Directing Lung Endoderm Differentiation in Pluripotent Stem Cells

Abstract

The lung is required for postnatal respiration and is composed of a multitude of distinct epithelial lineages that arise from the anterior foregut endoderm. Recent advances in our understanding of the pathways required for lung endoderm specification and subsequent differentiation have allowed the field to begin to generate differentiated lung epithelial lineages from pluripotent stem cells in vitro. This review will highlight the latest advances in both developmental and stem cell biology and show that our increased understanding of signaling mechanisms that regulate development of the lung endoderm has helped to move lung regeneration research forward into new and exciting areas.

Generation of multiciliated cells in functional airway epithelia from human induced pluripotent stem cells

“…5) (60). The research preceding the Rossant study (2) focused primarily on the differentiation of mouse pluripotent cells and demonstrated the generation of lung progenitor cells (3,32). There are significant differences in mouse-lung morphology and disease development.…”

“…In particular, this differentiation requires the generation of a specialized postmitotic multiciliated cell. The differentiation of embryonic stem cells and iPSCs to airway epithelial cells has recently received increased attention (2,3). The current manuscript describes developing a differentiation protocol based upon lessons learned from embryogenesis to generate multiciliated cells (4)(5)(6)(7)(8)(9).…”

“…Lung progenitor specification and lung maturation can be subsequently controlled by combinations of FGF, TGFβ, and BMP4 regulated signaling (3). In addition, the microenvironment can be critical to successful differentiation of cells; bronchial epithelial cells have been shown to differentiate into a mature polarized epithelium in vitro using an air-liquid interface model (22,23).…”

Human iPS cell–derived alveolar epithelium repopulates lung extracellular matrix

“…Additionally, these iPSC-derived AETII cells are capable of repopulating an acellular lung matrix and give rise to cell types that reside in the distal lung (Table 1). (14,20,21). Therefore, in the first step, we differentiated iPSC from DE by exposing them to saturating concentrations of activin A Figure 1 followed by a decrease with time in culture (Supplemental Figure 6A for C1 cells, and Supplemental Figure 6B for C2).…”

Three-Dimensional Culture and FGF Signaling Drive Differentiation of Murine Pluripotent Cells to Distal Lung Epithelial Cells

“…Many of these studies achieved distal lung differentiation with very low efficiencies ( < 3%), which could be considered a result of spontaneous differentiation, while more successful protocols with iPSCs use undefined culture conditions [19], providing no further insight as to how the differentiation is occurring. The most effective ESC [11,12,17] and iPSC [21,22] studies with respect to efficiency using defined factors have attempted to recapitulate what occurs during development in vivo in a stepwise fashion, starting with endoderm specification via the nodal pathway [23][24][25] followed by anterior endoderm induction and subsequent lengthy stimulation with a mixture of growth factors implicated in lung development. Differentiation efficiencies and duration of differentiation in vitro could be improved, however, if the in situ microenvironment of epithelialmesenchyme interactions, including the 3D matrix milieu, is better recapitulated.…”