Possible linkages between the inner and outer cellular states of human induced pluripotent stem cells

Background

Human iPS cells (hiPSCs) have attracted considerable attention for applications to drug screening and analyses of disease mechanisms, and even as next generation materials for regenerative medicine. Genetic reprogramming of human somatic cells to a pluripotent state was first achieved by the ectopic expression of four factors (Sox2, Oct4, Klf4 and c-Myc), using a retrovirus. Subsequently, this method was applied to various human cells, using different combinations of defined factors. However, the transcription factor-induced acquisition of replication competence and pluripotency raises the question as to how exogenous factors induce changes in the inner and outer cellular states.

Results

We analyzed both the RNA profile, to reveal changes in gene expression, and the glycan profile, to identify changes in glycan structures, between 51 cell samples of four parental somatic cell (SC) lines from amniotic mesodermal, placental artery endothelial, and uterine endometrium sources, fetal lung fibroblast (MRC-5) cells, and nine hiPSC lines that were originally established. The analysis of this information by standard statistical techniques combined with a network approach, named network screening, detected significant expression differences between the iPSCs and the SCs. Subsequent network analysis of the gene expression and glycan signatures revealed that the glycan transfer network is associated with known epitopes for differentiation, e.g., the SSEA epitope family in the glycan biosynthesis pathway, based on the characteristic changes in the cellular surface states of the hiPSCs.

Conclusions

The present study is the first to reveal the relationships between gene expression patterns and cell surface changes in hiPSCs, and reinforces the importance of the cell surface to identify established iPSCs from SCs. In addition, given the variability of iPSCs, which is related to the characteristics of the parental SCs, a glycosyltransferase expression assay might be established to define hiPSCs more precisely and thus facilitate their standardization, which are important steps towards the eventual therapeutic applications of hiPSCs.

Methylprednisolone reduces postoperative nausea in total knee and hip arthroplasty

WHAT IS KNOWN AND OBJECTIVE

Total knee and hip joint replacement has a high risk of postoperative nausea and vomiting (PONV), and steroid cover is used for cases associated with autoimmune diseases. Our aim is to evaluate the antiemetic efficacy of methylprednisolone as steroid cover in patients undergoing the surgery.

METHODS

A prospective cohort study design was used. Sixty-eight patients, aged between 20 and 80 years, were scheduled for a standardized general anaesthetic technique. Patients who were given methylprednisolone were assigned as the steroid cover group, and those who were not given methylprednisolone formed the non-steroid cover group. PONV were assessment by direct questioning or spontaneous complaints by patients 1 week after surgery. Postoperative pain was evaluated using Visual Analog Scale (VAS) 1 and 3 days after surgery.

RESULTS AND DISCUSSION

The incidence of nausea in the steroid cover group was significantly less than that in the non-steroid cover group (adjusted odds ratio, 0·17, P = 0·021), but there was no significant difference in vomiting between the two groups. Postoperative pain VAS score was not significantly different between groups.

WHAT IS NEW AND CONCLUSION

In total knee and hip arthroplasty, methylprednisolone is effective in preventing postoperative nausea; however, higher doses of methylprednisolone may be needed to prevent vomiting.

Neuroblastoma cells can be classified according to glycosphingolipid expression profiles identified by liquid chromatography-tandem mass spectrometry

It is hoped that the gangliosides contained in neuroblastomas (NBs) can be used as outcome predictors. We used liquid chromatography-tandem mass spectrometry (LC-MS) to analyze the gangliosides expressed in 11 NB cell lines. LC-MS analysis detected a number of gangliosides, including acetylated forms, with significantly higher sensitivity than conventional high-performance thin-layer chromatography analysis, and the results revealed that the expression profiles of the gangliosides GD1a, GD2, and acetylated GD2 differed according to the NB cell line. Hierarchical clustering based on the ganglioside expression profiles obtained by LC-MS analysis revealed that the NB cell lines could be classified into three types according to their expression of these three gangliosides: A-type characterized by high expression of GD1a and low or no expression of GD2/acetylated GD2, B-type characterized by low or no expression of GD1a and high expression of GD2/acetylated GD2, and AB-type characterized by expression of both GD1a and GD2/acetylated GD2. Interestingly, all three MYCN non-amplified cell lines were classified into the A-type. The classification was found to be correlated with mRNA expression of ganglioside synthase and neural-differentiation-related genes. The results of this study indicate that LC-MS analysis is useful as a tool for glycosphingolipid research on malignancies.

