Search results for "Pathway"

A functional zeaxanthin epoxidase from red algae shedding light on the evolution of light-harvesting carotenoids and the xanthophyll cycle in photosy…

2017

The epoxy-xanthophylls antheraxanthin and violaxanthin are key precursors of light-harvesting carotenoids and participate in the photoprotective xanthophyll cycle. Thus, the invention of zeaxanthin epoxidase (ZEP) catalyzing their formation from zeaxanthin has been a fundamental step in the evolution of photosynthetic eukaryotes. ZEP genes have only been found in Viridiplantae and chromalveolate algae with secondary plastids of red algal ancestry, suggesting that ZEP evolved in the Viridiplantae and spread to chromalveolates by lateral gene transfer. By searching publicly available sequence data from eleven red algae covering all currently recognized red algal classes we identified ZEP cand…

Systematic gene overexpression in Candida albicans identifies a regulator of early adaptation to the mammalian gut.

2018

International audience; Candida albicans is part of the human gastrointestinal (GI) microbiota. To better understand how C. albicans efficiently establishes GI colonisation, we competitively challenged growth of 572 signature-tagged strains (~10% genome coverage), each conditionally overexpressing a single gene, in the murine gut. We identified CRZ2, a transcription factor whose overexpression and deletion respectively increased and decreased early GI colonisation. Using clues from genome-wide expression and gene-set enrichment analyses, we found that the optimal activity of Crz2p occurs under hypoxia at 37°C, as evidenced by both phenotypic and transcriptomic analyses following CRZ2 geneti…

7-ketocholesterol and 7β-hydroxycholesterol: in vitro and animal models used to characterize their activities and to identify molecules preventing th…

2020

International audience; Oxysterols are molecules derived by the oxidation of cholesterol and can be formed either by auto-oxidation, enzymatically or by both processes. Among the oxysterols formed by auto-oxidation, 7-ketocholesterol and 7beta-hydroxycholesterol are the main forms generated. These oxysterols, formed endogenously and brought in large quantities by certain foods, have major cytotoxic properties. They are powerful inducers of oxidative stress, inducing dysfunction of organelles (mitochondria, lysosomes and peroxisomes) that can cause cell death. These molecules are often identified in increased amounts in common pathological states such as cardiovascular diseases, certain eye …

N-3 polyunsaturated fatty acids: An innovative strategy against obesity and related metabolic disorders, intestinal alteration and gut microbiota dys…

2019

Obesity is now widely recognized to be associated with low-grade systemic inflammation. It has been shown that high-fat feeding modulates gut microbiota which strongly increased intestinal permeability leading to lipopolysaccharide absorption causing metabolic endotoxemia that triggers inflammation and metabolic disorders. N-3 polyunsaturated fatty acids (PUFAs) have been shown associated with anti-obesity properties, but results still remain heterogeneous and very few studies underlined the metabolic pathways involved. Thus, the use of Fat-1 transgenic mice allows to better understanding whether endogenous n-3 PUFAs enrichment contributes to obesity and associated metabolic disorders preve…

Selective α-synuclein knockdown in monoamine neurons by intranasal oligonucleotide delivery: potential therapy for parkinson’s disease

2018

Progressive neuronal death in brainstem nuclei and widespread accumulation of α-synuclein are neuropathological hallmarks of Parkinson’s disease (PD). Reduction of α-synuclein levels is therefore a potential therapy for PD. However, because α-synuclein is essential for neuronal development and function, α-synuclein elimination would dramatically impact brain function. We previously developed conjugated small interfering RNA (siRNA) sequences that selectively target serotonin (5-HT) or norepinephrine (NE) neurons after intranasal administration. Here, we used this strategy to conjugate inhibitory oligonucleotides, siRNA and antisense oligonucleotide (ASO), with the triple monoamine reuptake …

2016

In the perinatal as well as the adult CNS, the subventricular zone (SVZ) of the forebrain is the largest and most active source of neural stem cells (NSCs) that generates neurons and oligodendrocytes (OLs), the myelin forming cells of the CNS. Recent advances in the field are beginning to shed light regarding SVZ heterogeneity, with the existence of spatially segregated microdomains that are intrinsically biased to generate phenotypically distinct neuronal populations. Although most research has focused on this regionalization in the context of neurogenesis, newer findings underline that this also applies for the genesis of OLs under the control of specific patterning molecules. In this min…

Wnt1 Promotes Cementum and Alveolar Bone Growth in a Time-Dependent Manner

2021

The WNT/β-catenin signaling pathway plays a central role in the biology of the periodontium, yet the function of specific extracellular WNT ligands remains poorly understood. By using a Wnt1-inducible transgenic mouse model targeting Col1a1-expressing alveolar osteoblasts, odontoblasts, and cementoblasts, we demonstrate that the WNT ligand WNT1 is a strong promoter of cementum and alveolar bone formation in vivo. We induced Wnt1 expression for 1, 3, or 9 wk in Wnt1Tg mice and analyzed them at the age of 6 wk and 12 wk. Micro–computed tomography (CT) analyses of the mandibles revealed a 1.8-fold increased bone volume after 1 and 3 wk of Wnt1 expression and a 3-fold increased bone volume aft…

Drosophila and humans share similar mechanisms of insulin secretion

2017

Drosophila and humans share similar mechanisms of insulin secretion

Melatonin in Early Nutrition: Long-Term Effects on Cardiovascular System

2021

Breastfeeding protects against adverse cardiovascular outcomes in the long term. Melatonin is an active molecule that is present in the breast milk produced at night beginning in the first stages of lactation. This indoleamine appears to be a relevant contributor to the benefits of breast milk because it can affect infant health in several ways. The melatonin concentration in breast milk varies in a circadian pattern, making breast milk a chrononutrient. The consumption of melatonin can induce the first circadian stimulation in the infant’s body at an age when his/her own circadian machinery is not functioning yet. This molecule is also a powerful antioxidant with the ability to act on infa…

ceRNA Network Regulation of TGF-β, WNT, FOXO, Hedgehog Pathways in the Pharynx of Ciona robusta

2021

The transforming growth factor-β (TGF-β) family of cytokines performs a multifunctional signaling, which is integrated and coordinated in a signaling network that involves other pathways, such as Wintless, Forkhead box-O (FOXO) and Hedgehog and regulates pivotal functions related to cell fate in all tissues. In the hematopoietic system, TGF-β signaling controls a wide spectrum of biological processes, from immune system homeostasis to the quiescence and self-renewal of hematopoietic stem cells (HSCs). Recently an important role in post-transcription regulation has been attributed to two type of ncRNAs: microRNAs and pseudogenes. Ciona robusta, due to its philogenetic position close to verte…