Expression Of Small Heat Shock Proteins Research Articles

Adaptation and carry over effects of extreme sporadic heat stress in Culex mosquitoes

Mosquitoes, as temperature-sensitive ectothermic vectors, exhibit temperature-dependence. This study investigates Culex pipiens pallens (Cx. pallens) responses to abrupt temperature increases and their implications on mosquito physiology.First instar larvae (24hr post hatching) and newly enclosed adults (24hr post emergence) were separately exposed to heat shock regimes of 33 °C, 37 °C, and 42 °C for 3 days alongside a control temperature of 27 °C. Results showed that mortality was triggered at 42 °C within a day. Adult male mosquitoes were less tolerant to all temperatures than larvae and adult females (p < 0.05). Exposing larvae to constant temperatures for 3 days significantly decreased larvae's development time, growth rate and adult emergence (p < 0.05). Reproductive fitness was significantly reduced (p < 0.05) in males emerging from larvae exposed to 37 °C. Life table parameters showed significant increased mortality rate, kill power and decreased life expectancy at the embryonic stage (p < 0.05). Furthermore, heatwaves deactivated the Transient receptor protein ankyrin 1 at 37 °C (p < 0.05) in larvae but not adults. Calmodium, Heat shock protein 90, and small heat shock protein expression were significantly decreased in larvae at 37 °C (p < 0.05) as compared to larvae raised at 33 °C and 27 °C.In conclusion, we classified the heat waves into three categories: adaptable (33 °C), critical (37 °C), and fatal (42 °C). Prolonged exposure of Culex pallens larvae to extreme heat affects the male reproductive output. These findings may serve as an important reference for forecasting vector and pest dynamics and used to tailor mosquito prevention and control measures.

Cerebellar injury induced by cadmium via disrupting the heat-shock response.

Cadmium (Cd) is a food contaminant that poses serious threats to animal health, including birds. It is also an air pollutant with well-known neurotoxic effects on humans. However, knowledge on the neurotoxic effects of chronic Cd exposure on chicken is limited. Thus, this study assessed the neurotoxic effects of chronic Cd on chicken cerebellum. Chicks were exposed to 0 (control), 35 (low), and 70 (high) mg/kg of Cd for 90days, and the expression of genes related to the heat-shock response was investigated. The chickens showed clinical symptoms of ataxia, and histopathology revealed that Cd exposure decreased the number of Purkinje cells and induced degeneration of Purkinje cells with pyknosis, and some dendrites were missing. Moreover, Cd exposure increased the expression of heat-shock factors, HSF1, HSF2, and HSF3, and heat-shock proteins, HSP60, HSP70, HSP90, and HSP110. These changes indicate that HSPs improve the tolerance of the cerebellum to Cd. Conversely, the expressions of HSP10, HSP25, and HSP40 were decreased significantly, which indicated that Cd inhibits the expression of small heat-shock proteins. However, HSP27 and HSP47 were upregulated following low-dose Cd exposure, but downregulated under high-dose Cd exposure. This work sheds light on the toxic effects of Cd on the cerebellum, and it may provide evidence for health risks posed by Cd. Additionally, this work also identified a novel target of Cd exposure in that Cd induces cerebellar injury by disrupting the heat-shock response. Cd can be absorbed into chicken's cerebellum through the food chain, which eventually caused cerebellar injury. This study provided a new insight that chronic Cd-induced neurotoxicity in the cerebellum is associated with alterations in heat-shock response-related genes, which indicated that Cd through disturbing heat-shock response induced cerebellar injury.

The involvement of small heat shock protein in chemoresistance in ovarian cancer - in vitro study.

