1
|
Padmanabhan U, Dahake R, Chowdhary AS, Koka PS. HIV-1 inhibits haematopoiesis via microRNA secreted by virus-infected CD4+ T cells. Eur J Haematol 2019; 104:170-180. [PMID: 31733152 DOI: 10.1111/ejh.13350] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 11/02/2019] [Accepted: 11/06/2019] [Indexed: 11/30/2022]
Abstract
INTRODUCTION HIV-1-infected patients develop haematological disorders such as cytopenias. One possible explanation is the inhibition of haematopoiesis at the level of differentiation of CD34+ haematopoietic progenitor stem cells. Based on our previous studies, we hypothesised that there may be viral encoded, or host cellular factors which participate in the process of inhibition of haematopoiesis. MATERIALS AND METHODS Virus-depleted media from infected CD4+ T cells was prepared by filtration and added to CD34+ cell differentiation semisolid medium. We have also used the virus-depleted media to isolate host/viral factors including miRNA. Isolated miRNAs were screened for their haematopoietic inhibitory function using the miRNA mining approach. RESULTS Addition of virus-depleted media caused a 40% inhibition of differentiation of CD34+ cells into myeloid and erythroid colony formation. Real-time RT-PCR showed miR-15a and miR-24 from both pIndie-C1 and pNL4.3 HIV-1-infected cells showed a significant differential expression when compared to control media. CONCLUSION In this study, we have identified two miRNAs, miR-15a and miR-24 secreted from purified HIV-1-infected CD4+ T cells that inhibited CD34+ haematopoietic progenitor stem cell differentiation into myeloid and erythroid colonies in vitro.
Collapse
Affiliation(s)
- Usha Padmanabhan
- Department of Cell Biology, Haffkine Institute for Training, Research & Testing, Mumbai, India
| | - Ritwik Dahake
- Department of Virology & Immunology, Haffkine Institute for Training, Research & Testing, Mumbai, India
| | - Abhay S Chowdhary
- Department of Microbiology, School of Medicine, D Y Patil University, Navi Mumbai, India
| | - Prasad S Koka
- Department of Virology & Immunology, Haffkine Institute for Training, Research & Testing, Mumbai, India
| |
Collapse
|
2
|
Kulkarni S, Mukherjee S, Das KMP, Prabhudesai K, Deshpande N, Karnik S, Chowdhary AS, Padmanabhan U. Expression of domain III of the envelope protein from GP-78: a Japanese encephalitis virus. Virusdisease 2017; 28:209-212. [PMID: 28770248 DOI: 10.1007/s13337-017-0379-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 04/20/2017] [Indexed: 12/22/2022] Open
Abstract
Acute encephalitis caused by the Japanese encephalitis virus (JEV) represents a growing epidemic and is a cause for concern in Southeast Asia. JEV is transmitted to humans through the bite of the Culicine mosquito species. The virus genome comprising of an RNA strand also encodes the envelope protein (E) which surrounds the virus. The E protein aids in fusion of virus with the cellular membrane of the host cell with the help of three structurally distinct domains (DI, DII, DIII) that are connected by flexible hinge regions. Of these domains, DIII (JEV-DIII) has been reported to interact with the cellular membrane, aid viral entry and viral replication. Hence JEV-DIII has the potential to be an antigen that can provide immune protection to a JEV infection. In this study, we describe the cloning and expression of DIII of GP-78, a virulent strain of JEV prevalent in India. Our data clearly shows that JEV-DIII expressed from pVAC1 in HEK293T cells is membrane targeted. To our knowledge, this is the first demonstration of a recombinant construct that may block JEV entry into the cells and/or evoke specific antibodies against JEV. Future studies will reveal if our construct will elicit significant immune responses which will alleviate or ameliorate the pro-inflammatory responses induced by JEV.
