Improved Differentiation of Mesenchymal Stem Cells into Hepatocyte-like Cells using FGF4 and IGF-1 in 3D Culture

Human Umbilical Cord Mesenchymal Stem Cells (UCMSCs) are considered as an excellent candidate for cell therapy to treat end-stage liver disease. Fibroblast Growth Factor-4 (FGF4), Hepatocyte Growth Factor, and Insulin-like Growth Factor-1 are some of the critical cytokines involved in liver development and regeneration. To evaluate the differentiation potency of cells into hepatocyte-like cells we used these cytokines. UCMSCs were isolated from Wharton's jelly of fullterm infants. The cells were characterized as MSCs by flow-cytometry and their multilineage differentiation capacity. Then, UCMSCs were cultured in 3D collagen scaffold and hepatogenic media with or without FGF4 for 21 days and the data were compared to control. The expression of liver specific genes was evaluated by real-time quantitative RT-PCR and immunocytochemistry. These cells expressed MSC markers and could differentiate into adipocytes and osteocytes. A non–significant higher level of liver specific genes, such as cytokeratin-18 and 19, alpha-fetoprotein and albumin, and also a significant higher level of CYP2B6 expressed by UCMSCs in hepatogenic medium containing FGF4 compared with control. In some specimens, cytokeratin-19-positive cells surrounded a luminal space within collagen scaffolds. Liver-specific marker expression was increased by pre-exposing the cells to FGF4 before treating with IGF-1 and HGF in 3D collagen scaffold. Abbreviations: UCMSCs: Human Umbilical Cord Mesenchymal Stem Cells; FGF4: Fibroblast Growth Factor 4; HGF: Hepatocyte Growth Factor; IGF-1: Insulin-like Growth Factor-1; MSCs: Mesenchymal Stem Cells; ICG: Indocyanine green; PAS: periodic acid Schiff; CK-18: cytokeratin-18; CK-19: Cytokeratin-19; AFP: alpha-fetoprotein; G6P: glucose 6 phosphatase; PEPCK: phosphoenolpyruvate carboxykinase; TAT: tyrosine amino transferase; FBS: Fetal Bovine Serum; OSM: oncostatin M; RT-PCR: Reverse Transcription Polymerase Chain Reaction; PBS: Phosphate-Buffered Saline; Hep- Par1: Hepatocyte paraffin 1; DAB: Diaminobenzidine; CYP2B6: Cytochrome P450 2B6

Multiple roots of systems of equations by repulsion merit functions

In this paper we address the problem of computing multiple roots of a system of nonlinear equations through the global optimization of an appropriate merit function. The search procedure for a global min- imizer of the merit function is carried out by a metaheuristic, known as harmony search, which does not require any derivative information. The multiple roots of the system are sequentially determined along several ite- rations of a single run, where the merit function is accordingly modified by penalty terms that aim to create repulsion areas around previously computed minimizers. A repulsion algorithm based on a multiplicative kind penalty function is proposed. Preliminary numerical experiments with a benchmark set of problems show the effectiveness of the proposed method.Fundação para a Ciência e a Tecnologia (FCT

Testing Nelder-Mead based repulsion algorithms for multiple roots of nonlinear systems via a two-level factorial design of experiments

This paper addresses the challenging task of computing multiple roots of a system of nonlinear equations. A repulsion algorithm that invokes the Nelder-Mead (N-M) local search method and uses a penalty-type merit function based on the error function, known as 'erf', is presented. In the N-M algorithm context, different strategies are proposed to enhance the quality of the solutions and improve the overall efficiency. The main goal of this paper is to use a two-level factorial design of experiments to analyze the statistical significance of the observed differences in selected performance criteria produced when testing different strategies in the N-M based repulsion algorithm. The main goal of this paper is to use a two-level factorial design of experiments to analyze the statistical significance of the observed differences in selected performance criteria produced when testing different strategies in the N-M based repulsion algorithm.Fundação para a Ciência e Tecnologia (FCT

Towards Applying River Formation Dynamics in Continuous Optimization Problems

River Formation Dynamics (RFD) is a metaheuristic that has been successfully used by different research groups to deal with a wide variety of discrete combinatorial optimization problems. However, no attempt has been done to adapt it to continuous optimization domains. In this paper we propose a first approach to obtain such objective, and we evaluate its usefulness by comparing RFD results against those obtained by other more mature metaheuristics for continuous domains. In particular, we compare with the results obtained by Particle Swarm Optimization, Artificial Bee Colony, Firefly Algorithm, and Social Spider Optimization

