Angiotensin II and vascular endothelial growth factor in the vitreous fluid of patients with proliferative diabetic retinopathy

AIMS: To investigate the correlation between the level of angiotensin II and vascular endothelial growth factor (VEGF) in the vitreous fluid and the severity of proliferative diabetic retinopathy (PDR). METHODS: During vitreoretinal surgery at the Tokyo Women's Medical University, vitreous fluid samples were obtained from 51 eyes of diabetic patients with PDR, six eyes of diabetic patients without retinopathy, and 16 eyes of non-diabetic patients with ocular disease (controls). The VEGF levels in vitreous fluid and plasma were determined by enzyme linked immunosorbent assay, while angiotensin II levels were measured by radioimmunoassay. RESULTS: The vitreous fluid levels of VEGF and angiotensin II were significantly higher in patients with PDR than in non-diabetic patients or diabetic patients without retinopathy (all p<0.0001). The vitreous fluid level of angiotensin II was significantly correlated with that of VEGF (p<0.0001), and the vitreous concentrations of both VEGF and angiotensin II were significantly higher in patients with active PDR than in those with quiescent PDR (p<0.0001 and p=0.0005, respectively). CONCLUSION: The authors found that both angiotensin II and VEGF levels were significantly higher in the vitreous fluid of patients with PDR than in that of non-diabetic patients or diabetic patients without retinopathy, and that the levels of both angiotensin II and VEGF were elevated in the active stage of PDR. These findings suggest that angiotensin II contributes to the development and progression of PDR in combination with VEGF.     

Free insulin growth factor-I and vascular endothelial growth factor in the vitreous fluid of patients with proliferative diabetic retinopathy

PURPOSE: To investigate the relationship between insulin-like growth factor-I (IGF-I) and vascular endothelial growth factor (VEGF) in the vitreous fluid of diabetic patients with proliferative diabetic retinopathy (PDR). DESIGN: Observational case-control study. METHODS: In a prospective study, 37 consecutive diabetic patients with PDR (14 type I and 23 type II diabetes mellitus) in whom a vitrectomy was performed were compared with 21 nondiabetic patients with other conditions requiring vitrectomy (control group). Free IGF-I and VEGF were measured by ELISA. RESULTS: Vitreal levels of both free IGF-1 and VEGF were higher in diabetic patients with PDR than in control subjects (P <.01, and P <.0001, respectively). After adjusting for total intravitreous protein concentration, VEGF (ng/mg of proteins) remained significantly higher in diabetic patients with PDR than in the control group (P <.0001), whereas free IGF-I (ng/mg of proteins) was lower in diabetic patients than in control subjects (P <.0001). The vitreous concentrations of VEGF were higher in patients with active PDR than in patients with quiescent PDR (P <.005), whereas vitreous free IGF-I was not related to PDR activity. Finally, we did not observe a correlation between the vitreal levels of free IGF-I and VEGF. CONCLUSIONS: We conclude that free IGF-I and VEGF are both increased, but not related, within the vitreous fluid of diabetic patients with PDR. In addition, our results support the current concept that VEGF is directly involved in the pathogenesis of PDR, whereas the precise role of free IGF-I remains to be established.     

Cytokines in the vitreous of patients with proliferative diabetic retinopathy.

Sixteen vitreous and paired serum samples from 13 patients with proliferative diabetic retinopathy, vitreous samples from seven cadaveric control subjects, and aqueous humor samples from 15 normal control subjects were assayed for the cytokines interleukin-1, tumor necrosis factor-alpha, interleukin-6, and interferon-gamma. Interleukin-6 was detected in 15 of 16 vitreous samples (94%) from diabetic patients, but it was not detected in any of the aqueous humor samples. Vitreous interleukin-6 levels positively correlated with ocular disease activity. Interleukin-1 was detected in seven of 16 vitreous samples (44%) and in four of ten aqueous humor samples (40%), whereas tumor necrosis factor-alpha and interferon-gamma were never detected in vitreous or aqueous fluid. Serum samples from diabetic patients and control subjects contained comparable low levels of interleukin-6. Interleukin-1, tumor necrosis factor-alpha, and interferon-gamma were not found in any of the sera. Because interleukin-6 can function as B-cell differentiation factor, this cytokine may have a role in immunoglobulin deposition in the ocular tissues and in the immunopathologic characteristics of proliferative retinopathy.     

