1
|
Neeraja CN, Hossain F, Hariprasanna K, Ram S, Satyavathi CT, Longvah L, Raghu P, Voleti SR, Sundaram RM. Towards nutrition security of India with biofortified cereal varieties. CURR SCI INDIA 2022. [DOI: 10.18520/cs/v123/i3/271-277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
2
|
Laxmaiah A, Rao NM, Arlappa N, Babu J, Kumar PU, Singh P, Sharma D, Anumalla VM, Kumar TS, Sabarinathan R, Kumar MS, Ananthan R, Basha DA, Blessy P, Kumar DC, Devaraj P, Devendra S, Kumar MM, Meshram II, Kumar BN, Sharma P, Raghavendra P, Raghu P, Rao KR, Ravindranadh P, Kumar BS, Sarika G, Rao JS, Surekha M, Sylvia F, Kumar D, Rao GS, Tallapaka KB, Sowpati DT, Srivastava S, Murhekar VM, Hemalatha R, Mishra RK. SARS-CoV-2 seroprevalence in the city of Hyderabad, India in early 2021. IJID Regions 2022; 2:1-7. [PMID: 35721436 PMCID: PMC8603330 DOI: 10.1016/j.ijregi.2021.10.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 12/17/2022]
Abstract
Background COVID-19 emerged as a global pandemic in 2020, spreading rapidly to most parts of the world. The proportion of infected individuals in a population can be reliably estimated via serosurveillance, making it a valuable tool for planning control measures. Our serosurvey study aimed to investigate SARS-CoV-2 seroprevalence in the urban population of Hyderabad at the end of the first wave of infections. Methods This cross-sectional survey, conducted in January 2021 and including males and females aged 10 years and above, used multi-stage random sampling. 9363 samples were collected from 30 wards distributed over six zones of Hyderabad, and tested for antibodies against SARS-CoV-2 nucleocapsid antigen. Results Overall seropositivity was 54.2%, ranging from 50% to 60% in most wards. Highest exposure appeared to be among those aged 30–39 and 50–59 years, with women showing greater seropositivity. Seropositivity increased with family size, with only marginal differences among people with varying levels of education. Seroprevalence was significantly lower among smokers. Only 11% of the survey subjects reported any COVID-19 symptoms, while 17% had appeared for COVID-19 testing. Conclusion Over half the city's population was infected within a year of onset of the pandemic. However, ∼ 46% of people remained susceptible, contributing to subsequent waves of infection.
Collapse
|
3
|
Sanjeeva Rao D, Neeraja CN, Madhu Babu P, Nirmala B, Suman K, Rao LVS, Surekha K, Raghu P, Longvah T, Surendra P, Kumar R, Babu VR, Voleti SR. Zinc Biofortified Rice Varieties: Challenges, Possibilities, and Progress in India. Front Nutr 2020; 7:26. [PMID: 32318582 PMCID: PMC7154074 DOI: 10.3389/fnut.2020.00026] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [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: 08/27/2019] [Accepted: 02/25/2020] [Indexed: 11/17/2022] Open
Abstract
Zinc malnutrition is a major issue in developing countries where polished rice is a staple food. With the existing significant genetic variability for high zinc in polished rice, the development of biofortified rice varieties was targeted in India with support from HarvestPlus, Department of Biotechnology, and Indian Council of Agricultural Research of Government of India. Indian Institute of Rice Research (IIRR) facilitates rice varietal release through All India Coordinated Rice Improvement Project (AICRIP) and also supports rice biofortification program in India. Various germplasm sets of several national institutions were characterized at IIRR for their zinc content in brown rice using energy-dispersive X-ray fluorescence spectroscopy indicating the range of zinc to be 7.3 to 52.7 mg/kg. Evaluation of different mapping populations involving wild germplasm, landraces, and varieties for their zinc content showed the feasibility of favorable recombination of high zinc content and yield. Ninety-nine genotypes from germplasm and 344 lines from mapping populations showed zinc content of ≥28 mg/kg in polished rice meeting the target zinc content set by HarvestPlus. Through AICRIP biofortification trial constituted since 2013, 170 test entries were nominated by various national institutions until 2017, and four biofortified rice varieties were released. Only the test entry with target zinc content, yield, and quality parameters is promoted to the next year; thus, each test entry is evaluated for 3 years across 17 to 27 locations for their performance. Multilocation studies of two mapping populations and AICRIP biofortification trials indicated the zinc content to be highly influenced by environment. The bioavailability of a released biofortified rice variety, viz., DRR Dhan 45 was found to twice that of control IR64. The technology efficacy of the four released varieties developed through conventional breeding ranged from 48 to 75% with zinc intake of 38 to be 47% and 46 to 57% of the RDA for male and female, respectively. The observations from the characterization of germplasm and mapping populations for zinc content and development of national evaluation system for the release of biofortified rice varieties have been discussed in the context of the five criteria set by biofortification program.
