Increased IL-21 secretion by aged CD4+T cells is associated with prolonged STAT-4 activation and CMV seropositivity

Advancing age leads to significant decline in immune functions. IL-21 is produced primarily by T follicular helper (Tfh) cells and is required for effective immune cell functions. Here we compared the induction of IL-21 in aged and young subjects. Our investigation demonstrates that CD4+T cells from healthy elderly individuals (age ≥ 65) secreted significantly higher levels of IL-21 on priming with aged and young dendritic cells (DC). Though the aged and young DCs secreted comparable levels of IL-12 on stimulation with anti-CD40 antibody and LPS, culture of DCs with aged CD4+ T cells resulted in increased production of IL-21 as compared to that with young CD4+ T cells. Further examination revealed that the response of aged naïve CD4+ T cells to IL-12 was altered, resulting in increased differentiation of aged Th cells towards Tfh cells. Investigation into the signaling mechanism suggested that phosphorylation of STAT-4 in response to IL-12 was sustained for a longer duration in aged CD4+ T cells as compared to CD4+ T cells from young subjects. Additional analysis demonstrated that increased IL-21 secretion correlated with chronic CMV infection in aged subjects. These findings indicate that chronic CMV infection alters the response of aged CD4+ T cells to IL-12 resulting in an increased secretion of IL-21 and that aging affects Tfh cell responses in humans which may contribute to age-associated inflammation and immune dysfunctions.

Elevated snoRNA biogenesis is essential in breast cancer

Hyperactive ribosomal biogenesis is widely observed in cancer, which has been partly attributed to the increased rDNA transcription by Pol I in cancer. However, whether small nucleolar RNAs (snoRNAs), a class of non-coding RNAs crucial in ribosomal RNA (rRNA) maturation and functionality, are involved in cancer remains elusive. We report that snoRNAs and fibrillarin (FBL, an enzymatic small nucleolar ribonucleoprotein, snoRNP) are frequently overexpressed in both murine and human breast cancer as well as in prostate cancers, and significantly, that this overexpression is essential for tumorigenicity in vitro and in vivo. We demonstrate that when the elevated snoRNA pathway is suppressed, the tumor suppressor p53 can act as a sentinel of snoRNP perturbation, the activation of which mediates the growth inhibitory effect. On the other hand, high level of FBL interferes with the activation of p53 by stress. We further show that p53 activation by FBL knockdown is not only regulated by the ribosomal protein-MDM2-mediated protein stabilization pathway, but also by enhanced PTB-dependent, cap-independent translation. Together, our data uncover an essential role of deregulated snoRNA biogenesis in tumors and a new mechanism of nucleolar modulation of p53.

Low-dose arsenic induces chemotherapy protection via p53/NF-κB-mediated metabolic regulation

Most chemotherapeutical drugs kill cancer cells chiefly by inducing DNA damage, which unfortunately also causes undesirable injuries to normal tissues, mainly due to p53 activation. We report a novel strategy of normal tissue-protection that involves p53/NF-κB coordinated metabolic regulation. Pretreatment of untransformed cells with low doses of arsenic induced concerted p53 suppression and NF-κB activation, which elicited a marked induction of glycolysis. Significantly, this metabolic shift provided cells effective protection against cytotoxic chemotherapy, coupling the metabolic pathway to cellular resistance. Using both in vitro and in vivo models, we demonstrated an absolute requirement of functional p53 in arsenic-mediated protection. Consistently, a brief arsenic-pretreatment selectively protected only normal tissues but not tumors from toxicity of chemotherapy. An indispensable role of glycolysis in protecting normal tissues was demonstrated by using an inhibitor of glycolysis, 2-deoxyglucose, which almost totally abolished low-dose arsenic-mediated protection. Together, our work demonstrates that low-dose arsenic renders normal cells and tissues resistance to chemotherapy-induced toxicity by inducting glycolysis.

Prognostic significance of β-catenin expression in patients with non-small cell lung cancer: a meta-analysis

β-Catenin has been reported to play a crucial role in the invasion and metastasis of lung cancer. However, the value of β-catenin as a prognostic factor for non-small cell lung cancer (NSCLC) remains controversial. The present study systematically reviewed the evidence of predicting significance of β-catenin expression in NSCLC patients with meta-analysis. Twelve literatures were included by searching PubMed, Cochrane library, and EMBASE databases. Separate hazard ratio estimates and a 95% confidence interval (CI) for the prognostic value of β-catenin in NSCLC were extracted and merged from the included literatures. The summary hazard ratios were 1.91 (95% CI 1.60-2.28), indicating a worse overall survival for NSCLC patients with reduced β-catenin expression. There was no significant heterogeneity among the studies (X(2) = 12.41, p = 0.413, I(2) = 3.3%). Publication bias was not statistically significant. Sensitivity analysis showed that omission of any single study had little effect on the combined risk estimates. This meta-study revealed that decreased β-catenin expression denoted a poor prognosis in NSCLC patients.

