Polycaprolactone-templated reduced-graphene oxide liquid crystal nanofibers towards biomedical applications

Here, we report a facile method to generate electrically conductive nanofibers by coating and subsequently chemically reducing graphene oxide (GO) liquid crystals on a polycaprolactone (PCL) mat.</p

Intranuclear localization of EGFP-mouse PPARγ1 in bovine fibroblast cells

Objective: The aim of this study was to clone PPARγ1 cDNA in an appropriate mammalian expression vector, with a chimeric cDNA form, encompassing PPARγ with enhanced green fluorescent protein (EGFP) cDNA. This recombinant plasmid will be used for further analyses to investigate the molecular mechanism of PPARγ1 for neural differentiation process. Moreover, the nuclear localization of the PPARγ1 protein linked to EGFP marker was chased by using transient transfection of a constructed plasmid into bovine fibroblast cells. Materials and Methods: Total RNA was extracted from the fatty tissue of an adult mouse. Using specific pair primers, PPARγ1 cDNA was synthesized and amplified to produce the entire length of ORF. RT-PCR products containing PPARγ1 cDNA were treated by enzymatic digestion and inserted into the pEGFP-C1 downstream from EGFP cDNA. The constructed vector was used for transformation into bacterial competent cells. Positive colonies which showed inserted PPARγ1 cDNA were selected for plasmid preparations and additional analysis was performed to ensure that PPARγ1 cDNA was inserted properly. Finally, to confirm the intracellular localization of EGFP-PPARγ1, bovine fibroblast cells were transfected with the recombinant plasmid. Results: Our results from enzymatic digestion and sequencing confirmed, as expected, that PPARγ1 cDNA was amplified and cloned correctly. This cDNA gene encompassed 1428 bp. The related product was entered into the nucleus of bovine fibroblasts after transfection of its cDNA. Conclusion: PPARγ1 cDNA was cloned and sorted into nuclear compartments of bovine fibroblast cells upon transfection

Human Embryonic Stem Cell Science in Iran: Pioneering in the Muslim World

La recherche sur les cellules souches embryonnaires humaines (CSEh) est un domaine qui a suscité un vif intérêt dans les milieux scientifiques mais aussi financiers. C’est aussi un champ d’investigation source de dilemmes éthiques et de développements politiques encadrant le statut moral de l’embryon humain, les sources d’embryons ou de gamètes humains destinés à la recherche, le clonage ainsi que l’utilisation thérapeutique des cellules souches. Dans le monde Musulman, l’Iran, une nation pionnière de la recherche sur les SCEh, a reporté l’établissement d’une nouvelle lignée de cellules souches dès 2003. Ce pays a aussi établi des recommandations éthiques nationales pour la recherche et la thérapie utilisant les cellules souches. Le présent manuscrit décrit le développement de la science entourant les CSEh ainsi que d’autres accomplissements scientifiques et bioéthiques connexes en Iran. Il explique aussi comment la recherche sur les CSEh est à la fois guidée et réglementée par les lois et principes éthiques issus de l’Islam, et montre comment l’expérience d’un pays en développement peut servir d’exemple à d’autres sociétés similaires. Cet article présente ensuite une brève revue de l’état actuel de la recherche et de la réglementation de ce domaine dans certains pays Musulmans du Moyen-Orient. En conclusion, on peut argumenter autour du fait que, bien que la science et la religion soient des facteurs clés dans les débats actuels autours des CSEh, d’autres facteurs influencent la manière avec laquelle un nouveau savoir est abordé dans des pays ayant par ailleurs la même obédience religieuse ou des intérêts scientifiques similaires.Human embryonic stem cell (hESC) research is a field that has attracted considerable scientific and financial investment and attention in many countries. It is also a field surrounded by ethical controversies and policy developments concerning the moral status of the human embryo, sourcing of human embryos and gametes for research, cloning as well as stem cell (SC) therapy. In the Muslim world, Iran, as a pioneer country in hESC research, reported the establishment of a new SC line in 2003. The country has also established the national ethical guidelines for SC research and therapy. This paper therefore depicts the development of hESC science, as well as some other relevant scientific achievements and bioethics in Iran. It also describes how hESC research is both formed and regulated by Islamic law and ethics, as the experience of a developing country can provide insight to many similar societies. This article then presents a brief review of the current state of this field of science and its regulatory policy in some selected Muslim Middle East countries. In conclusion, it shall argue that, although science and religion are key factors in the current debates around hESC research, additional factors influence the manner in which new knowledge is taken up in countries with the same religious background or scientific interests

