Addition Of Fibroblast Growth Factor Research Articles

Strategy.

While the establishment of an ovarian cancer biobank from patient-derived organoids along with their clinical background information promises advances in research and patient care, standardization remains a challenge due to the heterogeneity of this lethal malignancy, combined with the inherent complexity of organoid technology. This adaptable protocol provides a systematic framework to realize the full potential of ovarian cancer organoids considering a patient-specific variability of progenitors. By implementing a structured experimental workflow to select optimal culture conditions and seeding methods, with parallel testing of direct 3D seeding versus a 2D/3D route, we obtain, in most cases, robust long-term expanding lines suitable for a broad range of downstream applications. Notably, the protocol has been tested and proven efficient in a great number of cases (N = 120) of highly heterogeneous starting material, including high-grade and low-grade ovarian cancer and stages of the disease with primary debulking, recurrent disease, and post-neoadjuvant surgical specimens. Within a low Wnt, high BMP exogenous signaling environment, we observed progenitors being differently susceptible to the activation of the Heregulin 1 ß (HERß-1)-pathway, with HERß-1 promoting organoid formation in some while inhibiting it in others. For a subset of the patient's samples, optimal organoid formation and long-term growth necessitate the addition of fibroblast growth factor 10 and R-Spondin 1 to the medium. Further, we highlight the critical steps of tissue digestion and progenitor isolation and point to examples where brief cultivation in 2D on plastic is beneficial for subsequent organoid formation in the Basement Membrane Extract type 2 matrix. Overall, optimal biobanking requires systematic testing of all main conditions in parallel to identify an adequate growth environment for individual lines. The protocol also describes the handling procedure for efficient embedding, sectioning, and staining to obtain high-resolution images of organoids, which is required for comprehensive phenotyping.

The Prrx1eGFP Mouse Labels the Periosteum During Development and a Subpopulation of Osteogenic Periosteal Cells in the Adult.

The identity of the cells that form the periosteum during development is controversial with current dogma suggesting these are derived from a Sox9-positive progenitor. Herein, we characterize a newly created Prrx1eGFP reporter transgenic mouse line during limb formation and postnatally. Interestingly, in the embryo Prrx1eGFP-labeled cells become restricted around the Sox9-positive cartilage anlage without themselves becoming Sox9-positive. In the adult, the Prrx1eGFP transgene live labels a subpopulation of cells within the periosteum that are enriched at specific sites, and this population is diminished in aged mice. The green fluorescent protein (GFP)-labeled subpopulation can be isolated using fluorescence-activated cell sorting (FACS) and represents approximately 8% of all isolated periosteal cells. The GFP-labeled subpopulation is significantly more osteogenic than unlabeled, GFP-negative periosteal cells. In addition, the osteogenic and chondrogenic capacity of periosteal cells in vitro can be extended with the addition of fibroblast growth factor (FGF) to the expansion media. We provide evidence to suggest that osteoblasts contributing to cortical bone formation in the embryo originate from Prrx1eGFP-positive cells within the perichondrium, which possibly piggyback on invading vascular cells and secrete new bone matrix. In summary, the Prrx1eGFP mouse is a powerful tool to visualize and isolate periosteal cells and to quantify their properties in the embryo and adult. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

A Mammary Organoid Model to Study Branching Morphogenesis

Branching morphogenesis is the process that gives rise to branched structures in several organs, such as the lung, the kidney, and the mammary gland. Although morphologically well described, the exact mechanisms driving branch elongation and bifurcation are still poorly understood. Signaling cues from the stroma and extracellular matrix have an important role in driving branching morphogenesis. Organoid models derived from primary mammary epithelial cells have emerged as a powerful tool to gain insight into branching morphogenesis of the mammary gland. However, current available mammary organoid culture protocols result in morphologically simple structures which do not resemble the complex branched structure of the in vivo mammary gland. Supplementation of growth factors to mammary organoids cultured in basement membrane extract or collagen I were shown to induce bud formation and elongation but are not sufficient to drive true branching events. Here, we present an improved culture approach based on 3D primary mammary epithelial cell culture to develop branched organoids with a complex morphology. By alternating the addition of fibroblast growth factor 2 and epidermal growth factor to mammary organoids cultured in a basement membrane extract matrix enriched with collagen type I fibers, we obtain complex mammary organoid structures with primary, secondary, and tertiary branches over a period of 15–20 days. Mammary organoid structures grow >1 mm in size and show an elongated and branched shape which resembles in vivo mammary gland morphology. This novel branched mammary organoid model offers many possibilities to study the mechanisms of branching in the developing mammary gland.

