Early Osteogenic-Induced Adipose-Derived Stem Cells and Canine Bone Regeneration Potential Analyzed Using Biodegradable Scaffolds.

The complex process of bone regeneration is influenced by factors such as inflammatory responses, tissue interactions, and progenitor cells. Currently, multiple traumas can interfere with fracture healing, causing the prolonging or failure of healing. In these cases, bone grafting is the most effective treatment. However, there are several drawbacks, such as morbidity at the donor site and availability of suitable materials. Advantages have been provided in this field by a variety of stem cell types. Adipose-derived stem cells (ASCs) show promise. In the radiological examination of this study, it was confirmed that the C/S group showed faster regeneration than the other groups, and Micro-CT also showed that the degree of bone formation in the defect area was highest in the C/S group. Compared to the control group, the change in cortical bone area in the defect area decreased in the sham group (0.874), while it slightly increased in the C/S group (1.027). An increase in relative vascularity indicates a decrease in overall bone density, but a weak depression filled with fibrous tissue was observed outside the compact bone. It was confirmed that newly formed cortical bone showed a slight difference in bone density compared to surrounding normal bone tissue due to increased distribution of cortical bone. In this study, we investigated the effect of bone regeneration by ADMSCs measured by radiation and pathological effects. These data can ultimately be applied to humans with important clinical applications in various bone diseases, regenerative, and early stages of formative differentiation.

Whitening and moisturizing enhancing effects of three-dimensional human adipose-derived mesenchymal stem cell-conditioned medium-containing cream.

BACKGROUND: High-functional cosmetic products combined with the concept of "treatment" cosmetics are being introduced to the market. Cosmetic products containing a skin-derived microbiome, a three-dimensional (3D) stem cell culture medium, and low-molecular-weight collagen are being introduced, and these products are leading the cosmeceutical market. We aimed to confirm the potential of a 3D stem cell culture medium-containing cream as a skin-whitening and moisturizing product. AIM: To determine the enhancing effects of a cream containing 3D adipose tissue-derived mesenchymal stem cell-conditioned media (3D ADMSC-CM) on whitening and moisturization. METHODS: The inhibitory activities of tyrosinase (TYR) and melanin were confirmed using 3D ADMSC-CM. Furthermore, hyaluronic acid expression in 3D ADMSC-CM was verified. The clinical efficacy of the cream containing 3D ADMSC-CM was established by evaluating its antioxidant properties and effects on skin tone, radiance, freckles, and moisturization. RESULTS: The use of 3D ADMSC-CM suppressed the inhibitory effects of TYR and melanin by approximately 24% and 33%, respectively, and increased the expression of hyaluronic acid synthase. A significant difference was observed after 4 weeks of using 3D ADMSC-CM in the skin antioxidant evaluation. After 2 and 4 weeks of use, skin tone and radiance increased and skin freckles decreased significantly. Under extremely cold and dry weather conditions, the use of the cream increased skin moisturization. CONCLUSIONS: The 3D ADMSC-CM cream evaluated in an environment similar to the human body was found to enhance skin whitening and moisturization and can therefore be used in the skin care and cosmetic industries as a biocosmetic product.

In Vitro Tracking of Human Umbilical Vein Endothelial Cells Using Ultra-Sensitive Quantum Dot-Embedded Silica Nanoparticles.

The nanoscale spatiotemporal resolution of single-particle tracking (SPT) renders it a powerful method for exploring single-molecule dynamics in living cells or tissues, despite the disadvantages of using traditional organic fluorescence probes, such as the weak fluorescent signal against the strong cellular autofluorescence background coupled with a fast-photobleaching rate. Quantum dots (QDs), which enable tracking targets in multiple colors, have been proposed as an alternative to traditional organic fluorescence dyes; however, they are not ideally suitable for applying SPT due to their hydrophobicity, cytotoxicity, and blinking problems. This study reports an improved SPT method using silica-coated QD-embedded silica nanoparticles (QD2), which represent brighter fluorescence and are less toxic than single QDs. After treatment of QD2 in 10 µg/mL, the label was retained for 96 h with 83.76% of labeling efficiency, without impaired cell function such as angiogenesis. The improved stability of QD2 facilitates the visualization of in situ endothelial vessel formation without real-time staining. Cells retain QD2 fluorescence signal for 15 days at 4 °C without significant photobleaching, indicating that QD2 has overcome the limitations of SPT enabling long-term intracellular tracking. These results proved that QD2 could be used for SPT as a substitute for traditional organic fluorophores or single quantum dots, with its photostability, biocompatibility, and superior brightness.