Collapse
Affiliation(s)
- Sahil Kulkarni
- Department of Zoonosis, Haffkine Institute for Training, Research and Testing, Acharya Donde Marg, Parel, Mumbai, 400 012 India
| | - Sandeepan Mukherjee
- Department of Virology, Haffkine Institute for Training, Research and Testing, Acharya Donde Marg, Parel, Mumbai, 400 012 India
| | | | - Kaushiki Prabhudesai
- Department of Zoonosis, Haffkine Institute for Training, Research and Testing, Acharya Donde Marg, Parel, Mumbai, 400 012 India
| | - Nupur Deshpande
- Department of Zoonosis, Haffkine Institute for Training, Research and Testing, Acharya Donde Marg, Parel, Mumbai, 400 012 India
| | - Sushant Karnik
- Department of Zoonosis, Haffkine Institute for Training, Research and Testing, Acharya Donde Marg, Parel, Mumbai, 400 012 India
| | - Abhay S Chowdhary
- Department of Virology, Haffkine Institute for Training, Research and Testing, Acharya Donde Marg, Parel, Mumbai, 400 012 India
| | - Usha Padmanabhan
- Department of Cell Biology, Haffkine Institute for Training, Research and Testing, Acharya Donde Marg, Parel, Mumbai, 400 012 India
| |
Collapse
|
3
|
Kulkarni S, Mukherjee S, Pandey A, Dahake R, Padmanabhan U, Chowdhary AS. Bacillus Calmette-Guérin Confers Neuroprotection in a Murine Model of Japanese Encephalitis. Neuroimmunomodulation 2016; 23:278-286. [PMID: 28208151 DOI: 10.1159/000452171] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 10/03/2016] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Japanese encephalitis (JE) is a debilitating disease caused by infection with the JE virus (JEV; family: Flaviviridae), which leaves neurological sequelae in survivors but more often leads to mortality. Neurodegeneration caused by inflammation is the primary pathology behind the clinical manifestation of encephalitis caused by JEV. Bacillus Calmette-Guérin (BCG) has been used in immunoprophylaxis for tuberculosis and in the adjuvant therapy of many malignancies, and has exhibited neuroprotective activities in experimental models of Parkinson and Alzheimer disease. This study aimed at assessing the neuroprotective role of BCG in a murine model of JE. METHODS Suckling mice were inoculated with 106 CFU of BCG and at 18 days postinoculation were challenged with 100 LD50 of JEV. PBS-inoculated mice were used as controls. Mice were sacrificed on days 2, 4, 6, and 8. Brain tissue was homogenized for RNA extraction. One-step real-time RT-PCR was performed to assess the relative gene expressions of TNF-α, IL-6, and iNOS. RESULTS The BCG-inoculated (BCG+JEV) group exhibited a significant delay in the presentation of neuropathological symptoms, longer survival, and a downregulation in the expression of TNF-α, IL-6, and iNOS on days 2, 4, and 6 post-JEV challenge compared to the JEV group. CONCLUSION These findings indicate that the administration of BCG offers neuroprotection in the murine model of JE. BCG should therefore be further investigated as an adjuvant in the management of JE. BCG is an accepted vaccine for tuberculosis in many countries that are endemic for JEV. This approach may have a significant impact on the public health burden in these countries.
Collapse
Affiliation(s)
- Sahil Kulkarni
- Department of Zoonosis, Haffkine Institute for Training, Research and Testing, Mumbai, India
| | | | | | | | | | | |
Collapse
|
4
|
Padmanabhan U, Leslie K, Eer AS, Maruff P, Silbert BS. Early Cognitive Impairment After Sedation for Colonoscopy: The Effect of Adding Midazolam and/or Fentanyl to Propofol. Anesth Analg 2009; 109:1448-55. [DOI: 10.1213/ane.0b013e3181a6ad31] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
5
|
Padmanabhan U, Dollins DE, Fridy PC, York JD, Downes CP. Characterization of a selective inhibitor of inositol hexakisphosphate kinases: use in defining biological roles and metabolic relationships of inositol pyrophosphates. J Biol Chem 2009; 284:10571-82. [PMID: 19208622 DOI: 10.1074/jbc.m900752200] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inositol hexakisphosphate kinases (IP6Ks) phosphorylate inositol hexakisphosphate (InsP(6)) to yield 5-diphosphoinositol pentakisphosphate (5-[PP]-InsP(5) or InsP(7)). In this study, we report the characterization of a selective inhibitor, N(2)-(m-(trifluoromethy)lbenzyl) N(6)-(p-nitrobenzyl)purine (TNP), for these enzymes. TNP dose-dependently and selectively inhibited the activity of IP6K in vitro and inhibited InsP(7) and InsP(8) synthesis in vivo without affecting levels of other inositol phosphates. TNP did not inhibit either human or yeast Vip/PPIP5K, a newly described InsP(6)/InsP(7) 1/3-kinase. Overexpression of IP6K1, -2, or -3 in cells rescued TNP inhibition of InsP(7) synthesis. TNP had no effect on the activity of a large number of protein kinases, suggesting that it is selective for IP6Ks. TNP reversibly reduced InsP(7)/InsP(8) levels. TNP in combination with genetic studies was used to implicate the involvement of two pathways for synthesis of InsP(8) in yeast. TNP induced a fragmented vacuole phenotype in yeast, consistent with inhibition of Kcs1, a Saccharomyces cerevisiae IP6K. In addition, it also inhibited insulin release from Min6 cells in a dose-dependent manner further implicating InsP(7) in this process. TNP thus provides a means of selectively and rapidly modulating cellular InsP(7) levels, providing a new and versatile tool to study the biological function and metabolic relationships of inositol pyrophosphates.
