Genomic,evolutionary and expression profile analysis of <Emphasis Type="Italic">Hsp70</Emphasis> superfamily in A and D genome of cotton (<Emphasis Type="Italic">Gossypium</Emphasis> spp.) under the challenge of <Emphasis Type="Italic">Verticillium dahliae</Emphasis>

In this study, we comparatively analyzed the 115 Hsp70 genes identified in Gossypium raimondii, Gossypium hirsutum and Gossypium arboreum genomes. Those Hsp70 genes unequally distributed among chromosomes in A and D genome of cotton (Gossypium spp.), and were classified into 29 groups according to the homology of them. Based on the localization information of the orthologs in Arabidopsis, the Hsp70 proteins were predicted to locate in cytosol, endoplasmic reticulum, mitochondrion or chloroplast. Homologous analysis indicated the evolutionary conservation of Hsp70 in cotton. In addition, those Hsp70 genes were differently expressed in Suyuan-045, Hai-7124 and TM-1, which were highly resistant, resistant, and sensitive to Verticillium dahliae respectively. The expressions of 26 Hsp70 genes were induced by Verticillium dahliae except for Hsp70-07/16/25/26, and the result suggested the potential involvement of them in responding to Verticillium wilt. Hsp70-08/30/31 was highly expressed in both Suyuan-045 and Hai-7124, and it was hypothesized that they might be involved in the resistance to the invasion of Verticillium dahliae. 144h after inoculation with Verticillium dahliae, the expression of Hsp70-13/14/15 was only up-regulated in Suyuan-045, and it was assumed that they might be involved in resistance to the extension of Verticillium dahliae. Further study on those Hsp70 genes would be valuable to reveal the role of them in Verticillium wilt resistance.     

Geographic variation in thermal tolerance and strategies of heat shock protein expression in the land snail <Emphasis Type="Italic">Theba pisana</Emphasis> in relation to genetic structure

Land snails are exposed to conditions of high ambient temperature and low humidity, and their survival depends on a suite of morphological, behavioral, physiological, and molecular adaptations to the specific microhabitat. We tested in six populations of the land snail Theba pisana whether adaptations to different habitats affect their ability to cope with thermal stress and their strategies of heat shock protein (HSP) expression. Levels of Hsp70 and Hsp90 in the foot tissue were measured in field-collected snails and after acclimation to laboratory conditions. Snails were also exposed to various temperatures (32 up to 54 °C) for 2 h and HSP messenger RNA (mRNA) levels were measured in the foot tissue and survival was determined. To test whether the physiological and molecular data are related to genetic parameters, we analyzed T. pisana populations using partial sequences of nuclear and mitochondrial DNA ribosomal RNA genes. We show that populations collected from warmer habitats were more thermotolerant and had higher constitutive levels of Hsp70 isoforms in the foot tissue. Quantitative real-time polymerase chain reaction (PCR) analysis indicated that hsp70 and hsp90 mRNA levels increased significantly in response to thermal stress, although the increase in hsp70 mRNA was larger compared to hsp90 and its induction continued up to higher temperatures. Generally, warm-adapted populations had higher temperatures of maximal induction of hsp70 mRNA synthesis and higher upper thermal limits to HSP mRNA synthesis. Our study suggests that Hsp70 in the foot tissue of T. pisana snails may have important roles in determining stress resistance, while Hsp90 is more likely implicated in signal transduction processes that are activated by stress. In the phylogenetic analysis, T. pisana haplotypes were principally divided into two major clades largely corresponding to the physiological ability to withstand stress, thus pointing to genetically fixed tolerance.     

Ayurvedic <Emphasis Type="Italic">Amalaki Rasayana</Emphasis> promotes improved stress tolerance and thus has anti-aging effects in <Emphasis Type="BoldItalic">Drosophila melanogaster</Emphasis>

Amalaki Rasayana (AR) is a common Ayurvedic herbal formulation of Phyllanthus emblica fruits and some other ingredients, and is used for general good health and healthy aging. We reported it to improve life history traits and to suppress neurodegeneration as well as induced apoptosis in Drosophila. The present study examines responses of Drosophila reared on AR-supplemented food to crowding, thermal or oxidative stresses. Wild-type larvae/flies reared on AR-supplemented food survived the various cell stresses much better than those reared on control food. AR-fed mutant park ¹³ or DJ-1β ^Delta93 (Parkinson’s disease model) larvae/flies, however, showed only partial or no protection, respectively, against paraquat-induced oxidative stress, indicating essentiality of DJ-1β for AR-mediated oxidative stress tolerance. AR feeding reduced the accumulation of reactive oxygen species (ROS) and lipid peroxidation even in aged (35-day-old) wild-type flies while enhancing superoxide dismutase (SOD) activity. We show that while Hsp70 or Hsp83 expression under normal or stress conditions was not affected by AR feeding, Hsp27 levels were elevated in AR-fed wild-type control as well as heat-shocked larvae. Therefore, besides the known anti-oxidant activity of Phyllanthus emblica fruits, dietary AR also enhances cellular levels of Hsp27. Our in vivo study on a model organism shows that AR feeding significantly improves tolerance to a variety of cell stresses through reduced ROS and lipid peroxidation on the one hand, and enhanced SOD activity and Hsp27 on the other. The resulting better homeostasis improves life span and quality of organism’s life.     

Characterization and function analysis of Hsp60 and Hsp10 under different acute stresses in black tiger shrimp, <Emphasis Type="Italic">Penaeus monodon</Emphasis>

Heat shock proteins (Hsps) are a class of highly conserved proteins produced in virtually all living organisms from bacteria to humans. Hsp60 and Hsp10, the most important mitochondrial chaperones, participate in environmental stress responses. In this study, the full-length complementary DNAs (cDNAs) of Hsp60 (PmHsp60) and Hsp10 (PmHsp10) were cloned from Penaeus monodon. Sequence analysis showed that PmHsp60 and PmHsp10 encoded polypeptides of 578 and 102 amino acids, respectively. The expression profiles of PmHsp60 and PmHsp10 were detected in the gills and hepatopancreas of the shrimps under pH challenge, osmotic stress, and heavy metal exposure, and results suggested that PmHsp60 and PmHsp10 were involved in the responses to these stimuli. ATPase and chaperone activity assay indicated that PmHsp60 could slow down protein denaturation and that Hsp60/Hsp10 may be combined to produce a chaperone complex with effective chaperone and ATPase activities. Overall, this study provides useful information to help further understand the functional mechanisms of the environmental stress responses of Hsp60 and Hsp10 in shrimp.     

The Role of Epibionts of Bacteria of the Genus <Emphasis Type="Italic">Pseudoalteromonas</Emphasis> and Cellular Proteasomes in the Adaptive Plasticity of Marine Cold-Water Sponges

It was found that cells of different color morphs of the cold-water marine sponges Halichondria panicea (Pallas, 1766) of the class Demospongiae differ in the content of epibionts of bacteria of the genus Pseudoalteromonas. The sponge cells with elevated levels of epibionts of bacteria of the genus Pseudoalteromonas showed an increased expression of Hsp70 proteins but had a reduced level of the proteasomal catalytic beta 5 subunit, which was accompanied by a change in their activity. Probably, epibionts of bacteria of the genus Pseudoalteromonas may affect the ubiquitin–proteasome system in the cells of cold-water marine sponges and, thereby, ensure their adaptive plasticity.     

Involvement of small heat shock proteins,trehalose, and lipids in the thermal stress management in <Emphasis Type="Italic">Schizosaccharomyces pombe</Emphasis>

Changes in the levels of three structurally and functionally different important thermoprotectant molecules, namely small heat shock proteins (sHsps), trehalose, and lipids, have been investigated upon heat shock in Schizosaccharomyces pombe. Both α-crystallin-type sHsps (Hsp15.8 and Hsp16) were induced after prolonged high-temperature treatment but with different kinetic profiles. The shsp null mutants display a weak, but significant, heat sensitivity indicating their importance in the thermal stress management. The heat induction of sHsps is different in wild type and in highly heat-sensitive trehalose-deficient (tps1Δ) cells; however, trehalose level did not show significant alteration in shsp mutants. The altered timing of trehalose accumulation and induction of sHsps suggest that the disaccharide might provide protection at the early stage of the heat stress while elevated amount of sHsps are required at the later phase. The cellular lipid compositions of two different temperature-adapted wild-type S. pombe cells are also altered according to the rule of homeoviscous adaptation, indicating their crucial role in adapting to the environmental temperature changes. Both Hsp15.8 and Hsp16 are able to bind to different lipids isolated from S. pombe, whose interaction might provide a powerful protection against heat-induced damages of the membranes. Our data suggest that all the three investigated thermoprotectant macromolecules play a pivotal role during the thermal stress management in the fission yeast.     

Heat shock proteins in <Emphasis Type="Italic">Varroa destructor</Emphasis> exposed to heat stress and in-hive acaricides

Varroa destructor is one of the major pests that affect honeybees around the world. Chemical treatments are common to control varroosis, but mites possess biochemical adaptive mechanisms to resist these treatments, enabling them to survive. So far, no information is available regarding whether these pesticides can induce the expression of heat shock protein (Hsp) as a common protective mechanism against tissue damage. The aims of this study were to determine differences in heat shock tolerance between mites collected from brood combs and phoretic ones, and to examine patterns of protein expression of Hsp70 that occur in various populations of V. destructor after exposure to acaricides commonly employed in beekeeping, such as flumethrin, tau-fluvalinate and coumaphos. Curiously, mites obtained from brood cells were alive at 40 °C, unlike phoretic mites that reached 100% mortality, demonstrating differential thermo-tolerance. Heat treatment induced Hsp70 in mites 4?×?more than in control mites and no differences in response were observed in phoretic versus cell-brood-obtained mites. Dose–response assays were carried out at increasing acaricide concentrations. Each population showed a different stress response to acaricides despite belonging to the same geographic region. In one of them, coumaphos acted as a hormetic stressor. Pyrethroids also induced Hsp70, but mite population seemed sensitive to this treatment. We concluded that Hsp70 could represent a robust biomarker for measuring exposure of V. destructor to thermal and chemical stress, depending on the acaricide class and interpopulation variability. This is relevant because it is the first time that stress response is analyzed in this biological model, providing new insight in host-parasite-xenobiotic interaction.     

Overexpression of <Emphasis Type="Italic">MuHSP70</Emphasis> gene from <Emphasis Type="Italic">Macrotyloma uniflorum</Emphasis> confers multiple abiotic stress tolerance in transgenic <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

A 70-KD heat shock protein (HSP70) is one of the most conserved chaperones. It is involved in de novo protein folding and prevents the aggregation of unfolded proteins under lethal environmental factors. The purpose of this study is to characterise a MuHSP70 from horsegram (Macrotyloma uniflorum) and elucidating its role in stress tolerance of plants. A MuHSP70 was cloned and characterised from a natural drought stress tolerant HPK4 variety of horsegram (M. uniflorum). For functional characterization, MuHSP70 was overexpressed in transgenic Arabidopsis. Overexpression of MuHSP70 was found to provide tolerance to the transgenic Arabidopsis against various stresses such as heat, cold, drought, salinity and oxidative stress. MuHSP70 transgenics were observed to maintain the shoot biomass, root length, relative water content, and chlorophyll content during exposure to multi-stresses relative to non-transgenic control. Transgenic lines have further shown the reduced levels of MDA, H₂O₂, and proteolytic activity. Together, these findings suggest that overexpression of MuHSP70 plays an important role in improving abiotic stress tolerance and could be a crucial candidate gene for exploration in crop improvement program.     

Association between circulating levels of heat-shock protein 27 and aggressive periodontitis

Heat-shock protein (Hsp) 27 is a major intracellular molecular chaperone and controller of intracellular responses to inflammatory signals. In the extracellular space, recombinant Hsp27 has been described to exert anti-inflammatory activities. The aim of this study was to assess the association between circulating levels of Hsp27 and different types of periodontitis. Pro- and anti-inflammatory cytokines and the stress proteins Hsp27 and Hsp60 with proposed anti- and pro-inflammatory properties, respectively, were measured by two-site ELISA in the serum of patients with aggressive periodontitis (AgP, n?=?30), chronic periodontitis (CP, n?=?29) and periodontally healthy controls (H, n?=?28). Furthermore, Hsp27 and Hsp60 levels were also measured longitudinally in 12 AgP patients at 6 time points up to 3 months after treatment. AgP patients had lower levels of Hsp27 compared to CP patients and healthy subjects (adjusted one-way ANOVA, p?<?0.001, followed by post hoc Tukey HSD comparisons), while no differences in levels of Hsp60 or cytokines between the three groups were detected. In CP patients and H subjects, the systemic Hsp27 levels correlated with Hsp60 (r?=?0.43, p?<?0.001; r?=?0.59, p?<?0.001, respectively) and with pro-inflammatory cytokines TNF-α (r?=?0.48, p?<?0.001; r?=?0.55, p?<?0.001, respectively) and IL-6 (r?=?0.44, p?<?0.01). However, no such correlations were detected in AgP cases. No consistent temporal patterns of changes of Hsp27 concentration were detected across AgP patients following periodontal treatment. This study provides the first evidence that Hsp27 may be differentially expressed and regulated in AgP patients as compared with CP patients and healthy individuals.