scholarly journals Oxidative stress and the presence of bacteria increase gene expression of the antimicrobial peptide aclasin, a fungal CSαβ defensin in Aspergillus clavatus

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6290 ◽  
Author(s):  
Gabriela Contreras ◽  
Nessa Wang ◽  
Holger Schäfer ◽  
Michael Wink
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Heat Shock ◽  
Osmotic Stress ◽  
Broad Class ◽  
Stress Conditions ◽  
Aspergillus Clavatus ◽  
Stress Oxidative ◽  
Fungal Defensin ◽  
Β Sheet

Background Antimicrobial peptides (AMPs) represent a broad class of naturally occurring antimicrobial compounds. Plants, invertebrates and fungi produce various AMPs as, for example, defensins. Most of these defensins are characterised by the presence of a cysteine-stabilised α-helical and β-sheet (CSαβ) motif. The changes in gene expression of a fungal CSαβ defensin by stress conditions were investigated in Aspergillus clavatus. A. clavatus produces the CSαβ defensin Aclasin, which is encoded by the aclasin gene. Methods Aclasin expression was evaluated in submerged mycelium cultures under heat shock, osmotic stress, oxidative stress and the presence of bacteria by quantitative real-time PCR. Results Aclasin expression increased two fold under oxidative stress conditions and in the presence of viable and heat-killed Bacillus megaterium. Under heat shock and osmotic stress, aclasin expression decreased. Discussion The results suggest that oxidative stress and the presence of bacteria might regulate fungal defensin expression. Moreover, fungi might recognise microorganisms as plants and animals do.

scholarly journals Diverse and Specific Gene Expression Responses to Stresses in Cultured Human Cells

2004 ◽  
Vol 15 (5) ◽  
pp. 2361-2374 ◽  
Author(s):  
John Isaac Murray ◽  
Michael L. Whitfield ◽  
Nathan D. Trinklein ◽  
Richard M. Myers ◽  
Patrick O. Brown ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Heat Shock ◽  
Hela Cells ◽  
Stress Responses ◽  
Cell Communication ◽  
Lung Fibroblasts ◽  
Specific Gene ◽  
Primary Fibroblasts ◽  
Stress Oxidative

We used cDNA microarrays in a systematic study of the gene expression responses of HeLa cells and primary human lung fibroblasts to heat shock, endoplasmic reticulum stress, oxidative stress, and crowding. Hierarchical clustering of the data revealed groups of genes with coherent biological themes, including genes that responded to specific stresses and others that responded to multiple types of stress. Fewer genes increased in expression after multiple stresses than in free-living yeasts, which have a large general stress response program. Most of the genes induced by multiple diverse stresses are involved in cell-cell communication and other processes specific to higher organisms. We found substantial differences between the stress responses of HeLa cells and primary fibroblasts. For example, many genes were induced by oxidative stress and dithiothreitol in fibroblasts but not HeLa cells; conversely, a group of transcription factors, including c-fos and c-jun, were induced by heat shock in HeLa cells but not in fibroblasts. The dataset is freely available for search and download at http://microarray-pubs.stanford.edu/human_stress/Home.shtml .

scholarly journals Gene expression modulation by paraquat-induced oxidative stress conditions in Paracoccidioides brasiliensis

2013 ◽  
Vol 60 ◽  
pp. 101-109 ◽  
Author(s):  
Marcus Vinícius de Oliveira ◽  
Ana Claudia de Freitas Oliveira ◽  
Cláudio S. Shida ◽  
Regina Costa de Oliveira ◽  
Luiz R. Nunes
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Paracoccidioides Brasiliensis ◽  
Stress Conditions ◽  
Expression Modulation

scholarly journals A Cytosolic Heat Shock Protein Expressed in Carrot (Daucus carota L.) Enhances Cell Viability under Oxidative and Osmotic Stress Conditions

HortScience ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 143-148 ◽  
Author(s):  
Yeh-Jin Ahn ◽  
Na-Hyun Song
Keyword(s):  
Heat Shock ◽  
Osmotic Stress ◽  
Heat Shock Protein ◽  
Cell Viability ◽  
Daucus Carota ◽  
Leaf Tissue ◽  
Small Heat Shock Protein ◽  
Stress Conditions ◽  
Daucus Carota L ◽  
And Function

The expression and function of DcHsp17.7, a small heat shock protein expressed in carrot (Daucus carota L.), was examined under oxidative and osmotic stress conditions. Comparative analysis revealed that DcHsp17.7 is a cytosolic Class I protein. Sequence alignment showed that DcHsp17.7 has the characteristic α-crystalline domain-containing consensus regions I and II. Under oxidative [hydrogen peroxide (H2O2)] and osmotic (polyethylene glycol) stress conditions, DcHsp17.7 accumulated in carrot leaf tissue. To examine its function under these abiotic stress conditions, the coding sequence of DcHsp17.7 was introduced into Escherichia coli and expressed by isopropyl β-D-1-thiogalactopyranoside treatment. Under both oxidative and osmotic stress conditions, heterologously expressed DcHsp17.7 enhanced bacterial cell viability. The expression level of soluble proteins was higher in transgenic cells expressing DcHsp17.7 when compared with controls under these stress conditions. These results suggest that DcHsp17.7 confers tolerance to both oxidative and osmotic stresses and thereby functions as a molecular chaperone during the stresses examined.

scholarly journals Stress affects the epigenetic marks added by natural transposable element insertions in Drosophila melanogaster