Collapse
Affiliation(s)
- D Sanjeeva Rao
- ICAR-Indian Institute of Rice Research, Hyderabad, India
| | - C N Neeraja
- ICAR-Indian Institute of Rice Research, Hyderabad, India
| | - P Madhu Babu
- ICAR-Indian Institute of Rice Research, Hyderabad, India
| | - B Nirmala
- ICAR-Indian Institute of Rice Research, Hyderabad, India
| | - K Suman
- ICAR-Indian Institute of Rice Research, Hyderabad, India
| | - L V Subba Rao
- ICAR-Indian Institute of Rice Research, Hyderabad, India
| | - K Surekha
- ICAR-Indian Institute of Rice Research, Hyderabad, India
| | - P Raghu
- ICMR-National Institute of Nutrition, Hyderabad, India
| | - T Longvah
- ICMR-National Institute of Nutrition, Hyderabad, India
| | - P Surendra
- Agricultural Research Station, University of Agricultural Sciences-D, Bangalore, India
| | - Rajesh Kumar
- Department of Plant Breeding and Genetics, AICRIP (Rice), Rajendra Agricultural University, Samastipur, India
| | | | - S R Voleti
- ICAR-Indian Institute of Rice Research, Hyderabad, India
| |
Collapse
|
4
|
Nimgulkar C, Ghosh S, Sankar AB, Uday KP, Surekha MV, Madhusudhanachary P, Annapurna BR, Raghu P, Bharatraj DK. Combination of spices and herbal extract restores macrophage foam cell migration and abrogates the athero-inflammatory signalling cascade of atherogenesis. Vascul Pharmacol 2015; 72:53-63. [PMID: 25869517 DOI: 10.1016/j.vph.2015.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [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] [Received: 10/14/2014] [Revised: 02/06/2015] [Accepted: 02/07/2015] [Indexed: 11/16/2022]
Abstract
The trapping of lipid-laden macrophages in the arterial intima is a critical but reversible step in atherogenesis. However, information about possible treatments for this condition is lacking. Here, we hypothesized that combining the polyphenol-rich fractions (PHC) of commonly consumed spices (Allium sativum L (Liliaceae), Zingiber officinale R (Zingiberaceae), Curcuma longa L (Zingiberaceae)) and herbs (Terminalia arjuna (R) W & A (Combretaceae) and Cyperus rotundus L (Cyperaceae)) prevents foam cell formation and atherogenesis. Using an in vitro foam cell formation assay, we found that PHC significantly inhibited lipid-laden macrophage foam cell formation compared to the depleted polyphenol fraction of PHC (F-PHC). We further observed that PHC attenuated the LDL and LPS induced CD36, p-FAK and PPAR-γ protein expression in macrophages and increased their migration. NK-κB-DNA interaction, TNF-α, ROS generation, and MMP9 and MMP2 protein expression were suppressed in PHC-treated macrophages. The anti-atherosclerotic activity of PHC was investigated in a high fat- and cholesterol-fed rabbit model. The inhibition of foam cell deposition within the aortic intima and atheroma formation confirmed the atheroprotective activity of PHC. Therefore, we conclude that the armoury of polyphenols in PHC attenuates the CD36 signalling cascade-mediated foam cell formation, enhances the migration of these cells and prevents atherogenesis.
Collapse
Affiliation(s)
- Chetan Nimgulkar
- Food and Drug Toxicology Research Centre, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India
| | - Sudip Ghosh
- Molecular Biology Unit, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India
| | - Anand B Sankar
- Molecular Biology Unit, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India
| | - Kumar P Uday
- Pathology Division, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India
| | - M V Surekha
- Pathology Division, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India
| | - P Madhusudhanachary
- Pathology Division, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India
| | - B R Annapurna
- Food and Drug Toxicology Research Centre, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India
| | - P Raghu
- Biophysics Division, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India
| | - Dinesh Kumar Bharatraj
- Food and Drug Toxicology Research Centre, National Institute of Nutrition, (ICMR), Jamai Osmania, Hyderabad 500 007, India.
