代培养显示,14代以前的MSCs具有活跃的增殖能力,细胞周期分析显示有82%的MSCs处于G0/G1期.MSCs阳性表达CD44,阴性表达CD34、CD45.结论体外培养14代以前的的MSCs生长稳定,增殖较快,可作为组织工程的种子细胞.     

Substrates for Human Pluripotent Stem Cell Cultures in Conditioned Medium of Mesenchymal Stem Cells

We aimed to establish a culture system of human pluripotent stem cells (hPSCs), such as human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), free from xenogeneic proteins, Matrigel^? and conditioned medium of mouse embryonic fibroblasts. The conditioned culture medium consisted of mesenchymal stem cells derived from human bone marrow. We examined surface properties suitable for hPSC culture by using self-assembled monolayers (SAMs) of alkanethiols with four different functional groups: CH₃, OH, COOH and NH₂. hPSCs neither adhered nor proliferated on surfaces with a water contact angle higher than 40°. Based on this finding, the contact angle of a polystyrene (PSt) culture dish was reduced to less than 40°, and COOH and OH groups were introduced to its surface by oxygen plasma treatment, making the PSt dish suitable for hPSC culture. This combination of a PSt dish treated with oxygen plasma treatment and conditioned medium of mesenchymal stem cells achieved a long-term maintenance of hPSCs without differentiation.     

骨组织工程中人骨髓间质干细胞动态种植和静态种植的比较研究

分别采用动态种植(旋转烧瓶法)和静态种植方法种植人骨髓间质干细胞,于种植后的两周内测定细胞-载体构件中DNA含量;利用组织学光镜和扫描电镜观察细胞的分布情况;运用荧光标记RT-PCR技术测定相关成骨基因的表达。构件中DNA含量测定表明,对于静态种植,当初始种植密度为每载体400×103(8.9×104/mm3)时,DNA的含量达到最高;在此基础上提高初始种植密度,并不能进一步提高构件DNA含量。光镜和扫描电镜观察可见动态种植后人骨髓间质干细胞在载体中的分布相对均匀,静态种植后细胞在载体中出现聚集现象;荧光标记RT-PCR证明,体外构件培养两周后,动态种植后的细胞-载体构件中有较多的成骨基因表达。提示人骨髓间质干细胞的静态种植效率较低;动态种植是一种优于静态种植的可行方法。     

人脐血MSCs的生物学特性及其向神经细胞分化的研究进展

脐血间充质干细胞是从脐带血中分离和培养的一种多潜能成体干细胞,具有自我更新和多向分化潜能,在一定条件下可以分化成为神经细胞。脐血间充质干细胞的这些特性吸引了许多学者用它来治疗神经系统疾病如神经退行性疾病,神经损伤和中风等,并取得了一定进展。本文就脐血间充质干细胞的分离纯化和培养方法、生物学特性以及向神经细胞的分化作一简要综述。     

血小板裂解液快速扩增人羊膜来源间充质干细胞

目的:研究人血小板裂解液(HPL)扩增的羊膜来源间充质干细胞(AMMSCs)的细胞生物学特征。方法:分别以含7%HPL和10%胎牛血清(FBS)的LG-DMEM培养介质扩增人AMMSCs,比较含HPL和FBS介质培养扩增的AMMSCs的形态、扩增效率、免疫表型和多向分化潜能。结果:含HPL和FBS培养介质扩增的AMMSCs形态和免疫表型类似。含HPL培养介质能显著加速间充质干细胞(MSCs)的扩增,扩增的AMMSCs能向成骨、软骨和脂肪细胞分化。结论:含HPL培养介质可促进AMMSCs扩增,可为相关临床治疗提供更多人源化、无伦理争议、临床应用障碍少的MSCs。     

Characterization of Rat Hair Follicle Stem Cells Selected by Vario Magnetic Activated Cell Sorting System

Hair follicle stem cells (HfSCs) play crucial roles in hair follicle morphogenesis and hair cycling. These stem cells are self-renewable and have the multi-lineage potential to generate epidermis, sebaceous glands, and hair follicle. The separation and identification of hair follicle stem cells are important for further research in stem cell biology. In this study, we report on the successful enrichment of rat hair follicle stem cells through vario magnetic activated cell sorting (Vario MACS) and the biological characteristics of the stem cells. We chose the HfSCs positive surface markers CD34, α6-integrin and the negative marker CD71 to design four isolation strategies: positive selection with single marker of CD34, positive selection with single marker of α6-integrin, CD71 depletion followed by CD34 positive selection, and CD71 depletion followed by α6-integrin positive selection. The results of flow cytometry analysis showed that all four strategies had ideal effects. Specifically, we conducted a series of researches on HfSCs characterized by their high level of CD34, termed CD34^bri cells, and low to undetectable expression of CD34, termed CD34^dim cells. CD34^bri cells had greater proliferative potential and higher colony-forming ability than CD34^dim cells. Furthermore, CD34^bri cells had some typical characteristics as progenitor cells, such as large nucleus, obvious nucleolus, large nuclear:cytoplasmic ratio and few cytoplasmic organelles. Our findings clearly demonstrated that HfSCs with high purity and viability could be successfully enriched with Vario MACS.     

