STUDY HYPOTHESIS: In women with preterm premature rupture of the membranes (PPROM), increased oxidative stress may accelerate premature cellular senescence, senescence-associated inflammation and proteolysis, which may predispose them to rupture. STUDY FINDING: We demonstrate mechanistic differences between preterm birth (PTB) and PPROM by revealing differences in fetal membrane redox status, oxidative stress-induced damage, distinct signaling pathways and senescence activation. WHAT IS KNOWN ALREADY: Oxidative stress-associated fetal membrane damage and cell cycle arrest determine adverse pregnancy outcomes, such as spontaneous PTB and PPROM. STUDY DESIGN, SAMPLES/MATERIALS, METHODS: Fetal membranes and amniotic fluid samples were collected from women with PTB and PPROM. Molecular, biochemical and histologic markers were used to document differences in oxidative stress and antioxidant enzyme status, DNA damage, secondary signaling activation by Ras-GTPase and mitogen-activated protein kinases, and activation of senescence between membranes from the two groups. MAIN RESULTS AND THE ROLE OF CHANCE: Oxidative stress was higher and antioxidant enzymes were lower in PPROM compared with PTB. PTB membranes had minimal DNA damage and showed activation of Ras-GTPase and ERK/JNK signaling pathway with minimal signs of senescence. PPROM had higher numbers of cells with DNA damage, prosenescence stress kinase (p38 MAPK) activation and signs of senescence. LIMITATIONS, REASONS FOR CAUTION: Samples were obtained retrospectively after delivery. The markers of senescence that we tested are specific but are not sufficient to confirm senescence as the pathology in PPROM. WIDER IMPLICATIONS OF THE FINDINGS: Oxidative stress-induced DNA damage and senescence are characteristics of fetal membranes from PPROM, compared with PTB with intact membranes. PTB and PPROM arise from distinct pathophysiologic pathways. Oxidative stress and oxidative stress-induced cellular damages are likely determinants of the mechanistic signaling pathways and phenotypic outcome. STUDY FUNDING AND COMPETING INTERESTS: This study is supported by developmental funds to Dr R. Menon from the Department of Obstetrics and Gynecology at The University of Texas Medical Branch at Galveston and funds to Dr M. Kacerovský from the Ministry of Health Czech Republic (UHHK, 001799906). The authors report no conflict of interest.

• MeSH
• Adult MeSH
• Extraembryonic Membranes injuries   metabolism   MeSH
• Homeodomain Proteins genetics   metabolism   MeSH
• Lamin Type B genetics   metabolism   MeSH
• Humans MeSH
• MAP Kinase Kinase 4 genetics   metabolism   MeSH
• Mitogen-Activated Protein Kinase 1 genetics   metabolism   MeSH
• Mitogen-Activated Protein Kinase 3 genetics   metabolism   MeSH
• p38 Mitogen-Activated Protein Kinases genetics   metabolism   MeSH
• Infant, Premature MeSH
• Infant, Newborn MeSH
• Oxidative Stress genetics   MeSH
• DNA Damage MeSH
• Fetal Membranes, Premature Rupture genetics   metabolism   pathology   MeSH
• Premature Birth MeSH
• Gene Expression Regulation MeSH
• Signal Transduction genetics   MeSH
• Gene Expression Profiling MeSH
• Cellular Senescence MeSH
• Superoxide Dismutase genetics   metabolism   MeSH
• Pregnancy MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Primary interaction of an intracellular bacterium with its host cell is initiated by activation of multiple signaling pathways in response to bacterium recognition itself or as cellular responses to stress induced by the bacterium. The leading molecules in these processes are cell surface membrane receptors as well as cytosolic pattern recognition receptors recognizing pathogen-associated molecular patterns or damage-associated molecular patterns induced by the invading bacterium. In this review, we demonstrate possible sequences of events leading to recognition of Francisella tularensis, present findings on known mechanisms for manipulating cell responses to protect Francisella from being killed, and discuss newly published data from the perspective of early stages of host-pathogen interaction.

• MeSH
• Alarmins genetics   immunology   MeSH
• Bacterial Proteins genetics   immunology   MeSH
• Phagocytosis genetics   MeSH
• Francisella tularensis genetics   immunology   pathogenicity   MeSH
• Host-Pathogen Interactions genetics   immunology   MeSH
• Humans MeSH
• Macrophages immunology   microbiology   MeSH
• Pathogen-Associated Molecular Pattern Molecules immunology   metabolism   MeSH
• Immunity, Innate * MeSH
• Receptors, Cell Surface genetics   immunology   MeSH
• Receptors, Pattern Recognition genetics   immunology   MeSH
• Gene Expression Regulation MeSH
• Signal Transduction MeSH
• Tularemia genetics   immunology   microbiology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

