245 research outputs found
A novel function for the Caenorhabditis elegans torsin OOC-5 in nucleoporin localization and nuclear import.
Torsin proteins are AAA+ ATPases that localize to the endoplasmic reticular/nuclear envelope (ER/NE) lumen. A mutation that markedly impairs torsinA function causes the CNS disorder DYT1 dystonia. Abnormalities of NE membranes have been linked to torsinA loss of function and the pathogenesis of DYT1 dystonia, leading us to investigate the role of the Caenorhabditis elegans torsinA homologue OOC-5 at the NE. We report a novel role for torsin in nuclear pore biology. In ooc-5-mutant germ cell nuclei, nucleoporins (Nups) were mislocalized in large plaques beginning at meiotic entry and persisted throughout meiosis. Moreover, the KASH protein ZYG-12 was mislocalized in ooc-5 gonads. Nups were mislocalized in adult intestinal nuclei and in embryos from mutant mothers. EM analysis revealed vesicle-like structures in the perinuclear space of intestinal and germ cell nuclei, similar to defects reported in torsin-mutant flies and mice. Consistent with a functional disruption of Nups, ooc-5-mutant embryos displayed impaired nuclear import kinetics, although the nuclear pore-size exclusion barrier was maintained. Our data are the first to demonstrate a requirement for a torsin for normal Nup localization and function and suggest that these functions are likely conserved
Glutamylation regulates transport, specializes function, and sculpts the structure of cilia
Ciliary microtubules (MTs) are extensively decorated with post-translational modifications (PTMs), such as glutamylation of tubulin tails. PTMs and tubulin isotype diversity act as a âTubulin Codeâ that regulates cytoskeletal stability and the activity of MT-associated proteins such as kinesins. We previously showed that, in C. elegans cilia, the deglutamylase CCPP-1 affects ciliary ultrastructure, localization of the TRP channel PKD-2 and the kinesin-3 KLP-6, and velocity of kinesin-2 OSM-3/KIF17, while a cell-specific α-tubulin isotype regulates ciliary ultrastructure, intraflagellar transport, and ciliary functions of extracellular vesicle (EV)-releasing neurons. Here, we examine the role of PTMs and the Tubulin Code in the cililary specialization of EV-releasing neurons using genetics, fluorescence microscopy, kymography, electron microscopy, and sensory behavioral assays. Although the C. elegans genome encodes five tubulin tyrosine ligase-like (TTLL) glutamylases, only ttll-11 specifically regulates PKD-2 localization in EV- releasing neurons. In EV-releasing cephalic male (CEM) cilia, TTLL-11 and the deglutamylase CCPP-1 regulate remodeling of 9+0 MT doublets into 18 singlet MTs. Balanced TTLL-11 and CCPP-1 activity fine-tunes glutamylation to control velocity of kinesin-2 OSM-3/KIF17 and kinesin-3 KLP-6 without affecting the IFT kinesin-II. TTLL-11 is transported by ciliary motors. TTLL-11 and CCPP-1 are also required for the ciliary function of releasing bioactive EVs, and TTLL-11 is itself a novel EV cargo. Therefore, MT glutamylation, as part of the tubulin code, controls ciliary specialization, ciliary motor-based transport, and ciliary EV release in a living animal. We suggest that cell-specific control of MT glutamylation may be a conserved mechanism to specialize the form and function of cilia
âAdvocacy groups are the connectorsâ: Experiences and contributions of rare disease patient organization leaders in advanced neurotherapeutics
Introduction: Biomedical progress has facilitated breakthrough advanced neurotherapeutic interventions, whose potential to improve outcomes in rare neurological diseases has increased hope among people with lived experiences and their carers. Nevertheless, gene, somatic cell and other advanced neurotherapeutic interventions carry significant risks. Rare disease patient organizations (RDPOs) may enhance patient experiences, inform expectations and promote health literacy. However, their perspectives are understudied in paediatric neurology. If advanced neurotherapeutics is to optimize RDPO contributions, it demands further insights into their roles, interactions and support needs. Methods: We used a mixed-methodology approach, interviewing 20 RDPO leaders representing paediatric rare neurological diseases and following them up with two online surveys featuring closed and open-ended questions on advanced neurotherapeutics (19/20) and negative mood states (17/20). Qualitative and quantitative data were analysed using thematic discourse analysis and basic descriptive