[High dose chemotherapy combined with peripheral blood stem cell transplantation (PBSCT) in the treatment of patients with small cell lung cancer]

BACKGROUND

To investigate the therapeutic effect and safety of PBSCT combined with high dose chemotherapy in the treatment of small cell lung cancer(SCLC).

METHODS

From March, 1994 to June, 1999, high dose chemotherapy combined with PBSCT was carried out in 20 patients with SCLC. Eight patients were in CR status while twelve patients were for salvaging therapy. Allo-PBSCT was performed in 1 patient and Auto-PBSCT in 19 patients. After mobilization of stem cell, mononeuclear cell (MNC) was collected for ≥3.0×10⁸/kg, CD34+ cell≥2.0×10⁶/kg. The high dose chemotherapy included carboplatin 350 mg/m²×3 days, VP-16 120 mg/m²×5 days, and E-ADM 40 mg/m²×2 days.

RESULTS

Encouraging results were achieved in 8 patients who were in CR status. Seven of the eight patients survived after Auto-PBSCT. One patients survived more than 1 year, 4 cases over 2 years, and 3 cases over 3 years. Of the 3 patients, 2 survived more than 4 years. In the group of salvaging therapy, response was good, however there was no long-term survival and median remission time was only 3.5 months.

CONCLUSIONS

High dose chemotherapy combined with PBSCT in the treatment of SCLC with CR status is feasible and safe, although the side effects are severe too. It is worth further studying on clinical practice.

Risk of second primary cancer after treatment for esophageal cancer: a pooled analysis of nine cancer registries

The introduction of new treatments for esophageal cancer including surgery, chemotherapy, radiotherapy, or a combination of these modalities has not only improved patient survival, but may also increase the risk of the second primary cancers. The available evidence is conflicting with most risk estimates based on sparse numbers. Here we estimated standardized incidence ratios (SIRs) of second cancer among 24,557 esophageal cancer survivors (at least 2 months) in the Surveillance, Epidemiology, and End Results (SEER) Program between 1973 and 2007, who had been followed up for median 6.5 years (range 2 months-29.3 years). Second cancer risk was statistically significantly elevated (SIR = 1.34, 95% confidence interval [CI]= 1.25-1.42) among the survivors compared with the general population; the SIRs for cancers of oral and pharynx, stomach, small intestine, larynx, lung and bronchus, thyroid and prostate cancer were 8.64 (95% CI = 7.36-10.07), 2.87 (95% CI = 2.10-3.82), 3.80 (95% CI = 1.82-7.00), 3.19 (95% CI = 2.12-4.61), 1.68 (95% CI = 1.46-1.93), 2.50 (95% CI = 1.25-4.47), and 0.77 (95% CI = 0.65-0.90), respectively. Radiotherapy raised cancer risk of larynx (SIR = 3.98, 95% CI = 2.43-6.14) and thyroid (SIR = 3.57, 95% CI = 1.54-7.03) among all esophageal cancer survivors. For patients who had 5-9 years of follow up after radiotherapy, the SIR for lung cancer was 3.46 (95% CI = 2.41-4.82). Patients with esophageal cancer are at increased risks of second cancers of oral and pharynx, larynx, lung, and thyroid, while at a decreased risk for prostate cancer. These findings indicate that radiotherapy for esophageal cancer patients may increase risk of developing second cancers of larynx, lung, and thyroid. Thus, randomized clinical trials to address the association of radiotherapy and the risk of secondary cancer are warranted.

Effect of greyscale liquid crystal displays of different resolutions on observer performance during detection of small solitary pulmonary nodules

OBJECTIVE

The aim of this study was to evaluate the effect of monochrome liquid crystal displays (LCDs) with different resolutions on observer performance during detection of small solitary pulmonary nodules.

METHODS

Chest images of digital radiography were selected online from the hospital's picture archiving and communication system. Of the 164 images selected, small solitary non-calcified pulmonary nodules were present in 63 images and absent in 101 images. Observer performance was assessed among 3 extremely experienced, 3 very experienced and 3 moderately experienced radiologists, who independently interpreted these images on 2, 3 and 5 megapixel greyscale LCDs. A five-point confidence level rating scale was used to represent the presence of nodules: definite absence, probable absence, indetermination, probable presence and definite presence. The observers were requested to rank each image on the given display according to the presence of the pulmonary nodule. Observer performance was analysed in terms of receiver operating characteristics (ROCs).