| |
Collapse
|
5
|
Raghu P, Reddy TM, Gopal P, Reddaiah K, Sreedhar N. A novel horseradish peroxidase biosensor towards the detection of dopamine: A voltammetric study. Enzyme Microb Technol 2014; 57:8-15. [DOI: 10.1016/j.enzmictec.2014.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 01/02/2014] [Accepted: 01/04/2014] [Indexed: 11/30/2022]
|
6
|
Raghu P, Madhusudana Reddy T, Reddaiah K, Kumara Swamy B, Sreedhar M. Acetylcholinesterase based biosensor for monitoring of Malathion and Acephate in food samples: A voltammetric study. Food Chem 2014; 142:188-96. [DOI: 10.1016/j.foodchem.2013.07.047] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 07/08/2013] [Accepted: 07/10/2013] [Indexed: 10/26/2022]
|
7
|
Raghu P, Madhusudana Reddy T, Reddaiah K, Jaidev L, Narasimha G. A novel electrochemical biosensor based on horseradish peroxidase immobilized on Ag-nanoparticles/poly(l-arginine) modified carbon paste electrode toward the determination of pyrogallol/hydroquinone. Enzyme Microb Technol 2013; 52:377-85. [DOI: 10.1016/j.enzmictec.2013.02.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 02/21/2013] [Accepted: 02/24/2013] [Indexed: 11/17/2022]
|
8
|
Reddaiah K, Madhusudana Reddy T, Raghu P. Electrochemical investigation of L-dopa and simultaneous resolution in the presence of uric acid and ascorbic acid at a poly (methyl orange) film coated electrode: A voltammetric study. J Electroanal Chem (Lausanne) 2012. [DOI: 10.1016/j.jelechem.2012.07.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
9
|
Siruguri V, Kumar PU, Raghu P, Rao MVV, Sesikeran B, Toteja GS, Gupta P, Rao S, Satyanarayana K, Katoch V, Bharaj T, Mangat G, Sharma N, Sandhu J, Bhargav V, Rani S. Aflatoxin contamination in stored rice variety PAU 201 collected from Punjab, India. Indian J Med Res 2012; 136:89-97. [PMID: 22885269 PMCID: PMC3461724] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/30/2022] Open
Abstract
BACKGROUND & OBJECTIVES The present study was carried out on stored rice variety PAU 201 in Punjab that was not permitted for milling and public distribution due to the presence of damaged grains at levels exceeding the regulatory limits of 4.75 per cent. The aim of the study was to determine fungal and aflatoxin contamination in the rice samples to assess hazard from the presence of damaged grains. Presence of iron in discoloured rice grains was also assessed. METHODS Stored samples of paddy of PAU 201 rice variety were collected from six districts of Punjab, milled and analysed for presence of fungal and aflatoxin contamination. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and Prussian blue staining was used to determine fungal spores and presence of iron, respectively. RESULTS Aflatoxin analysis of rice samples indicated that none exceeded the Food Safety and Standards (Contaminants, Toxins and Residues) Regulations, 2011 tolerance limit of 30 μg/kg and majority of the samples had levels <15 μg/kg. The proportion of damaged grains exceeding the limit of 5 per cent was observed in 85.7 per cent of the samples. SEM and Prussian blue staining and EDX analysis of black tipped and pin point damaged rice grains did not show presence of fungal structures and presence of iron. INTERPRETATION & CONCLUSIONS The results of the study indicated that the stored rice samples did not pose any health concern with respect to aflatoxin contamination as per the criteria laid down by the Food Safety and Standards Authority of India.
Collapse
Affiliation(s)
| | - P Uday Kumar
- National Institute of Nutrition (ICMR), Hyderabad, India
| | - P. Raghu
- National Institute of Nutrition (ICMR), Hyderabad, India
| | | | - B. Sesikeran
- National Institute of Nutrition (ICMR), Hyderabad, India
| | - G. S. Toteja
- Indian Council of Medical Research, New Delhi, India,Reprint requests: Dr G.S. Toteja, Scientist F & Head (Nutrition), Indian Council of Medical Research, Ansari Nagar, New Delhi & “Centre for Promotion of Nutrition Research & Training with special focus on North-East, Tribal & Inaccessible population” (ICMR), ICMR Campus II, 3 Red Cross Road, Tuberculosis Association of India Building, 1st Floor, Near Parliament, New Delhi 110 001, India e-mail:
| | | | - Spriha Rao
- Indian Council of Medical Research, New Delhi, India
| | | | - V.M. Katoch
- Indian Council of Medical Research, New Delhi, India
| | - T.S. Bharaj
- Punjab Agricultural University, Ludhiana, Punjab, India
| | - G.S. Mangat
- Punjab Agricultural University, Ludhiana, Punjab, India
| | - Neerja Sharma
