Voltage-gated sodium channel β1 subunits are essential proteins that regulate excitability. They modulate sodium and potassium currents, function as cell adhesion molecules and regulate gene transcription following regulated intramembrane proteolysis. Biallelic pathogenic variants in SCN1B, encoding β1, are linked to developmental and epileptic encephalopathy 52, with clinical features overlapping Dravet syndrome. A recessive variant, SCN1B-c.265C>T, predicting SCN1B-p.R89C, was homozygous in two children of a non-consanguineous family. One child was diagnosed with Dravet syndrome, while the other had a milder phenotype. We identified an unrelated biallelic SCN1B-c.265C>T patient with a clinically more severe phenotype than Dravet syndrome. We used CRISPR/Cas9 to knock-in SCN1B-p.R89C to the mouse Scn1b locus (Scn1bR89/C89). We then rederived the line on the C57BL/6J background to allow comparisons between Scn1bR89/R89 and Scn1bC89/C89 littermates with Scn1b+/+ and Scn1b-/- mice, which are congenic on C57BL/6J, to determine whether the SCN1B-c.265C>T variant results in loss-of-function. Scn1bC89/C89 mice have normal body weights and ∼20% premature mortality, compared with severely reduced body weight and 100% mortality in Scn1b-/- mice. β1-p.R89C polypeptides are expressed in brain at comparable levels to wild type. In heterologous cells, β1-p.R89C localizes to the plasma membrane and undergoes regulated intramembrane proteolysis similar to wild type. Heterologous expression of β1-p.R89C results in sodium channel α subunit subtype specific effects on sodium current. mRNA abundance of Scn2a, Scn3a, Scn5a and Scn1b was increased in Scn1bC89/C89 somatosensory cortex, with no changes in Scn1a. In contrast, Scn1b-/- mouse somatosensory cortex is haploinsufficient for Scn1a, suggesting an additive mechanism for the severity of the null model via disrupted regulation of another Dravet syndrome gene. Scn1bC89/C89 mice are more susceptible to hyperthermia-induced seizures at post-natal Day 15 compared with Scn1bR89/R89 littermates. EEG recordings detected epileptic discharges in young adult Scn1bC89/C89 mice that coincided with convulsive seizures and myoclonic jerks. We compared seizure frequency and duration in a subset of adult Scn1bC89/C89 mice that had been exposed to hyperthermia at post-natal Day 15 versus a subset that were not hyperthermia exposed. No differences in spontaneous seizures were detected between groups. For both groups, the spontaneous seizure pattern was diurnal, occurring with higher frequency during the dark cycle. This work suggests that the SCN1B-c.265C>T variant does not result in complete loss-of-function. Scn1bC89/C89 mice more accurately model SCN1B-linked variants with incomplete loss-of-function compared with Scn1b-/- mice, which model complete loss-of-function, and thus add to our understanding of disease mechanisms as well as our ability to develop new therapeutic strategies.
- Publikační typ
- časopisecké články MeSH
The majority of patients with Crohn's disease and a proportion of patients with ulcerative colitis will ultimately require surgical treatment despite advances in diagnosis, therapy, and endoscopic interventions. The surgical procedures that are most commonly done include bowel resection with anastomosis, strictureplasty, faecal diversion, and ileal pouch. These surgical treatment modalities result in substantial alterations in bowel anatomy. In patients with inflammatory bowel disease, endoscopy plays a key role in the assessment of disease activity, disease recurrence, treatment response, dysplasia surveillance, and delivery of endoscopic therapy. Endoscopic evaluation and management of surgically altered bowel can be challenging. This consensus guideline delineates anatomical landmarks and endoscopic assessment of these landmarks in diseased and surgically altered bowel.
- MeSH
- anastomóza chirurgická metody MeSH
- anatomická značka diagnostické zobrazování MeSH
- chirurgie trávicího traktu škodlivé účinky MeSH
- Crohnova nemoc diagnóza chirurgie MeSH
- dospělí MeSH
- endoskopie metody MeSH
- idiopatické střevní záněty chirurgie MeSH
- konsensus MeSH
- lidé středního věku MeSH
- lidé MeSH
- pouch škodlivé účinky MeSH
- proktokolektomie rekonstrukční metody MeSH
- recidiva MeSH
- směrnice pro lékařskou praxi jako téma MeSH
- stenóza chirurgie MeSH
- střeva anatomie a histologie patologie chirurgie MeSH
- stupeň závažnosti nemoci MeSH
- ulcerózní kolitida diagnóza chirurgie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Research Support, N.I.H., Extramural MeSH
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.
- MeSH
- autofagie * fyziologie MeSH
- autofagozomy MeSH
- biologické markery MeSH
- biotest normy MeSH
- lidé MeSH
- lyzozomy MeSH
- proteiny spojené s autofagií metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- směrnice MeSH
The orange carotenoid protein (OCP) is a structurally and functionally modular photoactive protein involved in cyanobacterial photoprotection. Recently, based on bioinformatic analysis and phylogenetic relationships, new families of OCP have been described, OCP2 and OCPx. The first characterization of the OCP2 showed both faster photoconversion and back-conversion, and lower fluorescence quenching of phycobilisomes relative to the well-characterized OCP1. Moreover, OCP2 is not regulated by the fluorescence recovery protein (FRP). In this work, we present a comprehensive study combining ultrafast spectroscopy and structural analysis to compare the photoactivation mechanisms of OCP1 and OCP2 from Tolypothrix PCC 7601. We show that despite significant differences in their functional characteristics, the spectroscopic properties of OCP1 and OCP2 are comparable. This indicates that the OCP functionality is not directly related to the spectroscopic properties of the bound carotenoid. In addition, the structural analysis by X-ray footprinting reveals that, overall, OCP1 and OCP2 have grossly the same photoactivation mechanism. However, the OCP2 is less reactive to radiolytic labeling, suggesting that the protein is less flexible than OCP1. This observation could explain fast photoconversion of OCP2.