RESULTS

The areas under the ROC curves which represented the observer performance for the 2, 3 and 5 megapixel LCDs were found to be 0.705, 0.722 and 0.764, respectively, for the extremely experienced radiologists; 0.687, 0.712 and 0.721, respectively, for the very experienced radiologists; and 0.689, 0.696 and 0.711, respectively, for the moderately experienced radiologists. These differences were not statistically significant.

CONCLUSION

The observer performances for detection of small solitary non-calcified pulmonary nodules by radiologists with varying degrees of experience were comparable between the 2, 3 and 5 megapixel monochrome LCDs.

Effects of duration of treatment and dosage of eicosapentaenoic acid and stearidonic acid on red blood cell eicosapentaenoic acid content

OBJECTIVE

The purpose of this randomized, controlled, parallel group study was to characterize the relationships between dosages of stearidonic acid (SDA) and eicosapentaenoic acid (EPA), and incorporation of EPA into red blood cell (RBC) membranes over time.

METHODS

Healthy subjects (n=131) received capsules with placebo (safflower oil), SDA (0.43, 1.3, 2.6, or 5.2 g/d) or EPA (0.44, 1.3, or 2.7 g/d) for 12 weeks. RBC fatty acids were analyzed biweekly.

RESULTS

RBC %EPA increased in all EPA and SDA groups (p<0.02 vs. control) except the 0.43 g/d SDA group (p=0.187). For theoretical intakes of EPA of 0.25, 0.5, and 0.89 g/d, the amounts of SDA needed to achieve equivalent RBC EPA enrichment were 0.61, 1.89, and 5.32 g/d (conversion efficiencies of 41%, 26%, and 17%), respectively.

CONCLUSIONS

SDA increased RBC %EPA in a dosage and time-dependent manner at intakes as low as 1.3 g/d.

P2-02-04: Novel Functions of vps34 in Non-Transformed Epithelial Cells: Regulation of Cell Proliferation and Tumorigenesis

Autophagic and endocytic pathways are tightly regulated membrane rearrangement processes that are crucial for homeostasis, development and disease. A list of proteins regulating these cellular processes show altered expression in cancers, suggesting derailed autophagy or endocytosis as an emerging feature of cancer. Class III phosphatidylinositol 3-kinase (PI3kinase) Vps34 regulates both autophagic and endocytic systems by recruiting proteins containing PtdIns3P binding domains. Recently, many new insights into the biology of class III PI3Kinase have been reported. Most of these studies, however, used mainly transformed cells. It is unclear whether class III PI3Kinase works similarly in non-transformed cells. In the recent study, we explored this by depleting both transformed and non-transformed mammary epithelial cell lines of Vps34 using shRNA. In consistent with previous finding, vps34-depleted cells are defect in formation of FYVE-GFP puncta, and showed altered early and recycling endosome dynamics. In a shark contrast to transformed cells where knockdown of Vps34 was associated with decreased growth, Vps34 deficiency in non-transformed cells resulted in a marked increase in cell proliferation. The deregulated autophagy function found in Vps34-depleted cells appeared to be not involved in cell growth regulation as silence of either Atg7 or Beclin1 expression did not affect the growth rate. On the other hand, reporter luciferase-based ten-pathway screens suggested an altered activity of the MAPK pathway. Indeed, biochemical analysis indicated a sustained ERK activation resulting from the impediment of endosome-mediated EGFR turnover in Vps34 deficient cells. A contribution of the endosomal pathway to Vps34-mediated regulation of cell proliferation was further confirmed by using Rab5 and Rab11 mutants that deregulated early and recycling endosome, respectively. Importantly, inactivation of Vps34 compromised the cellular barrier against oncogene-mediated transformation, as demonstrated by the increased susceptibility of Vps34 depleted cells to Ras-induced colony formation in vitro and tumor development in mice. All together, our data uncover a novel role for the class III PI3Kinase-endosomal pathway in regulation of cell proliferation.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-02-04.

