Table 1.

Role of main stem/progenitor cells in the regeneration/repair after acute lung injury

Origin	Locus	Cell type	Way of acquisition	Main contribution	References
Intrapulmonary stem/progenitor cells	Trachea, bronchi	Basal cell	Activation	Differentiation toward goblet cells, ciliated cells, mucous cells and serous cells	[61]
	Trachea	Duct cell	Activation	Differentiation toward goblet cells, ciliated cells, mucous cells, serous cells and myoepithelial cells	[62, 63]
	Bronchiole	Clara cell	Activation	Differentiation toward ciliated, AT1 and AT2 cells	[58, 64, 65, 80]
	Bronchiole, bronchioalveolar duct junction	Variant Clara cell	Activation	Differentiation toward cilia cells, Clara cell and PNECs	[58, 64, 65]
	Bronchioalveolar duct junction	Bronchioalveolar stem cell	Activation	Differentiation toward bronchiolar Clara cells and alveolar cells	[72, 98]
	Mesenchymal	Mesenchymal stem cell, stromal cell	Activation	Bronchioalveolar stem cells increase, preservation of epithelial permeability, anti- oxidative stress	[83–85]
	Bronchiole, bronchioalveolar duct junction	Human lung stem cell	Activation	Differentiation toward Alveolar and endothelia cells	[81]
	Alveolus	Alveolar type II cells	Activation	Differentiation toward Alveolar type I cells and BASC	[64, 65, 69]
	Alveolus	AEPC	Activation	Differentiation toward Alveolar type I and II cells	[82]
Extrapulmonary stem/progenitor cells	Bone marrow	Mesenchymal stem cell	Mobilization, isolation	Bacteria clearance, anti-inflammation, tissue repair	[9]
		Epithelial progenitor cell	Mobilization, isolation	Anti-inflammation, tissue repair	[10]
		Hematopoietic stem/progenitor cell	Mobilization, isolation	Anti-inflammation, tissue repair	[14, 15]
	Placenta	Amniotic fluid stem cells	Isolation	Anti-inflammation, tissue repair	[38, 39]
		Amnion epithelial cells	Isolation	Anti-inflammation, tissue repair	[40]
		Umbilical cord CD34+ progenitor cells	Isolation	Anti-inflammation, tissue repair	[42]
		Umbilical cord mesenchymal stem cells	Isolation	Anti-inflammation, tissue repair	[41]
		Fetal membrane-derived mesenchymal stem cells	Isolation	Anti-inflammation, tissue repair	[37]
	Adipose	Mesenchymal stem cell	Isolation	Anti-inflammation through eNOS and eNOS-derived NO, tissue repair	[34–36]
	Embryo	Embryonic stem cells	Isolation	Anti-inflammation, generation of functional airway epithelium	[45]
		Embryonic stem cell-derived progenitor cells	Isolation	Anti-inflammation, tissue repair	[44]
	Blood	Mesenchymal stem cell	Isolation	Anti-inflammation, tissue repair	[43]
		Epithelial progenitor cell	Isolation	Anti-inflammation, tissue repair	[12]
		Hematopoietic stem/progenitor cell	Isolation	Anti-inflammation, tissue repair	[14]
	Engineering stem/progenitor cell	iPSCs	Isolation and genetic manipulation	Anti-inflammation via NF-KB and Src pathway, differentiation toward alveolar epithelial cells	[49–52]
		Modified mesenchymal stem cell	Isolation and genetic manipulation	Anti-inflammation, tissue repair	[53, 54, 56]