GM2 gangliosidosis, Tay‐Sachs and Sandhoff diseases, are lysosomal storage disorders characterized by the lysosomal accumulation of GM2 gangliosides. This accumulation is due to deficiency in the activity of the β‐hexosaminidases Hex‐A or Hex‐B, which are dimeric hydrolases formed by αβ or ββ subunits, respectively. These disorders show similar clinical manifestations that range from mild systemic symptoms to neurological damage and premature death. There is still no effective therapy for GM2 gangliosidoses, but some therapeutic alternatives, as enzyme replacement therapy, have being evaluated. Previously, we reported the production of active human recombinant β‐hexosaminidases (rhHex‐A and rhHex‐B) in the methylotrophic yeast Pichia pastoris. In this study, we evaluated in vitro the cellular uptake, intracellular delivery to lysosome, and reduction of stored substrates. Both enzymes were taken‐up via endocytic pathway mediated by mannose and mannose‐6‐phosphate receptors and delivered to lysosomes. Noteworthy, rhHex‐A diminished the levels of stored lipids and lysosome mass in fibroblasts from Tay‐Sachs patients. Overall, these results confirm the potential of P. pastoris as host to produce recombinant β‐hexosaminidases intended to be used in the treatment of GM2 gangliosidosis.

中文翻译：

---

巴斯德毕赤酵母产生的人重组溶酶体β-氨基己糖苷酶可有效减少泰萨克斯成纤维细胞中的脂质积累


GM2 神经节苷脂贮积症、Tay-Sachs 病和 Sandhoff 病是溶酶体贮积症，其特征是 GM2 神经节苷脂在溶酶体中积聚。这种积累是由于 β-己糖胺酶 Hex-A 或 Hex-B 活性缺陷所致，它们分别是由 αβ 或 ββ 亚基形成的二聚体水解酶。这些疾病表现出相似的临床表现，从轻微的全身症状到神经损伤和过早死亡。目前还没有针对 GM2 神经节苷脂沉积症的有效疗法，但已经对一些替代疗法（如酶替代疗法）进行了评估。此前，我们报道了在甲基营养酵母毕赤酵母中生产活性人类重组β-己糖胺酶（rhHex-A和rhHex-B）。在这项研究中，我们在体外评估了细胞摄取、细胞内向溶酶体的递送以及储存底物的减少。两种酶均通过甘露糖和甘露糖-6-磷酸受体介导的内吞途径被吸收并递送至溶酶体。值得注意的是，rhHex-A 降低了泰萨克斯患者成纤维细胞中储存的脂质和溶酶体质量的水平。总的来说，这些结果证实了巴斯德毕赤酵母作为宿主生产重组 β-己糖胺酶用于治疗 GM2 神经节苷脂贮积症的潜力。