Presence of Antibodies to Heat Stress Proteins and its Possible Significance in Workers Exposed to High Temperature and Carbon Monoxide

Antibodies to the ubiquitous group of stress proteins known as heat shock proteins (Hsps) have been found to be associated with a number of diseases in humans. Hsps are known to be induced by certain xenobiotics, some of which are common in the working environment. The biological significance of the presence of such autoantibodies is presently unclear. In the present study, we used immunoblotting to investigate the presence of antibodies against the different stress proteins, Hsp27, Hsp60, Hsp71, Hse (heat shock cognate ) 73 and Hsp89a and D in groups of workers exposed to high temperature or carbon monoxide. These data were related to a detailed clinical evaluation and to various laboratory measurements including electrocardiogram (ECG), B echogram, white blood cell counts and typing, the activity of alanine aminotransferase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) and lymphocyte DNA damage. Antibodies to Hsp27 and Hsp71 were found more frequently in the high temperature and carbon monoxide-exposed groups than in controls (P (0.05 ). The carbon monoxide-exposed group showed the highest incidence of anti-Hsp antibodies. Anti-Hsp60 antibodies were only detected in workers exposed to high temperature or carbon monoxide. The percentage of workers with abnormal ECG, B echogram changes and displaying hepatitis B antigen (HBsAg ) was higher in the carbon monoxide group than in the control group (P＜0.05 ).There was a significant inerease in the activity of ALT in the high temperature and carbon monoxide groups and in the activities of ACP and ALP in the carbon monoxide group (P＜0.05 ). The extent of DNA damage measured in lymphoeytes was higher in workers from the high temperature and carbon monoxide-cxposed groups. We suggest that the increased frequeney of antibodies to Hsps is the result of these damages, of the release of denatured Hsps and of a decrease in the phagocytic ability of macrophages in these workers. The data gathered in the present study show a statistical relation between the occurrence of antibodies against Hsps and the frequency of health problems in workers and suggest a potential role for the antibodies as useful biomarkers to assess whether workers are experieneing environmental stress

Expression of Heat Stress Protein 70 mRNA in Patients with Chronic Obstructive Pulmonary Disease and Its Significance

The effects of cigarette smoke extract (CSE) on the expression of heat stress protein 70 (Hsp70) in human bronchi smooth muscle cells were investigated in vitro, and the changes in Hsp70 mRNA in the patients with chronic obstructive pulmonary disease and their significance were explored. Human bronchi smooth muscle cells were cultured with CSE at the different concentrations. The expression of Hsp70 mRNA and Hsp70 was detected by reverse translation-polymerase chain reaction (RT-PCR) and Western blotting respectively. Levels of Hsp70 mRNA and Hsp70 in lymphocytes from 20 patients with COPD and 20 healthy smoking control subjects were measured by RT-PCR and Western blotting. The results showed the expression of both Hsp70 mRNA and Hsp70 was decreased conformably in human bronchi smooth muscle cells treated with CSE at certain concentration in vitro. The A values of the Hsp70 mRNA expression were 0.24±0.11 and 0.42±0.13 respectively in COPD patients and healthy smoking controls with the difference being significant (P<0.01). There was also significant difference in the A values of the Hsp70 expression between COPD patients and healthy smoking controls (20.9±9.9 vs 44.8±15.3, P<0.01). The levels of Hsp70 mRNA had strongly positive correlation with Hsp70 protein (r = 0.85, P<0 01). It was suggested that the expression of Hsp70 mRNA was in concordance with the expression of Hsp70, which could provide a basis on the study of Hsp70 gene regulation and Hsp70 gene in the development of COPD.

