SDF-1α Facilitates Mesenchymal Stem Cells to Induce Regulatory B Cell Differentiation from Patients with Immune Thrombocytopenia.

B cells play a central role in the pathogenesis of immune thrombocytopenia (ITP) by participating in humoral immunity. Meanwhile, regulatory B cells (Bregs), one subset of B cells, express negative regulatory effect on ITP. Mesenchymal stem cells (MSCs) have been demonstrated in the ability to induce immunosuppression, and stromal cell-derived factor-1α (SDF-1α) plays an important role in the migration and survival of MSCs. To investigate the mechanism of SDF-1α in controlling umbilical cord-derived MSCs (UC-MSCs) in inducing regulatory B cell differentiation of patients with ITP, we reconfirmed that SDF-1α promotes the proliferation of MSCs at the low doses of 0.05 µg/mL and 0.1 µg/mL but inhibits the proliferation and promotes the apoptosis of UC-MSCs at the high doses 0.5 µg/mL and 1 µg/mL; when UC-MSCs are cocultured with SDF-1α at 0.1 µg/mL, the decreased proportion of CD19+/CD24hi/CD38hi cells and IL-10-producing B cells (B 10 cell), considered as the Breg subset from ITP significantly enhanced, and the content of IL-10 in the supernatant is also obviously increased. The proportion of Bregs and the IL-10 secretion could be further promoted by the UC-MSCs treated with 0.1 µg/mL SDF-1α, which could also promote the miRNA-133 expression of UC-MSCs in an exosome-dependent manner; moreover, while the UC-MSCs were transfected with the miR-133 inhibitor, the proportion of induced Bregs decreased obviously when cocultured with peripheral blood mononuclear cells (PBMCs) of ITP. We conclude that UC-MSCs could effectively enhance the decreased proportion of Bregs from ITP; at appropriate concentrations, SDF-1α may promote the proliferating and survival ability of UC-MSCs and improve the production of Bregs induced by UC-MSCs through controlling miRNA-133 expression in the exosomes.

Evaluation of factors influencing the guide to read biomedical English literature course for Chinese new medical postgraduates-a multiple regression analysis.

BACKGROUND: There is a dearth of published literature that demonstrates the impact of a Guide to Reading Biomedical English Literature course on new Chinese medical postgraduates. Keeping this gap in mind, the objectives of this study were to assess the factors associated with course effectiveness using the teacher, postgraduate and organizational factors. METHODS: This study was conducted at Nanjing Medical University from December 2014 to December 2015. The participants were 440 new graduate students from different medical specialties. At baseline, each student was assessed for teacher factors, individual factors and organizational factors using a self-administered structured scored anonymous questionnaire. After that, Pearson chi-square analysis was conducted to evaluate the factors that impact teacher factors (knowledge level, teaching style, individualized teaching, logical teaching, heuristic teaching, literature difficulty, bilingual teaching), individual factors (gender, attitude toward studying, previewing literature, English literacy level) and course management (such as teaching objectives and assessment system) on this course. Furthermore, multiple logistic regression analyses were performed to determine the impact of the above factors on our outcome variables (knowledge level, teaching style, individualized teaching, heuristic teaching, study attitude, previewing literature, management). RESULTS: Nearly all of the participants (420 of 440, 95.5%) thought this course was helpful for learning to read scientific literature and understanding scientific research design. Multivariate logistic regression analyses showed that the participants perception of the course as effective was associated with teachers' high knowledge level (Adjusted Odds Ratio, AOR = 49.673; 95% confidence interval, 95% CI = 4.28, 575.90). In addition, heuristic teaching was found to be significantly associated with a positive teaching effect of teaching (AOR = 12.76; 95% CI = 1.78, 91.64). Furthermore, the participants perception of the course as effective was associated with positive attitude toward studying (AOR = 25.004; 95% CI = 2.51, 249.09). Previewing literature was also associated with course effectiveness (AOR = 0.02; 95% CI = 0.04, 0.11). CONCLUSIONS: This study indicated that the course effectiveness of the Guide for Reading Biomedical English Literature was associated with i) teachers' knowledge, ii) heuristic teaching, iii) students' positive attitude, and iv) students' previewing literature.

