46 results on '"Minaidou, A."'
Search Results
2. Evaluation of in silico predictors on short nucleotide variants in HBA1, HBA2, and HBB associated with haemoglobinopathies
- Author
-
Stella Tamana, Maria Xenophontos, Anna Minaidou, Coralea Stephanou, Cornelis L Harteveld, Celeste Bento, Joanne Traeger-Synodinos, Irene Fylaktou, Norafiza Mohd Yasin, Faidatul Syazlin Abdul Hamid, Ezalia Esa, Hashim Halim-Fikri, Bin Alwi Zilfalil, Andrea C Kakouri, ClinGen Hemoglobinopathy Variant Curation Expert Panel, Marina Kleanthous, and Petros Kountouris
- Subjects
variant classification ,in silico prediction ,haemoglobinopathies ,globin genes ,thalassaemia ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Haemoglobinopathies are the commonest monogenic diseases worldwide and are caused by variants in the globin gene clusters. With over 2400 variants detected to date, their interpretation using the American College of Medical Genetics and Genomics (ACMG)/Association for Molecular Pathology (AMP) guidelines is challenging and computational evidence can provide valuable input about their functional annotation. While many in silico predictors have already been developed, their performance varies for different genes and diseases. In this study, we evaluate 31 in silico predictors using a dataset of 1627 variants in HBA1, HBA2, and HBB. By varying the decision threshold for each tool, we analyse their performance (a) as binary classifiers of pathogenicity and (b) by using different non-overlapping pathogenic and benign thresholds for their optimal use in the ACMG/AMP framework. Our results show that CADD, Eigen-PC, and REVEL are the overall top performers, with the former reaching moderate strength level for pathogenic prediction. Eigen-PC and REVEL achieve the highest accuracies for missense variants, while CADD is also a reliable predictor of non-missense variants. Moreover, SpliceAI is the top performing splicing predictor, reaching strong level of evidence, while GERP++ and phyloP are the most accurate conservation tools. This study provides evidence about the optimal use of computational tools in globin gene clusters under the ACMG/AMP framework.
- Published
- 2022
- Full Text
- View/download PDF
3. P128: ITHANET: AN INFORMATION AND DATABASE COMMUNITY PORTAL FOR HAEMOGLOBINOPATHIES
- Author
-
A Minaidou, C Stephanou, S Tamana, M Xenophontos, C Lederer, P Kountouris, and M Kleanthous
- Subjects
Diseases of the blood and blood-forming organs ,RC633-647.5 - Published
- 2022
- Full Text
- View/download PDF
4. LRSAM1 Depletion Affects Neuroblastoma SH-SY5Y Cell Growth and Morphology: The LRSAM1 c.2047-1G>A Loss-of- Function Variant Fails to Rescue The Phenotype
- Author
-
Anna Minaidou, Paschalis Nicolaou, and Kyproula Christodoulou
- Subjects
LRSAM1 ,RING Domain ,Cell Growth ,Medicine ,Science - Abstract
Objective Deleterious variants in LRSAM1, a RING finger ubiquitin ligase which is also known as TSG101-associated ligase (TAL), have recently been associated with Charcot-Marie-Tooth disease type 2P (CMT2P). The mechanism by which mutant LRSAM1 contributes to the development of neuropathy is currently unclear. The aim of this study was to induce LRSAM1 deficiency in a neuronal cell model, observe its effect on cell growth and morphology and attempt to rescue the phenotype with ancestral and mutant LRSAM1 transfections. Materials and Methods In this experimental study, we investigated the effect of LRSAM1 downregulation on neuroblastoma SH-SY5Y cells by siRNA technology where cells were transfected with siRNA against LRSAM1. The effects on the expression levels of TSG101, the only currently known LRSAM1 interacting molecule, were also examined. An equal dosage of ancestral or mutant LRSAM1 construct was transfected in LRSAM1-downregulated cells to investigate its effect on the phenotype of the cells and whether cell proliferation and morphology could be rescued. Results A significant reduction in TSG101 levels was observed with the downregulation of LRSAM1. In addition, LRSAM1 knockdown significantly decreased the growth rate of SH-SY5Y cells which is caused by a decrease in cell proliferation. An effect on cell morphology was also observed. Furthermore, we overexpressed the ancestral and the c.2047-1G>A mutant LRSAM1 in knocked down cells. Ancestral LRSAM1 recovered cell proliferation and partly the morphology, however, the c.2047-1G>A mutant did not recover cell proliferation and further aggravated the observed changes in cell morphology. Conclusion Our findings suggest that depletion of LRSAM1 affects neuroblastoma cells growth and morphology and that overexpression of the c.2047-1G>A mutant form, unlike the ancestral LRSAM1, fails to rescue the phenotype.
- Published
- 2018
- Full Text
- View/download PDF
5. IthaPhen: An Interactive Database of Genotype-Phenotype Data for Hemoglobinopathies
- Author
-
Xenophontos, Maria, primary, Minaidou, Anna, additional, Stephanou, Coralea, additional, Tamana, Stella, additional, Kleanthous, Marina, additional, and Kountouris, Petros, additional
- Published
- 2023
- Full Text
- View/download PDF
6. Deregulation of LRSAM1 expression impairs the levels of TSG101, UBE2N, VPS28, MDM2 and EGFR.
- Author
-
Anna Minaidou, Paschalis Nicolaou, and Kyproula Christodoulou
- Subjects
Medicine ,Science - Abstract
CMT is the most common hereditary neuromuscular disorder of the peripheral nervous system with a prevalence of 1/2500 individuals and it is caused by mutations in more than 80 genes. LRSAM1, a RING finger ubiquitin ligase also known as TSG101-associated ligase (TAL), has been associated with Charcot-Marie-Tooth disease type 2P (CMT2P) and to date eight causative mutations have been identified. Little is currently known on the pathogenetic mechanisms that lead to the disease. We investigated the effect of LRSAM1 deregulation on possible LRSAM1 interacting molecules in cell based models. Possible LRSAM1 interacting molecules were identified using protein-protein interaction databases and literature data. Expression analysis of these molecules was performed in both CMT2P patient and control lymphoblastoid cell lines as well as in LRSAM1 and TSG101 downregulated SH-SY5Y cells.TSG101, UBE2N, VPS28, EGFR and MDM2 levels were significantly decreased in the CMT2P patient lymphoblastoid cell line as well as in LRSAM1 downregulated cells. TSG101 downregulation had a significant effect only on the expression of VPS28 and MDM2 and it did not affect the levels of LRSAM1. This study confirms that LRSAM1 is a regulator of TSG101 expression. Furthermore, deregulation of LRSAM1 significantly affects the levels of UBE2N, VPS28, EGFR and MDM2.
