Production of high-purity recombinant human vascular endothelial growth factor (rhVEGF165) by Pichia pastoris / 生物工程学报

Vascular endothelial growth factor (VEGF165) is a highly specific vascular endothelial growth factor that can be used to treat many cardiovascular diseases. The development of anti-tumor drugs and disease detection reagents requires highly pure VEGF165 (at least 95% purity). To date, the methods for heterologous expression and purification of VEGF165 require multiple purification steps, but the product purity remains to be low. In this study, we optimized the codons of the human VEGF165 gene (vegf165) according to the yeast codon preference. Based on the Pichia pastoris BBPB vector, we used the Biobrick method to construct a five-copy rhVEGF165 recombinant expression vector using Pgap as the promoter. In addition, a histidine tag was added to the vector. Facilitated by the His tag and the heparin-binding domain of VEGF165, we were able to obtain highly pure rhVEGF165 (purity > 98%) protein using two-step affinity chromatography. The purified rhVEGF165 was biologically active, and reached a concentration of 0.45 mg/mL. The new design of the expression vector enables production of active and highly pure rhVEGF165 ) in a simplified purification process, the purity of the biologically active natural VEGF165 reached the highest reported to date.

Netrin-1 works with UNC5B to regulate angiogenesis in diabetic kidney disease / 医学前沿

Netrin-1, an axon guidance factor, and its receptor UNC5B play important roles in axonal development and angiogenesis. This study examined netrin-1 and UNC5B expression in kidneys with diabetic kidney disease (DKD) and investigated their roles in angiogenesis. Netrin-1 and UNC5B were upregulated in streptozotocininduced DKD Wistar rats, and their expression was compared with that in healthy controls. However, exogenous netrin-1 in UNC5B-depleted human renal glomerular endothelial cells (HRGECs) inhibited cell migration and tubulogenesis. This effect was likely associated with SRC pathway deactivation. Netrin-1 treatment also eliminated the pro-angiogenic effects of exogenous VEGF-165 on UNC5B-silenced HRGECs. These results indicate that UNC5B antagonizes netrin-1 and that UNC5B upregulation contributes partly to enhancing angiogenesis in DKD. Therefore, introducing exogenous netrin-1 and depleting endogenous UNC5B are potential strategies for reducing the incidence of early angiogenesis and mitigating kidney injury in DKD.

Lopinavir and curcumin directly alters BAX/BCL2 and VEFG165b mRNA levels to suppress human squamous cervical carcinoma cell growth / Lopinavir y curcumina alteran directamente los niveles de ARNm de BAX/ BCL 2 y VEFG165 para suprimir el crecimiento de células de carcinoma cervical escamoso humano

Following the success of the highly active antiretroviral therapy, the potential of multidrug combination regimen for the management of cancer is intensely researched. The anticancer effects of curcumin on some human cell lines have been documented. Lopinavir is a FDA approved protease inhibitor with known apoptotic activities. Dysregulated apoptosis is important for the initiation of cancer while angiogenesis is required for cancer growth and development, this study therefore investigated the effects of the combination of lopinavir and curcumin on cell viability, apoptosis and the mRNA expression levels of key apoptotic and angiogenic genes; BAX, BCL2 and VEGF165b in two human cervical cell lines; human squamous cell carcinoma cells - uterine cervix (HCS-2) and transformed normal human cervical cells (NCE16IIA). The two human cervical cell lines were treated with physiologically relevant concentrations of the agents for 120 h following which BAX, BCL2 and VEGF165b mRNA expression were determined by Real Time qPCR. The Acridine Orange staining for the morphological evaluation of apoptotic cells was also performed. The combination of lopinavir and curcumin up-regulated pro-apoptotic BAX and antiangiogenic VEGF165b but down-regulated the mRNA levels of anti-apoptotic BCL2 mRNA in the human squamous cell carcinoma (HCS-2) cells only. The fold changes were statistically significant. Micrographs from Acridine Orange staining showed characteristic evidence of apoptosis in the human squamous cell carcinoma (HCS-2) cells only. The findings reported here suggest that the combination of curcumin and the FDA approved drug-lopinavir modulate the apoptotic and angiogenic pathway towards the inhibition of cervical cancer.

