183 research outputs found
Differentiation of Human Induced Pluripotent Stem Cells to Brain Microvascular Endothelial Cell-Like Cells with a Mature Immune Phenotype.
Blood-brain barrier (BBB) dysfunction is a pathological hallmark of many neurodegenerative and neuroinflammatory diseases affecting the central nervous system (CNS). Due to the limited access to disease-related BBB samples, it is still not well understood whether BBB malfunction is causative for disease development or rather a consequence of the neuroinflammatory or neurodegenerative process. Human induced pluripotent stem cells (hiPSCs) therefore provide a novel opportunity to establish in vitro BBB models from healthy donors and patients, and thus to study disease-specific BBB characteristics from individual patients. Several differentiation protocols have been established for deriving brain microvascular endothelial cell (BMEC)-like cells from hiPSCs. Consideration of the specific research question is mandatory for the correct choice of the respective BMEC-differentiation protocol. Here, we describe the extended endothelial cell culture method (EECM), which is optimized to differentiate hiPSCs into BMEC-like cells with a mature immune phenotype, allowing the study of immune cell-BBB interactions. In this protocol, hiPSCs are first differentiated into endothelial progenitor cells (EPCs) by activating Wnt/Ī²-catenin signaling. The resulting culture, which contains smooth muscle-like cells (SMLCs), is then sequentially passaged to increase the purity of endothelial cells (ECs) and to induce BBB-specific properties. Co-culture of EECM-BMECs with these SMLCs or conditioned medium from SMLCs allows for the reproducible, constitutive, and cytokine-regulated expression of EC adhesion molecules. Importantly, EECM-BMEC-like cells establish barrier properties comparable to primary human BMECs, and due to their expression of all EC adhesion molecules, EECM-BMEC-like cells are different from other hiPSC-derived in vitro BBB models. EECM-BMEC-like cells are thus the model of choice for investigating the potential impact of disease processes at the level of the BBB, with an impact on immune cell interaction in a personalized fashion
The Sp1 and CBF/NF-Y Transcription Factors Cooperatively Regulate the Mouse Pro-alpha3(V) Collagen Gene (Col5a3) in Osteoblastic Cells
The purpose of this study was to clarify the mechanism responsible for the transcriptional regulation of the mouse Col5a3 gene in osteoblastic cells. Transient transfection into rat osteosarcoma ROS17/2.8 cells demonstrated that a region from nucleotides 337 to 1 was involved in the transcriptional activity of the Col5a3 gene. An electrophoretic mobility shift assay showed that Sp1/Sp3 and CBF/NF-Y bound to a GC-rich domain (194/186) and a CCAAT box (134/130) in the Col5a3 gene, respectively. Introduction of mutations or deletion into a GC-rich domain, the CCAAT box, or both elements decreased the transcription activity. Overexpression of Sp1 increases the transcription activity and interferes with Sp family binding to the GC-rich domain to decrease promoter activity. Therefore, the transcription of the mouse Col5a3 gene is cooperatively regulated by Sp1 and CBF/NF-Y in osteoblastic cells.</p
Multifactor complex containing B element binding factor, BBF, and repressors regulate the human alpha 1(III) collagen gene (COL3A1).
