Hippo signaling in the ovary and polycystic ovarian syndrome.

PURPOSE: To provide a commentary on our understanding of the role that the Hippo signaling pathway may play in patients with polycystic ovarian syndrome (PCOS) and how this understanding may impact the diagnosis of PCOS. METHODS: We assessed publications discussing the role of the Hippo signaling pathway in the ovary. In particular, we discuss how Hippo signaling disruption after ovarian fragmentation, combined with treating ovarian fragments with phosphatase and tensin homolog (PTEN) inhibitors and phosphoinositide-3-kinase stimulators to augment AKT signaling, has been used in treatment of patients with primary ovarian insufficiency. Furthermore, we discuss our own data on variations in Hippo signaling pathway gene expression in cumulus cells isolated from women undergoing IVF with a previous diagnosis of PCOS. RESULTS AND CONCLUSIONS: Aberrant Hippo signaling in PCOS patients is likely a contributing mechanism to the multifactorial etiology of the disease. Given the challenge of discerning the underlying etiology of oligo-ovulation in some patients, especially those with normal body mass indices, and the need for customized stimulation protocols for PCOS patients who have an increased risk of over-response and higher percentage of immature oocyte yield, it is important to identify these patients prior to treatment. Hippo gene expression fingerprints could potentially be used to more accurately define patients with PCOS. Additionally, targeting this pathway with pharmacologic agents could lead to non-surgical therapeutic options for PCOS.

Targeting the leukocyte activation cascade: getting to the site of inflammation using microfabricated assays.

This paper describes the use of microfabricated devices to study the leukocyte activation cascade (LAC). The devices consist of microchannels fabricated in polydimethylsiloxane using soft lithography. Microfluidics, used to generate physiologically relevant levels of shear flow, was achieved by the simple attachment of a syringe pump. Microchannel surfaces were modified by self-assembled monolayer (SAM) chemistries. The devices were adapted to standard 96-well tissue culture format with microchannels that could accommodate either a monolayer of endothelial cells or a SAM with immobilized chemokines. Chemotaxis was performed using linear gradients of chemokine set in a 3D matrix. Using this approach, we demonstrated robust chemotaxis of primary human leukocytes (PHLs) in response to a gradient of the chemokine CCL2. Rolling and adhesion assays performed under shear flow demonstrated that leukocyte recruitment to the substrate was highly sensitive to both biological and physical forces. CCL2 and CXCL12 treatment of PHLs dose dependently increased activation and adhesion. These actions could be inhibited by the use of peptide or small molecule antagonists. These devices provide a robust platform to perform LAC assays under in vivo-like conditions.