RRM2 is a potential prognostic biomarker with functional significance in glioma.

Glioma is one of the most common brain tumors, suggesting the importance of investigating the molecular mechanism of gliomas. We studied the roles of Ribonucleotide Reductase Regulatory Subunit M2 (RRM2) in glioma. Expressions of RRM2 are higher in glioma tissues evidenced by TCGA data, western blot and immunohistochemistry. RRM2 is negatively correlated with glioma patient's survival. RNA-seq showed that genes involved in apoptosis, proliferation, cell adhesion and negative regulation of signaling were up-regulated upon RNAi-mediated knock-down of RRM2. Cell phenotypes specific for stably knocking down RRM2 were determined using stable transfection in vitro. In an in vivo model, knock-down of RRM2 inhibited tumor growth and caused suppression of AKT and ERK1/2 signalings. Interfering RRM2 also down-regulated the expression of cyclin A, cyclin B1, cyclin D1, Vimentin, and N-cadherin, and elevated E-cadherin expression. Moreover, overexpression of RRM2 failed to increase the expression of cyclin B1, cyclin D1, and N-cadherin when phosphorylation of AKT and ERK1/2 was suppressed by LY294002 or PD98059. These findings indicated that RRM2 is a positive regulator of glioma progression which contributes to the migration and proliferation of glioma cells through ERK1/2 and AKT signalings and might be a novel prognostic indicator for glioma patients.

PPAR-γ Agonist Alleviates Liver and Spleen Pathology via Inducing Treg Cells during Schistosoma japonicum Infection.

BACKGROUND: Peroxisome proliferator-activated receptor- (PPAR-) γ plays critical roles in human metabolic disorders and has recently been implicated as a regulator of cellular proliferation and inflammatory responses. Regulatory T cells (Tregs), which express high levels of PPAR-γ protein, have the ability to maintain immune tolerance to self-antigens and regulate immune response to Schistosoma infection. However, mechanisms involved in the resolution of these responses are elusive. METHODS: Liver and spleen tissue samples in Schistosoma japonicum-infected mice after administration of pioglitazone (a PPAR-γ agonist) were collected. The hepatic and splenic pathologies were detected by H&E and Masson staining. The percentages of Th1/2 and Treg cells in the liver and spleen of each mouse were determined using flow cytometry. Levels of gene expression of PPAR-γ and Foxp3 in tissues or cells were determined using real-time PCR (RT-PCR). Macrophages were treated with pioglitazone in vitro or cocultured with normal purified CD4+ T cells for detecting Treg cells by flow cytometry. The interactions of PPAR-γ with Foxp3 in CD4+ T cells were detected by coimmunoprecipitation. RESULTS: Administration of pioglitazone resulted in the prevention of the development of hepatic and splenic pathologies. Activation of PPAR-γ by pioglitazone resulted in increased percentages of CD4+CD25+Foxp3+ Treg cells and decreased percentages of CD3+CD4+IFN-γ+ and CD3+CD4+IL-4+ cells in the liver and spleen of Schistosoma japonicum-infected mice. In addition, the PPAR-γ agonist can induce Treg cells in vitro directly or by modulating the macrophage's function indirectly. Furthermore, through interaction with Foxp3 in CD4+ T cells, the PPAR-γ agonist can promote the expression of Foxp3; however, the inhibitor of PPAR-γ weakened the expression of Foxp3 by modifying the coexpression of Foxp3 and PPAR-γ. CONCLUSIONS: Our study reveals a previously unrecognized role for PPAR-γ/Foxp3 signaling in regulating the immunopathology that occurs during Schistosoma infection through induction of Treg cells.

PSMB8 regulates glioma cell migration, proliferation, and apoptosis through modulating ERK1/2 and PI3K/AKT signaling pathways.

