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Karpagavalli M, Sivagurunathan S, Panda TS, Srikakulam N, Arora R, Dohadwala L, Tiwary BK, Sadras SR, Arunachalam JP, Pandi G, Chidambaram S. piRNAs in the human retina and retinal pigment epithelium reveal a potential role in intracellular trafficking and oxidative stress. Mol Omics 2024; 20:248-264. [PMID: 38314503 DOI: 10.1039/d3mo00122a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Long considered active only in the germline, the PIWI/piRNA pathway is now known to play a significant role in somatic cells, especially neurons. In this study, piRNAs were profiled in the human retina and retinal pigment epithelium (RPE). Furthermore, RNA immunoprecipitation with HIWI2 (PIWIL4) in ARPE19 cells yielded 261 piRNAs, and the expression of selective piRNAs in donor eyes was assessed by qRT-PCR. Intriguingly, computational analysis revealed complete and partial seed sequence similarity between piR-hsa-26131 and the sensory organ specific miR-183/96/182 cluster. Furthermore, the expression of retina-enriched piR-hsa-26131 was positively correlated with miR-182 in HIWI2-silenced Y79 cells. In addition, the lnc-ZNF169 sequence matched with two miRNAs of the let-7 family, and piRNAs, piR-hsa-11361 and piR-hsa-11360, which could modulate the regulatory network of retinal differentiation. Interestingly, we annotated four enriched motifs among the piRNAs and found that the piRNAs containing CACAATG and CTCATCAKYG motifs were snoRNA-derived piRNAs, which are significantly associated with developmental functions. However, piRNAs consisting of ACCACTANACCAC and AKCACGYTCSC motifs were mainly tRNA-derived fragments linked to stress response and sensory perception. Additionally, co-expression network analysis revealed cell cycle control, intracellular transport and stress response as the important biological functions regulated by piRNAs in the retina. Moreover, loss of piRNAs in HIWI2 knockdown ARPE19 confirmed altered expression of targets implicated in intracellular transport, circadian clock, and retinal degeneration. Moreover, piRNAs were dysregulated under oxidative stress conditions, indicating their potential role in retinal pathology. Therefore, we postulate that piRNAs, miRNAs, and lncRNAs might have a functional interplay during retinal development and functions to regulate retinal homeostasis.
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Affiliation(s)
| | - Suganya Sivagurunathan
- RS Mehta Jain Department of Biochemistry and Cell Biology, Vision Research Foundation, Chennai, India
| | - T Sayamsmruti Panda
- Department of Bioinformatics, Pondicherry University, Puducherry-605014, India
| | - Nagesh Srikakulam
- Laboratory of RNA Biology and Epigenomics, Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai, India
| | - Reety Arora
- National Centre for Biological Sciences, TIFR, Bangalore, India
| | | | - Basant K Tiwary
- Department of Bioinformatics, Pondicherry University, Puducherry-605014, India
| | - Sudha Rani Sadras
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry-605014, India.
| | - Jayamuruga Pandian Arunachalam
- Central Inter-Disciplinary Research Facility, Sri Balaji Vidyapeeth (Deemed to be University), Pondicherry-607402, India
| | - Gopal Pandi
- Laboratory of RNA Biology and Epigenomics, Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai, India
| | - Subbulakshmi Chidambaram
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry-605014, India.
