12 results on '"Kumar, Amit"'
Search Results
2. Potential Drugs Targeting Nsp16 Protein May Corroborates a Promising Approach to Combat SARSCoV-2 Virus
- Author
-
Mishra Subodh Kumar, Shankar Uma, Rathi Brijesh, Kumar Amit, Majee Prativa, and Jain Neha
- Subjects
Drug ,biology ,media_common.quotation_subject ,Hepatitis C virus ,Druggability ,Active site ,Translation (biology) ,Computational biology ,SIRT2 ,medicine.disease_cause ,Virus ,Immune system ,medicine ,biology.protein ,media_common - Abstract
The recent ongoing pandemic caused by SARS-CoV-2 continues to impose devastating impacts and is accountable for the loss of more than 250,000 human lives within a short span of four months. This urges immediate therapeutic measures to control the impact of this disease. One of the most conserved and potentially druggable sites is the Nsp16 active site that performs the 2’-O-methyltransferase activity and puts a 5’ cap on the viral RNA molecules. This allows them to mimic endogenous transcripts for the efficient translation of viral proteins and evasion of the immune response. Herein, we screened three libraries of compounds (>5500) with chemical diversity to identify hits against Nsp16 active site of SARS-CoV-2. From each library a top hit was identified, namely Velpatasvir from the FDA compounds; JFD00244 from the LOPAC library and compound 6 from the SAM based analog library. Interestingly, all three hits showed higher affinity than the positive controls. Velpatasvir is a known anti-viral drug used against Hepatitis C virus, and JFD00244 is a SIRT2 inhibitor. 100ns molecular simulation studies showed all three molecules to have stable and energetically favourable interactions with the active site of Nsp16. In summary, this investigation identified three potential drug candidates that are predicted to be potent Nsp16 inhibitors and could be pursued further in cell-based studies.
- Published
- 2020
3. Ocean acidification affects biological activities of seaweeds: A case study of Sargassum vulgare from Ischia volcanic CO₂ vents
- Author
-
Kumar, Amit, Buia, Maria Cristina, Palumbo, Anna, Mohany, Mohamed, Wadaan, Mohammed A. M., Hozzein, Wael N., Beemster, Gerrit, and Abd Elgawad, Hamada
- Subjects
Chemistry ,Biology - Abstract
We utilized volcanic CO2 vents at Castello Aragonese off Ischia Island as a natural laboratory to investigate the effect of lowered pH/elevated CO2 on the bioactivities of extracts from fleshy brown algae Sargassum vulgare C. Agardh. We analysed the carbohydrate levels, antioxidant capacity, antibacterial, antifungal, antiprotozoal, anticancer properties and antimutagenic potential of the algae growing at the acidified site (pH similar to 6.7) and those of algae growing at the nearby control site Lacco Ameno (pH similar to 8.1). The results of the present study show that the levels of polysaccharides fucoidan and alginate were higher in the algal population at acidified site. In general, extracts for the algal population from the acidified site showed a higher antioxidant capacity, antilipidperoxidation, antibacterial, antifungal, antiprotozoal, anticancer activities and antimutagenic potential compared to the control population. The increased bioactivity in acidified population could be due to elevated levels of bioactive compounds of algae and/or associated microbial communities. In this snapshot study, we performed bioactivity assays but did not characterize the chemistry and source of presumptive bioactive compounds. Nevertheless, the observed improvement in the medicinal properties of S. vulgare in the acidified oceans provides a promising basis for future marine drug discovery. (C) 2019 Elsevier Ltd. All rights reserved.
- Published
- 2020
4. Corrosion inhibition by Justicia gendarussa plant extract in hydrochloric acid solution
- Author
-
G. Gunasekaran, Kumar Amit, A.K. Satapathy, P.V. Rodrigues, and S.C. Sahoo
- Subjects
biology ,Carbon steel ,Chemistry ,General Chemical Engineering ,Metallurgy ,Double-layer capacitance ,technology, industry, and agriculture ,Langmuir adsorption model ,Hydrochloric acid ,General Chemistry ,engineering.material ,biology.organism_classification ,Justicia gendarussa ,Corrosion ,symbols.namesake ,Corrosion inhibitor ,chemistry.chemical_compound ,Adsorption ,symbols ,engineering ,General Materials Science ,Nuclear chemistry - Abstract
Corrosion inhibition effect of Justicia gendarussa extract (JGPE) on mild steel in 1 M HCl medium has been investigated by weight loss and electrochemical techniques. Inhibition efficiency of 93% was achieved with 150 ppm JGPE at 25 °C. The polarization studies showed that JGPE acts as mixed-type inhibitor. The Nyquist plots showed that on increasing JGPE concentration, increases charge transfer resistance and decreases double layer capacitance. JGPE obeys the Langmuir adsorption isotherm. AFM and ESCA confirmed the adsorption of JGPE on mild steel surface. Finally, JGPE inhibition efficiency was discussed in terms of adsorption and protective film formation.
