Search results for "Mod"
showing 10 items of 39605 documents
Allosteric Cross-Talk among Spike’s Receptor-Binding Domain Mutations of the SARS-CoV-2 South African Variant Triggers an Effective Hijacking of Huma…
2021
The rapid and relentless emergence of novel highly transmissible SARS-CoV-2 variants, possibly decreasing vaccine efficacy, currently represents a formidable medical and societal challenge. These variants frequently hold mutations on the Spike protein's receptor-binding domain (RBD), which, binding to the angiotensin-converting enzyme 2 (ACE2) receptor, mediates viral entry into host cells. Here, all-atom molecular dynamics simulations and dynamical network theory of the wild-type and mutant RBD/ACE2 adducts disclose that while the N501Y mutation (UK variant) enhances the Spike's binding affinity toward ACE2, the concomitant N501Y, E484K, and K417N mutations (South African variant) aptly ad…
Biofilms of Lactobacillus plantarum and Lactobacillus fermentum: Effect on stress responses, antagonistic effects on pathogen growth and immunomodula…
2016
IF 3.682; International audience; Few studies have extensively investigated probiotic functions associated with biofilms. Here, we show that strains of Lactobacillus plantarum and Lactobacillus fermentum are able to grow as biofilm on abiotic surfaces, but the biomass density differs between strains. We performed microtiter plate biofilm assays under growth conditions mimicking to the gastrointestinal environment. Osmolarity and low concentrations of bile significantly enhanced Lactobacillus spatial organization. Two L. plantarum strains were able to form biofilms under high concentrations of bile and mucus. We used the agar well-diffusion method to show that supernatants from all Lactobaci…
Ancient bacterial genomes reveal a high diversity of Treponema pallidum Strains in early Modern Europe
2020
Syphilis is a globally re-emerging disease, which has marked European history with a devastating epidemic at the end of the 15th century. Together with non-venereal treponemal diseases, like bejel and yaws, which are found today in subtropical and tropical regions, it currently poses a substantial health threat worldwide. The origins and spread of treponemal diseases remain unresolved, including syphilis’ potential introduction into Europe from the Americas. Here, we present the first genetic data from archaeological human remains reflecting a high diversity of Treponema pallidum in early modern Europe. Our study demonstrates that a variety of strains related to both venereal syphilis and y…
Investigating fibrosis and inflammation in an ex vivo NASH murine model.
2020
Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease, characterized by excess fat accumulation (steatosis). Nonalcoholic steatohepatitis (NASH) develops in 15–20% of NAFLD patients and frequently progresses to liver fibrosis and cirrhosis. We aimed to develop an ex vivo model of inflammation and fibrosis in steatotic murine precision-cut liver slices (PCLS). NASH was induced in C57Bl/6 mice on an amylin and choline-deficient l-amino acid-defined (CDAA) diet. PCLS were prepared from steatohepatitic (sPCLS) and control (cPCLS) livers and cultured for 48 h with LPS, TGFβ1, or elafibranor. Additionally, C57Bl/6 mice were placed on CDAA diet for 12 wk to receive elafibranor…
The gelatinase MMP-9like is involved in regulation of LPS inflammatory response in Ciona robusta
2019
Matrix metalloproteinases (MMPs) are a family of endopeptidases collectively able to degrade the components of the extracellular matrix (ECM), with important roles in many biological processes, such as embryogenesis, normal tissue remodelling, angiogenesis and wound healing. New views on the function of MMPs reveal that they regulate inflammatory response and therefore might represent an early step in the evolution of the immune system. MMPs can affect the activity of cytokines involved in inflammation including TGF-β and TNF-α. MMPs are widely distributed in all kingdoms of life and have likely evolved from a single-domain protein which underwent successive rounds of duplications. In this …
Amyloid β-peptide insertion in liposomes containing GM1-cholesterol domains.
2015
Neuronal membrane damage is related to the early impairments appearing in Alzheimer's disease due to the interaction of the amyloid β-peptide (Aβ) with the phospholipid bilayer. In particular, the ganglioside GM1, present with cholesterol in lipid rafts, seems to be able to initiate Aβ aggregation on membrane. We studied the thermodynamic and structural effects of the presence of GM1 on the interaction between Aβ and liposomes, a good membrane model system. Isothermal Titration Calorimetry highlighted the importance of the presence of GM1 in recruiting monomeric Aβ toward the lipid bilayer. Light and Small Angle X-ray Scattering revealed a different pattern for GM1 containing liposomes, bot…
Dietary components modulate the risk of hepatocellular carcinoma in cirrhotic patients.
2018
Abstract Eighty percent of hepatocellular carcinoma (HCC) cases occur after cirrhosis from various etiologies. The association between diet and cancer is well accepted, but the links with cirrhosis progression and HCC risk have been poorly investigated. However, we hypothesized that diet could be a modifiable preventive factor for HCC. Thus, the aim of our study was to explore the relationships between dietary factors and the risk of HCC in a population of cirrhotic patients. A total of 582 cirrhotic patients were studied: 401 without HCC (controls) and 181 with HCC (cases). These patients were recruited between 2008 and 2012 for the “CiRCE” case-control study conducted in six French univer…
The membrane-bound O-acyltransferase domain-containing 7 variant rs641738 increases inflammation and fibrosis in chronic hepatitis B.
2017
Chronic hepatitis B (CHB) is characterized by hepatic inflammation that promotes progression to cirrhosis and predisposes to the development of hepatocellular carcinoma (HCC). Subtle interindividual genetic variation as well as viral and environmental factors interact to determine disease progression between individuals. Recently, the rs641738 membrane-bound O-acyltransferase domain-containing 7 (MBOAT7) polymorphism was demonstrated to influence histological liver damage in alcoholic liver disease, nonalcoholic fatty liver disease, and hepatitis C, but no data are available for CHB. We evaluated rs641738 influence on disease severity in a cohort of 1,101 patients with CHB. Forty-two patien…
Protein tyrosine phosphatase 1b deficiency protects against hepatic fibrosis by modulating nadph oxidases
2019
Inflammation is typically associated with the development of fibrosis, cirrhosis and hepatocellular carcinoma. The key role of protein tyrosine phosphatase 1B (PTP1B) in inflammatory responses has focused this study in understanding its implication in liver fibrosis. Here we show that hepatic PTP1B mRNA expression increased after bile duct ligation (BDL), while BDL-induced liver fibrosis was markedly reduced in mice lacking Ptpn1 (PTP1B−/−) as assessed by decreased collagen deposition and α-smooth muscle actin (α-SMA) expression. PTP1B−/− mice also showed a significant increase in mRNA levels of key markers of monocytes recruitment (Cd68, Adgre1 and Ccl2) compared to their wild-type (PTP1B+…
PI3K inhibition reduces murine and human liver fibrogenesis in precisioncut liver slices
2019
Background: Liver fibrosis results from continuous inflammation and injury. Despite its high prevalence worldwide, no approved antifibrotic therapies exist. Omipalisib is a selective inhibitor of the PI3K/mTOR pathway that controls nutrient metabolism, growth and proliferation. It has shown antifibrotic properties in vitro. While clinical trials for idiopathic pulmonary fibrosis have been initiated, an in-depth preclinical evaluation is lacking. We evaluated omipalisib's effects on fibrogenesis using the ex vivo model of murine and human precision-cut tissue slices (PCTS).Methods: Murine and human liver and jejunum PCTS were incubated with omipalisib up to 10 mu M for 48 h. PI3K pathway act…