Quantitative Analysis of Factors Regulating Angiogenesis for Stem Cell Therapy.

(1) Background: The control of angiogenesis is essential in disease treatment. We investigated angiogenesis-promoting or -suppressing factors and their molecular mechanisms. (2) Methods: Angiogenesis from HUVECs was quantitatively analyzed using the Angiogenesis Analysis Kit (Kurabo, Osaka, Japan). Human rAng-1-producing 107-35 CHO cells or mouse DFAT-D1 cells were co-cultured with HUVEC. Antioxidant polyphenols were added to the culture. Gene expression was analyzed by RT-PCR. (3) Results: The addition of rAng-1-producing cells, their culture supernatant, or commercially available rAng-1 showed a promoting effect on angiogenesis. The co-culture of DFAT-D1 cells promoted angiogenesis. Polyphenols showed a dose-dependent inhibitory effect on angiogenesis. Luteolin and quercetin showed remarkable anti-angiogenic effects. The expression of vWF, Flk1, and PECAM-1 was increased by adding rAng-1-producing cell culture supernatant. Polyphenols suppressed these genes. Apigenin and luteolin markedly suppressed α-SMA and Flk1. Resveratrol and quercetin enhanced the expression of PPARγ, and luteolin suppressed the expression of COX-1. The expression of endothelial nitric oxide synthase (eNOS), an oxidative stress-related gene, was slightly increased by luteolin. These results suggest that polyphenols induce ROS reduction. (4) Conclusions: We showed the promoting effect of Ang-1 or DFAT and the suppressing effect of polyphenols on angiogenesis and studied their molecular mechanisms. These results help control angiogenesis in regenerative therapy.

Isolation and characterization of neural crest-like progenitor cells in human umbilical cord blood.

INTRODUCTION: Neural crest (NC)-like stem/progenitor cells provide an attractive cell source for regenerative medicine because of their multipotent property and ease of isolation from adult tissue. Although human umbilical cord blood (HUCB) is known to be a rich source of stem cells, the presence of the NC-like stem/progenitor cells in HUCB remains to be elucidated. In this study, we have isolated NC-like progenitor cells using an antibody to p75 neurotrophin receptor (p75NTR) and examined their phenotype and stem cell function in vitro. METHODS: To confirm whether p75NTR+ NC-derived cells are present in cord blood, flow cytometric analysis of cord blood derived from P0-Cre/Floxed-EGFP reporter mouse embryos was performed. Freshly isolated HUCB mononuclear cells was subjected to flow cytometry to detect p75NTR+ cells and determined their immunophenotype. HUCB p75NTR+ cells were then collected by immunomagnetic separation and their immunophenotype, clonogenic potential, gene expression profile, and multilineage differentiation potential were examined. RESULTS: NC-derived EGFP+ cells co-expressing p75NTR was detected in cord blood of P0-Cre/Floxed-EGFP reporter mice. We found that freshly isolated HUCB mononuclear cells contained 0.23% of p75NTR+ cells. Isolated p75NTR+ cells from HUCB efficiently formed neurospheres and could differentiate into neuronal and glial cell lineages. The p75NTR+ cells expressed a set of NC-associated genes and undifferentiated neural cell marker genes before and after the culture. CONCLUSIONS: These findings revealed that HUCB contained the p75NTR+ NC-like progenitor cell population which have the self-renewal capacity and the potential to differentiate into both neuronal and glial cell lineages.

Can Human Embryonic Stem Cell-Derived Stromal Cells Serve a Starting Material for Myoblasts?

A large number of myocytes are necessary to treat intractable muscular disorders such as Duchenne muscular dystrophy with cell-based therapies. However, starting materials for cellular therapy products such as myoblasts, marrow stromal cells, menstrual blood-derived cells, and placenta-derived cells have a limited lifespan and cease to proliferate in vitro. From the viewpoints of manufacturing and quality control, cells with a long lifespan are more suitable as a starting material. In this study, we generated stromal cells for future myoblast therapy from a working cell bank of human embryonic stem cells (ESCs). The ESC-derived CD105+ cells with extensive in vitro proliferation capability exhibited myogenesis and genetic stability in vitro. These results imply that ESC-derived CD105+ cells are another cell source for myoblasts in cell-based therapy for patients with genetic muscular disorders. Since ESCs are immortal, mesenchymal stromal cells generated from ESCs can be manufactured at a large scale in one lot for pharmaceutical purposes.

