Endometrial stem cells in regenerative medicine
© Verdi et al.; licensee BioMed Central Ltd. 2014
Received: 5 April 2014
Accepted: 30 June 2014
Published: 1 August 2014
First described in 2004, endometrial stem cells (EnSCs) are adult stem cells isolated from the endometrial tissue. EnSCs comprise of a population of epithelial stem cells, mesenchymal stem cells, and side population stem cells. When secreted in the menstrual blood, they are termed menstrual stem cells or endometrial regenerative cells. Mounting evidence suggests that EnSCs can be utilized in regenerative medicine. EnSCs can be used as immuno-modulatory agents to attenuate inflammation, are implicated in angiogenesis and vascularization during tissue regeneration, and can also be reprogrammed into induced pluripotent stem cells. Furthermore, EnSCs can be used in tissue engineering applications and there are several clinical trials currently in place to ascertain the therapeutic potential of EnSCs. This review highlights the progress made in EnSC research, describing their mesodermal, ectodermal, and endodermal potentials both in vitro and in vivo.
Cells in the earliest developmental stages in the embryo can generate embryonic and extra-embryonic tissues . The ability to generate other cell types is known as potency. In the inner cell mass of the blastocyst in the embryo, the cells pluripotent, meaning they can give rise to the ectoderm, mesoderm, and endoderm lineages (entire organism). Pluripotent stem cells include embryonic stem cells (ESCs) from the inner cell mass of blastocysts, epiblast derived stem cells from embryos after implantation, embryonic germ cells (EGCs) from primordial germ cells, embryonic carcinoma cells (ECCs) derived from germ cells tumors, and germ line stem cells from testicular tissue [2–4]. As the reproductive cycle progresses, cell potency decreases and only a small fraction of cells retain their potency, namely adult stem and progenitor cells. These are limited to tissue generation within specific lineages. Adult stem cells (ASCs) are found in numerous human tissues including: intestines , muscles , skin , blood , nervous system [9–11], endometrium , heart, liver [13, 14], dental pulp, adipose tissue, synovial membrane, umbilical cord blood, amniotic fluid [15, 16], and the endometrium . In comparison to pluripotent stem cells, ASCs are considered safer for therapeutic purposes and several are currently used in clinical trials. The concept of using ASCs over embryonic stem (ES) cells in regenerative medicine has recently gained traction. The rationale for this trend include: (1) The complicated control of the culture conditions of ESCs; (2) the existence of several intermediate stages before reaching terminal differentiation of ESCs; (3) Teratoma formation is a major obstacle for clinical development of ESCs; (4) immunological rejection of cells derived from ES cells to the recipient and (5) ethical scrutiny involved in ESCs application.
Endometrium and endometrial stem cells (EnSCs)
The progenitor cells in the endometrium has a high proliferative potential that can generate 6 × 1011 cells from a single cell, with the ability to differentiate into large cytokeratin-expressing structures when cultured in Matrigel , comprising laminin, collagen IV and heparan sulfate proteoglycan. It was used instead of mouse embryonic fibroblast feeder layers for ES cells proliferation. Our data shows that mesenchymal stem cells from endometrium can be grown extensively both in vivo and in vitro. These cells are not tumorigenic in nude mice and could be passaged approximately 40 times in vitro.
Endometrial stem cells may be derived from fetal stem cells or bone marrow stem cells, including haemopoietic SCs, MSCs and endothelial progenitor cells [36–38]. The human endometrium shows expression of the pluripotency factors Sox-2, Oct-4 and Nanog. Sox-2 co-localized with telomerase, contribute to the immortality of embryonic stem cells . Reprogramming of differentiated cells to an induced pluripotent stem (iPS) cell is through induction or increasing in the expression of Oct-4, Sox-2, Klf-4, and c-Myc  that easily could be achieved from EnSCs that already express these factors. As a result, iPS cells from EnSCs have been established as early as 12 days after transduction rather than the usually reported 4 weeks for other cell types . As patient- or disease-specific biomedical research using iPS cells becomes more widespread, the endometrium may play a key role as reprogrammable cells into donor- or disease-specific pluripotent cell lines for the female population.
Markers of human EnSCs
Immunogenicity of EnSCs
Utilizing ES cells in regenerative therapy is associated with many hazards. Without adequate ES cells screening procedures, patients would face tissue rejection similar as rejection of organ transplants. A solution to this problem is to create patient specific stem cells. Unlike ES cells, adult stem cells are not rejected by the immune system . The human endometrium has unique immunological requirements. In pregnancy, the endometrium must tolerate the invading embryo, which expresses both paternal and maternal antigens. In 2012, Peron et al. demonstrated that endometrial MSCs were able to suppress neuro-inflammation in a mouse model of multiple sclerosis. This suppression is dependent on the secretion of anti-inflammatory cytokines such as IL-10 and IL-27, and also the expression of indoleamine-2,3-dioxigenase . Menstrual blood SCs were tested for allogeneic response in culture with peripheral blood mononuclear cells (PBMN). The SCs were analyzed at a 1:2 stimulator (mitomycin C treated PBMN) to responder cell (menstrual blood SCs) ratio for 6 days. The menstrual blood SCs demonstrated a moderately weak stimulatory response in a mixed lymphocyte reaction (MLR). An emerging bank of data allows for the classification of the mesenchymal stem cell from bone marrow as immunosuppressive cell source derived from studies with human cells [54, 55]. Some studies support that SC administration is a potential way to suppress tumor growth. It has been demonstrated that human skin-derived progenitor cells have selective tropism for malignant tissues. Also more interestingly, these cells have the ability to inhibit tumor growth . MSCs could selectively integrate into gliomas after intravascular or local delivery [57–59]. ERC administration inhibits C6 tumor growth and its administration associated with reduced neovascularization . Despite the angiogenic potential of ERC in the hindlimb ischemia model, these data support a paradoxical tumor inhibitory activity of ERC. Further studies are needed to determine the qualitative differences between physiological angiogenesis, which seems to be supported by ERC and tumor angiogenesis which appeared to be inhibited. Other studies have demonstrated that MSCs directly secrete tumor inhibitory factors [61, 62].
