scholarly journals Keep Your Friends Close, but Your Enemies Closer: Role of Acid Sphingomyelinase During Infection and Host Response

2021 ◽  
Vol 7 ◽  
Author(s):  
Ha-Yeun Chung ◽  
Ralf A. Claus
Keyword(s):  
Host Response ◽  
Damage Control ◽  
Severe Infection ◽  
Acid Sphingomyelinase ◽  
Lipid Mediator ◽  
Outer Leaflet ◽  
Highly Active ◽  
And Function ◽  
The Impact

Breakdown of the inert and constitutive membrane building block sphingomyelin to the highly active lipid mediator ceramide by extracellularly active acid sphingomyelinase is tightly regulated during stress response and opens the gate for invading pathogens, triggering the immune response, development of remote organ failure, and tissue repair following severe infection. How do one enzyme and one mediator manage all of these affairs? Under physiological conditions, the enzyme is located in the lysosomes and takes part in the noiseless metabolism of sphingolipids, but following stress the protein is secreted into circulation. When secreted, acid sphingomyelinase (ASM) is able to hydrolyze sphingomyelin present at the outer leaflet of membranes to ceramide. Its generation troubles the biophysical context of cellular membranes resulting in functional assembly and reorganization of proteins and receptors, also embedded in highly conserved response mechanisms. As a consequence of cellular signaling, not only induction of cell death but also proliferation, differentiation, and fibrogenesis are affected. Here, we discuss the current state of the art on both the impact and function of the enzyme during host response and damage control. Also, the potential role of lysosomotropic agents as functional inhibitors of this upstream alarming cascade is highlighted.

scholarly journals Irritable bowel syndrome: new insights into symptom mechanisms and advances in treatment

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 780 ◽  
Author(s):  
Robin Spiller
Keyword(s):  
Irritable Bowel Syndrome ◽  
New Agents ◽  
Enteric Nerves ◽  
Inflammatory Bowel ◽  
Magnetic Resonance Imaging Mri ◽  
Irritable Bowel ◽  
Fodmap Diet ◽  
And Function ◽  
The Impact

Despite being one of the most common conditions leading to gastroenterological referral, irritable bowel syndrome (IBS) is poorly understood. However, recent years have seen major advances. These include new understanding of the role of both inflammation and altered microbiota as well as the impact of dietary intolerances as illuminated by magnetic resonance imaging (MRI), which has thrown new light on IBS. This article will review new data on how excessive bile acid secretion mediates diarrhea and evidence from post infectious IBS which has shown how gut inflammation can alter gut microbiota and function. Studies of patients with inflammatory bowel disease (IBD) have also shown that even when inflammation is in remission, the altered enteric nerves and abnormal microbiota can generate IBS-like symptoms. The efficacy of the low FODMAP diet as a treatment for bloating, flatulence, and abdominal discomfort has been demonstrated by randomized controlled trials. MRI studies, which can quantify intestinal volumes, have provided new insights into how FODMAPs cause symptoms. This article will focus on these areas together with recent trials of new agents, which this author believes will alter clinical practice within the foreseeable future.

scholarly journals Peran Pendidikan Etika Kristen dalam Media Sosial di Era Disrupsi

2020 ◽  
Vol 1 (1) ◽  
pp. 38-46
Author(s):  
Mesirawati Waruwu ◽  
Yonatan Alex Arifianto ◽  
Aji Suseno
Keyword(s):  
Social Media ◽  
Ethics Education ◽  
Christian Ethics ◽  
Christian Faith ◽  
Ethical Challenges ◽  
Use Of Social Media ◽  
And Function ◽  
Meaning And Function ◽  
The Impact

The limitless development of social media, its meaning and function have begun to shift, no longer as a means of establishing relationships, communication, but at the stage of losing the role of ethics and morals, even disputes have occurred triggered by debates from communicating in social media. The purpose of this study is to describe the role of Christian ethics education in relation to the impact of social media development in the era of disruption. Using descriptive qualitative methods with literature literature can find solutions for believers in facing moral decadence due to social media abuse by knowing the era of disruption and ethical challenges from the wrong use of social media can affect moral decadence so that Christian ethics education on a biblical basis can bring modern humans. Believers in particular have become bright in social media and their use in accordance with Christian faith in this era of disruption.

scholarly journals Contribution of HIV Infection, AIDS, and Antiretroviral Therapy to Exocrine Pathogenesis in Salivary and Lacrimal Glands

2018 ◽  
Vol 19 (9) ◽  
pp. 2747 ◽  
Author(s):  
Imran Nizamuddin ◽  
Peter Koulen ◽  
Carole McArthur
Keyword(s):  
Antiretroviral Therapy ◽  
Hiv Infection ◽  
Immune Deficiency Syndrome ◽  
Deficiency Syndrome ◽  
Exocrine Function ◽  
Lacrimal Glands ◽  
Immunodeficiency Virus ◽  
And Function ◽  
The Impact

The structure and function of exocrine glands are negatively affected by human immunodeficiency virus (HIV) infection and its co-morbidities, including innate and adaptive immune responses. At the same time, exocrine function may also be influenced by pharmacotherapies directed at the infectious agents. Here, we briefly review the role of the salivary glands and lacrimal glands in normal physiology and exocrine pathogenesis within the context of HIV infection and acquired immune deficiency syndrome (AIDS), including the contribution of antiretroviral therapies on both. Subsequently, we discuss the impact of HIV infection and the types of antiretroviral therapy on disease management and therapy development efforts.