Short-term feeding at the wrong time is sufficient to desynchronize peripheral clocks and induce obesity with hyperphagia, physical inactivity and metabolic disorders in mice.

BACKGROUND: The circadian clock regulates various physiological and behavioral rhythms such as feeding and locomotor activity. Feeding at unusual times of the day (inactive phase) is thought to be associated with obesity and metabolic disorders in experimental animals and in humans. OBJECTIVE: The present study aimed to determine the underlying mechanisms through which time-of-day-dependent feeding influences metabolic homeostasis. METHODS: We compared food consumption, wheel-running activity, core body temperature, hormonal and metabolic variables in blood, lipid accumulation in the liver, circadian expression of clock and metabolic genes in peripheral tissues, and body weight gain between mice fed only during the sleep phase (DF, daytime feeding) and those fed only during the active phase (NF, nighttime feeding). All mice were fed with the same high-fat high-sucrose diet throughout the experiment. To the best of our knowledge, this is the first study to examine the metabolic effects of time-imposed restricted feeding (RF) in mice with free access to a running wheel. RESULTS: After one week of RF, DF mice gained more weight and developed hyperphagia, higher feed efficiency and more adiposity than NF mice. The daily amount of running on the wheel was rapidly and obviously reduced by DF, which might have been the result of time-of-day-dependent hypothermia. The amount of daily food consumption and hypothalamic mRNA expression of orexigenic neuropeptide Y and agouti-related protein were significantly higher in DF, than in NF mice, although levels of plasma leptin that fluctuate in an RF-dependent circadian manner, were significantly higher in DF mice. These findings suggested that the DF induced leptin resistance. The circadian phases of plasma insulin and ghrelin were synchronized to RF, although the corticosterone phase was unaffected. Peak levels of plasma insulin were remarkably higher in DF mice, although HOMA-IR was identical between the two groups. Significantly more free fatty acids, triglycerides and cholesterol accumulated in the livers of DF, than NF mice, which resulted from the increased expression of lipogenic genes such as Scd1, Acaca, and Fasn. Temporal expression of circadian clock genes became synchronized to RF in the liver but not in skeletal muscle, suggesting that uncoupling metabolic rhythms between the liver and skeletal muscle also contribute to DF-induced adiposity. CONCLUSION: Feeding at an unusual time of day (inactive phase) desynchronizes peripheral clocks and causes obesity and metabolic disorders by inducing leptin resistance, hyperphagia, physical inactivity, hepatic fat accumulation and adiposity.

Stem cells in asexual reproduction of Enchytraeus japonensis (Oligochaeta, Annelid): proliferation and migration of neoblasts.

Enchytraeus japonensis is a small oligochaete that reproduces mainly asexually by fragmentation (autotomy) and regeneration. As sexual reproduction can also be induced, it is a good animal model for the study of both somatic and germline stem cells. To clarify the features of stem cells in regeneration, we investigated the proliferation and lineage of stem cells in E. japonensis. Neoblasts, which have the morphological characteristics of undifferentiated cells, were found to firmly adhere to the posterior surface of septa in each trunk segment. Also, smaller neoblast-like cells, which are designated as N-cells in this study, were located dorsal to the neoblasts on the septa. By conducting 5-bromo-2'-deoxyuridine (BrdU)-labeling-experiments, we have shown that neoblasts are slow-cycling (or quiescent) in intact growing worms, but proliferate rapidly in response to fragmentation. N-cells proliferate more actively than do neoblasts in intact worms. The results of pulse-chase experiments indicated that neoblast and N-cell lineage mesodermal cells that incorporated BrdU early in regeneration migrated toward the autotomized site to form the mesodermal region of the blastema, while the epidermal and intestinal cells also contributed to the blastema locally near the autotomized site. We have also shown that neoblasts have stem cell characteristics by expressing Ej-vlg2 and by the activity of telomerase during regeneration. Telomerase activity was high in the early stage of regeneration and correlated with the proliferation activity in the neoblast lineage of mesodermal stem cells. Taken together, our results indicate that neoblasts are mesodermal stem cells involved in the regeneration of E. japonensis.

Sec14l3 is specifically expressed in mouse airway ciliated cells.