- Published
- 2009
5. Interaction between HLA-DRB1-DQB1 Haplotypes in Sardinian Multiple Sclerosis Population.
- Author
-
Cocco, Eleonora, Murru, Raffaele, Costa, Gianna, Kumar, Amit, Pieroni, Enrico, Melis, Cristina, Barberini, Luigi, Sardu, Claudia, Lorefice, Lorena, Fenu, Giuseppe, Frau, Jessica, Coghe, Giancarlo, Carboni, Nicola, and Marrosu, Maria Giovanna
- Subjects
MULTIPLE sclerosis risk factors ,HAPLOTYPES ,ALLELES ,MOLECULAR dynamics ,CELL communication ,CASE-control method ,MEDICAL statistics - Abstract
We performed a case-control study in 2,555 multiple sclerosis (MS) Sardinian patients and 1,365 healthy ethnically matched controls, analyzing the interactions between HLA-DRB1-DQB1 haplotypes and defining a rank of genotypes conferring a variable degree of risk to the disease. Four haplotypes were found to confer susceptibility (*13∶03-*03∶01 OR = 3.3, Pc 5.1×10
−5 , *04∶05-*03∶01 OR = 2.1, Pc 9.7×10−8 , *15∶01-*06∶02 OR = 2.0, Pc = 9.1×10−3 , *03∶01-*02∶01 OR = 1.7 Pc = 7.9×10−22 ) and protection (*11, OR = 0.8, Pc = 2.7×10−2 , *16∶01-*05∶02 OR = 0.6, Pc = 4.8×10−16 , *14∶01-4-*05∶031 = OR = 0.5, Pc = 9.8×10−4 and *15∶02-*06∶01 OR = 0.4, Pc = 5.1×10−4 ). The relative predispositional effect method confirms all the positively associated haplotypes and showed that also *08 and *04 haplotypes confers susceptibility, while the *11 was excluded as protective haplotype. Genotypic ORs highlighted two typologies of interaction between haplotypes: i) a neutral interaction, in which the global risk is coherent with the sum of the single haplotype risks; ii) a negative interaction, in which the genotypic OR observed is lower than the sum of the OR of the two haplotypes. The phylogenic tree of the MS-associated DRB1 alleles found in Sardinian patients revealed a cluster represented by *14∶01, *04∶05, *13∶03, *08∶01 and *03∶01 alleles. Sequence alignment analysis showed that amino acids near pocket P4 and pocket P9 differentiated protective from predisposing alleles under investigation. Furthermore, molecular dynamics simulation performed on alleles revealed that position 70 is crucial in binding of MBP 85–99 peptide. All together, these data suggest that propensity to MS observed in Sardinian population carried by the various HLA-DRB1-DQB1 molecules can be due to functional peculiarity in the antigen presentation mechanisms. [ABSTRACT FROM AUTHOR]- Published
- 2013
- Full Text
- View/download PDF
6. Structural and Dynamical Insights on HLA-DR2 Complexes That Confer Susceptibility to Multiple Sclerosis in Sardinia: A Molecular Dynamics Simulation Study.
- Author
-
Kumar, Amit, Cocco, Eleonora, Atzori, Luigi, Marrosu, Maria Giovanna, and Pieroni, Enrico
- Subjects
- *
MULTIPLE sclerosis , *HLA histocompatibility antigens , *MOLECULAR dynamics , *DISEASE susceptibility , *DISEASE incidence , *CENTRAL nervous system diseases - Abstract
Sardinia is a major Island in the Mediterranean with a high incidence of multiple sclerosis, a chronic autoimmune inflammatory disease of the central nervous system. Disease susceptibility in Sardinian population has been associated with five alleles of major histocompatibility complex (MHC) class II DRB1 gene. We performed 120 ns of molecular dynamics simulation on one predisposing and one protective alleles, unbound and in complex with the two relevant peptides: Myelin Basic Protein and Epstein Barr Virus derived peptide. In particular we focused on the MHC peptide binding groove dynamics. The predisposing allele was found to form a stable complex with both the peptides, while the protective allele displayed stability only when bound with myelin peptide. The local flexibility of the MHC was probed dividing the binding groove into four compartments covering the well known peptide anchoring pockets. The predisposing allele in the first half cleft exhibits a narrower and more rigid groove conformation in the presence of myelin peptide. The protective allele shows a similar behavior, while in the second half cleft it displays a narrower and more flexible groove conformation in the presence of viral peptide. We further characterized these dynamical differences by evaluating H-bonds, hydrophobic and stacking interaction networks, finding striking similarities with super-type patterns emerging in other autoimmune diseases. The protective allele shows a defined preferential binding to myelin peptide, as confirmed by binding free energy calculations. All together, we believe the presented molecular analysis could help to design experimental assays, supports the molecular mimicry hypothesis and suggests that propensity to multiple sclerosis in Sardinia could be partly linked to distinct peptide-MHC interaction and binding characteristics of the antigen presentation mechanism. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
