Isolation and characterization of equine amniotic fluid-derived multipotent stem cells

Background aimsAmniotic fluid (AF) is a well-known source of stem cells. However, there have been no reports regarding equine AF stem cells. We have isolated equine AF-derived multipotent stem cells (MSC) (eAF-MSC) and show that these cells exhibit self-renewal ability and multilineage differentiation.MethodsAF was obtained from thoroughbred mares and mononuclear cells (MNC) were isolated by Ficoll–Paque density gradient. We measured the cumulative population doubling level (CPDL) and characterized the immunophenotype by flow cytometry. To investigate differentiation ability, a trilineage differentiation assay was conducted.ResultseAF-MSC could be isolated and the proliferation level was high. eAF-MSC presented typical MSC phenotypic markers, as determined by flow cytometry. Moreover, eAF-MSC showed a trilineage differentiation capability.ConclusionsEquine AF is a good source of MSC. Furthermore, eAF-MSC may be useful as a cell therapy application for horses.     

Comprehensive characterization of human adipose tissue-derived stem cells expanded in vitro

Adipose tissue seems to be a rich and safe source of mesenchymal stem cells (MSCs). The present study was aimed to investigate the biological and morphological characteristics of human adipose tissue-derived stem cells (ATSCs). Light and transmission electron microscopy were used. Course of proliferation was analyzed by growth curve. Expression of surface antigens was assessed by flow cytometry. Chondrogenic potential was assessed by immunohistochemistry. Obtained results showed morphology typical of fibroblastoid cells. TEM analysis proved ultrastructural morphology similar to MSCs from other sources. ATSCs reflected their proteosynthetic and metabolic activity. Each cell had irregular shape of nucleus with noticeable nucleoli. Abundant cisterns of rough endoplasmic reticulum were present in their cytoplasm. Karyotype mapping showed normal count of human chromosomes (46,XX). The growth curve revealed high capability for proliferation and population doubling time was 27.36 hours. ATSCs were positive for CD13, CD29, CD44, CD73, CD90, CD105 and CD106, but did not express CD14, CD34, CD45 and HLA-DR. It was also proved that ATSCs underwent chondrogenic differentiation in vitro. On the basis of obtained results it should be emphasized that ATSCs are typical MSCs and after further investigations they may be used in tissue engineering and regenerative medicine.     

Human mesenchymal stem cells - current trends and future prospective

Stem cells are cells specialized cell, capable of renewing themselves through cell division and can differentiate into multi-lineage cells. These cells are categorized as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and adult stem cells. Mesenchymal stem cells (MSCs) are adult stem cells which can be isolated from human and animal sources. Human MSCs (hMSCs) are the non-haematopoietic, multipotent stem cells with the capacity to differentiate into mesodermal lineage such as osteocytes, adipocytes and chondrocytes as well ectodermal (neurocytes) and endodermal lineages (hepatocytes). MSCs express cell surface markers like cluster of differentiation (CD)29, CD44, CD73, CD90, CD105 and lack the expression of CD14, CD34, CD45 and HLA (human leucocyte antigen)-DR. hMSCs for the first time were reported in the bone marrow and till now they have been isolated from various tissues, including adipose tissue, amniotic fluid, endometrium, dental tissues, umbilical cord and Wharton''s jelly which harbours potential MSCs. hMSCs have been cultured long-term in specific media without any severe abnormalities. Furthermore, MSCs have immunomodulatory features, secrete cytokines and immune-receptors which regulate the microenvironment in the host tissue. Multilineage potential, immunomodulation and secretion of anti-inflammatory molecules makes MSCs an effective tool in the treatment of chronic diseases. In the present review, we have highlighted recent research findings in the area of hMSCs sources, expression of cell surface markers, long-term in vitro culturing, in vitro differentiation potential, immunomodulatory features, its homing capacity, banking and cryopreservation, its application in the treatment of chronic diseases and its use in clinical trials.     