- Published
- 2019
- Full Text
- View/download PDF
7. A novel tool for the analysis and detection of copy number variants associated with haemoglobinopathies
- Author
-
Anna Minaidou, Stella Tamana, Coralea Stephanou, Maria Xenophontos, Cornelis L. Harteveld, Celeste Bento, Marina Kleanthous, and Petros Kountouris
- Subjects
Genome ,haemoglobinopathies ,copy number variants (CNVs) ,MLPA ,DNA Copy Number Variations ,Organic Chemistry ,DNA ,Genomics ,General Medicine ,Catalysis ,Computer Science Applications ,Inorganic Chemistry ,Humans ,Physical and Theoretical Chemistry ,Multiplex Polymerase Chain Reaction ,Molecular Biology ,Spectroscopy - Abstract
Several types of haemoglobinopathies are caused by copy number variants (CNVs). While diagnosis is often based on haematological and biochemical parameters, a definitive diagnosis requires molecular DNA analysis. In some cases, the molecular characterisation of large deletions/duplications is challenging and inconclusive and often requires the use of specific diagnostic procedures, such as multiplex ligation-dependent probe amplification (MLPA). Herein, we collected and comprehensively analysed all known CNVs associated with haemoglobinopathies. The dataset of 291 CNVs was retrieved from the IthaGenes database and was further manually annotated to specify genomic locations, breakpoints and MLPA probes relevant for each CNV. We developed IthaCNVs, a publicly available and easy-to-use online tool that can facilitate the diagnosis of rare and diagnostically challenging haemoglobinopathy cases attributed to CNVs. Importantly, it facilitates the filtering of available entries based on the type of breakpoint information, on specific chromosomal and locus positions, on MLPA probes, and on affected gene(s). IthaCNVs brings together manually curated information about CNV genomic locations, functional effects, and information that can facilitate CNV characterisation through MLPA. It can help laboratory staff and clinicians confirm suspected diagnosis of CNVs based on molecular DNA screening and analysis.
- Published
- 2022
- Full Text
- View/download PDF
8. A Novel Tool for the Analysis and Detection of Copy Number Variants Associated with Haemoglobinopathies
- Author
-
Minaidou, Anna, primary, Tamana, Stella, additional, Stephanou, Coralea, additional, Xenophontos, Maria, additional, Harteveld, Cornelis L., additional, Bento, Celeste, additional, Kleanthous, Marina, additional, and Kountouris, Petros, additional
- Published
- 2022
- Full Text
- View/download PDF
9. Differential Expression of β-Catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in Intestinal and Pancreatobiliary-Type Ampullary Carcinomas
- Author
-
Perysinakis, Iraklis, Minaidou, Emilia, Leontara, Vasileia, Mantas, Dimitrios, Sotiropoulos, Georgios C., Tsipras, Hercules, Zografos, George N., Margaris, Ilias, and Kouraklis, Gregory
- Published
- 2017
- Full Text
- View/download PDF
10. P128: ITHANET: AN INFORMATION AND DATABASE COMMUNITY PORTAL FOR HAEMOGLOBINOPATHIES
- Author
-
Minaidou, A, primary, Stephanou, C, additional, Tamana, S, additional, Xenophontos, M, additional, Lederer, C, additional, Kountouris, P, additional, and Kleanthous, M, additional
- Published
- 2022
- Full Text
- View/download PDF
11. Evaluation of in silico predictors on short nucleotide variants in HBA1, HBA2, and HBB associated with haemoglobinopathies.
- Author
-
Tamana, Stella, Xenophontos, Maria, Minaidou, Anna, Stephanou, Coralea, Harteveld, Cornelis L., Bento, Celeste, Traeger-Synodinos, Joanne, Fylaktou, Irene, Yasin, Norafiza Mohd, Abdul Hamid, Faidatul Syazlin, Esa, Ezalia, Halim-Fikri, Hashim, Zilfalil, Bin Alwi, and Kakouri, Andrea C.
- Published
- 2022
- Full Text
- View/download PDF
12. Κλινική Εκπαίδευση Λογοθεραπείας: H εμπειρία του Τεχνολογικού Πανεπιστημίου Κύπρου
- Author
-
Binos, Paris, Charalambous, Marina, and Despo Minaidou
- Published
- 2021
- Full Text
- View/download PDF
13. A novel SLC30A10 missense variant associated with parkinsonism and dystonia without hypermanganesemia
- Author
-
Lambrianides, Sakis, Nicolaou, Paschalis, Michaelidou, Mikaela, Kakouris, Panos, Votsi, Christina, Petrou, Petros P., Drousiotou, Anthi, Minaidou, Anna, Demetriou, Praxitelis, Voulgaris, Costas, Christodoulou, Kyproula, Tanteles, George A., and Pantzaris, Marios
- Published
- 2020
- Full Text
- View/download PDF
14. Auditory- Verbal Therapy: A Systematic Review for the Effectiveness of Intervention in Children with Hearing Loss
- Author
-
Binos, Paris, Charalambous, Marina, and Minaidou, Despo
- Subjects
AVT ,Health Sciences ,Cochlear implants ,Medical and Health Sciences ,Hearing impairment - Abstract
This systematic review was designed to investigate the effectiveness of auditory-verbal therapy (AVT) based on recent research findings of the literature. AVT is seen today as the primary treatment approach for developing spoken language in children with cochlear implants despite the debate about educational options for these children. The AVT effectiveness should be examined by systematic reviews. The present review was conducted following PRISMA guidelines (preferred reporting items for systematic reviews). Search terms were chosen based on the research question and used in a search in PubMed/Medline. Last decade’s published peer-reviewed papers meeting inclusion criteria were reviewed. The reviewed articles measured many levels of language development and parent’s use of alternative communication models. The result of this review reveals AVT as an important clinical approach that improves young cochlear implant (CI) children to outperform peers in bilingual-bicultural programs in receptive vocabulary and speech perception or at the least be at a similar level on speech, language and self-esteem. Other aspects related with voice seemed also benefited, placing young CIs in the normal range for receptive vocabulary development. Less improvement noted in the area of reading. AVT approach can positively assist infants develop spoken language and support full integration into mainstream society despite the limited evidences presented. This position is supported by research findings of young CIs comparable to their hearing peers. Overall studies suggest AVT as a positive clinical approach for spoken language of young CIs and provide evidences that there is no advantage for the use of other alternative communication models before or after CI.
- Published
- 2020
15. A novel SLC30A10 missense variant associated with parkinsonism and dystonia without hypermanganesemia
- Author
-
Sakis Lambrianides, Anna Minaidou, George A. Tanteles, Costas Voulgaris, Marios Pantzaris, Petros Petrou, Praxitelis Demetriou, Anthi Drousiotou, Panos Kakouris, Kyproula Christodoulou, Mikaela Michaelidou, Christina Votsi, and Paschalis Nicolaou
- Subjects
Dystonia ,medicine.medical_specialty ,business.industry ,Parkinsonism ,Mutation, Missense ,medicine.disease ,Gastroenterology ,Neurology ,Parkinsonian Disorders ,Dystonic Disorders ,Internal medicine ,Missense mutation ,Medicine ,Humans ,Neurology (clinical) ,business - Published
- 2020
16. Neurobiological Bases of Autism Spectrum Disorders and Implications for Early Intervention: A Brief Overview
- Author
-
Despo Minaidou and Kakia Petinou
- Subjects
Risk ,Linguistics and Language ,Joint attention ,genetic structures ,Autism Spectrum Disorder ,Child Behavior ,Fixation, Ocular ,Early intervention ,Medical and Health Sciences ,behavioral disciplines and activities ,050105 experimental psychology ,Language and Linguistics ,Social Skills ,03 medical and health sciences ,Speech and Hearing ,0302 clinical medicine ,Neurobiology ,Social neuroscience ,Intervention (counseling) ,Early Intervention, Educational ,medicine ,Humans ,Attention ,Interpersonal Relations ,0501 psychology and cognitive sciences ,Autism spectrum disorder ,05 social sciences ,Brain morphometry ,Brain ,Infant ,LPN and LVN ,medicine.disease ,Social relation ,Early Diagnosis ,Child, Preschool ,Infant Behavior ,Eye tracking ,Autism ,Clinical Medicine ,Psychology ,Eye gaze ,030217 neurology & neurosurgery ,Cognitive psychology - Abstract
Objectives: To better understand the pathogenesis of autism spectrum disorder (ASD) and implications for intervention, the current paper reports on research related to the neurobiological underpinnings of ASD and the implication for early intervention with a focus on the importance of joint attention and eye gaze behaviors. Participants and Methods: An overview is provided on the available research findings from the fields of social neuroscience and experimental psychology specific to brain development, brain pathology, eye gaze, and joint attention behaviors. Results: The results of the review converge towards the existence of aberrant brain connections and atypical brain morphology areas, which in complex and dynamic ways hinder the prioritization of social information. Consequently, the atypical social interaction skills exhibited by infants at risk for developing ASD are traced in the malformation of respective brain connections. Conclusions: Given the importance of neurobiological findings and their mapping onto early social pragmatic skills, early intervention goals need to focus on increasing appropriate eye gaze skills and joint attention. Such goals could potentially improve intervention outcomes in terms of improving social communication skills in youngsters with ASD.