- Punjab Agricultural University, Ludhiana, Punjab, India
| | - J.S. Sandhu
- Indian Council of Agricultural Research, New Delhi, India
| | - V.K. Bhargav
- Central Institute of Post-Harvest Engineering & Technology, Ludhiana, India
| | - Shobha Rani
- Directorate of Rice Research (ICAR), Hyderabad, India
| |
Collapse
|
10
|
Raghu P, Kumara Swamy B, Madhusudana Reddy T, Chandrashekar B, Reddaiah K. Sol–gel immobilized biosensor for the detection of organophosphorous pesticides: A voltammetric method. Bioelectrochemistry 2012; 83:19-24. [DOI: 10.1016/j.bioelechem.2011.08.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 08/01/2011] [Accepted: 08/01/2011] [Indexed: 10/17/2022]
|
11
|
Raghu P, Nere CK, Jagtap RN. Effect of styrene-isoprene-styrene, styrene-butadiene-styrene, and styrene-butadiene-rubber on the mechanical, thermal, rheological, and morphological properties of polypropylene/polystyrene blends. J Appl Polym Sci 2003. [DOI: 10.1002/app.11677] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
12
|
Hardie RC, Martin F, Cochrane GW, Juusola M, Georgiev P, Raghu P. Molecular basis of amplification in Drosophila phototransduction: roles for G protein, phospholipase C, and diacylglycerol kinase. Neuron 2002; 36:689-701. [PMID: 12441057 DOI: 10.1016/s0896-6273(02)01048-6] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [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: 10/26/2022]
Abstract
In Drosophila photoreceptors, the amplification responsible for generating quantum bumps in response to photoisomerization of single rhodopsin molecules has been thought to be mediated downstream of phospholipase C (PLC), since bump amplitudes were reportedly unaffected in mutants with greatly reduced levels of either G protein or PLC. We now find that quantum bumps in such mutants are reduced approximately 3- to 5-fold but are restored to near wild-type values by mutations in the rdgA gene encoding diacylglycerol kinase (DGK) and also by depleting intracellular ATP. The results demonstrate that amplification requires activation of multiple G protein and PLC molecules, identify DGK as a key enzyme regulating amplification, and implicate diacylglycerol as a messenger of excitation in Drosophila phototransduction.
Collapse
Affiliation(s)
- R C Hardie
- Department of Anatomy, Cambridge University, Downing Street, Cambridge, United Kingdom
| | | | | | | | | | | |
Collapse
|
13
|
Abstract
Transthyretin (TTR), a homotetrameric thyroxine transport protein found in the plasma and cerebrospinal fluid, circulates normally as a innocuous soluble protein. In some individuals, TTR polymerizes to form insoluble amyloid fibrils. TTR amyloid fibril formation and deposition have been associated with several diseases like familial amyloid polyneuropathy and senile systemic amyloidosis. Inhibition of the fibril formation is considered a potential strategy for the therapeutic intervention. The effect of small water-soluble, hydrophobic ligand 2,4-dinitrophenol (2,4-DNP) on TTR amyloid formation has been tested. 2,4-DNP binds to TTR both at acidic and physiological pH, as shown by the quenching of TTR intrinsic fluorescence. Interestingly, 2,4-DNP not only binds to TTR at acidic pH but also inhibits amyloid fibril formation as shown by the light scattering and Congo red-binding assay. Inhibition of fibril formation by 2,4-DNP appears to be through the stabilization of TTR tetramer upon binding to the protein, which includes active site. These findings may have implications for the development of mechanism based small molecular weight compounds as therapeutic agents for the prevention/inhibition of the amyloid diseases.
Collapse
Affiliation(s)
- P Raghu
- National Institute of Nutrition, Indian Council of Medical Research, Hyderabad 500 007, India
| | | | | |
Collapse
|
14
|
Abstract
The brain's capacity to analyse and interpret information is limited ultimately by the input it receives. This sets a premium on information capacity of sensory receptors, which can be maximized by optimizing sensitivity, speed and reliability of response. Nowhere is selection pressure for information capacity stronger than in the visual system, where speed and sensitivity can mean the difference between life and death. Phototransduction in flies represents the fastest G-protein-signalling cascade known. Analysis in Drosophila has revealed many of the underlying molecular strategies, leading to the discovery and characterization of signalling molecules of widespread importance.
