BHU Institutional Repository :: Browsing by Author "Rajneesh"

Browsing by Author "Rajneesh"

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Bioprospection of Photoprotective Compounds from Cyanobacteria
(Springer Nature, 2023) Singh, Prashant R.; Singh, Ashish P.; Rajneesh; Gupta, Amit; Sinha, Rajeshwar P.; Pathak, Jainendra
Cyanobacteria are one of the oldest photosynthetic nitrogen fixers of the terrestrial as well as aquatic ecosystems. Cyanobacteria and microalgae produce a large number of secondary metabolites having biomedical, industrial, and biotechnological importance. Due to their presence in vast habitats, cyanobacteria and microalgae were exposed to variety of harsh environmental factors such as salt, desiccation, temperature, heavy metals, and ultraviolet radiation (UVR). In response, cyanobacteria have developed different mechanisms to cope these harsh environmental conditions. Photosynthetic nature of cyanobacteria continuously exposes them to lethal doses of UVR coming with solar radiation which affects their physiology, photosynthetic efficiency, productivity by reactive oxygen species (ROS) generation inside the cell and ultimately leads to cell death. In response to these stresses cyanobacteria have developed different protective mechanisms such as avoidance, enzymatic and non-enzymatic defence system and synthesis of novel secondary metabolites such as mycosporine-like amino acids (MAAs) and scytonemin. MAAs are water-soluble molecules that absorb short wavelength of solar UVR which release the energy in the form of heat. Scytonemin is a small hydrophobic alkaloid pigment present in the extracellular sheath of some cyanobacteria that acts as UVR protectant. Scytonemin and MAAs are highly photostable therefore, they primarily function as UV-screening compounds. They also show antioxidative properties. The capability of cyanobacteria to produce large number of secondary metabolites which serve as natural sunscreens, antibiotic, antifungal, anticancer and antiviral agents make them economically important organisms. These are readily biotechnologically exploitable in the cosmetics and other industrial sectors for the creation of novel medications and drugs. Hence, bioprospection of these photoprotective compounds and other secondary metabolites from cyanobacteria and microalgae becomes crucial. � The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.
Computational insights into diverse aspects of glutathione S-transferase gene family in Papaver somniferum
(Springer, 2022) Vaish, Swati; Parveen, Reshma; Rajneesh; Singh, Nootan; Gupta, Divya; Basantani, Mahesh Kumar
Plant glutathione S-transferases are an ancient protein superfamily having antioxidant activity. These proteins are primarily involved in diverse plant functions such as plant growth and development, secondary metabolism, signaling pathways and defense against biotic and abiotic stresses. The current study aimed to comprehensively identify and characterize the GST gene family in the medicinally important crop Papaver somniferum. A total of 93 GST proteins were identified belonging to eight GST classes and found to be majorly localized in the cytoplasm. All GST genes were found on eleven opium chromosomes. Gene duplication analysis showed segmental duplication as a key factor for opium GST gene family expansion under strong purifying selection. Phylogenetic analysis with gymnosperm, angiosperm and bryophyte revealed the evolution of GSTs earlier than their division into separate groups and also prior to the divergence of monocot and dicot. The secondary structure prediction showed the dominance of ?-helices indicative of PsomGSTs as structurally stable and elastic proteins. Gene architecture showed the conservation of number of exons across the classes. MEME analysis revealed only a few class specific and many across class conserved motifs. Ser was found to be the active site residue of tau, phi, theta and zeta class and Cys was catalytic residue of DHAR, lambda and GHR class. Promoter analyses identified many cis-acting regulatory elements related to hormonal, cellular, stress and light response functions. Ser was the key phosphorylation site. Only three glycosylation sites were found across the 93 PsomGSTs. 3D structure prediction was also performed and was validated. Interactome analyses revealed the correlation of PsomGSTs with glutathione metabolizing proteins. Gene enrichment analysis and KEGG pathway analyzed the involvement of PsomGSTs in three major pathways i.e. glutathione metabolism, tyrosine metabolism and ascorbate metabolism. The outcome revealed high model quality of PsomGSTs. The results of the current study will be of potential significance to understand the functional and structural importance of the GST gene family in opium, a medicinally important crop. � 2022, The Author(s) under exclusive licence to The Botanical Society of Japan.
