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Tirella A, Kloc-Muniak K, Good L, Ridden J, Ashford M, Puri S, Tirelli N. CD44 targeted delivery of siRNA by using HA-decorated nanotechnologies for KRAS silencing in cancer treatment. Int J Pharm 2019; 561:114-123. [DOI: 10.1016/j.ijpharm.2019.02.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/21/2019] [Accepted: 02/18/2019] [Indexed: 12/15/2022]
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Touzard S, Kou A, Frattini NE, Sivak VV, Puri S, Grimm A, Frunzio L, Shankar S, Devoret MH. Gated Conditional Displacement Readout of Superconducting Qubits. PHYSICAL REVIEW LETTERS 2019; 122:080502. [PMID: 30932609 DOI: 10.1103/physrevlett.122.080502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Indexed: 06/09/2023]
Abstract
We have realized a new interaction between superconducting qubits and a readout cavity that results in the displacement of a coherent state in the cavity, conditioned on the state of the qubit. This conditional state, when it reaches the cavity-following, phase-sensitive amplifier, matches its measured observable, namely, the in phase quadrature. In a setup where several qubits are coupled to the same readout resonator, we show it is possible to measure the state of a target qubit with minimal dephasing of the other qubits. Our results suggest novel directions for faster readout of superconducting qubits and implementations of bosonic quantum error-correcting codes.
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Al-Hebshi NN, Baraniya D, Chen T, Hill J, Puri S, Tellez M, Hasan NA, Colwell RR, Ismail A. Metagenome sequencing-based strain-level and functional characterization of supragingival microbiome associated with dental caries in children. J Oral Microbiol 2018; 11:1557986. [PMID: 30671194 PMCID: PMC6327923 DOI: 10.1080/20002297.2018.1557986] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/05/2018] [Accepted: 12/07/2018] [Indexed: 12/15/2022] Open
Abstract
Studies of the microbiome associated with dental caries have largely relied on 16S rRNA sequence analysis, which is associated with PCR biases, low taxonomic resolution, and inability to accurately study functions. Here, we employed whole metagenome shotgun sequencing, coupled with high-resolution analysis algorithm, to analyze supragingival microbiomes from 30 children with or without dental caries. A total of 726 bacterial strains belonging to 406 species, in addition to 34 bacteriophages were identified. A core bacteriome was identified at the species and strain levels. Species of Prevotella, Veillonella, as yet unnamed Actinomyces, and Atopobium showed strongest association with caries; Streptococcus sp. AS14 and Leptotrichia sp. Oral taxon 225, among others, were overabundant in caries-free. For several species, the association was strain-specific. Furthermore, for some species, e.g. Streptococcus mitis and Streptococcus sanguinis, sister strains showed differential associations. Noteworthy, associations were also identified for phages: Streptococcus phage M102 with caries and Haemophilus phage HP1 with caries-free. Functionally, potentially relevant features were identified including urate, vitamin K2, and polyamine biosynthesis in association with caries; and three deiminases and lactate dehydrogenase with health. The results demonstrate new associations between the microbiome and dental caries at the strain and functional levels that need further investigation.
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Krishan K, Kanchan T, Singh B, Baryah N, Puri S. Germline Editing: Editors Cautionary. LA CLINICA TERAPEUTICA 2018; 169:e58-e59. [PMID: 29595865 DOI: 10.7417/t.2018.2053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This communication is regarding the recent editing of the genome of the human embryo with CRISPR/Cas9 which generated a debate amongst the biological scientists around the world. Editing human germline genes may act as godsend in some serious genetic and other disorders as the genes related to these disorders can be replaced effectively. The scientists are in dilemma whether the human germline gene modification is a boon or bane for the human society. Though editing human germline genes may be an answer to many serious genetic disorders however; it may have unpredictable effects on future generations. The ethical issues regarding the germline editing need further discussion which may have implications on human race and on-going human evolution. Thus, the researchers need to be doubly cautious and some stringent regulations should be framed regarding the various aspects of germ line gene modifications and any potential conflict with nature for future outcome.
