The mechanistic target of rapamycin complex 1 (mTORC1) pathway regulates cell growth and metabolism in response to many environmental cues, including nutrients. Amino acids signal to mTORC1 by modulating the guanine nucleotide loading states of the heterodimeric Rag GTPases, which bind and recruit mTORC1 to the lysosomal surface, its site of activation. The Rag GTPases are tethered to the lysosome by the Ragulator complex and regulated by the GATOR1, GATOR2, and KICSTOR multiprotein complexes that localize to the lysosomal surface through an unknown mechanism(s). Here, we show that mTORC1 is completely insensitive to amino acids in cells lacking the Rag GTPases or the Ragulator component p18. Moreover, not only are the Rag GTPases and Ragulator required for amino acids to regulate mTORC1, they are also essential for the lysosomal recruitment of the GATOR1, GATOR2, and KICSTOR complexes, which stably associate and traffic to the lysosome as the "GATOR" supercomplex. The nucleotide state of RagA/B controls the lysosomal association of GATOR, in a fashion competitively antagonized by the N terminus of the amino acid transporter SLC38A9. Targeting of Ragulator to the surface of mitochondria is sufficient to relocalize the Rags and GATOR to this organelle, but not to enable the nutrient-regulated recruitment of mTORC1 to mitochondria. Thus, our results reveal that the Rag-Ragulator complex is the central organizer of the physical architecture of the mTORC1 nutrient-sensing pathway and underscore that mTORC1 activation requires signal transduction on the lysosomal surface.

• MeSH
• adaptorové proteiny signální transdukční metabolismus   MeSH
• aminokyseliny * metabolismus   MeSH
• HEK293 buňky MeSH
• lidé MeSH
• lyzozomy * metabolismus   MeSH
• monomerní proteiny vázající GTP * metabolismus   MeSH
• mTORC1 * metabolismus   MeSH
• myši MeSH
• signální transdukce * MeSH
• živiny * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

TAIMAN (TAI), the only insect ortholog of mammalian Steroid Receptor Coactivators (SRCs), is a critical modulator of ecdysone and juvenile hormone (JH) signaling pathways, which govern insect development and reproduction. The modulatory effect is mediated by JH-dependent TAI's heterodimerization with JH receptor Methoprene-tolerant and association with the Ecdysone Receptor complex. Insect hormones regulate insect physiology and development in concert with abiotic cues, such as photo- and thermoperiod. Here we tested the effects of JH and ecdysone signaling on the circadian clock by a combination of microsurgical operations, application of hormones and hormone mimics, and gene knockdowns in the linden bug Pyrrhocoris apterus males. Silencing taiman by each of three non-overlapping double-strand RNA fragments dramatically slowed the free-running period (FRP) to 27-29 hours, contrasting to 24 hours in controls. To further corroborate TAIMAN's clock modulatory function in the insect circadian clock, we performed taiman knockdown in the cockroach Blattella germanica. Although Blattella and Pyrrhocoris lineages separated ~380 mya, B. germanica taiman silencing slowed the FRP by more than 2 hours, suggesting a conserved TAI clock function in (at least) some insect groups. Interestingly, the pace of the linden bug circadian clock was neither changed by blocking JH and ecdysone synthesis, by application of the hormones or their mimics nor by the knockdown of corresponding hormone receptors. Our results promote TAI as a new circadian clock modulator, a role described for the first time in insects. We speculate that TAI participation in the clock is congruent with the mammalian SRC-2 role in orchestrating metabolism and circadian rhythms, and that TAI/SRCs might be conserved components of the circadian clock in animals.

