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result(s) for
"Renwick, Neil"
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Dysregulation of microRNA-219 promotes neurodegeneration through post-transcriptional regulation of tau
by
Cela, Carolina
,
Fulga, Tudor A.
,
McCabe, Brian D.
in
3' Untranslated Regions
,
Alzheimer Disease - genetics
,
Alzheimer Disease - metabolism
2015
Tau is a highly abundant and multifunctional brain protein that accumulates in neurofibrillary tangles (NFTs), most commonly in Alzheimer's disease (AD) and primary age-related tauopathy. Recently, microRNAs (miRNAs) have been linked to neurodegeneration; however, it is not clear whether miRNA dysregulation contributes to tau neurotoxicity. Here, we determined that the highly conserved brain miRNA miR-219 is downregulated in brain tissue taken at autopsy from patients with AD and from those with severe primary age-related tauopathy. In a Drosophila model that produces human tau, reduction of miR-219 exacerbated tau toxicity, while overexpression of miR-219 partially abrogated toxic effects. Moreover, we observed a bidirectional modulation of tau levels in the Drosophila model that was dependent on miR-219 expression or neutralization, demonstrating that miR-219 regulates tau in vivo. In mammalian cellular models, we found that miR-219 binds directly to the 3'-UTR of the tau mRNA and represses tau synthesis at the post-transcriptional level. Together, our data indicate that silencing of tau by miR-219 is an ancient regulatory mechanism that may become perturbed during neurofibrillary degeneration and suggest that this regulatory pathway may be useful for developing therapeutics for tauopathies.
Journal Article
Topology preserving stratification of tissue neoplasticity using Deep Neural Maps and microRNA signatures
2022
Background
Accurate cancer classification is essential for correct treatment selection and better prognostication. microRNAs (miRNAs) are small RNA molecules that negatively regulate gene expression, and their dyresgulation is a common disease mechanism in many cancers. Through a clearer understanding of miRNA dysregulation in cancer, improved mechanistic knowledge and better treatments can be sought.
Results
We present a topology-preserving deep learning framework to study miRNA dysregulation in cancer. Our study comprises miRNA expression profiles from 3685 cancer and non-cancer tissue samples and hierarchical annotations on organ and neoplasticity status. Using unsupervised learning, a two-dimensional topological map is trained to cluster similar tissue samples. Labelled samples are used after training to identify clustering accuracy in terms of tissue-of-origin and neoplasticity status. In addition, an approach using activation gradients is developed to determine the attention of the networks to miRNAs that drive the clustering. Using this deep learning framework, we classify the neoplasticity status of held-out test samples with an accuracy of 91.07%, the tissue-of-origin with 86.36%, and combined neoplasticity status and tissue-of-origin with an accuracy of 84.28%. The topological maps display the ability of miRNAs to recognize tissue types and neoplasticity status. Importantly, when our approach identifies samples that do not cluster well with their respective classes, activation gradients provide further insight in cancer subtypes or grades.
Conclusions
An unsupervised deep learning approach is developed for cancer classification and interpretation. This work provides an intuitive approach for understanding molecular properties of cancer and has significant potential for cancer classification and treatment selection.
Journal Article
Deep sequencing reveals distinct microRNA-mRNA signatures that differentiate pancreatic neuroendocrine tumor from non-diseased pancreas tissue
by
Matyasovska, N
,
Valkova, N
,
Gala, M
in
Biomarkers
,
Biomarkers, Tumor - genetics
,
Biomedical and Life Sciences
2025
Background
Only a limited number of biomarkers guide personalized management of pancreatic neuroendocrine tumors (PanNETs). Transcriptome profiling of microRNA (miRs) and mRNA has shown value in segregating PanNETs and identifying patients more likely to respond to treatment. Because miRs are key regulators of mRNA expression, we sought to integrate expression data from both RNA species into miR-mRNA interaction networks to advance our understanding of PanNET biology.
Methods
We used deep miR/mRNA sequencing on six low-grade/high-risk, well-differentiated PanNETs compared with seven non-diseased tissues to identify differentially expressed miRs/mRNAs. Then we crossed a list of differentially expressed mRNAs with a list of in silico predicted mRNA targets of the most and least abundant miRs to generate high probability miR-mRNA interaction networks.
