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Biology subjects

Knauer-Meyer, T.

Publications and source records attributed to Knauer-Meyer, T..

3 recordsLinked to original sources

Developmental senescence profiling reveals Eda2r as a common mediator in the core senescence program

Cellular senescence is a distinct state of stable cell-cycle arrest coupled to a dynamic secretory phenotype. Although transient senescence contributes to embryonic development and regeneration, its relationship to the chronic forms associated with damage and aging is unclear. Here, we generated a p21-reporter mouse to isolate and transcriptionally profile senescent cells in Apical Ectodermal Ridge of the developing limb. Comparative analysis of these cells with diverse in vitro and in vivo senescence models revealed a conserved gene program encompassing canonical markers and regulators, with previously unassociated factors. Among these, ectodysplasin A2 receptor (Eda2r) emerged as a critical modulator required for senescence-associated transcriptional and functional features. Our findings define a shared molecular framework linking developmental and pathological senescence and identify conserved effectors such as Eda2r as potential targets for therapeutic modulation of senescent cell function.

cell biology↗

Valproic acid induces p19Arf-mediated cellular senescence to cause neurodevelopmental defects

Timely induction of cellular senescence is important during embryonic development and tissue repair, while aberrant activation contributes to many age-related diseases. However, whether abnormal induction of senescence in the embryo contributes to developmental defects remains unclear. To explore this, we investigated the clinically significant model of Valproic acid- (VPA) induced developmental defects. VPA is a widely prescribed drug to treat epilepsy, bipolar disorder and migraine. If taken during pregnancy however, exposure to the developing embryo can cause birth defects, cognitive impairment and Autism-Spectrum Disorder. How VPA causes these developmental defects remains unknown. We used embryonic mice and human organoids to model key features of drug exposure, including exencephaly, microcephaly and spinal defects. In the malformed tissues, in which neurogenesis is defective, we find pronounced induction of cellular senescence in the neuroepithelial cells. Critically, through genetic and functional studies, we identified p19Arf as the instrumental mediator of senescence and microcephaly, but surprisingly, not exencephaly and spinal defects. Together, these findings uncover how misregulated senescence in neuroepithelial cells can contribute to developmental defects.

developmental biology↗

Senolytic treatment targets aberrant p21-expression to restore liver regeneration in adult mice

Young mammals possess a limited regenerative capacity in tissues such as the liver, heart and limbs, but which is quickly lost upon maturation or transition to adulthood. Chronic cellular senescence is a known mediator of decreased tissue function in aging and disease. Here we investigated whether senescence plays a role in the progressive loss of liver regenerative capacity that develops in young adult mice. We find that following partial hepatectomy, the senescence markers p21, p16Ink4a and p19Arf become dynamically expressed at an age when regenerative capacity decreases. In addition, we demonstrate that treatment with a senescence-inhibiting drug improves regenerative capacity, through targeting of aberrant p21 expression. Surprisingly, we also find that the senescence marker p16Ink4a is expressed in a different cell-population to p21, and is unaffected by senescence targeting. This work suggests that senescence may initially develop as a heterogeneous cellular response, and that treatment with senolytic drugs may aid in promoting organ regeneration.

cell biology↗