• MeSH
• buněčná membrána MeSH
• cirkadiánní hodiny * genetika   MeSH
• cirkadiánní rytmus genetika   MeSH
• ekdyson genetika   MeSH
• hmyz MeSH
• juvenilní hormony genetika   MeSH
• savci MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Axiální spondyloartritida (axSpA) je zastřešující termín, který zahrnuje ankylozující spondylitidu (AS) a non-radiografickou axSpA; ankylozující spondylitidu (nazývanou také radiografická axSpA) odlišuje od non-radiografické axSpA přítomnost nebo absence definitivní sakroiliitidy na rentgenových snímcích. Dlouholeté trvání choroby je spojeno s rizikem obtížně ovlivnitelných strukturálních změn, které mají negativní dopad na běžný život pacientů. Proto časné stanovení diagnózy dává nejen vyšší šanci na úspěch léčby, ale zejména na snížení rizika vzniku ireverzibilního poškození. Vzhledem k tomu, že řada cytokinů využívá ke své signalizaci molekuly JAK/STAT, nabízí inhibice JAK potenciál modulovat mnohočetné zánětlivé dráhy zapojené do patogeneze AS. Tofacitinib preferenčně inhibuje signalizaci heterodimerními cytokinovými receptory, které se asociují s JAK3 a/nebo JAK1 s funkční selektivitou nad cytokinovými receptory, které signalizují prostřednictvím párů JAK2. Tofacitinib je schválen k použití v řadě indikací (revmatoidní artritida, psoriatická artritida, juvenilní idiopatická artritida, ulcerózní kolitida), k nimž nově na podzim roku 2021 na základě pozitivních výsledků studie III. fáze přibyla právě ankylozující spondylitida.

Axial spondyloarthritis (axSpA) is an umbrella term that includes ankylosing spondylitis (AS) and non-radiographic axSpA; ankylosing spondylitis (also called radiographic axSpA) differs from non-radiographic axSpA by the presence or absence of definite sacroiliitis on radiography. The long duration of the disease is associated with the risk of difficult-to-control structural changes that have a negative impact on the patients ́ daily life. Therefore, early diagnosis not only gives a higher chance of treatment success, but especially of reducing the risk of irreversible damage. As many cytokines use JAK/STAT molecules for their signalling, JAK inhibition offers the potential to modulate multiple inflammatory pathways involved in pathogenesis of AS. Tofacitinib preferentially inhibits signaling by heterodimeric cytokine receptors that associate with JAK3 and/or JAK1 with functional selectivity over cytokine receptors that signal through JAK2 pairs. Tofacitinib is approved for use in a number of indications (rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis, ulcerative colitis), with ankylosing spondylitis newly added in the fall of 2021 based on positive results from a phase III study.

• Klíčová slova
• tofacitinib,
• MeSH
• ankylózující spondylitida * farmakoterapie   patofyziologie   MeSH
• biologická terapie MeSH
• inhibitory Janus kinas * aplikace a dávkování   MeSH
• klinické zkoušky, fáze III jako téma MeSH
• lidé MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

In mammals, integrins are heterodimeric transmembrane glycoproteins that represent a large group of cell adhesion receptors involved in cell-cell, cell-extracellular matrix, and cell-pathogen interactions. Integrin receptors are an important part of signalization pathways and have an ability to transmit signals into and out of cells and participate in cell activation. In addition to somatic cells, integrins have also been detected on germ cells and are known to play a crucial role in complex gamete-specific physiological events, resulting in sperm-oocyte fusion. The main aim of this review is to summarize the current knowledge on integrins in reproduction and deliver novel perspectives and graphical interpretations presenting integrin subunits localization and their dynamic relocation during sperm maturation in comparison to the oocyte. A significant part of this review is devoted to discussing the existing view of the role of integrins during sperm migration through the female reproductive tract; oviductal reservoir formation; sperm maturation processes ensuing capacitation and the acrosome reaction, and their direct and indirect involvement in gamete membrane adhesion and fusion leading to fertilization.

• MeSH
• integriny metabolismus   MeSH
• interakce spermie a vajíčka fyziologie   MeSH
• kapacitace spermií * MeSH
• lidé MeSH
• oocyty cytologie   metabolismus   MeSH
• spermie cytologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND: Interleukin-35 (IL-35) is a recently described heterodimeric cytokine that belongs to the IL-12 family and consists of p35 (IL-12a) and EBI3 (IL-27b) subunits. The expression of IL-35 in humans is inducible in response to inflammatory stimuli. Increased IL-35 levels were documented in several autoimmune inflammatory diseases, suggesting a possible immunomodulatory role in their pathogenesis. OBJECTIVES: The aim of this study was to explore a potential role of IL-35 in the pathogenesis of idiopathic inflammatory myopathies (IIM) by studying the expression of IL-35 subunits in muscle biopsy samples and by evaluating serum levels of IL-35 and their association with disease activity in IIM patients. METHODS: The expression of IL-35 subunits was studied in serial sections of 9 muscle biopsy samples [4 polymyositis (PM), 5 dermatomyositis (DM)] and in 7 non-inflammatory control muscle biopsies. Serum levels of IL-35 were measured in 23 PM, 28 DM and 15 cancer associated myositis (CAM) patients as well as in 40 healthy controls. Disease activity was evaluated using the Myositis Disease Activity Assessment Tool (MDAAT) and by serum muscle enzymes. RESULTS: Expression of both IL-35 subunits was evident in the inflammatory infiltrates in IIM muscle biopsies, while no IL-35 expression was observed in control muscle samples. IL-35 serum levels were increased in all IIM patients compared to healthy controls [median 119.5 (range 32.1-1074.5) vs 36.2 (range 1.5-86.5) pg/ml, P < 0.001]. There were no differences in IL-35 serum levels between myositis subgroups (DM, PM or CAM). Serum IL-35 levels correlated significantly with physician's assessment of global (r = 0.29, p = 0.021), muscle (r = 0.30, p = 0.017) and extramuscular (r = 0.30, p = 0.016) disease activity as well as creatine kinase (r = 0.26, p = 0.044) and lactate dehydrogenase (r = 0.40, p = 0.003) levels. There was a significant correlation with pulmonary activity in patients with interstitial lung disease (r = 0.39, p = 0.037). Serum IL-35 correlated negatively with duration of treatment (r = -34, p = 0.009). CONCLUSIONS: IL-35 is overexpressed in inflammatory infiltrates in muscle tissue and serum in IIM patients and there is correlation with several disease activity parameters. These data suggest potential role of locally produced IL-35 in the pathogenesis of inflammatory myopathies.

• MeSH
• biopsie MeSH
• dítě MeSH
• dospělí MeSH
• interleukiny krev   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• myozitida krev   metabolismus   patologie   MeSH
• polymyozitida krev   metabolismus   patologie   MeSH
• senioři MeSH
• svaly metabolismus   patologie   MeSH
• upregulace MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Kinetoplastids, including Trypanosoma brucei, control gene expression primarily at the posttranscriptional level. Nuclear mRNA export is an important, but understudied, step in this process. The general heterodimeric export factors, Mex67/Mtr2, function in the export of mRNAs and tRNAs in T. brucei, but RNA binding proteins (RBPs) that regulate export processes by controlling the dynamics of Mex67/Mtr2 ribonucleoprotein formation or transport have not been identified. Here, we report that DRBD18, an essential and abundant T. brucei RBP, associates with Mex67/Mtr2 in vivo, likely through its direct interaction with Mtr2. DRBD18 downregulation results in partial accumulation of poly(A)+ mRNA in the nucleus, but has no effect on the localization of intron-containing or mature tRNAs. Comprehensive analysis of transcriptomes from whole-cell and cytosol in DRBD18 knockdown parasites demonstrates that depletion of DRBD18 leads to impairment of nuclear export of a subset of mRNAs. CLIP experiments reveal the association of DRBD18 with several of these mRNAs. Moreover, DRBD18 knockdown leads to a partial accumulation of the Mex67/Mtr2 export receptors in the nucleus. Taken together, the current study supports a model in which DRBD18 regulates the selective nuclear export of mRNAs by promoting the mobilization of export competent mRNPs to the cytosol through the nuclear pore complex.

