Ginsenoside Rd attenuates mitochondrial dysfunction and sequential apoptosis after transient focal ischemia

We previously found that ginsenoside Rd (Rd), one of the major active ingredients in Panax ginseng, protects neuronal cells from hydrogen peroxide and oxygen-glucose deprivation, an in vitro model of cerebral ischemia. In this study, we examined the protective effects of Rd in an animal model of focal cerebral ischemia. Rats administered with Rd or vehicle were subjected to transient middle cerebral artery occlusion (MCAO). Rd (50 mg/kg) significantly reduced the infarct volume by 52.8%. This reduction of injury volume was associated with an improvement in neurological function and was sustained for at least 2 weeks after the induction of ischemia. To evaluate the underlying mechanisms of Rd against stroke, brain tissues were assayed for mitochondrial enzyme activities, mitochondrial membrane potential (MMP), production of reactive oxygen species (ROS), energy metabolites, and apoptosis. Rd markedly protected mitochondria as indicated by preserved respiratory chain complex activities and aconitase activity, lowered mitochondrial hydrogen peroxide production, and hyperpolarized MMP. Microdialysis results illustrated that Rd significantly decreased the accumulation of lactate, the end product of anaerobic glycolysis, and increased pyruvate, the end product of aerobic glycolysis, hence inducing a lower lactate/pyruvate ratio. Additionally, in vitro studies further exhibited that Rd protected isolated mitochondria from calcium-induced damage by attenuating mitochondrial swelling, preserving MMP and decreasing ROS production. Moreover, Rd treatment reduced mitochondrial release of cytochrome c (CytoC) and apoptosis-inducing factor (AIF), thereby minimizing mitochondria-mediated apoptosis following ischemia. In conclusion, these findings demonstrated that Rd exerts neuroprotective effects in transient focal ischemia, which may involve an integrated process of the mitochondrial protection, energy restoration and inhibition of apoptosis.

Effects of common dissolved anions on the reduction of para-chloronitrobenzene by zero-valent iron in groundwater

Batch tests were conducted to evaluate the influences of several common dissolved anions in groundwater on the reduction of para-chloronitrobenzene (p-CNB) by zero-valent iron (ZVI). The results showed that p-CNB reduction was enhanced by both Cl(-) and SO(4)(2-). HCO(3)(-) could either improve or inhibit p-CNB reduction, depending on whether the mixing speed was intense enough to rapidly eliminate Fe-carbonate complex deposited on ZVI surface. Above a concentration of 100 mg L(-1), NO(3)(-) increased the p-CNB reduction rate. The reduction rate by ClO(4)(-) decreased because the ClO(4)(-) competed with p-CNB for electrons. The p-CNB reduction was inhibited by PO(4)(3-), SiO(3)(2-) and humic acid, in the order humic acid < PO(4)(3-) < SiO(3)(2-), since these ions could form inner-sphere complexes on iron surface. The reaction even ceased when the ion concentrations were greater than 4, 0.5, and 30 mg L(-1), respectively. The results indicated that common dissolved anions in groundwater should be taken into account when ZVI is applied for contaminated groundwater remediation.

Abstract P6-05-05: Signaling Pathways Activated in Her 2 and ER Negative Breast Cancers

Introduction: Breast cancer is the most common cancer in women (192,370 new cases in 2009) and the second leading cause of cancer death (40,000) among women in USA. Current multimodality treatment of breast cancer is based on the level of ER expression and Her 2 gene amplification. However, no effective treatment is currently available for breast cancers with low level expression of ER and no amplification of Her 2 gene. The aim of this study is to identify protein pathways activated in the breast cancer with negative expression of ER and Her 2. Method: Protein Pathway Array was used to assess the level of protein expression and phosphorylation in 71 paired fresh frozen breast samples (tumor and adjacent benign tissue). A total 159 antibodies were evaluated which represent most important signal transduction pathways involved in proliferation, apoptosis, angiogenesis, invasion and metastasis. Several potential therapeutic kinase proteins were also assessed. Results: A total 20 proteins (PCNA, phospho-PTEN, cyclin B1 cyclin E1, CDK6, E-cadherin, NFkB, ect) were differentially expressed between normal and tumor tissues based on the statistical analysis. In Her 2 negative tumors (n=37), 3 proteins were differentially expressed and among them, 2 were up-regulated (CDK6 and HSD1) and 1 was down-regulated (IGF). In ER negative tumors (n=18), 4 proteins (HSD, SK, TDP and Slug) was up-regulated and 1 proteins were down-regulated (E-cadherin). In triple negative tumors (n=13), one protein (E-cadherin) down-regulated and 2 proteins (TDP and HSD) were up-regulated. Furthermore, based on the expression pattern of these proteins, tumors negative for both ER and Her 2 (n=15) can be clustered into 3 groups

Figure 1: Subclassification of breast cancers negative for ER and Her-2 based protein pattern.

