Suitability and limitations of mesenchymal stem cells to elucidate human bone illness

Table 1 Mouse models developed for OI

OI type	Mutations at gene	Human phenotype	Ref.	Mouse model	Mouse phenotype	Effectiveness	Ref.
I	COL1A1/2	α1 chain collagen haplo-insufficiency; vertebral compression fractures; short height; low lumbar spine bone mineral density	[32,33]	Col1a1+/Mov13	Decreased type I collagen in mineralized tissue, weakened bone strength; abnormal shape of long bones; alterations of the mechanical properties of long bones	+	[44-46]
II	COL1A1/2	Perinatal lethal	[32,33]	BrtlII; Aga2/b	Perinatal lethal	+	[44,47]
III	COL1A1/2	High bone turnover; decreased mineralization; increased osteoclastic activity; small size; fractures; osteopenia; bone deformities	[32,33]	COL1A2 KO	Increased bone formation rate; fractures; reduced size; osteopenia; decreased mineralization; abnormal bone shape	+	[44,48-51]
IV	COL1A1/2	Increased bone fragility; growth deficiency; weak bone geometry; impaired bone remodeling; decreased bone volume	[32,33]	349G->C COL1A1	Decreases in severity with age; increased bone brittleness; reduced bone size; abnormal bone shape; impaired bone remodeling	+	[52-56]
V	IFITM5	Increased mineralization; increased osteoblast markers; decreased COL1A1 expression, secretion and deposition in the matrix; hyperplastic callus; calcification of the forearm interosseous membrane; radial-head dislocation; subphyseal metaphyseal radiodense band	[32,33]	14C->T IFITM5	Severe skeletal defects; perinatal lethality; decreased mineralization; reduced expression of osteoblast markers	-	[64-66]
VI Atypical	IFITM5	Decreased levels of PEDF; decreased mineralization	[32,33]	IFITM5 Knock-Down	Reduced skeletal size less extreme in adults; no abnormal osteoclastogenesis; no abnormal osteoblasto-genesis	-	[67]
VI	SERPINF1	Decreased mineralization; decreased trabecular bone	[32,33]	PEDF KO	Decreased ECM mineralization; reduced trabecular bone volume	+	[57]
VII	CRTAP	Growth delay; osteopenia; decreased bone formation; decreased mineralization; multiple fractures	[32,33]	CRTAP KO	Growth underdevelopment; osteopenia; decreased osteoblastogenesis; decreased mineralization; no spontaneous fractures	+	[58-61]
VIII	LEPRE1	Lethal; severe growth deficiency; bone fragility; poorly mineralized skull; scoliosis; decreased mineralization	[32,33]	LEPRE1 Knock-Down	No lethality; abnormal collagen fibril ultrastructure in bone, tendon and skin	-	[60,68,69]
IX	PPIB	Lethality; severe bone mass reduction; extreme bone strength reduction	[32,33]	PPIB KO	Bone mass reduction; bone strength reduction	No enough information	[35,36]
X	SERPINH1	Embryonic lethality; delayed type I collagen secretion; collagen accumulation in Golgi apparatus; osteopenia; dentinogenesis imperfecta; thin bones	[32,33]	HSP47 KO	Delayed type I collagen secretion; collagen accumulation in the endoplasmic reticulum	-	[70,71]
XI	FKBP10	Growth delay; neonatal lethality; bone fragility	[32,33]	FKBP10 KO	Bone brittleness; underdeveloped growth; lethality	+	[62,63]
XII	OSX	Skeletal deformities; fractures; osteoporosis	[32,33]	Osx KO	No bone formation; decreased mineralization	No enough information	[37,38]
XIII	BMP1	Skull defects; reduced bone mass; reduced bone strength	[32,33]	BMP1 KO	Reduced ossification of certain skull bones	No enough information	[39]
XIV	Tric-b	Reduced bone mass	[32,33]	Tric-b	No incorporation of collagen in the matrix; matrix insufficiency	No enough information	[40,41]
XV	WNT1	Reduced bone mass; reduced bone strength; fractures; increased ductility	[32,33]	sw/sw	Bone fragility; low bone mass	No enough information	[42]
XVI	CREB3L1	Reduced bone mass and fractures	[32,33]	CREB3L1 KO	Severe osteopenia; reduced type I collagen	No enough information	[43]

+/- stand for positive mimicry of the OI type symptoms in humans (+) or negative mimicry of OI type symptoms in humans (-). OI: Osteogenesis Imperfecta; KO: Knock-out; ECM: Extracellular matrix.