Glioma has been considered as one of the most aggressive and popular brain tumors of patients. It is essential to explore the mechanism of glioma. In this study, we established PSMB8 as a therapeutic target for glioma treatment. Expression of PSMB8 as well as Ki-67 was higher in glioma tissues demonstrated by western blot and immunohistochemistry. Then, the role of PSMB8 in migration and proliferation of glioma cells was investigated by conducting wound-healing, trans-well assay, cell counting kit (CCK)-8, flow cytometry assay and colony formation analysis. The data showed that interfering PSMB8 may inhibit the migration and proliferation of glioma cells by reducing expression of cyclin A, cyclin B1, cyclin D1, Vimentin, and N-cadherin, and by increasing expression of E-cadherin. Additionally, interfering PSMB8 may induce apoptosis of glioma cells by upregulating caspase-3 expression. Furthermore, these in vitro findings were validated in vivo and the ERK1/2 and PI3k/AKT signaling pathways were involved in PSMB8-triggered migration and proliferation of glioma cells. In an in vivo model, downregulation of PSMB8 suppressed tumor growth. In conclusion, PSMB8 is closely associated with migration, proliferation, and apoptosis of glioma cells, and might be considered as a novel prognostic indicator in patients with gliomas.

Praziquantel treatment after Schistosoma japonicum infection maintains hepatic insulin sensitivity and improves glucose metabolism in mice.

BACKGROUND: Epidemiological studies in China have revealed that Schistosoma japonicum infection is inversely correlated with metabolic syndrome, even after repeated chemotherapy with praziquantel (PZQ). We investigated the effect of chronic S. japonicum infection, PZQ chemotherapy, and soluble egg antigen (SEA) treatment on whole-body metabolic homeostasis and hepatic insulin sensitivity in mouse models. RESULTS: Infection with S. japonicum was found to increase whole-body and hepatic insulin sensitivity in mice. PZQ chemotherapy significantly improved the physiological status of infected mice, maintaining Th2 immune-deviation and enhancing hepatic insulin sensitivity. Multiple linear regression analysis revealed positive correlations between anti-inflammatory cytokine expression and insulin signalling-related genes in the liver, as demonstrated by an in vitro stimulated hepatic cell line with IL-13 and IL-22. SEA treatment also improved the glucose tolerance and insulin sensitivity in Lepr db/db mice. CONCLUSIONS: This study indicated that chronic S. japonicum infection with PZQ chemotherapy and SEA treatment can regulate metabolic homeostasis and protect against metabolic syndrome by promoting Th2 and regulatory responses in the liver.

Modulation of Salmonella Tumor-Colonization and Intratumoral Anti-angiogenesis by Triptolide and Its Mechanism.

The weakened tumour colonization of attenuated Salmonella has severely hampered its clinical development. In this study, we investigated whether an anti-inflammation and antiangiogenesis compound triptolide could improve the efficacy of VNP20009, a highly attenuated Salmonella strain, against mice melanoma. By comparing the effects of conventional VNP20009 monotherapy and a combination therapy that uses both triptolide and VNP20009, we found that triptolide significantly improved the tumour colonization of VNP20009 by reducing the number of infiltrated neutrophils in the melanoma, which led to a larger necrotic area in the melanoma. Moreover, the combination therapy suppressed tumour angiogenesis by reducing the expression of VEGF in a synergistic manner, retarding the growth of the melanoma. Our study revealed that triptolide could significantly enhance the antitumour effect of VNP20009 by modulating tumour angiogenesis and the host immune response, providing a new understanding of the strategy to improve Salmonella-mediated tumour therapy.

Absence of Batf3 results in reduced liver pathology in mice infected with Schistosoma japonicum.

BACKGROUND: The involvement of CD8+T cells in schistosomiasis is being increasingly appreciated, but the underlying mechanism is not well defined. RESULTS: In this study, we showed that the absence of Batf3 alleviated liver damage in Batf3 -/- mice infected with S. japonicum. We found alleviated liver granulomatous inflammation in Batf3 -/- mice with schistosomiasis japonica could not be attributed to the difference in schistosome egg or worm burden. The stronger Tc1 cell responses observed in Batf3 -/- mice suggested that the deletion of Batf3 resulted in more activation of CD8+T cells unexpectedly during the natural infection of schistosomes. We detected a small amount of CD8α+ DCs in the spleen of Batf3 -/- mice at 9w post-infection. This small amount of newly generated CD8α+ DCs might contribute to enhanced activation of CD8+T cells via cross-presentation and activation which then attenuate hepatic pathological damage found in Batf3 -/- mice. CONCLUSIONS: Our study provides evidence that Batf3 is associated with the immunoregulation of the liver granuloma formation, which may confer a new options for schistosomiasis treatment.

