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Ptbp1 knockdown failed to induce astrocytes to neurons in vivo


The conversion of non-neuronal cells to neurons is a promising potential strategy for the treatment of neurodegenerative diseases. Recent studies have reported that shRNA-, CasRx-, or ASO-mediated Ptbp1 suppression could reprogram resident astrocytes to neurons. However, some groups have disputed the interpretation of the data underlying the reported neuron conversion events. These controversies surrounding neuron conversion may be due to differences in the astrocyte fate-mapping systems. Here, we suppressed Ptbp1 using Cas13X and labelled astrocytes with an HA tag fused to Cas13X (Cas13X-NLS-HA). We found no astrocyte-to-neuron conversion in the mouse striatum via the HA-tagged labelling system compared with the GFAP-driven tdTomato labelling system (AAV-GFAP::tdTomato-WPRE) used in previous studies. Our findings indicate that Cas13X-mediated Ptbp1 knockdown failed to induce neuron conversion in vivo.

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Fig. 1: Ptbp1-knockdown by Cas13X and sgRNA in vitro and in vivo.
Fig. 2: Astrocyte-to-Neuron conversion after Ptbp1 knockdown validated by tdTomato mediated astrocyte-labeling system.
Fig. 3: No astrocyte-to-Neuron conversion occurred after Ptbp1 knockdown validated by HA mediated astrocyte labeling system.


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We thank Weiya Bai and Guannan Geng for AAV vector preparation, Yanxia Gao and Leping Cheng for project discussion.


This work was supported by National Science and Technology Innovation 2030 Major Program (2021ZD0200900); Lingang Laboratory (LG202106-01-02); Strategic Priority Research Program of Chinese Academy of Sciences (XDB32060000); National Natural Science Foundation of China (31925016, 82021001); Basic Frontier Scientific Research Program of Chinese Academy of Sciences From 0 to 1 original innovation project (ZDBS-LY-SM001); Shanghai Municipal Science and Technology Major Project (2018SHZDZX05); Project of Shanghai Municipal Science and Technology Commission (20MC1920400).

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LS, HY, and KF designed the research, GY, ZY, XW, and MZ performed experiments and analyzed data. CX, HY, and KF wrote the manuscript with input from all authors.

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Correspondence to Hui Yang or Kailun Fang.

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Competing interests

HY and LS are co-founders of HuiGene Therapeutics Co., Ltd. GY, XW and MZ are employees of HuiGene Therapeutics Co. The remaining authors declare no conflict of interest.

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This study was approved by Animal Care and Use Committee of the Institute of Huigene Therapeutics Inc., Shanghai, China. All the procedure was performed with sterile, clinical-grade surgical instruments and by experienced technicians.

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Yang, G., Yan, Z., Wu, X. et al. Ptbp1 knockdown failed to induce astrocytes to neurons in vivo. Gene Ther 30, 801–806 (2023).

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