Collapse
Affiliation(s)
- Usha Padmanabhan
- Division of Molecular Physiology, James Black Centre, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | | | | | | | | |
Collapse
|
6
|
Abstract
A wide spectrum of practice in sedation for gastrointestinal endoscopy in adult patients is documented overseas, but a current profile of the practice of Australian anaesthetists is unavailable. We therefore surveyed 200 Fellows of the Australian and New Zealand College of Anaesthetists on the choice of drugs and monitoring, use of analgesic throat spray and prophylactic intravenous fluids and the depth of sedation for gastrointestinal endoscopy. Our response rate was 57% and endoscopy formed a significant part of most respondents’ practices. Propofol was used for almost all procedures, in combination with midazolam alone (14%), fentanyl alone (6%), midazolam and fentanyl (61%), another drug (15%) or no adjuvant(4%). The majority of patients received prophylactic intravenous fluids for endoscopic retrograde cholangio-pancreatography (83%) and colonoscopy (64%), but not for gastroscopy (20%). All patients received supplemental oxygen and monitoring with pulse oximetry. However, over 20% of patients having gastroscopy or colonoscopy did not have noninvasive blood pressure monitoring. A maximum depth of sedation during which the patient was unresponsive to painful stimulation (commensurate with general anaesthesia) was targeted by 54% of respondents. Significant variations exist in the practice of sedation and monitoring for endoscopy in adult patients by anaesthetists in Australia.
Collapse
Affiliation(s)
- U. Padmanabhan
- Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - K. Leslie
- Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, Melbourne, Victoria, Australia
- Head of Research, Department of Anaesthesia and Pain Management and Honorary Principal Fellow, Department of Pharmacology, University of Melbourne
| |
Collapse
|
7
|
Padmanabhan U, Dasgupta S, Biswas BB, Dasgupta D. High affinity association of myo-inositol trisphosphates with phytase and its effect upon the catalytic potential of the enzyme. J Biol Chem 2001; 276:43635-44. [PMID: 11527980 DOI: 10.1074/jbc.m107531200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 11/06/2022] Open
Abstract
A neutral phytase from germinating mung bean (Vigna radiata) seeds dephosphorylates myo-inositol hexakisphosphate sequentially to myo-inositol. The enzyme also binds with higher affinity to myo-inositol trisphosphates (1,4,5), (2,4,5), and (1,3,4) isomers without catalysis. The high affinity complex elicits Ca(2+) mobilization in vitro from microsomes/vacuoles via the formation of a ternary complex with the receptor for Ins(1,4,5)P(3). As a sequel to our previous report, we have carried out a detailed characterization of the two sites and examined the mutual interactions between them. Presaturation of the high affinity site leads to an increase in the affinity of the enzyme for phytic acid and its rate of dephosphorylation as well. From the products of limited tryptic cleavage of phytase, two peptides, each with one activity, have been isolated. The larger peptide ( approximately 66 kDa) contains the catalytic site, and the smaller peptide ( approximately 5 kDa) has the high affinity myo-inositol trisphosphate-binding site. The interaction between the dual activities of phytase has been observed also at the level of the two peptides. A sequence homology search using N-terminal 12 amino acid residues of the 5-kDa fragment has revealed significant homology with the Homer class of proteins implicated in signaling pathways involving metabotropic glutamate receptor and myo-inositol 1,4,5-trisphosphate receptor. These results indicate a second role of phytase in Ca(2+) mobilization during germination of mung been seed via a salvage pathway that involves allosteric activation by myo-inositol trisphosphate.