A stochastic roadmap method to model protein structural transitions

Robotica ◽  
2015 ◽  
Vol 34 (8) ◽  
pp. 1705-1733 ◽  
Author(s):  
Kevin Molloy ◽  
Rudy Clausen ◽  
Amarda Shehu
Keyword(s):  
Protein Structure ◽  
Molecular Basis ◽  
Structure And Function ◽  
Structural Transitions ◽  
Simulation Framework ◽  
Human Disorders ◽  
Model Protein ◽  
And Function ◽  
The Impact

SUMMARYEvidence is emerging that the role of protein structure in disease needs to be rethought. Sequence mutations in proteins are often found to affect the rate at which a protein switches between structures. Modeling structural transitions in wildtype and variant proteins is central to understanding the molecular basis of disease. This paper investigates an efficient algorithmic realization of the stochastic roadmap simulation framework to model structural transitions in wildtype and variants of proteins implicated in human disorders. Our results indicate that the algorithm is able to extract useful information on the impact of mutations on protein structure and function.

scholarly journals The conformational and mutational landscape of the ubiquitin-like marker for the autophagosome formation in cancer

2019 ◽  
Author(s):  
Burcu Aykac Fas ◽  
Mukesh Kumar ◽  
Valentina Sora ◽  
Maliha Mashkoor ◽  
Matteo Lambrughi ◽  
...  
Keyword(s):  
Physical Models ◽  
Missense Mutations ◽  
Cancer Types ◽  
Neutral Mutations ◽  
And Function ◽  
Cellular Components ◽  
The Impact ◽  
Pan Cancer ◽  
Structural Ensemble

AbstractAutophagy is a cellular process to recycle damaged cellular components and its modulation can be exploited for disease treatments. A key autophagy player is a ubiquitin-like protein, LC3B. Compelling evidence attests the role of autophagy and LC3B in different cancer types. Many LC3B structures have been solved, but a comprehensive study, including dynamics, has not been yet undertaken. To address this knowledge gap, we assessed ten physical models for molecular dynamics for their capabilities to describe the structural ensemble of LC3B in solution using different metrics and comparison with NMR data. With the resulting LC3B ensembles, we characterized the impact of 26 missense mutations from Pan-Cancer studies with different approaches. Our findings shed light on driver or neutral mutations in LC3B, providing an atlas of its modifications in cancer. Our framework could be used to assess the pathogenicity of mutations by accounting for the different aspects of protein structure and function altered by mutational events.

scholarly journals Estradiol Inhibits Human Brain Vascular Pericyte Migration Activity: A Functional and Transcriptomic Analysis

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2314
Author(s):  
Lisa Kurmann ◽  
Michal Okoniewski ◽  
Raghvendra K. Dubey
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Human Brain ◽  
Neurovascular Unit ◽  
Active Role ◽  
Migration Activity ◽  
Akt Phosphorylation ◽  
And Function ◽  
The Impact

Stroke is the third leading cause of mortality in women and it kills twice as many women as breast cancer. A key role in the pathophysiology of stroke plays the disruption of the blood–brain barrier (BBB) within the neurovascular unit. While estrogen induces vascular protective actions, its influence on stroke remains unclear. Moreover, experiments assessing its impact on endothelial cells to induce barrier integrity are non-conclusive. Since pericytes play an active role in regulating BBB integrity and function, we hypothesize that estradiol may influence BBB by regulating their activity. In this study using human brain vascular pericytes (HBVPs) we investigated the impact of estradiol on key pericyte functions known to influence BBB integrity. HBVPs expressed estrogen receptors (ER-α, ER-β and GPER) and treatment with estradiol (10 nM) inhibited basal cell migration but not proliferation. Since pericyte migration is a hallmark for BBB disruption following injury, infection and inflammation, we investigated the effects of estradiol on TNFα-induced PC migration. Importantly, estradiol prevented TNFα-induced pericyte migration and this effect was mimicked by PPT (ER-α agonist) and DPN (ER-β agonist), but not by G1 (GPR30 agonist). The modulatory effects of estradiol were abrogated by MPP and PHTPP, selective ER-α and ER-β antagonists, respectively, confirming the role of ER-α and ER-β in mediating the anti-migratory actions of estrogen. To delineate the intracellular mechanisms mediating the inhibitory actions of estradiol on PC migration, we investigated the role of AKT and MAPK activation. While estradiol consistently reduced the TNFα-induced MAPK and Akt phosphorylation, only the inhibition of MAPK, but not Akt, significantly abrogated the migratory actions of TNFα. In transendothelial electrical resistance measurements, estradiol induced barrier function (TEER) in human brain microvascular endothelial cells co-cultured with pericytes, but not in HBMECs cultured alone. Importantly, transcriptomics analysis of genes modulated by estradiol in pericytes showed downregulation of genes known to increase cell migration and upregulation of genes known to inhibit cell migration. Taken together, our findings provide the first evidence that estradiol modulates pericyte activity and thereby improves endothelial integrity.

