401 research outputs found
The effect of foreign direct investment on Indonesian economic growth, 1970-1996
This paper estimates the effects of foreign investment on Indonesia's economic growth for the period 1970 to 1996. Economic growth is measured by growth in gross domestic product (GDP) and gross domestic income (GNI), Two types of foreign investment are considered: foreign direct investment (FDI) and net private capital flows. Other determinants of economic growth included in the analysis are human capital and gross domestic savings. The results suggest that foreign direct investment, net private capital, human capital and gross domestic savings jointly influence economic growth. Foreign direct investment has a significant positive effect on economic growth, while net private capital has no significant effect. Human capital, proxied by the proportion of the population in the labour force and secondary school enrolments, and gross domestic savings, also exert a positive influence on economic growth. On the basis of the analysis, it is suggested that, to enhance the role of FDI in Indonesia's economic growth, the government should encourage the participation of foreign-owned enterprises (FOEs) in export-oriented industries and encourage the use of domestic inputs. There is also the need to enhance the quality of human capital through improved education and improved skills training
Chromatin immunoprecipitation-based analysis of gene regulatory networks operative in human embryonic stem cells
Chromatin immunoprecipitation (ChIP) followed by microarray-based (ChIP-Chip) or next-generation sequencing-based (ChIP-Seq) analysis has been established as a powerful and widely used method to investigate DNA-protein interactions relative to a genomic location in vivo. Here, we present a ChIP-Chip protocol, which utilizes an alternative, easier amplification protocol and when using high-quality ChIP-grade antibodies, will generate enough material for hybridization or sequencing with negligible enrichment bias due to amplification
Crosstalk between age accumulated DNA-damage and the SIRT1-AKT-GSK3ß axis in urine derived renal progenitor cells
The aging process is manifested by a multitude of inter-linked biological processes. These processes contribute to genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, de-regulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. The mammalian ortholog of the yeast silent information regulator (Sir2) SIRT1 is a NAD+-dependent class III histone deacetylase and has been recognized to be involved in many of the forementioned processes. Furthermore, the physiological activity of several Sirtuin family members has been connected to the regulation of life span of lower organisms (Caenorhabditis elegans and Drosophila melanogaster) as well as mammals. In the present study, we provide evidence that SIX2-positive urine derived renal progenitor cells-UdRPCs isolated directly from human urine show typical hallmarks of aging. This includes the subsequent transcriptional downregulation of SIRT1 and its downstream targets AKT and GSK3ß with increased donor age. This transcriptional downregulation is accompanied by an increase in DNA damage and transcriptional levels of several cell cycle inhibitors such as P16. We provide evidence that the renal progenitor transcription factor SIX2 binds to the coding sequence of SIRT1. Furthermore, we show that the SIRT1 promoter region is methylation sensitive and becomes methylated during aging, dividing them into SIRT1-high and -low expressing UdRPCs. Our results highlight the importance of SIRT1 in DNA damage repair recognition in UdRPCs and the control of differentiation by regulating the activation of GSK3β through AKT
Analysis of the methylome of human embryonic stem cells employing methylated DNA immunoprecipitation coupled to next-generation sequencing
The analysis of DNA-methylation on a genome-wide scale by next-generation sequencing techniques is an invaluable tool towards the understanding of the epigenetic basis of cellular differentiation. Methylated DNA immunoprecipitation (MeDIP) is an immunocapturing method using an antibody targeting 5-methylcytidine (5 mC) and thereby enriching methylated DNA. MeDIP combined with next-generation sequencing (MeDIP-seq) provides a powerful tool for the analysis of genome-wide DNA-methylation profiles. Here, we describe a protocol for the preparation of MeDIP samples suitable for next-generation sequencing on a Genome Analyser (Illumina)
Episomal plasmid-based generation of induced pluripotent stem cells from fetal femur-derived human mesenchymal stromal cells.
