Huafang Wang

EGFP-EGF1-conjugated nanoparticles for targeting both neovascular and glioma cells in therapy of brain glioma.

As neovascular and glioma cells were closely associated and might be mutually promoted in glioma growth, a dual-targeting strategy targeting to both neovascular and glioma cells would be more promising as compared with those targeting one of them. In this study, we reported a drug delivery system where nanoparticles were decorated with EGFP-EGF1 (ENP), a fusion protein derived from factor VII with special affinity for tissue factor (TF) over-expressed in glioma tissues, to facilitate anti-glioma delivery of paclitaxel (PTX) by targeting both neovascular and glioma cells. In vitro protein binding assay demonstrated that EGFP-EGF1 bound well to C6 cells and perturbed human umbilical vein endothelial cells (HUVEC) with a concentration-dependent manner but not to unperturbed HUVEC. EGFP-EGF1-TF interaction significantly enhanced nanoparticles uptake by perturbed HUVEC and glioma C6 cells as well as nanoparticles penetration in C6 glioma spheroids, and thus improved the cytotoxicity of their payload in both monolayer cells and glioma spheroids models. In vivo imaging of glioma-bearing mice demonstrated the specific accumulation of ENP in glioma tissues. In vivo distribution of nanoparticles intuitively showed ENP mainly sited in both extravascular glioma cells and neovascular cells. Pharmacodynamic results revealed that PTX-loaded ENP (ENP-PTX) significantly prolonged the median survival time of glioma-bearing mice compared with that of any other group. TUNEL assay and H&E staining showed that ENP-PTX treatment induced significantly more cell apoptosis and tumor necrosis compared with other treatments. In conclusion, the results of this contribution demonstrated the great potential of EGFP-EGF1-functionalized nanoparticles for dual-targeting therapy of brain glioma.

Genetic background analysis of protein C deficiency demonstrates a recurrent mutation associated with venous thrombosis in Chinese population.

Background Protein C (PC) is one of the most important physiological inhibitors of coagulation proteases. Hereditary PC deficiency causes a predisposition to venous thrombosis (VT). The genetic characteristics of PC deficiency in the Chinese population remain unknown. Methods Thirty-four unrelated probands diagnosed with hereditary PC deficiency were investigated. PC activity and antigen levels were measured. Mutation analysis was performed by sequencing the PROC gene. In silico analyses, including PolyPhen-2, SIFT, multiple sequence alignment, splicing prediction, and protein molecular modeling were performed to predict the consequences of each variant identified. One recurrent mutation and its relative risk for thrombosis in relatives were analyzed in 11 families. The recurrent mutation was subsequently detected in a case (VT patients)-control study, and the adjusted odds ratio (OR) for VT risk was calculated by logistic regression analysis. Results A total of 18 different mutations, including 12 novel variants, were identified. One common mutation, PROC c.565C>T (rs146922325:C>T), was found in 17 of the 34 probands. The family study showed that first-degree relatives bearing this variant had an 8.8-fold (95%CI = 1.1–71.6) increased risk of venous thrombosis. The case-control (1003 vs. 1031) study identified this mutation in 5.88% patients and in 0.87% controls, respectively. The mutant allele conferred a high predisposition to venous thrombosis (adjusted OR = 7.34, 95%CI = 3.61–14.94). The plasma PC activity and antigen levels in heterozygotes were 51.73±6.92 U/dl and 75.17±4.84 U/dl, respectively. Conclusions This is the first study on the genetic background of PC deficiency in the Chinese population. The PROC c.565C>T mutation is the most frequent cause of PC deficiency as well as a prevalent risk factor for VT in Chinese individuals. The inclusion of this variant in routine thrombophilic detection may improve the diagnosis and prevention of venous thrombosis.

Resveratrol as a novel agent for treatment of multiple myeloma with matrix metalloproteinase inhibitory activity.

