Table 1.

Expression of BMP signaling components before and after SCI in rodent models

BMP signaling component	SCI model	Outcomes	Ref.
BMP ligands	Rats	BMP7 mRNA was mildly expressed in glial cells in intact spinal cord but markedly expressed in glial cells and motoneurons post-SCI	[27]
	Rats	BMP2/4 mRNA was mildly expressed in intact spinal cord but markedly expressed in oligodendrocytes, astrocytes, and microglia surrounding the damaged site post-SCI	[23]
	Mice	BMP2, 4, and 7 levels were increased in neurons, microglia, oligodendrocytes, and NSCs post-SCI, which enhanced astrocyte proliferation. BMP4 promoted differentiation of astrocytes and inhibited differentiation of neurons and oligodendrocytes	[37]
	Rats	BMP2 and 4 levels were increased post-SCI and promoted differentiation of the engrafted OPCs cells into astrocytes	[40]
	Mice	BMP7 expression was increased after SCI and further augmented after agmatine treatment, leading to reduced collagen scar formation and improved BBB score post-SCI	[30]
	Rats	BMP4 expression was increased in astrocytes cultured from injured thoracic spinal cord	[36]
	Rats	BMP2/4 expression was increased after SCI and associated with low BBB scores	[29]
	Rats	BMP7 was expressed in glial cells of the intact spinal cord and increased in glial cells and motoneurons after SCI	[27]
	Mice	BMP2 was slightly expressed in intact spinal cord and markedly increased post-SCI	[38]
	Mice	BMP4 level was increased in neurons of gray and white matter and ependyma cells near the damaged site post-SCI	[28]
	Rats	BMP4 was overexpressed after acute SCI	[57]
	Rats	BMP2, 3, 4, 5, 7, 9,12, and 13 were expressed in intact spinal cord	[16]
BMP receptors	Rats	BMPR1A and BMPR2 expression levels were increased in neurons post-SCI	[23]
BMP antagonists	Rats	Noggin was minimally expressed in intact spinal cord	[16]
Canonical pathway	Mice	p-Smad1, 5, and 8 were activated in neurons, oligodendrocytes, OPCs, astrocytes, and NSCs post-SCI	[37]

BMP: bone morphogenic protein; SCI: spinal cord injury; OPCs: oligodendrocyte precursor cells; NSCs: neural stem cells; BBB: Basso, Beattie, and Bresnahan; BMPR: BMP receptor