Epigenetic modifications such as DNA methylation, histone post-translational modifications, non-coding RNA are reversible, heritable alterations which are induced by environmental stimuli. Major risk factors of diabetes and diabetic complications including hyperglycemia, oxidative stress and advanced glycation end products, can lead to abnormal epigenetic modifications in retinal vascular endothelial cells and retinal pigment epithelium cells. Epigenetic mechanisms are involved in the pathogenesis of macular edema and neovascularization of diabetic retinopathy (DR), as well as diabetic metabolic memory. The heritable nature of epigenetic marks also playsakey role in familial diabetes mellitus. Further elucidation of epigenetic mechanisms in DR can open the way for the discovery of novel therapeutic targets to prevent DR progression.
ObjectiveTo observe the transthyretin (TTR) gene mutation, protein and mRNA expression in patients with familial vitreous amyloidosis. MethodsSubjects were divided into three groups: (1) illness group: seven patients with familial vitreous amyloidosis. (2) No-illness group: 9 unaffected family members. (3) Control group: 9 healthy individuals in same area. Subjects' peripheral venous blood were collected and DNA were extracted, 4 exons of TTR gene were amplified by reverse transcription polymerase chain reaction(RT-PCR), the gene fragments were sequencing by the fluorescence labelling method. Serum TTR protein expression was detected by Western blot, and TTR mRNA in leukocyte was assayed by RT-PCR. Results4 exons of TTR gene of all samples were amplified, and DNA sequencing data showed that 7 patients and 3 subjects DNA from unaffected family members had mutated in the 3rd exon of 107th base, changing from G to C. Heterozygous mutation occurred in codon of the 83th amino acid in exon 3, namely, Gly83Arg, resulted in the change of GGC to CGC. The protein and mRNA expression of TTR was lower in illness group than no-illness group and control groups(P < 0.05). Compared with control group, TTR mRNA expression in unaffected family members groups was significant decreased(P < 0.05). ConclusionHeterozygous mutation occurred in codon of the 83th amino acid in exon 3, namely Gly83Arg, and suggested that Gly83Arg is connected with the change of TTR mRNA and protein expression.
Objective To investigate the polymorphism of the vitamin D receptor gene (VDR)TaqⅠin relation to diabetic retinopathy. Method Fragment length discrepant allele specific PCR(FLDAS-PCR) were used to determine VDR genetypes in 158 patients with diabetic retinopathy and in 198 normal subjects. Results The frequency distribution of VDR genotypes in diabetic retinopathy patients was 106 (67.1%) in TT, 33(20.9%) in Tt, 19(12.0%) in tt; and in normal persons was 165 (83.3%) in TT, 23(11.6%) in Tt, 10 (5.1%) in tt. There was a significant difference between diabetic retinopathy patients and normal persons in distribution of VDR gene TaqⅠgenotypes(Plt;0.05). Conclusions There is some distribution alterations of VDR gene polymorphism in diabetic retinopathy patients. (Chin J Ocul Fundus Dis, 2006, 22: 94-96)
Olfactory bulb is a critical component in encoding and processing olfactory signals, characterized by its intricate neural projections and networks dedicated to this function. It has been found that descending neural projections from the olfactory cortex and other advanced brain regions can modulate the excitability of olfactory bulb output neurons in the olfactory bulb, either directly or indirectly, which can further influence olfactory discrimination, learning, and other abilities. In recent years, advancements in optogenetic technology have facilitated extensive application of neuron manipulation for studying neural circuits, thereby greatly accelerating research into olfactory mechanisms. This review summarizes the latest research progress on the regulatory effects of neural projections from the olfactory cortex, basal forebrain, raphe nucleus, and locus coeruleus on olfactory bulb function. Furthermore, the important role that photogenetic technology plays in olfactory mechanism research is evaluated. Finally, the existing problems and future development trends in current research are preliminarily proposed and explained. This review aims to provide new insights into the mechanisms underlying olfactory neural regulation as well as applications of optogenetic technology, which are crucial for advancing the research on olfactory mechanism and the application of optogenetic technology.