Comparison of guidelines for biological ancillary materials used for the manufacture of gene and cellular therapy products in Asia.

BACKGROUND AIMS: Although biologiocal ancillay materials (AMs) have specific risk associated with their derivations, it plays key role to manufature cell and gene therapy (CGT) products. It is important to understand the regulation relevant to AMs for developers. METHODS: The authors investigated the guidelines and pharmacopeia (hereinafter referred to as "guidelines") for biological AMs used for the manufacture of CGT products in Asia (China, India, Japan, Korea and Taiwan). In addition, the authors benchmarked the relevant guidelines in the United States (US) and European Union (EU). RESULTS AND DISCUSSIONS: The guidelines could be classified into two types based on whether specific AMs are scoped: (i) general guidelines for risk assessment of AMs and (ii) guidelines for specific AMs. The authors compared the risk categories for each type of AM provided in the general guidelines between the US and China and the specific requirements for bovine serum and trypsin in the guidelines of China, Japan, Taiwan, US and EU. The authors further compiled in-depth descriptions of the respective regulations in China, India, Japan, Korea and Taiwan. There is limited availability of some guidelines for specific AMs. Moreover, there are no common requirements established across the surveyed countries and regions. Therefore, the authors suggest a risk assessment approach for AMs with consideration of their biological origin and traceability, production steps applied and ability to control or remove AMs from the final medicinal product over the CGT manufacturing process.

Medroxyprogesterone Reverses Tolerable Dose Metformin-Induced Inhibition of Invasion via Matrix Metallopeptidase-9 and Transforming Growth Factor-ß1 in KLE Endometrial Cancer Cells.

This study was performed to evaluate the anticancer effects of tolerable doses of metformin with or without medroxyprogesterone (MPA) in endometrial cancer cells. Cell viability, cell invasion, and levels of matrix metallopeptidase (MMP) and transforming growth factor (TGF)-ß1 were analyzed using three human endometrial adenocarcinoma cell lines (Ishikawa, KLE, and uterine serous papillary cancer (USPC)) after treatment with different dose combinations of MPA and metformin. Combining metformin (0, 100, 1000 µM) and 10 µM MPA induced significantly decreased cell viability in a time- and dose-dependent manner in Ishikawa cells, but not in KLE and USPC cells. In KLE cells, metformin treatment alone significantly inhibited cell invasion in a dose-dependent manner. The inhibitory effect of metformin was reversed when 10 µM MPA was combined, which was significantly inhibited again after treatment of MMP-2/9 inhibitor and/or TGF-ß inhibitor. Changes of MMP-9 and TGF-ß1 according to combinations of MPA and metformin were similar to those of invasion in KLE cells. In conclusion, the anticancer effects of tolerable doses of metformin varied according to cell type and combinations with MPA. Anti-invasive effect of metformin in KLE cells was completely reversed by the addition of MPA; this might be associated with MMP-9 and TGF-ß1.

Development of a three-dimensional in vitro co-culture model to increase drug selectivity for humans.

