Mechanism of antiandrogen action: Conformational changes of the receptor

Androgen receptor mRNA was translated in vitro, and androgen- and antiandrogen-bound receptor complexes were studied using limited proteolytic digestion by trypsin. Partial proteolysis of androgen-bound receptor protein resulted in a 29-kDa proteolysis-resisting fragment, whereas antiandrogen binding stabilised a 35-kDa fragment. Both fragments contain the entire ligand binding domain, and the 35-kDa fragment extended into the hinge region of the receptor. Several antiandrogens show agonistic properties for a mutated androgen receptor (LNCaP cell variant); trypsin digestion of antiandrogen-bound mutated receptor also resulted in a 29-kDa fragment. Our results point to an important difference between antiandrogens and antagonists of other steroid hormone receptors. Antiandrogens result in protection of both the hinge region and C-terminus of the androgen receptor against proteolytic attack, whereas other studies showed that antiestrogens and antiprogestagens expose the C-terminal end of the ligand binding domain of their respective receptors to protease. Differences in conformation of the hinge region distinguish androgen-bound from antiandrogen-bound receptor complexes, which represents an important feature of antiandrogen action

Deoxyribonucleic acid-binding ability of androgen receptors in whole cells: implications for the actions of androgens and antiandrogens

In whole cells, the effects of several androgens and antiandrogens on the in the induction of DNA binding for the human wild-type androgen receptor (AR) and a mutant receptor ARL (LNCaP mutation; codon 868, Thr to Ala) were examined and related to the transcription activation ability of these receptors. To study DNA binding, an AR expression vector was cotransfected in Chinese hamster ovary cells with a promoter interference plasmid cytomegalovirus-(androgen-responsive element)3-luciferase, containing one or more androgen-responsive elements between the TATA box of the cytomegalovirus promoter and the start site of luciferase gene transcription. Expression levels of the AR are up-regulated by some agonists, but receptor expression levels are comparable for all antiandrogens studied. In the presence of androgens, the wild-type AR is able to reduce promoter activity of the cytomegalovirus-(androgen-responsive element)3-luciferase plasmid, indicating androgen-dependent DNA binding of the AR. The full antagonists hydroxyflutamide, ICI 176.334, and RU 23908 block AR binding to DNA. The antagonists cyproterone acetate and RU 38486 induce approximately 50% of the DNA binding found for androgens. In a transcription activation assay, the RU 38646-bound receptor was almost inactive, and the receptor complexed with cyproterone acetate showed partial agonistic activity. Interaction of the antagonists cyproterone acetate, hydroxyflutamide, and RU 23908 with the mutant receptor ARL resulted in both DNA-bound and a transcriptionally active receptor. In conclusion, transformation of the AR to a DNA-binding state in whole cells is blocked by several antiandrogens. Furthermore, studies with the antiandrogens cyproterone acetate and RU 38486 show that DNA binding alone is not sufficient to accomplish full transcriptional activity. Full activity requires additional changes, presumably in the protein structure of the receptor

A Method Helping to Define Eco-innovative Systems Based on Upgradability

AbstractEnvironmental issues due to emerging markets and rapid development of consumer goods’ consumption require a new model to design more sustainable products. While traditional eco-design methods (LCA, Check-lists, Guidelines, DfX tools…) are generally restricted to a local optimization of the product or to macro-rules for defining an environmental strategy, this article presents an eco-innovative method based on product upgradability which is the integration of functional enrichments on the product. Indeed, the integration of upgrades offers new opportunities for facilitating the dissemination of the remanufacturing approach, the dissemination of Product-Service Systems, or for increasing the lifetime of product.This article presents an eco-innovative method based on upgradability consisting in: exploring the potential upgrades of modules - PMoL (SADT activity A4), the potential value network structures for upgradability - VaNS (A3) and the potential serviceable upgrades including eco-learning strategies - SMoL (A5). This method combines then the results PMoL, VaNS and SMoL to form promising Upgradable Modules Scenarios – UpMoS (A6), which are completed by the specification of an associated value network (A7) and the consolidation of eco-usage services and services offers (A8). The final result obtained, Upgradable systems concepts– UpSys are then assessed thanks to a multicriteria approach (A9) considering environmental, economic and user's and stakeholder's attractiveness criteria.To summarize, this method is structured in two rounds. The first round (A3, A4, A5) aims to explore widely the possibilities offered by the upgradability avoiding the complexity of an approach dealing with several parameters simultaneously. The purpose of the second round (A6, A7, A8, A9) is to specify and assess Upgradable systems encompassing the overall results of the exploration. Before performing this work, relevant information needs to be collected for the project (market information, customer segments, technologies, stakeholders, environmental impacts of the current product, etc.) and acceptability domains of upgradable systems have to be analyzed (A1, A2).This paper presents therefore this eco-innovative approach based on five founding principles and answering to the requirements identified in the literature for a good and effective eco-design method

