Different expression of placental pyruvate kinase in normal, preeclamptic and intrauterine growth restriction pregnancies

INTRODUCTION

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are two diseases that affect pregnant women and their unborn children. These diseases cause low birth weight, pre-term delivery, and neurological and cardiovascular disorders in babies. Combined they account for 20% of preterm deliveries. Pyruvate kinase M2 (PKM2) is a metabolism enzyme found in developing embryonic and cancer tissues. Our objective is to determine the expression of PKM2 in human PE and IUGR compared to normal pregnancies. Understanding expression of PKM2 in PE and IUGR could help us to better understand the mechanisms and find treatments for PE and IUGR.

METHODS

Human placental tissues were obtained for PKM2 determination and analyzed by immunohistochemistry, Western blot, and a pyruvate assay. Placental samples were homogenized and cytoplasmic and nuclear proteins were extracted for Western blot analysis.

RESULTS

Preeclampsia samples had elevated levels of p-PKM2, p-ERK, and ERK in the cytoplasm. Beta-catenin and lactose dehydrogenase (LDH) were also elevated in preeclampsia placenta samples.

DISCUSSION AND CONCLUSION

We conclude that PKM2 is expressed in normal, PE and IUGR pregnancies. Also, that this expression is increased in the PE placenta at delivery. These results suggest placental metabolism through PKM2 could play a role in human preeclampsia.

Etanercept attenuates myocardial ischemia/reperfusion injury by decreasing inflammation and oxidative stress

The protective role of etanercept in myocardial ischemia/reperfusion is not well understood. The aim of this study was to investigate whether etanercept modulates neutrophil accumulation, TNF-α induction and oxidative stress in an ischemia/reperfusion injured rat heart model. Rats were randomly exposed to sham operation, myocardial ischemia/reperfusion (MI/R) alone, MI/R+ etanercept. The results demonstrated that compared to MI/R, etanercept reduced myocardial infarction area, myocardial myeloperoxidase (MPO) levels, serum creatinine kinase (CK) and lactate dehydrogenase (LDH) levels, and both serum and myocardial TNF-α production. Etanercept also markedly enhanced the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), and reduced the level of malondialdehyde (MDA) in MI/R rats. In summary, our data suggested that etanercept has protective effects against MI/R injury in rats, which may be attributed to attenuating inflammation and oxidative stress.

Hypothermia protects human neurons

BACKGROUND AND AIMS

Hypothermia provides neuroprotection after cardiac arrest, hypoxic-ischemic encephalopathy, and in animal models of ischemic stroke. However, as drug development for stroke has been beset by translational failure, we sought additional evidence that hypothermia protects human neurons against ischemic injury.

METHODS

Human embryonic stem cells were cultured and differentiated to provide a source of neurons expressing β III tubulin, microtubule-associated protein 2, and the Neuronal Nuclei antigen. Oxygen deprivation, oxygen-glucose deprivation, and H2 O2 -induced oxidative stress were used to induce relevant injury.

RESULTS

Hypothermia to 33°C protected these human neurons against H2 O2 -induced oxidative stress reducing lactate dehydrogenase release and Terminal deoxynucleotidyl transferase dUTP nick end labeling-staining by 53% (P ≤ 0·0001; 95% confidence interval 34·8-71·04) and 42% (P ≤ 0·0001; 95% confidence interval 27·5-56·6), respectively, after 24 h in culture. Hypothermia provided similar protection against oxygen-glucose deprivation (42%, P ≤ 0·001, 95% confidence interval 18·3-71·3 and 26%, P ≤ 0·001; 95% confidence interval 12·4-52·2, respectively) but provided no protection against oxygen deprivation alone. Protection (21%) persisted against H2 O2 -induced oxidative stress even when hypothermia was initiated six-hours after onset of injury (P ≤ 0·05; 95% confidence interval 0·57-43·1).

CONCLUSION

We conclude that hypothermia protects stem cell-derived human neurons against insults relevant to stroke over a clinically relevant time frame. Protection against H2 O2 -induced injury and combined oxygen and glucose deprivation but not against oxygen deprivation alone suggests an interaction in which protection benefits from reduction in available glucose under some but not all circumstances.

