A Small Conductance Calcium-Activated K⁺ Channel in C. elegans, KCNL-2, Plays a Role in the Regulation of the Rate of Egg-Laying

In the nervous system of mice, small conductance calcium-activated potassium (SK) channels function to regulate neuronal excitability through the generation of a component of the medium afterhyperpolarization that follows action potentials. In humans, irregular action potential firing frequency underlies diseases such as ataxia, epilepsy, schizophrenia and Parkinson's disease. Due to the complexity of studying protein function in the mammalian nervous system, we sought to characterize an SK channel homologue, KCNL-2, in C. elegans, a genetically tractable system in which the lineage of individual neurons was mapped from their early developmental stages. Sequence analysis of the KCNL-2 protein reveals that the six transmembrane domains, the potassium-selective pore and the calmodulin binding domain are highly conserved with the mammalian homologues. We used widefield and confocal fluorescent imaging to show that a fusion construct of KCNL-2 with GFP in transgenic lines is expressed in the nervous system of C. elegans. We also show that a KCNL-2 null strain, kcnl-2(tm1885), demonstrates a mild egg-laying defective phenotype, a phenotype that is rescued in a KCNL-2-dependent manner. Conversely, we show that transgenic lines that overexpress KCNL-2 demonstrate a hyperactive egg-laying phenotype. In this study, we show that the vulva of transgenic hermaphrodites is highly innervated by neuronal processes and by the VC4 and VC5 neurons that express GFP-tagged KCNL-2. We propose that KCNL-2 functions in the nervous system of C. elegans to regulate the rate of egg-laying. © 2013 Chotoo et al

Дифференциальная экспрессия микроРНК и их генов-мишеней при цервикальных интраэпителиальных неоплазиях разной степени тяжести