Results
Gene ontology and pathway analyses revealed several miR-mRNA pairs implicated in cellular processes and pathways suggesting perturbed neuroendocrine function (miR-7 and
Reg
family genes), cell adhesion (miR-216 family and
NLGN1
,
NCAM1
, and
CNTN1
; miR-670 and the claudins,
CLDN1
and
CLDN2
), and metabolic processes (miR-670 and
BCAT1
/
MPST
; miR-129 and
CTH
).
Conclusion
These novel miR-mRNA interaction networks identified dysregulated pathways not observed when assessing mRNA alone and provide a foundation for further investigation of their utility as diagnostic and predictive biomarkers.
Journal Article
MicroRNAs MiR-17, MiR-20a, and MiR-106b Act in Concert to Modulate E2F Activity on Cell Cycle Arrest during Neuronal Lineage Differentiation of USSC
by
Iwaniuk, Katharina M.
,
Tuschl, Thomas
,
Renwick, Neil
in
Apoptosis
,
Biocompatibility
,
Bioinformatics
2011
MicroRNAs are short (∼22 nt) non-coding regulatory RNAs that control gene expression at the post-transcriptional level. Here the functional impact of microRNAs on cell cycle arrest during neuronal lineage differentiation of unrestricted somatic stem cells from human cord blood (USSC) was analyzed.
Expression profiling revealed downregulation of microRNAs miR-17, -20a, and -106b in USSC differentiated into neuronal lineage but not in USSC differentiated into osteogenic lineage. Transfection experiments followed by Ki67 immunostainings demonstrated that each of these microRNAs was able to promote proliferation of native USSC and to prevent in part cell cycle arrest during neuronal lineage differentiation of USSC. Bioinformatic target gene predictions followed by experimental target gene validations revealed that miR-17, -20a, and -106b act in a common manner by downregulating an overlapping set of target genes mostly involved in regulation and execution of G(1)/S transition. Pro-proliferative target genes cyclinD1 (CCND1) and E2F1 as well as anti-proliferative targets CDKN1A (p21), PTEN, RB1, RBL1 (p107), RBL2 (p130) were shown as common targets for miR-17, -20a, and -106b. Furthermore, these microRNAs also downregulate WEE1 which is involved in G(2)/M transition. Most strikingly, miR-17, -20a, and -106b were found to promote cell proliferation by increasing the intracellular activity of E2F transcription factors, despite the fact that miR-17, -20a, and -106b directly target the transcripts that encode for this protein family.
Mir-17, -20a, and -106b downregulate a common set of pro- and anti-proliferative target genes to impact cell cycle progression of USSC and increase intracellular activity of E2F transcription factors to govern G(1)/S transition.
Journal Article
Emerging Evidence of Noncoding RNAs in Bleb Scarring after Glaucoma Filtration Surgery
2022
Purpose: To conduct a narrative review of research articles on the potential anti- and pro-fibrotic mechanisms of noncoding RNAs following glaucoma filtration surgery. Methods: Keyword searches of PubMed, and Medline databases were conducted for articles discussing post-glaucoma filtration surgeries and noncoding RNA. Additional manual searches of reference lists of primary articles were performed. Results: Fifteen primary research articles were identified. Four of the included papers used microarrays and qRT-PCR to identify up- or down-regulated microRNA (miRNA, miR) profiles and direct further study, with the remainder focusing on miRNAs or long noncoding RNAs (lncRNAs) based on previous work in other organs or disease processes. The results of the reviewed papers identified miR-26a, -29b, -139, -155, and -200a as having anti-fibrotic effects. In contrast, miRs-200b and -216b may play pro-fibrotic roles in filtration surgery fibrosis. lncRNAs including H19, NR003923, and 00028 have demonstrated pro-fibrotic effects. Conclusions: Noncoding RNAs including miRNAs and lncRNAs are emerging and promising therapeutic targets in the prevention of post-glaucoma filtration surgery fibrosis.
Journal Article
A miR-375/YAP axis regulates neuroendocrine differentiation and tumorigenesis in lung carcinoid cells
by
Wang, Xiantao
,
Yang, Xiaolong
,
Nanayakkara, Jina
in
631/337/384/331
,
631/67/1459/1963
,
Adaptor Proteins, Signal Transducing - genetics
2021
Lung carcinoids are variably aggressive and mechanistically understudied neuroendocrine neoplasms (NENs). Here, we identified and elucidated the function of a miR-375/yes-associated protein (YAP) axis in lung carcinoid (H727) cells. miR-375 and
YAP
are respectively high and low expressed in wild-type H727 cells. Following lentiviral CRISPR/Cas9-mediated miR-375 depletion, we identified distinct transcriptomic changes including dramatic YAP upregulation. We also observed a significant decrease in neuroendocrine differentiation and substantial reductions in cell proliferation, transformation, and tumor growth in cell culture and xenograft mouse disease models. Similarly, YAP overexpression resulted in distinct and partially overlapping transcriptomic changes, phenocopying the effects of miR-375 depletion in the same models as above. Transient YAP knockdown in miR-375-depleted cells reversed the effects of miR-375 on neuroendocrine differentiation and cell proliferation. Pathways analysis and confirmatory real-time PCR studies of shared dysregulated target genes indicate that this axis controls neuroendocrine related functions such as neural differentiation, exocytosis, and secretion. Taken together, we provide compelling evidence that a miR-375/YAP axis is a critical mediator of neuroendocrine differentiation and tumorigenesis in lung carcinoid cells.
Journal Article
China's Approach to International Development: A Study of Southeast Asia
2015
China is establishing itself as a new international aid donor. This study explains China's emerging approach to international development assistance. The paper addresses the question of how far China's understanding of \"development\" is an appropriate basis for genuinely \"win-win\" relationships? The paper explores this question by examining China's relationship with Southeast Asia. China is re-emphasising its commitment and partnership credentials with neighbouring states, some of whom have many people living in poverty and as countries are in need of development assistance. The paper identifies key facets of China's approach to international development, examines economic, political and strategic factors underpinning China's approach in Southeast Asia. Adopting a Human Security perspective, it assesses China's development contribution with reference to Cambodia, Laos and Myanmar and highlights popular opposition. The study finds that Chinese trade and investment are making a significant contribution to the region's economic growth. However, the analysis identifies two problems in China's approach, an over-reliance on the level of state-to-state relations and too narrow a domain of engagement centred upon economic cooperation. China needs to incorporate a societal engagement strategy highlighting transparency and accountability of Chinese corporate behaviour. It also needs to re-balance its approach by emphasising human capital capability and capacity-building across the non-economic social and cultural domains. China's approach to international development is a rapid learning process and is emerging, but still has further to go.
Journal Article
Adult-onset autosomal dominant spastic paraplegia linked to a GTPase-effector domain mutation of dynamin 2
by
Osakovskiy, Vladimir L.
,
Ylakhova, Anastasia N.
,
Hinshaw, Jenny E.
in
Adult
,
Care and treatment
,
Development and progression
2015
Background
Hereditary Spastic Paraplegia (HSP) represents a large group of clinically and genetically heterogeneous disorders linked to over 70 different loci and more than 60 recognized disease-causing genes. A heightened vulnerability to disruption of various cellular processes inherent to the unique function and morphology of corticospinal neurons may account, at least in part, for the genetic heterogeneity.
Methods
Whole exome sequencing was utilized to identify candidate genetic variants in a four-generation Siberian kindred that includes nine individuals showing clinical features of HSP. Segregation of candidate variants within the family yielded a disease-associated mutation. Functional as well as
in-silico
structural analyses confirmed the selected candidate variant to be causative.
