Nitric oxide regulates homeoprotein OTX1 and OTX2 expression in the rat myenteric plexus after intestinal ischemia-reperfusion injury.
Neuronal and inducible nitric oxide synthase (nNOS and iNOS) play a protective and damaging role, respectively, on the intestinal neuromuscular function after ischemia-reperfusion (I/R) injury. To uncover the molecular pathways underlying this dichotomy we investigated their possible correlation with the orthodenticle homeobox proteins OTX1 and OTX2 in the rat small intestine myenteric plexus after in vivo I/R. Homeobox genes are fundamental for the regulation of the gut wall homeostasis both during development and in pathological conditions (inflammation, cancer). I/R injury was induced by temporary clamping the superior mesenteric artery under anesthesia, followed by 24 and 48 h of reperfusion. At 48 h after I/R intestinal transit decreased and was further reduced byNω-propyl-l-arginine hydrochloride (NPLA), a nNOS-selective inhibitor. By contrast this parameter was restored to control values by 1400W, an iNOS-selective inhibitor. In longitudinal muscle myenteric plexus (LMMP) preparations, iNOS, OTX1, and OTX2 mRNA and protein levels increased at 24 and 48 h after I/R. At both time periods, the number of iNOS- and OTX-immunopositive myenteric neurons increased. nNOS mRNA, protein levels, and neurons were unchanged. In LMMPs, OTX1 and OTX2 mRNA and protein upregulation was reduced by 1400W and NPLA, respectively. In myenteric ganglia, OTX1 and OTX2 staining was superimposed with that of iNOS and nNOS, respectively. Thus in myenteric ganglia iNOS- and nNOS-derived NO may promote OTX1 and OTX2 upregulation, respectively. We hypothesize that the neurodamaging and neuroprotective roles of iNOS and nNOS during I/R injury in the gut may involve corresponding activation of molecular pathways downstream of OTX1 and OTX2.NEW & NOTEWORTHYIntestinal ischemia-reperfusion (I/R) injury induces relevant alterations in myenteric neurons leading to dismotility. Nitrergic neurons seem to be selectively involved. In the present study the inference that both neuronal and inducible nitric oxide synthase (nNOS and iNOS) expressing myenteric neurons may undergo important changes sustaining derangements of motor function is reinforced. In addition, we provide data to suggest that NO produced by iNOS and nNOS regulates the expression of the vital transcription factors orthodenticle homeobox protein 1 and 2 during an I/R damage.
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Viviana
V
Filpa
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Elisa
E
Carpanese
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Silvia
S
Marchet
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Cristina
C
Pirrone
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Andrea
A
Conti
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Alessia
A
Rainero
Department of Internal Medicine and Therapeutics, Section of Pharmacology, University of Pavia, Pavia, Italy.
Elisabetta
E
Moro
Department of Pathology, Ospedale di Circolo, Varese, Italy; and.
Anna Maria
AM
Chiaravalli
ITB Consiglio Nazionale delle Ricerche, Segrate, Milan, Italy.
Ileana
I
Zucchi
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Andrea
http://orcid.org/0000-0002-9423-5446
A
Moriondo
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Daniela
D
Negrini
Department of Internal Medicine and Therapeutics, Section of Pharmacology, University of Pavia, Pavia, Italy.
Francesca
F
Crema
Department of Internal Medicine and Therapeutics, Section of Pharmacology, University of Pavia, Pavia, Italy.
Gianmario
G
Frigo
Department of Medicine and Surgery, University of Insubria, Varese, Italy; cristina.giaroni@uninsubria.it.
Cristina
C
Giaroni
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Giovanni
G
Porta
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D005772:Gastrointestinal Transit / Q000187:drug effects / Q000502:physiology; D007421:Intestine, Small / Q000098:blood supply*; D008297:Male; D009197:Myenteric Plexus / Q000378:metabolism* / Q000473:pathology; D009474:Neurons / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors; D051857:Otx Transcription Factors / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology
C109599:N(omega)-propylarginine; D051857:Otx Transcription Factors; D009569:Nitric Oxide; D001120:Arginine; D052248:Nitric Oxide Synthase Type I
OTX; ischemia-reperfusion; myenteric plexus; nitric oxide; rat small intestine