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.
PURPOSE:Investigating on histopathologic changes of the photoreceptors in retinitis pigmentosa. METHODS:Observation of the photoreceptors of retinitis pigmentosa in 11 eyes among 9 cases using light and electron microscope. RESULTS: The pathologic changes of the photoreceptors were found to be mostly marded at the equatorial area and less at the periphery,posterior pole and macular region of the retina. In relatively early cases,degeneration and shortening of outer segments,reduction or loss of connecting cilia,stubby inner segments and swollen mitochondria Were the predominant findings. In advanced cases,the inner and outer segments and connecting cilia were diminished with reduction of nuclei in number and disarangement,cellular degeneration and disorganization. The outer limiting membrane adhered to RPE or Bruch membrane. The spaces left over by the above pathologic changes were replaced by the displaced Muuml;ller cells and their hypertrophic processes. Also there were degeneration of the RPE cells,and some of them might migrate into the retina. CONCLUSION:Obvious invasions of pathologic processes in photoreceptors of the retina did present in patients with retinitis pigmentosa. （Chin J Ocul Fundus Dis,1996,12:160-162）
Objective To observe the mutifocal electroretinogram (mfERG) characteristics of rod and cone cells in patients with retinitis pigmentosa (RP) and to evaluate the function of photosensory cell.Methods The mfERG recording technique for rod cell in eight normal subjects (eight eyes) were established and the influence of different brightness lightstimulus in P1 wave amplitude were analyzed. The cone and rod cells mfERG of 38 eyes in 19 patients were recorded and then calculated positive ratio from local signalnoise ratio. The average visual acuity and P1 wave amplitude density of cone mfERG in different types were compared and statistically analyzed. Meanwhile, the changes in P1 wave amplitude of cone and rod mfERG in four quadrants also compared and analyzed. Results Rod cell mfERG in normal subjects can be recorded stably by using blue flashes with low light intensity as 0.04 cd/m2. In patients with RP, the cone and rod cells mfERG can be detectd 65.79% and 10.51% respectively. P1 wave amplitude density in type I of cone cell mfERG was significantly higher than that in type II (t=5.21,P=0.000). There were no differences in average visual acuity (t=1.15, P=0.612). P1 wave amplitude density in type I was negatively related to logMAR visual acuity （r=-0.48，P=0.04）.The comparison of rod and cone cells mfERG in local wave characteristics showed that P1 wave amplitude densities had spatial relationship in each area. Conclusions The results suggested highly variable central responses in cone cell in RP patients, higher positive recorded ratio in cone cell than rod cell and spatial correspondence between the function of reserved cone and rod cells.
Objective To observe the expression of cyclin dependent kinase 5 (Cdk5) and p25 in the pathogenesis of retinitis pigmentosa (RP) in Royal College of Surgeon (RCS) rats and its relationships with apoptosis. To explore the mechanism of Cdk5 and p25 induced photoreceptor apoptosis in the pathogenesis of RP. Methods Retinas of RCS and RCS-rdy+ rats were obtained at the ages of postnatal day 17, 25, 35, 60. The retinal structure and thickness of outer nuclear layer were measured by optical microscopy. The expression of Cdk5, p25, cleave-caspase 3 in the retina was evaluated by immunohistochemistry. The protein expression of cleave-caspase 3 in the retina was determined by Western blot. The apoptosis of retinal cells was examined by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The mean absorbance value of apoptotic cells was analyzed by SPSS 17.0 software. Results The retinal thickness of the RCS rats was significantly reduced in comparison to the RCS-rdy+ rats as the postnatal days progressed, particularly in the layer of rods and cones and the outer nuclear layer. The expression level of Cdk5, p25, cleave-caspase 3 of RCS rats increased from postnatal 17 days to postnatal 35 days, while decreased on postnatal 60 days; but there was no obvious change of above indexes in RCS-rdy+ rats. The protein expression of cleave-caspase 3 in the RCS rats was significantly increased with progression of postnatal days to postnatal 35; but there was no obvious similar change in RCS-rdy+ rats. The results of TUNEL showed that the apoptotic cells significantly increased in the outer nuclear layer of RCS rats from postnatal 17 days to postnatal 35 days, while decreased on postnatal 60 days; but there was no obvious change of above index in RCS-rdy+ rats. This study showed that there were significant correlations between the following variables: Cdk5 expression and p25 expression, Cdk5 expression and cleave-caspase 3 expression, Cdk5 expression and apoptotic cells, p25 expression and cleave-caspase 3 expression, p25 expression and apoptotic cells, cleave-caspase 3 expression and apoptotic cells. The partial correlation coefficients were 0.949, 0.808, 0.959, 0.887, 0.979, 0.852, respectively and the P value was 0.000. Conclusions The apoptotic cells significantly increases and the expression level of Cdk5, p25, cleave-caspase 3 of RCS rats increases from postnatal 17 days to postnatal 35 days. The tendency of apoptotic cells to increase is consistent with the change of Cdk5, p25, cleave-caspase 3 expression. The apoptosis of photoreceptor cells is related to increasing expression of Cdk5 and p25 in RCS rats. Cdk5 may be involved in the development of RP in RCS rats.