增生性糖尿病视网膜病变患者玻璃体内血管内皮生长因子的表达

目的 探讨增生性糖尿病视网膜病变(PDR)患者玻璃体内血管内皮生长因子(VEGF)的表达及相关影响因素.方法 病例对照研究.对50例(50只眼)接受玻璃体切除治疗的PDR患者进行分析.术中获取玻璃体标本,并用双抗体夹心酶联免疫吸附试验ELISA法对术中获取的玻璃体标本进行VEGF含量的定量检测,并分析增生性糖尿病视网膜病变患者玻璃体内VEGF的表达情况.平均随访9个月(6～26个月).用成组t检验比较PDR组和正常对照组玻璃体VEGF含量差异,以及硅油填充组与非硅油填充组VEGF含量差异.用方差分析方法比较PDR进展组、稳定组和好转组玻璃体VEGF含量有无差异.用单因素方差分析方法分析玻璃体VEGF含量对PDR术后疗效的影响.结果 PDR组玻璃体VEGF含量平均(592.4801±587.4267)ng/L,正常对照组玻璃体VEGF含量平均(131.3022±26.9192)ng/L.PDR组玻璃体VEGF含量高于对照组(t=3.2315,P＜0.05).术后PDR进展有10只眼(20%),稳定10只眼(20%),好转30只眼(60%).PDR进展组玻璃体VEGF含量显著高于PDR稳定和好转组(q=-3.3187,-4.0843;P＜0.05).术前未接受视网膜光凝组玻璃体VEGF含量显著高于接受全视网膜光凝或局部视网膜光凝组(q=-4.2187,-3.9672;P＜0.05).结论玻璃体VEGF表达与PDR严重程度有一定关系.术后PDR稳定或好转者玻璃体VEGF水平呈相对低表达.(中华眼科杂志,2009,45:206-209)     

增殖性糖尿病视网膜病变患者玻璃体中血管内皮细胞生长因子含量…

检测增殖性糖尿病视网膜病变患者玻璃体中血管内皮细胞生长因子的含量并与正常人进行对比研究，探讨了ＶＥＧＦ在ＰＤＲ病理过程中的作用。应用酶联免疫吸附测定法对７例正常人及１９例ＰＤＲ患者玻璃体中的ＶＥＧＦ进行定量分析研究。结果７例正常人玻璃体中，ＶＥＧＦ的含量为０．１８－０．６０ｎｇ／ｍｌ，平均值为０．３５ｎｇ／ｍｌ。     

Vascular endothelial growth factor levels in vitreous and serum of patients with either proliferative diabetic retinopathy or proliferative vitreoretinopathy

PURPOSES: To confirm the role of vascular endothelial growth factor (VEGF) in the pathogenesis of proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR) and to investigate the relationship between the level of VEGF in serum and its vitreal level in patients with either disease. METHODS: Venous blood and vitreous of 18 patients with PDR, 15 patients with PVR and 20 patients forming a control group were collected during vitrectomy. The VEGF level was quantified by using ELISA methods in either serum or vitreous. RESULTS: The VEGF level in serum and vitreous was similarly high in the case of PDR, but its level was only high in serum in the case of PVR. DISCUSSION: PDR is closely linked with systemic diabetes mellitus whereas PVR is more localized. More selective systemic anti-VEGF medications with reduced side effects are required to treat PDR successfully.     

Hepatocyte growth factor in vitreous and serum from patients with proliferative diabetic retinopathy

BACKGROUND: Hepatocyte growth factor (HGF) is an endothelium specific growth factor that has been implicated in angiogenesis, a crucial event for the development of proliferative diabetic retinopathy (PDR). The aim of the study is to determine the intravitreous concentrations of HGF in diabetic patients with PDR, and to investigate whether its serum levels could contribute to its intravitreous concentration. METHODS: 17 diabetic patients and seven non-diabetic patients in whom a vitrectomy was performed were studied. Both groups were matched by serum levels of HGF. Venous blood and vitreous samples were collected simultaneously at the time of vitreoretinal surgery. Vitreous and serum HGF were determined by ELISA. RESULTS: Intravitreous concentrations of HGF (median and range) were higher in diabetic patients (17.04 ng/ml (9.98-80)) in comparison with non-diabetic patients (5.88 ng/ml (2.57-14.20); p=0. 003). Intravitreous HGF concentrations were strikingly higher than serum HGF concentrations both in diabetic patients (17.04 ng/ml (9. 98-80) v 0.66 ng/ml (0.26-1.26); p<0.001) and in the control group (5.88 ng/ml (2.57-14.20) v 0.68 ng/ml (0.49-0.96); p=0.003). No correlation was found between serum and vitreous levels of HGF in both groups (diabetic patients, r= -0.31; p=0.5 and control subjects r= -0.15; p=0.5). CONCLUSION: The high vitreous levels of HGF observed in diabetic patients with PDR cannot be attributed to serum diffusion across the blood-retinal barrier. Therefore, intraocular synthesis appears to be the main contributing factor for the high vitreous HGF concentrations in diabetic patients, a cytokine that seems to be directly involved in the pathogenesis of PDR.     