AbstractAim:To examine the in vitro antitumor activity of resveratrol against multiple myeloma (MM) cell lines (RPMI 8226, U266, and KM3), and the mechanisms involved.Methods:The growth inhibition of resveratrol was determined by 3-(4, 5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The effect of resveratrol on the apoptosis was investigated by combined annexin V-propidium iodide staining. The effect of resveratrol on the invasion through Matrigel matrix was detected by transwell invasion analyses. The activity of matrix metalloproteinase (MMP)-2 and -9 proteins were determined by gelatin zymography analysis. The expression of MMP-2, MMP-9, Bcl-2, Bcl-xL, XIAP and Bax protein were detected using Western blotting analysis.Results:Resveratrol inhibited proliferation of MM cells in a dose- and time-dependent manner. Incubation of MM cells with resveratrol resulted in apoptotic cell death. Resveratrol down-regulated the expression of the antiapoptotic proteins Bcl-2, Bcl-xL and XIAP and up-regulated the expression of the proapoptotic protein Bax. Furthermore, resveratrol inhibited invasion of RPMI 8226, U266, and KM3 cells with IC50 values of 64±8 umol/L, 93±11 umol/L, and 153±11 umol/L, respectively. Resveratrol inhibited the constitutive expression of MMP-2 and -9 proteins of MM cells and suppressed its gelatinolytic activity.Conclusion:Resveratrol inhibits the proliferation of MM cells by inducing apoptotic cell death. Resveratrol also inhibits MM cell invasion. The inhibition of invasion may be associated with the attenuation of the enzymatic activities of MMP-2 and -9.

Potential biomarkers of acute cerebral infarction detected by SELDI-TOF-MS.

No single biologic marker is used in the routine diagnosis of acute cerebral infarction. We screened for potential biomarkers in 92 plasma samples, including samples from 32 patients with acute cerebral infarction and 60 hospital control subjects. Pretreated plasma samples were analyzed using SELDI-TOF-MS (Ciphergen Biosystems, Fremont, CA). Proteomic spectra of mass to charge ratio (m/z) were generated by the application of plasma to weak cation exchange (CM10 ProteinChip, Ciphergen Biosystems) arrays. A differential pattern consisting of 13 biomarkers was selected based on their collective contribution to the optimal separation between patients with acute cerebral infarction and control subjects with a sensitivity of 84.4% and specificity of 95.0%, respectively. Plasma proteomic profiling with SELDI-TOF-MS and ProteinChip technologies shows potential in discriminating patients with acute cerebral infarction and control subjects. Diagnosis of acute cerebral infarction should probably depend on the use of a panel of biomarkers.

EGFP-EGF1-Conjugated PLGA Nanoparticles for Targeted Delivery of siRNA into Injured Brain Microvascular Endothelial Cells for Efficient RNA Interference

Injured endothelium is an important target for drug and/or gene therapy because brain microvascular endothelial cells (BMECs) play critical roles in various pathophysiological conditions. RNA-mediated gene silencing presents a new therapeutic approach for treating such diseases, but major challenge is to ensure minimal toxicity and target delivery of siRNA to injured BMECs. Injured BMECs overexpress tissue factor (TF), which the fusion protein EGFP-EGF1 could be targeted to. In this study, TNF alpha (TNF-α) was chosen as a stimulus for primary BMECs to produce injured endothelium in vitro. The EGFP-EGF1-PLGA nanoparticles (ENPs) with loaded TF-siRNA were used as a new carrier for targeted delivery to the injured BMECs. The nanoparticles then produced intracellular RNA interference against TF. We compared ENP-based transfections with NP-mediated transfections, and our studies show that the ENP-based transfections result in a more efficient downregulation of TF. Our findings also show that the TF siRNA-loaded ENPs had minimal toxicity, with almost 96% of the cells viable 24 h after transfection while Lipofectamine-based transfections resulted in only 75% of the cells. Therefore, ENP-based transfection could be used for efficient siRNA transfection to injured BMECs and for efficient RNA interference (RNAi). This transfection could serve as a potential treatment for diseases, such as stroke, atherosclerosis and cancer.