- Published
- 2017
- Full Text
- View/download PDF
17. Deregulation of LRSAM1 expression impairs the levels of TSG101, UBE2N, VPS28, MDM2 and EGFR
- Author
-
Minaidou A, Nicolaou P, and Christodoulou K
- Abstract
CMT is the most common hereditary neuromuscular disorder of the peripheral nervous system with a prevalence of 1/2500 individuals and it is caused by mutations in more than 80 genes. LRSAM1, a RING finger ubiquitin ligase also known as TSG101-associated ligase (TAL), has been associated with Charcot-Marie-Tooth disease type 2P (CMT2P) and to date eight causative mutations have been identified. Little is currently known on the pathogenetic mechanisms that lead to the disease. We investigated the effect of LRSAM1 deregulation on possible LRSAM1 interacting molecules in cell based models. Possible LRSAM1 interacting molecules were identified using protein-protein interaction databases and literature data. Expression analysis of these molecules was performed in both CMT2P patient and control lymphoblastoid cell lines as well as in LRSAM1 and TSG101 downregulated SH-SY5Y cells.TSG101, UBE2N, VPS28, EGFR and MDM2 levels were significantly decreased in the CMT2P patient lymphoblastoid cell line as well as in LRSAM1 downregulated cells. TSG101 downregulation had a significant effect only on the expression of VPS28 and MDM2 and it did not affect the levels of LRSAM1. This study confirms that LRSAM1 is a regulator of TSG101 expression. Furthermore, deregulation of LRSAM1 significantly affects the levels of UBE2N, VPS28, EGFR and MDM2.
- Published
- 2019
18. Genetic Modifiers at the Crossroads of Personalised Medicine for Haemoglobinopathies
- Author
-
Coralea Stephanou, Marina Kleanthous, Petros Kountouris, Stella Tamana, Anna Minaidou, and Panayiota Papasavva
- Subjects
Candidate gene ,Vascular Endothelial Growth Factor Receptor ,thalassaemia ,lcsh:Medicine ,Disease ,Computational biology ,Article ,haemoglobinopathies ,03 medical and health sciences ,0302 clinical medicine ,gene modifiers ,Gene ranking ,Medicine ,Cytokine signalling ,030304 developmental biology ,protein network ,0303 health sciences ,business.industry ,lcsh:R ,biomarkers ,General Medicine ,Gene Annotation ,Phenotype ,3. Good health ,gene ranking ,030220 oncology & carcinogenesis ,Urea cycle ,sickle cell disease ,business - Abstract
Haemoglobinopathies are common monogenic disorders with diverse clinical manifestations, partly attributed to the influence of modifier genes. Recent years have seen enormous growth in the amount of genetic data, instigating the need for ranking methods to identify candidate genes with strong modifying effects. Here, we present the first evidence-based gene ranking metric (IthaScore) for haemoglobinopathy-specific phenotypes by utilising curated data in the IthaGenes database. IthaScore successfully reflects current knowledge for well-established disease modifiers, while it can be dynamically updated with emerging evidence. Protein&ndash, protein interaction (PPI) network analysis and functional enrichment analysis were employed to identify new potential disease modifiers and to evaluate the biological profiles of selected phenotypes. The most relevant gene ontology (GO) and pathway gene annotations for (a) haemoglobin (Hb) F levels/Hb F response to hydroxyurea included urea cycle, arginine metabolism and vascular endothelial growth factor receptor (VEGFR) signalling, (b) response to iron chelators included xenobiotic metabolism and glucuronidation, and (c) stroke included cytokine signalling and inflammatory reactions. Our findings demonstrate the capacity of IthaGenes, together with dynamic gene ranking, to expand knowledge on the genetic and molecular basis of phenotypic variation in haemoglobinopathies and to identify additional candidate genes to potentially inform and improve diagnosis, prognosis and therapeutic management.
- Published
- 2019
- Full Text
- View/download PDF
19. PDXK mutations cause polyneuropathy responsive to pyridoxal 5'-phosphate supplementation
- Author
-
Chelban, V., Wilson, M. P., Warman Chardon, J., Vandrovcova, J., Zanetti, M. N., Zamba-Papanicolaou, E., Efthymiou, S., Pope, S., Conte, M. R., Abis, G., Liu, Y. -T., Tribollet, E., Haridy, N. A., Botia, J. A., Ryten, M., Nicolaou, P., Minaidou, A., Christodoulou, K., Kernohan, K. D., Eaton, A., Osmond, M., Ito, Y., Bourque, P., Jepson, J. E. C., Bello, O., Bremner, F., Cordivari, C., Reilly, M. M., Foiani, M., Heslegrave, A., Zetterberg, H., Heales, S. J. R., Wood, N. W., Rothman, J. E., Boycott, K. M., Mills, P. B., Clayton, P. T., Houlden, H., Kriouile, Y., Khorassani, M. E., Aguennouz, M., Groppa, S., Marinova Karashova, B., Van Maldergem, L., Nachbauer, W., Boesch, S., Arning, L., Timmann, D., Cormand, B., Perez-Duenas, B., Di Rosa, G., Goraya, J. S., Sultan, T., Mine, J., Avdjieva, D., Kathom, H., Tincheva, R., Banu, S., Pineda-Marfa, M., Veggiotti, P., Ferrari, M. D., van den Maagdenberg, A. M. J. M., Verrotti, A., Marseglia, G., Savasta, S., Garcia-Silva, M., Ruiz, A. M., Garavaglia, B., Borgione, E., Portaro, S., Sanchez, B. M., Boles, R., Papacostas, S., Vikelis, M., Giunti, P., Salpietro, V., Oconnor, E., Kullmann, D., Kaiyrzhanov, R., Sullivan, R., Khan, A. M., Yau, W. Y., Hostettler, I., Papanicolaou, E. Z., Dardiotis, E., Maqbool, S., Ibrahim, S., Kirmani, S., Rana, N. N., Atawneh, O., Lim, S. -Y., Shaikh, F., Koutsis, G., Breza, M., Mangano, S., Scuderi, C., Morello, G., Stojkovic, T., Torti, E., Zollo, M., Heimer, G., Dauvilliers, Y. A., Striano, P., Al-Khawaja, I., Al-Mutairi, F., Alkuraya, F. S., Sherifa, H., Rizig, M., Okubadejo, N. U., Ojo, O. O., Oshinaike, O. O., Wahab, K., Bello, A. H., Abubakar, S., Obiabo, Y., Nwazor, E., Ekenze, O., Williams, U., Iyagba, A., Taiwo, L., Komolafe, M., Oguntunde, O., Pchelina, S., Senkevich, K., Shashkin, C., Zharkynbekova, N., Koneyev, K., Manizha, G., Isrofilov, M., Guliyeva, U., Salayev, K., Khachatryan, S., Rossi, S., Silvestri, Gabriella, Bourinaris, T., Xiromerisiou, G., Fidani, L., Spanaki, C., Tucci, A., Silvestri G. (ORCID:0000-0002-1950-1468), Chelban, V., Wilson, M. P., Warman Chardon, J., Vandrovcova, J., Zanetti, M. N., Zamba-Papanicolaou, E., Efthymiou, S., Pope, S., Conte, M. R., Abis, G., Liu, Y. -T., Tribollet, E., Haridy, N. A., Botia, J. A., Ryten, M., Nicolaou, P., Minaidou, A., Christodoulou, K., Kernohan, K. D., Eaton, A., Osmond, M., Ito, Y., Bourque, P., Jepson, J. E. C., Bello, O., Bremner, F., Cordivari, C., Reilly, M. M., Foiani, M., Heslegrave, A., Zetterberg, H., Heales, S. J. R., Wood, N. W., Rothman, J. E., Boycott, K. M., Mills, P. B., Clayton, P. T., Houlden, H., Kriouile, Y., Khorassani, M. E., Aguennouz, M., Groppa, S., Marinova