Tras el éxito de la terapia antirretroviral altamente activa, se investiga intensamente el potencial del régimen de combinación de múltiples fármacos para el tratamiento del cáncer. Se han documentado los efectos anticancerígenos de la curcumina en algunas líneas celulares humanas. Lopinavir es un inhibidor de proteasa aprobado por la FDA con actividades apoptóticas conocidas. La apoptosis disrregulada es importante para el inicio del cáncer, mientras que la angiogénesis es necesaria para el crecimiento y desarrollo del cáncer. Por lo tanto, este estudio investigó los efectos de la combinación de lopinavir y curcumina sobre la viabilidad celular, la apoptosis y los niveles de expresión del ARNm de genes apoptóticos y angiogénicos clave: BAX, BCL2 y VEGF165b en dos líneas celulares cervicales humanas; células de carcinoma de células escamosas humanas: cérvix uterino (HCS-2) y células cervicales humanas transformadas (NCE16IIA). Las dos líneas celulares cervicales humanas se trataron con concentraciones fisiológicamente relevantes de los agentes durante 120 horas, después de lo cual la expresión de ARNm de BAX, BCL2 y VEGF165b se determinó mediante qPCR en tiempo real. También se realizó la tinción con naranja de acridina para la evaluación morfológica de células apoptóticas. La combinación de lopinavir y curcumina reguló incrementando BAX proapoptósicos y VEGF165b antiangiogénicos, pero reguló a la baja los niveles de ARNm del BCL2 antiapoptótico en células de carcinoma de células escamosas humanas (HCS-2) únicamente. Los cambios en el pliegue fueron estadísticamente significativos. Las micrografías de la tinción con naranja de acridina mostraron evidencia característica de apoptosis solo en las células del carcinoma de células escamosas humanas (HCS-2). Los hallazgos reportados aquí sugieren que la combinación de curcumina y el fármaco aprobado por la FDA lopinavir modulan la vía apoptótica y angiogénica hacia la inhibición del cáncer cervical.

Construction of eukaryotic expression vector of hypoxic inducible VEGF and its in vitro delivery application and functional identification / 解放军医学杂志

Objective To construct the eukaryotic expression vector of hypoxia inducible vascular endothelial growth factor (VEGF), and establish its in vitro delivery method. Methods Erythropoietin (EPO) enhancer was inserted into eukaryotic expression vector pGL4.73 [hRluc/SV40] (pSV) promoter by gene recombination technique to construct hypoxia inducible expression system (pEPO-SV). Renilla luciferase (Rluc) was used as downstream reporter gene. Then the VEGF165 gene was inserted into the pEPO-SV plasmid instead of Rluc, and the pEPO-SV-VEGF and pSV-VEGF expression vectors were obtained by inserting the pEPO-SV-VEGF gene into pSV as control. The pSV plasmid expressing Rluc or VEGF165 and pEPO-SV plasmid were transfected in vitro into human embryonic kidney 293T cells. The expression of Rluc or VEGF165 was used to identify the hypoxia induction function of the constructed vector after being treated under normal and hypoxic conditions for 24h and 48h. The intracellular delivery method of plasmids was then established based on poly (lactic acid-glycolic acid) copolymer (PLGA) nanoparticles as carrier, and the efficiency of the eukaryotic expression plasmids induced by hypoxia was evaluated under the in vitro hypoxia model. Results In the construction of plasmid, the successful insertion and correctness of EPO enhancer and VEGF165 gene were confirmed by restriction endonuclease digestion, PCR amplification and DNA sequencing. The plasmid expressing Rluc or VEGF165 was transfected into 293T cells respectively. There was no significant difference in the expression of reporter gene Rluc (one, plasmid pSV and pEPO-SV fluorescence expression values were 2448.24±158.51 and 3173.97±379.92, the second, plasmid pSV and pEPO-SV fluorescence expression values were 55 500.00±3237.05 and 51 193.18±866.32, respectively) or target gene VEGF165 in normal culture (P>0.05). But the expression of Rluc (In the cobalt chloride of hypoxia, the fluorescence expression values of pSV and pEPO-SV were 4857.70±1223.28 and 16 432.64±1618.73, respectively. In the hypoxia incubator, the fluorescence expression values of pSV and pEPO-SV were 2504.45±213.20 and 17 274.35±685.60, respectively) or VEGF165 in hypoxia was significantly higher than that in control group (P<0.01). The results showed that the constructed pEPO-SV and pEPO-SV-VEGF plasmids had typical hypoxia inducible expression activity. PLGA nanoparticles were used to in vitro deliver pEPO-SV and pSV in 293T cells. The results of detecting the reporter gene Rluc in normal culture and hypoxic conditions were consistent with those mentioned above, that is, under normal conditions, the 24h and 48h fluorescence expression values of plasmids pSV and pEPO-SV were 149.44±4.01 and 127.09±15.05, 1074.91±114.78 and 1064.56±137.48, respectively; under hypoxic conditions, the 24h and 48h fluorescence expression values of pSV and pEPO-SV were 3265.34±440.00 and 8828.87±637.03, 3202.06±33.43 and 9114.75±292.06, respectively. Conclusion A typical hypoxia inducible VEGF eukaryotic expression system has been successfully established, and an in vitro effective delivery method is also established, which may have an important application prospect in ischemia, hypoxia and other tissue injury diseases.