The ongoing digital revolution in the age of big data is opening new research opportunities. Culturomics and iEcology, two emerging research areas based on the analysis of online data resources, can provide novel scientific insights and inform conservation and management efforts. To date, culturomics and iEcology have been applied primarily in the terrestrial realm. Here, we advocate for expanding such applications to the aquatic realm by providing a brief overview of these new approaches and outlining key areas in which culturomics and iEcology are likely to have the highest impact, including the management of protected areas; fisheries; flagship species identification; detection and distribution of threatened, rare, and alien species; assessment of ecosystem status and anthropogenic impacts; and social impact assessment. When deployed in the right context with awareness of potential biases, culturomics and iEcology are ripe for rapid development as low-cost research approaches based on data available from digital sources, with increasingly diverse applications for aquatic ecosystems.
The Orange Carotenoid Protein (OCP) is a water-soluble protein that governs photoprotection in many cyanobacteria. The 35 kDa OCP is structurally and functionally modular, consisting of an N-terminal effector domain (NTD) and a C-terminal regulatory domain (CTD); a carotenoid spans the two domains. The CTD is a member of the ubiquitous Nuclear Transport Factor-2 (NTF2) superfamily (pfam02136). With the increasing availability of cyanobacterial genomes, bioinformatic analysis has revealed the existence of a new family of proteins, homologs to the CTD, the C-terminal domain-like carotenoid proteins (CCPs). Here we purify holo-CCP2 directly from cyanobacteria and establish that it natively binds canthaxanthin (CAN). We use small-angle X-ray scattering (SAXS) to characterize the structure of this carotenoprotein in two distinct oligomeric states. A single carotenoid molecule spans the two CCPs in the dimer. Our analysis with X-ray footprinting-mass spectrometry (XFMS) identifies critical residues for carotenoid binding that likely contribute to the extreme red shift (ca. 80 nm) of the absorption maximum of the carotenoid bound by the CCP2 dimer and a further 10 nm shift in the tetramer form. These data provide the first structural description of carotenoid binding by a protein consisting of only an NTF2 domain.
- MeSH
- bakteriální proteiny chemie ultrastruktura MeSH
- kanthaxanthin chemie MeSH
- krystalografie rentgenová MeSH
- maloúhlový rozptyl MeSH
- nukleocytoplazmatické transportní proteiny chemie genetika ultrastruktura MeSH
- proteinové domény genetika MeSH
- sinice chemie ultrastruktura MeSH
- vazba proteinů účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Cíl Posoudit relativní podíl ovlivnitelných kardiovaskulárních rizikových faktorů na vzniku významných srdečních příhod u stárnoucích osob přežívajících po zhoubném nádoru v dětství. Pacienti a metody U 10 724 osob přežívajících 5 let (medián věku 33,7 roku) a 3 159 jejich sourozenců ve studii Childhood Cancer Survivor Study byly stanoveny prevalence hypertenze, diabetes mellitus, dyslipidémie a obezity, a také incidence a závažnost významných srdečních příhod, např. příhod v rámci ischemické choroby srdeční, srdečního selhání, onemocnění chlopní a arytmie. Na základě dlouhodobého sledovány byly pomocí mnohorozměrných modelů Poissonovy regrese stanoveny poměry četností (RR) následných srdečních příhod spojených s kardiovaskulárními rizikovými faktory a kardiotoxickou terapií. Výsledky U přežívajících byly kumulativní incidence příhod ischemické choroby srdeční, srdečního selhání, onemocnění chlopní a arytmie vesměs hodnocené do 45 let věku 5,3 %, 4,8 %, 1,5 %, resp. 1,3 %. Dva nebo více kardiovaskulárních rizikových faktorů nahlásilo 10,3 % přežívajících a 7,9 % sourozenců. Riziko všech srdečních příhod se zvyšovalo s rostoucím počtem kardiovaskulárních rizikových faktorů (pro všechny hodnoty ptrend < 0,001). Hypertenze významně zvýšila riziko vzniku ischemické choroby srdeční (RR 6,1), srdečního selhání (RR 19,4), onemocnění chlopní (RR 13,6) a arytmie (RR 6,0; všechny hodnoty p < 0,01). Kombinovaný vliv radioterapie hrudníku a hypertenze se projevil zvýšením rizika všech významných srdečních příhod, které bylo vyšší, než by odpovídalo pouhému sečtení očekávání pro jednotlivé rizikové faktory. Hypertenze byla nezávisle spojena s rizikem úmrtí ze srdečních příčin (RR 5,6; 95% CI 3,2–9,7). Závěr Ovlivnitelné kardiovaskulární rizikové faktory, zejména hypertenze, zvyšují v této populaci riziko významných srdečních příhod spojených s terapií a měly by být zkoumány v budoucích studiích intervencí k ovlivnění rizikových faktorů.
- MeSH
- antitumorózní látky * škodlivé účinky MeSH
- dospělí MeSH
- lidé středního věku MeSH
- mladý dospělý MeSH
- náchylnost k nemoci epidemiologie etiologie MeSH
- nádory * komplikace mortalita MeSH
- nemoci srdce * epidemiologie etiologie MeSH
- Poissonovo rozdělení MeSH
- přežívající * MeSH
- rizikové faktory MeSH
- věk při počátku nemoci MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