AIM: Insulin resistance is a metabolic state where insulin sensitivity is lower than normal condition and strongly related to type 2 diabetes. However, an in vitro model mimicking insulin resistance is rare and thus screening drugs for insulin resistance severely depends on an in vivo model. Here, to increase anti-diabetic drug selectivity for humans, 3D ADMSCs and macrophages were co-cultured with in-house fabricated co-culture plates. MATERIAL AND METHODS: 3D co-culture plates were designed to load ADMSCs and RAW264.7 cells containing hydrogels in separate wells while allowing cell-cell interaction with co-culturing media. Hydrogels were constructed using a 3D cell-printing system containing 20 mg/ml alginate, 0.5 mg/ml gelatin and 0.5 mg/ml type I collagen. Cells containing hydrogels in 3D co-culture plates were incubated for 10 min to allow stabilization before the experiment. 3D co-culture plates were incubated with the CaCl2 solution for 5 min to complete the cross linking of alginate hydrogel. Cells in 3D co-culture plates were cultured for up to 12 days depending on the experiment and wells containing adipocytes and macrophages were separated and used for assays. RESULTS: KR-1, KR-2 and KR-3 compounds were applied during differentiation (12 days) in 3D co-cultured mouse 3T3-L1 adipocytes and 3D co-cultured human ADMSCs. Glucose uptake assay using 2-DG6P and 2-NBDG and western blot analysis were performed to investigate changes of insulin resistance in the 3D co-cultured model for interspecies selectivity of drug screening. KR-1 (mouse potent enantiomer) and KR-3 (racemic mixture) showed improvement of 2-DG and 2-NBDG uptake compared with KR-2 (human potent enantiomer) in 3D co-cultured 3T3-L1 adipocytes. In connection with insulin resistance in a 3D 3T3-L1 co-cultured model, KR-1 and KR-3 showed improvement of insulin sensitivity compared to KR-2 by markedly increasing GLUT4 expression. In contrast to the result of 3D co-cultured 3T3-L1 adipocytes, KR-1 failed to significantly improve 2-DG and 2-NBDG uptake in 3D co-cultured ADMSC adipocytes. Results of 2-NBDG accumulation and western blot analysis also showed that KR-2 and KR-3 improved insulin sensitivity relatively better than KR-1. CONCLUSIONS: Our 3D co-culture model with/without 3D co-culture plates can successfully mimic insulin resistance while allowing investigation of the effects of anti-obesity or anti-diabetic drugs on human or mouse co-culturing cell type. This 3D co-culture system may accelerate screening of drugs for insulin resistance depending on species.

Differentiation of equine induced pluripotent stem cells into mesenchymal lineage for therapeutic use.

In previous work, we established an equine induced pluripotent stem cell line (E-iPSCs) from equine adipose-derived stem cells (ASCs) using a lentiviral vector encoding four transcription factors: Oct4, Sox2, Klf4, and c-Myc. In the current study, we attempted to differentiate these established E-iPSCs into mesenchymal stem cells (MSCs) by serial passaging using MSC-defined media for stem cell expansion. Differentiation of the MSCs was confirmed by analyzing expression levels of the MSC surface markers CD44 and CD29, and the pluripotency markers Nanog and Oct4. Results indicated that the E-iPSC-derived MSCs (E-iPSC-MSCs) retained the characteristics of MSCs, including the ability to differentiate into chondrogenic, osteogenic, or myogenic lineages. E-iPSC-MSCs were rendered suitable for therapeutic use by inhibiting immune rejection through exposure to transforming growth factor beta 2 (TGF-ß2) in culture, which down-regulated the expression of major histocompatibility complex class I (MHC class I) proteins that cause immune rejection if they are incompatible with the MHC antigen of the recipient. We reported 16 cases of E-iPSC-MSC transplantations into injured horses with generally positive effects, such as reduced lameness and fraction lines. Our findings indicate that E-iPSC-MSCs can demonstrate MSC characteristics and be safely and practically used in the treatment of musculoskeletal injuries in horses.

Establishment of stably expandable induced myogenic stem cells by four transcription factors.

Life-long regeneration of healthy muscle by cell transplantation is an ideal therapy for patients with degenerative muscle diseases. Yet, obtaining muscle stem cells from patients is very limited due to their exhaustion in disease condition. Thus, development of a method to obtain healthy myogenic stem cells is required. Here, we showed that the four transcription factors, Six1, Eya1, Esrrb, and Pax3, converts fibroblasts into induced myogenic stem cells (iMSCs). The iMSCs showed effective differentiation into multinucleated myotubes and also higher proliferation capacity than muscle derived stem cells both in vitro and in vivo. The iMSCs do not lose their proliferation capacity though the passaging number is increased. We further isolated CD106-negative and α7-integrin-positive iMSCs (sort-iMSCs) showing higher myogenic differentiation capacity than iMSCs. Moreover, genome-wide transcriptomic analysis of iMSCs and sort-iMSCs, followed by network analysis, revealed the genes and signaling pathways associated with enhanced proliferation and differentiation capacity of iMSCs and sort-iMSCs, respectively. The stably expandable iMSCs provide a new source for drug screening and muscle regenerative therapy for muscle wasting disease.

Dipeptide-functionalized polyamidoamine dendrimer-mediated apoptin gene delivery facilitates apoptosis of human primary glioma cells.

Glioblastoma multiform (GBM) is the most frequent and aggressive form of brain tumors in adults. However, the development of more efficient and safe nonviral vector gene therapy represents a promising therapeutic approach, using a tumor-specific killer gene, named apoptin. In this study, we describe the efficacy of non-viral gene delivery vectors, the amino acid-conjugated PAMAM derivatives (PAMAM-H-R and PAMAM-H-K) in delivering a therapeutic gene, displaying affinity toward human primary glioma cells (GBL-14 cells) and dermal fibroblasts. We analyzed transfection efficiency, using luciferase (Luci) and a pDNA encoding for enhanced fluorescent protein (EGFP), and cytotoxicity in both cells. The results show that transfection efficiency of PAMAM-H-R improved compared to native PAMAM dendrimer, but cytotoxicity of PAMAM-H-R and PAMAM-H-K were very low. We treated both cells with a polyplex formation of PAMAM-H-R or PAMAM-H-K/apoptin, and analyzed their cellular uptake and localization by flow cytometry and confocal microscopy. Furthermore, we analyzed the endosomal escape effect using TEM images, and found that PAMAM-H-R showed very fast escape from endosome to the cytosol. Caspase 3 activity assay, cell cycle distribution, and JC-1 analysis showed apoptosis induced by apoptin in GBL-14 cells. This indicates that PAMAM-H-R can be a potential nonviral vector gene delivery carrier for brain tumor therapy. The present study demonstrates that PAMAM-H-R/apoptin gene polyplex can be used as an effective therapeutic candidate for GBM due to its selective induction of apoptosis in primary glioma cells as a potential nonviral gene delivery carrier for brain tumor therapy.

Characterization of glycol chitosan grafted with low molecular weight polyethylenimine as a gene carrier for human adipose-derived mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have a great capacity for self-renewal while still maintaining their multipotency, and can differentiate into a variety of cell types. The delivery of genes to a site of injury is a current and interesting field of gene therapy. In the present study, we describe a nonviral gene delivery carrier, glycol chitosan-methyl acrylate-polyethylenimine (GMP) polymer targeted towards human adipose-derived mesenchymal stem cells (AD-MSCs). Transfection efficiency, using luciferase (Luc) and a pDNA encoding enhanced green fluorescent protein (EGFP), along with cytotoxicity assays, were performed in human AD-MSCs. The results show that the transfection efficiency of the GMP polymer was similar to that of PEI25kD, and the cytotoxicity was lower. Moreover, human AD-MSCs were treated with the GMP polymer/pDNA polyplex and its cellular uptake and distribution were analyzed by flow cytometry and confocal microscopy. Furthermore, we performed endosomal escape analysis using LysoTracker Red, and found that the conjugated GMP polymer could escape from the endosome to the cytosol. Human AD-MSCs treated with the GMP polymer maintained their potential for osteogenic differentiation and phenotypic expression of human AD-MSCs based on flow cytometry analysis. The present study demonstrates that the GMP polymer can be used as a potential targeted-delivery carrier for effective gene delivery.

Characterization of basic amino acids-conjugated PAMAM dendrimers as gene carriers for human adipose-derived mesenchymal stem cells.

Since mesenchymal stem cells (MSCs) can self-renew and differentiate into multiple cell types, the delivery of genes to this type of cell can be an important tool in the emerging field of tissue regeneration and engineering. However, development of more efficient and safe nonviral vectors for gene delivery to stem cells in particular still remains a great challenge. In this study, we describe a group of nonviral gene delivery vectors, conjugated PAMAM derivatives (PAMAM-H-R, PAMAM-H-K, and PAMAM-H-O), displaying affinity toward human adipose-derived mesenchymal stem cells (AD-MSCs). Transfection efficiency using pDNA encoding for luciferase (Luc) and enhanced green fluorescent protein (EGFP), and cytotoxicity assays were performed in human AD-MSCs. The results show that transfection efficiencies of conjugated PAMAM derivatives are improved significantly compared to native PAMAM dendrimer, and that among PAMAM derivatives, cytotoxicity of PAMAM-H-K and PAMAM-H-O were very low. Also, treatment of human AD-MSCs to polyplex formation in conjugated PAMAM derivatives, their cellular uptake and localization were analyzed by flow cytometry and confocal microscopy.

Recurrent variations in DNA methylation in human pluripotent stem cells and their differentiated derivatives.

Human pluripotent stem cells (hPSCs) are potential sources of cells for modeling disease and development, drug discovery, and regenerative medicine. However, it is important to identify factors that may impact the utility of hPSCs for these applications. In an unbiased analysis of 205 hPSC and 130 somatic samples, we identified hPSC-specific epigenetic and transcriptional aberrations in genes subject to X chromosome inactivation (XCI) and genomic imprinting, which were not corrected during directed differentiation. We also found that specific tissue types were distinguished by unique patterns of DNA hypomethylation, which were recapitulated by DNA demethylation during in vitro directed differentiation. Our results suggest that verification of baseline epigenetic status is critical for hPSC-based disease models in which the observed phenotype depends on proper XCI or imprinting and that tissue-specific DNA methylation patterns can be accurately modeled during directed differentiation of hPSCs, even in the presence of variations in XCI or imprinting.

Comparison of mesenchymal-like stem/progenitor cells derived from supernumerary teeth with stem cells from human exfoliated deciduous teeth.

AIMS: Dental tissue has been the focus of attention as an easily accessible postnatal tissue source of high-quality stem cells. Since the first report on the dental pulp stem cells (DPSCs) from permanent third molar teeth, stem cells from human exfoliated deciduous teeth (SHED) were identified as a population distinct from DPSCs. In this study, we compared DPSCs from supernumerary teeth and SHED in three age- and sex-matched patients. PATIENTS & METHODS: Dental samples were obtained from the three patients, who were 6 years old and male, with the parental consent of the three donors, and then isolated cells from dental pulp for comparative analysis between supernumerary DPSCs and SHED. RESULTS: Colony-forming unit fibroblast levels and the proliferation rate of supernumerary DPSCs were slightly lower than that of SHED. The expression of cell surface antigens in supernumerary DPSCs and SHED were almost identical. Cells were mainly expressing endogenous mesodermal and ectodermal lineage markers. Differentiation capacity to osteogenic, adipogenic and chondrogenic lineage was similar in the SHED and supernumerary DPSCs. Migration assay revealed that both supernumerary DPSCs and SHED rapidly migrated toward wounded areas. Supernumerary DPSCs were altered in cell growth after storage for 2 years. Specially, the population doubling time of supernumerary DPSCs increased while that of SHED remained nearly unchanged. CONCLUSION: Both supernumerary teeth and deciduous teeth share many characteristics, such as highly proliferative clonogenic cells with a similar immunophenotype to that of mesenchymal stem cells, although they are inferior to SHED for long-term banking. Our findings suggest that supernumerary teeth are also easily accessible and noninvasive sources of postnatal stem cells with multipotency and regenerative capacity.

The effects of the physical properties of culture substrates on the growth and differentiation of human embryonic stem cells.

The physical factors of cell-culture environment have received little attention despite their anticipated significant role in human embryonic stem cell (hESC) culture optimization. Here we show that hESC culture conditions can be optimized by utilizing polyethylene terephthalate (PET) membranes whose defined pore densities (PDs) determine membrane surface hardness. The PET membranes with 1-4 × 10(6) pores/cm(2) (0.291-0.345 GPa) supported the adherence and survival of hESCs without matrix coating. Furthermore, PET membrane with 4 × 10(6) pores/cm(2) (0.345 GPa) supported optimal hESC self renewal as well as by the increase in cell proliferation. The expression level and activity of Rho-associated kinase (ROCK) were specifically down-regulated in hESCs cultured on the optimal PET membrane. We suggest that PET membranes of a defined PD/hardness provide an excellent culture substrate for the maintenance of uniform and undifferentiated hESCs.

