Objective To analyze the expression of apoptosis-related genes of retinal blood vessel in early diabetic rats by gene chip technology. Methods To make diabetic rat model by intraperitoneal injection of streptozotocin (STZ). On the 6th week after blood pressure increased, 10 rats were executed in Diabetic group and normal control group respectively. 20 retinal blood vessels were extracted and the RNA was isolated. The probe was made of alpha;-32 P-deoxyadenosine triphosphate (dATP)-labeled sample which hybridized 1176 nylon chips, and then analyzed by software. Three different expression genes were selected to verify by reverse transcription polymerase chain reaction (RT-PCR). Results On the 6th week, 136 （11.5％） genes were differentially expressed ［up-regulated genes were 90(7.6%), down-regulated genes were 46(3.9%)］in diabetic group. These genes involved into different groups according to their function. Especially in 72 apoptosis-related genes, 15 genes were differentially expressed. The up-regulated genes were some TNF receptor family members such as TNFRSF12, TRAIL, TNFRSF9, FADD；Bcl-2 family members such as bcl-w, bax, bak1 and AKT. The down-regulated genes were FAF1 which related to fas. Conclusions The expression of retinal vascular gene in early diabetic rats has been changed complicatedly. In particular, the multiple apoptosis-related genes have been changed in early diabetic, and most of them are at the upstream of apoptosis pathway. These findings indicate that the development of diabetic retinopathy is associated with multiple signaling pathways leading to apoptosis, while the alterations on the level of molecular biochemistry are still limited in apoptosis induction period. （Chin J Ocul Fundus Dis，2008，24：244-248）
Purpose To identify the expression of alternatively spliced mRNA isoforms of the NMDA-R1 in the visual cortex of strabismic cats. Methods Two pai rs of normal and strabismic cats were used．The amblyopic cats had been made monocularly esotropic (by tenotomy) at the age of weeks，resulting in behavioral am blyopia．Animals were sacrificed about 6 months by intraperitoneal administration of Nembutal．Cryostat sections of fresh，frozen central visual cortex of the ats were cut to 20 micron thickness．A series of digoxygenin-labelled oligonucle otide probes basing on the human gene sequence were used for ISH．Control probes included sense oligonucleotides and short segment probes which were adjacent to ，but did not，span the splice junctions．A computer-assisted systematic morphometric ounting procedure was used to enumerate hybridising cells． Results The number of positive cells expressing NMDA-R1 mRNA in t he strabismic amblyopic cats was decreased，notably in layer IV of visual cortex (P＜0．0001)．The pattern of isoform expression varied between normal and strabismic amblyopic cats with decreased numbers of 1-a，1- b and 1-1 isoforms and apparently increased expression of 1-3 P ＜0．0001)，whereas no significant difference was found for the 1-2 and 1-4 isoforms (P＞0．05)． Conclusion Transcriptional inhibition of NMDA-R1 mRNA and of specifie isoforms may underlie the change in receptor expression．Alternatively，preferentialloss of neurones bearing particular NMDA-R1 isoforms and compensation with a proportional increase in cells expressing other isoforms may occurr during the critical period of visual plasticity． (Chin J Ocul Fundus Dis，2000，16：71-138)
Optic atrophy,hereditary／diagnosis; Polymerase chain reaction; DNA,mitochondrial; Point mutation; Sequence analysis
Objective Molecular cloning of rat retinal degeneration slow(RDS)gene cDNA. Methods Using PolyA+RNA from retina of SD rat as template,a 1555bp positive cDNA band was obtained by RT-PCR and subcloned into pBluescriptⅡKS(+) vector.The cloned fragment was analyzed with restriction endonucleases and sequencing. Results It had been proved that the cloned fragment was rat RDS/peripherin cDNA.Except for the substitute of A1242G and CA1409-1411CCA,the other sequences corresponded to that reported by Begy. Conclusion Rat RDS/peripherin cDNA was obtained.Researches on function of rat RDS/peripherin gene and its role in retinal degeneration are under way. (Chin J Ocul Fundus Dis,1999,15:97-99)
PURPOSE:To investigate the status and detailed structure of Rb gene in primary tumors and somatic cells of patients with retinoblastoma. To identify the character, origin and transmission of oncogenie point mutations. METHODS:DNA hybridization,SSCP analysis and PCR-associated direct sequencing. RESULTS:Among 108 RB patients examined 80 cases were found to have subtle alterations affecting Rb locus,including 44 cases with homozygous Rb point mutations, 20 cases with two independent heterozygous Rb point mutations, 16 cases with heterozygous mutations involved in one allele of Rb gene. Majority of bilateral RB patients and a small fraction of unilateral RB patients were detected to have a germline mutation. In addition the higher frequency of new germline mutation and parental origin of mutation were observed. CONCLUSION :Rb gene is closely associated with retinoblastoma. Two mutation events and resulting inaetivations of both Rb alleles are required for RB tumorigenesis. Based on our own data,the first event is exclusively point mutation. As for the second event,LOH accounts for two third of cases,point mutation for one third of cases. （Chin J Ocul Fundus Dis,1997,13: 12- 16）
