Genetic analysis of the ALMS1 gene in two families affected with Alstr?m syndrome / 中华眼底病杂志

Objective:To identify two pathogenic gene mutations in two families with Alstr?m syndrome (ALMS).Methods:A retrospective clinical study. Two patients and five family members from two Han families of ALMS diagnosed at Henan Eye Hospital from August 2020 to December 2021 were enrolled in this study. All participants underwent comprehensive ophthalmic examinations including best corrected visual acuity (BCVA), color test, slit-lamp, fundus biomicroscopy with slit lamp, fundus color photography, optical coherence tomography (OCT) and full-field electroretinography (ff-ERG) after the detailed history of the patient was taken. Five millilitres peripheral venous blood of each subject was collected, and the whole genome DNA was extracted. The pathogenic genes and mutation sites were identified using whole exome sequencing and the identified mutations were verified by Sanger sequencing. Mutation sites were analyzed via bioinformatics softwares.Results:Family one included one victim and two members and family two included one victim and three members. Proband in the first family was a four-year old boy whose chief complaint was poor vision along with photophobia since born, while proband in the second family was a 12-year old girl whose chief complaint was the same. The boy proband could not distinguish color, and both the anterior segment and fundus were normal. Ellipsoid zone of the boy was unclear in both eyes in OCT, and though rod system function decreased mildly-moderately in both eyes, the cone system function decreased severely in ff-ERG. The girl could not distinguish color as well, and the anterior segment was normal, though obvious pigmentary change could be seen in both retinas. The integrity of outer retinal bands was unclear in both eyes in OCT, and both cone and rod systems function decreased severely in both eyes in ff-ERG. Gene tests and bioinformatics analyze showed c.468dupT and c.10819C>T of ALMS1 gene in family one were novel mutations and c.10819C>T in family one and c.10831_10832del in family two were pathogenic mutations. Conclusions:M1, M2 and M3, M4 may be pathogenic gene variants in family 1 and family 2, respectively. The compound heterozygous mutation, c.468dupT and c.10819C>T of ALMS1 gene was a novel mutation.

Transcriptome sequencing of transgelin-2 inhibiting high glucose induced microglia inflammation / 中华眼底病杂志

Objective:To analyze the change of differential genes and signaling pathways in high glucose induced BV2 cells, and to explore the mechanism of transgelin-2 (TAGLN2) regulating cellular inflammatory response and metabolic process.Methods:An experimental study. The cultured BV2 cells were divided into mannitol treatment (Man) group, glucose treatment (Glu) group, overexpression control Glu treatment (Con) group, overexpression TAGLN2 Glu treatment group, silence control Glu treatment (shCon Glu) group, and silence TAGLN2 Glu treatment (shTAGLN2 Glu) group. Cells in the Man group were cultured in modified Eagle high glucose medium (DMEM) containing 25 mmol/L mannitol and 25 mmol/L glucose, cells in other groups (Glu group, Con Glu group, TAGLN2 Glu group, shCon Glu group and shTAGLN2 Glu group) were cultured in DMEM medium containing 50 mmol/L glucose. After 24 hours of cells culture, transcriptome sequencing of cells in each group were performed using high-throughput sequencing technology, and significantly differentially expressed genes (DEG) were screened. |log 2 (fold change)|≥1 and P≤0.05 were adopted as criteria to screen for DEG. Gene Ontology (GO) function enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and protein-protein interaction network analysis were performed. Real-time polymerase chain reaction (RT-PCR) was used to detect the relative expression level of DEG mRNA. The data between groups were compared by independent sample t-test. Results:When compared with Man group, a total of 517 differentially expressed genes were screened in Glu group, which including 277 up-regulated genes and 240 down-regulated genes. KEGG pathway enrichment analysis showed that the up-regulated genes were significantly enriched in immune system processes such as nuclear factor (NF)-κB signal pathway, Jak-signal transducers and activators of transcription (STAT) signal pathway, while down-regulated genes were significantly enriched in glycosaminoglycan degradation and glyceride metabolic pathway. Compared with Con Glu group, a total of 480 DEG were screened in TAGLN2 Glu group, among which 147 up-regulated and 333 down-regulated genes were detected. Up-regulated genes were significantly enriched in the metabolic processes of fatty acid, glyceride and pyruvate, while down-regulated genes were significantly enriched in immune system processes such as NF-κB signal pathway, Jak-STAT signal pathway and tumor necrosis factor (TNF) signal pathway. Compared with shCon Glu group, a total of 582 DEG were screened in shTAGLN2 Glu group, among which 423 up-regulated and 159 down-regulated genes were detected. Up-regulated DEG were significantly enriched in immune system processes such as TNF signal pathway and chemokine signal pathway, while down-regulated DEG were significantly enriched in pattern recognition receptor signal pathway. RT-PCR results showed that the relative expression levels of DEG mRNA Card11 ( t=13.530), Icos ( t=3.482), Chst3 ( t=6.949), Kynu ( t=5.399), interleukin (IL)-1β ( t=2.960), TNF-α ( t=5.800), IL-6 ( t=3.130), interferon-γ ( t=7.690) and IL-17 ( t=6.530) in the TAGLN2 Glu treatment group were decreased significantly compared with Con Glu group, and the difference was statistically significant. Conclusion:TAGLN2 can inhibit glucose induced microglia inflammation by NF-κB and Jak-STAT signaling pathways, Card11, Icos, Chst3 and Kynu play an important role in the anti-inflammatory process of TAGLN2.

Genetic analysis of the CACNA1F gene in a family affected with incomplete form Schubert-Bornschein type congenital stationary night blindness / 中华眼底病杂志

Objective:To determine the pathogenic gene mutation in a family with incomplete congenital quiescent night blindness (CSNB) of Schubert-Bornschein type.Methods:A retrospective clinical study. In February 2021, one patient and his parents and elder brother from a Han Chinese incomplete CSNB of Schubert-Bornschein type family diagnosed by clinical and genetic examination at Henan Provincial People's Hospital were included in the study. The patient’s medical history, family history were inquired; best corrected visual acuity (BCVA), color vision, fundus color photography, full-field electroretinogram (ERG), and frequency domain optical coherence tomography (OCT) were examined in detail. Five ml of the subject’s peripheral venous blood was collected and the whole genome DNA was extracted. The genomic DNA of the subject was library constructed, and all-exon probes were polymerized for capture. The suspected pathogenic mutation site was verified by Sanger, and the pathogenicity of the gene mutation site was determined by parallel bioinformatics analysis.Results:The BCVA of both eyes of the proband (Ⅱ2) was 0.4; the color vision test could not recognize the red color. Fundus examination showed no obvious abnormalities. The retina thickness in the macular area of both eyes was slightly thinned. ERG examination of the whole field showed that the amplitude of ERG b wave was significantly reduced under the stimulation of binocular dark adaptation 3.0 and showed a negative waveform. The mother of the proband (Ⅰ2) had normal BCVA, color vision, fundus color photography, and frequency domain OCT examination. The full-field ERG examination showed that the amplitude of each eye reaction was slightly reduced, and the amplitude of the dark adaptation shock potential was significantly reduced. Genetic testing showed that the proband (Ⅱ2) had a c.1761dupC hemizygous mutation in exon 14 of the voltage-dependent calcium channel α1F subunit gene ( CACNA1F gene). The results of protein sequence homology analysis showed that the site was highly conserved in multiple species; the results of bioinformatics analysis showed that the CACNA1F gene c.1761dupC (pY588fs) subsequently had a frameshift mutation and became a stop at position 10. Codons appear translational termination in the conserved regions of the protein. According to the standards and guidelines of the American College of Medical Genetics and Genomics, the mutation was judged to be a possible pathogenic variant. The mother of the proband (Ⅰ2) was a carrier of this site mutation. The clinical and genetic test results of the father and elder brother of the proband were not abnormal. Conclusion:CACNA1F gene c.1761dupC is the pathogenic mutation site of the Schubert-Bornschein type incomplete CSNB family.

Transcriptomics analysis of hypoxia-induced retinal pigment epithelium cell injury / 中华实验眼科杂志

Objective:To analyze differentially expressed genes (DEGs) and the changes of signal pathways in human retinal pigment epithelium cells (ARPE-19) under hypoxic and normoxic conditions and to explore the biological mechanism of hypoxia-induced ARPE-19 cell damage via transcriptome sequencing (RNA-seq) and bioinformatics technology.Methods:The ARPE-19 cells were divided into the hypoxia treatment group and the normoxia control group treated with 1% and 21% O 2 by volume for 8, 24, 48, 72 hours, respectively.The relative expression levels of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) mRNA were detected with real-time fluorescent quantitative PCR at different time points.RNA-seq and bioinformatics analysis were performed at 8 hours and 24 hours after hypoxia and normoxia treatment.DEGs were screened out under the conditions of |log 2FC|≥1 and P≤0.05.Then the cluster heat map analysis, Gene Ontology (GO) functional enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and protein-protein interaction network analysis were also carried out.Real-time fluorescent quantitative PCR was employed at 24 hours after hypoxia to detect the relative mRNA expression of genes that might be related to hypoxia in DEGs.Cell viability kit was used to verify and compare the damage effect of hypoxia on ARPE-19 cells at different time points between the two groups. Results:The relative mRNA expression levels of VEGF at 8, 24, 48 and 72 hours after hypoxia treatment and the relative HIF-1α mRNA expression levels at 8, 24 and 48 hours after hypoxia treatment were significantly higher than those of the normoxia control group (all at P<0.05). There were large differences in the mRNA expression levels at 8-hour and 24-hour treatment between the two groups.A total of 62 significant DEGs were screened between the hypoxia treatment group and the normoxia control group after 8-hour hypoxia treatment, among which 45 genes were significantly up-regulated and 17 genes were significantly down-regulated.A total of 255 significant DEGs were screened out between the hypoxia treatment group and the normoxia control group after 24-hour hypoxia treatment, among which 228 genes were significantly up-regulated and 27 genes were significantly down-regulated.The GO functional analysis of DEGs was mainly enriched in processes such as protein degradation, nucleotide biosynthesis, and material transport.KEGG pathway analysis was mainly enriched in PI3K-Akt, cGMP-PKG, and other signaling pathways closely related to metabolism, cell cycle, cell growth, and apoptosis.The core genes HPCA, MT3 and NOS3 were found by protein-protein interaction network analysis.Real-time fluorescent quantitative PCR test results showed that after 24-hour hypoxia treatment, the mRNA expression levels of hypoxia related genes DEPP1, NPPB, PDZK1, HILPDA, TCEA3, NDRG1 and RORC in ARPE-19 cells were significantly increased and the mRNA expression levels of TFRC and NQO1 were significantly decreased (all at P<0.05). The cell morphology was normal and the growth state was good without dead cells after 8-hour and 24-hour hypoxia treatment in ARPE-19 cells.There were dead cells after 48-hour hypoxia treatment, and the number of dead cells was increased at 72 hours after hypoxia treatment. Conclusions:The PI3K-Akt and cGMP-PKG signaling pathways related to metabolism may be involved in hypoxia-induced injury of ARPE-19 cells.Core genes of HPCA, MT3 and NOS3 can be used as functional target genes and play key roles in hypoxia response of cells.

Bioinformatics analysis of transcriptome sequencing of early hypoxia damage in photoreceptor 661W cell line / 中华眼底病杂志