Chronic neuroprotective effects of low concentration lithium on SH-SY5Y cells:possible involvement of stress proteins and gene expression

To investigate the molecular mechanism underlying the neuroprotective effect of lithium on cells, in this study, we exposed SH-SY5Y cells to 0.5 mmol/L lithium carbonate （Li2CO2） for 25-50 weeks and then detected the expression levels of some neurobiology related genes and post-translational modifications of stress proteins in SH-SYSY cells, cDNA arrays showed that pyruvate kinase 2 （PKM2） and calmodulin 3 （CaM 3） expression levels were significantly down-regulated, phosphatase protein PP2A expression was lightly down-regulated, and casein kinase II （CK2）, threonine/tyrosine phosphatase 7 （PYST2）, and dopamine beta-hydroxylase （DBH） expression levels were significantly up-regulated. Besides, western blot analysis of stress proteins （HSP27, HSP70, GRP78 and GRP94） showed an over-expression of two proteins： a 105 kDa protein which is a hyper-phosphorylated isoform of GRP94, and a 108 kDa protein which is a phosphorylated tetramer of HSP27. These results suggest that the neuroprotective effects of lithium are likely related to gene expressions and post-translational modifications of proteins cited above.

Detection and Its Implication of Heat Stress Protein 27 and P21 in Nasopharyngeal Carcinoma

To study the expression of heat stress protein 27 (HSP27) and P21 in nasopharyngeal car- cinoma (NPC) tissue, and to evaluate the significance of both HSP27 and P21 in the pathogenesis, development and prognosis of NPC. Indirect immunofluorescence method combined with SABC was applied. Our results showed that (1) the positive rates of HSP27 and P21 expressed in NPC tissue in 36 cases were 88. 9 % and 94. 4%; (2) while in 10 hyperplastic nasopharyngitis tissues, the positive rate of HSP27 and P21 were both 5; (3) all the 5 normal tissues were negatively stained. It is obvi- ous that a co-expressing tendency of HSP27 and P21 could be identified, and it was associated with the degree of malignancy and the clinical stage of NPC. It is concluded that the positive expression of HSP27 and P21 may have clinical significance in the evaluation of the occurring, development and prognosis of NPC, and in NPC treatment.

Effects of realgar on stress proteins, inflammatory mediators, and complement in brain tissue and serum of rats with inflammatory brain injury

BACKGROUND：The Chinese herbal compound realgar exerts detoxification effects as an adjuvant. It is suggested that realgar exerts detoxification via the following pathways： in the pathological state, realgar corrects the oxidative stress state by increasing stress levels, activating some endogenous protective factors and antagonizing the excessive release of inflammatory factors, as well as inhibiting complement activation. OBJECTIVE： To observe the changes in stress proteins, inflammatory mediators, and complement in the brain tissue and serum of rats with inflammatory brain injury, which have been treated with the Chinese herbal compound Angong Niuhuang, and to compare the efficacy of Angong Niuhuang with that of realgar, to verify the mechanism of action of realgar. DESIGN, TIME AND SETTING： Randomized, controlled, cytological experiment, performed in the Institute of Clinical Pharmacology, Guangzhou University of Traditional Chinese Medicine in March 2006. MATERIALS： Thirty-six healthy, male, Sprague Dawley rats received 250 U/kg Bordetella pertussis via the common carotid artery within 15 seconds to induce inflammatory brain injury. Reagents and kits were as follows： Realgar and Angong Niuhuang powder （Foshan Second Pharmaceutical Factory, China）, Bordetella pertussis diagnostic antigen （National Institute for the Control of Pharmaceutical and Biological Products, China）, heat shock protein 70 （HSP70） enzyme-labeled immunosorbent assay （ELISA） kit （Stressgen, USA）, tumor necrosis factor-α （TNF-α） ELISA kit （Biosource, USA）, nitric oxide synthase （NOS） kit, Coomassie brilliant blue protein kit （Nanjing Jiancheng Bioengineering Co.,Ltd., China）, and complements C3 and C4 （Shanghai Kehua Dongling Diagnositic Products Co.,Ltd., China）. METHODS： Thirty-six rats were randomly and evenly divided into the following six groups： normal control, model, high-, middle-, and low-dose realgar-treated, and Angong Niuhuang-treated groups. At one hour prior to establishing the model, rats in the high-, middle-, and low-dose realgar-treated groups were administered 300, 150, and 75 mg/kg realgar, respectively; while rats in the Angong Niuhuang group received 1.5 g/kg Angong Niuhuang powder; In the model group, rats were administered Bordetalla pertussis only. MAIN OUTCOME MEASURES： Two hours after the administration of Bordetalla pertussis, the HSP70 level in the brain tissue and serum levels of interleukin-1β （IL-1β）, interleukin-6 （IL-6）, and TNF-α were determined by ELISA tests, hemooxygenase-1 （HO-1） activity in the brain tissue and serum was determined by dual-wavelength spectrophotometry, NOS and inducible nitric oxide synthase （iNOS） activities in the brain tissue were measured by the Bradford assay method, and serum levels of complement C3 and C4 were determined by immunoturbidimetry. RESULTS： In the high-dose realgar and Angong Niuhuang groups, the HSP70 level in the brain tissue of rats with inflammatory brain injury was increased significantly （P 〈 0.01）. In the realgar-treated groups, HO-1 activity in the brain tissue and serum was dose-dependently enhanced with increasing realgar doses. However, no significant difference existed between the realgar groups and the model group （P 〉 0.05）. In the Angong Niuhuang group, HO-1 activity in the brain tissue and serum was increased （P 〈 0.05）. In the realgar and Angong Niuhuang groups, serum levels of IL-1β, IL-6, and TNF-α were significantly decreased; the serum IL-1β level recovered to the normal level and serum levels of IL-6 and TNF-α dose-dependently decreased in the realgar groups. NOS activity in the brain tissue was lower in the high-dose realgar group than in the model group （P 〈 0.05）. iNOS activity was significantly lower in the middle- and high-dose realgar groups than in the model group （P 〈 0.01）. NOS and iNOS activities were significantly lower in the Angong Niuhuang group than in the model group （P 〈 0.01）. The serum C3 level was significantly decreased in the middle-dose realgar and Angong Niuhuang groups （P 〈 0.01）. CONCLUSION： At certain doses, realgar is able to correct the oxidative stress state, by inducing and activating endogenous protective factors, such as HSP70, and inhibiting the excessive release of inflammatory mediators, such as IL-1β, IL-6, and TNF-α. However, it remains unclear whether realgarinhibits the activation of C3 and C4.

