Biology subjects

Moog, S.

Publications and source records attributed to Moog, S..

3 recordsLinked to original sources

bioRxiv2025

Envenomation leads to venom protein reduction and recovery delay in bumblebee workers

The evolution and deployment of venom systems in animals has been central to their ecological success, though not without costs. For social bees, venom plays a key role in nest defence yet for species, such as honeybees, the act of stinging generally leads to death. However, for other social bee species, such as bumblebees, where stinging is not apparently fatal, it raises the question of what, if any, are the costs associated with venom usage (envenomation). Here, we investigated proteomic changes in the venom sac, the primary reservoir for venom storage, of Bombus terrestris workers over a short time-course post-envenomation. Our analysis reveals three key findings: 1) envenomation leads to changes in the venom sac proteome with affected proteins generally reduced in the bumblebee venom sac, suggestive of a molecular cost; 2) quantified reductions of traditional venom-associated proteins post-envenomation indicate changes in venom composition post-usage; and 3) recovery of reduced venom-associated proteins post-envenomation was delayed further indicating a potential cost at the molecular level associated with usage. Overall, our findings provide new insights into the consequences of venom usage in bumblebees.

zoology↗

bioRxiv2021

Dysfunction of exocytosis causes catecholamine hypersecretion in patient with pheochromocytoma

Pheochromocytoma (Pheo) is a neuroendocrine tumor that develops from chromaffin cells of the adrenal medulla, and is responsible of an excess of catecholamines secretion leading to severe clinical symptoms such as hypertension, elevated stroke risk and various cardiovascular complications. Surprisingly, hypersecretory activity of Pheo has never been explored at the cellular and molecular levels from individual tumor cells. In the present study, we have combined catecholamine secretion measurement by carbon fiber amperometry on human tumor cells directly cultured from freshly resected Pheo, with the analysis by mass spectrometry of the exocytotic proteins differentially expressed between the tumor and the matched adjacent non-tumor tissue. Catecholamine secretion recordings from individual Pheo cells obtained from most patients reveal a higher number of exocytic events per cell associated with faster kinetic parameters. Accordingly, we unravel significant tumor-associated modifications in the expression of key proteins involved in different steps of the calcium-regulated exocytic pathway. Altogether, our findings indicate that dysfunction of the calcium-regulated exocytosis at the level of individual Pheo cell is a cause of the tumor-associated hypersecretion of catecholamines.

cancer biology↗

bioRxiv2020

Lamin-related congenital muscular dystrophy alters mechanical signaling and skeletal muscle growth

BackgroundLaminopathies are a clinically heterogeneous group of disorders caused by mutations in the LMNA gene, which encodes the nuclear envelope proteins lamins A and C. The most frequent diseases associated with LMNA mutations are characterized by skeletal and cardiac involvement, and include autosomal dominant Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy type 1B, and LMNA-related congenital muscular dystrophy (LMNA-CMD). Although the exact pathophysiological mechanisms responsible for LMNA-CMD are not yet understood, severe contracture and muscle atrophy suggest that impair skeletal muscle growth may contribute to the disease severity. MethodsWe used human muscle stem cells (MuSCs) carrying 4 different LMNA mutations and two mouse models of muscle laminopathies, representing a spectrum of disease severity, to investigate the ability of skeletal muscle to differentiate and to hypertrophy in response to mechanical challenges. We extended these finding to individuals with LMNA-related muscular dystrophy using muscle biopsies. ResultsIn vitro, we observe impaired myogenic differentiation with disorganized cadherin/{beta} catenin adhesion complexes in MuSCs carrying LMNA-CMD. We show that skeletal muscle from Lmna-CMD mice is unable to hypertrophy in response to functional overload, due to defective accretion of activated MuSCs, defective protein synthesis and defective remodeling of the neuro-muscular junction. Moreover, stretched myotubes and overloaded muscle fibers with LMNA-CMD mutations display aberrant mechanical regulation of the Yes-Associated Protein (YAP), a key sensor and mediator of mechanical cues. We also observe defects in MuSC activation and YAP signaling in muscle biopsies from LMNA-CMD patients. These phenotypes are not recapitulated in closely-related EDMD models. ConclusionsCombining studies in vitro, in vivo and patient samples, we find that LMNA-CMD mutations interfere with mechano-signaling pathways in skeletal muscle, implicating defective skeletal muscle growth as a pathogenic contributor for the severity of LMNA-related muscular dystrophy.

physiology↗