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Puri S, Aldhahi M, Chin LM, Jain V, Herrick JE. 0138 Characterization of Oxygen Uptake On- and Off- Kinetics in Patients with Obstructive Sleep Apnea. Sleep 2018. [DOI: 10.1093/sleep/zsy061.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Puri S, Sharma N, Newcombe R, Kaushik M, Al-Attar M, Pascaline S, Hajaj M, Wallis M, Elsberger B, Goyal A. Axillary tumour burden in women with one abnormal node on ultrasound compared to women with multiple abnormal nodes. Clin Radiol 2018; 73:391-395. [DOI: 10.1016/j.crad.2017.12.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 12/14/2017] [Indexed: 11/27/2022]
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Norris HL, Friedman J, Chen Z, Puri S, Wilding G, Edgerton M. Salivary metals, age, and gender correlate with cultivable oral Candida carriage levels. J Oral Microbiol 2018; 10:1447216. [PMID: 29686781 PMCID: PMC5907636 DOI: 10.1080/20002297.2018.1447216] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 02/27/2018] [Indexed: 02/06/2023] Open
Abstract
Background: Little is known about the normal range of metal levels in unstimulated saliva, nor whether these might impact Candida carriage in healthy individuals. Both are important in determining which populations are at risk for candidiasis, as the availability of metal ions can influence the growth and pathogenesis of Candida albicans. Objective: We quantified salivary metals of healthy individuals to determine the correlation with C. albicans oral colonization. Design: Unstimulated whole saliva was collected from healthy adults and plated to determine fungal carriage, and metal content was measured using ICP-mass spectrometry (ICP-MS). Results: Zinc was most abundant, followed by iron, copper, manganese, and nickel. Cultivable oral Candida carriage was found in 48% of people. Total protein levels did not differ in salivas from donors with or without carriage. However, innate fungicidal activity was increased in donors with carriage; correlations between levels of several metals were stronger in salivas with fungal carriage, indicating a shift in the oral environment. Concentrations of copper and manganese, as well as age and gender, were significantly predictive of carriage levels in a multiple regression model. Conclusions: Salivary copper and manganese content along with age and gender could be used as a predictive metric for individuals that are more susceptible to Candida overgrowth.
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Kumar M, Chatterjee S, Paul R, Puri S. Ordering kinetics in the random-bond XY model. Phys Rev E 2018; 96:042127. [PMID: 29347537 DOI: 10.1103/physreve.96.042127] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Indexed: 11/07/2022]
Abstract
We present a comprehensive Monte Carlo study of domain growth in the random-bond XY model with nonconserved kinetics. The presence of quenched disorder slows down domain growth in d=2,3. In d=2, we observe power-law growth with a disorder-dependent exponent on the time scales of our simulation. In d=3, we see the signature of an asymptotically logarithmic growth regime. The scaling functions for the real-space correlation function are seen to be independent of the disorder. However, the same does not apply for the two-time autocorrelation function, demonstrating the breakdown of superuniversality.
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Jephthah S, Henriques J, Cragnell C, Puri S, Edgerton M, Skepö M. Structural Characterization of Histatin 5-Spermidine Conjugates: A Combined Experimental and Theoretical Study. J Chem Inf Model 2017; 57:1330-1341. [PMID: 28586222 DOI: 10.1021/acs.jcim.7b00150] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Histatin 5 (Hst5) is a naturally occurring antimicrobial peptide that acts as the first line of defense against oral candidiasis. It has been shown that conjugation of the active Hst5 fragment, Hst54-15, and the polyamine spermidine (Spd) improves the candidacidal effect. Knowledge about the structure of these conjugates is, however, very limited. Thus, the aim of this study was to characterize the structural properties of the Hst54-15-Spd conjugates by performing atomistic molecular dynamics simulations in combination with small-angle X-ray scattering. It was shown that the Hst54-15-Spd conjugates adopt extended and slightly rigid random coil conformations without any secondary structure in aqueous solution. It is hypothesized that the increased fungal killing potential of Hst54-15-Spd, in comparison with the Spd-Hst54-15 conjugate, is due to the more extended conformations of the former, which cause the bonded Spd molecule to be more accessible for recognition by polyamine transporters in the cell.
