Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology

Chennai, India

Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology

Chennai, India
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Rishi E.,Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology | Rishi P.,Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology | Sengupta S.,Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology | Jambulingam M.,L and crobiology Research Center | And 3 more authors.
Ophthalmology | Year: 2013

Objective: To study the clinicomicrobiologic characteristics and treatment outcomes in eyes with acute postoperative endophthalmitis (APE) owing to Bacillus cereus from a tertiary eye-care center. Design: Retrospective, interventional case series. Participants: Case records of all eyes with culture-proven APE attributable to B cereus from January 2000 to May 2011 were identified from a computerized database and evaluated. Methods: Clinical features at time of presentation, microbiological characteristics, and treatment measures were recorded. A thorough literature search using PubMed and the Cochrane Library databases was done to identify all cases of APE owing to Bacillus species reported to date and clinical characteristics of these eyes was compared with our series. Main Outcome Measures: Structural (globe salvage) and functional (visual rehabilitation) outcomes at last follow-up visit. Results: We found 6 sporadic cases that experienced APE during the study period. All eyes had a fulminant onset within the first 24 hours of cataract surgery with extremely high intraocular pressure (IOP) and corneal edema similar to toxic anterior segment syndrome (TASS). However, these eyes progressed rapidly to develop corneal infiltrates, scleral and uveal tissue necrosis with hyphema, brownish exudates in anterior chamber and necrotizing retinitis within hours despite immediate initiation of intravitreal pharmacotherapy and vitrectomy. All eyes demonstrated gram-positive bacilli from the aqueous and B cereus was isolated, which was sensitive to conventional antibiotics except penicillin. Two eyes required therapeutic keratoplasty, combined with a scleral patch graft in 1 eye, 1 eye was eviscerated after 48 hours of onset of symptoms, and 2 eyes experienced phthisical changes within 10 days of onset. Conclusions: We found that APE owing to B cereus has an onset within 12 to 24 hours of intraocular surgery and simulates TASS in the first few hours. The clinical course is marked by rapidly worsening necrotizing infection, leading to very poor outcomes despite early institution of appropriate therapy. One must closely observe every case of TASS that presents with intense pain and extremely high IOP and rule out APE owing to B cereus with microbiologic testing. Financial Disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article. © 2013 American Academy of Ophthalmology.

Kanwar J.R.,Deakin University | Mahidhara G.,Deakin University | Roy K.,Deakin University | Sasidharan S.,Universiti Sains Malaysia | And 4 more authors.
Nanomedicine | Year: 2015

Aim: To validate the anticancer efficacy of alginate-enclosed, chitosan-conjugated, calcium phosphate, iron-saturated bovine lactoferrin (Fe-bLf) nanocarriers/nanocapsules (NCs) with improved sustained release and ability to induce apoptosis by downregulating survivin, as well as cancer stem cells. Materials & methods: The stability, nanotoxicity of the modified nanoformulation was evaluated and their anticancer efficacy was re-examined. Their mechanism of internalization was studied and we identified the role of various miRNAs in absorption of these NCs/iron in various body parts of mice. We determined the effect of these NCs on survivin, stem cell markers, red blood cell count, iron, calcium and zinc concentration in mice, determined the antiangiogenic properties of these NCs and studied their effect on cancer stem-like cells. Results: Spherical NCs (396.1 ± 27.2 nm) exceedingly reduced viability of Caco-2 cells (32 ± 2.83%). The NCs also showed effective internalization and reduction of cancer stem cell markers in triple-positive CD133, survivin and CD44 cancer stem-like cells. Mice treated with the NCs showed no nanotoxicity and did not develop any tumors in xenograft colon cancer models. We found that the serum iron, zinc and calcium absorption were increased. DMT1, LRP, transferrin and lactoferrin receptors were responsible for internalization of the NCs. Different miRNAs were responsible for iron regulation in different organs. Interestingly, NCs inhibited survivin and its different isoforms. Conclusion: Our results confirmed that NCs internalized and changed the expression of selected miRNAs that further enhanced their uptake. The NCs activated both extrinsic, as well as intrinsic apoptotic pathways to induce apoptosis by targeting survivin in cancer cells and cancer stem cells, without inducing any nonspecific nanotoxicity. Apart from inhibiting angiogenesis and stem cell markers, NCs also maintained iron and calcium levels. © 2015 Future Medicine Ltd.

