Reducing polypyrimidine tract‑binding protein 1 fails to promote neuronal transdifferentiation on HT22 and mouse astrocyte cells under physiological conditions

Exp Ther Med. 2023 Dec 19;27(2):72. doi: 10.3892/etm.2023.12360. eCollection 2024 Feb.

Abstract

In contrast to prior findings that have illustrated the conversion of non-neuronal cells into functional neurons through the specific targeting of polypyrimidine tract-binding protein 1 (PTBP1), accumulated evidence suggests the impracticality of inducing neuronal transdifferentiation through suppressing PTBP1 expression in pathological circumstances. Therefore, the present study explored the effect of knocking down PTBP1 under physiological conditions on the transdifferentiation of mouse hippocampal neuron HT22 cells and mouse astrocyte (MA) cells. A total of 20 µM negative control small interfering (si)RNA and siRNA targeting PTBP1 were transfected into HT22 and MA cells using Lipo8000 for 3 and 5 days, respectively. The expression of early neuronal marker βIII-Tubulin and mature neuronal markers NeuN and microtubule-associated protein 2 (MAP2) were detected using western blotting. In addition, βIII-tubulin, NeuN and MAP2 were labeled with immunofluorescence staining to evaluate neuronal cell differentiation in response to PTBP1 downregulation. Under physiological conditions, no significant changes in the expression of βIII-Tubulin, NeuN and MAP2 were found after 3 and 5 days of knockdown of PTBP1 protein in both HT22 and MA cells. In addition, the immunofluorescence staining results showed no apparent transdifferentiation in maker levels and morphology. The results suggested that the knockdown of PTBP1 failed to induce neuronal differentiation under physiological conditions.

Keywords: HT22 cells; astrocyte; cell differentiation; mouse astrocyte cells; neuron; polypyrimidine tract-binding protein 1.

Grants and funding

Funding: This research was funded by The National Natural Science Foundation of China (grant nos. 81471279 and 81171138), Jiangsu Province Shuangchuang Talent Plan (grant no. JSSCRC 2021533), The Research Start-up Fund of Jiangnan University (grant no. 1285081903200020) and The Research Start-up Fund of Wuxi School of Medicine, Jiangnan University (grant no. 1286010242190060).