Apoptotic death of prostate cancer cells by a gonadotropin-releasing hormone-II antagonist

Gonadotropin-releasing hormone-I (GnRH-I) has attracted strong attention as a hormonal therapeutic tool, particularly for androgen-dependent prostate cancer patients. However, the androgen-independency of the cancer in advanced stages has spurred researchers to look for new medical treatments. In previous reports, we developed the GnRH-II antagonist Trp-1 to inhibit proliferation and stimulate the autophagic death of various prostate cancer cells, including androgen-independent cells. We further screened many GnRH-II antagonists to identify molecules with higher efficiency. Here, we investigated the effect of SN09-2 on the growth of PC3 prostate cancer cells. SN09-2 reduced the growth of prostate cancer cells but had no effect on cells derived from other tissues. Compared with Trp-1, SN09-2 conspicuously inhibited prostate cancer cell growth, even at low concentrations. SN09-2-induced PC3 cell growth inhibition was associated with decreased membrane potential in mitochondria where the antagonist was accumulated, and increased mitochondrial and cytosolic reactive oxygen species. SN09-2 induced lactate dehydrogenase release into the media and annexin V-staining on the PC3 cell surface, suggesting that the antagonist stimulated prostate cancer cell death by activating apoptotic signaling pathways. Furthermore, cytochrome c release from mitochondria to the cytosol and caspase-3 activation occurred in a concentration- and time-dependent manner. SN09-2 also inhibited the growth of PC3 cells xenotransplanted into nude mice. These results demonstrate that SN09-2 directly induces mitochondrial dysfunction and the consequent ROS generation, leading to not only growth inhibition but also apoptosis of prostate cancer cells.

Effects of metoprolol and small intestine RNA on marrow-derived endothelial progenitor cells applied for autograft transplantation in heart disease

AIMS

The objective of this project was to improve the effect of EPC autograft transplantation and observe the tolerance of EPCs to I/R injury affected by metoprolol and small intestine RNA.

MATERIALS AND METHODS

We isolated bone marrow-derived EPCs and examined the effects of metoprolol and small intestine RNA on EPCs to ischemia at different time points after reperfusion. EPCs growth curve, secretion, apoptosis and mortality were also analyzed.

RESULTS

EPCs will be better protected if the blood can be recovered within 4 hours after ischemia for cardiac muscle cells and pretreatment of EPCs with metoprolol or small intestine RNA could protect and promote EPCs proliferation.

CONCLUSIONS

Our study demonstated that pretreatment of EPCs with metoprolol or small intestine RNA will increase the EPCs proliferation and may improve the EPCs autograft transplantation ability.

Synaptosomal lactate dehydrogenase isoenzyme composition is shifted toward aerobic forms in primate brain evolution

With the evolution of a relatively large brain size in haplorhine primates (i.e. tarsiers, monkeys, apes, and humans), there have been associated changes in the molecular machinery that delivers energy to the neocortex. Here we investigated variation in lactate dehydrogenase (LDH) expression and isoenzyme composition of the neocortex and striatum in primates using quantitative Western blotting and isoenzyme analysis of total homogenates and synaptosomal fractions. Analysis of isoform expression revealed that LDH in synaptosomal fractions from both forebrain regions shifted towards a predominance of the heart-type, aerobic isoform LDH-B among haplorhines as compared to strepsirrhines (i.e. lorises and lemurs), while in the total homogenate of the neocortex and striatum there was no significant difference in LDH isoenzyme composition between the primate suborders. The largest increase occurred in synapse-associated LDH-B expression in the neocortex, with an especially remarkable elevation in the ratio of LDH-B/LDH-A in humans. The phylogenetic variation in the ratio of LDH-B/LDH-A was correlated with species-typical brain mass but not the encephalization quotient. A significant LDH-B increase in the subneuronal fraction from haplorhine neocortex and striatum suggests a relatively higher rate of aerobic glycolysis that is linked to synaptosomal mitochondrial metabolism. Our results indicate that there is a differential composition of LDH isoenzymes and metabolism in synaptic terminals that evolved in primates to meet increased energy requirements in association with brain enlargement.

Muscular cholinesterase and lactate dehydrogenase activities in deep-sea fish from the NW Mediterranean

Organisms inhabiting submarine canyons can be potentially exposed to higher inputs of anthropogenic chemicals than their counterparts from the adjacent areas. To find out to what extend this observation applies to a NW Mediterranean canyon (i.e. Blanes canyon) off the Catalan coast, four deep-sea fish species were collected from inside the canyon (BC) and the adjacent open slope (OS). The selected species were: Alepocephalus rostratus, Lepidion lepidion, Coelorinchus mediterraneus and Bathypterois mediterraneus. Prior to the choice of an adequate sentinel species, the natural variation of the selected parameters (biomarkers) in relation to factors such as size, sex, sampling depth and seasonality need to be characterised. In this study, the activities of cholinesterases (ChEs) and lactate dehydrogenase (LDH) enzymes were determined in the muscle of the four deep-sea fish. Of all ChEs, acetylcholinesterase (AChE) activity was dominant and selected for further monitoring. Overall, AChE activity exhibited a significant relationship with fish size whereas LDH activity was mostly dependent on the sex and gonadal development status, although in a species-dependent manner. The seasonal variability of LDH activity was more marked than for AChE activity, and inside-outside canyon (BC-OS) differences were not consistent in all contrasted fish species, and in fact they were more dependent on biological traits. Thus, they did not suggest a differential stress condition between sites inside and outside the canyon.

