Non-myeloablative conditioning with busulfan before hematopoietic stem cell transplantation leads to phenotypic correction of murine Bernard-Soulier syndrome

BACKGROUND

Bernard-Soulier syndrome (BSS) is an inherited bleeding disorder characterized by macrothrombocytopenia. Platelet transfusion is used for the management of bleeding, but repeated transfusion often results in alloimmunization. We have recently shown phenotypic correction of murine BSS (GPIbα(null) ) using lethal radiation conditioning followed by hematopoietic lentivirus-mediated gene transfer.

OBJECTIVES

For application of gene therapy to treatment of human patients, it is important to minimize treatment-related side effects. The objective of this study is to model a clinically relevant non-myeloablative hematopoietic stem cell (HSC) transplantation strategy.

METHODS

Using transplantation of bone marrow (BM) HSCs from transgenic mice that express hGPIbα (hGPIbα(tg+/+) ), we sought to (i) determine the percentage of hGPIbα(tg+/+) HSCs required for therapeutic benefit, (ii) evaluate the efficacy of non-myeloablative conditioning using busulfan, and (iii) test the ability of anti-thymocyte globulin (ATG) to prevent/reduce undesirable immune responses.

RESULTS

Transplantation of 10-20% hGPIbα(tg+/+) BM HSCs mixed with GPIbα(null) BM HSCs into irradiated GPIbα(null) mice was sufficient to correct bleeding time (n = 5). Transplantation of hGPIbα(tg+/+) BM HSCs into busulfan-conditioned GPIbα(null) mice corrected bleeding time in 21 of 27 recipients. Antibody response to hGPIbα and immune-mediated thrombocytopenia was documented in eight of 27 recipients, suggesting immunogenicity of hGPIbα in busulfan-conditioned GPIbα(null) mice. However, these antibodies disappeared without treatment within 30 weeks after transplantation. A combination of busulfan plus ATG conditioning successfully prevented antibody development and significantly increased therapeutic engraftment.

CONCLUSION

A conditioning regimen of busulfan in combination with ATG could potentially be used in non-myeloablative autologous gene therapy in human BSS.

COUP-TFII regulates metastasis of colorectal adenocarcinoma cells by modulating Snail1

BACKGROUND

Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII, also known as NR2F2) promotes metastasis by functioning in the tumour microenvironment; however, the role of COUP-TFII in colorectal cancer remains unknown.

METHODS

Human colon adenocarcinoma tissues were collected to test COUP-TFII expression. Wound-healing and cell invasion assay were used to evaluate migration and invasion of cells. Chicken ovalbumin upstream promoter-transcription factor II and related protein expression was assessed by immunostaining, immunoblotting and real-time PCR assay. Tamoxifen-inducible COUP-TFII knockout mice were employed to test COUP-TFII functions on colon cancer metastasis in vivo.

RESULTS

Elevated expression of COUP-TFII in colorectal adenocarcinoma tissue correlated with overexpression of the Snail1 transcription factor. High COUP-TFII expression correlated with metastasis and shorter patient survival. Chicken ovalbumin upstream promoter-transcription factor II regulated the migration and invasion of cancer cells. With Snail1, COUP-TFII inhibited expression of adherence molecules such as ZO-1, E-cadherin and β-catenin in colorectal cancer cells. Overexpression of COUP-TFII was required for cancer cells to metastasise in vivo. Chicken ovalbumin upstream promoter-transcription factor II regulated the transcription and expression of Snail1 by directly targeting the Snail1 promoter and regulated associated genes.

CONCLUSIONS

Chicken ovalbumin upstream promoter-transcription factor II was crucial for colorectal cancer metastasis and regulated cell migration and metastasis in conjunction with Snail1. Chicken ovalbumin upstream promoter-transcription factor II was found to be a biomarker associated with patient survival and colorectal cancer metastasis.

Large-scale analysis of factors influencing nonalcoholic fatty liver disease and its relationship with liver enzymes

Serum liver enzyme levels are often used effectively for the evaluation of nonalcoholic fatty liver disease (NAFLD). We aimed to investigate the associations between serum liver enzyme levels and risks for NAFLD in over 8000 cases in a large-scale analysis. A cross-sectional survey with multiple stages and random samplings was performed from May 2007 to May 2009 on 8102 workers at Tongji University. A questionnaire was given, assessments of physical measurements, plasma glucose, lipid profiles, and liver enzymes were made, and real-time liver ultrasounds conducted. The prevalence of NAFLD in Tongji University was 22.2%. It was higher in males than in females (P = 0.0023). The body mass index, waist-to-hip ratio, serum total triglycerides, serum total cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) values were all higher in the NAFLD group than in the control group. For moderate and severe NAFLD patients, the ALT, AST and GGT values were significantly increased, high density lipoprotein cholesterol was decreased, and drinking much, heavy entertainment and less exercise were more prevalent (P < 0.001). There were strong correlations between serum liver enzyme levels and NAFLD (P < 0.001), with GGT being a more sensitive marker for NAFLD than ALT or AST. ALT and GGT were independent predictors for NAFLD, and GGT was a better predictor than ALT for NAFLD.

In vivo enrichment of genetically manipulated platelets corrects the murine hemophilic phenotype and induces immune tolerance even using a low multiplicity of infection

BACKGROUND

Our previous studies have demonstrated that platelet-specific gene delivery to hematopoietic stem cells can induce sustained therapeutic levels of platelet factor VIII (FVIII) expression in mice with hemophilia A.

OBJECTIVE

In this study, we aimed to enhance platelet FVIII expression while minimizing potential toxicities.