statistics, respectively. Results: Leaders perceived their roles to be targeted at educational provision (20/20), community preparation for advanced neurotherapeutic clinical trials (19/20), information simplification (19/20) and focused research pursuits (20/20). Although most leaders perceived the benefits of collaboration between stakeholders, some cited challenges around collaborative engagement under the following subthemes: conflicts of interest, competition and logistical difficulties. Regarding neurotherapeutics, RDPO leaders identified support needs centred on information provision, valuing access to clinician experts and highlighting a demand for co-developed, centralized, high-level and understandable, resources that may improve information exchange. Leaders perceived a need for psychosocial support within themselves and their communities, proposing that this would facilitate informed decision-making, reduce associated psychological vulnerabilities and maintain hope throughout neurotherapeutic development. Conclusion: This study provides insights into RDPO research activities, interactions and resource needs. It reveals a demand for collaboration guidelines, central information resources and psychosocial supports that may address unmet needs and assist RDPOs in their advocacy. Patient or Public Contribution: In this study, RDPO leaders were interviewed and surveyed to examine their perspectives and roles in advanced neurotherapeutic development. Some participants sent researchers postinterview clarification emails regarding their responses to questions
Use of bioanalyzer electropherograms for quality control and target evaluation in microarray expression profiling studies of ocular tissues
Expression profiling with DNA microarrays has been used to examine the transcriptome of a wide spectrum of vertebrate cells and tissues. The sensitivity and accuracy of the data generated is dependent on the quality and composition of the input RNA. In this report, we examine the quality and array performance of over 200 total RNA samples extracted from ocular tissues and cells that have been processed in a microarray core laboratory over a 7-year period. Total RNA integrity and cRNA target size distribution were assessed using the 2100 Bioanalyzer. We present Affymetrix GeneChip array performance metrics for different ocular samples processed according to a standard microarray assay workflow including several quality control checkpoints. Our review of ocular sample performance in the microarray assay demonstrates the value of considering tissue-specific characteristics in evaluating array data. Specifically, we show that Bioanalyzer electropherograms reveal highly abundant mRNAs in lacrimal gland targets that are correlated with variation in array assay performance. Our results provide useful benchmarks for other gene expression studies of ocular systems
CD4 T lymphocyte autophagy is upregulated in the salivary glands of primary Sjögrenâs syndrome patients and correlates with focus score and disease activity
Background: Primary Sjögrenâs syndrome (pSS) is a common chronic autoimmune disease characterized by
lymphocytic infiltration of exocrine glands and peripheral lymphocyte perturbation. In the current study, we
aimed to investigate the possible pathogenic implication of autophagy in T lymphocytes in patients with pSS.
Methods: Thirty consecutive pSS patients were recruited together with 20 patients affected by sicca syndrome a
nd/or chronic sialoadenitis and 30 healthy controls. Disease activity and damage were evaluated according to SS
disease activity index, EULAR SS disease activity index, and SS disease damage index. T lymphocytes were analyzed
for the expression of autophagy-specific markers by biochemical, molecular, and histological assays in peripheral
blood and labial gland biopsies. Serum interleukin (IL)-23 and IL-21 levels were quantified by enzyme-linked
immunosorbent assay.
Results: Our study provides evidence for the first time that autophagy is upregulated in CD4+ T lymphocyte salivary
glands from pSS patients. Furthermore, a statistically significant correlation was detected between lymphocyte
autophagy levels, disease activity, and damage indexes. We also found a positive correlation between autophagy
enhancement and the increased salivary gland expression of IL-21 and IL-23, providing a further link between innate
and adaptive immune responses in pSS.
Conclusions: These findings suggest that CD4+ T lymphocyte autophagy could play a key role in pSS pathogenesis.
