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Aim: The objective of this study is to determine if exuberant sympathetic nerve activity is involved in muscle satellite cell differentiation and myoblast fusion., Methods and Results: By using immunoassaying and western blot analyses, we found that β1 and β2-adrenergic receptors (AdR) were expressed in C2C12 cells. The differentiated satellite cells exhibited an increased expression of β2-AdR, as compared with the proliferating cells. Continuous exposure of isoprenaline (ISO), a β-AdR agonist, delayed C2C12 cell differentiation, and myoblast fusion in time- and dose-dependent manner. ISO also increased short myotube numbers while decreasing long myotube numbers, consistent with the greater reduction in MyHC1, MyHC2a, and MyHC2x expression. Moreover, continuous exposure of ISO gradually decreased the ratio of PKA RI/RII, and PKA RI activator efficiently reversed the ISO effect on C2C12 cell differentiation and myoblast fusion while PKA inhibitor H-89 deteriorated the effects. Continuous single-dose ISO increased β1-AdR expression in C2C12 cells. More importantly, the cells showed enhanced phospho-ERK1/2 levels, resulting in increasing phospho-β2-AdR levels while decreasing β2-AdR levels, and the specific effects could be abolished by ERK1/2 inhibitor. Furthermore, continuous exposure of ISO induced FOXO1 nuclear translocation and increased the levels of FOXO1 in nuclear extracts while reducing pAKT, p-p38MAPK, and pFOXO1 levels. Conversely, blockade of ERK1/2 signaling partially abrogated ISO effects on AKT, p38MAPK, and FOXO1signaling, which partially restored C2C12 cell differentiation and myoblast fusion, leading to an increase in the numbers of medium myotube along with the increased expression of MyHC1 and MyHC2a., Conclusion: Continuous exposure of ISO impedes satellite cell differentiation and myoblast fusion, at least in part, through PKA-ERK1/2-FOXO1 signaling pathways, which were associated with the reduced β2-AdR and increased β1-AdR levels.

As a member of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION-related (CLE) peptide family, tracheary element differentiation inhibitory factor (TDIF) plays crucial roles in vascular meristem maintenance by promoting cell proliferation and inhibiting xylem cell differentiation. In Populus trichocarpa , six TDIF-encoding genes are all expressed in vascular tissues, and in Arabidopsis PtTDIFpro:GUS lines, the expression driven by PtTDIF promoters were predominantly detected in stem vascular bundles, initiating leaves and leaf veins. Although exogenous application of two poplar TDIF peptides did not evidently affect the shoot growth in vitro , overexpression of PtTDIF genes in hybrid poplar severely retarded the internodal elongation by upregulating the expression of GA2ox and GA20ox genes and thus decreasing the level of endogenous gibberellins (GAs), which phenotypic defect could be rescued by exogenously applied GA3. In addition, TDIF overexpression unexpectedly induced a more complex venation pattern in poplar leaves, which was underpinned by the elevated expression of WOX4 and WOX13 genes. Upon TDIF treatment, the DR5:GUS poplar leaves revealed a higher GUS activity and in TDIF -overexpressing leaves, the transcript abundances of several PIN-FORMED (PIN) genes, especially that of PIN1 , were increased, which implied an integration of TDIF and auxin in mediating this process. Collectively, data of this work presented novel activities of TDIF involved in internode elongation and leaf vein formation, thus revealing the divergent functions of TDIF in perennial tree species from those in annual herbaceous Arabidopsis. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: It has been reported that integrin-α5 (ITGA5) activity is related to cell proliferation, differentiation, migration, and organ development. However, the involvement of ITGA5 in the biological functions of human dental pulp stem cells (hDPSCs) has not been explored. The aim of this study was to investigate the role of ITGA5 in the proliferation and odontogenic differentiation of hDPSCs. Methods: We knocked down ITGA5 in hDPSCs using lentivirus-mediated ITGA5 short hairpin RNA (shRNA). Changes in the proliferation in hDPSCs infected with lentiviruses expressing ITGA5-specific shRNA or negative control shRNA were examined using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 5-ethynyl-2′-deoxyuridine labeling. Both ITGA5 knockdown cells and shMock cells were cultured in mineralization medium for 3 weeks, and the differentiation of cells was detected with alizarin red S staining. The expression of odontogenic differentiation-related molecular markers was assessed using real-time polymerase chain reaction and Western blot assays. Results: The knockdown of ITGA5 decreased the proliferation capacity of hDPSCs. ITGA5 shRNA promoted odontogenic differentiation of hDPSCs with the enhanced formation of mineralized nodules. It also up-regulated the messenger RNA expression of multiple markers of odontogenesis and the expression of dentin sialophosphoprotein protein. Conclusions: These findings suggest that ITGA5 plays an important role in maintaining hDPSCs in a proliferative state. The inhibition of ITGA5 signaling promotes the odontogenic differentiation of hDPSCs. [Copyright &y& Elsevier]