Therapeutic Effects of the Addition of Fibroblast Growth Factor-2 to Biodegradable Gelatin/Magnesium-Doped Calcium Silicate Hybrid 3D-Printed Scaffold with Enhanced Osteogenic Capabilities for Critical Bone Defect Restoration.

Worldwide, the number of bone fractures due to traumatic and accidental injuries is increasing exponentially. In fact, repairing critical large bone defects remains challenging due to a high risk of delayed union or even nonunion. Among the many bioceramics available for clinical use, calcium silicate-based (CS) bioceramics have gained popularity due to their good bioactivity and ability to stimulate cell behavior. In order to improve the shortcomings of 3D-printed ceramic scaffolds, which do not easily carry growth factors and do not provide good tissue regeneration effects, the aim of this study was to use a gelatin-coated 3D-printed magnesium-doped calcium silicate (MgCS) scaffold with genipin cross-linking for regulating degradation, improving mechanical properties, and enhancing osteogenesis behavior. In addition, we consider the effects of fibroblast growth factor-2 (FGF-2) loaded into an MgCS scaffold with and without gelatin coating. Furthermore, we cultured the human Wharton jelly-derived mesenchymal stem cells (WJMSC) on the scaffolds and observed the biocompatibility, alkaline phosphatase activity, and osteogenic-related markers. Finally, the in vivo performance was assessed using micro-CT and histological data that revealed that the hybrid bioscaffolds were able to further achieve more effective bone tissue regeneration than has been the case in the past. The above results demonstrated that this type of processing had great potential for future clinical applications and studies and can be used as a potential alternative for future bone tissue engineering research, as well as having good potential for clinical applications.

Collagen hydrogels loaded with fibroblast growth factor-2 as a bridge to repair brain vessels in organotypic brain slices

Vessel damage is a general pathological process in many neurodegenerative disorders, as well as spinal cord injury, stroke, or trauma. Biomaterials can present novel tools to repair and regenerate damaged vessels. The aim of the present study is to test collagen hydrogels loaded with different angiogenic factors to study vessel repair in organotypic brain slice cultures. In the experimental set up I, we made a cut on the organotypic brain slice and tested re-growth of laminin + vessels. In the experimental set up II, we cultured two half brain slices with a gap with a collagen hydrogel placed in between to study endothelial cell migration. In the experimental set up I, we showed that the number of vessels crossing the cut was tendencially increased with the addition of fibroblast growth factor-2 (FGF-2), vascular endothelial growth factor, or platelet-derived growth factor-BB compared to the control group. In the experimental set up II, we demonstrated that a collagen hydrogel loaded with FGF-2 resulted in a significantly increased number of migrated laminin + cells in the gap between the slices compared to the control hydrogel. Co-administration of several growth factors did not further potentiate the effects. Taken together, we show that organotypic brain slices are good models to study brain vessels and FGF-2 is a potent angiogenic factor for endothelial cell proliferation and migration. Our results provide evidence that the collagen hydrogels can be used as an extracellular matrix for the vascular endothelial cells.

Optimal stimulation toward the dermal papilla lineage can be promoted by combined use of osteogenic and adipogenic inducers.

Dermal papilla cells (DPCs) play crucial roles in hair regeneration, but they readily lose their hair‐forming ability during in vitro culture. Although the formation of spheroids partially restores the ability, shrinkage of the spheroids makes it difficult to maintain cellular viability. To address this problem, we stimulated DPCs with factors known to induce adipogenic and/or osteogenic differentiation, because DPCs share unique gene expression profiles with adipocytes and osteocytes. We isolated DPCs from versican (vcan)–GFP mice, in which GFP is expressed under the control of a vcan promoter, which is strongly active in DPCs of anagen hair follicles. GFP fluorescence was most intense when the spheroids were made from DPCs cultured in a half‐diluted combination of adipogenic and osteogenic media (CAO1/2), a Dulbecco’s modified Eagle’s medium‐based medium that contains 10% FBS, 275 nm dexamethasone, 2.5 mm β‐glycerol phosphate, 12.5 µg·mL−1 ascorbic acid, 0.125 µm isobutylmethylxanthine and 2.5 ng·mL−1 insulin. The dose of each additive used was less than the optimal dose for adipogenic or osteogenic differentiation, and shrinkage of the spheroids was avoided through the addition of fibroblast growth factor 2 and platelet‐derived growth factor‐AA to CAO1/2. In addition, the gene and protein expression of vcan, osteopontin, alkaline phosphatase and α‐smooth muscle actin in the spheroids were augmented to levels similar to those of the intact dermal papillae, which exhibited restored hair‐forming activity. In conclusion, a combination of certain adipogenic and osteogenic inducers, together with fibroblast growth factor 2 and platelet‐derived growth factor‐AA, can promote differentiation toward the DPC lineage.

Conditioned medium of sympathetic ganglia with addition of fibroblast growth factor 2 promotes plasticity of cardiomyocytes in culture

Conditioned medium of sympathetic ganglia with addition of fibroblast growth factor 2 promotes plasticity of cardiomyocytes in culture

New data concerning oocyte maturationand embryo production in vitro

It is reviewed last science data concerning oocyte maturation and pig embryo production in vitro. The aim of the work is to present new data concerning oocyte maturation and embryo production in vitro. Efficiency of different assistant reproductive methods can be improved by treatment of gametes and embryos with sublethal hydrostatic pressure. COCs denudation is better to perform 44 hours from the initiation of maturation procedure. Last 11 hours of maturation is better to perform in medium with decreased quantity of NaCl. Lipid content in oocyte significantly correlates with number of granulose cells per follicle. Larger size pre- and post pubertal oocytes are characterized by greater ability to development. Supplementation of culture medium with glycine leads to increase number of blastocyst cells. Addition of fibroblast growth factor to COCs culture medium benefits its development and blastocyst formation. COCs maturation normalization decreases polyspermy. Bringing endothelial growth factor in COCs medium culture increases rate of blastocyst formation. Different cells processes require different quantity of calcium ion oscillations. Temperature of liquid of preovulatory follicle can be indicator for oocyte quality. 14-days culture of COCs, recovered from early antral follicles, on polyacrylamide gel, results in achievement of larger size oocytes. It is improved method for optical observation of fertilization. It is worked out morula - blastocyst transportation for long distances. Introduction of Lysophosphatidic acid accelerates development of porcine embryos by activating formation of the blastocoel. Conclusion: last literature data show that row of different means of improvement for oocyte maturation and obtaining embryo in vitro is worked out.

GRHL2-Dependent Enhancer Switching Maintains a Pluripotent Stem Cell Transcriptional Subnetwork after Exit from Naive Pluripotency

The enhancer landscape of pluripotent stem cells undergoes extensive reorganization during early mammalian development. The functions and mechanisms behind such reorganization, however, are unclear. Here, we show that the transcription factor GRHL2 is necessary and sufficient to activate an epithelial subset of enhancers as naive embryonic stem cells (ESCs) transition into formative epiblast-like cells (EpiLCs). Surprisingly, many GRHL2 target genes do not change in expression during the ESC-EpiLC transition. Instead, enhancers regulating these genes in ESCs diminish in activity in EpiLCs while GRHL2-dependent alternative enhancers become activated to maintain transcription. GRHL2 therefore assumes control over a subset of the naive network via enhancer switching to maintain expression of epithelial genes upon exit from naive pluripotency. These data evoke a model where the naive pluripotency network becomes partitioned into smaller, independent networks regulated by EpiLC-specific transcription factors, thereby priming cells for lineage specification.