Potency and differentiation of EnSCs
Identification and isolation of differentiated cells
Research pertaining to stem cell biology in the female reproductive tract is still in its infancy, and although surface markers of prospective isolation of human endometrial stromal colony-forming cells (putative endometrial stromal/progenitor cells) have recently identified [17, 44], there remains a need for definitive markers of both myometrial and endometrial stem cells for more selective isolation and enrichment. Complete characterization of uterine stem/ progenitor cells will improve our understanding of the mechanisms supporting physiological regeneration of the female reproductive tract. In addition, such studies will enhance our understanding of uterine cancer, hyperplasia, endometriosis, leiomyomas and adenomyosis. Indeed, our data and the published observations from other laboratories have enabled us to propose a novel hypothetical model for eutopic and ectopic endometrial regeneration. Finally, availability of these stem cells suggests new approaches to reconstruction of the human uterus and perhaps other organs as well.
The final step for processing stem cells before transplantation would be the identification and isolation of the differentiated cells. Recognition and selection of desired cells can be done via reverse transcriptase polymerase chain reaction, flow cytometry or fluorescence-activated cell sorting (FACS). Unfortunately, these methods would destroy many of the differentiated cells, thereby rendering them unusable. Also, flow cytometry and FACS is dependent on the presence of specific markers on the cell surface, which are not always displayed on every type of differentiated cells . Thus, a more viable technique for identification of differentiated cells can be made with the transient transfection of a reporter gene into a stem cell source. The reporter gene can encode a fluorescent (green fluorescent protein) or a drug selectable protein. The transient transfection would be favorable for human cell therapy because the reporter is only meant for selection purposes.
Comparison between EnSCs, MSCs, and umbilical cord blood stem cells
Genetic profiling of EnSCs and bone marrow MSCs revealed that they had similar (although not identical) cytokine production, miRNAs, and gene expression . It was reported that EnSCs express higher levels of ICAM-1 and IL-8, while bone marrow MSCs express higher levels of TGFβ1, TGFβ2, IL-6, and vascular endothelial growth factor (VEGF). This observation suggests that EnSCs may play a role in acute inflammation, and may be more suitable for tissue engineering applications. It was also reported that, compared to MSCs, EnSCs had a 27-fold higher level of PDGF-BB, and 14-fold higher level of angiopoietin. This indicates that EnSCs may activate alternative angiogenesis pathways. However, more studies are required to ascertain if EnSCs stimulate higher levels of angiogenesis than bone marrow MSCs in vivo. It was shown that EnSCs produced collagen type II and proteoglycans when cultured on nanofibrous polycaprolactone material, suggesting their cartilaginous tissue differentiation potential . It was also observed that proliferation of EnSCs was faster than bone marrow MSCs, and EnSCs express the pluripotency marker OCT-4, but lack the MSC marker STRO1 . Umbilical cord blood was first used in bone marrow transplant in a patient with Fanconi’s anaemia in 1988 . Considering that a large proportion of haematopoietic stem cells are found in the fetal circulation, there is also a correspondingly large proportion of haematopoietic stem cells in the umbilical cord. Bone marrow MSCs are distinct from haematopoietic stem cells, as they are CD45-. Mature bone marrow MSCs are a heterogeneous population of cells that are able to support haematopoiesis, and capable of differentiating into different lineages such as neural cells [74, 75], muscle [76–78], liver cells [79, 80], among many others. Various studies have reported that a single mesenchymal progenitor cell is responsible for all lineages are produced from bone marrow MSC in vitro. It has been shown that bone marrow MSCs contain more mesenchymal progenitor cells when compared to umbilical cord blood stem cells. Indeed, the proportion of MSCs within umbilical cord blood is extremely low and difficult to detect . Nevertheless, more studies comparing EnSCs, MSCs and umbilical cord blood stem cells are required to accurately ascertain their similarities and differences.
EnSCs in regenerative therapeutics
To date, EnSCs have been used in several pre-clinical and small animal studies. The regenerative potential of EnSCs was first seen in an experimental model of Duchenne muscular dystrophy in immunodeficient mdx mice, whereby EnSCs that were transplanted into atrophied skeletal muscle fibres contributed to muscle repair . Although the exact mechanism of repair has not been elucidated, it was postulated that cell fusion and in situ differentiation might have been involved, in part due to the observation that the transplanted EnSCs homed to peri-muscle fibre regions and promoted angiogenesis. The concept of angiogenesis was also supported by another study, where EnSCs were improved critical limb ischaemia induced by femoral artery ligation .
The use of EnSCs to treat myocardial infarction in a murine model was also seen. In this study, EGFP-labelled EnSCs were grafted into the infarct area of nude rat hearts, which subsequently differentiated into α-actinin+, troponin+ striated cardiac muscle cells . Furthermore, it was observed that a significantly larger reduction in infarct area was seen in animals treated with EnSCs, compared to control bone marrow MSCs.
Gargett et al., the first group that reported the existence of EnSCs in 2004 , are currently developing an autologous tissue engineered scaffold using artificial meshes and EnSCs for the treatment of pelvic organ prolapse, and was tested in vivo, on an animal skin wound repair model [84, 85]. Results indicated that EnSCs promoted neovascularization, increased tissue integration, reduced chronic inflammation, increased deposition of collagen fibres and distensibility of the mesh at 3 months post-implantation. They also found that EnSCs downregulated foreign body reactions and enhanced mesh integration, indicating they have a role to play in modulating tissue response with regards to implanted foreign materials.