Dynamic changes in the copy number of pluripotency and cell proliferation genes in human ESCs and iPSCs during reprogramming and time in culture.

Genomic stability is critical for the clinical use of human embryonic and induced pluripotent stem cells. We performed high-resolution SNP (single-nucleotide polymorphism) analysis on 186 pluripotent and 119 nonpluripotent samples. We report a higher frequency of subchromosomal copy number variations in pluripotent samples compared to nonpluripotent samples, with variations enriched in specific genomic regions. The distribution of these variations differed between hESCs and hiPSCs, characterized by large numbers of duplications found in a few hESC samples and moderate numbers of deletions distributed across many hiPSC samples. For hiPSCs, the reprogramming process was associated with deletions of tumor-suppressor genes, whereas time in culture was associated with duplications of oncogenic genes. We also observed duplications that arose during a differentiation protocol. Our results illustrate the dynamic nature of genomic abnormalities in pluripotent stem cells and the need for frequent genomic monitoring to assure phenotypic stability and clinical safety.

Promyelocytic leukemia is a direct inhibitor of SAPK2/p38 mitogen-activated protein kinase.

The promyelocytic leukemia gene (PML) encodes a growth/tumor suppressor protein that is essential for the induction of apoptosis in response to various apoptotic signals. The mechanism by which PML plays a role in the regulation of cell death is still unknown. In the current study, we demonstrate that PML negatively regulated the SAPK2/p38 signaling pathway by sequestering p38 from its upstream kinases, MKK3, MKK4, and MKK6, whereas PML did not affect the SAPK1/c-Jun NH(2)-terminal kinase pathway. PML associated with p38 both in vitro and in vivo and the carboxyl terminus of PML mediated the interaction. In contrast to other studies of PML and PML-nuclear bodies (NB), our study shows that the formation of PML-NBs was not required for PML to suppress p38 activity because PML was still able to bind and inhibit p38 activity under the conditions in which PML-NBs were disrupted. In addition, we show that the promotion of Fas-induced cell death by PML correlated with the extent of p38 inhibition by PML, suggesting that PML might regulate apoptosis through manipulating SAPK2/p38 pathways. Our findings define a novel function of PML as a negative regulator of p38 kinase and provide further understanding on the mechanism of how PML induces multiple pathways of apoptosis.

Human cytomegalovirus inhibits tapasin-dependent peptide loading and optimization of the MHC class I peptide cargo for immune evasion.

The immune evasion protein US3 of human cytomegalovirus binds to and arrests MHC class I molecules in the endoplasmic reticulum (ER). However, substantial amounts of class I molecules still escape US3-mediated ER retention, suggesting that not all class I alleles are affected equally by US3. Here, we identify tapasin inhibition as the mechanism of MHC retention by US3. US3 directly binds tapasin and inhibits tapasin-dependent peptide loading, thereby preventing the optimization of the peptide repertoire presented by class I molecules. Due to the allelic specificity of tapasin toward class I molecules, US3 affects only class I alleles that are dependent on tapasin for peptide loading and surface expression. Accordingly, tapasin-independent class I alleles selectively escape to the cell surface.

Soluble HLA-G generated by proteolytic shedding inhibits NK-mediated cell lysis.

In contrast to the classical HLA class Ia molecules, the nonclassical HLA-G primary transcript is alternatively spliced to generate several mRNAs that encode four membrane-bound and three soluble isoforms. This study demonstrated that the soluble form of HLA-G can also be generated by metalloproteinase-dependent shedding at post-translational level. These soluble HLA-G1 molecules generated by the cleavage of membrane-bound HLA-G1 associate with beta2-microglobulin and contain bound peptides that are stable at physiological conditions. This report further showed that the soluble HLA-G1 is able to protect HLA class I-negative K562 cells from NK lysis, suggesting that soluble HLA-G could act as an immunoregulator in NK cell recognition and possibly in other immune responses.