Safety and efficacy of intravitreal anti vascular endothelial growth factor for severe posterior retinopathy of prematurity with flat fibrovascular proliferation

BACKGROUND Intravitreal anti-vascular endothelial growth factor(IVA)injection is known to cause contraction of fibrovascular proliferation(FVP),when present in severe retinopathy of prematurity(ROP).AIM To assess the structural outcomes of IVA injection in the treatment of severe posterior ROP with significant FVP.METHODS It was a retrospective study in which 36 eyes of 18 preterm babies who developed>4 clock hours of FVP in zone I or posterior zone II,were treated with either intravitreal 0.625 mg bevacizumab or intravitreal 0.2 mg of ranibizumab.Favorable structural outcome included resolution of plus disease and FVP without the development of tractional retinal detachment.Secondary outcome measure included either full retinal maturation at follow-up or development of recurrent disease requiring additional treatment.Adverse outcomes included progression to retinal detachment.RESULTS The mean gestational age of the 18 preterm babies was 30 wk(range 27-36),and mean birth weight was 1319 g(range 650-1980 g).Mean post-menstrual age(PMA)at the time of primary treatment was 35.5 wk(range 31-41 wk).All eyes showed regression of plus disease and FVP.5 eyes of 3 babies showed reactivation of disease and were treated with repeat IVA(n=2 eyes)or peripheral laser photocoagulation(n=3 eyes)respectively.16 out of 36(44%)reached retinal vascular maturation at final follow up at 5 years.CONCLUSION There was good resolution of severe posterior ROP with FVP with IVA,with retinal maturity of 44%at 5 year follow-up and a reactivation rate of 13.8%.When the IVA injection is given prior to 37 wk PMA,while disease is in phase 2,it is less likely to cause contracture of pre-existing FVP.

Expression and significance of pigment epithelium-derived factor and vascular endothelial growth factor in colorectal adenoma and cancer

BACKGROUND The incidence and mortality of colorectal cancer(CRC)are among the highest in the world,and its occurrence and development are closely related to tumor neovascularization.When the balance between pigment epithelium-derived factors(PEDF)that inhibit angiogenesis and vascular endothelial growth factors(VEGF)that stimulate angiogenesis is broken,angiogenesis is out of control,resulting in tumor development.Therefore,it is very necessary to find more therapeutic targets for CRC for early intervention and later treatment.AIM To investigate the expression and significance of PEDF,VEGF,and CD31-stained microvessel density values(CD31-MVD)in normal colorectal mucosa,adenoma,and CRC.METHODS In this case-control study,we collected archived wax blocks of specimens from the Digestive Endoscopy Center and the General Surgery Department of Chengdu Second People's Hospital from April 2022 to October 2022.Fifty cases of specimen wax blocks were selected as normal intestinal mucosa confirmed by electronic colonoscopy and concurrent biopsy(normal control group),50 cases of specimen wax blocks were selected as colorectal adenoma confirmed by electronic colonoscopy and pathological biopsy(adenoma group),and 50 cases of specimen wax blocks were selected as CRC confirmed by postoperative pathological biopsy after inpatient operation of general surgery(CRC group).An immunohistochemical staining experiment was carried out to detect PEDF and VEGF expression in three groups of specimens,analyze their differences,study the relationship between the two and clinicopathological factors in CRC group,record CD31-MVD in the three groups,and analyze the correlation of PEDF,VEGF,and CD31-MVD in the colorectal adenoma group and the CRC group.The F test or adjusted F test is used to analyze measurement data statistically.Kruskal-Wallis rank sum test was used between groups for ranked data.The chi-square test,adjusted chi-square test,or Fisher's exact test were used to compare the rates between groups.All differences between groups were compared using the Bonferroni method for multiple comparisons.Spearman correlation analysis was used to test the correlation of the data.The test level(α)was 0.05,and a two-sided P<0.05 was considered statistically significant.RESULTS The positive expression rate and expression intensity of PEDF were gradually decreased in the normal control group,adenoma group,and CRC group(100%vs 78%vs 50%,χ^(2)=34.430,P<0.001;++~++vs+~++vs-~+,H=94.059,P<0.001),while VEGF increased gradually(0%vs 68%vs 96%,χ^(2)=98.35,P<0.001;-vs-~+vs++~+++,H=107.734,P<0.001).In the CRC group,the positive expression rate of PEDF decreased with the increase of differen-tiation degree,invasion depth,lymph node metastasis,distant metastasis,and TNM stage(χ^(2)=20.513,4.160,5.128,6.349,5.128,P<0.05);the high expression rate of VEGF was the opposite(χ^(2)=10.317,13.134,17.643,21.844,17.643,P<0.05).In the colorectal adenoma group,the expression intensity of PEDF correlated negatively with CD31-MVD(r=-0.601,P<0.001),whereas VEGF was not significantly different(r=0.258,P=0.07).In the CRC group,the expression intensity of PEDF correlated negatively with the expression intensity of CD31-MVD and VEGF(r=-0.297,P<0.05;r=-0.548,P<0.05),while VEGF expression intensity was positively related to CD31-MVD(r=0.421,P=0.002).CONCLUSION It is possible that PEDF can be used as a new treatment and prevention target for CRC by upregulating the expression of PEDF while inhibiting the expression of VEGF.

