140 research outputs found

    STAT3, a hub protein of cellular signaling pathways, is triggered by ÎČ-hexaclorocyclohexane

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    Background: Organochlorine pesticides (OCPs) are widely distributed in the environment and their toxicity is mostly associated with the molecular mechanisms of endocrine disruption. Among OCPs, particular attention was focused on the effects of ÎČ-hexaclorocyclohexane (ÎČ-HCH), a widely common pollutant. A detailed epidemiological study carried out on exposed population in the “Valle del Sacco” found correlations between the incidence of a wide range of diseases and the occurrence of ÎČ-HCH contamination. Taking into account the pleiotropic role of the protein signal transducer and activator of transcription 3 (STAT3), its function as a hub protein in cellular signaling pathways triggered by ÎČ-HCH was investigated in different cell lines corresponding to tissues that are especially vulnerable to damage by environmental pollutants. Materials and Methods: Human prostate cancer (LNCaP), human breast cancer (MCF-7 and MDA-MB 468), and human hepatoma (HepG2) cell lines were treated with 10 ”M ÎČ-HCH in the presence or absence of specific inhibitors for different receptors. All samples were subjected to analysis by immunoblotting and RT-qPCR. Results and Conclusions: The preliminary results allow us to hypothesize the involvement of STAT3, through both its canonical and non-canonical pathways, in response to ÎČ-HCH. Moreover, we ascertained the role of STAT3 as a master regulator of energy metabolism via the altered expression and localization of HIF-1α and PKM2, respectively, resulting in a Warburg-like effect

    Effect of testosterone metabolites on ABC half-transporter relative gene expression in X-linked adrenoleukodystrophy

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    X-linked adrenoleukodystrophy (X-ALD) is an inherited neurodegenerative disorder associated with reduced very long-chain fatty acid beta-oxidation, mainly affecting the nervous system, the adrenal cortex and the testes. The clinical manifestations of hypogonadism, alopecia and the impairment of the enzyme 5alpha-reductase, which converts testosterone into dihydrotestosterone, clearly point to an involvement of androgens in this pathology. The disease is characterized by mutations in the ABCD1 gene, which codes for the peroxisomal ABC half-transporter ALDP, and by a broad range of clinical manifestations. The altered function of ALDP can be compensated by the overexpression of proteins belonging to the same family of ABC half-transporters. A promising therapeutic approach is represented by the activation of these proteins by specific agonists. In this study we evaluated the effect of the testosterone metabolite dihydrotestosterone (DHT) and 5alpha-androstan-3alpha,17beta-diol (3alpha-diol) on the expression of the ABC half-transporters encoded by the ABCD2 and ABCD3 genes, in fibroblasts drawn from controls and from two affected brothers. The two patients presented the same mutation in exon 9 but had different clinical manifestations, one patient being asymptomatic and the second one severely affected. When the cells were stimulated with testosterone metabolites, only the severely affected patient showed a significant increase in ABCD2 mRNA levels, while the ABCD3 expression remained unchanged in both patients

