Copy Number Variation of Age-Related Macular Degeneration Relevant Genes in the Korean Population

PURPOSE: Studies that analyzed single nucleotide polymorphisms (SNP) in various genes have shown that genetic factors are strongly associated with age-related macular degeneration (AMD) susceptibility. Copy number variation (CNV) may be an additional type of genetic variation that contributes to AMD pathogenesis. This study investigated CNV in 4 AMD-relevant genes in Korean AMD patients and control subjects. METHODS: Four CNV candidate regions located in AMD-relevant genes (VEGFA, ARMS2/HTRA1, CFH and VLDLR), were selected based on the outcomes of our previous study which elucidated common CNVs in the Asian populations. Real-time PCR based TaqMan Copy Number Assays were performed on CNV candidates in 273 AMD patients and 257 control subjects. RESULTS: The predicted copy number (PCN, 0, 1, 2 or 3+) of each region was called using the CopyCaller program. All candidate genes except ARMS2/HTRA1 showed CNV in at least one individual, in which losses of VEGFA and VLDLR represent novel findings in the Asian population. When the frequencies of PCN were compared, only the gain in VLDLR showed significant differences between AMD patients and control subjects (p = 0.025). Comparisons of the raw copy values (RCV) revealed that 3 of 4 candidate genes showed significant differences (2.03 vs. 1.92 for VEGFA, p<0.01; 2.01 vs. 1.97 for CFH, p<0.01; 1.97 vs. 2.01, p<0.01 for ARMS2/HTRA1). CONCLUSION: CNVs located in AMD-relevant genes may be associated with AMD susceptibility. Further investigations encompassing larger patient cohorts are needed to elucidate the role of CNV in AMD pathogenesis

Whole genomic approach in mutation discovery of infantile spasms patients

Infantile spasms (IS) are a clinically and genetically heterogeneous group of epilepsy disorders in early infancy. The genetic backgrounds of IS have been gradually unraveled along with the increased application of next-generation sequencing (NGS). However, to date, only selected genomic regions have been sequenced using a targeted approach in most cases of IS, and the genetic etiologies of the majority of patients remain unknown. We conducted a proof-of-concept study using whole-genome sequencing (WGS) for the genetic diagnosis of IS. We included 16 patients with IS for this study, and WGS was applied as a first-tier test for genetic diagnosis. In total, we sequenced the whole genomes of 28 participants, including the genomes of six patients, which were sequenced with those of their parents. Among variants identified, we focused on those located in epilepsy or seizure-associated genes. We used two different methods to call relevant large deletions from WGS results. We found pathogenic or likely pathogenic variants in four patients (25.0%); a de novo variant in HDAC4, compound heterozygous variants in GRM7, and heterozygous variants in CACNA1E and KMT2E. We also selected two more candidate variants in SOX5 and SHROOM4 intronic regions. Although there are currently several difficulties in applying WGS for genetic diagnosis, especially in clinical interpretation of non-coding variants, we believe that developing sequencing technologies would overcome these hurdles in the near future. Considering the vast genetic heterogeneity and the substantial portion of patients with unknown etiologies, further studies using whole genomic approaches are necessary for patients with IS

Distinct sites in E-cadherin regulate different steps in Drosophila tracheal tube fusion.

We have investigated how E-cadherin controls the elaboration of adherens junction associated cytoskeletal structures crucial for assembling tubular networks. During Drosophila development, tracheal branches are joined at branch tips through lumens that traverse doughnut-shaped fusion cells. Fusion cells form E-cadherin contacts associated with a track that contains F-actin, microtubules, and Shot, a plakin that binds F-actin and microtubules. Live imaging reveals that fusion occurs as the fusion cell apical surfaces meet after invaginating along the track. Initial track assembly requires E-cadherin binding to b- catenin. Surprisingly, E-cadherin also controls track maturation via a juxtamembrane site in the cytoplasmic domain. Fusion cells expressing an E-cadherin mutant in this site form incomplete tracks that contain F-actin and Shot, but lack microtubules. These results indicate that Ecadherin controls track initiation and maturation using distinct, evolutionarily conserved signals to F-actin and microtubules, and employs Shot to promote adherens junction-associated cytoskeletal assembly.The authors thank K. Miller, T. Uemura, M. Peifer and S. Myster, A. Pacquelet, P. Rorth, S. Rogers, R. Vale, G. Beitel, U. Tepass and E. Giniger for providing fly stocks and reagents. Hanwei Cao provided excellent technical assistance. D. Greenstein,V. Bennett and anonymous reviewers provided helpful comments on the manuscript. One reviewer prompted us to carry out the co-expression experiment. We also thank A. Reynolds for helpful discussions. This research was supported by NIH RO1 GM62101 to P.A.K