2016 ◽  
Author(s):  
Lain Guio ◽  
Cristina Vieira ◽  
Josefa González
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Transposable Element ◽  
Stress Conditions ◽  
Regulatory Sequences ◽  
Epigenetic Marks ◽  
Cis Acting ◽  
Comprehensive Picture ◽  
Epigenetic Gene Regulation

ABSTRACTTransposable elements are emerging as an important source of cis-acting regulatory sequences and epigenetic marks that could influence gene expression. However, few studies have dissected the role of specific transposable element insertions on epigenetic gene regulation. Bari-Jheh is a natural transposon that mediates resistance to oxidative stress by adding cis-regulatory sequences that affect expression of nearby genes. In this work, we integrated publicly available data with chromatin immunoprecipitation experiments to get a more comprehensive picture of Bari-Jheh molecular effects. We showed that Bari-Jheh was enriched for H3K9me3 in nonstress conditions, and for H3K9me3, H3K4me3 and H3K27me3 in oxidative stress conditions, which is consistent with expression changes in adjacent genes. We further showed that under oxidative stress conditions, H3K4me3 and H3K9me3 spread to the promoter region of Jheh1 gene. Finally, another insertion of the Bari1 family was associated with increased H3K27me3 in oxidative stress conditions suggesting that Bari1 histone marks are copy-specific. We concluded that besides adding cis-regulatory sequences, Bari-Jheh influences gene expression by affecting the local chromatin state.

scholarly journals Melatonin alleviates heat-induced damage of tomato seedlings by balancing redox homeostasis and modulating polyamine and nitric oxide biosynthesis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mohammad Shah Jahan ◽  
Sheng Shu ◽  
Yu Wang ◽  
Zheng Chen ◽  
Mingming He ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Nitric Oxide ◽  
Hydrogen Peroxide ◽  
Heat Stress ◽  
Heat Shock ◽  
Defense Mechanism ◽  
Enzymatic Antioxidants ◽  
Tomato Seedlings ◽  
Glutathione Cycle

Abstract Background Melatonin is a pleiotropic signaling molecule that plays multifarious roles in plants stress tolerance. The polyamine (PAs) metabolic pathway has been suggested to eliminate the effects of environmental stresses. However, the underlying mechanism of how melatonin and PAs function together under heat stress largely remains unknown. In this study, we investigated the potential role of melatonin in regulating PAs and nitric oxide (NO) biosynthesis, and counterbalancing oxidative damage induced by heat stress in tomato seedlings. Results Heat stress enhanced the overproduction of reactive oxygen species (ROS) and damaged inherent defense system, thus reduced plant growth. However, pretreatment with 100 μM melatonin (7 days) followed by exposure to heat stress (24 h) effectively reduced the oxidative stress by controlling the overaccumulation of superoxide (O2•−) and hydrogen peroxide (H2O2), lowering the lipid peroxidation content (as inferred based on malondialdehyde content) and less membrane injury index (MII). This was associated with increased the enzymatic and non-enzymatic antioxidants activities by regulating their related gene expression and modulating the ascorbate–glutathione cycle. The presence of melatonin induced respiratory burst oxidase (RBOH), heat shock transcription factors A2 (HsfA2), heat shock protein 90 (HSP90), and delta 1-pyrroline-5-carboxylate synthetase (P5CS) gene expression, which helped detoxify excess ROS via the hydrogen peroxide-mediated signaling pathway. In addition, heat stress boosted the endogenous levels of putrescine, spermidine and spermine, and increased the PAs contents, indicating higher metabolic gene expression. Moreover, melatonin-pretreated seedlings had further increased PAs levels and upregulated transcript abundance, which coincided with suppression of catabolic-related genes expression. Under heat stress, exogenous melatonin increased endogenous NO content along with nitrate reductase- and NO synthase-related activities, and expression of their related genes were also elevated. Conclusions Melatonin pretreatment positively increased the heat tolerance of tomato seedlings by improving their antioxidant defense mechanism, inducing ascorbate–glutathione cycle, and reprogramming the PAs metabolic and NO biosynthesis pathways. These attributes facilitated the scavenging of excess ROS and increased stability of the cellular membrane, which mitigated heat-induced oxidative stress.

scholarly journals Modulation of Heat-Shock Proteins Mediates Chicken Cell Survival against Thermal Stress

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2407
Author(s):  
Abdelrazeq M. Shehata ◽  
Islam M. Saadeldin ◽  
Hammed A. Tukur ◽  
Walid S. Habashy
Keyword(s):  
Oxidative Stress ◽  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Cell Survival ◽  
Cell Damage ◽  
Stress Conditions ◽  
Economic Losses ◽  
Chicken Cell ◽  
Shock Proteins

Heat stress is one of the most challenging environmental stresses affecting domestic animal production, particularly commercial poultry, subsequently causing severe yearly economic losses. Heat stress, a major source of oxidative stress, stimulates mitochondrial oxidative stress and cell dysfunction, leading to cell damage and apoptosis. Cell survival under stress conditions needs urgent response mechanisms and the consequent effective reinitiation of cell functions following stress mitigation. Exposure of cells to heat-stress conditions induces molecules that are ready for mediating cell death and survival signals, and for supporting the cell’s tolerance and/or recovery from damage. Heat-shock proteins (HSPs) confer cell protection against heat stress via different mechanisms, including developing thermotolerance, modulating apoptotic and antiapoptotic signaling pathways, and regulating cellular redox conditions. These functions mainly depend on the capacity of HSPs to work as molecular chaperones and to inhibit the aggregation of non-native and misfolded proteins. This review sheds light on the key factors in heat-shock responses for protection against cell damage induced by heat stress in chicken.

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