Papers by Rajendra Prasad
Biochemistry and Molecular Biology International, Jun 1, 1995
The phospholipid composition of various morphological mutants of Candida albicans revealed a comp... more The phospholipid composition of various morphological mutants of Candida albicans revealed a complete absence of phosphatidylinositol (PI) from plasma membranes of those cells which completely lacked mycelial growth. No other phospholipid was found to be specific to morphogenesis. The plasma membrane fractions isolated from mutants were more rigid than its wild type as was evident from their unsaturation index and fluorescence polarization measurements. The enhanced membrane rigidity of mutant cells was noted regardless whether the cells could grow only as mycelia or in their budding forms. Although some amino acids are considered to affect the morphological transition of C. albicans, this was not reflected in the transport activities of L-proline, L-alanine, L-lysine and L-glutamic acid.
Journal of Porphyrins and Phthalocyanines, Jan 25, 2012
Abstract: The (bpy) 2 Ru II and (phen) 2 Ru II moieties were linked to [Ni (OBTTAP)] 1, periphery... more Abstract: The (bpy) 2 Ru II and (phen) 2 Ru II moieties were linked to [Ni (OBTTAP)] 1, periphery through coordinate bonds in order to synthesize cationic di-and pentanuclear complexes 2-5 that were obtained as PF 6− salts. They were characterized by IR, 1 H ...
Mycopathologia, Jun 16, 2007
In the absence of steroid receptors and any known mechanism of gene regulation by steroid hormone... more In the absence of steroid receptors and any known mechanism of gene regulation by steroid hormones in Candida albicans, we did a genome-wide analysis of C. albicans cells treated with progesterone using Eurogentec cDNA microarrays to find the complete repertoire of steroid responsive genes. Northern blotting analysis was employed to validate the genes that were differentially regulated by progesterone in the microarray experiments. A total of 99 genes were found to be significantly regulated by progesterone, among them 60 were up-regulated and 39 were down-regulated. It was observed that progesterone considerably enhanced the expression of multi-drug resistance (MDR) genes belonging to ATP Binding Cassette (CDR1 and CDR2) super-family of multidrug transporters, suggesting a possible relationship between steroid stress and MDR genes. Several genes associated with hyphal induction and the establishment of pathogenesis were also found up-regulated. In silico search for various transcription factor (TF) binding sites in the promoter of the affected genes revealed that EFG1, CPH1, NRG1, TUP1, MIG1 and AP-1 regulated genes are responsive to progesterone. The stress responsive elements (STRE; AG(4) or C(4)T) were also found in the promoters of several responsive genes. Our data sheds new light on the regulation of gene expression in C. albicans by human steroids, and its correlation with drug resistance, virulence, morphogenesis and general stress response. A comparison with drug induced stress response has also been discussed.
Cystic Fibrosis (CF) is the severe autosomal recessive disorder of chloride conductance across th... more Cystic Fibrosis (CF) is the severe autosomal recessive disorder of chloride conductance across the epithelial cells. CF is considered as most common disease in Caucasian with an average prevalence of 1 in 2500 live birth however it is considered as uncommon in Asian and African populations. The estimated prevalence of CF in Indian population is 1 in 43,321 to 1 in 100,323 CF is caused by mutation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene which results in wide spectrum of clinical phenotypes including chronic infections and pulmonary obstruction, pancreatic insufficiency, neonatal meconeum ileus, failure to thrive, diabetes mellitus, elevated sweat electrolytes, and male infertility. CFTR gene cover 250kb region on chromosome 7q31.3 and consist of 27 exons, the human CFTR gene encodes a 6,129-bp transcript that lead to the synthesis of a 1,480-aa protein and functions as a chloride channel. It is a member of ATP binding cassette (ABC) transporter super fa...
