Journal of Stem Cells最新文献

Blastocyst activation, a process for the blastocyst to achieve implantation competency is equally important as attainment of uterine receptivity for the success of embryo implantation. While a wide range of regulatory molecules have been identified as essential players in conferring uterine receptivity in both laboratory animal models and humans, it remains largely unknown how blastocysts achieve implantation competency. This chapter will highlight our current knowledge about the mechanisms governing the process of blastocyst activation. A better understanding of this periimplantation event is hoped to alleviate female infertility and help to develop novel contraceptives and new strategies for accessing embryo quality in clinical practice.

Recent advances in the field of regenerative medicines manifested the unique properties of stem cells including the ability of self-renewal and differentiation to make them available for their replacement in tissue injury. Mesenchymal stem cells (MSCs) are important tools in treating immune disorders and in tissue repair due to their multipotency, immunosuppressive properties, and production of cytokines or growth factors. MSC-mediated therapy is a fast-growing field that has proven safe and effective in the treatment of various degenerative diseases and tissue injuries. Generation of induced pluripotent stem (iPS) cells holds a great promise for regenerative medicine and other aspects of clinical applications. The mechanisms governing multipotency in MSCs are not well understood. This review mainly throws light on the biology of MSCs, including their efficiency in treating several diseases and also the progress of the use of iPSC-derived MSC widely in the clinic.

The aim of this study was to investigate the expression of Nodal (NODAL Homolog (mouse), Nanog (Nanog Homeobox), DAZL (Deleted in Azoospermia Like) and SMAD (SMAD Family member) genes and their potential role in the regulation of self-renewal in human amniotic fluid-derived stem cells. In this experimental study human amniotic fluid-derived stem cells were analyzed for messenger RNA expression of Nodal. Immunocytochemistry also was performed to determine Nanog and DAZL. SMAD genes expression analysis was performed using cDNA Microarray analysis. Nodal mRNA was positively expressed in all samples of amniotic fluid derived stem cells. Amniotic fluid-derived stem cells showed strong immunoreactivity for molecular markers of undifferentiated human embryonic stem cells including Nanog and DAZL. Among the 8 SMAD genes expressions analyzed SMAD1, SMAD2, SMAD3, SMAD4 and SMAD7 showed positive expression. In conclusion amniotic fluid-derived stem cells seem to express Nodal, Nanog and DAZL and it speculated that the regulation of self-renewal in AFSc could be similar as in human embryonic stem cells.

Dental pulp are known to contains stem cells or dentinogenic progenitors that are responsible for dentin repair. Dental pulp Stem cells from Human Exfoliated Deciduous teeth (SHED) represent a population of postnatal stem cells capable of extensive proliferation and multipotential or multilineage differentiations. This potential for tissue regeneration has become the current basis for dental pulp stem cell banking. Here, we have attempted to develop a protocol for harvesting stem cells from patients with High Caries tooth, which are most often electively discarded. We have characterized the stem cells with mesenchymal stem cell markers and have compared their potential to grow in culture, doubling times, and differentiate into different lineages, with normal bone marrow mesenchymal stem cells (MSCs). We observed that the MSCs from dental pulp grew faster, with lower doubling time, and had equal efficiency in differentiating to various lineages, when subjected to standard directed differentiation protocols. This paper establishes that discarded High Carries Tooth can be a good source for regenerative medicine and also could be a potential source for MSCs and dental pulp MSC banking.

Regeneration of bony defects caused by periodontal disease continues to be a challenge for clinicians. Application of stem cells from different tissue sources and scaffolds for regeneration have been reported in animal models but clinical studies with long term follow-ups are limited. Herein we report the three years follow-up of the application of autologous bone marrow mononuclear cells (BMMNCs) embedded in a thermo-reversible gelation polymer (TGP) for periodontal regeneration. A 23-year female patient with advanced periodontitis (class IV gingival recession, probing pocket depth (PPD) of 5 mm and 6 mm in relation to mandibular lateral and central incisors respectively, and clinical attachment level (CAL) of 13 mm) correlated with radiographic evidence of severe horizontal bone loss extending up to the apex of mandibular incisors was selected for the treatment. After debridement, the defect was implanted with BMMNCs impregnated in TGP. Then the clinical parameters and radiographic evaluation were made at periodic intervals of 6, 12, 24 and 36 months. At six months, significant improvement with the clinical parameters (PPD had reduced to 2 mm, clinical attachment level had improved by 6 mm) was observed. At 36 months, the radiograph revealed bone regeneration with improvement in vertical and horizontal bone height. Transplantation of BMMNCs in a novel TGP is safe and results in a relatively significant and stable clinical outcome in horizontal alveolar bony defects.

Vertebrate extremities develop from limb buds, which emerge as paired protrusions in the lateral plate mesoderm. Forelimb buds are located anteriorly and hindlimb buds are positioned posteriorly. The morphogenesis of the limb requires coordinated actions of several organizing centers, among which the apical ectodermal ridge (AER) plays crucial roles in limb development. Recent studies have shown how the life of the AER (induction, maturation, maintenance and regression) is regulated. This regulation includes cell type- and process- specific roles of previously identified molecules, such as fibroblast growth factors (FGFs), Wnts and bone morphogenetic proteins (BMPs). The studies have also revealed several new players, such as Arid3b, R-Spondin 2 and Flrt3. These advances have enhanced the understanding of how the AER is regulated from its emergence to its regression. Progress has also been made in understanding AER function in relation to processes critical for limb development: proximal-distal patterning, anterior-posterior patterning, chondrogenesis and apoptosis. By focusing on two major model systems, chick and mouse embryos, we will review recent advances in combination with relevant previous studies in the development and function of the AER.

