Different sympathetic pathways control the metabolism of distinct bone envelopes.
Bone remodeling, the mechanism that modulates bone mass adaptation, is controlled by the sympathetic nervous system through the catecholaminergic pathway. However, resorption in the mandible periosteum envelope is associated with cholinergic Vasoactive Intestinal Peptide (VIP)-positive nerve fibers sensitive to sympathetic neurotoxics, suggesting that different sympathetic pathways may control distinct bone envelopes. In this study, we assessed the role of distinct sympathetic pathways on rat femur and mandible envelopes. To this goal, adult male Wistar rats were chemically sympathectomized or treated with agonists/antagonists of the catecholaminergic and cholinergic pathways; femora and mandibles were sampled. Histomorphometric analysis showed that sympathectomy decreased the number of preosteoclasts and RANKL-expressing osteoblasts in mandible periosteum but had no effect on femur trabecular bone. In contrast, pharmacological stimulation or repression of the catecholaminergic cell receptors impacted the femur trabecular bone and mandible endosteal retromolar zone. VIP treatment of sympathectomized rats rescued the disturbances of the mandible periosteum and alveolar wall whereas the cholinergic pathway had no effect on the catecholaminergic-dependent envelopes. We also found that VIP receptor-1 was weakly expressed in periosteal osteoblasts in the mandible and was increased by VIP treatment, whereas osteoblasts of the retromolar envelope that was innervated only by tyrosine hydroxylase-immunoreactive fibers, constitutively expressed beta-2 adrenergic receptors. These data highlight the complexity of the sympathetic control of bone metabolism. Both the embryological origin of the bone (endochondral for the femur, membranous for the mandibular periosteum and the socket wall) and environmental factors specific to the innervated envelope may influence the phenotype of the sympathetic innervation. We suggest that an origin-dependent imprint of bone cells through osteoblast-nerve interactions determines the type of autonomous system innervating a particular bone envelope.
EA2496 Laboratoire Pathologies et Biothérapies de l'Organe Dentaire, Faculté de Chirurgie Dentaire, Université Paris Descartes, Sorbonne Paris Cité, 1 rue Maurice Arnoux 92120 Montrouge, France. caroline.bataille@parisdescartes.fr
Caroline
C
Bataille
Cédric
C
Mauprivez
Eric
E
Haÿ
Brigitte
B
Baroukh
Adrian
A
Brun
Catherine
C
Chaussain
Pierre J
PJ
Marie
Jean-Louis
JL
Saffar
Marc
M
Cherruau
D000818:Animals; D002799:Cholinergic Fibers / Q000187:drug effects / Q000378:metabolism; D005269:Femur / Q000166:cytology / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006145:Guanethidine / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism; D008297:Male; D008334:Mandible / Q000166:cytology / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism*; D010012:Osteogenesis / Q000187:drug effects / Q000235:genetics; D053244:Osteoprotegerin / Q000235:genetics / Q000378:metabolism; D010521:Periosteum / Q000166:cytology / Q000187:drug effects / Q000294:innervation / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018343:Receptors, Adrenergic, beta-2 / Q000378:metabolism; D018005:Receptors, Vasoactive Intestinal Peptide / Q000378:metabolism; D013562:Sympathectomy; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000378:metabolism* / Q000601:surgery; D013997:Time Factors; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology
D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger; D018343:Receptors, Adrenergic, beta-2; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide; D016173:Macrophage Colony-Stimulating Factor; D011433:Propranolol; D014446:Tyrosine 3-Monooxygenase; D007545:Isoproterenol; D006145:Guanethidine