Objective To investigate the expression and significance of inducible co-stimulator (ICOS) in experimental autoimmune uveoretinitis (EAU). Methods EAU was induced in 24 Lewis rats (immune group) by immunization with retinal S-antigen (50 mu;g) and complete Freundprime;s adjuvant, and another 4 rats were in the control group. Anterior segment of the ratsprime; eyes were observed by split microscope every day. Immunohistochemical staining was performed using polyclonal antibodies to ICOS on the sections of the spleen which were obtained from the rats in immune group at the 7th, 12th, 15th and 21st days after immunisation respectively. Western blotting was performed to investigate the dynamic expression of ICOS protein in the spleen. The same procedures were made at the corresponding time points in the rats in control group. Results A few ICOS positive cells were observed in the normal spleen. The number of ICOS positive cells in immune group increased obviously at the 7th and 12th days after immunization, reached the peak at the 15th day, and decreased at the 21st day which was still higher than that in the control group. The result of Western blotting showed that the dynamic changes of ICOS protein was identical with the changes of positive-cell number detected by immunohistochemistry. Conclusions The enhanced expression of ICOS happens before EAU occurs, which increases when the inflammation occurs and deteriorates, and decreases at the alleviative stage of EAU. It suggests that ICOS participates in the formation, development and disappearance of EAU and plays an important role in the incidence of EAU. (Chin J Ocul Fundus Dis, 2005,21:114-117)
Objective To analyze the pathogenic gene and clinical phenotypes of a family affected with rare sector retinitis pigmentosa (sector RP). Methods A retrospective clinical study. A patient with sector RP diagnosed in Renmin Hospital of Wuhan University and his parents were included in the study. Detailed medical history was collected; best corrected visual acuity (BCVA), fundus color photography, autofluorescence (AF), visual field, optical coherence tomography (OCT), electroretinogram, fluorescein fundus angiography (FFA), indocyanine green angiography (ICGA) examination were performed. The peripheral venous blood of the patient and his parents were collected, and DNA was extracted. A whole exon sequencing was used for the proband. The mutations were verified by targeted Sanger sequencing and quantitative polymerase chain reaction. Bioinformatics analysis and cosegregation analysis were performed. ResultsThe proband, a 17-year-old male, had presented with gradually decreased vision in the past 2 years with BCVA of 0.4 in both eyes. Retinal vessels attenuation and macular dystrophy without obvious pigmentation on the fundus were observed. AF showed, in bilateral eyes, a symmetrical hypo-autofluorescent region only in the inferonasal quadrant and “petal-like” hyper-AF macula. The visual field examination showed defects in the superotemporal quadrant corresponding to the affected retina. OCT showed loss of the photoreceptor layer except for the foveal region. Electroretinogram examination presented reduced scotopic wave peaks and extinct photopic response. FFA and ICGA showed the atrophy retinal pigment epithelium around the optic disk and in the inferior retina. The clinical phenotypes of the parents were normal. The whole exon sequencing identified one mutation in SPATA7 gene, c.1112T>C (p.Ile371Thr) in exon10 and a copy number variation in trans. The missense mutation resulted in the change of isoleucine to threonine at amino acid 371 in the encoded SPATA7 protein, and the mother carried this heterozygous mutation c.1112T>C. According to the guidelines of the American College of Medical Genetics and Genomics (ACMG) criteria and guidelines for classification of genetic variants, the missense mutation was classified as the uncertain significance. The CNV, originating from his father, contributed to the loss of exon10 and was confirmed as the likely pathogenic variant. ConclusionsThe macula can be involved in sector RP, leading to the macular dystrophy. The missense variant in SPATA7 gene, c.1112T>C (p.Ile371Thr), might be a pathogenic mutation site in this pedigree.
