Lysosomal destabilization activates the NLRP3 inflammasome in human umbilical vein endothelial cells (HUVECs).

Inflammation is a crucial component in the pathogenesis of many vascular diseases, such as atherosclerosis and diabetes. Inflammasomes are intracellular signalling complexes whose activation promotes inflammation. Nucleotide-binding domain and Leucine-rich repeat Receptor containing a Pyrin domain 3 (NLRP3) is a pattern recognition receptor (PRR) forming the best-known inflammasome. Disturbances in NLRP3 have been associated with multiple diseases. The purpose of this study was to explore the lysosomal destabilization-related NLRP3 inflammasome signaling pathway in human endothelial cells. In order to prime and activate NLRP3, human umbilical vein cells (HUVECs) were exposed to TNF-α and the lysosomal destructive agent Leusine-Leusine-O-Methylesther (Leu-Leu-OMe), respectively. A caspase-1 inhibitor was used to block caspase-1's enzymatic function and an interleukin 1 receptor antagonist (IL-1RA) to prevent any possible secondary effects of IL-1ß. Leu-Leu-OMe increased the expression of NLRP3, IL-1ß, and IL-18 in HUVECs. Exposure to Leu-Leu-OMe significantly promoted the production of IL-6 and IL-8 in primed HUVECs; this effect was prevented by the pre-treatment of cells with an IL-1RA. Our results suggest that lysosomal destabilization activates the NLRP3 inflammasome pathway that promotes the production of IL-6 and IL-8 in an autocrine manner in HUVEC cells.

High intravitreal TGF-ß1 and MMP-9 levels in eyes with retinal vein occlusion.

PURPOSE: Vascular endothelial growth factor is a leading target to reduce macular oedema and improve visual acuity in patients with retinal vein occlusion (RVO), whereas the role of vascular destabilizing and fibroproliferative transforming growth factor (TGF)-ß1 and matrix metalloproteinases (MMP)-2 and -9 in pathological manifestations of RVO is anticipated but less studied. METHODS: Undiluted vitreous samples were collected from three central RVO and one branch RVO eyes, all with neovascularization and fibrosis-related sight-threatening complications of RVO. Undiluted vitreous samples of 40 eyes operated due to non-ischemic condition either macular hole or pucker were used as controls. Growth factor and protease concentrations were measured by ELISA and gelatin zymography. RESULTS: Vitreous concentrations of TGF-ß1 (92.0 ± 17.4 pg/ml vs 18.3 ± 27.0 pg/ml, mean ± SD; P=0.002) and MMP-9 (847.9 ± 1196.4 AU/ml vs 87.7 ± 174.0 AU/ml; P=0.010) were higher in the eyes with ischemic RVO than in the controls. CONCLUSIONS: High intravitreal levels of TGF-ß1 and MMP-9 are found in RVO eyes having neovascular and fibrosis manifestation. Further studies are warranted to elucidate whether targeting TGF-ß1 and MMP-9 could be beneficial in patients with ischemic RVO.

Cord serum insulin-like growth factor binding protein-1 and -3: effect of maternal diabetes and relationships to fetal growth.

OBJECTIVES: Insulin-like growth factor binding protein-1 and -3 (IGFBP-1 and -3) are the main insulin-like growth factor (IGF) carriers in fetal blood whose concentrations are regulated by hormonal factors such as insulin. IGFBPs may regulate fetal growth by altering the biological activity of IGF-I and IGF-II. We studied the effect of maternal diabetes on cord serum IGFBP-1 and IGFBP-3 levels, and the usability of IGFBP-1 and IGFBP-3 in the detection of birth weight variations. METHODS: Cord serum IGFBP-1 and IGFBP-3 concentrations were measured at birth by immunofluorometric assays in 67 pregnancies with type 1 diabetes and in 62 normal pregnancies. RESULTS: Concentrations of IGFBP-1 in cord serum were lower in diabetic pregnancies than in normal pregnancies (156 +/- 28 microg/l vs 266 +/- 29 microg/l, P = 0.007), whereas those of IGFBP-3 did not differ significantly (3327 +/- 158 microg/l vs 2982 +/- 105 microg/l, P = 0.076). IGFBP-1 correlated negatively and IGFBP-3 positively with birth weight z-score in diabetic pregnancies. The trend was similar in normal pregnancies. In multiple regression models, birth weight z-score was significantly associated with IGFBP-1 in diabetic and normal pregnancies, and with IGFBP-3 in diabetic pregnancies. CONCLUSION: Maternal diabetes is associated with suppressed levels of IGFBP-1 in cord serum, whereas those of IGFBP-3 do not change markedly. In diabetic pregnancies, both cord serum IGFBP-1 and IGFBP-3 correlate with fetal growth.