PubMed | Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology, Medical Research Foundation, Indian Institute of Technology Madras, Deakin University and Bionivid Technologies
Type: | Journal: Molecular therapy. Nucleic acids | Year: 2017

Retinoblastoma (RB) is an intraocular childhood tumor which, if left untreated, leads to blindness and mortality. Nucleolin (NCL) protein which is differentially expressed on the tumor cell surface, binds ligands and regulates carcinogenesis and angiogenesis. We found that NCL is over expressed in RB tumor tissues and cell lines compared to normal retina. We studied the effect of nucleolin-aptamer (NCL-APT) to reduce proliferation in RB tumor cells. Aptamer treatment on the RB cell lines (Y79 and WERI-Rb1) led to significant inhibition of cell proliferation. Locked nucleic acid (LNA) modified NCL-APT administered subcutaneously (s.c.) near tumor or intraperitoneally (i.p.) in Y79 xenografted nude mice resulted in 26 and 65% of tumor growth inhibition, respectively. Downregulation of inhibitor of apoptosis proteins, tumor miRNA-18a, altered serum cytokines, and serum miRNA-18a levels were observed upon NCL-APT treatment. Desorption electrospray ionization mass spectrometry (DESI MS)-based imaging of cell lines and tumor tissues revealed changes in phosphatidylcholines levels upon treatment. Thus, our study provides proof of concept illustrating NCL-APT-based targeted therapeutic strategy and use of DESI MS-based lipid imaging in monitoring therapeutic responses in RB.

PubMed | Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology and Tamil University
Type: Journal Article | Journal: Bioinformation | Year: 2016

Polycystic ovary syndrome (PCOS) is a complex disorder affecting approximately 5-10 percent of all women of reproductive age. It is a multi-factorial endocrine disorder, which demonstrates menstrual disturbance, infertility, anovulation, hirsutism, hyper androgenism and others. It has been indicated that differential expression of genes, genetic level variations, and other molecular alterations interplay in PCOS and are the target sites for clinical applications. Therefore, integrating the PCOS-associated genes along with its alteration and underpinning the underlying mechanism might definitely provide valuable information to understand the disease mechanism. We manually curated the information from 234 published literatures, including gene, molecular alteration, details of association, significance of association, ethnicity, age, drug, and other annotated summaries. PCOSDB is an online resource that brings comprehensive information about the disease, and the implication of various genes and its mechanism. We present the curated information from peer reviewed literatures, and organized the information at various levels including differentially expressed genes in PCOS, genetic variations such as polymorphisms, mutations causing PCOS across various ethnicities. We have covered both significant and non-significant associations along with conflicting studies. PCOSDB v1.0 contains 208 gene reports, 427 molecular alterations, and 46 phenotypes associated with PCOS.

Subramanian N.,Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology | Subramanian N.,Deakin University | Kanwar J.R.,Deakin University | Kanwar R.K.,Deakin University | And 4 more authors.
PLoS ONE | Year: 2015

Epithelial cell adhesion molecule (EpCAM), a cancer stem cell (CSC) marker is over expressed in epithelial cancers and in retinoblastoma (RB). We fabricated an EpCAM targeting aptamer-siRNA chimera and investigated its anti-tumor property and EpCAM intracellular domain (EpICD) mediated signaling in epithelial cancer. The anti-tumor efficacy of EpCAM aptamer-siEpCAM chimera (EpApt-siEp) was evaluated by qPCR, northern and Western blotting in WERI-Rb1- RB cell line, primary RB tumor cells and in MCF7- breast cancer cell line. Anti-tumor activity of EpApt-siEp was studied in vivo using epithelial cancer (MCF7) mice xenograft model. The mechanism and pathways involved in the anti-tumor activity was further studied using protein arrays and qPCR. EpApt-siEp chimera was processed in vitro by dicer enzyme. Treatment of the WERI-Rb1 and MCF7 cells with EpAptsiEp revealed statistically significant down regulation of EpCAM expression (P<0.005) and concomitant reduction in cellular proliferation. In primary RB cells cultured from RB tumors, EpApt-siEp silenced EpCAM, significantly inhibited (P<0.01) cell proliferation and induced cytotoxicity. Knockdown of EpICD expressed in RB primary tumors led to repression of pluripotency markers, SOX2, OCT4, NANOG, and CD133. In vivo studies showed complete tumor growth regression without any toxicity in animals (P<0.001) and tumor tissues showed significant downregulation (P<0.05) of EpCAM, MRP1, ABCG2, stathmin, survivin and upregulation of ATM (P<0.05) leading to apoptosis by intrinsic pathway with minor alteration in cytokines. Our results revealed that EpApt-siEp potentially eradicated EpCAM positive cancer cells through CSC marker suppression and apoptosis, while sparing normal EpCAM negative adjacent cells. Copyright: © 2015 Subramanian et al.