Airway epithelium is a key component for airway integrity. Previously, we found that expression of the Sec14l3 gene that encodes a 45-kDa secretory protein is inversely associated with the progression of experimentally induced airway inflammation and degeneration/necrosis of alveolar epithelium. In this report, using in situ hybridization we demonstrated that the ciliated cells in mouse lung selectively express Sec14l3 mRNA. In a three-dimensional culture of mouse tracheal epithelial cells, levels of the Sec14l3 mRNA correlated with the differentiation of ciliated cells. Intranasal infection of adult mice with influenza virus resulted in a 20-fold, progressive decrease in Sec14l3 mRNA expression over 10 days post infection. These results enhance the potential value of Sec14l3 as a ciliated epithelial cell-specific biomarker for the progression of airway inflammations such as airway viral infection and asthma.

Moderate low temperature preserves the stemness of neural stem cells and suppresses apoptosis of the cells via activation of the cold-inducible RNA binding protein.

We hypothesized that one of the mechanisms underlying the protection of brain injury by therapeutic hypothermia is associated with preservation of neural stem cells. We investigated effects of moderate low temperature and the contribution of a cold-inducible molecule for the stemness of neural stem cells. The MEB5 mouse neural stem cell line was cultured in the presence or absence of EGF, and apoptosis, mRNA expression, and immunocytochemistry of the differentiation markers nestin and GFAP were evaluated at 37 or 32°C. We investigated the contribution of the cold-inducible RNA binding protein (CIRP) on apoptosis and differentiation of MEB5 cells at 32°C. EGF deprivation increased the number of apoptotic cells, decreased expression of nestin, and increased expression of GFAP. The moderate low temperature prevented apoptosis and decreases in expression of GFAP in MEB5 by EGF deprivation. The moderate low temperature significantly increased expression of CIRP. siRNA against CIRP significantly increased the apoptotic cell population of MEB5 cells via EGF deprivation at 32°C. These findings suggest that moderate low temperature preserved stemness of neural stem cells and prevented cell apoptosis via the stimulation of CIRP, and one of the mechanisms of rescue of brain injury by the moderate hypothermia is associated with preservation of neural stem cells.

Functional analysis of grimp, a novel gene required for mesodermal cell proliferation at an initial stage of regeneration in Enchytraeus japonensis (Enchytraeidae, Oligochaete).

Enchytraeus japonensis is a small oligochaete species, which has a remarkable regeneration capacity. It has been proposed as a new model animal for the study of regeneration, and some histological studies of this species have been carried out. On the other hand, the molecular biological mechanism of regeneration is almost unknown in this species. To clarify the molecular biological mechanism operating at an initial stage of regeneration in E. japonensis, we isolated by the cDNA subtraction method five genes whose expression levels changed in the regeneration process occurring between growing and early regenerating worms. One of the isolated genes (a novel gene named grimp) was expressed transiently from 3 to 12 h post amputation only in neoblasts and a population of mesodermal cells (the non-neoblast grimp-expressing cells) incorporating BrdU simultaneously showed mitotic activity. We succeeded in inhibiting grimp expression by RNA interference (RNAi), thus applying this technique for the first time in Oligochaeta. In knock-down worms, the number of BrdU-positive neoblasts and the non-neoblast grimp-expressing cells in the coelom drastically decreased. Moreover, the elongation and the segmentation of blastemas were inhibited, while no statistically significant inhibitory effect was observed in epidermal and intestinal cells. These results suggest that grimp is required for initial proliferation of neoblasts and some mesodermal cells for regeneration.

Stem cell system in asexual and sexual reproduction of Enchytraeus japonensis (Oligochaeta, Annelida).

Enchytraeus japonensis is a small oligochaete species that proliferates asexually via fragmentation and regeneration. As sexual reproduction can also be induced, it is a good model system for the study of both regenerative and germline stem cells. It has been shown by histological study that putative mesodermal stem cells called neoblasts, and dedifferentiated epidermal and endodermal cells are involved in blastema formation. Recently, we isolated three region-specific marker genes expressed in the digestive tract and showed by in situ hybridization that morphallactic as well as epimorphic regulation of the body patterning occurs during regeneration. We also cloned two vasa-related genes and analyzed their expression during development and in mature worms that undergo sexual reproduction. The results arising form these studies suggest that the origin and development of germline stem cells and neoblasts may be independent. Furthermore, we carried out functional analysis using RNA interference (RNAi) and showed that a novel gene termed grimp is required for mesodermal cell proliferation at the initial stages of regeneration. These findings indicate that the stem cell system in E. japonensis is regulated by both internal and external environmental factors.

Development of pyrrole-imidazole polyamide for specific regulation of human aurora kinase-A and -B gene expression.