Computational studies on photolyase (Phr) proteins of cyanobacteria
(Canadian Science Publishing, 2022) Rajneesh; Mondal, Soumila; Pathak, Jainendra; Singh, Prashant R.; Singh, Shailendra P.; Sinha, Rajeshwar P.
Photolyases (Phrs) are enzymes that utilize the blue/ultraviolet (UV-A) region of light for repairing UV-induced cyclopyramidine dimers. We studied Phr groups by bioinformatic analyses as well as active-site and structural modeling. Analysis of 238 amino acid sequences from 85 completely sequenced cyanobacterial genomes revealed five classes of Phrs, CPD Gr I, 6-4 Phrs/cryptochrome, Cry-DASH, Fe-S bacteria Phrs, and a group with fewer amino acids (276�385) in length. The distribution of Phr groups in cyanobacteria belonging to the order Synechococcales was found to be influenced by the habitats of the organisms. Class V Phrs are exclusively present in cyanobacteria. Unique motifs and binding sites were reported in groups II and III. The Fe-S protein binding site was only present in group V and the active site residues and putative CPD/6-4PP binding residues are charged amino acids present on the surface of the proteins. The majority of hydrophilic amino acid residues were present on the surface of the Phrs. Sequence analysis confirmed the diverse nature of Phrs, although sequence diversity did not affect the overall three-dimensional structure. Protein�ligand interaction analysis identified novel CPD/6-4PP binding sites on Phrs. This structural information of Phrs can be used for the preparation of efficient Phr-based formulations. � 2021 The Author(s).
Evaluation of blood based quantitative PCR as a molecular diagnostic tool for post kala-azar dermal leishmaniasis (PKDL)
(Springer Science and Business Media B.V., 2024) Kumar A.; Singh V.K.; Madhukar P.; Tiwari R.; Roy R.; Rajneesh; Mehrotra S.; Sundar S.; Kumar R.
Background: Post kala-azar dermal leishmaniasis (PKDL) is a consequential dermal manifestation of visceral leishmaniasis (VL), serving as a parasite reservoir. The traditional diagnostic approach, which requires an invasive skin biopsy is associated with inherent risks and necessitates skilled healthcare practitioners in sterile settings. There is a critical need for a rapid, less invasive method for Leishmania detection. The main objective of this study was to evaluate and compare the diagnostic efficacy of PCR and qPCR in detecting PKDL, utilizing both skin and blood samples and to assess the utility of blood samples for molecular diagnosis. Methods and results: 73 individuals exhibiting clinical symptoms of PKDL and who had tested positive for rK39 rapid diagnostic test (RDT) were enrolled in this study. For the diagnosis of PKDL, both PCR and real-time quantitative PCR (qPCR), employing SYBR Green and TaqMan assays, were performed on blood and skin matched samples. qPCR results using both TaqMan and SYBR Green assay, indicated higher parasite loads in the skin compared to blood, as evident by the Ct values. Importantly, when blood samples were used for PKDL diagnosis by qPCR, an encouraging sensitivity of 69.35% (TaqMan assay) and 79.36% (SYBR Green) were obtained, compared to 8.2% with conventional PCR. Conclusion: The findings of the study suggest the potential utility of blood for molecular diagnosis by qPCR, offering a less invasive alternative to skin biopsies in field setting for the early detection of parasitaemia in PKDL patients and effective management and control of the disease. � The Author(s), under exclusive licence to Springer Nature B.V. 2024.
MHC tetramer technology: Exploring T cell biology in health and disease
(Academic Press Inc., 2024) Tiwari R.; Singh V.K.; Rajneesh; Kumar A.; Gautam V.; Kumar R.