Ovarian cancer is the most deadly gynecologic malignancy worldwide. Although the primary response to chemotherapy is high, the majority of patients will develop resistance against applied treatment. In this study, we focused on resistance to cisplatin, a first-line drug used for the treatment of ovarian cancer. The mechanism of the resistance development process is widely described, but there is a lack of information about the involvement of members of small heat shock proteins (HSPs) and their transport via exosomes. In this study, we used two cell lines: A2780 and SKOV3, and their cisplatin-resistance variants: A2780 CDDP and SKOV3 CDDP. We have shown that the expression of three small HSPs (HSPB5, HSPB6, and HSPB8) in cisplatin-resistant cell lines differs from their sensitive counterparts. Further, we isolated exosomes and determined the small HSPs in their cargo. In A2780 WT we observed a low amount of HSPB5 and HSPB6. We did not observe the expression of small HSPs in the SKOV3 cell line in both sensitive and resistant variants. Our data suggest the involvement of small HSPs in drug resistance of ovarian cancer and their presence is not related to exosomal transport. Analysis of the biological consequences of the imbalance of small HSPs expression in cisplatin resistance needs further investigation.

Quantitative proteomics analysis provides insight into the biological role of Hsp90 in BmNPV infection in Bombyx mori

Heat shock protein 90, an essential chaperone responsible for the correct maturation of key proteins, has been confirmed to facilitate Bombyx mori nucleopolyhedrovirus (BmNPV) proliferation but the mechanism is not clear. In this study, we use quantitative proteomics analysis to investigate the mechanism of Hsp90 in BmNPV replication. In total, 195 differentially expressed proteins (DEPs) were identified with 136 up-regulated proteins and 59 down-regulated proteins. The protein expression level of small heat shock proteins, immune-related proteins, cellular DNA repair-related proteins and zinc finger proteins is significantly enhanced while that of protein kinases is declined. KEGG pathway analysis reveals that DEPs are involved in longevity regulating pathway, mTOR signaling pathway, FoxO signaling pathway and Toll and Imd signaling pathway. Based on the DEPs results, we speculate that inhibition of Hsp90 suppresses the BmNPV infection may because it could not only stimulate the host innate immune, induce small heat shock proteins expression to maintain the cellular proteostasis but activate host transcription factors to bind to virus DNA or protein and subsequently hinder virus replication. The results will help understand the roles of Hsp90 in BmNPV infection and shed light on new clue to illustrate the molecular mechanism of silkworm-virus interaction. SignificanceThis is the first report on Hsp90 roles in BmNPV infection based on proteomic analysis. Our findings may provide new clue and research orientation to illustrate the molecular mechanism of silkworm-virus interaction and a set of BmHsp90 candidate clients, which may involve in BmNPV infection in BmN cells.

Rapidly progressive amyotrophic lateral sclerosis is associated with microglial reactivity and small heat shock protein expression in reactive astrocytes.

AimsAmyotrophic lateral sclerosis (ALS) is a chronic neurodegenerative disease characterized by progressive loss of motor neurons, muscle weakness, spasticity, paralysis and death usually within 2–5 years of onset. Neuroinflammation is a hallmark of ALS pathology characterized by activation of glial cells, which respond by upregulating small heat shock proteins (HSPBs), but the exact underlying pathological mechanisms are still largely unknown. Here, we investigated the association between ALS disease duration, lower motor neuron loss, TARDNA‐binding protein 43 (TDP‐43) pathology, neuroinflammation and HSPB expression.MethodsWith immunohistochemistry, we examined HSPB1, HSPB5, HSPB6, HSPB8 and HSP16.2 expression in cervical, thoracic and sacral spinal cord regions in 12 ALS cases, seven with short disease duration (SDD), five with moderate disease duration (MDD), and ten age‐matched controls. Expression was quantified using ImageJ to examine HSP expression, motor neuron numbers, microglial and astrocyte density and phosphorylated TDP‐43 (pTDP‐43+) inclusions.ResultsSDD was associated with elevated HSPB5 and 8 expression in lateral tract astrocytes, while HSP16.2 expression was increased in astrocytes in MDD cases. SDD cases had higher numbers of motor neurons and microglial activation than MDD cases, but similar levels of motor neurons with pTDP‐43+ inclusions.ConclusionsIncreased expression of several HSPBs in lateral column astrocytes suggests that astrocytes play a role in the pathogenesis of ALS. SDD is associated with increased microgliosis, HSPB5 and 8 expression in astrocytes, and only minor changes in motor neuron loss. This suggests that the interaction between motor neurons, microglia and astrocytes determines neuronal fate and functional decline in ALS.