METHODS

A novel lentiviral vector (LV), which harbors dual genes, the FVIII gene driven by the αIIb promoter (2bF8) and a drug-resistance gene, the MGMT(P140K) cassette, was constructed. Platelet FVIII expression in mice with hemophilia A was introduced by transduction of hematopoietic stem cells and transplantation. The recipients were treated with O(6)-benzylguanine followed by 1,3-bis-2 chloroethyl-1-nitrosourea monthly three or four times. Animals were analyzed by using polymerase chain reaction (PCR), quantitative PCR, FVIII:C assays, and inhibitor assays. Phenotypic correction was assessed by tail clipping tests and rotational thromboelastometry analysis.

RESULTS

Even using a low multiplicity of infection of 1 and a non-myeloablative conditioning regimen, after in vivo selection, the levels of platelet FVIII expression in recipients increased to 4.33 ± 5.48 mU per 10(8) platelets (n = 16), which were 19.7-fold higher than the levels obtained from the recipients before treatment. Quantitative PCR results confirmed that 2bF8/MGMT-LV-transduced cells were effectively enriched after drug-selective treatment. Fifteen of 16 treated animals survived tail clipping. Blood loss and whole blood clotting time were normalized in the treated recipients. Notably, no anti-FVIII antibodies were detected in the treated animals even after recombinant human B-domain deleted FVIII challenge.

CONCLUSION

we have established an effective in vivo selective system that allows us to enrich 2bF8LV-transduced cells, enhancing platelet FVIII expression while reducing the potential toxicities associated with platelet gene therapy.

Deletion of the lmna gene induces growth delay and serum biochemical changes in C57BL/6 mice

The A-type lamin deficient mouse line (Lmna^−/−) has become one of the most frequently used models for providing insights into many different aspects of A-type lamin function. To elucidate the function of Lmna in the growth and metabolism of mice, tissue growth and blood biochemistry were monitored in Lmna-deficient mice, heterozygous (Lmna^+/−) and wide-type (Lmna^+/+) backcrossed to C57BL/6 background. At 4 weeks after birth, the weight of various organs of the Lmna^−/−, Lmna^+/− and Lmna^+/+ mice was measured. A panel of biochemical analyses consisting of 15 serological tests was examined. The results showed that Lmna deficient mice had significantly decreased body weight and increased the ratio of organ to body weight in most of tissues. Compared with Lmna^+/+ and Lmna^+/− mice, Lmna^−/− mice exhibited lower levels of ALP (alkaline phosphatase), Chol (cholesterol), CR (creatinine), GLU (glucose), HDL (high-density lipoprotein cholesterol) and higher levels of ALT (alanine aminotransferase) (p<0.05). Lmna^−/− mice displayed higher AST (aspartate aminotransferase) values and lower LDL (lowdensity lipoprotein cholesterol), CK-MB (creatine kinase-MB) levels than Lmna^+/+ mice (p<0.05). There were no significant differences among the three groups of mice with respect to BUN (blood urea nitrogen), CK (creatine kinase), Cyc C (cystatin C), TP (total protein), TG (triacylglycerols) and UA (uric acid) levels (p>0.05). These changes of serological parameters may provide an experimental basis for the elucidation of Lmna gene functions.

Over-reported peripheral neuropathy symptoms in a cohort of HIV infected and uninfected Rwandan women: the need for validated locally appropriate questionnaires

BACKGROUND

Peripheral neuropathy symptoms (PNS) are commonly manifested in HIV-infected (HIV+) individuals, although data are limited on the prevalence and predictors of PNS in HIV+ patients from sub-Saharan Africa.

OBJECTIVE

To determine the prevalence and predictors of PNS in HIV+ and HIV-uninfected (HIV-) Rwandan women.

METHODS

Data were analysed from 936 (710 HIV+ and 226 HIV-) women from the Rwanda Women Interassociation Study and Assessment (RWISA), an observational prospective cohort study investigating the effectiveness and toxicity of ART in HIV+ women.

RESULTS

Of 936 enrolled, 920 (98.3%) were included in this analysis with 44% of HIV- and 52% of the HIV+ women reporting PNS (p=0.06). CD4+ count was not associated with PNS, although there was a non-significant trend towards higher prevalence in those with lower CD4+ counts. For the HIV- women, only alcohol and co-trimoxazole use were independently associated with PNS. WHO HIV stage IV illness and albumin ≤ 3.5 were associated with PNS in HIV+ women.

CONCLUSIONS

The rate of peripheral neuropathy symptoms reported in this cohort of HIV-infected African women seems implausible, and rather suggests that the screening tool for peripheral neuropathy in culturally diverse African settings be locally validated.

Impact of exercise intensity on cardiac function in adolescent runners

BACKGROUND

Prolonged exercise may induce a transient reduction in the left ventricular (LV) function (exercise-induced cardiac fatigue) in adults. However, data related to the cardiovascular consequences of prolonged exercise in adolescents are extremely limited. This study examined the impact of exercise intensity adopted in routine long-distance run training on LV function in trained adolescent runners in a laboratory-based setting.

METHODS

Twelve male adolescent runners (14.5 ± 1.5 years) performed two 90-min treadmill runs with intensity set at the running speeds that corresponded to either 80% (T1) or 100% (T2) ventilatory threshold. LV function was examined echocardiographically pre- and post-exercise.