Efficacy and safety of anti-vascular endothelial growth factor agents on corneal neovascularization: A meta-analysis

BACKGROUND Corneal neovascularization(CoNV)is the second major cause of blindness.Vascular endothelial growth factor(VEGF)inhibitors,e.g.,bevacizumab,have been used to prevent CoNV.AIM We conducted an updated systematic review and meta-analysis of clinical trials to examine the efficacy and safety of anti-VEGF in CoNV.METHODS A literature search was conducted using three electronic databases.Mean difference(MD),standard mean difference(SMD),and relative risk(RR)are used to estimate the effect size.RESULTS Nine randomized controlled and three non-randomized trials were obtained.The pooled results demonstrated a significant reduction of CoNV area/Length(SMD=-1.17,95%CI:-1.58 to-0.75),best corrected visual acuity(MD=-0.54,95%CI:-0.91 to-0.17),and graft rejection(RR=0.44,95%CI:0.24 to 0.8)and failure(RR=0.39,95%CI:0.19 to 0.78)rates in the anti-VEGF group than the placebo group.A non-significant reduction of the epithelial defect was also observed in the bevacizumab group compared with the placebo(RR=0.56,95%CI:0.30 to 1.06).Compared with a placebo,the unsynthesizable trials also support that bevacizumab improves visual acuity,CoNV,graft rejection,and failure rates.Trials reporting other comparisons revealed the superiority of combined remedy with bevacizumab compared to other treatments in reducing CoNV.CONCLUSION Anti-VEGF agents,mainly bevacizumab,are an effective and safe treatment for CoNV of all causes and prevent corneal graft rejection and failure in corneal transplantation.

Bilateral same-session intravitreal injections of antivascular endothelial growth factors

AIMTo document the indications, safety and possible complications of bilateral same-session intravitreal anti-vascular endothelial growth factor (VEGF) injections performed in the ophthalmic operating room.

Combined therapy versus anti-vascular endothelial growth factor monotherapy for polypoidal choroidal vasculopathy： a Meta-analysis

AIM： To evaluate the efficacy and safety of anti-vascular endothelial growth factor （VEGF） combined with photodynamic therapy （PDT） versus anti-VEGF monotherapy for polypoidal choroidal vasculopathy （PCV）. METHODS： We conducted a Meta-analysis of 9 studies to compare the efficacy and safety between combined therapy and anti-VEGF monotherapy for PCV. The programs of RevMan 5.3 and Stata 12.0 were used to analyze data. RESULTS： The best corrected visual acuity （BCVA） in combined therapy group were significantly better than those of anti-VEGF monotherapy group at 6, 24 and 36mo, with pooled weighted means differences （WMDs） of 0.12 （0.06, 0.18）, 0.25 （0.12, 0.38） and 0.28 （0.13, 0.43）, respectively. The central retinal thickness （CRT） reductions in combined therapy group were higher than that in anti- VEGF monotherapy group at 1, 3, 6 and 9mo, with pooled WMDs of 63.90 （20.41, 107.38）, 33.47 （4.69, 62.24）, 30.57 （0.12, 60.01） and 28.00 （2.51, 53.49）, respectively. The regression rate of polyps in combined therapy group was much higher than that in anti-VEGF monotherapy group [RD： 0.47 （0.26, 0.68）; P〈0.0001]. The adverse event retinal hemorrhage did not differ significantly between the two groups. CONCLUSION： Our findings clearly document that anti- VEGF combined with PDT is a more effective therapy for PCV compared with anti-VEGF monotherapy. Furthermore, combined therapy does not increase the incidence of retinal hemorrhage.

Real-world outcomes of anti-vascular endothelial growth factor therapy for retinal vascular vein occlusion in Tibet,China

AIM: To evaluate the outcomes of intravitreal antivascular endothelial growth factor(anti-VEGF) agents for patients with retinal vein occlusion(RVO) related-macular edema(ME) in Tibetan.METHODS: A retrospective, observational, single-center study. The demographic and clinical data of 90 RVO Tibetan patients(93 eyes) treated with either ranibizumab or conbercept in Tibet Autonomous Region People’s Hospital from Jan 2018 to December 2019 were collected.RESULTS: The mean patient age was 56.8±10.6y, 45(50%) of them were female. The mean living altitude was 3867.8±567.9 m. At the last visit, the best-corrected visual acuity(BCVA) significantly increased(52.2±21.8 letters) in comparison with the baseline(38.2±24.1 letters, P<0.001);while the central retinal thickness(CRT) significantly reduced(245.5±147.6 μm) in comparison with the baseline(504.1±165.2 μm, P<0.001). The 43.0% of the eyes gained≥15 letters, 60.2% of the eyes gained ≥10 letters, and 78.5% of the eyes gained ≥5 letters. No vision loss was noted in 92.5% of the eyes, 4 eyes lost more than 10 letters during follow-up period. The mean number of injections was 2.4±1.8. No severe ocular or systemic adverse events related to either the drug or injection were noted.CONCLUSION: Anti-VEGF therapy is effective and safe in Tibetan patients for the treatment of RVO related ME.

Reduction of tumorigenicity of SMMC-7721 hepatoma cells by vascular endothelial growth factor antisense gene therapy

AIM To test the hypothesis to block VEGFexpression of SMMC-7721 hepatoma cells mayinhibit tumor growth using the rat hepatomamodel.METHODS Amplifiy the 200 VEGF cDNAfragment and insert it into human U6 genecassette in the reverse orientation transcribingsmall antisense RNA which could specificallyinteract with VEGF165, and VEGF121 mRNA.Construct the retroviral vector containing thisantisense VEGF U6 cassette and package thereplication-deficient recombinant retrovirus.SMMC-7721 cells were transduced with thesevirus and positive clones were selected withG418. PCR and Southern blot analysis wereperformed to determine if U6 cassette integratedinto the genomic DNA of positive clone.Transfected tumor cells were evaluated for RNAexpression by ribonuclease protection assays.The VEGF protein in the supernatant of parentaltumor cells and genetically modified tumor cellswas determined with ELISA. In vitro and in vivogrowth properties of antisense VEGF cell clonein nude mice were analyzed.RESULTS Restriction enzyme digestion andPCR sequencing verified that the antisense VEGFRNA retroviral vector was successfullyconstructed. After G418 selection, resistantSMMC-7721 cell clone was picked up. PCR andSouthern blot analysis suggested that U6cassette was integrated into the cell genomicDNA. Stable SMMC-7721 cell clone transducedwith U6 antisense RNA cassette could express200bp small antisense VEGF RNA and secretereduced levels of VEGF in culture condition.Production of VEGF by antisense transgeneexpressing cells was 65 ± 10 ng / L per 106 cells,420 ± 45 ng/L per 106 cells in sense group and 485± 30 ng/L per 106 cells in the negative control group, (P＜0.05). The antisense-VEGF cell clone appeared phenotypically indistinguishable from SMMC-7721 cells and SMMC-7721 cells transfected sense VEGF. The growth rate of the antisense-VEGF cell clone was the same as the control cells. When S. C. was implanted into nude mice, growth of antisense-VEGF cell lines was greatly inhibited compared with control cells.CONCLUSION Expression of antisense VEGFRNA in SMMC-7721 cells could decrease thetumorigenicity, and antisense-VEGF genetherapy may be an adjuvant treatment forhepatoma.