Subramanian N.,Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology | Subramanian N.,Deakin University | Kanwar J.R.,Deakin University | Kanwar R.K.,Deakin University | Krishnakumar S.,Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology
Nucleic Acid Therapeutics | Year: 2015

The miR-17∼92. or oncomiR-1, cluster encodes oncogenic microRNAs (miRNAs), and it also promotes retinoblastoma (RB) tumor formation. Antagomir and miRNA mimics based approaches are widely tried against oncogenic and tumor suppressive miRNAs. Other methods for targeting cancer related miRNAs are still under development. In the current study, we focused on the pri-miRNA-17∼92 aptamer (pri-apt), which can potentially replace the mix of five antagomirs by one aptamer that function to abrogate the maturation of miR-17, miR-18a, and miR-19b (P<0.05) for targeting RB. We used RB cell lines WERI-Rb1 and Y79 as an in vitro model. Cellular changes upon transfecting the pri-apt led to S-phase arrest in WERI-Rb1 cells and onset of apoptosis in both Y79 and WERI-Rb1 cell lines. There was increased cytotoxicity as measured by lactate dehydrogenase activity in pri-apt treated Y79 cells (P<0.05), and significant inhibition of cell proliferation was observed in both of the cell lines. Thus we showed the antiproliferative property of pri-apt in RB cell lines, which can be readily modified by developing appropriate vectors for the delivery of the aptamer specifically to cancer cells. © Copyright 2015, Mary Ann Liebert, Inc. 2015.

PubMed | Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology and Birla Institute of Technology and Science
Type: | Journal: Bioinformatics and biology insights | Year: 2016

Fatty acid synthase (FASN, UniProt ID: P49327) is a multienzyme dimer complex that plays a critical role in lipogenesis. Consequently, this lipogenic enzyme has gained tremendous biomedical importance. The role of FASN and its inhibition is being extensively researched in several clinical conditions, such as cancers, obesity, and diabetes. X-ray crystallographic structures of some of its domains, such as -ketoacyl synthase, acetyl transacylase, malonyl transacylase, enoyl reductase, -ketoacyl reductase, and thioesterase, (TE) are already reported. Here, we have attempted an in silico elucidation of the uncrystallized dehydratase (DH) catalytic domain of human FASN. This theoretical model for DH domain was predicted using comparative modeling methods. Different stand-alone tools and servers were used to validate and check the reliability of the predicted models, which suggested it to be a highly plausible model. The stereochemical analysis showed 92.0% residues in favorable region of Ramachandran plot. The initial physiological substrate -hydroxybutyryl group was docked into active site of DH domain using Glide. The molecular dynamics simulations carried out for 20 ns in apo and holo states indicated the stability and accuracy of the predicted structure in solvated condition. The predicted model provided useful biochemical insights into the substrate-active site binding mechanisms. This model was then used for identifying potential FASN inhibitors using high-throughput virtual screening of the National Cancer Institute database of chemical ligands. The inhibitory efficacy of the top hit ligands was validated by performing molecular dynamics simulation for 20 ns, where in the ligand NSC71039 exhibited good enzyme inhibition characteristics and exhibited dose-dependent anticancer cytotoxicity in retinoblastoma cancer cells in vitro.

