Differential localization of heat shock proteins 90, 70, 60 and 27 in human decidua and placenta during pregnancy

Progesterone modulates extracellular heat-shock proteins and interlukin-1β in human choriodecidual after Escherichia coli infection

INTRODUCTION

Chorioamnionitis is an adverse condition in human pregnancy caused by many bacterial pathogens including Escherichia coli (E. coli); which has been associated with higher risk of preterm birth. We recently reported that human maternal decidua (MDec) tissue responds to E. coli infection by secreting extracellular heat-shock proteins (eHsp)-60, -70 and interlukin-1β (IL-1β). Previous studies have shown that progesterone (P4) regulates the immune response, but it is unknown whether P4 inhibits the secretion of eHsp. The aim of this investigation was to determine the role of P4 on the secretion of eHsp-27, -60, -70 and IL-1β in MDec after 3, 6, and 24 h of E. coli infection.

METHODS

Nine human feto-maternal interface (HFMi) tissues were included and mounted in the Transwell culture system. Only the maternal decidua (MDec) was stimulated for 3, 6 and 24 h with E. coli alone or in combination with progesterone and RU486. After each treatment, the HFMi tissue was recovered to determine histological changes and the culture medium recovered to evaluate the levels of eHsp-27, -60, -70 and IL-1β by ELISA and mRNA expression by RT-PCR.

RESULTS

No structural changes were observed in the HFMi tissue treated with P4 and RU486. However, stimulation with E. coli produces diffuse inflammation and ischemic necrosis. E. coli induced infection decreases, in time- and dose-dependent manner, eHsp-27 and increases eHsp-60, eHsp-70 and IL-1β levels. In contrast, incubation of HFMi tissue with E. coli + P4 reversed eHsp and IL-1β secretion levels relative to E. coli stimulation group but not relative to the control group. The same profile was observed on the expression of eHsp-27 and eHsp-60.

DISCUSSION

we found that progesterone modulates the anti-inflammatory (eHsp-27) and pro-inflammatory (eHsp-60 and eHsp-70) levels of eHsp induced by E. coli infection in human choriodecidual tissue. eHsp-60 and eHsp-70 levels were not completely reversed; maintaining the secretion of IL-1β, which has been associated with adverse events during pregnancy.

Elevated human placental heat shock protein 5 is associated with spontaneous preterm birth

BACKGROUND

Specific heat shock proteins are associated with pregnancy complications, including spontaneous preterm birth (SPTB). Placental proteomics and whole exome sequencing recently suggested an association between heat shock protein HSPA5 and uncomplicated SPTB. In the present study, we investigated the localization of and possible roles for HSPA5 in SPTB.

METHODS

Western blot was performed to validate the result from the previously published proteomic analysis. We used qPCR to assess mRNA expression of genes and immunohistochemistry and immunoelectron microscopy to examine localization of HSPA5 in placental tissue. We silenced the HSPA5 gene in the HTR8/SVneo human trophoblast cell line to investigate possible functions of HSPA5.

RESULTS

HSPA5 was upregulated in placentas from SPTBs compared to spontaneous term births. We did not observe upregulation of HSPA5 mRNA in placental samples. The protein was localized in placental trophoblast in both spontaneous preterm and term placentas. Gene silencing of HSPA5 in human trophoblast cell culture affected the inflammatory response and decreased the expression of several proinflammatory genes.

CONCLUSIONS

We suggest that upregulation of HSPA5 in the placenta is associated with spontaneous preterm labor. HSPA5 may promote the inflammatory response and alter the anti-inflammatory state of the placenta which could eventually lead to premature labor.

IMPACT

We validated upregulation of HSPA5 in placentas from spontaneous preterm birth. HSPA5 was not upregulated at transcriptional level which suggests that it may be regulated post-translationally. Silencing HSPA5 in a human trophoblast-derived cell line suggested that HSPA5 promotes expression of proinflammatory cytokines. The emerging inflammation could lead to spontaneous preterm labor. Identifying inflammatory pathways and factors associated with spontaneous preterm birth increases knowledge of the molecular mechanisms of premature labor. This could provide cues to predict imminent premature labor and lead to information about how to safely maintain pregnancies.

Human Decidual CD1a+ Dendritic Cells Undergo Functional Maturation Program Mediated by Gp96

Heat shock proteins (hsps), in certain circumstances, could shape unique features of decidual dendritic cells (DCs) that play a key role in inducing immunity as well as maintaining tolerance. The aim of the study was to assess the binding of gp96 to Toll-like receptor (TLR) 4 and CD91 receptors on decidual CD1a⁺ DCs present at the maternal-fetal interface in vitro as well as the influence of CD1a⁺ DCs maturation status. Immunohistology and immunofluorescence of paraffin-embedded first-trimester decidua tissue sections of normal and pathological (missed abortion MA and blighted ovum BO) pregnancies were performed together with flow cytometry detection of antigens in CD1a⁺ DCs after gp96 stimulation of decidual mononuclear cells. Gp96 efficiently bound CD91 and TLR4 receptors on decidual CD1a⁺ DCs in a dose-dependent manner and increased the expression of CD83 and HLA-DR. The highest concentration of gp96 (1000 ng/mL) increased the percentage of Interferon-γ (INF-γ) and IL-15 expressing gp96⁺ cells. Gp96 binds CD91 and TLR4 on decidual CD1a⁺ DCs, which causes their maturation and significantly increases INF-γ and IL-15 in the context of Th1 cytokine/chemokine domination, which could support immune response harmful for ongoing pregnancy.

Porcine endometrial heat shock proteins are differentially influenced by pregnancy status, heat stress, and altrenogest supplementation during the peri-implantation period

Heat stress (HS) deleteriously affects multiple components of porcine reproduction and is causal to seasonal infertility. Environment-induced hyperthermia causes a HS response (HSR) typically characterized by increased abundance of intracellular heat shock proteins (HSP). Gilts exposed to HS during the peri-implantation period have compromised embryo survival, however if (or how) HS disrupts the porcine endometrium is not understood. Study objectives were to evaluate the endometrial HSP abundance in response to HS during this period and assess the effect of oral progestin (altrenogest; ALT) supplementation. Postpubertal gilts (n = 42) were artificially inseminated during behavioral estrus (n = 28) or were kept cyclic (n = 14), and randomly assigned to thermal neutral (TN; 21 ± 1 °C) or diurnal HS (35 ± 1 °C for 12 h/31.6 ± 1 °C for 12 h) conditions from day 3 to 12 postestrus (dpe). Seven of the inseminated gilts from each thermal treatment group received ALT (15 mg/d) during this period. Using quantitative PCR, transcript abundance of HSP family A (Hsp70) member 1A (HSPA1A, P = 0.001) and member 6 (HSPA6, P < 0.001), and HSP family B (small) member 8 (HSB8, P = 0.001) were increased while HSP family D (Hsp60) member 1 (HSPD1, P = 0.01) was decreased in the endometrium of pregnant gilts compared to the cyclic gilts. Protein abundance of HSPA1A decreased (P = 0.03) in pregnant gilt endometrium due to HS, while HSP family B (small) member 1 (HSPB1) increased (P = 0.01) due to HS. Oral ALT supplementation during HS reduced the transcript abundance of HSP90α family class B member 1 (HSP90AB1, P = 0.04); but HS increased HSP90AB1 (P = 0.001), HSPA1A (P = 0.02), and HSPA6 (P = 0.04) transcript abundance irrespective of ALT. ALT supplementation decreased HSP90α family class A member 1 (HSP90AA1, P = 0.001) protein abundance, irrespective of thermal environment, whereas ALT only decreased HSPA6 (P = 0.02) protein abundance in TN gilts. These results indicate a notable shift of HSP in the porcine endometrium during the peri-implantation period in response to pregnancy status and heat stress.

Circulating heat shock protein 27 (HSPB1) levels in prediction of pre-eclampsia: A pilot study

OBJECTIVE

To determine whether circulating heat shock proteins HSP27/HSPB1 and HSP90α/HSPC1 may be useful for early prediction of the occurrence of pre-eclampsia in asymptomatic women.

