Primordial germ cells (PGCs) are destined to form gametes in vivo, and they can be reprogrammed into pluripotent embryonic germ (EG) cells in vitro. Buffalo PGC have been reported to be reprogrammed into EG-like cells, but the identities of the major signaling pathways and culture media involved in this derivation remain unclear. Here, the effects of basic fibroblast growth factor (bFGF) and downstream signaling pathways on the reprogramming of buffalo PGCs into EG-like cells were investigated. Results showed bFGF to be critical to buffalo PGCs to dedifferentiate into EG-like cells (20 ng/mL is optimal) with many characteristics of pluripotent stem cells, including alkaline phosphatase (AP) activity, expression of pluripotency marker genes such as OCT4, NANOG, SOX2, SSEA-1, CDH1, and TRA-1-81, and the capacity to differentiate into all three embryonic germ layers. After chemically inhibiting pathways or components downstream of bFGF, data showed that inhibition of the PI3K/AKT pathway led to significantly lower EG cell derivation, while inhibition of P53 activity resulted in an efficiency of EG cell derivation comparable to that in the presence of bFGF. These results suggest that the role of bFGF in PGC-derived EG-like cell generation is mainly due to the activation of the PI3K/AKT/P53 pathway, in particular, the inhibition of P53 function.

The application of neurotrophic factors as a therapy to improve morphological and behavioral outcomes after experimental spinal cord injury (SCI) has been the focus of many studies. These studies vary markedly in the type of neurotrophic factor that is delivered, the mode of administration, and the location, timing, and duration of the treatment. Generally, the majority of studies have had significant success if neurotrophic factors are applied in or close to the lesion site during the acute or the subacute phase after SCI. Comparatively fewer studies have administered neurotrophic factors in order to directly target the somata of injured neurons. The mode of delivery varies between acute injection of recombinant proteins, subacute or chronic delivery using a variety of strategies including osmotic minipumps, cell-mediated delivery, delivery using polymer release vehicles or supporting bridges of some sort, or the use of gene therapy to modify neurons, glial cells, or precursor/stem cells. In this brief review, we summarize the state of play of many of the therapies using these factors, most of which have been undertaken in rodent models of SCI.

Oral squamous cell carcinoma (OSCC) is the most prevalent neoplasia of oral cavity worldwide and prognosis remains unchanged in decades. Recently, different authors reported that head and neck squamous cell carcinomas have a subpopulation of tumor initiating cells that apparently correspond to cancer stem cells (CSC) and are also responsible for tumor growth and metastasis. The purpose of the present study was to investigate the microscopic and phenotypic characteristics of OSCC tumors induced after orthotopic xenoimplantation of SCC9WT cell line and CSC-enriched subpopulation isolated from SCC9 cell line based on high expression of the putative CSC marker CD44. Different numbers of FACS-sorted SCC9 CD44high and CD44low cells as well as SCC9WT (wild type) were transplanted into the tongue of BALB/C nude (NOD/SCID) mice to evaluate their tumorigenic potential. Sixty days post-induction, tumors were morphologically characterized and immunostained for CSC markers (CD44, Nanog and Bmi-1), epithelial-mesenchymal transition (Snail, Slug) and epithelial differentiating cell markers (cytokeratins 4, 13, 15, 17 and 19), as well as E-cadherin and β-catenin. The data presented here shows that SCC9 CD44high cells have higher ability to form tumors than SCC9 CD44low cells, even when significantly lower numbers of SCC9 CD44high cells were transplanted. Immunoassessment of tumors derived from SCC9 CD44high cells revealed high expression of cytokeratin CK19, β-catenin, E-cadherin and CD44, and negative or low expression of CK17, CK4, CK15, CK13, Nanog, Bmi-1, Snail and Slug. While tumors derived from SCC9WT showed high expression of CK17, CK19, CD44, Nanog, Bmi-1, Snail and Slug, and negative or low expression of CK4, CK15, CK13, β-catenin and E-cadherin. Thus, SCC9 CD44high cells were highly tumorigenic, capable of originating heterogeneous tumors and these tumors have a immunohistochemical profile different from those formed by the wild type cell line.

