Kernekoncepter
The rete ovarii is a complex, multi-regional epithelial structure directly connected to the ovary that plays an important role in ovary development and homeostasis through secretion of proteins into the ovary.
Resumé
The rete ovarii (RO) is an epithelial structure directly connected to the ovary that has been historically overlooked. This study used advanced imaging techniques, genetic mouse models, and proteomic analysis to characterize the development and function of the RO.
The RO consists of three distinct regions - the extraovarian rete (EOR), the connecting rete (CR), and the intraovarian rete (IOR). The EOR is a convoluted tubular epithelium with ciliated cells that ends in a distal dilated tip. The CR and IOR have different cellular morphologies.
During development, the EOR undergoes rapid expansion and becomes the largest region of the RO by embryonic day 18.5. The RO is highly integrated with the surrounding environment, being tightly associated with vasculature, smooth muscle, neurons, and macrophages.
Experiments showed that the fluid contents of the EOR lumen flow towards the ovary, suggesting a secretory function. Mass spectrometry identified secreted proteins in the EOR lumen, including components of the SNARE complex involved in vesicle trafficking and secretion, as well as IGFBP2, which can regulate ovarian function by sequestering IGF1.
These findings indicate that the RO is not a vestigial structure, but rather plays an active role in ovary development and homeostasis through secretion of proteins into the ovary. The RO should be considered an integral component of the female reproductive tract that warrants further investigation.
Statistik
The fluid within the lumen of the extraovarian rete (EOR) travels towards the ovary.
Cells of the EOR express components of the SNARE complex involved in vesicle trafficking and secretion, including STX3 and RAB11.
The EOR secretes IGFBP2, which can regulate ovarian function by sequestering IGF1.
Citater
"The direct proximity of the RO to the ovary and its integration with the extraovarian landscape suggest that it plays an important role in ovary development and homeostasis."
"Our studies reveal that the RO is a continuous structure, surrounded by smooth muscle actin, a dense vascular network, and several macrophage populations. We also show that the RO is directly contacted by neurons."
"The enrichment of secretory machinery in RO cells as well as our experimental analysis of directional flow and luminal contents, together suggest that the RO sends material to the ovary."