Objective:To analyze the early changes of gene expression levels and signaling pathways in 661W cell line under hypoxic conditions and to find potential functional target genes.Methods:The cultured mouse 661W cells were divided into hypoxia treatment group and normoxia control group. Cells in the hypoxia treatment group were cultured in a three-gas incubator with volume fraction of 1% and 5% CO 2 at 37 ℃. Cells in the normoxia control group were cultured in an incubator at 37 ℃ with volume fraction of 5% CO 2. High-throughput sequencing technology was used to sequence the transcriptome of 661W cell treated with hypoxia and normoxia for 4 hours to screen for differentially expressed genes (DEG). Clustering heat map analysis, gene ontology (GO) functional enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and protein-protein interaction network (PPI) analysis were performed. The reverse transcription-polymerase chain reaction (RT-PCR) was used to verify the accuracy of the sequencing results. Results:A total of 506 differentially expressed genes were screened, including 459 up-regulated genes and 47 down-regulated genes. GO functional enrichment analysis showed that the main biological processes of DEG were the cell's response to hypoxia, glycolysis, negative regulation of cell proliferation and apoptosis. hypoxia inducible factor (HIF)-1α pathway, glycolysis, Forkhead box O (FoxO) pathway, Insulin signaling pathway and Adenosine 5′-monophosphate-activated protein kinase (AMPK) pathway were involved in the above process. PPI analysis results showed that hub genes related to hypoxia were Aldoa, Aldoc, Gpi1, Hk2, Hk1, Pfkl, Pfkp, Vhl, Fbxo10 and Fbxo27. The RT-PCR results showed that the relative expression levels of 15 DEG mRNA in the hypoxic treatment group were higher than that of the normoxic control group, and the difference was statistically significant ( P<0.05). The mRNA expression levels of N-myc downstream-regulated gene-1 ( Ndrg1 ), Mt1, and vascular endothelial growth factor A ( VEGFA) were time-dependent on hypoxia. Conclusions:Under hypoxia, DEG is mainly related to glucose metabolism, cell response to hypoxia, regulation of proliferation and apoptosis. HIF-1α pathway, glycolysis, FoxO pathway and AMPK pathway are involved in the early changes of 661W cells under hypoxia. Aldoa, Aldoc, Gpi1, Hk2, Hk1, Pfkl, Pfkp, Vhl, Fbxo10, Fbxo27 may play key roles in the response of 661W cells to hypoxia. Ndrg1, Mt1 and VEGFA could be potential functional target genes for the study of ischemia and hypoxia-related fundus diseases.

Novel mutations in the TULP1 and CNGB1 genes in a family affected with early onset severe retinal dystrophy / 中华眼底病杂志

Objective:To identify the pathogenic gene mutations in a family with early onset severe retinal dystrophy (EOSRD).Methods:A retrospective clinical study. One patient and three family members from a Han of EOSRD who were diagnosed at Henan Eye Hospital in August 2018 were included in the study. After the detailed history of the patients was collected, all participants underwent best corrected visual acuity (BCVA), slit-lamp, fundus biomicroscopy with the slit lamp, untra-widefield fundus color photography, spectral-domain optical coherence tomography (SD-OCT) and full-field electroretinography (ff-ERG). The subject’s peripheral venous blood of 5 ml was collected and the whole genome DNA was extracted. A genetic eye disease capture chip containing 441 disease-causing genes was used for targeted capture and enrichment of high-throughput sequencing, and Sanger sequencing was performed for the clear pathogenic mutation sites; the analysis software was used for bioinformatics analysis of the mutation sites.Results:A 6-year-old female proband developed poor night vision in both eyes after 1 year old. The BCVA of both eyes were 0.1. The color of the optic disc was slightly lighter; the diameter of the retinal vessels was slightly reduced, and extensive pigment changes can be seen in the retina outside the vascular arch. SD-OCT examination showed that the outer membrane, ellipsoid zone and chimera zone in the central fovea of both eyes were unclear and intermittent. The visual area outside the fovea was neuroepithelial outer plexiform layer, outer nuclear layer, outer membrane, ellipsoid zone. The chimera zone gradually disappeared, and the thickness of the pigment epithelial layer was not uniform. In ff-ERG examination, the functions of the binocular cone and rod system were severely decreased. The results of genetic testing showed that there were c.921C>A homozygous mutations in the Tubby-like protein (TULP1) gene of the proband, and c.3121C>T and c.3488G>A compound heterozygous mutations in the cyclic nucleotide gated channel beta 1 (CNGB1) gene. Amino acid conservation analysis results showed that the above three mutation sites were highly conserved in multiple species; bioinformatics analysis results showed that TULP1 gene c.921C>A (p.Cys307*) had translation termination in the protein conserved region, CNGB1 gene c.3121C>T (p.Arg1041Trp) and c.3488G>A (p.Gly1163Glu) had amino acid polarity changes in the protein conserved region, which led to major changes in the protein spatial structure.Conclusion:TULP1 gene c.921C>A homozygous mutation, CNGB1 gene c.3121C>T and c.3488G>A compound heterozygous mutation are the mutation sites of this EOSRD family.