• MeSH
• aktivní transport - buněčné jádro MeSH
• genový knockdown metody   MeSH
• membránové transportní proteiny metabolismus   MeSH
• messenger RNA metabolismus   MeSH
• nukleocytoplazmatické transportní proteiny metabolismus   MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• RNA transferová metabolismus   MeSH
• transkriptom MeSH
• transport RNA MeSH
• Trypanosoma brucei brucei genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Receptory velké rodiny HER hrají v případě karcinomu prsu významnou roli, která prochází postupným rozvojem v souvislosti s biologickým vývojem, a to jak na poli diagnostickém tak terapeutickém. HER2 pozitivita u karcinomu prsu původně sama o sobě představovala nepříznivý prognostický faktor. To se změnilo díky moderní léčbě pomocí monoklonálních protilátek. Další mezník poté představuje konečná analýza dat ze studie CLEOPATRA. Tato studie se zaměřila na přínos přidání monoklonální protilátky pertuzumabu ke standardní terapii trastuzumabem a docetaxelem. Pertuzumab se váže na stejný cíl jako trastuzumab, avšak na jiném vazebném místě, inhibuje tak heterodimerizaci HER2 a HER3 receptorů. Dimerizace HER2 s dalšími členy skupiny HER je přitom největším hnacím mechanismem růstu a přežívání nádorových buněk. Pertuzumab má sám o sobě minimální protinádorovou účinnost, používá se proto výhradně v kombinaci s trastuzumabem. Tento kombinovaný přístup tedy zlepšuje blokádu HER2 signální dráhy porušením dimerizace HER3 a HER2 receptoru. Velice zajímavé se ovšem jeví využití exprese HER3, jako možného prognostického markeru u TNBC převážně ve spojitosti s graviditou a kojením. Dále se předpokládá, že HER-3 receptor se podílí nejen na přežití a proliferaci buněk, ale také na regulaci exprese PD-L1. Mohlo by se tedy jednat o potenciální cíl imunoterapie. Pohled na receptor HER-3 bude však daleko složitější a jak se zdá, nadměrná exprese tohoto receptoru, bude mít jak negativní, tak pozitivní prognostický význam.

In the case of breast cancer, receptors of the large HER family play an important role that undergoes gradual evolution in association with the biological development, both in the diagnostic and therapeutic fields. Originally, HER-2 positivity in breast cancer was an unfavourable prognostic factor in itself. This has changed due to modern treatment with monoclonal antibodies. The final analysis of data from the CLEOPATRA trial has been another landmark. This trial focused on the benefit of adding the monoclonal antibody pertuzumab to standard treatment with trastuzumab and docetaxel. Pertuzumab binds to the same target as trastuzumab, yet at a different binding site, thus inhibiting heterodimerization of the HER-2 and HER-3 receptors. In fact, dimerization of HER-2 and of other members of the HER family is the major driving mechanism of tumour cell growth and survival. Pertuzumab itself has minimal anticancer efficacy; therefore, it is used exclusively in combination with trastuzumab. Hence, this combined approach improves HER-2 signalling pathway inhibition by disrupting the dimerization of HER-3 and HER-2 receptors. What appears to be intriguing, however, is the use of HER-3 expression as a possible prognostic marker in TNBC predominantly in association with pregnancy and breast-feeding. The HER-3 receptor is supposed to be involved not only in cell survival and proliferation, but also in the regulation of PD-L1 expression. It could thus be a potential target for immunotherapy. Indeed, the view of the HER-3 receptor is likely to be much more complex and, as it seems, overexpression of this receptor will have both negative and positive prognostic significance.

• MeSH
• erbB receptory fyziologie   MeSH
• exprese genu MeSH
• klinická studie jako téma MeSH
• lidé MeSH
• nádorové komplikace v těhotenství MeSH
• nádory prsu * diagnóza   epidemiologie   etiologie   farmakoterapie   MeSH
• prognóza MeSH
• receptor erbB-2 MeSH
• receptor erbB-3 * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

The CD94 receptor, expressed on natural killer (NK) and CD8+ T cells, is known as a relatively non-polymorphic receptor with orthologues in humans, other primates, cattle, and rodents. In the house mouse (Mus musculus), a single allele is highly conserved among laboratory strains, and reports of allelic variation in lab- or wild-living mice are lacking, except for deficiency in one lab strain (DBA/2J). The non-classical MHC-I molecule Qa-1b is the ligand for mouse CD94/NKG2A, presenting alternative non-americ fragment of leader peptides (Qa-1 determinant modifier (Qdm)) from classical MHC-I molecules. Here, we report a novel allele identified in free-living house mice captured in Norway, living among individuals carrying the canonical Cd94 allele. The novel Cd94LocA allele encodes 12 amino acid substitutions in the extracellular lectin-like domain. Flow cytometric analysis of primary NK cells and transfected cells indicates that the substitutions prevent binding of CD94 mAb and Qa-1b/Qdm tetramers. Our data further indicate correlation of Cd94 polymorphism with the two major subspecies of house mice in Europe. Together, these findings suggest that the Cd94LocA/NKG2A heterodimeric receptor is widely expressed among M. musculus subspecies musculus, with ligand-binding properties different from mice of subspecies domesticus, such as the C57BL/6 strain.