Molecular cloning, expression, and imprinting status of maternally expressed gene 8 (Meg8) in dairy cattle

At present, small number imprinted genes have been reported in cattle compare to human and mouse. Maternally expressed gene 8 (Meg8), a non-coding gene, have been identified maternally expressed in mouse and sheep, but its sequences and imprinting status have not been established in cattle. In this study, the full-length of cattle Meg8cDNA sequence was obtained by reverse transcript polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) method, which has a high homology in exons sequences with the corresponding region of sheep Meg8. The isolation of cDNA sequence showed the presence of multiple splice variants in cattle Meg8 gene. The Meg8 was found to be expressed in all adult examined tissues, including heart, liver, spleen, lung, kidney, brain, subcutaneous fat and skeletal muscle. A single nucleotide polymorphism (SNP) was identified in exon 6 by Single-Strand Conformation Polymorphism (SSCP), and used to distinguish between monoallelic and biallelic expression in cattle tissues. The expression analysis of Meg8 in a heterozygous cattle showed that only one parental allele was expressed in all examined tissues, suggesting that Meg8 is imprinted in cattle.

Transforming growth factor-β1 polymorphisms and chronic obstructive pulmonary disease: a meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a complex polygenic disease in which gene- environment interactions play a critical role in disease onset and progression. Transforming growth factor-β 1 (TGF-β 1) is one of several candidate loci for the pathogenesis of COPD, and is highly polymorphic.

OBJECTIVE

To derive a more precise estimation of the relationship between the T869C and C-509T polymorphisms of the TGF-β 1 gene and COPD, a meta-analysis of 11 published case-control studies was performed.

METHODS

Ten studies with 1507 cases and 2542 controls for T869C polymorphism and six studies with 955 cases and 2136 controls for C-509T polymorphism were included. The pooled odds ratios were performed respectively for allele contrasts, additive genetic model, dominant genetic model and recessive genetic model. A subgroup analysis was also performed by ethnicity for T869C polymorphism.

RESULTS

With respect to T869C polymorphism, a significant association of TGF-β 1 gene polymorphism at 869T/C with COPD was observed in the overall analysis (C vs. T: OR 0.82, 95%CI 0.70-0.96, P = 0.01). In the subgroup analysis by ethnicity, significant risks were also found in the Caucasian population for C vs. T (OR 0.77, 95%CI 0.60-0.98, P = 0.03), but not in the Asian population (C vs. T: OR 0.88, 95%CI 0.76-1.03, P = 0.10). With respect to C-509T polymorphism, no significant association with COPD was demonstrated in the overall analysis (T vs. C: OR 0.84, 95%CI 0.68- 1.04, P = 0.11).

CONCLUSION

Potentially functional TGF-β 1 T869C polymorphism may play a low penetrance role in COPD susceptibility in an ethnicity-specific manner.

COP9 signalosome subunit 8 is required for postnatal hepatocyte survival and effective proliferation

Studies using lower organisms and cultured mammalian cells have revealed that the COP9 signalosome (CSN) has important roles in multiple cellular processes. Conditional gene targeting was recently used to study CSN function in murine T-cell development and activation. Using the Cre-loxP system, here we have achieved postnatal hepatocyte-restricted knockout of the csn8 gene (HR-Csn8KO) in mice. The protein abundance of other seven CSN subunits was differentially downregulated by HR-Csn8KO and the deneddylation of all cullins examined was significantly impaired. Moreover, HR-Csn8KO-induced massive hepatocyte apoptosis and evoked extensive reparative responses in the liver, including marked intralobular proliferation of biliary lineage cells and trans-differentiation and proliferation of the oval cells. However, division of pre-existing hepatocytes was significantly diminished in HR-Csn8KO livers. These findings indicate that Csn8 is essential to the ability of mature hepatocytes to proliferate effectively in response to hepatic injury. The histopathological examinations revealed striking hepatocytomegaly in Csn8-deficient livers. The hepatocyte nuclei were dramatically enlarged and pleomorphic with hyperchromasia and prominent nucleoli, consistent with dysplasia or preneoplastic cellular alteration in HR-Csn8KO mice at 6 weeks. Pericellular and perisinusoid fibrosis with distorted architecture was also evident at 6 weeks. It is concluded that CSN8/CSN is essential to postnatal hepatocyte survival and effective proliferation.