Generation of Otic Sensory Neurons from Mouse Embryonic Stem Cells in 3D Culture.

The peripheral hearing process taking place in the cochlea mainly depends on two distinct sensory cell types: the mechanosensitive hair cells and the spiral ganglion neurons (SGNs). The first respond to the mechanical stimulation exerted by sound pressure waves on their hair bundles by releasing neurotransmitters and thereby activating the latter. Loss of these sensorineural cells is associated with permanent hearing loss. Stem cell-based approaches aiming at cell replacement or in vitro drug testing to identify potential ototoxic, otoprotective, or regenerative compounds have lately gained attention as putative therapeutic strategies for hearing loss. Nevertheless, they rely on efficient and reliable protocols for the in vitro generation of cochlear sensory cells for their implementation. To this end, we have developed a differentiation protocol based on organoid culture systems, which mimics the most important steps of in vivo otic development, robustly guiding mouse embryonic stem cells (mESCs) toward otic sensory neurons (OSNs). The stepwise differentiation of mESCs toward ectoderm was initiated using a quick aggregation method in presence of Matrigel in serum-free conditions. Non-neural ectoderm was induced via activation of bone morphogenetic protein (BMP) signaling and concomitant inhibition of transforming growth factor beta (TGFβ) signaling to prevent mesendoderm induction. Preplacodal and otic placode ectoderm was further induced by inhibition of BMP signaling and addition of fibroblast growth factor 2 (FGF2). Delamination and differentiation of SGNs was initiated by plating of the organoids on a 2D Matrigel-coated substrate. Supplementation with brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) was used for further maturation until 15 days of in vitro differentiation. A large population of neurons with a clear bipolar morphology and functional excitability was derived from these cultures. Immunostaining and gene expression analysis performed at different time points confirmed the transition trough the otic lineage and final expression of the key OSN markers. Moreover, the stem cell-derived OSNs exhibited functional electrophysiological properties of native SGNs. Our established in vitro model of OSNs development can be used for basic developmental studies, for drug screening or for the exploration of their regenerative potential.

Fibroblast Growth Factor 23 and Kidney Disease Progression in Autosomal Dominant Polycystic Kidney Disease.

Increases in fibroblast growth factor 23 precede kidney function decline in autosomal dominant polycystic kidney disease; however, the role of fibroblast growth factor 23 in autosomal dominant polycystic kidney disease has not been well characterized. We measured intact fibroblast growth factor 23 levels in baseline serum samples from 1002 participants in the HALT-PKD Study A (n=540; mean eGFR =91±17 ml/min per 1.73 m2) and B (n=462; mean eGFR =48±12 ml/min per 1.73 m2). We used linear mixed and Cox proportional hazards models to test associations between fibroblast growth factor 23 and eGFR decline, percentage change in height-adjusted total kidney volume, and composite of time to 50% reduction in eGFR, onset of ESRD, or death. Median (interquartile range) intact fibroblast growth factor 23 was 44 (33-56) pg/ml in HALT-PKD Study A and 69 (50-93) pg/ml in Study B. In adjusted models, annualized eGFR decline was significantly faster in the upper fibroblast growth factor 23 quartile (Study A: quartile 4, -3.62; 95% confidence interval, -4.12 to -3.12 versus quartile 1, -2.51; 95% confidence interval, -2.71 to -2.30 ml/min per 1.73 m2; P for trend <0.001; Study B: quartile 4, -3.74; 95% confidence interval, -4.14 to -3.34 versus quartile 1, -2.78; 95% confidence interval, -2.92 to -2.63 ml/min per 1.73 m2; P for trend <0.001). In Study A, higher fibroblast growth factor 23 quartiles were associated with greater longitudinal percentage increase in height-adjusted total kidney volume in adjusted models (quartile 4, 6.76; 95% confidence interval, 5.57 to 7.96 versus quartile 1, 6.04; 95% confidence interval, 5.55 to 6.54; P for trend =0.03). In Study B, compared with the lowest quartile, the highest fibroblast growth factor 23 quartile was associated with elevated risk for the composite outcome (hazard ratio, 3.11; 95% confidence interval, 1.84 to 5.25). Addition of fibroblast growth factor 23 to a model of annualized decline in eGFR≥3.0 ml/min per 1.73 m2 did not improve risk prediction. Higher serum fibroblast growth factor 23 concentration was associated with kidney function decline, height-adjusted total kidney volume percentage increase, and death in patients with autosomal dominant polycystic kidney disease. However, fibroblast growth factor 23 did not substantially improve prediction of rapid kidney function decline.

