SDS-PAGE heat-shock protein profiles of environmental Aeromonas strains

Aeromonas microorganisms normally grow at temperatures between 5 degrees C and 45 degrees C and therefore should have high thermotolerance. Thus it was of interest to find out whether A. hydrophila, A. caviae and A. veronii biovar sobria serovars respond to abrupt temperature changes with a heat shock-like response. To this end the present study was undertaken to determine whether Aeromonas species exhibits a heat shock response to different temperatures and time factors. The response of Aeromonas serovars to 24 h and 48 h of thermal stress at 25 degrees C, 42 degrees C and 50 degrees C involved the synthesis of 12-18 heat shock proteins (HSPs) bands with molecular weights ranging between 83.5-103.9 kDa in the high HSP molecular mass and 14.5-12.0 as low molecular mass HSP. Electrophoretic analysis of the HSPs showed that the serovars do not cluster very tightly and also that they are distinct from each other.

[Construction of pGEX-KG/mTSARG3 recombinant vector and preparation of anti-mTSARG3 polyclonal antibody]

OBJECTIVE

To construct pGEX-KG/mTSARG3 recombinant vector and prepare the fusion protein to obtain rabbit polyclonal antibody against mTSARG3.

METHODS

The open reading frame (ORF) of mTSARG3 gene was amplified from mouse testis cDNA library by PCR. The products were cloned into pGEM-T Easy vectors and sequenced. The recombinant plasmids were digested by EcoRI and SalI and subcloned into PGEX-KG vector. After identification by DNA sequence analysis, the recombinant plasmids were transformed into component E.coli BL21 cells, and the GST/mTSARG3 fusion protein was expressed with IPTG induction. The anti-mTSARG3 polyclonal antibody was produced by immunization of rabbits with the fusion protein. The resultant antibody was purified by antigen column and used for Western blotting for detecting mTSARG3 expression.

RESULTS

The recombinant vector pGEX-KG/mTSARG3 was successfully constructed. GST/mTSARG3 fusion protein was expressed abundantly at 4 h after IPTG induction and polyclonal antibodies were obtained. Western blot analysis demonstrated that the antibodies specifically detected mTSARG3 expression in E.coli BL21.

CONCLUSION

We have successfully constructed pGEX-KG/mTSARG3 recombinant vector and obtained rabbit polyclonal antibody, which may facilitate further investigation of the role of mTSARG3 in spermatogenesis.

Ageing enhances alpha-synuclein, ubiquitin and endoplasmic reticular stress protein expression in the nigral neurons of Asian Indians

Accumulating evidences suggest that dopaminergic neuronal loss in the substantia nigra pars compacta (SNpc) during ageing and in Parkinson's disease (PD) is linked to neurodegenerative changes like exponential increase in alpha-synuclein expression and protein misfolding. Lewy body formation is also a quintessential observation in neurodegeneration and PD. In experimental models of PD, GRP78 a neuroprotective endoplasmic reticulum (ER) chaperone protein targets misfolded proteins for degradation and prevents release of caspase12 from the ER. Release of active caspase12 and its translocation to the nucleus induces ER mediated apoptosis. The effect of ageing on these proteins in human nigra is not known. We evaluated alpha-synuclein, caspase12, GRP78 and ubiquitin expression in the SNpc of Asian Indians, using immunohistochemistry and stereology. The number of alpha-synuclein and caspase12 immunoreactive neurons increased gradually with age whereas the number of GRP78-labeled neurons remained stable. In contrast, GRP78 protein expression was significantly upregulated with age, while alpha-synuclein and caspase12 increased slightly. An increase in the size and numbers of marinesco bodies was prominent after the sixth decade. The mild increase in alpha-synuclein expression and occurrence of marinesco bodies suggests ageing induced protein misfolding and GRP78 upregulation indicates presence of ER stress. The logarithmic upregulation of GRP78 could even be an indicator of neuroprotective or neuromodulatory response of ER to protein misfolding and initiation of unfolded protein response pathway. Since dopaminergic neurons are preserved in ageing Asian Indians, our study possibly signifies better proteasomal or ER response and partially explains the lower prevalence of PD in them.

Deoxyribonucleic acid methylation and gene expression of PPARGC1A in human muscle is influenced by high-fat overfeeding in a birth-weight-dependent manner

CONTEXT

Low birth weight (LBW) and unhealthy diets are risk factors of metabolic disease including type 2 diabetes (T2D). Genetic, nongenetic, and epigenetic data propose a role of the key metabolic regulator peroxisome proliferator-activated receptor gamma, coactivator 1alpha (PPARGC1A) in the development of T2D.

OBJECTIVE

Our objective was to investigate gene expression and DNA methylation of PPARGC1A and coregulated oxidative phosphorylation (OXPHOS) genes in LBW and normal birth weight (NBW) subjects during control and high-fat diets. DESIGN, SUBJECTS, AND MAIN OUTCOME MEASURES: Twenty young healthy men with LBW and 26 matched NBW controls were studied after 5 d high-fat overfeeding (+50% calories) and after a control diet in a randomized manner. Hyperinsulinemic-euglycemic clamps were performed and skeletal muscle biopsies excised. DNA methylation and gene expression were measured using bisulfite sequencing and quantitative real-time PCR, respectively.