Pyrrole-imidazole polyamide (PIP) is a nuclease-resistant novel compound that inhibits gene expression through binding to the minor groove of DNA. Human aurora kinase-A (AURKA) and -B (AURKB) are important regulators in mitosis during the cell cycle. In this study, two specific PIPs (PIP-A and PIP-B) targeting AURKA and AURKB promoter regions were designed and synthesized, and their biological effects were investigated by several in vitro assays. PIP-A and PIP-B significantly inhibited the promoter activities, mRNA expression, and protein levels of AURKA and AURKB, respectively, in a concentration-dependent manner. Moreover, 1:1 combination treatment with both PIPs demonstrated prominent antiproliferative synergy (CI value [ED(50)] = 0.256) to HeLa cells as a result of inducing apoptosis-mediated severe catastrophe of cell-cycle progression. The novel synthesized PIP-A and PIP-B are potent and specific gene-silencing agents for AURKA and AURKB.

Morphallactic regeneration as revealed by region-specific gene expression in the digestive tract of Enchytraeus japonensis (Oligochaeta, Annelida).

Enchytraeus japonensis is a small oligochaete, which primarily reproduces asexually by fragmentation and regeneration. For precise analysis of the pattern formation during regeneration, we isolated three region-specific genes (EjTuba, mino, and horu) expressed in the digestive tract. In growing worms, the expression of EjTuba in the head and mino in the trunk region just posterior to the head were observed in defined body segments, while the expression areas of EjTuba in the trunk and horu were proportional to the total number of body segments. In the regeneration process, expression of these genes disappeared once and recovered to their original pattern by day 7. In abnormal regeneration such as a bipolar head, mino was still expressed in the region next to both the normal and the ectopic heads. These results suggest that there is morphallactic as well as epimorphic or inductive regulation of the body patterning during regeneration of E. japonensis.

Exploration of embryonic origins of germline stem cells and neoblasts in Enchytraeus japonensis (Oligochaeta, Annelida).

An oligochaete annelid species, Enchytraeus japonensis, reproduces not only asexually but also sexually. It has been reported that putative mesodermal stem cells called neoblasts contribute to blastema formation and that Ej-piwi(+) germline stem cells participate in gonadal regeneration. To delineate the origin and formation of both of these stem cells, we isolated two vasa-related genes (Ej-vlg1 and Ej-vlg2) and analyzed the expression of each along with that of germline marker gene Ej-piwi. In adults, Ej-vlg1 and Ej-vlg2 were expressed in Ej-piwi(+) germline stem cells and germ cells in gonads, while only Ej-vlg2 mRNAs were detected in neoblasts. Expression analysis during embryogenesis indicated that clusters of Ej-vlg1(+)/Ej-vlg2(+) cells, located at the posterior ventral region in late embryos, became Ej-vlg1(+)/Ej-vlg2(+)/Ej-piwi(+) germline stem cells just after embryogenesis. On the other hand, Ej-vlg2 single positive cells with morphological characteristics of neoblasts became detectable much later after embryogenesis at the ventral position on each septum where adult neoblasts exist, although these early detected cells were much smaller in size than adult neoblasts. The present results suggest that (1) germline stem cells specified just after embryogenesis are derived from Ej-vlg1(+)/Ej-vlg2(+) cells which appear at the posterior ventral region in late embryos, and that (2) neoblasts appear much later in development.

Analysis of tissue-specific differentially methylated regions (TDMs) in humans.

Alterations in DNA methylation have been implicated in mammalian development. Hence, the identification of tissue-specific differentially methylated regions (TDMs) is indispensable for understanding its role. Using restriction landmark genomic scanning of six mouse tissues, 150 putative TDMs were identified and 14 were further analyzed. The DNA sequences of the 14 mouse TDMs are analyzed in this study. Six of the human homologous regions show TDMs to both mouse and human and genes in five of these regions have conserved tissue-specific expression: preferential expression in testis. A TDM, DDX4, is further analyzed in nine testis tissues. An increase in methylation of the promoter region is significantly associated with a marked reduction of the gene expression and defects in spermatogenesis, suggesting that hypomethylation of the DDX4 promoter region regulates DDX4 gene expression in spermatogenic cells. Our results indicate that some genomic regions with tissue-specific methylation and expression are conserved between mouse and human and suggest that DNA methylation may have an important role in regulating differentiation and tissue-/cell-specific gene expression of some genes.