PPAR-γ agonist ameliorates liver pathology accompanied by increasing regulatory B and T cells in high-fat-diet mice.

OBJECTIVE: Peroxisome proliferator-activated receptor (PPAR)-γ plays critical roles in human metabolic disorders. However, the mechanism remains incompletely understood. Regulatory cells contribute to these metabolic improvements; therefore, whether PPAR-γ agonist regulates regulatory cells was investigated. METHODS: C57BL/6J mice received a normal or high-fat diet (HFD) with or without pioglitazone treatment. Mice were sacrificed for detecting the metabolic parameters. Lymphocytes from spleen and visceral adipose tissue (VAT) were collected and analyzed for ST2+ Tregs and Bregs by flow cytometry. IL-10 in the liver or VAT was detected by immunofluorescence and ELISA. Correlation analysis between IL-10 and liver weight or serum total cholesterol was made by Pearson correlation analysis. RESULTS: Pioglitazone increased VAT weight but reduced serum total cholesterol, hepatic steatosis, and cholesterol crystallization formation. Pioglitazone treatment enhanced ST2+ Tregs and Bregs in the VAT and spleen of HFD-fed mice (all P < 0.05). Pioglitazone treatment increased IL-10 in the livers or VAT of HFD-fed mice (all P < 0.05). The expression of IL-10 in the liver was significantly negatively correlated with liver weight or serum total cholesterol in pioglitazone-treated HFD-fed mice (r2 = 0.74, P < 0.05; r2 = 0.58, P < 0.05). CONCLUSIONS: PPAR-γ signaling plays a critical role in the regulation of metabolic disorders through promoting regulatory cell response.

Establishment of a nested-ASP-PCR method to determine the clarithromycin resistance of Helicobacter pylori.

AIM: To investigate clarithromycin resistance positions 2142, 2143 and 2144 of the 23SrRNA gene in Helicobacter pylori (H. pylori) by nested-allele specific primer-polymerase chain reaction (nested-ASP-PCR). METHODS: The gastric tissue and saliva samples from 99 patients with positive results of the rapid urease test (RUT) were collected. The nested-ASP-PCR method was carried out with the external primers and inner allele-specific primers corresponding to the reference strain and clinical strains. Thirty gastric tissue and saliva samples were tested to determine the sensitivity of nested-ASP-PCR and ASP-PCR methods. Then, clarithromycin resistance was detected for 99 clinical samples by using different methods, including nested-ASP-PCR, bacterial culture and disk diffusion. RESULTS: The nested-ASP-PCR method was successfully established to test the resistance mutation points 2142, 2143 and 2144 of the 23SrRNA gene of H. pylori. Among 30 samples of gastric tissue and saliva, the H. pylori detection rate of nested-ASP-PCR was 90% and 83.33%, while the detection rate of ASP-PCR was just 63% and 56.67%. Especially in the saliva samples, nested-ASP-PCR showed much higher sensitivity in H. pylori detection and resistance mutation rates than ASP-PCR. In the 99 RUT-positive gastric tissue and saliva samples, the H. pylori-positive detection rate by nested-ASP-PCR was 87 (87.88%) and 67 (67.68%), in which there were 30 wild-type and 57 mutated strains in gastric tissue and 22 wild-type and 45 mutated strains in saliva. Genotype analysis showed that three-points mixed mutations were quite common, but different resistant strains were present in gastric mucosa and saliva. Compared to the high sensitivity shown by nested-ASP-PCR, the positive detection of bacterial culture with gastric tissue samples was 50 cases, in which only 26 drug-resistant strains were found through analyzing minimum inhibitory zone of clarithromycin. CONCLUSION: The nested-ASP-PCR assay showed higher detection sensitivity than ASP-PCR and drug sensitivity testing, which could be performed to evaluate clarithromycin resistance of H. pylori.

FADD is a key regulator of lipid metabolism.