PubMed | Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology, SASTRA University and Medical Research Foundation
Type: Journal Article | Journal: Cytotherapy | Year: 2016

Skin keratinocytes (SKs) share the same surface ectodermal origin as that of corneal epithelium. In this study, the plasticity of epidermal keratinocytes was exploited to generate corneal epithelial-like cells, which might serve as an alternative source of autologous tissue for the treatment of bilateral limbal stem cell deficiency.Skin samples were subjected to collagenase digestion to isolate SKs and transdifferentiated to corneal epithelial-like cells using limbal fibroblast conditioned medium (LFCM). SKs and transdifferentiated corneal epithelial cells (TDCECs) were characterized using immunofluorescence and fluorescence-activated cell sorting. The propensity for expression of angiogenic genes in TDCECs was compared with cultured oral mucosal epithelial cells (COMEC) in vitro. RT(2) quantitative polymerase chain reaction profiler array was performed to study the signaling pathways involved in the transdifferentiation process.The TDCECs obtained from SKs showed corneal epithelial-like morphology and expressed corneal epithelial markers, CK3 and CK12. Hematoxylin-eosin and immunohistochemistry showed stratified layers of TDCECs expressing CK 3/12, confirming the corneal epithelial phenotype. We found that the expression of several angiogenic and epithelial mesenchymal transition factors were down-regulated in TDCECs compared with COMEC, suggesting a lower capacity to induce angiogenesis in TDCECs. There was considerable difference in the signaling mechanisms between TDCECs and SKs on testing by RT(2) profiler array, signifying differences at the global gene profile. The comparison of TDCECs and limbal derived corneal epithelial cells showed similar gene expression.Our study shows that SKs have the potential to transdifferentiate into corneal epithelial-like cells using LFCM.

PubMed | Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology and Birla Institute of Technology and Science
Type: | Journal: Journal of biomolecular structure & dynamics | Year: 2016

Human fatty acid synthase (hFASN), a homo dimeric lipogenic enzyme with seven catalytic domains, is an important clinical target in cancer, metabolic syndrome and infections. Here, molecular modelling and docking methods were implemented to examine the inter-molecular interactions of thioesterase (TE) domain in hFASN with its physiological substrate, and to identify potential chemical inhibitors. TE catalyses the hydrolysis of thioester bond between palmitate and the 4 phosphopantetheine of acyl carrier protein, releasing 16-carbon palmitate. The crystal structure of hFASN TE in two inhibitory conformations (A and B) were geometry-optimized and used for molecular docking with palmitate, orlistat (a known FASN inhibitor) and virtual screening against compounds from National Cancer Institute (NCI) database. Relatively, low binding affinity was observed during the complex formation of palmitate with A (-.164kcal/mol) and B (-.332kcal/mol) forms of TE, when compared with orlistat-docked TE (A form: -5.872kcal/mol and B form: -5.484kcal/mol), clearly indicating that the native inhibited conformation (crystal structure) was unfavourable for substrate binding. We used these orlistat dual binding modes as positive controls for prioritizing the ligands during virtual screening. From 2, 31,617 molecules in the NCI database, 916 high-scoring compounds (hit ligands) were obtained for A-form and 4582 for B-form of the TE-domain, which were then ranked according to glide docking score, XP H bond score, absorption, distribution, metabolism and excretion and binding free energy (Prime/MM-GBSA). Consequently, two top scoring ligands (NSC: 319661 and NSC: 153166) emerged as promising drug candidates that may be tested in FASN-over-expressing diseases.

PubMed | Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology and SASTRA University
Type: | Journal: Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie | Year: 2016

Ornithine is a non-essential amino acid produced as an intermediate molecule in urea cycle. It is a key substrate for the synthesis of proline, polyamines and citrulline. Ornithine also plays an important role in the regulation of several metabolic processes leading to diseases like hyperorithinemia, hyperammonemia, gyrate atrophy and cancer in humans. However, the mechanism of action behind the multi-faceted roles of ornithine is yet to be unraveled completely. Several types of cancers are also characterized by excessive polyamine synthesis from ornithine by different rate limiting enzymes. Hence, in this review we aim to provide extensive insights on potential roles of ornithine in many of the disease related cellular processes and also on the structural features of ornithine interacting proteins, enabling development of therapeutic modalities.

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