增殖性糖尿病视网膜病变患者玻璃体中血管内皮细胞生长因子含量的检测

目的检测增殖性糖尿病视网膜病变（ｐｒｏｌｉｆｅｒａｔｉｖｅｄｉａｂｅｔｉｃｒｅｔｉｎｏｐａｔｈｙ，ＰＤＲ）患者玻璃体中血管内皮细胞生长因子（ｖａｓｃｕｌａｒｅｎｄｏｔｈｅｌｉａｌｇｒｏｗｔｈｆａｃｔｏｒ，ＶＥＧＦ）的含量并与正常人进行对比研究，探讨ＶＥＧＦ在ＰＤＲ病理过程中的作用。方法应用酶联免疫吸附测定法（ｅｎｚｙｍｅｌｉｎｋｅｄｉｍｍｕｎｏｓｏｒｂｅｎｔａｓｓａｙ，ＥＬＩＳＡ）对７例正常人及１９例ＰＤＲ患者玻璃体中的ＶＥＧＦ进行定量分析研究。结果７例正常人玻璃体中，ＶＥＧＦ的含量为０．１８～０．６０ｎｇ／ｍｌ，平均值为０．３５ｎｇ／ｍｌ。１９例ＰＤＲ患者玻璃体中ＶＥＧＦ的含量升高，范围为０．８４～１５．６４ｎｇ／ｍｌ，平均值为５．６６ｎｇ／ｍｌ。两组比较，差异有显著性（Ｐ＜０．０５），其中男性组玻璃体中ＶＥＧＦ的含量为０．８４～１５．６４ｎｇ／ｍｌ，平均值为４．８３ｎｇ／ｍｌ；女性组为１．３４～１２．３４ｎｇ／ｍｌ，平均值为７．０８ｎｇ／ｍｌ，两组比较，差异无显著性（Ｐ＞０．０５）。结论ＰＤＲ患者玻璃体中ＶＥＧＦ的含量升高，在ＰＤＲ的病理过程中起一定作用     

增生性糖尿病视网膜病变玻璃体中结缔组织生长因子的定量分析

目的 定量测定结缔组织生长因子(connective tissue growth factor,CTGF)在增生性糖尿病视网膜病变(proliferative di-abetic retinopathy,PDR)患者玻璃体中的浓度,探讨其在PDR发病机制中的作用.方法 采用双抗体夹心酶联免疫吸附测定法定量检测27眼PDR、5眼非增生性糖尿病视网膜病变及5眼正常对照组玻璃体中CTGF的浓度.结果 PDR组玻璃体中CTGF浓度(567.09±181.15)ng·L-1明显大于对照组(128.06±57.28)ng·L-1及非增生性糖尿病视网膜病变组(150.70±52.39)ng·L-1(P均<0.01).PDR组中Ⅵ期患者玻璃体中CTGF浓度(706.17±88.78)ng·L-1大于Ⅳ期(349.20±110.60)ng·L-1及Ⅴ期(526.70±122.50)ng·L-1(P均<0.01).结论 PDR患者玻璃体中CTGF浓度升高可能与视网膜新生血管纤维膜的形成有关,CTGF在PDR发展过程中起着一定作用.     

Lysosomal acid hydrolases in vitreous fluid of patients with proliferative diabetic retinopathy.

Using a new method to collect vitreous fluid safely during vitrectomy, vitreous specimens were obtained from 18 eyes of diabetic patients with proliferative diabetic retinopathy (PDR) and from 14 eyes of nondiabetic patients. The activities of four lysosomal acid hydrolases in these samples were measured and compared with those in serum. Of these enzymes, only N-acetyl-beta-glucosaminidase (NAG), a suspected retinal angiogenic factor, showed higher activity in the vitreous than in the serum in both diabetic (P less than 0.005) and nondiabetic eyes (P less than 0.05). However, no significant difference was found in any enzyme activity between diabetic and nondiabetic samples. These results suggested that this enzyme apparently does not have a significant effect, at least on the pathologic condition, during the late stage of PDR, and that NAG is usually present at higher activity in the vitreous than in the serum of diabetic as well as nondiabetic patients.     

