Rab11 and Actin Cytoskeleton Participate in Giardia lamblia Encystation, Guiding the Specific Vesicles to the Cyst Wall

The encystation process is crucial for survival and transmission of Giardia lamblia to new hosts. During this process, vesicular trafficking and the cytoskeleton play important roles. In eukaryotic cells, intracellular transport is regulated by proteins, including Rab-GTPases and SNAREs, which regulate vesicle formation along with recognition of and binding to the target membrane. Cytoskeletal structures are also involved in these processes. In this study, we demonstrate the participation of Rab11 in the transport of encystation-specific vesicles (ESVs). Additionally, we demonstrate that disruption of actin microfilaments affects ESVs transport. The modification of actin dynamics was also correlated with a reduction in rab11 and cwp1 expression. Furthermore, down-regulation of rab11 mRNA by a specific hammerhead ribozyme caused nonspecific localization of CWP1. We thus provide new information about the molecular machinery that regulates Giardia lamblia encystation. Given our findings, Rab11 and actin may be useful targets to block Giardia encystation

IL-1β Inflammatory Cytokine-Induced TP63 Isoform ∆NP63α Signaling Cascade Contributes to Cisplatin Resistance in Human Breast Cancer Cells

The mechanisms behind the induction of malignancy and chemoresistance in breast cancer cells are still not completely understood. Inflammation is associated with the induction of malignancy in different types of cancer and is highlighted as an important factor for chemoresistance. In previous work, we demonstrated that the inflammatory cytokine interleukin 1β (IL-1β)-induced upregulation of genes was associated with chemoresistance in breast cancer cells. Here, we evaluated the participation and the expression profile of TP63 in the induction of resistance to cisplatin. By loss-of-function assays, we identified that IL-1β particularly upregulates the expression of the tumor protein 63 (TP63) isoform ΔNP63α, through the activation of the IL-1β/IL-1RI/β-catenin signaling pathway. Upregulation of ΔNP63α leads to an increase in the expression of the cell survival factors epidermal growth factor receptor (EGFR) and phosphatase 1D (Wip1), and a decrease in the DNA damage sensor, ataxia-telangiectasia mutated (ATM). The participation of these processes in the increase of resistance to cisplatin was confirmed by silencing TP63 expression or by inhibition of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) activity in the IL-1β/IL-1RI/β-catenin signaling pathway. These data reinforced the importance of an inflammatory environment in the induction of drug resistance in cancer cells and uncovered a molecular mechanism where the IL-1β signaling pathway potentiates the acquisition of cisplatin resistance in breast cancer cells

Transcriptional profiling of sugarcane leaves and roots under progressive osmotic stress reveals a regulated coordination of gene expression in a spatiotemporal manner

<div><p>Sugarcane is one of the most important crops worldwide and is a key plant for the global production of sucrose. Sugarcane cultivation is severely affected by drought stress and it is considered as the major limiting factor for their productivity. In recent years, this plant has been subjected to intensive research focused on improving its resilience against water scarcity; particularly the molecular mechanisms in response to drought stress have become an underlying issue for its improvement. To better understand water stress and the molecular mechanisms we performed a <i>de novo</i> transcriptomic assembly of sugarcane (var. Mex 69–290). A total of 16 libraries were sequenced in a 2x100 bp configuration on a HiSeq-Illumina platform. A total of 536 and 750 genes were differentially up-regulated along with the stress treatments for leave and root tissues respectively, while 1093 and 531 genes were differentially down-regulated in leaves and roots respectively. Gene Ontology functional analysis showed that genes related to response of water deprivation, heat, abscisic acid, and flavonoid biosynthesis were enriched during stress treatment in our study. The reliability of the observed expression patterns was confirmed by RT-qPCR. Additionally, several physiological parameters of sugarcane were significantly affected due to stress imposition. The results of this study may help identify useful target genes and provide tissue-specific data set of genes that are differentially expressed in response to osmotic stress, as well as a complete analysis of the main groups is significantly enriched under this condition. This study provides a useful benchmark for improving drought tolerance in sugarcane and other economically important grass species.</p></div

Comparative analysis of the unique and shared DEGs among the osmotic stress treatments for sugarcane var. Mex 69–290.

<p>The Venn diagrams show the overlap of the DEGs for leaves and roots submitted to a 3 time-series of osmotic stress treatments. A and C) Comparison among the genes differentially up-regulated for the stress treatments for leaf and root tissues respectively. D and F) Comparison among the genes differentially down-regulated for the stress treatments for leaf and root tissues respectively. B and E) Comparison among the core set of up- and down-regulated genes respectively for both tissues. CULG = CORE of Up-regulated Leaf Genes, CURG = CORE of Up-regulated Root genes, COSUG = CORE of Osmotic Stress Up-regulated Genes, CDLG = CORE of Down-regulated Leaf Genes, CDRG = CORE of Down-regulated Root Genes, and COSDG = CORE of Osmotic Stress Down-regulated Genes. The Venn diagrams were done by using Vennerable R package.</p

Stress-related DEGs detected in the CORE sets (CULG and CDLG) of regulated genes in leaves during the osmotic stress treatments.

<p>Stress-related DEGs detected in the CORE sets (CULG and CDLG) of regulated genes in leaves during the osmotic stress treatments.</p

Correlation and clustering analysis of the sugarcane DEGs subjected to osmotic stress treatments.

<p>A) Tissue-specific heatmap clustering of 12,662 significant DEGs (FDR ≤ 0.001 and FC ≥2) for the 0, 24, 48, and 72 h treatments ASI. B-G) Osmotic stress DEG profiles for the organ specific behavior clusters. Clusters were built according to their expression patterns during the stress treatments. Gray lines indicate the behavior of each gene into the treatment and the mean expression profile for each cluster is plotted as blue lines. Bottom number indicates the number of time series genes. L = leaf, R = root. L0 and R0 = non-stress treatment, L1 and R1 = 24 h treatment ASI, L2 and R2 = 48 h treatment ASI, L3 and R3 = 72 h treatment ASI. * = biological replicate.</p

Correlation of sample replicates and hierarchical clustering analysis of gene expression levels in each sample (0, 24, 48, and 72 h) under osmotic stress treatment.

<p>A) Sample relatedness is plotted using the first two principal component (PCs) showing the variability between replicates and different treatments. Non-stressed leaf and root samples are in blue shade background. In dark-green and in red background colors are the samples corresponding to stressed leaves and roots (24, 48, 72 h ASI), respectively. C = control, D = Drought. B) Correlation dendrogram of gene expression in all samples. Correlation <i>r</i> values are coded into key colors where green indicates lower <i>r</i> values; reds indicates higher <i>r</i> above the mean. Blue squares in the nodes represent non-stressed samples, green stars represent leaf stressed samples, and the red stars represent root stressed samples. L = leaf, R = root, L0 and R0 = non-stress treatment, L1 and R1 = 24 h treatment ASI, L2 and R2 = 48 h treatment ASI, L3 and R3 = 72 h treatment ASI. * = biological replicate.</p

Differentially expressed gene analysis along the osmotic stress treatments in sugarcane.

<p>A) Volcano plots show DEGs in each of the stress treatments for leaf and root tissues. The x-axis represents the log2FoldChange of genes, and the y-axis represents the statistical significance degree by–log10 (PValue). DEGs are shown in red dots and were detected using their statistical significance differences (FDR<0.001 and a log2FoldChange>2). B) Comparison of the up- and down-regulated DEGs for leaf and root tissues in all three stress treatments and comparison of shared genes among all the treatments (CORE gene sets).</p

Principal findings of the analysis of sugarcane transcriptome under osmotic stress.

<p>A) Genes regulated under osmotic stress treatments. Inside blue square are the DEGs regulated in the three treatments. The green square represents the DEG regulated only in the T1 treatment, within the yellow square are the DEGs expressed only in T2 treatment, and within the red square are the DEGs regulated only in T3 treatment. Inside gray circles are DEGs shared among treatments. Letters in black color represent the up-regulated DEGs and letters in orange color represent the down-regulated DEGs per treatment. B) Schematic depiction of the physiological results obtained in sugarcane var. Mex 69–290, imposed to an osmotic stress treatment by PEG 8000 for 24, 48, and 72 h. The green arrow under the depiction indicates the directions of the time-stress treatments. RCW = relative content water, OsPot = osmotic potential, AR = assimilation rate. Complete name of the genes in A) are listed in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0189271#pone.0189271.s007" target="_blank">S4 File</a>.</p

Functional enrichment analysis for the CORE set of DEGs regulated in the osmotic stress treatments for sugarcane var. Mex 69–290.

<p>Significant groups (FDR<0.05) for COSUG and COSDG groups are plotted according to their enriched adjusted p-value (x axis). The size is proportional to the number of enriched genes among the total number of their GO term associated unigenes. COSUG = CORE of Osmotic Stress Up-regulated Genes for both leaf and root tissues, COSDG = CORE of Osmotic Stress Down-regulated Genes for both leaf and root tissues.</p