Gene, 2015
In this study, we analyzed 100 cases of renal cell carcinoma (RCC) for telomerase activity, telom... more In this study, we analyzed 100 cases of renal cell carcinoma (RCC) for telomerase activity, telomere length and alternative lengthening of telomeres (ALT) using the TRAP assay, TeloTTAGGG assay kit and immunohistochemical analysis of ALT associated promyelocytic leukemia (PML) bodies respectively. A significantly higher (P=0.000) telomerase activity was observed in 81 cases of RCC which was correlated with clinicopathological features of tumor for instance, stage (P=0.000) and grades (P=0.000). Notwithstanding, no correlation was found between telomerase activity and subtypes of RCC. Strikingly, the telomere length was found to be significantly shorter in RCC (P=0.000) to that of corresponding normal renal tissues and it is well correlated with grades (P=0.016) but not with stages (P=0.202) and subtypes (P=0.669) of RCC. In this study, telomere length was also negatively correlated with the age of patients (r(2)=0.528; P=0.000) which supports the notion that it could be used as a marker for biological aging. ALT associated PML bodies containing PML protein was found in telomerase negative cases of RCC. It suggests the presence of an ALT pathway mechanism to maintain the telomere length in telomerase negative RCC tissues which was associated with high stages of RCC, suggesting a prevalent mechanism for telomere maintenance in high stages. In conclusion, the telomerase activity and telomere length can be used as a diagnostic as well as a predictive marker in RCC. The prevalence of ALT mechanism in high stages of RCC is warranted for the development of anti-ALT inhibitors along with telomerase inhibitor against RCC as a therapeutic approach.
Molecular and cellular biochemistry, 1997
Exposure of animals to cadmium (Cd) (25 mg kg(-1) body wt day(-1)) for 10 weeks resulted in prefe... more Exposure of animals to cadmium (Cd) (25 mg kg(-1) body wt day(-1)) for 10 weeks resulted in preferential accumulation of the metal in liver and kidney. Cd accumulation concomitantly increased zinc (Zn) concentration in both the organs. However, significant decrease in copper level was observed in liver, whereas kidney showed increase in copper (Cu) level. Cd exposure resulted in decreased total GST activity in liver (63%) and kidney (41%) as compared to control group monkeys on normal diet (group I). On isoelectric focusing (IEF) control liver GST segregated into thirteen isoenzymes, while in Cd-treated experimental animals (group II) liver GST resolved into nine isoenzymes. Similarly kidney GST from control animals separated into seven isoenzymes as compared to four isoenzymes from Cd-treated animals. Kinetic analysis showed that Cd exposure did not alter the affinity constant (Km) of GST for GSH and CDNB whereas maximal velocity (Vmax) for these substrates decreased as compared to...
PloS one, 2015
Telomere binding factors viz. TRF1 and TRF2 are a part of sheltrin complex that are present exclu... more Telomere binding factors viz. TRF1 and TRF2 are a part of sheltrin complex that are present exclusively at the ends of chromosomes. These factors play an important role in maintaining chromosomal integrity at the ends. However, their status and role are not clear in renal cell carcinoma (RCC). Therefore, the present study was conducted to evaluate TRF1 and TRF2 expressions in RCC tissues. Further, the role of these factors involved in tumorigenesis was elucidated by gene silencing using siRNA in RCC cell line (A498). The present study documented a significant over-expression of TRF1 (P = 0.005) and TRF2 (P = 0.0048) mRNAs by real time PCR in RCC tissues as compared with adjacent normal kidney tissues. Immunohistochemistry studies also revealed higher expression of TRF1 and TRF2 proteins in RCC. Moreover, TRF1 or TRF2 gene silencing using siRNA showed marked reduction in proliferation of RCC cells (P = 0.000). Further, significantly induced cell cycle arrest (P = 0.000) and apoptosis...
Advances in microbial physiology, 2002
In view of the increasing threat posed by fungal infections in immunocompromised patients and due... more In view of the increasing threat posed by fungal infections in immunocompromised patients and due to the non-availability of effective treatments, it has become imperative to find novel antifungals and vigorously search for new drug targets. Fungal pathogens acquire resistance to drugs (antifungals), a well-established phenomenon termed multidrug resistance (MDR), which hampers effective treatment strategies. The MDR phenomenon is spread throughout the evolutionary scale. Accordingly, a host of responsible genes have been identified in the genetically tractable budding yeast Saccharomyces cerevisiae, as well as in a pathogenic yeast Candida albicans. Studies so far suggest that, while antifungal resistance is the culmination of multiple factors, there may be a unifying mechanism of drug resistance in these pathogens. ABC (ATP binding cassette) and MFS (major facilitator superfamily) drug transporters belonging to two different superfamilies, are the most prominent contributors to MD...