7. HCMV Activates the IL-6-JAK-STAT3 Axis in HepG2 Cells and Primary Human Hepatocytes.
- Author
-
Lepiller, Quentin, Abbas, Wasim, Kumar, Amit, Tripathy, Manoj K., and Herbein, Georges
- Subjects
HUMAN cytomegalovirus ,INTERLEUKIN-6 ,LIVER cells ,LIVER cancer ,SEROPREVALENCE ,CELL culture ,ENZYME-linked immunosorbent assay ,INFLAMMATION - Abstract
Objectives: There has been increased interest in the possible role of human cytomegalovirus (HCMV) in carcinogenesis during the last decade. HCMV seroprevalence was enhanced in patients with hepatocellular carcinoma (HCC) but a possible relationship between HCC and HCMV infection remained to be assessed. The aim of this work was to investigate the pro-tumor influence of HCMV on primary human hepatocytes (PHH) and HepG2 cells. Methods: Following infection of PHH and HepG2 cells by two different strains of HCMV, we measured the production of IL-6 in culture supernatants by ELISA and the protein levels of STAT3, pSTAT3, JAK, cyclin D1, survivin, p53, p21, and Mdm2 by western Blotting in infected and uninfected cells. Cell proliferation and transformation were investigated using Ki67Ag expression measurement and soft-agar colony formation assay respectively. Results: Infection of HepG2 cells and PHH by HCMV resulted in the production of IL-6 and the subsequent activation of the IL-6R-JAK-STAT3 pathway. HCMV increased the expression of cyclin D1 and survivin. Cell proliferation was enhanced in HepG2 and PHH infected with HCMV, despite a paradoxical overexpression of p53 and p21. More importantly, we observed the formation of colonies in soft agar seeded with PHH infected with HCMV and when we challenged the HepG2 cultures to form tumorspheres, we found that the HCMV-infected cultures formed 2.5-fold more tumorspheres than uninfected cultures. Conclusion: HCMV activated the IL-6-JAK-STAT3 pathway in PHH and HepG2 cells, favored cellular proliferation, induced PHH transformation and enhanced HepG2 tumorsphere formation. Our observations raise the possibility that HCMV infection might be involved in the genesis of hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
8. Development and implementation of integrated biomass supply analysis and logistics model (IBSAL)
- Author
-
Sokhansanj, Shahab, Kumar, Amit, and Turhollow, Anthony F.
- Subjects
- *
BIOMASS , *BIOLOGY , *RAINFALL , *METEOROLOGICAL precipitation - Abstract
Abstract: This paper describes the framework development of a dynamic integrated biomass supply analysis and logistics model (IBSAL) to simulate the collection, storage, and transport operations for supplying agricultural biomass to a biorefinery. The model consists of time dependent events representing the working rate of equipment and queues representing the capacity of storage structures. The discrete event and queues are inter-connected to represent the entire network of material flow from field to a biorefinery. Weather conditions including rain and snow influence the moisture content and the dry matter loss of biomass through the supply chain and are included in the model. The model is developed using an object oriented high level simulation language EXTEND™. A case of corn stover collection and transport scenario using baling system is described. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
9. [Untitled]
- Author
-
Abbas, Wasim, Kumar, Amit, and Herbein, Georges
- Subjects
Cancer Research ,Programmed cell death ,Cell growth ,Viral pathogenesis ,apoptosis ,EF1A ,HIV ,EEF1A2 ,Actin remodeling ,Translation (biology) ,Review Article ,virus ,Biology ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,medicine.disease_cause ,lcsh:RC254-282 ,Eukaryotic translation elongation factor 1 alpha 1 ,Cell biology ,eEF1A ,Oncology ,Immunology ,medicine ,cancer ,Carcinogenesis - Abstract
Eukaryotic translation elongation factors 1 alpha, eEF1A1 and eEF1A2, are not only translation factors but also pleiotropic proteins that are highly expressed in human tumors, including breast cancer, ovarian cancer, and lung cancer. eEF1A1 modulates cytoskeleton, exhibits chaperone-like activity and also controls cell proliferation and cell death. In contrast, eEF1A2 protein favors oncogenesis as shown by the fact that overexpression of eEF1A2 leads to cellular transformation and gives rise to tumors in nude mice. The eEF1A2 protein stimulates the phospholipid signaling and activates the Akt-dependent cell migration and actin remodeling that ultimately favors tumorigenesis. In contrast, inactivation of eEF1A proteins leads to immunodeficiency, neural and muscular defects, and favors apoptosis. Finally, eEF1A proteins interact with several viral proteins resulting in enhanced viral replication, decreased apoptosis, and increased cellular transformation. This review summarizes the recent findings on eEF1A proteins indicating that eEF1A proteins play a critical role in numerous human diseases through enhancement of oncogenesis, blockade of apoptosis, and increased viral pathogenesis.