Drosophila Graf regulates mushroom body β-axon extension and olfactory long-term memory

Abstract Loss-of-function mutations in the human oligophrenin-1 (OPHN1) gene cause intellectual disability, a prevailing neurodevelopmental condition. However, the role OPHN1 plays during neuronal development is not well understood. We investigated the role of the Drosophila OPHN1 ortholog Graf in the development of the mushroom body (MB), a key brain structure for learning and memory in insects. We show that loss of Graf causes abnormal crossing of the MB β lobe over the brain midline during metamorphosis. This defect in Graf mutants is rescued by MB-specific expression of Graf and OPHN1. Furthermore, MB α/β neuron-specific RNA interference experiments and mosaic analyses indicate that Graf acts via a cell-autonomous mechanism. Consistent with the negative regulation of epidermal growth factor receptor (EGFR)-mitogen-activated protein kinase (MAPK) signaling by Graf, activation of this pathway is required for the β-lobe midline-crossing phenotype of Graf mutants. Finally, Graf mutants have impaired olfactory long-term memory. Our findings reveal a role for Graf in MB axon development and suggest potential neurodevelopmental functions of human OPHN1.This work was supported by grants from the National Research Foundation of Korea (2017M3C7A1025368 and 2019R1A2C2089437)

Reversible Plasticity of Fear Memory-Encoding Amygdala Synaptic Circuits Even after Fear Memory Consolidation

It is generally believed that after memory consolidation, memory-encoding synaptic circuits are persistently modified and become less plastic. This, however, may hinder the remaining capacity of information storage in a given neural circuit. Here we consider the hypothesis that memory-encoding synaptic circuits still retain reversible plasticity even after memory consolidation. To test this, we employed a protocol of auditory fear conditioning which recruited the vast majority of the thalamic input synaptic circuit to the lateral amygdala (T-LA synaptic circuit; a storage site for fear memory) with fear conditioning-induced synaptic plasticity. Subsequently the fear memory-encoding synaptic circuits were challenged with fear extinction and re-conditioning to determine whether these circuits exhibit reversible plasticity. We found that fear memory-encoding T-LA synaptic circuit exhibited dynamic efficacy changes in tight correlation with fear memory strength even after fear memory consolidation. Initial conditioning or re-conditioning brought T-LA synaptic circuit near the ceiling of their modification range (occluding LTP and enhancing depotentiation in brain slices prepared from conditioned or re-conditioned rats), while extinction reversed this change (reinstating LTP and occluding depotentiation in brain slices prepared from extinguished rats). Consistently, fear conditioning-induced synaptic potentiation at T-LA synapses was functionally reversed by extinction and reinstated by subsequent re-conditioning. These results suggest reversible plasticity of fear memory-encoding circuits even after fear memory consolidation. This reversible plasticity of memory-encoding synapses may be involved in updating the contents of original memory even after memory consolidation

Tanshinone IIA inhibits osteoclast differentiation through down-regulation of c-Fos and NFATc1.

Bone is a dynamic tissue that is regulated by the activity of bone-resorbing osteoclasts and boneforming osteoblasts. Excessive osteoclast forma - tion causes diseases such as osteoporosis and rheumatoid arthritis. Natural substances may be useful as therapeutic drugs to prevent many diseases in humans because they avoid the many side effects of treatment with chemical compounds. Here we show that tanshinone IIA isolated from Salvia miltiorrhiza Bunge inhibits the receptor activator of NF-κB ligand (RANKL)-mediated osteoclast differen - tiation of osteoclast precursors. Tanshinone IIA suppressed the expression levels of c-Fos and NFATc1 induced by RANKL. However, retrovirusmediated overexpression of c-Fos induced the expression of NFATc1 despite the presence of tans - hinone IIA and reversed the inhibitory effect of tanshinone IIA on osteoclast differentiation. Also, the introduction of osteoclast precursors with the NFATc1 retrovirus led to osteoclast differentiation in the presence of tanshinone IIA. Our results suggest that tanshinone IIA may have a role as a therapeutic drug in the treatment of bone disease such as osteoporosis

Comprehensive genomic analyses associate UGT8 variants with musical ability in a Mongolian population