Our group has also advocated the tissue engineering approach to the application of EnSCs. To this end, we have fabricated nanofibrous silk-collagen fibres that were seeded with EnSCs for the reconstruction of urinary bladder wall for women . We had also shown that EnSCs were capable of differentiating into smooth muscle cells , potentially functioning as an autologous cell source for bladder tissue engineering.
Intraperitoneal delivery of EnSCs were also studied in a murine model of encephalomyelitis . It was founds that EnSCs exerted a an anti-inflammatory effect, as evidenced by a lower number of infiltrating mononuclear cells in the lesions, upregulation of IL-10 and IL-27 in the spleen, and reduced recruitment of Th1 and Th17 cells in the central nervous system.
EnSCs were also used to demonstrate neural regenerative capabilities, whereby reduced neuronal cell death was seen when oxygen-deprived primary neuronal cell cultures were exposed to EnSCs . It was also observed that EnSCs released neuroprotective trophic factors such as neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), and VEGF. The in vivo part of the study was done in a murine model of ischaemic stroke, whereby injection of EnSCs resulted in significantly lower histological and behavioural impairments. It was reported that EnSCs exerted a trophic effect, releasing factors that promoted survival of neural cells.
The use of EnSCs to treat glioma was observed in a murine model. In this study, EnSCs were administered intravenously in a murine model of intracranial glioma. Results revealed a reduction of tumour size of almost 50%, possibly due to its anti-angiogenic effects .
The applications of EnSCs have also been reported in several human studies. The first reported use of EnSCs was demonstrated by Zhong et al. . Clinical-grade menstrual blood-derived EnSCs have been used in a small Phase I clinical trial of 4 patients suffering from multiple sclerosis, whereby EnSCs were delivered via intravenous and intrathecal routes. Results showed no immunological reactions or adverse side effects after 1 year .
Another human study involved a patient suffering from Duchenne muscular dystrophy that was given intramuscular injections of EnSCs. Follow-up observations reported no adverse effects even after 3 years, and increased muscle strength and decreased respiratory infections was also reported .
The third reported use of EnSCs in human was a patient with congestive heart failure, who was given intravenous administration of EnSCs. Results revealved that ejection fraction of the patient increased from 30% to 40%, decreased basic natriuretic peptide values (Pro-BNP), and decreased Minnesota Living with Heart Failure Questionnaire score at 1-year follow up .
The promise and limitations of EnSCs
EnSCs are an attractive source of stem cells for regenerative therapeutics as they are easily obtainable and easily expandable in culture, as has been demonstrated to be safe for clinical use. Protocols and methods for extraction and isolation of EnSCs are well established, as purified EnSCs can be obtained using magnetic bead sorting using the W5C5/SUSD2 marker. In addition, clinical-grade good manufacturing practice (cGMP) are currently being developed for culture expansion of EnSCs, and have been tested in animals. However, there is a lack of published information on the exact cGMP protocols in place for the production of EnSCs. This is compounded by the fact that there is no general scientific consensus regarding specific MSC markers to detect EnSCs; rather, researchers rely on the ability of MSCs to adhere to plastic. Hence, the purity of EnSCs is not guaranteed as the cultures could potentially contain fibroblasts.
EnSCs can be obtained from menstrual blood; hence no invasive procedures are needed to harvest these cells. A menstrual cup is used to collect menstrual blood over several hours on days 2 to 3 of the menstrual period. Although there is a potential risk of infection via vaginal contact, there have been no reports of any complications after antibiotic use.
Although the ability of EnSCs to re-integrate into tissue in vivo has been demonstrated, there is a theoretical risk that endometriosis could develop from using EnSCs. However, none of the animal model studies have reported this. Nevertheless, it is an aspect of EnSC application that warrants attention. Indeed, transdifferentiation (sometimes referred to as adult stem cell plasticity) is a controversial topic in the field of stem cells. It is highly probable that nuclear reprogramming and altered transcriptional activity of important developmental genes are in part responsible for transdifferentiation. Transdifferentiation can be seen as a form of metaplasia due to alterations in the extracellular environment, and often happens during tissue damage . Hence, one probable cause of endometriosis is thought to be due to metaplasia of the peritoneal lining. However, there is also evidence to suggest that circulating stem cells can be a source of metaplastic transdifferentiation when it gains access into the pelvic cavity. Genetically-tagged bone marrow MSCs were tracked in a murine transplant model, and it was established that a small population of it integrated into endometriosis lesions and transdifferentiated into stromal cells (0.1%) and epithelial cells (<0.04%) . It was found that these bone marrow MSCs contributed to the progression of endometriosis rather than initiating it . Changes in cellular phenotype may involve processes that are associated with both embryogenesis and carcinogenesis, such as mesenchymal epithelial transition (MET) and epithelial mesenchymal transition (EMT) . Correspondingly, the invasiveness of endometriotic cells may be attributed to the changes in cellular phenotype in endometriotic lesions. For instance, well differentiated CK+E+-Cadherin cells, CK-E-Cadherin- stromal cells, and an invasive CK+E-Cadherin-N-Cadherin+ epithelial cells (similar to carcinoma micrometastasis) are found in endometriotic lesions . In line with carcinoma characteristics, a regression of endometriotic lesion is seen in estrogen depletion therapy, but recur when therapy stops. This indicates that a quiescent stem cell population is present within the lesion, which reactivates on exposure to estrogen. Thus it may also follow that EnSCs within lesions may also contribute to subsequent lesions.