Journal of Indian Association of Pediatric Surgeons
Biochemistry, 2006
Candida drug resistance protein 1 (Cdr1p), an ATP-dependent drug efflux pump, confers multidrug r... more Candida drug resistance protein 1 (Cdr1p), an ATP-dependent drug efflux pump, confers multidrug resistance in immunocompromised and debilitated patients. A member of the ATP-binding cassette (ABC) superfamily of membrane transporters, Cdr1p contains two nucleotide binding/utilization sites (NBDs) and two transmembrane domains (TMDs). We had earlier characterized Cdr1p by its overexpression as a GFP-tagged fusion protein that elicits oligomycin-sensitive ATPase activity and is linked to drug extrusion. However, it is essential to have highly purified Cdr1p to understand the detailed molecular basis of structure and functions of this protein. In this study, we have developed a two-step purification protocol using stably overexpressed His-tagged Cdr1p in Saccharomyces cereVisiae. Purified Cdr1p exhibited divalent cation-dependent ATPase activity [∼1.2 µmol (mg of protein) -1 min -1 ] with an apparent K M in the range of 1.8 to 2.1 mM and V max between 1.0 and 1.4 µmol (mg of protein) -1 min -1 . Unlike its close homologue human P-gp/MDR1, purified Cdr1p only moderately displayed drug stimulated ATPase activity. By exploiting intrinsic fluorescence intensity of purified Cdr1p, which contains 24 tryptophan residues, we could monitor defined conformational changes upon substrate drug and ATP binding. It is observed that ATP binding to Cdr1p (K d ) ∼1.7 mM) is not a prerequisite for drug binding, and both the mechanisms of drug as well as ATP binding, which induce specific conformational changes, occur independent of each other. Our study for the first time provides a catalytically active purified ABC transporter from a fungal pathogen, which is amenable to fluorescence measurements and thus would be useful in understanding the molecular basis of antifungal transport. †
International Journal of Bio-resource and Stress Management, 2014
Manuscript No. AR571
The Indian journal of medical research, 2008
Multi-drug resistant (MDR) Mycobacterium tuberculosis isolates may be transmitted within communit... more Multi-drug resistant (MDR) Mycobacterium tuberculosis isolates may be transmitted within communities due to dense population and poor hygienic conditions. For proper management and control of MDR-TB, understanding drug susceptibility pattern of M. tuberculosis isolates and their transmission pattern in every health care setting are essential. In the present study, we attempted to describe the current prevalence of MDR-TB in Lucknow district, Uttar Pradesh, and our observations on transmission of MDR isolates among populations in and around this area. Patients diagnosed as that of pulmonary tuberculosis (PTB) were enrolled from primary level (PLH), secondary level (SLH) and tertiary level (TLH) healthcare centres from Lucknow district. Detailed history of intake of antitubercular drug in the past was taken to decipher initial/ acquired drug resistance. Sputum samples were cultured on Lowenstein-Jensen media to isolate mycobacteria. Drug susceptibility patterns of isolated M. tubercul...
The Indian journal of medical research, 2008
Ethambutol (EMB) resistance, thought to be occurring due to mutations in embB gene of Mycobacteri... more Ethambutol (EMB) resistance, thought to be occurring due to mutations in embB gene of Mycobacterium tuberculosis on the rise is a cause of grave concern. The present study was planned to investigate the presence of EMB resistance in M. tuberculosis isolates and to look for prevalent mutations in embB gene. A total of 591(283 from new and 308 from previously treated cases) sputum samples from the same number of pulmonary tuberculosis cases were cultured. Isolates were tested by 1 per cent proportion method for resistance to isoniazid, rifampicin streptomycin and ethambutol. Minimum inhibitory concentration (MIC) of EMB was measured by absolute concentration method. Ten randomly selected isolates were subjected to single strand conformational polymorphism (SSCP) and direct DNA sequencing to look for mutation in 364 bp segments of embB gene. Of 353 isolates of M. tuberculosis from 591 sputum samples, 62 (17.58%) were resistant to EMB, of which, 16 (25.8%) showed initial resistance and ...
Progress In Electromagnetics Research B, 2009
Abstract: A robust algorithm has been developed for improving the backscattered signal and recogn... more Abstract: A robust algorithm has been developed for improving the backscattered signal and recognizing the shape of the shallow buried metallic object using Artificial Neural Network (ANN) and image analysis techniques for remote sensing at X-band. An ANN with image ...