Type III collagen is found in fetal skin and blood vessels. Previously, we characterized the proximal promoter of the human alpha1(III) collagen gene (COL3A1) using the human rhabdomyosarcoma cell line, A204, and NIH3T3 cells (Yoshino et al., Biochim Biophys Acta, 2005). In the present study, we further analyzed this promoter using additional cell lines, namely a human embryonal rhabdomyosarcoma cell line (RD) and bovine vascular smooth muscle cells (vSMCs), both of which show high expression of type III collagen. Using a luciferase assay, electrophoretic mobility shift assays (EMSA), and DNase footprinting assay, 2 types of multifactor complexes were shown to bind to the DNA region in the vicinity of the B element (- 80 to - 58), depending on the cell type. Next, we used cells stably transfected with a GFP-linked type III collagen promoter fragment for analysis of promoter expression. Usually, transfected cells retained the characteristics of the original cells. However, in several clones derived from RD cells, promoter expression as well as cell shape changed to patterns characteristic of the A204 cell line. Nuclear factors expressed by these clones were also characteristic of the A204 line.</p
Induction of Autoimmunity in a Bleomycin-Induced Murine Model of Experimental Systemic Sclerosis: An Important Role for CD4+ T Cells
Systemic sclerosis (SSc) is an autoimmune disease characterized by the excessive deposition of collagen in the skin or other organs and the production of specific antinuclear antibodies (ANAs). Recently, bleomycin (BLM)-induced experimental scleroderma was reported in a murine model. Here, we present further development of this model and suggest that it is appropriate for the analysis of human diffuse type SSc. BLM was injected into the shaved backs of C3H or BALB/c mice (100Ī¼g/mouse) 5 days per week for 3 weeks. Skin fibrosis was confirmed and pathological changes were seen in the lower part of the esophagus and stomach similar to those seen in SSc. The sera from these mice had autoantibodies specific to the damaged tissues and ANAs. Transfer of CD4+ T cells from BLM-treated BALB/c mice induced the same pathological changes and antibody production in untreated-BALB/c nude mice. Hence, tissue fibrosis and the production of ANAs are probably associated with CD4+ T-cell activity in this model. In conclusion, this model will be valuable for investigating the relationship between tissue fibrosis and abnormalities of the immune system
Early transplantation of mesenchymal stem cells after spinal cord injury relieves pain hypersensitivity through suppression of pain-related signaling cascades and reduced inflammatory cell recruitment
Bone marrow-derived mesenchymal stem cells (BMSC) modulate inflammatory/immune responses and promote motor functional recovery after spinal cord injury (SCI). However, the effects of BMSC transplantation on central neuropathic pain and neuronal hyperexcitability after SCI remain elusive. This is of importance because BMSC-based therapies have been proposed for clinical treatment. We investigated the effects of BMSC transplantation on pain hypersensitivity in green fluorescent protein (GFP)-positive bone marrow-chimeric mice subjected to a contusion SCI, and the mechanisms of such effects. BMSC transplantation at day 3 post-SCI improved motor function and relieved SCI-induced hypersensitivities to mechanical and thermal stimulation. The pain improvements were mediated by suppression of protein kinase C-Ī³ and phosphocyclic AMP response element binding protein expression in dorsal horn neurons. BMSC transplants significantly reduced levels of p-p38 mitogen-activated protein kinase and extracellular signal-regulated kinase (p-ERK1/2) in both hematogenous macrophages and resident microglia and significantly reduced the infiltration of CD11b and GFP double-positive hematogenous macrophages without decreasing the CD11b-positive and GFP-negative activated spinal-microglia population. BMSC transplants prevented hematogenous macrophages recruitment by restoration of the blood-spinal cord barrier (BSCB), which was associated with decreased levels of (a) inflammatory cytokines (tumor necrosis factor-Ī±, interleukin-6); (b) mediators of early secondary vascular pathogenesis (matrix metallopeptidase 9); (c) macrophage recruiting factors (CCL2, CCL5, and CXCL10), but increased levels of a microglial stimulating factor (granulocyte-macrophage colony-stimulating factor). These findings support the use of BMSC transplants for SCI treatment. Furthermore, they suggest that BMSC reduce neuropathic pain through a variety of related mechanisms that include neuronal sparing and restoration of the disturbed BSCB, mediated through modulation of the activity of spinal-resident microglia and the activity and recruitment of hematogenous macrophages
