Overexpression of GRK6 alleviates chronic visceral hypersensitivity through downregulation of P2Y6 receptors in anterior cingulate cortex of rats with prenatal maternal stress

• Published in: CNS neuroscience & therapeutics Vol. 28; no. 6; pp. 851 - 861
• Main Authors: Tian, Yuan‐Qing, Li, Jia‐Hui, Li, Yong‐Chang, Xu, Yu‐Cheng, Zhang, Ping‐An, Wang, Qian, Li, Rui, Xu, Guang‐Yin
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.06.2022; John Wiley and Sons Inc
• Subjects: Abdomen; Age; Animals; anterior cingulate cortex; Cortex (cingulate); Disease Models, Animal; Distension; Down-Regulation; Drug withdrawal; Experiments; Female; G-Protein-Coupled Receptor Kinases; GRK6; Gyrus Cinguli; Humans; Hypersensitivity; Immunohistochemistry; Immunoprecipitation; Inflammation; Information processing; Irritable Bowel Syndrome; Kinases; Laboratory animals; Membrane proteins; Microinjection; mRNA; Nervous system; Original; P2Y6; Pain; Phosphorylation; Pregnancy; Prenatal experience; prenatal maternal stress; Proteins; Rats; Rats, Sprague-Dawley; Receptors, Purinergic P2; RNA, Messenger; Rodents; Software; visceral pain; Visceral Pain - pathology; Western blotting; visceral pain; P2Y6; anterior cingulate cortex; GRK6; prenatal maternal stress
• ISSN: 1755-5930; 1755-5949; 1755-5949
• DOI: 10.1111/cns.13827

Aims Visceral hypersensitivity is a major clinic symptom in patients with irritable bowel syndrome (IBS). Anterior cingulate cortex (ACC) is involved in processing the information of pain. Both G protein‐coupled receptor kinase 6 (GRK6) and P2Y purinoceptor 6 (P2Y6) are associated with neuroinflammation and pathological pain. The aim of this study was to investigate the interaction between GRK6 and P2Y6 in ACC in the development of visceral hypersensitivity of adult offspring rats with prenatal maternal stress (PMS). Methods Visceral hypersensitivity was quantified by abdominal withdrawal reflex threshold to colorectal distension (CRD). The expression and cellular distribution of GRK6 and P2Y6 were determined by Western blotting, qPCR, and fluorescence immunohistochemistry. Co‐immunoprecipitation was used to evaluate the interaction between GRK6 and P2Y6. Results The mRNA and protein levels of GRK6 were significantly decreased in ACC of PMS rats. The injection of GRK6 overexpression virus significantly attenuated visceral hypersensitivity of PMS rats. P2Y6’s mRNA level, protein level, and ratio of membrane protein over total protein expression was markedly increased in PMS rats. P2Y6 antagonist MRS2578 microinjection reversed visceral hypersensitivity of PMS rats. GRK6 overexpression significantly reduced P2Y6’s expression in membrane proteins and P2Y6’s ratio of membrane protein over total protein expression. Conclusions These results indicate that decreased GRK6 leads to the accumulation of P2Y6 at neuron membrane in ACC, thereby contributing to visceral hypersensitivity of PMS rats. The present study has shown that PMS reduced GRK6 expression in the anterior cingulate cortex, and then decreased GRK6 led to an enhanced expression of P2Y6 in the neuronal cell membrane, thus eventually contributing to visceral pain of PMS offspring. Our findings suggest that the GRK6/P2Y6 signal pathway might be a promising strategy to treat visceral pain.