METHODS

We have measured by ELISA the levels of HSPB1, HSPC1, and placental protein 13 (PP13) in serum samples from 44 women in the first trimester (10-12 weeks) and second trimester (17-20 weeks) of pregnancy. Western blot and immunohistochemistry for HSPB1 and HSPC1 were performed.

RESULTS

HSPB1 serum levels were higher in women with pre-eclampsia than in normotensive pregnant women at the first and second trimester (P = 0.003), whereas PP13 levels decreased in women with pre-eclampsia only in the first trimester of gestation (P = 0.021). We also observed higher HSPB1 levels in patients with early-onset pre-eclampsia in the first and second trimester (P = 0.014).

CONCLUSION

This pilot study points out that circulating HSPB1 levels in first and second trimester might be useful for predicting the occurrence of pre-eclampsia in asymptomatic women. Further validation studies are needed to finally establish this protein as a candidate predictive biomarker of pre-eclampsia.

Integrative genetic, genomic and transcriptomic analysis of heat shock protein and nuclear hormone receptor gene associations with spontaneous preterm birth

Heat shock proteins are involved in the response to stress including activation of the immune response. Elevated circulating heat shock proteins are associated with spontaneous preterm birth (SPTB). Intracellular heat shock proteins act as multifunctional molecular chaperones that regulate activity of nuclear hormone receptors. Since SPTB has a significant genetic predisposition, our objective was to identify genetic and transcriptomic evidence of heat shock proteins and nuclear hormone receptors that may affect risk for SPTB. We investigated all 97 genes encoding members of the heat shock protein families and all 49 genes encoding nuclear hormone receptors for their potential role in SPTB susceptibility. We used multiple genetic and genomic datasets including genome-wide association studies (GWASs), whole-exome sequencing (WES), and placental transcriptomics to identify SPTB predisposing factors from the mother, infant, and placenta. There were multiple associations of heat shock protein and nuclear hormone receptor genes with SPTB. Several orthogonal datasets supported roles for SEC63, HSPA1L, SACS, RORA, and AR in susceptibility to SPTB. We propose that suppression of specific heat shock proteins promotes maintenance of pregnancy, whereas activation of specific heat shock protein mediated signaling may disturb maternal–fetal tolerance and promote labor.

Heat Shock Proteins and Their Role in Pregnancy: Redefining the Function of "Old Rum in a New Bottle"

Pregnancy in humans is a multi-step complex physiological process comprising three discrete events, decidualization, implantation and placentation. Its overall success depends on the incremental advantage that each of the preceding stages passes on to the next. The success of these synchronized sequels of events is an outcome of timely coordination between them. The pregnancy events are coordinated and governed primarily by the ovarian steroid hormones, estrogen and progesterone, which are essentially ligand-activated transcription factors. It's well known that intercellular signaling of steroid hormones engages a plethora of adapter proteins that participate in executing the biological functions. This involves binding of the hormone receptor complex to the DNA response elements in a sequence specific manner. Working with Drosophila melanogaster, the heat shock proteins (HSPs) were originally described by Ferruccio Ritossa back in the early 1960s. Over the years, there has been considerable advancement of our understanding of these conserved families of proteins, particularly in pregnancy. Accumulating evidence suggests that endometrial and uterine cells have an abundance of HSP27, HSP60, HSP70 and HSP90, implying their possible involvement during the pregnancy process. HSPs have been found to be associated with decidualization, implantation and placentation, with their dysregulation associated with implantation failure, pregnancy loss and other feto-maternal complications. Furthermore, HSP is also associated with stress response, specifically in modulating the ER stress, a critical determinant for reproductive success. Recent advances suggest a therapeutic role of HSPs proteins in improving the pregnancy outcome. In this review, we summarized our latest understanding of the role of different members of the HSP families during pregnancy and associated complications based on experimental and clinical evidences, thereby redefining and exploring their novel function with new perspective, beyond their prototype role as molecular chaperones.

Ageing in human parturition: impetus of the gestation clock in the decidua†

Despite sharing many common features, the relationship between ageing and parturition remains poorly understood. The decidua is a specialized lining of endometrial tissue, which develops in preparation for pregnancy. The structure and location of the decidua support its role as the physical scaffold for the growing embryo and placenta, and thus, it is vital to sustain pregnancy. Approaching term, the physical support properties of the decidua are naturally weakened to permit parturition. In this review, we hypothesize that the natural weakening of decidual tissue at parturition is promoted by the ageing process. Studies of the ageing-related functional and molecular changes in the decidua at parturition are reviewed and classified using hallmarks of ageing as the framework. The potential roles of decidual mesenchymal stem/stromal cell (DMSC) ageing in labor are also discussed because, although stem cell exhaustion is also a hallmark of ageing, its role in labor is not completely understood. In addition, the potential roles of extracellular vesicles secreted by DMSCs in labor, and their parturition-related miRNAs, are reviewed to gain further insight into this research area. In summary, the literature supports the notion that the decidua ages as the pregnancy progresses, and this may facilitate parturition, suggesting that ageing is the probable impetus of the gestational clocks in the decidua. This conceptual framework was developed to provide a better understanding of the natural ageing process of the decidua during parturition as well as to encourage future studies of the importance of healthy ageing for optimal pregnancy outcomes.

Targeting Toll-like receptor-4 to tackle preterm birth and fetal inflammatory injury

Every year, 15 million pregnancies end prematurely, resulting in more than 1 million infant deaths and long-term health consequences for many children. The physiological processes of labour and birth involve essential roles for immune cells and pro-inflammatory cytokines in gestational tissues. There is compelling evidence that the mechanisms underlying spontaneous preterm birth are initiated when a premature and excessive inflammatory response is triggered by infection or other causes. Exposure to pro-inflammatory mediators is emerging as a major factor in the 'fetal inflammatory response syndrome' that often accompanies preterm birth, where unscheduled effects in fetal tissues interfere with normal development and predispose to neonatal morbidity. Toll-like receptors (TLRs) are critical upstream gatekeepers of inflammatory activation. TLR4 is prominently involved through its ability to sense and integrate signals from a range of microbial and endogenous triggers to provoke and perpetuate inflammation. Preclinical studies have identified TLR4 as an attractive pharmacological target to promote uterine quiescence and protect the fetus from inflammatory injury. Novel small-molecule inhibitors of TLR4 signalling, specifically the non-opioid receptor antagonists (+)-naloxone and (+)-naltrexone, are proving highly effective in animal models for preventing preterm birth induced by bacterial mimetic LPS, heat-killed Escherichia coli, or the TLR4-dependent pro-inflammatory lipid, platelet-activating factor (PAF). Here, we summarise the rationale for targeting TLR4 as a master regulator of inflammation in fetal and gestational tissues, and the potential utility of TLR4 antagonists as candidates for preventative and therapeutic application in preterm delivery and fetal inflammatory injury.

Chaperoning STAT3/5 by Heat Shock Proteins: Interest of Their Targeting in Cancer Therapy

While cells from multicellular organisms are dependent upon exogenous signals for their survival, growth, and proliferation, commitment to a specific cell fate requires the correct folding and maturation of proteins, as well as the degradation of misfolded or aggregated proteins within the cell. This general control of protein quality involves the expression and the activity of molecular chaperones such as heat shock proteins (HSPs). HSPs, through their interaction with the STAT3/STAT5 transcription factor pathway, can be crucial both for the tumorigenic properties of cancer cells (cell proliferation, survival) and for the microenvironmental immune cell compartment (differentiation, activation, cytokine secretion) that contributes to immunosuppression, which, in turn, potentially promotes tumor progression. Understanding the contribution of chaperones such as HSP27, HSP70, HSP90, and HSP110 to the STAT3/5 signaling pathway has raised the possibility of targeting such HSPs to specifically restrain STAT3/5 oncogenic functions. In this review, we present how HSPs control STAT3 and STAT5 activation, and vice versa, how the STAT signaling pathways modulate HSP expression. We also discuss whether targeting HSPs is a valid therapeutic option and which HSP would be the best candidate for such a strategy.

