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Differential gene expression of adenosine A1, A2a, A2b, and A3 receptors in the human enteric nervous system
Author(s) -
Christofi Fievos L.,
Zhang Huiming,
Yu JunGe,
Guzman Jorge,
Xue Jianjing,
Kim Minsoo,
Wang Y.Z.,
Cooke Helen J.
Publication year - 2001
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.1334
Subject(s) - enteric nervous system , medicine , adenosine , endocrinology , adenosine receptor , adenosine a3 receptor , vasoactive intestinal peptide , myenteric plexus , receptor , jejunum , biology , immunohistochemistry , neuropeptide , agonist
Adenosine receptors (ADORs) in the enteric nervous system may be of importance in the control of motor and secretomotor functions. Gene expression and distribution of neural adenosine A1, A2a, A2b, or A3 receptors (Rs) in the human intestine was investigated using immunochemical, Western blotting, RT‐PCR, and short‐circuit current (I sc ) studies. Adenosine A1R, A2aR, A2bR, or A3R mRNAs were differentially expressed in neural and nonneural layers of the jejunum, ileum, colon, and cecum and in HT‐29, T‐84, T98G, and Bon cell lines. A1R, A2aR, A2bR, and A3R immunoreactivities (IRs) were differentially expressed in PGP 9.5‐immunoreactive neurons. A2bR IR occurs exclusively in 50% of submucosal vasoactive intestinal peptide (VIP) neurons (interneurons, secretomotor or motor neurons) in jejunum, but not colon; A2aR is also found in other neurons. A3R IR occurs in 57% of substance P‐positive jejunal submucosal neurons (putative intrinsic primary afferent neurons) and less than 10% of VIP neurons. Western blots revealed bands for A3R at 44 kDa, 52 kDa, and 66 kDa. A2aR and A2bR are coexpressed in enteric neurons and epithelial cells. 5′‐N‐methylcarboxamidoadenosine or carbachol evoked an increase in I sc . A2bR IR is more prominent than A2aR IR in myenteric neurons, nerve fibers, or glia. A1R is expressed in jejunal myenteric neurons and colonic submucosal neurons. Regional differences also exist in smooth muscle expression of ADOR IR(s). It is concluded that neural and nonneural A1, A2a, A2b, and A3Rs may participate in the regulation of neural reflexes in the human gut. Clear cell and regional differences exist in ADOR gene expression, distribution, localization, and coexpression. J. Comp. Neurol. 439:46–64, 2001. © 2001 Wiley‐Liss, Inc.