RESULTS

When challenged with high-fat overfeeding, LBW subjects developed peripheral insulin resistance and reduced PPARGC1A and OXPHOS (P < 0.05) gene expression. PPARGC1A methylation was significantly higher in LBW subjects (P = 0.0002) during the control diet. However, PPARGC1A methylation increased in only NBW subjects after overfeeding in a reversible manner. DNA methylation of PPARGC1A did not correlate with mRNA expression.

CONCLUSIONS

LBW subjects developed peripheral insulin resistance and decreased gene expression of PPARGC1A and OXPHOS genes when challenged with fat overfeeding. The extent to which our finding of a constitutively increased DNA methylation in the PPARGC1A promoter in LBW subjects may contribute needs to be determined. We provide the first experimental support in humans that DNA methylation induced by overfeeding is reversible.

Expression of two Listeria monocytogenes antigens (P60 and LLO) in Lactococcus lactis and examination for use as live vaccine vectors

Listeria monocytogenes is a food-borne intracellular pathogen that mainly infects pregnant and immunocompromised individuals. The pore-forming haemolysin listeriolysin O (LLO), the main virulence factor of Listeria monocytogenes, allows bacteria to escape from the harsh environment of the phagosome to the cytoplasm of the infected cell. This leads to processing of bacterial antigens predominantly through the cytosolic MHC class I presentation pathway. We previously engineered the food-grade bacterium Lactococcus lactis to express LLO and demonstrated an LLO-specific CD8(+) response upon immunization of mice with the engineered L. lactis vaccine strains. In the present work, we examined the immune response and protective efficacy of an L. lactis strain co-expressing LLO and a truncated form of the listerial P60 antigen (tP60). Oral immunization revealed no significant protection against listeriosis with L. lactis expressing LLO, tP60 or the combined LLO/tP60. In contrast, intraperitoneal vaccination induced an LLO-specific CD8(+) immune response with LLO-expressing L. lactis but no significant improvement in protection was observed following vaccination with the combined LLO/tP60 expressing L. lactis strain. This may be due to the low level of tP60 expression in the LLO/tP60 strain. These results demonstrate the necessity for improved oral vaccination strategies using LLO-expressing L. lactis vaccine vectors.

Targeted nanoparticles that deliver a sustained, specific release of Paclitaxel to irradiated tumors

To capitalize on the response of tumor cells to XRT, we developed a controlled-release nanoparticle drug delivery system using a targeting peptide that recognizes a radiation-induced cell surface receptor. Phage display biopanning identified Gly-Ile-Arg-Leu-Arg-Gly (GIRLRG) as a peptide that selectively recognizes tumors responding to XRT. Membrane protein extracts of irradiated glioma cells identified glucose-regulated protein GRP78 as the receptor target for GIRLRG. Antibodies to GRP78 blocked the binding of GIRLRG in vitro and in vivo. Conjugation of GIRLRG to a sustained-release nanoparticle drug delivery system yielded increased paclitaxel concentration and apoptosis in irradiated breast carcinomas for up to 3 weeks. Compared with controls, a single administration of the GIRLRG-targeted nanoparticle drug delivery system to irradiated tumors delayed the in vivo tumor tripling time by 55 days (P = 0.0001) in MDA-MB-231 and 12 days in GL261 (P < 0.005). This targeting agent combines a novel recombinant peptide with a paclitaxel-encapsulating nanoparticle that specifically targets irradiated tumors, increasing apoptosis and tumor growth delay in a manner superior to known chemotherapy approaches.

Depletion of oxidative and endoplasmic reticulum stress regulators in Pick disease

Both oxidative and endoplasmic reticulum (ER) stress is associated with multiple neurodegenerative, age-related diseases. The rare disorder Pick disease (PiD) shares some pathological hallmarks of other neurodegenerative diseases that may be related to oxidative stress. Importantly, activation of an ER stress response, which is also involved in aging, has not yet been investigated in PiD. In this study, we assessed the implication of ER stress associated with oxidative stress in PiD as a potential mechanism involved in its pathogenesis. Samples from morphologically affected frontal cortex and apparently pathologically preserved occipital cortex showed region-dependent increases in different protein oxidative damage pathways. The oxidative modifications targeted antioxidant enzymes, proteases, heat shock proteins, and synaptic proteins. These effects were associated with compromised proteasomal function and ER stress in frontal cortex samples. In addition, we observed a depletion in ER chaperones (glucose-regulated proteins Grp78/BiP and glucose-regulated protein 94) and differences in tissue content and distribution of nuclear factor-erythroid 2 p45-related respiratory 2, required for cell survival during the unfolded protein response. These results demonstrate increased region-specific protein oxidative damage in PiD, with proteasomal alteration and dysfunctional ER stress response. We suggest this was caused by complete and specific depletion of Grp78/BiP, contributing to the pathophysiology of this neurodegenerative disease.

