Publications

Steroid myopathy is a clinically challenging condition exacerbated by prolonged corticosteroid use or adrenal tumors. In this study, we engineered a functional three-dimensional (3D) in vitro skeletal muscle model to investigate steroid myopathy. By subjecting our bioengineered muscle tissues to dexamethasone treatment, we reproduced the molecular and functional aspects of this disease. Dexamethasone caused a substantial reduction in muscle force, myotube diameter and induced fatigue. We observed nuclear translocation of the glucocorticoid receptor (GCR) and activation of the ubiquitin-proteasome system within our model, suggesting their coordinated role in muscle atrophy. We then examined the therapeutic potential of taurine in our 3D model for steroid myopathy. Our findings revealed an upregulation of phosphorylated AKT by taurine, effectively countering the hyperactivation of the ubiquitin- proteasomal pathway. Importantly, we demonstrate that discontinuing corticosteroid treatment was insufficient to restore muscle mass and function. Taurine treatment, when administered concurrently with corticosteroids, notably enhanced contractile strength and protein turnover by upregulating the AKT-mTOR axis. Our model not only identifies a promising therapeutic target, but also suggests combinatorial treatment that may benefit individuals undergoing corticosteroid treatment or those diagnosed with adrenal tumors.

JTD Keywords: 3d bioengineered skeletal muscle tissues, Adrenal cortex hormones, Atroph, Colocalization, Corticosteroids, Dexamethasone, Glucocorticoid-receptor, Humans, Mechanisms, Models, biological, Mtor protein, human, Muscle contraction, Muscle fibers, skeletal, Muscle strength, Muscle, skeletal, Muscular diseases, Organ size, Phosphorylation, Proteasome endopeptidase complex, Proto-oncogene proteins c-akt, Receptors, glucocorticoid, Signal transduction, Skeletal-muscle, Steroid myopathy, Steroids, Supplementation, Taurin, Taurine, Tor serine-threonine kinases, Ubiquitin

We report a new strategy for immunochemical screening of small organic molecules based on the use of a hapten microarray. Using DNA-directed immobilization strategies, we have been able to convert a DNA chip into a hapten microarray by taking advantage of all the benefits of the structural and electrostatic homogeneous properties of DNA. The hapten microarray uses hapten-oligonucleotide probes instead of proteins, avoiding the limitations of preparing stochiometrically-defined protein-oligonucleotide bioconjugates. As proof of concept, we show here the development of a microarray for analysis of anabolic androgenic steroids. The microchip is able to detect several illegal substances with sufficient detectability to be used as a screening method, according to the regulations of the World Anti-Doping Agency for sport and the European Commision for food safety. The results that we show corroborate the universal possibilities of the DNA chip, and, in this case, they open the way to develop hapten microarrays for the immunochemical analysis of small organic molecules.

JTD Keywords: Anti-doping, DNA chip, DNA-directed immobilization (DDI), Fluorescence, Food safety, Hapten microarray, Immunochemical screening, Proof of concept, Small organic molecule, Steroid

A first step towards the multidetection of anabolic androgenic steroids by Enzyme-linked immunosorbent assays (ELISA) has been performed in this study. This proposal combines an array of classical ELISA assays with different selectivities and multivariate data analysis techniques. Data has been analyzed by principal component analysis in conjunction with a k-nearest line classifier has been used. This proposal allows to detect simultaneously four different compounds in the range of concentration from 10(-1.5) to 10(3) mM with a total rate of 90.6% of correct detection.

JTD Keywords: Immunoarray, Anabolic androgenic steroid, Multidetection, Pattern recognition, K-nearlest line