Umbilical Cord Mesenchymal Stem Cells Increase Expansion of Cord Blood Natural Killer Cells

Natural killer (NK) cell-mediated cytotoxicity can control leukemia relapse while protecting patients from graft-versus-host disease (GVHD) after allogeneic stem cell transplant. Cord blood (CB) is rich in NK cell progenitors with similar properties of proliferation and cytotoxicity as adult blood NK cells. Hence, it is attractive to expand and potentially utilize these cells for adoptive immunotherapy. In this study, CB mononuclear cells were CD3-depleted by immunomagnetic microbead selection to remove T cells. This CD3^dep CB-MNC fraction was then plated for ex vivo expansion, with or without a feeder layer of irradiated umbilical cord mesenchymal stem cells (UC-MSC), with or without cytokines that have been shown to be critical for NK expansion: IL-2, IL-15, IL-3, and FLT-3L. At an average of 2 weeks of culture, there was significantly higher expansion (64.7 ± 8.4-fold) of CD56⁺/CD3⁻ NK cells in the presence of the UC-MSC feeder layer and cytokines compared to controls (no increase with feeder layer only and 6.4 ± 1.5-fold increase with cytokines only, P < .05). Contact between CD3^dep CB-MNC cells and UC-MSC augmented NK expansion. The combination of all 4 cytokines was superior to IL-2 alone or 2 cytokines combinations: mean 64.7 ± 8.4-fold expansion with 4 cytokines combination versus IL-2 alone, IL-2 + FLT-3L, IL-2 + IL-15 or IL-2 + IL-3 (12.2 ± 2.0, 14.4 ± 2.4, 10.4 ± 4.1, 25.2 ± 8.1 respectively). We also observed that only fresh CD3^dep CB-MNC preparations could be expanded reliably, whereas frozen and thawed CD3^dep CB-MNC cells did not expand consistently (mean fold increase 6.5 ± 3.2). Cytotoxicity of expanded NK cells was compared with NK cells from fresh and overnight IL-2 activated CD3^dep CB-MNC. Whereas fresh cells displayed no discernible killing, strong cytotoxicity against K562, Raji, REH, and SUP-B15 cells lines was noted after overnight activation in IL-2. Cytotoxicity of expanded NK cells against Raji, REH, and SUP-B15 was lower, which, however, correlated with a predominant expansion of CD56⁺/CD16⁻ cells known to have less cytolytic activity than CD56⁺/CD16⁺. To test the transfection efficiency in NK cells, fresh or expanded CD3^dep CB-MNC cells were electroporated with either DNA or mRNA constructs for GFP. DNA had a low transfection efficiency (<10%), whereas the one for mRNA reached 52%, but at the cost of significant cell death. Our results suggest that CB NK cell progenitors can be expanded to obtain large numbers by using an irradiated feeder of UC-MSC. They maintain an elevated cytotoxic profile, and may be genetically manipulated—all characteristics that make them suitable for cellular therapies.     

Comparison of Mesenchymal Stem Cells Obtained from Different Human Tissues

We studied mesenchymal stem cells from human bone marrow, adipose tissue, skin, placenta, and thymus. Morphological study and cytofluorometrical analysis by the main marker genes (CD10, CD13, CD31, CD44, CD90, CD105) were carried out. Mesemchymal stem cells of the studied tissues during isolation and culturing were morphologically similar and did not differ by the expression of the main marker genes.__________Translated from Kletochnye Tekhnologii v Biologii i Meditsine, No. 2, pp. 89–94, 2005     

Effects of Human Fibroblast-Derived Extracellular Matrix on Mesenchymal Stem Cells

Stem cell fate is largely determined by the microenvironment called niche. The extracellular matrix (ECM), as a key component in the niche, is responsible for maintaining structural stability and regulating cell proliferation, differentiation, migration and other cellular activities. Each tissue has a unique ECM composition for its needs. Here we investigated the effect of a bioengineered human dermal fibroblast-derived ECM (hECM) on the regulation of human mesenchymal stem cell (hMSC) proliferation and multilineage differentiation. Human MSCs were maintained on hECM for two passages followed by the analysis of mRNA expression levels of potency- and lineage-specific markers to determine the capacity of MSC stemness and differentiation, respectively. Mesenchymal stem cells pre-cultured with or without hECM were then induced and analyzed for osteogenesis, adipogenesis and chondrogenesis. Our results showed that compared to MSCs maintained on control culture plates without hECM coating, cells on hECM-coated plates proliferated more rapidly with a higher percentage of cells in S phase of the cell cycle, resulting in an increase in the CD90⁺/CD105⁺/CD73⁺/CD45^? subpopulation. In addition, hECM downregulated osteogenesis and adipogenesis of hMSCs but significantly upregulated chondrogenesis with increased production of collagen type 2. In sum, our findings suggest that hECM may be used to culture hMSCs for the application of cartilage tissue engineering.