Influence of Intensive Insulin Therapy on Vascular Endothelial Growth Factor in Patients with Severe Trauma

The influence of early-stage intensive insulin therapy on the plasma levels of vascular en- dothelial growth factor （VEGF） and the related parameters in patients with severe trauma and the clini- cal implication were investigated. Sixty-four cases of severe trauma （injury severity score 〉20） with stress hyperglycemia （blood glucose 〉9 mmol/L） were randomly divided into intensive insulin therapy group and conventional therapy group. ELISA method, radioimmunoassay and density gradient grada- tion one-step process were used to determine plasma VEGF, endothelin-1 （ET-1）, and the number of circulating endothelial cells （CECs） at the day of 0, 2, 3, 5 and 7 after admission. Simultaneously, the changes of CRP concentration in plasma were monitored to evaluate inflammatory response. The results showed that plasma levels of observational indexes in patients receiving early-stage intensive insulin therapy were all significantly lower than those in conventional therapy groups 2, 3, 5 and 7 days after admission [for VEGF （ng/L）, 122.2±23.8 vs. 135.9±26.5, 109.6±27.3 vs. 129.0±18.4, 88.7±18.2 vs. 102.6±27.3, 54.2±26.4 vs. 85.7±35.2, P〈0.05, 0.01, 0.05, 0.05 respectively; for ET-1 （ng/L）, 162.8±23.5 vs. 173.7±13.2, 128.6±17.5 vs. 148.8±22.4, 96.5±14.8 vs. 125.7±14.8, 90.7±16.9 vs. 104.9±22.5, P〈0.05, 0.01, 0.01, 0.01 respectively; for CRP （mg/L）, 23.2±13.8 vs. 31.9±16.5, 13.6±17.3 vs. 23.5±18.4, 8.7±10.2 vs. 15.6±13.3, 5.2±9.4 vs. 10.7±11.2, all P〈0.05; for CECs （/0.9 μL）, 10.9±5.6 vs. 13.9±6.2, 8.5±4.9 vs. 11.3±5.3, 6.3±6.4 vs. 9.4±5.7, 4.8±7.1 vs. 7.8±4.8, all P〈0.05]. It was concluded that intensive insulin therapy could antagonize the endothelium injury after trauma and reduce inflammation response quickly, which was one of important mechanisms by which intensive insulin therapy improves the prognosis of trauma patients.

Experimental Study of Vascular Endothelial Growth Factor Gene Therapy for Avascular Necrosis of the Femoral Head

To explore a new method for the therapy of the avascular necrosis of the femoral head, the recombinant plasmid pCD-hVEGF 165 was mixed with collagen and was implanted in the necrotic femoral head The expression of vascular endothelial growth factor (VEGF) was detected by RNA dot hybridization and immunohistochemical method The repair of the femoral head was observed by histological method The results showed that the expression of VEGF was detectable in the femoral head treated with VEGF gene Angiogenesis in these femoral heads was more abundant than the control Bone repairing was augmented in the femoral head treated with VEGF gene The results suggest that angiogenesis in bone tissue could be augmented by gene transfection of VEGF and bone repairing would be accelerated accordingly

Efficacy of internal limiting membrane peeling for diabetic macular edema after preoperative anti-vascular endothelial growth factor injection

AIM:To explore the efficacy of minimally invasive vitrectomy(MIV)with or without internal limiting membrane(ILM)peeling on the treatment of diabetic macular edema(DME)in proliferative diabetic retinopathy(PDR)combining with preoperative anti-vascular endothelial growth factor(anti-VEGF)injection.METHODS:Totally 132 eyes(132 patients)diagnosed PDR with DME were included between June 2015 and June 2018 in Tianjin Eye Hospital.The single MIV treatment group included 68 eyes and the MIV combined with ILM peeling group included 64 eyes.Anti-VEGF drugs were injected intravitreally 1wk before the operation and the period of follow-up was 1 to 3y.Best-corrected visual acuity(BCVA),central retinal thickness(CRT),total macular volume(TMV),macular edema(ME)severity,intraocular pressure(IOP),and complications were recorded.Prognostic factors of visual acuity following ILM peeling were analyzed.RESULTS:The BCVA was higher than preoperative values at 1,3,6,and 12mo after surgery in both groups(all P<0.05).At 6 and 12mo,the BCVA of the combined group was significantly higher than that of the MIV only group(0.52±0.23 v/s 0.64±0.29 IogMAR,P=0.011 in 6mo;0.41±0.25\/s 0.52±0.25 IogMAR,P=0.008 in 12mo).Mean CRT values postoperative were significantly lower than preoperative values in both groups from the 1^(st) month(lmo 397.65±106.18 vs 451.94±118.88 μm in MIV only group;388.88±108.68 v/s 464.36±111.53 μm in combined group;both P<0.05)and decreased gradually.The differences between the two groups were statistically significant at 3,6,and 12mo(P=0.004,0.003,0.00 respectively).The TMV was decreased from the 3^(rd) month in the single treatment group(3mo 11.14±1.66 vs 12.20±2.09 mm^(3),P<0.05).At 12mo,the proportion of eyes with edema that had CRT more than 350μm was significantly lower than before surgery(13.24%vs 77.94%in MIV only group;1.56%vs 81.25%in combined group;both P<0.05).There was no significant difference in the recurrence incidence of macular epiretinal membrane,ME,transient IOP increase,vitreous rebleeding,or traction retinal detachment between the two groups.BCVA after ILM excision was positively correlated with the CRT and ME degree before and after surgery(r=0.430,0.485,respectively;P<0.05).CONCLUSION:MIV combined with ILM peeling accelerates the absorption of ME,improves vision,reduces the postoperative CRT and TMV,and reduces the recurrence rate of postoperative ME.