A role for trichosanthin in the expansion of CD4CD25 regulatory T cells

CD4(+)CD25(+) regulatory T cells (Tregs) are critical for the peripheral immune tolerance. Understanding the signals for the generation of Tregs is important for the clinical immunotherapy, but only limited progress has been made on obtaining enough peripheral Tregs. The aim of this study was to evaluate the role of trichosanthin (Tk) extracted from Chinese medicinal herb Trichosanthes kirilowi on the function of Tregs in vitro and in vivo. We reported here that Tk is needed for the expansion of freshly isolated CD4(+)CD25(+)Tregs (nTregs) into Tk-expanded CD4(+)CD25(+)Tregs (Tk-Tregs) through up-regulating CD25 and Foxp3 expression. The dose-response analyses indicated that 100 ng/ml Tk was the most appropriate dose. The result of real-time PCR showed that Tk-Tregs expressed 1.5-fold higher levels of Foxp3 than those observed in nTregs. Tk-Tregs markedly suppressed activation of effector T cells at a suppressor/responder ratio of 1:1, 1:2, 1:4, 1:8 or 1:16, and their effect was dose dependent. Moreover, Tk-Tregs secreted more immunosuppressive cytokines interleukin (IL)-10 and transforming growth factor (TGF)-beta1 after stimulating with antigen and antigen-presenting cells (APC). Transwell experiments showed that not only cell-to-cell contact but also soluble cytokines were involved in suppressive mechanism of Tk-Tregs. And Tk-Tregs were more efficient in suppressing CD25(-)T cell response to specific antigen than to irrelative antigen. Most importantly, it was revealed for the first time that Tk-Tregs could prolong the survival duration of mice with acute graft-versus-host disease (aGVHD). In conclusion, the study suggests a possible therapeutic potential of Tk-Tregs for clinical treatment on aGVHD.

Weight Gain Is Associated with Increased Risk of Hot Flashes in Breast Cancer Survivors on Aromatase Inhibitors

Objective: Hot flashes in breast cancer survivors (BCS) receiving adjuvant aromatase inhibitor (AI) therapy are common, but risk factors for these symptoms are not well-defined. This study tested if body size is associated with hot flashes in BCS on AI therapy.Materials and methods: We performed a cross-sectional analysis of a cohort of postmenopausal women with Stages 0-III breast cancer receiving adjuvant AI therapy at a university hospital-based outpatient breast oncology clinic. Subjects provided patient-reported outcomes on hot flashes, current and pre-breast cancer weight and height, and additional demographic and treatment data.The primary outcome was occurrence of hot flashes. Secondary outcomes included hot flash severity and frequency. The exposures of interest were 1) current weight and 2) weight change since breast cancer diagnosis, categorized as weight loss (lost 10 pounds or more), maintenance (+/- 10 pounds), or gain (gained 10 pounds or more). Multivariable logistic regression models examined the independent association between hot flash outcomes and current weight or weight change while controlling for confounders.Results: 300 participants were enrolled at a mean age of 61 years (range 33-86) after mean duration of AI exposure of 23 months (range 1 month-9 years). 177 (59%) reported hot flashes overall, 96 (32%) reported moderate to very severe hot flashes, and 60 (20%) had at least 4 hot flashes daily. 182 (61%) experienced weight maintenance, while 81 (27%) had weight gain and 34 (11%) had weight loss. In a multivariable model, weight gain was independently associated with hot flash occurrence (OR 2.1, 95% CI 1.1-4.4) and hot flash severity (OR 2.4, 95% CI 1.4-4.9), but not hot flash frequency, after adjusting for current weight and height, age, smoking, race, prior chemotherapy and prior tamoxifen therapy. Hot flash occurrence was also significantly associated with current smoking (OR 5.1, 95% CI 1.1-24.0) and age (OR for each additional year of age 0.93, 95% CI 0.90-0.97). Current weight, alcohol use, AI type, and AI duration were not associated with any of the three outcomes.Conclusions: In an outpatient BCS population on AI therapy, weight gain is a risk factor for both hot flash occurrence and severity. Women who gained at least ten pounds since breast cancer diagnosis were two times more likely to have hot flashes than women who maintained or lost weight. These results support the thermoregulatory model of hot flashes and argue against a protective effect of body fat in this population.Support: ACS MRSG-08-110-01-CCE, ACS CCDA#-08-107-01, Pennsylvania Department of Aging

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1059.

Genetic considerations relevant to intracranial hemorrhage and brain arteriovenous malformations

Brain arteriovenous malformations (AVMs) cause intracranial hemorrhage (ICH), especially in young adults. Molecular characterization of lesional tissue provides evidence for involvement of both angiogenic and inflammatory pathways, but the pathogenesis remains obscure and medical therapy is lacking. Abnormal expression patterns have been observed for proteins related to angiogenesis (e.g., vascular endothelial growth factor, angiopoietin-2, matrix metalloproteinase-9), and inflammation (e.g., interleukin-6 [IL-6] and myeloperoxidase). Macrophage and neutrophil invasion have also been observed in the absence of prior ICH. Candidate gene association studies have identified a number of germline variants associated with clinical ICH course and AVM susceptibility. A single nucleotide polymorphism (SNP) in activin receptor-like kinase-1 (ALK-1) is associated with AVM susceptibility, and SNPs in IL-6, tumor necrosis factor-alpha (TNF-alpha), and apolipoprotein-E (APOE) are associated with AVM rupture. These observations suggest that even without a complete understanding of the determinants of AVM development, the recent discoveries of downstream derangements in vascular function and integrity may offer potential targets for therapy development. Further, biomarkers can now be established for assessing ICH risk. These data will generate hypotheses that can be tested mechanistically in model systems, including surrogate phenotypes, such as vascular dysplasia and/or models recapitulating the clinical syndrome of recurrent spontaneous ICH.