Accelerated biosynthesis of neolacto-series glycosphingolipids in differentiated mouse embryonal carcinoma F9 cells detected by using dodecyl N-acetylglucosaminide as a saccharide primer

Using dodecyl N-acetylglucosaminide (GlcNAc-C12) as a saccharide primer, we investigated the biosynthetic changes of neolacto-series glycosphingolipids (GSLs) in mouse embryonal carcinoma F9 cells during differentiation induced by retinoic acid plus dibutyryl cyclic AMP (RA/dbcAMP). In the differentiated cells, the glycosylation of GlcNAc-C12 was greatly enhanced. The sugar compositions of glycosylated primers were assigned as Hex-GlcNAc, [Hex](2)-GlcNAc, [Hex](2)[HexNAc]-GlcNAc, and [NeuAc][Hex]-GlcNAc by liquid chromatography-tandem mass spectrometry. The detection of augmented biosynthesis of endogenous sialylparagloboside indicated that [NeuAc][Hex]-GlcNAc was predicted to be the non-reducing end trisaccharide of sialylparagloboside. The transcription of B3gnt5, B4galt1, Ggta1, Fut4 and St3gal6, encoding glycosyltransferases involved in the neolacto-series glycosphingolipids biosynthesis, was increased, whereas that of Fut9 and St6galI was decreased after RA/dbcAMP treatment. Furthermore, the sialyltransferase activity of ST3GalVI sialylating paragloboside was enhanced with the increase in St3gal6 expression. Since most stage-specific embryonic antigen-1 (SSEA-1) active determinants are carried by glycoproteins in F9 cells, the changes in glycolipid metabolism do not seem to be closely related to loss of cell surface SSEA-1 expression upon F9 differentiation. These results indicate that RA/dbcAMP treatment activates the biosynthesis of neolacto-series GSL and enhances sialylation of paragloboside in F9 cells with down-regulation of Fut9 expression.

Efficient generation of hepatoblasts from human ES cells and iPS cells by transient overexpression of homeobox gene HEX

Human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have the potential to differentiate into all cell lineages, including hepatocytes, in vitro. Induced hepatocytes have a wide range of potential application in biomedical research, drug discovery, and the treatment of liver disease. However, the existing protocols for hepatic differentiation of PSCs are not very efficient. In this study, we developed an efficient method to induce hepatoblasts, which are progenitors of hepatocytes, from human ESCs and iPSCs by overexpression of the HEX gene, which is a homeotic gene and also essential for hepatic differentiation, using a HEX-expressing adenovirus (Ad) vector under serum/feeder cell-free chemically defined conditions. Ad-HEX-transduced cells expressed α-fetoprotein (AFP) at day 9 and then expressed albumin (ALB) at day 12. Furthermore, the Ad-HEX-transduced cells derived from human iPSCs also produced several cytochrome P450 (CYP) isozymes, and these P450 isozymes were capable of converting the substrates to metabolites and responding to the chemical stimulation. Our differentiation protocol using Ad vector-mediated transient HEX transduction under chemically defined conditions efficiently generates hepatoblasts from human ESCs and iPSCs. Thus, our methods would be useful for not only drug screening but also therapeutic applications.

A microfabricated scaffold induces the spheroid formation of human bone marrow-derived mesenchymal progenitor cells and promotes efficient adipogenic differentiation

Here, we report the highly efficient in vitro differentiation of human bone marrow-derived mesenchymal stem/progenitor cells (MPCs) using a novel nanotechnology-based culture plate, nanoculture plate(®) (NCP). The NCP contains uneven microfabrications with diameters of ∼2-3 μm arranged in a honeycomb pattern on its culture surface, which is devoid of animal-derived protein sources. When human MPCs were subjected to three-dimensional (3D) culture using an NCP, they rapidly formed adhesive spheroids. We showed that adipogenic differentiation in NCP-mediated 3D cultures led to more rapid accumulation of triglycerides than that in two-dimensional cultures. During adipogenesis in 3D cultures, the rapid and intense induction of adipocyte-specific gene expressions, such as peroxisome proliferator-activated receptor γ (PPAR-γ), CCAAT-enhancer-binding protein α (C/EBP-α), adipocyte protein 2 (aP2), and adiponectin was observed. Together, these results indicate that this 3D culture system is suitable for the differentiation of human MPCs into adipogenic lineage, and could be applicable to adipose tissue engineering under xeno-free condition.

