Pregnancy-associated progenitor cells: An under-recognized potential source of stem cells in maternal lung

Abstract

Novel therapies are needed for the treatment of acute and chronic lung diseases, many of which are incurable. The use of exogenous stem cells has shown promise in both animal models and clinical trials. However, to date, the stem cell literature has under-recognized naturally acquired pregnancy-associated progenitor cells (PAPCs). These cells are found at sites of injury or disease in female tissues. They persist for decades after parturition in maternal blood and organs, with the largest number being found in the maternal lungs. Their presence there may be one explanation for the sex differences observed in the prevalence and prognosis of some lung diseases. Although the clinical significance of these cells is as yet unknown, the literature suggests that some of the PAPCs are stem cells or have stem cell-like properties. PAPCs harvested from the blood or organs of parous women could potentially be used as an alternate source of cells with regenerative properties for the woman herself or her children. Because PAPCs preferentially traffic to the maternal lung they may play a significant role in recovery or protection from lung disease. In this review article, we discuss ongoing research investigating the administration of both adult and placenta-derived stem cells to treat lung disease, and how PAPCs may also play an important future therapeutic role.

Fetal cell microchimerism: a protective role in autoimmune thyroid diseases

“…Clinical Study V Cirello and others Microchimerism in autoimmune thyroid diseases to target diseased tissue (40,41,42). Consistently in the GD cases in the present study, male cells were documented to 'travel' into a blood vessel and were found interposed between female cells and forming follicles in the thyroid.…”

Fetal Cells in the Murine Maternal Lung Have Well-Defined Characteristics and Are Preferentially Located in Alveolar Septum

“…There has been great interest in whether these exogenously derived stem cells prevent or ameliorate various types of lung injuries. None of these studies, however, consider or indeed even acknowledge the potential presence of fetal cells in the adult lung [25]. The results presented here, in conjunction with those of previous studies that demonstrate the possible involvement of pregnancy-associated progenitor cells in maternal tissue repair [9,12,17], suggest that the naturally acquired population of fetal cells should be considered in any studies investigating the role of stem cells in the lung.…”

Comprehensive Analysis of Genes Expressed by Rare Microchimeric Fetal Cells in the Maternal Mouse Lung1

“…MSCs are stromal cells characterized by an absence of hematopoietic lineage markers, in vitro adherence to plastic, and their ability to differentiate into adipocytes, chondrocytes, and osteocytes [34]. We have previously suggested that fetal cells in the maternal organs may be MSCs [35]. Earlier work from our laboratory showed expression of surface markers on fetal cells that were characteristic of MSCs [8,15].…”

“…These isolated fetal cells were able to differentiate in vitro into adipocytes and osteocytes. Furthermore, microchimeric fetal cells are known to differentiate in vivo in response to injury in both mice and humans, contributing to repair of injury in multiple maternal organs, demonstrating pluripotency [16,35]. The possibility that the MSCs and placental cells are the same population cannot be excluded, as the placenta is known to contain MSCs [37].…”