Preterm Labor
In considering how best to mitigate neonatal morbidity and mortality, we embarked on an exploratory line of research on preterm labor, where our expertise in vascular biology, smooth muscle, and ion channel physiology could be leveraged to address abnormal uterine contractility. Over the past 9 years, we have increasingly focused on uterine contractility. Significant findings in this area include the identification of an ion channel, transient receptor potential vanilloid 4, that plays a central and critical role in controlling uterine tone during both quiescence and activation.
Our laboratory has created multiple experimental models, established collaborations, and acquired reagents (specifically genetically modified mice). Furthermore, in a collaborative effort with Jessica Ansari from the Anesthesia Department at Lucile Packard Children's Hospital Stanford over the past two years, we conducted studies using myometrial samples obtained from both term and preterm pregnant patients. This partnership afforded us the chance to delve into the transcriptomic profile, revealing promising results that will have an impact on the prevention of preterm pregnancies.
We are confident that these findings will not only expand our understanding of the underlying mechanisms of preterm labor but will also pave the way for the development of effective treatments addressing this concerning condition, which affects a significant number of women worldwide. We are ready to build upon our recent findings with a team of scientists and clinicians to generate new knowledge and consider the best way to translate these discoveries from the laboratory to clinical practice.
Projects
TRPV4 Channel-Mediated Calcium Signaling and human Myometrial Contractility
Researchers: Daiana Fornes, David N. Cornfield
During myometrial activation, an increase in cytosolic calcium concentration among myometrial smooth muscle cells drives sustained and coordinated myometrial contractions. However, the mechanism by which calcium enters the cell remains poorly understood, as the pharmacologic blockade of L-type calcium channels does not consistently halt preterm labor. Previously, our lab demonstrated that TRPV4 channel activation induces myometrial contraction, and pharmacologic blockade attenuates myometrial contraction in murine models. Nevertheless, the role of the TRPV4 channel in human myometrial contractility remains incompletely understood. To better characterize the biology of the TRPV4 channel in the pregnant human uterus, we have established a collaboration with Dr. Jessica Ansari to obtain human uterine tissue. Preliminary data from non-laboring human myometrium supports the notion that the TRPV4 channel modulates human myometrial contractility.
TRPV4 Channel Modulates Mouse Uterine Tone During Pregnancy
Researchers: Lihua Ying, David N. Cornfield
The significance of understanding the mechanisms governing uterine quiescence and contractility is underscored by the lack of effective strategies to prevent or treat preterm labor, a leading cause of perinatal mortality and morbidity worldwide. In our investigation, we explored the potential modulation of uterine contractility through calcium entry via transient receptor potential vanilloid 4 (TRPV4) channels. In smooth muscle cells (mSMC), both TRPV4 gene and protein expression increased with gestation. Additionally, TRPV4-mediated calcium entry and contractility were heightened in mSMC from pregnant rat compared to nonpregnant ones. Furthermore, direct pharmacologic activation of TRPV4 intensified uterine contraction, while pharmacologic inhibition blocked oxytocin-induced myometrial contraction and reduced in mice with global deletion of TRPV4. Notably, blocking TRPV4 channels extended pregnancy duration in two distinct in vivo murine models of preterm labor. These findings suggest that TRPV4 channel activity play a crucial role in modulating uterine contractility and could potentially serve as a therapeutic target addressing preterm labor.
[Sci Transl Med. 2015 Dec 23;7(319) :319ra204].
TRPV4 Inflammation
Researchers: Judith Ingles, Lihua Ying, Zahidee Rodriguez, David N. Cornfield
Preterm birth is a major health epidemic that kills around one million babies and effects approximately 15 million births each year. Inflammation is the only known pathology with substantial evidence of causality for both spontaneous term and preterm labor. The transient receptor potential vanilloid 4 (TRPV4) channel is a non-selective calcium permeable cation channel, that has recently been demonstrated to promote inflammatory signaling through the activation NFkB and upregulation of multiple pro-inflammatory cytokines in adipose tissue and lung epithelial cells. Thus, this project investigates the role of TRPV4 in the regulation of uterine inflammation and the subsequent molecular processes that lead to the onset of contraction, both in the context of term and preterm labor. Our laboratory hopes that a more concrete understanding of the physiological processes of labor will lead to the development of powerful anti-contractile or tocolytic therapies and thus the eradication of preterm birth.