Multiple myeloma (MM) is the second most common hematologic malignancy. The diagnosis of MM requires ⩾10% clonal plasma cells in the bone marrow or biopsy-proven plasmacytoma, plus evidence of end-organ damage (hypercalcemia, renal failure, anemia, and lytic bone lesions). The definition of MM has recently been expanded to include a ⩾60% clonal plasma cell burden in the bone marrow, serum involved/uninvolved light chain ratio of ⩾100, or more than one focal lesion on magnetic resonance imaging ⩾5 mm in the absence of end-organ damage. MM is an incurable malignancy previously associated with poor survival rates. However, over the past two decades, the introduction of novel treatment options has resulted in a dramatic improvement in response rates and overall survival (OS). The combination of a proteasome inhibitor and an immunomodulator (IMiD) is the preferred induction treatment for newly diagnosed transplant-eligible MM patients. After induction, high-dose therapy with autologous stem cell transplant (ASCT) is still the standard of care for these patients. In patients who are transplant ineligible, dose adjusted IMiDs or proteasome inhibitor-based combinations are the preferred treatment option. With the recent approval of novel drugs like carfilzomib, ixazomib, pomalidomide, panobinostat, and monoclonal antibodies (elotuzumab and daratumumab), as well as improved understanding of risk stratification, management of comorbidities and treatment side effects, clinicians can optimize anti-MM therapy, particularly in relapse/refractory MM patients. In this review, we outline the current therapeutic approach to the management of MM.

Assessing the quality of life of adult patients with hematological cancer in the 100 days after transplantation of hematopoietic stem cells and verifying whether the variable graft-versus-host disease (GvHD) is predictive of worse results.

Relapse in cancer patients following an apparent cure and a prolonged latency period, known as tumor dormancy, remains an unrelenting clinical crisis. Here, I expand on our recent findings that potentially link cancer cell cannibalism of bone marrow-derived mesenchymal stem/stromal cells (BM-MSCs) to the senescence-associated secretory phenotype (SASP) and tumor dormancy.

Cancer cells with stem-like properties are believed to contribute to treatment resistance, dissemination, and recurrence. SOX9 controls stem cell plasticity and its deregulation may provide a basis for tumor progression. Here, we summarize our findings of targeted SOX9 destruction by SCFFBW7 (Skp1/Cul1/F-box) in medulloblastoma and its potential for therapeutic intervention.

The phenomenon of adult neurogenesis is now an accepted occurrence in mammals and also in humans. At least two discrete places house stem cells for generation of neurons in adult brain. These are olfactory system and the hippocampus. In animals, newly generated neurons have been directly or indirectly demonstrated to generate a significant amount of new neurons to have a functional role. However, the data in humans on the extent of this process is still scanty and such as difficult to comprehend its functional role in humans. This paper explores the available data on as extent of adult hippocampal neurogenesis in humans and makes comparison to animal data.

The objective of this study was to four-dimensional (4D) print novel biomimetic gradient tissue scaffolds with highly biocompatible naturally derived smart polymers. The term "4D printing" refers to the inherent smart shape transformation of fabricated constructs when implanted minimally invasively for seamless and dynamic integration. For this purpose, a series of novel shape memory polymers with excellent biocompatibility and tunable shape changing effects were synthesized and cured in the presence of three-dimensional printed sacrificial molds, which were subsequently dissolved to create controllable and graded porosity within the scaffold. Surface morphology, thermal, mechanical, and biocompatible properties as well as shape memory effects of the synthesized smart polymers and resultant porous scaffolds were characterized. Fourier transform infrared spectroscopy and gel content analysis confirmed the formation of chemical crosslinking by reacting polycaprolactone triol and castor oil with multi-isocyanate groups. Differential scanning calorimetry revealed an adjustable glass transition temperature in a range from -8°C to 35°C. Uniaxial compression testing indicated that the obtained polymers, possessing a highly crosslinked interpenetrating polymeric networks, have similar compressive modulus to polycaprolactone. Shape memory tests revealed that the smart polymers display finely tunable recovery speed and exhibit greater than 92% shape fixing at -18°C or 0°C and full shape recovery at physiological temperature. Scanning electron microscopy analysis of fabricated scaffolds revealed a graded microporous structure, which mimics the nonuniform distribution of porosity found within natural tissues. With polycaprolactone serving as a control, human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and differentiation greatly increased on our novel smart polymers. The current work will significantly advance the future design and development of novel and functional biomedical scaffolds with advanced 4D printing technology and highly biocompatible smart biomaterials.