增生型糖尿病视网膜病变眼内液中血管内皮生长因子定量测定

目的：检测增生型糖尿病视网膜病变（PDR）患者房水和玻璃体中血管内皮生长因子（VEGF）水平。方法：应用酶联免疫吸附测定法（ELISA）。结果：房水VEGF含量,PDR患者（4例）较正常人升高,差异有显著性（P＜0.05）。玻璃体VEGF的含量,PDR患者（11例）较正常人（10例）升高,差异有显著性（P＜0.05）。结论：PDR患者房水和玻璃体中VEGF的含量升高,在PDR的病理过程中起一定的作用。     

Macrophage migration inhibitory factor levels in the vitreous of patients with proliferative diabetic retinopathy

AIMS: To assess the potential role of macrophage migration inhibitory factor (MIF) in the pathogenesis of proliferative diabetic retinopathy (PDR). METHODS: MIF levels were assayed in the vitreous and paired serum samples of 73 consecutive patients with PDR (32 eyes) and macular hole or idiopathic epiretinal membrane (controls, 41 eyes). An enzyme linked immunosorbent assay technique was used to determine the concentrations of MIF. RESULTS: The median vitreous level of MIF was 11.93 ng/ml (range 4.16-103.85) in the patients with PDR, and 1.79 ng/ml (undetectable-8.93) in the controls. Vitreous levels in eyes with PDR were significantly greater than those in the controls (p<0.0001). Vitreous levels were significantly higher than serum levels in eyes with PDR (p=0.0026). MIF levels were significantly higher in the vitreous of PDR patients with severe fibrous proliferation than in those with slight proliferation (p<0.05). CONCLUSION: The results indicate increased levels of MIF in the vitreous of patients with PDR and a significant association between MIF levels and grades of fibrous proliferation, suggesting the possibility that MIF may play a part in the development of the proliferative phase of PDR.     

Elevations of AGE and vascular endothelial growth factor with decreased total antioxidant status in the vitreous fluid of diabetic patients with retinopathy

BACKGROUND/AIMS: Advanced glycation end product (AGE) induces vascular endothelial growth factor (VEGF) expression in cell culture and animal models, being considered to be involved in development of diabetic retinopathy; oxidative stress also has a part in diabetic retinopathy. However, the interrelations between AGE, VEGF, and oxidative stress remain to be elucidated. In this study, vitreous AGE, VEGF, and total antioxidant levels in were determined in diabetic patients with retinopathy, and the relations among them investigated. METHODS: ELISA (enzyme linked immunosorbent assay) was used to determine the vitreous levels of AGE and VEGF in 41 patients with diabetic retinopathy and 28 non-diabetic control subjects. Total antioxidant levels in vitreous of 20 diabetic patients and 18 controls were also analysed by ELISA. RESULTS: The vitreous levels of AGE and VEGF were significantly higher in diabetic patients than in control subjects (p<0.01 for both). There was a significant correlation between the vitreous AGE and VEGF levels (p<0.001). Total antioxidant status was decreased in vitreous in patients with diabetes compared with the controls (p<0.01). Furthermore, both AGE and VEGF levels were inversely correlated with the total antioxidant status (p<0.01 and p<0.05, respectively). CONCLUSION: This study suggests that AGE and decreased total antioxidant status may contribute to the pathogenesis of diabetic retinopathy via induction of VEGF.     

Positive association of pigment epithelium-derived factor with total antioxidant capacity in the vitreous fluid of patients with proliferative diabetic retinopathy

BACKGROUND: Pigment epithelium-derived factor (PEDF), a glycoprotein with potent neuronal differentiating activity, was recently found to inhibit advanced glycation end product (AGE)-induced retinal hyperpermeability and angiogenesis through its antioxidative properties, suggesting that it may exert beneficial effects on diabetic retinopathy by acting as an endogenous antioxidant. However, the inter-relationship between PEDF and total antioxidant capacity in the eye remains to be elucidated. AIMS: To determine vitreous PEDF and total antioxidant levels in patients with proliferative diabetic retinopathy (PDR), and to investigate the relationship between them. METHODS: Vitreous levels of PEDF and total antioxidant capacity were measured by an ELISA in 39 eyes of 36 patients with diabetes and PDR and in 29 eyes of 29 controls without diabetes. RESULTS: Vitreous levels of total antioxidant capacity were significantly lower in patients with diabetes and PDR than in controls (mean (SD) 0.16 (0.05) vs 0.24 (0.09) mmol/l, respectively, p<0.001). PEDF levels correlated positively with total antioxidant status in the vitreous of patients with PDR (r = 0.37, p<0.05) and in controls (r = 0.41, p<0.05). Further, vitreous levels of PEDF in patients with PDR without vitreous haemorrhage (VH(-)) were significantly (p<0.05) decreased, compared with those in the controls or in patients with PDR with vitreous haemorrhage (VH(+); PDR VH(-), 4.5 (1.1) microg/ml; control, 7.4 (4.1) microg/ml; PDR VH(+) 8.5 (3.6) microg/ml). CONCLUSION: This study demonstrates that PEDF levels are associated with total antioxidant capacity of vitreous fluid in humans, and suggests that PEDF may act as an endogenous antioxidant in the eye and could play a protective role against PDR.