Alarmins at the maternal-fetal interface: involvement of inflammation in placental dysfunction and pregnancy complications 1

Inflammation is known to be associated with placental dysfunction and pregnancy complications. Infections are well known to be a cause of inflammation but they are frequently undetectable in pregnancy complications. More recently, the focus has been extended to inflammation of noninfectious origin, namely caused by endogenous mediators known as "damage-associated molecular patterns (DAMPs)" or alarmins. In this manuscript, we review the mechanism by which inflammation, sterile or infectious, can alter the placenta and its function. We discuss some classical DAMPs, such as uric acid, high mobility group box 1 (HMGB1), cell-free fetal deoxyribonucleic acid (DNA) (cffDNA), S100 proteins, heat shock protein 70 (HSP70), and adenosine triphosphate (ATP) and their impact on the placenta. We focus on the main placental cells (i.e., trophoblast and Hofbauer cells) and describe the placental response to, and release of, DAMPs. We also covered the current state of knowledge about the role of DAMPs in pregnancy complications including preeclampsia, fetal growth restriction, preterm birth, and stillbirth and possible therapeutic strategies to preserve placental function.

Placental Malaria: A New Insight into the Pathophysiology

Malaria in pregnancy poses a great health risk to mother and her fetus and results into complications, such as abortion, still birth, intra uterine growth retardation, and low birth weight. The heavy infiltration of Plasmodium falciparum-infected RBCs in the intervillous spaces of placenta seems to be responsible for all the complications observed. Infected RBCs in the placenta cause an inflammatory environment with increase in inflammatory cells and cytokines which is deleterious to the placenta. Increased inflammatory responses in the infected placenta result into oxidative stress that in turn causes oxidative stress-induced placental cell death. Moreover, heat shock proteins that are produced in high concentration in stressed cells to combat the stress have been reported in fewer concentrations in malaria-infected placenta. Pathologies associated with placental malaria seems to be the effect of a change in immune status from antibody-mediated immune response to cell-mediated immune response resulting into excess inflammation, oxidative stress, apoptosis, and decreased heat shock protein expression. However, we also need to study other aspects of pathologies so that better drugs can be designed with new molecular targets.

The Potential Functions of Small Heat Shock Proteins in the Uterine Musculature during Pregnancy

The small heat shock protein B (HSPB) family is comprised of eleven members with many being induced by physiological stressors. In addition to being molecular chaperones, it is clear these proteins also play important roles in cell death regulation, cytoskeletal rearrangements, and immune system activation. These processes are important for the uterine smooth muscle or myometrium during pregnancy as it changes from a quiescent tissue, during the majority of pregnancy, to a powerful and contractile tissue at labor. The initiation and progression of labor within the myometrium also appears to require an inflammatory response as it is infiltrated by immune cells and it produces pro-inflammatory mediators. This chapter summarizes current knowledge on the expression of HSPB family members in the myometrium during pregnancy and speculates on the possible roles of these proteins during myometrial programming and transformation of the myometrium into a possible immune regulatory tissue.

Potential role of heat-shock protein 70 and interleukin-15 in the pathogenesis of threatened spontaneous abortions

PROBLEM

The role of HSP70 and both its constitutive (Hsc) and inducible (Hsp) forms in the pathogenesis of threatened spontaneous abortions was investigated.

METHOD OF STUDY

Immunohistology and/or immunofluorescence was used to analyze paraffin-embedded tissue sections, and reverse transcriptase-quantitative polymerase chain reaction and flow cytometry were used for analyses of decidual mononuclear cells (DMCs) and confocal microscopy for the detection of perforin, granulysin, and lysosome-associated membrane protein-1 (LAMP-1) in decidual lymphocytes (DLs).

RESULTS

The percentage of single Hsp70(+) , Hsc70(+) , and IL-15(+) cells and mRNA levels of HSP70, CD91, and TLR4 were lower in the decidua basalis in cases of threatened miscarriages compared to that in cases of normal pregnancy. In a suspension of normal DMCs, IL-15 significantly decreased the HSP70 members and TLR4 in dendritic cells, T cells, and NK cells while increasing CD91 in NK cells alone.

CONCLUSION

Downregulation of Hsc70, Hsp70, and IL-15 expression at gene and/or protein levels might support the retention of fertilization products in cases of missed abortion and blighted ovum.

Heat-Shock Proteins 70 Induce Pro-Inflammatory Maturation Program in Decidual CD1a(+) Dendritic Cells

PROBLEM

The aim of the study was to assess possible binding of a mixture of constitutive Hsc70 and inducible Hsp70 forms (HSP70) to Toll-like receptor (TLR) 4 and CD91 receptors on decidual CD1a(+) dendritic cells (DCs) and their influence on DCs maturation status.

METHOD OF STUDY

Immunohistology and immunofluorescence of paraffin-embedded first trimetester and term pregnancy decidua were performed together with flow cytometry detection of antigens in DCs after stimulation of decidual mononuclear cells with HSP70.

RESULTS

Hsc70 and Hsp70 labeling revealed intracellular and nuclear staining in trophoblast cells. The numbers of Hsc70(+) and Hsp70(+) cells of decidual tissue were higher in early pregnancy decidua than in decidua at term. HSP70 binds CD91 and TLR4 receptors on CD1a(+) DCs and increased the expression of CD83, HLA-DR, CD80, and CD86, but decreased CC receptor (CCR) 5. HSP70 increased CC ligand (CCL) 3 and CCL22. HSP70 in the concentration of 1 μg/mL increased the percentage of interferon-γ and interleukin (IL)-15-expressing cells over the cells expressing IL-4.

CONCLUSION

HSP70 binds CD91 and TLR4 on decidual CD1a(+) DCs, causes their maturation, and increases IL-15 in the context of Th1 cytokine/chemokine domination, which could support immune response harmful for ongoing pregnancy.

Molecular characterization and expression analysis of hsp60 gene homologue of sheep blowfly, Lucilia cuprina

The 60kDa heat shock protein (Hsp60) or chaperonin is one among the highly conserved families of heat shock proteins, known to be involved in variety of cellular activities, including protein folding, thermal protection, etc. In this study we sequence characterized hsp60 gene homologue of Lucilia cuprina, isolated and cloned from the genomic library as well as by genomic PCR, followed by RACE- PCR. The L. cuprina hsp60 gene/protein expression pattern was analyzed in various tissues, either at normal temperature (25±1°C) or after exposure to heat stress (42°C). The analysis of nucleotide sequence of Lchsp60 gene revealed absence of intron and the nuclear localizing signal (NLS). The deduced amino acid sequence showed presence of unique conserved sequences, such as those for mitochondrial localization, ATP binding, etc. Unlike Drosophila, Lucilia showed presence of only one isoform, i.e., hsp60A. Phylogenetic analysis of hsp60 gene homologues from different species revealed Lchsp60 to have >88.36% homology with D. melanogaster, 76.86% with L. sericata, 58.31% with mice, 57.99% with rat, and 57.72% with human. Expression analysis using Real Time PCR and fluorescence imaging showed significant enhancement in the expression level of Lchsp60 upon heat stress in a tissue specific manner, indicating its likely role in thermo-tolerance as well as in normal cellular activities.

Escherichia coli-induced temporal and differential secretion of heat-shock protein 70 and interleukin-1β by human fetal membranes in a two-compartment culture system

INTRODUCTION

Escherichia coli is recognized as an etiological bacteria associated with chorioamnionitis and the preterm premature rupture of fetal membranes. This pathological condition induces pro-inflammatory cytokines and degradative metalloproteinases, which are considered biological markers secreted in an acute stage of infection. Heat-shock proteins (HSPs) are an important component of the innate immunity response and are found in different pathological conditions. They have not been previously measured in human fetal membranes in response to infectious conditions. We hypothesized that the choriodecidual tissue and amniotic epithelium secreted temporal and differential Hsp-60, Hsp-70, and interleukin (IL)-1β mediated by E. coli infection.

METHODS

Fetal membranes were mounted in a two-compartment culture system and infected with two passes of live E. coli at different doses (10², 10⁴, 10⁵, and 10⁶ colony-forming units (CFU)/mL) and intervals of incubation (3, 6, and 24 h). The culture medium was collected, and Hsp-60, Hsp-70, and IL-1β were assessed using the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

After 3 and 6 h of infection, E. coli induced an increase in Hsp-70 secretion in the choriodecidual tissue. However, after 24 h of incubation, Hsp-70 was downregulated and we observed an increase in IL-1β secretion. By contrast, E. coli induced a lower Hsp-60 secretion in the amnion compared to Hsp-70.

DISCUSSION

Human fetal membranes responded actively to E. coli infection, with an increase in Hsp-70 during the first hours of infection. After 24 h, there was an increase in the liberation of IL-1β.

The effect of heat shock protein 27 on extravillous trophoblast differentiation and on eukaryotic translation initiation factor 4E expression

Heat shock protein (HSP27) is expressed in human placentae. Previously, we showed that HSP27 is expressed in the villous cell column of first trimester placental explants and in extravillous trophoblast (EVT) cells. EVT differentiation is accompanied by increased motility, matrix metalloproteinase (MMP) activity, decreased proliferation and expression of specific markers such as HLAG and CD9. HSP27 regulates cell apoptosis, migration, protein stability and the availability of eukaryotic translation initiation factors, such as eukaryotic translation initiation factor 4E (eIF4E). eIF4E supports trophoblast cell proliferation and survival. We wanted to explore the effect of HSP27 silencing on trophoblast cell phenotype, EVT markers and eIF4E expression and regulators [4E-binding protein (4E-BP1) and MAP kinase-interacting kinase (MNK1)]. This study evaluated the effect of HSP27 siRNA on placental explant and HTR-8/SVneo migration, MMP activity/mRNA, cell death, cell cycle, HLAG/CD9 levels, and eIF4E and its regulators' total and phosphorylated levels. Furthermore, we evaluated HSP27 levels in placentae exposed to ribavirin, which triggers EVT differentiation. We found that HSP27 silencing increased cell death in HTR-8/SVneo and placental explants. Furthermore, it reduced HTR-8/SVneo migration and EVT outgrowth from the explants (P < 0.05), MMP2 activity and expression of EVT markers HLAG and CD9 (in placental explants and HTR-8/SVneo, respectively, P < 0.05). Induction of EVT differentiation by ribavirin elevated HSP27 levels. Finally, HSP27 silencing in both HTR-8/SVneo and placental explants reduced eIF4E levels (33 and 28%, respectively, P < 0.05) and the levels of its regulators 4E-BP1 and MNK1 (37 and 32%, respectively, done on HTR-8/SVneo only), but not their phosphorylated forms. Altogether, our results suggest that HSP27 contributes to EVT cell differentiation.

Oxygen governs Galβ1-3GalNAc epitope in human placenta

It is becoming increasingly apparent that the dynamics of glycans reflect the physiological state of cells involved in several cell functions including growth, response to signal molecules, migration, as well as adhesion to, interaction with, and recognition of other cells. The presence of glycoconjugates in human placenta suggests their major role in maternal-fetal exchanges, intercellular adhesion, cellular metabolism, and villous vessel branching. Although several studies have described glycoconjugate distribution in the human placenta descriptions of their physiological function and control mechanisms during placental development are lacking. In this study we investigated the developmental distribution and regulation of placental core 1 O- and N-glycans focusing on early and late first trimester human pregnancy. To define the control mechanisms of the oligosaccharide chains during early placentation process, chorionic villous explants and human trophoblast cell lines were exposed to various oxygen levels. We found that oxygen tension regulates changes in core-1 O-glycan (the disaccharide Galβ1-3GalNAc) epitope expression levels. Moreover, by double affinity chromatography and subsequent analysis with mass spectrometry, we identified in the heat shock protein 90-α (HSP90α) a good candidate as carrier of the Galβ1-3GalNAc epitope at low oxygen tension. Our results support a fundamental role of oxygen tension in modulating glycosylation of proteins during placental development.

Heat shock protein 70 expression is spatially distributed in human placenta and selectively upregulated during labor and preeclampsia

Placental oxidative stress is a feature of both human labor and the pregnancy syndrome preeclampsia. Heat shock proteins (HSPs) can be induced in cells as a protective mechanism to cope with cellular stress. We hypothesized that HSP 70 would increase during labor and preeclampsia and that expression would vary in different placental zones. Samples were obtained from 12 sites within each placenta: 4 equally spaced apart pieces were sampled from the inner, middle and outer placental regions. Non-labor, labor and preeclampsia were studied. HSP 70 expression was investigated by Western blot analysis. HSP 70 protein expression was increased in the middle compared with the outer area (p = 0.03) in non-labor and in both the inner and middle areas compared with the outer area (p = 0.01 and p = 0.02 respectively) in labor. HSP 70 was increased in the preeclampsia non-labor group compared to the control non-labor group in the inner region (p = 0.003) and in the control labor group compared with the preeclampsia labor group at the middle area (p = 0.001). In conclusion HSP 70 is expressed in a spatial manner in the placenta. Changes in HSP 70 expression occur during labor and preeclampsia but at different zones within the placenta. The physiological and pathological significance of these remains to be elucidated but the results have important implications for how data obtained from studies in placental disease (and other organs) can be influenced by sampling methods.

Immunohistochemical expression of heat shock protein 70 in vitiligo

Heat shock proteins (HSPs) are proteins that are expressed under variety of stresses including pathologic conditions. How stresses affect vitiligo is not fully understood and little is known about the role of HSPs generally and Hsp70 specifically in vitiligo. The current study investigated the expression of Hsp70 in vitiliginous (32) and normal skin (10) by immunohistochemistry together with correlating this expression with the clinicopathologic parameters in the studied vitiligo group. Hsp70 was expressed in the cytoplasm of epidermis in all normal skin compared with its localization to the cytoplasm in 35.5% and to the nuclei in 64.5% of epidermis in vitiligo lesions. Intense (P < .001) and diffuse (P < .001) expression of Hsp70 was in favor of vitiligo skin compared with normal skin. Nuclear form of Hsp70 tended to be expressed in progressive forms of the disease. The percentage of Hsp70 expression tended to be decreased with the duration of the disease. From the present study, up-regulation of HSP 70, in the form of its intense and diffuse expression, may be blamed in pathogenesis of vitiligo. Nuclear localization of HSP 70 may be more important than its presence or absence, beside it may be related to progression of the disease.

Role of heat shock proteins in stem cell behavior

Stress response is well appreciated to induce the expression of heat shock proteins (Hsps) in the cell. Numerous studies have demonstrated that Hsps function as molecular chaperones in the stabilization of intracellular proteins, repairing damaged proteins, and assisting in protein translocation. Various kinds of stem cells (embryonic stem cells, adult stem cells, or induced pluripotent stem cells) have to maintain their stemness and, under certain circumstances, undergo stress. Therefore, Hsps should have an important influence on stem cells. Actually, numerous studies have indicated that some Hsps physically interact with a number of transcription factors as well as intrinsic and extrinsic signaling pathways. Importantly, alterations in Hsp expression have been demonstrated to affect stem cell behavior including self-renewal, differentiation, sensitivity to environmental stress, and aging. This chapter summarizes recent findings related to (1) the roles of Hsps in maintenance of stem cell dormancy, proliferation, and differentiation; (2) the expression signature of Hsps in embryonic/adult stem cells and differentiated stem cells; (3) the protective roles of Hsps in transplanted stem cells; and (4) the possible roles of Hsps in stem cell aging.

Proteomic analysis of pregnancy-related proteins from pig uterus endometrium during pregnancy

Many important molecular events associated with implantation and development occur within the female reproductive tract, especially within the uterus endometrium, during pregnancy periods. The endometrium includes the mucosal lining of the uterus, which provides a suitable site for implantation and development of a fertilized egg and fetus. To date, the molecular cascades in the uterus endometrium during pregnancy periods in pigs have not been elucidated fully. In this study, we compared the functional regulated proteins in the endometrium during pregnancy periods with those in non-pregnant conditions and investigated changes in expression patterns during pregnancy (days 40, 70, and 93) using two-dimensional gel electrophoresis (2-DE) and western blotting. The functional regulated proteins were identified and discovered from differentially expressed proteins in the uterus endometrium during pregnancy. We discovered 820 protein spots in a proteomic analysis of uterus endometrium tissues with 2-DE gels. We identified 63 of the 98 proteins regulated differentially among non-pregnant and pregnant tissues (matched and unmatched spots). Interestingly, 10 of these 63 proteins are development-, cytoskeleton- and chaperon-related proteins such as transferrin, protein DJ-1, transgelin, galectin-1, septin 2, stathmin 1, cofilin 1, fascin 1, heat shock protein (HSP) 90β and HSP 27. The specific expression patterns of these proteins in the endometrium during pregnancy were confirmed by western blotting. Our results suggest that the expressions of these genes involved in endometrium function and endometrium development from early to late gestation are associated with the regulation of endometrium development for maintaining pregnancy.

Comparison of hemodynamic, biochemical and hematological parameters of healthy pregnant women in the third trimester of pregnancy and the active labor phase

BACKGROUND

Pregnancy is accompanied by several hemodynamic, biochemical and hematological changes which revert to normal values after labor. The mean values of these parameters have been reported for developed countries, but not for Mexican women. Furthermore, labor constitutes a stress situation, in which these factors may be altered. It is known that serologic increase of heat shock protein (Hsp) 70 is associated with abnormal pregnancies, presenting very low level in normal pregnant women. Nevertheless, there are no studies where these measurements are compared in healthy pregnant women at their third trimester of pregnancy (3TP) and the active labor phase (ActLP).

METHODS

Seventy five healthy Mexican pregnant women were included. Hemodynamic, biochemical and hematological parameters were obtained in all cases, and serum Hsp70 levels were measured in a sample of 15 women at 3TP and at ActLP.

RESULTS

Significant differences were found in most analysis performed and in Hsp70 concentration at 3TP as compared to ActLP, however all were within normal range in both conditions, supporting that only in pathological pregnancies Hsp70 is drastically increased.

CONCLUSION

Results obtained indicate that 3TP and ActLP have clinical similarities in normal pregnancies, therefore if abnormalities are found during 3TP, precautions should be taken before ActLP.

Heat shock protein 70 is upregulated in the intestine of intrauterine growth retardation piglets

The objective of this study is to investigate the expression and distribution of heat shock protein 70 (Hsp70) in the intestine of intrauterine growth retardation (IUGR) piglets. Samples from the duodenum, prejejunum, distal jejunum, ileum, and colon of IUGR and normal-body-weight (NBW) piglets were collected at birth. The results indicated that the body and intestine weight of IUGR piglets were significantly lower than NBW piglets. The villus height and villus/crypt ratio in jejunum and ileum of IUGR piglets were significantly reduced compared to NBW piglets. These results indicated that IUGR causes abnormal gastrointestinal morphologies and gastrointestinal dysfunction. The mRNA of hsp70 was increased in prejejunum (P < 0.05), distal jejunum (P < 0.05), and colon in IUGR piglets. However, the hsp70 mRNA in ileum of piglets with IUGR was decreased. Similar to hsp70 mRNA, the protein levels of Hsp70 in prejejunum (P < 0.05), distal jejunum, and colon (P < 0.05) in IUGR piglets were higher than those in NBW piglets. These results indicated that the expression of Hsp70 in the intestinal piglets was upregulated by IUGR, and different intestinal sites had different responses to stress. Meanwhile, the localization of Hsp70 in the epithelial cells of the whole villi and intestinal gland rather than in the lamina propria and myenteron suggested that Hsp70 has a cytoprotective role in epithelial cell function and structure.

Circulating heat shock protein 70 (HSPA1A) in normal and pathological pregnancies

Heat shock proteins (Hsps) are ubiquitous and phylogenetically conserved molecules. They are usually considered to be intracellular proteins with molecular chaperone and cytoprotective functions. However, Hsp70 (HSPA1A) is present in the peripheral circulation of healthy nonpregnant and pregnant individuals. In normal pregnancy, circulating Hsp70 levels are decreased, and show a positive correlation with gestational age and an inverse correlation with maternal age. The capacity of extracellular Hsp70 to elicit innate and adaptive proinflammatory (Th1-type) immune responses might be harmful in pregnancy and may lead to the maternal immune rejection of the fetus. Decreased circulating Hsp70 level, consequently, may promote the maintenance of immunological tolerance to the fetus. Indeed, elevated circulating Hsp70 concentrations are associated with an increased risk of several pregnancy complications. Elevated Hsp70 levels in healthy pregnant women at term might also have an effect on the onset of labor. In preeclampsia, serum Hsp70 levels are increased, and reflect systemic inflammation, oxidative stress and hepatocellular injury. Furthermore, serum Hsp70 levels are significantly higher in patients with the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome) than in severely preeclamptic patients without HELLP syndrome. In HELLP syndrome, elevated serum Hsp70 level indicates tissue damage (hemolysis and hepatocellular injury) and disease severity. Increased circulating Hsp70 level may not only be a marker of these conditions, but might also play a role in their pathogenesis. Extracellular Hsp70 derived from stressed and damaged, necrotic cells can elicit a proinflammatory (Th1) immune response, which might be involved in the development of the maternal systemic inflammatory response and resultant endothelial damage in preeclampsia and HELLP syndrome. Circulating Hsp70 level is also elevated in preterm delivery high-risk patients, particularly in treatment-resistant cases, and may be a useful marker for evaluating the curative effects of treatment for preterm delivery. In addition, increased circulating Hsp70 levels observed in asthmatic pregnant patients might play a connecting role in the pathomechanism of asthmatic inflammation and obstetrical/perinatal complications. Nevertheless, a prospective study should be undertaken to determine whether elevated serum Hsp70 level precedes the development of any pregnancy complication, and thus can help to predict adverse maternal or perinatal pregnancy outcome. Moreover, the role of circulating Hsp70 in normal and pathological pregnancies is not fully known, and further studies are warranted to address this important issue.

Increased expression of heat shock protein 105 in rat uterus of early pregnancy and its significance in embryo implantation

BACKGROUND

Heat shock proteins (Hsps) are a set of highly conserved proteins, Hsp105, has been suggested to play a role in reproduction.

METHODS

Spatio-temporal expression of Hsp105 in rat uterus during peri-implantation period was examined by immunohistochemistry and Western blot, pseudopregnant uterus was used as control. Injection of antisense oligodeoxynucleotides to Hsp105 into pregnant rat uteri was carried out to look at effect of Hsp105 on embryo implantation.

RESULTS

Expression of Hsp105 was mainly in the luminal epithelium on day 1 of pregnancy, and reached a peak level on day 5, whereas in stroma cells, adjacent to the implanting embryo, the strongest expression of Hsp105 was observed on day 6. The immunostaining profile in the uterus was consistent with that obtained by Western blot in the early pregnancy. In contrast, no obvious peak level of Hsp105 was observed in the uterus of pseudopregnant rat on day 5 or day 6. Furthermore, injection of antisense oligodeoxynucleotides to Hsp105 into the rat uterine horn on day 3 of pregnancy obviously suppressed the protein expression as expected and reduced number of the implanted embryos as compared with the control.

CONCLUSION

Temporal and spatial changes in Hsp105 expression in pregnant rat uterus may play a physiological role in regulating embryo implantation.

TEAD1 inhibits prolactin gene expression in cultured human uterine decidual cells

Forced overexpression of TEAD1 in human uterine fibroblast (HUF) and human endometrial stromal cells markedly inhibited prolactin promoter activity in both cell types in a dose-dependent manner, with maximal inhibition of greater than 90%. Conversely, the knockdown of TEAD1 expression in HUF cells with a TEAD1 siRNA resulted in a 75-80% increase in prolactin mRNA levels (p<0.01) compared to control cells exposed to a scrambled nonsense RNA. Mutagenesis of the putative TEAD site inhibited basal promoter activity by about 80%. However, mutagenesis of the TEAD site did not prevent TEAD1-induced inhibition of promoter activity; and the transcription activity of a minimal promoter fragment lacking a putative TEAD binding site was repressed by overexpression of TEAD1. Taken together, these findings suggest that the TEAD binding site on the prolactin promoter is important for the maintenance of basal prolactin promoter activity and that overexpression of TEAD1 has a dominant-negative effect on prolactin promoter activity, probably by interacting directly with other transcription factors.

HSP70 is associated with endothelial activation in placental vascular diseases

Endothelial cell injury and activation in the placenta are features of placental vascular disease (PVD). While advances in PVD have been made, the pathogenesis of this disease is still unknown. The objective of this study was to pursue potential risk factors and signal transcription pathways involved in PVD pathogenesis. Gene expression in subjects with PVD and with normal pregnancies was compared using a two-channel microarray technique. Higher expression of HSPA6 and HSPA1A was exhibited in PVD subjects. HSPA6 and HSPA1A both encode HSP70, and, therefore, we localized HSP70 expression in placental tissue. Using quantitative polymerase chain reaction (PCR) and Western blot, we observed a significant upregulation of HSP70 in both mRNA and protein levels in placental tissue and microvascular endothelial cells of PVD subjects when compared with normal pregnancies (P< 0.05). HSP70 mRNA and protein expression also correlated negatively with infant birth weight (P< 0.05). HSP70 was expressed mainly in endothelial cells and smooth muscle cells in the placental microvessels. We therefore conclude that HSP70 may mediate endothelial activation and play a role in pathogenesis of PVD.

Amniotic fluid heat shock protein 70 concentration in histologic chorioamnionitis, term and preterm parturition

OBJECTIVE

Heat shock protein (HSP) 70, a conserved member of the stress protein family, is produced in almost all cell types in response to a wide range of stressful stimuli, and its production has a survival value. Evidence suggests that extracellular HSP70 is involved in the activation of the innate and adaptive immune response. Furthermore, increased mRNA expression of HSP70 has been observed in human fetal membranes following endotoxin stimulation. This study was conducted to determine the changes in amniotic fluid HSP70 concentrations during pregnancy, term and preterm parturition, intra-amniotic infection (IAI), and histologic chorioamnionitis.

STUDY DESIGN

A cross-sectional study was conducted in 376 pregnant women in the following groups: (1) women with a normal pregnancy who were classified into the following categories: (a) women in the mid-trimester (14-18 weeks) who underwent amniocentesis for genetic indications and delivered normal infants at term (n=72); (b) women at term not in labor (n = 23); and (c) those at term in labor (n = 48). (2) Women with spontaneous preterm labor and intact membranes who were subdivided into the following categories: (a) preterm labor who delivered at term without IAI (n = 42); (b) preterm labor who delivered preterm without IAI (n = 57); and (c) preterm labor and delivery with IAI (n = 30). (3) Women with preterm prelabor rupture of membranes (PROM) with (n = 50) and without (n = 54) IAI. Among patients with preterm labor with intact membranes and preterm PROM who delivered within 72 hours of amniocentesis, placenta, umbilical cord, and chorioamniotic membranes were collected and assessed for the presence or absence of acute inflammatory lesions in the extraplacental membranes (histologic chorioamnionitis) and/or umbilical cords (funisitis). HSP70 concentrations in amniotic fluid were determined using a sensitive and specific immunoassay. Non-parametric statistics were used for analysis. A p value of <0.05 was considered statistically significant.

RESULTS

Immunoreactive HSP70 was detected in 88% (332/376) of amniotic fluid samples. The median amniotic fluid HSP70 concentration was significantly higher in women at term without labor than in those in the mid-trimester (term no labor: median 34.9 ng/mL, range 0-78.1 ng/mL vs. mid-trimester; median 6.6 ng/mL, range 0-20.8 ng/mL; p<0.001). Among patients with spontaneous preterm labor and preterm PROM, those with IAI had a significantly higher median amniotic fluid HSP70 concentration than those without IAI (preterm labor with IAI: median 82.9 ng/mL, range 0-500 ng/mL vs. preterm labor without IAI: median 41.7 ng/mL, range 0-244 ng/mL; p = 0.001; preterm PROM with IAI: median 86.5 ng/mL, range 0-428 ng/mL vs. preterm PROM without IAI: median 55.9 ng/mL, range 14.9-299.9 ng/mL; p = 0.007). There was no significant difference in the median amniotic fluid HSP70 concentration between patients with preterm labor who delivered preterm without IAI and those who delivered at term (p = 0.6). However, among patients with preterm labor without IAI, there was an inverse relationship between amniotic fluid concentration of HSP70 and the amniocentesis-to-spontaneous delivery interval (Spearman's Rho = -0.26; p = 0.02). Patients with histologic chorioamnionitis/funisitis had a significantly higher median amniotic fluid HSP70 concentration than those without inflammation (inflammation: median 108.7 ng/mL, range 0-500 ng/mL vs. without inflammation: median 67.9 ng/mL, range 7.1-299.9 ng/mL; p = 0.02). Women at term in labor had a median amniotic fluid concentration of HSP70 significantly higher than those not in labor (term in labor: median 60.7 ng/mL, range 0-359.9 ng/mL vs. term not in labor: median 34.9 ng/mL, range 0-78.1 ng/mL; p = 0.02).

CONCLUSIONS

Intra-amniotic infection, histologic chorioamnionitis, and term parturition are associated with elevated amniotic fluid HSP70 concentrations. HSP70 plays a role in the host defense mechanism by activating the innate arm of the immune response in women with intrauterine infection. The mechanisms of preterm and term parturition in humans may involve extracellular HSP70.

Association of increased heat shock protein 70 levels in the lymphocyte with high risk of adverse pregnancy outcomes in early pregnancy: a nested case-control study

Studies suggest that heat shock proteins (Hsps), Hsp70 in particular, may play a role in embryogenesis and reproduction. As the first trimester is the critical period of human fetal development, we tested whether there is an association between Hsp70 expression in lymphocytes and adverse pregnancy outcomes (APOs) during that period. We measured lymphocyte Hsp70 levels by immunoblot in 55 pregnant women with APOs and 110 well-matched controls selected from 778 pregnant women in a nested case-control study. Multivariate logistic regression models were used to investigate the association between lymphocyte Hsp70 levels and risk of developing APOs. Our data showed that Hsp70 levels in women with APOs, especially those younger than 29 years old, were significantly higher than controls (193 vs 135 units, P < 0.001) and that the elevated Hsp70 levels were associated with a significantly increased risk of APOs (adjusted OR = 1.014; 95% CI = 1.008-1.020, P < 0.001). Our results also showed that the sensitivity, specificity, and positive and negative predictive values were 78%, 60%, 50%, and 85%, respectively, among these pregnant women. Adjusted ORs and 95% CI for the association between a Hsp70 value > 153 IOD and APOs were statistically significant (OR = 8.78, 95% CI = 2.79-27.64, P < 0.001). These results suggest that Hsp70 may play a role in the etiology of APOs. However, the underlying mechanisms for the elevation of Hsp70 in women with APOs and whether Hsp70 can be applied as a clinical indicator of APOs warrant further investigations.

Antibodies to the 70 kDa heat shock protein in midtrimester amniotic fluid and intraamniotic immunity

OBJECTIVE

Antibodies to the 70 kDa heat shock protein (hsp70) immunoglobulin (Ig) G are markers for exposure to adverse or nonphysiological stimuli. In addition, these antibodies cross-link hsp-70 microbial antigen complexes and enhance development of antimicrobial immunity. The association between intraamniotic hsp70 IgG concentrations and intraamniotic immune responses were evaluated.

STUDY DESIGN

Midtrimester amniotic fluids from 90 women undergoing an amniocentesis were tested for hsp70 IgG, hsp70 antigen, tumor necrosis factor (TNF)-alpha, secretory leukocyte protease inhibitor (SLPI), and interferon (IFN)-alpha by enzyme-linked immunosorbent assay. Clinical outcomes were obtained after completion of all testing. Associations were analyzed by nonparametric statistics.

RESULTS

Intraamniotic hsp70 IgG concentrations, but not hsp70 antigen levels, were positively associated with levels of TNF-alpha (P < .0001), IFN-alpha (P = .0001), and SLPI (P = .0038). There were no associations between hsp70 IgG and maternal age or parity, race/ethnicity or pregnancy outcome.

CONCLUSION

The hsp70 IgG levels correlate with intraamniotic concentrations of antimicrobial immune mediators. This antibody may potentiate antimicrobial immunity during fetal development.

Global gene expression analysis and regulation of the principal genes expressed in bovine placenta in relation to the transcription factor AP-2 family

BACKGROUND

Cell-cell communication is an important factor in feto-maternal units during placentogenesis. The placenta produces pivotal hormones and cytokines for communication between cotyledonary villi and the maternal caruncle. Gene expression in bovine placenta throughout pregnancy was comprehensively screened by a cDNA microarray, and we searched for a common transcription factor in a gene cluster that showed increasing expression throughout gestation in cotyledonary villi and caruncle.

METHODS

Placentomal tissues (villi and caruncle) were collected from Day 25 to Day 250 of gestation for microarray analysis. Global gene expression profiles were analyzed using the k-means clustering method. A consensus sequence cis-element that may control up-regulated genes in a characteristic cluster was examined in silico. The quantitative expression and localization of a specific transcription factor were investigated in each tissue using quantitative real-time RT-PCR and in situ hybridization.

RESULTS

The microarray expression profiles were classified into ten clusters. The genes with most markedly increased expression became concentrated in cluster 2 as gestation proceeded. Cluster 2 included placental lactogen (CSH1), pregnancy-associated glycoprotein-1 (PAG1), and sulfotransferase family 1E estrogen-preferring member 1 (SULT1E1), which were mainly detected in giant trophoblast binucleate cells (BNC). Consensus sequence analysis identified transcription factor AP-2 binding sites in some genes in this cluster. Quantitative real-time RT-PCR analysis confirmed that high level expression of transcription factor AP-2 alpha (TFAP2A) was common to cluster 2 genes during gestation. In contrast, the expression level of another AP-2 family gene, transcription factor AP-2 beta (TFAP2B), was extremely low over the same period. Another gene of the family, transcription factor AP-2 gamma (TFAP2C), was expressed at medium level compared with TFAP2A and TFAP2B. In situ hybridization showed that TFAP2A, TFAP2B and TFAP2C mRNAs were localized in trophoblast cells but were expressed by different cells. TFAP2A was expressed in cotyledonary epithelial cells including BNC, TFAP2B was specifically expressed in BNC, and TFAP2C in mononucleate cells.

CONCLUSION

We detected gestational-stage-specific gene expression profiles in bovine placentomes using a combination of microarray and in silico analysis. In silico analysis indicated that the AP-2 family may be a consensus regulator for the gene cluster that characteristically appears in bovine placenta as gestation progresses. In particular, TFAP2A and TFAP2B may be involved in regulating binucleate cell-specific genes such as CSH1, some PAG or SULT1E1. These results suggest that the AP-2 family is a specific transcription factor for clusters of crucial placental genes. This is the first evidence that TFAP2A may regulate the differentiation and specific functions of BNC in bovine placenta.

Chaperone‐rich cell lysate embedded with BCR‐ABL peptide demonstrates enhanced anti‐tumor activity against a murine BCR‐ABL positive leukemia

Chaperone proteins are effective antitumor vaccines when purified from a tumor source, some of which are in clinical trials. Such vaccines culminate in tumor-specific T cell responses, implicating the role of adaptive immunity. We have developed a rapid and efficient procedure utilizing an isoelectric focusing technique to obtain vaccines from tumor or normal tissues called chaperone-rich cell lysate (CRCL). Tumor-associated peptides, the currency of T cell-mediated anticancer immunity, are believed to be purveyed by chaperone vaccines. Our purpose was to demonstrate our ability to manipulate the peptide antigen repertoire of CRCL vaccines as a novel anticancer strategy. Our methods allow us to prepare "designer" CRCL, utilizing the immunostimulation activity and the carrying capacity of CRCL to quantitatively acquire and deliver exogenous antigenic peptides (e.g., derived from the oncogenic BCR/ABL protein in chronic myelogenous leukemia). Using fluorescence-based and antigen-presentation assays, we determined that significant quantities of exogenously added peptide could accumulate in "designer" CRCL and could stimulate T cell activation. Further, we concluded that peptide-embedded CRCL, devoid of other antigens, could generate potent immunity against pre-established murine leukemia. Designer CRCL allows for the development of personalized vaccines against cancers expressing known antigens, by embedding antigens into CRCL derived from normal tissue.

Serum heat shock protein 70 levels are decreased in normal human pregnancy

Heat shock proteins (Hsps) are primarily known to be intracellular proteins with molecular chaperone and cytoprotective functions. However, Hsp60 and Hsp70 have been found in the serum and plasma of healthy non-pregnant individuals. We aimed to compare serum Hsp70 concentrations in healthy pregnant women with those of healthy non-pregnant women and to determine factors influencing serum Hsp70 levels in normal pregnancy. One hundred and seventy six healthy pregnant women with uncomplicated pregnancies (age, 17-44 years; gestational age, 20-41 weeks) and 81 healthy, age-matched non-pregnant women (age, 22-40 years) were enrolled in this cross-sectional study. Serum Hsp70 concentrations were measured using an enzyme-linked immunosorbent assay, and were significantly lower in healthy pregnant women than in healthy non-pregnant women (median (25-75 percentile): 0.29 (0.20-0.35)ng/ml versus 1.27 (0.86-1.72)ng/ml; p<0.001). In healthy pregnant women, there was a statistically significant negative correlation between maternal age and serum Hsp70 concentration (Spearman R=-0.35; p<0.001) and a significant positive correlation between gestational age and serum Hsp70 level (Spearman R=0.35; p<0.001). The capacity of extracellular Hsp70 to elicit innate and adaptive proinflammatory immune responses might be harmful in pregnancy and lead to immune rejection of the fetal semi-allograft. We hypothesize that decreased circulating Hsp70 levels are due to unknown regulatory mechanisms aimed at maintaining immune tolerance in pregnancy. In conclusion, serum Hsp70 concentrations are decreased in normal human pregnancy; however, further studies are needed to explain the observed differences between pregnant and non-pregnant women.

Heat shock protein 1 and the mitogen-activated protein kinase 14 pathway are important for mouse trophoblast stem cell differentiation

Differentiation of trophoblast cells is a critical process for the proper establishment of the placenta and is, therefore, necessary to maintain embryonic development. Trophoblast stem (TS) cells grown in culture can differentiate into different trophoblast subtypes in vitro mimicking normal trophoblast cell differentiation. Therefore, TS cells are a valuable model system that can be used to elucidate genetic factors that regulate trophoblast cell differentiation. Several transcription factors, when analyzed by targeted gene mutation in mice, have resulted in embryonic lethality due to placental defects and, more specifically, defects of the trophoblast lineages. These studies have helped improve our knowledge about trophoblast cell differentiation, but much is still unknown about the specific mechanisms involved. This study uses TS cell culture to detect proteins with differential expression in proliferating and differentiating TS cells in order to identify proteins with potential roles in the differentiation process. We identified four proteins with differential expression: dimethylarginine dimethylaminohydrolase1 (DDAH1), keratin 8, keratin 18, and HSPB1 (also known as heat shock protein 25, HSP25). Further investigation confirmed the presence of HSPB1 protein during in vitro TS cell differentiation. In addition, we confirmed that phosphorylation of HSPB1 and MAP kinase-activated protein kinase 2 (MAPKAPK2) increased in TS cells during differentiation. Inhibition of MAPK14 (also known as p38 MAPK) resulted in a reduction of HSPB1 phosphorylation and an increase in cell death during TS cell differentiation. These results suggest that HSPB1 and the MAPK14 pathway are important during TS cell differentiation.