Alternating array of tyrosine hydroxylase and heat shock protein 25 immunopositive Purkinje cell stripes in zebrin II-defined transverse zone of the cerebellum of rolling mouse Nagoya

The present study examined the spatial organization of tyrosine hydroxylase (TH) immunopositive Purkinje cells in the cerebellum of rolling mouse Nagoya with reference to the distribution pattern of the cerebellar compartmentation antigen, heat shock protein 25 (HSP25). Whole-mount immunostaining revealed a striking pattern of parasagittal stripes of TH staining in the rolling mouse cerebellum but not in the control cerebellum. Although the TH stripes resembled the zebrin II stripes in the rolling cerebellum, these two distributions did not completely overlap. The TH stripes were present in the lobules VI and VII (central zone), the lobule X (nodular zone), and the paraflocculus, where zebrin II immunostaining was uniformly expressed. Double immunostaining revealed that TH stripes were aligned in an alternative fashion with HSP25 stripes within the caudal half of lobule VIb, lobules IXb and X, and paraflocculus. Some, but not all, TH stripes shared boundaries with HSP25 stripes. These results revealed an alternating array of TH immunopositive Purkinje cell subsets with HSP25 immunopositive Purkinje cells in the zebrin II-defined transverse zone of the rolling mouse cerebellum. The constitutive expression of HSP25 may prevent the ectopic expression of TH in zebrin II immunopositive Purkinje cell subsets.

Cr-(III)-organic compounds treatment causes genotoxicity and changes in DNA and protein level in Saccharomyces cerevisiae

Natural Cr-(III)-organic species are being known as the part of natural biogeochemical cycle of chromium, but unfortunately, their mechanism of toxicity as well as genotoxic potentiality is still unknown. To evaluate the characteristic toxic effect exerted by natural Cr-(III)-organic species on the cellular macromolecules, changes in DNA and protein level was observed. Besides, Comet assay was applied to measure genotoxic potentiality of Cr-(III)-organic species in the target organism Saccharomyces cerevisiae exposed to Cr-(III)-citrate and Cr-(III)-histidine. It has been observed that both of the Cr-(III)-organic compounds are responsible for diminution in macromolecules concentration. Cr-(III)-citrate showed ladder pattern of DNA fragmentation in support of apoptosis. Two new protein bands appeared in protein profile of the Saccharomyces cerevisiae treated with Cr-(III)-organic compounds. Thus it supports the possibility of the synthesis of stress proteins. Comet assay proved positive correlation between Cr-(III)-organic compounds' concentration and DNA damage. The Cr-(III)-citrate causes DNA damage at the concentrations ranging from 50 to 150 mg L(-1), whereas the DNA damaging capacity of Cr-(III)-histidine was found insignificant, except at highest concentration (150 mg L(-1)). These results can throw light on the mechanism of the toxic effect as well as genotoxicity exerted by natural Cr-(III)-organic species.

Hepatocyte growth factor (HGF), heat shock proteins (HSPs) and multidrug resistance protein (MRP) expression in co-culture of colon tumor spheroids with normal cells after incubation with interleukin-1beta (IL-1beta) and/or camptothecin (CPT-11)

Tumor chemoresistance and metastasis are some of the most important problems in colon cancer therapy. In the present study, co-cultures of human colon carcinoma cell spheroids, obtained from different grades of tumor, with human colon epithelium, myofibroblast and endothelial cell monolayers were performed. The purpose of these co-cultures was to reflect, in in vitro conditions, different stages of colon tumor development. In order to investigate the invasive capacities of the tumor cells and their resistance to chemotherapy, HGF, HSP27, HSP72 and MRP levels were analyzed after incubation of the co-cultures with IL-1beta and irinotecan (CPT-11) added as single agents or in combination. Myofibroblasts produced significantly higher amounts of HGF than epithelial cells. Tumor cells released trace amounts of this molecule. In cocultures, IL-1beta induced HGF release, while CPT-11 alone or combined with IL-1beta decreased HGF secretion. An immunoblotting analysis followed by densitometry revealed that the combination of IL-1beta plus CPT-11 added to the cocultures led to a decrease in HSPs and MRP levels. In conclusion, direct and paracrine interactions of colon tumor cell spheroids with normal cells and exogenously added CPT-11 change HSP27, HSP72 and MRP expression in comparison to monocultures. IL-1beta and CPT-11, dependent on whether they are added separately or jointly, differentially modulate HGF expression in monocultures of colon tumor spheroids or normal cells and their co-cultures.

Heat shock protein and heat shock factor expression in sperm: relation to oligozoospermia and varicocele

PURPOSE

Varicocele may be associated with normozoospermia or oligozoospermia. Much controversy still exists regarding the diagnosis, management and pathophysiology of spermatogenesis alterations associated with varicocele. The increased temperature induced by varicocele and stress in general may activate heat shock proteins and heat shock factors with a protective function in cells. We analyzed the expression of 5 heat shock proteins and heat shock factors in the sperm of men with normozoospermia and oligozoospermia with or without varicocele.