Inflammatory markers and retinopathy in pregnancies complicated with type I diabetes.

AIM: The relation of maternal cytokine levels to retinopathy progression during diabetic pregnancy is a less studied subject. Therefore, we investigated levels of systemic proinflammatory markers, C-reactive peptide (CRP), interleukin-6 (IL-6) and circulating vascular cell adhesion molecule-1 (VCAM-1) during pregnancy and postpartum in relation to the progression of diabetic retinopathy (DR). METHODS: A prospective follow-up study of 39 pregnant women with Type I diabetes and eight nondiabetic pregnant women was performed. DR was graded from fundus photographs. Plasma levels of systemic proinflammatory markers were measured by immunofluorometric assay (CRP) and by enzyme-linked immunosorbent assay (IL-6 and VCAM-1) in the first, second (diabetics only), third trimester of pregnancy, and 3 and 6 months postpartum (diabetics only). RESULTS: Our diabetic women had good glycaemic control (HbA1c 6.9 +/- 0.8). The levels of IL-6, VCAM-1, and CRP did not differ between diabetic and nondiabetic women throughout pregnancy and postpartum (repeated measures ANOVA between the groups). An association between CRP and progression of retinopathy was observed in diabetic women (P = 0.037). Additional evidence of inter-relationship could be revealed as CRP was higher in those diabetic women with worse glycaemic control (HbA1c) (P = 0.038). CONCLUSIONS: During pregnancy and postpartum, levels of proinflammatory factors (IL-6, CRP, VCAM-1) seem to be generally similar in Type I diabetic women compared to nondiabetic controls. However, CRP levels were higher in those diabetic women with progression of retinopathy and in those with worse glycaemic control.

Angiopoietic factors and retinopathy in pregnancies complicated with Type 1 diabetes.

AIMS: To evaluate the role of systemic angiopoietic factors in the progression of diabetic retinopathy during pregnancy. METHODS: In a prospective study of 26 pregnant women with diabetes and eight non-diabetic pregnant women, retinopathy was graded from fundus photographs. Plasma levels of angiopoietin-1, angiopoietin-2, human vascular endothelial growth factor A (hVEGF-A), and total soluble receptor of vascular endothelial growth factor (sVEGF) receptor-1 were measured during the first and third trimester and 3 months postpartum. RESULTS: In diabetic women, levels of angiopoietin-2 were 26.5 ng/ml (12.1-47.7) (median and range) during the first trimester, 2.9 ng/ml (0.6-3.5) during the third trimester, and 0.5 ng/ml (0.3-0.7) 3 months postpartum, compared with 44.3 (38.3-61.9), 5.7 (3.1-8.4) and 0.9 (0.6-4.9) ng/ml, respectively, in non-diabetic women (P = 0.002 between groups). Levels of angiopoietin-1 and sVEGF receptor-1 did not differ between the groups. Postpartum hVEGF-A levels were lowest in women with progression of retinopathy. In logistic regression analyses, progression of retinopathy during pregnancy was not explained by the levels of the angiopoietic factors. CONCLUSIONS: The circulating levels of angiopoietic factors in pregnant diabetic women were either lower than (Ang-2) or similar to (Ang-1, hVEGF-A, VEGFR-1) those levels observed in non-diabetic pregnant women. The levels of angiopoietic factors measured here appear not to be connected with the progression of retinopathy during pregnancy.