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Puri S, Aldhahi M, Chin LM, Herrick JE. 0618 PULMONARY OXYGEN UPTAKE ON-KINETICS DURING SUBMAXIMAL TREADMILL WALKING IN ADULTS WITH OBSTRUCTIVE SLEEP APNEA. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Du H, Puri S, McCall A, Norris HL, Russo T, Edgerton M. Human Salivary Protein Histatin 5 Has Potent Bactericidal Activity against ESKAPE Pathogens. Front Cell Infect Microbiol 2017; 7:41. [PMID: 28261570 PMCID: PMC5309243 DOI: 10.3389/fcimb.2017.00041] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/03/2017] [Indexed: 11/13/2022] Open
Abstract
ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanni, Pseudomonas aeruginosa, and Enterobacter species) pathogens have characteristic multiple-drug resistance and cause an increasing number of nosocomial infections worldwide. Peptide-based therapeutics to treat ESKAPE infections might be an alternative to conventional antibiotics. Histatin 5 (Hst 5) is a salivary cationic histidine-rich peptide produced only in humans and higher primates. It has high antifungal activity against Candida albicans through an energy-dependent, non-lytic process; but its bactericidal effects are less known. We found Hst 5 has bactericidal activity against S. aureus (60–70% killing) and A. baumannii (85–90% killing) in 10 and 100 mM sodium phosphate buffer (NaPB), while killing of >99% of P. aeruginosa, 60–80% E. cloacae and 20–60% of E. faecium was found in 10 mM NaPB. Hst 5 killed 60% of biofilm cells of P. aeruginosa, but had reduced activity against biofilms of S. aureus and A. baumannii. Hst 5 killed 20% of K. pneumonia biofilm cells but not planktonic cells. Binding and uptake studies using FITC-labeled Hst 5 showed E. faecium and E. cloacae killing required Hst 5 internalization and was energy dependent, while bactericidal activity was rapid against P. aeruginosa and A. baumannii suggesting membrane disruption. Hst 5-mediated killing of S. aureus was both non-lytic and energy independent. Additionally, we found that spermidine conjugated Hst 5 (Hst5-Spd) had improved killing activity against E. faecium, E. cloacae, and A. baumannii. Hst 5 or its derivative has antibacterial activity against five out of six ESKAPE pathogens and may be an alternative treatment for these infections.
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Mahesh E, Puri S, Varma V, Madhyastha PR, Bande S, Gurudev KC. Pregnancy-related acute kidney injury: An analysis of 165 cases. Indian J Nephrol 2017; 27:113-117. [PMID: 28356662 PMCID: PMC5358150 DOI: 10.4103/0971-4065.194394] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Pregnancy-related acute kidney injury (PRAKI) contributes to 3–7% of overall acute kidney injury (AKI) cases in Indian subcontinent. The aim of this study was to determine the outcomes of PRAKI and risk factors associated with renal injury and maternal mortality. One hundred and sixty-five patients with PRAKI, seen at M. S. Ramaiah Medical College between 2005 and 2014, were included in this, observational study. AKI was analyzed in terms of maximal stage of renal injury attained as per Risk, Injury, Failure, Loss of function, and End-stage renal disease (RIFLE) criteria. Outcomes included requirement for renal replacement therapy (RRT), maternal, and fetal mortality. Incidence of PRAKI was 1.56%, and the mean age of the study population was 25 years. Fifty percent of the patients were diagnosed with PRAKI during their first pregnancy. PRAKI was observed most commonly in the postpartum period (60%), followed by third trimester (32%); as per RIFLE criteria, failure was seen in 36% and injury in 34%. Thirty percent of cases required RRT. Sepsis (59%), pre-eclampsia, and eclampsia (56%) were the leading causes of PRAKI, while sepsis was the leading cause of maternal mortality. Maternal and fetal mortality were 20% and 22%, respectively. In univariate analysis, shock, hemorrhage requiring transfusion of >5 units packed red blood cells, oliguria, and “Loss” category of RIFLE were significantly associated with mortality. Majority of the patients (57%) required Intensive Care Unit care with a mean duration of admission at 7.3 days, and 75% was diagnosed with AKI at the time of admission. We report the lowest incidence of PRAKI in contemporary Indian literature. PRAKI was associated with high maternal and fetal mortality, with sepsis being the leading cause. No association was noted between mortality and initial stages of RIFLE criteria.