MATERIALS AND METHODS

We performed a prospective study between June 2008 and February 2009 at an academic clinic in 117 consecutive patients with varicocele and 68 controls without varicocele. Four groups were based on the presence/absence of varicocele and normozoospermia/oligozoospermia. Subjects were studied by history, physical examination, scrotal Doppler ultrasound, semen analysis, reproductive hormone plasma levels and quantitative real-time polymerase chain reaction in RNA extracted from ejaculated sperm to analyze HSP90, HSPA4, HSF1, HSF2 and HSFY expression.

RESULTS

Increased HSPA4, HSF1 and HSF2 were observed in the sperm of men with varicocele and in those with oligozoospermia. Levels were maximum when the 2 conditions were present. Increased HSP90 was observed in oligozoospermia cases independent of varicocele. HSFY was up-regulated only in patients with varicocele, especially those with normozoospermia.

CONCLUSIONS

To our knowledge we describe for the first time the expression of different heat shock proteins and heat shock factors in ejaculated sperm. While some of these proteins are up-regulated in men with oligozoospermia and varicocele, HSFY is up-regulated only in the presence of varicocele and especially in men with normozoospermia. This suggests that it may be a molecular marker of an adequate or inadequate response to the damaging effect of varicocele on spermatogenesis.

An RNA helicase, CrhR, regulates the low-temperature-inducible expression of heat-shock genes groES, groEL1 and groEL2 in Synechocystis sp. PCC 6803

The crhR gene for RNA helicase, CrhR, was one of the most highly induced genes when the cyanobacterium Synechocystis sp. PCC 6803 was exposed to a downward shift in ambient temperature. Although CrhR may be involved in the acclimatization of cyanobacterial cells to low-temperature environments, its functional role during the acclimatization is not known. In the present study, we mutated the crhR gene by replacement with a spectinomycin-resistance gene cassette. The resultant DeltacrhR mutant exhibited a phenotype of slow growth at low temperatures. DNA microarray analysis of the genome-wide expression of genes, and Northern and Western blotting analyses indicated that mutation of the crhR gene repressed the low-temperature-inducible expression of heat-shock genes groEL1 and groEL2, at the transcript and protein levels. The kinetics of the groESL co-transcript and the groEL2 transcript after addition of rifampicin suggested that CrhR stabilized these transcripts at an early phase, namely 5-60 min, during acclimatization to low temperatures, and enhanced the transcription of these genes at a later time, namely 3-5 h. Our results suggest that CrhR regulates the low-temperature-inducible expression of these heat-shock proteins, which, in turn, may be essential for acclimatization of Synechocystis cells to low temperatures.

[Prokaryotic expression of Listeria monocytogenes (LM) hly and development of monoclonal antibodies against listeriolysin O (LLO)]

In order to study the pathogenesis of Listeria monocytogenes (LM), we cloned listeriolysin gene into prokaryotic expression vector PET21a. The expression vector was transformed into Escherichia coli BL21 for expression of listeriolysin O (LLO). LLO-His tag fusion protein was purified with a Ni-NTA affinity column and was used as an immunogen to vaccinate BALB/C mice. Hybridomas were developed by fusing mouse myeloma cells Sp2/0 and splenocytes from the immunized mice and screened with purified LLO. Three hybridomas secreting antibodies against listeriolysin O were obtained and named anti-LLO1, anti-LLO2 and anti-LLO3, respectively. Western blotting analysis showed that all of them could specifically bind to the LLO secreted by the LM. The titers of anti-LLO monoclonal antibodies in the supernatants of three hybridomas cultures were 1:3.6 x 10(4), 1:6.4 x 10(4) and 1:1.6 x 10(4), respectively, and the titers of ascites from the hybridoma-injected mice were 1:2 x 10(7), 1:2 x 10(7) and 1:1 x 10(7), respectively, based on ELISA test. The isotypes of the monoclonal antibodies were determined to be IgG1. The dissociation constants (Kd) of these three monoclonal antibodies were determined to be 6.18 x 10(-11), 7.50 x 10(-11) and 6.27 x 10(-11) respectively. These data and reagents will be of great assistance to elucidate the pathogenesis of Listeriosis.