Development of a cerebral microvascular dysplasia model in rodents

Normal vasculature development of the central nervous system is extremely important because patients with vascular malformations are at life-threatening risk for intracranial hemorrhage or cerebral ischemia. The etiology and pathogenesis of abnormal vasculature development in the central nervous system are unknown, and progress is hampered by the lack of animal models for human cerebrovascular diseases. Here, we report our current study on cerebral microvascular dysplasia (CMVD) development. Using vascular endothelial growth factor hyper-stimulation, we demonstrated that aberrant microvessels could be developed in the rodent brain under certain conditions (such as genetic deficient background, local cytokine and chemokine release, or exogenous vessel dilating stimulation) that may speed up focal angiogenesis and lead to cerebral vascular dysplasia.

Multiple logistic regression analysis of risk factors for carcinogenesis of oral submucous fibrosis in mainland China

Oral submucous fibrosis (OSF), a chronic progressive disorder, is regarded as the premalignant lesion of oral squamous cell carcinoma (OSCC). Its distribution is associated with chewing betel quid (BQ). The objective of the present study was to investigate risk factors for the carcinogenesis of OSF in mainland China. A case-control study was performed in 42 patients with OSCC that originated from OSF and 40 OSF controls. Epidemiological data and information related to risk factors were collected using a short structured questionnaire. Odd ratios (OR) and 95% confidence intervals (CI) were derived from logistic regression analysis. In multivariate analysis, only age, duration of BQ chewing, duration of cigarette smoking, and OSF accompanied by oral leukoplakia or oral lichen planus were associated with significantly increased risk for the malignant transformation of OSF. These findings contribute to current knowledge on the prevention of carcinogenesis of OSF in mainland China.

AAV serotype 1 mediates more efficient gene transfer to pig myocardium than AAV serotype 2 and plasmid

Adeno-associated virus (AAV) has many properties of an ideal vector for delivery of therapeutic genes into the myocardium. Previous studies in a mouse model of myocardial infarction showed that AAV serotype 1 (AAV1) is superior to AAV serotypes 2-5 to transfer genes into the myocardium by direct injection. Since vectors may behave differently in humans and because the human and the pig hearts resemble each other closely, we tested whether AAV1 is also superior to AAV2 in transferring genes into the pig myocardium. We also compared gene transduction efficiency between AAV vectors and plasmid. We injected CMVLacZ and CMVVEGF (vectors with the cytomegalovirus (CMV) promoter driving LacZ and VEGF gene expression) unpackaged or packaged in AAV serotypes 1 or 2 capsids into pig myocardium. Hearts were collected 3, 14 and 28 days after the injection. Gene expression was analyzed by real-time reverse-transcription polymerase chain reaction (RT-PCR) and histological staining. Capillaries and smooth muscle alpha-actin (SMA)-positive vessels were quantified. Potential lymphocyte infiltration at the injection sites was analyzed by immunostaining using specific antibodies. As in the mouse, AAV1 mediated better gene transduction than AAV2. Plasmid mediated minimal gene expression only. More capillaries and SMA-positive vessels were detected at AAV1CMVVEGF- and AAV2CMVVEGF-injected than AAV1CMVLacZ-injected sites. We did not detect inflammatory cell infiltration at the injection sites. In conclusion, by direct injection, AAV1 is more efficient than AAV2, and plasmid is inefficient in mediating gene transfer into the pig myocardium. AAV-mediated VEGF gene transfer can also induce neovascular formation in the pig myocardium.

Immuno-inflammatory regulation effect of mesenchymal stem cell transplantation in a rat model of myocardial infarction

BACKGROUND

Mesenchymal stem cells (MSC) have recently been shown to possess immunomodulatory properties in vitro and in vivo. The present study aimed to investigate the regulatory effect of MSC transplantation on the immuno-inflammatory response in myocardial infarction (MI).