Major histocompatibility complex (MHC) tetramers stand as formidable tools within T cell biology, facilitating the exploration and comprehension of immune responses. These artificial molecules, comprising four bound MHC molecules, typically with a specified peptide and a fluorescent label, play a pivotal role in characterizing T cell subsets, monitoring clonal expansion, and unraveling T cell dynamics during responses to infections or immunotherapies. Beyond their applications in T cell biology, MHC tetramers prove valuable in investigating a spectrum of diseases such as infectious diseases, autoimmune disorders, and cancers. Their instrumental role extends to vaccine research and development. Notably, when appropriately configured, tetramers transcend T cell biology research and find utility in exploring natural killer T cells and contributing to specific T cell clonal deletions. � 2024
MicroRNAs-mediated regulation of immune responses in parasitic infection
(Elsevier, 2024) Roy R.; Madhukar P.; Singh V.K.; Tiwari R.; Kumar A.; Rajneesh; Rai M.; Gautam V.; Sundar S.; Kumar R.
Leishmaniasis is a group of diseases that predominantly affect impoverished individuals in developing regions. Recent research has highlighted the significant role of microRNAs (miRNAs), small noncoding RNA molecules, in regulating gene expression and contributing to disease pathogenesis in leishmaniasis. Understanding the intricate miRNA-mediated interactions provides valuable insights into the underlying mechanisms of leishmaniasis and facilitates the development of targeted interventions. Moreover, miRNAs demonstrate altered expression levels, and their presence in the bloodstream enables noninvasive detection, making them promising biomarker candidates for diagnosis and prognosis. This chapter focuses on the role of miRNAs in regulating the immune response during leishmania infection, emphasizing their potential as both biomarkers and therapeutic targets. � 2024 Elsevier Inc. All rights reserved.
Nanomedicine in Cardiovascular Diseases: Diagnostic and Therapeutic Innovations for Better Health
(Springer Science and Business Media B.V., 2024) Madhukar P.; Singh V.K.; Chauhan S.B.; Tiwari R.; Kumar A.; Rajneesh; Kumar R.
Cardiovascular diseases (CVDs) are a major cause of global mortality, responsible for approximately 17.9 million deaths in 2019 and 20.5 million deaths in 2021. Limited access to specialised testing, especially for marginalised population, complicate the diagnosis of cardiovascular conditions. Disparities in treatment, sub-optimal pharmaceuticals, toxicity from conventional drugs, diagnostic errors, and the underutilization of non-invasive diagnostic methods contribute to adverse outcomes. Additionally, cost and insurance barriers hinder access to necessary tests, delaying diagnosis and treatment. Therefore, there is an urgent need for improved therapies for CVDs. Additionally, cost and insurance barriers hinder access to necessary tests, delaying diagnosis and treatment. Therefore, there is an urgent need for improved therapies for CVDs. Nanotechnology, which involves the precise control and manipulation of materials at the atomic and molecular levels, shows promise in addressing cardiovascular diseases. Nanoparticles, with their unique properties such as ultra-small size, tunable physicochemical characteristics, and biocompatibility, offer potential for targeted drug delivery. Nanoparticle-based drug delivery systems can enhance therapeutic effectiveness, prolong drug action, improve drug absorption, target specific areas passively or actively, reduce drug resistance, and minimize adverse drug reactions. This chapter comprehensively examines the use of nanoparticle-based diagnostic methods, targeting strategies, and therapeutic interventions for cardiovascular diseases, providing a thorough explanation of the fundamental principles and key considerations in this field. � The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.
Phylogenetic distribution, structural analysis and interaction of nucleotide excision repair proteins in cyanobacteria
(Elsevier B.V., 2023) Singh, Prashant R.; Gupta, Amit; Rajneesh; Pathak, Jainendra; Sinha, Rajeshwar P.