The potential biomarkers for thromboembolism detected by SELDI-TOF-MS

INTRODUCTION Few studies were concerned about searching for specific biomarkers for thromboembolic (arterial and venous) diseases by the use of Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF-MS). MATERIALS AND METHODS We screened for potential biomarkers in 69 plasma samples, including samples from 20 patients with idiopathetic deep vein thrombosis (DVT), 20 patients with acute myocardial infarction (AMI), and 29 healthy controls without a history of thromboembolism. Pretreated plasma samples were analyzed on the Protein Biology System IIc plus SELDI-TOF-MS (Ciphergen Biosystems, Fremont, CA). Proteomic spectra of mass to charge ratio (m/z) were generated by the application of plasma to immobilized metal affinity capture (IMAC-3) ProteinChip arrays activated with copper. RESULTS A pattern of three biomarkers (m/z: 2 667, 5 914, and 6 890 Da, respectively) with a total accuracy of 100% was selected based on their collective contribution to the optimal separation between patients with AMI and healthy controls. Another spattern consisting of only one biomarker (m/z: 5 914 Da) could totally discriminate patients with DVT and control subjects. For further analysis between patients with AMI and those with DVT, a pattern of four biomarkers (m/z: 3 418, 5 271, 33 378, and 68 125 Da, respectively) was selected with a total accuracy of 82.5%. CONCLUSIONS Plasma proteomic profiling with SELDI-TOF-MS and ProteinChip technologies provides high sensitivity and specificity in discriminating patients with thrombosis and healthy subjects. The discovered biomarkers might show great potential for early diagnosis of thromboembolic diseases.

Molecular basis of protein S deficiency in China

Protein S (ProS) is a physiological inhibitor of coagulation with an important function in the down‐regulation of thrombin generation. ProS deficiency is a major risk factor for venous thrombosis. This study enrolled 40 ProS‐deficient probands to investigate the molecular basis of hereditary ProS deficiency in Chinese patients. A mutation analysis was performed by resequencing the PROS1 gene. Large deletions were identified by multiplex ligation‐dependent probe amplification (MLPA) analysis. A total of 20 different mutations, including 15 novel mutations, were identified in 21 of the 40 index probands. Small mutations were detected in 18 (45.0%) probands, and large deletions were found in 3 (7.5%) probands, leaving 19 (47.5%) patients without causative variants. To evaluate the functional consequences of 2 novel missense variants, ex vivo thrombin‐generation assays, bioinformatics tools, and in vitro expression studies were employed. The p.Asn365Lys ProS variant was found to have moderately impaired secretion and reduced activated protein C cofactor activity. In contrast, the p.Pro410His mutant appeared to have severely impaired secretion but full anticoagulant activity. This study is the largest investigation of ProS deficiency in China and the first investigation of the influence of Type I ProS missense mutations on the global level of coagulation function. The p.K196E mutation, which is common in the neighboring Japanese population, was not found in our Chinese population, and null mutations were common in our Chinese population but not common in Japan. Further genetic analysis is warranted to understand the causes of ProS deficiency in patients without a genetic explanation. Am. J. Hematol. 88:899–905, 2013.

Binding of EGF1 domain peptide in coagulation factor VII with tissue factor and its implications for the triggering of coagulation