METHODS

MI was induced in Sprague-Dawley rats by left anterior descending coronary artery ligation, and the animals were randomly assigned into the following three groups: sham ( n=8); phosphate-buffered saline (PBS) injected (MI+PBS, n=8); and MSC transplantation (MI+MSC, n=8). BrdU-labeled MSC or PBS was transplanted into peri-infarct myocardium by direct myocardial injection. At 1 and 28 days post-transplantation, cardiac function was evaluated by echocardiography. Transplanted cells were investigated through immunohistochemistry. Lymphocyte cytotoxic activity was evaluated with the crystal violet method. The activity of NF-kappaB and protein expression of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and IL-10 in myocardium were assessed by immunohistochemistry and Western blot.

RESULTS

Echocardiographic examination revealed that the MSC transplantation prevented left ventricular dilation and dysfunction at 28 days after the operation. BrdU-stained cells were found living in host heart 4 weeks after transplantation. MSC transplantation attenuated the cytotoxic activity of spleen lymphocytes. Transplantation of MSC inhibited the activity of NF-kappaB, attenuated the protein production of TNF-alpha and IL-6, and increased the expression of IL-10 in peri-infarct myocardium.

DISCUSSION

MSC transplantation modulated the immuno-inflammatory response in MI. The immuno-inflammatory regulatory effect of MSC transplantation might partly account for the cardiac protection in myocardial infarction.

Differential sensitivity of naïve and subsets of memory CD4+ and CD8+ T cells to hydrogen peroxide-induced apoptosis

CD4+ and CD8+ memory T cells are identified into central and effector memory subsets, which are characterized by distinct homing patterns and functions. In this investigation, we show that naïve and central memory CD4+ and CD8+ T cells are sensitive to hydrogen peroxide (H2O2)-induced apoptosis, whereas effector memory CD4+ and CD8+ T cells are relatively resistant to H2O2-induced apoptosis. Apoptosis in naïve and central memory CD4+ and CD8+ is associated with the release of cytochrome c and activation of caspase-9 and caspase-3, upregulation of Bax and voltage-dependent anion channel (VDAC) expression, and decreased intracellular glutathione (GSH). In vitro GSH and a superoxide dismutase mimetic Mn(III) tetrakis (1-methyl-4-pyridyl) porphyrin inhibited H2O2-induced apoptosis in both naïve and central memory CD4+ and CD8+ T cells. Furthermore, VDAC inhibitor 4,4'-diisothiocynostilbene-2,2'-disulfonic acid blocked H2O2-induced apoptosis. These data demonstrate that H2O2 induces apoptosis preferentially in human naïve and central memory CD4+ and CD8+ T cells via the mitochondrial pathway by regulating intracellular GSH and the expression of Bax and VDAC.

Altered innate immune functioning of dendritic cells in elderly humans: a role of phosphoinositide 3-kinase-signaling pathway

Aging represents a state of paradox where chronic inflammation is associated with declining immune responses. Dendritic cells (DCs) are the major APCs responsible for initiating an immune response. However, DC functions in aging have not been studied in detail. In this study, we have compared the innate immune functions of monocyte-derived myeloid DCs from elderly subjects with DCs from young individuals. We show that although phenotypically comparable, DCs from the aging are functionally different from DCs from the young. In contrast to DCs from the young, DCs from elderly individuals display 1) significantly reduced capacity to phagocytose Ags via macropinocytosis and endocytosis as determined by flow cytometry; 2) impaired capacity to migrate in vitro in response to the chemokines MIP-3beta and stromal cell-derived factor-1; and 3) significantly increased LPS and ssRNA-induced secretion of TNF-alpha and IL-6, as determined by ELISA. Investigations of intracellular signaling revealed reduced phosphorylation of AKT in DCs from the aging, indirectly suggesting decreased activation of the PI3K pathway. Because the PI3K-signaling pathway plays a positive regulatory role in phagocytosis and migration, and also functions as a negative regulator of TLR signaling by inducing activation of p38 MAPK, this may explain the aberrant innate immune functioning of DCs from elderly subjects. Results from real-time PCR and protein expression by flow cytometry demonstrated an increased expression of phosphatase and tensin homolog, a negative regulator of the PI3K-signaling pathway, in DCs from the aging. Increased phosphatase and tensin homolog may thus be responsible for the defect in AKT phosphorylation and, therefore, the altered innate immune response of DCs from elderly humans.

Aberrant Innate Immune Functions of Dendritic Cells in Aged Humans (85.12)

The molecular mechanisms underlying the chronic inflammation and reduced immunity observed during aging are not well understood. Comparison of the innate immune functions of monocyte-derived DCs from aging subjects with DCs from young individuals showed that MDDCs from aging individuals display

significantly reduced capacity to capture antigens via macropinocytosis and receptor-mediated endocytosis as determined by flow cytometry;impaired capacity to migrate in vitro in response to the chemokine MIP3-beta; andsignificantly increased LPS induced secretion of TNF-alpha and IL-6.

