RPGR isoform imbalance causes ciliary defects due to exon ORF15 mutations in X-linked retinitis pigmentosa (XLRP).
RPGR isoform imbalance causes ciliary defects due to exon ORF15 mutations in X-linked retinitis pigmentosa (XLRP).
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DOI：
10.1093/hmg/ddaa269
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发表时间：
2021-01-21
影响因子：
3.5
通讯作者：
Khanna H
中科院分区：
文献类型：
--
作者：
Moreno-Leon L;West EL;O'Hara-Wright M;Li L;Nair R;He J;Anand M;Sahu B;Chavali VRM;Smith AJ;Ali RR;Jacobson SG;Cideciyan AV;Khanna H
视网膜色素变性GTP酶调节因子(RPGR)基因突变会导致严重的视网膜纤毛病变，即X连锁视网膜色素变性。虽然RPGRex1-19和RPGRORF15是两种主要的选择性剪接异构体，但这两种异构体在疾病发病机制中的相对重要性尚不清楚。在这里，我们分析了8名患者的成纤维细胞样本，发现他们都比正常对照组形成了更长的纤毛，尽管程度不同。虽然所有突变的RPGRORF15信使RNAs(MRNAs)都是不稳定的，但它们的稳态水平与对照细胞相似或更高，这表明可能存在转录增加。突变型RPGRORF15基因表达水平较高的成纤维细胞中，有三种细胞的RPGRex1-19基因表达水平也显著高于对照组。四个RPGRex1-19水平未改变的样本携带RPGRORF15突变，导致该亚型相对不稳定。因此，在所有病例中，RPGRex1-19/RPGRORF15亚型比值升高，这与纤毛伸展缺陷高度相关。此外，过表达RPGRex1-19(模拟RPGRex1-19与RPGRORF15异构体比率的增加)或RPGRORF15(模拟比率的降低)分别导致纤毛显著延长或缩短。值得注意的是，纤毛长度缺陷似乎可归因于野生型RPGRORF15蛋白的丢失和RPGRex1-19亚型的较高水平，表明观察到的缺陷是由于异构体比率的改变。这些结果表明，保持RPGRex1-9与RPGRORF15的最佳比例对纤毛生长至关重要，设计专注于恢复RPGRex1-19/RPGRORF15比例的最佳方法的策略可能会带来更好的治疗结果。
Mutations in retinitis pigmentosa GTPase regulator (RPGR) cause severe retinal ciliopathy, X-linked retinitis pigmentosa. Although two major alternatively spliced isoforms, RPGRex1-19 and RPGRORF15, are expressed, the relative importance of these isoforms in disease pathogenesis is unclear. Here, we analyzed fibroblast samples from eight patients and found that all of them form longer cilia than normal controls, albeit to different degrees. Although all mutant RPGRORF15 messenger RNAs (mRNAs) are unstable, their steady-state levels were similar or higher than those in the control cells, suggesting there may be increased transcription. Three of the fibroblasts that had higher levels of mutant RPGRORF15 mRNA also exhibited significantly higher levels of RPGRex1-19 mRNA. Four samples with unaltered RPGRex1-19 levels carried mutations in RPGRORF15 that resulted in this isoform being relatively less stable. Thus, in all cases, the RPGRex1-19/RPGRORF15 isoform ratio was increased, and this was highly correlative to the cilia extension defect. Moreover, overexpression of RPGRex1-19 (mimicking the increase in RPGRex1-19 to RPGRORF15 isoform ratio) or RPGRORF15 (mimicking reduction of the ratio) resulted in significantly longer or shorter cilia, respectively. Notably, the cilia length defect appears to be attributable to both the loss of the wild-type RPGRORF15 protein and to the higher levels of the RPGRex1-19 isoform, indicating that the observed defect is due to the altered isoform ratios. These results suggest that maintaining the optimal RPGRex1-9 to RPGRORF15 ratio is critical for cilia growth and that designing strategies that focus on the best ways to restore the RPGRex1-19/RPGRORF15 ratio may lead to better therapeutic outcomes.
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影响因子：
9.8
作者：
Breuer, DK;Yashar, BM;Swaroop, A
通讯作者：
Swaroop, A
DOI：
10.1073/pnas.93.10.4526
发表时间：
1996-05-14
影响因子：
11.1
作者：
Berson, EL
通讯作者：
Berson, EL
DOI：
10.1073/pnas.1913179117
发表时间：
2020-02-04
影响因子：
11.1
作者：
Hanany, Mor;Rivolta, Carlo;Sharon, Dror
通讯作者：
Sharon, Dror
影响因子：
6
作者：
Khanna H
通讯作者：
Khanna H
影响因子：
4.4
作者：
Hong, DH;Pawlyk, BS;Li, TS
通讯作者：
Li, TS