Sponsors
Immunocytochemistry was performed to analyze nuclear translocation of the inflammatory transcription factor NFkB in human uterine smooth muscle cells in response to the inflammatory stimuli, lipopolysaccharide. This is image was capture using confocal microscopy, and shows co-localization of NFkB (Red) with chromatin (Blue) indicating positive nuclear translocation.
In-situ hybridization was performed using RNAscope technologies to simultaneously characterize the expression of three pro-inflammatory cytokines in uterine tissue collected from mice treated with the inflammatory stimuli, lipopolysaccharide. Individual RNA transcripts of pro-inflammatory cytokines IL-1b (Red), MCP-1 (Green), and IL-6 (White), in addition to chromatin (Blue) were visualized and captured via confocal microscopy at 20X magnification.
In-situ hybridization was performed using RNAscope technologies to characterize the expression of individual RNA transcripts of pro-inflammatory cytokines in uterine tissue collected from mice treated with the inflammatory stimuli, lipopolysaccharide. Confocal microscopy was then used to visualize and capture MCP-1 RNA transcripts (White), in addition to chromatin (Blue) at 25X magnification.
In-situ hybridization was performed using RNAscope technologies to characterize the expression of individual RNA transcripts of pro-inflammatory cytokines in uterine tissue collected from mice treated with the inflammatory stimuli, lipopolysaccharide. Confocal microscopy was then used to visualize and capture MCP-1 RNA transcripts (White), in addition to chromatin (Blue) at 40X magnification.
People
David N. Cornfield, M.D.
Lihua Ying, Ph.D.
Daiana Fornes, M.D.
Zahidee Rodriguez, M.D.
Judith Ingles, Ph.D.
Related Publications
- Ying L,, Becard M, Lyell D, Han X, Shortliffe L, Husted CI, Alvira CM, Cornfield DN. Sci Transl Med. 2015 7(319):319ra204. The transient receptor potential vanilloid 4 channel modulates uterine tone during pregnancy.
- Ying L ,Alvir CM, Cornfield DN. Am J Physiol Lung Cell Mol Physiol. 2018 315(1):L66-L77 Developmental differences in focal adhesion kinase expression modulate pulmonary endothelial barrier function in response to inflammation.
- Mahapatra S, Ying L, Ho PP, Kurnellas M. Rothbard J, Steinman L and Cornfield DN. PLoS One 2018 Jul 10;13(7):e0199206. An amyloidogenic hexapeptide derived from amylin attenuates inflammation and acute lung injury in murine sepsis.
- Chia Wang, Lihua Ying, Elizabeth A. Barnes, Eloa S. Adams, Francis Y. Kim, Karl W. Engel, Cristina M. Alvira and David N. Cornfield Am J Physiol Lung Cell Mol Physiol 315: L422–L431, 2018 Pulmonary artery smooth muscle cell HIF-1regulates endothelin expressionvia microRNA-543.
- Kim YM, Barnes EA, Alvira CM, Ying L, Reddy S, Cornfield DN. Circ Res. 2013 Apr 26;112(9):1230-3. Hypoxia-inducible factor-1α in pulmonary artery smooth muscle cells lowers vascular tone by decreasing myosin light chain phosphorylation.
- Alvira CM, Umesh A, Husted C, Ying L, Hou Y, Lyu SC, Nowak J, Cornfield DN. Am J Respir Cell Mol Biol. 2012 Nov;47(5):669-78. Voltage-dependent anion channel-2 interaction with nitric oxide synthase enhances pulmonary artery endothelial cell nitric oxide production.