Related Experiment Video
Updated: Jun 30, 2026
In Vivo Immunofluorescence Localization for Assessment of Therapeutic and Diagnostic Antibody Biodistribution in Cancer Research
Published on: September 16, 2019
Immunohistochemistry using an antibody to unphosphorylated connexin 43 to identify human myometrial interstitial
Graham Hutchings1, Thomas Gevaert, Jan Deprest
1Department of Obstetrics and Gynaecology, University Hospital Gasthuisberg, Katholieke Universiteit Leuven, Leuven, Belgium. graham.hutchings@uclouvain.be
Insights
Researchers identified myometrial interstitial cells (MICs) in the uterus, distinct from fibroblasts. These cells express connexin 43, potentially forming hemichannels, and may play a role in uterine contractility.
Area of Science:
- Reproductive biology
- Smooth muscle physiology
- Cell biology
Background:
- Myometrial smooth muscle cell contraction relies on excitation-contraction coupling, but signal coordination is unclear.
- Interstitial cells of Cajal are crucial for gastrointestinal tract signaling; similar cells may exist in the myometrium.
Purpose of the Study:
- To investigate the presence and characteristics of interstitial cells in the human myometrium.
- To determine if these cells express connexin 43 and KIT, and their relationship with fibroblasts.
Main Methods:
- Utilized immunohistochemistry and immunofluorescence on myometrial biopsies from 26 women.
- Antibodies targeted connexin 43 (total and unphosphorylated), KIT, alpha-SMA, and prolyl 4-hydroxylase.
Main Results:
- Identified myometrial interstitial cells (MICs) expressing unphosphorylated connexin 43 and KIT, located on smooth muscle bundle boundaries.
- MICs showed uniform connexin 43 staining, unlike smooth myocytes' punctate gap junction pattern.
- MICs were distinct from prolyl 4-hydroxylase-identified fibroblasts.
Conclusions:
- Myometrial interstitial cells (MICs) are consistently found in the pregnant and non-pregnant uterus, separate from fibroblasts.
- Uniform connexin 43 distribution in MICs suggests potential connexin hemichannel function.
- Further study of MICs may elucidate their role in myometrial contractility.
Background:
Myometrial smooth myocytes contract as a result of electrical signalling via a process called excitation-contraction coupling. This process is understood in great detail at the cellular level but the generation and coordination of electrical signals throughout the myometrium are incompletely understood. Recent evidence concerning the vital role of interstitial cells of Cajal in tissue-level signalling in gastrointestinal tract, and the presence of similar cells in urinary tract smooth muscle may be relevant for future research into myometrial contractility but there remains a lack of evidence regarding these cells in the myometrium.
Methods:
Single stain immunohistochemical and double stain immunofluorescence techniques visualised antibodies directed against total connexin 43, unphosphorylated connexin 43, KIT, alpha-SMA and prolyl 4-hydroxylase in myometrial biopsies from 26 women representing all stages of reproductive life.
Results:
Myometrial smooth myocytes from term uterine biopsies expressed connexin 43 in a punctate pattern typical of gap junctions. However, on the boundaries of the smooth muscle bundles, cells were present with a more uniform staining pattern. These cells continued to possess the same staining characteristics in non-pregnant biopsies whereas the smooth myocytes no longer expressed connexin 43. Immunohistochemistry using an antibody directed against connexin 43 unphosphorylated at serine 368 showed that it is this isoform that is expressed continually by these cells. Double-stain immunofluorescence for unphosphorylated connexin 43 and KIT, an established marker for interstitial cells, revealed a complete match indicating these cells are myometrial interstitial cells (MICs). MICs had elongated cell processes and were located mainly on the surface of the smooth muscle bundles and within the fibromuscular septum. No particular arrangement of cells as plexuses was observed. Antibody to prolyl 4-hydroxylase identified fibroblasts as separate from MICs.
Conclusion:
MICs are identified consistently on the boundaries of smooth muscle bundles in both the pregnant and non-pregnant uterus and are distinct from fibroblasts. The uniform distribution of connexin 43 on the cell membrane of MICs, rather than localisation in gap junction plaques, may represent the presence of connexin hemichannels. This antibody specificity may aid future study of this potentially important cell type.
More Related Videos
11:31Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands
Published on: May 30, 2017
06:51Dual-modality Molecular Cartography: Integrating Multiplex mRNA Detection with Protein Imaging Mass Cytometry
Published on: November 14, 2025