• MeSH
• Cell Biology MeSH
• Liver Cirrhosis etiology   MeSH
• Molecular Biology MeSH
• Publication type
• Congress MeSH
• Collected Work MeSH
• News MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• hepatologie
• molekulární biologie, molekulární medicína

• MeSH
• Alarmins physiology   immunology   MeSH
• Skin Physiological Phenomena * immunology   MeSH
• Interleukin-23 drug effects   MeSH
• Humans MeSH
• Models, Immunological MeSH
• Models, Molecular MeSH
• Antibodies, Monoclonal pharmacology   MeSH
• Pathogen-Associated Molecular Pattern Molecules immunology   MeSH
• Psoriasis * drug therapy   immunology   physiopathology   MeSH
• Tumor Necrosis Factor-alpha MeSH
• Ustekinumab * pharmacology   MeSH
• Check Tag
• Humans MeSH

Nedílnou součástí řešení závažného chirurgického onemocnění je provedení operačního zákroku. Intervence ovšem pro pacienta zároveň znamená i potenciální riziko související především s tzv. chirurgickým traumatem, které vyvolává imunologickou reakci. Ta pak při své dysregulaci může na jednu stranu vést zprvu k rozvoji lokálních komplikací (např. dehiscence operační rány, porucha hojení), na druhou stranu může, při své systémové dekompartmentizaci, negativně ovlivnit dlouhodobé klinické výsledky (délka hospitalizace, mortalita). Zmíněná aktivace imunitního systému má, vzhledem k asepsi operačních sálů, zpočátku téměř vždy charakter sterilního zánětu, na kterém se podílejí tzv. alarminy, látky z rodiny tzv. damage-associated molecular patterns. Patří k nim např. high-mobility group box 1, heat-shock proteiny, proteiny S100A a další. Alarminy za normální situace plní fyziologickou funkci v buňkách. Při zátěži nebo poškození buňky jsou tyto látky uvolněny extracelulárně, kde pravděpodobně hrají roli při aktivaci vrozeného imunitního systému. Existuje řada experimentálních a klinických prací, které se zabývají postavením alarminů v rámci některých akutních i chronických zánětlivých stavů. Nicméně vztah alarminů a chirurgického traumatu doposud extenzivně zkoumán nebyl. Identifikace alarminů, které ovlivňují patofyziologii chirurgického traumatu, by mohla vést ke zpřesnění monitorace a předpovědi klinického výsledku pacientů po velkých operačních výkonech.

Surgical intervention is an inseparable part of the management of serious surgical disease. However, surgery also presents a potential risk related to the so-called surgical injury causing immune response. When dysregulated the immune activation is able to cause local complications (i.e. wound dehiscence, impaired healing). Systemic decompartmentization of the immunologic disturbance can negatively influence long-term outcomes (i.e. hospital length of stay, mortality). Due to aseptic conditions in the operating room, such an immune activation is almost always of sterile nature. This involves the release of alarmins, protein-based molecules of the damage-associated molecular patterns family. The group includes e.g. high-mobility group box 1, heat-shock proteins, proteins S100A, and more. Under normal conditions, alarmins fulfil their physiologic intracellular functions. When the cell is stressed and/or damaged, alarmins are released into the extracellular space where they probably play their cytokine-like roles activating preferably the innate immune system. A number of experimental and clinical publications have been published concerning the role of alarmins in various acute and chronic diseases. However, to date a potential relationship between alarmins and surgical injury has not been extensively studied. Identification of alarmins that influence the pathological physiology of surgical trauma might play a role in the improvement of monitoring and predicting outcomes after major surgery.

• MeSH
• Alarmins * physiology   classification   MeSH
• Surgical Procedures, Operative contraindications   MeSH
• Help-Seeking Behavior MeSH
• Immune System Phenomena physiology   MeSH
• Cardiac Surgical Procedures contraindications   MeSH
• Humans MeSH
• Pilot Projects MeSH
• HMGB1 Protein physiology   MeSH
• Inflammation etiology   complications   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Overall MeSH