Effects of antiandrogens on transformation and transcription activation of wild-type and mutated (LNCaP) androgen receptors

LNCaP cells contain androgen receptors with a mutation in the steroid binding domain (Thr 868 changed to Ala) resulting in a changed hormone specificity. Both the wild-type and mutated androgen receptors were transfected into COS cells. Transcription activation was studied in cells co-transfected with an androgen sensitive reporter (CAT) gene. The wild-type androgen receptor was activated by the agonist R1881, but the antiandrogens did not enhance transcription apart from a partial agonistic effect at high concentrations of cyproterone acetate. The mutated androgen receptor was fully activated by R1881, cypoterone acetate and hydroxyflutamide, but not by ICI 176,334. Receptor transformation to a tight nuclear binding state was studied by preparation of detergent washed nuclei and Western blotting with a specific antibody against the androgen receptor. Nuclei of COS cells transfected with wild-type receptor retained the receptor when the cells had been treated with the agonist R1881, partially retained receptors when treated with antiandrogen cyproterone acetate, but did not retain receptor when treated with hydroxyflutamide or ICI 176,334. The cells transfected with the mutated receptor additionally retained nuclear receptors after treatment with hydroxyflutamide. We conclude that each one of the three antiandrogens tested displayed different characteristics with respect to its effect on transformation and transcription activation

Superabsorbent Polymers:From long-established, microplastics generating systems, to sustainable, biodegradable and future proof alternatives

Superabsorbent polymers (SAPs) play important roles in our daily life, as they are applied in products for hygiene, agriculture, construction, etc. The most successful commercially used types of SAPs are acrylate-based, which include poly(acrylic acid)s, poly(acrylamide)s, poly(acrylonitrile)s and their salts. The acrylate-based SAPs have superior water-absorbent properties, but they have high molecular weight and in addition an entirely carbon atom-based and cross-linked backbone. These factors endow them with poor (bio)degradability, which has a devastating impact on the environment where such SAP-containing materials may end up at the end of their lifetime. Furthermore, the raw materials for production of acrylate-based SAPs are mostly petroleum-based. From the viewpoint of sustainability, a bio-based resource would be the ideal candidate to replace the fossil-based ones. To overcome the shortcomings of the existing SAPs, bio-based and degradable SAPs are required. This review will then cover the following topics: (1) the technology development history and state-of-the-art of current SAPs; (2) the product designing principles of SAPs; (3) an in-depth introduction and discussion of the structural characteristics and properties of different kinds of SAPs derived from both fossil or renewable resources and (4) novel polycondensate-based, potentially biodegradable SAPs with promising industrial applicability

Phylogenomic reclassification of the world's most venomous spiders (Mygalomorphae, Atracinae), with implications for venom evolution

Here we show that the most venomous spiders in the world are phylogenetically misplaced. Australian atracine spiders (family Hexathelidae), including the notorious Sydney funnel-web spider Atrax robustus, produce venom peptides that can kill people. Intriguingly, eastern Australian mouse spiders (family Actinopodidae) are also medically dangerous, possessing venom peptides strikingly similar to Atrax hexatoxins. Based on the standing morphology-based classification, mouse spiders are hypothesized distant relatives of atracines, having diverged over 200 million years ago. Using sequence-capture phylogenomics, we instead show convincingly that hexathelids are non-monophyletic, and that atracines are sister to actinopodids. Three new mygalomorph lineages are elevated to the family level, and a revised circumscription of Hexathelidae is presented. Re-writing this phylogenetic story has major implications for how we study venom evolution in these spiders, and potentially genuine consequences for antivenom development and bite treatment research. More generally, our research provides a textbook example of the applied importance of modern phylogenomic research.Fil: Hedin, Marshal. San Diego State University; Estados UnidosFil: Derkarabetian, Shahan. University of California; Estados Unidos. San Diego State University; Estados UnidosFil: Ramirez, Martin Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Vink, Cor. Canterbury Museum Christchurch; Nueva ZelandaFil: Bond, Jason E.. Auburn University; Estados Unido