FADD, a classical apoptotic signaling adaptor, was recently reported to have non-apoptotic functions. Here, we report the discovery that FADD regulates lipid metabolism. PPAR-α is a dietary lipid sensor, whose activation results in hypolipidemic effects. We show that FADD interacts with RIP140, which is a corepressor for PPAR-α, and FADD phosphorylation-mimic mutation (FADD-D) or FADD deficiency abolishes RIP140-mediated transcriptional repression, leading to the activation of PPAR-α. FADD-D-mutant mice exhibit significantly decreased adipose tissue mass and triglyceride accumulation. Also, they exhibit increased energy expenditure with enhanced fatty acid oxidation in adipocytes due to the activation of PPAR-α. Similar metabolic phenotypes, such as reduced fat formation, insulin resistance, and resistance to HFD-induced obesity, are shown in adipose-specific FADD knockout mice. Additionally, FADD-D mutation can reverse the severe genetic obesity phenotype of ob/ob mice, with elevated fatty acid oxidation and oxygen consumption in adipose tissue, improved insulin resistance, and decreased triglyceride storage. We conclude that FADD is a master regulator of glucose and fat metabolism with potential applications for treatment of insulin resistance and obesity.

SjTat-TPI facilitates adaptive T-cell responses and reduces hepatic pathology during Schistosoma japonicum infection in BALB/c mice.

BACKGROUND: Schistosomiasis is a kind of parasitic zoonoses which causes serious damage to public health and social development. China is one of the countries most affected by Schistosoma japonicum and an effective vaccine is still needed. In this study, we adopted Tat-mediated protein transduction technology to investigate the impact of different antigen presented approaches on host's immune response and the potential protection against Schistosoma japonicum infection. RESULTS: We successfully constructed the recombinant S. japonicum triosephosphate isomerase, Tat-TPI, as a vaccine candidate. Whether injected with Tat-TPI in foot pad or vaccinated with Tat-TPI in the back subcutaneously for three times, the draining popliteal lymph nodes and spleen both developed a stronger CD8(+)T response (Tc1) in mice. Not only that, but it also helped CD4(+)T cells to produce more IFN-γ than TPI immunisation. In addition, it could boost IgG production, especially IgG1 subclass. Most importantly, Tat-TPI immunisation led to the significant smaller area of a single egg granuloma in the livers as compared with TPI-vaccinated or control groups. However, the anti-infection efficiency induced by Tat-TPI was still restricted. CONCLUSION: This study indicated that immunisation with Tat-fused TPI could contribute to enhance CD4(+)T-cell response and decrease hepatic egg granulomatous area after S. japonicum infection though it did not achieve our expected protection against Schistosoma japonicum infection. The optimal vaccine strategy warrants further research.

Use of 16S rRNA Gene-Targeted Group-Specific Primers for Real-Time PCR Analysis of Predominant Bacteria in Mouse Feces.

Mouse models are widely used for studying gastrointestinal (GI) tract-related diseases. It is necessary and important to develop a new set of primers to monitor the mouse gut microbiota. In this study, 16S rRNA gene-targeted group-specific primers for Firmicutes, Actinobacteria, Bacteroidetes, Deferribacteres, "Candidatus Saccharibacteria," Verrucomicrobia, Tenericutes, and Proteobacteria were designed and validated for quantification of the predominant bacterial species in mouse feces by real-time PCR. After confirmation of their accuracy and specificity by high-throughput sequencing technologies, these primers were applied to quantify the changes in the fecal samples from a trinitrobenzene sulfonic acid-induced colitis mouse model. Our results showed that this approach efficiently predicted the occurrence of colitis, such as spontaneous chronic inflammatory bowel disease in transgenic mice. The set of primers developed in this study provides a simple and affordable method to monitor changes in the intestinal microbiota at the phylum level.

Protective Effect of Procyanidin B2 against CCl4-Induced Acute Liver Injury in Mice.

