Integral membrane proteins carry out essential functions in the cell, and their activities are often modulated by specific protein-lipid interactions in the membrane. Here, we elucidate the intricate role of cardiolipin (CDL), a regulatory lipid, as a stabilizer of membrane proteins and their complexes. Using the in silico-designed model protein TMHC4_R (ROCKET) as a scaffold, we employ a combination of molecular dynamics simulations and native mass spectrometry to explore the protein features that facilitate preferential lipid interactions and mediate stabilization. We find that the spatial arrangement of positively charged residues as well as local conformational flexibility are factors that distinguish stabilizing from non-stabilizing CDL interactions. However, we also find that even in this controlled, artificial system, a clear-cut distinction between binding and stabilization is difficult to attain, revealing that overlapping lipid contacts can partially compensate for the effects of binding site mutations. Extending our insights to naturally occurring proteins, we identify a stabilizing CDL site within the E. coli rhomboid intramembrane protease GlpG and uncover its regulatory influence on enzyme substrate preference. In this work, we establish a framework for engineering functional lipid interactions, paving the way for the design of proteins with membrane-specific properties or functions.
- MeSH
- DNA-Binding Proteins MeSH
- Endopeptidases metabolism chemistry genetics MeSH
- Escherichia coli metabolism genetics MeSH
- Cardiolipins * metabolism chemistry MeSH
- Membrane Proteins * metabolism chemistry genetics MeSH
- Protein Engineering * MeSH
- Escherichia coli Proteins * metabolism chemistry genetics MeSH
- Molecular Dynamics Simulation MeSH
- Protein Binding MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Duchenne muscular dystrophy (DMD) patients are monitored periodically for cardiac involvement, including cardiac MRI with gadolinium-based contrast agents (GBCA). Texture analysis (TA) offers an alternative approach to assess late gadolinium enhancement (LGE) without relying on GBCA administration, impacting DMD patients' care. The study aimed to evaluate the prognostic value of selected TA features in the LGE assessment of DMD patients. RESULTS: We developed a pipeline to extract TA features of native T1 parametric mapping and evaluated their prognostic value in assessing LGE in DMD patients. For this evaluation, five independent TA features were selected using Boruta to identify relevant features based on their importance, least absolute shrinkage and selection operator (LASSO) to reduce the number of features, and hierarchical clustering to target multicollinearity and identify independent features. Afterward, logistic regression was used to determine the features with better discrimination ability. The independent feature inverse difference moment normalized (IDMN), which measures the pixel values homogeneity in the myocardium, achieved the highest accuracy in classifying LGE (0.857 (0.572-0.982)) and also was significantly associated with changes in the likelihood of LGE in a subgroup of patients with three yearly examinations (estimate: 23.35 (8.7), p-value = 0.008). Data are presented as mean (SD) or median (IQR) for normally and non-normally distributed continuous variables and numbers (percentages) for categorical ones. Variables were compared with the Welch t-test, Wilcoxon rank-sum, and Chi-square tests. A P-value < 0.05 was considered statistically significant. CONCLUSION: IDMN leverages the information native T1 parametric mapping provides, as it can detect changes in the pixel values of LGE images of DMD patients that may reflect myocardial alterations, serving as a supporting tool to reduce GBCA use in their cardiac MRI examinations.
- MeSH
- Child MeSH
- Muscular Dystrophy, Duchenne * diagnostic imaging pathology MeSH
- Gadolinium MeSH
- Contrast Media MeSH
- Humans MeSH
- Magnetic Resonance Imaging * methods MeSH
- Adolescent MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection is not limited to the respiratory tract as receptors, including the angiotensin-converting enzyme 2 (ACE2), are expressed across many tissues. This study employed a new conditional mouse model, Rosa26creERT2/chACE2, which expresses human ACE2 (hACE2) across multiple organs, to investigate the effects of SARS-CoV-2 infection beyond the respiratory system. This strain demonstrated susceptibility to SARS-CoV-2 infection in a dose and sex-dependent manner, showing that infected male mice exhibited more severe disease outcomes, including significant weight loss, pronounced lung pathology and dysfunction, and increased mortality, compared to females. In contrast to intratracheal infection, intranasal virus administration facilitated viral spread to the brain, thereby underscoring the nasal route's role in the pathogenesis of neurological manifestations. Intranasal infection also led to increased innate immune system activation as compared to intratracheal virus administration, even though both routes activated the adaptive immune response. This model provides a valuable tool to study SARS-CoV-2 in individual tissues or use a multisystemic approach, and it also advances possibilities for preclinical evaluation of antiviral therapies and vaccine strategies.
- MeSH
- Angiotensin-Converting Enzyme 2 * genetics metabolism MeSH
- COVID-19 * pathology virology immunology genetics MeSH
- Respiratory System virology pathology MeSH
- Humans MeSH
- Disease Models, Animal MeSH
- Mice, Transgenic MeSH
- Mice MeSH
- Lung virology pathology MeSH
- Immunity, Innate MeSH
- SARS-CoV-2 * pathogenicity MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
In RNA interference (RNAi), long double-stranded RNA is cleaved by the Dicer endonuclease into small interfering RNAs (siRNAs), which guide degradation of complementary RNAs. While RNAi mediates antiviral innate immunity in plants and many invertebrates, vertebrates have adopted a sequence-independent response and their Dicer produces siRNAs inefficiently because it is adapted to process small hairpin microRNA precursors in the gene-regulating microRNA pathway. Mammalian endogenous RNAi is thus a rudimentary pathway of unclear significance. To investigate its antiviral potential, we modified the mouse Dicer locus to express a truncated variant (DicerΔHEL1) known to stimulate RNAi and we analyzed how DicerΔHEL1/wt mice respond to four RNA viruses: coxsackievirus B3 and encephalomyocarditis virus from Picornaviridae; tick-borne encephalitis virus from Flaviviridae; and lymphocytic choriomeningitis virus (LCMV) from Arenaviridae. Increased Dicer activity in DicerΔHEL1/wt mice did not elicit any antiviral effect, supporting an insignificant antiviral function of endogenous mammalian RNAi in vivo. However, we also observed that sufficiently high expression of DicerΔHEL1 suppressed LCMV in embryonic stem cells and in a transgenic mouse model. Altogether, mice with increased Dicer activity offer a new benchmark for identifying and studying viruses susceptible to mammalian RNAi in vivo.
- MeSH
- DEAD-box RNA Helicases genetics metabolism MeSH
- RNA, Small Interfering genetics MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- Immunity, Innate * genetics MeSH
- Ribonuclease III * genetics metabolism MeSH
- RNA Interference * MeSH
- Encephalomyocarditis virus genetics immunology MeSH
- Lymphocytic choriomeningitis virus immunology genetics MeSH
- Encephalitis Viruses, Tick-Borne genetics immunology MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
The knowledge about the contribution of the innate immune system to health and disease is expanding. However, to obtain reliable results, it is critical to select appropriate mouse models for in vivo studies. Data on genetic and phenotypic changes associated with different mouse strains can assist in this task. Such data can also facilitate our understanding of how specific polymorphisms and genetic alterations affect gene function, phenotypes, and disease outcomes. Extensive information is available on genetic changes in all major mouse strains. However, comparatively little is known about their impact on immune response and, in particular, on innate immunity. Here, we analyzed a mouse model of chronic multifocal osteomyelitis, an autoinflammatory disease driven exclusively by the innate immune system, which is caused by an inactivating mutation in the Pstpip2 gene. We investigated how the genetic background of BALB/c, C57BL/6J, and C57BL/6NCrl strains alters the molecular mechanisms controlling disease progression. While all mice developed the disease, symptoms were significantly milder in BALB/c and partially also in C57BL/6J when compared to C57BL/6NCrl. Disease severity correlated with the number of infiltrating neutrophils and monocytes and with the production of chemokines attracting these cells to the site of inflammation. It also correlated with increased expression of genes associated with autoinflammation, rheumatoid arthritis, neutrophil activation, and degranulation, resulting in altered neutrophil activation in vivo. Together, our data demonstrate striking effects of genetic background on multiple parameters of neutrophil function and activity influencing the onset and course of chronic multifocal osteomyelitis.
- MeSH
- Adaptor Proteins, Signal Transducing genetics MeSH
- Neutrophil Activation genetics MeSH
- Cytoskeletal Proteins MeSH
- Genetic Background * MeSH
- Disease Models, Animal MeSH
- Mice, Inbred BALB C MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- Neutrophils * immunology pathology MeSH
- Osteomyelitis * genetics immunology pathology MeSH
- Immunity, Innate genetics MeSH
- Severity of Illness Index MeSH
- Inflammation genetics pathology MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Mikroorganismy si během evoluce vyvinuly širokou škálu strategií, jak uniknout vrozenému i adaptivnímu imunitnímu systému, a některým těmto strategiím se věnujeme v našem přehledu. Mikroorganismy mohou využívat podobnost svých proteinů s proteiny hostitele, produkovat protizánětlivé faktory, narušovat komplementový systém, ovlivňovat funkci a blokovat syntézu cytokinů, inhibovat rozpoznávání imunoglobulinů, snižovat expresi a modifikovat antigeny na svém povrchu, narušovat zpracování a prezentaci antigenu imunitními buňkami, vstupovat do imunitních buněk, ovlivňovat apoptózu buněk, modulovat funkce imunitních buněk nebo ovlivňovat produkci hormonů. S těmito únikovými strategiemi je nutné počítat při léčbě infekčních onemocnění.
Microorganisms have evolved a wide variety of strategies to evade both the innate and adaptive immune systems during evolution, and some of these strategies are addressed in our review. Microorganisms can use the similarity of their proteins to host proteins, produce anti-inflammatory factors, disrupt the complement system, affect the function and block the synthesis of cytokines, inhibit the recognition of immunoglobulins, reduce the expression and modify antigens on their surface, disrupt the processing and presentation of antigen by immune cells, enter immune cells , influence cell apoptosis, modulate immune cell functions or influence hormone production. These escape strategies must be taken into account when treating infectious diseases.
- Keywords
- únikové strategie mikroorganismů,
- MeSH
- Host-Pathogen Interactions MeSH
- Humans MeSH
- Microbiological Phenomena * MeSH
- Immunity, Innate * MeSH
- Trained Immunity MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
Bakteriální lyzáty nespecificky stimulují celkovou imunitu organismu. Působí na nespecifické obranné mechanismy, což vede ke zvýšení IgA na sliznicích, fagocytární aktivitě a produkci interferonu gama. Mohou také stimulovat tvorbu specifických protilátek proti bakteriálním antigenům, které tvoří přípravek. V mnoha klinických studiích bylo prokázáno, že perorální bakteriální lyzáty snižují četnost opakovaných respiračních infekcí u dětí i dospělých a snižují potřebu podávání antibiotik.
Bacterial lysates stimulate the general immunity of the body in a non-specific way. They act on non-specific defense mechanisms, leading to an increase IgA in mucous membranes, phagocytic activity and interferon gamma production. They can also stimulate the production of specific antibodies against the bacterial antigens that make up the preparation. In many clinical trials, oral bacterial lysates have been shown to decrease the risk of recurrent respiratory infections in children and adults and reduce the need for antibiotics.
- Keywords
- bakteriální lyzáty,
- MeSH
- Adaptive Immunity drug effects MeSH
- Adjuvants, Immunologic * administration & dosage pharmacology therapeutic use MeSH
- Respiratory Tract Infections immunology pathology prevention & control MeSH
- Urinary Tract Infections immunology prevention & control MeSH
- Reproductive Tract Infections immunology MeSH
- Humans MeSH
- Immunity, Innate drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
The RNA content is crucial for the formation of nuclear compartments, such as nuclear speckles and nucleoli. Phosphatidylinositol 4,5-bisphosphate (PIP2) is found in nuclear speckles, nucleoli, and nuclear lipid islets and is involved in RNA polymerase I/II transcription. Intriguingly, the nuclear localization of PIP2 was also shown to be RNA-dependent. We therefore investigated whether PIP2 and RNA cooperate in the establishment of nuclear architecture. In this study, we unveiled the RNA-dependent PIP2-associated (RDPA) nuclear proteome in human cells by mass spectrometry. We found that intrinsically disordered regions (IDRs) with polybasic PIP2-binding K/R motifs are prevalent features of RDPA proteins. Moreover, these IDRs of RDPA proteins exhibit enrichment for phosphorylation, acetylation, and ubiquitination sites. Our results show for the first time that the RDPA protein Bromodomain-containing protein 4 (BRD4) associates with PIP2 in the RNA-dependent manner via electrostatic interactions, and that altered PIP2 levels affect the number of nuclear foci of BRD4 protein. Thus, we propose that PIP2 spatiotemporally orchestrates nuclear processes through association with RNA and RDPA proteins and affects their ability to form foci presumably via phase separation. This suggests the pivotal role of PIP2 in the establishment of a functional nuclear architecture competent for gene expression.