Isolation, proliferation, cytogenetic, and molecular characterization and in vitro differentiation potency of canine stem cells from foetal adnexa: a comparative study of amniotic fluid, amnion, and umbilical cord matrix

The possibility to isolate canine mesenchymal stem cells (MSCs) from foetal adnexa is interesting since several canine genetic disorders are reported to resemble similar dysfunctions in humans. In this study, we successfully isolated, cytogenetically and molecularly characterized, and followed the differentiation potency of canine MSCs from foetal adnexa, such as amniotic fluid (AF), amniotic membrane (AM), and umbilical cord matrix (UCM). In the three types of cell lines, the morphology of proliferating cells typically appeared fibroblast‐like, and the population doubling time (DT) significantly increased with passage number. For AF‐ and AM‐MSCs, cell viability did not change with passages. In UCM‐MSCs, cell viability remained at approximately constant levels up to P6 and significantly decreased from P7 (P < 0.05). Amnion and UCM‐MSCs expressed embryonic and MSC markers, such as Oct‐4 CD44, CD184, and CD29, whereas AF‐MSCs expressed Oct‐4, CD44. Expression of the hematopoietic markers CD34 and CD45 was not found. Dog leucocyte antigens (DLA‐DRA1 and DLA‐79) were expressed only in AF‐MSCs at P1. Isolated cells of the three cell lines at P3 showed multipotent capacity, and differentiated in vitro into neurocyte, adipocyte, osteocyte, and chondrocyte, as demonstrated by specific stains and expression of molecular markers. Cells at P4 showed normal chromosomal number, structure, and telomerase activity. These results demonstrate that, in dog, MSCs can be successfully isolated from foetal adnexa and grown in vitro. Their proven stemness and chromosomal stability indicated that MSCs could be used as a model to study stem cell biology and have an application in therapeutic programs. Mol. Reprod. Dev. 78:361–373, 2011. © 2011 Wiley‐Liss, Inc.     

Culture of human amniotic fluid stem cells in 3D collagen matrix

Most of the researchers attribute amniotic fluid stem cells (AF SCs) to mesenchymal stem cells (MSCs). However, AF SCs express both mesenchymal and epithelial markers, which distinguishes them from postnatal MSCs. Cultivation in the three-dimensional (3D) matrix provides a different look at the nature of the cells. We showed that in 3D collagen gel AF SCs form epithelial structures (tubules and cysts). The active contraction of the gel during the first days of cultivation, which is characteristic of mesenchymal cells, does not occur. Electron microscopic study showed that adherent junctions typical to epithelial cells are formed between AF SCs. On the other hand, during culturing in the gel AF SCs continue to express MSCs markers. Thus, AF SCs may be not true mesenchymal cells because they can display properties of epithelial cells. Perhaps these cells undergo epithelial-mesenchymal transition, a process which actively takes place during embryogenesis.     

Ascorbic acid induces in vitro proliferation of human subcutaneous adipose tissue derived mesenchymal stem cells with upregulation of embryonic stem cell pluripotency markers Oct4 and SOX 2

Mesenchymal stem cells (MSCs) have immense therapeutic potential because of their ability to self-renew and differentiate into various connective tissue lineages. The in vitro proliferation and expansion of these cells is necessary for their use in stem cell therapy. Recently our group has developed and characterized mesenchymal stem cells from subcutaneous and visceral adipose tissue. We observed that these cells show a slower growth rate at higher passages and therefore decided to develop a supplemented medium, which will induce proliferation. Choi et al. have recently shown that the use of ascorbic acid enhances the proliferation of bone marrow derived MSCs. We therefore studied the effect of ascorbic acid on the proliferation of MSCs and characterized their phenotypes using stem cell specific molecular markers. It was observed that the use of 250 μM ascorbic acid promoted the significant growth of MSCs without loss of phenotype and differentiation potential. There was no considerable change in gene expression of cell surface markers CD105, CD13, Nanog, leukemia inhibitory factor (LIF) and Keratin 18. Moreover, the MSCs maintained in the medium supplemented with ascorbic acid for a period of 4 weeks showed increase in pluripotency markers Oct4 and SOX 2. Also cells in the experimental group retained the typical spindle shaped morphology. Thus, this study emphasizes the development of suitable growth medium for expansion of MSCs and maintenance of their undifferentiated state for further therapeutic use.     

Comparative analysis of human UCB and adipose tissue derived mesenchymal stem cells for their differentiation potential into brown and white adipocytes

The differentiation potential of umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) into brown and white adipocytes in comparison to Adipose tissue derived MSCs (AD-MSCs) were investigated in order to characterize their potency for future cell therapies. MSCs were isolated from ten UCB samples and six liposuction materials. MSCs were differentiated into white and brown adipocytes after characterization by flow cytometry. Differentiated adipocytes were stained with Oil Red O and hematoxylin/eosin. The UCP1 protein levels in brown adipocytes were investigated by immunofluoresence and western blot analysis. Cells that expressed mesenchymal stem cells markers (CD34?, CD45?, CD90+ and CD105+) were successfully isolated from UCB and adipose tissue. Oil Red O staining demonstrated that white and brown adipocytes obtained from AD-MSCs showed 85 and 61% of red pixels, while it was 3 and 1.9%, respectively for white and brown adipocytes obtained from UCB-MSCs. Fluorescence microscopy analysis showed strong uncoupling protein 1 (UCP1) signaling in brown adipocytes, especially which were obtained from AD-MSCs. Quantification of UCP1 protein amount showed 4- and 10.64-fold increase in UCP1 contents of brown adipocytes derived from UCB-MSCs and AD-MSCs, respectively in comparison to undifferentiated MSCs (P?<?0.004). UCB-MSCs showed only a little differentiation tendency into adipocytes means it is not an appropriate stem cell type to be differentiated into these cell types. In contrast, high differentiation efficiency of AD-MSCs into brown and white adipocytes make it appropriate stem cell type to use in future regenerative medicine of soft tissue disorders or fighting with obesity and its related disorders.     

Hepatic differentiation from human mesenchymal stem cells on a novel nanofiber scaffold

The emerging fields of tissue engineering and biomaterials have begun to provide potential treatment options for liver failure. The goal of the present study is to investigate the ability of a poly L-lactic acid (PLLA) nanofiber scaffold to support and enhance hepatic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs). A scaffold composed of poly L-lactic acid and collagen was fabricated by the electrospinning technique. After characterizing isolated hMSCs, they were seeded onto PLLA nanofiber scaffolds and induced to differentiate into a hepatocyte lineage. The mRNA levels and protein expression of several important hepatic genes were determined using RT-PCR, immunocytochemistry and ELISA. Flow cytometry revealed that the isolated bone marrow-derived stem cells were positive for hMSC-specific markers CD73, CD44, CD105 and CD166 and negative for hematopoietic markers CD34 and CD45. The differentiation of these stem cells into adipocytes and osteoblasts demonstrated their multipotency. Scanning electron microscopy showed adherence of cells in the nanofiber scaffold during differentiation towards hepatocytes. Our results showed that expression levels of liver-specific markers such as albumin, α-fetoprotein, and cytokeratins 8 and 18 were higher in differentiated cells on the nanofibers than when cultured on plates. Importantly, liver functioning serum proteins, albumin and α-1 antitrypsin were secreted into the culture medium at higher levels by the differentiated cells on the nanofibers than on the plates, demonstrating that our nanofibrous scaffolds promoted and enhanced hepatic differentiation under our culture conditions. Our results show that the engineered PLLA nanofibrous scaffold is a conducive matrix for the differentiation of MSCs into functional hepatocyte-like cells. This represents the first step for the use of this nanofibrous scaffold for culture and differentiation of stem cells that may be employed for tissue engineering and cell-based therapy applications.     

Multipotent mesenchymal stem cells from adult human eye conjunctiva stromal cells

Abstract Identification of mesenchymal stem cells (MSCs) derived from alternative sources has provided an exciting prospect for intensive investigation. This work focused on characterizing a new source of MSCs from stromal cells from human eye conjunctiva. In this study, after conjunctiva biopsies and culture of stromal segment of this tissue, fibroblast-like (SH2⁺, SH3⁺, CD29⁺, CD44⁺, CD166⁺, CD13⁺) human stromal cells, which can be differentiated toward the osteogenic, adipogenic, chondrogenic, and neurogenic lineages, were obtained. These cells expressed Oct-4, Nanog, Rex-1 genes, and some lineage-specific markers like cardiac actin and Keratin. Taken together, the results indicate that conjunctiva stromal-derived cells are a new source of multipotent MSCs and despite originating from an adult source, they express undifferentiated stem cell markers.     

Enhanced hepatic differentiation of mesenchymal stem cells after pretreatment with injured liver tissue

Liver failure represents a serious challenge for cell based therapies. Mesenchymal stem cells (MSCs) possess potential for regeneration of fibrotic liver; however, there is a dire need to improve their hepatic differentiation. This study examines a pretreatment strategy to augment the differentiation potential of MSCs towards hepatic lineage. MSCs were isolated from C57BL/6 wild type mice and were characterized by flow cytometry for CD44 (92.4%), CD90 (96.6%), CD105 (94.7%), CD45 (0.8%) and CD34 (1.4%) markers. To improve the differentiation potential of MSCs towards hepatic lineage, cells were pretreated with injured liver tissue in an in-vitro model, which resulted in high expression of albumin, cytokeratin 8, 18, TAT and HNF1α as compared to untreated MSCs. The efficacy of pretreated MSCs was evaluated by preparing in-vivo mouse model with liver fibrosis by intraperitoneal administration of CCl(4). Pretreated MSCs were transplanted in the left lateral lobe of mice with liver fibrosis and showed enhanced localization and differentiation abilities after 1 month. The expression for cytokeratin 8, 18, albumin and Bcl-xl was up-regulated and that of HGF, Bax and Caspase- 3 was down-regulated in animals transplanted with pretreated MSCs. Sirus red staining also confirmed a significant reduction in the fibrotic area in liver tissue transplanted with pretreated MSCs as compared to untreated MSCs and was concomitant with improved serum levels of bilirubin and alkaline phosphatase (ALP). Therefore, it was concluded that pretreatment with injured liver tissue augment homing and hepatic differentiation abilities of MSCs and provides an improved procedure for the treatment of liver fibrosis.     

The efficiency of in vitro isolation and myogenic differentiation of MSCs derived from adipose connective tissue,bone marrow,and skeletal muscle tissue

The objective of the study is to evaluate efficiency of in vitro isolation and myogenic differentiation of mesenchymal stem cells (MSCs) derived from adipose connective tissue (AD-MSCs), bone marrow (BM-MSCs), and skeletal muscle tissue (MC-MSCs). MSCs were isolated from adipose connective tissue, bone marrow, and skeletal muscle tissue of two adult 6-wk-old rats. Cultured MSCs were treated with 5-azacytidine (AZA) to induce myogenic differentiation. Isolated MSCs and differentiated cells were evaluated by immunocytochemistry (ICC), fluorescence-activated cell sorting (FACS), PCR, and RT-PCR. AD-MSCs showed the highest proliferation rate while BM-MSCs had the lowest one. In ICC, isolated MSCs had strong CD90- and CD44-positive expression and negative expression of CD45, CD31, and CD34, while AZA-treated MSCs had strong positive desmin expression. In FACS analysis, AD-MSCs had the highest percentage of CD90- and CD44-positive-expressing cells (99% and 96%) followed by BM-MSCs (97% and 94%) and MC-MSCs (92% and 91%).At 1 wk after incubation with AZA treatment, the peak of myogenin expression reached 93% in differentiated MC-MSCs, 83.3% in BM-MSCs, and 77% in AD-MSCs. MSCs isolated from adipose connective tissue, bone marrow, and skeletal muscle tissue have the same morphology and phenotype, but AD-MSCs were the most easily accessible and had the highest rate of growth on cultivation and the highest percentage of stem cell marker expression. Moreover, although MC-MSCs showed the highest rate of myogenic differentiation potential and expression of myoblast markers, AD-MSCs and BM-MSCs still can be valuable alternatives. The differentiated myoblastic cells could be an available new choice for myoblastic auto-transplantation in regeneration medicine.     