Arsenic trioxide induces apoptosis in NB-4, an acute promyelocytic leukemia cell line, through up-regulation of p73 via suppression of nuclear factor kappa B-mediated inhibition of p73 transcription and prevention of NF-kappaB-mediated induction of XIAP, cIAP2, BCL-XL and survivin

The purpose of the present study is to evaluate the effects of arsenic trioxide (ATO) on human acute promyelocytic leukemia NB-4 cells. Microculture tetrazolium test, bromodeoxyuridine (BrdU) cell proliferation assay, caspase 3 activity assay, cell-based nuclear factor kappa B (NF-kappaB) phosphorylation measurement by ELISA and real-time RT-PCR were employed to appraise the effects of ATO on metabolic activity, DNA synthesis, induction of programmed cell death and NF-kappaB activation. The suppressive effects of ATO on metabolic potential, cell proliferation and NF-kappaB activation were associated with induction of apoptosis in NB-4 cells. In addition, an expressive enhancement in mRNA levels of p73, cyclin-dependent kinase inhibitor 1A (p21), tumor protein 53-induced nuclear protein 1 (TP53INP1), WNK lysine deficient protein kinase 2 (WNK2) and lipocalin 2 coupled with a significant reduction in transcriptional levels of NF-kappaB inhibitor beta (IKK2), Nemo, BCL2-like 1 (BCL-X(L)), inhibitor of apoptosis protein 1 (cIAP2), X-linked inhibitor of apoptosis protein (XIAP), survivin, Bcl-2, TIP60, ataxia telangiectasia (ATM), SHP-2 and sirtuin (SIRT1) were observed. Altogether, these issues show for the first time that ATO treatment could trammel cell growth and proliferation as well as induces apoptosis in NB-4 cells through induction of transcriptional levels of p73, TP53INP1, WNK2, lipocalin 2 as well as suppression of NF-kappaB-mediated induction of BCL-X(L), cIAP2, XIAP and survivin. Furthermore, the inductionary effects of ATO on transcriptional stimulation of p73 might be through cramping the NF-kappaB module (through suppression of p65 phosphorylation as well as transcriptional hindering of IKK2, ATM and Nemo) along with diminishing the mRNA expression of TIP60, SHP-2 and SIRT1.

CAP2 enhances germination of transgenic tobacco seeds at high temperature and promotes heat stress tolerance in yeast

We reported earlier that ectopic expression of CAP2, a single AP2 domain containing transcription activator from chickpea (Cicer arietinum) in tobacco improves growth and development, and tolerance to dehydration and salt stress, of the transgenic plants. Here, we report that, in addition, the CAP2-transgenic tobacco seeds also exhibit higher germination efficiency at high temperature and show higher expression levels of genes for tobacco heat shock proteins and a heat shock factor. CAP2 was able to activate the 5'-upstream activating sequence of tobacco heat shock factor. Surprisingly, expression of CAP2 cDNA in Saccharomyces cerevisiae also enhanced heat tolerance, with increased expression of the gene for yeast heat shock factor 1 (Hsf1) and its target, the gene for yeast heat shock protein 104 (Hsp104). Sequence analysis of the Hsf1 promoter revealed the presence of a dehydration-responsive element/C-repeat-like element (DRE/CRE). Recombinant CAP2 protein bound to the DRE/CRE in the Hsf1 promoter in a gel shift assay and transactivated the Hsf1 promoter-His reporter construct. The full-length CAP2 protein was required to provide thermotolerance in yeast. If these findings are taken together, our results suggest that CAP2 is involved in the heat stress response and provides an example of functioning of a plant transcription factor in yeast, highlighting the strong evolutionary conservation of the stress response mechanism.

[Protective effects of L-carnitine upon testicular ischemia-reperfusion damage in rats]

OBJECTIVE

To investigate the protective effects of L-carnitine upon testicular ischemia-reperfusion injury in rats.

METHODS

Sprague-Dawley rats were divided into 3 groups (n = 10). In those animals undergoing unilateral testicular torsion, right testes were rotated 720 degrees for 2 h. Sham operated group served as a control group. Torsion group underwent 2 h torsion and saline was injected intraperitoneally at 30 min pre-detorsion. Treatment group underwent similar torsion but L-carnitine (500 mg/kg) was infused intraoperatively. The right testes of 5 animals in each group were excised after 4 h reperfusion for measuring the levels of malondialdehyde (MDA) and heat shock protein 70 (HSP70), evaluation of activities of antioxidant enzyme including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Histopathological changes and germ cell apoptosis indices (AI) were determined at 24 h post-detorsion in right testes of the remaining 5 animals in each group.

RESULTS

The mean number of apoptotic nuclei per tubule cross section and the malondialdehyde level were significantly lower in treatment group as compared with torsion group [AI( 6.87 +/- 2.47) vs (17.13 +/- 3.56), MDA (160 +/- 15) vs (199 +/- 15) nmol/g]. Activities of antioxidant enzyme and the level of HSP70 were significantly higher in treatment group than those in torsion group [SOD (1638 +/- 153) vs (1078 158) U/g, CAT (317 +/- 28) vs (188 +/- 33) U/g, GPx (667 +/- 94) vs (311 +/- 65) U/g, HSP70 (0.87 +/- 0.13) vs (0.25 +/- 0.04)]. The pathological damage of testes in the treatment group was lighter than that in the torsion group (all P < 0.05).

CONCLUSIONS

The administration of L-carnitine exerts a beneficial effect upon testicular ischemia-reperfusion injury. This effect may be achieved through an induced expression of HSP70.