Collapse
Affiliation(s)
- R C Hardie
- Department of Anatomy, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
| | | |
Collapse
|
15
|
Hardie RC, Raghu P, Moore S, Juusola M, Baines RA, Sweeney ST. Calcium influx via TRP channels is required to maintain PIP2 levels in Drosophila photoreceptors. Neuron 2001; 30:149-59. [PMID: 11343651 DOI: 10.1016/s0896-6273(01)00269-0] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.3] [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: 01/01/2023]
Abstract
The trp (transient receptor potential) gene encodes a Ca2+ channel responsible for the major component of the phospholipase C (PLC) mediated light response in Drosophila. In trp mutants, maintained light leads to response decay and temporary total loss of sensitivity (inactivation). Using genetically targeted PIP2-sensitive inward rectifier channels (Kir2.1) as biosensors, we provide evidence that trp decay reflects depletion of PIP2. Two independent mutations in the PIP2 recycling pathway (rdgB and cds) prevented recovery from inactivation. Abolishing Ca2+ influx in wild-type photoreceptors mimicked inactivation, while raising Ca2+ by blocking Na+/Ca2+ exchange prevented inactivation in trp. The results suggest that Ca2+ influx prevents PIP2 depletion by inhibiting PLC activity and facilitating PIP2 recycling. Without this feedback one photon appears sufficient to deplete the phosphoinositide pool of approximately 4 microvilli.
Collapse
Affiliation(s)
- R C Hardie
- Department of Anatomy, Cambridge, United Kingdom.
| | | | | | | | | | | |
Collapse
|
16
|
Raghu P, Colley NJ, Webel R, James T, Hasan G, Danin M, Selinger Z, Hardie RC. Normal phototransduction in Drosophila photoreceptors lacking an InsP(3) receptor gene. Mol Cell Neurosci 2000; 15:429-45. [PMID: 10833300 DOI: 10.1006/mcne.2000.0846] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [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: 11/22/2022] Open
Abstract
The Drosophila light-sensitive channels TRP and TRPL are prototypical members of an ion channel family responsible for a variety of receptor-mediated Ca(2+) influx phenomena, including store-operated calcium influx. While phospholipase Cbeta is essential, downstream events leading to TRP and TRPL activation remain unclear. We investigated the role of the InsP(3) receptor (InsP(3)R) by generating mosaic eyes homozygous for a deficiency of the only known InsP(3)R gene in Drosophila. Absence of gene product was confirmed by RT-PCR, Western analysis, and immunocytochemistry. Mutant photoreceptors underwent late onset retinal degeneration; however, whole-cell recordings from young flies demonstrated that phototransduction was unaffected, quantum bumps, macroscopic responses in the presence and absence of external Ca(2+), light adaptation, and Ca(2+) release from internal stores all being normal. Using the specific TRP channel blocker La(3+) we demonstrated that both TRP and TRPL channel functions were unaffected. These results indicate that InsP(3)R-mediated store depletion does not underlie TRP and TRPL activation in Drosophila photoreceptors.
Collapse
MESH Headings
- Animals
- Calcium/metabolism
- Calcium Channels/genetics
- Calcium Channels/metabolism
- Drosophila melanogaster/physiology
- Gene Deletion
- Homozygote
- Immunohistochemistry
- Inositol 1,4,5-Trisphosphate Receptors
- Light
- Microscopy, Electron
- Microscopy, Electron, Scanning
- Mutation/physiology
- Photoreceptor Cells, Invertebrate/physiology
- Photoreceptor Cells, Invertebrate/radiation effects
- Photoreceptor Cells, Invertebrate/ultrastructure
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Reference Values
- Tissue Distribution
- Vision, Ocular/physiology
Collapse
Affiliation(s)
- P Raghu
- Department of Anatomy, Cambridge University, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Raghu P, Usher K, Jonas S, Chyb S, Polyanovsky A, Hardie RC. Constitutive activity of the light-sensitive channels TRP and TRPL in the Drosophila diacylglycerol kinase mutant, rdgA. Neuron 2000; 26:169-79. [PMID: 10798401 DOI: 10.1016/s0896-6273(00)81147-2] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.8] [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: 11/18/2022]
Abstract
Mutations in the Drosophila retinal degeneration A (rdgA) gene, which encodes diacylglycerol kinase (DGK), result in early onset retinal degeneration and blindness. Whole-cell recordings revealed that light-sensitive Ca2+ channels encoded by the trp gene were constitutively active in rdgA photoreceptors. Early degeneration was rescued in rdgA;trp double mutants, lacking TRP channels; however, the less Ca2+-permeable light-sensitive channels (TRPL) were constitutively active instead. No constitutive activity was seen in rdgA;trpI;trp mutants lacking both classes of channel, although, like rdgA;trp, these still showed a residual slow degeneration. Responses to light were restored in rdgA;trp but deactivated abnormally slowly, indicating that DGK is required for response termination. The findings suggest that early degeneration in rdgA is caused by uncontrolled Ca2+ influx and support the proposal that diacylglycerol or its metabolites are messengers of excitation in Drosophila photoreceptors.