Early Transplantation of Mesenchymal Stem Cells After Spinal Cord Injury Relieves Pain Hypersensitivity Through Suppression of Pain-Related Signaling Cascades and Reduced Inflammatory Cell Recruitment
This novel study demonstrated that mesenchymal stem cell transplants after spinal cord injury reduce neuropathic pain, giving details of reduced pain signalling pathways affected. The work is essential in the translation of stem cell therapies for CNS regeneration.Bone marrow-derived mesenchymal stem cells (BMSC) modulate inflammatory/immune responses and promote motor functional recovery after spinal cord injury (SCI). However, the effects of BMSC transplantation on central neuropathic pain and neuronal hyperexcitability after SCI remain elusive. This is of importance because BMSC-based therapies have been proposed for clinical treatment. We investigated the effects of BMSC transplantation on pain hypersensitivity in green fluorescent protein (GFP)-positive bone marrow-chimeric mice subjected to a contusion SCI, and the mechanisms of such effects. BMSC transplantation at day 3 post-SCI improved motor function and relieved SCI-induced hypersensitivities to mechanical and thermal stimulation. The pain improvements were mediated by suppression of protein kinase C-Ī³ and phosphocyclic AMP response element binding protein expression in dorsal horn neurons. BMSC transplants significantly reduced levels of p-p38 mitogen-activated protein kinase and extracellular signal-regulated kinase (p-ERK1/2) in both hematogenous macrophages and resident microglia and significantly reduced the infiltration of CD11b and GFP double-positive hematogenous macrophages without decreasing the CD11b-positive and GFP-negative activated spinal-microglia population. BMSC transplants prevented hematogenous macrophages recruitment by restoration of the blood-spinal cord barrier (BSCB), which was associated with decreased levels of (a) inflammatory cytokines (tumor necrosis factor-Ī±, interleukin-6); (b) mediators of early secondary vascular pathogenesis (matrix metallopeptidase 9); (c) macrophage recruiting factors (CCL2, CCL5, and CXCL10), but increased levels of a microglial stimulating factor (granulocyte-macrophage colony-stimulating factor). These findings support the use of BMSC transplants for SCI treatment. Furthermore, they suggest that BMSC reduce neuropathic pain through a variety of related mechanisms that include neuronal sparing and restoration of the disturbed BSCB, mediated through modulation of the activity of spinal-resident microglia and the activity and recruitment of hematogenous macrophages
Prediction of Total Drug Clearance in Humans Using Animal Data: Proposal of a Multimodal Learning Method Based on Deep Learning
Research into pharmacokinetics plays an important role in the development process of new drugs. Accurately predicting human pharmacokinetic parameters from preclinical data can increase the success rate of clinical trials. Since clearance (CL) which indicates the capacity of the entire body to process a drug is one of the most important parameters, many methods have been developed. However, there are still rooms to be improved for practical use in drug discovery research; "improving CL prediction accuracy" and "understanding the chemical structure of compounds in terms of pharmacokinetics". To improve those, this research proposes a multimodal learning method based on deep learning that takes not only the chemical structure of a drug but also rat CL as inputs. Good results were obtained compared with the conventional animal scale-up method; the geometric mean fold error was 2.68 and the proportion of compounds with prediction errors of 2-fold or less was 48.5%. Furthermore, it was found to be possible to infer the partial structure useful for CL prediction by a structure contributing factor inference method. The validity of these results of structural interpretation of metabolic stability was confirmed by chemists
Predicting Total Drug Clearance and Volumes of Distribution Using the Machine Learning-Mediated Multimodal Method through the Imputation of Various Nonclinical Data