Results
Nine known patients had young-adult onset of bilateral slowly progressive lower-limb spasticity, weakness and hyperreflexia progressing over two-to-three decades to wheel-chair dependency. In the advanced stage of the disease, some patients also had distal wasting of lower leg muscles,
pes cavus
, mildly decreased vibratory sense in the ankles, and urinary urgency along with electrophysiological evidence of a mild distal motor/sensory axonopathy. Molecular analyses uncovered a missense c.2155C > T, p.R719W mutation in the highly conserved GTP-effector domain of dynamin 2. The mutant
DNM2
co-segregated with HSP and affected endocytosis when expressed in HeLa cells.
In-silico
modeling indicated that this HSP-associated dynamin 2 mutation is located in a highly conserved bundle-signaling element of the protein while dynamin 2 mutations associated with other disorders are located in the stalk and PH domains; p.R719W potentially disrupts dynamin 2 assembly.
Conclusion
This is the first report linking a mutation in dynamin 2 to a HSP phenotype. Dynamin 2 mutations have previously been associated with other phenotypes including two forms of Charcot-Marie-Tooth neuropathy and centronuclear myopathy. These strikingly different pathogenic effects may depend on structural relationships the mutations disrupt. Awareness of this distinct association between HSP and c.2155C > T, p.R719W mutation will facilitate ascertainment of additional
DNM2
HSP families and will direct future research toward better understanding of cell biological processes involved in these partly overlapping clinical syndromes.
Journal Article
A Computational Approach to Identification of Candidate Biomarkers in High-Dimensional Molecular Data
by
Gerolami, Justin
,
Glasgow, Janice Irene
,
Jamaspishvili, Tamara
in
Accuracy
,
Algorithms
,
big data analysis
2022
Complex high-dimensional datasets that are challenging to analyze are frequently produced through ‘-omics’ profiling. Typically, these datasets contain more genomic features than samples, limiting the use of multivariable statistical and machine learning-based approaches to analysis. Therefore, effective alternative approaches are urgently needed to identify features-of-interest in ‘-omics’ data. In this study, we present the molecular feature selection tool, a novel, ensemble-based, feature selection application for identifying candidate biomarkers in ‘-omics’ data. As proof-of-principle, we applied the molecular feature selection tool to identify a small set of immune-related genes as potential biomarkers of three prostate adenocarcinoma subtypes. Furthermore, we tested the selected genes in a model to classify the three subtypes and compared the results to models built using all genes and all differentially expressed genes. Genes identified with the molecular feature selection tool performed better than the other models in this study in all comparison metrics: accuracy, precision, recall, and F1-score using a significantly smaller set of genes. In addition, we developed a simple graphical user interface for the molecular feature selection tool, which is available for free download. This user-friendly interface is a valuable tool for the identification of potential biomarkers in gene expression datasets and is an asset for biomarker discovery studies.
Journal Article
Genetic fitness and selection intensity in a population affected with high-incidence spinocerebellar ataxia type 1
by
Neustroyeva, Tatyana S.
,
Sidorova, Oksana G.
,
Yakovleva, Natalya V.
in
Adult
,
Aged
,
Aged, 80 and over
2016
Spinocerebellar ataxia type 1 (SCA1) is the major and likely the only type of autosomal dominant cerebellar ataxia in the Sakha (Yakut) people of Eastern Siberia. The prevalence rate of SCA1 has doubled over the past 21 years peaking at 46 cases per 100,000 rural population. The age at death correlates closely with the number of CAG triplet repeats in the mutant
ATXN1
gene (
r
= −0.81); most patients with low-medium (39–55) repeat numbers survived until the end of reproductive age. The number of CAG repeats expands in meiosis, particularly in paternal transmissions; the average total increase in intergenerational transmissions in our cohort was estimated at 1.6 CAG repeats. The fertility rates of heterozygous carriers of 39–55 CAG repeats in women were no different from those of the general Sakha population. Overall, the survival of mutation carriers through reproductive age, unaltered fertility rates, low childhood mortality in SCA1-affected families, and intergenerational transmission of increasing numbers of CAG repeats in the
ATXN1
gene indicate that SCA1 in the Sakha population will be maintained at high prevalence levels. The low (0.19) Crow’s index of total selection intensity in our SCA1 cohort implies that this mutation is unlikely to be eliminated through natural selection alone.
Journal Article