Structural characterization of neutral glycosphingolipids by thin-layer chromatography coupled to matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight MS/MS.

Rapid and convenient structural analysis of neutral glycosphingolipids (GSLs) was achieved by direct coupling of thin-layer chromatography (TLC) to matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight (MALDI-QIT-TOF) MS/MS. Positions of unstained GSL spots on developed TLC plates were determined by comparison to orcinol-stained references. A matrix solution of 2,5-dihydroxybenzoic acid (DHB) in acetonitrile/water (1:1 v/v) was then added directly to the unstained GSL spots, and the GSLs were directly analyzed by MALDI-QIT-TOF MS. The acetonitrile/water DHB solution proved to be suitable for MS/MS structural analysis with high sensitivity. MS/MS and MS/MS/MS of GSLs yielded simple and informative spectra that revealed the ceramide and long-chain base structures, as well as the sugar sequences. Hydroxy fatty acids in ceramide provided characteristic MS/MS fragment ions. GSLs were stained with primuline, a nondestructive dye, after TLC development, and successfully analyzed by MALDI-QIT-TOF MS/MS with high sensitivity. Immunostaining of GSLs after TLC development is a powerful method for characterizing antibody-specific sugars, but not ceramides. By coupling TLC-immunostaining of GSLs to MALDI-QIT-TOF MS/MS, we were able to identify both the sugar and the ceramide structures. The detection limits of asialo GM1 (Galbeta1-3GalNAcbeta1-4Galbeta1-4Glcbeta1-1'Cer) were 25 and 50 pmol in primuline staining and immunostaining, respectively.

Bipolar head regeneration induced by artificial amputation in Enchytraeus japonensis (Annelida, Oligochaeta).

The Enchytraeida Oligochaeta Enchytraeus japonensis propagates asexually by spontaneous autotomy. Normally, each of the 5-10 fragments derived from a single worm regenerates a head anteriorly and a tail posteriorly. Occasionally, however, a head is formed posteriorly in addition to the normal anterior head, resulting in a bipolar worm. This phenomenon prompted us to conduct a series of experiments to clarify how the head and the tail are determined during regeneration in this species. The results showed that (1) bipolar head regeneration occurred only after artificial amputation, and not by spontaneous autotomy, (2) anesthesia before amputation raised the frequency of bipolar head regeneration, and (3) an extraordinarily high proportion of artificially amputated head fragments regenerated posterior heads. Close microscopic observation of body segments showed that each trunk segment has one specific autotomic position, while the head segments anterior to the VIIth segment do not. Only the most posterior segment VII in the head has an autotomic position. Examination just after amputation found that the artificial cutting plane did not correspond to the normal autotomic position in most cases. As time passed, however, the proportion of worms whose cutting planes corresponded to the autotomic position increased. It was suspected that the fragments autotomized after the artificial amputation (corrective autotomy). This post-amputation autotomy was probably inhibited by anesthesia. The rate at which amputated fragments did not autotomize corresponded roughly to the rate of bipolar regeneration. It was hypothesized then that the head regenerated posteriorly if a fragment was not amputated at the precise autotomic position from which it regenerated without succeeding in corrective autotomy.

Detection of the Initial Step of Mesenchymal Differentiation of Teratocarcinoma Cells Using the Monoclonal Antibody Eccd-11 : (teratocarcinoma/cell-cell adhesion/mesenchymal differentiation/clonal culture).

The monoclonal antibody ECCD-1 recognizes the Ca2+ -dependent cell-cell adhesion molecule of teratocarcinoma stem cells (EC cells) and of a certain class of differentiated epithelial cells. It actively disrupts cell-cell adhesion when added to monolayer cultures of these cells, but does not affect adhesion of mesenchymal or neuronal cells. When ECCD-1 was added to clonal cultures of EC cells (PCC3/A/1 line), all the cells were initially sensitive to the antibody, but after 5 to 6 days of culture a fraction of the cells in certain colonies no longer reacted with the antibody although they expressed alkaline phosphatase activity, which is a marker of undifferentiated EC cells. We isolated these ECCD-1-resistant cells by recloning and examined their differentiation by clonal culture. Most of them differentiated into fibroblastic cells and a few into skeletal muscle-like cells, but none differentiated into any other cell types. From these observations, we suppose that the ECCD-1-resistant population of EC cells are committed to mesenchymal differentiation. The use of ECCD-1, thus, permitted us to detect EC cells at the initial stage of a particular differentiation pathway.