[Expression and clinical significance of CD40 in diffuse large B-cell lymphoma]

OBJECTIVE

To study the expression of CD40 in diffuse large B-cell lymphoma (DLBCL) and its relationship with various clinical parameters, pathologic findings and prognostic data.

METHODS

The clinical information of 87 patients with DLBCL diagnosed in Jilin Province Cancer Hospital during the period from January, 2008 to october, 2012 was retrospectively reviewed. Immunohistochemical study using SP technique for CD40 was carried out. The correlation between clinicopathologic findings, CD40 expression and survival data was analyzed using statistical software.

RESULTS

Cases of CD40-positive DLBCL were characterized by lower age group, early clinical stage, less extranodal involvement, lower IPI index and lower ECOG score. However, there was no significant correlation between gender of patients and site of involvement (P = 0.141 and 0.729). The overall survival of patients with CD40-positive DLBCL was significantly higher than that in patients with CD40-negative DLBCL. One-way analysis of variance showed that the prognosis of DLBCL was closely associated with CD40 expression, age of patients, ECOG score, IPI index, extranodal involvement and LDH level (P < 0.05, respectively). Stratified analysis showed that CD40-positive DLBCL carried a better prognosis, irrespective of other immunophenotyping results. COX model multivariate analysis showed that the expression of CD40 closely correlated with other immunophenotyping results, ECOG score, clinical staging, treatment regimen and prognosis (P < 0.05).

CONCLUSION

The expression of CD40 is a favorable prognostic indicator in patients with DLCBL.

Decreased hematocrit-to-viscosity ratio and increased lactate dehydrogenase level in patients with sickle cell anemia and recurrent leg ulcers

Leg ulcer is a disabling complication in patients with sickle cell anemia (SCA) but the exact pathophysiological mechanisms are unknown. The aim of this study was to identify the hematological and hemorheological alterations associated with recurrent leg ulcers. Sixty-two SCA patients who never experienced leg ulcers (ULC-) and 13 SCA patients with a positive history of recurrent leg ulcers (ULC+) - but with no leg ulcers at the time of the study – were recruited. All patients were in steady state condition. Blood was sampled to perform hematological, biochemical (hemolytic markers) and hemorheological analyses (blood viscosity, red blood cell deformability and aggregation properties). The hematocrit-to-viscosity ratio (HVR), which reflects the red blood cell oxygen transport efficiency, was calculated for each subject. Patients from the ULC+ group were older than patients from the ULC- group. Anemia (red blood cell count, hematocrit and hemoglobin levels) was more pronounced in the ULC+ group. Lactate dehydrogenase level was higher in the ULC+ group than in the ULC- group. Neither blood viscosity, nor RBC aggregation properties differed between the two groups. HVR was lower and RBC deformability tended to be reduced in the ULC+ group. Our study confirmed increased hemolytic rate and anemia in SCA patients with leg ulcers recurrence. Furthermore, our data suggest that although systemic blood viscosity is not a major factor involved in the pathophysiology of this complication, decreased red blood cell oxygen transport efficiency (i.e., low hematocrit/viscosity ratio) may play a role.

Engineering and adaptive evolution of Escherichia coli W for L-lactic acid fermentation from molasses and corn steep liquor without additional nutrients

The D-lactic acid producing strain, Escherichia coli HBUT-D, was reengineered for L(+)-lactic acid fermentation by replacing the D-lactate dehydrogenase gene (ldhA) with an L(+)-lactate dehydrogenase gene (ldhL) from Pedicoccus acidilactici, followed by adaptive evolution in sucrose. The resulting strain, WYZ-L, has enhanced expression of the sucrose operon (cscA and cscKB). In 100 g L(-1) of sucrose fermentation using mineral salt medium, WYZ-L produced 97 g L(-1) of l(+)-lactic acid, with a yield of 90%, a maximum productivity of 3.17 g L(-1)h(-1) and an optical purity of greater than 99%. In fermentations using sugarcane molasses and corn steep liquor without additional nutrients, WYZ-L produced 75 g L(-1) of l(+)-lactic acid, with a yield of 85%, a maximum productivity of 1.18 g L(-1)h(-1), and greater than 99% optical purity. These results demonstrated that WYZ-L has the potential to use waste molasses and corn steep liquor as a resource for L(+)-lactic acid fermentation.

Supplementation of medium with diammonium hydrogen phosphate enhanced the D-lactate dehydrogenase levels leading to increased D-lactic acid productivity

The production of D-lactic acid by Lactobacillus lactis RM2-24 was investigated using modified media to increase the efficiency of the fermentation process. The results indicated that the addition of 5 g/l peptone and 1 g/l (NH4)2HPO4 enhanced D-lactic acid production by 32%, as compared to that obtained from non supplemented media, with a productivity of 3.0 g/l/h. Lactate dehydrogenase (LDH) expression profile in these different media was studied which resulted in appearance of additional LDH isoform produced by cells when they were grown in HSYE supplemented with (NH4)2HPO4. The additional LDH appears to be L-LDH contributing to production of L-lactic acid in the fermented broth. This is totally new information in the lactic acid fermentation and could be very useful to industries engaged in D-lactic acid production.

[Effects of chlorogenic acid on the viability and HIF-1alpha mRNA expression of PC12 cells exposed to hypoxia]

OBJECTIVE

To investigate the effects of chlorogenic acid on the viability and HIF-1alpha mRNA expression of PC12 cells exposed to hypoxia.

METHODS

PC12 cells were cultured in trigas incubator in order to establish the hypoxic condition. The effects of chlorogenic acid on the cells were evaluated by morphological observation, cell viability and LDH release assays as well as the examination of mRNA expression level of HIF-1alpha.

RESULTS

Chlorogenic acid significantly improved the viability of cells exposed to hypoxia, decreased LDH release, arrested the cell cycle on G1 phase, and increased the gene expression level of HIF-1alpha.

CONCLUSION

Chlorogenic acid protects PC12 cells from hypoxic damage by improving the expression of HIF-1alpha.

[Diffuse large B-cell lymphoma of testis: a clinicopathologic and immunophenotypic study of 58 cases]

OBJECTIVE

To investigate the clinicopathologic features, immunophenotype, diagnosis and differential diagnosis, and prognostic factors of testicular diffuse large B-cell lymphoma (DLBCL).

METHODS

The clinical and pathologic profiles of 58 cases of testicular DLBCL were investigated.Immunohistochemical stainings and EBER1/2 in situ hybridization were performed on formalin fixed tissues.

RESULTS

The average age of the patients was 62.1 years, and the median age was 65 years. The course of disease was short in most of the cases. Clinical stages at diagnosis were mainly stage I or II (87.9%, 51/58). Forty eight patients (82.8%) had unilateral testis involvement. Inguinal lymphadenopathy was observed in 12 (20.7%) patients and the other organs were seldom involved. Morphologically, centroblast-like neoplastic cells infiltrated interstitial tissue of testis diffusely and invaded into seminiferous tubules. Tunica albuginea and vessels were involved in 14 (24.1%) and 10 (17.2%) patients, respectively. Immunophenotype analysis showed predominant non-GCB type of DLBCL (48/58, 82.8%) by Hans classification. No EBV infection was detected. Follow-up data were available in 48 (82.8%) patients. Twenty eight patients (58.3%) died of the disease. One-year, 3-year, and 5-year overall survivals were 55.7%, 31.6% and 27.6%, respectively. Age (older than 60 years), B-symptoms, high serum level of LDH, advanced Ann Arbor stage as well as lack of combination of therapy were associated with a poor prognosis.

CONCLUSIONS

This large series of testicular DLBCL mainly present with local disease at diagnosis. Most cases show non-GCB immunophenotype. Despite early clinical stage at presentation, the prognosis is poor. Combined chemotherapy postoperation may prolong survival of the patients.

[The salivary factors related to caries and periodontal disease in children and adolescents with diabetes mellitus]

OBJECTIVE

To detect the salivary factors related to caries and periodontal disease and to analyze the risk of caries and periodontal disease in children and adolescents with diabetes mellitus.

METHODS

The study comprised 30 children with diabetic mellitus, aged 7-15 years old, and 60 healthy age-and gender-matched children. Caries and periodontal indexes were recorded and saliva related factors were analyzed.

RESULTS

Caries indexes of diabetes children [permanent teeth: decay missing filling tooth (DMFT) M (Q1,Q3) = 0(0, 4), deciduous teeth: decay missing filling tooth (dmft) M (Q1,Q3) = 0(0, 1)] were not significantly different with those of healthy children [DMFT M (Q1,Q3) = 1(0, 3), dmft M (Q1,Q3) = 0(0, 4)], but plaque index (PLI) (1.25 ± 0.33) and bleeding index (BI) (0.74 ± 0.45) of diabetes children were significantly higher than those of healthy children (PLI was 0.93 ± 0.31,BI was 0.34 ± 0.22) (P < 0.001). Salivary pH of diabetes children (7.68 ± 0.36) was significantly higher than that of healthy children (7.30 ± 0.32) (P < 0.05), and salivary acid buffering capacity had no significant difference between the two groups (P > 0.05). Salivary glucose, immunoglobulin sIgA and sIgG were not significantly different between the two groups (P > 0.05).Salivary lysozyme of diabetes children was significantly higher than that of healthy children (P < 0.05). Total protein was significantly lower in diabetes children than in healthy children (P < 0.05). Salivary lactate dehydrogenase had no significant difference between the two groups (P > 0.05).

