The cellular and biochemical changes that define ripening of the prepartum cervix occur well before birth. Recent findings indicate that the ripening process is associated with inflammation;immigration and activation of leukocytes coincide with the discovery of an increased local innervation and plasticity of central connections to the murine cervix by the day before birth. Based upon these findings, the main objective of this proposal is to test the hypothesis that neural signals are essential to the mechanism for remodeling the cervix in preparation for birth. A systematic approach is taken in the Research Plan to focus on the contribution of pelvic, hypogastric, and vagus pathways, their sensory and autonomic projections, as well as the role of progesterone withdrawal on inflammation and remodeling in the cervix at the conclusion of pregnancy. Methods were developed to estimate nerve fiber density and to trace neural projections from the cervix to the brain in mice and rats. Although central connections to the nonpregnant cervix have been reported, determination of precisely which pathways are responsible for the increase in nitric oxide-producing fibers and neuropeptidergic fibers at the conclusion of pregnancy is the major objective of this proposal. Three approaches will be taken to understand the importance of innervation for remodeling the pregnant cervix:
In Specific Aim 1, effects of surgical denervation will be assessed histologically to determine the relative contribution of each pathway to enhance the density of nerve fibers into the pregnant cervix before birth. Denervation of specific sensory afferents, but not other neural projections, is proposed to disrupt cervical ripening. A second study will explore the possibility that specific neurotransmitters, as eliminated by chemical neurectomy, block remodeling of cervix.
In Specific Aim 2, retrograde neural tract tracers will be used to study the primary and multisynaptic neural connections between the cervix, spinal cord, and brain. In the last specific aim, regulation of neural projections and their activity in the cervix before term is proposed to depend upon functional withdrawal of progesterone. The reduced trophic action of progesterone is proposed to induce local neural proliferation, central plasticity, and initiation of the inflammatory cascade that ripens the cervix in preparation for birth. Relevant assessments of the time course for neurogenic inflammation in the cervix may foretell the progress of pregnancy and could prove useful to accurately predict when birth will occur at term or, with pathological remodeling, be indicative of preterm delivery. Thus, our findings are expected to provide new insights about the mechanism of ripening and novel neuroimmune therapeutic approaches to either promote dilation of the cervix or inhibit the incidence of preterm birth.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD054931-04
Application #
7758823
Study Section
Pregnancy and Neonatology Study Section (PN)
Program Officer
Signore, Caroline
Project Start
2007-02-10
Project End
2011-07-31
Budget Start
2010-02-01
Budget End
2011-07-31
Support Year
4
Fiscal Year
2010
Total Cost
$198,540
Indirect Cost
Name
Loma Linda University
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
009656273
City
Loma Linda
State
CA
Country
United States
Zip Code
92350
Kirby, Michael A; Heuerman, Anne C; Yellon, Steven M (2018) Utility of Optical Density of Picrosirius Red Birefringence for Analysis of Cross-Linked Collagen in Remodeling of the Peripartum Cervix for Parturition. Integr Gynecol Obstet J 1:
Yellon, Steven M (2017) Contributions to the dynamics of cervix remodeling prior to term and preterm birth. Biol Reprod 96:13-23
Kirby, Michael A; Heuerman, Anne C; Custer, Melisa et al. (2016) Progesterone Receptor-Mediated Actions Regulate Remodeling of the Cervix in Preparation for Preterm Parturition. Reprod Sci 23:1473-1483
Dubicke, Aurelija; Ekman-Ordeberg, Gunvor; Mazurek, Patricia et al. (2016) Density of Stromal Cells and Macrophages Associated With Collagen Remodeling in the Human Cervix in Preterm and Term Birth. Reprod Sci 23:595-603
Dobyns, Abigail E; Goyal, Ravi; Carpenter, Lauren Grisham et al. (2015) Macrophage gene expression associated with remodeling of the prepartum rat cervix: microarray and pathway analyses. PLoS One 10:e0119782
Yellon, Steven M; Dobyns, Abigail E; Beck, Hailey L et al. (2013) Loss of progesterone receptor-mediated actions induce preterm cellular and structural remodeling of the cervix and premature birth. PLoS One 8:e81340
Nold, Christopher; Maubert, Monique; Anton, Lauren et al. (2013) Prevention of preterm birth by progestational agents: what are the molecular mechanisms? Am J Obstet Gynecol 208:223.e1-7
Payne, Kimberly J; Clyde, Lindsey A; Weldon, Abby J et al. (2012) Residency and activation of myeloid cells during remodeling of the prepartum murine cervix. Biol Reprod 87:106
Yellon, Steven M; Oshiro, Bryan T; Chhaya, Tejas Y et al. (2011) Remodeling of the cervix and parturition in mice lacking the progesterone receptor B isoform. Biol Reprod 85:498-502
Clyde, Lindsey A; Lechuga, Thomas J; Ebner, Charlotte A et al. (2011) Transection of the pelvic or vagus nerve forestalls ripening of the cervix and delays birth in rats. Biol Reprod 84:587-94

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