Cyanobacteria are photosynthetic Gram-negative, oxygen evolving prokaryotes with cosmopolitan distribution. Ultraviolet radiation (UVR) and other abiotic stresses result in DNA lesions in cyanobacteria. Nucleotide excision repair (NER) pathway removes the DNA lesions produced by UVR to normal DNA sequence. In cyanobacteria, detailed knowledge about NER proteins is poorly studied. Therefore, we have studied the NER proteins in cyanobacteria. Analyses of 289 amino acids sequence from 77 cyanobacterial species have revealed the presence of a minimum of one copy of NER protein in their genome. Phylogenetic analysis of NER protein shows that UvrD has maximal rate of amino acid substitutions which resulted in increased branch length. The motif analysis shows that UvrABC proteins is more conserved than UvrD, Further, UvrA with UvrB protein interacts with each other and form stable complex which have DNA binding domain on the surface of the complex. UvrB also have DNA binding domain. Positive electrostatic potential was found in the DNA binding region, which is followed by negative and neutral electrostatic potential. Additionally, the surface accessibility values at the DNA strands of T5-T6 dimer binding site were maximal. Protein nucleotide interaction shows the strong binding of T5-T6 dimer with NER proteins of Synechocystis sp. PCC 6803. This process repairs the UV-induced DNA lesions in dark when photoreactivation is inactive. Regulation of NER proteins protect cyanobacterial genome and maintain the fitness of organism under different abiotic stresses. � 2023 Elsevier B.V.
Physiological responses of the cyanobacterium Synechocystis sp. PCC 6803 under rhythmic light variations
(Springer Nature, 2023) Singh, Prashant R.; Pathak, Jainendra; Rajneesh; Ahmed, Haseen; H�der, Donat-P.; Sinha, Rajeshwar P.
Cyanobacteria are challenged by daily fluctuations of light intensities and photoperiod in their natural habitats, which affect the physiology and fitness of cyanobacteria. Circadian rhythms (CRs), an important endogenous process found in all organisms including cyanobacteria, control their physiological activities and helps in coping with 24-h light/dark (LD) cycle. In cyanobacteria, physiological responses under rhythmic ultraviolet radiation (UVR) are poorly studied. Therefore, we studied the changes in photosynthetic pigments, and physiological parameters of Synechocystis sp. PCC 6803 under UVR and photosynthetically active radiation (PAR) of light/dark (LD) oscillations having the combinations of 0, 4:20, 8:16, 12:12, 16:8, 20:4, and 24:24�h. The LD 16:8 enhanced the growth, pigments, proteins, photosynthetic efficiency, and physiology of Synechocystis sp. PCC6803. Continuous light (LL 24) of UVR and PAR exerted negative impact on the photosynthetic pigments, and chlorophyll fluorescence. Significant increase in reactive oxygen species (ROS) resulted in loss of plasma membrane integrity followed by decreased viability of cells. The dark phase played a significant role in Synechocystis�to withstand the�LL 24 under PAR and UVR. This study offers detailed understanding of the physiological responses of the cyanobacterium to changing light environment. � 2023, The Author(s), under exclusive licence to European Photochemistry Association, European Society for Photobiology.
Phytoplankton assemblage and UV-protective compounds in the river Ganges
(National Institute of Science Communication and Policy Research, 2021) Ahmed, H.; Pathak, J.; Singh, D.K.; Pandey, A.; Rajneesh; Singh, V.; Kumar, D.; Singh, P.R.; Sinha, R.P.
Interactions between physico-chemical parameters such as pH, temperature, nitrate, phosphate, alkalinity, acidity, biological oxygen demand (BOD), chemical oxygen demand (COD) and solar ultraviolet radiation (UVR) strongly affect aquatic ecosystems. Due to fluctuations in several environmental factors including river water pollution and UVR, organisms are under constant threat. However, phytoplankton protects themselves from environmental extremes by adopting several defense strategies including synthesis of photoprotective compounds such as scytonemin and mycosporine-like amino acids (MAAs). We investigated the presence of scytonemin and MAAs in phytoplankton of some polluted sites of one of the holy rivers of the world, the Ganges at Varanasi, India. We observed phytoplankton assemblages and studied certain environmental parameters which could possibly affect phytoplankton diversity in the river. Phytoplankton consisted mainly of 49 taxa of 34 genera belonging to Bacillariophyceae, Chlorophyceae, Cyanophyceae, and Chrysophyceae. The members belonging to Bacillariophyceae and Chlorophyceae were the two dominant classes, which comprised up to 75% of the total phytoplankton. Photoprotective compounds were isolated and characterized from phytoplankton. Electrospray ionization-mass spectrometry (ESI-MS) analysis of MAAs showed the presence of shinorine, palythinol, mycosporine-glycine and palythine. A high concentration of scytonemin was also observed with an absorption maximum at 386 nm in the studied phytoplankton. � 2021, National Institute of Science Communication and Policy Research. All rights reserved.
