<p>Autosomal dominant optic atrophy (ADOA) caused by mutations in the nuclear-encoded OPA1 gene result in the preferential loss of retinal ganglion cells (RGCs) and progressive optic nerve degeneration. The severity of ADOA can be highly variable. This study compared the pathophysiological consequences of the c.1034 G &gt; A OPA1 missense mutation and the c.1305+2delGT OPA1 deletion. There was a significant correlation between the severity of visual loss and the extent of macular RGC loss as determined by optical coherence tomography imaging. In cells transfected with the c.1034 G &gt; A mutant, the percentage of fragmented mitochondria was greater than 60% with cytochrome c (cyt c) overflow, and significantly elevated levels of reactive oxygen species (ROS) and apoptosis. In contrast, the c.1305+2delGT mutant caused mitochondrial fragmentation in ~ 20% of HeLa cells, resulting in less cyt c overflow and apoptosis. The extent of mitochondrial network fragmentation and apoptosis increased with decreasing WT OPA1 mRNA expression levels. The c.1034 G &gt; A OPA1 missense mutation is likely to induce a dominant-negative effect compared with haploinsufficiency with the c.1305+2delGT OPA1 deletion. These contrasting pathophysiological mechanisms could influence disease severity in ADOA through their differential consequences on mitochondrial structure and function. The small drug molecule Paromomycin was able to rescue the mitochondrial fragmentation induced by the c.1034 G &gt; A mutation, providing proof-of-concept for further therapeutic validation in ADOA.</p><p></p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Contrasting pathophysiological mechanisms of OPA1 mutations in autosomal dominant optic atrophy

  • Shi-Qi Yao,
  • Jia-Jian Liang,
  • Hui Zhou,
  • Shaoying Tan,
  • Yingjie Cao,
  • Chong-Bo Chen,
  • Ciyan Xu,
  • Ruixi Wang,
  • Tai-Ping Li,
  • Fang-Fang Zhao,
  • Yun Wang,
  • Han-Jie He,
  • Dan Zhang,
  • Meng Wang,
  • Lifang Liu,
  • Patrick Yu-Wai-Man,
  • Shihui Wei,
  • Ling-Ping Cen

摘要

Autosomal dominant optic atrophy (ADOA) caused by mutations in the nuclear-encoded OPA1 gene result in the preferential loss of retinal ganglion cells (RGCs) and progressive optic nerve degeneration. The severity of ADOA can be highly variable. This study compared the pathophysiological consequences of the c.1034 G > A OPA1 missense mutation and the c.1305+2delGT OPA1 deletion. There was a significant correlation between the severity of visual loss and the extent of macular RGC loss as determined by optical coherence tomography imaging. In cells transfected with the c.1034 G > A mutant, the percentage of fragmented mitochondria was greater than 60% with cytochrome c (cyt c) overflow, and significantly elevated levels of reactive oxygen species (ROS) and apoptosis. In contrast, the c.1305+2delGT mutant caused mitochondrial fragmentation in ~ 20% of HeLa cells, resulting in less cyt c overflow and apoptosis. The extent of mitochondrial network fragmentation and apoptosis increased with decreasing WT OPA1 mRNA expression levels. The c.1034 G > A OPA1 missense mutation is likely to induce a dominant-negative effect compared with haploinsufficiency with the c.1305+2delGT OPA1 deletion. These contrasting pathophysiological mechanisms could influence disease severity in ADOA through their differential consequences on mitochondrial structure and function. The small drug molecule Paromomycin was able to rescue the mitochondrial fragmentation induced by the c.1034 G > A mutation, providing proof-of-concept for further therapeutic validation in ADOA.