Mutations in the gene encoding KIAA1199 protein,an inner-ear protein expressed in Deiters’ cells and the fibrocytes,as the cause of nonsyndromic hearing loss

We report three possibly disease-causing point mutations in one of the inner-ear-specific genes, KIAA1199. We identified an R187C mutation in one family, an R187H mutation in two unrelated families, and an H783Y mutation in one sporadic case of nonsyndromic hearing loss. In situ hybridization indicated that the murine homolog of KIAA1199 mRNA is expressed specifically in Deiters cells in the organ of Corti at postnatal day zero (Pn) P0 before the onset of hearing, but expression in those cells disappears by day P7. The signal of KIAA1199 was also observed in fibrocytes of the spiral ligament and the spiral limbus through to P21, when the murine cochlea matures. Thus, the gene product may be involved in uptake of potassium ions or trophic factors with a particular role in auditory development. Although the R187C and R187H mutations did not appear to affect subcellular localization of the gene product in vitro, the H783Y mutation did present an unusual cytoplasmic distribution pattern that could underlie the molecular mechanism of hearing impairment. Our data bring attention to a novel candidate for hearing loss and indicate that screening of mutations in inner-ear-specific genes is likely to be an efficient approach to finding genetic elements responsible for deafness.Nucleotide sequence data reported herein are available in the DDBJ/EMBL/GenBank databases; for details, see the electronic eatabase section of this article.     

Mice with a conditional deletion of Talpid3 (KIAA0586) – a model for Joubert syndrome

Joubert syndrome (JS) is a ciliopathy associated with mutations in numerous genes encoding cilia components. TALPID3 encoded by KIAA0856 in man (2700049A03Rik in mouse) is a centrosomal protein essential for the assembly of primary cilia. Mutations in KIAA0856 have been recently identified in JS patients. Herein, we describe a novel mouse JS model with a conditional deletion of the conserved exons 11–12 of Talpid3 in the central nervous system which recapitulates the complete cerebellar phenotype seen in JS. Talpid3 mutant mice exhibit key hallmarks of JS including progressive ataxia, severely hypoplastic cerebellar hemispheres and vermis, together with abnormal decussation of the superior cerebellar peduncles. The Purkinje cell layer is disorganised with abnormal dendritic arborisation. The external granule layer (EGL) is thinner, lacks primary cilia, and has a reduced level of proliferation. Furthermore, we describe novel cellular defects including ectopic clusters of mature granule neurons, and abnormal parallel fibre-derived synapses and disorientation of cells in the EGL. The defective glial scaffold results in abnormal granule cell migration which manifests as ectopic clusters of granule neurons. In addition, we show a reduction in Wnt7a expression suggesting that defects may arise not only from deficiencies in the Hedgehog (Hh) pathway but also due to the additional roles of Talpid3. The Talpid3 conditional knockout mouse is a novel JS model which fully recapitulates the JS cerebellar phenotype. These findings reveal a role for Talpid3 in granule precursor cell migration in the cerebellum (either direct or indirect) which together with defective Hh signalling underlies the JS phenotype. Our findings also illustrate the utility of creating conditional mouse models to assist in unravelling the molecular and cellular mechanisms underlying JS. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

Expression and function of microRNA-188-5p in activated rheumatoid arthritis synovial fibroblasts

Activated synovial fibroblasts in rheumatoid arthritis (RASF) play a critical role in the pathology of rheumatoid arthritis (RA). Recent studies suggested that deregulation of microRNAs (miRs) affects the development and progression of RA. Therefore, we aimed to identify de-regulated miRs in RASF and to identify target genes that may contribute to the aggressive phenotype of RASF. Quantitative real-time PCR revealed a marked downregulation of miR-188-5p in synovial tissue samples of RA patients as well as in RASF. Exposure to the cytokine interleukine-1β lead to a further downregulation of miR-188-5p expression levels compared to control cells. Re-expression of miR-188-5p in RASF by transient transfection significantly inhibited cell migration. However, miR-188-5p re-expression had no effects on glycosaminoglycan degradation or expression of repellent factors, which have been previously shown to affect the invasive behavior of RASF. In search for target genes of miR-188-5p in RASF we performed gene expression profiling in RASF and found a strong regulatory effect of miR-188-5p on the hyaluronan binding protein KIAA1199 as well as collagens COL1A1 and COL12A1, which was confirmed by qRT-PCR. In silico analysis revealed that KIAA1199 carries a 3’UTR binding site for miR-188-5p. COL1A1 and COL12A1 showed no binding site in the mRNA region, suggesting an indirect regulation of these two genes by miR-188-5p. In summary, our study showed that miR-188-5p is down-regulated in RA in vitro and in vivo, most likely triggered by an inflammatory environment. MiR-188-5p expression is correlated to the activation state of RASF and inhibits migration of these cells. Furthermore, miR-188-5p is directly and indirectly regulating the expression of genes, which may play a role in extracellular matrix formation and destruction in RA. Herewith, this study identified potential novel therapeutic targets to inhibit the development and progression of RA.     

