Heat shock proteins in human endometrium throughout the menstrual cycle

The role of viral infection in implantation failure: direct and indirect effects

Implantation is the key initial complex stage of pregnancy. Several factors are involved in implantation, but acute and controlled inflammation has been shown to play as a key role. On the other hand, the role of viral infections in directly infecting blastocyst and trophoblast and inducing chronic and uncontrolled inflammation and disrupting microRNAs expression can make this review strongly attractive and practical. We aim to provide an overview of viral infections as the potential etiology of unsuccessful implantation pathophysiology through alteration of the cellular and molecular endometrial microenvironment. Based on our search, this is the first review to discuss the role of inflammation associated with viral infection in implantation failure.

Immunohistochemical localization and expression of heat shock proteins (HSP27, HSP60, HSP70, and HSP90) during the oestrous cycle, pregnancy, and lactation in rat ovaries

This study aimed to determine the expressions of HSP27, HSP60, HSP70, and HSP90 in rat ovaries during the oestrous cycle, pregnancy, and lactation. In follicle cells, HSP27 and HSP70 expression was not observed. HSP60 in oocytes was higher in the early stages of follicular development but decreased and disappeared as the follicle grew. HSP60 in granulosa and theca cells increased with follicle development and decreased with atresia. HSP90 in follicle cells did not change during follicle development or atresia. The expression of HSPs in interstitial cells was higher in the proestrus and estrus phases of the estrous cycle. The expression of HSPs in these cells was higher on day 5 of pregnancy, decreased on day 10, and decreased further on days 15 and 20. The expression of HSPs, which decreased in the second half of pregnancy, increased again on the first day of lactation. The expression of HSPs then decreased on day 5 of lactation and further decreased on days 10 and 20. HSP60 and HSP90 were positive in new and old corpus luteums (CLs) and their expression did not change during luteal development or regression. HSP27 and HSP70 were absent in new CLs. HSP27 was positive in old CLs and showed the same staining pattern during luteal regression. HSP70 expression was determined in old cyclic CLs during the oestrous cycle and pregnancy and decreased with luteal regression. HSP70 expression in old pregnancy CLs during lactation was very weak compared to the oestrous cycle and pregnancy. In conclusion, HSP60 and HSP90 may participate in folliculogenesis, luteal development, and steroidogenesis in luteal cells, and HSP27, HSP60, HSP70, and HSP90 may be effective in luteal regression and steroidogenesis in interstitial cells. HSP27 and HSP70 may be used as markers to identify old CLs in rats.

Impact of Non-Invasive Physical Plasma on Heat Shock Protein Functionality in Eukaryotic Cells

Recently, biomedical research has increasingly investigated physical plasma as an innovative therapeutic approach with a number of therapeutic biomedical effects. It is known from radiation and chemotherapy that these applications can lead to the induction and activation of primarily cytoprotective heat shock proteins (HSP). HSP protect cells and tissues from physical, (bio)chemical, and physiological stress and, ultimately, along with other mechanisms, govern resistance and treatment failure. These mechanisms are well known and comparatively well studied in drug therapy. For therapies in the field of physical plasma medicine, however, extremely little data are available to date. In this review article, we provide an overview of the current studies on the interaction of physical plasma with the cellular HSP system.

Heat shock protein HSP90 immunoexpression in equine endometrium during oestrus, dioestrus and anoestrus

Heat shock proteins play a crucial role in cellular development, proliferation, differentiation and apoptosis. Heat shock protein 90 (HSP90) has been localised in the human endometrium, where its immunoexpression changes during the menstrual cycle. Similar studies have not been done for the equid species, so the present study aimed to describe endometrial HSP90 immunoexpression in mare endometrium. Endometrial biopsies were formalin-fixed and paraffin-embedded, and sections were stained with haematoxylin-eosin in preparation for HSP90 immunohistochemistry. Immunostaining and morphometric analyses were performed on the epithelial lining, endometrial glands and connective stroma during oestrus, dioestrus phase and anoestrus period (n = 7 per phase or period). Immunoexpression was localised in the basal region of the epithelial cells lining the lumen. Immunoexpression was greater during oestrus than during either dioestrus or anoestrus. During anoestrus, there was little immunostaining in the endometrium, suggesting that HSP90 is involved in the functional modulation of sex steroid receptors in cyclic mares. Indeed, the function of HSP90 as a chaperone in the folding of proteins, such as steroid receptors, might explain the greater intensity of immunostaining during the oestrus and dioestrus phases, compared the anoestrus period. We conclude that, in the mare, HSP90 plays a role in endometrial function and that further studies are needed to test whether it is important in pathological conditions as endometritis.

Effect of summer heat stress on gene expression in bovine uterine endometrial tissues

Heat stress negatively affects reproductive functions in cows. Increased temperature disturbs fetal development in utero. However, the effect of heat stress on uterine endometrial tissues has not been fully examined. Using qPCR analysis, we measured the mRNA expression of various molecular markers in uterine endometrial tissue of dairy cows from Hokkaido, Japan, in winter and summer. Markers examined were heat shock proteins (HSPs), antioxidant enzymes (catalase, copper/zinc superoxide dismutase, manganese superoxide dismutase, and glutathione peroxidase 4), inflammatory cytokines, and interferon stimulated genes. Our results showed heat stress, body and milk temperatures were higher during summer than during winter. Expression levels of HSP27, HSP60, and HSP90 mRNA, and of catalase and copper/zinc superoxide dismutase mRNA were lower in summer than in winter. Tumor necrosis factor alpha expression was higher in summer than in winter. In conclusion, summer heat stress may reduce the expression of HSPs, affecting the levels of inflammatory cytokines in bovine uterine endometrial tissue.

Global gene expression profiling of proliferative phase endometrium reveals distinct functional subdivisions

The human endometrium follows a predictable pattern of development during the proliferative phase. Endometrial thickness increases after day 3 and then plateaus at days 9 to 10 of the menstrual cycle despite continued high serum levels of estrogen. We hypothesized that proliferative phase endometrium undergoes more than simple estrogen responsive growth, rather it is characterized by complex time-dependent functional activities reflected in differential gene expression. Nine endometrial RNA samples from healthy participants were subjected to microarray analysis and 15 samples were used for quantitative real-time polymerase chain reaction. The samples were divided into early, mid, or late proliferative phase. The early proliferative phase showed higher expression of genes including transforming growth factor β2, chemokine (C-C motif) ligand 18 (CCL18), and metallothionein 2A. The mid-proliferative phase was characterized by higher expression of heat shock proteins and implantation-associated genes including Indian hedgehog, secreted frizzled protein 4, and progesterone receptor. In the late proliferative phase, we identified increased angiotensin II receptor, type 2 and large decrease in expression of genes related to natural killer (NK) cell function. We demonstrate a unique gene expression signature at distinct time points within the proliferative phase. The early proliferative phase is characterized by tissue remodeling, angiogenesis, and modulation of inflammation; the mid-proliferative phase is characterized not only by proliferation in response to estrogens but also marks the onset of expression of genes required for endometrial receptivity and a dampening of estrogen responsiveness. In the late proliferative phase, changes in immune function and NK cells predominate. The proliferative phase is not simply a uniform period of estrogen responsive endometrial growth that can be considered as a single experimental time point when evaluating endometrial development; rather the proliferative phase is complex with differing functions and patterns of gene expression.

Comparison of expression levels of candidate genes in endometrium of dairy heifers and lactating dairy cows

Pretheeban, T., Gordon, M. B., Singh, R. and Rajamahendran, R. 2011. Comparison of expression levels of candidate genes in endometrium of dairy heifers and lactating dairy cows. Can. J. Anim. Sci. 91: 255–264. Pregnancy rates (PR) in high-producing lactating dairy cows have declined drastically over the past several decades, but those of heifers have remained constant. Reduced PR could be due to multiple causes, and the underlying pathophysiological mechanisms are still unclear. A compromised maternal uterine environment could be one of factors that could affect the PR. This study was performed to compare the nature of the uterine environment in dairy heifers and lactating dairy cows (2nd/3rd parity) by analyzing the expression levels of selected endometrial genes. Estrus was synchronized in heifers (n=5) and lactating dairy cows (n=5) and endometrial biopsies were performed during the mid luteal phase (day 11) of the estrous cycle. Real-time polymerase chain reaction (Q-RT PCR) and immunohistochemistry were performed to analyse the mRNA and protein levels of genes respectively. Relative abundance of BCL2, HSPA1A, IL1A, TNF, IGF1, FGF2 and SERPINA14 transcripts and the protein expression of IL1A, TNF and FGF2 were significantly higher in heifers in comparison with lactating dairy cows. Our findings suggest an altered endometrial environment in lactating dairy cows compared with heifers. However, whether these differences play a role in pregnancy outcomes should be further investigated.

The hippocampal protein machinery varies over the estrous cycle

Information about estrous cycle (EC) and sex-dependent protein levels is limited. Cognitive functions vary over the EC and the aim of this study was to investigate rat protein fluctuations in the hippocampus, the main cognitive brain area for learning and memory, in the individual phases of the EC and in males and indeed protein fluctuations may reflect functional variation over the EC. Sprague-Dawley rats were used in the studies and estrous phases were determined. Hippocampi were taken, proteins extracted, run on 2-DE, and identified using MALDI-TOF/TOF and nano-LC-ESI-MS/MS; protein levels were quantified using Proteomweaver software. Levels of protein synthetic machinery components transcriptional activator protein PUR(α,β), elongation factor 2, heterogeneous nuclear ribonucleoprotein K, chaperones 78 kDa glucose-regulated protein, heat shock cognate 71 kDa protein, Hsp 105, stress-70 protein, peptidyl-prolyl cis-trans isomerase A, prefoldin subunit 2, T-complex protein 1 subunit alpha and subunit delta, and degradation principle proteasome subunit alpha type 1 and ubiquitin carboxyl-terminal hydrolase isozyme L1, were different between sex and phase of the EC. We suggest that differences in the protein synthetic, chaperoning, and degradation machinery indicate different function in the individual EC phases. Results herein are relevant for further design of studies in the hippocampus at the protein level and interpretation of previous studies because EC phases will have to be respected and taken into account.