Biology subjects

Dupont, N.

Publications and source records attributed to Dupont, N..

3 recordsLinked to original sources

bioRxiv2026

Parathyroid Hormone Receptor 1 Signaling Encodes Multifaceted Metabolic Programs in AgRP Neurons

Organisms continuously adapt food intake and nutrient utilization to fluctuating energy demands, requiring the brain to accurately integrate signals coming from diverse metabolic organs and local signals into distinct physiological responses. How hypothalamic neurons discriminate these signals to independently regulate feeding behavior and peripheral metabolism remains poorly understood. In recent years, a coordinated regulation between bone physiology and the central control of energy metabolism has emerged, opening questions about potential common hormonal networks and signaling pathways between the bone and the brain. Here, we identify parathyroid hormone receptor 1 (PTH1R) signaling, a master regulator of calcium ion biochemistry and bone formation, in Agouti-related peptide (AgRP) neurons as an unexpected neuroendocrine mechanism for the control of feeding behaviourand nutrient partitioning. the two cognate endocrine and paracrine ligands, PTH and PTH-related peptide (PTHrP), selectively activat segregated intracellular kinases activation and lipophagic processes in AgRP neuron, ultimately producing convergent physiological outputs. Together, our findings identify the parathyroid hormonal system acts as a fine-tuning mechanism in specialized neuronal circuits allowing for hypothalamic adaptive responses to energy demands and systemic metabolic signals. Keywords: Parathyroid hormone-related peptide (PTHrP), hypothalamus, arcuate nucleus, agouti-related peptide neurons, energy metabolism, fasting, autophagy, free fatty acids

neuroscience↗

bioRxiv2023

Abnormal autophagy is a critical mechanism in TANGO2-related rhabdomyolysis

Patients with pathogenic variants in the TANGO2 gene suffer from severe and recurrent rhabdomyolysis (RM) episodes precipitated by fasting. Since starvation promotes autophagy induction, we wondered whether TANGO2-related muscle symptoms result from autophagy insufficiency to meet cellular demands in stress conditions. Autophagy functioning was analyzed in vitro, in primary skeletal muscle cells from TANGO2 patients in basal and fasting conditions. In addition, we developed a tango2 morphant zebrafish model to assess the effect of tango2 knockdown (KD) on locomotor function and autophagy efficiency in vivo. We report that TANGO2 mutations are associated with decreased LC3-II levels upon starvation in primary muscle cells, but not in fibroblasts. In zebrafish larvae, tango2 knockdown induces locomotor defects characterized by reduced evoked movements which are exacerbated by exposure to atorvastatin, a compound known to cause RM. Importantly, RM features of tango2 KD are also associated with autophagy and mitophagy defects in zebrafish. Calpeptin treatment, a known activator of autophagy, is sufficient to rescue the locomotor properties, thanks to its beneficial effect on autophagy functioning in zebrafish and independently to its effect on calpain activity. LC3-II levels of primary muscle cells of TANGO2 patients are also improved by calpeptin treatment. Overall, we demonstrate that TANGO2 plays an important role in autophagy, and that autophagy efficiency is critical to prevent RM, thus giving rise to new therapeutic perspectives in the prevention of these life-threatening episodes in TANGO2 pathology.

cell biology↗

bioRxiv2023

YAP-dependent autophagy is controlled by AMPK, SIRT1 and flow intensity in kidney epithelial cells.

Shear stress generated by the urinary fluid flow is an important regulator of renal function. Its dysregulation is observed in various chronic and acute kidney diseases. Previously, we demonstrated that primary cilium-dependent autophagy allows kidney epithelial cells to adapt their metabolism in response to fluid flow. Here, we show that nuclear YAP/TAZ negatively regulates autophagy machinery in kidney epithelial cells subjected to fluid flow. This crosstalk is supported by a primary cilium-dependent activation of AMPK and SIRT1, independently of the Hippo pathway. We confirmed the relevance of the YAP/TAZ-autophagy molecular dialog in vivo using a zebrafish model of kidney development and a unilateral ureteral obstruction mouse model. In addition, an in vitro assay simulating the pathological flow observed at early stages of chronic kidney disease (CKD) activated YAP, leading to a primary cilium-dependent inhibition of autophagy. Our findings demonstrate the importance of YAP/TAZ and autophagy in the translation of fluid flow into cellular and physiological responses. Dysregulation of this pathway is associated with the early onset of CKD.

cell biology↗