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Rajendran R, Arunachalam JP, Chidambaram S, Krishnagopal S, Krishnamurthy B, Vinayagam S, Veeravarmal V, Prasad H, Verma K, U R A. Protein Drug Delivery Using a Novel Maxillofacial Technique Targeting the Visual Pathway in the Brain, the Optic Nerve, and the Retina. ACS Chem Neurosci 2023; 14:3368-3384. [PMID: 37665674 DOI: 10.1021/acschemneuro.3c00184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023] Open
Abstract
Protein drugs are used for treating many diseases of the eye and the brain. The formidable blood neural barriers prevent the delivery of these drugs into the eye and the brain. Hence, there is a need for a protein drug delivery system to deliver large proteins across blood-neural barriers. Low half-life, poor penetration of epithelial barriers, low stability, and immunogenicity limit the use of non-invasive systemic routes for delivering proteins. In this pre-clinical study, the efficacy of a new maxillofacial route for administering protein drugs using a novel drug delivery system is compared with systemic administration through intra-peritoneal injection and ocular administration through topical eye drops and subconjunctival and intravitreal injections. Bevacizumab and retinoschisin proteins were administered using the maxillofacial technique along with systemic and ocular routes in wild-type male C57BL/6J mice. Liquid chromatography with tandem mass spectrometry and western blot was used to detect bevacizumab in tissue samples. Furthermore, immunohistochemistry was performed to detect the presence and localization of bevacizumab and retinoschisin in the retina and brain. The maxillofacial route of delivery could target the brain including regions involved in the visual pathway and optic nerve. The maxillofacial technique and intravitreal injection were effective in delivering the drugs into the retina. A new concept based on the glymphatic pathway, cerebrospinal fluid drug distribution, and the crossover of ipsilateral optic nerve fibers at optic chiasma is proposed to explain the presence of the drug in contralateral eye following maxillofacial administration and intravitreal injection.
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Affiliation(s)
- Rahini Rajendran
- Central Inter-Disciplinary Research Facility, Sri Balaji Vidyapeeth [Deemed to be University], SBV-Mahatma Gandhi Medical College & Research Institute Campus, Puducherry 607402, India
| | - Jayamuruga Pandian Arunachalam
- Central Inter-Disciplinary Research Facility, Sri Balaji Vidyapeeth [Deemed to be University], SBV-Mahatma Gandhi Medical College & Research Institute Campus, Puducherry 607402, India
| | - Subbulakshmi Chidambaram
- Sensory Neural Engineering and Cell Therapeutics Lab, Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry 605014, India
| | - Srikanth Krishnagopal
- Department of Ophthalmology, Sri Balaji Vidyapeeth [Deemed to be University], Mahatma Gandhi Medical College & Research Institute, Puducherry 607402, India
| | - Bhavani Krishnamurthy
- Department of Pathology, Sri Balaji Vidyapeeth [Deemed to be University], Mahatma Gandhi Medical College & Research Institute, Puducherry 607402, India
| | - Subha Vinayagam
- Department of Pharmacology, Sri Balaji Vidyapeeth [Deemed to be University], Mahatma Gandhi Medical College & Research Institute, Puducherry 607402, India
| | - Veeran Veeravarmal
- Department of Oral & Maxillofacial Pathology and Oral Microbiology, Government Dental College, Cuddalore, Annamalai Nagar, Chidambaram 608002, Tamil Nadu, India
| | - Harikrishnan Prasad
- Department of Oral Pathology and Microbiology, KSR Institute of Dental Science and Research, Tiruchengode 637215, Tamil Nadu, India
| | - Kavita Verma
- UR Anoop Research Group, Puducherry 605008, India
| | - Anoop U R
- UR Anoop Research Group, Puducherry 605008, India
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Rajendran R, Sudha D, Chidambaram S, Nagarajan H, Vetrivel U, Arunachalam JP. Retinoschisis and Norrie disease: a missing link. BMC Res Notes 2021; 14:204. [PMID: 34039417 PMCID: PMC8157631 DOI: 10.1186/s13104-021-05617-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/15/2021] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Retinoschisis and Norrie disease are X-linked recessive retinal disorders caused by mutations in RS1 and NDP genes respectively. Both are likely to be monogenic and no locus heterogeneity has been reported. However, there are reports showing overlapping features of Norrie disease and retinoschisis in a NDP knock-out mouse model and also the involvement of both the genes in retinoschisis patients. Yet, the exact molecular relationships between the two disorders have still not been understood. The study investigated the association between retinoschisin (RS1) and norrin (NDP) using in vitro and in silico approaches. Specific protein-protein interaction between RS1 and NDP was analyzed in human retina by co-immunoprecipitation assay and MALDI-TOF mass spectrometry. STRING database was used to explore the functional relationship. RESULT Co-immunoprecipitation demonstrated lack of a direct interaction between RS1 and NDP and was further substantiated by mass spectrometry. However, STRING revealed a potential indirect functional association between the two proteins. Progressively, our analyses indicate that FZD4 protein interactome via PLIN2 as well as the MAP kinase signaling pathway to be a likely link bridging the functional relationship between retinoschisis and Norrie disease.