Antiangiogenic VEGF165b expression in human breast MCF-7 and MCF-10A cells exposed to reverse transcriptase and protease inhibitors / Expresión de VEGF165b antiangiogénico en células MCF-7 y MCF-10A de mama humana expuesto a inhibidores de la transcriptasa inversa y la proteasa

The combined antiretroviral therapy (cART), a multidrug combination regimen, usually consisting Nucleoside Reverse Transcriptase Inhibitors, non- Nucleoside Reverse Transcriptase Inhibitors and Protease Inhibitors has altered the morbidity pattern affecting HIV-infected individuals to include non-AIDS-defining malignancies (nADMs). The speculation is rife; does cART induce or promote the progression of nADMs such as breast cancer? This study was therefore designed to investigate of the effects of some antiretroviral drugs (at clinically relevant concentrations) on the expression of anti-angiogenic gene; VEGF165b in two human breast cell lines; MCF-7 and MCF-10A by Real Time qPCR and immuno-fluorescence. All of the antiretroviral drugs and combinations tested produced patterns of slight up or downregulation of VEGF165b mRNA expression but the alterations did not attain statistical significance. They also did not alter VEGF165bprotein localisation in both cell lines. The findings reported here suggest that antiretroviral drugs probably do not influence the angiogenic pathway in the development of breast cancer in patients under the combined antiretroviral regimen.

El tratamiento antirretroviral combinado (TARc), un régimen de combinación de múltiples fármacos, consistiendo generalmente en inhibidores nucleósidos de la transcriptasa reversa, inhibidores no-nucleósidos de la transcriptasa reversa e inhibodres de proteasa que alteran el patrón de mortalidad que afecta a infectados por el VIH incluyendo neoplasias definidas como no HIV (nADMs). La especulación es moneda corriente; TARc induce o promueve la progresión de nADMs como cáncer de mama? Por lo tanto, este estudio se diseñó para investigar los efectos de algunos de los fármacos antirretrovirales (en concentraciones clínicamente relevantes) sobre la expresión del gen anti-angiogénico; VEGF165b en dos líneas celulares de mama humana; MCF-7 y MCF-10A por PCR tiempo real e inmunofluorescencia. Todos los fármacos antirretrovirales y las combinaciones probadas pueden regular en forma ligera hacia arriba o hacia abajo la expresión de ARNm producidos por VEGF165b pero las alteraciones no fueron estadísticamente significativos. Además, no se alteran los niveles de proteína VEGF165b, para la localización en ambas líneas celulares. Los resultados aquí presentados sugieren que los medicamentos antirretrovirales probablemente no influyen en la vía angiogénica en el desarrollo del cáncer de mama en pacientes bajo el régimen antirretroviral combinado.