Hierarchical clustering analysis of 20 differentially expressed proteins in

15 ER/Her-2 negative breast cancers. The cancers can be separated into 3 subtypes. Red indicates overexpression, green underexpression, black no change, and gray no expression. Each column represents a protein. Each row represents a sample.

Conclusion: Our study showed that distinct sets of signaling pathways activated in ER and Her 2 negative breast cancers. The increased expression of cell cycle progression proteins in Her 2 negative tumors suggests activation of cell proliferation via different growth promotion pathway. Similarly, different cell proliferation pathways are also activated in ER negative tumors. This finding may be used to design future clinical trial based on the activation of different signaling pathways.

Combined effects of short-term calorie restriction and exercise on insulin action in normal rats

The present study examined the effect of combination of short-term calorie restriction (CR) and moderate exercise on insulin action in normal rats. Rats were divided randomly into 4 groups: ad libitum, sedentary (A-Sed); calorie restriction, sedentary (CR-Sed); ad libitum, exercise (A-Ex); and calorie restriction, exercise (CR-Ex). Rats in the exercise groups were run on a rodent treadmill. Rats in the CR groups were fed every alternate day. Oral glucose tolerance test (OGTT) showed improvements in both CR-Sed and A-Ex groups compared with the A-Sed group; no further improvement in glucose tolerance was observed in the CR-Ex group. In contrast, glucose infusion rates (GIRs) determined by the hyperinsulinemic-euglycemic clamp method indicated that the GIR of the CR and exercise combination was significantly better than that of the sole intervention of CR or exercise. There was no difference in the levels of fasting glucose, insulin, or high-molecular weight forms of adiponectin among the 4 groups. Protein expression of GLUT-4 in the skeletal muscle increased by exercise, but not by CR. Our findings indicate that the combination of exercise and CR may be effective in enhancing insulin sensitivity at the skeletal muscle in normal subjects.

Multiorgan engraftment of human somatic cells in swine foetuses after intra-blastocyst transplantation

Adult human stem cells, mainly from hematopoietic lineage, have been injected into developing pre-immune animal foetuses, and xenogenic engraftment of liver and other organs has been reported. We isolated a rare cell population from adult human liver, fat and skin. Colonies with few cells became visible as early as 2-3 days, and a fully formed colony took 10-14 days to form. These colonies were named as liver-derived cell lines (LDCs), fat-derived cell lines (FDCs) and skin-derived cell lines (SDCs). All these cells express few pluripotency markers like Klf4, c-myc and Sox2. Pig blastocysts were injected with LDCs, FDCs and SDCs and transferred to recipient pigs. We achieved an overall pregnancy rate of 71.4% at day 35. The foetuses were analysed for human cell chimerism in liver, kidney and heart both by RT-PCR and real-time PCR using primers specific to human and pig mitochondrial DNA. The percentage of foetuses showing chimerism was 17.4% (4/23), 12.5% (2/16) and 11.1% (1/9) for LDCs, FDCs and SDCs, respectively. Of these, 42.9% (three out of seven) showed chimerism in liver and 71.4% (five out of seven) showed kidney chimerism. However, we did not detect any chimerism in the heart. The level of chimerism varied and was in the range of one human cell per one hundred thousand to one million pig cells.

Differences in HIV burden and immune activation within the gut of HIV-positive patients receiving suppressive antiretroviral therapy

BACKGROUND

The gut is a major reservoir for human immunodeficiency virus (HIV) in patients receiving antiretroviral therapy (ART). We hypothesized that distinct immune environments within the gut may support varying levels of HIV.

METHODS

In 8 HIV-1-positive adults who were receiving ART and had CD4(+) T cell counts of >200 cells/μL and plasma viral loads of <40 copies/mL, levels of HIV and T cell activation were measured in blood samples and endoscopic biopsy specimens from the duodenum, ileum, ascending colon, and rectum.

RESULTS

HIV DNA and RNA levels per CD4(+) T cell were higher in all 4 gut sites compared with those in the blood. HIV DNA levels increased from the duodenum to the rectum, whereas the median HIV RNA level peaked in the ileum. HIV DNA levels correlated positively with T cell activation markers in peripheral blood mononuclear cells (PBMCs) but negatively with T cell activation markers in the gut. Multiply spliced RNA was infrequently detected in gut, and ratios of unspliced RNA to DNA were lower in the colon and rectum than in PBMCs, which reflects paradoxically low HIV transcription, given the higher level of T cell activation in the gut.

CONCLUSIONS

HIV DNA and RNA are both concentrated in the gut, but the inverse relationship between HIV DNA levels and T cell activation in the gut and the paradoxically low levels of HIV expression in the large bowel suggest that different processes drive HIV persistence in the blood and gut.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00884793 (PLUS1).

