Desarrollo de una plataforma motoneuronal para el estudio de la ELA: impacto funcional de la mutación de TARDBP en respuesta al estrés muscular

How does the pathogenic cross-talk between the peripheral microenvironment and motor neurons drive neurodegeneration in Amyotrophic Lateral Sclerosis (ALS)? While historically studied from a strictly neurocentric perspective, there is a growing recognition of the critical contribution of non-autonomous mechanisms, particularly from skeletal muscle, to the progression of this disease. This doctoral thesis explores this neuromuscular interplay by utilizing a highly robust, human-derived in vitro model. During the upcoming defense, we will present the development and validation of a protocol (a dual lentiviral transduction system combining NGN2-ASCL1 and ISL1-LHX3) optimized to yield functionally mature human motor neurons. We will examine how the TDP-43 Q331K mutation acts as an intrinsic «first hit,» predisposing these cells to metabolic exhaustion, mitochondrial calcium overload, and aberrant electrophysiological firing. Furthermore, we will discuss the impact of a «second hit» via exposure to skeletal muscle secretomes, derived from both clinical patient samples and experimental TDP-43-silenced models. Our findings reveal a striking physiological divergence: while healthy wild-type networks exhibit adaptive homeostatic plasticity to save energy, mutant motor neurons undergo a bioenergetic and electrophysiological collapse, accompanied by a loss of cellular identity. We cordially invite you to attend this defense, where we will integrate these findings and discuss why shifting the therapeutic focus from isolated neuroprotection to restoring paracrine signaling across the entire neuromuscular unit represents a crucial step forward in ALS research.