Beta-Estradiol Regulates Voltage-Gated Calcium Channels and Estrogen Receptors in Telocytes from Human Myometrium

Abstract

Voltage-gated calcium channels and estrogen receptors are essential players in uterine physiology, and their association with different calcium signaling pathways contributes to healthy and pathological conditions of the uterine myometrium. Among the properties of the various cell subtypes present in human uterine myometrium, there is increasing evidence that calcium oscillations in telocytes (TCs) contribute to contractile activity and pregnancy. Our study aimed to evaluate the effects of beta-estradiol on voltage-gated calcium channels and estrogen receptors in TCs from human uterine myometrium and to understand their role in pregnancy. For this purpose, we employed patch-clamp recordings, ratiometric Fura-2-based calcium imaging analysis, and qRT-PCR techniques for the analysis of cultured human myometrial TCs derived from pregnant and non-pregnant uterine samples. In human myometrial TCs from both non-pregnant and pregnant uterus, we evidenced by qRT-PCR the presence of genes encoding for voltage-gated calcium channels (Cav3.1, Ca3.2, Cav3.3, Cav2.1), estrogen receptors (ESR1, ESR2, GPR30), and nuclear receptor coactivator 3 (NCOA3). Pregnancy significantly upregulated Cav3.1 and downregulated Cav3.2, Cav3.3, ESR1, ESR2, and NCOA3, compared to the non-pregnant condition. Beta-estradiol treatment (24 h, 10, 100, 1000 nM) downregulated Cav3.2, Cav3.3, Cav1.2, ESR1, ESR2, GRP30, and NCOA3 in TCs from human pregnant uterine myometrium. We also confirmed the functional expression of voltage-gated calcium channels by patch-clamp recordings and calcium imaging analysis of TCs from pregnant human myometrium by perfusing with BAY K8644, which induced calcium influx through these channels. Additionally, we demonstrated that beta-estradiol (1000 nM) antagonized the effect of BAY K8644 (2.5 or 5 µM) in the same preparations. In conclusion, we evidenced the presence of voltage-gated calcium channels and estrogen receptors in TCs from non-pregnant and pregnant human uterine myometrium and their gene expression regulation by beta-estradiol in pregnant conditions. Further exploration of the calcium signaling in TCs and its modulation by estrogen hormones will contribute to the understanding of labor and pregnancy mechanisms and to the development of effective strategies to reduce the risk of premature birth.

Reappraising the microscopic anatomy of human testis: identification of telocyte networks in the peritubular and intertubular stromal space

“…3A,B ). We then characterized more in depth the immunophenotype of these testicular stromal cells by CD34/platelet-derived growth factor receptor α (PDGFRα) double immunofluorescence staining, a cell surface antigenic combination currently considered among the most reliable for the identification of TCs by light microscopy 6 , 7 , 16 , 17 , 37 , 46 , 52 – 54 . Such double immunolabeling showed coexpression of PDGFRα in all CD34-positive interstitial cells distributed in the outer layer of the peritubular tissue and in the intertubular stroma (Fig.…”

Telocytes: New Connecting Devices in the Stromal Space of Organs

“…The mechano-sensing function should also be considered, due to the presence of catenins that make up the junctions [18,71]. Moreover, TCs express T-type calcium (CaV3.1 and CaV3.2) channels and smallconductance calcium-activated potassium channels (SK3) and calcium-dependent hyperpolarization-activated chloride inward channels, the levels of expression being dependent on the physiological state, pregnant or non-pregnant [70,77,78]. This point to a TCs' involvement in calcium signaling mechanisms with neighboring cells [79].…”

Estrogen receptors (review). Part 2.

“…Оценка экспрессии мРНК РЭβ дала достаточно разные результаты. По одним данным она практически не была выражена [32,34], по другим, обнаруживалась в малых количествах [3], еще одна группа исследователей выявляла существенный переход от экспрессии РЭα к экспрессии РЭβ в миометрии в период гестации, который, по их мнению, необходим для поддержания беременности [35]. Возможно, разноречивость данных можно объяснить тем, что в разные гестационные сроки экспрессия РЭβ выражается по-разному.…”

“…Данный вывод был сделан при изучении ингибирования кальциевой проводимости через каналы L-типа клеточной мембраны. Как оказалось, через РЭα происходит ингибирование L-и Т-кальциевых каналов в миометрии [3,32]. В целом можно отметить, что данные литературы о регуляции кальциевых каналов L-типа с помощью РЭ носят противоречивый характер.…”

“…В целом можно отметить, что данные литературы о регуляции кальциевых каналов L-типа с помощью РЭ носят противоречивый характер. Тем не менее, существует мнение, объясняющее разницу тканеспецифичностью действия эстрогенов через рецепторы [3,9]. Так, например, эстрогены модулируют тонус маточных и плацентарных артерий во время беременности по-разному [7].…”