Preliminary Studies on the Relationship betweenAutoantibodies to Heat Stress Proteins and Heat Injury of Pilots during Acute Heat Stress

Comparison in the heart rate, oral temperature and lymphocyte DNAdamage during heat stress was made in pilots with negative antibodies to heatstress proteins (HSPs) and those with positive antibodies in the man-made climate room with Western blot and comet assay. Our results showed that the increase in oral temperature, heart rate and lymphocyte DNA damage in pilots with the posi-tive antibodies to HSPs were higher than those in pilots with the negative antibod-ies during heat stress. These results indicated that the presence of autoantibodies in plasma of pilots might reflect heat damage and high sensitivity to heat.

Stress protein expression in early phase spinal cord ischemia/reperfusion injury

Spinal cord ischemia/reperfusion injury is a stress injury to the spinal cord. Our previous studies using differential proteomics identified 21 differentially expressed proteins （n 〉 2） in rabbits with spinal cord ischemia/reperfusion injury. Of these proteins, stress-related proteins included protein disulfide isomerase A3, stress-induced-phosphoprotein 1 and heat shock cognate protein 70. In this study, we established New Zealand rabbit models of spinal cord ischemia/reperfusion injury by abdominal aorta occlusion. Results demonstrated that hind limb function initially improved after spinal cord ischemia/reperfusion injury, but then deteriorated. The pathological morphology of the spinal cord became aggravated, but lessened 24 hours after reperfusion. However, the numbers of motor neurons and interneurons in the spinal cord gradually decreased. The expression of protein disulfide isomerase A3, stress-induced-phosphoprotein 1 and heat shock cognate protein 70 was induced by ischemia/reperfusion injury. The expression of these proteins increased within 12 hours after reperfusion, and then decreased, reached a minimum at 24 hours, but subsequently increased again to similar levels seen at 6-12 hours, showing a characterization of induction-inhibition-induc- tion. These three proteins were expressed only in cytoplasm but not in the nuclei. Moreover, the expression was higher in interneurons than in motor neurons, and the survival rate of interneurons was greater than that of motor neurons. It is assumed that the expression of stress-related proteins exhibited a protective effect on neurons.

Antagonistic Effects of N-acetylcysteine on Mitogen-activated Protein Kinase Pathway Activation, Oxidative Stress and Inflammatory Responses in Rats with PM2.5 Induced Lung Injuries

Objective To evaluate the antagonistic effects of N-acetylcysteine(NAC)on mitogen-activated protein kinases(MAPK)pathway activation,oxidative stress and inflammatory responses in rats with lung injury induced by fine particulate matter(PM2.5).Methods Forty eight male Wistar rats were randomly divided into six groups:blank control group(C1),water drip control group(C2),PM2.5 exposed group(P),low-dose NAC treated and PM2.5 exposed group(L),middle-dose NAC treated and PM2.5 exposed group(M),and high-dose NAC treated and PM2.5 exposed group(H).PM2.5 suspension(7.5 mg/kg)was administered tracheally once a week for four times.NAC of 125 mg/kg,250 mg/kg and 500 mg/kg was delivered intragastrically to L,M and H group respectively by gavage(10 ml/kg)for six days before PM2.5 exposure.The histopathological changes and human mucin 5 subtype AC(MUC5AC)content in lung tissue of rats were evaluated.We investigated IL-6 in serum and bronchoalveolar lavage fluid(BALF)by Enzyme-linked immunosorbent assay(ELISA),MUC5AC in lung tissue homogenate by ELISA,glutathione peroxidase(GSH-PX)in serum and BALF by spectrophotometry,and the expression of p-ERK1/2,p-JNK1/2 and p-p38 proteins by Western blot.All the measurements were analyzed and compared statistically.Results Lung tissue of rats exposed to PM2.5 showed histological destruction and increased mucus secretion of bronchial epithelial cells.Rats receiving NAC treatment showed less histological destruction and mucus secretion.Of P,L,M and H group,MUC5AC in lung tissue,IL-6 in serum and BALF were higher than controls(C1 and C2)(all P<0.05),with the highest levels found in the P group and a decreasing trend with increase of NAC dose.The activity of GSH-PX in serum and BALF of PM2.5 exposed rats(P,L,M and H)was lower than that of controls(all P<0.05),with higher activities found in NAC treated rats(L,M,and H),and an increasing trend with increase of NAC dose.The expressions of p-ERK1/2,p-JNK1/2 and p-p38 proteins in PM2.5 exposed lung tissue(P,L,M and H)was higher than controls(all P<0.05),with decreased levels and dose dependent downregulation found in NAC treated rats.Conclusion NAC can antagonize major MAPK pathway activation,lung oxidative stress and inflammatory injury induced by PM2.5 in rats.

Role of endoplasmic reticulum stress protein C / EBP homologous protein-10 in ischemia and hypoxia induced human aortic endothelial cells injury

Objective To investigate the expression of endoplasmic reticulum stress(ESR)marker C/EBP homologous protein-10(CHOP-10)in the human aortic endothelial cells(HAEC)under the ischemia and hypoxia stress and to study the effects of atorvastatin on the process.Methods The cultured HAEC were divided into normal control group,ischemia/hypoxia model group。

Relationship Between Soluble Protein,Chlorophyll and ATP in Drought-Resistant Sweet Potato Under Water Stress

Some indices concerning the metabolism of substance and energy in sweet potato leaves under water stress were studied. The results showed an obvious increase in soluble protein content. Compared with control, Chl a, Chl b, total Chl contents and the ratio of Chl a to Chl b all decreased to some extent. ATP content increased in some varieties and decreased in others, but the stronger the drought resistance of the variety , the higher the ATP content. The correlation coefficient(r)of the soluble protein content, ratio of Chl a to Chl b and ATP content as a percentage of the drought-resistant sweet potato control variety are 0. 8968, - 0. 8509 and 0. 8200, respectively, P<0. 01. So these indices can be used to evaluate the drought resistance of different sweet potato varieties.

Hypoxia-induced Stress Proteins in Heart of Rats

Stress proteins are synthesized in all organisms from bacteria, plants, animals and humans, even in incubated cells and tissues by induction of environmental stress. This protein was first observed in the chromosomes of fruit fly in response to unlethal hyperthermia, so it is also called'heat shock protein'（Hsp）. Except for heat shock, the stress or heat shock proteins can also be induced by exposure to environmental stress, such as cold injury, chemicals such as alcohol, Cd2+ and other heavy metal, amino acid analogues

Effects of Heavy Metal Stress on the Protein Content of Microorganisms

[Objective] The aim was to study the effects of heavy metal stress on the protein content of microorganisms.[Method] By using traditional microbiological culture method,four typical microorganisms(including Escherichia coli,Bacillus subtilis,Saccharomyces cerevisiae Hansen and Streptomycetaceae) were cultured under the stress of heavy metal ions(like Hg2+,Cd2+,Cr6+ and Pb2+) with different concentrations,and the effects of heavy metal stress on the synthesis of protein in four typical microorganisms were discussed through measuring protein content.[Result] Heavy metals with low concentration were beneficial to the synthesis of protein in four typical microorganisms to a certain extent,but the synthesis of protein in four typical microorganisms was inhibited differently with the increase of heavy metal concentration.The tolerance of B.subtilis to four heavy metals was stronger compared with other three microorganisms,and the four heavy metals with concentration of 5-50 mg/L promoted the protein synthesis of B.subtilis.Cr6+ with low concentration promoted the protein synthesis of E.coli greatly;Pb2+ inhibited the protein synthesis of E.coli obviously,and promoted the protein synthesis of other three microorganisms under certain concentration;Cd2+ with low concentration was beneficial to the protein synthesis of four microorganisms.[Conclusion] The study could provide theoretical foundation for discussing the physiological response of microorganism to heavy metal stress.

Water Stress Effects on Leaf Growth and Chlorophyll Content but Not the Grain Yield in Traditional Rice (<i>Oryza sativa</i>Linn.) Genotypes of Assam, India II. Protein and Proline Status in Seedlings under PEG Induced Water Stress

Abiotic stresses can directly or indirectly affect the physiological status of an organism by altering its metabolism, growth, and development. The leaf growth and Chlorophyll content has significantly shown to vary from the control ones while the grain yield was not affected. While many plant species naturally accumulate proline and protein as major organic osmolytes when subjected to different abiotic stresses. These compounds are thought to play adaptive roles in mediating osmotic adjustment and protecting sub cellular structures in stressed plants. Different approaches have been contemplated to increase the concentrations of proline like compounds in plants grown under stress conditions to increase their stress tolerance. Seven different traditional rice varieties of Assam were evaluated for their response to osmolyte production under physiological drought condition through simulation at three levels of osmotic stress of 0.15 bar, 0.25 bar and 0.56 bar of physiological drought initiated by polyethylene glycol (PEG 6000). Along with the evaluation for osmolyte response the different components of genotypic variation for six different drought-sustaining characters in the seven rice varieties were also substantiated. The results indicated that plant height and seed number have significant genotypic coefficient of variability (GCV) and heritability. Verities like Laodubi, Leserihali, Beriabhanga and Borah were screened out as the best drought sustaining variety.

Uncoupling protein 2 in the glial response to stress:implications for neuroprotection

Reactive oxygen species（ROS） are free radicals thought to mediate the neurotoxic effects of several neurodegenerative disorders.In the central nervous system,ROS can also trigger a phenotypic switch in both astrocytes and microglia that further aggravates neurodegeneration,termed reactive gliosis.Negative regulators of ROS,such as mitochondrial uncoupling protein 2（UCP2） are neuroprotective factors that decrease neuron loss in models of stroke,epilepsy,and parkinsonism.However,it is unclear whether UCP2 acts purely to prevent ROS production,or also to prevent gliosis.In this review article,we discuss published evidence supporting the hypothesis that UCP2 is a neuroprotective factor both through its direct effects in decreasing mitochondrial ROS and through its effects in astrocytes and microglia.A major effect of UCP2 activation in glia is a change in the spectrum of secreted cytokines towards a more anti-inflammatory spectrum.There are multiple mechanisms that can control the level or activity of UCP2,including a variety of metabolites and micro RNAs.Understanding these mechanisms will be key to exploitingthe protective effects of UCP2 in therapies for multiple neurodegenerative conditions.

Protein Profiles and Dehydrin Accumulation in Some Soybean Varieties (<i>Glycine max</i>L. Merr) in Drought Stress Conditions

Drought is one of environmental stresses which the most limiting to plant growth and productivity. Drought stress led to a series of changes including biochemical changes like accumulation of osmolit and specific proteins involved in stress tolerance. One of the proteins that play a role in the mechanism of drought resistance is dehydrin protein. This study aimed to identify the protein profiles and dehydrin accumulation in 7 varieties of local Indonesian soybeans: Tanggamus, Nanti, Seulawah and Tidar (tolerant), Wilis and Burangrang (moderate) and Detam-1 (drought stress sensitive). Plants were treated with drought stress by adjusting soil water content to 25% below field capacity and compared with plants which were grown on normal condition as control plants. The results of SDS-PAGE electrophoresis showed a new protein with the molecular weight of 13 and 52 kDa were induced in Tanggamus, Nanti, Seulawah and Tidar varieties. Western blotting analysis for dehydrin showed that the quantity of the protein in the leaves of all varieties except Tanggamus decreased in drought stress conditions. The quantity of dehydrin protein in tolerant varieties higher than the protein quantity in both moderate varieties and drought sensitive.

Prostaglandin E1 protects hepatocytes against endoplasmic reticulum stress-induced apoptosis via protein kinase A-dependent induction of glucose-regulated protein 78 expression

AIM To investigate the protective effect of prostaglandin E1(PGE1) against endoplasmic reticulum(ER) stressinduced hepatocyte apoptosis, and to explore its underlying mechanisms.METHODS Thapsigargin(TG) was used to induce ER stress in the human hepatic cell line L02 and hepatocarcinomaderived cell line Hep G2. To evaluate the effects of PGE1 on TG-induced apoptosis, PGE1 was used an hour prior to TG treatment. Activation of unfolded protein response signaling pathways were detected by western blotting and quantitative real-time RTPCR. Apoptotic index and cell viability of L02 cells and Hep G2 cells were determined with flow cytometry and MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 H-tetrazolium] assay. RESULTS Pretreatment with 1 μmol/L PGE1 protected against TG-induced apoptosis in both L02 cells and Hep G2 cells. PGE1 enhanced the TG-induced expression of C/EBP homologous protein(CHOP), glucose-regulated protein(GRP) 78 and spliced X box-binding protein 1 at 6 h. However, it attenuated their expressions after 24 h. PGE1 alone induced protein and m RNA expressions of GRP78; PGE1 also induced protein expression of DNA damage-inducible gene 34 and inhibited the expressions of phospho-PKR-like ER kinase, phosphoeukaryotic initiation factor 2α and CHOP. Treatment with protein kinase A(PKA)-inhibitor H89 or KT5720 blocked PGE1-induced up-regulation of GRP78. Further, the cytoprotective effect of PGE1 on hepatocytes was not observed after blockade of GRP78 expression by H89 or small interfering RNA specifically targeted against human GRP78.CONCLUSION Our study demonstrates that PGE1 protects against ER stress-induced hepatocyte apoptosis via PKA pathwaydependent induction of GRP78 expression.

Chronic stress causes protein kinase C epsilon-aldehyde dehydrogenase 2 signaling pathway perturbation in the rat hippocampus and prefrontal cortex,but not in the myocardium

Chronic stress is strongly associated with the occurrence and development of depression and cardiovascular disease.Stress can induce altered mitochondrial function and activation of apoptosis in the cardio-cerebral system.However,it is unknown whether the protein kinase C ε（PKCε）-aldehyde dehydrogenase 2（ALDH2） pathway is altered under chronic stress,and this study sought to address this question.A rat model of depression was established using a chronic unpredictable mild stress（CUMS） protocol.After experiencing CUMS for 4 weeks,the sucrose preference test and the forced swim test verified depressive-like behaviors.Enzyme linked immunosorbent assays showed that ALDH2 activity was decreased in the rat hippocampus and prefrontal cortex,but was not altered in the myocardium.Western blot assays demonstrated reduced levels of ALDH2 and PKCε,but increased levels of 4-hydroxy-2-nonenal（4 HNE） adducts.Caspase-3 expression did not obviously alter,but active forms of caspase-3 were increased in the hippocampus and prefrontal cortex.In the myocardium,expression of ALDH2,PKCε and 4 HNE adducts did not remarkably alter;while caspase-3 expression was reduced and the active forms of caspase-3 were upregulated.Pearson＇s correlation test demonstrated that expression of 4 HNE adducts was positively correlated with levels of the active forms of caspase-3 in the hippocampus and prefrontal cortex,but not in the myocardium.In conclusion,chronic stress can damage the PKCε-ALDH2 signaling pathway in the hippocampus and prefrontal cortex,but not in the myocardium.Moreover,4 HNE is associated with active forms of caspase-3 in the hippocampus and prefrontal cortex.

Enriched environment upregulates growth-associated protein 43 expression in the hippocampus and enhances cognitive abilities in prenatally stressed rat offspring

In our previous study, we reported that prenatal restraint stress could induce cognitive deficits, which correlated with a change in expression of growth-associated protein 43 in the hippocampus. In this study, we investigated the effects of enriched environment on cognitive abilities in prenatally stressed rat offspring, as well as the underlying mechanisms. Reverse transcription-PCR and western blot assay results revealed that growth-associated protein 43 mRNA and protein levels were upregulated on postnatal day 15 in the prenatal restraint stress group. Growth-associated protein 43 expression was significantly lower in the prenatal restraint stress group compared with the negative control and prenatal restraint stress plus enriched environment groups on postnatal days 30 and 50. Morris water maze test demonstrated that cognitive abilities were noticeably increased in rats from the prenatal restraint stress plus enriched environment group on postnatal day 50. These results indicate that enriched environment can improve the spatial learning and memory ability of prenatally stressed offspring by upregulating growth-associated protein 43 expression.

Hippocampal activation of c-Jun N-terminal kinase,protein kinase B,and p38 mitogen-activated protein kinase in a chronic stress rat model of depression

Recent studies have shown that varied stress stimuli activate c-Jun N-terminal kinase （JNK）, protein kinase B （Akt）, and p38 mitogen-activated protein kinase （p38） signal transduction pathway, and also regulate various apoptotic cascades. JNK and p38 promote apoptosis, but Akt protects against apoptosis, in hippocampal neurons. However, changes in the transduction pathway in different regions of brain tissues in a chronic stress rat model of depression remain poorly understood. Results from this study showed that JNK phosphorylation levels were significantly greater in the stress group hippocampus compared with the control group （P 〈 0.05）. No significant difference in JNK phosphorylation levels was detected in the rat cerebral cortex between stress and control groups, and no significant difference in Akt and p38 phosphorylation levels was detected in the rat hippocampus and cerebral cortex between stress and control groups （P 〉 0.05）. These results suggested that the JNK signal pathway is activated by JNK phosphorylation and participates in pathophysiological changes in rat models of depression.

Accumulation characteristic of protein bodies in different regions of wheat endosperm under drought stress

The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar （XM33） and soft wheat cultivar （NM13） under drought stress were investigated. Drought stress treatment was implemented from plant regreening to the caryopsis mature stage. Microscope images of endosperm cells were obtained using resin semi- thin slice technology to observe the distribution and relative area of protein body （PB）. Compared with NM13, relative PB area of XM33 was significantly higher in sub-aleurone endosperm region. The amount of accumulation, including the size and relative area of PB, in two wheat cultivars was higher in sub-aleurone region than that in central region at 18 days post anthesis （DPA）. Drought stress significantly enhanced the sizes and relative areas of PBs in the dorsal and abdominal endosperms in two wheat cultivars. Particularly for dorsal endosperm, drought stress enhanced the relative PB area at 18 DPA and NM13 （5.0% vs. 6.73%） showed less enhancement than XM33 （5.49% vs. 8.96%）. However, NM13 （9.58% vs. 12.02%） showed greater enhancement than XM33 （10.25% vs. 11.7%） at 28 DPA. The protein content in the dorsal and abdominal endosperms of the two wheat cultivars decreased at 12 DPA and then increased until 38 DPA. Drought stress significantly increased the protein contents in the two main regions. From 12 to 38 DPA, the amount of PB accumulation and the protein content were higher in XM33 than those in NM13. The results revealed that PB distribution varied in different endosperm tissues and that the amount of PB accumulation was remarkably augmented by drought stress.