Retinoic Acid Receptor β Controls Development of Striatonigral Projection Neurons through FGF-Dependent and Meis1-Dependent Mechanisms.

The mammalian striatum controls sensorimotor and psychoaffective functions through coordinated activities of its two striatonigral and striatopallidal output pathways. Here we show that retinoic acid receptor β (RARβ) controls development of a subpopulation of GABAergic, Gad65-positive striatonigral projection neurons. In Rarb(-/-) knock-out mice, concomitant reduction of Gad65, dopamine receptor D1 (Drd1), and substance P expression at different phases of prenatal development was associated with reduced number of Drd1-positive cells at birth, in contrast to normal numbers of striatopallidal projection neurons expressing dopamine receptor D2. Fate mapping using BrdU pulse-chase experiments revealed that such deficits may originate from compromised proliferation of late-born striosomal neurons and lead to decreased number of Drd1-positive cells retaining BrdU in postnatal day (P) 0 Rarb(-/-) striatum. Reduced expression of Fgf3 in the subventricular zone of the lateral ganglionic eminence (LGE) at embryonic day 13.5 may underlie such deficits by inducing premature differentiation of neuronal progenitors, as illustrated by reduced expression of the proneural gene Ascl1 (Mash1) and increased expression of Meis1, a marker of postmitotic LGE neurons. In agreement with a critical role of FGF3 in this control, reduced number of Ascl1-expressing neural progenitors, and a concomitant increase of Meis1-expressing cells, were observed in primary cell cultures of Rarb(-/-) LGE. This defect was normalized by addition of fibroblast growth factor (FGF). Such data point to role of Meis1 in striatal development, also supported by reduced neuronal differentiation in the LGE of Meis1(-/-) embryos. Our data unveil a novel mechanism of development of striatonigral projection neurons involving retinoic acid and FGF, two signals required for positioning the boundaries of Meis1-expressing cells.

Self-Organization of Polarized Cerebellar Tissue in 3D Culture of Human Pluripotent Stem Cells

During cerebellar development, the main portion of the cerebellar plate neuroepithelium gives birth to Purkinje cells and interneurons, whereas the rhombic lip, the germinal zone at its dorsal edge, generates granule cells and cerebellar nuclei neurons. However, it remains elusive how these components cooperate to form the intricate cerebellar structure. Here, we found that a polarized cerebellar structure self-organizes in 3D human embryonic stem cell (ESC) culture. The self-organized neuroepithelium differentiates into electrophysiologically functional Purkinje cells. The addition of fibroblast growth factor 19 (FGF19) promotes spontaneous generation of dorsoventrally polarized neural-tube-like structures at the level of the cerebellum. Furthermore, addition of SDF1 and FGF19 promotes the generation of a continuous cerebellar plate neuroepithelium with rhombic-lip-like structure at one end and a three-layer cytoarchitecture similar to the embryonic cerebellum. Thus, human-ESC-derived cerebellar progenitors exhibit substantial self-organizing potential for generating a polarized structure reminiscent of the early human cerebellum at the first trimester.

WT1 controls antagonistic FGF and BMP-pSMAD pathways in early renal progenitors.

