Knockdown of fibrillin-1 suppresses retina-blood barrier dysfunction by inhibiting vascular endothelial apoptosis under diabetic conditions.

AIM: To investigate the effects of fibrillin-1 (FBN1) deletion on the integrity of retina-blood barrier function and the apoptosis of vascular endothelial cells under diabetic conditions. METHODS: Streptozotocin (STZ)-induced diabetic mice were used to simulate the diabetic conditions of diabetic retinopathy (DR) patients, and FBN1 expression was detected in retinas from STZ-diabetic mice and controls. In the Gene Expression Omnibus (GEO) database, the GSE60436 dataset was selected to analyze FBN1 expressions in fibrovascular membranes from DR patients. Using lentivirus to knock down FBN1 levels, vascular leakage and endothelial barrier integrity were detected by Evans blue vascular permeability assay, fluorescein fundus angiography (FFA) and immunofluorescence labeled with tight junction marker in vivo. High glucose-induced monkey retinal vascular endothelial cells (RF/6A) were used to investigate effects of FBN1 on the cells in vitro. The vascular endothelial barrier integrity and apoptosis were detected by trans-endothelial electrical resistance (TEER) assay and flow cytometry, respectively. RESULTS: FBN1 mRNA expression was increased in retinas of STZ-induced diabetic mice and fibrovascular membranes of DR patients (GSE60436 datasets) using RNA-seq approach. Besides, knocking down of FBN1 by lentivirus intravitreal injection significantly inhibited the vascular leakage compared to STZ-DR group by Evans blue vascular permeability assay and FFA detection. Expressions of tight junction markers in STZ-DR mouse retinas were lower than those in the control group, and knocking down of FBN1 increased the tight junction levels. In vitro, 30 mmol/L glucose could significantly inhibit viability of RF/6A cells, and FBN1 mRNA expression was increased under 30 mmol/L glucose stimulation. Down-regulation of FBN1 reduced high glucose (HG)-stimulated retinal microvascular endothelial cell permeability, increased TEER, and inhibited RF/6A cell apoptosis in vitro. CONCLUSION: The expression level of FBN1 increases in retinas and vascular endothelial cells under diabetic conditions. Down-regulation of FBN1 protects the retina of early diabetic rats from retina-blood barrier damage, reduce vascular leakage, cell apoptosis, and maintain vascular endothelial cell barrier function.

[The mitochondrial tRNA(Thr) A15951G mutation may be associated with Leber's hereditary optic neuropathy in two Chinese families].

OBJECTIVE: To explore clinical, genetic and molecular features of two Chinese Han families with Leber's hereditary optic neuropathy (LHON). METHODS: Ophthalmologic examinations revealed variable severity and age-at-onset of visual loss among probands and other matrilineal relatives of both families. The families exhibited extremely low penetrance of visual impairment. The entire mitochondrial genome of two probands was amplified by PCR in 24 overlapping fragments using sets of oligonucleotide primers. RESULTS: Sequence analysis of complete mitochondrial genome in the pedigrees excluded three common LHON associated mutations G11778A, G3460A and T14484C, but revealed the presence of a known homoplasmic tRNA(Thr) A15951G mutation. It also showed distinct sets of mtDNA polymorphisms belonging to Eastern Asian haplogroup D4b1. The A15951G mutation is located at the extremely conserved nucleotide (conventional position 71) of tRNA(Thr). Thus, this mutation may alter the structure and stability of mitochondrial tRNA(Thr), thereby leading to a failure in the tRNA metabolism and mitochondrial dysfunction, causing visual impairment. CONCLUSION: The results suggested that the A15951G mutation might be involved in the pathogenesis of Leber's hereditary optic neuropathy in the two families.

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.

[Associations between six functional genes and schizophrenia].

OBJECTIVE: To assess the associations between schizophrenia and six functional genes: dopamine D2 receptor gene (DRD2), dopamine D4 receptor gene (DRD4), 5-hydroxytryptamine 2A receptor gene (5-HT2A), 5-HT6 receptor gene (5-HT6), catechol-O-methyltransferase gene (COMT) and dopamine transporter gene (DAT1). METHODS: With the techniques of Amp-RFLP and Amp-FLP, association analysis was made between schizophrenia and the six genes in 67 schizophrenic patients from Chinese Han population. RESULTS: (1) Neither genotypes nor alleles of DRD2, 5-HT2A, 5-HT6 and COMT gene showed significant differences between patients and controls (P>0.05). (2) Six repeats (6R) in DRD4 gene, the allele of 480 bp and the genotype of 480/520 in DAT1 gene were found to be of significant differences between the two groups (P<0.05). (3) Only one negative association was observed between the 480 bp allele of DAT1 gene and schizophrenia (OR=0.441, 95% CI:0.202-0.963, Z=2.05, P<0.05). CONCLUSION: The 480 bp allele of DAT1 gene is negatively associated with schizophrenia in Chinese Han population, which stands for the dopamine hypothesis of schizophrenia.

[A case-control study on the risk factors for attempted suicide in patients with major depression].

OBJECTIVE: To understand the environmental risk factors on attempted suicide in patients with major depression, and to study the interaction between factors as single nucleotide polymorphism(SNP) of TPH2 gene rs7305115 associated to attempted suicide in major depression. METHODS: Paired case-control study on 215 suicide attempters with major depression (92 male, 123 female) and molecular biological techniques were used to study the relation between TPH2 gene rs7305115 SNP,interrelated environmental factors and the rate of attempted suicide. Controls were paired with cases according to the same gender, similar age (no more than 3 years) and from the same district. RESULTS: There were remarkably significant differences in gene types and gene frequency between case and control groups (P < 0.001). Data from multivariate conditional logistic regression model analysis showed that hopelessness, negative life-events and family history of suicide were relationship of attempted suicide in patients with major depression with OR values as 0.33 (95% CI: 0.22-0.99), 7.68 (95% CI: 5.79-13.74), 6.64 (95% CI: 2.48-11.04), 2.98 (95% CI: 1.17-5.04) respectively. There was no first level interaction between any of the two risk factors. CONCLUSION: Results from the study supported the idea that hopelessness, negative life-events and family history of suicide were risk factors of attempted suicide in major deprbssion while TPH2 gene rs7305115 A/A might be the protective factor.