Acrolein induces Hsp72 via both PKCδ/JNK and calcium signaling pathways in human umbilical vein endothelial cells

Acrolein is a highly electrophilic alpha,beta-unsaturated aldehydes to which humans are exposed in a variety of environment situations and is also a product of lipid peroxidation. Increased levels of unsaturated aldehydes play an important role in the pathogenesis of a number of human diseases such as Alzheimer's disease, atherosclerosis and diabetes. A number of studies have reported that acrolein evokes downstream signaling via an elevation in cellular oxidative stress. Here, we report that low concentrations of acrolein induce Hsp72 in human umbilical vein endothelial cells (HUVEC) and that both the PKCdelta/JNK pathway and calcium pathway were involved in the induction. The findings confirm that the production of reactive oxygen species (ROS) is not directly involved in the pathway. The induction of Hsp72 was not observed in other cells such as smooth muscle cells (SMC) or COS-1 cells. The results suggest that HUVEC have a unique defense system against cell damage by acrolein in which Hsp72 is induced via activation of both the PKCd/JNK and the calcium pathway.

Exposure to mercury reduces heat tolerance and heat hardening ability of the springtail Folsomia candida

We investigated the combined effects of mercury (HgCl(2)) and acute heat on survival of the springtail Folsomia candida. The springtails were exposed to a range of aqueous concentrations (0-48 mg Hg(2+)/L) of HgCl(2) for 24 h. Subsequently, the same individuals were exposed to a range of high temperatures, from 20 to 35.5 degrees C. We found a highly significant synergistic interaction between effects of mercury and heat, with a reduced tolerance to heat after exposure to sublethal concentrations of mercury. Further, the heat hardening ability of F. candida was studied at sublethal concentrations of mercury. F. candida was able to heat harden (exposure to a mild heat treatment increasing survival of subsequent severe heat); however, when the springtails experienced a previous exposure to as little as 1 mg Hg(2+)/L, heat hardening failed to improve survival of heat shock at 34.5 degrees C, even though this was much lower than concentrations affecting survival without heat stress. Mild heat stress is known to induce the heat shock protein, HSP70, and real-time quantitative PCR confirmed that pre-acclimation to 32 degrees C did indeed cause >5-fold up-regulation of HSP70 expression. This up-regulation was not affected by previous exposure to 1 mg Hg(2+)/L.

Heat shock protein 27 overexpression mitigates cytokine-induced islet apoptosis and streptozotocin-induced diabetes

Beta-cell apoptosis occurs in diabetes mellitus (DM). Heat shock protein (HSP) 27 (human homolog of rodent HSP25) mitigates stress-induced apoptosis but has not been studied in beta-cells. We tested whether HSP27 overexpression attenuates streptozotocin (SZ)-induced DM in vivo and cytokine-induced islet apoptosis in vitro. DM was ascertained by ip glucose tolerance testing, and fasting serum insulin/glucose was measured. Pancreas was stained for insulin, HSP27, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling, and insulin content was measured. HSP25/27 was measured by immunoblotting, isoelectric focusing, and RT-PCR. Islet HSP25/27 oligomerization and inhibitory kappaB protein kinase gamma (nuclear factor kappaB essential modulator) binding were assessed by coimmunoprecipitation. HSP27 transgene (TG) in pancreas localized predominantly in beta-cells. Baseline pancreatic insulin levels in wild-type (WT) and HSP27TG mice were similar, but lower in WT than HSP27TG after SZ (P < 0.01). Intraperitoneal glucose tolerance testing confirmed protection from SZ-DM in HSP27TG. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and inducible nitric oxide synthase staining were increased in WT vs. HSP27TG islets (P < 0.05) after SZ. Caspase-3 activity was lower in islets from HSP27TG vs. WT mice after cytokine stress in vitro (P < 0.05). There was more HSP25 plus 27 protein from HSP27TG islets than HSP25 from WT (P < 0.01). HSP25 protein but not mRNA was increased in HSP27TG mice. Isoelectric focusing showed similar relative HSP phosphorylation in HSP27TG and WT (P > 0.05). HSP27 bound native HSP25 in TG islets; both bound to inhibitory kappaB protein kinase gamma (nuclear factor kappaB essential modulator). These data show islet protection by HSP27 by mitigation of apoptosis, possibly through nuclear factor kappaB regulation.

Protective effect of geranylgeranylacetone via enhancement of HSPB8 induction in desmin-related cardiomyopathy

Background

An arg120gly (R120G) missense mutation in HSPB5 (α-β-crystallin ), which belongs to the small heat shock protein (HSP) family, causes desmin-related cardiomyopathy (DRM), a muscle disease that is characterized by the formation of inclusion bodies, which can contain pre-amyloid oligomer intermediates (amyloid oligomer). While we have shown that small HSPs can directly interrupt amyloid oligomer formation, the in vivo protective effects of the small HSPs on the development of DRM is still uncertain.