This study was aimed to determine the expression and localization of nerve growth factor (NGF) in the gastric mucosa. Transmural gastric specimens were obtained from euthanized rats.

Cytokines play an important role in the immune response. The calcineurin inhibitors (cyclosporine CsA, tacrolimus TAC) widely used after renal transplantation to prevent allograft rejection are immunosuppressive drugs suppressing the production of cytokines. These drugs are characterized by interindividual variability and require monitoring their blood concentrations to predict their optimal dosage. Therefore, the aim of the study was to determine the correlation between therapeutic effects of immunosuppressants and the tumor necrosis factor-α (TNF-α)-308G>A polymorphism in renal transplant patients. A total of 412 patients receiving TAC and CsA were included in the study. Genotype frequencies were determined using the real-time PCR method. Patients with the GG genotype received higher doses of TAC as compared to carriers of the GA genotype (5.24 mg versus 3.35 mg) and had lower mean drug concentration in blood (5.86 ng/ml versus 6.92 ng/ml). Similar results were also obtained for CsA (GG: 185.33 mg versus GA: 153.30 mg, P < 0.05). The comparison of the TNF-α-308G>A polymorphism with the biochemical parameters did not reveal a potential risk for transplant rejection. These results indicate that the TNF-α-308G>A polymorphism may influence the dosage of immunosuppressive drugs in patients after transplantation as far as individualization of drug therapy is concerned.

Advances in the studies with adult mesenchymal stem cells (MSCs) have turned tissue regenerative therapy into a promising tool in many areas of medicine. In orthopedics, one of the main challenges has been the regeneration of cartilage tissue, mainly in diarthroses. In the induction of the MSCs, in addition to cytodifferentiation, the microenvironmental context of the tissue to be regenerated and an appropriate spatial arrangement are extremely important factors. Furthermore, it is known that MSC differentiation is fundamentally determined by mechanisms such as cell proliferation (mitosis), biochemical-molecular interactions, movement, cell adhesion, and apoptosis. Although the use of MSCs for cartilage regeneration remains at a research level, there are important questions to be resolved in order to make this therapy efficient and safe. It is known, for instance, that the expansion of chondrocytes in cultivation, needed to increase the number of cells, could end up producing fibrocartilage instead of hyaline cartilage. However, the latest results are promising. In 2014, the first stage I/II clinical trial to evaluate the efficacy and safety of the intra-articular injection of MSCs in femorotibial cartilage regeneration was published, indicating a decrease in injured areas. One issue to be explored is how many modifications in the articulate inflammatory environment could induce differentiation of MSCs already allocated in that region. Such issue arose from studies that suggested that the suppression of the inflammation may increase the efficiency of tissue regeneration. Considering the complexity of the events related to the chondrogenesis and cartilage repair, it can be concluded that the road ahead is still long, and that further studies are needed.

Cell membrane chromatography (CMC) is an ideal method for screening potential active components acting on target cell membranes from a complex system, such as herbal medicines. But due to the decay and falling-off of membranes, the CMC column suffers from short life span and low reproducibility. This has greatly limited the application of this model, especially when the cell materials are hard to obtain. To solve this problem, a novel type of (3-aminopropyl)triethoxysilane (APTES)-decorated silica gel was employed. The silica gel was decorated with aldehydes with the help of APTES, which react with the amino groups on cell membranes to form a covalent bond. In this way, cell membranes were immobilized on the surface of silica gel, so it is not easy for membranes to fall off. According to our investigation, the column life of the APTES-decorated group was prolonged to more than 12 days, while the control group showed a sharp decline in column efficiency in the first 3 days. To verify this model, a novel APTES-decorated HepG2 cancer stem cell membrane chromatography (CSCMC) was established and applied in a comprehensive two-dimensional chromatographic system to screen potential active components in Salvia miltiorrhiza. As a result, tanshinone IIA, cryptotanshinone, and dihydrotanshinone I were retained on this model and proved to be effective on HepG2 cancer stem cells by the following cell proliferation and apoptosis assay, with IC50 of 10.30 μM, 17.85 μM, and 2.53 μM, respectively. This improvement of CMC can significantly prolong its column life span and broaden the range of its application, which is very suitable for making invaluable or hard-to-obtain cell materials, such as stem cells, for specific drug screening.

Cellular cardiomyoplasty has rapidly risen to prominence in the clinic following a myocardial infarction; however, low engraftment of transplanted cells limits the therapeutic benefit to these procedures. Recently, lineage-specific stem cells differentiated into cardiomyocytes have gained much attention to assist in the repair of an injured heart tissue; however, questions regarding the ideal cell source remain. In the present study, we have identified a source that is easy to extract stem cells from and show that the cells present have a high plasticity toward the cardiomyogenic lineage. We focused on the recently discovered neural crest stem cells residing in the periodontal ligament that can be easily obtained through dental procedures.

Research in the last decade strongly suggests that mesenchymal stem cell (MSC)-mediated therapeutic benefits are mainly due to their secretome, which has been proposed as a possible therapeutic tool for the treatment of Parkinson's disease (PD). Indeed, it has been shown that the MSC secretome increases neurogenesis and cell survival, and has numerous neuroprotective actions under different conditions. Additionally, using dynamic culturing conditions (through computer-controlled bioreactors) can further modulate the MSC secretome, thereby generating a more potent neurotrophic factor cocktail (i.e., conditioned medium). In this study, we have characterized the MSC secretome by proteomic-based analysis, investigating its therapeutic effects on the physiological recovery of a 6-hydroxidopamine (6-OHDA) PD rat model. For this purpose, we injected MSC secretome into the substantia nigra (SNc) and striatum (STR), characterizing the behavioral performance and determining histological parameters for injected animals versus untreated groups. We observed that the secretome potentiated the increase of dopaminergic neurons (i.e., tyrosine hydroxylase-positive cells) and neuronal terminals in the SNc and STR, respectively, thereby supporting the recovery observed in the Parkinsonian rats' motor performance outcomes (assessed by rotarod and staircase tests). Finally, proteomic characterization of the MSC secretome (through combined mass spectrometry analysis and Bioplex assays) revealed the presence of important neuroregulatory molecules, namely cystatin C, glia-derived nexin, galectin-1, pigment epithelium-derived factor, vascular endothelial growth factor, brain-derived neurotrophic factor, interleukin-6, and glial cell line-derived neurotrophic factor. Overall, we concluded that the use of human MSC secretome alone was able to partially revert the motor phenotype and the neuronal structure of 6-OHDA PD animals. This indicates that the human MSC secretome could represent a novel therapeutic for the treatment of PD. Stem Cells Translational Medicine 2017;6:634-646.

Although a variety of reprogramming strategies have been reported to create transgene-free induced pluripotent stem (iPS) cells from differentiated cell sources, a fundamental question still remains: Can we generate safe iPS cells that have the full spectrum of features of corresponding embryonic stem (ES) cells? Studies in transgene-free mouse iPS cells have indicated a positive answer to this question. However, the reality is that no other species have a derived transgene-free iPS cell line that can truly mimic ES cell quality. Specifically, critical data for chimera formation and germline transmission are generally lacking. To date, the rat is the only species, other than the mouse, that has commonly recognized authentic ES cells that can be used for direct comparison with measure features of iPS cells. To help find the underlying reasons of the current inability to derive germline-competent ES/iPS cells in nonrodent animals, we first used optimized culture conditions to isolate and establish rat ES cell lines and demonstrated they are fully competent for chimeric formation and germline transmission. We then used episomal vectors bearing eight reprogramming genes to improve rat iPS (riPS) cell generation from Sprague-Dawley rat embryonic fibroblasts. The obtained transgene-free riPS cells exhibit the typical characteristics of pluripotent stem cells; moreover, they are amenable to subsequent genetic modification by homologous recombination. Although they can contribute significantly to chimeric formation, no germline transmission has been achieved. Although this partial success in achieving competency is encouraging, it suggests that more efforts are still needed to derive ground-state riPS cells. Stem Cells Translational Medicine 2017;6:340-351.