CONCLUSIONS

Diabetes mellitus can lead to the changes of some salivary factors related to gingivitis in diabetes children. Children and adolescents with diabetes mellitus may have a higher risk of periodontal disease.

Free radical scavenging and anti-oxidative activities of an ethanol-soluble pigment extract prepared from fermented Zijuan Pu-erh tea

An ethanol-soluble pigment extract was separated from fermented Zijuan Pu-erh tea. The compositions of the ethanol soluble pigment extract were analyzed by high-performance liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS). The extract was prepared into a series of ethanol solutions and analyzed for free radical-scavenging activities (against two free radicals: 1,1-diphenyl-2-picrylhydrazyl (DPPH) and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)) and in vitro anti-oxidative properties. Electron spin resonance spectroscopy showed that the peaks of DPPH and TEMPO decreased with increasing extract concentration, suggesting that the extract had excellent free radical-scavenging activities. In vitro cell culture suggested that, at 50-200 mg/L, the extract had no measurable effect on the viability of vascular endothelial cells (ECV340) but produced significant protective effects for cells that underwent oxidative injuries due to hydrogen peroxide (H₂O₂) treatment. Compared with the H₂O₂ treatment alone cells group, 200 mg/L of the extract increased the activity of superoxide dismutase (SOD) in cells by 397.3%, and decreased the concentration of malondialdehyde (MDA) and the activity of lactate acid dehydrogenase (LDH) by 47.8% and 69.6%, respectively. These results suggest that the extract has excellent free radical scavenging and anti-oxidative properties.

[Effect of ZnSO4 on L-lactic acid production by Rhizopus oryzae]

OBJECTIVE

To improve the yield and quality of L-lactic acid by Rhizopus oryzae, we aim to understand the relationship between inorganic salts utilization and the L-lactic acid metabolism of the strain RLC41-6, through systematic analysis of the effects of zinc ion concentration on the production of L-lactic acid and the Lactic Dehydrogenase (LDH) activity.

METHODS

Rhizopus oryzae was cultured at 36 degrees C for 36h with different quantity of ZnSO4 in fermentation medium. The fermentation products were monitored by reversed-phase high performance liquid chromatography (RP-HPLC), LDH isoenzyme composition in the cell was analysed by non-denatured polyacrylamide gel electrophoresis (PAGE).

RESULTS

Our results showed that the concentration of ZnSO4 in medium could modulate the expression of LDH isoenzyme except LDH1, especially stimulated the expression of LDH4 and LDH5. When initial concentration of ZnSO4 is above 0.02%, the LDH4 and LDH5 reached the highest level. However, the activity of LDH was inhibited by higher concentration zinc ion in extracellular environment. When ZnSO4 concentration is 0.02%, LDH activity reaches its maximum 200U/mL, the HPLC assay showed only L-lactic in the fermentation products (137 g/L), while the conversion rate of glucose to lactic acid is 91%.

CONCLUSION

Zinc ion can regulate the metabolic processes of Rhizopus oryzae and modulate the types of the final fermentation products. An optimal concentration of ZnSO4 can not only facilitate the LDH expression but also prevent pyruvate from transformation into the malic acid and fumaric acid during the metabolism process, thereby enhance the metabolism of glucose to lactic acid of Rhizopus oryzae.

Cerium chloride improves protein and carbohydrate metabolism of fifth-instar larvae of Bombyx mori under phoxim toxicity

The organophosphorus pesticide poisoning of the silkworm Bombyx mori is one of the major events causing serious damage to sericulture. Added low-dose rare earths are demonstrated to increase resistance in animals. However, very little is known about whether or not added CeCl₃ can increase resistance of silkworm to phoxim poisoning. The present findings suggested that added CeCl₃ to mulberry leaves markedly increased contents of protein, glucose and pyruvate, and carbohydrate metabolism-related enzyme activities, including lactate dehydrogenase, succinate dehydrogenase and malate dehydrogenase, and attenuated free amino acids, urea, uric acid and lactate levels and inhibited the protein metabolism-related enzymes activities, such as protease, alanine aminotransferase and aspartate aminotransferase in the haemolymph of B. mori, under phoxim toxicity. These findings suggest that added CeCl₃ may improve protein and carbohydrate metabolisms, thus leading to increases of growth and survival rate of B. mori under phoxim stress.