In terms of regenerative medicine applications, it is envisioned that bone marrow MSCs are more suited for osteogenic differentiation and therefore used for bone tissue engineering, while EnSCs are more suited for soft tissue engineering, such as bladder reconstruction. Due to the intense interest generated with using EnSCs for regenerative medicine, we believe that EnSCs were introduced too quickly into human tests without adequately assessing its impact on large animal models. Furthermore, the exact mechanism of how EnSCs exert is regenerative potential is not clearly understood. Hence more robust large animal studies are needed to fill this information gap that currently exists.
Concluding remarks and future perspectives
Although EnSCs would form a non-invasive and steady supply of autologous stem cells for women, we must not forget that this means that 50% of the population (i.e. the male population) is excluded. Furthermore, non-invasive harvesting of EnSCs would not be possible from post-menopausal women (in this case, endometrial biopsy might be possible, but data regarding the potency of EnSCs in post-menopausal women has not been published). In addition, the issue of EnSCs storage could also develop into the same debates we are facing regarding the storage of cord blood; is there enough scientific evidence to justify storage of EnSCs for future use?
Nevertheless, given the significant progress made in the application of EnSCs in regenerative medicine, it is envisioned that human clinical trials would be conducted in the near future. Indeed, the RECOVER-ERC trial was recently launched by Medistem Inc (a start-up company based in San Diego, California), which aims to evaluate the potency of EnSCs in 60 heart failure patients in a double-blind placebo controlled Phase II clinical trial . Furthermore, a search in the clinicaltrials.gov database reveals that several clinical trials regarding EnSCs are underway, with applications ranging from treating critical limb ischaemia (NCT 01558908), liver cirrhosis (NCT01483248), type I diabetes (NCT01496339), and in vitro fertilization (NCT01649752). Hence, it can be envisioned that data from human patients would be available in due course to evaluate the clinical impact of EnSCs.
In conclusion, the discovery of EnSCs represents a paradigm shift for the use of adult stem cells by offering an “off the shelf” therapeutic application regenerative medicine. The EnSCs niche and in situ role highlight these cells as being important for cell and tissue regeneration. This work highlights crucial features of an interesting population of mesenchymal progenitors isolated form endometrial tissue. Cells grown in vitro were characterized by a high clonogenic potential and a long-term survival. Advantages in comparison with MSC from other sources include a greater ease of supply and the protracted availability during a woman’s lifetime with the additional benefit of deriving stem cells from a waste tissue, thus avoiding critical ethical issues.
In the light of their capacity to differentiate into mesenchymal tissues and their propensity to undergo genetic manipulation, EnSCs hold considerable promise for novel therapeutic approaches for diseases in the wider field of regenerative medicine.
- Kelly SJ: Studies of the developmental potential of 4‒and 8‒cell stage mouse blastomeres. J Exp Zool. 1977, 200 (3): 365-376.View ArticleGoogle Scholar
- Conrad S, Renninger M, Hennenlotter J, Wiesner T, Just L, Bonin M, Aicher W, Bühring H-J, Mattheus U, Mack A: Generation of pluripotent stem cells from adult human testis. Nature. 2008, 456 (7220): 344-349.View ArticleGoogle Scholar
- Ko K, Araúzo-Bravo MJ, Tapia N, Kim J, Lin Q, Bernemann C, Han DW, Gentile L, Reinhardt P, Greber B: Human adult germline stem cells in question. Nature. 2010, 465 (7301): E1-E1.View ArticleGoogle Scholar
- Stadtfeld M, Hochedlinger K: Induced pluripotency: history, mechanisms, and applications. Genes Dev. 2010, 24 (20): 2239-2263.View ArticleGoogle Scholar
- Bjerknes M, Cheng H: Clonal analysis of mouse intestinal epithelial progenitors. Gastroenterology. 1999, 116 (1): 7-14.View ArticleGoogle Scholar
- Jankowski R, Deasy B, Huard J: Muscle-derived stem cells. Gene Ther. 2002, 9 (10): 642-647.View ArticleGoogle Scholar
- Alonso L, Fuchs E: Stem cells of the skin epithelium. Proc Natl Acad Sci U S A. 2003, 100 (Suppl 1): 11830-11835.View ArticleGoogle Scholar
- Spangrude GJ, Smith L, Uchida N, Ikuta K, Heimfeld S, Friedman J, Weissman I: Mouse hematopoietic stem cells. Blood. 1991, 78 (6): 1395-1402.Google Scholar
- Morrison SJ, White PM, Zock C, Anderson DJ: Prospective identification, isolation by flow cytometry, and in vivo self-renewal of multipotent mammalian neural crest stem cells. Cell. 1999, 96 (5): 737-749.View ArticleGoogle Scholar