Background: Musical abilities such as recognising music and singing performance serve as means for communication and are instruments in sexual selection. Specific regions of the brain have been found to be activated by musical stimuli, but these have rarely been extended to the discovery of genes and molecules associated with musical ability. Methods: A total of 1008 individuals from 73 families were enrolled and a pitch-production accuracy test was applied to determine musical ability. To identify genetic loci and variants that contribute to musical ability, we conducted family-based linkage and association analyses, and incorporated the results with data from exome sequencing and array comparative genomic hybridisation analyses. Results: We found significant evidence of linkage at 4q23 with the nearest marker D4S2986 (LOD=3.1), whose supporting interval overlaps a previous study in Finnish families, and identified an intergenic single nucleotide polymorphism (SNP) $(rs1251078, p=8.4×10^{−17})$ near UGT8, a gene highly expressed in the central nervous system and known to act in brain organisation. In addition, a non-synonymous SNP in UGT8 was revealed to be highly associated with musical ability $(rs4148254, p=8.0×10^{−17})$, and a 6.2 kb copy number loss near UGT8 showed a plausible association with musical ability $(p=2.9×10^{−6})$. Conclusions: This study provides new insight into the genetics of musical ability, exemplifying a methodology to assign functional significance to synonymous and non-coding alleles by integrating multiple experimental methods

Directly converted patient-specific induced neurons mirror the neuropathology of FUS with disrupted nuclear localization in amyotrophic lateral sclerosis

Background Mutations in the fused in sarcoma (FUS) gene have been linked to amyotrophic lateral sclerosis (ALS). ALS patients with FUS mutations exhibit neuronal cytoplasmic mislocalization of the mutant FUS protein. ALS patients fibroblasts or induced pluripotent stem cell (iPSC)-derived neurons have been developed as models for understanding ALS-associated FUS (ALS-FUS) pathology; however, pathological neuronal signatures are not sufficiently present in the fibroblasts of patients, whereas the generation of iPSC-derived neurons from ALS patients requires relatively intricate procedures. Results Here, we report the generation of disease-specific induced neurons (iNeurons) from the fibroblasts of patients who carry three different FUS mutations that were recently identified by direct sequencing and multi-gene panel analysis. The mutations are located at the C-terminal nuclear localization signal (NLS) region of the protein (p.G504Wfs*12, p.R495*, p.Q519E): two de novo mutations in sporadic ALS and one in familial ALS case. Aberrant cytoplasmic mislocalization with nuclear clearance was detected in all patient-derived iNeurons, and oxidative stress further induced the accumulation of cytoplasmic FUS in cytoplasmic granules, thereby recapitulating neuronal pathological features identified in mutant FUS (p.G504Wfs*12)-autopsied ALS patient. Importantly, such FUS pathological hallmarks of the patient with the p.Q519E mutation were only detected in patient-derived iNeurons, which contrasts to predominant FUS (p.Q519E) in the nucleus of both the transfected cells and patient-derived fibroblasts. Conclusions Thus, iNeurons may provide a more reliable model for investigating FUS mutations with disrupted NLS for understanding FUS-associated proteinopathies in ALS

A family-based association study after genome-wide linkage analysis identified two genetic loci for renal function in a Mongolian population

The estimated glomerular filtration rate is a well-known measure of renal function and is widely used to follow the course of disease. Although there have been several investigations establishing the genetic background contributing to renal function, Asian populations have rarely been used in these genome-wide studies. Here, we aimed to find candidate genetic determinants of renal function in 1007 individuals from 73 extended families of Mongolian origin. Linkage analysis found two suggestive regions near 9q21 (logarithm of odds (LOD) 2.82) and 15q15 (LOD 2.70). The subsequent family-based association study found 2 and 10 significant single-nucleotide polymorphisms (SNPs) in each region, respectively. The strongest SNPs on chromosome 9 and 15 were rs17400257 and rs1153831 with P-values of 7.21 x 10(-9) and 2.47 x 10(-11), respectively. Genes located near these SNPs are considered candidates for determining renal function and include FRMD3, GATM, and SPATA5L1. Thus, we identified possible loci that determine renal function in an isolated Asian population. Consistent with previous reports, our study found genes linked and associated with renal function in other populations.This work was supported by the Korean Ministry of Education, Science and Technology (Grant No. 2003-2001558).OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000040632/13SEQ:13PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000040632ADJUST_YN:YEMP_ID:A077602DEPT_CD:902CITE_RATE:7.916FILENAME:11.a family-based association study after genome-wide_2003_2001558.pdfDEPT_NM:보건학과EMAIL:[email protected]: