Trophoblasts Modulate the Ca²⁺ Oscillation and Contraction of Myometrial Smooth Muscle Cells by Small Extracellular Vesicle- (sEV-) Mediated Exporting of miR-25-3p during Premature Labor

Figure 5

The sEVs from LPS-stimulated trophoblasts induced Ca²⁺ oscillation and affect contraction of HMSMs. The HTR-8/SVneo cells were stimulated with LPS for different time points; then, the sEVs were derived, and the expression of miR-25-3p was measured by real-time PCR (a). The HTR-8/SVneo cells were stimulated with LPS, and sEVs were isolated and applied to the HMSMs; the expression of CACNA1H and ATP2A2 in the HMSMs was determined by real-time PCR (b). The expression of Cav3.2 and SERCA2a in HMSMs was measured by western blot (c). The sEVs were derived from the HTR-8/SVneo cells with or without the stimulation of LPS and then applied to the HMSMs. The Ca²⁺ transients of HMSMs were measured in the presence of cyclopiazonic acid (CPA) (d). The cells were preincubated with the indicated sEVs and perfused with Ca²⁺ free PSS and then resumed with Ca²⁺; next, the Ca²⁺ transients of HMSMs were measured (e). The cells were preincubated with the indicated sEVs and then stimulated with oxytocin for 200 s; after that, NNC 55-0396 (the L-type Ca²⁺ channel antagonist) was added, and the Ca²⁺ transients of HMSMs were measured (f). The HMSMs were preincubated with the indicated sEVs; then, the contraction was detected by the collagen matrix contraction assay (g).

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