Topical KGF treatment as a therapeutic strategy for vaginal atrophy in a model of ovariectomized mice

Abstract

One of the most frequent complaints for post-menopausal women is vaginal atrophy, because of reduction in circulating oestrogens. Treatments based on local oestrogen administration have been questioned as topic oestrogens can reach the bloodstream, thus leading to consider their safety as controversial, especially for patients with a history of breast or endometrial cancers. Recently, growth factors have been shown to interact with the oestrogen pathway, but the mechanisms still need to be fully clarified. In this study, we investigated the effect of keratinocyte growth factor (KGF), a known mitogen for epithelial cells, on human vaginal mucosa cells, and its potential crosstalk with oestrogen pathways. We also tested the in vivo efficacy of KGF local administration on vaginal atrophy in a murine model. We demonstrated that KGF is able to induce proliferation of vaginal mucosa, and we gained insight on its mechanism of action by highlighting its contribution to switch ERα signalling towards non-genomic pathway. Moreover, we demonstrated that KGF restores vaginal trophism in vivo similarly to intravaginal oestrogenic preparations, without systemic effects. Therefore, we suggest a possible alternative therapy for vaginal atrophy devoid of the risks related to oestrogen-based treatments, and a patent (no. RM2012A000404) has been applied for this study.

Neuropilin 1 Mediates Keratinocyte Growth Factor Signaling in Adipose-Derived Stem Cells: Potential Involvement in Adipogenesis

“…Immunofluorescence was performed as previously described [ 28 ]. Briefly, cells grown on coverslips onto 24-well plates were fixed in 4% paraformaldehyde for 30 min at room temperature, followed by treatment with 0.1 M glycine in PBS for 20 min and with 0.1% Triton X-100 in PBS for additional 5 min to allow permeabilization.…”

“…Bound antibody was detected by enhanced chemiluminescence detection reagents (Pierce Biotechnology Inc., Rockford, IL, USA), according to the manufacturer's instructions. For Western blot analysis, total proteins (50–150 μ g) were resolved under reducing conditions by 7–10% SDS-PAGE and transferred to Immobilon-FL membranes (Merck Millipore, Billerica, MA, USA), as previously described [ 28 ]. Membranes were blocked in TBS containing 0.1% Tween 20 (TBS-T) and 5% milk for 1 h at 25°C and then incubated overnight at 4°C with the following primary antibodies: anti-phospho-p44/42 MAPK (Thr202/Tyr204), anti-phospho-Akt (Ser473), anti-Akt, anti-phospho-p38 MAPK (Thr180/Tyr182), anti-p38 MAPK, anti-phospho-Rb (Ser807/811), anti-Rb (Cell Signaling Technology Inc., Danvers, MA, USA), anti-ERK2, anti-Bek (C-17), anti-Neuropilin 1 (A-12), anti-FGF7 (Santa Cruz Biotechnology, Santa Cruz, CA, USA), and anti- β -tubulin (Sigma-Aldrich).…”

Keratinocyte growth factor receptor: a therapeutic target in solid cancer

“…Estrogen could stimulate the synthesis of KGF in mammary stroma in vivo. Estradiol treatment could cause a dose-and timedependent decrease in KGFR mRNA level in mice [50]. KGF can restore vaginal trophism in vivo similarly to intravaginal estrogenic preparations, without systemic effects.…”

Post-menopausal vulvovaginal atrophy — an overview of the current treatment options

“…KGF administration in the developing vagina of mice results in the proliferation of the vaginal epithelium, suggesting a potential relationship between oestrogen treatment and activation of KGF pathway [47,48]. Ceccarelli et al [49] compared, an animal model in vivo and local vaginal KGF and E 2 therapy, showing a positive impact of KGF on vaginal epithelium proliferation, without systemic effects. In contrast to oestrogens, KGF does not affect the genomic pathway EREs, moreover it can prevent the activation of this pathway by retaining ER-alpha at the plasma membrane, thus avoiding its nuclear translocation.…”

“…These observations suggest the existence of an overlapping between oestrogen and KGF signalling. Topical administration of KGF causes the recovery of vaginal atrophy in ovariectomized mice, thus provides a rationale for its pre-clinical development in humans [49]. Further studies are required to assess the efficiency of KGF in the VVA therapy in postmenopausal women.…”