New insights into human endometrial aminopeptidases in both implantation and menstruation

Publication date: Available online 23 November 2019Source: Biochimica et Biophysica Acta (BBA) - Proteins and ProteomicsAuthor(s): Shigehiko Mizutani, Kunio Matsumoto, Yukio Kato, Eita Mizutani, Hidesuke Mizutani, Akira Iwase, Kiyosumi ShibataAbstractThe endometrium cycle involves proliferation of endometrial epithelial cells in preparation for implantation of fertilized ovum. With ovulation, the endometrium secretes nutrients such as peptides and amino acids into the endometrial cavity. The histological evidence of ovulation in normal menstrual cycle includes subnuclear glycogen vacuoles surrounded by placental leucine aminopeptidase (P-LAP) in endometrial epithelial cells. P-LAP is an essentially involved in intracellular trafficking of glucose transporter (GLUT) 4 which is primarily important for glucose uptake in skeletal muscles and fat tissues. On the other hand, glucose influx from blood into endometrial epithelial cells is not mainly mediated by GLUTs, but by coincident appearing progesterone just after ovulation. Progesterone increases permeability of not only plasma membranes, but also lysosomal membranes, and this may be primarily involved in glucose influx. Progesterone also expands the exocytosis in the endometrium after ovulation, and endometrial secretion after ovulation is possibly apocrine and holocrine, which is augmented and exaggerated exocytosis of the lysosomal contents. The endometrial spiral arteries/arterioles are surrounded by endometrial stromal cel...

Source: Biochimica et Biophysica Acta (BBA) Proteins and Proteomics - November 23, 2019 Category: Biochemistry Source Type: research