Biology subjects

Landi, C.

Publications and source records attributed to Landi, C..

3 recordsLinked to original sources

bioRxiv2023

Proteomics reveals how the tardigrade damage suppressor protein teaches transfected human cells to survive UV-C stress

The genome sequencing of the tardigrade Ramazzottius varieornatus revealed a unique nucleosome-binding protein, named Damage Suppressor (Dsup), which resulted to be crucial for the extraordinary abilities of tardigrades in surviving extreme stresses, such as UV. Evidence in Dsup transfected human cells, suggests that Dsup mediates an overall response of DNA damage signaling, DNA repair and cell cycle regulation resulting in an acquired resistance to stress. Given these promising outcomes, our study attempts to provide a wider comprehension of the molecular mechanisms modulated by Dsup in human cells, and to explore the Dsup-activated molecular pathways under stress. We performed a differential proteomic analysis of Dsup-transfected and control human cells, under basal condition and at 24-hour recovery after exposure to UV-C. We demonstrate by enrichment and network analyses, for the first time, that even in the absence of external stimuli and more significantly after stress, Dsup activates mechanisms involved with the Unfolded Protein Response, the mRNA processing and stability, cytoplasmic stress granules, the DNA Damage Response and the telomere maintenance. In conclusion, our results shed new light on Dsup-mediated protective mechanisms, and increase our knowledge of the molecular machineries of extraordinary protection against UV-C stress.

cell biology↗

bioRxiv2021

A cytofluorimetric analysis of a Saccharomyces cerevisiae population cultured in a fed-batch bioreactor

The yeast Saccharomyces cerevisiae is a reference model system and one of the widely used microorganisms in many biotechnological processes. In industrial yeast applications, combined strategies aim to maximize biomass/product yield, with the fed-batch culture being one of the most frequently used. Flow cytometry (FCM) is widely applied in biotechnological processes and represents a key methodology to monitor cell population dynamics. We propose here an application of FCM in the analysis of yeast cell cycle along the time course of a typical S. cerevisiae fed-batch culture. We used two different dyes, SYTOX Green and SYBR Green, with the aim to better define each stage of cell cycle during S. cerevisiae fed-batch culture. The results provide novel insights in the use of FCM cell cycle analysis for the real-time monitoring of S. cerevisiae bioprocesses.

cell biology↗

bioRxiv2019

Local sleep-like cortical reactivity in the awake brain after focal injury

The functional consequences of brain injury are known to depend on neuronal alterations extending beyond the area of structural damage. Although a lateralized EEG slowing over the injured hemisphere was known since the early days of clinical neurophysiology, its electrophysiological mechanisms were not systematically investigated. In parallel, basic sleep research has thoroughly characterized the neuronal events underlying EEG slow waves in physiological conditions. These EEG events reflect brief interruptions of neuronal firing (OFF-periods) that can occur locally and have prominent consequences on network and behavioral functions. Notably, the EEG slow waves observed following focal brain injury have been never explicitly connected to local sleep-like neuronal events. In previous works, probing cortical circuits with transcranial magnetic stimulation coupled with EEG (TMS/EEG) proved as an effective way to reveal the tendency of cortical circuits to transiently plunge into silent OFF-periods. Here, using this approach, we show that the intact cortex surrounding focal brain injuries engages locally in pathological sleep-like dynamics. Specifically, we employed TMS/EEG in a cohort of thirty conscious awake patients with chronic focal and multifocal brain injuries of various etiologies. TMS systematically evoked prominent slow waves associated with sleep-like OFF-periods in the area surrounding focal cortico-subcortical lesions. These events were associated with a local disruption of signal complexity and were absent when stimulating the contralateral hemisphere. Perilesional sleep-like OFF-periods may represent a valid read-out of the electrophysiological state of discrete cortical circuits following brain injury as well as a potential target of interventions aimed at fostering functional recovery. One Sentence SummaryFocal cortical injuries are associated with local intrusion of sleep-like dynamics over the perilesional areas which disrupt local signal complexity and coexist with typical wakefulness cortical reactivity patterns within the same brain.

neuroscience↗