ON THE NYMPH AND PROSOPON OF THE TSUTSUGAMUSHI, LEPTOTROMBIDIUM AKAMUSHI, N. SP. (TROMBIDIUM AKAMUSHI BRUMPT), CARRIER OF THE TSUTSUGAMUSHI DISEASE

Nomenclature. As mentioned above, the prosopon and the nymph of the tsutsugamushi have many characteristics which distinguish it from the other trombidia. These are the pale color and small size of the body, delicacy of the skin, the conspicuous constriction between the cephalothoracic region and the abdomen, rudimentary eyes and tracheal openings, absence of tracheal capillaries, etc. The fact that the thumb or the appendage of the palpus does not start from the side of the fourth joint of the latter but from its end, is another charac teristic which does not occur in other trombidia. From the biological point of view two facts should be mentioned; i.e., the adult female does not deposit eggs in heaps, and in contrast to those of other species, the larvaæ hatch out all through the year and feed on mammals. From these characteristics running through all the stages of development, we believe that we are justified in claiming a new genus for the tsutsugamushi. We therefore propose to change the scientific name given to this mite by Brumpt in 1910, Trombidium akamushi, and to introduce instead, according to the suggestion of Drs. Goto and Watase, the name Leptotrombidium akamushi. Determinaton of Leptotrombidium akamushi, N. Sp. Prosopon and Nymph. 1. Pale color. 2. Delicacy of the skin. 3. Distinct constriction between the cephalothoracic region and the abdomen. 4. Rudimentary, sessile eyes. 5. Indistinctnes of tracheal openings. 6. Absence of tracheal capillaries. 7. Crista abruptly widened at the end. 8. One palpal claw. Larva. 1. One scutum. 2. Round pinacles. 3. Legs, six joints, not counting the coxa. 4. Haris on the coza: one each on Joints 1, 2, and 3. 5. Hairs on the scutum, including two tactile hairs, seven; one is in the median line. Specific Determination of Leptotrombidium akamushi, N. Sp. (Trombidium akamushi Brumpt, 1910). Prosopon. 1. Small size 2. Three pairs of sucking discs on the external genitalia. 3. Hairs of the body feathered, club-shaped at the end, and the colorless. 4. The appendage of the palpus tapes distinctly towards the end. Nymph. 1. The size of the body is smaller thant that of the prosopon. 2. Two pairs of sucking discs on the external genitalia. There are no other distinct differences in the external morphology between the proposon and the nymph. Larva. 1. The color of the body is orange-red, but becomes paler after sucking on mammals. 2. The hairs of the body average 110 to 120 in number. 3. One pair of double eyes. 4. The sucking tube is visible when feeding on mammals (Hayashi). 5. The salivary gland is relatively large (Kawamura and Komagata). 6. The number and arrangemetn of the hairs on the legs and mouth parts correspond to the description given by Hirst. 7. The larvæ are found all through the year. 8. The larva is the carrier of tsutsugamushi disease in man.

Kinetics and effect of integrin expression on human CD34(+) cells during murine leukemia virus-derived retroviral transduction with recombinant fibronectin for stem cell gene therapy

The CH-296 recombinant fragment of human fibronectin is essential for murine leukemia virus (MLV)-derived retroviral transduction of CD34(+) cells for the purpose of stem cell gene therapy. Although the major effect of CH-296 is colocalization of the MLV-derived retrovirus and target cells at specific adhesion domains of CH-296 mediated by integrins expressed on CD34(+) cells, the precise roles of the integrins are unclear. We examined the kinetics of integrin expression on CD34(+) cells during the course of MLV-derived retrovirus-mediated gene transduction with CH-296. Flow cytometry revealed that the levels of both very late activation protein (VLA)-4 and VLA-5 on CD34(+) cells freshly isolated from cord blood were insufficient for effective MLV-derived retroviral transduction. However, increases were achieved during culture for preinduction and MLV-derived retrovirus-mediated gene transduction in the presence of a cocktail of cytokines. In addition, we confirmed by using specific antibodies that inhibition of the cell adhesion mediated by the integrins significantly reduced transduction efficiency, indicating that integrin expression is indeed important for CH-296-based MLV-derived retroviral transduction. Only a few cytokines are capable of inducing integrin expression, and stem cell factor plus thrombopoietin was found to be the minimal combination that was sufficient for effective transduction of an MLV-derived retrovirus based on CH-296. Our findings should be useful for improving the culture conditions for CH-296-based MLV-derived retroviral transduction in stem cell gene therapy.

