Characterization of exosomal release in bovine endometrial intercaruncular stromal cells

Abstract

BackgroundCell-to-cell communication between the blastocyst and endometrium is critical for implantation. In recent years, evidence has emerged from studies in humans and several other animal species that exosomes are secreted from the endometrium and trophoblast cells and may play an important role in cell-to-cell communication maternal-fetal interface during early pregnancy. Exosomes are stable extracellular lipid bilayer vesicles that encapsulate proteins, miRNAs, and mRNAs, with the ability to deliver their cargo to near and distant sites, altering cellular function(s). Furthermore, the exosomal cargo can be altered in response to environmental cues (e.g. hypoxia). The current study aims to develop an in vitro system to evaluate maternal-embryo interactions via exosomes (and exosomal cargo) produced by bovine endometrial stromal cells (ICAR) using hypoxia as a known stimulus associated with the release of exosomes and alterations to biological responses (e.g. cell proliferation).MethodsICAR cells cultured under 8 % O2 or 1 % O2 for 48 h and changes in cell function (i.e. migration, proliferation and apoptosis) were evaluated. Exosome release was determined following the isolation (via differential centrifugation) and characterization of exosomes from ICAR cell-conditioned media. Exosomal proteomic content was evaluated by mass spectrometry.ResultsUnder hypoxic conditions (i.e. 1 % O2), ICAR cell migration and proliferation was decreased (~20 and ~32 %, respectively) and apoptotic protein caspase-3 activation was increased (∼1.6 fold). Hypoxia increased exosome number by ~3.6 fold compared with culture at 8 % O2. Mass spectrometry analysis identified 128 proteins unique to exosomes of ICAR cultured at 1 % O2 compared with only 46 proteins unique to those of ICAR cultured at 8 % O2. Differential production of proteins associated with specific biological processes and molecular functions were identified, most notably ADAM10, pantetheinase and kininogen 2.ConclusionsIn summary, we have shown that a stimulus such as hypoxia can alter both the cellular function and exosome release of ICAR cells. Alterations to exosome release and exosomal content in response to stimuli may play a crucial role in maternal-fetal crosstalk and could also affect placental development.

Levels of ADAM10 are reduced in Alzheimer’s disease CSF

“…Interestingly, proADAM10 and ADAM10f were also detected in culture media from CHO cells. Abundant ADAM10 has been found in exosomes of bovine endometrial stromal cells cultured at hypoxic conditions [ 42 ]. Thus, an exosomal contribution of ADAM10-CSF cannot be discounted.…”

Potential roles of metalloproteinases of endometrium‐derived exosomes in embryo‐maternal crosstalk during implantation

“…Existence of several metalloproteinases in endometrium‐derived exosomes has been reported (Greening et al, ; Koh et al, ). Importantly, it has been shown that the hormonal regulation of endometrial receptivity during the menstrual cycle can also affect the metalloproteinase content of the exosomes (Greening et al, ).…”

“…Although the existence and possible roles of uterine metalloproteinase have been documented (Chevronnay et al, ; Goldman & Shalev, ), the biological functions of exosome‐derived metalloproteinases in implantation have been poorly characterized. To date, proteomics and transcriptomics analyses have detected MMP‐14 (Greening et al, ) and ADAM‐10 (Greening et al, ; Koh et al, ) in endometrium‐derived exosomes. In the following sections, we describe the importance of these metalloproteinases in embryo implantation and their possible effects as members of endometrium‐derived exosomes on embryo‐endometrial interaction during the implantation period.…”

“…If exosomes do play an important role in embryo‐endometrial crosstalk, exploring their molecular mechanisms could provide insight into embryo implantation. Interestingly, studies have revealed the existence of several metalloproteinases in endometrium‐derived exosomes (Greening, Nguyen, Elgass, Simpson, & Salamonsen, ; Koh et al, ) which are under control of hormonal regulation during menstrual cycle (Greening et al, ). Therefore, in this review, we focus on the potential involvement of metalloproteinases of endometrium‐derived exosomes in the embryo implantation process.…”

Physiological impact of extracellular vesicles on female reproductive system; highlights to possible restorative effects on female age‐related fertility

“…The presence of exosomes in reproductive system secretions also highlights their feasible roles in intercellular communications that are required in preconception and postconception; nevertheless, their alterations have recently been used as a marker for pregnancy and pathologies associated with pregnancy in humans .…”