Karashova, B., Van Maldergem, L., Nachbauer, W., Boesch, S., Arning, L., Timmann, D., Cormand, B., Perez-Duenas, B., Di Rosa, G., Goraya, J. S., Sultan, T., Mine, J., Avdjieva, D., Kathom, H., Tincheva, R., Banu, S., Pineda-Marfa, M., Veggiotti, P., Ferrari, M. D., van den Maagdenberg, A. M. J. M., Verrotti, A., Marseglia, G., Savasta, S., Garcia-Silva, M., Ruiz, A. M., Garavaglia, B., Borgione, E., Portaro, S., Sanchez, B. M., Boles, R., Papacostas, S., Vikelis, M., Giunti, P., Salpietro, V., Oconnor, E., Kullmann, D., Kaiyrzhanov, R., Sullivan, R., Khan, A. M., Yau, W. Y., Hostettler, I., Papanicolaou, E. Z., Dardiotis, E., Maqbool, S., Ibrahim, S., Kirmani, S., Rana, N. N., Atawneh, O., Lim, S. -Y., Shaikh, F., Koutsis, G., Breza, M., Mangano, S., Scuderi, C., Morello, G., Stojkovic, T., Torti, E., Zollo, M., Heimer, G., Dauvilliers, Y. A., Striano, P., Al-Khawaja, I., Al-Mutairi, F., Alkuraya, F. S., Sherifa, H., Rizig, M., Okubadejo, N. U., Ojo, O. O., Oshinaike, O. O., Wahab, K., Bello, A. H., Abubakar, S., Obiabo, Y., Nwazor, E., Ekenze, O., Williams, U., Iyagba, A., Taiwo, L., Komolafe, M., Oguntunde, O., Pchelina, S., Senkevich, K., Shashkin, C., Zharkynbekova, N., Koneyev, K., Manizha, G., Isrofilov, M., Guliyeva, U., Salayev, K., Khachatryan, S., Rossi, S., Silvestri, Gabriella, Bourinaris, T., Xiromerisiou, G., Fidani, L., Spanaki, C., Tucci, A., and Silvestri G. (ORCID:0000-0002-1950-1468)
- Abstract
Objective: To identify disease-causing variants in autosomal recessive axonal polyneuropathy with optic atrophy and provide targeted replacement therapy. Methods: We performed genome-wide sequencing, homozygosity mapping, and segregation analysis for novel disease-causing gene discovery. We used circular dichroism to show secondary structure changes and isothermal titration calorimetry to investigate the impact of variants on adenosine triphosphate (ATP) binding. Pathogenicity was further supported by enzymatic assays and mass spectroscopy on recombinant protein, patient-derived fibroblasts, plasma, and erythrocytes. Response to supplementation was measured with clinical validated rating scales, electrophysiology, and biochemical quantification. Results: We identified biallelic mutations in PDXK in 5 individuals from 2 unrelated families with primary axonal polyneuropathy and optic atrophy. The natural history of this disorder suggests that untreated, affected individuals become wheelchair-bound and blind. We identified conformational rearrangement in the mutant enzyme around the ATP-binding pocket. Low PDXK ATP binding resulted in decreased erythrocyte PDXK activity and low pyridoxal 5′-phosphate (PLP) concentrations. We rescued the clinical and biochemical profile with PLP supplementation in 1 family, improvement in power, pain, and fatigue contributing to patients regaining their ability to walk independently during the first year of PLP normalization. Interpretation: We show that mutations in PDXK cause autosomal recessive axonal peripheral polyneuropathy leading to disease via reduced PDXK enzymatic activity and low PLP. We show that the biochemical profile can be rescued with PLP supplementation associated with clinical improvement. As B6 is a cofactor in diverse essential biological pathways, our findings may have direct implications for neuropathies of unknown etiology characterized by reduced PLP levels. ANN NEUROL 2019;86:225–240.
- Published
- 2019
20. Differentiation and prognostic markers in ampullary cancer: Role of p53, MDM2, CDX2, mucins and cytokeratins
- Author
-
Emilia Minaidou, Dimitrios Mantas, Iraklis Perysinakis, Ilias Margaris, George C. Sotiropoulos, Hercules Tsipras, George N Zografos, Gregory Kouraklis, and Vasileia Leontara
- Subjects
Adult ,Male ,Ampulla of Vater ,medicine.medical_specialty ,Pathology ,Multivariate analysis ,Adolescent ,Common Bile Duct Neoplasms ,Kaplan-Meier Estimate ,Adenocarcinoma ,Gastroenterology ,Pathology and Forensic Medicine ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Biomarkers, Tumor ,medicine ,Humans ,CDX2 Transcription Factor ,Stage (cooking) ,CDX2 ,Survival rate ,MUC1 ,Survival analysis ,Aged ,Proportional Hazards Models ,Aged, 80 and over ,business.industry ,Mucin ,Mucins ,Cell Differentiation ,Proto-Oncogene Proteins c-mdm2 ,Cell Biology ,Middle Aged ,Prognosis ,Immunohistochemistry ,digestive system diseases ,030220 oncology & carcinogenesis ,Keratins ,Female ,030211 gastroenterology & hepatology ,Tumor Suppressor Protein p53 ,business - Abstract
Introduction Subclassification of ampullary adenocarcinomas into intestinal and pancreatobiliary type has prognostic and therapeutic implications. Immunohistochemical staining against specific biomarkers has been proven to be a useful adjunct in determining the exact histotype. Furthermore the immunohistochemical profile is suggestive of the molecular pathogenic mechanisms through which the tumor evolved. The aim of this study was to correlate p53, MDM2, CK7, CK20, MUC1, MUC2 and CDX2 expression in ampullary adenocarcinomas with the type of differentiation and patients’ survival. Material and methods Forty-seven radically resected ampullary adenocarcinomas were included in this study. Thirty-eight of them were eligible for survival analysis. Patients’ data were retrospectively collected. All tumors were classified as intestinal or pancreatobiliary type, according to histologic criteria, and immunohistochemically stained against the aforementioned markers. Results There were 18 intestinal and 29 pancreatobiliary type ampullary adenocarcinomas. A trend was found between intestinal type tumors and large tumor size. CK20, MUC2 and CDX2 expression was more prevalent in intestinal type tumors, while MUC1 was more frequently expressed in pancreatobiliary type tumors. Neither p53 nor MDM2 differential expression between the two histotypes reached statistical significance. Multivariate analysis indicated CK20 and MUC1 as independent predictors of the histotype. Mean and median survival was 90.3 and 55 months respectively. Overall 5-year survival rate was 48%. Survival analysis indicated TNM stage as the only independent prognostic factor. Although significant difference in survival rates among the two histotypes was implied based on survival plots, this difference could not gain statistical significance. Conclusion Immunoreactivity against CK20 and MUC1 in ampullary carcinomas is a useful adjunct to histologic examination in determining histotype. None of the immunohistochemical markers studied has prognostic significance. Future studies focused on other signaling pathways should seek further evidence of distinct tumorigenic mechanisms between histotypes of ampullary adenocarcinoma.
- Published
- 2016
- Full Text
- View/download PDF
21. Differential Expression of β-Catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in Intestinal and Pancreatobiliary-Type Ampullary Carcinomas
- Author
-
Emilia Minaidou, Gregory Kouraklis, Ilias Margaris, Georgios C. Sotiropoulos, Vasileia Leontara, Iraklis Perysinakis, Dimitrios Mantas, George N Zografos, and Hercules Tsipras
- Subjects
Adult ,Male ,Ampulla of Vater ,Pathology ,medicine.medical_specialty ,Adolescent ,Common Bile Duct Neoplasms ,Kaplan-Meier Estimate ,Keratin-20 ,Adenocarcinoma ,Biology ,Pathology and Forensic Medicine ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Biomarkers, Tumor ,medicine ,Humans ,CDX2 Transcription Factor ,Differential expression ,CDX2 ,beta Catenin ,MUC1 ,Aged ,Proportional Hazards Models ,Aged, 80 and over ,Mucin-2 ,Keratin-7 ,Mucin-1 ,Ampullary Adenocarcinoma ,Middle Aged ,Prognosis ,Immunohistochemistry ,Peptide Fragments ,digestive system diseases ,ErbB Receptors ,030220 oncology & carcinogenesis ,Catenin ,Female ,030211 gastroenterology & hepatology ,Surgery ,Anatomy - Abstract
Introduction: The purpose of this study was to associate immunohistochemical expression of β-catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in ampullary adenocarcinomas with the type of differentiation and prognosis. Methods: Forty-seven patients with ampullary adenocarcinoma who underwent pancreatoduodenectomy with curative intent from 1997 to 2014 were included in this study. Nine patients with perioperative death were included in the association analysis but excluded from survival analysis. All tumors were classified as intestinal or pancreatobiliary type, according to histologic criteria, and immunohistochemically stained against the aforementioned markers. Results: Eighteen carcinomas were classified as intestinal type and 29 carcinomas as pancreatobiliary type. Univariate analysis revealed that CK20 and CDX2 expression correlates with intestinal type, whereas MUC1 positivity indicates pancreatobiliary type. A marginally significant trend was shown for intestinal-type tumors toward larger size and more frequent MUC2 expression. Using multivariate analysis CK20 ( P = .003) and MUC1 ( P = .004) were identified as independent predictors of the intestinal and pancreatobiliary types, respectively. Mean and median survival was 90.3 and 55 months, respectively. Overall 5-year survival rate was 48%. On univariate survival analysis, overall survival was adversely influenced by the number of infiltrated lymph nodes, elevated Ca19-9 serum levels, jaundice, poor differentiation, T4 stage, N1 stage, TNM stage III, and CDX2 immunonegativity. Multivariate analysis identified TNM stage as the only independent prognostic factor in ampullary adenocarcinoma ( P = .048). Conclusions: Immunoreactivity against CK20 and MUC1 in ampullary carcinomas is a useful adjunct to histologic examination in determining histotype. None of the immunohistochemical markers studied had prognostic significance.
- Published
- 2016
- Full Text
- View/download PDF
22. Deregulation of LRSAM1 expression impairs the levels of TSG101, UBE2N, VPS28, MDM2 and EGFR
- Author
-
Paschalis Nicolaou, Anna Minaidou, and Kyproula Christodoulou
- Subjects
0301 basic medicine ,Peripheral neuropathy ,Regulator ,Molecular biology assays and analysis techniques ,Biochemistry ,Ligases ,0302 clinical medicine ,Ubiquitin ,Gene expression ,TSG101 ,Small interfering RNAs ,Post-Translational Modification ,chemistry.chemical_classification ,0303 health sciences ,Multidisciplinary ,Nucleic acid analysis ,biology ,Proto-Oncogene Proteins c-mdm2 ,Transfection ,RNA analysis ,Enzymes ,3. Good health ,Ubiquitin ligase ,DNA-Binding Proteins ,ErbB Receptors ,Nucleic acids ,medicine.anatomical_structure ,Neurology ,Medicine ,Mdm2 ,Research Article ,Genetic diseases ,Ubiquitin-Protein Ligases ,Science ,Research and Analysis Methods ,Charcot-Marie-Tooth disease ,03 medical and health sciences ,Downregulation and upregulation ,Cell Line, Tumor ,Genetics ,Ring finger ,medicine ,Humans ,Clinical genetics ,Non-coding RNA ,Molecular Biology Techniques ,Protein Interactions ,Molecular Biology ,Gene ,030304 developmental biology ,Medicine and health sciences ,DNA ligase ,Endosomal Sorting Complexes Required for Transport ,Biology and life sciences ,Ubiquitination ,Proteins ,Gene regulation ,Neuropathy ,030104 developmental biology ,Gene Expression Regulation ,chemistry ,Protein-Protein Interactions ,Ubiquitin-Conjugating Enzymes ,Enzymology ,biology.protein ,Cancer research ,RNA ,030217 neurology & neurosurgery ,Transcription Factors - Abstract
CMT is the most common hereditary neuromuscular disorder of the peripheral nervous system with a prevalence of 1/2500 individuals and it is caused by mutations in more than 80 genes. LRSAM1, a RING finger ubiquitin ligase also known as TSG101-associated ligase (TAL), has been associated with Charcot-Marie-Tooth disease type 2P (CMT2P) and to date eight causative mutations have been identified. Little is currently known on the pathogenetic mechanisms that lead to the disease. We investigated the effect of LRSAM1 deregulation on possible LRSAM1 interacting molecules in cell based models. Possible LRSAM1 interacting molecules were identified using protein-protein interaction databases and literature data. Expression analysis of these molecules was performed in both CMT2P patient and control lymphoblastoid cell lines as well as in LRSAM1 and TSG101 downregulated SH-SY5Y cells.TSG101, UBE2N, VPS28, EGFR and MDM2 levels were significantly decreased in the CMT2P patient lymphoblastoid cell line as well as in LRSAM1 downregulated cells. TSG101 downregulation had a significant effect only on the expression of VPS28 and MDM2 and it did not affect the levels of LRSAM1. This study confirms that LRSAM1 is a regulator of TSG101 expression. Furthermore, deregulation of LRSAM1 significantly affects the levels of UBE2N, VPS28, EGFR and MDM2.