Effects of Exogenous VEGF165b on Invasion and Migration of Human Lung Adenocarcinoma A549 Cells / 华中科技大学学报（医学）（英德文版）

Vascular endothelial growth factor 165 (VEGF165)-mediated autocrine stimulation of tumor cells enhances the progression to a malignant phenotype.VEGF165b competes with VEGF165 and binds to vascular endothelial growth factor receptor (VEGFR),resulting in inhibition of downstream signal transduction pathways.This study was designed to investigate the role of VEGF165b in the migration and invasion of human lung adenocarcinoma A549 cells.The full-length of VEGF165b was constructed and cloned into an expression plasmid (pVEGF165b),and then transfected into A549 cells.Dimethylthiazolyl-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect the effect of VEGF165b on proliferation of transfected cells.Reverse transcription polymerase chain reaction (RT-PCR) was employed to examine the effect of VEGF165b on the expression of VEGF165 in transfected cells.Wound-healing assays were used to investigate the effect of VEGF165b on migration of transfected cells.Matrix metalloproteinase (MMPs) activity assay and in vitro invasion assay were used to determine the role of VEGF165b in invasion of transfected cells.There was no significant change in proliferation of A549 cells after transfection of pVEGF165b,but the expression of VEGF165,migration and invasion in A549 cells were inhibited.Furthermore,exogenous VEGF165b inhibited the activity of MMP9 in the supematant of A549 cells and the subsequent invasion capacity of those cells.We therefore conclude that exogenous VEGF165b can inhibit the expression of VEGF165,as well as the migration and invasion ofA549 cells,but has no effect on the proliferation ofA549 cells.

Generation of fully human anti-vascular endothelial growth factor 165 monoclonal antibody with antitumor efficacy from transgenic five-feature mice / 中国药科大学学报

Aim: To prepare a fully human anti-VEGF_(165)(vascular endothelial growth factor 165) monoclonal antibody with antitumor activity from five-feature mice which express human immunoglobin loci. Methods: A routine method for the generation of monoclonal antibodies( mAbs) against the human VEGF_(165) was developed. The immunizing effect between five-feature mice and BALB/c was observed and the mAb was purified through MBP IgM affinity chromatography. The effect of mAbs on antitumor was tested ire vitro by T24 cell line. Results: Four hybri-domata secreting mAbs steadily were isolated successfully, and the serum titer of mAb in BALB/c mice was almost 10 times higher than that in five-feature mice. The indirect ELISA method for mAb titer determination was also established. The anti-VEGF_(165) mAb was purified to homogeneity by precipitation with ammonium sulfate followed by the affinity chromatography on MBP IgM purification column. Moreover, both purified human IgM V_2, V_(75) and mouse ascites were characterized by SDS-PAGE and Western blotting. Proliferation of T24 cell line was considerably inhibited by V_2 and V_(75). Conclusion: Five-feature mice could be used to produce fully human monoclonal antibody. The fully human anti-VEGF mAb is potential in the cancer treatment.

The differential expression of VEGF_(165)b in the transitional cell carcinoma of the bladder and normal bladder tissues and its clinical significance / 重庆医科大学学报

Objective:To investigate the differential expression of VEGF165b in the transitional cell carcinoma of the bladder (TCCB) and normal bladder tissues and its role in the development of TCCB. Methods: S-P immunohistochemistry was used to detect the expression of VEGF165b protein in 38 specimens of paraffin-embedded TCCB tissues and 36 specimens of paraffin-embedded normal bladder tissues. RT-PCR was performed to detect the expression of VEGF165b mRNA in 55 specimens of fresh TCCB tissues and 43 specimens of fresh normal bladder tissues. Results: Among 36 of normal bladder tissues, 35 specimens had positive expression of VEGF165b protein, with the positive rate of 97.22% (35/36) that was significantly higher than 21.05% (8/38) (P

Expression of Human Vascular Endothelial Growth Factor 165 in Ischemically Damaged Bind Limb in a Rabbit Model with Transplantation of Mesenchymal Stem Cells / 医学研究杂志

Objective To observe the expression of Vascular endothelial growth factor 165 (VEGF165) in transplantation of MSCs to repair an ischemically damaged bind limb in a rabbit model.Methods MSCs were cultivated in vitro and transfected with non-replicative adenoviral vector with VEGF165 gene. Four weeks after treatment, Real-time PCR assessed the expression of VEGF165 in the damaged limb.Results It was confirmed that VEGF165 was successfully transfected into MSCs.Real-time PCR assessments revealed the expression of Vascular endothelial growth factor 165 (VEGF165) in 4 weeks after treatment. Conclusion VEGF165 can be transfected into MSCs and express in rabbit model of ischemic limb.