- Uchida N, Buck DW, He D, Reitsma MJ, Masek M, Phan TV, Tsukamoto AS, Gage FH, Weissman IL: Direct isolation of human central nervous system stem cells. Proc Natl Acad Sci U S A. 2000, 97 (26): 14720-14725.View ArticleGoogle Scholar
- Rietze RL, Valcanis H, Brooker GF, Thomas T, Voss AK, Bartlett PF: Purification of a pluripotent neural stem cell from the adult mouse brain. Nature. 2001, 412 (6848): 736-739.View ArticleGoogle Scholar
- Chan RW, Gargett CE: Identification of Label‒Retaining Cells in Mouse Endometrium. Stem Cells. 2006, 24 (6): 1529-1538.View ArticleGoogle Scholar
- Beltrami AP, Cesselli D, Bergamin N, Marcon P, Rigo S, Puppato E, D’Aurizio F, Verardo R, Piazza S, Pignatelli A: Multipotent cells can be generated in vitro from several adult human organs (heart, liver, and bone marrow). Blood. 2007, 110 (9): 3438-3446.View ArticleGoogle Scholar
- Crisan M, Yap S, Casteilla L, Chen C-W, Corselli M, Park TS, Andriolo G, Sun B, Zheng B, Zhang L: A perivascular origin for mesenchymal stem cells in multiple human organs. Cell Stem Cell. 2008, 3 (3): 301-313.View ArticleGoogle Scholar
- da Silva ML, Chagastelles PC, Nardi NB: Mesenchymal stem cells reside in virtually all post-natal organs and tissues. J Cell Sci. 2006, 119 (11): 2204-2213.View ArticleGoogle Scholar
- Kalervo Väänänen H: Mesenchymal stem cells. Ann Med. 2005, 37 (7): 469-479.View ArticleGoogle Scholar
- Gargett CE, Schwab KE, Zillwood RM, Nguyen HP, Wu D: Isolation and culture of epithelial progenitors and mesenchymal stem cells from human endometrium. Biol Reprod. 2009, 80 (6): 1136-1145.View ArticleGoogle Scholar
- McLennan CE, Rydell AH: Extent of endometrial shedding during normal menstruation. Obstet Gynecol. 1965, 26 (5): 605-621.Google Scholar
- Padykula HA: Regeneration in the primate uterus: the role of stem cells. Ann NY Acad Sci. 1991, 622: 47-56.View ArticleGoogle Scholar
- Okulicz WC, Ace CI, Scarrell R: Zonal changes in proliferation in the rhesus endometrium during the late secretory phase and menses. Exp Biol Med. 1997, 214 (2): 132-138.View ArticleGoogle Scholar
- Chan RW, Schwab KE, Gargett CE: Clonogenicity of human endometrial epithelial and stromal cells. Biol Reprod. 2004, 70 (6): 1738-1750.View ArticleGoogle Scholar
- Gargett CE, Masuda H: Adult stem cells in the endometrium. Mol Hum Reprod. 2010, 16 (11): 818-834.View ArticleGoogle Scholar
- Meng X, Ichim TE, Zhong J, Rogers A, Yin Z, Jackson J, Wang H, Ge W, Bogin V, Chan KW: Endometrial regenerative cells: a novel stem cell population. J Transl Med. 2007, 5 (1): 57-View ArticleGoogle Scholar
- Patel AN, Park E, Kuzman M, Benetti F, Silva FJ, Allickson JG: Multipotent menstrual blood stromal stem cells: isolation, characterization, and differentiation. Cell Transplant. 2008, 17 (3): 303-311.View ArticleGoogle Scholar
- Schüring AN, Schulte N, Kelsch R, Röpke A, Kiesel L, Götte M: Characterization of endometrial mesenchymal stem-like cells obtained by endometrial biopsy during routine diagnostics. Fertil Steril. 2011, 95 (1): 423-426.View ArticleGoogle Scholar
- Cui CH, Uyama T, Miyado K, Terai M, Kyo S, Kiyono T, Umezawa A: Menstrual blood-derived cells confer human dystrophin expression in the murine model of Duchenne muscular dystrophy via cell fusion and myogenic transdifferentiation. Mol Biol Cell. 2007, 18 (5): 1586-1594.View ArticleGoogle Scholar
- Musina R, Belyavski A, Tarusova O, Solovyova E, Sukhikh G: Endometrial mesenchymal stem cells isolated from the menstrual blood. Bull Exp Biol Med. 2008, 145 (4): 539-543.View ArticleGoogle Scholar
- Elsheikh E, Sylven C, Ericzon BG, Palmblad J, Mints M: Cyclic variability of stromal cell-derived factor-1 and endothelial progenitor cells during the menstrual cycle. Int J Mol Med. 2011, 27 (2): 221-226.View ArticleGoogle Scholar
- Schwab KE, Chan RWS, Gargett CE: Putative stem cell activity of human endometrial epithelial and stromal cells during the menstrual cycle. Fertil Steril. 2005, 84: 1124-1130.View ArticleGoogle Scholar
- Gargett C: Uterine stem cells: what is the evidence?. Hum Reprod Update. 2007, 13 (1): 87-101.View ArticleGoogle Scholar
- Sasson IE, Taylor HS: Stem cells and the pathogenesis of endometriosis. Ann NY Acad Sci. 2008, 1127 (1): 106-115.View ArticleGoogle Scholar
- Kim C, Oh Y, Cho S, Chung D, Hwang J, Park K, Cho D, Choi Y, Lee B: Increased telomerase activity and human telomerase reverse transcriptase mRNA expression in the endometrium of patients with endometriosis. Hum Reprod. 2007, 22 (3): 843-849.View ArticleGoogle Scholar
- Wu JM, Wechter ME, Geller EJ, Nguyen TV, Visco AG: Hysterectomy rates in the United States, 2003. Obstet Gynecol. 2007, 110 (5): 1091-1095.View ArticleGoogle Scholar
- Götte M, Wolf M, Staebler A, Buchweitz O, Kelsch R, Schüring A, Kiesel L: Increased expression of the adult stem cell marker Musashi‒1 in endometriosis and endometrial carcinoma. J Pathol. 2008, 215 (3): 317-329.View ArticleGoogle Scholar
