Tian Jiao, Zeng Cheng, Tian Zhen, Lin Yan, Wang Baoxi, Pan Yongkang, Shu Zhen, Jiang Xun
Department of Pediatrics, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China.
Department of Nature Medicine, School of Pharmacy, The Fourth Military Medical University, Xi'an, China.
Front Mol Neurosci. 2019 Apr 10;12:92. doi: 10.3389/fnmol.2019.00092. eCollection 2019.
Hirschsprung disease (HSCR) is a common developmental disorder of the enteric nervous system (ENS). However, the disease mechanisms have not been fully elucidated. To better understand the etiology of HSCR, the role and mechanism of HSCR associated PTPRR (protein tyrosine phosphatase receptor-type R) in the multipotency of ENS progenitors and ENS development were explored. In the present study, the downregulated PTPRR expression in HSCR was reflected by microarray and validated by real-time PCR analyses. Moreover, PTPRR protein was mainly expressed in the cytoplasmic area of primary cultured ENS progenitors (Enteric neural crest cells, ENCCs) and significantly decreased after differentiation induction, which implies the anti-differentiation role in ENCCs. Further study employed an adenovirus transfection system. After genetic modulation, the ENCCs maintained undifferentiated patterns even in GDNF (Glial cell-line derived neurotrophic factor)-mediated directional differentiation, as well as significantly increased EdU positive immunofluorescence in the PTPRR overexpressing group while the development of the ENS was stunted in the PTPRR knockdown fetal gut. Moreover, the expression of ERK1/2 activated by GDNF was significantly decreased as reflected by western-blot or immunofluorescence analyses after genetic modulation in the PTPRR overexpressing group, which suggests the potential mechanism in regulating the MAPK/ERK1/2 pathway. Taken together, These data support the idea that PTPRR may ensure a certain number of neural precursor cells by inhibiting ENCC overt differentiation and maintaining ENCC proliferation, which is considered to be the multipotency of ENCCs, and eventually participate in the development of the ENS, and establish PTPRR protein as negative regulator of MAPK/ERK1/2 signaling cascades in neuronal differentiation and demonstrate their involvement in the pathophysiology of HSCR.
先天性巨结肠症（HSCR）是一种常见的肠神经系统（ENS）发育障碍性疾病。然而，该疾病的发病机制尚未完全阐明。为了更好地理解HSCR的病因，我们探讨了HSCR相关的蛋白酪氨酸磷酸酶受体R型（PTPRR）在ENS祖细胞多能性和ENS发育中的作用及机制。在本研究中，通过微阵列检测反映出HSCR中PTPRR表达下调，并经实时PCR分析验证。此外，PTPRR蛋白主要表达于原代培养的ENS祖细胞（肠神经嵴细胞，ENCCs）的细胞质区域，在诱导分化后显著降低，这表明其在ENCCs中具有抗分化作用。进一步的研究采用了腺病毒转染系统。基因调控后，即使在胶质细胞源性神经营养因子（GDNF）介导的定向分化过程中，ENCCs仍保持未分化状态，并且在PTPRR过表达组中EdU阳性免疫荧光显著增加，而在PTPRR敲低的胎儿肠道中ENS发育受阻。此外，通过蛋白质免疫印迹或免疫荧光分析反映出，在PTPRR过表达组基因调控后，GDNF激活的ERK1/2表达显著降低，这提示了其调节丝裂原活化蛋白激酶/细胞外信号调节激酶1/2（MAPK/ERK1/2）信号通路的潜在机制。综上所述，这些数据支持以下观点：PTPRR可能通过抑制ENCCs的过度分化并维持ENCCs的增殖来确保一定数量的神经前体细胞，这被认为是ENCCs的多能性，最终参与ENS的发育，并确立PTPRR蛋白作为神经元分化中MAPK/ERK1/2信号级联的负调节因子，并证明它们参与了HSCR的病理生理学过程。
