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Kochersberger, A.

Publications and source records attributed to Kochersberger, A..

3 recordsLinked to original sources

Oxytocin-like signaling couples reproductive state to intestinal lipid metabolism in aging C. elegans

Oxytocin and vasopressin are endogenous bioactive peptides with conserved roles in reproduction and, more recently recognized, in peripheral lipid metabolism. Whether this signaling system also shapes how reproduction declines with age has not been tested in any animal. Here we show that in C. elegans, the oxytocin/vasopressin-like neuropeptide nematocin restrains reproductive output as animals reach mid-life. Nematocin and its two receptors are produced throughout adult life and peak as reproduction begins to wane. Animals lacking receptor signaling produce more offspring in mid-life, an improvement that reflects better egg quality and fertilization rather than improved embryo survival. This benefit is accompanied by changes in intestinal fat metabolism, the worms equivalent of liver and adipose tissue: nematocin normally limits the activity of a fatty-acid desaturase that is otherwise induced by mating, and it shapes how much yolk reaches developing eggs. The two receptors act through separate routes, one tuning intestinal fat metabolism and the other controlling yolk delivery to the egg. Together, these findings reveal nematocin as a regulator of the intestinal metabolic environment across reproductive age, mirroring the recently described oxytocin-hepatocyte-adipocyte lipid axis in mammals and implicate this conserved signaling system in the coordination of maternal investment during reproductive aging.

physiology↗

Aging disrupts spatiotemporal coordination in the cycling ovary

Throughout the female reproductive lifespan, the ovary completes hundreds of cycles of follicle development, ovulation, and tissue regeneration1-3. These processes rely on the precisely coordinated intricate multicellular interactions across time and space4. How aging disrupts these interactions, leading to an overall decline in reproductive and endocrine functions, remains understudied. To understand the multicellular dynamics that underlie ovarian function and their changes with age, here we use Slide-seq, a near-cellular spatial transcriptomics method, to profile 22 mouse ovaries across the reproductive cycle and chronological age, representing 610,620 near-cellular spots across 69 spatial transcriptomic profiles5,6. We develop a segmentation analysis to identify spatial niches that capture different states of folliculogenesis from static snapshots in situ, allowing us to examine the multicellular dynamics of 358 oocytes, 668 follicles, and 236 corpora lutea. We find that aging disrupts both the spatial organization and temporal coordination of folliculogenesis before the cessation of cycling, which may contribute to the dysregulation of hormone production and signaling. These disruptions are marked by altered immune cell dynamics, inflammatory signaling, and global tissue disorganization that impair the cyclic remodeling required for ovarian function. Our findings reveal how multicellular niches orchestrate ovarian function and demonstrate how age-related breakdown of tissue organization across time and space precedes reproductive decline.

genomics↗

Programmed Cell Death Modifies Neural Circuits and Tunes Intrinsic Behavior

Programmed cell death (PCD) is a common feature of animal development. During development of the C. elegans hermaphrodite, programmed cell death eliminates 131 cells in stereotyped positions in the cell lineage, mostly in neuronal lineages. Blocking cell death results in supernumerary "undead" neurons. We find that undead neurons can be wired into circuits, can display activity, and can modify specific behaviors. The two undead RIM-like neurons participate in the RIM-containing circuit that computes movement. The presence of these two extra neurons results in animals that initiate fewer reversals and lengthens the duration of those reversals that do occur. We describe additional behavioral alterations of cell-death mutants, including in locomotory turning angle and pharyngeal pumping. These findings indicate that physiological or evolutionary variations in PCD might reveal latent neuronal elements that the nervous system can incorporate to modify nervous system function and animal behavior.

neuroscience↗