SummaryThe binding function of EGF1 domain peptide with tissue factor (TF) and its ability of triggering coagulation were explored. The TF expression model in vitro was established by lipopolysaccharide induction. The affinity of EGFP-EGF1 and TF expressing cells was analyzed by fluorescence microscopy and flow cytometry (FCM). The affinity of EGFP-EGF1 and rat soluble TF was quantitated by surface plasmon resonance (SPR). The ability of EGFP-EGF1 in triggering coagulation was tested by prothrombin time assay. The FCM results showed recombinant factor VII (rFVII) could definitely depress the integration of EGFP-EGF1 with recombinant TF (rTF) (68.65%±3.86% vs 57.98%±4.71%, P<0.01). The SPR results indicated the association constant ka of EGFP-EGF1 proteins was higher than rFVII (8.29±1.39 vs 3.75±0.32, P<0.01). However, the EGFP-EGF1 protein lost the activity of triggering coagulation as compared with blood plasma of normal SD rats (56.8±3.2 s vs 17.8±3.4 s, P<0.01). It was concluded that the rat EGF1 peptide could specifically bind to TF without the ability of triggering coagulation. EGF1 peptide may be a good target head for delivering drugs to TF in anticoagulation therapy.The binding function of EGF1 domain peptide with tissue factor (TF) and its ability of triggering coagulation were explored. The TF expression model in vitro was established by lipopolysaccharide induction. The affinity of EGFP-EGF1 and TF expressing cells was analyzed by fluorescence microscopy and flow cytometry (FCM). The affinity of EGFP-EGF1 and rat soluble TF was quantitated by surface plasmon resonance (SPR). The ability of EGFP-EGF1 in triggering coagulation was tested by prothrombin time assay. The FCM results showed recombinant factor VII (rFVII) could definitely depress the integration of EGFP-EGF1 with recombinant TF (rTF) (68.65%±3.86% vs 57.98%±4.71%, P<0.01). The SPR results indicated the association constant ka of EGFP-EGF1 proteins was higher than rFVII (8.29±1.39 vs 3.75±0.32, P<0.01). However, the EGFP-EGF1 protein lost the activity of triggering coagulation as compared with blood plasma of normal SD rats (56.8±3.2 s vs 17.8±3.4 s, P<0.01). It was concluded that the rat EGF1 peptide could specifically bind to TF without the ability of triggering coagulation. EGF1 peptide may be a good target head for delivering drugs to TF in anticoagulation therapy.

Genetic analysis should be included in clinical practice when screening for antithrombin deficiency

Antithrombin (AT) deficiency increases the risk of thrombosis. Current evidence shows that some SERPINC1 mutations responsible for antithrombin deficiency often present a slightly decreased or normal activity and therefore could not be detected by functional tests. This study was designed to compare activity assays and direct genetic analyses in identifying hereditary antithrombin deficiency. In total, 400 consecutive patients with venous thrombosis were enrolled. Functional assays showed that 16 of the 400 individuals had decreased antithrombin activity, and 14 of them were confirmed by genetic analysis. Of the remaining 384 patients, 95 individuals without a known risk factor and 95 individuals with predisposing factors were also selected for gene sequencing. Eight additional causative mutations were identified in nine individuals and they should also be considered as antithrombin deficiency. In addition, a recurrent mutation, p.Arg356_Phe361del, was characterised. The mutant appeared to have a partially impaired secretion and a reduction in functional activity by 50 %. This study indicated that including genetic analysis in screening tests for identifying antithrombin deficiency was essential. Specifically, a genetic analysis of SERPINC1 is strongly recommended when individuals experience unprovoked thrombotic diseases, even if the AT activities are normal.

Inhibition of Tissue Factor Expression in Brain Microvascular Endothelial Cells by Nanoparticles Loading NF-κB Decoy Oligonucleotides

To investigate a nuclear factor-kappa B decoy oligonucleotides strategy on the inhibition of tissue factor (TF) expression in cultured rat brain microvascular endothelial cells (BMECs) by polylactic acid (PLA) nanoparticles delivery system and to evaluate this new vector for in vitro gene therapy. Nanoparticles were formulated using poly D,L-polylactic acid with surface modifying by polysorbates 80. 3-[4,5-Dimethylthiazol-2,5-diphenyl-2H-tetrazolium bromide] (MTT) assays showed that PLA nanoparticles were not toxic to the cultured BMECs.The decoy oligonuceotides (ODNs) loaded within nanoparticles was 6 μg/mg, encapsulation efficacy was (60.5±1.5)%. It was observed by flow cytometry that the cellular uptake of nanoparticles depended on the time of incubation and the concentration of nanoparticles in the medium. And confocal microscopy demonstrated that nanoparticles localized mostly in the BMECs cytoplasm. The released decoy oligonuceotides (ODNs) uptaked by BMECs retained their biologic activity and led to reduced level of tissue factor expression as compared to control cultures. These findings offer a potential therapeutic strategy in the control of TF expression in BMECs in vitro and suggest that PLA nanoparticles may be appropriate as delivery vehicles for decoy strategy in the gene therapy of cerebral thrombosis.