Search results for "Acellular"
showing 10 items of 1986 documents
The shell matrix and microstructure of the Ram's Horn squid: Molecular and structural characterization.
2020
20 pages; International audience; Molluscs are one of the most diversified phyla among metazoans. Most of them produce an external calcified shell, resulting from the secretory activity of a specialized epithelium of the calcifying mantle. This biomineralization process is controlled by a set of extracellular macromolecules, the organic matrix. In spite of several studies, these components are mainly known for bivalves and gastropods. In the present study, we investigated the physical and biochemical properties of the internal planispiral shell of the Ram's Horn squid Spirula spirula. Scanning Electron Microscope investigations of the shell reveal a complex microstructural organization. The…
Osmotic stress affects the stability of freeze-dried Lactobacillus buchneri R1102 as a result of intracellular betaine accumulation and membrane char…
2014
Aims To help cells to better resist the stressful conditions associated with the freeze-drying process during starter production, we investigated the effect of various osmotic conditions on growth, survival and acidification activity of Lactobacillus buchneri R1102, after freeze-drying and during storage for 3 months at 25°C. Methods and Results High survival rates during freeze-drying, but not during storage, were obtained when 0·1 mol l−1 KCl was added at the beginning of fermentation, without any change in membrane properties and betaine accumulation. This condition made it possible to maintain a high acidification rate throughout the process. In contrast, the addition of 0·6 mol l−1 KCl…
Exploring the diversity of listeria monocytogenes biofilm architecture by high-throughput confocal laser scanning microscopy and the predominance of …
2015
ABSTRACT Listeria monocytogenes is involved in food-borne illness with a high mortality rate. The persistence of the pathogen along the food chain can be associated with its ability to form biofilms on inert surfaces. While most of the phenotypes associated with biofilms are related to their spatial organization, most published data comparing biofilm formation by L. monocytogenes isolates are based on the quantitative crystal violet assay, which does not give access to structural information. Using a high-throughput confocal-imaging approach, the aim of this work was to decipher the structural diversity of biofilms formed by 96 L. monocytogenes strains isolated from various environments. Pr…
The multiple facets of Cajal-Retzius neurons.
2021
ABSTRACTCajal-Retzius neurons (CRs) are among the first-born neurons in the developing cortex of reptiles, birds and mammals, including humans. The peculiarity of CRs lies in the fact they are initially embedded into the immature neuronal network before being almost completely eliminated by cell death at the end of cortical development. CRs are best known for controlling the migration of glutamatergic neurons and the formation of cortical layers through the secretion of the glycoprotein reelin. However, they have been shown to play numerous additional key roles at many steps of cortical development, spanning from patterning and sizing functional areas to synaptogenesis. The use of genetic l…
The σ B -dependent regulatory sRNA Rli47 represses isoleucine biosynthesis in Listeria monocytogenes through a direct interaction with the ilvA trans…
2019
International audience; The facultative intracellular pathogen Listeria monocytogenes can persist and grow in a diverse range of environmental conditions, both outside and within its mammalian host. The alternative sigma factor Sigma B (sigma(B)) plays an important role in this adaptability and is critical for the transition into the host. While some of the functions of the sigma(B) regulon in facilitating this transition are understood the role of sigma(B)-dependent small regulatory RNAs (sRNAs) remain poorly characterized. In this study, we focused on elucidating the function of Rli47, a sigma(B)-dependent sRNA that is highly induced in the intestine and in macrophages. Using a combinatio…
Candida albicans-epithelial interactions: dissecting the roles of active penetration, induced endocytosis and host factors on the infection process
2012
International audience; Candida albicans frequently causes superficial infections by invading and damaging epithelial cells, but may also cause systemic infections by penetrating through epithelial barriers. C. albicans is a remarkable pathogen because it can invade epithelial cells via two distinct mechanisms: induced endocytosis, analogous to facultative intracellular enteropathogenic bacteria, and active penetration, similar to plant pathogenic fungi. Here we investigated the contributions of the two invasion routes of C. albicans to epithelial invasion. Using selective cellular inhibition approaches and differential fluorescence microscopy, we demonstrate that induced endocytosis contri…
Extracellular Vesicles and Tumor-Immune Escape: Biological Functions and Clinical Perspectives
2020
The modulation of the immune system is one of the hallmarks of cancer. It is now widely described that cancer cells are able to evade the immune response and thus establish immune tolerance. The exploration of the mechanisms underlying this ability of cancer cells has always attracted the scientific community and is the basis for the development of new promising cancer therapies. Recent evidence has highlighted how extracellular vesicles (EVs) represent a mechanism by which cancer cells promote immune escape by inducing phenotypic changes on different immune cell populations. In this review, we will discuss the recent findings on the role of tumor-derived extracellular vesicles (TEVs) in re…
Intraflagellar transport protein 172 is essential for primary cilia formation and plays a vital role in patterning the mammalian brain
2008
AbstractIFT172, also known as Selective Lim-domain Binding protein (SLB), is a component of the intraflagellar transport (IFT) complex. In order to evaluate the biological role of the Ift172 gene, we generated a loss-of-function mutation in the mouse. The resulting Slb mutant embryos die between E12.5 and 13.0, and exhibit severe cranio-facial malformations, failure to close the cranial neural tube, holoprosencephaly, heart edema and extensive hemorrhages. Cilia outgrowth in cells of the neuroepithelium is initiated but the axonemes are severely truncated and do not contain visible microtubules. Morphological and molecular analyses revealed a global brain-patterning defect along the dorsal–…
Chaperonopathies and chaperonotherapy. Hsp60 as therapeutic target in cancer: potential benefits and risks.
2013
In this minireview we focus on Hsp60 as a target for anticancer therapy. We discuss the new concepts of chaperonopathies and chaperonotherapy and present information on Hsp60 localization in the cell membrane of human tumor cells. We describe novel mechanisms for Hsp60 reaching the extracellular environment that involve membrane-associated stages, as well as data on anti-Hsp60 antibodies found in human sera, both in normal subjects and patients affected by autoimmune diseases. Finally, we discuss possible therapeutic applications of anti-Hsp60 antibodies in cancer treatment, evaluating also side effects on non-tumor cells. In conclusion, the way for investigating Hsp60-targeted anti-tumor t…
Procollagen C-proteinase Enhancer Stimulates Procollagen Processing by Binding to the C-propeptide Region Only*
2011
Background: Procollagen C-proteinase enhancer-1 (PCPE-1) is an extracellular glycoprotein that increases activity of certain zinc metalloproteinases involved in tissue development and repair. Results: PCPE-1 binds uniquely to the C-propeptide region of the procollagen molecule. Conclusion: PCPE-1 enhances proteolysis by binding solely to the procollagen C-propeptides. Significance: These data may lead to future applications in the development of antifibrotic therapies.