Collapse
Affiliation(s)
- P Raghu
- Department of Anatomy, Cambridge University, United Kingdom
| | | | | | | | | | | |
Collapse
|
18
|
Abstract
Phototransduction in invertebrate microvillar photoreceptors is thought to be mediated by the activation of phospholipase C (PLC), but how this leads to gating of the light-sensitive channels is unknown. Most attention has focused on inositol-1,4,5-trisphosphate, a second messenger produced by PLC from phosphatidylinositol-4,5-bisphosphate; however, PLC also generates diacylglycerol, a potential precursor for several polyunsaturated fatty acids, such as arachidonic acid and linolenic acid. Here we show that both of these fatty acids reversibly activate native light-sensitive channels (transient receptor potential (TRP) and TRP-like (TRPL)) in Drosophila photoreceptors as well as recombinant TRPL channels expressed in Drosophila S2 cells. Recombinant channels are activated rapidly in both whole-cell recordings and inside-out patches, with a half-maximal effector concentration for linolenic acid of approximately 10 microM. Four different lipoxygenase inhibitors, which might be expected to lead to build-up of endogenous fatty acids, also activate native TRP and TRPL channels in intact photoreceptors. As arachidonic acid may not be found in Drosophila, we suggest that another polyunsaturated fatty acid, such as linolenic acid, may be a messenger of excitation in Drosophila photoreceptors.
Collapse
Affiliation(s)
- S Chyb
- Cambridge University Department of Anatomy, UK
| | | | | |
Collapse
|
19
|
Abstract
Light-sensitive channels encoded by the Drosophila transient receptor potential-like gene (trpl) are activated in situ by an unknown mechanism requiring activation of Gq and phospholipase C (PLC). Recent studies have variously concluded that heterologously expressed TRPL channels are activated by direct Gq-protein interaction, InsP3 or Ca2+. In an attempt to resolve this confusion we have explored the mechanism of activation of TRPL channels co-expressed with a PLC-specific muscarinic receptor in a Drosophila cell line (S2 cells). Simultaneous whole-cell recordings and ratiometric Indo-1 Ca2+ measurements indicated that agonist (CCh)-induced activation of TRPL channels was not always associated with a rise in Ca2+. Internal perfusion with BAPTA (10 mM) reduced, but did not block, the response to agonist. In most cases, releasing caged Ca2+ facilitated the level of spontaneous channel activity, but similar concentrations (200-500 nM) could also inhibit TRPL activity. Releasing caged InsP3 invariably released Ca2+ from internal stores but had only a minor influence on TRPL activity and none at all when Ca2+ release was buffered with BAPTA. Caged InsP3 also failed to activate any light-sensitive channels in situ in Drosophila photoreceptors. Two phospholipase C inhibitors (U-73122 4 microM and bromo-phenacyl bromide 50 microM) reduced both spontaneous and agonist-induced TRPL activity in S2 cells. The results suggest that, as in situ, TRPL activation involves G-protein and PLC; that Ca2+ can both facilitate and in some cases inhibit TRPL channels, but that neither Ca2+ nor InsP3 is the primary activator of the channel.
Collapse
Affiliation(s)
- R C Hardie
- Department of Anatomy, Cambridge University, UK.
| | | |
Collapse
|
20
|
Raghu P, Habib S, Hasnain SE, Hasan G. Development of a functional assay for Ca2+ release activity of IP3R and expression of an IP3R gene fragment in the baculovirus-insect cell system. Gene 1997; 190:151-6. [PMID: 9185861 DOI: 10.1016/s0378-1119(97)80001-7] [Citation(s) in RCA: 2] [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: 02/04/2023]
Abstract
Receptor-stimulated phosphoinositide (PI) hydrolysis is an important and ubiquitous mechanism of intracellular signaling. Inositol 1,4,5-trisphosphate (IP3), generated by phosphoinositide (PI) hydrolysis, binds to and gates an intracellular Ca2+ channel, the IP3 receptor (IP3R), which is therefore a central component of this signaling cascade. Here we describe the development of a baculovirus (BV)/Sf (S. frugiperda) cell system that can be used to look at IP3R function. Agonist-evoked changes in intracellular Ca2+ levels [Ca2+]i were measured (using Fura2) in Sf cells expressing the gene encoding the muscarinic acetylcholine receptor (vm1AchR). Furthermore, we have constructed a recombinant BV (vIP3R), with the core of the IP3R ligand-binding domain from the Drosophila IP3R, under the polyhedrin promoter. The recombinant protein from such a virus was expected to act as a large ligand sink for IP3, generated by stimulation of vm1AchR. Cells coinfected with recombinant BV carrying the potential dominant-negative vIP3R construct and vm1AchR have been used to assay the modulation of IP3R-mediated Ca2+ release, by the ligand sink.