- Shoae Hassani A, Mortazavi Tabatabaei SA, Sharif S, Seifalian AM, Azimi A, Samadikuchaksaraei A, Verdi J: Differentiation of human endometrial stem cells into urothelial cells on a three‒dimensional nanofibrous silk–collagen scaffold: an autologous cell resource for reconstruction of the urinary bladder wall. J Tissue Eng Regen Med. 2013, [In press]Google Scholar
- Mayani H, Alvarado-Moreno JA, Flores-Guzmán P: Biology of human hematopoietic stem and progenitor cells present in circulation. Arch Med Res. 2003, 34 (6): 476-488.View ArticleGoogle Scholar
- He Q, Wan C, Li G: Concise review: multipotent mesenchymal stromal cells in blood. Stem Cells. 2007, 25 (1): 69-77.View ArticleGoogle Scholar
- Robb A, Mills N, Smith I, Short A, Tura-Ceide O, Barclay G, Blomberg A, Critchley H, Newby D, Denison F: Influence of menstrual cycle on circulating endothelial progenitor cells. Hum Reprod. 2009, 24 (3): 619-625.View ArticleGoogle Scholar
- Kyo S, Masutomi K, Maida Y, Kanaya T, Yatabe N, Nakamura M, Tanaka M, Takarada M, Sugawara I, Murakami S: Significance of immunological detection of human telomerase reverse transcriptase: re-evaluation of expression and localization of human telomerase reverse transcriptase. Am J Pathol. 2003, 163 (3): 859-867.View ArticleGoogle Scholar
- Takahashi K, Tanabe K, Ohnuki M, Narita M, Ichisaka T, Tomoda K, Yamanaka S: Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007, 131 (5): 861-872.View ArticleGoogle Scholar
- Park JH, Daheron L, Kantarci S, Lee BS, Teixeira JM: Human endometrial cells express elevated levels of pluripotent factors and are more amenable to reprogramming into induced pluripotent stem cells. Endocrinology. 2011, 152 (3): 1080-1089.View ArticleGoogle Scholar
- Dominici M, Le Blanc K, Mueller I, Slaper-Cortenbach I, Marini F, Krause D, Deans R, Keating A, Prockop D, Horwitz E: Minimal criteria for defining multipotent mesenchymal stromal cells. The International Society for Cellular Therapy position statement. Cytotherapy. 2006, 8 (4): 315-317.View ArticleGoogle Scholar
- Dimitrov R, Timeva T, Kyurkchiev D, Stamenova M, Shterev A, Kostova P, Zlatkov V, Kehayov I, Kyurkchiev S: Characterization of clonogenic stromal cells isolated from human endometrium. Reproduction. 2008, 135 (4): 551-558.View ArticleGoogle Scholar
- Schwab K, Gargett C: Co-expression of two perivascular cell markers isolates mesenchymal stem-like cells from human endometrium. Hum Reprod. 2007, 22 (11): 2903-2911.View ArticleGoogle Scholar
- Lynch L, Golden-Mason L, Eogan M, O’Herlihy C, O’Farrelly C: Cells with haematopoietic stem cell phenotype in adult human endometrium: relevance to infertility?. Human Reprod. 2007, 22 (4): 919-926.View ArticleGoogle Scholar
- Wang J, Rao S, Chu J, Shen X, Levasseur DN, Theunissen TW, Orkin SH: A protein interaction network for pluripotency of embryonic stem cells. Nature. 2006, 444 (7117): 364-368.View ArticleGoogle Scholar
- Ishikawa M, Nakayama K, Yeasmin S, Katagiri A, Iida K, Nakayama N, Miyazaki K: NAC1, a potential stem cell pluripotency factor expression in normal endometrium, endometrial hyperplasia and endometrial carcinoma. Int J Oncol. 2010, 36 (5): 1097-1103.Google Scholar
- Sobiesiak M, Sivasubramaniyan K, Hermann C, Tan C, Örgel M, Treml S, Cerabona F, de Zwart P, Ochs U, Müller CA: The mesenchymal stem cell antigen MSCA-1 is identical to tissue non-specific alkaline phosphatase. Stem Cells Dev. 2009, 19 (5): 669-677.View ArticleGoogle Scholar
- Krusche CA, Kroll T, Beier HM, Classen-Linke I: Expression of leucine-rich repeat-containing G-protein-coupled receptors in the human cyclic endometrium. Fertil Steril. 2007, 87 (6): 1428-1437.View ArticleGoogle Scholar
- Gil Sanchis C, Cervelló I, Mas A, Faus A, Pellicer A, Simón C: Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) as a putative human endometrial stem cell marker. Mol Hum Reprod. 2013, 19 (7): 407-414.View ArticleGoogle Scholar
- Masuda H, Anwar SS, Bühring H-J, Rao JR, Gargett CE: A novel marker of human endometrial mesenchymal stem-like cells. Cell Transplant. 2012, 21 (10): 2201-2214.View ArticleGoogle Scholar
- Awong G, Herer E, Surh CD, Dick JE, La Motte-Mohs RN, Zúñiga-Pflücker JC: Characterization in vitro and engraftment potential in vivo of human progenitor T cells generated from hematopoietic stem cells. Blood. 2009, 114 (5): 972-982.View ArticleGoogle Scholar
- Peron J, Jazedje T, Brandao W, Perin P, Maluf M, Evangelista L, Halpern S, Nisenbaum M, Czeresnia C, Zatz M: Human endometrial-derived mesenchymal stem cells suppress inflammation in the central nervous system of EAE mice. Stem Cell Rev. 2012, 8 (3): 940-952.View ArticleGoogle Scholar
