βcR.	β-common receptor
BSA	bovine serum albumin
CKD	chronic kidney disease
DMEM	Dulbecco’s modified Eagle medium
Epo	erythropoietin
FBS	fetal bovine serum
GPCR	G protein-coupled receptor
HIF	hypoxia-inducible factor
HRE	hypoxia response element
kd	knockdown
PBS	phosphate-buffered saline
PI3K	phosphoinositide 3-kinase
PK	protein kinase
REPC	renal Epo producing cells
S1P	sphingosine 1-phosphate
SDS-PAGE	sodium dodecyl sulfate-polyacrylamide gel electrophoresis
shRNA	small hairpin RNA
SphK	sphingosine kinase
UUO	unilateral ureteral obstruction