Efficient reprogramming of human and mouse primary extra-embryonic cells to pluripotent stem cells

Practical clinical applications for current induced pluripotent stem cell (iPSC) technologies are hindered by very low generation efficiencies. Here, we demonstrate that newborn human (h) and mouse (m) extra-embryonic amnion (AM) and yolk-sac (YS) cells, in which endogenous KLF4/Klf4, c-MYC/c-Myc and RONIN/Ronin are expressed, can be reprogrammed to hiPSCs and miPSCs with efficiencies for AM cells of 0.02% and 0.1%, respectively. Both hiPSC and miPSCs are indistinguishable from embryonic stem cells in colony morphology, expression of pluripotency markers, global gene expression profile, DNA methylation status of OCT4 and NANOG, teratoma formation and, in the case of miPSCs, generation of germline transmissible chimeric mice. As copious amounts of human AM cells can be collected without invasion, and stored long term by conventional means without requirement for in vitro culture, they represent an ideal source for cell banking and subsequent 'on demand' generation of hiPSCs for personal regenerative and pharmaceutical applications.

Ex vivo expanded cord blood CD4 T lymphocytes exhibit a distinct expression profile of cytokine-related genes from those of peripheral blood origin

With an increase in the importance of umbilical cord blood (CB) as an alternative source of haematopoietic progenitors for allogenic transplantation, donor lymphocyte infusion (DLI) with donor CB-derived activated CD4(+) T cells in the unrelated CB transplantation setting is expected to be of increased usefulness as a direct approach for improving post-transplant immune function. To clarify the characteristics of activated CD4(+) T cells derived from CB, we investigated their mRNA expression profiles and compared them with those of peripheral blood (PB)-derived activated CD4(+) T cells. Based on the results of a DNA microarray analysis and quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR), a relatively high level of forkhead box protein 3 (Foxp3) gene expression and a relatively low level of interleukin (IL)-17 gene expression were revealed to be significant features of the gene expression profile of CB-derived activated CD4(+) T cells. Flow cytometric analysis further revealed protein expression of Foxp3 in a portion of CB-derived activated CD4(+) T cells. The low level of retinoic acid receptor-related orphan receptor gamma isoform t (RORgamma t) gene expression in CB-derived activated CD4(+) T cells was speculated to be responsible for the low level of IL-17 gene expression. Our data indicate a difference in gene expression between CD4(+) T cells from CB and those from PB. The findings of Foxp3 expression, a characteristic of regulatory T cells, and a low level of IL-17 gene expression suggest that CB-derived CD4(+) T cells may be a more appropriate source for DLI.

Cloning and characterization of a ribonuclease L inhibitor from the silkworm,Bombyx mori

The ribonuclease L (RNase L) pathway plays an important role in the response of cells to double-stranded RNA (dsRNA) during the events such as virus infection. Ribonuclease L inhibitor (RLI) belonging to the ABC transporter family is known as a regulator of the RNase L pathway. The homologs of RLI were reported in many organisms including the fruit fly and mosquito, but their functions in insects and arthropods have not been elucidated to date. In the present study, we cloned a cDNA of a silkworm RLI homolog, termed BmRLI, and its nucleotide sequence was determined. RT-PCR analysis revealed that the expression of BmRLI mRNA was marked in the testis, ovary and fat body. From the cDNA, recombinant protein with an apparent molecular mass of 69 kDa was expressed in Escherichia coli and cultured insect cells. Although no obvious effect of up-regulation of the BmRLI expression on RNAi was observed, its down-regulation slightly reduced RNAi efficiency.