The rapid development of genetic diagnosis-related technologies has paved a wide road for gene therapy. Different gene therapy clinical trials for retinal disorders, including gene-replacement therapy, anti-neovascular gene therapy and opotogenetic gene therapy, have been developed and achieved fruitful results, which have gradually confirmed the efficacy and safety of adeno-associated virus (AAV)-mediated gene therapy for recessive retinal diseases. In recent years, novel gene editing technologies also shows great potential to treat dominant retinal disease, or recessive retinal disease when the therapeutic gene fragments are too long to fit into the AAV vectors. These results make it possible for most of the patients with inherited retinal diseases to be treated by the safe and effective AAV-mediated gene therapy, which will also benefit Chinese patients soon.
Objective To determine the association of -429T/C and G1704T polymorphisms in the receptor for advanced glycation end products gene with proliferative diabetic retinopathy (PDR). Methods Case-control study. From the Beijing Desheng Diabetic Eye Study cohort of 1467 patients with type 2 diabetes mellitus (T2DM),atotal of 97 patients with PDR and 105 diabetic patients without retinopathy (DWR, duration of diabetes 15 years) were included for this study. Questionnaires were collected and general ophthalmologic examinations were performed. Biochemical analysis was conducted. DNA was extracted from peripheral venous blood. The -429T/C and G1704T single nucleotide polymorphisms were detected by the means of PCR-restrication fragment length polymorphisms. Results The frequency distribution of -429T/C in DWR group was 81.0% in TT, 16.1% in TC, 2.9% in CC. The frequency distribution of -429T/C in PDR group was 77.3% in TT, 20.6% in TC, 2.1% in CC. There was no significant statistical difference between the two groups (χ2=0.40, P > 0.05). Frequency of the -429T/C minor alleleCin the DWR and PDR group were 11.0% and 12.4%, respectively, with no significant statistical difference between the two groups (χ2=0.20，P > 0.05). The frequency distribution of G1704T in DWR group was 66.7% in GG, 29.5% in GT, 3.8% in TT. The frequency distribution of G1704T in PDR group was 78.4% in GG, 21.6% in GT. There was no significant statistical difference between the two groups (χ2=3.44, P > 0.05). Frequency of the G1704T minor alleleTin the DWR and PDR group were 18.6% and 10.8%, respectively, in which significant difference was found within the two groups (χ2=4.79, OR=1.88，95%CI: 1.06 - 3.33, P > 0.05). Conclusions G1704T polymorphism is associated with PDR presence and 1704G allele may increase the risk of PDR.
Objective To analyze the relationship of human leukocyte antigen alleles (HLA-A/B, HLA-DRB/DQB) polymorphism and Eales disease, tuberculosis infection in a Han population in Zunyi city of China. Methods The subjects were analyzed by case control study, which consisted of three groups including Eales disease group (47 patients), pulmonary tuberculosis group (36 patients) and normal control group (100 healthy people). Thirty-nine patients in Eales disease group who had complete history were divided into 4 subgroups according to the history and tuberculin PPD test. Twelve patients with past or present pulmonary tuberculosis were in group A, 27 patients without pulmonary tuberculosis were in group B, 27 patients with positive PPD test were in group C, and 12 patients with negative PPD test were in group D. Fifty-nine alleles of HLA-A/B and HLA-DRB/DQB were analyzed by polymerase chain reaction with sequencespecific primers (PCR-SSP) in all subjects. Odds ratios between each group (OR) and 95% confidence interval (CI) were calculated; Frequency distribution of HLA-A02 gene were analyzed for the group A and the TB group. Results The frequency distribution of HLA-A02 （OR=9.719, OR95% CI:4.377-21.580,P=0.000）and HLA-B07 （OR=11.605, OR95% CI:2.397-56.191,P=0.001）alleles in Eales disease group were obviously higher than that in normal control group, but frequency distribution of HLA-A11（OR=0.495, OR95% CI:0.245-1.000,P=0.048）in Eales disease group was obviously lower than that in normal control group. There was no significant difference in frequency distribution of HLA-A02, HLA-A11 and HLA-B07 alleles between groups A and B, and between groups C and D (P＞0.05). The distribution frequency of HLA-A02, HLA-A24, HLA-B07 and HLA-DRB16 alleles among Eales disease group, pulmonary tuberculosis group and control group was statistically different (P＜0.05). The frequency distribution of HLA-A24 alleles in pulmonary tuberculosis group was lower than that in Eales disease group （chi;2=7.289,P=0.007）, but the frequency distribution of HLA-A02 alleles had no significant difference (OR=0.515,P=0.202) between two groups. Conclusions The alleles of HLA-A02 and HLA-B07 may be genetic predisposing genes of Eales disease, but HLA-A11 alleles may be protective gene in population of Han nationality from Zunyi city. The alleles of HLA-DRB16 and HLA-A02 may be genetic predisposing genes of pulmonay tuberculosis. The alleles of HLA-A02 may be a common susceptible gene for Eales disease and pulmonary tuberculosis. HLA-A11 and HLA-A24 alleles were protective genes of Eales disease and pulmonary tuberculosis respectively.