Kidney organogenesis requires the tight control of proliferation, differentiation and apoptosis of renal progenitor cells. How the balance between these cellular decisions is achieved remains elusive. The Wilms' tumour suppressor Wt1 is required for progenitor survival, but the molecular cause for renal agenesis in mutants is poorly understood. Here we demonstrate that lack of Wt1 abolishes fibroblast growth factor (FGF) and induces BMP/pSMAD signalling within the metanephric mesenchyme. Addition of recombinant FGFs or inhibition of pSMAD signalling rescues progenitor cell apoptosis induced by the loss of Wt1. We further show that recombinant BMP4, but not BMP7, induces an apoptotic response within the early kidney that can be suppressed by simultaneous addition of FGFs. These data reveal a hitherto unknown sensitivity of early renal progenitors to pSMAD signalling, establishes FGF and pSMAD signalling as antagonistic forces in early kidney development and places WT1 as a key regulator of pro-survival FGF signalling pathway genes.

Chondrogenic potential of rat mesenchymal stem cells in vitro under the influence of electromagnetic fields

Objective To determine the chondrogenic potential of mesenchymal stem cells (BMSCs) under exposure of extremely low frequency electromagnetic fields (ELF-EMF) and discuss the application prospect of EMF in cartilage tissue engineering.Methods Cell pellets of rat bone marrow-derived BMSCs were cultured in vitro under the addition of fibroblast growth factor 2 (FGF-2) and transforming growth factor-β3 (TGF-β3).Pellet cultures were exposed to sinusoidal ELF-EMF (1.0 mT,50 Hz).After 3 weeks of inductive differentiation culture,chondrogenesis was detected by alcian blue staining,and quantitative real-time polymerase chain reaction (real-time PCR) was used for detection of chondrogenesis related proteins.Glycosaminoglycan (GAG) contents of pellet cultures were determined using the dimethylmethylene blue (DMMB) dye-binding assay.Results With the effects of growth factors,EMF could significantly promote chondrogenic differentiation of BMSCs pellet cultures,and the gene expression of collagen type Ⅱ,X and aggrecan in rat BMSCs was also significantly up-regulated.The gene expression of sex determining region Y box 2 (SOX9) did not show significant difference between EMF exposed groups and nonexposed groups.The glycosaminoglycan (GAG)/DNA ratio of EMF exposed pellet cultures reached 3.108 ±0.341,which was significantly higer than those unexposed pellet cultures.Conclusion Increased expression of collagen type Ⅱ,X and GAG content in pellet cultures under EMF exposure may contribute to the chonderogenic differentiation of rat BMSCs.EMF was able to stimulate and maintain chondrogenic differentiation of rat BMSCs under influence of growth factors.EMF alone,however,could not induce chondrogenic differentiation. Key words: Electromagnetic fields; Mesenchymal stem cells; Pellet culture; Chondrogenic differentiation

Neutralization Of Vascular Endothelial Growth Factor-A Induced CD138-Expression In Bone Marrow Cells From Multiple Myeloma Patients