- MeSH
- Cell Nucleus * metabolism genetics MeSH
- Phosphatidylinositol 4,5-Diphosphate * metabolism MeSH
- Phosphorylation MeSH
- Nuclear Proteins * metabolism genetics MeSH
- Humans MeSH
- Cell Cycle Proteins metabolism genetics MeSH
- Bromodomain Containing Proteins MeSH
- RNA metabolism genetics MeSH
- Transcription Factors * metabolism genetics MeSH
- Protein Binding MeSH
- Intrinsically Disordered Proteins * metabolism genetics chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Do vývoja metód na meranie tlaku krvi sa významne zapojili aj pracovníci, ktorí sa narodili na území dnešného Slovenska a Českej republiky: Samuel von Basch (Plzeň) skonštruoval prvý ľahko prenosný sfygmomanometer vhodný na meranie tlaku krvi aj u detí. Gustav Gärtner (Pardubice) svojim tonometrom aplikovaným na prst dal základ flush metóde používanej neskôr na meranie tlaku krvi u detí a novorodencov. Eva Kellerová (Bratislava) zdokonalila ultrazvukovú metódu merania tlaku krvi, ktorá sa stala vhodnou i na merania u novorodencov. Jan Peňáz (Brno) vynašiel originálnu neinvazívnu metódu kontinuálnej beat-to-beat registrácie tlaku krvi v prstových artériách tzv. volume-clamp metódou. Otto Klein (Plzeň) urobil niekoľko mesiacov po pokusoch W. Forssmanna 11 úspešných katetrizácií pravého srdca u pacientov v Prahe, ako prvý s diagnostickým účelom. William Ganz (Košice) spolu s Jeremy Swanom skonštruovali originálny katéter, ktorým sa dá merať tlak krvi v pravej predsieni i komore, v a. pulmonalis, špeciálny tlak (PCWP – Pulmonary Capillary Wedge Pressure), ako aj vývrhový objem srdca termodilučnou metódou. Ako vidieť i z tohto prehľadu, rodáci z územia súčasného Česka a Slovenska významne prispeli k rozvoju neinvazívneho i invazívneho merania tlaku krvi u dospelých ľudí, ako aj u novorodencov a detí.
Researchers who were born in the territories of today‘s Slovakia and the Czech Republic were also significantly involved in the development of methods for measuring blood pressure: Samuel von Basch (Pilsen) constructed the first easily portable sphygmomanometer suitable for measuring blood pressure even in children. Gustav Gärtner (Pardubice), with his finger-applied tonometer, provided the basis for the flush method later used to measure blood pressure in children and newborns. Eva Kellerová (Bratislava) improved the ultrasound method of measuring blood pressure, which has become suitable also for measurements in newborns. Jan Peňáz (Brno) invented a unique non-invasive method of continuous beat-to-beat registration of blood pressure in finger arteries by the so-called volume-clamp method. Otto Klein (Pilsen) performed 11 successful right heart catheterizations on patients in Prague, the first for for diagnostic purposes, only a few months after W. Forssmann‘s experiments. William Ganz (Košice) together with Jeremy Swan constructed an original catheter that can measure blood pressure in the right atrium and ventricle, a.pulmonalis, special pressure (PCWP - Pulmonary Capillary Wedge Pressure), as well as cardiac output by thermodilution method. As can be seen from this review, natives of the territory of the present-day Czech Republic and Slovakia have contributed significantly to the development of non-invasive and invasive blood pressure measurement in adult humans as well as in neonates and children.
- MeSH
- Adaptive Immunity physiology immunology MeSH
- Hypersensitivity classification physiopathology MeSH
- Macrophages, Alveolar physiology MeSH
- Respiratory System * cytology immunology MeSH
- Mucus physiology immunology MeSH
- Immunologic Tests classification MeSH
- Respiratory Tract Infections immunology MeSH
- Humans MeSH
- Lymphocytes physiology immunology classification MeSH
- Immunity, Innate physiology immunology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
