Dynamics of IGF Signaling During the Ovulatory Peak in Women Undergoing Ovarian Stimulation.

Context: Insulin-like growth factor (IGF) signaling is known to affect human ovarian follicular function during growth and development. However, the role of the IGF system is unknown during the ovulatory peak, which is characterized by profound changes in granulosa cell (GCs) mitosis and function.

Objective: How is the IGF system expressed and regulated during the midcycle surge in women?

Methods: Follicular fluid (FF) and GCs were collected during the ovulatory peak from 2 specific time points.

Characterisation of the Stromal Microenvironment in Lobular Breast Cancer.

Invasive lobular carcinoma (ILC) is the second most common histological subtype of breast cancer, and it exhibits a number of clinico-pathological characteristics distinct from the more common invasive ductal carcinoma (IDC). We set out to identify alterations in the tumor microenvironment (TME) of ILC. We used laser-capture microdissection to separate tumor epithelium from stroma in 23 ER+ ILC primary tumors.

The metalloproteinase Papp-aa controls epithelial cell quiescence-proliferation transition.

Human patients carrying inactivating mutations have low bone mineral density. The underlying mechanisms for this reduced calcification are poorly understood. Using a zebrafish model, we report that Papp-aa regulates bone calcification by promoting Ca-transporting epithelial cell (ionocyte) quiescence-proliferation transition.

A common variant of the pregnancy-associated plasma protein-A (PAPPA) gene encodes a protein with reduced proteolytic activity towards IGF-binding proteins.

Pregnancy-associated plasma protein-A (PAPP-A) is a key regulator of insulin-like growth factor (IGF) bioactivity, by releasing the IGFs from their corresponding IGF-binding proteins (IGFBPs). The minor allele of the single nucleotide polymorphism (SNP), rs7020782 (serine < tyrosine), in PAPPA has previously been associated with recurrent pregnancy loss as well as with significant reduced levels of PAPP-A protein in human ovarian follicles. The aim of the present study was to reveal a possible functional effect of the rs7020782 SNP in PAPPA by comparing recombinant PAPP-A proteins from transfected human embryonic kidney 293 T cells.

Effect of pregnancy-associated plasma protein-A (PAPP-A) single-nucleotide polymorphisms on the level and activity of PAPP-A and the hormone profile in fluid from normal human small antral follicles.

Objective: To reveal a possible relationship between two single nucleotide polymorphisms (SNPs) in PAPP-A-1224 (rs7020782) and 327 (rs12375498)-and the level and activity of PAPP-A in follicular fluid (FF) of human small antral follicles, and to analyze the intrafollicular hormone levels.

Design: Laboratory investigation.

Setting: University hospital.