Recent advances in epigenetics indicate that several epigenetic modifications, including acetylation, methylatio, and microRNA (miRNA), play an important role in the pathogenesis of acute kidney injury (AKI). Our study reveales that enhancement of protein acetylation by pharmacological inhibition of class I histone deacetylases leads to more severe tubular injury, and delays the restoration of renal structure and function. The changes in promoter DNA methylation occurs in the kidney with ischemia/reperfusion. MiRNA expression is associated with the regulation of both renal injury and regeneration after AKI. Targeting the epigenetic process may provide a therapeutic treatment for patients with AKI. The purpose of this review is to summarize recent advances in epigenetic regulation of AKI and provide mechanistic insight into the role of acetylation, methylation, and miRNA expression in the pathological processes of AKI.
Usher syndrome (USH) is the most common cause of deaf-blindness diseases characterized by sensorineural hearing loss and retinitis pigmentosa. Patients are clinically and genetically heterogeneous, however, there are no convincing methods for prevention and treatment. USH2A is the most common disease-causing gene among 14 genes related to Usher syndrome. Great progress has been achieved in the pathogenic mechanism, animal models studies, diagnosis, and treatments based on gene therapy, cells transplantation and antisense oligonucleotide-based splice correction. Mutations in USH2A result in defects in USH complex proteins which involved in the transport function of the peripheral cilia region. There is respective limitations in established mouse and zebrafish animal models. Two promising treatments of this disease are introduced. One is clinical transplantation of visual organs which induced from corrected patient-derived induced pluripotent stem cells by the CRISPR/Cas9 system and another one is the RNA splicing therapy based on antisense oligonucleotides.
ObjectiveTo reveal the pathogenic mutation in a three-generation Chinese family with autosomal dominant familial exudative vitreoretinopathy (FEVR). MethodsThree patients and a healthy spouse from the index family with FEVR were recruited. The proband was a 5 years old boy. His mother and grandpa were presented with typical FEVR presentations, while his father with normal ocular fundus. DNA was extracted from peripheral blood samples taken from all four participants. All coding and exon-intron boundary regions of five targeted genes, including NDP, FZD4, LRP5, TSPAN12 and ZNF408 were amplified with polymerase chain reaction and sequenced using direct sequencing. In silico analyses were applied to determine the conservation of the mutation site, pathogenic effect and the potential protein crystal structural changes caused by the mutation. ResultsFZD4 c.478G > A, a susceptible mutation was found after four high frequency mutation sites which MAF values were higher than 0.001 was filtered among 5 single nucleotide variations detected in four participants, leading to the residue 160 changing from glutamate to lysine (p.E160K). Co-segregation analysis between genotypes and phenotypes revealed FZD4 p.E160K as the disease-causing mutation for this family. Conservational analysis suggested that this mutation site was highly conserved among all tested species. Functional analysis predicated that this mutation may be a damaging mutation. Crystal structural analysis also indicated that this mutation could lead to the elimination of the hydrogen bond between residue 160 and asparagine at residue 152, thus altering the tertiary structure of the protein and further impairing the protein function. ConclusionOur study demonstrates FZD4 p.E160K as a novel pathogenic mutation for FEVR.