Additionally, our data highlight the potential exploitation of T cell autophagy as a biomarker of disease activity and
provide new ground to verify the therapeutic implications of autophagy as an innovative drug target in pSS
Altered balance of interleukin-13/interferon-gamma contributes to lacrimal gland destruction and secretory dysfunction in CD25 knockout model of Sjögrenâs syndrome
Indium Tin Oxide@Carbon CoreâShell Nanowire and Jagged Indium Tin Oxide Nanowire
This paper reports two new indium tin oxide (ITO)-based nanostructures, namely ITO@carbon coreâshell nanowire and jagged ITO nanowire. The ITO@carbon coreâshell nanowires (~50 nm in diameter, 1â5 ÎŒm in length,) were prepared by a chemical vapor deposition process from commercial ITO nanoparticles. A carbon overlayer (~5â10 in thickness) was observed around ITO nanowire core, which was in situ formed by the catalytic decomposition of acetylene gas. This carbon overlayer could be easily removed after calcination in air at an elevated temperature of 700°C, thus forming jagged ITO nanowires (~40â45 nm in diameter). The growth mechanisms of ITO@carbon coreâshell nanowire and jagged ITO nanowire were also suggested
Tear proteomic analysis of Sjogren syndrome patients with dry eye syndrome by two-dimensional-nano-liquid chromatography coupled with tandem mass spectrometry
We examined the tear film proteome of patients with Sjögren's syndrome (SS) and dry eye syndrome (group A), patients with dry eye symptoms (group B) and normal volunteers (group C). Tear samples were pooled from 8 subjects from each group and were subjected to two-dimensional-nano-liquid chromatography coupled with tandem mass spectrometry (2D-nano-LC-MS/MS). The tear breakup time for group A was significantly reduced compared with group B and C (P < 0.001). Group A (Schirmer I test, 2.13 +/- 2.38 mm/5 min) had markedly lower tear volume than group B (5.94 +/- 4.75 mm/5 min) and C (14.44 +/- 6.57 mm/5 min) (P < 0.001). Group A had significantly higher normalized tear protein content (1.8291 +/- 0.2241 mu g/mm) than group B (1.0839 +/- 0.1120 mu g/mm) (P = 0.001) and C (0.2028 +/- 0.0177 mu g/mm) (P = 0.001). The 2D-nano-LC-MS/MS analysis identified a total of 435 proteins, including 182 (54.8%),247 (74.4%) and 278 (83.7%) in group A, B, and C, respectively, with 56 (16.7%) proteins including defensin alpha 1, clusterin and lactotransferrin unique to group A. In conclusion, dry eye syndrome in SS patients is associated with an altered proteomic profile with dysregulated expression of proteins involved in a variety of important cellular process including inflammation, immunity, and oxidative stress
Rheological and biological properties of a hydrogel support for cells intended for intervertebral disc repair
<p>Abstract</p> <p>Background</p> <p>Cell-based approaches towards restoration of prolapsed or degenerated intervertebral discs are hampered by a lack of measures for safe administration and placement of cell suspensions within a treated disc. In order to overcome these risks, a serum albumin-based hydrogel has been developed that polymerizes after injection and anchors the administered cell suspension within the tissue.</p> <p>Methods</p> <p>A hydrogel composed of chemically activated albumin crosslinked by polyethylene glycol spacers was produced. The visco-elastic gel properties were determined by rheological measurement. Human intervertebral disc cells were cultured <it>in vitro </it>and <it>in vivo </it>in the hydrogel and their phenotype was tested by reverse-transcriptase polymerase chain reaction. Matrix production and deposition was monitored by immuno-histology and by biochemical analysis of collagen and glycosaminoglycan deposition. Species specific <it>in situ </it>hybridization was performed to discriminate between cells of human and murine origin in xenotransplants.</p> <p>Results</p> <p>The reproducibility of the gel formation process could be demonstrated. The visco-elastic properties were not influenced by storage of gel components. <it>In vitro </it>and <it>in vivo </it>(subcutaneous implants in mice) evidence is presented for cellular differentiation and matrix deposition within the hydrogel for human intervertebral disc cells even for donor cells that have been expanded in primary monolayer culture, stored in liquid nitrogen and re-activated in secondary monolayer culture. Upon injection into the animals, gels formed spheres that lasted for the duration of the experiments (14 days). The expression of cartilage- and disc-specific mRNAs was maintained in hydrogels <it>in vitro </it>and <it>in vivo</it>, demonstrating the maintenance of a stable specific cellular phenotype, compared to monolayer cells. Significantly higher levels of hyaluronan synthase isozymes-2 and -3 mRNA suggest cell functionalities towards those needed for the support of the regeneration of the intervertebral disc. Moreover, mouse implanted hydrogels accumulated 5 times more glycosaminoglycans and 50 times more collagen than the <it>in vitro </it>cultured gels, the latter instead releasing equivalent quantities of glycosaminoglycans and collagen into the culture medium. Matrix deposition could be specified by immunohistology for collagen types I and II, and aggrecan and was found only in areas where predominantly cells of human origin were detected by species specific <it>in situ </it>hybridization.</p> <p>Conclusions</p> <p>The data demonstrate that the hydrogels form stable implants capable to contain a specifically functional cell population within a physiological environment.</p
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