Macular hole closure following anti-vascular endothelial growth factor injection in an eye with myopic choroidal neovascularization

Dear Editor,I am Cheolmin Yun,from the Department of Ophthalmology,Korea University College of Medicine.I write to present a case report of a female patient with a myopic patient suffering from atrophic choroidal neovascularization（CNV）and a full thickness macular hole（FTMH）,who was treated with an intravitreal anti-vascular endothelial growth factor （VEGF） injection without vitrectomy.

Antitumor and antiangiogenic activities of anti-vascular endothelial growth factor hairpin ribozyme in human hepatocellular carcinoma cell cultures and xenografts

AIM: To study the effectiveness and mechanisms of anti-human vascular endothelial growth factor (hVEGF) hairpin ribozyme on angiogenesis,oncogenicity and tumor growth in a hepatocarcinoma cell line and a xenografted model. METHODS: The artificial anti-hVEGF hairpin ribozyme was transfected into hepatocarcinoma cell line SMMC-7721 and,subsequently,polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) were performed to confirm the ribozyme gene integration and transcription. To determine the effects of ribozyme ,VEGF expression was detected by semiquantitative RT-PCR and enzyme liked immunosorbent assay (ELISA). MTT assay was carried out to measure the cell proliferation. Furthermore,the transfected and control cells were inoculated into nude mice respectively,the growth of cells in nude mice and angiogenesis were observed. RESULTS: VEGF expression was down-regulated sharply by ribozyme in transfected SMMC-7721 cells and xenografted tumor. Compared to the control group,the transfected cells grew slower in cell cultures and xenografts,and the xenograft formation was delayed as well. In addition,the microvessel density of the xenografted tumor was obviously declined in the transfected group. As demonstratedby microscopy,reduction of VEGF production induced by ribozyme resulted in a significantly higher cell differentiation and less proliferation vigor in xenografted tumor. CONCLUSION: Anti-hVEGF hairpin ribozyme can effectively inhibit VEGF expression and growth of hepatocarcinoma in vitro and in vivo. VEGF is functionally related to cell proliferation,differentiation and tumori-genesis in hepatocarcinoma.

Diabetic macular edema:Efficacy and safety of antivascular endothelial growth factor therapy

Diabetic retinopathy is one of the prominent causes of vision impairment in the working-age population in industrialized countries and is related to 1%-5% of cases of blindness in the world. Among patients with diabetic retinopathy, diabetic macular edema(DME) is the major reason of vision impairment and represents a significant public health problem. Previous studies demonstrated the role of vascular endothelial growth factor(VEGF) in diabetic retinopathy and DME pathogenesis, and also revealed the efficacy of anti-VEGF agents for the management of these disorders. This review summarizes the outcomes of clinical studies that evaluated the anti-VEGF therapy including pegaptanib, ranibizumab, bevacizumab, and aflibercept for the management of DME. A significant number of clinical trials indicated favorable functional and anatomical results of anti-VEGF therapy for DME. Therefore, these agents should be considered an option in the treatment of DME in routine clinical practice.