Small heat shock protein expression and functions during development

The expression of small heat shock proteins is tightly regulated during development in multiple organisms. As housekeeping proteins, small heat shock proteins help protect cells from apoptosis, stabilize the cytoskeleton and contribute to proteostasis. Consistently, depletion of one small heat shock protein is usually not detrimental due to a certain level of redundancy between the functions of each small heat shock protein. However, while their stress-induced expression is regulated by heat shock factors, their constitutive expression is under the control of other specific transcription factors, suggesting the existence of very specialized functions. This review focuses on the expression patterns and functions of small heat shock proteins in various organisms during development.This article is part of a Directed Issue entitled: Small HSPs in physiology and pathology.

Pathology-Dependent Effects Linked to Small Heat Shock Proteins Expression: An Update

Small heat shock proteins (small Hsps) are stress-induced molecular chaperones that act as holdases towards polypeptides that have lost their folding in stress conditions or consequently of mutations in their coding sequence. A cellular protection against the deleterious effects mediated by damaged proteins is thus provided to cells. These chaperones are also highly expressed in response to protein conformational and inflammatory diseases and cancer pathologies. Through specific and reversible modifications in their phospho-oligomeric organization, small Hsps can chaperone appropriate client proteins in order to provide cells with resistance to different types of injuries or pathological conditions. By helping cells to better cope with their pathological status, their expression can be either beneficial, such as in diseases characterized by pathological cell degeneration, or deleterious when they are required for tumor cell survival. Moreover, small Hsps are actively released by cells and can act as immunogenic molecules that have dual effects depending on the pathology. The cellular consequences linked to their expression levels and relationships with other Hsps as well as therapeutic strategies are discussed in view of their dynamic structural organization required to interact with specific client polypeptides.

Cinnamomum cassia Bark in Two Herbal Formulas Increases Life Span in Caenorhabditis elegans via Insulin Signaling and Stress Response Pathways

BackgroundProving the efficacy and corresponding mode of action of herbal supplements is a difficult challenge for evidence-based herbal therapy. A major hurdle is the complexity of herbal preparations, many of which combine multiple herbs, particularly when the combination is assumed to be vitally important to the effectiveness of the herbal therapy. This issue may be addressed through the use of contemporary methodology and validated animal models.Methods and Principal FindingsIn this study, two commonly used traditional herbal formulas, Shi Quan Da Bu Tang (SQDB) and Huo Luo Xiao Ling Dan (HLXL) were evaluated using a survival assay and oxidative stress biomarkers in a well-established C. elegans model of aging. HLXL is an eleven herb formula modified from a top-selling traditional herbal formula for the treatment of arthritic joint pain. SQDB consists of ten herbs often used for fatigue and energy, particularly in the aged. We demonstrate here that SQDB significantly extend life span in a C. elegans model of aging. Among all individual herbs tested, two herbs Cinnamomum cassia bark (Chinese pharmaceutical name: Cinnamomi Cortex, CIN) and Panax ginseng root (Chinese pharmaceutical name: Ginseng Radix, GS) significantly extended life span in C. elegans. CIN in both SQDB and HLXL formula extended life span via modulation of multiple longevity assurance genes, including genes involved in insulin signaling and stress response pathways. All the life-span-extending herbs (SQDB, CIN and GS) also attenuated levels of H2O2 and enhanced small heat shock protein expression. Furthermore, the life span-extending herbs significantly delayed human amyloid beta (Aβ)-induced toxicity in transgenic C. elegans expressing human Aβ.Conclusion/SignificanceThese results validate an invertebrate model for rapid, systematic evaluation of commonly used Chinese herbal formulations and may provide insight for designing future evidence-based herbal therapy(s).