- Published
- 2018
- Full Text
- View/download PDF
23. Genetic Modifiers at the Crossroads of Personalised Medicine for Haemoglobinopathies
- Author
-
Stephanou, Coralea, primary, Tamana, Stella, additional, Minaidou, Anna, additional, Papasavva, Panayiota, additional, Kleanthous, Marina, additional, and Kountouris, Petros, additional
- Published
- 2019
- Full Text
- View/download PDF
24. The ITHANET-Human Variome Project: Moving Functional Annotation Forward
- Author
-
Kountouris, Petros, primary, Stephanou, Coralea, additional, Lederer, Carsten W., additional, Tamana, Stella, additional, Minaidou, Anna, additional, Xenophontos, Maria, additional, Angastiniotis, Michael, additional, Eleftheriou, Androulla, additional, Zilfalil, Bin Alwi, additional, Ramesar, Raj S., additional, Elion, Jacques, additional, Robinson, Helen M., additional, and Kleanthous, Marina, additional
- Published
- 2019
- Full Text
- View/download PDF
25. ITHANET: An Information and Database Community Portal for Hemoglobinopathies
- Author
-
Stephanou, Coralea, primary, Kountouris, Petros, additional, Tamana, Stella, additional, Minaidou, Anna, additional, Lederer, Carsten W., additional, and Kleanthous, Marina, additional
- Published
- 2019
- Full Text
- View/download PDF
26. Deregulation of LRSAM1 expression impairs the levels of TSG101, UBE2N, VPS28, MDM2 and EGFR
- Author
-
Minaidou, Anna, primary, Nicolaou, Paschalis, additional, and Christodoulou, Kyproula, additional
- Published
- 2019
- Full Text
- View/download PDF
27. Metastasis to the ovary as an initial manifestation of a primary tumour: Report of two cases
- Author
-
Emilia Minaidou
- Published
- 2017
- Full Text
- View/download PDF
28. Adenosarcoma of the uterus: A case report
- Author
-
Emilia Minaidou
- Published
- 2017
- Full Text
- View/download PDF
29. Teratoma with malignant transformation: Review of three cases
- Author
-
Emilia Minaidou
- Published
- 2017
- Full Text
- View/download PDF
30. Immature teratoma: Review of five cases
- Author
-
Emilia Minaidou
- Published
- 2017
- Full Text
- View/download PDF
31. Differential Expression of beta-Catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in Intestinal and Pancreatobiliary-Type Ampullary Carcinomas
- Author
-
Perysinakis, Iraklis Minaidou, Emilia Leontara, Vasileia and Mantas, Dimitrios Sotiropoulos, Georgios C. Tsipras, Hercules and Zografos, George N. Margaris, Ilias Kouraklis, Gregory
- Subjects
digestive system diseases - Abstract
Introduction: The purpose of this study was to associate immunohistochemical expression of -catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in ampullary adenocarcinomas with the type of differentiation and prognosis. Methods: Forty-seven patients with ampullary adenocarcinoma who underwent pancreatoduodenectomy with curative intent from 1997 to 2014 were included in this study. Nine patients with perioperative death were included in the association analysis but excluded from survival analysis. All tumors were classified as intestinal or pancreatobiliary type, according to histologic criteria, and immunohistochemically stained against the aforementioned markers. Results: Eighteen carcinomas were classified as intestinal type and 29 carcinomas as pancreatobiliary type. Univariate analysis revealed that CK20 and CDX2 expression correlates with intestinal type, whereas MUC1 positivity indicates pancreatobiliary type. A marginally significant trend was shown for intestinal-type tumors toward larger size and more frequent MUC2 expression. Using multivariate analysis CK20 (P = .003) and MUC1 (P = .004) were identified as independent predictors of the intestinal and pancreatobiliary types, respectively. Mean and median survival was 90.3 and 55 months, respectively. Overall 5-year survival rate was 48%. On univariate survival analysis, overall survival was adversely influenced by the number of infiltrated lymph nodes, elevated Ca19-9 serum levels, jaundice, poor differentiation, T4 stage, N1 stage, TNM stage III, and CDX2 immunonegativity. Multivariate analysis identified TNM stage as the only independent prognostic factor in ampullary adenocarcinoma (P = .048). Conclusions: Immunoreactivity against CK20 and MUC1 in ampullary carcinomas is a useful adjunct to histologic examination in determining histotype. None of the immunohistochemical markers studied had prognostic significance.
- Published
- 2017
32. 272 Inherited peripheral neuropathies: analysis of PDXK gene identifies a new treatable disorder
- Author
-
Stephanie Efthymiou, Pierre R. Bourque, Oscar D. Bello, Maria R. Conte, Mina Ryten, Yo-Tsen Liu, Kristin D. Kernohan, Simon Heales, Fion Bremner, Kyproula Christodoulou, Simon Pope, Juan A. Botía, Henry Houlden, Martha S. Foiani, Mary M. Reilly, Paschalis Nicolaou, Nicholas W. Wood, Yoko Ito, Carla Cordivari, Matthew Osmond, Matthew P. Wilson, Jodi Warman Chardon, Eleni Zamba-Papanicolaou, Peter E. Clayton, Eloise Tribollet, Anna Minaidou, James E. Rothman, Henrik Zetterberg, M. Natalia Zanetti, Viorica Chelban, Alison Eaton, Jana Vandrovcova, Kym M. Boycott, Philippa B. Mills, Giancarlo Abis, James E.C. Jepson, Amanda Heslegrave, and Nourelhoda A Haridy
- Subjects
Mutation ,Kinase ,medicine.disease ,medicine.disease_cause ,Molecular biology ,Pyridoxal kinase ,law.invention ,Psychiatry and Mental health ,chemistry.chemical_compound ,Atrophy ,chemistry ,law ,medicine ,Recombinant DNA ,Biomarker (medicine) ,Surgery ,Neurology (clinical) ,Pyridoxal ,Gene - Abstract
Polyneuropathies are amongst the most common neurological conditions worldwide affecting over 20 million people. However, 40% of patients with primary polyneuropathies have no disease-causing mutation identified.We investigated patients with gene-negative primary polyneuropathies using a combination of whole genome sequencing, homozigosity mapping and segregation analysis. Pathogenicity was confirmed via enzymatic assays and mass spectroscopy on recombinant protein and patient-derived fibroblasts, plasma and erythrocytes. We used circular dichroism to show secondary structure changes and isothermal titration calorimetry to investigate the ATP binding.We report that biallelic mutations in human PDXK are associated with primary axonal polyneuropathy and optic atrophy. Pyridoxal kinase (PDXK) is involved in converting vitamin B6 to its active form, pyridoxal 5’-phosphate (PLP). We show that PDXK mutations lead to disease via decreased plasma PLP concentrations. Our functional studies revealed conformational rearrangement in the mutant enzyme around the kinase ATP-binding pocket with impaired PDXK ability to bind ATP and leading to reduced erythrocyte PDXK activity. We show that both the human clinical picture and biochemical profile in PDXK mutations are rescued by PLP supplementation. Patients regained their ability to walk independently. Furthermore, treatment-led normalisation of plasma PLP levels, correlated with reduction of neurofilament light chain concentrations, a biomarker of axonal breakdown.In conclusion, biallelic mutations in human PDXK are associated with a novel disorder leading to treatable primary axonal polyneuropathy and optic atrophy and identifies PLP as therapeutic target.
- Published
- 2019
- Full Text
- View/download PDF
33. The ITHANET-Human Variome Project: Moving Functional Annotation Forward
- Author
-
Stella Tamana, Androulla Eleftheriou, Maria Xenophontos, Helen M. Robinson, Petros Kountouris, Michael Angastiniotis, Marina Kleanthous, Anna Minaidou, Bin Alwi Zilfalil, Coralea Stephanou, Jacques Elion, Raj Ramesar, and Carsten W. Lederer
- Subjects
World Wide Web ,Functional annotation ,Computer science ,education ,Biochemistry (medical) ,Clinical Biochemistry ,Human Variome Project ,Hematology ,Genetics (clinical) - Abstract
Hemoglobinopathies are the most common monogenic diseases, with millions of carriers and patients worldwide. Online resources for hemoglobinopathies are largely divided into specialized sites cater...
- Published
- 2019
- Full Text
- View/download PDF
34. ITHANET: An Information and Database Community Portal for Hemoglobinopathies
- Author
-
Coralea Stephanou, Petros Kountouris, Marina Kleanthous, Carsten W. Lederer, Stella Tamana, and Anna Minaidou
- Subjects
World Wide Web ,Text mining ,business.industry ,Computer science ,Biochemistry (medical) ,Clinical Biochemistry ,Hematology ,business ,Genetics (clinical) - Published
- 2019
- Full Text
- View/download PDF
35. Deregulation of LRSAM1 expression impairs the levels of TSG101, UBE2N, VPS28, MDM2 and EGFR
- Author
-
Minaidou, Anna, primary, Nicolaou, Paschalis, additional, and Christodoulou, Kyproula, additional
- Published
- 2018
- Full Text
- View/download PDF
36. Differentiation and prognostic markers in ampullary cancer: Role of p53, MDM2, CDX2, mucins and cytokeratins
- Author
-
Perysinakis, Iraklis Minaidou, Emilia Mantas, Dimitrios and Sotiropoulos, George C. Leontara, Vasileia Tsipras, Hercules and Zografos, George N. Margaris, Ilias Kouraklis, Gregory
- Subjects
digestive system diseases - Abstract
Introduction: Subclassification of ampullary adenocarcinomas into intestinal and pancreatobiliary type has prognostic and therapeutic implications. Immunohistochemical staining against specific biomarkers has been proven to be a useful adjunct in determining the exact histotype. Furthermore the immunohistochemical profile is suggestive of the molecular pathogenic mechanisms through which the tumor evolved. The aim of this study was to correlate p53, MDM2, CK7, CK20, MUC1, MUC2 and CDX2 expression in ampullary adenocarcinomas with the type of differentiation and patients’ survival. Material and methods: Forty-seven radically resected ampullary adenocarcinomas were included in this study. Thirty-eight of them were eligible for survival analysis. Patients’ data were retrospectively collected. All tumors were classified as intestinal or pancreatobiliary type, according to histologic criteria, and immunohistochemically stained against the aforementioned markers. Results: There were 18 intestinal and 29 pancreatobiliary type ampullary adenocarcinomas. A trend was found between intestinal type tumors and large tumor size. CK20, MUC2 and CDX2 expression was more prevalent in intestinal type tumors, while MUC1 was more frequently expressed in pancreatobiliary type tumors. Neither p53 nor MDM2 differential expression between the two histotypes reached statistical significance. Multivariate analysis indicated CK20 and MUC1 as independent predictors of the histotype. Mean and median survival was 90.3 and 55 months respectively. Overall 5-year survival rate was 48%. Survival analysis indicated TNM stage as the only independent prognostic factor. Although significant difference in survival rates among the two histotypes was implied based on survival plots, this difference could not gain statistical significance. Conclusion: Immunoreactivity against CK20 and MUC1 in ampullary carcinomas is a useful adjunct to histologic examination in determining histotype. None of the immunohistochemical markers studied has prognostic significance. Future studies focused on other signaling pathways should seek further evidence of distinct tumorigenic mechanisms between histotypes of ampullary adenocarcinoma. (C) 2016 Elsevier GmbH. All rights reserved.
- Published
- 2016
37. Adenosarcoma of the uterus: A case report
- Author
-
Minaidou, Emilia, primary
- Published
- 2017
- Full Text
- View/download PDF
38. Teratoma with malignant transformation: Review of three cases
- Author
-
Minaidou, Emilia, primary
- Published
- 2017
- Full Text
- View/download PDF
39. Metastasis to the ovary as an initial manifestation of a primary tumour: Report of two cases
- Author
-
Minaidou, Emilia, primary
- Published
- 2017
- Full Text
- View/download PDF
40. Immature teratoma: Review of five cases
- Author
-
Minaidou, Emilia, primary
- Published
- 2017
- Full Text
- View/download PDF
41. PDXK mutations cause polyneuropathy responsive to pyridoxal 5'-phosphate supplementation.
- Author
-
Chelban, Viorica, Wilson, Matthew P., Warman Chardon, Jodi, Vandrovcova, Jana, Zanetti, M. Natalia, Zamba‐Papanicolaou, Eleni, Efthymiou, Stephanie, Pope, Simon, Conte, Maria R., Abis, Giancarlo, Liu, Yo‐Tsen, Tribollet, Eloise, Haridy, Nourelhoda A., Botía, Juan A., Ryten, Mina, Nicolaou, Paschalis, Minaidou, Anna, Christodoulou, Kyproula, Kernohan, Kristin D., and Eaton, Alison
- Subjects
LEBER'S hereditary optic atrophy ,RECESSIVE genes ,ISOTHERMAL titration calorimetry ,NATURAL history ,COFACTORS (Biochemistry) ,MASS spectrometry ,ETIOLOGY of diseases ,CIRCULAR dichroism ,RESEARCH ,GENETIC mutation ,RESEARCH methodology ,EVALUATION research ,MEDICAL cooperation ,VITAMIN B complex ,DIETARY supplements ,TREATMENT effectiveness ,COMPARATIVE studies ,POLYNEUROPATHIES ,TRANSFERASES ,MOLECULAR structure - Abstract
Objective: To identify disease-causing variants in autosomal recessive axonal polyneuropathy with optic atrophy and provide targeted replacement therapy.Methods: We performed genome-wide sequencing, homozygosity mapping, and segregation analysis for novel disease-causing gene discovery. We used circular dichroism to show secondary structure changes and isothermal titration calorimetry to investigate the impact of variants on adenosine triphosphate (ATP) binding. Pathogenicity was further supported by enzymatic assays and mass spectroscopy on recombinant protein, patient-derived fibroblasts, plasma, and erythrocytes. Response to supplementation was measured with clinical validated rating scales, electrophysiology, and biochemical quantification.Results: We identified biallelic mutations in PDXK in 5 individuals from 2 unrelated families with primary axonal polyneuropathy and optic atrophy. The natural history of this disorder suggests that untreated, affected individuals become wheelchair-bound and blind. We identified conformational rearrangement in the mutant enzyme around the ATP-binding pocket. Low PDXK ATP binding resulted in decreased erythrocyte PDXK activity and low pyridoxal 5'-phosphate (PLP) concentrations. We rescued the clinical and biochemical profile with PLP supplementation in 1 family, improvement in power, pain, and fatigue contributing to patients regaining their ability to walk independently during the first year of PLP normalization.Interpretation: We show that mutations in PDXK cause autosomal recessive axonal peripheral polyneuropathy leading to disease via reduced PDXK enzymatic activity and low PLP. We show that the biochemical profile can be rescued with PLP supplementation associated with clinical improvement. As B6 is a cofactor in diverse essential biological pathways, our findings may have direct implications for neuropathies of unknown etiology characterized by reduced PLP levels. ANN NEUROL 2019;86:225-240. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
42. Differentiation and prognostic markers in ampullary cancer: Role of p53, MDM2, CDX2, mucins and cytokeratins
- Author
-
Perysinakis, Iraklis, primary, Minaidou, Emilia, additional, Mantas, Dimitrios, additional, Sotiropoulos, George C., additional, Leontara, Vasileia, additional, Tsipras, Hercules, additional, Zografos, George N., additional, Margaris, Ilias, additional, and Kouraklis, Gregory, additional
- Published
- 2016
- Full Text
- View/download PDF
43. Differential Expression of β-Catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in Intestinal and Pancreatobiliary-Type Ampullary Carcinomas
- Author
-
Perysinakis, Iraklis, primary, Minaidou, Emilia, additional, Leontara, Vasileia, additional, Mantas, Dimitrios, additional, Sotiropoulos, Georgios C., additional, Tsipras, Hercules, additional, Zografos, George N., additional, Margaris, Ilias, additional, and Kouraklis, Gregory, additional
- Published
- 2016
- Full Text
- View/download PDF
44. LRSAM1 Depletion Affects Neuroblastoma SH-SY5Y Cell Growth and Morphology: The LRSAM1 c.2047-1G>A Loss-of-Function Variant Fails to Rescue The Phenotype.