Liver

2018 ◽  
Author(s):  
Hugh Devlin ◽  
Rebecca Craven
Keyword(s):  
Liver Function ◽  
Dental Care ◽  
Impaired Liver Function ◽  
Drug Products ◽  
Dental Patients ◽  
Dental Patient ◽  
Impaired Liver ◽  
And Function ◽  
The Impact

Liver in relation to dentistry is the topic of this chapter. Structure and function of the liver are discussed: metabolism of nutrients and toxins, exocrine functions, and synthesis of key proteins. Drugs and the liver are then discussed: the role of plasma proteins in transport or binding drugs; the liver’s role in metabolizing drugs; and the liver’s role in excreting some drug products into the bile. The effects of chronic excess alcohol on the liver are described and the role of the dentist in spotting potential liver problems in dental patients. The impact of liver disease on patient physiology is next explored, and the relevance for management of the dental patient. Types of hepatitis are described with relevance to dental care for hepatitis transmission. Key tests of liver function are described. The concluding section deals with the dental care of patients with impaired liver function.

scholarly journals FOXL2: a central transcription factor of the ovary

2013 ◽  
Vol 52 (1) ◽  
pp. R17-R33 ◽  
Author(s):  
Adrien Georges ◽  
Aurelie Auguste ◽  
Laurianne Bessière ◽  
Anne Vanet ◽  
Anne-Laure Todeschini ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Forkhead Transcription Factor ◽  
Gene Encoding ◽  
Post Translational Modifications ◽  
Forkhead Box ◽  
Molecular Aspects ◽  
And Function ◽  
Craniofacial Defects ◽  
The Impact

Forkhead box L2 (FOXL2) is a gene encoding a forkhead transcription factor preferentially expressed in the ovary, the eyelids and the pituitary gland. Its germline mutations are responsible for the blepharophimosis ptosis epicanthus inversus syndrome, which includes eyelid and mild craniofacial defects associated with primary ovarian insufficiency. Recent studies have shown the involvement of FOXL2 in virtually all stages of ovarian development and function, as well as in granulosa cell (GC)-related pathologies. A central role of FOXL2 is the lifetime maintenance of GC identity through the repression of testis-specific genes. Recently, a highly recurrent somatic FOXL2 mutation leading to the p.C134W subtitution has been linked to the development of GC tumours in the adult, which account for up to 5% of ovarian malignancies. In this review, we summarise data on FOXL2 modulators, targets, partners and post-translational modifications. Despite the progresses made thus far, a better understanding of the impact of FOXL2 mutations and of the molecular aspects of its function is required to rationalise its implication in various pathophysiological processes.

scholarly journals DNA Gyrase Inhibition Assays Are Necessary To Demonstrate Fluoroquinolone Resistance Secondary togyrBMutations in Mycobacterium tuberculosis

2011 ◽  
Vol 55 (10) ◽  
pp. 4524-4529 ◽  
Author(s):  
Alix Pantel ◽  
Stéphanie Petrella ◽  
Stéphanie Matrat ◽  
Florence Brossier ◽  
Sylvaine Bastian ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Dna Gyrase ◽  
Fluoroquinolone Resistance ◽  
Wild Type ◽  
Content Type ◽  
Clinical Strains ◽  
Highly Active ◽  
The Impact

ABSTRACTThe main mechanism of fluoroquinolone (FQ) resistance inMycobacterium tuberculosisis mutation in DNA gyrase (GyrA2GyrB2), especially ingyrA. However, the discovery of unknown mutations ingyrBwhose implication in FQ resistance is unclear has become more frequent. We investigated the impact on FQ susceptibility of eightgyrBmutations inM. tuberculosisclinical strains, three of which were previously identified in an FQ-resistant strain. We measured FQ MICs and also DNA gyrase inhibition by FQs in order to clarify the role of these mutations in FQ resistance. Wild-type GyrA, wild-type GyrB, and mutant GyrB subunits produced from engineeredgyrBalleles by mutagenesis were overexpressed inEscherichia coli, purified to homogeneity, and used to reconstitute highly active gyrase complexes. MICs and DNA gyrase inhibition were determined for moxifloxacin, gatifloxacin, ofloxacin, levofloxacin, and enoxacin. We demonstrated that the eight substitutions in GyrB (D473N, P478A, R485H, S486F, A506G, A547V, G551R, and G559A), recently identified in FQ-resistant clinical strains or encountered inM. tuberculosisstrains isolated in France, are not implicated in FQ resistance. These results underline that, as opposed to phenotypic FQ susceptibility testing, the DNA gyrase inhibition assay is the only way to prove the role of a DNA gyrase mutation in FQ resistance. Therefore, the use of FQ in the treatment of tuberculosis (TB) patients should not be ruled out only on the basis of the presence of mutations ingyrB.

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