TABLE 4.

Modulators of renal cilia length.

	Cilia length	Cell type	Mechanism or cellular effect	References
In vitro
↓ intracellular Ca2+	↑	IMCD, MEK, BME	Increased anterograde IFT speed	Besschetnova et al., 2010
↑ intracellular cAMP	↑	IMCD, MEK, BME	Activated PKA; increased anterograde IFT speed	Besschetnova et al., 2010
Fluid flow	↓	IMCD, MEK, BME	↓ cAMP; decreased cAMP and cilia length response abolished by Pkd1 and Pkd2 kd or mutation	Besschetnova et al., 2010
H2O2 (reactive oxygen species)	Deciliation	MDCK		Kim et al., 2013
Dopamine	↑	LLC-PK1	Increased cilia length increases intracellular Ca2+ response to fluid shear stress	Upadhyay et al., 2014
Cobalt chloride (hypoxia)	↑	MDCK	Increased HIF1-alpha	Verghese et al., 2011
aldosterone	↑	mCCD	Reduced degradation of IFT88	Komarynets et al., 2020
In vivo
Pkd1RC/RC; Pkd1 ko or Pkd2 ko; Pkd1RC/RC:Pkhd1 ko	↑	Collecting duct; cyst-lining renal epithelia		Hopp et al., 2012; Liu et al., 2018; Olson et al., 2019
Nek8jck/jck mutant	↑	Cyst lining renal epithelia		Smith et al., 2006
Ischemia	↓ 1 day after; ↑ 8 days after	Bowman’s capsule parietal epithelium, proximal tubule, collecting duct	Deciliation	Verghese et al., 2008; Kim et al., 2013
RBPj ko (Notch signaling downregulation)	↑	Cystic renal epithelia of developing kidney	Increased Akap12, a scaffolding protein that interacts with PKA, cyclins, and protein kinase C	Mukherjee et al., 2020
Hypoxia (chronic renal injury)	↑	Fetal ovine renal epithelia	Increased cilia length increased intracellular Ca2+ response to fluid shear stress	Shamloo et al., 2017
Mineralocorticoid receptor ko	↓	Distal nephron	Inability to respond to aldosterone	Komarynets et al., 2020

IMCD, mouse inner medullary collecting duct cells; MEK, mouse embryonic kidney cells; BME, bone mesenchymal cells; MDCK, Madin–Darby Canine Kidney cells; LLC-PK1, Lilly Laboratories Cell-Porcine Kidney 1 cells; mCCD, murine cortical collecting duct cells.