A novel mutation of CNGB3 gene in a Chinese achromatopsia family / 中华实验眼科杂志

Objective:To identify the pathogenic gene mutations in a Chinese achromatopsia family.Methods:A pedigree investigation was performed.A Chinese Han pedigree from Luoyang city of China was enrolled in Henan Eye Hospital in November 2018.The medical history of the patients was collected.The best corrected visual acuity (BCVA) of the families was examined.The maniafestations of the anterior segment and fundus were obtained via slit lamp biomicroscope and slit lamp lens.The diopter was determined by objective and subjective refraction.Color vision was examined by Farnsworth-Munsell Hue Test.Retinal function was evaluated by international standard electroretinogram (ERG). Retina was observed by color photography, and its structural image was obtained by spectral-domain optical coherence tomography (SD-OCT). The peripheral blood sample was collected from the proband (Ⅲ1) and her younger brother (Ⅲ2) and parents for whole blood DNA extraction, and a whole genome sequencing (WGS) was performed to identify the pathogenic genes and mutation sites, and the sequencing data was compared through disease-related databases such as the Human Genome Databases due to a negative detective result of specific hereditary eye disease enrichment panel based on targeted exome capture technology.Sanger sequencing and bioinformatics analysis was carried out with softwares.The cosegregation analysis was performed.This study protocol was approved by an Ethics Committee of Henan Eye Hospital (No.HNEECKY-2019[15]) and complied with Declaration of Helsinki.Written informed consent was obtained from each subject or the guardian before any medical examination.Results:This family included 2 patients and 8 members with normal phenotypes in 3 generations and showed an autosomal recessive inheritance model.Poor vision and photophobia appeared after birth in both Ⅲ1 and Ⅲ2, and these symptoms did not deteriorate with aging.Pigmentary mottling and atrophic changes could be seen in the retinas of the patients.Reflection bands of external membrane and ellipsoid line in macula of patients were irregular on the OCT image.Color vision examination showed achromatopsia of the patients.ERG indicated that the amplitudes of a-, b-waves of scotopic 0.01, 3.0, 10.0 ERG and oscillatory potentials were slightly reduced, and the amplitudes of a-, b-waves of photopic ERG and wavelets of 30 Hz were seriously reduced in both eyes of Ⅲ1 and Ⅲ2.WGS showed that heterozygous mutations of a novel mutation c. 129+ 1G>A and a known mutation c. 1285dupT of CNGB3 gene in Ⅲ1 and Ⅲ2.The mutations were confirmed by Sanger sequencing.Conclusions:The compound heterozygous mutation in c. 129+ 1G>A/c.1285dupT of CNGB3 gene may be responsible for the achromatopsia pathogenesis in this Chinese Han pedigree.The abnormal phenotype of the patients is the result of both CNGB3 c. 129+ 1G>A and CNGB3 c. 1285dupT mutations simultaneously.

Novel mutations of RPGRIP1 gene in a family with Leber congenital amaurosis / 中华眼底病杂志

Objective:To identify the pathogenic gene mutations in a family with Leber congenital amaurosis (LCA).Methods:In October 2018, 1 patient and 3 normal family members from a LCA family was enrolled in this retrospective study. Detailed medical history of proband was obtained and fixation test, cycloplegic refraction, slit-lamp, fundus color photography and full-field ERG were performed. And other family members underwent BCVA, refraction slit-lamp, fundus biomicroscopy with the slit lamp, fundus color photography and full-field ERG. The family was investigated with a specific hereditary eye disease enrichment panel which contained 441 known pathogenic genes and based on targeted exome capture technology first to indentify the potential pathogenic genes and mutations. Then the potential pathogenic mutations were conformed by Sanger sequencing. Finally, the results were analyzed via bioinformatics analysis.Results:The proband showed no trace object from childhood, but had obvious photophobia and nystagmus. No positive changes were found in the anterior segment, vitreous and retina in both eyes. Both cone and rod system function decreased significantly in full-field ERG in both eyes. Gene tests showed the proband carried both RPGRIP1 c.1635dupA and c.3565C> T, which composited a heterozygous mutation. Bioinformatics analysis showed RPGRIP1 c.1635dupA was a pathogenic mutation, and RPGRIP1 c.3565C> T which was a novel potential pathogenic mutation in LCA.Conclusion:The compound heterozygous mutation, c.1635dupA and c.3565C> T in RPGRIP1 may be responsible for the pathogenesis in this Chinese Han LCA pedigree.