- Author
-
Minaidou, Anna, Nicolaou, Paschalis, and Christodoulou, Kyproula
- Subjects
- *
UBIQUITIN ligases , *CHARCOT-Marie-Tooth disease , *CELL growth , *CELL morphology , *NEUROBLASTOMA , *SMALL interfering RNA , *CELL proliferation - Abstract
Objective: Deleterious variants in LRSAM1, a RING finger ubiquitin ligase which is also known as TSG101-associated ligase (TAL), have recently been associated with Charcot-Marie-Tooth disease type 2P (CMT2P). The mechanism by which mutant LRSAM1 contributes to the development of neuropathy is currently unclear. The aim of this study was to induce LRSAM1 deficiency in a neuronal cell model, observe its effect on cell growth and morphology and attempt to rescue the phenotype with ancestral and mutant LRSAM1 transfections. Materials and Methods: In this experimental study, we investigated the effect of LRSAM1 downregulation on neuroblastoma SH-SY5Y cells by siRNA technology where cells were transfected with siRNA against LRSAM1. The effects on the expression levels of TSG101, the only currently known LRSAM1 interacting molecule, were also examined. An equal dosage of ancestral or mutant LRSAM1 construct was transfected in LRSAM1-downregulated cells to investigate its effect on the phenotype of the cells and whether cell proliferation and morphology could be rescued. Results: A significant reduction in TSG101 levels was observed with the downregulation of LRSAM1. In addition, LRSAM1 knockdown significantly decreased the growth rate of SH-SY5Y cells which is caused by a decrease in cell proliferation. An effect on cell morphology was also observed. Furthermore, we overexpressed the ancestral and the c.2047-1G>A mutant LRSAM1 in knocked down cells. Ancestral LRSAM1 recovered cell proliferation and partly the morphology, however, the c.2047-1G>A mutant did not recover cell proliferation and further aggravated the observed changes in cell morphology. Conclusion: Our findings suggest that depletion of LRSAM1 affects neuroblastoma cells growth and morphology and that overexpression of the c.2047-1G>A mutant form, unlike the ancestral LRSAM1, fails to rescue the phenotype. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
45. Neurobiological Bases of Autism Spectrum Disorders and Implications for Early Intervention: A Brief Overview.
- Author
-
Petinou, Kakia and Minaidou, Despo
- Subjects
- *
TREATMENT of autism , *ATTENTION , *BRAIN , *INTERPERSONAL relations , *NEUROBIOLOGY , *EARLY medical intervention - Abstract
Objectives: To better understand the pathogenesis of autism spectrum disorder (ASD) and implications for intervention, the current paper reports on research related to the neurobiological underpinnings of ASD and the implication for early intervention with a focus on the importance of joint attention and eye gaze behaviors. Participants and Methods: An overview is provided on the available research findings from the fields of social neuroscience and experimental psychology specific to brain development, brain pathology, eye gaze, and joint attention behaviors. Results: The results of the review converge towards the existence of aberrant brain connections and atypical brain morphology areas, which in complex and dynamic ways hinder the prioritization of social information. Consequently, the atypical social interaction skills exhibited by infants at risk for developing ASD are traced in the malformation of respective brain connections. Conclusions: Given the importance of neurobiological findings and their mapping onto early social pragmatic skills, early intervention goals need to focus on increasing appropriate eye gaze skills and joint attention. Such goals could potentially improve intervention outcomes in terms of improving social communication skills in youngsters with ASD. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
46. 15.09 Inherited peripheral neuropathies: analysis of PDXK gene identifies a new treatable disorder
- Author
-
Chelban, Viorica, Wilson, Matthew P, Chardon, Jodi Warman, Vandrovcova, Jana, Natalia Zanetti, M, Zamba-Papanicolaou, Eleni, Efthymiou, Stephanie, Pope, Simon, Conte, Maria R, Abis, Giancarlo, Liu, Yo-Tsen, Tribollet, Eloise, Haridy, Nourelhoda A, Botía, Juan A, Ryten, Mina, Nicolaou, Paschalis, Minaidou, Anna, Christodoulou, Kyproula, Kernohan, Kristin D, Eaton, Alison, Osmond, Matthew, Ito, Yoko, Bourque, Pierre, Jepson, James EC, Bello, Oscar, Bremner, Fion, Cordivari, Carla, Reilly, Mary M, Foiani, Martha, Heslegrave, Amanda, Zetterberg, Henrik, Heales, Simon JR, Wood, Nicholas W, Rothman, James E, Boycott, Kym M, Mills, Philippa B, Clayton, Peter T, and Houlden, Henry
- Abstract
Polyneuropathies are amongst the most common neurological conditions worldwide affecting over 20 million people. However, 40% of patients with primary polyneuropathies have no disease-causing mutation identified.We investigated patients with gene-negative primary polyneuropathies using a combination of whole genome sequencing, homozygosity mapping and segregation analysis. Pathogenicity was confirmed via enzymatic assays and mass spectroscopy on recombinant protein and patient-derived fibroblasts, plasma and erythrocytes. We used circular dichroism to show secondary structure changes and isothermal titration calorimetry to investigate the ATP binding.We report that biallelic mutations in human PDXK are associated with primary axonal polyneuropathy and optic atrophy. Pyridoxal kinase (PDXK) is involved in converting vitamin B6 to its active form, pyridoxal 5’-phosphate (PLP). We show that PDXK mutations lead to disease via decreased plasma PLP concentrations. Our functional studies revealed conformational rearrangement in the mutant enzyme around the kinase ATP-binding pocket with impaired PDXK ability to bind ATP and leading to reduced erythrocyte PDXK activity. We show that both the human clinical picture and biochemical profile in PDXK mutations are rescued by PLP supplementation. Patients regained their ability to walk independently. Furthermore, treatment-led normalisation of plasma PLP levels, correlated with reduction of neurofilament light chain concentrations, a biomarker of axonal breakdown.In conclusion, biallelic mutations in human PDXK are associated with a novel disorder leading to treatable primary axonal polyneuropathy and optic atrophy and identifies PLP as therapeutic target.
- Published
- 2019
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.