Induction of active demethylation and 5hmC formation by 5-azacytidine is TET2 dependent and suggests new treatment strategies against hepatocellular carcinoma

Background: Global deregulation of DNA methylation is one of the crucial causes of hepato cellular carcinoma (HCC). It has been reported that the anti-cancer drug 5-azacytidine (5-AZA) mediates the activation of tumor suppressor genes through passive demethylation by inhibiting DNMT1. Recent evidence suggests that active demethylation which is mediated by ten-eleven translocation (TET) proteins may also be an important step to control global methylation. However, there exists a controversial discussion in which TET proteins are involved in the demethylation process in HCC. Therefore, we firstly wanted to identify which of the TETs are involved in demethylation and later to study whether or not 5-AZA could trigger the TET-dependent active demethylation process in HCC. HCC cell lines (Huh-7, HLE, HLF), primary human hepatocytes (hHeps), and tissues from both healthy (55 patients) and HCC patients (55 patients) were included in this study; mRNA levels of isocitrate dehydrogenase (IDH1, 2) and TETs (TET1–3) were studied via qPCR and confirmed by Western blot. The expression of 5hmC/5mC was determined by immunohistochemistry in human HCC tissues and the corresponding adjacent healthy liver. HCC cell lines were stimulated with 5-AZA (0–20 μM) and viability (Resazurin conversion), toxicity (LDH release), proliferation (PCNA), and 5hmC/5mC distribution were assessed. In addition, knockdown experiments on TET proteins in HCC cell lines using short interference RNAs (siRNAs), in the presence and absence of 5-AZA, were performed. Results: Our data applying qPCR, immunofluorescence, and Western blotting clearly show that TET2 and TET3 but not TET1 were significantly decreased in HCC tissue and different HCC cell lines compared to non-tumor liver tissues and hHeps. In addition, we show here for the first time applying knockdown experiments that 5-AZA is able to trigger an active TET2-dependent demethylation process with concomitant significant changes in 5hmC/5mC in HCC cell lines and hHeps. Conclusions: Our data clearly show that the expression and activity of TET2 and TET3 proteins but not TET1 are impaired in hepatocellular carcinoma leading to the reduction of 5hmC in HCCs. Furthermore, this study identified a novel function of 5-azacytidine in promoting a TET-mediated generation of 5hmC suggesting that the availability of 5-AZA in cancer cells will have various effects on different epigenetic targets. These findings may open new therapeutic strategies for epigenetic drugs to treat HCC

Brief Azacytidine Step Allows The Conversion of Suspension Human Fibroblasts into Neural Progenitor-Like Cells

In recent years transdifferentiation technology has enabled direct conversion of human fibroblasts to become a valuable, abundant and accessible cell source for patient-specific induced cell generation in biomedical research. The majority of transdifferentiation approaches rely upon viral gene delivery which due to random integration with the host genome can cause genome instability and tumorigenesis upon transplantation. Here, we provide a simple way to induce neural progenitor-like cells from human fibroblasts without genetic manipulation by changing physicochemical culture properties from monolayer culture into a suspension in the presence of a chemical DNA methyltransferase inhibitor agent, Azacytidine. We have demonstrated the expression of neural progenitor-like markers, morphology and the ability to spontaneously differentiate into neural-like cells. This approach is simple, inexpensive, lacks genetic manipulation and could be a foundation for future chemical neural transdifferentiation and a safe induction of neural progenitor cells from human fibroblasts for clinical applications

Comprehensive Gene Expression Analysis of Human Embryonic Stem Cells during Differentiation into Neural Cells

Global gene expression analysis of human embryonic stem cells (hESCs) that differentiate into neural cells would help to further define the molecular mechanisms involved in neurogenesis in humans. We performed a comprehensive transcripteome analysis of hESC differentiation at three different stages: early neural differentiation, neural ectoderm, and differentiated neurons. We identified and validated time-dependent gene expression patterns and showed that the gene expression patterns reflect early ESC differentiation. Sets of genes are induced in primary ectodermal lineages and then in differentiated neurons, constituting consecutive waves of known and novel genes. Pathway analysis revealed dynamic expression patterns of members of several signaling pathways, including NOTCH, mTOR and Toll like receptors (TLR), during neural differentiation. An interaction network analysis revealed that the TGFβ family of genes, including LEFTY1, ID1 and ID2, are possible key players in the proliferation and maintenance of neural ectoderm. Collectively, these results enhance our understanding of the molecular dynamics underlying neural commitment and differentiation

Co-transplantation of Human Embryonic Stem Cell-derived Neural Progenitors and Schwann Cells in a Rat Spinal Cord Contusion Injury Model Elicits a Distinct Neurogenesis and Functional Recovery

Co-transplantation of neural progenitors (NPs) with Schwann cells (SCs) might be a way to overcome low rate of neuronal differentiation of NPs following transplantation in spinal cord injury (SCI) and the improvement of locomotor recovery. In this study, we initially generated NPs from human embryonic stem cells (hESCs) and investigated their potential for neuronal differentiation and functional recovery when co-cultured with SCs in vitro and co-transplanted in a rat acute model of contused SCI. Co-cultivation results revealed that the presence of SCs provided a consistent status for hESC-NPs and recharged their neural differentiation toward a predominantly neuronal fate. Following transplantation, a significant functional recovery was observed in all engrafted groups (NPs, SCs, NPs+SCs) relative to the vehicle and control groups. We also observed that animals receiving co-transplants established a better state as assessed with the BBB functional test. Immunohistofluorescence evaluation five weeks after transplantation showed invigorated neuronal differentiation and limited proliferation in the co-transplanted group when compared to the individual hESC-NPs grafted group. These findings have demonstrated that the co-transplantation of SCs with hESC-NPs could offer a synergistic effect, promoting neuronal differentiation and functional recovery

Engineering Folate-Targeting Diselenide-containing Triblock Copolymer as a Redox-Responsive Shell-sheddable Micelle for Antitumor Therapy In Vivo

The oxidation-reduction (redox)–responsive micelle system is based on a diselenide-containing triblock copolymer, poly(ε-caprolactone)-bis(diselenide-methoxy poly(ethylene glycol)/poly(ethylene glycol)-folate) [PCL-(SeSe-mPEG/PEG-FA)2]. This has helped in the development of tumor-targeted delivery for hydrophobic anticancer drugs. The diselenide bond, as a redox-sensitive linkage, was designed in such a manner that it is located at the hydrophilic–hydrophobic hinge to allow complete collapse of the micelle and thus efficient drug release in redox environments. The amphiphilic block copolymers self-assembled into micelles at concentrations higher than the critical micelle concentration (CMC) in an aqueous environment. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses showed that the micelles were spherical with an average diameter of 120 nm. The insoluble anticancer drug paclitaxel (PTX) was loaded into micelles, and its triggered release behavior under different redox conditions was verified. Folate-targeting micelles showed an enhanced uptake in 4T1 breast cancer cells and in vitro cytotoxicity by flow cytometry and (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay, respectively. Delayed tumor growth was confirmed in the subcutaneously implanted 4T1 breast cancer in mice after intraperitoneal injection. The proposed redox-responsive copolymer offers a new type of biomaterial for drug delivery into cancer cells in vivo. Statement of Significance On-demand drug actuation is highly desired. Redox-responsive polymeric DDSs have been shown to be able to respond and release their cargo in a selective manner when encountering a significant change in the potential difference, such as that present between cancerous and healthy tissues. This study offers an added advantage to the field of redox-responsive polymers by reporting a new type of shell-sheddable micelle based on an amphiphilic triblock co-polymer, containing diselenide as a redox-sensitive linkage. The linkage was smartly located at the hydrophilic-hydrophilic bridge in the co-polymer offering complete collapse of the micelle when exposed to the right trigger. The system was able to delay tumor growth and reduce toxicity in a breast cancer tumor model following intraperitoneal injection in mice