- Tse WT, Pendleton JD, Beyer WM, Egalka MC, Guinan EC: Suppression of allogeneic T-cell proliferation by human marrow stromal cells: implications in transplantation. Transplantation. 2003, 75 (3): 389-397.View ArticleGoogle Scholar
- Kiss J, Urban V, Dudics V, Vas V: Uher F: [Mesenchymal stem cells and the immune system–immunosuppression without drugs?]. Orv Hetil. 2008, 149 (8): 339-346.View ArticleGoogle Scholar
- Pisati F, Belicchi M, Acerbi F, Marchesi C, Giussani C, Gavina M, Javerzat S, Hagedorn M, Carrabba G, Lucini V: Effect of human skin-derived stem cells on vessel architecture, tumor growth, and tumor invasion in brain tumor animal models. Cancer Res. 2007, 67 (7): 3054-3063.View ArticleGoogle Scholar
- Ehtesham M, Kabos P, Kabosova A, Neuman T, Black KL, John SY: The use of interleukin 12-secreting neural stem cells for the treatment of intracranial glioma. Cancer Res. 2002, 62 (20): 5657-5663.Google Scholar
- Ehtesham M, Kabos P, Gutierrez MA, Chung NH, Griffith TS, Black KL, John SY: Induction of glioblastoma apoptosis using neural stem cell-mediated delivery of tumor necrosis factor-related apoptosis-inducing ligand. Cancer Res. 2002, 62 (24): 7170-7174.Google Scholar
- Nakamizo A, Marini F, Amano T, Khan A, Studeny M, Gumin J, Chen J, Hentschel S, Vecil G, Dembinski J: Human bone marrow–derived mesenchymal stem cells in the treatment of gliomas. Cancer Res. 2005, 65 (8): 3307-3318.Google Scholar
- Han X, Meng X, Yin Z, Rogers A, Zhong J, Rillema P, Jackson JA, Ichim TE, Minev B, Carrier E: Inhibition of intracranial glioma growth by endometrial regenerative cells. Cell Cycle. 2009, 8 (4): 606-610.View ArticleGoogle Scholar
- Qiao L, Xu ZL, Zhao TJ, Ye LH, Zhang XD: Dkk-1 secreted by mesenchymal stem cells inhibits growth of breast cancer cells < i > via</i > depression of Wnt signalling. Cancer Lett. 2008, 269 (1): 67-77.View ArticleGoogle Scholar
- Qiao L, Zhao TJ, Wang FZ, Shan CL, Ye LH, Zhang XD: NF-kappaB downregulation may be involved the depression of tumor cell proliferation mediated by human mesenchymal stem cells. Acta Pharmacol Sin. 2008, 29 (3): 333-340.View ArticleGoogle Scholar
- Pittenger MF, Mackay AM, Beck SC, Jaiswal RK, Douglas R, Mosca JD, Moorman MA, Simonetti DW, Craig S, Marshak DR: Multilineage potential of adult human mesenchymal stem cells. Science. 1999, 284 (5411): 143-147.View ArticleGoogle Scholar
- Colter DC, Class R, DiGirolamo CM, Prockop DJ: Rapid expansion of recycling stem cells in cultures of plastic-adherent cells from human bone marrow. Proc Natl Acad Sci U S A. 2000, 97 (7): 3213-3218.View ArticleGoogle Scholar
- Zuk PA, Zhu M, Mizuno H, Huang J, Futrell JW, Katz AJ, Benhaim P, Lorenz HP, Hedrick MH: Multilineage cells from human adipose tissue: implications for cell-based therapies. Tissue Eng. 2001, 7 (2): 211-228.View ArticleGoogle Scholar
- Cho NH, Park YK, Kim YT, Yang H, Kim SK: Lifetime expression of stem cell markers in the uterine endometrium. Fertil and Steril. 2004, 81 (2): 403-407.View ArticleGoogle Scholar
- Gargett CE, Chan RW, Schwab KE: Endometrial stem cells. Curr Opin Obstet Gynecol. 2007, 19 (4): 377-383.View ArticleGoogle Scholar
- Kao AP, Wang KH, Chang CC, Lee JN, Long CY, Chen HS, Tsai CF, Hsieh TH, Tsai EM: Comparative study of human eutopic and ectopic endometrial mesenchymal stem cells and the development of an in vivo endometriotic invasion model. Fertil Steril. 2011, 95 (4): 1308-1315. e1301View ArticleGoogle Scholar
- Hong I-S, Kim S-H, Koong MK, Jun JH, Kim S-H, Lee Y-S, Kang K-S: Roles of p38 and c-jun in the differentiation, proliferation and immortalization of normal human endometrial cells. Hum Reprod. 2004, 19 (10): 2192-2199.View ArticleGoogle Scholar
- Giudice A, Trounson A: Genetic modification of human embryonic stem cells for derivation of target cells. Cell Stem Cell. 2008, 2 (5): 422-433.View ArticleGoogle Scholar
- Wang H, Jin P, Sabatino M, Ren J, Civini S, Bogin V, Ichim TE, Stroncek DF: Comparison of endometrial regenerative cells and bone marrow stromal cells. J Transl Med. 2012, 10 (1): 207-View ArticleGoogle Scholar
- Kazemnejad S, Akhondi M-M, Soleimani M, Zarnani AH, Khanmohammadi M, Darzi S, Alimoghadam K: Characterization and chondrogenic differentiation of menstrual blood-derived stem cells on a nanofibrous scaffold. Int J Artif Organs. 2012, 35 (1): 55-66.View ArticleGoogle Scholar
- Gluckman E, Broxmeyer H, Auerbach AD, Friedman HS, Douglas GW, Devergie A, Esperou H, Thierry D, Socie G, Lehn P: Hematopoietic reconstitution in a patient with Fanconi’s anemia by means of umbilical-cord blood from an HLA-identical sibling. N Engl J Med. 1989, 321 (17): 1174-1178.View ArticleGoogle Scholar
- Zhao LR, Duan WM, Reyes M, Keene CD, Verfaillie CM, Low WC: Human bone marrow stem cells exhibit neural phenotypes and ameliorate neurological deficits after grafting into the ischemic brain of rats. Exp Neurol. 2002, 174 (1): 11-20.View ArticleGoogle Scholar
