Comprehensive analysis of temporal alterations in cellular proteome of bacillus subtilis under curcumin treatment

Curcumin is a natural dietary compound with antimicrobial activity against various gram positive and negative bacteria. This study aims to investigate the proteome level alterations in Bacillus subtilis due to curcumin treatment and identification of its molecular/cellular targets to understand the mechanism of action. We have performed a comprehensive proteomic analysis of B. subtilis AH75 strain at different time intervals of curcumin treatment (20, 60 and 120 min after the drug exposure, three replicates) to compare the protein expression profiles using two complementary quantitative proteomic techniques, 2D-DIGE and iTRAQ. To the best of our knowledge, this is the first comprehensive longitudinal investigation describing the effect of curcumin treatment on B. subtilis proteome. The proteomics analysis revealed several interesting targets such UDP-N-acetylglucosamine 1-carboxyvinyltransferase 1, putative septation protein SpoVG and ATP-dependent Clp protease proteolytic subunit. Further, in silico pathway analysis using DAVID and KOBAS has revealed modulation of pathways related to the fatty acid metabolism and cell wall synthesis, which are crucial for cell viability. Our findings revealed that curcumin treatment lead to inhibition of the cell wall and fatty acid synthesis in addition to differential expression of many crucial proteins involved in modulation of bacterial metabolism. Findings obtained from proteomics analysis were further validated using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) assay for respiratory activity, resazurin assay for metabolic activity and membrane integrity assay by potassium and inorganic phosphate leakage measurement. The gene expression analysis of selected cell wall biosynthesis enzymes has strengthened the proteomics findings and indicated the major effect of curcumin on cell division

Understanding HIV-Mycobacteria synergism through comparative proteomics of intra-phagosomal mycobacteria during mono- and HIV co-infection

Mycobacterium tuberculosis (Mtb) is the most common co-infection in HIV patients and a serious co-epidemic. Apart from increasing the risk of reactivation of latent tuberculosis (TB), HIV infection also permits opportunistic infection of environmental non-pathogenic mycobacteria. To gain insights into mycobacterial survival inside host macrophages and identify mycobacterial proteins or processes that influence HIV propagation during co-infection, we employed proteomics approach to identify differentially expressed intracellular mycobacterial proteins during mono- and HIV co-infection of human THP-1 derived macrophage cell lines. Of the 92 proteins identified, 30 proteins were upregulated during mycobacterial mono-infection and 40 proteins during HIV-mycobacteria co-infection. We observed down-regulation of toxin-antitoxin (TA) modules, up-regulation of cation transporters, Type VII (Esx) secretion systems, proteins involved in cell wall lipid or protein metabolism, glyoxalate pathway and branched chain amino-acid synthesis during co-infection. The bearings of these mycobacterial factors or processes on HIV propagation during co-infection, as inferred from the proteomics data, were validated using deletion mutants of mycobacteria. The analyses revealed mycobacterial factors that possibly via modulating the host environment, increased viral titers during co-infection. The study provides new leads for investigations towards hitherto unknown molecular mechanisms explaining HIV-mycobacteria synergism, helping address diagnostics and treatment challenges for effective co-epidemic management

Comprehensive analysis of temporal alterations in cellular proteome of Bacillus subtilis under curcumin treatment.

Curcumin is a natural dietary compound with antimicrobial activity against various gram positive and negative bacteria. This study aims to investigate the proteome level alterations in Bacillus subtilis due to curcumin treatment and identification of its molecular/cellular targets to understand the mechanism of action. We have performed a comprehensive proteomic analysis of B. subtilis AH75 strain at different time intervals of curcumin treatment (20, 60 and 120 min after the drug exposure, three replicates) to compare the protein expression profiles using two complementary quantitative proteomic techniques, 2D-DIGE and iTRAQ. To the best of our knowledge, this is the first comprehensive longitudinal investigation describing the effect of curcumin treatment on B. subtilis proteome. The proteomics analysis revealed several interesting targets such UDP-N-acetylglucosamine 1-carboxyvinyltransferase 1, putative septation protein SpoVG and ATP-dependent Clp protease proteolytic subunit. Further, in silico pathway analysis using DAVID and KOBAS has revealed modulation of pathways related to the fatty acid metabolism and cell wall synthesis, which are crucial for cell viability. Our findings revealed that curcumin treatment lead to inhibition of the cell wall and fatty acid synthesis in addition to differential expression of many crucial proteins involved in modulation of bacterial metabolism. Findings obtained from proteomics analysis were further validated using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) assay for respiratory activity, resazurin assay for metabolic activity and membrane integrity assay by potassium and inorganic phosphate leakage measurement. The gene expression analysis of selected cell wall biosynthesis enzymes has strengthened the proteomics findings and indicated the major effect of curcumin on cell division