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Affiliation(s)
- Rahini Rajendran
- Central Inter-Disciplinary Research Facility (CIDRF), Sri Balaji Vidyapeeth (Deemed To Be University), Mahatma Gandhi Medical College and Research Institute Campus, Pondicherry, 607402, India
| | - Dhandayuthapani Sudha
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Nungambakkam, Chennai, 600006, India
| | - Subbulakshmi Chidambaram
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry, 605014, India
| | - Hemavathy Nagarajan
- Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology, Vision Research Foundation, Sankara Nethralaya, Chennai, 600006, India
| | - Umashankar Vetrivel
- National Institute of Traditional Medicine, Indian Council of Medical Research, Belagavi, 590010, India
| | - Jayamuruga Pandian Arunachalam
- Central Inter-Disciplinary Research Facility (CIDRF), Sri Balaji Vidyapeeth (Deemed To Be University), Mahatma Gandhi Medical College and Research Institute Campus, Pondicherry, 607402, India. .,SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Nungambakkam, Chennai, 600006, India.
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Arunachalam JP, U.R. A, Verma K, Rajendran R, Chidambaram S. SARS-CoV-2: The Road Less Traveled-From the Respiratory Mucosa to the Brain. ACS Omega 2021; 6:7068-7072. [PMID: 33748620 PMCID: PMC7970566 DOI: 10.1021/acsomega.1c00030] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
Neurological manifestations have been reported in COVID-19; however, the route used by SARS-CoV-2 to enter the brain is still under debate. Recent studies have focused on the olfactory route. SARS-CoV-2 viral proteins were also detected in the glossopharyngeal and vagal nerves originating from the lower brainstem and in isolated cells of the brainstem. Our proof of concept in vivo real-time imaging study of mice using an indocyanine green dye indicated that the neurovascular component of the connective tissue of the respiratory mucosa can also provide an alternate route to the brain.
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Affiliation(s)
- Jayamuruga Pandian Arunachalam
- Central
Inter-Disciplinary Research Facility, Sri
Balaji Vidyapeeth [Deemed to be University], SBV-Mahatma Gandhi Medical
College & Research Institute Campus, Pondicherry 607402, India
| | - Anoop U.R.
- UR
Anoop Research Group, Pondicherry 605008, India
| | - Kavita Verma
- UR
Anoop Research Group, Pondicherry 605008, India
| | - Rahini Rajendran
- Central
Inter-Disciplinary Research Facility, Sri
Balaji Vidyapeeth [Deemed to be University], SBV-Mahatma Gandhi Medical
College & Research Institute Campus, Pondicherry 607402, India
| | - Subbulakshmi Chidambaram
- Department
of Biochemistry and Molecular Biology, Pondicherry
Central University, Puducherry 605014, India
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Sivagurunathan S, Arunachalam JP, Chidambaram S. PIWI-like protein, HIWI2 is aberrantly expressed in retinoblastoma cells and affects cell-cycle potentially through OTX2. Cell Mol Biol Lett 2017; 22:17. [PMID: 28861107 PMCID: PMC5576095 DOI: 10.1186/s11658-017-0048-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/22/2017] [Indexed: 12/30/2022] Open
Abstract
Retinoblastoma (RB), a childhood cancer, is caused by biallelic mutation of the RB1 gene, but its development is not clearly understood. Furthermore, the presence of a cancer stem cell subpopulation in RB might impact its treatment. PIWI protein, known for its role in stem cell self-renewal, is aberrantly expressed in cancers. We examined the role of the PIWI-like protein HIWI2 in RB and its effect on the stem cell markers in cells of the RB line, Y79. The expression of HIWI2 is significantly increased in Y79 compared with its level in HeLa and ARPE19 cells. The stem cell markers Oct-3/4, Nanog and Sox-2 were not altered upon HIWI2 knockdown in Y79 cells. Interestingly, OTX2 was significantly downregulated in the absence of HIWI2. Otx2 transcripts also decreased in HIWI2-silenced Y79 and ARPE19 cells. Moreover, silencing HIWI2 in Y79 accumulated the cells at G2–M phase and reduced the levels of proliferating cell nuclear antigen (PCNA) and the tumor suppressor, p16. Our results demonstrate that HIWI2 is aberrantly expressed in Y79 cells and silencing of HIWI2 downregulates OTX2, suggesting that HIWI2 might play a role in the progression of RB.