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Salvatori O, Puri S, Tati S, Edgerton M. Innate Immunity and Saliva in Candida albicans-mediated Oral Diseases. J Dent Res 2016; 95:365-71. [PMID: 26747422 DOI: 10.1177/0022034515625222] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The oral cavity is a unique niche where Candida albicans infections occur in immunocompetent as well as immunosuppressed individuals. Here we critically review the significance of human innate immune response in preventing oral candidiasis. One important line of defense against oropharyngeal candidiasis is the oral microbiota that prevents infection by competing for space and nutrients as well as by secreting antagonistic molecules and triggering local inflammatory responses. C. albicans is able to induce mucosal defenses through activation of immune cells and production of cytokines. Also, saliva contains various proteins that affect C. albicans growth positively by promoting mucosal adherence and negatively through immune exclusion and direct fungicidal activity. We further discuss the role of saliva in unifying host innate immune defenses against C. albicans as a communicating medium and how C. albicans overgrowth in the oral cavity may be a result of aberrations ranging from microbial dysbiosis and salivary dysfunction to epithelial damage. Last we underscore select oral diseases in which C. albicans is a contributory microorganism in immune-competent individuals.
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Sheth K, Mehta T, Sheth V, Soni R, Puri S, Parke A. SAT0405 Risk of Status Epilepticus and Intractable Epilepsy in Systemic Lupus Erythematosus Patients with Antiphospholipid Antibodies. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.5335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Mehta T, Sheth K, Puri S, Soni R, Sheth V, Parke A. THU0352 Risk of Status Epilepticus and Intractable Epilepsy in Systemic Lupus Erythematosus Patients with Lupus Nephritis. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.5371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Puri S, Ashat M, Pandey A, Goel NK, Singh A, Kaushal V. Socio-demographic characteristics of cancer patients: hospital based cancer registry in a tertiary care hospital of India. Indian J Cancer 2015; 51:1-4. [PMID: 24947086 DOI: 10.4103/0019-509x.134593] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To determine the socio-demographic characteristics of cancer patients. MATERIALS AND METHODS Review of the Cancer registry, and patient interview. Information on socio-demographic profile, medical history, family history and previous treatment, if any, was retrieved from the patient. If the patient couldn't be contacted then information was taken from pathology/radiotherapy or medical records department. RESULTS A total of 684 patients participated in the study. More than 40% of males and 53.7% of females were illiterate, P < 0.05. The majority (33.5%) of participants were of low socioeconomic status. The most frequently reported cancer (ca) in males it was ca lung (40.9) and ca oesophagus (9.8). In females most common cancer were ca breast (23.9) followed by ca cervix (11.7).
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Singh V, Singla SK, Jha V, Puri V, Puri S. Hepatocyte nuclear factor-1β: A regulator of kidney development and cystogenesis. Indian J Nephrol 2015; 25:70-6. [PMID: 25838642 PMCID: PMC4379628 DOI: 10.4103/0971-4065.139492] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The understanding of the genomics of the renal tissue has gathered a considerable interest and is making rapid progress. The molecular mechanisms as well as the precise function of the associated molecular components toward renal pathophysiology have recently been realized. For the cystic kidney disease, the regulation of gene expression affecting epithelial cells proliferation, apoptosis as well as process of differentiation/de-differentiation represent key molecular targets. For the cystic disorders, molecular targets have been identified, which besides lending heterogeneity to cysts may also provide tools to unravel their functional importance to understand the renal tissue homeostasis. This review focuses on providing comprehensive information about the transcriptional regulatory role of hepatocyte nuclear factor-1β, a homeoprotein, as well as its interacting partners in renal tissue development and pathophysiology.