Post kala-azar dermal leishmaniasis in the Indian sub-continent: challenges and strategies for elimination
(Frontiers Media SA, 2023) Kumar, Awnish; Singh, Vishal Kumar; Tiwari, Rahul; Madhukar, Prasoon; Rajneesh; Kumar, Shashi; Gautam, Vibhav; Engwerda, Christian; Sundar, Shyam; Kumar, Rajiv
Visceral leishmaniasis (VL) is a severe and often fatal form of leishmaniasis caused by Leishmania donovani in the Indian sub-continent. Post Kala-azar Dermal Leishmaniasis (PKDL) is a late cutaneous manifestation of VL, typically occurring after apparent cure of VL, but sometimes even without a prior history of VL in India. PKDL serves as a significant yet neglected reservoir of infection and plays a crucial role in the transmission of the disease, posing a serious threat to the VL elimination program in the Indian sub-continent. Therefore, the eradication of PKDL should be a priority within the current VL elimination program aimed at achieving a goal of less than 1 case per 10,000 in the population at the district or sub-district levels of VL endemic areas. To accomplish this, a comprehensive understanding of the pathogenesis of PKDL is essential, as well as developing strategies for disease management. This review provides an overview of the current status of diagnosis and treatment options for PKDL, highlighting our current knowledge of the immune responses underlying disease development and progression. Additionally, the review discusses the impact of PKDL on elimination programs and propose strategies to overcome this challenge and achieve the goal of elimination. By addressing the diagnostic and therapeutic gaps, optimizing surveillance and control measures, and implementing effective intervention strategies, it is possible to mitigate the burden of PKDL and facilitate the successful elimination of VL in the Indian sub-continent. Copyright � 2023 Kumar, Singh, Tiwari, Madhukar, Rajneesh, Kumar, Gautam, Engwerda, Sundar and Kumar.
Purification, characterization and assessment of stability, reactive oxygen species scavenging and antioxidative potentials of mycosporine-like amino acids (MAAs) isolated from cyanobacteria
(Springer Science and Business Media B.V., 2022) Singh, Deepak K.; Pathak, Jainendra; Pandey, Abha; Rajneesh; Singh, Vidya; Sinha, Rajeshwar P.
Mycosporine-like amino acids (MAAs) were characterized and their stability and free radical scavenging potentials were investigated in Anabaena sp. HKAR-7 and Fischerella sp. AR-5. UV/VIS absorption spectroscopy, high performance liquid chromatography and electrospray ionization-mass spectrometry showed occurrence of diverse forms of MAAs at retention time (RT) 1.16 (shinorine), 2.18 (mycosporine glycine-310) and 3.14�min (palythinol) with UV?max 310, 332 and 334�nm respectively, in Fischerella sp. when contrasted with Anabaena sp. (prominent peak at RT 3.21�min (porphyra 334; P-334) with UV?max 334�nm. MAAs showed dose-dependent in vitro antioxidative and in vivo reactive oxygen species (ROS) scavenging potentials. The MAA P-334 was used against strong allelochemical pyrogallic acid in Anabaena sp. P-334 reducing the negative impacts brought about by ROS, in this way, the malondialdehyde content and unwinding of dsDNA were similarly low. This clarifies the role of MAA P-334 against cell�s ROS under studied stressed conditions. � 2022, The Author(s), under exclusive licence to Springer Nature B.V.
Responses of a hot spring cyanobacterium under ultraviolet and photosynthetically active radiation: photosynthetic performance, antioxidative enzymes, mycosporine-like amino acid profiling and its antioxidative potentials
(Springer Science and Business Media Deutschland GmbH, 2021) Ahmed, Haseen; Pathak, Jainendra; Rajneesh; Sonkar, Piyush K.; Ganesan, Vellaichamy; H�der, Donat-P.; Sinha, Rajeshwar P.