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Affiliation(s)
- Suganya Sivagurunathan
- RS Mehta Jain Department of Biochemistry and Cell Biology, Vision Research Foundation, Chennai, India.,School of Chemical and Biotechnology, SASTRA University, Thanjavur, India
| | - Jayamuruga Pandian Arunachalam
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India.,Central Inter-Disciplinary Research Facility (CIDRF), Sri Balaji Vidyapeeth University, Mahatma Gandhi Medical College and Research Institute Campus, Pondicherry, India
| | - Subbulakshmi Chidambaram
- RS Mehta Jain Department of Biochemistry and Cell Biology, Vision Research Foundation, Chennai, India.,Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry, India
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Neriyanuri S, Dhandayuthapani S, Arunachalam JP, Raman R. Phenotypic characterization of X-linked retinoschisis: Clinical, electroretinography, and optical coherence tomography variables. Indian J Ophthalmol 2017; 64:513-7. [PMID: 27609164 PMCID: PMC5026077 DOI: 10.4103/0301-4738.190140] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aims: To study the phenotypic characteristics of X-linked retinoschisis (XLRS) and report the clinical, electroretinogram (ERG), and optical coherence tomography (OCT) variables in Indian eyes. Design: A retrospective study. Materials and Methods: Medical records of 21 patients with retinoschisis who were genetically confirmed to have RS1 mutation were reviewed. The phenotype characterization included the age of onset, best-corrected visual acuity, refractive error, fundus findings, OCT, and ERG. Statistical Analysis Used: Data from both the eyes were used for analysis. A P < 0.05 was set as statistical significance. Data were not normally distributed (P < 0.05, Shapiro wilk); hence, nonparametric tests were used for statistical analysis. Results: All were males whose mean age of presentation was 9 years. Visual acuity was moderately impaired (median 0.6 logMAR, interquartile range: 0.47, 1) in these eyes with a hyperopic refractive error of median +1.75 Ds (interquartile range: +0.50 Ds, +4.25 Ds). About 54.7% of the eyes had both foveal and peripheral schisis, isolated foveal schisis was seen in 28.5% of the eyes, and schisis with retinal detachment was seen in 16.6% of the eyes. The inner nuclear layer was found to be commonly involved in the schisis, followed by outer nuclear and plexiform layers as evident on OCT. On ERG, a- and b-wave amplitudes were significantly reduced in eyes with foveal and peripheral schisis when compared to the eyes with only foveal schisis (P < 0.05). Conclusions: XLRS has phenotypic heterogeneity as evident on OCT, ERG, and clinical findings.