Objective To investigate the expression of T cell receptor (TCR) Vβ8.3 gene on CD4+ T lymphocytes in the rats with experimental autoimmune uveoretinitis (EAU). Methods Eighteen Lewis rats were divided into EAU, complete Freund′s adjuvant, and the control group. Inter photoreceptor retinoid-binding protein (IRBP) R16 peptide was synthesized using Fmoc procedure for induction of EAU. Magnetic absorption cell sorting (MACS) me thod was used to isolate the CD4+T lymphocytes from the spleen of the rats. Flow cytometry was used to monitor the efficiency of isolation. The expression of TCR Vβ8.3 gene segment on CD4+T lymphocytes was determined by fluorescent quantitative polymerase chain reaction. Results EAU was successfully induced in the Lewis rats immunized with IRBP R16 peptide. The proportion of CD4+T lymphocytes isolated by means of MACS was statistically higher than that before isolation (P＜0.001). The expression of TCR Vβ8.3 gene segment on CD4+ T lymphocytes in EAU rats was significantly higher than that in the control (P＜0.05). Conclusions There is a predominant usage of antigen-specific TCR Vβ 8.3 gene in EAU rats induced by IR BP R16 peptide, which may serve as a target for immunotherapy of EAU. (Chin J Ocul Fundus Dis，2004，20：165-167)
Retinitis pigmentosa is a hereditary disease which is characterized by damage in retinal photoreceptor cells and retinal pigment epithelium. Its main clinical features include low vision with night blindness, progressive visual field defects, and abnormal electroretinograms. The development of gene sequencing, the diagnosis and treatment methods of retinitis pigmentosa update year by year, including gene therapy, stem cell therapy, optogenetic therapy, etc. However, there is still a big gap in these treatments from laboratory technology into effective clinical treatment drugs. Some problems which include immune response, potential mutagenesis and tumorigenesis of the inserted region, genetic toxicity, quality and stability of gene technology and stem cell technology, mass production and promotion of clinical grade drugs, and optimization of the effectiveness of drugs and surgery, etc, remain to be solved by researchers.
Objective To investigate whether mutations exist in codon 58 and codon 347 of the rhodopsin gene in patients with autosomal dominant retinitis pigmentosa(ADRP)． Methods Point mutations at codons 58 and 347 were detected by restriction endonuclease digestion of exons 1 and 5 amplified by polymerase chain reaction(PCR)．This method was applied to screen genomic DNAs from 57 patients of 38 families with ADRP and 60 normal controls． Results Four patients from one family of ADRP were confirmed to have a point mutation at the second nucleotide of codon 58,and 6 patients from two families of ADRP were found to have a mutation at codon 347．None of these mutations were found in 60 normal subjects． Conclusion It is suggested that molecular genetic heterogeneity exists within ADRP and some subtypes of ADRP are caused by points mutations of the rhodopsin gene． (Chin J Ocul Fundus Dis,1998,14:108-110)
Retinitis pigmentosa (RP) is a group of hereditary blinding fundus diseases caused by abnormalities in photoreceptors of the retina. RP is highly heterogeneous in hereditary and cdinical phenotypes. It can be divided into simple type RP and syndrome type RP. The main inheritance patterns are autosomal dominant, autosomal recessive inheritance and X-linked inheritance. With the popularization and clinical application of gene sequencing technology, more and more disease-causing genes have been discovered, and these genes are mainly expressed in photoreceptor cells and retinal pigment epithelial cell. ln-depth understanding of RP pathogenic genes not only provides a theoretical basis for RP diagnosis and genetic counseling, but also provides guidance for RP gene therapy.