Activated Schwann cells put out cytoplasmic processes that play a significant role in cell migration and axon regeneration. Following nerve injury, axonal mitochondria release mitochondrial damage-associated molecular patterns (mtDAMPs), including formylated peptides and mitochondrial DNA (mtDNA). We hypothesize that mtDAMPs released from disintegrated axonal mitochondria may stimulate Schwann cells to put out cytoplasmic processes. We investigated RT4-D6P2T schwannoma cells (RT4) in vitro treated with N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP) or cytosine-phospho-guanine oligodeoxynucleotide (CpG ODN) for 1, 6 and 24 h. We also used immunohistochemical detection to monitor the expression of formylpeptide receptor 2 (FPR2) and toll-like receptor 9 (TLR9), the canonical receptors for formylated peptides and mtDNA, in RT4 cells and Schwann cells distal to nerve injury. RT4 cells treated with fMLP put out a significantly higher number of cytoplasmic processes compared to control cells. Preincubation with PBP10, a selective inhibitor of FPR2 resulted in a significant reduction of cytoplasmic process outgrowth. A significantly higher number of cytoplasmic processes was also found after treatment with CpG ODN compared to control cells. Pretreatment with inhibitory ODN (INH ODN) resulted in a reduced number of cytoplasmic processes after subsequent treatment with CpG ODN only at 6 h, but 1 and 24 h treatment with CpG ODN demonstrated an additive effect of INH ODN on the development of cytoplasmic processes. Immunohistochemistry and western blot detected increased levels of tyrosine-phosphorylated paxillin in RT4 cells associated with cytoplasmic process outgrowth after fMLP or CpG ODN treatment. We found increased immunofluorescence of FPR2 and TLR9 in RT4 cells treated with fMLP or CpG ODN as well as in activated Schwann cells distal to the nerve injury. In addition, activated Schwann cells displayed FPR2 and TLR9 immunostaining close to GAP43-immunopositive regenerated axons and their growth cones after nerve crush. Increased FPR2 and TLR9 immunoreaction was associated with activation of p38 and NFkB, respectively. Surprisingly, the growth cones displayed also FPR2 and TLR9 immunostaining. These results present the first evidence that potential mtDAMPs may play a key role in the induction of Schwann cell processes. This reaction of Schwann cells can be mediated via FPR2 and TLR9 that are canonical receptors for formylated peptides and mtDNA. The possible role for FPR2 and TLR9 in growth cones is also discussed.

• Publication type
• Journal Article MeSH

Alarminy jsou látky proteinové povahy, které se za normálního stavu nacházejí v buňkách a plní zde svou fyziologickou funkci. V současné době je již identifikována celá řada alarminů, z nichž k nejvíce zkoumaným patří high-mobility group box 1, heat-shock proteiny, proteiny S100A, mitochondriální DNA a formylované formy tripeptidu methionin-leucin-fenylalanin. V patologickém stavu se tyto látky uvolňují, popř. jsou aktivně vylučovány extracelulárně, kde hrají důležitou roli v procesu aktivace vrozeného imunitního systému. Role alarminů byla v posledních desetiletích zkoumána v rámci patofyziologie některých chronických onemocnění, ale existuje i řada prací, které se zabývají vztahem alarminů k akutním zánětlivým stavům, jako např. k syndromu systémové zánětlivé odpovědi infekční i neinfekční etiologie. Rozsáhlý chirurgický výkon by pravděpodobně také mohl vést k vyplavení alarminů z poškozených tkání. Stanovení hladiny alarminů by v těchto případech mohlo vést k lepšímu pochopení patofyziologie chirurgického traumatu, zpřesnit jeho monitorování a zlepšit stanovení klinické prognózy pacientů. Tento fakt ale doposud extenzivně zkoumán nebyl.

Alarmins are mostly protein-based substances which, under normal conditions, are localized intracellularly, fulfilling their physiological functions. Currently, the most studied group of alarmins consists of the high-mobility group box 1, heat-shock proteins, proteins S100A, mitochondrial DNA and formylated methionine-leucyl-phenylalanine. In pathological condition, alarmins are released or actively secreted into the extracellular space where they presumably play an important role in activation of innate immunity. A wide spectrum of alarmins has been identified. Alarmins were studied in several chronic diseases during the last decades but there is also an increasing number of research papers concerning their relationship with acute inflammatory conditions, e.g. the systemic inflammatory response syndrome caused by infectious or non-infectious insults. Extensive surgery has some attributes which might lead to the release of alarmins from the injured/damaged tissues. In such cases, the measuring of blood levels of alarmins could bring better understanding of the pathophysiology of surgical trauma, refine its monitoring and improve our ability to predict the clinical outcome of the patients. This issue warrants further thorough studying.

• MeSH
• Alarmins * physiology   immunology   MeSH
• Humans MeSH
• Multiple Organ Failure immunology   MeSH
• Pathogen-Associated Molecular Pattern Molecules MeSH
• Perioperative Period MeSH
• Immunity, Innate immunology   MeSH
• HMGB1 Protein MeSH
• S100 Proteins MeSH
• Heat-Shock Proteins MeSH
• Signal Transduction MeSH
• Systemic Inflammatory Response Syndrome immunology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH

OBJECTIVES: Our previous studies have demonstrated that the Damage Associated Molecular Pattern (DAMP) protein, S100A4, is overexpressed in the involved skin and peripheral blood of patients with SSc. It is associated with skin and lung involvement, and disease activity. By contrast, lack of S100A4 prevented the development of experimental dermal fibrosis. Herein we aimed to evaluate the effect of murine anti-S100A4 mAb 6B12 in the treatment of preestablished experimental dermal fibrosis. METHODS: The effects of 6B12 were assessed at therapeutic dosages in a modified bleomycin-induced dermal fibrosis mouse model by evaluating fibrotic (dermal thickness, proliferation of myofibroblasts, hydroxyproline content, phosphorylated Smad3-positive cell count) and inflammatory (leukocytes infiltrating the lesional skin, systemic levels of selected cytokines and chemokines) outcomes, and transcriptional profiling (RNA sequencing). RESULTS: Treatment with 7.5 mg/kg 6B12 attenuated and might even reduce pre-existing dermal fibrosis induced by bleomycin as evidenced by reduction in dermal thickness, myofibroblast count and collagen content. These antifibrotic effects were mediated by the downregulation of TGF-β/Smad signalling and partially by reducing the number of leukocytes infiltrating the lesional skin and decrease in the systemic levels of IL-1α, eotaxin, CCL2 and CCL5. Moreover, transcriptional profiling demonstrated that 7.5 mg/kg 6B12 also modulated several profibrotic and proinflammatory processes relevant to the pathogenesis of SSc. CONCLUSION: Targeting S100A4 by the 6B12 mAb demonstrated potent antifibrotic and anti-inflammatory effects on bleomycin-induced dermal fibrosis and provided further evidence for the vital role of S100A4 in the pathophysiology of SSc.

• MeSH
• Alarmins * MeSH
• Bleomycin toxicity   MeSH
• Fibrosis MeSH
• Skin * pathology   MeSH
• Humans MeSH
• Disease Models, Animal MeSH
• Antibodies, Monoclonal pharmacology   MeSH
• Mice MeSH
• S100 Calcium-Binding Protein A4 genetics   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

• MeSH
• Cell Biology MeSH
• Molecular Biology MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Biochemie. Molekulární biologie. Biofyzika
• NML Fields
• biologie
• cytologie, klinická cytologie

Biologická léčba je nadějí pro těžké astmatiky a jsou očekávána další biologika ve fázích klinických zkoušek cílená na typy respiračního zánětu. Výběr biologik u pacientů s těžkým astmatem vychází z diagnostického posouzení, zda se jedná o T2-high (tj. eozinofilní, alergický či nealergický) anebo T2-low (t. j. noneozinofilní) zánětlivý endotyp/fenotyp astmatu. V klinické praxi máme dostupné tři molekuly s antieozinofilním přístupem do dráhy cytokinu 5 (mepolizumab, benralizumab, reslizumab), molekulu zaměřenou na receptor pro IL4/13 (dupilumab), molekulu s vazbou na imunoglobulin E (omalizumab). Poslední molekulou, která vstoupila do klinické praxe, je tezepelumab blokující cytokin ze skupiny epiteliálních alarminů - thymický stromální lymfopoetin. Inhibice alarminů ("upstream" cytokinů) je novým konceptem cytokinové blokace. Studovány jsou další molekuly určené k inhibici alarminových drah, z nichž jako slibný se jeví anti­‐IL33 itepekimab. Blokace epiteliálních alarminů může být i perspektivou pro astmatiky s T2-low typem zánětu, kde účinné biologikum zatím chybí.

Biological therapy shows promise for patients with severe asthma, and more biological drugs in clinical trial phases targeted at types of airway inflammation are expected. The choice of biologicals in patients with severe asthma is based on a diagnostic assessment of whether the inflammatory asthma endotype/phenotype is T2-high (i.e., eosinophilic, allergic, or non-allergic) or T2-low (i.e., non-eosinophilic). In clinical practice, three molecules with an anti-eosinophilic access to the cytokine 5 pathway (mepolizumab, benralizumab, reslizumab), a molecule targeted at the IL4/13 receptor (dupilumab), and a molecule binding to immunoglobulin E (omalizumab) are available. The latest molecule to have been introduced in clinical practice is tezepelumab that blocks thymic stromal lymphopoietin, an epithelial alarmin cytokine. Inhibition of alarmins (upstream cytokines) is a novel concept of cytokine blockade. Other molecules intended to inhibit alarmin pathways are also being studied, among which anti‐IL33 itepekimab shows promise. Blockade of epithelial alarmins can be promising for asthma patients with the T2-low type inflammation where an effective biological drug is lacking.

• Keywords
• tezepelumab, brodalumab, itepekimab,
• MeSH
• Alarmins antagonists & inhibitors   MeSH
• Biological Therapy methods   MeSH
• Asthma * drug therapy   immunology   physiopathology   MeSH
• Antibodies, Monoclonal, Humanized administration & dosage   pharmacology   therapeutic use   MeSH
• Interleukins antagonists & inhibitors   MeSH
• Clinical Studies as Topic MeSH
• Humans MeSH
• Thymic Stromal Lymphopoietin antagonists & inhibitors   immunology   MeSH
• Check Tag
• Humans MeSH