Establishment of a Transgenic Zebrafish Line for Superficial Skin Ablation and Functional Validation of Apoptosis Modulators In Vivo

BACKGROUND: Zebrafish skin is composed of enveloping and basal layers which form a first-line defense system against pathogens. Zebrafish epidermis contains ionocytes and mucous cells that aid secretion of acid/ions or mucous through skin. Previous studies demonstrated that fish skin is extremely sensitive to external stimuli. However, little is known about the molecular mechanisms that modulate skin cell apoptosis in zebrafish. METHODOLOGY/PRINCIPAL FINDINGS: This study aimed to create a platform to conduct conditional skin ablation and determine if it is possible to attenuate apoptotic stimuli by overexpressing potential apoptosis modulating genes in the skin of live animals. A transgenic zebrafish line of Tg(krt4:NTR-hKikGR)(cy17) (killer line), which can conditionally trigger apoptosis in superficial skin cells, was first established. When the killer line was incubated with the prodrug metrodinazole, the superficial skin displayed extensive apoptosis as judged by detection of massive TUNEL- and active caspase 3-positive signals. Great reductions in NTR-hKikGR(+) fluorescent signals accompanied epidermal cell apoptosis. This indicated that NTR-hKikGR(+) signal fluorescence can be utilized to evaluate apoptotic events in vivo. After removal of metrodinazole, the skin integrity progressively recovered and NTR-hKikGR(+) fluorescent signals gradually restored. In contrast, either crossing the killer line with testing lines or transiently injecting the killer line with testing vectors that expressed human constitutive active Akt1, mouse constitutive active Stat3, or HPV16 E6 element displayed apoptosis-resistant phenotypes to cytotoxic metrodinazole as judged by the loss of reduction in NTR-hKikGR(+) fluorescent signaling. CONCLUSION/SIGNIFICANCE: The killer/testing line binary system established in the current study demonstrates a nitroreductase/metrodinazole system that can be utilized to conditionally perform skin ablation in a real-time manner, and provides a valuable tool to visualize and quantify the anti-apoptotic potential of interesting target genes in vivo. The current work identifies a potential use for transgenic zebrafish as a high-throughput platform to validate potential apoptosis modulators in vivo

Prevalence, Distribution and Functional Significance of the −237C to T Polymorphism in the IL-12Rβ2 Promoter in Indian Tuberculosis Patients

Cytokine/cytokine receptor gene polymorphisms related to structure/expression could impact immune response. Hence, the −237 polymorphic site in the 5′ promoter region of the IL-12Rβ2 (SNP ID: rs11810249) gene associated with the AP-4 transcription motif GAGCTG, was examined. Amplicons encompassing the polymorphism were generated from 46 pulmonary tuberculosis patients, 35 family contacts and 28 miscellaneous volunteers and sequenced. The C allele predominated among patients, (93.4%, 43/46), and in all volunteers and contacts screened, but the T allele was exclusively limited to patients, (6.5%, 3/46). The functional impact of this polymorphism on transcriptional activity was assessed by Luciferase-reporter and electrophoretic mobility shift assays (EMSA). Luciferase-reporter assays showed a significant reduction in transcriptional efficiency with T compared to C allele. The reduction in transcriptional efficiency with the T allele construct (pGIL-12Rb2-T), in U-87MG, THP-1 and Jurkat cell lines, were 53, 37.6, and 49.8% respectively, compared to the C allele construct (pGIL-12Rb2-C). Similarly, densitometric analysis of the EMSA assay showed reduced binding of the AP-4 transcription factor, to T compared to the C nucleotide probe. Reduced mRNA expression in all patients (3/3) harboring the T allele was seen, whereas individuals with the C allele exhibited high mRNA expression (17/25; 68%, p = 0.05). These observations were in agreement with the in vitro assessment of the promoter activity by Luciferase-reporter and EMSA assays. The reduced expression of IL-12Rβ2 transcripts in 8 patients despite having the C allele was attributed to the predominant over expression of the suppressors (IL-4 and GATA-3) and reduced expression of enhancers (IFN-α) of IL-12Rβ2 transcripts. The 17 high IL-12Rβ2 mRNA expressers had significantly elevated IFN-α mRNA levels compared to low expressers and volunteers. Notwithstanding the presence of high levels of IL-12Rβ2 mRNA in these patients elevated IFN-α expression could modulate their immune responses to Mycobacterium tuberculosis