The specification of cell identity depends on the exposure of cells to sequences of bioactive ligands. All-trans retinoic acid (ATRA) affects neuronal development in the early stage, and it is involved in neuronal lineage reprogramming. We previously established a fibroblast-like dedifferentiated fat cells (DFATs) derived from highly homogeneous mature adipocytes, which are more suitable for the study of cellular reprogramming. Canine cognitive dysfunction is similar to human cognitive dysfunction, suggesting that dogs could be a pathological and pharmacological model for human neuronal diseases. However, the effect of ATRA on neuronal reprogramming in dogs has remained unclear. Therefore, in this study, we investigated the effect of ATRA on the neuronal reprogramming of canine DFATs. ATRA induced the expression of neuronal marker mRNA/protein. The neuron-like cells showed Ca²⁺ influx with depolarization (50 mM KCl; 84.75 ± 4.05%) and Na⁺ channel activation (50 μM veratridine; 96.02 ± 2.02%). Optical imaging of presynaptic terminal activity and detection of neurotransmitter release showed that the neuron-like cells exhibited the GABAergic neuronal property. Genome-wide RNA-sequencing analysis shows that the transcriptome profile of canine DFATs is effectively reprogrammed towards that of cortical interneuron lineage. Collectively, ATRA can produce functional GABAergic cortical interneuron-like cells from canine DFATs, exhibiting neuronal function with > 80% efficiency. We further demonstrated the contribution of JNK3 to ATRA-induced neuronal reprogramming in canine DFATs. In conclusion, the neuron-like cells from canine DFATs could be a powerful tool for translational research in cell transplantation therapy, in vitro disease modeling, and drug screening for neuronal diseases.

细胞身份的规范取决于细胞对生物活性配体序列的暴露程度。全反式维甲酸（ATRA）在早期会影响神经元的发育，并且参与神经元谱系的重新编程。我们先前建立了源自高度均质的成熟脂肪细胞的成纤维细胞样去分化脂肪细胞（DFAT），它更适合于细胞重编程的研究。犬的认知功能障碍与人类的认知功能障碍相似，表明狗可能是人类神经元疾病的病理和药理模型。但是，ATRA对犬神经元重编程的影响仍不清楚。因此，在这项研究中，我们调查了ATRA对犬DFATs神经元重编程的影响。ATRA诱导神经元标记mRNA /蛋白的表达。²⁺流入并带有去极化（50 mM KCl; 84.75±4.05％）和Na ⁺通道激活（50μM藜芦碱; 96.02±2.02％）。突触前终末活动的光学成像和神经递质释放的检测表明，神经元样细胞表现出GABA能神经元特性。全基因组的RNA测序分析表明，犬DFAT的转录组图谱可以有效地重编程为皮层中神经元谱系。总的来说，ATRA可以从犬DFAT中产生功能性GABA能的皮质中神经元样细胞，并以> 80％的效率发挥神经元功能。我们进一步证明了JNK3对犬DFAT中ATRA诱导的神经元重编程的贡献。总之，来自犬DFAT的神经元样细胞可能是体外细胞移植治疗中转化研究的有力工具 疾病建模和神经元疾病药物筛选。