Caenorhabditis elegans lifespan extension caused by treatment with an orally active ROS-generator is dependent on DAF-16 and SIR-2.1

In Caenorhabditis elegans pretreatment with juglone, a generator of reactive oxygen species (ROS) provides a subsequently increased ROS-resistance. We investigated whether juglone at low or high concentrations when provided via the oral route in a liquid axenic medium affects normal lifespan of C. elegans. High juglone concentrations led to premature death, low concentrations were tolerated well and caused a prolongation of lifespan. Lifespan extension under moderate oxidative stress was associated with increased expression of small heat-shock protein HSP-16.2, enhanced glutathione levels, and nuclear translocation of DAF-16. Silencing or deletion of DAF-16 prevented the juglone-induced adaptations. RNA-interference for SIR-2.1 had the same effects as the deletion of DAF-16 but did not affect nuclear accumulation of DAF-16. Our studies demonstrate that DAF-16- and SIR-2.1-dependent alterations in gene expression after a ROS challenge lead to a lifespan extension in C. elegans as long as the stressor concentration does not exceed the saturable protective capacity.

Proteomic Analysis Reveals Significant Alternations of Cardiac Small Heat Shock Protein Expression in Congestive Heart Failure

Background Because congestive heart failure (CHF) is a complex syndrome with many different underlying mechanisms of worsening of heart function, it is important to recognize the global alternations in protein expression associated with the processes of CHF. Methods and Results The purpose of our study was to use a proteomic approach to investigate global alternations in protein expression in tachycardia induced CHF dogs. We compared the 2-dimensional electrophoresis protein patterns of left ventricular samples from the normal with those from failing myocardium. Differentially expressed cardiac proteins showed approximately 500 cardiac protein spots. A total of 20 spots (14 increased, 6 decreased) was altered in CHF, whereas the more distinguishably increased spots in CHF were identified by using mass spectrometry as alpha B crystallin, heat shock protein (HSP) 27, and HSP20, which maintain both the morphologic and functional integrity of the cardiomyocytes and increase tolerance against various types of stress. Because phosphorylation is one of the most important posttranslational modifications, we evaluated whether or not the overexpressed small HSPs were phosphorylated in CHF. Phosphoprotein staining and Western blotting demonstrated that the phosphorylation of alpha B crystallin at serine (Ser)-59 site and of HSP27 at both Ser-78 and Ser-82 sites increased in CHF. Conclusion Proteomics studies can provide new insights into molecular mechanisms in CHF and phosphorylated small HSPs may be involved in preventing cardiac dysfunction.

Proteome analysis reveals the significant alternations of cardiac small heat shock proteins expression in heart failure

Purpose: Considering that the number of functional gene productions far exceeds the number of genes that encode them, the causes of heart failure (HF) are likely to results from alternations in cardiac protein expression. The aim of our study was to use a proteomics approach to investigate global alternations in protein expression in tachycardia induced HF dogs. Method and Results: We compared the two-dimensional (2D) gel electrophoresis protein patterns of left ventricular samples from the normal and failing myocardium. Differentially expressed cardiac proteins showed as many as 200 cardiac protein spots. Seven protein spots were significantly upregulated in HF compared to the normals. Those spots were identified as alpha B crystalline, HSP 20, and HSP27 by MALDI-TOF/MS. They are members of the small heat shock protein (HSP) family and exert maintaining the morphological and functional integrity of the cardiac contractile apparatus and increase a tolerance against apoptosis. Since phosphorylation is one of the most important post-translational modifications, we evaluated whether the overexpressed HSPs were phosphorylated in HF. 2D-phosphoprotein staining and western blotting demonstrated phosphorylated forms of those small HSPs were significantly increased compared to the normals. Conclusion: Proteomics studies are anticipated to provide new insights into cellular mechanisms involved in HF and post-translational modification of small HSPs may be a therapeutic targets for improving the function of failing cardiomyocytes.

Evolution and plasticity of photosynthetic thermal tolerance, specific leaf area and leaf size: congeneric species from desert and coastal environments.

• We examined whether increased high temperature photosynthetic thermal tolerance (PT), reduced specific leaf area (SLA) and reduced leaf size represent correlated and convergent adaptations for recently diverged Encelia, Salvia, Atriplex and Eriogonum congeneric species pairs from contrasting thermal and water environments (the Mojave Desert and coastal California). We also studied whether variation in PT is associated with inducible small heat shock protein expression (sHsp). • Traits were measured in a common environment (CE) and in the field to partition effects of phenotypic plasticity and genetic divergence. • We found little evidence for convergent adaptation of PT (CE measurements). Field measurements revealed significant plasticity for PT, which was also associated with increased sHsp expression. Compared to coastal congeners desert species had lower SLA in the CE. These differences were magnified in the field. There was a negative correlation between SLA and PT. Desert species also tended to have smaller leaves both in the CE and in the field. • SLA and leaf size reductions represent repeated evolutionary divergences and are perhaps convergent adaptations for species radiating into the desert, while PT is highly plastic and shows little evidence for convergent adaptation in the congeneric species pairs we studied.

Nestin and small heat shock protein expression on reactive astrocytes and endothelial cells in cerebral abscess.

Cerebral abscess results in an extensive capsular formation, which is an important limiting barrier for the spread of microorganism. Reactive astrocytes and endothelial cells are major cellular components of the abscess capsule together with fibrocytes. Molecular pathogenesis that results in the migration and proliferation of these cells remain speculative. Intermediate filament (IF) nestin and small heat shock proteins (sHSP) are developmentally regulated protein. In this study, we found that nestin expression is re-induced in not only reactive astrocytes, but also in endothelial cells in the gliotic area of the capsule. These nestin expressing astrocytes and endothelial cells also expressed sHSPs, such as heat shock protein 27 (HSP27) and alphaB-crystalline. These results indicated that embryonic reversions of cytoskeletal proteins to nestin and the increased expression of sHSPs in in reactive astrocytes and endothelial cells are caused by pathogenic microorganism induced inflammatory stress.

Glucocorticoid treatment induces expression of small heat shock proteins in human satellite cell populations: consequences for a desmin-related myopathy involving the R120G alpha B-crystallin mutation

A missense mutation (R120G) of the molecular chaperone alpha B-crystallin has recently been linked to a familial form of desmin-related myopathy characterized by intrasarcoplasmic aggregates of desmin. It was previously demonstrated that the mutant R120G had a defective chaperone-like function. However, the cellular and physiopathological consequences of R120G mutant expression in human muscle cells are as yet unclear. Thus, we developed a cellular model for the study of this R120G alpha B-crystallin-related desmin-related myopathy. We demonstrate that dexamethasone enhances alpha B-crystallin and HSP27 expression in normal and desmin-related myopathy-derived muscle cells. In the undifferentiated desmin-related myopathy satellite cell population no intracytoplasmic aggregates were observed. However, in differentiated satellite cells derived from a related myopathy patient, we observed an enhanced plasma membrane localization of alpha B-crystallin following glucocorticoid. We also observed that the protective effect against stress of alpha B-crystallin is altered upon glucocorticoid-induced small heat shock protein expression for the desmin-related myopathy-derived cells.

Small heat shock proteins expression in rat kidneys treated with cyclosporine A alone and combined with melatonin.