Mesenchymal to embryonic incomplete transition of human cells by chimeric OCT4/3 (POU5F1) with physiological co-activator EWS

POU5F1 (more commonly known as OCT4/3) is one of the stem cell markers, and affects direction of differentiation in embryonic stem cells. To investigate whether cells of mesenchymal origin acquire embryonic phenotypes, we generated human cells of mesodermal origin with overexpression of the chimeric OCT4/3 gene with physiological co-activator EWS (product of the EWSR1 gene), which is driven by the potent EWS promoter by translocation. The cells expressed embryonic stem cell genes such as NANOG, lost mesenchymal phenotypes, and exhibited embryonal stem cell-like alveolar structures when implanted into the subcutaneous tissue of immunodeficient mice. Hierarchical analysis by microchip analysis and cell surface analysis revealed that the cells are subcategorized into the group of human embryonic stem cells and embryonal carcinoma cells. These results imply that cells of mesenchymal origin can be traced back to cells of embryonic phenotype by the OCT4/3 gene in collaboration with the potent cis-regulatory element and the fused co-activator. The cells generated in this study with overexpression of chimeric OCT4/3 provide us with insight into cell plasticity involving OCT4/3 that is essential for embryonic cell maintenance, and the complexity required for changing cellular identity.

EWS/ETS regulates the expression of the Dickkopf family in Ewing family tumor cells

Background

The Dickkopf (DKK) family comprises a set of proteins that function as regulators of Wnt/β–catenin signaling and has a crucial role in development. Recent studies have revealed the involvement of this family in tumorigenesis, however their role in tumorigenesis is still remained unclear.

Methodology/Principal Findings

We found increased expression of DKK2 but decreased expression of DKK1 in Ewing family tumor (EFT) cells. We showed that EFT-specific EWS/ETS fusion proteins enhance the DKK2 promoter activity, but not DKK1 promoter activity, via ets binding sites (EBSs) in the 5′ upstream region. EWS/ETS-mediated transactivation of the promoter was suppressed by the deletion and mutation of EBSs located upstream of the DKK2 gene. Interestingly, the inducible expression of EWS/ETS resulted in the strong induction of DKK2 expression and inhibition of DKK1 expression in human primary mesenchymal progenitor cells that are thought to be a candidate of cell origin of EFT. In addition, using an EFT cell line SK-ES1 cells, we also demonstrated that the expression of DKK1 and DKK2 is mutually exclusive, and the ectopic expression of DKK1, but not DKK2, resulted in the suppression of tumor growth in immuno-deficient mice.

Conclusions/Significance

Our results suggested that DKK2 could not functionally substitute for DKK1 tumor-suppressive effect in EFT. Given the mutually exclusive expression of DKK1 and DKK2, EWS/ETS regulates the transcription of the DKK family, and the EWS/ETS-mediated DKK2 up-regulation could affect the tumorigenicity of EFT in an indirect manner.

B-cell-activating factor inhibits CD20-mediated and B-cell receptor-mediated apoptosis in human B cells

B-cell-activating factor (BAFF) is a survival and maturation factor for B cells belonging to the tumour necrosis factor superfamily. Among three identified functional receptors, the BAFF receptor (BAFF-R) is thought to be responsible for the effect of BAFF on B cells though details of how remain unclear. We determined that a hairy-cell leukaemia line, MLMA, expressed a relatively high level of BAFF-R and was susceptible to apoptosis mediated by either CD20 or B-cell antigen receptor (BCR). Using MLMA cells as an in vitro model of mature B cells, we found that treatment with BAFF could inhibit apoptosis mediated by both CD20 and BCR. We also observed, using immunoblot analysis and microarray analysis, that BAFF treatment induced activation of nuclear factor-kappaB2 following elevation of the expression level of Bcl-2, which may be involved in the molecular mechanism of BAFF-mediated inhibition of apoptosis. Interestingly, BAFF treatment was also found to induce the expression of a series of genes, such as that for CD40, related to cell survival, suggesting the involvement of a multiple mechanism in the BAFF-mediated anti-apoptotic effect. MLMA cells should provide a model for investigating the molecular basis of the effect of BAFF on B cells in vitro and will help to elucidate how B cells survive in the immune system in which BAFF-mediated signalling is involved.