Collapse
Affiliation(s)
- P Raghu
- National Center for Biological Sciences, TIFR Center, IISc Campus, Bangalore, India
| | | | | | | |
Collapse
|
21
|
Raghu P, Hasan G. The inositol 1,4,5-triphosphate receptor expression in Drosophila suggests a role for IP3 signalling in muscle development and adult chemosensory functions. Dev Biol 1995; 171:564-77. [PMID: 7556937 DOI: 10.1006/dbio.1995.1305] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [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: 01/25/2023]
Abstract
Inositol 1,4,5-triphosphate (IP3) is generated as a second messenger in many diverse cellular signalling pathways. In general these signalling pathways activate a membrane-bound phospholipase C, which cleaves the phospholipid phosphatidylinositol bisphosphate to generate IP3 and diacylglycerol. IP3 binds to a specific intracellular receptor, which is a membrane protein and a ligand-gated Ca2+ channel, that causes Ca2+ release from intracellular stores. The inositol 1,4,5-triphosphate receptor (IP3R) is thus an integral part of the IP3 signalling pathway and can be used as a marker to identify biological processes that use IP3 as a second messenger. We have used an affinity-purified antibody, directed against a bacterial fusion protein and containing 339 amino acids of the Drosophila IP3R, to detect this protein in adult heads and during embryonic and pupal development. Our results suggest that in Drosophila the IP3 signalling pathway is used during muscle development, primarily when myoblasts undergo rapid multiplication, in both embryos and pupae. In adults, IP3 is probably a second messenger in more than one sensory transduction pathway, as well as in other as yet undefined brain and muscle functions.
Collapse
Affiliation(s)
- P Raghu
- National Centre for Biological Sciences, TIFR Centre, Bangalore, India
| | | |
Collapse
|
22
|
Sutton M, Klaff LJ, Asplin CM, Clemons P, Tatpati O, Lyen K, Raghu P, Baker L, Guthrie R, Sperling M. Insulin autoantibodies at diagnosis of insulin-dependent diabetes: effect on the antibody response to insulin treatment. Metabolism 1988; 37:1005-7. [PMID: 3185283 DOI: 10.1016/0026-0495(88)90058-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Insulin autoantibodies (IAA) are frequently found in newly diagnosed untreated insulin-dependent diabetics. We evaluated whether the insulin antibody response over the first year of treatment with insulin was different in individuals with IAA v those without IAA. One hundred five previously untreated type I diabetics were randomly assigned to treatment with either pure porcine or mixed bovine/porcine insulin. Twenty-one in each group had detectable IAA at diagnosis. Percent binding rose in all patients after commencing insulin therapy and was significantly greater in those with IAA at diagnosis irrespective of the type of insulin administered. The elevated binding in the IAA positive patients at all time points was equivalent to the binding that could be attributed to the insulin autoantibodies. Two different mechanisms could explain this greater insulin antibody binding during insulin therapy in the IAA positive patients. First, there may be summation of binding due to insulin autoantibodies and binding due to insulin antibodies formed in response to the exogenous insulin. Alternatively, the insulin antibodies formed in response to exogenous insulin could replace the IAA, with those individuals positive for IAA at diagnosis having a proportionately greater antibody response to injected insulin. Irrespective of the mechanism, patients with IAA at diagnosis develop higher insulin antibody measurements when subsequently treated with exogenous insulin.
Collapse
Affiliation(s)
- M Sutton
- Department of Medicine, University of Washington, Seattle
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Johnston C, Raghu P, McCulloch DK, Beard JC, Ward WK, Klaff LJ, McKnight B, Bergman RN, Palmer JP. Beta-cell function and insulin sensitivity in nondiabetic HLA-identical siblings of insulin-dependent diabetics. Diabetes 1987; 36:829-37. [PMID: 3556281 DOI: 10.2337/diab.36.7.829] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Insulin secretion and insulin sensitivity were compared in 12 HLA-identical siblings of insulin-dependent diabetics and nondiabetic controls. Only the maximum acute insulin response to intravenous arginine was lower in the siblings than in the matched controls (P less than .05); other measures of insulin secretion, including the acute insulin response to glucose or arginine, the second-phase insulin response to glucose, and the slope of glucose potentiation, were not significantly different. Insulin sensitivity, derived from an intravenous glucose tolerance test with a minimal-modeling technique, was lower in the siblings (P less than .01). In a large group of nondiabetic controls of various adiposity, insulin secretion and insulin sensitivity were inversely related. In view of the difference in insulin sensitivity between siblings and matched controls, a direct comparison of beta-cell function tests may be inappropriate, and the measures of insulin secretion were compared with those of nondiabetics when adjusted for differences in insulin sensitivity. This analysis revealed that all measures of insulin secretion were significantly lower in the siblings. We conclude that HLA-identical siblings of insulin-dependent diabetics show evidence of both insulin resistance and impaired beta-cell function and that analysis of beta-cell function in relation to insulin sensitivity shows a greater frequency of beta-cell secretory abnormalities than previously appreciated.