10. Effects of ocean acidification on the levels of primary and secondary metabolites in the brown macroalga Sargassum vulgare at different time scales
- Author
-
Anna Palumbo, Han Asard, Amit Kumar, Gerrit T.S. Beemster, Samy Selim, Immacolata Castellano, Maria Cristina Buia, Hamada AbdElgawad, Kumar, Amit, Abdelgawad, Hamada, Castellano, Immacolata, Selim, Samy, Beemster, Gerrit T S, Asard, Han, Buia, Maria Cristina, and Palumbo, Anna
- Subjects
0106 biological sciences ,Environmental Engineering ,Oceans and Seas ,Oceans and Sea ,Transplant ,010603 evolutionary biology ,01 natural sciences ,Acclimatization ,Island ,chemistry.chemical_compound ,Algae ,Macroalgae ,Aquatic plant ,Environmental Chemistry ,Primary and secondary metabolite ,Seawater ,14. Life underwater ,Waste Management and Disposal ,Biology ,Islands ,CO(2) vent ,biology ,Chemistry ,010604 marine biology & hydrobiology ,Ocean acidification ,Sargassum ,15. Life on land ,Carbon Dioxide ,Hydrogen-Ion Concentration ,biology.organism_classification ,Seaweed ,Pollution ,Thallus ,Natural population growth ,13. Climate action ,Environmental chemistry ,Carbon dioxide ,Environmental Monitoring - Abstract
Most of the studies regarding the impact of ocean acidification on macroalgae have been carried out for short-term periods, in controlled laboratory conditions, thus hampering the possibility to scale up the effects on long-term. In the present study, the volcanic CO2 vents off Ischia Island were used as a natural laboratory to investigate the metabolic response of the brown alga Sargassum vulgare to acidification at different time scales. For long-term effects, algal populations naturally growing at acidified and control sites were compared. For short-term responses, in situ reciprocal transplants from control to acidified site and vice-versa were performed. Changes in the levels of sugars, fatty acids (FAs), amino acids (AAs), antioxidants, and phenolic compounds were examined. Our main finding includes variable metabolic response of this alga at different time scales to natural acidification. The levels of sugars, FAs, and some secondary metabolites were lower in the natural population at the acidified site, whereas the majority of AAs were higher than those detected in thalli growing at control site. Moreover, in algae transplanted from control to acidified site, soluble sugars (glucose and mannose), majority of AAs, and FAs increased in comparison to control plants transplanted within the same site. The differences in the response of the macroalga suggest that the metabolic changes observed in transplants may be due to acclimation that supports algae to cope with acidification, thus leading to adaptation to lowered pH in long time scale. (c) 2018 Elsevier B.V. All rights reserved.
- Published
- 2018
11. Evolution of Marine Organisms under Climate Change at Different Levels of Biological Organisation
- Author
-
Rebekah Cioffi, Lindzai T. Santa Rosa, Simon Stenberg, Balsam Al-Janabi, Ben P. Harvey, Allison Bailey, Laura Stapp, Amit Kumar, Carina M. Gsottbauer, Stefanie Broszeit, María Aranguren-Gassis, Elena Ricevuto, Emilie F. Hall, Leon Green, Camila O. Pereira, Francesco Paolo Mancuso, Maria Lechler, Julie B. Schram, Harvey, Ben P, Al-Janabi, Balsam, Broszeit, Stefanie, Cioffi, Rebekah, Kumar, Amit, Aranguren-Gassis, Maria, Bailey, Allison, Green, Leon, Gsottbauer, Carina M., Hall, Emilie F., Lechler, Maria, Mancuso, Francesco P., Pereira, Camila O., Ricevuto, Elena, Schram, Julie B., Stapp, Laura S., Stenberg, Simon, and Santa Rosa, Lindzai T.
- Subjects
0106 biological sciences ,lcsh:Hydraulic engineering ,Geography, Planning and Development ,Population ,Climate change ,Ecological forecasting ,Aquatic Science ,Biology ,010603 evolutionary biology ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,biologically-relevant scales ,lcsh:Water supply for domestic and industrial purposes ,lcsh:TC1-978 ,Biologically-relevant scale ,Effects of global warming ,Evolutionary potential ,14. Life underwater ,Adaptation ,education ,030304 developmental biology ,Water Science and Technology ,Biological organisation ,lcsh:TD201-500 ,0303 health sciences ,education.field_of_study ,Ecology ,Ocean acidification ,Global warming ,Global change ,13. Climate action ,Acclimation - Abstract
Research to date has suggested that both individual marine species and ecological processes are expected to exhibit diverse responses to the environmental effects of climate change. Evolutionary responses can occur on rapid (ecological) timescales, and yet studies typically do not consider the role that adaptive evolution will play in modulating biological responses to climate change. Investigations into such responses have typically been focused at particular biological levels (e.g., cellular, population, community), often lacking interactions among levels. Since all levels of biological organisation are sensitive to global climate change, there is a need to elucidate how different processes and hierarchical interactions will influence species fitness. Therefore, predicting the responses of communities and populations to global change will require multidisciplinary efforts across multiple levels of hierarchy, from the genetic and cellular to communities and ecosystems. Eventually, this may allow us to establish the role that acclimatisation and adaptation will play in determining marine community structures in future scenarios.
- Published
- 2014
12. Molecular response of Sargassum vulgare to acidification at volcanic CO2 vents: insights from de novo transcriptomic analysis
- Author
-
Amit Kumar, Anna Palumbo, Gerrit T.S. Beemster, Han Asard, Massimo Delledonne, Immacolata Castellano, Francesco Paolo Patti, Hamada AbdElgawad, Maria Cristina Buia, Kumar, Amit, Castellano, Immacolata, Patti, Francesco Paolo, Delledonne, Massimo, Abdelgawad, Hamada, Beemster, Gerrit T S, Asard, Han, Palumbo, Anna, and Buia, Maria Cristina
- Subjects
0301 basic medicine ,CO2 vents ,Acclimatization ,ocean acidification ,Photosynthesis ,brown algae ,Transcriptome ,03 medical and health sciences ,Hydrothermal Vents ,Heat shock protein ,Botany ,Genetics ,Acid ,Seawater ,14. Life underwater ,Biology ,Ecology, Evolution, Behavior and Systematics ,CO2 vent ,mRNA-Seq ,biology ,fleshy macroalgae ,RuBisCO ,Sargassum ,Ocean acidification ,molecular response ,climate change ,Acids ,Carbon ,Carbon Dioxide ,Hydrogen-Ion Concentration ,15. Life on land ,biology.organism_classification ,Cell biology ,Brown algae ,Chemistry ,030104 developmental biology ,Ion homeostasis ,13. Climate action ,biology.protein ,Hydrothermal Vent - Abstract
Ocean acidification is an emerging problem that is expected to impact ocean species to varying degrees. Currently, little is known about its effect on molecular mechanisms induced in fleshy macroalgae. To elucidate genome wide responses to acidification, a comparative transcriptome analysis was carried out between Sargassum vulgare populations growing under acidified conditions at volcanic CO2 vents and a control site. Several transcripts involved in a wide range of cellular and metabolic processes were differentially expressed. No drastic changes were observed in the carbon acquisition processes and RuBisCO level. Moreover, relatively few stress genes, including those for antioxidant enzymes and heat shock proteins, were affected. Instead, increased expression of transcripts involved in energy metabolism, photosynthetic processes, and ion homeostasis suggested that algae increased energy production to maintain ion-homeostasis and other cellular processes. Also, an increased allocation of carbon to cell wall and carbon storage was observed. A number of genes encoding proteins involved in cellular signaling, information storage and processing, and transposition were differentially expressed between the two conditions. The transcriptional changes of key enzymes were largely confirmed by enzymatic activity measurements. Altogether, the changes induced by acidification indicate an adaptation of growth and development of S. vulgare at the volcanic CO2 vents, suggesting that this fleshy alga exhibits a high plasticity to low pH and can adopt molecular strategies to grow also in future more acidified waters. This article is protected by copyright. All rights reserved.
- Published
- 2017
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.