RESULTS

The two-factor repeated-measures ANOVA revealed no significant (P>0.05) main effects for the intensity and the interaction of intensityÍ pre- and postexercise in ejection fraction (EF), systolic blood pressure/end systolic volume ratio (SBP/ESV) and early to atrial diastolic flow velocity ratio (E:A). Nevertheless, the main effect for time course in EF was significant (P<0.05). Pre-exercise EF in T1 (74 ± 5 vs. 70 ± 5%, P<0.05), but not in T2 (75 ± 4 vs. 72 ± 7%, P>0.05), decreased significantly post-exercise, yet this did not reach clinical levels. Further, no difference (P>0.05) was found between pre- and post-exercise in SBP/ESV (T1: 3.9 ± 0.9 vs. 3.7 ± 1.1; T2: 4.0 ± 0.7 vs. 4.6 ± 1.9 mmHg·ml⁻¹) and E:A (T1: 1.87 ± 0.11 vs. 1.87 ± 0.11; T2: 1.83 ± 0.11 vs. 1.87 ± 0.09) in both trials.

CONCLUSION

These findings suggest that the training intensities adopted in routine long-distance run training in the adolescent runners do not seem to induce cardiac fatigue. Adolescent hearts appear to cope well with prolonged run performed on training.

Complete closure of large gastric defects after endoscopic full-thickness resection, using endoloop and metallic clip interrupted suture

BACKGROUND AND STUDY AIM

Successful closure of wall defects is the key procedure following endoscopic full-thickness resection (EFTR). In this report we describe a new method similar to interrupted suture to repair gastric defects by means of endoloops and metallic clips.

PATIENTS AND METHODS

We retrospectively analyzed 20 patients who presented at our institute between March 2011 and February 2012 with gastric submucosal tumors and who consequently underwent EFTR, with the resulting large gastric defects being closed using endoloops and metallic clips. Tumor characteristics, en bloc resection rates, and postoperative complications were evaluated in all the patients.

RESULTS

The median age of the 20 patients was 47 years. The mean maximum size of lesions was 1.47 ± 0.72 cm (range 0.4 - 3 cm). All lesions were diagnosed by endoscopic ultrasound as tumors in the muscularis propria layer. The en bloc resection rate was 100 %. Five patients developed fever and complained of slight abdominal pain in the first day after treatment. No patient had severe complications such as peritonitis or abdominal abscess. In all cases, wounds healed after 1 month. We observed the persistence of the clips for over 3 months in 6 out of 19 cases without any clinical manifestations or large injury to the intestine.

CONCLUSIONS

Our study provides evidence that the use of metallic clips and endoloops is a relatively safe, easy, and feasible method for repairing gastric defects resulting from EFTR.

Abstract S2-06: Extracellular matrix stiffness modulates tissue inflammation to promote breast tumor aggression

Tumor progression is influenced by the dynamic interplay between the genetically-modified epithelium and the associated microenvironment. We previously showed that the extra-cellular matrix (ECM) progressively stiffens as mammary tumors evolve, and that stiffening the ECM promotes malignant transformation while inhibiting ECM stiffening reduces tumor progression (Levental et al., 2009; reviewed in Butcher et al., 2009). Yet breast cancers also exhibit elevated influx of inflammatory cells and tissue inflammation promotes tumor progression by fostering angiogenesis and enhancing tumor cell growth and motility (Ruffell et al., 2011). Tumor-associated macrophages additionally stimulate stromal fibroblasts, implying that tissue inflammation could promote malignancy by stiffening the ECM. To address this possibility, we explored the relationship between ECM tension and macrophages in human breast cancer and during mammary tumor development in transgenic mice. Using fresh and archived tissue samples, we quantified a progressive increase in ECM remodeling and stiffening as human breast tumors and mouse mammary cancers developed. We found that the ECM associated with triple negative breast cancers was almost twice as stiff as the ECM adjacent to ER+/PR+ tumors and that ECM stiffness correlated significantly with increased numbers of infiltrating activated macrophages. Consistently, we established a positive correlation between tumor progression, elevated mechanosignaling, ECM stiffness and tissue inflammation in both human and mouse tissue. However surprisingly, when macrophages were depleted from the mammary glands of MMTV-PyMT tumors, ECM tension did not change. Instead we found that inhibiting lysyl oxidase activity to decrease collagen cross-linking and ECM stiffness reduced the activation state of the macrophages within the mammary glands of 14-week old mice. Consistently, in vitro studies showed that ECM tension potentiates the expression of pro-inflammatory chemokines and increases levels of phosphoStat3 and that ECM tension directly modifies macrophage polarity. These findings suggest that ECM tension may promote malignancy either by directly regulating macrophage activity or indirectly through enhancing expression of pro-inflammatory chemokines. Further studies are now underway to explore these findings and to clarify their impact on tumor progression and response to therapy.

Acknowledgements: supported by W81XWH-05-1-0330 and R01 CA138818-01A1 to VMW, 1U01 ES019458-01 to VMW and ZW, and P50 CA 58207 to JG, VW, SH and LC, U54CA143836-01 to JL and VW, and Susan G. Komen for the Cure PSF12230246 to IA.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S2-06.

