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Sekaran S, Warrier S, Selvaraj V, Ganapathy D, Ramasamy P. NLRP3 Inflammasome: A Potential Therapeutic Target in Head and Neck Cancers. Clin Oncol (R Coll Radiol) 2024; 36:e115-e117. [PMID: 38368227 DOI: 10.1016/j.clon.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 02/09/2024] [Indexed: 02/19/2024]
Affiliation(s)
- S Sekaran
- Department of Prosthodontics, Saveetha Dental College & Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, Tamil Nadu, India
| | - S Warrier
- Department of Biotechnology, Faculty of Biomedical Sciences and Technology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - V Selvaraj
- Department of Biomedical Engineering, Indian Institute of Technology, Chennai, Tamil Nadu, India
| | - D Ganapathy
- Department of Prosthodontics, Saveetha Dental College & Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, Tamil Nadu, India
| | - P Ramasamy
- Department of Prosthodontics, Saveetha Dental College & Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, Tamil Nadu, India; Polymer Research Laboratory, Centre for Marine Research and Conservation, Saveetha Dental College & Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, Tamil Nadu, India
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Sequiera G, Bailey K, Sareen N, Moudgil M, Abu-El Rub E, Sekaran S, Rockman-Greenberg C, Dhingra S. ESTABLISHMENT OF STABLE IN VITRO CARDIAC MODELS OF KEARNS-SAYRE SYNDROME USING INDUCED PLURIPOTENT STEM CELL TECHNOLOGY. Can J Cardiol 2017. [DOI: 10.1016/j.cjca.2017.07.324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Sekaran S, Balaganapathy P, Parsanathan R, Elangovan S, Gunashekar J, Bhat FA, Jagadeesan A. Lactational exposure of phthalate causes long-term disruption in testicular architecture by altering tight junctional and apoptotic protein expression in Sertoli cells of first filial generation pubertal Wistar rats. Hum Exp Toxicol 2014; 34:575-90. [DOI: 10.1177/0960327114555926] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental contaminant and a well-known endocrine disruptor (ED) that interferes with the reproductive function in both humans and animals. This study aimed to find out the impact of lactational exposure of DEHP in testes of first filial generation (F1) progeny male rat postnatal day (PND)-60. Lactating dams were orally treated with DEHP (0, 1, 10 and 100 mg/kg body weight/day, respectively) from the PND-1 to PND-21. Rats were killed at PND 60. Testes were removed and used for histological analysis and for isolation of Sertoli cells (SCs). The histoarchitecture of DEHP-treated rats showed disturbed testicular structure. DEHP-treated rats also showed increased oxidative stress by decreasing antioxidant levels in the SCs; it disrupted SC tight junctional proteins occludin, claudin, junctional adhesion molecule, zona occludens protein-1 (ZO-1), zona occludens protein-2 (ZO-2), and afadin-6 (AF-6), increased apoptosis by altering the apoptotic genes Bax, cytochrome c, caspase-8, -9, -3 and antiapoptotic gene Bcl-2. It is concluded that early postnatal exposure to DEHP disturbs histoarchitecture of testis and SC function in pubertal Wistar rats.
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Affiliation(s)
- S Sekaran
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, India
| | - P Balaganapathy
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, India
| | - R Parsanathan
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, India
| | - S Elangovan
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, India
| | - J Gunashekar
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, India
| | - FA Bhat
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, India
| | - A Jagadeesan
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, India
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Sekaran S, Lupi D, Jones SL, Sheely CJ, Hattar S, Yau KW, Lucas RJ, Foster RG, Hankins MW. Melanopsin-dependent photoreception provides earliest light detection in the mammalian retina. Curr Biol 2005; 15:1099-107. [PMID: 15964274 PMCID: PMC4316668 DOI: 10.1016/j.cub.2005.05.053] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Revised: 05/17/2005] [Accepted: 05/18/2005] [Indexed: 01/22/2023]
Abstract
BACKGROUND The visual system is now known to be composed of image-forming and non-image-forming pathways. Photoreception for the image-forming pathway begins at the rods and cones, whereas that for the non-image-forming pathway also involves intrinsically photosensitive retinal ganglion cells (ipRGCs), which express the photopigment melanopsin. In the mouse retina, the rod and cone photoreceptors become light responsive from postnatal day 10 (P10); however, the development of photosensitivity of the ipRGCs remains largely unexplored. RESULTS Here, we provide direct physiological evidence that the ipRGCs are light responsive from birth (P0) and that this photosensitivity requires melanopsin expression. Interestingly, the number of ipRGCs at P0 is over five times that in the adult retina, reflecting an initial overproduction of melanopsin-expressing cells during development. Even at P0, the ipRGCs form functional connections with the suprachiasmatic nucleus, as assessed by light-induced Fos expression. CONCLUSIONS The findings suggest that the non-image-forming pathway is functional long before the mainstream image-forming pathway during development.