• MeSH
• alely MeSH
• buňky NK metabolismus   MeSH
• CD8-pozitivní T-lymfocyty metabolismus   MeSH
• CHO buňky MeSH
• Cricetulus MeSH
• druhová specificita MeSH
• HEK293 buňky MeSH
• křečci praví MeSH
• lektinové receptory NK-buněk - podrodina C chemie   genetika   metabolismus   MeSH
• lektinové receptory NK-buněk - podrodina D chemie   genetika   metabolismus   MeSH
• lidé MeSH
• MHC antigeny I. třídy chemie   genetika   metabolismus   MeSH
• multimerizace proteinu MeSH
• myši inbrední C57BL MeSH
• myši inbrední DBA MeSH
• peptidy chemie   genetika   metabolismus   MeSH
• polymorfismus genetický * MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Norsko MeSH

Interleukin-23 (IL-23), a heterodimeric cytokine of covalently bound p19 and p40 proteins, has recently been closely associated with development of several chronic autoimmune diseases such as psoriasis, psoriatic arthritis or inflammatory bowel disease. Released by activated dendritic cells, IL-23 interacts with IL-23 receptor (IL-23R) on Th17 cells, thus promoting intracellular signaling, a pivotal step in Th17-driven pro-inflammatory axis. Here, we aimed to block the binding of IL-23 cytokine to its cell-surface receptor by novel inhibitory protein binders targeted to the p19 subunit of human IL-23. To this goal, we used a combinatorial library derived from a scaffold of albumin-binding domain (ABD) of streptococcal protein G, and ribosome display selection, to yield a collection of ABD-derived p19-targeted variants, called ILP binders. From 214 clones analyzed by ELISA, Western blot and DNA sequencing, 53 provided 35 different sequence variants that were further characterized. Using in silico docking in combination with cell-surface competition binding assay, we identified a group of inhibitory candidates that substantially diminished binding of recombinant p19 to the IL-23R on human monocytic THP-1 cells. Of these best p19-blockers, ILP030, ILP317 and ILP323 inhibited IL-23-driven expansion of IL-17-producing primary human CD4+ T-cells. Thus, these novel binders represent unique IL-23-targeted probes useful for IL-23/IL-23R epitope mapping studies and could be used for designing novel p19/IL-23-targeted anti-inflammatory biologics.

• MeSH
• aktivace lymfocytů imunologie   MeSH
• buněčné linie MeSH
• buňky Th17 imunologie   metabolismus   MeSH
• dendritické buňky imunologie   metabolismus   MeSH
• fagocyty imunologie   metabolismus   MeSH
• interleukin-23 - podjednotka p19 chemie   metabolismus   farmakologie   MeSH
• interleukin-23 chemie   metabolismus   MeSH
• konformace proteinů MeSH
• lidé MeSH
• makrofágy imunologie   metabolismus   MeSH
• molekulární modely MeSH
• receptory interleukinů metabolismus   MeSH
• rekombinantní proteiny MeSH
• signální transdukce MeSH
• T-lymfocyty - podskupiny imunologie   metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Integrins are heterodimeric cell surface adhesion and signaling receptors that are essential for metazoan existence. Some integrins contain an I-domain that is a major ligand binding site. The ligands preferentially engage the active forms of the integrins and trigger signaling cascades that alter numerous cell functions. Here we found that the adenylate cyclase toxin (CyaA), a key virulence factor of the whooping cough agent Bordetella pertussis, preferentially binds an inactive form of the integrin complement receptor 3 (CR3), using a site outside of its I-domain. CyaA binding did not trigger downstream signaling of CR3 in human monocytes and CyaA-catalyzed elevation of cAMP effectively blocked CR3 signaling initiated by a natural ligand. This unprecedented type of integrin-ligand interaction distinguishes CyaA from all other known ligands of the I-domain-containing integrins and provides a mechanistic insight into the previously observed central role of CyaA in the pathogenesis of B. pertussis.

• MeSH
• adenylátcyklasový toxin metabolismus   MeSH
• Bordetella pertussis patogenita   MeSH
• buněčné linie MeSH
• interakce hostitele a patogenu * MeSH
• křečci praví MeSH
• lidé MeSH
• makrofágový antigen 1 metabolismus   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH