Functional organization of hsp70 cluster in camel (Camelus dromedarius) and other mammals

Heat-shock proteins, oxidative stress, and antioxidants in one-humped camels

One-humped camels (Camelus dromedarius) exhibit remarkable adaptability to harsh desert environments through various physiological adaptations. This study aimed to assess variations and reference values of Heat-shock proteins (HSPs), physiological parameters, mineral concentrations, total antioxidant capacity (TAC), and malondialdehyde (MDA) in 90 healthy female one-humped camels from Zabol's outskirts in Iran. The objective was to understand how these camels adapt to heat stress. Blood samples were collected from camels located at five geographical regions and analyzed using standard kits and methods. Reference intervals for heat-shock protein 30 (HSP30), heat-shock protein 40 (HSP40), heat-shock protein 70 (HSP70), and heat-shock protein 90 (HSP90) were determined using the reference value advisor (RVA). The study found significant differences among different regions for HSPs (P < 0.05), MDA (P = 0.021), and TAC (P = 0.042) levels, indicating variations in adaptation mechanisms. However, no notable differences were observed for other measured parameters between these regions. There were no significant differences observed in the evaluated parameters between the age categories of > 36 months and < 36 months. The positive correlation between HSPs and MDA levels (ranging from 0.754 to 0.884) suggests that the synthesis of HSPs is triggered as a response to oxidative stress caused by an imbalance between the production of reactive oxygen species (ROS) and the body's antioxidant defenses. This oxidative stress, in turn, is a consequence of thermal stress. Additionally, the study reveals a negative association between TAC and HSP levels (ranging from - 0.660 to - 0.820), emphasizing the role of antioxidants in mitigating heat stress. The findings of this research offer compelling support for the critical role that HSPs play in protecting cells from heat-induced damage. Additionally, the presence of higher levels of HSPs in regions with more severe climate conditions serves as evidence of camels' adaptation to heat stress. These findings emphasize the substantial impact of environmental factors on HSP production and further reinforce the crucial role of HSPs in bolstering the resilience of camels. Further research is needed to explore HSP expression and mechanisms to effectively manage and enhance camel resilience in extreme temperatures.

Heat shock proteins: a history of study in Russia

This review describes a brief history of the discovery and studies in Russia and associated countries of the main stress protein (Hsp70) that plays important roles both in the normal function of the cell and body as well as under various stressful stimuli. Research on this protein at the Institute of Molecular Biology (Moscow) began with the elucidation of its adaptive functions at the cellular level and at the level of the whole organism. These studies examined the function of Hsp70 under normal and extreme conditions using a wide range of model and non-model animal species, from Leishmania and Drosophila to camels and humans. These analyses made it possible to elucidate the primary regulations in the evolution and function of heat shock (HS) genes in the studied organisms. Next, we studied the structure and characteristic features of heat shock genes and proteins in species with contrasting habitat temperatures. The systems of Hsp70 expression and isolation we developed using various research objects allowed us to proceed to study the protective properties of human recombinant Hsp70 in normal-aging animal models as well as animal models experiencing sepsis, Alzheimer's disease, and stroke. The results obtained open the prospects of using recombinant Hsp70 for the treatment of various neuropathologies in humans. This review describes the logic and history of investigation of Hsp70 performed by one group of scientists from Engelhardt Institute of Molecular Biology, Russian Academy of Sciences. It was not the goal of this paper to give a comprehensive general picture of other similar studies carried out in Russia during this period.

Heat shock protein and gene regulation in goats during heat stress

Heat shock proteins (HSPs), also known as molecular chaperons are prominent stress markers. Heat shock proteins consist of highly conserved protein expressed at the time of stress, and play an important role in adaptation to the environmental stress. Although, the expression pattern of HSP70 gene is species and breed specific, variations in adaptation and thermal tolerance is due to the nature of environment and adaptive capacity of a species. The present study was conducted to evaluate the adaptive capability of different goat (Capra hircus) breeds, i.e. Jamunapari, Barbari, Jakhrana and Sirohi under peak dry summer. The targeted gene HSP70 (HSPA6) was evaluated for this purpose using specific primers. The expression of HSP70 gene and protein was estimated by RT PCR and ELISA kits respectively. The expression of HSP70 gene was found lowest in sirohi breeds implying that this breed was more adapted followed by Jakhrana, Barbari and Jamunapari during peak summer season. Whereas, the level of HSP70 protein in blood was significantly higher in Jamunapari, followed by Barbari, Jakhrana and lowest in Sirohi. These results indicated that, during adverse climatic stress the quantum of expression (HSP70 gene and protein) was more in Jamunapari. It is concluded that Sirohi breed is better adapted to heat stress than Jamunapari, Jakhrana and Barbari and HSP70 may be a potential molecular biomarker in the future for selection of climate resilient animals.

Cellular and Molecular Adaptation of Arabian Camel to Heat Stress

To cope with the extreme heat stress and drought of the desert, the Arabian camel (Camelus dromedarius) has developed exceptional physiological and biochemical particularities. Previous reports focused mainly on the physiological features of Arabian camel and neglected its cellular and molecular characteristics. Heat shock proteins are suggested to play a key role in the protein homeostasis and thermotolerance. Therefore, we aim by this review to elucidate the implication of camel HSPs in its physiological adaptation to heat stress and compare them with HSPs in related mammalian species. Correlation of these molecules to the adaptive mechanisms in camel is of special importance to expand our understanding of the overall camel physiology and homeostasis.

Heat shock proteins expressed in the marsupial Tasmanian devil are potential antigenic candidates in a vaccine against devil facial tumour disease

The Tasmanian devil (Sarcophilus harrisii), the largest extant carnivorous marsupial and endemic to Tasmania, is at the verge of extinction due to the emergence of a transmissible cancer known as devil facial tumour disease (DFTD). DFTD has spread over the distribution range of the species and has been responsible for a severe decline in the global devil population. To protect the Tasmanian devil from extinction in the wild, our group has focused on the development of a prophylactic vaccine. Although this work has shown that vaccine preparations using whole DFTD tumour cells supplemented with adjuvants can induce anti-DFTD immune responses, alternative strategies that induce stronger and more specific immune responses are required. In humans, heat shock proteins (HSPs) derived from tumour cells have been used instead of whole-tumour cell preparations as a source of antigens for cancer immunotherapy. As HSPs have not been studied in the Tasmanian devil, this study presents the first characterisation of HSPs in this marsupial and evaluates the suitability of these proteins as antigenic components for the enhancement of a DFTD vaccine. We show that tissues and cancer cells from the Tasmanian devil express constitutive and inducible HSP. Additionally, this study suggests that HSP derived from DFTD cancer cells are immunogenic supporting the future development of a HSP-based vaccine against DFTD.

Roles of Heat Shock Proteins in Apoptosis, Oxidative Stress, Human Inflammatory Diseases, and Cancer

Heat shock proteins (HSPs) play cytoprotective activities under pathological conditions through the initiation of protein folding, repair, refolding of misfolded peptides, and possible degradation of irreparable proteins. Excessive apoptosis, resulting from increased reactive oxygen species (ROS) cellular levels and subsequent amplified inflammatory reactions, is well known in the pathogenesis and progression of several human inflammatory diseases (HIDs) and cancer. Under normal physiological conditions, ROS levels and inflammatory reactions are kept in check for the cellular benefits of fighting off infectious agents through antioxidant mechanisms; however, this balance can be disrupted under pathological conditions, thus leading to oxidative stress and massive cellular destruction. Therefore, it becomes apparent that the interplay between oxidant-apoptosis-inflammation is critical in the dysfunction of the antioxidant system and, most importantly, in the progression of HIDs. Hence, there is a need to maintain careful balance between the oxidant-antioxidant inflammatory status in the human body. HSPs are known to modulate the effects of inflammation cascades leading to the endogenous generation of ROS and intrinsic apoptosis through inhibition of pro-inflammatory factors, thereby playing crucial roles in the pathogenesis of HIDs and cancer. We propose that careful induction of HSPs in HIDs and cancer, especially prior to inflammation, will provide good therapeutics in the management and treatment of HIDs and cancer.

Characterization of a deletion in the Hsp70 cluster in the bovine reference genome

The 70 kilodalton heat shock proteins (Hsp70) are highly conserved molecular chaperones which have a crucial role in the stress response of the cell. In mammals, the Hsp70 proteins are encoded by a cluster of three genes: HSPA1A, HSPA1B and HSPA1L. In bovines, this cluster is located on chromosome 23 downstream of the major histocompatibility complex (BoLA). We detected inconsistencies in the location of markers on the Hsp70 genes reported in the literature that pointed to a potential deletion in the bovine reference genome UMD 3.1.1. An in silico analysis of the bovine genomic region of the Hsp70 cluster, using available information from public databases, confirmed the existence of a deletion of 11.1-kb spanning the HSPA1B gene and the intergenic region between HSPA1B and HSPA1A. Although we originally considered this an assembly error, it is most likely a particular condition of L1 Dominette 01449, the cow sequenced in the Bovine Genome Project. Moreover, we suggest a new classification of bovine Hsp70 sequences reported in NCBI and a reassignment of the location of SNPs from dbSNP that map to the deletion on BTA23. We also compared the location of selected transcription factor binding sites on the promoters of HSPA1A and HSPA1B. The results generated in the present work could be helpful to refine the reference genome of an important livestock species and also to understand the role and the regulation of the bovine Hsp70 genes.

Expression of HSP70 genes in skin of zebu (Tharparkar) and crossbred (Karan Fries) cattle during different seasons under tropical climatic conditions

Skin is most important environmental interface providing a protective envelope to animals. It's always under the influence of both internal and external stressors. Heat shock proteins (HSP) are highly conserved stress proteins which play crucial roles in environmental stress tolerance and thermal adaptation. Present study was planned to observe the relative mRNA expression of inducible (HSP70.1 and HSP70.2) and constitutive (HSP70.8) HSP in skin of zebu (Tharparkar) and crossbred (Karan Fries) cattle during different seasons. Skin biopsies were collected from rump region of each animal, aseptically during winter, spring and summer season. Quantitative real time polymerase chain reaction was performed to examine the gene expression of constitutive (HSP70.8) and inducible (HSP70.1 and HSP70.2) HSP in skin of both the breeds during different seasons. Present study observed higher expression of both constitutive and inducible HSP genes in both the breeds during summer and winter than spring season, but magnitude of increase was higher during summer than winter. During summer season, expression pattern of HSPs in skin showed breed differences, where constitutive HSP expression was higher in Tharparkar than Karan Fries and that of inducible HSP was higher in Karan Fries than Tharparkar. Hence, present study suggested that HSP may be conveniently used as biomarkers for assessing protective response of skin against heat stress in zebu and crossbred cattle. Variation in expression between breeds is associated with their heat tolerance and thermal adaptability. In summary, skin of zebu cattle (Tharparkar) is more resistant to summer stress than crossbred (Karan Fries), providing greater protection against heat stress during summer season. Superior skin protective mechanism of zebu (Tharparkar) than crossbred (Karan-Fries) cattle against heat stress may contribute to superior adaptability of zebu cattle to tropical climatic conditions than crossbreed.

Extrapolation of Inter Domain Communications and Substrate Binding Cavity of Camel HSP70 1A: A Molecular Modeling and Dynamics Simulation Study

Heat shock protein 70 (HSP70) is an important chaperone, involved in protein folding, refolding, translocation and complex remodeling reactions under normal as well as stress conditions. However, expression of HSPA1A gene in heat and cold stress conditions associates with other chaperons and perform its function. Experimental structure for Camel HSP70 protein (cHSP70) has not been reported so far. Hence, we constructed 3D models of cHSP70 through multi- template comparative modeling with HSP110 protein of S. cerevisiae (open state) and with HSP70 protein of E. coli 70kDa DnaK (close state) and relaxed them for 100 nanoseconds (ns) using all-atom Molecular Dynamics (MD) Simulation. Two stable conformations of cHSP70 with Substrate Binding Domain (SBD) in open and close states were obtained. The collective mode analysis of different transitions of open state to close state and vice versa was examined via Principal Component Analysis (PCA) and Minimum Distance Matrix (MDM). The results provide mechanistic representation of the communication between Nucleotide Binding Domain (NBD) and SBD to identify the role of sub domains in conformational change mechanism, which leads the chaperone cycle of cHSP70. Further, residues present in the chaperon functioning site were also identified through protein-peptide docking. This study provides an overall insight into the inter domain communication mechanism and identification of the chaperon binding cavity, which explains the underlying mechanism involved during heat and cold stress conditions in camel.

Activity of heat shock genes' promoters in thermally contrasting animal species

Heat shock gene promoters represent a highly conserved and universal system for the rapid induction of transcription after various stressful stimuli. We chose pairs of mammalian and insect species that significantly differ in their thermoresistance and constitutive levels of Hsp70 to compare hsp promoter strength under normal conditions and after heat shock (HS). The first pair includes the HSPA1 gene promoter of camel (Camelus dromedarius) and humans. It was demonstrated that the camel HSPA1A and HSPA1L promoters function normally in vitro in human cell cultures and exceed the strength of orthologous human promoters under basal conditions. We used the same in vitro assay for Drosophila melanogaster Schneider-2 (S2) cells to compare the activity of the hsp70 and hsp83 promoters of the second species pair represented by Diptera, i.e., Stratiomys singularior and D. melanogaster, which dramatically differ in thermoresistance and the pattern of Hsp70 accumulation. Promoter strength was also monitored in vivo in D. melanogaster strains transformed with constructs containing the S. singularior hsp70 ORF driven either by its own promoter or an orthologous promoter from the D. melanogaster hsp70Aa gene. Analysis revealed low S. singularior hsp70 promoter activity in vitro and in vivo under basal conditions and after HS in comparison with the endogenous promoter in D. melanogaster cells, which correlates with the absence of canonical GAGA elements in the promoters of the former species. Indeed, the insertion of GAGA elements into the S. singularior hsp70 regulatory region resulted in a dramatic increase in promoter activity in vitro but only modestly enhanced the promoter strength in the larvae of the transformed strains. In contrast with hsp70 promoters, hsp83 promoters from both of the studied Diptera species demonstrated high conservation and universality.

Seasonal variation in expression pattern of genes under HSP70 : Seasonal variation in expression pattern of genes under HSP70 family in heat- and cold-adapted goats (Capra hircus)

Heat shock protein 70 (HSP70) is one of the most abundant and best characterized heat shock protein family that consists of highly conserved stress proteins, expressed in response to stress, and plays crucial roles in environmental stress tolerance and adaptation. The present study was conducted to identify major types of genes under the HSP70 family and to quantify their expression pattern in heat- and cold-adapted Indian goats (Capra hircus) with respect to different seasons. Five HSP70 gene homologues to HSPA8, HSPA6, HSPA1A, HSPA1L, and HSPA2 were identified by gene-specific primers. The cDNA sequences showed high similarity to other mammals, and proteins have an estimated molecular weight of around 70 kDa. The expression of HSP70 genes was observed during summer and winter. During summer, the higher expression of HSPA8, HSPA6, and HSPA1A was observed, whereas the expression levels of HSPA1L and HSPA2 were found to be lower. It was also observed that the expression of HSPA1A and HSPA8 was higher during winter in both heat- and cold-adapted goats but downregulates in case of other HSPs. Therefore, both heat and cold stress induced the overexpression of HSP70 genes. An interesting finding that emerged from the study is the higher expression of HSP70 genes in cold-adapted goats during summer and in heat-adapted goats during winter. Altogether, the results indicate that the expression pattern of HSP70 genes is species- and breed-specific, most likely due to variations in thermal tolerance and adaptation to different climatic conditions.

Diversity in the origins of proteostasis networks--a driver for protein function in evolution

Although the sequence of a protein largely determines its function, proteins can adopt different folding states in response to changes in the environment, some of which may be deleterious to the organism. All organisms--Bacteria, Archaea and Eukarya--have evolved a protein homeostasis, or proteostasis, network comprising chaperones and folding factors, degradation components, signalling pathways and specialized compartmentalized modules that manage protein folding in response to environmental stimuli and variation. Surveying the origins of proteostasis networks reveals that they have co-evolved with the proteome to regulate the physiological state of the cell, reflecting the unique stresses that different cells or organisms experience, and that they have a key role in driving evolution by closely managing the link between the phenotype and the genotype.

Sexual dimorphism of STGC3 tumor suppressor function in nasopharyngeal carcinoma CNE2 cells

STGC3 is a potential tumor suppressor in nasopharyngeal carcinoma. We previously found that CNE2 cells that re-expressed STGC3 formed smaller tumors in female mice than in male mice. Here, we investigated the sexual dimorphism of STGC3 as a tumor-suppressor in female and male nude mice injected subcutaneously with pcDNA3.1(+)-STGC3/CNE2 cells. ER-α was positively expressed in vitro in the CNE2 cells. The pcDNA3.1(+)-STGC3/CNE2 cell growth rate decreased after treatment with β-estradiol in vitro. There were significant differences in tumor size or mass between pcDNA3.1(+)-STGC3/CNE2 and control cases (P < 0.05), but there were significant differences in tumor size between female and male nude mice in the STGC3 transfection groups, and the pcDNA3.1(+)-STGC3/CNE2 tumor growth rate in the female nude mice was the lowest in all cases (P < 0.05). There were no significant differences between female and male nude mice in control groups. Furthermore, a greater number of cells were blocked in the G(0)/G(1) phase in pcDNA3.1(+)-STGC3/ CNE2 tumor xenografts in the female mice. Protemic analysis found 9 differentially expressed proteins in the pcDNA3.1-STGC3/CNE2 xenograft tissues in females and males. A heat shock 70 protein 8 isoform 2 variant was identified as a down-regulated protein associated with cell cycle control and its downstream factor cyclin D1 was also decreased in STGC3-repressed xenografts in female mice. The data above suggest that STGC3 and its associated proteins play an important role in nasopharyngeal carcinoma gender differences.