Vascular endothelial growth factor trap-eye(Aflibercept) for the management of diabetic macular edema

Diabetic retinopathy(DR)is the most common cause of visual loss among working age individuals.Diabetic macular edema(DME)is an important complication of DR that affects around one third of the patients with DR.Several treatments have been approved for DME ranging from blood pressure and glycemic control to photocoagulation and more recently the use of vascular endothelial growth factor(VEGF)antagonists.The index review discusses aflibercept(EYLEA-Regeneron Pharmaceuticals,Inc.,Tarrytown,New York,NY,and Bayer Healthcare Pharmaceuticals,Berlin,Germany)in the context of other VEGF antagonists currently available for the treatment of DME.A systematic search of literature was conducted on PubMed,Scopus,and Google Scholar with no limitation on language or year of publication.Pre-clinical studies of aflibercept have shown a higher affinity of this molecule for vascular endothelial growth factor A(VEGF-A)along with a longer duration of action as compared to other VEGF antagonists.Recent clinical trials have shown visual outcome results for aflibercept to be similarly favorable as compared to other available agents with the added benefit of fewer required injections and less frequent monitoring.Aflibercept presents a potential exciting new addition to the armamentarium of current VEGF antagonists available for the treatment of DME and other retinal vascular diseases.However,further studies are indicated to confirm the role,safety,and efficacy of aflibercept for DME.

Effect of Antisense Oligodeoxynucleotide of Vascular Endothelial Growth Factor C on Lymphangiogenesis and Angiogenesis of Pancreatic Cancer

In order to investigate the effect of antisense oligonucleotide （ASODN） of vascular endothelial growth factor C （VEGF-C） on lymphangiogenesis and angiogenesis of pancreatic cancer, antisense and scamble-sense oligonucleotide of VEGF-C were constructed, and the model of nude mice with orthotopically xenografied human pancreatic cancer cells （Panc-1） was established. Thirty nude mice were randomly divided into 3 groups： PBS control group （group A）, scramble-sense control group （group B） and antisense group （group C）. All nude mice were treated once every 2 days as 3 times per week, for 3 weeks （oligonucleotide 10 mg/kg every time）. After treatments were completed, ELISA method was used to examine the concentration of VEGF-C in plasma and immunohistochemical method to examine microvessel density （MVD）, lymphtic vessel density （LVD） of pancreatic cancer. The results showed that the expression of VEGF-C was inhibited significantly in group C. The concentrations were 237.5±41.5, 221.5±52.3 and 108.6±14.9 pg/mL in groups A, B and C respectively （P〈0.01）. LVD in groups A, B and C was 13.8±2.1, 12.4±1.9 and 4.2±1.6 respectively （P〈0.01）. MVD in groups A, B and C was 27.5±8.7, 25.9±4.2 and 19.4±5.6 respectively with no significant difference among the groups （P〉0.05）. It was suggested that VEGF-C ASODN decreased the expression levels of VEGF-C in nude mice with orthotopically xenografted human pancreatic cancer, and it could inhibit lymphangiogenesis, but had no significant effect on angiogenesis.

Intrastriatal Gene Transfer of Vascular Endothelial Growth Factor Rescues Dopaminergic Neurons in a Rat Parkinson's Disease Model

To examine the ability of intrastriatal gene transfer of vascular endothelial growth factor 165 mediated by adenoviral vector to rescue dopaminergic neurons in a rat model of Parkinson＇s disease （PD）, we constructed recombinant replication-deficent adenoviral vectors carrying the gene of VEGF165 （Ad-VEGF）, and injected Ad-VEGF （or Ad-LacZ and PBS as controls） into the striatum of rats 7 days after the lesion by 6-hydroxydopamine. The rat rotational behavior analysis and tyrosine hydroxylase （TH） immunohistochemistry were performed to assess the change of dopaminergic neurons. Our results showed that the rats receiving Ad-VEGF injection displayed a significant improvement in apomorphine-induced rotational behavior and a significant preservation of TH-positive neurons and fibers compared with control animals, It is concluded that intrastriatal gene transfer by Ad-VEGF may rescue the dopaminergic neurons from degeneration in a rat model of PD.

Lentiviral-mediated vascular endothelial growth factor 165 gene transfer into neural stem cells promotes proliferation

We constructed a lentiviral vector carrying vascular endothelial growth factor 165, which was used to transfect neural stem cells. The transfection rate was approximately 50%, as determined by flow cytometry. Vascular endothelial growth factor protein was detected in neural stem cells and promoted proliferation.