Small heat shock proteins (sHSPs) are cytoskeletal chaperones constitutively expressed in the normal kidney but enhanced with beneficial roles during adverse stimuli. Cyclosporine A is an immunosuppressive drug with major adverse side effect such as severe nephrotoxicity. Among possible mechanisms of cyclosporine A-induced renal damage, oxidative stress and cytoskeletal damage have been suggested. Melatonin has been successfully used as antioxidant against many renal diseases. This in vivo study was performed to shed light on the protective effect of melatonin against cyclosporine A-induced renal alterations. We treated rats with cyclosporine A alone, or combined with melatonin, and with melatonin alone (as controls) for 40 days and analysed the renal abundance and distribution of two sHSPs, HSP25 and alpha B-crystallin. These data were correlated with the histopathological effects of the treatments. Cyclosporine A induced insoluble isoforms that moved to soluble fractions after melatonin coadministration as in controls. After cyclosporine A treatment, an intense signal for sHSPs was found within the glomeruli, nucleus and cytoplasm of cortical tubules, collecting ducts and vascular wall. After melatonin supply, the staining was faint, limited to the cytoplasm of cortical tubules, similar to controls. Both fibrosis and tubular alterations significantly decreased after melatonin coadministration. In conclusion, HSP25 and alpha B-crystallin are overexpressed in the rat kidney treated with cyclosporine A but are similar to controls after combined melatonin. This could be a consequence of the cytoprotective effect of melatonin in this nephrotoxic model so that a beneficial sHSPs response is unnecessary.

Expression of small heat-shock proteins at low temperatures. A possible role in protecting against chilling injuries.

We previously reported that short exposure of tomato (Lycopersicon esculentum L.) fruits to high temperature protects them from chilling injury. To study the involvement of heat-shock proteins (HSPs) in the acquisition of low-temperature tolerance, we cloned two heat-shock-induced genes that are also expressed at low temperatures. The cloned cDNAs belong to the small HSP group. Sequence analyses of the clones showed perfect homology to the tomato-ripening gene tom66 and to the tomato chloroplastic HSP21 gene tom111. The expression of both genes was induced by high temperature in fruits, flowers, leaves, and stems, but not by low or ambient temperatures or by other stresses such as drought and anaerobic conditions. When the heated fruits were transferred to low temperature, tom66 and tom111 mRNA levels first decreased but were then reinduced. Induction was not observed in nonheated fruits at low temperature. Immunodetection of tom111-encoded protein indicated that this protein is present at low temperatures in the heated fruits. The results of this study show that the expression of tom66 and tom111 is correlated with protection against some, but not all, symptoms of chilling injury.

Developmental control of small heat shock protein expression during pea seed maturation

SummaryPlants synthesize four classes of small heat shock proteins (sHSPs); two classes are targeted to the plastid and endoplasmic reticulum, respectively, and two are found in the cytoplasm. In this paper, we describe a new role for the two classes of cytoplasmic HSPs in maturing embryos of developing seeds. The expression of each class of sHSPs was examined in pea seeds grown under non‐stress conditions using Western and Northern analysis. Class I and class II cytoplasmic sHSPs are coordinately expressed in the embryo and accumulate to levels seen in moderately heat‐stressed leaves. Their induction in cotyledons coincides with the mid‐maturation phase of seed development, and induction in axes roughly coincides with abscission of the seed from the ovary wall. Both classes of sHSPs persisted in cotyledons for 4 days after the onset of imbibition, but disappeared from axes shortly after germination. Neither class of cytoplasmic sHSP is expressed in non‐embryonic organs associated with the seed. The timing and organ specificity of sHSP expression is paralleled by the expression of the corresponding mRNAs. Neither the plastid nor the endoplasmic reticulum sHSPs were consistently expressed during seed development, but both could be induced by heat‐stressing the developing seed. Developmental regulation of the cytoplasmic sHSPs is evidence that these proteins function not only in responding to heat‐stress but also during seed development and/or germination.