Mass spectrometry and bioinformatics analysis data

2DE and 2D-DIGE based proteomics analysis of serum from women with endometriosis revealed several proteins to be dysregulated. A complete list of these proteins along with their mass spectrometry data and subsequent bioinformatics analysis are presented here. The data is related to “Investigation of serum proteome alterations in human endometriosis” by Dutta et al. [1]

Investigation of serum proteome alterations in human endometriosis

Endometriosis is a common benign gynecological disease, characterized by proliferation of functional endometrial glands and stroma outside the uterine cavity. The present study involves investigation of alterations in the serum proteome of endometriosis patients compared to healthy controls using 2DE and 2D-DIGE combined with MALDI TOF/TOF-MS. Comparison of serum proteome of endometriosis patients and healthy subjects revealed 25 significant differentially expressed proteins. Gene ontology and network analysis, performed using PANTHER, DAVID, WebGestalt and STRING, revealed that the differentially expressed proteins are majorly involved in response to stimulus, immune system, metabolic, localization and cellular processes. For serum diagnostic marker identification, several robust statistical screening procedures were applied to identify the set of the most significant proteins responsible for successful diagnosis of different endometriosis stages. Partial least squares (PLS) based marker selection tool and orthogonal partial least squares-discriminant analysis (OPLS-DA) were used to identify the most significant proteins for disease prediction. Western blotting validation in a separate cohort of patients revealed that haptoglobin (HP), Ig kappa chain C region (IGKC), alpha-1B-glycoprotein (A1BG) can be considered effective serum protein markers for the diagnosis of Stage II, III and IV endometriosis. For diagnosis of Stage I, only IGKC and HP seemed promising

(A) CTC staining and flow cytometric analysis for respiratory activity.

<p>Graphical representation of CTC mean intensity (PE-Texas Red-A) <i>vs</i>. FSC-A obtained in the FACS analysis of control, 20, 60 and 120 min curcumin treated samples and negative control. Both dot plot and histogram representations are displayed for each sample. <b>(B) & (C)</b> Potassium and phosphorus leakage assay; curcumin (20 and 40 μM) was added to the <i>B</i>. <i>subtilis</i> in HEPES-glucose medium and K⁺ and P levels were measured at 20, 60, 90 and 120 min time intervals, and also in the untreated control and positive control (heated at 70° C for 30 min) samples using ICP-AES and data was normalized with baseline HEPES-glucose medium. <b>(D)</b> Metabolic activity assay using resazurin. 20 min curcumin treatment has showed lower metabolic activity whereas the metabolic activity increased as time of exposure increased to 60 min and 120 min as compared to control. * indicates <i>p</i> < 0.05. <b>(E)</b> Gene expression analysis using RT-PCR for <i>murAA</i>, <i>spoVG</i> and <i>ftsH</i> genes and the relative expression was calculated by taking mean C_t values from triplicate runs. * indicates <i>p</i> < 0.05 and ** indicates <i>p</i> < 0.001. <b>(F)</b> Physical interaction analysis of curumin with <i>B</i>. <i>subtilis</i> FtsZ immobilized on CM-5 sensor chip. The interaction was monitored by measuring the response unit and the response unit was increased as the concentration of curcumin increased. Both sensorgram and the bar diagram showing the binding to FtsZ was displayed.</p

Quantitative profiles of the differentially expressed proteins involved in diverse biological processes identified in iTRAQ-based quantitative proteomics analysis using LTQ-Orbitrap.

<p><b>(A)</b> Peptidoglycan biosynthesis, <b>(B)</b> Fatty acid synthesis, <b>(C)</b> Cell division and sporulation, <b>(D)</b> TCA cycle, <b>(E)</b> Stress response and <b>(F)</b> Nucleotide biosynthesis. Data from QTOF is provided in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120620#pone.0120620.s002" target="_blank">S2 Fig</a>.</p

List of differentially expressed proteins in <i>B</i>. <i>subtilis</i> due to curcumin treatment obtained from DIGE analysis and its comparison with iTRAQ analysis^$.

<p> This is a partial list having selected candidates with >1.5 fold change and complete list is provided in S2 Table

#: Proteins unique in DIGE, Bold: Same trend in both DIGE and iTRAQ (Orbitrap data);

* or NS: No significant change in iTRAQ in Orbitrap data (less than 1.2 fold up and down);

NI- Not identified in iTRAQ analysis.

List of differentially expressed proteins in B. subtilis due to curcumin treatment obtained from DIGE analysis and its comparison with iTRAQ analysis</a>.</p</sup>

List of the primers used for quantitative RT-PCR analysis for selected genes.

<p>List of the primers used for quantitative RT-PCR analysis for selected genes.</p