Pharmacokinetic research plays an important role in the development of new drugs. Accurate predictions of human pharmacokinetic parameters are essential for the success of clinical trials. Clearance (CL) and volume of distribution (Vd) are important factors for evaluating pharmacokinetic properties, and many previous studies have attempted to use computational methods to extrapolate these values from nonclinical laboratory animal models to human subjects. However, it is difficult to obtain sufficient, comprehensive experimental data from these animal models, and many studies are missing critical values. This means that studies using nonclinical data as explanatory variables can only apply a small number of compounds to their model training. In this study, we perform missing-value imputation and feature selection on nonclinical data to increase the number of training compounds and nonclinical datasets available for these kinds of studies. We could obtain novel models for total body clearance (CLtot) and steady-state Vd (Vdss) (CLtot: geometric mean fold error [GMFE], 1.92; percentage within 2-fold error, 66.5%; Vdss: GMFE, 1.64; percentage within 2-fold error, 71.1%). These accuracies were comparable to the conventional animal scale-up models. Then, this method differs from animal scale-up methods because it does not require animal experiments, which continue to become more strictly regulated as time passes
Microsatellite loci in Japanese quail andļæ½cross-species amplification inļæ½chicken andļæ½guinea fowl
In line with the Gifu University's initiative to map the Japanese
quail genome, a total of 100 Japanese quail microsatellite markers
isolated in our laboratory were evaluated in a population of 20
unrelated quails randomly sampled from a colony of wild quail
origin. Ninety-eight markers were polymorphic with an average of 3.7
alleles per locus and a mean heterozygosity of 0.423. To determine the
utility of these markers for comparative genome mapping in
Phasianidae, cross-species amplification of all the markers was tested
with chicken and guinea fowl DNA. Amplification products similar in
size to the orthologous loci in quail were observed in 42 loci in
chicken and 20 loci in guinea fowl. Of the cross-reactive markers,
57.1% in chicken and 55.0% in guinea fowl were polymorphic when tested
in 20 birds from their respective populations. Five of 15Ā markers that
could cross-amplify Japanese quail, chicken, and guinea fowl DNA were
polymorphic in all three species. Amplification of orthologous loci
was confirmed by sequencing 10 loci each from chicken and guinea fowl
and comparing with them the corresponding quail sequence. The
microsatellite markers reported would serve as a useful resource base
for genetic mapping in quail and comparative mapping in Phasianidae
Independent calculation-based verification of volumetric-modulated arc therapyāstereotactic body radiotherapy plans for lung cancer
This study aimed to investigate the feasibility of independent calculationābased verification of volumetricāmodulated arc therapy (VMAT)āstereotactic body radiotherapy (SBRT) for patients with lung cancer using a secondary treatment planning system (sTPS). In all, 50 patients with lung cancer who underwent VMATāSBRT between April 2018 and May 2019 were included in this study. VMATāSBRT plans were devised using the CollapsedāCone Convolution in RayStation (primary TPS: pTPS). DICOM files were transferred to Eclipse software (sTPS), which utilized the Eclipse software, and the dose distribution was then recalculated using Acuros XB. For the verification of dose distribution in homogeneous phantoms, the differences among pTPS, sTPS, and measurements were evaluated using passing rates of a dose difference of 5% (DD5%) and gamma index of 3%/2 mm (Ī³3%/2 mm). The ArcCHECK cylindrical diode array was used for measurements. For independent verification of doseāvolume parameters per the patientās geometry, doseāvolume indices for the planning target volume (PTV) including D95% and the isocenter dose were evaluated. The mean differences (Ā± standard deviations) between the pTPS and sTPS were then calculated. The gamma passing rates of DD5% and Ī³3%/2 mm criteria were 99.2 Ā± 2.4% and 98.6 Ā± 3.2% for pTPS vs. sTPS, 92.9 Ā± 4.0% and 94.1 Ā± 3.3% for pTPS vs. measurement, and 93.0 Ā± 4.4% and 94.3 Ā± 4.1% for sTPS vs. measurement, respectively. The differences between pTPS and sTPS for the PTVs of D95% and the isocenter dose were ā3.1 Ā± 2.0% and ā2.3 Ā± 1.8%, respectively. Our investigation of VMATāSBRT plans for lung cancer revealed that independent calculationābased verification is a timeāefficient method for patientāspecific quality assurance
- ā¦