Background. Currently, little is known about the specific microRNAs involved in the development of cervical intraepithelial neoplasia (CIN1, 2, 3) and the transition to cancer in situ (CIS). Our meta-analysis allowed us to isolate 8 microRNAs (hsa-miR-1246, hsa-miR- 145-5p, hsa-miR-196b-5p, hsa-miR-34a-5p, hsa-miR-20a-5p, hsa-miR-21-5p, hsa-miR-375-5p, hsa-miR-96-5p) with potential significance in the progression of precancerous diseases to cervical cancer. Objective: to analyze the expression features of hsa-miR-1246, hsa-miR-145-5p, hsa-miR-196b-5p, hsa-miR-34a-5p, hsa-miR-20a-5p, hsa-miR-21-5p, hsa-miR-375-5p, hsa-miR-96-5p and their target genes, as well as genes associated with them in common signaling pathways in the tissues of the cervix in patients with CIN1–3 and CIS. Materials and methods. To assess the expression level of microRNA and matrixRNA, the quantitative polymerase chain reaction in real time method was used. Data analysis was carried out in the Python programming language using the SciPy library. Search for target genes was performed using the TarPmiR algorithm and the overrepresentation of microRNAs in signaling pathways (Over-Representation Analysis) was analyzed. To identify genes associated with target genes in common signaling pathways, GIANT (Genome-scale Integrated Analysis of gene Networks in Tissues) and network integration with several associations algorithms were used. Results. For microRNAs miR-145, miR-196b, miR-34a, miR-20a, miR-21, miR-375 and miR-96 a decrease in expression was found in the subgroup of patients with CIS, while for 4 microRNAs (miR-145, miR-34a, miR-20a and miR-375), an increase in the expression level was found for CIN1, 2. The detected features of microRNA expression in subgroups of patients with CIN1–3 and CIS also affected the expression of their target genes (CDKN2A, MKI67, TOP2A and CD82), as well as the genes associated with them in common signaling pathways (PGK1, THBS4 (TSP4) and ECM1). Conclusion. Thus, the study revealed that each degree of CIN is characterized by its own specific molecular profile – the differential expression of microRNAs, their target genes and the genes associated with them in the general signaling pathways.Введение. В настоящее время недостаточно известно о специфических микроРНК (мкРНК), задействованных в развитии цервикальной интраэпителиальной неоплазии I, II, III степеней тяжести (CIN1, 2, 3) и переходе к карциноме in situ (CIS). Проведенный нами ранее метаанализ позволил выделить 8 мкРНК (hsa-miR-1246, hsa-miR-145-5p, hsa-miR-196b-5p, hsa-miR-34a-5p, hsa-miR-20a-5p, hsa-miR-21-5p, hsa-miR-375-5p, hsa-miR-96-5p), обладающих потенциальной значимостью в прогрессировании предраковых заболеваний в рак шейки матки. Цель исследования – анализ особенностей экспрессии hsa-miR-1246, hsa-miR-145-5p, hsa-miR-196b-5p, hsa-miR-34a-5p, hsa-miR- 20a-5p, hsa-miR-21-5p, hsa-miR-375-5p, hsa-miR-96-5p и их генов-мишеней, а также генов, ассоциированных с ними в общих сигнальных путях, в тканях шейки матки у пациенток с CIN1–3 и CIS. Материалы и методы. Для оценки уровня экспрессии мкРНК и матричной РНК использовали метод количественной полимеразной цепной реакции в режиме реального времени. Анализ данных проводили на языке программирования Python с использованием библиотеки SciPy. Поиск генов-мишеней осуществляли с помощью алгоритма TarPmiR и анализировали избыточную представленность мкРНК в сигнальных путях (Over-Representation Analysis). Для выявления генов, ассоциированных с генами-мишенями в общих сигнальных путях, использовали алгоритмы GIANT (Genome-scale Integrated Analysis of gene Networks in Tissues) и «сетевая интеграция с несколькими ассоциациями». Результаты. Для мкРНК miR-145, miR-196b, miR-34a, miR-20a, miR-21, miR-375 и miR-96 обнаружено снижение экспрессии в подгруппе пациенток с CIS, при этом для 4 мкРНК (miR-145, miR-34a, miR-20a и miR-375) выявлено увеличение уровня экспрессии при CIN1, 2. Обнаруженные особенности экспрессии мкРНК в подгруппах пациенток с CIN1–3 и CIS были ассоциированы с экспрессией их генов-мишеней (CDKN2A, MKI67, TOP2A и CD82), а также генов, связанных с ними в общих сигнальных путях (PGK1, THBS4 (TSP4) и ECM1). Заключение. Результаты исследования позволили установить, что каждая степень CIN характеризуется особым молекулярным профилем – дифференциальной экспрессией мкРНК, их генов-мишеней и генов, ассоциированных с ними в общих сигнальных путях

Динамика маркеров острого почечного повреждения при резекции почки по поводу рака