Multipotent mesenchymal stem cells from amniotic fluid originate neural precursors with functional voltage-gated sodium channels

Background aimsAmniotic fluid (AF) contains stem cells with high proliferative and differentiative potential that might be an attractive source of multipotent stem cells. We investigated whether human AF contains mesenchymal stem cells (MSC) and evaluated their phenotypic characteristics and differentiation potential in vitro.MethodsAF was harvested during routine pre-natal amniocentesis at 14–16 weeks of pregnancy. AF sample pellets were plated in α-minimum essential medium (MEM) with 10% fetal bovine serum (FBS). We evaluated cellular growth, immunophenotype, stemness markers and differentiative potential during in vitro expansion. Neural progenitor maintenance medium (NPMM), a medium normally used for the growth and maintenance of neural stem cells, containing hFGF, hEGF and NSF-1, was used for neural induction.ResultsTwenty-seven AF samples were collected and primary cells, obtained from samples containing more than 6 mL AF, had MSC characteristics. AF MSC showed high proliferative potential, were positive for CD90, CD105, CD29, CD44, CD73 and CD166, showed Oct-4 and Nanog molecular and protein expression, and differentiated into osteoblasts, adypocytes and chondrocytes. The NPMM-cultured cells expressed neural markers and increased Na⁺ channel density and channel inactivation rate, making the tetrodotoxin (TTX)-sensitive channels more kinetically similar to native neuronal voltage-gated Na⁺ channels.ConclusionsThese data suggest that AF is an important multipotent stem cell source with a high proliferative potential able to originate potential precursors of functional neurons.     

Stem cells in human amniotic fluid

Amniotic fluid (AF) contains a heterogeneous population of cells of fetal origin in which stem cells are present. These cells are characterized by the expression of mesenchymal (CD73, CD90, CD105) and neural (Nestin, β3-tubulin, NEFH) markers, and also some markers of pluripotency (Oct4, Nanog), and they are capable of differentiating into diverse derivatives in vitro. We have shown that epithelial markers (Keratin 19, Keratin 18, and p63) are expressed in AF stem cells simultaneously with mesenchymal ones. During cloning, colonies of cells with fibroblastoid and epithelioid cells are formed. The status and differentiation potential of stem cells from AF have been discussed.     

CXCR4 Receptor Overexpression in Mesenchymal Stem Cells Facilitates Treatment of Acute Lung Injury in Rats

Novel therapeutic regimens for tissue renewal incorporate mesenchymal stem cells (MSCs) as they differentiate into a variety of cell types and are a stem cell type that is easy to harvest and to expand in vitro. However, surface chemokine receptors, such as CXCR4, which are involved in the mobilization of MSCs, are expressed only on the surface of a small proportion of MSCs, and the lack of CXCR4 expression may underlie the low efficiency of homing of MSCs toward tissue damage, which results in a poor curative effect. Here, a rat CXCR4 expressing lentiviral vector was constructed and introduced into MSCs freshly prepared from rat bone marrow. The influence of CXCR4 expression on migration, proliferation, differentiation, and paracrine effects of MSCs was examined in vitro. The in vivo properties of CXCR4-MSCs were also investigated in a model of acute lung injury in rats induced by lipopolysaccharide. Expression of CXCR4 in MSCs significantly enhanced the chemotactic and paracrine characteristics of the cells in vitro but did not affect self-renewal or differentiation into alveolar and vascular endothelial cells. In vivo, CXCR4 improved MSC homing and colonization of damaged lung tissue, and furthermore, the transplanted CXCR4-MSCs suppressed the development of acute lung injury in part by modulating levels of inflammatory molecules and the neutrophil count. These results indicated that efficient mobilization of MSCs to sites of tissue injury may be due to CXCR4, and therefore, increased expression of CXCR4 may improve their therapeutic potential in the treatment of diseases where tissue damage develops.     

Differentiation of Human Umbilical Cord Matrix Mesenchymal Stem Cells into Neural-Like Progenitor Cells and Maturation into an Oligodendroglial-Like Lineage

Mesenchymal stem cells (MSCs) are viewed as safe, readily available and promising adult stem cells, which are currently used in several clinical trials. Additionally, their soluble-factor secretion and multi-lineage differentiation capacities place MSCs in the forefront of stem cell types with expected near-future clinical applications. In the present work MSCs were isolated from the umbilical cord matrix (Wharton''s jelly) of human umbilical cord samples. The cells were thoroughly characterized and confirmed as bona-fide MSCs, presenting in vitro low generation time, high proliferative and colony-forming unit-fibroblast (CFU-F) capacity, typical MSC immunophenotype and osteogenic, chondrogenic and adipogenic differentiation capacity. The cells were additionally subjected to an oligodendroglial-oriented step-wise differentiation protocol in order to test their neural- and oligodendroglial-like differentiation capacity. The results confirmed the neural-like plasticity of MSCs, and suggested that the cells presented an oligodendroglial-like phenotype throughout the differentiation protocol, in several aspects sharing characteristics common to those of bona-fide oligodendrocyte precursor cells and differentiated oligodendrocytes.     