BackgroundWe previously reported that when adult human dermal fibroblasts were cultured with interleukin (IL)-1-b, vascular endothelial growth factor (VEGF)-A was produced significantly (54th ASH). And, when antihuman VEGF-A neutralizing antibody (VEGF-A Ab) was added to the cultures, CD138 (Syndecan-1) expressed significantly. CD138 is a member of cell-surface transmembrane haparan sulfate proteoglycans, and expresses in plasma cells from multiple myeloma (MM) cases. Membrane-anchoring CD138 shows a better prognosis in an immunodeficiency murine transplantation model in vivo; however, when extra-domain of CD138 is digested by heparanase to be shed from the cell-surface, MM cells invade to various kinds of tissues, and the patients show poor prognosis. AimsTo validate a biological implication of inhibition of VEGF-A-signaling in MM cells, we observed effects of VEGF-A Ab to bone marrow cells from MM patients. Cell-proliferations as well as morphological changes were also observed time-dependently. Materials and MethodsInstitutional ethical committee approved our study, and bone marrow cells were obtained from the informed MM patients as well as normal individuals. Cells were separated with gravity-sedimentation method, and the prepared mononuclear cells were cultured with or without VEGF-A Ab, and the expression of specific genes was analyzed. ResultsTwenty MM patients were eligible, in which three showed significant poor prognosis, and worsened after underwent intensive chemotherapy or allogeneic hematopoietic stem cells transplantation. Thirteen out of twenty expressed CD138, and when cells were cultured with VEGF-A Ab for four days, CD138-expression increased significantly in all cases. Four did not express CD138; however, CD138-expression was observed after 4 day's culture with VEGF-A Ab. In three progressed cases CD138-expression decreased in accordance with the disease-progression; however, when VEGF-A Ab was added to the cell-cultures, CD138 was induced to express. Heparanase-expression was observed in 10 cases out of 20, which were down-regulated when VEGF-A Ab was added to the cultures. In contrast, in bone marrow cells from seven normal individuals CD138-expression was very low, which was down-regulated with the addition of VEGF-A Ab. Heparanase-expression was not observed in these normal cells, and were induced to be observed in four out of seven when VEGF-A Ab was added to the cultures. DiscussionExpression of CD138 is induced in fibroblast by the addition of fibroblast growth factor-2, and in keratinocytes by epidermal growth factor and keratinocyte growth factor; however, an induction of CD138 by the VEGF-A Ab has not been reported. Several cytokines including VEGF-A influence plasma cell-proliferation; however, little is reported on cytokine-suppression therapy. Inhibition of the signaling of VEGF receptors by the chemicals including solafenib is not specific for VEGF-A. Currently we validate the efficacy of the inhibition of VEGF-A-signaling to MM cells and their environmental cells using RNA interference. Disclosures:No relevant conflicts of interest to declare.

Noncanonical Transforming Growth Factor β (TGFβ) Signaling in Cranial Neural Crest Cells Causes Tongue Muscle Developmental Defects

Microglossia is a congenital birth defect in humans and adversely impacts quality of life. In vertebrates, tongue muscle derives from the cranial mesoderm, whereas tendons and connective tissues in the craniofacial region originate from cranial neural crest (CNC) cells. Loss of transforming growth factor β (TGFβ) type II receptor in CNC cells in mice (Tgfbr2(fl/fl);Wnt1-Cre) causes microglossia due to a failure of cell-cell communication between cranial mesoderm and CNC cells during tongue development. However, it is still unclear how TGFβ signaling in CNC cells regulates the fate of mesoderm-derived myoblasts during tongue development. Here we show that activation of the cytoplasmic and nuclear tyrosine kinase 1 (ABL1) cascade in Tgfbr2(fl/fl);Wnt1-Cre mice results in a failure of CNC-derived cell differentiation followed by a disruption of TGFβ-mediated induction of growth factors and reduction of myogenic cell proliferation and differentiation activities. Among the affected growth factors, the addition of fibroblast growth factor 4 (FGF4) and neutralizing antibody for follistatin (FST; an antagonist of bone morphogenetic protein (BMP)) could most efficiently restore cell proliferation, differentiation, and organization of muscle cells in the tongue of Tgfbr2(fl/fl);Wnt1-Cre mice. Thus, our data indicate that CNC-derived fibroblasts regulate the fate of mesoderm-derived myoblasts through TGFβ-mediated regulation of FGF and BMP signaling during tongue development.

The effect of fibroblast growth factor and periodontal ligament fibroblast-conditioned medium on fibroblast-related gene expression in bone marrow stromal cells

