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Myometrial interstitial cells and the coordination of myometrial contractility.

Hutchings G, Williams O, Cretoiu D, Ciontea SM - J. Cell. Mol. Med. (2009)

Bottom Line: The dominant cell population of the uterine wall consists of smooth muscle cells that contain the contractile apparatus responsible for the generation of contractile force.Recent interest has focused on a new population of cells located throughout the myometrium on the borders of smooth muscle bundles.Calcium imaging of live tissue slices suggests that contractile signalling starts on the borders of smooth muscle bundles where m-ICLC are located and recently the possible role of extracellular ATP signalling from m-ICLC has been studied.

View Article: PubMed Central - PubMed

Affiliation: Perinatal Research Group, 10 floor, St Luc University Hospital, Brussels, Belgium. Graham.Hutchings@uclouvain.be

ABSTRACT
A strict regulation of contractility in the uterus and fallopian tube is essential for various reproductive functions. The uterus contributes, through either increased contractility or periods of relative quiescence, to: (i) expulsion of menstrual debris, (ii) sperm transport, (iii) adequate embryo placement during implantation, (iv) enlarging its capacity during pregnancy and (v) parturition. The dominant cell population of the uterine wall consists of smooth muscle cells that contain the contractile apparatus responsible for the generation of contractile force. Recent interest has focused on a new population of cells located throughout the myometrium on the borders of smooth muscle bundles. These cells are similar to interstitial cells of Cajal (ICC) in the gut that are responsible for the generation of electrical slow waves that control peristalsis. A precise role for myometrial Cajal-like interstitial cells (m-ICLC) has not been identified. m-ICLC express the c-kit receptor, involved in creating and maintaining the ICC phenotype in the gastrointestinal tract. However, both acute and prolonged inhibition of this receptor with the c-kit antagonist imatinib mesylate does not appear to affect the spontaneous contractility of myometrium. Calcium imaging of live tissue slices suggests that contractile signalling starts on the borders of smooth muscle bundles where m-ICLC are located and recently the possible role of extracellular ATP signalling from m-ICLC has been studied. This manuscript reviews the evidence regarding tissue-level signalling in the myometrium with a particular emphasis on the anatomical and possible functional aspects of m-ICLC as new elements of the contractile mechanisms in the uterus.

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Extracellular single-unit recording performed on m-ICLC cultures (human pregnant myometrium), at the third passage. (A) Notice the spontaneous electrical activity in MIC. (B) Spontaneous field potential pattern. Reprinted from Ref. [8], with permission from FCMM.
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fig10: Extracellular single-unit recording performed on m-ICLC cultures (human pregnant myometrium), at the third passage. (A) Notice the spontaneous electrical activity in MIC. (B) Spontaneous field potential pattern. Reprinted from Ref. [8], with permission from FCMM.

Mentions: In the first study, isolated myometrial ICs were shown to possess a stable resting membrane potential of −58 ± 7 mV compared to −65 ± 13 mV seen with smooth muscle cells. Outward currents were not observed implying these cells were not capable of generating spontaneous action potentials [62]. The authors concluded that m-ICLC were not likely to be pacemaking cells in view of their inability to generate ‘slow waves’ of spontaneous electrical activity. In contrast, another study showed that isolated myometrial ICs exhibited spontaneous electrical activity with field potentials of 62.4 ± 7.22 mV of short duration (1.197 ± 0.04ms) [8] (Fig. 10). Therefore, it is unclear from these contrasting studies as to whether or not isolated m-ICLC are electrically active.


Myometrial interstitial cells and the coordination of myometrial contractility.

Hutchings G, Williams O, Cretoiu D, Ciontea SM - J. Cell. Mol. Med. (2009)

Extracellular single-unit recording performed on m-ICLC cultures (human pregnant myometrium), at the third passage. (A) Notice the spontaneous electrical activity in MIC. (B) Spontaneous field potential pattern. Reprinted from Ref. [8], with permission from FCMM.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4496132&req=5

fig10: Extracellular single-unit recording performed on m-ICLC cultures (human pregnant myometrium), at the third passage. (A) Notice the spontaneous electrical activity in MIC. (B) Spontaneous field potential pattern. Reprinted from Ref. [8], with permission from FCMM.
Mentions: In the first study, isolated myometrial ICs were shown to possess a stable resting membrane potential of −58 ± 7 mV compared to −65 ± 13 mV seen with smooth muscle cells. Outward currents were not observed implying these cells were not capable of generating spontaneous action potentials [62]. The authors concluded that m-ICLC were not likely to be pacemaking cells in view of their inability to generate ‘slow waves’ of spontaneous electrical activity. In contrast, another study showed that isolated myometrial ICs exhibited spontaneous electrical activity with field potentials of 62.4 ± 7.22 mV of short duration (1.197 ± 0.04ms) [8] (Fig. 10). Therefore, it is unclear from these contrasting studies as to whether or not isolated m-ICLC are electrically active.

Bottom Line: The dominant cell population of the uterine wall consists of smooth muscle cells that contain the contractile apparatus responsible for the generation of contractile force.Recent interest has focused on a new population of cells located throughout the myometrium on the borders of smooth muscle bundles.Calcium imaging of live tissue slices suggests that contractile signalling starts on the borders of smooth muscle bundles where m-ICLC are located and recently the possible role of extracellular ATP signalling from m-ICLC has been studied.

View Article: PubMed Central - PubMed

Affiliation: Perinatal Research Group, 10 floor, St Luc University Hospital, Brussels, Belgium. Graham.Hutchings@uclouvain.be

ABSTRACT
A strict regulation of contractility in the uterus and fallopian tube is essential for various reproductive functions. The uterus contributes, through either increased contractility or periods of relative quiescence, to: (i) expulsion of menstrual debris, (ii) sperm transport, (iii) adequate embryo placement during implantation, (iv) enlarging its capacity during pregnancy and (v) parturition. The dominant cell population of the uterine wall consists of smooth muscle cells that contain the contractile apparatus responsible for the generation of contractile force. Recent interest has focused on a new population of cells located throughout the myometrium on the borders of smooth muscle bundles. These cells are similar to interstitial cells of Cajal (ICC) in the gut that are responsible for the generation of electrical slow waves that control peristalsis. A precise role for myometrial Cajal-like interstitial cells (m-ICLC) has not been identified. m-ICLC express the c-kit receptor, involved in creating and maintaining the ICC phenotype in the gastrointestinal tract. However, both acute and prolonged inhibition of this receptor with the c-kit antagonist imatinib mesylate does not appear to affect the spontaneous contractility of myometrium. Calcium imaging of live tissue slices suggests that contractile signalling starts on the borders of smooth muscle bundles where m-ICLC are located and recently the possible role of extracellular ATP signalling from m-ICLC has been studied. This manuscript reviews the evidence regarding tissue-level signalling in the myometrium with a particular emphasis on the anatomical and possible functional aspects of m-ICLC as new elements of the contractile mechanisms in the uterus.

Show MeSH