Search bioRxiv⌕ Search

Biology subjects

Dau, T. T. D.

Publications and source records attributed to Dau, T. T. D..

3 recordsLinked to original sources

Convergent molecular signatures of ageing and injury in the peripheral nervous system

Peripheral nervous system (PNS) ageing is marked by structural and functional decline, yet it remains unclear whether ageing constitutes a distinct biological programme or reflects a chronic injury-like state. To address this, we performed an unbiased, comparative molecular analysis of PNS ageing, neuroprotective dietary restriction (DR), and nerve injury. We conducted transcriptomic and proteomic profiling of peripheral nerves from young, old and geriatric mice fed ad libitum or subjected to long-term DR, and proteomics of nerves collected at multiple time points following injury. Age-associated molecular changes followed both linear and non-linear trajectories, and DR partially attenuated these ageing-related alterations. Notably, ageing-and injury-induced proteomic signatures showed considerable similarities, supporting the concept that an aged nerve resembles an injured nerve. Together, our study provides the most comprehensive molecular resource of PNS changes during ageing, DR, and injury, enabling the definition of key molecular signatures underlying PNS physiology. All datasets are integrated into the "PNS-omics Viewer", a Shiny web application designed to facilitate data mining of the herein presented datasets (tba).

neuroscience↗

Leiomodin 1 promotes myogenic differentiation by modulating Sirtuin 1

During myogenic differentiation the cellular architecture and proteome of muscle stem cells and myoblasts undergo extensive remodeling. These molecular processes are only partially understood and display alterations in disease conditions as well as during aging resulting in impaired regeneration. Here, we used mass spectrometry to quantify the temporal dynamics of more than 6000 proteins during myogenic differentiation. We identified the actin nucleator leiomodin 1 (LMOD1) among a restricted subset of cytoskeletal proteins increasing in abundance in early phases of myogenic differentiation. We show that LMOD1 is already expressed by muscle stem cells in vivo and displays increased abundance during skeletal muscle regeneration, especially during early regeneration suggesting that LMOD1 is important for induction of myotube formation. Of note, knockdown of LMOD1 in primary myoblasts and during skeletal muscle regeneration severely affects myogenic differentiation, while overexpression accelerates and improves the initiation of myotube formation suggesting that LMOD1 is a critical component regulating myogenic differentiation. Mechanistically, we show that LMOD1 physically and functionally interacts with the deacetylase sirtuin1 (SIRT1), a regulator of myogenic differentiation, especially at the onset of myogenic differentiation. We demonstrate that LMOD1 influences SIRT1 localization and the expression of a subset of its target genes. Consistently, depletion or pharmacological inhibition of SIRT1 partially rescues the impairment of myogenic differentiation observed after knockdown of LMOD1. Our work identifies a new regulator of myogenic differentiation that might be targeted to improve muscle regeneration in aging and disease.

cell biology↗

Impact of inflammatory preconditioning on murine microglial proteome response induced by focal ischemic brain injury

Preconditioning with LPS induces neuroprotection against subsequent cerebral ischemic injury, mainly involving innate immune pathways. Microglia are CNS-resident immune cells that respond early to danger signals through memory-like differential reprogramming. However, the cell-specific molecular mechanisms underlying preconditioning are not fully understood. To elucidate the distinct molecular mechanisms of preconditioning on microglia, we compared these cell-specific proteomic profiles in response to LPS preconditioning and without preconditioning and subsequent transient focal brain ischemia and reperfusion, - using an established mouse model of transient focal brain ischemia and reperfusion. A proteomic workflow, based on isolated microglia obtained from mouse brains by cell sorting and coupled to mass spectrometry for identification and quantification, was applied. Our data confirm that LPS preconditioning induces marked neuroprotection, as indicated by a significant reduction in brain infarct volume. The established brain cell separation method was suitable for obtaining an enriched microglial cell fraction for valid proteomic analysis. The results show a significant impact of LPS preconditioning on microglial proteome patterns by type I interferons, presumably driven by the interferon cluster regulator proteins Stat1/2.

neuroscience↗