The concurrent stimulation of Wnt and FGF8 signaling induce differentiation of dental mesenchymal cells into odontoblast-like cells

Fibroblast growth factor 8 (FGF8) is known to be a potent stimulator of canonical Wnt/β-catenin activity, an essential factor for tooth development. In this study, we analyzed the effects of co-administration of FGF8 and a CHIR99021 (GSK3β inhibitor) on differentiation of dental mesenchymal cells into odontoblasts. Utilizing Cre-mediated EGFP reporter mice, dentin matrix protein 1 (Dmp1) expression was examined in mouse neonatal molar tooth germs. At birth, expression of Dmp1-EGFP was not found in mesenchymal cells but rather epithelial cells, after which Dmp1-positive cells gradually emerged in the mesenchymal area along with disappearance in the epithelial area. Primary cultured mesenchymal cells from neonatal tooth germ specimens showed loss of Dmp1-EGFP positive signals, whereas addition of Wnt3a or the CHIR99021 significantly regained Dmp1 positivity within approximately 2 weeks. Other odontoblast markers such as dentin sialophosphoprotein (Dspp) could not be clearly detected. Concurrent stimulation of primary cultured mesenchymal cells with the CHIR99021 and FGF8 resulted in significant upregulation of odonto/osteoblast proteins. Furthermore, increased expression levels of runt-related transcription factor 2 (Runx2), osterix, and osteocalcin were also observed. The present findings indicate that coordinated action of canonical Wnt/β-catenin and FGF8 signals is essential for odontoblast differentiation of tooth germs in mice.

3D Bioprinting Mesenchymal Stem Cell-Derived Neural Tissues Using a Fibrin-Based Bioink

Current treatments for neurodegenerative diseases aim to alleviate the symptoms experienced by patients; however, these treatments do not cure the disease nor prevent further degeneration. Improvements in current disease-modeling and drug-development practices could accelerate effective treatments for neurological diseases. To that end, 3D bioprinting has gained significant attention for engineering tissues in a rapid and reproducible fashion. Additionally, using patient-derived stem cells, which can be reprogrammed to neural-like cells, could generate personalized neural tissues. Here, adipose tissue-derived mesenchymal stem cells (MSCs) were bioprinted using a fibrin-based bioink and the microfluidic RX1 bioprinter. These tissues were cultured for 12 days in the presence of SB431542 (SB), LDN-193189 (LDN), purmorphamine (puro), fibroblast growth factor 8 (FGF8), fibroblast growth factor-basic (bFGF), and brain-derived neurotrophic factor (BDNF) to induce differentiation to dopaminergic neurons (DN). The constructs were analyzed for expression of neural markers, dopamine release, and electrophysiological activity. The cells expressed DN-specific and early neuronal markers (tyrosine hydroxylase (TH) and class III beta-tubulin (TUJ1), respectively) after 12 days of differentiation. Additionally, the tissues exhibited immature electrical signaling after treatment with potassium chloride (KCl). Overall, this work shows the potential of bioprinting engineered neural tissues from patient-derived MSCs, which could serve as an important tool for personalized disease models and drug-screening.

The giant axolotl genome uncovers the evolution, scaling, and transcriptional control of complex gene loci

Vertebrates harbor recognizably orthologous gene complements but vary 100-fold in genome size. How chromosomal organization scales with genome expansion is unclear, and how acute changes in gene regulation, as during axolotl limb regeneration, occur in the context of a vast genome has remained a riddle. Here, we describe the chromosome-scale assembly of the giant, 32 Gb axolotl genome. Hi-C contact data revealed the scaling properties of interphase and mitotic chromosome organization. Analysis of the assembly yielded understanding of the evolution of large, syntenic multigene clusters, including the Major Histocompatibility Complex (MHC) and the functional regulatory landscape of the Fibroblast Growth Factor 8 (Axfgf8) region. The axolotl serves as a primary model for studying successful regeneration.

Fibroblast growth factor 8 overexpression is predictive of poor prognosis in pancreatic ductal adenocarcinoma

Summary Background Despite distinctive advances in the field of pancreatic cancer therapy over the past few years, patient survival remains poor. Fibroblast growth factors 8 (FGF8) and 18 (FGF18) both play a role in modulating the activity of malignant cells and have been identified as promising biomarkers in a number of cancers. However, no data exist on the expression of FGF8 and FGF18 in pancreatic ductal adenocarcinoma (PDAC). Methods Protein expression levels of FGF8 and FGF18 in postoperative specimens of neoadjuvantly treated and primarily resected patients were investigated using immunohistochemistry. Immunostaining scores were calculated as the products of the staining intensity and the staining rate. Scores exceeding the median score were considered as high expression. Results Specimens from 78 patients with PDAC were available and met the eligibility criteria for analysis of protein expression using immunohistochemistry. 15 (19.2%) patients had received neoadjuvant chemotherapy. High protein levels of FGF8 and FGF18 were detected in 40 (51.8%) and 33 (42.3%) patients, respectively. Kaplan–Meier analysis demonstrated significantly shorter overall survival in patients with high expression of FGF8 (p = 0.04). Multivariable Cox proportional hazard regression models revealed that high expression of FGF8 (Hazard ratio [HR] 0.53, 95% Confidence interval [CI] 0.32–0.89, p = 0.016) was an independent prognostic factor for diminished overall survival in patients with PDAC. By contrast, no statistical significance was found for FGF18 overexpression. In addition, the FGF8 protein level correlated with the factor resection margin (p = 0.042). Conclusion FGF8 is a promising target for new anticancer therapies using FGF inhibitors in pancreatic ductal adenocarcinomas.

Therapeutic effect of TO901317 on 6-OHDA-induced Parkinson rats in vitro and in vivo

Background: Stem cells from different sources could differentiate into dopamine-producing cells and ameliorate behavioral deficits in Parkinsonian models. Especially, human bone marrow mesenchymal stem cells (hBMSCs) have many advantages without ethical dispute. Liver X receptor s (LXRs) are involved in the maintenance of the normal function of the central nervous system myelin. We have reported the induction of cocktail-induced da phenotypes from adult rat BMSCs by using sonic hedgehog (SHH), fibroblast growth factor 8 (FGF8), basic fibroblast growth factor (bFGF) and TO901317 (agonist of LXRs) with 87.42% of efficiency in 6 days of period of induction. But the previous work did not verify whether the induced cells had the corresponding neural function. Methods: In this study, we demonstrated that TO901317 could promote the differentiation of hBMSCs into dopaminergic neurons. Neuronal markers (Tuj1, Neun and Nestin), dopamine neuron markers (tyrosine hydroxylase, TH), LXRa and LXRb were detected by immunofluorescence. RT-qPCR was used to measure the mRNA expressions of adenosine triphosphate-binding cassette transporter A1 (ABCA1). Western Blotting detected the changes of LXRa, LXRb and TH expression. Results: TO901317 significantly enhanced the differentiation from hBMSCs to DA neurons. Only the LXR+GF group released dopamine by the result of enzyme linked immunosorbent assay (ELISA). Compared with the control group and GF group, the optimal time for differentiation of hBMSCs treated by 0.5mM TO901317 combined with GF was six days. And the maximum induction efficiency was 91.67%. After transplanting induced-cells into Parkinson's disease rats, the symptoms of Parkinson's rats decreased, and the number of dopamine neurons increased in the substantia nigra and striatum. Conclusions: TO901317 promoted differentiation of hBMSCs into dopamine neurons may be related to activation of LXR-ABCA1 signaling pathway. These data suggest that TO901317 may serve as a potential therapeutic methods for Parkinson's disease.

Therapeutic effect of TO901317 on 6-OHDA-induced Parkinson rats in vitro and in vivo

Background: Stem cells from different sources could differentiate into dopamine-producing cells and ameliorate behavioral deficits in Parkinsonian models. Especially, human bone marrow mesenchymal stem cells (hBMSCs) have many advantages without ethical dispute. Liver X receptor s (LXRs) are involved in the maintenance of the normal function of the central nervous system myelin. We have reported the induction of cocktail-induced da phenotypes from adult rat BMSCs by using sonic hedgehog (SHH), fibroblast growth factor 8 (FGF8), basic fibroblast growth factor (bFGF) and TO901317 (agonist of LXRs) with 87.42% of efficiency in 6 days of period of induction. But the previous work did not verify whether the induced cells had the corresponding neural function. Methods: In this study, we demonstrated that TO901317 could promote the differentiation of hBMSCs into dopaminergic neurons. Neuronal markers (Tuj1, Neun and Nestin), dopamine neuron markers (tyrosine hydroxylase, TH), LXRa and LXRb were detected by immunofluorescence. RT-qPCR was used to measure the mRNA expressions of adenosine triphosphate-binding cassette transporter A1 (ABCA1). Western Blotting detected the changes of LXRa, LXRb and TH expression. Results: TO901317 significantly enhanced the differentiation from hBMSCs to DA neurons. Only the LXR+GF group released dopamine by the result of enzyme linked immunosorbent assay (ELISA). Compared with the control group and GF group, the optimal time for differentiation of hBMSCs treated by 0.5mM TO901317 combined with GF was six days. And the maximum induction efficiency was 91.67%. After transplanting induced-cells into Parkinson's disease rats, the symptoms of Parkinson's rats decreased, and the number of dopamine neurons increased in the substantia nigra and striatum. Conclusions: TO901317 promoted differentiation of hBMSCs into dopamine neurons may be related to activation of LXR-ABCA1 signaling pathway. These data suggest that TO901317 may serve as a potential therapeutic methods for Parkinson's disease.

A Review of the Genetics and Pathogenesis of Syndactyly in Humans and Experimental Animals: A 3-Step Pathway of Pathogenesis

Embryology of normal web space creation and the genetics of syndactyly in humans and experimental animals are well described in the literature. In this review, the author offers a 3-step pathway of pathogenesis for syndactyly. The first step is initiated either by the overactivation of the WNT canonical pathway or the suppression of the Bone Morphogenetic Protein (BMP) canonical pathway. This leads to an overexpression of Fibroblast Growth Factor 8 (FGF8). The final step is the suppression of retinoic acid in the interdigital mesenchyme leading to suppression of both apoptosis and extracellular matrix (ECM) degradation, resulting in syndactyly.