Expression of thymidine kinase mediated by a novel non-viral delivery system under the control of vascular endothelial growth factor receptor 2 promoter selectively kills human umbilical vein endothelial cells

AIM: To investigate the killing efficiency of a recombinant plasmid containing a thymidine kinase (TK) domain insert driven by the vascular endothelial growth factor receptor 2 (VEGFR2) promoter (KDR) on vascular endothelial cells.METHODS: The KDR-TK fragment was extracted from pBluescript Ⅱ KDR-TK plasmid by enzymatic digestion with Xho I and Sal I. The enhanced green fluorescence protein (EGFP) carrier was extracted from pEGFP by the same procedure. The KDR-TK was inserted into the pEGFP carrier to construct pEGFP-KDR-TK. Using ultrasound irradiation and microbubble, pEGFP-KDR-TK was transferred into human umbilical vein endothelial cells (HUVECs). The transient infection rate was estimated by green fluorescent protein (GFP) expression. Transfected HUVECs, non-transfected HUVECs, and HepG2 cells were cultured in the presence of different concentrations of ganciclovir (GCV), and the killing efficacy of HSV-TK/GCV was analyzed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The recombinant pEGFP-KDR-TK was successfully constructed by inserting the KDR-TK fragment into the pEGFP carrier. Transfected HUVECs showed cytoplasmic green fluorescence, and the transient transfection rate was about 20.3%. Pools of G418-resistant cells exhibited a higher sensitivity to theprodrug/GCV compared to non-transfected HUVECs or non-transfected HepG2 cells, respectively. CONCLUSION: KDR promoter and the suicide gene/prodrug system mediated by diagnostic ultrasound combined with microbubble can significantly kill HUVECs. Such therapy may present a novel and attractive approach to target gene therapy on tumor vessels.

The Mechanical Study of Vascular Endothelial Growth Factor on the Prevention of Restenosis after Angioplasty

The mechanism of vascular endothelial growth factor (VEGF) on the prevention of restenosis after angioplasty was investigated. The cultured vascular endothelial cells (VEC) were incubated with the conditioned medium (CM) from vascular smooth muscle cells (VSMC) infected with recombinant adenoviruses containing the hVEGF 165 gene. To observe the effects of VEGF on proliferation and NO, ET, 6-keto-PGF1α secretion of VEC, WST-1 method, Griess method and radioimmunoassay were used respectively. The PDGF-B mRNA transcription in VECs was detected by RT-PCR. It was showed that NO, 6-keto-PGF1α and OD value were markedly increased in a dose-dependent manner in the VEGF-treated groups as compared with those in the control group, while ET and PDGF-B mRNA were significantly decreased in the VEGF-treated groups (P<0.05 or P<0.01). Adenovirus vector mediated hVEGF 165 gene could promote the proliferation of VECs and improve NO, PGI 2 secretion, inhibit ET secretion and PDGF-B mRNA transcription in the VECs. The above results offered further theoretical evidence for VEGF on the prevention of restenosis after angioplasty.

One-year outcomes of intravitreal conbercept combined rescue therapy for polypoidal choroidal vasculopathy in a Chinese population: a real-life clinical data

AIM: To evaluate the real-life clinical outcomes of intravitreal injection of conbercept combined rescue therapy for polypoidal choroidal vasculopathy(PCV). METHODS: This was an open label, single center, and interventional study. All enrolled patients were treated initially with three consecutive monthly intravitreal conbercept injections(0.5 mg). Additional conbercept injections were administered upon substantial polyp regression with improved visual acuity(VA). Eyes with partial or no polyp regression and poor VA were rescue treated with photodynamic therapy(PDT) for subfoveal polyps or thermal laser photocoagulation for extrafoveal polyps. Best-corrected visual acuity(BCVA), central foveal thickness(CFT) and polyp regression were observed as primary outcomes. Side effects were also collected during the follow-up period. RESULTS: A total of 56 eyes(56 patients) with PCV were included. BCVA increased significantly from the baseline of 43.52±24.21 letters to 55.88±21.94 letters(P<0.001) at 12 mo, while CFT decreased significantly from 457.41±207.86 μm to 247.98±127.08 μm(P<0.001). All patients showed polyp regression. Twenty-three eyes achieved complete polyp regression after the three initial injections, which increased to 44 eyes at 12 mo. Seventeen eyes underwent rescue therapy, among which 2 eyes treated with PDT and 15 eyes treated with laser photocoagulation. A mean of 4.30±1.43 injections were given per eye. No intraocular inflammation, retinal or vitreous hemorrhage, or systemic complication occurred. CONCLUSION: Conbercept is an effective and safe option for the treatment of PCV in Chinese population. The treatment regimen of three initial conbercept injections followed by additional injections or rescue therapies is efficacious for treating PCV.