Table 1.

Signaling pathways and molecules implicated in formation of reactive astrocytes.

Categories	Molecules
Extracellular molecules and signaling pathways
Cytokines & growth factors	IL-1β, IL-1α, IL-6, IL-10, IL-17, TNF-α, IFN-γ, CNTF, EGF, Sonic hedgehog (SHH) [32, 70, 71]
Neurodegeneration-associated molecules	Amyloid-beta, α-synuclein [6]
Transmitters	Glutamate, noradrenalin [72]
Oxidative stress molecules	NO, ROS [73]
Immune-related molecules	LPS, Toll-like receptor ligands [74]
Hormones	Estrogens, glucocorticoids [75]
Intrinsic molecules in reactive astrocytes
Signal transducers	STAT3, NFκB, JAK2, MAPK, SOX9, mTOR, c-JUN, Olig2, SOC3, PKA, PKC [31, 57]
Receptors	EGFR, cannabinoid-2 receptor (CB2R), CD36 [76, 77]
MicroRNAs	miR-21, miR-140, miR-145, miR-17 [65, 78–80]

CNTF: ciliary neurotrophic factor; EGF: epidermal growth factor; ROS: reactive oxygen species; PKA: protein kinase A; PKC: protein kinase C.