- Meletis K, Frisen J: Have the bloody cells gone to our heads?. J Cell Biol. 2001, 155 (5): 699-702.View ArticleGoogle Scholar
- Hakuno D, Fukuda K, Makino S, Konishi F, Tomita Y, Manabe T, Suzuki Y, Umezawa A, Ogawa S: Bone marrow–derived regenerated cardiomyocytes (CMG cells) express functional adrenergic and muscarinic receptors. Circulation. 2002, 105 (3): 380-386.View ArticleGoogle Scholar
- Wakitani S, Saito T, Caplan AI: Myogenic cells derived from rat bone marrow mesenchymal stem cells exposed to 5‒azacytidine. Muscle Nerve. 1995, 18 (12): 1417-1426.View ArticleGoogle Scholar
- Prockop DJ: Marrow stromal cells as stem cells for nonhematopoietic tissues. Science. 1997, 276 (5309): 71-74.View ArticleGoogle Scholar
- Theise ND, Badve S, Saxena R, Henegariu O, Sell S, Crawford JM, Krause DS: Derivation of hepatocytes from bone marrow cells in mice after radiation‒induced myeloablation. Hepatology. 2000, 31 (1): 235-240.View ArticleGoogle Scholar
- Theise ND, Nimmakayalu M, Gardner R, Illei PB, Morgan G, Teperman L, Henegariu O, Krause DS: Liver from bone marrow in humans. Hepatol. 2000, 32 (1): 11-16.View ArticleGoogle Scholar
- Wexler SA, Donaldson C, Denning Kendall P, Rice C, Bradley B, Hows JM: Adult bone marrow is a rich source of human mesenchymal ‘stem’cells but umbilical cord and mobilized adult blood are not. Br J Haematol. 2003, 121 (2): 368-374.View ArticleGoogle Scholar
- Murphy MP, Wang H, Patel AN, Kambhampati S, Angle N, Chan K, Marleau AM, Pyszniak A, Carrier E, Ichim TE, Riordan NH: Allogeneic endometrial regenerative cells: an “Off the shelf solution” for critical limb ischemia?. J Transl Med. 2008, 6: 45-View ArticleGoogle Scholar
- Hida N, Nishiyama N, Miyoshi S, Kira S, Segawa K, Uyama T, Mori T, Miyado K, Ikegami Y, Cui C: Novel Cardiac Precursor‒Like Cells from Human Menstrual Blood‒Derived Mesenchymal Cells. Stem Cells. 2008, 26 (7): 1695-1704.View ArticleGoogle Scholar
- Ulrich D, Edwards SL, White JF, Supit T, Ramshaw JA, Lo C, Rosamilia A, Werkmeister JA, Gargett CE: A preclinical evaluation of alternative synthetic biomaterials for fascial defect repair using a rat abdominal hernia model. PLoS One. 2012, 7 (11): e50044-View ArticleGoogle Scholar
- Edwards SL, Werkmeister JA, Rosamilia A, Ramshaw JA, White JF, Gargett CE: Characterisation of clinical and newly fabricated meshes for pelvic organ prolapse repair. J Mech Behav Biomed Mater. 2013, 23: 53-61.View ArticleGoogle Scholar
- Shoae-Hassani A, Sharif S, Seifalian AM, Mortazavi-Tabatabaei SA, Rezaie S, Verdi J: Endometrial stem cell differentiation into smooth muscle cell: a novel approach for bladder tissue engineering in women. BJU Int. 2013, 112 (6): 854-863.View ArticleGoogle Scholar
- Borlongan CV, Kaneko Y, Maki M, Yu S-J, Ali M, Allickson JG, Sanberg CD, Kuzmin-Nichols N, Sanberg PR: Menstrual blood cells display stem cell-like phenotypic markers and exert neuroprotection following transplantation in experimental stroke. Stem Cells Dev. 2010, 19 (4): 439-452.View ArticleGoogle Scholar
- Zhong Z, Patel AN, Ichim TE, Riordan NH, Wang H, Min W-P, Woods EJ, Reid M, Mansilla E, Marin GH: Feasibility investigation of allogeneic endometrial regenerative cells. J Transl Med. 2009, 7 (15): 29-37.Google Scholar
- Ichim TE, Alexandrescu DT, Solano F, Lara F, Campion RDN, Paris E, Woods EJ, Murphy MP, Dasanu CA, Patel AN: Mesenchymal stem cells as anti-inflammatories: implications for treatment of Duchenne muscular dystrophy. Cell Immunol. 2010, 260 (2): 75-82.View ArticleGoogle Scholar
- Ichim TE, Solano F, Lara F, Rodriguez JP, Cristea O, Minev B, Ramos F, Woods EJ, Murphy MP, Alexandrescu DT, Patel AN, Riordan NH: Combination stem cell therapy for heart failure. Int Arch Med. 2010, 3 (1): 5-View ArticleGoogle Scholar
- Tosh D, Slack JM: How cells change their phenotype. Nat Rev Mol Cell Biol. 2002, 3 (3): 187-194.View ArticleGoogle Scholar
- Du H, Taylor HS: Contribution of Bone Marrow‒Derived Stem Cells to Endometrium and Endometriosis. Stem Cells. 2007, 25 (8): 2082-2086.View ArticleGoogle Scholar
- Du H, Taylor HS: Reviews: stem cells and female reproduction. Reprod Sci. 2009, 16 (2): 126-139.View ArticleGoogle Scholar
- Polyak K, Weinberg RA: Transitions between epithelial and mesenchymal states: acquisition of malignant and stem cell traits. Nature Rev Cancer. 2009, 9 (4): 265-273.View ArticleGoogle Scholar
- Starzinski-Powitz A, Zeitvogel A, Schreiner A, Baumann R: In search of pathogenic mechanisms in endometriosis: the challenge for molecular cell biology. Curr Mol Med. 2001, 1 (6): 655-664.View ArticleGoogle Scholar
- Bockeria L, Bogin V, Bockeria O, Le T, Alekyan B, Woods EJ, Brown AA, Ichim TE, Patel AN: Endometrial regenerative cells for treatment of heart failure: a new stem cell enters the clinic. J Transl Med. 2013, 11: 56-View ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.