Methodology/Principal Findings

In order to extend the previous in vitro findings to in vivo, we used geranylgeranylacetone (GGA), a potent HSP inducer. Oral administration of GGA resulted not only in up-regulation of the expression level of HSPB8 and HSPB1 in the heart of HSPB5 R120G transgenic (R120G TG) mice, but also reduced amyloid oligomer levels and aggregates. Furthermore, R120G TG mice treated with GGA exhibited decreased heart size and less interstitial fibrosis, as well as improved cardiac function and survival compared to untreated R120G TG mice. To address possible mechanism(s) for these beneficial effects, cardiac-specific transgenic mice expressing HSPB8 were generated. Overexpression of HSPB8 led to a reduction in amyloid oligomer and aggregate formation, resulting in improved cardiac function and survival. Treatment with GGA as well as the overexpression of HSPB8 also inhibited cytochrome c release from mitochondria, activation of caspase-3 and TUNEL-positive cardiomyocyte death in the R120G TG mice.

Conclusions/Significance

Expression of small HSPs such as HSPB8 and HSPB1 by GGA may be a new therapeutic strategy for patients with DRM.

Bioactive pyridine-N-oxide disulfides from Allium stipitatum

From Allium stipitatum, three pyridine-N-oxide alkaloids (1-3) possessing disulfide functional groups were isolated. The structures of these natural products were elucidated by spectroscopic means as 2-(methyldithio)pyridine-N-oxide (1), 2-[(methylthiomethyl)dithio]pyridine-N-oxide (2), and 2,2'-dithio-bis-pyridine-N-oxide (3). The proposed structure of 1 was confirmed by synthetic S-methylthiolation of commercial 2-thiopyridine-N-oxide. Compounds 1 and 2 are new natural products, and 3 is reported for the first time from an Allium species. All compounds were evaluated for activity against fast-growing species of Mycobacterium, methicillin-resistant Staphylococcus aureus, and a multidrug-resistant (MDR) variants of S. aureus. Compounds 1 and 2 exhibited minimum inhibitory concentrations (MICs) of 0.5-8 microg/mL against these strains. A small series of analogues of 1 were synthesized in an attempt to optimize antibacterial activity, although the natural product had the most potent in vitro activity. In a whole-cell assay at 30 microg/mL, 1 was shown to give complete inhibition of the incorporation of (14)C-labeled acetate into soluble fatty acids, indicating that it is potentially an inhibitor of fatty acid biosynthesis. In a human cancer cell line antiproliferative assay, 1 and 2 displayed IC(50) values ranging from 0.3 to 1.8 microM with a selectivity index of 2.3 when compared to a human somatic cell line. Compound 1 was evaluated in a microarray analysis that indicated a similar mode of action to menadione and 8-quinolinol by interfering with the thioredoxin system and up-regulating the production of various heat shock proteins. This compound was also assessed in a mouse model for in vivo toxicity.

[Leukemic dendritic cells in patients with acute myeloid leukemia]

AIM

To determine surface and intracellular expression of ACE antigen and Bip shaperon on leukemic dendritic cells (LDC); to study expression of ACE genes and Bip, Calnexin, calreticulin shaperons in LDC at diagnosis of acute myeloid leukemia (AML) under standard and stress cultivation.

MATERIAL AND METHODS

Expression of ACE antigens and Bip was studied with immunophenotyping and flow cytometry using monoclonal antibodies to shaperon Bip and to CD143), expression of genes of ACE and shaperons Bip, Calnexin, Calreticulin--with polymerase chain reaction (RT-PCR). Dendritic cells (DC) were obtained by culturing of a monoclonal fraction of donor peripheral blood and AML patients in the presence of 180 ng/ml calcium ionophor A23187 (Sigma) for 4 days in parallel at 37 degrees C and 33 degrees C in the atmosphere of 5% CO2. The trial included 9 patients (5 males and 4 females) aged 39-53 years (median 43 years). The control group consisted of 8 healthy donors.

RESULTS

Lowering of cultivation temperature did not increase ACE expression. Intracellular shaperon Bip rose insignificantly (1.3-fold) in DC of the controls. ACE and Bip shaperon expression on LDC membrane increased 15- and 11-fold, respectively, while the level of intracellular ACE and Bip decreased 11- and 2-fold, respectively. Expression of the genes was investigated in cultivation temperature lowering from 37 to 33 degrees C and was presented as a logarithmic scale. Changes in expression of the genes Bip, Calnexin, Calreticulin in LDc and DC of the controls were insignificant. ACE expression in LDC significantly differed from ACE gene expression in DC (p = 0.05).

CONCLUSION

LCD and DC of healthy donors are cells which differ by genetic and functional characteristics. Therefore, LDC may response inadequately in development of antitumor immune response. The phenomenon of ACE antigen expression normalization on cell membrane in stress open new opportunities for regulating functional activity of LDC.