The purpose of the study is to investigate the effect of epidural block on the functional state of the kidneys in patients with localized cancer during kidney resection under the conditions of warm ischemia.Materials and methods. We examined 45 patients (25 men and 20 women) with a localized kidney cancer (T1N0M0) aged 56.5±8.7 years. All the patients underwent kidney resection performed under conditions of warm ischemia (15—20 minutes). Patients were divided into 2 groups: the main group (25 subjects) in which the perioperative epidural block was applied and the reference group (20 patients) without the epidural block. The following parameters were tested in blood and urine using the ELISA technique: cystatin C, L-FABP, KIM-1 , IL-18, and GFR. The test was carried out 1 hour prior to surgery, 20 minutes after the warm ischemia stage, and on Days 1 and 3. Based on the baseline cystatin С level, the patients in each group were divided into 2 subgroups: subgroup 1 —cystatin C is 1000 ng/ml and lower; subgroup 2 — more than 1000 ng/ml. The statistical processing of the findings was performed using the Statistica 6.0 software based on the t-test for two independent samples. Differences were considered to be statistically significant at P<0.05.Results. It has been demonstrated that functional parameters of kidneys were recovered to the baseline values by the 3rd day after the kidney resection under the warm ischemia due to perioperative epidural block. Impairment of the tubulointerstitium and glomerular apparatus were observed in the reference group. GFR values in the patients of the main group were within normal limits by Day 3, whereas in the patients of the GFR was lower by 38.8% as compared to the baseline (P<0.05).Conclusion. The use of the perioperative epidural block in patients with localized kidney cancer who underwent the organ resection under the warm ischemia demonstrated the nephroprotective effect, while maintaining the functional parameters of kidneys at the baseline level. Цель исследования — изучить влияние эпидуральной блокады на функциональное состояние почек у больных локализованным раком при поведении резекции почки в условиях тепловой ишемии.Материал и методы. Обследовали 45 больных (25 мужчин и 20 женщин) локализованным раком почки T1N0M0 в возрасте 56,5±8,7 года. Всем больным выполнили резекцию почки в условиях тепловой ишемии (15—20 минут). Больных разделили на 2 группы: основную (25 человек), в которой в периоперационном периоде применяли эпидуральную блокаду, и контрольную (20 пациентов) — без эпидуральной блокады. В крови и моче методом ИФА исследовали — цистатин С, L-FABP, КИМ-1 , ИЛ-18, а также СКФ. Обследование проводили за 1 час до операции, через 20 минут после этапа тепловой ишемии, в 1-е и 3-и сутки. По исходной концентрации цистатина С в крови больные каждой группы были разделены на 2 подгруппы: 1 — концентрация цистатина С 1000 нг/мл и ниже, 2 — выше 1000 нг/мл. Статистическую обработку результатов проводили с использованием пакета программ «Statistiсa 6.0» по t-критерию Стъюдента для 2-х независимых выборок. Различия считали статистически значимыми при p<0,05.Результаты. Установили, что при выполнении резекции почки в условиях тепловой ишемии функциональные показатели почек к 3-м суткам после операции на фоне проводимой в периоперационном периоде эпидуральной блокады соответствовали исходным. В контрольной группе наблюдали нарушения со стороны тубулоинтерстиция и гломерулярного аппарата. Значения СКФ у больных основной группы к 3-м суткам сохранялись в пределах нормальных значений, тогда как у больных контрольной группы СКФ была снижена относительно исходных значений на 38,8% (p<0,05).Заключение. Применение в периоперационном периоде эпидурального блока у больных локализованным раком почки, подвергнутых резекции органа в условиях тепловой ишемии, оказывает нефропротективное влияние, обеспечивая сохранение функциональных показателей почек на исходном уровне.

Self-oligomerization regulates stability of survival motor neuron protein isoforms by sequestering an SCF^Slmb degron

Spinal muscular atrophy (SMA) is caused by homozygous mutations in human SMN1. Expression of a duplicate gene (SMN2) primarily results in skipping of exon 7 and production of an unstable protein isoform, SMNΔ7. Although SMN2 exon skipping is the principal contributor to SMA severity, mechanisms governing stability of survival motor neuron (SMN) isoforms are poorly understood. We used a Drosophila model system and label-free proteomics to identify the SCFSlmb ubiquitin E3 ligase complex as a novel SMN binding partner. SCFSlmb interacts with a phosphor degron embedded within the human and fruitfly SMN YG-box oligomerization domains. Substitution of a conserved serine (S270A) interferes with SCFSlmb binding and stabilizes SMNΔ7. SMA-causing missense mutations that block multimerization of full-length SMN are also stabilized in the degron mutant background. Overexpression of SMNΔ7S270A, but not wild-type (WT) SMNΔ7, provides a protective effect in SMA model mice and human motor neuron cell culture systems. Our findings support a model wherein the degron is exposed when SMN is monomeric and sequestered when SMN forms higher-order multimers

Динамика маркеров острого повреждения почек при использовании эпидуральной блокады во время резекции в условиях тепловой ишемии

Objective: to investigate the time course of changes in the early biomarkers of acute kidney injury in patients with clinically localized cancer during partial nephrectomy, as electively indicated, under thermal ischemia with prior epidural block.Materials and methods. To analyze the nephroprotective effect of an epidural block in kidney resection with warm ischemia, markers of acute kidney injury (cystatin C, interleukin 18, NGAL, L-FABP and KIM-1) were studied by ELISA in the blood and urine of 35 patients with local cancer with an epidural block (main group) and 37 patients with local cancer without an epidural block (control group) before surgery and 40 min after its beginning and on days 1 and 3 of the postoperative period. All patients were divided into 2 groups by the levels of cystatin C in the blood serum: 1000 ng/ml and lower, and over 1000 ng/ml.Results. Epidural block during the perioperative period in kidney resection with warm ischemia for patients with local cancer had an obvious nephroprotective effect allowing maintaining the initial renal functional parameters, in contrast to the standard disease management.Цель исследования – изучение динамики ранних биомаркеров острого повреждения почек у больных клинически локализованным раком при резекции почки по элективным показаниям в условиях тепловой ишемии с предварительным проведением эпидуральной блокады.Материалы и методы. Для изучения нефропротективного влияния эпидуральной блокады при резекции почки и тепловой ишемии в крови и моче 35 больных локализованным раком с проведением эпидуральной блокады (основная группа) и 37 пациентов с локализованным раком без проведения эпидуральной блокады (контрольная группа) до вмешательства и через 40 мин после начала операции, а также на 1-е и 3-и сутки послеоперационного периода методом иммуноферментного анализа были исследованы 5 маркеров острого повреждения почек: цистатин С, интерлейкин 18, NGAL, L-FABP и КIМ-1. По фоновому уровню цистатина С в сыворотке крови все больные были разделены на 2 группы: с уровнем показателя ≤1000 нг/мл и >1000 нг/мл.Результаты. Применение эпидуральной блокады в периоперационном периоде у больных локализованным раком при резекции почки в условиях тепловой ишемии оказывает нефропротективный эффект, позволяя сохранить функциональные показатели почек на исходном уровне в отличие от стандартного ведения больных

Conserved Genes Act as Modifiers of Invertebrate SMN Loss of Function Defects

Spinal Muscular Atrophy (SMA) is caused by diminished function of the Survival of Motor Neuron (SMN) protein, but the molecular pathways critical for SMA pathology remain elusive. We have used genetic approaches in invertebrate models to identify conserved SMN loss of function modifier genes. Drosophila melanogaster and Caenorhabditis elegans each have a single gene encoding a protein orthologous to human SMN; diminished function of these invertebrate genes causes lethality and neuromuscular defects. To find genes that modulate SMN function defects across species, two approaches were used. First, a genome-wide RNAi screen for C. elegans SMN modifier genes was undertaken, yielding four genes. Second, we tested the conservation of modifier gene function across species; genes identified in one invertebrate model were tested for function in the other invertebrate model. Drosophila orthologs of two genes, which were identified originally in C. elegans, modified Drosophila SMN loss of function defects. C. elegans orthologs of twelve genes, which were originally identified in a previous Drosophila screen, modified C. elegans SMN loss of function defects. Bioinformatic analysis of the conserved, cross-species, modifier genes suggests that conserved cellular pathways, specifically endocytosis and mRNA regulation, act as critical genetic modifiers of SMN loss of function defects across species

Bioenergetic status modulates motor neuron vulnerability and pathogenesis in a zebrafish model of spinal muscular atrophy

Degeneration and loss of lower motor neurons is the major pathological hallmark of spinal muscular atrophy (SMA), resulting from low levels of ubiquitously-expressed survival motor neuron (SMN) protein. One remarkable, yet unresolved, feature of SMA is that not all motor neurons are equally affected, with some populations displaying a robust resistance to the disease. Here, we demonstrate that selective vulnerability of distinct motor neuron pools arises from fundamental modifications to their basal molecular profiles. Comparative gene expression profiling of motor neurons innervating the extensor digitorum longus (disease-resistant), gastrocnemius (intermediate vulnerability), and tibialis anterior (vulnerable) muscles in mice revealed that disease susceptibility correlates strongly with a modified bioenergetic profile. Targeting of identified bioenergetic pathways by enhancing mitochondrial biogenesis rescued motor axon defects in SMA zebrafish. Moreover, targeting of a single bioenergetic protein, phosphoglycerate kinase 1 (Pgk1), was found to modulate motor neuron vulnerability in vivo. Knockdown of pgk1 alone was sufficient to partially mimic the SMA phenotype in wild-type zebrafish. Conversely, Pgk1 overexpression, or treatment with terazosin (an FDA-approved small molecule that binds and activates Pgk1), rescued motor axon phenotypes in SMA zebrafish. We conclude that global bioenergetics pathways can be therapeutically manipulated to ameliorate SMA motor neuron phenotypes in vivo