Background: Creation of artificial gametes may provide a universal solution for these patients with no gametes. Stem cell technology may provide a way to obtain fully functional gametes. Retinoic acid (RA) can initiate meiosis. Several studies have demonstrated that RA can promote sperm cells differentiation from mouse embryonic stem cells (mESCs) and other cells from human embryonic stem cells (hESCs). Objective: We sought to determine whether RA could promote differentiation of germ cells from hESCs. Materials and Methods: hESCs were differentiated as embryoid bodies (EBs) in suspension with all-trans RA (atRA) or without atRA for 0, 1, 3, 5 and 7 days, and then the expression of VASA, SCP3, GDF9 and TEKT1 were compared by realtime PCR. The statistical differences were evaluated by one way ANOVA. Results: The expression of germ cell-specific markers including the gonocyte marker VASA, the meiotic marker SCP3, and post meiotic markers, GDF9 and TEKT1, all increased in the presence and absence of RA as EB differentiation progressed. In addition, the expression of these markers increased an average of 9.3, 6.9, 7.2 and 11.8 fold respectively in the presence of RA, compared to the absence of RA, over 5 days differentiation. Conclusion: Our results indicate that hESCs may have the potential to differentiate to primordial germ cells (PGCs) and early gametes. RA can improve germ cells differentiation from hESCs. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: It is suggested that dental pulp stem cells are involved in tooth regeneration and play an important role in maintaining pulp homeostasis. Previously, normal dental pulps were more widely used for experimental models than carious dental pulps. The aim of this study was to isolate and culture the dental pulp stem cells from carious and normal teeth and to evaluate stem cell parameters. Methods: Pulp tissues were obtained and dissociated from normal and carious teeth. Single-cell suspensions were seeded into 6-well plates and purified by collecting multiple colonies. Normal dental pulp stem cells (DPSCs) and carious dental pulp stem cells (CDPSCs) were compared for morphologic appearance and for their capacity to differentiate into 3 lineages. Colony-forming and MTT assays, cell cycle analysis, gene expression, and alkaline phosphatase activity were also evaluated. Results: Stem cells were cultured successfully from normal and carious dental pulps. CDPSCs displayed increased proliferation ability compared with DPSCs. CDPSCs also showed enhanced ALP activity, mineralization ability, and expression of osteogenesis/dentinogenesis-related genes. All cultures differentiated into 3 cell types. Conclusions: Our data suggest that caries as a local microenvironment should be taken into account when DPSCs are intended to be used for investigations and application. Furthermore, the mechanism of the underlying changes in cell properties requires further study. [Copyright &y& Elsevier]

Background: Esophageal squamous cell carcinoma (ESCC) cells are heterogeneous, easily develop radioresistance, and recur. Single-cell RNA-seq (scRNA-seq) is a next-generation sequencing method that can delineate diverse gene expression profiles of individual cells and mining their heterogeneous behaviors in response to irradiation. Our aim was using scRNA-seq to describe the difference between parental cells and cells that acquired radioresistance, and to investigate the dynamic changes of the transcriptome of cells in response to FIR. Results: We sequenced ESCC cell lines KYSE180 with and without fractionated irradiation (FIR). A total of 218 scRNA-seq libraries were obtained from 88 cells exposed to 12 Gy (KYSE-180-12 Gy), 89 exposed to 30 Gy (KYSE-180-30 Gy), and 41 parental KYSE-180 cells not exposed to FIR. Dynamic gene expression patterns were determined by comprehensive consideration of genes and pathways. Biological experiments showed that KYSE-180 cells became radioresistant after FIR. PCA analysis of scRNA-seq data showed KYSE-180, KYSE-180-12 Gy and KYSE-180-30 Gy cells were discrete away from each other. Two sub-populations found in KYSE-180-12 Gy and only one remained in KYSE-180-30 Gy. This sub-population genes exposure to FIR through 12 Gy to 30 Gy were relevant to the PI3K-AKT pathway, pathways evading apoptosis, tumor cell migration, metastasis, or invasion pathways, and cell differentiation and proliferation pathways. We validated DEGs, such as CFLAR, LAMA5, ITGA6, ITGB4, and SDC4 genes, in these five pathways as radioresistant genes in bulk cell RNA-seq data from ESCC tissue of a ESCC patient treated with radiotherapy and from KYSE-150 cell lines. Conclusions: Our results delineated the divergent gene expression patterns of individual ESCC cells exposure to FIR, and displayed genes and pathways related to development of radioresistance. [ABSTRACT FROM AUTHOR]