In vitro activity of isoimperatorin, alone and in combination, against Mycobacterium tuberculosis

Previous studies have shown that isoimperatorin (IO), a furanocoumarin isolated from several medicinal plants, has antimycobacterial activity against Mycobacterium tuberculosis strain H37Rv (ATCC 27294). This study demonstrated that IO has antimycobacterial activity against 2 drug-sensitive and 6 drug-resistant isolates, with minimum inhibitory concentrations (MICs) of 50-100 μg ml(-1) and 100-200 μg ml(-1), respectively. IO exhibited synergistic antimycobacterial effects with rifampin (RMP), isoniazid (INH) and ethambutol (EMB) against 6 drug-resistant strains, with fractional inhibitory concentration index (FICI) values of 0·133-0·472, 0·123-0·475 and 0·124-0·25, respectively. The IO/RMP, IO/INH and IO/EMB combination treatments had synergistic effects or no interaction in the 2 drug-sensitive strains and the standard strain ATCC 27294. The synergism of combined drugs against drug-resistant strains was better than drug-sensitive strains. No antagonism was observed in with the aforementioned combinations against all strains tested. IO exhibited relatively low cytotoxicity to Vero cells. Our results indicate that IO may serve as promising a template for future antimycobacterial drug development.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report on the in vitro synergistic antimycobacterial effects of isoimperatorin (IO) in combination with three first-line drugs: rifampin (RMP), isoniazid (INH) and ethambutol (EMB). The results indicated that the antimycobacterial activity of IO was modest; however, IO was a useful and effective agent against Myco. tuberculosis when it was combined with first-line antimycobacterial drugs and is worthy of further development as a lead compound for the development of novel antimycobacterial therapeutic agents.

Coral communities of the remote atoll reefs in the Nansha Islands, southern South China Sea

During the months of May and June in the year 2007, a survey was conducted regarding coral reef communities in the remote atolls (Zhubi Reef and Meiji Reef) of Nansha Islands, southern South China Sea. The goals of the survey were to: (1) for the first time, compile a scleractinian coral check-list; (2) estimate the total richness, coral cover, and growth forms of the community; and (3) describe preliminary patterns of community structure according to geomorphological units. Findings of this survey revealed a total of 120 species of scleractinia belonging to 40 genera, while the average coral cover was 21 %, ranging from less than 10 % to higher than 50 %. Branching and massive corals were also found to be the most important growth forms of the whole coral community, while Acropora, Montipora, and Porites were the three dominant genera in the overall region, with their contributions to total coral cover measuring 21, 22, and 23 %, respectively. Overall, coral communities of the Nansha Islands were in a relative healthy condition with high species diversity and coral cover. Spatial pattern of coral communities existed among various geomorphological units. Mean coral cover was highest in the patch reef within the lagoon, followed by the fore reef slope, reef flat, and lagoon slope. The greatest contributors to total coral cover were branching Acropora (45 %) in the lagoon slope, branching Montipora (44 %) in the reef flat, and massive Porites (51 %) in the patch reef. Coral cover in the fore reef revealed a greater range of genera than in other habitats. The leeward fore reef slope had higher coral cover (> 50 %) when compared with the windward slope (< 10 %). The coral communities of the inner reef flat were characterized by higher coral cover (27 %) and dominant branching Montipora corals, while lower coral cover (4 %) was dominated by Psammocora with massive growth forms on the outer reef flat. Destructive fishing and coral bleaching were two major threats to coral communities in the study area.

The association of vitamin D receptor gene polymorphisms and serum 25-hydroxyvitamin D levels with generalized vitiligo

BACKGROUND

Vitiligo is an acquired depigmentation autoimmune disorder that has been described as being associated with lower levels of 25-hydroxyvitamin D [25(OH)D]. Genetic variations within the vitamin D receptor (VDR) gene could lead to significant receptor dysfunction, and could further affect the formation of the biologically active 25(OH)D. Therefore, we hypothesized that VDR polymorphisms might be involved in vitiligo by affecting the formation of 25(OH)D.

OBJECTIVES

To evaluate the potential association between VDR polymorphisms and vitiligo susceptibility and the serum levels of 25(OH)D.

METHODS

We performed a hospital-based study of 749 patients with vitiligo and 763 matched controls. We investigated four VDR polymorphisms (FokI, BsmI, ApaI and TaqI) to determine whether they are associated with vitiligo susceptibility in the Chinese population. In addition, the levels of 25(OH)D were measured to evaluate possible associations between the VDR polymorphic variants and clinical and laboratory findings of vitiligo.

RESULTS

A significantly decreased risk of developing vitiligo was found to be associated with the BsmI-B, ApaI-A and TaqI-t alleles. According to the genotype distribution, 25(OH)D concentrations were significantly higher in patients carrying the FokI ff or ApaI AA genotypes compared with those carrying the FF or aa genotypes. Logistic regression analysis also showed a dose-response relationship between decreased risk of vitiligo and increased 25(OH)D levels in ApaI-A variant genotype carriers.

CONCLUSIONS

Our findings suggest that these VDR polymorphisms are associated with 25(OH)D levels and that there exists a genetic predisposition for vitiligo in the Chinese population.

The loss of the BH3-only Bcl-2 family member Bid delays T-cell leukemogenesis in Atm-/- mice

Multicellular organisms maintain genomic integrity and resist tumorigenesis through a tightly regulated DNA damage response (DDR) that prevents propagation of deleterious mutations either through DNA repair or programmed cell death. An impaired DDR leads to tumorigenesis that is accelerated when programmed cell death is prevented. Loss of the ATM (ataxia telangiectasia mutated)-mediated DDR in mice results in T-cell leukemia driven by accumulation of DNA damage accrued during normal T-cell development. Pro-apoptotic BH3-only Bid is a substrate of Atm, and Bid phosphorylation is required for proper cell cycle checkpoint control and regulation of hematopoietic function. In this report, we demonstrate that, surprisingly, loss of Bid increases the latency of leukemogenesis in Atm-/- mice. Bid-/-Atm-/- mice display impaired checkpoint control and increased cell death of DN3 thymocytes. Loss of Bid thus inhibits T-cell tumorigenesis by increasing clearance of damaged cells, and preventing propagation of deleterious mutations.