Collapse
Affiliation(s)
- U Padmanabhan
- Biophysics Division, Saha Institute of Nuclear Physics, 37 Belgachia Road, Kolkata 700 037, India
| | | | | | | |
Collapse
|
8
|
Padmanabhan U, Dasgupta S, Biswas BB, Dasgupta D. Effect of myo-inositol(1,4,5)trisphosphate on the hydrolysis of phytic acid by phytase. Indian J Biochem Biophys 2001; 38:53-5. [PMID: 11563331] [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] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Phytase is a monomeric enzyme of molecular mass 160 kDa which catalyzes the hydrolysis of phytic acid (D-myo inositol hexakisphosphate, InsP6) in a stepwise manner to myo-inositol. The enzyme-InsPn (n = 1-6) interaction at the catalytic site has a dissociation constant in the micro molar range. There also exists in the enzyme, a non-catalytic site specific for InsP3 with dissociation constant in the nano molar range. We have probed the effect of the high affinity InsP3 binding on the dissociation constant (Kd) of the phytase-InsP6 interaction and the kinetics of hydrolysis. These studies demonstrate the effect exerted by the high affinity InsP3 binding on the catalytic site of the enzyme.
Collapse
Affiliation(s)
- U Padmanabhan
- Biophysics Division, Saha Institute of Nuclear Physics, 37 Belgachia Road, Belgachia, Calcutta 700 037
| | | | | | | |
Collapse
|
9
|
Sit TL, White KA, Holy S, Padmanabhan U, Eweida M, Hiebert M, Mackie GA, AbouHaidar MG. Complete nucleotide sequence of clover yellow mosaic virus RNA. J Gen Virol 1990; 71 ( Pt 9):1913-20. [PMID: 2212986 DOI: 10.1099/0022-1317-71-9-1913] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [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: 12/30/2022] Open
Abstract
The entire genomic RNA of clover yellow mosaic virus was sequenced from cDNA clones and run-off cDNA transcripts. The genomic RNA is 7015 nucleotides in length [excluding a 3' poly(A) tail], with six open reading frames (ORFs) greater than 150 nucleotides in length. The first five ORFs encode proteins of Mr 191K, 26K, 12K, 6.5K and 28K, respectively. The sixth ORF lies completely within ORF1 and codes for a protein of Mr 14K. The capsid protein coding region (Mr 23K) is found within ORF5 which encodes the Mr 28K protein. Proteins encoded by ORFs 1 to 3 and ORF5 show strong homology with proteins of other potexviruses, especially papaya mosaic virus.
Collapse
Affiliation(s)
- T L Sit
- Department of Botany, University of Toronto, Ontario, Canada
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
The kinetic complexity of Acetabularia cliftonii chloroplast DNA is 1.52 +/- 0.26 . 10(9) daltons, compared to 0.2 .10(9) daltons for Chlamydomonas chloroplast DNA. There is an average of three genomes per chloroplast. The unusually large size of the Acetabularia genome may reflect the ancient evolutionary history of this organism.
Collapse
|
11
|
Padmanabhan U, Wort DJ. Metabolism and distribution of cyclohexanecarboxylic Acid, a plant growth stimulant, in bush bean. Plant Physiol 1977; 60:22-5. [PMID: 16660034 PMCID: PMC542538 DOI: 10.1104/pp.60.1.22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A foliar spray of 10 mm cyclohexanecarboxylic acid (CHC), a component of the growth stimulant naphthenic acid, to primary leaves of 14-day-old plants of bush bean, Phaseolus vulgaris L., cv Top Crop, resulted in increased vegetative growth and pod production. One minute after the application of 0.5 mm CHC-7-(14)C (CHC(*)) to a primary leaf, CHC(*) was present within it. The chief conversion of the CHC(*) in the leaf during the interval 15 minutes to 4 hours after the acid had been applied appeared to be CHC(*) to its glucose conjugate (CHC(*)-G), and during 4 to 48 hours, CHC(*)-G to CHC(*)-aspartate and an unknown metabolite. Radioactivity was confined to the leaf for at least 1 hour, but by the 12th hour was detected throughout the plant. In the interval 1 to 4 weeks after CHC(*) application, the mean percentage distribution of radioactivity was: treated leaf, 65.3; roots, 18.8; stem, 7.7; trifoliate leaves, 5.9; flower buds-flowers-pods, 2.3. During this period CHC(*)-G was the most prominent metabolite in all organs; no free CHC(*) was detected. Light favored the movement of CHC(*) conjugates out of the leaf; glucose fed to dark-grown plants substituted for light to some extent but aspartate was relatively ineffective, suggesting the dependence of outward movement on ATP. The presence of the glucose and aspartate conjugates of the acid in all organs of CHC-treated plants and the absence of free CHC from them suggest that one or both conjugates, rather than the acid itself, are involved in growth stimulation.
Collapse
Affiliation(s)
- U Padmanabhan
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | | |
Collapse
|