[Effect of lemon essential oil on caries factors of Streptococcus sobrinus]

OBJECTIVE

To investigate the mechanism of lemon peel essential oil (LPE) on the cariogenicity of Streptococcus sobrinus (Ss).

METHODS

LPE was extracted by the authors, and the minimum inhibition concentration (MIC) was measured by disc diffusion method. The LPE was used as the experimental group with concentrations ranging from 2.250 g/L to 0.281 g/L prepared with trypticase peptone yeast (TPY) culture medium, and TPY culture medium was used as the control group. Ss at the concentration of 10(8) CFU/ml was added to each group, and cultured for 6, 18, 24, 48 hours. Neson-Somogyi method was used to measure the content of reducing sugar, and glucosyltransferase (GTF) activity. The activity of lactate dehydrogenase (LDH) was measured by lactic acid and pyruvic acid continuous monitoring method. The content of water insoluble glucan (WIG) was measured by anthrone method, and the pH value of the culture solution was detected. The value of pH before the experiment and the time difference was alculated as ΔpH.

RESULTS

At the same time point, the activity of GTF and LDH and the concentration of WIG and the value ΔpH decreased gradually with the increase of concentration of LPE. There were significant differences between each experimental group and control group (P < 0.01). The control group had the maximum value, GTF: (6.71 ± 0.61) mIU, LDH: (135.8 ± 1.7) U/L, WIG: (47.15 ± 5.12) mg/L, ΔpH: (2.67 ± 0.01). The highest drug concentration group had the minimum value: GTF: (0.39 ± 0.07) mIU, LDH: (95.0 ± 5.4) U/L, WIG: (2.44 ± 0.38) mg/L, ΔpH: (0.61 ± 0.01).

CONCLUSIONS

The LPE below the MIC could still inhibit the GTF, LDH activity and lead to the decrease of WIG and the acid production.

[Comparative experiment on nanoparticle-induced toxicity in human vascular endothelial cells]

OBJECTIVE

To compare the toxic effects of three different particles on vascular endothelial cells, and to investigate the influences of particle composition and sizes on the cardiovascular toxic effects.

METHODS

Nano-SiO2 particles, nano-TiO2 particles, and standard quartz particles were selected as the test substances, and the nano-TiO2 particles and standard quartz particles were used as composition controls and size controls, respectively. The human umbilical vein endothelial cells were exposed to different doses (5.0, 10.0, 20.0, 40.0 µg/ml) of the three particles as well as particle-free DMEM medium (0 µg/ml dust) for 24 h. Then, the culture supernatants were collected, and the activities of lactic dehydrogenase (LDH) and total superoxide dismutase (SOD) as well as the releases of NO, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured.

RESULTS

Compared with those of 0 µg/ml dose group, the LDH activities of all nano-SiO2 groups, 10.0, 20.0, and 40.0 µg/ml nano-TiO2 groups, and 10.0, 20.0, and 40.0 µg/ml standard quartz groups were significantly increased (P < 0.01); the SOD activities of 5.0, 10.0, and 20.0 µg/ml nano-SiO2 groups, 40.0 µg/ml nano-TiO2 group, and 20.0 and 40.0 µg/ml standard quartz groups were significantly increased (P < 0.05), but that of the 40.0 µg/ml nano-SiO2 group was significantly decreased (P < 0.01); the TNF-α releases of 10.0, 20.0, and 40.0 µg/ml nano-SiO2 groups, all nano-TiO2 groups, and 40.0 µg/ml standard quartz group were significantly increased (P < 0.01); the IL-6 releases of 10.0, 20.0, and 40.0 µg/ml nano-SiO2 groups, 20.0 and 40.0 µg/ml nano-TiO2 groups, and 40 µg/ml standard quartz group were significantly increased (P < 0.01). When the dust doses were 5.0, 10.0, 20.0, and 40.0 µg/ml, the LDH activities of nano-SiO2 groups were significantly higher than those of standard quartz groups (P < 0.05); when the dust doses were 10.0, 20.0, and 40.0 µg/ml, the LDH activities of nano-TiO2 groups were significantly lower than those of standard quartz groups (P < 0.05). When the dust doses were 5.0, 10.0, 20.0, and 40.0 µg/ml, the SOD activities of nano-SiO2 groups were significantly higher than those of standard quartz groups (P < 0.01); when the dust dose was 20 µg/ml, the SOD activity of nano-TiO2 group was significantly higher than that of standard quartz group (P < 0.01). When the dust doses were 5.0, 10.0, 20.0, and 40.0 µg/ml, the TNF-α releases of nano-SiO2 groups were significantly higher than those of standard quartz groups (P < 0.01); when the dust doses were 5.0 and 10.0 µg/ml, the TNF-α releases of nano-TiO2 groups were significantly higher than those of standard quartz groups (P < 0.01). When the dust doses were 5.0, 10.0, 20.0, and 40.0 µg/ml, the IL-6 releases of nano-SiO2 groups were significantly higher than those of standard quartz groups (P < 0.05); when the dust doses were 20 and 40 µg/ml, the IL-6 releases of nano-TiO2 groups were significantly higher than those of standard quartz groups (P < 0.05).

CONCLUSION

All the three particles are able to exert certain toxic effects on vascular endothelial cells. Nano-SiO2 particles have the most toxic effects, and nano-TiO2 particles and standard quartz particles show uncertain effects. The toxicity of particles is linked to their composition and sizes.

OsLEA3-2, an abiotic stress induced gene of rice plays a key role in salt and drought tolerance

Late embryogenesis abundant (LEA) proteins are involved in tolerance to drought, cold and high salinity in many different organisms. In this report, a LEA protein producing full-length gene OsLEA3-2 was identified in rice (Oryza sativa) using the Rapid Amplification of cDNA Ends (RACE) method. OsLEA3-2 was found to be only expressed in the embryo and can be induced by abiotic stresses. The coding protein localizes to the nucleus and overexpression of OsLEA3-2 in yeast improved growth performance compared with control under salt- and osmotic-stress conditions. OsLEA3-2 was also inserted into pHB vector and overexpressed in Arabidopsis and rice. The transgenic Arabidopsis seedlings showed better growth on MS media supplemented with 150 mM mannitol or 100 mM NaCl as compared with wild type plants. The transgenic rice also showed significantly stronger growth performance than control under salinity or osmotic stress conditions and were able to recover after 20 days of drought stress. In vitro analysis showed that OsLEA3-2 was able to protect LDH from aggregation on freezing and inactivation on desiccation. These results indicated that OsLEA3-2 plays an important role in tolerance to abiotic stresses.

Protective role of morin, a flavonoid, against high glucose induced oxidative stress mediated apoptosis in primary rat hepatocytes

Apoptosis is an early event of liver damage in diabetes and oxidative stress has been linked to accelerate the apoptosis in hepatocytes. Therefore, the compounds that can scavenge ROS may confer regulatory effects on high-glucose induced apoptosis. In the present study, primary rat hepatocytes were exposed to high concentration (40 mM) of glucose. At this concentration decreased cell viability and enhanced ROS generation was observed. Depleted antioxidant status of hepatocytes under high glucose stress was also observed as evident from transcriptional level and activities of antioxidant enzymes. Further, mitochondrial depolarisation was accompanied by the loss of mitochondrial integrity and altered expression of Bax and Bcl-2. Increased translocation of apoptotic proteins like AIF (Apoptosis inducing factor) & Endo-G (endonuclease-G) from its resident place mitochondria to nucleus was also observed. Cyt-c residing in the inter-membrane space of mitochondria also translocated to cytoplasm. These apoptotic proteins initiated caspase activation, DNA fragmentation, chromatin condensation, increased apoptotic DNA content in glucose treated hepatocytes, suggesting mitochondria mediated apoptotic mode of cell death. Morin, a dietary flavonoid from Psidium guajava was effective in increasing the cell viability and decreasing the ROS level. It maintained mitochondrial integrity, inhibited release of apoptotic proteins from mitochondria, prevented DNA fragmentation, chromatin condensation and hypodiploid DNA upon exposure to high glucose. This study confirms the capacity of dietary flavonoid Morin in regulating apoptosis induced by high glucose via mitochondrial mediated pathway through intervention of oxidative stress.

Phenolic alkaloids from Menispermum dauricum rhizome protect against brain ischemia injury via regulation of GLT-1, EAAC1 and ROS generation

Menispermum dauricum rhizome has been widely used in China to treat various cardiovascular and thrombosis disorders. Some studies have reported that the phenolic alkaloids of Menispermum dauricum rhizome (PAM) have protective effects against brain ischemia injury, but the mechanism of this action remains to be clarified. In the present study, we investigated the possible mechanisms of action of PAM on experimental brain ischemia injury. Oxygen and glucose deprivation (OGD) in rat primary cortical cultures and middle cerebral artery occlusion in rats were used to mimic ischemia-reperfusion injury, respectively. The results suggested that PAM protected rat primary cortical cultures against OGD-reoxygenation induced cytotoxicity. PAM decreased extracellular glutamate content and markedly prevented the effects induced by OGD on protein level of GLT-1 and EAAC1 glutamate transporters. In addition, it reduced intracellular ROS generation. In vivo, PAM significantly reduced cerebral infarct area and ameliorated neurological functional deficits at different time points. Our findings revealed that the possible mechanism of action of PAM protected against brain ischemia injury involves regulation of GLT-1, EAAC1 and ROS generation.

[Association between the expression and methylation of energy-related genes with Helicobacter pylori infection in gastric cancer]

OBJECTIVE

To explore the association between the Helicobacter pylori (H. pylori) infection and the expression and methylation of energy-related genes in gastric cancer.

METHODS

Real-time fluorescence quantitative reverse transcription (RT)-PCR was performed to quantify the expressions level of lactate dehydrogenase (LDH), dihydrolipoamide dehydrogenase (DLD) and Ran-specific GTPase-activating protein (RanGAP) genes in the samples of human gastric cancer (n = 30), metastatic lymph node (n = 30) and peri-cancerous tissues (n = 30) as confirmed by pathological examinations. Those patients were chosen of Affiliated Hospital of Guiyang Medical University, from January 2005 to December 2009. The relationship between the gene expression and H. pylori infection was analyzed. The methylation of LDH, DLD and RanGAP genes at promoter CpG island was measured by bisulfite sequencing (BSP).

RESULTS

The relative gene expressions of LDH, DLD and RanGAP in peri-cancerous tissues, gastric cancer and metastatic lymph nodes were 1.0, 3.1, 3.0 and 1.0, 3.1, 2.8, and 1.0, 0.4, 0.5 respectively (all P < 0.05). The expression levels of LDH and DLD genes in H. pylori-positive gastric cancer was high than those in the negative group (2.3 vs 1.0, 3.0 vs 1.0, 2.6 vs 1.0, all P < 0.05). The demethylation of LDH and DLD genes at promoter -2325 and -1885 site as well as the over methylation of RanGAP gene at the promoter -570 and -170 sites respectively were detected in H. pylori infection and cagA-overexpressed cells.

CONCLUSION

H. pylori infection may promote the development and progression of gastric cancer by inducing the aberrant methylation of LDH, DLD and RanGAP genes to up-regulate the gene expressions of LDH and DLD and down-regulate the gene expression of RanGAP.

[Study on protective effect of salvianolic acid B on glutamate-induced excitotoxicity in pheochromocytoma PC12 cells]

OBJECTIVE

To study the protective effect and mechanism of salvianolic acid B (Sal B) on glutamate-induced excito-toxicity.

METHOD

Glutamate-induced PC12 cell injury model was established to detect the cell survival rate by MTT, the leakage rate of lactic dehydrogenases using LDH, and the cell apoptosis by using AO/EB double staining for fluorescence microscope and PI single staining flow cytometry which was also used to detect the content of intracellular reactive oxygen species. The expression of Caspase-3 protein was also detected by the Western blotting method.

RESULT

Sal B is proved to inhibit glutamate-induced PC12 cells from injury and prevent them from releasing LDH within the range from 50 micromol x L(-1) to 200 micromol x L(-1). Meanwhile, Sal B has an effect on significantly reducing the expression of inhibit glutamate-induced active Caspase-3 protein, inhibiting accumulated glutamate-induced ROS and decreasing PC12 cell apoptosis rate within the range from 50 micromol x L(-1) to 200 micromol x L(-1).

CONCLUSION

The study proves that Sal B prevented against glutamate-induced cell injury via inhibiting ROS formation and Caspase-3 pathway-dependent apoptosis in PC12 cells.

Immunotoxic effects of triclosan in the clam Ruditapes philippinarum

The effects of Triclosan (TCS) on the immune parameters of the clam Ruditapes philippinarum were investigated after a 7-day exposure to sublethal TCS concentrations (300, 600, and 900 ng l(-1)). Hemocytes from controls and exposed clams were collected, and the effects of TCS on total hemocyte count (THC), hemocyte diameter and volume, uptake of the vital dye Neutral Red (an indicator of pinocytosis), lysozyme activity, and proliferation were evaluated. The cytotoxicity, which was evaluated using the lactate dehydrogenase assay, and the capability of TCS to induce DNA fragmentation, which indicated apoptosis, were also investigated. The exposure of clams to all tested TCS concentrations significantly decreased THC, whereas the highest tested TCS concentration significantly reduced the diameter and volume of hemocytes. TCS negatively affected pinocytosis and the proliferation of hemocytes, but it did not alter hemocyte lysozyme activity. TCS exerted cytotoxic effects and induced DNA fragmentation in hemocytes of R. philippinarum. Overall, these results suggest a relationship between TCS exposure and changes in the measured immune parameters and indicate immunosuppression in TCS-treated clams.