Investigations of intracellular signaling revealed reduced phosphorylation of AKT in MDDCs from aging, suggesting decreased activation of PI3kinase signaling pathway. Since PI3K signaling pathway plays a positive regulatory role in phagocytosis and migration, and it also functions as a negative regulator of TLR signaling by inducing activation of p38 MAP kinase, this may explain the aberrant innate immune functioning of DCs from aged subjects. Results further revealed an increased expression of PTEN, a negative regulator of PI3Kinase signaling pathway, in MDDCs from aged subjects. Increased PTEN may thus be responsible for the defect in AKT phosphorylation and therefore, altered innate immune response of DCs from aged humans.

This study is supported in part by a grant AG027512 from NIH and partly by new scholar grant from the Ellison Medical Foundation.

Evidence of anti-obesity effects of the pomegranate leaf extract in high-fat diet induced obese mice

OBJECTIVE

To investigate the anti-obesity effects of the pomegranate leaf extract (PLE) in a mouse model of high-fat diet induced obesity and hyperlipidemia.

DESIGN

For the anti-obesity experiment, male and female ICR mice were fed with a high-fat diet to induce obesity. When the weight of the high-fat diet group was 20% higher than the normal diet group, the animals were treated with 400 or 800 mg/kg/day of PLE for 5 weeks. Body weight and daily food intake were measured regularly during the experimental period. The various adipose pads were weighed and serum total cholesterol (TC), triglyceride (TG), glucose and high-density lipoprotein cholesterol (HDL-C) were measured after 5 weeks, treatment with PLE. In the fat absorption experiment, both the normal and obese mice were given 0.5 ml lipid emulsion and PLE at a dose of 800 mg/kg at the same time. Serial serum TG levels were measured at times 1, 2, 3, 4 and 6 h after the treatment. TGs in fecal excretions were measured after the mice were orally given a lipid emulsion. Effects of PLE and its isolated compounds (ellagic acid and tannic acid) on pancreatic lipase activity were examined in vitro.

RESULTS

The PLE-treated groups showed a significant decrease in body weight, energy intake and various adipose pad weight percents and serum, TC, TG, glucose levels and TC/HDL-C ratio after 5 weeks treatment. Furthermore, PLE significantly attenuated the raising of the serum TG level and inhibited the intestinal fat absorption in mice given a fat emulsion orally. PLE showed a significant difference in decreasing the appetite of obese mice fed a high-fat diet, but showed no effect in mice fed a normal diet.

CONCLUSION

PLE can inhibit the development of obesity and hyperlipidemia in high-fat diet induced obese mice. The effects appear to be partly mediated by inhibiting the pancreatic lipase activity and suppressing energy intake. PLE may be a novel appetite suppressant that only affects obesity owing to a high-fat diet.

Arsenic trioxide induces apoptosis via the mitochondrial pathway by upregulating the expression of Bax and Bim in human B cells

Arsenic trioxide (As2O3) has been approved for the treatment of acute promyelocytic leukemia (APML) and it is a promising candidate for the treatment of patients with lymphoproliferative disorders, such as relapsed or refractory multiple myeloma and myelodysplastic syndromes. The effects of As2O3 on B cells, specifically which do not express Bcl-2, have not been studied. In this study, we have demonstrated that As2O3, at clinically achievable therapeutic concentrations, induces apoptosis in Bcl-2 negative human B cell line Ramos. As2O3-induced apoptosis is associated with reduced mitochondrial transmembrane potential (delta psi), enhanced generation of intracellular reactive oxygen species (ROS), release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria into cytoplasm, activation of caspases, and upregulation of Bax and Bim expression. Exogenous glutathione (GSH) reverses the As2O3-induced apoptosis in a dose-dependent manner. Altogether, these data indicate that As2O3 induces apoptosis in B cells, regardless of Bcl-2 expression, via the mitochondrial pathway by enhancing oxidative stress.

The EPRI EDE calculator--a software package for assessing effective dose equivalent from hot particles on the skin

Whole body exposure from photon-emitting hot particles is receiving new attention because of changes in skin dose regulations. A recent study calculated and tabulated effective dose equivalent (EDE) and effective dose (ED) for photon energies between 0.1 MeV and 2 MeV for point sources at 74 locations on the skin. This technical note describes a software package called the EPRI EDE Calculator that allows a user to input exposure data and to calculate the EDE and ED automatically.