Prognosis of colorectal cancer with liver metastasis: value of a prognostic index

The objective of the present study was to explore the factors related to the prognosis of colorectal cancer (CRC) and to establish a prognostic model for the selection of patients who might benefit from hepatic resection for metastatic CRC. A total of 293 patients undergoing liver resection for metastatic CRC (172 males and 80 females ranging in age from 26 to 80 years) were selected and clinical, pathological and outcome data were examined in this retrospective study. The prognostic index (PI) of the patients was calculated on the basis of results of multivariate analysis. Patients were stratified into different groups, with survival curves projected according to PI. The 1-, 3-, and 5-year overall survival rates were 58.3, 26.4, and 11.3%, respectively. Univariate analysis indicated that degree of primary tumor differentiation, resection margin, preoperative carcinoembryonic antigen (CEA) level, number of liver metastases, and resection of liver metastases were associated with prognosis (P < 0.05). In multivariate analysis, the last three factors were found to be independent prognostic factors. The resection of liver metastases was a favorable factor. Patients were classified into three groups according to PI, which differed significantly in survival rate (P < 0.05). The individual survival rate was evaluated based on PI. Resection of hepatic colorectal metastases may produce long-term survival and cure. The proposed PI was easy to use, was highly predictive of patient outcome, and permitted categorization of patients into treatment groups.

Proteome profile and lentiviral transduction of cultured honey bee (Apis mellifera L.) cells

Honey bees (Apis mellifera L.) play a vital role in agriculture as pollinators, and serve as model organisms of social behaviour and immunity. The lack of both immortalized cell lines and methods to introduce recombinant DNA reliably into primary cells hinders cellular and molecular studies in this organism. We hereby demonstrate the expression of a GFP gene delivered by lentivirus transduction to cultured embryonic cells. The success of this approach indicates that viral transduction could be used to deliver constitutively active oncogenes in order to immortalize honey bee cells. We were able to revive cells successfully after several months of cryogenic storage and we show how the proteome varies between freshly collected and cultured embryonic cells.

Novel application of Locked Nucleic Acid chemistry for a Taqman assay for measuring diverse human immunodeficiency virus type 1 subtypes

There remains a need for sensitive and cost-effective assays to monitor therapy in human immunodeficiency virus type-1 (HIV-1) infection. However, the genetic diversity of HIV poses difficulties for traditional real-time PCR assays that require long oligonucleotides probes. LNA™ probes may be useful in overcoming these limits to traditional probe design. A new application of LNA™ chemistry in a Taqman assay applicable to a wide range of HIV-1 subtypes is described. This assay, based on a 13-mer LNA™ probe that matches the majority of HIV-1 sequences in the Los Alamos database, exhibited a wide dynamic range (10(1)-10(7) copies of HIV DNA), high sensitivity (limit of detection of 1 copy of HIV DNA in 10(5) cells), and broad applicability to a range of HIV-1 subtypes (including A, B, C, D, F, H, B/C, and A/E CRFs). Using the LNA™ probe assay, HIV-1 DNA was detected in all dried blood spots (DBS) from treatment naïve HIV-1 positive Ugandan children, and HIV DNA levels significantly correlated with viral RNA levels in plasma (r=0.765, p<0.0001). This approach to Taqman probe design should be explored further for use in diagnosis and monitoring of HIV in resource-limited settings, especially where several subtypes co-circulate.

Polymorphisms of PXK are associated with autoantibody production, but not disease risk, of systemic lupus erythematosus in Chinese mainland population

Systemic lupus erythematosus (SLE) is a complex immune disease. The genetic variation in the PXK gene was found to associate with SLE in Caucasian populations. However, the association of rs6445975 with SLE has not been extensively studied in a Chinese mainland population. A total of 288 SLE patients and 357 controls were recruited. Unlabeled probe-based high-resolution melting analysis (HRMA) was used in genotyping. HRMA with unlabeled probe successfully distinguished all genotypes. Neither genotype nor allele frequencies of SNP rs6445975 showed statistically significant differences between SLE patients and controls. The association of SNP rs6445975 with the diagnostic criteria of SLE was also examined. No obvious association was observed between rs6445975 and the incidence of clinical symptoms. However, the minor allele (G) of rs6445975 was found to significantly associate with increased abnormalities of anti-Smith (p = 0.004, odds ratio (OR) = 1.95, 95% confidence interval (CI) = 1.22-3.09), anti-Ro (p = 0.015, OR = 1.69, 95% CI = 1.10-2.58), anti-La (p = 0.008, OR = 1.86, 95% CI = 1.17-2.93) and C3C4 (p = 0.007, OR = 1.79, 95% CI = 1.17-2.74). Polymorphisms of rs6445975 in the PXK gene were associated with autoantibody production, but not disease risk, of systemic lupus erythematosus in a Chinese population.