Collapse
|
24
|
Asplin C, Raghu P, Clemons P, Lyen K, Tatpati O, McKnight B, Baker L, Guthrie R, Sperling M, Palmer J. Randomized prospective trial of pure porcine and conventional bovine/porcine insulin. Diabetes Care 1987; 10:337-42. [PMID: 2954800 DOI: 10.2337/diacare.10.3.337] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Use of pure porcine insulin versus partially purified insulin of bovine/porcine origin might be expected to have certain clinical benefits, e.g., a lower incidence of skin reactions, a lower insulin dosage, better diabetes regulation, and greater preservation of endogenous insulin secretion. To test this hypothesis, we randomly assigned 112 newly diagnosed, untreated, insulin-dependent diabetic children to therapy with either pure porcine or partially purified bovine/porcine insulin. They were followed for 1 yr, data being available on at least 90 subjects at each visit. More skin reactions were found in the group treated with the bovine/porcine insulin. This insulin was of higher antigenicity, and binding of radiolabeled insulin (mean +/- SE) by serum from bovine/porcine insulin treatment was 35.5 +/- 2.6 versus 16.8 +/- 1.4% (P less than .001) for pure porcine insulin treatment 12 mo after initiation of insulin therapy. However, throughout the 12 mo of observation the levels of glycosylated hemoglobin, insulin dosage, fasting plasma glucose, and C-peptide concentration were similar for the groups. Reported incidences of hypoglycemia and nocturia were also similar. Thus, insulin-antibody formation and skin reactions were minimized by the use of pure porcine versus partially purified bovine/porcine insulin, but no other clinical advantages were apparent.
Collapse
|
25
|
Raghu P, Johnston C, Beard JC, Bergman R, McCulloch DK, Palmer JP. Reduced insulin sensitivity in nondiabetic, HLA-identical siblings of insulin-dependent diabetic subjects. Diabetes 1985; 34:991-4. [PMID: 4043555 DOI: 10.2337/diab.34.10.991] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nondiabetic, HLA-identical siblings of insulin-dependent diabetic subjects have an increased risk of developing diabetes. Since insulin resistance is present in newly diagnosed diabetic subjects, we studied 12 HLA-identical siblings to determine whether they have impaired insulin sensitivity. Each sibling was carefully matched for age, sex, and body weight to a control from a nondiabetic family. The insulin sensitivity index (SI) was determined after an intravenous glucose tolerance test (IVGTT) using the minimal model of insulin kinetics. The insulin sensitivity index was significantly lower in the HLA-identical siblings compared with their matched controls.
Collapse
|
26
|
Abstract
To investigate whether glucose has an effect on the pancreatic A cell independent of intraislet or paracrine B cell mediation, we have tested the ability of changes in plasma glucose (PG) level to influence the acute glucagon response (AGR) to 5 g of intravenous arginine in 8 C-peptide negative insulin dependent diabetics (IDD). Insulin was infused (1 mU/kg/min) for a 90 min basal period during which PG levels were maintained constant by the glucose clamp technique. Basal AGR was then determined. In 4 of the diabetics, the PG level was subsequently lowered to a new steady state and, in 2 diabetics, PG level was raised. In 2 additional IDDs, two manipulations in PG level were carried out (PG ranges 51-390 mg/dl). The same insulin infusion was continued throughout. The acute glucagon response to arginine was determined at each PG level. The ability of unit changes in PG to influence (modulate) the AGR (MdIRG) was calculated as the difference in AGRs divided by the PG difference. MdIRG was consistent between diabetics (means +/- SEM = 2.1 +/- 0.2) and was independent of both direction and magnitude of the PG change. Thus, in vivo, in man, glucose has an effect on the pancreatic A cell which is independent of intraislet B cell influences.
Collapse
|
27
|
Raghu P, Dornan T, Dye B, Palmer JP. Diabetes mellitus and skeletal fracture. JAMA 1983; 249:353. [PMID: 6336800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
28
|
|
29
|
Anjaneyulu A, Raghu P, Rao K, Row L. Synthetic experiments in lignans part IV. Observation of unusual loss bromine or methoxyl substituents during thermal cyclization of 1,2-diarylidene succinic anhydrides. Tetrahedron Lett 1978. [DOI: 10.1016/s0040-4039(00)70547-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|