Human placental Hofbauer cells express sprouty proteins: a possible modulating mechanism of villous branching

The development of the chorionic villous tree into a complex and organized ramified tubular network can be termed branching morphogenesis. Studying the molecular mechanisms involved in this process may contribute to the understanding of pregnancy complications such as preeclampsia. Sprouty (Spry) proteins are important regulators of branching morphogenesis and growth factor signaling. We analyzed the expression of Spry genes in human placenta. RT-PCR and immunohistochemistry were employed to detect placental Spry expression. Quantitative RT-PCR was used to assess the effect of FGF and reduced oxygen fraction on Spry gene expression. Spry 1, 2 and 3 expression was observed in placental tissue from all three trimesters. Our results reveal for the first time that Spry proteins are localized in the stroma of the chorionic villi, adjacent to cytotrophoblasts in areas of villous sprouting. Immunofluorescent double staining with anti-Spry and anti-CD68 confirmed that placental macrophages (Hofbauer cells) express Spry. Reduced oxygen fraction, FGF-4 and FGF-10 stimulated Spry-2 expression. Hofbauer cells also expressed c-Cbl, a protein that interacts with Spry. Placental expression of Spry and c-Cbl implies an important role for Hofbauer cells in placental development, possibly through a mesenchymal-epithelial interaction with trophoblasts. Regulation of Spry-2 expression by FGF-4 and FGF-10 suggests an orchestrated regulatory system that modulates villous branching.

Decreased expression of angiogenic factors in placentas with chorioamnionitis after preterm birth

Chorioamnionitis and funisitis are associated with neonatal morbidity and mortality. We hypothesized that chorioamnionitis may stress fetal endothelium, activate proinflammatory gene transcription. and affect angiogenic homeostasis in fetal capillaries. Placentas from preterm infants were stained for heat-shock protein 70, nuclear factor-kappaB, hypoxia-inducible factor-1alpha, and vascular endothelial growth factor (VEGF). VEGF receptors (VEGF-R) 1 and 2 as well as the receptor tyrosine kinase with immunoglobulin and epidermal growth factor homology domains (TIE-2), which is involved in vascular remodeling, were quantified. Immunohistochemistry was analyzed by counting positive capillaries in placental terminal villi. Staining intensity was quantified by a three-step semiquantitative scale. The samples were divided into three matched groups according to histology: chorioamnionitis with funisitis ("funisitis"), chorioamnionitis without funisitis ("chorioamnionitis"), and control group with no inflammation. In tissues from the funisitis or chorioamnionitis group, heat-shock protein 70 expression was increased over the control group. More nuclear factor-kappaB-positive nuclei of endothelial cells in capillaries were counted in the funisitis and chorioamnionitis groups. Expression of VEGF and VEGF-R1 and -R2 were reduced in cases of funisitis or chorioamnionitis in comparison with controls. Hypoxia-inducible factor-1alpha expression tended to be slightly lower in the funisitis and chorioamnionitis groups but did not reach statistical significance. We speculate that cellular stress and changes in angiogenic homeostasis induced by proinflammatory activation of fetal endothelium in chorioamnionitis may not be limited to the placenta but may also involve other fetal organs.

Small heat shock protein 27 (Hsp27) expression is highly induced in rat myometrium during late pregnancy and labour

The underlying mechanisms that regulate uterine contractions during labour are still poorly understood. A candidate regulatory protein is heat shock protein 27 (Hsp27). It belongs to the small heat shock protein family and can regulate actin cytoskeleton dynamics, act as a chaperone, and may regulate contractile protein activation. As a result, we hypothesized that Hsp27 expression would be highly induced during late pregnancy and labour. Hsp27 mRNA expression was significantly elevated (P <0.05) on days 17 to 22 of gestation. In addition, immunoblot analysis demonstrated that detection of total Hsp27 increased (P <0.05) between day 21 and 1 day post-partum (PP) inclusive. Since phosphorylation of Hsp27 has been reported to be a prerequisite for smooth muscle contraction, we examined the temporal and spatial expression of Ser-15 phosphorylated Hsp27. Immunoblot analysis showed that the detection of Ser-15 phosphorylated Hsp27 significantly increased (P <0.05) between days 19 and 23 (active labour) inclusive, in parallel with detection of total Hsp27. Immunocytochemical analysis of Ser-15 phosphorylated Hsp27 expression in situ demonstrated that phosphorylated Hsp27 in circular muscle became detectable in peri-nuclear and membrane regions on days 19 to 22, but was primarily restricted to the cytoplasm on days 23 to PP. In contrast, phosphorylated Hsp27 in longitudinal muscle was primarily detected in myocyte membranes on days 15 to 22, and then also became detectable in the cytoplasm of myocytes on days 23 and PP. Our results demonstrate that Hsp27 expression is highly upregulated during late pregnancy and labour and suggest that Hsp27 is a potential candidate contraction-associated protein.

Changes in serum levels of heat shock protein 70 in preterm delivery and pre-eclampsia

AIM

The aim of this study was to investigate heat-shock protein (Hsp)70 as a novel marker to evaluate the curative effects of treatment for preterm delivery high-risk patients and pre-eclampsia.

METHODS

After obtaining informed consent, serum samples were collected from 31 preterm delivery high-risk patients with a tocolysis index of three points or above (A), seven pre-eclampsia patients (P), 46 normal pregnant women (B), and seven non-pregnant women (C). Of the 31 preterm delivery high-risk patients, 15 had preterm delivery (Ap) and 16 had full-term delivery (Af). The levels of Hsp70 were measured using enzyme-linked immunosorbent assay.

RESULTS

The Hsp70 levels in normal pregnant women were 8.6 +/- 1.9 ng/mL (first trimester), 5.5 +/- 1.0 ng/mL (second trimester) and 5.5 +/- 0.7 ng/mL (third trimester). There was no statistical difference in the Hsp70 levels between the three trimesters. The mean Hsp70 levels were 21.9 +/- 5.3 ng/mL (A), 35.3 +/- 9.6 ng/mL (Ap), 9.4 +/- 2.2 ng/mL (Af), 24.4 +/- 3.6 ng/mL (P), 6.1 +/- 0.6 ng/mL (B), and 2.4 +/- 0.6 ng/mL (C). Group Ap had significantly higher Hsp70 levels than group Af (P = 0.0112) and group B (P <0.0001). The duration of pregnancy after hospitalization for group Ap was significantly shorter than that for group Af (P=0.0088) and group B (P <0.0001). Group P also had significantly higher Hsp70 levels than group B (P <0.0001).

CONCLUSION

Because Hsp70 levels were particularly high in treatment-resistant preterm delivery cases, Hsp70 may prove to be a useful marker for evaluating the curative effects of treatment for preterm delivery.

Protein expression profiling of endometrial malignancies reveals a new tumor marker: chaperonin 10

Endometrial carcinoma is a common malignancy in women, being exceeded in incidence only by that of breast, lung, and colorectal cancers. At present, no serum tumor markers are available for the monitoring of endometrial carcinoma patients, and patients with recurrent disease are detected only following the development of symptoms or abnormalities in imaging assessments. Similarly, no screening tools are available for endometrial carcinoma. Protein profiling by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has proven to be a sensitive and fast method of analysis for small proteins or peptides to yield specific biomarkers. In this study, a variety of normal and malignant endometrial tissue samples were fractionated and analyzed by SELDI-TOF MS (SELDI is a version of MALDI utilizing protein "chips"). A number of proteins displayed differential expression in malignant endometrial tissues. One of the prominent proteins fractionated by weak cation exchange chromatography and displaying enhanced expression in these malignant tissues was identified as chaperonin 10. The increased expression of chaperonin 10 in malignant endometrial tissues was further confirmed by parallel Western blot and immunohistochemistry analyses.

Heat shock proteins in mammalian development

Mammalian development follows a defined but adjustable program, depending on the plasticity of embryonic cells 'response to environmental changes. Heat shock proteins (Hsp) are integral part of this developmental program and gene targeting experiments have started to unravel developmental processes, which exhibit specific requirements for Hsps (e.g. Hsp70.2 for spermatogenesis). In the present paper, we will review available data on Hsp function and discuss the roles of heat shock factors (HSF), their major regulators, in mammalian development.