Can colorectal cancer be prevented or treated by oral hormone replacement therapy?

Guanylyl cyclase C (GCC) is the receptor specifically expressed by intestinal cells for the paracrine hormones guanylin and uroguanylin and diarrheagenic bacterial heat-stable enterotoxins. This tissue-specific receptor coordinates lineage-dependent regulation of epithelial homeostasis, and its disruption contributes to intestinal tumorigenesis. It coordinates regenerative and metabolic circuits by restricting the cell cycle and proliferation and programming metabolic transitions central to organizing the dynamic crypt-surface axis. Further, mice deficient in GCC signaling are more susceptible to colon cancer induced by Apc mutations or the carcinogen azoxymethane. Moreover, guanylin and uroguanylin are gene products most commonly lost, early, in colon cancer in animals and humans. The role of GCC as a tumor suppressing receptor regulating proliferation and metabolism, together with the universal loss of guanylin and uroguanylin in tumorigenesis, suggests a model in which colorectal cancer is a paracrine hormone deficiency syndrome. In that context, activation of GCC reverses the tumorigenic phenotype by limiting growth of colorectal cancer cells by restricting progression through the G1/S transition and reprogramming metabolic circuits from glycolysis to oxidative phosphorylation, limiting bioenergetic support for rapid proliferation. These observations suggest a pathophysiological hypothesis in which GCC is a lineage-dependent tumor suppressing receptor coordinating proliferative homeostasis whose dysregulation through hormone loss contributes to neoplasia. The correlative therapeutic hypothesis suggests that colorectal cancer is a disease of hormone insufficiency that can be prevented or treated by oral supplementation with GCC ligands.

Specific immunotherapy suppresses Th2 responses via modulating TIM1/TIM4 interaction on dendritic cells

BACKGROUND

Specific immunotherapy (SIT) is the only curable remedy for allergic disorders currently; however, the underlying mechanism is not fully understood yet. This study aimed to elucidate the mechanism of SIT on suppressing TIM4 (T cell immunoglobulin mucin domain molecule 4) expression in dendritic cells (DCs) and modulating the skewed T helper 2 (Th2) responses in patients with airway allergy.

METHODS

Twenty patients with allergic rhinitis (AR) were treated with SIT for 3 months. Before and after SIT, the expression of TIM4 in peripheral DC and TIM1 in Th2 cells was examined. The role of Fc gamma receptor (FcgammaR) I and II in modulating the expression of TIM4 in DCs was investigated.

RESULTS

The interaction of TIM1/TIM4 played a critical role in sustaining the polarization status of Th2 cells in AR patients. Cross-linking FcgammaRI by antigen/IgG complexes increased the production of TIM4 by dendritic cells via upregulating tumor necrosis factor-alpha in DCs. Exposure to microbial products promoted the expression of FcgammaRI in DCs that further increased the expression of TIM4. Exposure to specific antigens alone upregulated the expression of FcgammaRII in DCs, that suppressed the expression of TIM4.

CONCLUSIONS

We conclude that SIT suppresses the skewed Th2 responses via disrupting the interaction of TIM1/TIM4 in antigen-specific Th2 cells.

Color Doppler twinkling artifact in fetuses with echogenic intracardiac foci: echocardiographic observation and clinical significance

OBJECTIVE

To evaluate echocardiographic characteristics and clinical relevance of color Doppler twinkling artifacts in fetuses with isolated echogenic intracardiac foci (EIF).

METHODS

This study included 50 fetuses with EIF, at 18-38 weeks of gestation. Echocardiographic examination, which was performed using a 1.0-5.0-MHz phased array probe, included gray-scale, color and spectral Doppler imaging. Twinkling artifacts were assessed using fetal color Doppler echocardiography on isolated EIF situated in the left and/or right ventricles. The prevalence, appearance and clinical relevance of the color Doppler twinkling artifacts were analyzed.

RESULTS

Eight of 50 fetuses with EIF (16%) showed color Doppler twinkling artifacts, which appeared as a rapidly changing color complex seen persistently behind the EIF. The spectra obtained in all eight with color Doppler artifacts were composed of straight vertical bands occurring in mid to late systole and early diastole. After birth, none of 50 fetuses with EIF had structural heart diseases or showed clinical signs of cardiac failure.

CONCLUSIONS

Color Doppler twinkling artifacts from isolated EIF occur in some fetuses and may be considered as an additional echocardiographic feature of EIF. Attention should be paid to the identification and interpretation of these artifacts so that they may be accurately distinguished from true color flow generated by atrioventricular valvular regurgitation jets.