Estrogen receptor related beta is expressed in human endometrium throughout the normal menstrual cycle

BACKGROUND

Estrogen receptor related beta (ERRbeta, ESRRB/NR3B2) is an orphan receptor that shares significant sequence homology with estrogen receptors ERalpha and ERbeta. ERR family members are reported to exhibit constitutive transcriptional activity; however, little is known about the biological function of ERRbeta. In an attempt to delineate its role, we examined expression of ERRbeta in normal human endometrium, a tissue that undergoes cyclic remodelling under the influence of estrogen and progesterone.

METHODS

Well-characterized endometrial tissue (n = 31), including full-thickness biopsies, was obtained from women with regular menstrual cycles. RT-PCR was used to measure mRNA encoding ERRbeta, the peroxisome proliferator activated receptor gamma coactivators (PGC)-1alpha and beta and to determine whether ERRbeta splice variant mRNAs were expressed. ERRbeta was immunolocalized using both single and double antibody immunohistochemistry.

RESULTS

Total ERRbeta mRNA appeared higher in proliferative phase samples but results did not reach significance. Transcripts corresponding to the long- and short-splice variants of ERRbeta as well as PGC1alpha and beta were detected but ERRbetaDelta10 was absent. ERRbeta protein was localized to cell nuclei within multiple endometrial cell types including the glands, stroma, endothelium and immune cells, including uterine natural killer (uNK) cells and macrophages. Fluorescent immunohistochemistry revealed that some cells co-expressed ERRbeta and ERalpha or ERbeta, for example, endothelial and uNK cells were ERRbeta+/ERbeta+.

CONCLUSIONS

ERRbeta mRNA and protein are expressed in healthy human endometrium. Further studies are warranted to characterize the functional impact of ERRbeta on endometrial biology.

Contribution of IL-6 to the Hsp72, Hsp25, and alphaB-crystallin [corrected] responses to inflammation and exercise training in mouse skeletal and cardiac muscle

The heat shock proteins (Hsps) Hsp72, Hsp25, and alphaB-crystallin (alphaB C) [corrected]may protect tissues during exercise and/or inflammatory insults; however, no studies have investigated whether exercise training increases both basal and inflammation-induced expression of these Hsps in skeletal or cardiac muscle. IL-6 is produced by muscle during both exercise and inflammation and has been shown to modulate Hsp expression. These studies tested the hypothesis that voluntary wheel running (RW) increases basal and inflammation-induced Hsp72, Hsp25, and alphaB C [corrected] protein through an IL-6-dependent mechanism. We compared Hsp72, Hsp25, alphaB C, [corrected] and IL-6 protein levels 4 h after systemic inflammation induced by lipopolysaccharide (LPS) in skeletal and cardiac muscles of wild-type (IL-6(+/+)) and IL-6 deficient (IL-6(-/-)) mice after 2 wk of RW or normal cage activity (Sed). LPS significantly increased skeletal Hsp72 and Hsp25 relative to saline in Sed IL-6(+/+), but not IL-6(-/-) mice. LPS increased Hsp72 relative to saline in Sed IL-6(+/+) cardiac muscle. RW increased basal Hsp72, Hsp25, and alphaB C [corrected] in skeletal muscle in IL-6(+/+) and IL-6(-/-) mice. However, LPS was not associated with increases in any Hsp in RW IL-6(+/+) or IL-6(-/-) mice. LPS increased IL-6 protein in skeletal muscle and plasma in Sed and RW groups, with a significantly greater response in RW. The major results provide the first in vivo evidence that the absence of IL-6 is associated with reduced skeletal muscle Hsp72 and Hsp25 responses to LPS, but that IL-6 is not required for exercise-induced Hsp upregulation in skeletal or cardiac muscle.

[Effect of melafen on expression of Elip1 and Elip2 genes encoding chloroplast light-induced stress proteins in barley]

The effect of melafen, a plant growth regulator of a new generation, on the growth, pigment composition, and expression of nuclear genes Elip1 and Elip2 encoding chloroplast light-stress proteins in barley (Hordeum vulgare L) seedlings was studied. It is shown that the height of seedlings treated with melafen at concentrations of 0.5 x 10(-10) and 0.5 x 10(-8) M increased by approximately 10 and 20%, respectively, as compared to the control. At high concentrations (10(-5) and 10(-3) M), melafen had no effect on the growth of seedlings. The content of chlorophylls and carotenoids in chloroplasts barely differed from the control at all melafen concentrations tested. Reverse transcription-polymerase chain reaction (RT-PCR) showed that melafen did not influence the expression of the nuclear gene encoding the low-molecular-weight plastid stress protein ELIP1. At the same time, the expression of the nuclear gene encoding the high-molecular-weight light-inducible stress protein ELIP2 in the plants treated with melafen at a concentration of 0.5 x 10(-8) M, increased by approximately 70 %. At higher concentrations, melafen suppressed the Elip2 gene expression. Thus, melafen affects the expression of the Elip2 gene, which is involved in the regulation of chlorophyll synthesis and chloroplast biogenesis, which, in turn, may lead to changes in the resistance of plants to light-induced stress.