Procyanidin B2 has demonstrated several health benefits and medical properties. However, its protective effects against CCl4-induced hepatotoxicity have not been clarified. The present study aimed to investigate the hepatoprotective effects of procyanidin B2 in CCl4-treated mice. Our data showed that procyanidin B2 significantly decreased the CCl4-induced elevation of serum alanine aminotransferase activities, as well as improved hepatic histopathological abnormalities. Procyanidin B2 also significantly decreased the content of MDA but enhanced the activities of antioxidant enzymes SOD, CAT and GSH-Px. Further research demonstrated that procyanidin B2 decreased the expression of TNF-α, IL-1ß, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), as well as inhibited the translocation of nuclear factor-kappa B (NF-κB) p65 from the cytosol to the nuclear fraction in mouse liver. Moreover, CCl4-induced apoptosis in mouse liver was measured by (terminal-deoxynucleotidyl transferase mediated nick end labeling) TUNEL assay and the cleaved caspase-3. Meanwhile, the expression of apoptosis-related proteins Bax and Bcl-xL was analyzed by Western blot. Results showed that procyanidin B2 significantly inhibited CCl4-induced hepatocyte apoptosis, markedly suppressed the upregulation of Bax expression and restored the downregulation of Bcl-xL expression. Overall, the findings indicated that procyanidin B2 exhibited a protective effect on CCl4-induced hepatic injury by elevating the antioxidative defense potential and consequently suppressing the inflammatory response and apoptosis of liver tissues.

FADD phosphorylation impaired islet morphology and function.

Previous studies have indicated that Fas-FasL pathway and its downstream caspase-8 can regulate islet mass and insulin secretion. As a classical adaptor in Fas-FasL signaling, Fas-associated death domain-containing protein (FADD) takes part in many non-apoptosis processes regulated by its phosphorylation. However, its role in islets has not been evaluated to date. Here, through comparative proteomics and bioinformatic analysis on FADD phosphorylated (FADD-D) and wild-type (WT) MEFs, we found three proteins involved in islet differentiation and function were dysregulated due to FADD phosphorylation. The mouse model of FADD-D, which mimics constitutive phosphorylated FADD expression in mice, was further analyzed to address this issue. We confirmed the proteomic results by immunohistological analyses on pancreatic islets. In addition, we found that FADD-D mice displayed decreased islet area, and the glucose stimulated insulin secretion (GSIS) of FADD-D islets was impaired. These data suggest a novel role of FADD in islet development and insulin secretion.

FADD is essential for glucose uptake and survival of thymocytes.

Fas-associated protein with death domain (FADD) has been implicated in T lymphocytes, but the nature of FADD-dependent mechanism in early T cell development has not been completely elucidated. In this study, using T-cell specific deletion mice, we observed that FADD deficiency in thymocytes led to increased apoptosis and reduced cell numbers, which may be attributed to the reduction of Glut1 expression and correspondingly decreased glucose uptake. Furthermore, an abnormal transduction of Akt signaling was discovered in FADD(-/-) thymocytes, which may be responsible for the declined Glut1 expression. Collectively, our results demonstrate the new function of FADD in glucose metabolism and survival of early T cells.

[Expression characteristics of microRNA in mice with schistosomiasis and praziquantel treatment].

OBJECTIVE: To investigate the expression characteristics of miR-155 and miR-146a in mice with schistosomiasis and praziquantel (PZQ) treatment. METHODS: Totally 40 BABL/c mice were divided into 4 groups: a normal group, a 6W infected group that were infected cutaneously with 10 Schistosoma japonicum cercariae for 6 weeks, a 12W infected group that were infected cutaneously with 10 Schistosoma japonicum cercariae for 12 weeks, and a praziquantel treated group that were infected cutaneously with 10 Schistosomajaponicum cercariae and intragastrically administered with PZQ (300 mg/kg/day) for 1 day in 6 weeks post-infection and continuing surviving 6 weeks. The animals were sacrificed in 6 weeks and 12 weeks post-infection respectively. The left front lobe of each liver was stained with hematoxylin-eosin (HE) to detect pathological lesions. The levels of mRNA expressions of miR-155, miR-146a and pro-inflammatory cytokines (TNF-alpha, IL-1beta and IL-6) in the liver tissue were determined by using quantitative real-time PCR. RESULTS: The levels of mRNA expressions of miR-155, miR-146a and pro-inflammatory cytokines (TNF-alpha, IL-1beta and IL-6) in the 6W infected mice were significantly higher than those of the normal mice and of the 12W infected mice. Compared with the 12W infected mice, the inflammation response of liver egg granuloma in the PZQ-treated mice was ameliorated. Furthermore, there was a marked increase in the levels of mRNA expressions of miR-155, miR-146a and three pro-inflammatory cytokines in the PZQ-treated mice compared to the 12W infected mice. CONCLUSION: miR-155 and miR-146a may play a role in schistosomiasis liver inflammation response and the inflammation regulation of praziquantel treatment.