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Thapa P, Mishra SR, Bista B, Dhungana RR, Adhikari N, Soti L, Puri S, Aryal KK. Social Consequences of Alcohol Use among Urban Poor: A Cross-sectional Study in Kathmandu Valley. JOURNAL OF NEPAL HEALTH RESEARCH COUNCIL 2015; 13:54-58. [PMID: 26411714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND Nepal is not an exception to alcohol use; urban poor are more prone than the general population. The question of social consequences of alcohol use among urban poor remains largely unanswered in Nepal. Study explored the alcohol linked social consequences among the urban poor of Kathmandu Valley. METHODS Taking 422 urban poor from four squatter settlements of Kathmandu Valley, a cross-sectional study was carried out. A series of univariate and bivariate analysis were performed in R version 3.1.2. RESULTS Four out of 10 current drinkers (42.86%, 95% CI: 31.4-54.3) encountered various social consequences. The number one consequence hitting 23.19% drinkers was money loss. Male drinkers were 4.43 times (95% CI: 1.810.8) more likely to face social consequences than their female counterparts. Being male frequent drinker increased the odds of social consequence 3.80 times (95% CI:1.3-11.0) than that of female frequent drinker. CONCLUSIONS A behaviour change communication campaign needs initiation; male populace and frequent drinkers being the target.
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Puri S, Li R, Ruszaj D, Tati S, Edgerton M. Iron binding modulates candidacidal properties of salivary histatin 5. J Dent Res 2014; 94:201-8. [PMID: 25365968 DOI: 10.1177/0022034514556709] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Salivary protein histatin 5 (Hst 5) is fungicidal toward Candida albicans, the causative agent of oropharyngeal candidiasis. However, its activity in saliva is compromised by salivary protease-mediated degradation and interaction with salivary salts. Hst 5 has also been shown to bind various metals in saliva-namely, Zn, Cu, and Ni. Surprisingly, interactions of Hst 5 with Fe have not been studied, although iron is one of the most abundant metals present in saliva. Using circular dichroism, we show that Hst 5 can bind up to 10 equivalents of iron as measured by loss of its alpha-helical secondary structure that is normally observed for it in trifluoroethylene. A significant decrease in the candidacidal ability of Hst 5 was observed upon iron binding, with increasing iron concentrations being inversely proportional to Hst 5 killing activity. Binding assays showed that the decrease in killing was likely a result of reduced binding (10-fold reduction) of Fe-Hst 5 to C. albicans cells. Protease stability analysis showed that Fe-Hst 5 was completely resistant to trypsin digestion. In contrast, zinc binding had limited effects on Hst 5 fungicidal activity or protease susceptibility. RNA sequencing results identified changes in iron uptake genes in Hst 5-treated C. albicans cells. Our findings thus suggest that consequences of Hst 5 binding iron not only affect candidacidal ability and proteolyic stability of Hst 5, but may also contribute to a novel killing mechanism involving interference with cellular iron metabolism.