Innovative estimation of survival using log-normal survival modelling on ACCENT database

Background:

The ACCENT database, with individual patient data for 20 898 patients from 18 colon cancer clinical trials, was used to support Food and Drug Administration (FDA) approval of 3-year disease-free survival as a surrogate for 5-year overall survival. We hypothesised substantive differences in survival estimation with log-normal modelling rather than standard Kaplan–Meier or Cox approaches.

Methods:

Time to relapse, disease-free survival, and overall survival were estimated using Kaplan–Meier, Cox, and log-normal approaches for male subjects aged 60–65 years, with stage III colon cancer, treated with 5-fluorouracil-based chemotherapy regimens (with 5FU), or with surgery alone (without 5FU).

Results:

Absolute differences between Cox and log-normal estimates with (without) 5FU varied by end point. The log-normal model had 5.8 (6.3)% higher estimated 3-year time to relapse than the Cox model; 4.8 (5.1)% higher 3-year disease-free survival; and 3.2 (2.2)% higher 5-year overall survival. Model checking indicated greater data support for the log-normal than the Cox model, with Cox and Kaplan–Meier estimates being more similar. All three model types indicate consistent evidence of treatment benefit on both 3-year disease-free survival and 5-year overall survival; patients allocated to 5FU had 5.0–6.7% higher 3-year disease-free survival and 5.3–6.8% higher 5-year overall survival.

Conclusion:

Substantive absolute differences between estimates of 3-year disease-free survival and 5-year overall survival with log-normal and Cox models were large enough to be clinically relevant, and warrant further consideration.

Effect of Natural Hirudin on Random Pattern Skin Flap Survival in a Porcine Model

Objective:

The effect of local administration of hirudin on random pattern skin flap survival was investigated in a porcine model.

Methods:

Three random pattern skin flaps (4 × 14 cm) were created on each flank of five Chinese minipigs. The experimental group (10 flaps) received 20 antithrombin units of hirudin, injected subdermally into the distal half immediately after surgery and on days 1 and 2; a control group (10 flaps) was injected with saline and a sham group (10 flaps) was not injected. All flaps were followed for 10 days postoperatively.

Results:

Macroscopically, the congested/necrotic length in the experimental group was significantly decreased compared with the other two groups by day 3. Histopathological evaluation revealed venous congestion and inflammation in the control and sham groups from day 1, but minimal changes in the experimental group. By day 10, the mean ± SD surviving area was significantly greater in the experimental group (67.6 ± 2.1%) than in the control (45.2 ± 1.4%) or sham (48.3 ± 1.1%) groups.

Conclusions:

Local administration of hirudin can significantly increase the surviving area in overdimensioned random pattern skin flaps, in a porcine model.

Factor VIII inhibitors: von Willebrand factor makes a difference in vitro and in vivo

BACKGROUND

The important association between von Willebrand factor (VWF) and factor VIII (FVIII) has been investigated for decades, but the effect of VWF on the reactivity of FVIII inhibitory antibodies, referred to as inhibitors, is still controversial.

OBJECTIVE

To investigate the interaction among VWF, FVIII and FVIII inhibitory antibodies.

METHODS

Three sources of inhibitors were used for in vitro studies, including the plasma from immunized VWF(null) FVIII(null) mice, purified plasma IgG from human inhibitor patients, or human monoclonal antibody from inhibitor patients' B-cell clones. Inhibitors were incubated with recombinant human FVIII (rhFVIII) either with or without VWF. The remaining FVIII activity was determined by chromogenic assay and inhibitor titers were determined. For in vivo studies, inhibitors and rhFVIII were infused into FVIII(null) or VWF(null) FVIII(null) mice followed by a tail clip survival test.

RESULTS

VWF has a dose-dependent protective effect on FVIII, limiting inhibitor inactivation of FVIII in both mouse and human samples. A preformed complex of VWF with FVIII provides more effective protection from inhibitors than competitive binding of antibodies and VWF to FVIII. The protective effect of VWF against FVIII inactivation by inhibitors was further confirmed in vivo by infusing inhibitors and FVIII into FVIII(null) or VWF(null) FVIII(null) mice followed by a tail clip survival test.

CONCLUSION

Our results demonstrate that VWF exerts a protective effect, reducing inhibitor inactivation of FVIII, both in vitro and in vivo.

Endoscopic management of impacted esophageal foreign bodies

There are many reports on the endoscopic management of ingested foreign bodies in the upper gastrointestinal tract, however, little is known about the management of a specific subset of esophageal foreign bodies - impacted esophageal foreign bodies (IEFBs), especially perforating esophageal foreign bodies (PEFBs). The aim of this retrospective study on 78 cases was to report experience and outcome in the endoscopic management of the IEFBs in Chinese patients. From January 2006 to July 2011, a total of 750 patients with suspected upper gastrointestinal foreign bodies were admitted to the endoscopy center. Among these 750 patients, 78 cases that met the defined criteria of IEFBs were retrospectively enrolled in the present study, including 12 cases (12/78, 15.4%) with PEFBs. The major types of IEFBs were poultry bones (35.9%) and fish bones (17.9%). Most of the IEFBs (80.8%) were located in the upper esophagus, as were two thirds (66.7%) of the PEFBs. Foreign-body retrieval forceps were the most frequently used accessory devices. Extraction of IEFBs failed in eight patients (10.3%) during the endoscopic procedure. The difficult points in endoscopic management were PEFBs, IEFBs with sharp points, and those with impaction for more than 24 hours. IEFBs should be treated as early as possible, and their endoscopic management is safe and effective. Endoscopic management is the first choice for PEFBs when the duration of impaction is less than 24 hours and there are no abscesses outside of the esophageal tract as determined by a computed tomography scan.