Tumor-specific delivery of histidine-rich glycoprotein suppresses tumor growth and metastasis by anti-angiogenesis and vessel normalization.

Histidine-proline-rich glycoprotein (HPRG) is a plasma protein of vertebrates, which has potent antiangiogenic and tumor vessel normalization properties. Attenuated Salmonella Typhimurium strain VNP20009 preferentially accumulates and replicates in hypoxic tumor regions. In this study, we engineered VNP20009 to express HPRG under the control of a hypoxia-induced NirB promoter and evaluated the efficacy of the VNP20009-mediated targeted expressionof HPRG (VNP-pNHPRG) on tumor growth in primary and metastatic tumor models. When VNP-pNHPRG was administered to melanoma tumor mice by intraperitoneal injection, the NirB promoter controlled HPRG expression in tumor, which inhibited tumor vessel density and areas as well as regulated vascular normalization. VNP-pNHPRG significantly delayed tumor growth and enhanced survival time in primary B16F10 mice model and markedly suppressed lung metastatic tumor growth and prolonged survival time in B16F10 metastatic tumor models. Furthermore, VNP-pNHPRG down-regulated the HIF-1α-VEGF/Ang-2 signal pathway by altering the hypoxic tumor microenvironment. These results showed that VNP20009-mediated targeted expression of HPRG provides a novel cancer gene therapeutic approach for the treatment of primary and metastatic cancer.

Fas-Associated Protein with Death Domain Regulates Notch Signaling during Muscle Regeneration.

Notch signaling plays critical roles during myogenesis by promoting the proliferation and inhibiting the differentiation of myogenic progenitors. However, the mechanism of the temporal regulation of Notch signaling during the myogenic lineage progression remains elusive. In the present study, we show that a constitutively phosphoryl-mimicking mutation of Fas-associated death domain (FADD-D) enhances Notch-1 signaling and compromises Wnt signaling in both cultured myoblasts and regenerating muscles, which results in inhibited myogenic differentiation and muscle regeneration. Inhibition of Notch signaling recovers the regeneration ability in injured FADD-D muscles through rescuing Wnt signaling. Furthermore, we found that protein kinase Cα mediates FADD-D-induced Notch-1 signaling by stabilizing Notch-1. Collectively, these data identify a novel mechanism for the temporal regulation of Notch signaling during myogenic lineage progression and muscle regeneration.

A critical role of Fas-associated protein with death domain phosphorylation in intracellular reactive oxygen species homeostasis and aging.

AIM: Reactive oxygen species (ROS) plays important roles in aging. However, the specific mechanisms for intracellular ROS accumulation, especially during aging, remain elusive. RESULTS: We have reported that Fas-associated protein with death domain (FADD) phosphorylation abolishes the recruitment of phosphatase type 2A C subunit (PP2Ac) to protein kinase C (PKC)ßII, which specifically regulates mitochondrial ROS generation by p66shc. Here, we have studied the role of FADD phosphorylation in an FADD constitutive-phosphorylation mutation (FADD-D) mouse model. In FADD-D mice, the constitutive FADD phosphorylation led to ROS accumulation (hydrogen peroxide [H2O2]), in a process that was dependent on PKCß and accompanied by increased PKCß and p66shc phosphorylation, impaired mitochondrial integrity, and enhanced sensitivity to oxidative stress-mediated apoptosis. Moreover, FADD-D mice exhibited premature aging-like phenotypes, including DNA damage, cellular senescence, and shortened lifespan. In addition, we demonstrate that FADD phosphorylation and the recruitment of PP2A and FADD to PKCß are induced responses to oxidative stress, and that the extent of FADD phosphorylation in wild-type mice was augmented during aging, accompanied by impairment of the interaction between PKCß and PP2A. INNOVATION: The present study first addresses the role of FADD phosphorylation in aging through controlling mitochondrial ROS specifically generated by PKCß. CONCLUSION: These data identify that FADD phosphorylation is critical for the PKCß-p66shc signaling route to generate H2O2 and to implicate enhanced FADD phosphorylation as a primary cause of ROS accumulation during aging.