This study summarizes the response of a hot spring cyanobacterium Fischerella sp. strain HKAR-14, under simulated light conditions of ultraviolet radiation (UVR), photosynthetically active radiation (PAR), PAR + UV-A (PA) and PAR + UV-A + UV-B (PAB). Exposure to UVR caused a decline in growth and Chl a while total carotene content increased under PA and PAB. Maximum photochemical efficiency of photosystem II (Fv/Fm) and relative electron transport rate decreased significantly in PA and PAB exposure. Higher non-photochemical quenching and lower photochemical quenching values were observed in UVR-exposed samples as compared to the control. Levels of intracellular reactive oxygen species (ROS) increased significantly in PAB and PA. Fluorescence microscopic images showed an increase in green fluorescence, indicating the generation of ROS in UVR. The antioxidant machinery including superoxide dismutase, catalase and peroxidase showed an increase of 1.76-fold and 2.5-fold superoxide dismutase, 2.4-fold and 3.7-fold catalase, 1.83-fold and 2.5-fold peroxidase activities under PA and PAB, respectively. High-performance liquid chromatography equipped with photodiode array detector, electrospray ionization mass spectrometry, Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy analyses reveal the occurrence of a single mycosporine-like amino acid, shinorine (?max 332.3 � 2�nm, m/z 333.1), with a retention time of 1.157�min. The electrochemical characterization of shinorine was determined by cyclic voltammetry. The shinorine molecule possesses electrochemical activity and represents diffusion-controlled process in 0.1�M (pH 7.0) phosphate buffer. An antioxidant assay of shinorine showed its efficient activity as antioxidant which increased in a dose-dependent manner. � 2021, King Abdulaziz City for Science and Technology.
UV-induced physiological changes and biochemical characterization of mycosporine-like amino acid in a rice-field cyanobacterium Fischerella sp. strain HKAR-13
(Elsevier B.V., 2022) Singh, Vidya; Pathak, Jainendra; Pandey, Abha; Ahmed, Haseen; Rajneesh; Kumar, Deepak; Sinha, Rajeshwar P.
Mycosporine-like amino acids (MAAs) are valuable secondary metabolite with notable photoprotective potential. The present study investigateS the im???ts of ?h?t?syntheti? ??tive r?di?ti?n (??R) and ultraviolet radiation (UVR) on various physiological processes in the cyanobacterium Fischerella sp. strain HKAR-13. Cell viability was reduced by 36 and 65% after 72h of ex??sure to ??R+UV-? (PA) and ??R+UV-?+UV-B (PAB) radiations respectively. Significant decline in Chl a content was observed during PA and PAB exposure after 36h. Carotenoid content increased significantly after 48h of exposure, thereafter began to decline. Cultures exposed to PAB showed maximum detrimental effect on protein synthesis. In PAB and PA, the levels of intracellular reactive oxygen species (ROS) increased significantly. Fluorescence microscopic images of cyanobacteria revealed generation of ROS in UVR as indicated by increase in green fluorescence. Besides, Fischerella sp. strain HKAR-13 was also tested for the ?resen?e of M??s and their induction under UVR. UV-Vis spectrophotometry and high-?erf?rm?n?e liquid ?hr?m?t?gr??hy ?n?lyses revealed the ?resen?e of a MAA having absorption maxima ?max 334 nm and retention time of 1.5 min. Maximum induction of MAA was found in samples exposed to PAB followed by PA. Based on electrospray ionization-mass s?e?tr?s???y (m/z: 333+1), fourier transform infrared and nuclear magnetic res?n?n?e s?e?tr?s???y, the MAA was identified as shinorine. Shinorine was found to be highly stable under some abiotic stress factors such as UV-B, temperature and H2O2. It also showed efficient antioxidant activity in a dose-dependent manner as depicted by in vitro antioxidant assays. � 2022 SAAB

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