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Kumar S, Mehrotra R, Puri S. PR22 Lymphatic cancer spread assessment by podoplanin (D2-40) in breast cancer. Breast 2014. [DOI: 10.1016/s0960-9776(14)70032-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Puri S, Sarpal S, Ashat M. Screening of retinopathy of prematurity: a neglected public health issue. Ann Med Health Sci Res 2014; 4:S65-6. [PMID: 25031916 PMCID: PMC4083728 DOI: 10.4103/2141-9248.131726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Puri S, Lai WKM, Rizzo JM, Buck MJ, Edgerton M. Iron-responsive chromatin remodelling and MAPK signalling enhance adhesion in Candida albicans. Mol Microbiol 2014; 93:291-305. [PMID: 24889932 DOI: 10.1111/mmi.12659] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2014] [Indexed: 11/29/2022]
Abstract
Recent cumulative data show that various transcription factors are recruited to the chromatin in an iron-responsive manner to affect diverse cellular functions in the pathogenic fungus Candida albicans. Here we identified groups of iron-responsive genes in C. albicans by chromatin remodelling analysis at gene promoters, using micrococcal nuclease (MNase) digestion followed by deep sequencing. Chromatin in the promoter regions of iron uptake and utilization genes showed repressed and active configuration, respectively, under iron-replete conditions. GO Term enrichment analysis of genes with differentially remodelled chromatin, in respective promoter locales, suggested that many genes involved in adhesion are also iron-responsive. C. albicans was observed to be more self-adherent (twofold increase) and formed higher biofilm mass (77% increase) in the presence of iron. Furthermore, we identified various known and novel adhesion-related genes with iron-dependent active chromatin profiles that are indicative of potential upregulation under iron-replete conditions. Transcription factor Cph1 that is activated upon Cek1 phosphorylation also showed an active chromatin profile under iron-replete conditions and cells showed iron-responsive Cek1 MAPK phosphorylation in the presence of iron. Thus, iron affects diverse biological functions by modulating chromatin profiles of large gene sets and by signalling through Cek1 MAPK in C. albicans.
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Tjon-Kon-Fat RI, Bensdorp AJ, Maas J, Oosterhuis GJE, Hoek A, Hompes PGA, Broekmans FJ, Verhoeve HR, de Bruin JP, Repping S, Cohlen BJ, Groen H, Mol BWJ, van der Veen F, Wely M, Peeraer K, Debrock S, De Loecker P, Laenen A, Welkenhuyzen M, Spiessens C, De Neubourg D, D'Hooghe TM, Puri S, Mohan B, Herbemont C, Adda E, Hugues JN, Sermondade N, Dupont C, Cedrin-Durnerin I, Poncelet C, Levy R, Sifer C, Bellver J, Pellicer A, Garcia-Velasco JA, Ballesteros A, Remohi J, Meseguer M. Session 45: Clinical female infertility. Hum Reprod 2013. [DOI: 10.1093/humrep/det178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Tati S, Jang WS, Li R, Kumar R, Puri S, Edgerton M. Histatin 5 resistance of Candida glabrata can be reversed by insertion of Candida albicans polyamine transporter-encoding genes DUR3 and DUR31. PLoS One 2013; 8:e61480. [PMID: 23613860 PMCID: PMC3632557 DOI: 10.1371/journal.pone.0061480] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 03/11/2013] [Indexed: 12/29/2022] Open
Abstract
Candida albicans and Candida glabrata are predominant fungi associated with oral candidiasis. Histatin 5 (Hst 5) is a small cationic human salivary peptide with high fungicidal activity against C. albicans, however many strains of C. glabrata are resistant. Since Hst 5 requires fungal binding to cell wall components prior to intracellular translocation, reduced Hst 5 binding to C. glabrata may be the reason for its insensitivity. C. glabrata has higher surface levels of β-1,3-glucans as compared with C. albicans; however these differences did not account for reduced Hst 5 uptake and killing in C. glabrata. Similarly, the biofilm matrix of C. glabrata contained significantly higher levels of β-1,3-glucans compared with C. albicans, but it did not reduce the percentage of Hst 5 positive fungal cells in the biofilm. Hst 5 enters C. albicans cell through polyamine transporters Dur3p and Dur31p that are uncharacterized in C. glabrata. C. glabrata strains expressing CaDur3 and CaDur31 had two-fold higher killing and uptake of Hst 5. Thus, neither C. glabrata cell surface or biofilm matrix β-1,3-glucan levels affected Hst 5 toxicity; rather the crucial rate limiting step is reduced uptake that can be overcome by expression of C. albicans Dur proteins in C. glabrata.
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