CD28 superagonist antibody treatment attenuated obliterative bronchiolitis in rat allo-orthotopic tracheal transplantation by preferentially expanding Foxp3-expressing regulatory T cells

Obliterative airway disease (OAD) due to chronic alloantigen rejection remains a major challenge for long-term graft survival in lung transplantation. It is known that superagonistic CD28-specific monoclonal antibody JJ316 (supCD28 MAb) has the ability to induce regulatory T cells (Tregs) efficiently. Here we used a rat orthotopic tracheal transplantation model to investigate the effects of supCD28 MAb on expanding Tregs in vivo and its application in suppression of acute and chronic airway allograft rejection. SupCD28 MAb administration revealed a significant increase in the CD4+CD25+ T cells, CD4+FoxP3+ T cells, and CD4+CD25+ FoxP3+ T cells population among CD4+ T cells in spleen, peripheral blood, as well as cervical lymph nodes. The allografts from animals treated with supCD28 MAb showed significantly less airway obliteration and rejection of the respiratory epithelium compared with allografts of the mouse immunoglobulin G-treated group on the 5th day and the 60th day after transplantation. Overall, our data demonstrated that an intraperitoneally administrated low dose of supCD28 MAb was sufficient to induce Treg cell expansion in vivo and was effective in protecting the airway graft from early rejection and chronic OAD development. These findings provide the basis for new therapies to prevent OAD and perhaps rejection of allografts in other human transplantations.

Contribution of platelet vs. endothelial VWF to platelet adhesion and hemostasis

BACKGROUND

von Willebrand factor (VWF) is a glycoprotein that plays an important role in primary hemostasis. VWF is synthesized and stored in endothelial cells (ECs) and megakaryocytes/platelets. Plasma VWF is primarily derived from ECs and is generally believed to be essential for hemostasis. VWF synthesized in megakaryocytes is stored in platelet α-granules, from which it is released following platelet activation. The relative contribution of VWF stored in ECs or megakaryocytes/platelets or present in plasma to hemostasis is not clear.

OBJECTIVES

We investigated whether EC-derived VWF plays the major role in hemostasis while the contribution of platelet-derived VWF is negligible, or if platelet-derived VWF also significantly contributes to hemostasis.

METHODS AND RESULTS

Mice expressing VWF only in ECs (EC-VWF) or platelets (Plt-VWF) were created by reciprocal bone marrow transplantation between C57BL/6J (WT) and VWF knockout mice (VWF-/-). Plasma VWF levels in EC-VWF were similar to WT. Plt-VWF mice had a trace amount of VWF in their plasma while VWF levels in platelet lysate were comparable to WT. Tail bleeding time was normal in EC-VWF. Interestingly, Plt-VWF showed partially corrected bleeding time and significantly decreased blood loss volume compared with VWF-/-. Adhesion of platelets perfused over immobilized collagen under shear stress was significantly higher in both EC-VWF and Plt-VWF compared with VWF-/-.

CONCLUSION

VWF synthesized in ECs is sufficient to support hemostasis in VWF-/- mice, and VWF produced in megakaryocytes/platelets can also contribute to hemostasis in the absence of EC-derived VWF.

Lentivirus-mediated platelet gene therapy of murine hemophilia A with pre-existing anti-factor VIII immunity

BACKGROUND

The development of inhibitory antibodies, referred to as inhibitors, against exogenous factor VIII in a significant subset of patients with hemophilia A remains a persistent challenge to the efficacy of protein replacement therapy. Our previous studies using the transgenic approach provided proof-of-principle that platelet-specific expression could be successful in treating hemophilia A in the presence of inhibitory antibodies.

OBJECTIVE

To investigate a clinically translatable approach for platelet gene therapy of hemophilia A with pre-existing inhibitors.

METHODS

Platelet FVIII expression in preimmunized FVIII(null) mice was introduced by transplantation of lentivirus-transduced bone marrow or enriched hematopoietic stem cells. FVIII expression was determined with a chromogenic assay. The transgene copy number per cell was quantitated with real-time PCR. Inhibitor titer was measured with the Bethesda assay. Phenotypic correction was assessed by the tail clipping assay and an electrolytically induced venous injury model. Integration sites were analyzed with linear amplification-mediated PCR.

RESULTS

Therapeutic levels of platelet FVIII expression were sustained in the long term without evoking an anti-FVIII memory response in the transduced preimmunized recipients. The tail clip survival test and the electrolytic injury model confirmed that hemostasis was improved in the treated animals. Sequential bone marrow transplants showed sustained platelet FVIII expression resulting in phenotypic correction in preimmunized secondary and tertiary recipients.

CONCLUSIONS

Lentivirus-mediated platelet-specific gene transfer improves hemostasis in mice with hemophilia A with pre-existing inhibitors, indicating that this approach may be a promising strategy for gene therapy of hemophilia A even in the high-risk setting of pre-existing inhibitory antibodies.