Intestinal failure is a rare life-threatening condition that results in the inability to maintain normal growth and hydration status by enteral nutrition alone. Although parenteral nutrition and whole organ allogeneic transplantation have improved the survival of these patients, current therapies are associated with a high risk for morbidity and mortality. Development of methods to propagate adult human intestinal stem cells (ISCs) and pluripotent stem cells raises the possibility of using stem cell-based therapy for patients with monogenic and polygenic forms of intestinal failure. Organoids have demonstrated the capacity to proliferate indefinitely and differentiate into the various cellular lineages of the gut. Genome-editing techniques, including the overexpression of the corrected form of the defective gene, or the use of CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 to selectively correct the monogenic disease-causing variant within the stem cell, make autologous ISC transplantation a feasible approach. However, numerous techniques still need to be further optimized, including more robust ex vivo ISC expansion, native ISC ablation, and engraftment protocols. Large-animal models can to be used to develop such techniques and protocols and to establish the safety of autologous ISC transplantation because outcomes in such models can be extrapolated more readily to humans. Stem Cells Translational Medicine 2017;6:666-676.

Iatrogenic tumorigenesis is a major limitation for the use of human induced pluripotent stem cells (hiPSCs) in hematology. The teratoma risk comes from the persistence of hiPSCs in differentiated cell populations. Our goal was to evaluate the best system to purge residual hiPSCs before graft without compromising hematopoietic repopulation capability. Teratoma risk after systemic injection of hiPSCs expressing the reporter gene luciferase was assessed for the first time. Teratoma formation in immune-deficient mice was tracked by in vivo bioimaging. We observed that systemic injection of hiPSCs produced multisite teratoma as soon as 5 weeks after injection. To eliminate hiPSCs before grafting, we tested the embryonic-specific expression of suicide genes under the control of the pmiR-302/367 promoter. This promoter was highly active in hiPSCs but not in differentiated cells. The gene/prodrug inducible Caspase-9 (iCaspase-9)/AP20187 was more efficient and rapid than thymidine kinase/ganciclovir, fully specific, and without bystander effect. We observed that iCaspase-9-expressing hiPSCs died in a dose-dependent manner with AP20187, without reaching full eradication in vitro. Unexpectedly, nonspecific toxicity of AP20187 on iCaspase-9-negative hiPSCs and on CD34+ cells was evidenced in vitro. This toxic effect strongly impaired CD34+ -derived human hematopoiesis in adoptive transfers. Survivin inhibition is an alternative to the suicide gene approach because hiPSCs fully rely on survivin for survival. Survivin inhibitor YM155 was more efficient than AP20187/iCaspase-9 for killing hiPSCs, without toxicity on CD34+ cells, in vitro and in adoptive transfers. hiPSC purge by survivin inhibitor fully eradicated teratoma formation in immune-deficient mice. This will be useful to improve the safety management for hiPSC-based medicine. Stem Cells Translational Medicine 2017;6:382-393.

Mature nephrons originate from a small population of uninduced nephrogenic progenitor cells (NPs) within the cap mesenchyme. These cells are characterized by the coexpression of SIX2 and CITED1. Many studies on mouse models as well as on human pluripotent stem cells have advanced our knowledge of NPs, but very little is known about this population in humans, since it is exhausted before birth and strategies for its direct isolation are still limited. Here we report an efficient protocol for direct isolation of human NPs without genetic manipulation or stepwise induction procedures. With the use of RNA-labeling probes, we isolated SIX2+ CITED1+ cells from human fetal kidney for the first time. We confirmed their nephrogenic state by gene profiling and evaluated their nephrogenic capabilities in giving rise to mature renal cells. We also evaluated the ability to culture these cells without complete loss of SIX2 and CITED1 expression over time. In addition to defining the gene profile of human NPs, this in vitro system facilitates studies of human renal development and provides a novel tool for renal regeneration and bioengineering purposes. Stem Cells Translational Medicine 2017;6:419-433.