Search results for "cycle"

Chronic hyperammonemia alters extracellular glutamate, glutamine and GABA and membrane expression of their transporters in rat cerebellum. Modulation…

2018

Trafficking of glutamate, glutamine and GABA between astrocytes and neurons is essential to maintain proper neurotransmission. Chronic hyperammonemia alters neurotransmission and cognitive function. The aims of this work were to analyze in cerebellum of rats the effects of chronic hyperammonemia on: a) extracellular glutamate, glutamine and GABA concentrations; b) membrane expression of glutamate, glutamine and GABA transporters; c) how they are modulated by extracellular cGMP. Hyperammonemic rats show increased levels of extracellular glutamate, glutamine, GABA and citrulline in cerebellum in vivo. Hyperammonemic rats show: a) increased membrane expression of the astrocytic glutamine trans…

Unique Organization of the Nuclear Envelope in the Post-natal Quiescent Neural Stem Cells

2017

Summary Neural stem cells (B1 astrocytes; NSCs) in the adult ventricular-subventricular-zone (V-SVZ) originate in the embryo. Surprisingly, recent work has shown that B1 cells remain largely quiescent. They are reactivated postnatally to function as primary progenitors for neurons destined for the olfactory bulb and some corpus callosum oligodendrocytes. The cellular and molecular properties of quiescent B1 cells remain unknown. Here we found that a subpopulation of B1 cells has a unique nuclear envelope invagination specialization similar to envelope-limited chromatin sheets (ELCS), reported in certain lymphocytes and some cancer cells. Using molecular markers, [3H]thymidine birth-dating, …

2019

During lytic herpes simplex virus 1 (HSV-1) infection, the expansion of the viral replication compartments leads to an enrichment of the host chromatin in the peripheral nucleoplasm. We have shown previously that HSV-1 infection induces the formation of channels through the compacted peripheral chromatin. Here, we used three-dimensional confocal and expansion microscopy, soft X-ray tomography, electron microscopy, and random walk simulations to analyze the kinetics of host chromatin redistribution and capsid localization relative to their egress site at the nuclear envelope. Our data demonstrated a gradual increase in chromatin marginalization, and the kinetics of chromatin smoothening arou…

Large Blooms of Bacillales (Firmicutes) Underlie the Response to Wetting of Cyanobacterial Biocrusts at Various Stages of Maturity.

2018

ABSTRACT Biological soil crusts (biocrusts) account for a substantial portion of primary production in dryland ecosystems. They successionally mature to deliver a suite of ecosystem services, such as carbon sequestration, water retention and nutrient cycling, and climate regulation. Biocrust assemblages are extremely well adapted to survive desiccation and to rapidly take advantage of the periodic precipitation events typical of arid ecosystems. Here we focus on the wetting response of incipient cyanobacterial crusts as they mature from “light” to “dark.” We sampled a cyanobacterial biocrust chronosequence before (dry) and temporally following a controlled wetting event and used high-throug…

PTTG1-interacting protein (PTTG1IP/PBF) predicts breast cancer survival.

2017

Background: PTTG1-interacting protein (PTTG1IP) is an oncogenic protein, which participates in metaphase-anaphase transition of the cell cycle through activation of securin (PTTG1). PTTG1IP promotes the shift of securin from the cell cytoplasm to the nucleus, allowing the interaction between separase and securin. PTTG1IP overexpression has been previously observed in malignant disease, e.g. in breast carcinoma. However, the prognostic value of PTTG1IP in breast carcinoma patients has not previously been revealed. Methods: A total of 497 breast carcinoma patients with up to 22-year follow-up were analysed for PTTG1IP and securin immunoexpression. The results were evaluated for correlations w…

Phospho-Akt overexpression is prognostic and can be used to tailor the synergistic interaction of Akt inhibitors with gemcitabine in pancreatic cancer

2017

Background There is increasing evidence of a constitutive activation of Akt in pancreatic ductal adenocarcinoma (PDAC), associated with poor prognosis and chemoresistance. Therefore, we evaluated the expression of phospho-Akt in PDAC tissues and cells, and investigated molecular mechanisms influencing the therapeutic potential of Akt inhibition in combination with gemcitabine. Methods Phospho-Akt expression was evaluated by immunohistochemistry in tissue microarrays (TMAs) with specimens tissue from radically-resected patients (n = 100). Data were analyzed by Fisher and log-rank test. In vitro studies were performed in 14 PDAC cells, including seven primary cultures, characterized for their…

The role of miR-26a and miR-30b in HER2+ breast cancer trastuzumab resistance and regulation of the CCNE2 gene

2016

AbstractA subset of HER2+ breast cancer patients manifest clinical resistance to trastuzumab. Recently, miR-26a and miR-30b have been identified as trastuzumab response regulators, and their target gene CCNE2 seems to play an important role in resistance to trastuzumab therapy. Cell viability was evaluated in trastuzumab treated HER2+ BT474 wt (sensitive), BT474r (acquired resistance), HCC1954 (innate resistance), and MDA-MB-231 (HER2−) cell lines, and the expression of miR-26a, miR-30b, and their target genes was measured. BT474 wt cell viability decreased by 60% and miR-26a and miR-30b were significantly overexpressed (~3-fold, p = 0.003 and p = 0.002, respectively) after trastuzumab trea…

Suppressive role exerted by microRNA-29b-1-5p in triple negative breast cancer through SPIN1 regulation

2017

MiR-29 family dysregulation occurs in various cancers including breast cancers. We investigated miR-29b-1 functional role in human triple negative breast cancer (TNBC) the most aggressive breast cancer subtype. We found that miR-29b-1-5p was downregulated in human TNBC tissues and cell lines. To assess whether miR- 29b-1-5p correlated with TNBC regenerative potential, we evaluated cancer stem cell enrichment in our TNBC cell lines, and found that only MDA-MB-231 and BT-20 produced primary, secondary and tertiary mammospheres, which were progressively enriched in OCT4, NANOG and SOX2 stemness genes. MiR-29b-1-5p expression inversely correlated with mammosphere stemness potential, and miR-29b…

Towards a Unified Functional Trait Framework for Parasites

2019

Trait-based research holds high potential to unveil ecological and evolutionary processes. Functional traits are fitness-related characteristics of individuals, which are measured at individual level and defined without using information external to the individual. Despite the usefulness of the functional approach to understand the performance of individuals in ecosystems, and parasitism being the most common life-history strategy on Earth, studies based on functional traits of parasites are still scarce. Since the choice of functional traits is a critical step for any study, we propose a core list of seven functional traits of metazoan parasites, related to three universal challenges faced…

Cytotoxicity and mode of action of a naturally occurring naphthoquinone, 2-acetyl-7-methoxynaphtho[2,3-b]furan-4,9-quinone towards multi-factorial dr…

2017

Abstract Introduction Malignacies are still a major public concern worldwide and despite the intensive search of new chemotherapeutic agents, treatment still remains a challenging issue. The present study was designed to evaluate the cytotoxicity of 2-acetyl-7-methoxynaphtho[2,3-b]furan-4,9-quinone (AMNQ) isolated from the bark of Milletia versicolor towards a panel of drug-sensitive and multidrug-resistant (MDR) cancer cell lines. Methods The resazurin reduction assay was used to evaluate the cytotoxicity of AMNQ against 9 drug-sensitive and multidrug-resistant (MDR) cancer cell lines. Cell cycle, mitochondrial membrane potential (MMP) and levels of reactive oxygen species were all analyze…