Neuroprotection of neurotrophin-3 against focal cerebral ischemia/reperfusion injury is regulated by hypoxia-responsive element in rats

Exogenous delivery of the neurotrophin-3 (NT-3) gene may provide a potential therapeutic strategy for ischemic stroke. To investigate the neuroprotective effects of NT-3 expression controlled by 5HRE after focal cerebral ischemia, we constructed a recombinant retrovirus vector (RV) with five copies of hypoxia-responsive elements (5HRE or 5H) and NT-3 and delivered it to the rat brain. Three groups of rats received RV-5H-NT3, RV-5H-EGFP or saline injection. Three days after gene transfer, the rats underwent 90min of transient middle cerebral artery occlusion (tMCAO), followed by 1-28days of reperfusion. Three days after tMCAO, brain NT-3 expression was significantly increased in the RV-5H-NT3-transduced animals compared with the RV-5H-EGFP or saline group, and brain infarct volume was smaller in the RV-5H-NT3-transduced group than the RV-5H-EGFP or saline group. The percentage of TUNEL-positive cells was reduced in RV-5H-NT3-transduced brains compared with the RV-5H-EGFP or saline group 3 and 7days after tMCAO. Furthermore, the neurological status of RV-5H-NT3-transduced rats was better than that of RV-5H-EGFP- or saline-transduced animals from 1day to 4weeks after tMCAO. Our results demonstrated that 5HRE could modulate NT-3 expression in the ischemic brain environment and that the up-regulated NT-3 could effectively improve neurological status following tMCAO due to decreased initial damage. To avoid unexpected side effects, 5HRE-controlled gene expression might be a useful tool for gene therapy of ischemic disorders in the central nervous system.

Endogenous expansion of regulatory T cells leads to long-term islet graft survival in diabetic NOD mice

Donor pancreatic lymph node cells (PLNC) protect islet transplants in Non-obese diabetic (NOD) mice. We hypothesized that induced FoxP3(+) regulatory T cells (Tregs) were required for long-term islet engraftment. NOD or NOD.NON mice were treated with ALS (antilymphocyte serum) and transplanted with NOR islets +/-PLNC (5 × 10(7) ). In vivo proliferation and expansion of FoxP3(+) Tregs was monitored in spleen and PLN from ALS- and ALS/PLNC-treated recipient mice. Anti-CD25 depletion was used to determine the necessity of Tregs for tolerance. FoxP3(+) numbers significantly increased in ALS/PLNC-treated recipients compared to ALS-treated mice. In ALS/PLNC-treated mice, recipient-derived Tregs localized to the transplanted islets, and this was associated with intact, insulin-producing β cells. Proliferation and expansion of FoxP3(+) Tregs was markedly increased in PLNC-treated mice with accepted islet grafts, but not in diabetic mice not receiving PLNC. Deletion of Tregs with anti-CD25 antibodies prevented islet graft tolerance and resulted in rejection. Adoptive transfer of Tregs to secondary NOD.scid recipients inhibited autoimmunity by cotransferred NOD effector T cells. Treg expansion induced by ALS/PLNC-treatment promoted long term islet graft survival. Strategies leading to Treg proliferation and localization to the transplant site represent a therapeutic approach to controlling recurrent autoimmunity.

Platelet adhesion to radiofrequency glow-discharge-deposited fluorocarbon polymers preadsorbed with selectively depleted plasmas show the primary role of fibrinogen

Fluorocarbon radio-frequency glow-discharge (RFGD) treatment has previously been shown to cause decreased platelet adhesion despite the presence of adsorbed fibrinogen on the surfaces. In this study platelet adhesion to fluorocarbon RFGD-treated surfaces preadsorbed with human plasma was further examined. A series of plasma deposited fluorocarbon thin films were made by varying the C3F6/CH4 ratio in the monomer feed. The surfaces were preadsorbed with plasma, serum, or plasma selectively depleted of fibronectin, vitronectin, or Von Willebrand factor, and platelet adhesion was measured. We also measured fibrinogen adsorption to the surfaces from plasma, monoclonal antibody binding to adsorbed fibrinogen and SDS elutability of the adsorbed fibrinogen. The antibodies used bind to the three putative platelet binding sites on fibrinogen, namely, M1 antibody binds to the dodecapeptide at the C-terminus of the gamma chain, gamma (402-411), R1 antibody binds to a sequence in the Aalpha chain (87-100) which includes RGDF at Aalpha (95-98) and R2 antibody binds a sequence in the Aalpha chain (566-580) which includes RGDS at Aalpha (572-575). Fibrinogen was found to play a decisive role in mediating platelet adhesion to the fluorocarbon surfaces contacting plasma. Few platelets adhered to the fluorocarbon surfaces preadsorbed with serum, while preadsorption with plasma selectively-depleted of either fibronectin, vitronectin, or von Willebrand factor did not decrease platelet adhesion significantly. Replenishment of exogenous fibrinogen to serum restored platelet adhesion, while replenishment of the other proteins had no effect. Platelet adhesion to the fluorocarbon surfaces was lower than to PET or the methane glow-discharge-treated PET. However, there was no apparent correlation between platelet adhesion and the amount of fibrinogen adsorption or monoclonal antibody binding to surface-bound fibrinogen.

Intravascular recovery of VWF and FVIII following intraperitoneal injection and differences from intravenous and subcutaneous injection in mice

Intravenous infusion studies in humans suggest that both von Willebrand factor (VWF) and factor VIII (FVIII) remain intravascular in contrast to other coagulation proteins. We explored whether infusion of VWF and FVIII by either intraperitoneal (i.p.) or subcutaneous (s.c.) injection would result in efficient absorption of these large proteins into the vascular circulation. FVIII(null) or VWF(null) mice were infused with plasma-derived or recombinant VWF and/or FVIII by i.p., s.c., or intravenous (i.v.) injection. Both VWF and FVIII were absorbed into the blood circulation after i.p. injection with a peak between 2 and 4 h at levels similar to those observed in mice infused intravenously. In contrast, neither VWF nor FVIII was detected in the plasma following s.c. injection. Although i.v. injection achieved peak plasma levels quickly, both human VWF and FVIII rapidly decreased during the first 2 h following i.v. injection. Following both i.v. and i.p. infusion of VWF, the multimeric structure of circulating VWF was similar to that observed in the infusate. These results demonstrate that both VWF and FVIII can be efficiently absorbed into the blood circulation following i.p., but not s.c. injection, indicating that i.p. administration could be an alternative route for VWF or FVIII infusion.

A novel monoclonal antibody against human CD80 and its immune protection in a mouse lupus-like disease

Blockade of the interactions between CD28/CTLA-4 and their ligands, CD80 (B7, B7.1)/CD86 (B70, B7.2), is an attractive means to induce antigen-specific peripheral tolerance in autoimmune disease and organ transplantation. In this study, we generated and characterized a monoclonal antibody (Clone 4E5) against human CD80. 4E5 could recognize both human and mouse CD80 and suppress mixed lymphocyte reaction in vitro. To investigate their potency for clinical use, we further administrated 4E5 to a mouse lupus-like disease model (C57BL/J6) induced by Pristane. 4E5 could inhibit the immune response and attenuate the severity of lupus-like disease. The data showed 4E5 function and suggested that blockade of CD80/CD28 co-stimulatory signal pathway with 4E5 is a promising strategy to decelerate the progression of lupus-like disease and other autoimmune diseases.

MicroRNAs of rat articular cartilage at different developmental stages identified by Solexa sequencing

BACKGROUND

Expression profiles of microRNAs (miRNAs) can shape the repertoire of proteins expressed in development, differentiation and diseases. This study aimed to identify miRNA profile of articular cartilage at different developmental stages in rats.

METHODS

Three small RNA libraries were constructed from the femoral head cartilage of Sprague-Dawley (SD) rats at postnatal day 0, day 21 and day 42 and sequenced by a deep sequencing approach. Then a bioinformatics approach was employed to distinguish genuine miRNAs from small RNAs represented in the mass sequencing data. The expression of indicated miRNAs was determined by stem-loop RT-qPCR to valuate the consistency with Solexa sequencing.

RESULTS

Two hundred and fifty-eight of 310 known miRNA and miRNA* genes were organized into 91 compact clusters. Two hundred and forty-six miRNAs were detected in all three small RNA libraries of rat articular cartilage. Forty-six, fifty-two and fifty-six miRNA* genes were identified from three small RNA libraries, respectively, and 86 novel miRNA candidate genes were found simultaneously. In addition, 23 known miRNAs were up-regulated (fold change ≥ 4); six were down-regulated (fold change ≤ -4) during articular cartilage development. The predicted targets of differentially expressed miRNAs were locally secreted factors and transcription factors that regulate proliferation and differentiation of chondrocytes. The same expression tendency of indicated miRNAs during articular cartilage development stages was observed by using Solexa sequencing and stem-loop RT-qPCR.

CONCLUSION

Our study provided a unique opportunity to decipher how the elaboration of the miRNA repertoire contributes to the development process of articular cartilage.

Downregulation of transcription factor SOX2 in cancer stem cells suppresses growth and metastasis of lung cancer

Background:

The cancer stem cell hypothesis suggests that neoplastic clones are maintained exclusively by a small subpopulation of cells, which have indefinite proliferation and differentiation potentials and give rise to phenotypically diverse cancer cells. Cancer stem cells have been isolated by their ability to efflux Hoechst 33342 dye and are referred to as the ‘side population’ (SP).

Methods and results:

The Hoechst efflux assay was used to isolate and characterize the SP from murine D121 lung carcinoma cells. Here, we demonstrated that D121-SP cells contain cancer stem cell characteristics, that is, upregulation of the transcription factors SOX2 and Oct 4 in D121-SP cells. In addition, the migration of D121-SP was decreased, and apoptosis of D121-SP was upregulated following knocking down of SOX2 in D121 cells. Importantly, downregulation of SOX2 in D121 cells markedly suppressed their metastatic potential in syngeneic mice.

Conclusions:

These results suggest that the SP is an enriched source of lung tumour cells with stem cell properties and that SOX2 has an important role in maintaining stem cell properties and functions that may be a potential target for effective lung cancer therapy.

GCC expression in lymph nodes (LNs) as a significant determinant of recurrence in stage II colon cancer (CC) patients (pts)

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Background: A multi-center prospectively specified retrospective study Validating Indicators to Associate Recurrence (VITAR) is assessing the relationship between guanylyl cyclase C (GCC) gene expression in formalin fixed LNs and recurrence risk in stage II CC pts not treated with adjuvant chemotherapy. Here we report the preplanned initial analysis performed with 241 pts.

Methods: GCC mRNA was quantified by RT-qPCR using FFPE LNs tissues from untreated stage II CC pts diagnosed from 1999-2006 with at least 10 LN examined blinded to clinical outcomes. Cox regression models examined the relationship between GCC nodal status and the prespecified primary endpoint of recurrence risk.

Results: Twenty-ninepts (12%) had a disease recurrence or cancer death, median follow-up was 60 months and median LNs examined was 15. The ratio of the number of GCC+ LNs over the total number of informative LNs (LNR) significantly predicted higher recurrence risk for 84 pts classified as high risk (HR, 2.38; p=0.02). The estimated 5-yr recurrence rates were 10% and 27% for the low and high risk group, respectively. After adjusting for age, T stage, number of LNs assessed, and MMR status, the significant association remained (HR, 2.61; 95% CI, 1.17-5.83; p=0.02). In a subset of 181 pts with negative margin, T3 tumor only and ≥12 LN examined, the GCC LNR had a HR for recurrence of 5.06 (95% CI 1.61-15.91, p=0.003), translating into 5-yr recurrence rates of 4% among low risk pts and 27% for the high-risk group.

Conclusions: Our results suggest that GCC expression in LNs is a significant determinant of recurrence in appropriately staged CC pts not treated with adjuvant chemotherapy. The validation component of the study is ongoing.

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