    Effect of Degumming in the Characteristics of Silk Fibroin Nanoparticles

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    Several studies have stated that the process used for sericin removal, or degumming, from silk cocoons has a strong impact on the silk fibroin integrity and consequently in their mechanical or biochemical properties after processing it into several biomaterials (e.g., fibers, films or scaffolds) but still, there is a lack of information of the impact on the features of silk nanoparticles. In this work, silk cocoons were degummed following four standard methods: autoclaving, short alkaline (Na2CO3) boiling, long alkaline (Na2CO3) boiling, and ultrasounds. The resultant silk fibroin fibers were dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate and used for nanoparticle synthesis by rapid desolvation in polar organic solvents. The relative efficiencies of the degumming processes and the integrity of the resulting fibroin fibers obtained were analyzed by mass loss, optical microscopy, thermogravimetric analysis, infrared spectroscopy, and SDS-PAGE. Particle sizes and morphology were analyzed by Dynamic Light Scattering and Field Emission Scanning Electronic Microscopy. The results showed that the different treatments had a remarkable impact on the integrity of the silk fibroin chains, as confirmed by gel electrophoresis, which can be correlated with particle mean size and size distribution changes. The smallest nanoparticles (156 ± 3 nm) and the most negative Z potential (−30.2 ± 1.8 mV) were obtained with the combination of long treatment (2 h) of boiling in alkaline solution (Na2CO3 0.02 eq/L). The study confirms that parameters of the process, such as the composition of the solution and time of the degumming step, must be controlled in order to reach an optimum reproducibility of the nanoparticle production.This work has been partially supported (80%) by the European Commission ERDF/FEDER Operational Programme 'Murcia' CCI N° 2007ES161PO001 (Project No. 14-20/20), and the Spanish MINECO (Ref. CTQ2017-87708-R) and the programme of support to the research of the Seneca Foundation of Science and Technology of Murcia, Spain (Ref. 20977/PI/18). A.A.L.-P.’s research contract was partially supported (80%) by the ERDF/FEDER Operational Programme 'Murcia' CCI N° 2007ES161PO001 (Project No. 14-20/20),. M.G. MontalbĂĄn’s research contract is funded by the Spanish MINECO (Juan de la Cierva-FormaciĂłn contract, Ref. FJCI-2016-28081). S.D.A.-C.’s research contract is funded by the program INIA-CCAA (DOC INIA 2015), announced by the National Institute for Agricultural and Food Research and Technology (INIA) and supported by the Spanish State Research Agency (AEI) under the Spanish Ministry of Economy, Industry and Competitiveness

    Biopolymeric Nanoparticle Synthesis in Ionic Liquids

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    Recently, much research has focused on the use of biopolymers, which are regarded as biodegradable, natural, and environmentally friendly materials. In this context, biopolymeric nanoparticles have attracted great attention in the last few years due to their multiple applications especially in the field of biomedicine. Ionic liquids have emerged as promising solvents for use in a wide variety of chemical and biochemical processes for their extraordinary properties, which include negligible vapor pressure, high thermal and chemical stability, lower toxicity than conventional organic solvents, and the possibility of tuning their physical–chemical properties by choosing the appropriate cation and anion. We here review the published works concerning the synthesis of biopolymeric nanoparticles using ionic liquids, such as trimethylsilyl cellulose or silk fibroin. We also mention our recent studies describing how high-power ultrasounds are capable of enhancing the dissolution process of silk proteins in ionic liquids and how silk fibroin nanoparticles can be directly obtained from the silk fibroin/ionic liquid solution by rapid desolvation in polar organic solvents. As an example, their potential biomedical application of curcumin-loaded silk fibroin nanoparticles for cancer therapy is also discussed

    Complex Polysaccharide-Based Nanocomposites for Oral Insulin Delivery

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    Polyelectrolyte nanocomposites rarely reach a stable state and aggregation often occurs. Here, we report the synthesis of nanocomposites for the oral delivery of insulin composed of alginate, dextran sulfate, poly-(ethylene glycol) 4000, poloxamer 188, chitosan, and bovine serum albumin. The nanocomposites were obtained by Ca2+-induced gelation of alginate followed by an electrostatic-interaction process among the polyelectrolytes. Chitosan seemed to be essential for the final size of the nanocomposites and there was an optimal content that led to the synthesis of nanocomposites of 400–600 nm hydrodynamic size. The enhanced stability of the synthesized nanocomposites was assessed with LUMiSizer after synthesis. Nanocomposite stability over time and under variations of ionic strength and pH were assessed with dynamic light scattering. The rounded shapes of nanocomposites were confirmed by scanning electron microscopy. After loading with insulin, analysis by HPLC revealed complete drug release under physiologically simulated conditions
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