Periodontal ligament fibroblasts (PDLFs) are essential to most periodontal tissue regeneration processes. This study evaluated the potential of fibroblast growth factor (FGF) and PDLF-conditioned media to modulate fibroblast differentiation from bone marrow stromal cells (BMSCs) that were obtained from mongrel dogs. The medium obtained from culture of periodontal ligament fibroblasts of dogs was used for the PDLF-conditioned media. In the control group, the BMSCs were only cultured without FGF and PDLF-conditioned media. In experimental group 1, the BMSCs were loaded with FGF (3 ng/mL). In experimental group 2, the BMSCs were treated with PDLF-conditioned media. The BMSCs in experimental group 3 were loaded with FGF (3 ng/mL) and PDLF-conditioned media. The media was changed every 2 days. The cells of the control and experimental groups were cultured for 1, 11 and 14 days. The effects of the FGF and PDLF-conditioned media on fibroblast-related gene expression from the bone marrow stromal cells were examined by reverse transcription-polymerase chain reaction. Intensity of each band of the genes expressed was evaluated. The addition of FGF and PDLF-conditioned media enhanced the differentiation of fibroblast like cells from bone marrow stromal cell. The experimental group-treated FGF and PDLFconditioned media showed the strong expression of the fibroblast cell-specific marker: UNCL-, S100A2- and S100A4-mRNA at 14 days. Strong nestin mRNA expression was observed in the control group. This study suggests that FGF and PDLF-conditioned medium can enhance fibroblast-related gene expression in BMSCs in vitro.

P114. Sema4C-Plexin B2 signalling modulates ureteric branching in developing kidney

Semaphorins, originally identified as axon guidance molecules, have recently been implicated in angiogenesis, function of the immune system and cancerous growth. Here we show that the deletion of Plexin B2 (Plxnb2), a semaphorin receptor that is expressed both in the pretubular aggregates and the tips of the ureteric buds in the developing kidney, results in renal hypoplasia and occasional double ureters. The rate of cell proliferation in ureteric epithelium and consequently the number of ureteric tips are reduced in the kidneys lacking Plexin B2 (Plxnb2−/−). Semaphorin 4C, a ligand for Plexin B2, stimulates branching of the ureteric epithelium in wild type and Plxnb2+/− kidney explants, but not in Plxnb2−/− explants. Isolated Plxnb2−/− ureteric buds fail to respond to branching induction by glial-cell-line-derived neurotrophic factor in vitro, but this response is rescued by either the presence of the metanephric mesenchyme or addition of Fibroblast growth factor 7 and Follistatin. The differentiation of the nephrogenic mesenchyme, its morphology and rate of apoptosis in the Plxnb2−/− kidneys are normal. Plexin B2 is co-expressed with Plexin B1 (Plxnb1). The deletion of Plxnb1 results in a transient embryonic phenotype with enhanced branching of the ureteric bud. The double homozygous Plxnb1−/− Plxnb2−/− mice show high embryonic lethality prior to onset of nephrogenesis. The only double homozygous embryo surviving to E12 showed hypoplastic kidneys with ureteric branches and diffentiating mesenchyme. Taken together, our results show that Sema4C-Plexin B2 signalling regulates ureteric branching and suggest non-redundant roles for Plexin B1 and Plexin B2 in kidney development.

Embryonic germ cells from mice and rats exhibit properties consistent with a generic pluripotent ground state.

Mouse and rat embryonic stem cells can be sustained in defined medium by dual inhibition (2i) of the mitogen-activated protein kinase (Erk1/2) cascade and of glycogen synthase kinase 3. The inhibitors suppress differentiation and enable self-renewal of pluripotent cells that are ex vivo counterparts of naïve epiblast cells in the mature blastocyst. Pluripotent stem cell lines can also be derived from unipotent primordial germ cells via a poorly understood process of epigenetic reprogramming. These are termed embryonic germ (EG) cells to denote their distinct origin. Here we investigate whether EG cell self-renewal and derivation are supported by 2i. We report that mouse EG cells can be established with high efficiency using 2i in combination with the cytokine leukaemia inhibitory factor (LIF). Furthermore, addition of fibroblast growth factor or stem cell factor is unnecessary using 2i-LIF. The derived EG cells contribute extensively to healthy chimaeric mice, including to the germline. Using the same conditions, we describe the first derivations of EG cells from the rat. Rat EG cells express a similar marker profile to rat and mouse ES cells. They have a diploid karyotype, can be clonally expanded and genetically manipulated, and are competent for multilineage colonisation of chimaeras. These findings lend support to the postulate of a conserved molecular ground state in pluripotent rodent cells. Future research will determine the extent to which this is maintained in other mammals and whether, in some species, primordial germ cells might be a more tractable source than epiblast for the capture of naïve pluripotent stem cells.