Evidence suggests that there is a link between high-risk human papillomaviruses (HPVs) and cervical cancer. Studies indicate that persistence of high risk HPVs may determine progression to more severe stages of cervical disease, while the majority of HPV infections are transient and do not seem to be important in cervical carcinogenesis. Earlier studies in different cancers have shown that tumor initiating cells TICs are responsible for tumor formation and progression and interestingly, they are endowed with stem/ progenitor cell properties. In particular, TICs share with stem cells the key feature of self-renewal. The most efficacious therapeutic intervention for cervical cancer is probably vaccination. This review gives an overview on cervical cancer and its potential therapeutic interventions.

Chemotherapy drugs and radiotherapy are highly toxic and both damage adjacent healthy cells. Side effects may be acute (occurring within few weeks after therapy), intermediate or late (occurring months or years after the therapy). Some important side effects of chemotherapy are: nausea, vomiting, diarrhea, mucositis, alopecia, constipation etc; whereas radiation therapy though administered locally, can produce systemic side effects such as fatigue, anorexia, nausea, vomiting, alteration in the taste, sleep disturbance, headache, anemia, dry skin, constipation etc. Late complications of these therapies also include pharyngitis, esophagitis, laryngitis, persistent dysphagia, fatigue, hepatotoxicity, infertility and cognitive deficits. These arrays of side effects have a devastating effect on the quality of life of cancer survivors. Due to the inadequacy of most of the radio-protectors and chemo-protectors in controlling the side effects of conventional cancer therapy the complementary and alternative medicines have attracted the view of researchers and medical practitioners more recently. This review aims at providing a comprehensive management protocol of above mentioned chemo-radiotherapy induced side effects based on Ayurveda, which is an ancient system of traditional medicine practiced in Indian peninsula since 5000 BC. When the major side effects of chemo-radiotherapy are looked through an ayurvedic perspective, it appears that they are the manifestations of aggravated pitta dosha, especially under the group of disorders called Raktapitta (haemorrhage) or Raktadushti (vascular inflammation). Based on comprehensive review of ancient vedic literature and modern scientific evidences, ayurveda based interventions are put forth. This manuscript should help clinicians and people suffering from cancer to combat serious chemo-radiotherapy related side effects through simple but effective home-based ayurveda remedies. The remedies described are commonly available and safe. These simple ayurveda based solutions may act as an important adjuvant to chemo-radiotherapy and enhance the quality of life of cancer patients.

Stem cells based tissue engineering is a promising approach for the regenerative treatment of various tissue disorders. Adipose tissue is an abundant source of cells which are competent of multipotential differentiation, called adipose-derived stem cells (ADSCs). The present study was contemplated with the objective of assessing the osteogenic differentiation potential of the canine ADSCs in vitro. The canine ADSCs were isolated from adipose tissue around falciform ligament and abdominal subcutaneous fat. Yield of viable ADSCs from both the tissue sources was found to be nearly equivalent. Tissue subjected to trypsinization yielded more viable, but lesser number of cells as compared to collagenase treatment. The stemness of ADSCs was affirmed by reverse transcriptase PCR which exhibited the expression of stem cell specific genes, OCT4 and NANOG.The monolayer of ADSCs was subjected to differentiation into adipogenic and osteogenic lineages. Assessment of the osteogenic potential of ADSCs in vitro opens a new therapeutic horizon for development of in vivo strategies employing autologous stem cell based tissue regeneration in orthopedics.

Circulating bone marrow-derived endothelial progenitor cells (EPCs) seem to play a crucial role in both vasculogenesis and vascular homeostasis. Chronic kidney disease is a state of endothelial dysfunction, accelerated progression of atherosclerosis and high cardiovascular risk. As a consequence, cardiovascular disorders are the main cause of death in end-stage renal disease (ESRD). It has been shown that patients with advanced renal failure have decreased number of bone marrow-derived endothelial progenitor cells and impaired EPCs function. Moreover, in kidney transplant patients, renal graft function significantly correlated with EPC number. The reduced number of EPCs in patients with ESRD has been ascribed to the uremia. Therefore, therapies that improve the uremic status in dialysis patients such as nocturnal hemodialysis are associated with restoration of impaired EPCs number and migratory function. In fact, some of the common treatments for patients with chronic kidney disease such as erythropoietin, statins and angiotensin II receptor antagonist increase the number of EPCs. Nowadays, there is growing evidence indicating that, under pathophysiological conditions, stem cells (SCs) derived from bone marrow are able to migrate in the injured kidney, and they seem to play a role in glomerular and tubular regeneration. After acute tubular renal injury, surviving tubular epithelial cells and putative renal stem cells proliferate and differentiate into tubular epithelial cells to promote structural and functional repair. Moreover, bone marrow stem cells, including hematopoietic stem cells and mesenchymal stem cells can also participate in the repair process by proliferation and differentiation into renal lineages. For instance, mesenchymal SCs have been shown to decrease inflammation and enhance renal regeneration. The administration of ex vivo expanded bone marrow-derived mesenchymal SCs have been proved to be beneficial in various experimental models of acute renal failure. The mechanisms underlining this beneficial effect are still a matter of debate. Thus, therapeutic strategies aimed at correcting the regenerative potential of stem cells based on the administration of ex vivo expanded SCs or stimulating expansion and differentiation of local progenitor/SC populations are another exciting area of future research.