Human bone mesenchymal stromal cells derived from fetal femur 55 days post-conception were reprogrammed to induced pluripotent stem cells using episomal plasmid-based expression of OCT4, SOX2, NANOG, LIN28, SV40LT, KLF4 and c-MYC and supplemented with the following pathway inhibitors — TGF? receptor inhibitor (A-83-01), MEK inhibitor (PD325901), GSK3? inhibitor (CHIR99021) and ROCK inhibitor (HA-100). Successful induction of pluripotency in two iPS-cell lines was demonstrated in vitro and by the Plurites
Fibroblast growth factor 2 modulates transforming growth factor ß signaling in mouse embryonic fibroblasts and human ESCs (hESCs) to support hESC self-renewal
Fibroblast growth factor 2 (FGF2) is known to promote self-renewal of human embryonic stem cells (hESCs). In addition, it has been shown that transforming growth factor ß (TGFß) signaling is crucial in that the TGFß/Activin/Nodal branch of the pathway needs to be activated and the bone morphogenic protein (BMP)/GDF branch repressed to prevent differentiation. This holds particularly true for Serum Replacement-based medium containing BMP-like activity. We have reinvestigated a widely used protocol for conditioning hESC medium with mouse embryonic fibroblasts (MEFs). We show that FGF2 acts on MEFs to release supportive factors and reduce differentiation-inducing activity. FGF2 stimulation experiments with supportive and nonsupportive MEFs followed by genome-wide expression profiling revealed that FGF2 regulates the expression of key members of the TGFß pathway, with Inhba, Tgfb1, Grem1, and Bmp4 being the most likely candidates orchestrating the above activities. In addition, restimulation experiments in hESCs combined with global expression analysis revealed downstream targets of FGF2 signaling in these cells. Among these were the same factors previously identified in MEFs, thus suggesting that FGF2, at least in part, promotes self-renewal of hESCs by modulating the expression of TGFß ligands, which, in turn, act on hESCs in a concerted and autocrine manner
Characterisation of neurofilament protein NF70 mRNA from the gastropod Helix aspersa reveals that neuronal and non-neuronal intermediate filament proteins of cerebral ganglia arise from separate lamin-related genes
Analysis of Oct4-dependent transcriptional networks regulating self-renewal and pluripotency in human embryonic stem cells
The POU domain transcription factor OCT4 is a key regulator of pluripotency in the early mammalian embryo and is highly expressed in the inner cell mass of the blastocyst. Consistent with its essential role in maintaining pluripotency, Oct4 expression is rapidly downregulated during formation of the trophoblast lineage. To enhance our understanding of the molecular basis of this differentiation event in humans, we used a functional genomics approach involving RNA interference-mediated suppression of OCT4 function in a human ESC line and analysis of the resulting transcriptional profiles to identify OCT4-dependent genes in human cells. We detected altered expression of >1,000 genes, including targets regulated directly by OCT4 either positively (NANOG, SOX2, REX1, LEFTB, LEFTA/EBAF DPPA4, THY1, and TDGF1) or negatively (CDX2, EOMES, BMP4, TBX18, Brachyury [T], DKK1, HLX1, GATA6, ID2, and DLX5), as well as targets for the OCT4-associated stem cell regulators SOX2 and NANOG. Our data set includes regulators of ACTIVIN, BMP, fibroblast growth factor, and WNT signaling. These pathways are implicated in regulating human ESC differentiation and therefore further validate the results of our analysis. In addition, we identified a number of differentially expressed genes that are involved in epigenetics, chromatin remodeling, apoptosis, and metabolism that may point to underlying molecular mechanisms that regulate pluripotency and trophoblast differentiation in humans. Significant concordance between this data set and previous comparisons between inner cell mass and trophectoderm in human embryos indicates that the study of human ESC differentiation in vitro represents a useful model of early embryonic differentiation in humans
FGF inhibition directs BMP4-mediated differentiation of human embryonic stem cells to syncytiotrophoblast
Bone morphogenetic protein (BMP) signaling is known to support differentiation of human embryonic stem cells (hESCs) into mesoderm and extraembryonic lineages, whereas other signaling pathways can largely influence this lineage specification. Here, we set out to reinvestigate the influence of ACTIVIN/NODAL and fibroblast growth factor (FGF) pathways on the lineage choices made by hESCs during BMP4-driven differentiation. We show that BMP activation, coupled with inhibition of both ACTIVIN/NODAL and FGF signaling, induces differentiation of hESCs, specifically to betahCG hormone-secreting multinucleated syncytiotrophoblast and does not support induction of embryonic and extraembryonic lineages, extravillous trophoblast, and primitive endoderm. It has been previously reported that FGF2 can switch BMP4-induced hESC differentiation outcome to mesendoderm. Here, we show that FGF inhibition alone, or in combination with either ACTIVIN/NODAL inhibition or BMP activation, supports hESC differentiation to hCG-secreting syncytiotrophoblast. We show that the inhibition of the FGF pathway acts as a key in directing BMP4-mediated hESC differentiation to syncytiotrophoblast
Nijmegen Breakage Syndrome fibroblasts and iPSCs: cellular models for uncovering disease-associated signaling pathways and establishing a screening platform for anti-oxidants.
Nijmegen Breakage Syndrome (NBS) is associated with cancer predisposition, premature aging, immune deficiency, microcephaly and is caused by mutations in the gene coding for NIBRIN (NBN) which is involved in DNA damage repair. Dermal-derived fibroblasts from NBS patients were reprogrammed into induced pluripotent stem cells (iPSCs) in order to bypass premature senescence. The influence of antioxidants on intracellular levels of ROS and DNA damage were screened and it was found that EDHB-an activator of the hypoxia pathway, decreased DNA damage in the presence of high oxidative stress. Furthermore, NBS fibroblasts but not NBS-iPSCs were found to be more susceptible to the induction of DNA damage than their healthy counterparts. Global transcriptome analysis comparing NBS to healthy fibroblasts and NBS-iPSCs to embryonic stem cells revealed regulation of P53 in NBS fibroblasts and NBS-iPSCs. Cell cycle related genes were down-regulated in NBS fibroblasts. Furthermore, oxidative phosphorylation was down-regulated and glycolysis up-regulated specifically in NBS-iPSCs compared to embryonic stem cells. Our study demonstrates the utility of NBS-iPSCs as a screening platform for anti-oxidants capable of suppressing DNA damage and a cellular model for studying NBN de-regulation in cancer and microcephaly
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