Angiotensin II drives proliferation and extracellular matrix deposition in human uterine fibroid cells in vitro

Abstract

Objective

To investigate the effect of angiotensin II (Ang II) on proliferation and extracellular matrix (ECM) deposition in human uterine leiomyoma cells and normal myometrial cells.

Design

Experimental in vitro study using immortalized human leiomyoma (HuLM) cells, immortalized human uterine smooth muscle (UTSM) cells, and patient-derived primary fibroid and myometrial cells.

Subjects

Women with uterine fibroids who underwent hysterectomy.

Exposure

Administration of physiological and supraphysiological levels of Ang II (to mimic essential hypertension) to cultured HuLM, UTSM, primary fibroid, and myometrial cells to assess effects on cellular proliferation and ECM deposition.

Main Outcome Measures

We evaluated HuLM, UTSM, primary fibroid, and UTSM cells for the presence of the Ang II type 1 receptor. Angiotensin II-induced proliferation and ECM deposition was assessed through MTS assay, Western blot analysis, immunofluorescence, and real-time polymerase chain reaction.

Results

Immortalized and primary leiomyoma and myometrial cells expressed Ang II type 1 receptor. Leiomyoma cells responded to Ang II with increased cellular proliferation measured by MTS assay, proliferating cell nuclear antigen protein levels, and Ki67 staining. The Ang II treatment of fibroid cells showed increased expression of Collagen 1A1, the predominant fibroid and myometrial collagen. Integrin β1, an upstream regulator of fibrosis, also showed an increase in protein and messenger ribonucleic acid expression in fibroid cells treated with Ang II. No difference in proliferation or ECM production was observed in myometrial cell controls.

Conclusion

Angiotensin II promoted growth and matrix accumulation in fibroid cells, highlighting a potential link between fibroids and cardiovascular disease.