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Affiliation(s)
- S Sekaran
- Department of Visual Neuroscience, Division of Neuroscience and Mental Health, Imperial College London, Charing Cross Hospital Campus, London, W6 8RF, United Kingdom.
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Sekaran S, Cunningham J, Neal MJ, Hartell NA, Djamgoz MBA. Nitric oxide release is induced by dopamine during illumination of the carp retina: serial neurochemical control of light adaptation. Eur J Neurosci 2005; 21:2199-208. [PMID: 15869516 DOI: 10.1111/j.1460-9568.2005.04051.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Several lines of indirect evidence have suggested that nitric oxide may play an important role during light adaptation of the vertebrate retina. We aimed to verify directly the effect of light on nitric oxide release in the isolated carp retina and to investigate the relationship between nitric oxide and dopamine, an established neuromodulator of retinal light adaptation. Using a biochemical nitric oxide assay, we found that steady or flicker light stimulation enhanced retinal nitric oxide production from a basal level. The metabotropic glutamate receptor agonist L-amino-4-phosphonobutyric acid, inhibited the light adaptation-induced nitric oxide production suggesting that the underlying cellular pathway involved centre-depolarizing bipolar cell activity. Application of exogenous dopamine to retinas in the dark significantly enhanced the basal production of nitric oxide and importantly, inhibition of endogenous dopaminergic activity completely suppressed the light-evoked nitric oxide release. The effect of dopamine was mediated through the D1 receptor subtype. Imaging of the nitric oxide-sensitive fluorescent indicator 4,5-diaminofluorescein di-acetate in retinal slices revealed that activation of D1 receptors resulted in nitric oxide production from two main spatial sources corresponding to the photoreceptor inner segment region and the inner nuclear layer. The results taken together would suggest that during the progression of retinal light adaptation there is a switch from dopaminergic to nitrergic control, probably to induce further neuromodulatory effects at higher levels of illumination and to enable more efficient spreading of the light adaptive signal.
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Affiliation(s)
- S Sekaran
- Department of Visual Neuroscience, Faculty of Medicine, Imperial College London, Charing Cross Campus, W6 8RF, UK.
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Djamgoz MB, Sekaran S, Angotzi AR, Haamedi S, Vallerga S, Hirano J, Yamada M. Light-adaptive role of nitric oxide in the outer retina of lower vertebrates: a brief review. Philos Trans R Soc Lond B Biol Sci 2000; 355:1199-203. [PMID: 11079398 PMCID: PMC1692835 DOI: 10.1098/rstb.2000.0667] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [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: 11/12/2022] Open
Abstract
The role of nitric oxide (NO) as a novel neurochemical mechanism controlling light adaptation of the outer retina is discussed by considering mainly published results. The emphasis is on the retinae of fishes and amphibia, but some data from the mammalian (rabbit) retinae have also been included for completeness. In the fish retina, application of NO donors in the dark caused light-adaptive photomechanical movements of cones. The normal effect of light adaptation in inducing cone contractions was suppressed by pretreatment of retinae with an NO scavenger. NO donors modulated horizontal cell activity by uncoupling the cells' lateral gap junctional interconnections and enhancing negative feedback to cones, again consistent with a light-adaptive role of NO. Direct evidence for light adaptation-induced release of NO has been obtained in fish (carp) and rabbit retinae. The results strongly suggest that control of retinal light adaptation is, under multiple neurochemical control, with NO and dopamine having an interactive role.
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Affiliation(s)
- M B Djamgoz
- Department of Biology, Imperial College of Science, Technology and Medicine, London, UK.
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