ObjectiveTo construct eukaryotic expression vector of pEGFP-N3-TFPI-2, and to provide the base of studying the function of TFPI-2 gene. MethodsExtraction of total RNA from placental tissue was extracted at first, and then reverse transcriptase synthesis of cDNA was carried out. The cDNA fragment of TFPI-2 gene which was obtained by real time PCR (RT-PCR) was inserted into eukaryotic expression vector of pEGFP-N3. After double digestion with XhoⅠand KpnⅠ, the recombinant vector of pEGFP-N3-TFPI-2 was identified in 1% agarose gel electrophoresis and was tested by the sequence analysis. Then, the recombinant vector of pEGFP-N3-TFPI-2 (transfection group) and vector of pEGFP-N3 (blank control group) were transfected into Top10 competent cells with LipofectamineTM 2000, but no transfection-related treatment was performed in cells of untransfection group. Western blot method was used to test the expression of TFPI-2 protein in cells of 3 groups. ResultsThe purity of total RNA which were analysis by agarose gel electrophoresis and spectrophotometry were fit for PCR. After coding of TFPI-2 gene fragment and eukaryotic expression vector of pEGFP-N3, the recombinant plasmid of pEGFP-N3-TFPI-2 were got double digestion with XhoⅠand KpnⅠ, and was identified in 1% agarose gel electrophoresis, of which showing that there were 2 specific amplification of strips at 708 bp and 4 700 bp. Result of sequence analysis confirmed that the size of recombinant vector was consistent with the theoretical value. Results of Western blot showed that the expression of TFPI-2 protein in transfection group (0.657 3±0.032 5) was higher than those of blank control group (0.301 7±0.028 7) and untransfection group (0.314 3±0.026 6), P < 0.01. ConclusionsThe eukaryotic expression vector of pEGFP-N3-TFPI-2 has been constructed successfully, which laiding the foundation for the analysis about function of TFPI-2 gene.
ObjectiveTo identify the pathogenic mutation in a three generation Chinese family with low penetrance retinoblastoma (RB). Methods8 from 9 family members received complete ophthalmic examinations. DNA was extracted from 6 family members. Using exon combined target region capture sequencing chip to screen the candidate disease-causing mutations. Sanger sequencing were used to confirm the disease-causing mutation. ResultsAmong 9 family members, the proband (Ⅲ2) was bilateral RB, Ⅲ1 was unilateral RB, Ⅲ3 was dead for bilateral RB. Normal fundus were observed in the left eye ofⅢ1 and the eyes of other family members except the proband. Sequence analysis of RB1 gene revealed a missense mutation c.1981C > T (p.Arg661Trp) in the proband and two carriers (Ⅱ2, Ⅱ3), but not in the two normal subjects (Ⅱ1, Ⅱ4). We suspect that the RB penetrance in the family was 50%. ConclusionsThere is a missense mutation c.1981C > T in a Chinese family with low penetrance RB. The RB penetrance is 50%.
ObjectiveTo observe the disease-causing genes and the inheritance in sporadic retinitis pigmentosa (sRP) in Ningxia region. Methods49 sRP patients and 128 family members were recruited for this study. All the patients and family members received complete ophthalmic examinations including best corrected visual acuity, slit-lamp microscope, indirect ophthalmoscopy, fundus color photography, visual field, optic coherence tomography, full view electroretinogram. DNA was extracted from patients and family members. Using exon combined target region capture sequencing chip to screen the 230 candidate disease-causing gene mutations, polymerase chain reaction and direct sequencing were used to confirm the disease-causing mutations. Results24/49 patients (49.0%) had identified disease-causing genes, totally 16 genes were involved. There were 41 mutation sites were found, including 32 new mutations (78.0%). The disease-causing genes include USH2A, C2orf71, GNGA1, RPGR1, IFT140, TULP1, CLRN1, RPE65, ABCA4, GUCA1, EYS, CYP4V2, GPR98 and ATXN7. Based on pedigree analysis, 20 patients were autosomal recessive retinitis pigmentosa, 3 patients were autosomal dominant retinitis pigmentosa and 1 patient was X linked retinitis pigmentosa. 3/7 patients with USH2A mutations were identified as Usher syndrome. ConclusionsUSHZA is the main disease-causing of sRP patients in Ningxia region. 83.3% of sRP in this cohort are autosomal recessive retinitis pigmentosa.
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.