Embryonic stem cells conditioned medium enhances Wharton’s jelly-derived mesenchymal stem cells expansion under hypoxic condition

Mesenchymal stem cells (MSCs) are accepted as a promising tool for therapeutic purposes. However, low proliferation and early senescence are still main obstacles of MSCs expansion for using as cell-based therapy. Thus, clinical scale of cell expansion is needed to obtain a large number of cells serving for further applications. In this study, we investigated the value of embryonic stem cells conditioned medium (ESCM) for in vitro expansion of Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) as compared to typical culture medium for MSCs, Dulbecco’s modified Eagle’s medium with 1.0 g/l glucose (DMEM-LG) supplemented with 10 % FBS, under hypoxic condition. The expanded cells from ESCM (ESCM-MSCs) and DMEM-LG (DMEM-MSCs) were characterized for both phenotype and biological activities including proliferation rate, population doubling time, cell cycle distribution and MSCs characteristics. ESCM and DMEM-LG could enhance WJ-MSCs proliferation as 204.66 ± 10.39 and 113.77 ± 7.89 fold increase at day 12, respectively. ESCM-MSCs could express pluripotency genes including Oct-4, Oct-3/4, Nanog, Klf-4, C-Myc and Sox-2 both in early and late passages whereas the downregulations of Oct-4 and Nanog were detected in late passage cells of DMEM-MSCs. The 2 cell populations also showed common MSCs characteristics including normal cell cycle, fibroblastic morphology, cell surface markers expressions (CD29⁺, CD44⁺, CD90⁺, CD34⁻, CD45⁻) and differentiation capacities into adipogenic, chondrogenic and osteogenic lineages. Moreover, our results revealed that ESCM exhibited as a rich source of several factors which are required for supportive WJ-MSCs proliferation. In conclusion, ESCM under hypoxic condition could accelerate WJ-MSCs expansion while maintaining their pluripotency properties. Our knowledge provide short term and cost-saving in WJ-MSCs expansion which has benefit to overcome insufficient cell numbers for clinical applications by reusing the discarded cell culture supernates from human ES culture system. Moreover, these findings can also apply for stem cell banking, regenerative medicine and pharmacological applications.     

脂肪干细胞与间充质干细胞体外诱导分化为心肌细胞的差别

本文旨在探讨脂肪干细胞(adipose-derived stem cells, ASCs)和骨髓间充质干细胞(mesenchymal stem cells, MSCs)在组织含量、体外培养和诱导分化为心肌细胞方面的差别.ASCs从新西兰白兔皮下脂肪组织提取,MSCs从大鼠四肢长骨骨髓提取,体外培养扩增,免疫细胞学方法鉴定.采用细胞集落形成法检测组织中干细胞的含量.将不同代的干细胞用不同浓度的5-氮胞苷诱导,观察其形态变化,免疫细胞化学方法检测诱导后细胞是否转化为心肌细胞.结果显示,体外培养的ASCs呈短梭形,分布均匀,生长迅速,细胞形态单一、稳定.MSCs原代生长非常缓慢,呈簇生长,细胞纯度偏低,容易混杂其它细胞类型,传代细胞容易分化和老化.脂肪组织中ASCs含量显著高于骨髓中MSCs含量,且前者含量受年龄影响小.5-氮胞苷诱导ASCs分化为心肌细胞的有效浓度为6～9μmol/L,而MSCs在3～15μmol/L 5-氮胞苷诱导下可见心肌细胞形成.ASCs诱导分化的心肌细胞呈球形细胞团,MSCs分化的心肌细胞呈条形或棒状,其心肌细胞分化率低于ASCs.幼年动物MSCs的组织含量和心肌细胞分化率均高于老年动物,而ASCs受动物年龄影响较小.结果表明,ASCs在组织含量、细胞纯度、生长速度和心肌细胞分化率等方面均明显优于骨髓MSCs,在心肌细胞再生方面较MSCs具有更大的优势.