Biochimie, 2014
Extracellular regulated kinase 1/2 (ERK1/2) has been shown to be activated in renal cell carcinom... more Extracellular regulated kinase 1/2 (ERK1/2) has been shown to be activated in renal cell carcinoma (RCC). Previously, we have reported aberrant expression/activity of Liver/Bone/Kidney alkaline phosphatase (L/B/K ALP) in RCC. The present study was conducted to find out whether L/B/K ALP has any role in the dephosphorylation of ERK1/2 in renal cancer cell lines. Two renal cancer cell lines viz. ACHN and A498 were transfected with full length L/B/K ALP cDNA. ALP expression/activity and ERK1/2 phosphorylation were evaluated. Increased L/B/K ALP expression/activity was associated with significantly reduced (P = 0.001) phosphorylation status of ERK1/2 in ALP cDNA transfected cells in comparison to that of control. This is the first study that suggests deactivation of ERK1/2 by stimulation of ALP in renal cancer cell lines which can be used as a therapeutic target of RCC.
Multi-Targeted Approach to Treatment of Cancer, 2014
Telomeres and telomerase are attractive targets for anticancer therapy. This is evidenced with th... more Telomeres and telomerase are attractive targets for anticancer therapy. This is evidenced with the facts that majority of human cancers express the enzyme telomerase which is utmost important to maintain the telomere length, thereby to ensure indefinite cell proliferation -a hallmark of cancer. In human cells, a structure referred to as telomere has been identified to cap the terminal regions of chromosomes which can protect the ends of DNA strands from degradation and fusion, whereas telomerase plays a pivotal role in cellular immortality and tumorigenesis. Henceforth, strategies have been made to induce telomerase inhibition target virtually all of the major components of ribonucleoprotein holoenzyme and related cell signal pathways that regulates its activity which includes telomerase reverse transcriptase (hTERT) catalytic subunit, the telomere RNA component (hTERC), and associated proteins. It is noteworthy here that most of the cancers have an alternative lengthening of telomere termed as ALT even in the absence of telomerase activity. In these cases, there is an urgent need to understand the cell signaling pathways for ALT mechanism which can be used as therapeutic targets. Other strategies have been developed to target the protein associated with telomerase at the telomeric ends of chromosomes such as tankyrase. Increasing evidences suggest that directly targeting telomeric DNA using agents directed against the shelterin complex may also have anticancer activity. The limitations of strategies remain to be resolved to facilitate the clinical applications. In this chapter, recent development of strategies against these targets shall be discussed.
Indian Journal of Clinical Biochemistry, 2013
Alkaline phosphatase (ALP; E.C.3.I.3.1.) is an ubiquitous membrane-bound glycoprotein that cataly... more Alkaline phosphatase (ALP; E.C.3.I.3.1.) is an ubiquitous membrane-bound glycoprotein that catalyzes the hydrolysis of phosphate monoesters at basic pH values. Alkaline phosphatase is divided into four isozymes depending upon the site of tissue expression that are Intestinal ALP, Placental ALP, Germ cell ALP and tissue nonspecific alkaline phosphatase or liver/bone/kidney (L/B/K) ALP. The intestinal and placental ALP loci are located near the end of long arm of chromosome 2 and L/B/K ALP is located near the end of the short arm of chromosome 1. Although ALPs are present in many mammalian tissues and have been studied for the last several years still little is known about them. The bone isoenzyme may be involved in mammalian bone calcification and the intestinal isoenzyme is thought to play a role in the transport of phosphate into epithelial cells of the intestine. In this review, we tried to provide an overview about the various forms, structure and functions of alkaline phosphatase with special focus on liver/bone/kidney alkaline phosphatase.
Gene, 2014
Zinc is an indispensable trace element which is vital for the functioning of numerous cellular pr... more Zinc is an indispensable trace element which is vital for the functioning of numerous cellular processes like cell replication and growth. Cellular zinc homeostasis is tightly regulated by zinc transporters involved in zinc influx and efflux processes. Notwithstanding, the association of zinc transporters with the aggressiveness of cancer, especially renal cell carcinoma (RCC), is unknown. In view of the fact, the present study was initiated to ascertain whether ZIP10 transporter expression is modulated during RCC progression. A total of 57 samples of RCC and corresponding normal renal tissue were analyzed for ZIP10 gene expression by real time PCR. We observed significantly higher expression of ZIP10 mRNA (P=0.002) in high grade clear cell RCC tissue (Grades III & IV) as compared to low grade clear cell RCC tissue (Grades I & II). A significant difference was also observed in the ZIP10 expression in different types of RCC (P=0.001). This is the first study which shows a significant correlation between ZIP10 mRNA expressions with aggressiveness of RCC. Therefore, ZIP10 mRNA expression could be used as a possible biomarker for the aggressive behavior of RCC and a promising target of novel treatment strategies.
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Papers by Rajendra Prasad