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Affiliation(s)
- Srividya Neriyanuri
- Department of Optometry, Elite School of Optometry, Chennai and Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Sudha Dhandayuthapani
- Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Jayamuruga Pandian Arunachalam
- Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Rajiv Raman
- Department of Vitreo-retina, Shri Bhagwan Mahaveer Vitreoretinal Services, Sankara Nethralaya, Chennai, Tamil Nadu, India
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Sudha D, Kohansal-Nodehi M, Kovuri P, Manda SS, Neriyanuri S, Gopal L, Bhende P, Chidambaram S, Arunachalam JP. Proteomic profiling of human intraschisis cavity fluid. Clin Proteomics 2017; 14:13. [PMID: 28450823 PMCID: PMC5404285 DOI: 10.1186/s12014-017-9148-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 04/07/2017] [Indexed: 12/24/2022] Open
Abstract
Background X-linked retinoschisis (XLRS) is a vitreoretinal degenerative disorder causing vision deterioration, due to structural defects in retina. The hallmark of this disease includes radial streaks arising from the fovea and splitting of inner retinal layers (schisis). Although these retinal changes are attributed to mutations in the retinoschisin gene, schisis is also observed in patients who do not carry mutations. In addition, the origin of intraschisis fluid, the triggering point of schisis formation and its progression are largely unknown still. So far, there is no report on the complete proteomic analysis of this fluid. Schisis fluid proteome could reflect biochemical changes in the disease condition, helping in better understanding and management of retinoschisis. Therefore it was of interest to investigate the intraschisis fluid proteome using high-resolution mass spectrometry. Methods Two male XLRS patients (aged 4 and 40 years) underwent clinical and genetic evaluation followed by surgical extraction of intraschisis fluids. The two fluid samples were resolved on a SDS-PAGE and the processed peptides were analyzed by Q-Exactive plus hybrid quadrupole-Orbitrap mass spectrometry. Functional annotation of the identified proteins was performed using Ingenuity pathway analysis software. Results Mass spectrometry analysis detected 770 nonredundant proteins in the intraschisis fluid. Retinol dehydrogenase 14 was found to be abundant in the schisis fluid. Gene ontology based analysis indicated that 19% of the intraschisis fluid proteins were localized to the extracellular matrix and 15% of the proteins were involved in signal transduction. Functional annotation identified three primary canonical pathways to be associated with the schisis fluid proteome viz., LXR/RXR activation, complement system and acute phase response signalling, which are involved in immune and inflammatory responses. Collectively, our results show that intraschisis fluid comprises specific inflammatory proteins which highly reflect the disease environment. Conclusion Based on our study, it is suggested that inflammation might play a key role in the pathogenesis of XLRS. To our knowledge, this is the first report describing the complete proteome of intraschisis fluid, which could serve as a template for future research and facilitate the development of therapeutic modalities for XLRS. Electronic supplementary material The online version of this article (doi:10.1186/s12014-017-9148-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dhandayuthapani Sudha
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India.,School of Biotechnology, SASTRA University, Thanjavur, India
| | | | - Purnima Kovuri
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry, India
| | | | - Srividya Neriyanuri
- Elite School of Optometry, Unit of Medical Research Foundation, Chennai, India
| | - Lingam Gopal
- Shri Bhagwan Mahavir Vitreo-Retinal Services, Medical Research Foundation, Chennai, India
| | - Pramod Bhende
- Shri Bhagwan Mahavir Vitreo-Retinal Services, Medical Research Foundation, Chennai, India
| | | | - Jayamuruga Pandian Arunachalam
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India.,Central Inter-Disciplinary Research Facility (CIDRF), Sri Balaji Vidyapeeth Medical University, Mahatma Gandhi Medical College and Research Institute Campus, Puducherry, India
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Sivagurunathan S, Palanisamy K, Arunachalam JP, Chidambaram S. Possible role of HIWI2 in modulating tight junction proteins in retinal pigment epithelial cells through Akt signaling pathway. Mol Cell Biochem 2016; 427:145-156. [DOI: 10.1007/s11010-016-2906-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/03/2016] [Indexed: 12/22/2022]
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Sudha D, Patric IRP, Ganapathy A, Agarwal S, Krishna S, Neriyanuri S, Sripriya S, Sen P, Chidambaram S, Arunachalam JP. Genetic studies in a patient with X-linked retinoschisis coexisting with developmental delay and sensorineural hearing loss. Ophthalmic Genet 2016; 38:260-266. [PMID: 28574807 DOI: 10.1080/13816810.2016.1214972] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND In this study, we present a juvenile retinoschisis patient with developmental delay, sensorineural hearing loss, and reduced axial tone. X-linked juvenile retinoschisis (XLRS) is a retinal dystrophy, most often not associated with systemic anomalies and also not showing any locus heterogeneity. Therefore it was of interest to understand the genetic basis of the condition in this patient. MATERIALS AND METHODS RS1 gene screening for XLRS was performed by Sanger sequencing. Whole genome SNP 6.0 array analysis was carried out to investigate gross chromosomal aberrations that could result in systemic phenotype. In addition, targeted next generation sequencing (NGS) was employed to determine any possible involvement of X-linked syndromic and non-syndromic mental retardation genes. This NGS panel consisted of 550 genes implicated in several other rare inherited diseases. RESULTS RS1 gene screening revealed a pathogenic hemizygous splice site mutation (c.78+1G>T), inherited from the mother. SNP 6.0 array analysis did not indicate any significant chromosomal aberrations that could be disease-associated. Targeted resequencing did not identify any mutations in the X-linked mental retardation genes. However, variations in three other genes (NSD1, LARGE, and POLG) were detected, which were all inherited from the patient's unaffected father. CONCLUSIONS Taken together, RS1 mutation was found to segregate with retinoschisis phenotype while none of the other identified variations were co-segregating with the systemic defects. Hereby, we infer that the multisystemic defects harbored by the patient are a rare coexistence of XLRS, developmental delay, sensorineural hearing loss, and reduced axial tone reported for the first time in the literature.
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Affiliation(s)
- Dhandayuthapani Sudha
- a SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation , Chennai , India.,b School of Biotechnology , SASTRA University , Thanjavur , India
| | | | | | | | | | - Srividya Neriyanuri
- d Elite School of Optometry, Medical Research Foundation , Chennai , India.,e Birla Institute of Technology and Science , Pilani , India
| | - Sarangapani Sripriya
- a SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation , Chennai , India
| | - Parveen Sen
- f Department of Vitreo-Retinal Services, Medical Research Foundation , Chennai , India
| | - Subbulakshmi Chidambaram
- g R.S. Mehta Jain Department of Biochemistry and Cell Biology, Vision Research Foundation , Chennai , India
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Kifayathullah LA, Arunachalam JP, Bodda C, Agbemenyah HY, Laccone FA, Mannan AU. MeCP2 mutant protein is expressed in astrocytes as well as in neurons and localizes in the nucleus. Cytogenet Genome Res 2010; 129:290-7. [PMID: 20625242 DOI: 10.1159/000315906] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2010] [Indexed: 11/19/2022] Open
Abstract
The MECP2 gene, located at Xq28, encodes methyl-CpG-binding protein 2 (MeCP2), which is frequently mutated (up to 90%) in Rett syndrome (RTT). RTT is a progressive neurodevelopmental disorder, which affects primarily girls during early childhood and it is one of the most common causes of mental retardation in females. R270X is one of the most frequent recurrent MECP2 mutations among RTT cohorts. The R270X mutation resides within the TRD-NLS (Transcription Repression Domain-Nuclear Localization Signal) region of MeCP2 and causes a more severe clinical phenotype with increased mortality as compared to other mutations. To evaluate the functional role of the R270X mutation, we generated a transgenic mouse model expressing MeCP2(270_EGFP) (human mutation equivalent) by BAC recombineering. The expression pattern of MeCP2(270_EGFP) was similar to that of endogenous MeCP2. Strikingly, MeCP2(270_EGFP) localizes in the nucleus, contrary to the conjecture that R270X could cause disruption of the NLS. In primary hippocampal cells, we show that MeCP2(270_EGFP) was expressed in astrocytes by colocalization with the astrocyte-specific marker glial fibrillary acidic protein. Our data showing expression of MeCP2(270_EGFP) in transgenic mice astrocytes further reinforce the recent findings concerning the expression of MeCP2 in the glial cells.
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Affiliation(s)
- L A Kifayathullah
- Institute of Human Genetics, University of Goettingen, Goettingen, Germany
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