Expression and function of microRNA-188-5p in activated rheumatoid arthritis synovial fibroblasts

Activated synovial fibroblasts in rheumatoid arthritis (RASF) play a critical role in the pathology of rheumatoid arthritis (RA). Recent studies suggested that deregulation of microRNAs (miRs) affects the development and progression of RA. Therefore, we aimed to identify de-regulated miRs in RASF and to identify target genes that may contribute to the aggressive phenotype of RASF. Quantitative real-time PCR revealed a marked downregulation of miR-188-5p in synovial tissue samples of RA patients as well as in RASF. Exposure to the cytokine interleukine-1β lead to a further downregulation of miR-188-5p expression levels compared to control cells. Re-expression of miR-188-5p in RASF by transient transfection significantly inhibited cell migration. However, miR-188-5p re-expression had no effects on glycosaminoglycan degradation or expression of repellent factors, which have been previously shown to affect the invasive behavior of RASF. In search for target genes of miR-188-5p in RASF we performed gene expression profiling in RASF and found a strong regulatory effect of miR-188-5p on the hyaluronan binding protein KIAA1199 as well as collagens COL1A1 and COL12A1, which was confirmed by qRT-PCR. In silico analysis revealed that KIAA1199 carries a 3’UTR binding site for miR-188-5p. COL1A1and COL12A1 showed no binding site in the mRNA region, suggesting an indirect regulation of these two genes by miR-188-5p. In summary, our study showed that miR-188-5p is down-regulated in RA in vitro and in vivo, most likely triggered by an inflammatory environment. MiR-188-5p expression is correlated to the activation state of RASF and inhibits migration of these cells. Furthermore, miR-188-5p is directly and indirectly regulating the expression of genes, which may play a role in extracellular matrix formation and destruction in RA. Herewith, this study identified potential novel therapeutic targets to inhibit the development and progression of RA.     

利用RNAi沉默KIAA0280后对缺氧诱导大鼠神经元凋亡的影响

目的利用RNA干扰(RNAi)技术,观察脑缺血相关新蛋白KIAA0280被特异性沉默后对正常神经元和缺氧诱导神经元凋亡的影响。方法取新生大鼠培养至5~7 d的神经元,经由密闭容器引起缺氧诱导神经元凋亡模型。采用RNAi技术封闭KIAA0280的表达,观察该基因被封闭后对正常神经元的生长以及缺氧诱导神经元凋亡的作用和影响。结果脂质体转染KIAA0280基因特异性siRNA12、24 h后对正常细胞生长具有一定的影响;在此基础上缺氧4、8 h,发现RNAi组的神经元对缺氧诱导的神经元凋亡比对照组对缺氧更加敏感,更易受损伤。结论KIAA0280对正常神经元具有一定的作用,并且对缺氧诱导凋亡神经元具有一定的保护作用。     

Expression and bioinformatic analysis of lymphoma-associated novel gene KIAA0372

The purpose of this study was to explore the differentially expressed genes in lymph-node cells (LNC) of lymphomas and reactive lymph node hyperplasia, and to perform an initial bioinformatic analysis on a novel gene, KIAA0372, which is highly expressed in the LNC of lymphomas. mRNA extracted from LNC of lymphomas and reactive lymph node hyperplasia were respectively marked with biotin and hybridized with Gene Expression Chips, resulting in differentially expressed genes. Initial bioinformatic analysis was then performed on a novel gene named KIAA0372, whose function has not yet been explored. Its structure and genomic location, its product’s physical and chemical properties, subcellular localization and functional domains, were also predicted. Further, a systematic evolution analysis was performed on similar proteins from among several species. Using Gene Expression Chips, many differentially expressed genes were uncovered. Efficient bioinformatic analysis has fundamentally determined that KIAA0372 is an extracellular protein which may be involved in TGF-β signaling. Microarray is an efficient and high throughput strategy for detection of differentially expressed genes. And KIAA0372 is thought to be a potential target for tumor research using bioinformatic analysis.     

人KIAA1173基因的克隆、转染及生物学特性的实验研究

目的建立表达KIAA1173基因的鼻咽癌6-10B细胞模型,并观察转染细胞的生物学活性.方法从新鲜肌肉组织中提取总RNA,采取逆转录PCR得到人KIAA1173基因cDNA.获得的人KIAA1173基因克隆到真核表达载体pcDNA3.1（＋）,进行酶切和序列鉴定.将重组质粒pcDNA3.1（＋）-KIAA1173和空载体利用阳离子脂质体介导转入鼻咽癌6-10B细胞,经G418筛选阳性克隆.用RT-PCR、原位杂交及免疫细胞化学等方法检测KIAA1173基因在6-10B细胞中的稳定表达情况,并通过MTT法、肿瘤细胞侵袭实验及裸鼠体内成瘤性实验方法,检测KIAA1173基因对鼻咽癌细胞的增殖、侵袭及成瘤能力的影响.以空白质粒转染组作为对照.结果在mRNA和蛋白水平证实,转染细胞内有KIAA1173基因的高表达,表明细胞可表达人KIAA1173基因.6-10B在转染了pcDNA3.1（＋）-KIAA1173后,较转染空载体pcDNA3.1（＋）,肿瘤细胞的增殖能力、侵袭能力及裸鼠体内成瘤能力明显降低（P＜0.05）.结论结果提示KIAA1173基因可能是一鼻咽癌肿瘤抑制基因.获得生物学活性稳定的KIAA1173基因高表达的鼻咽癌细胞模型,为进一步研究奠定了基础.