Polymorphism of the gene encoding mucin 1 (MUC1) is associated with skeletal and dental phenotypes in human genomic studies. Animals lacking MUC1 exhibit mild reduction in bone density. These phenotypes could be a consequence of modulation of bodily Ca homeostasis by MUC1, as suggested by the previous observation that MUC1 enhances cell surface expression of the Ca2+-selective channel, TRPV5, in cultured unpolarized cells. Using biotinylation of cell surface proteins, we asked whether MUC1 influences endocytosis of TRPV5 and another Ca2+-selective TRP channel, TRPV6, in cultured polarized epithelial cells. Our results indicate that MUC1 reduces endocytosis of both channels, enhancing cell surface expression. Further, we found that mice lacking MUC1 lose apical localization of TRPV5 and TRPV6 in the renal tubular and duodenal epithelium. Females, but not males, lacking MUC1 exhibit reduced blood Ca2+. However, mice lacking MUC1 exhibited no differences in basal urinary Ca excretion or Ca retention in response to PTH receptor signaling, suggesting compensation by transport mechanisms independent of TRPV5 and TRPV6. Finally, humans with autosomal dominant tubulointerstitial kidney disease due to frame-shift mutation of MUC1 (ADTKD-MUC1) exhibit reduced plasma Ca concentrations compared to control individuals with mutations in the gene encoding uromodulin (ADTKD-UMOD), consistent with MUC1 haploinsufficiency causing reduced bodily Ca2+. In summary, our results provide further insight into the role of MUC1 in Ca2+-selective TRP channel endocytosis and the overall effects on Ca concentrations.

Department of Developmental Biology University of Pittsburgh Pittsburgh Pennsylvania USA

Department of Geology and Environmental Science University of Pittsburgh Pittsburgh Pennsylvania USA

Renal Electrolyte Division Department of Medicine University of Pittsburgh Pittsburgh Pennsylvania USA

Renal Electrolyte Division Department of Medicine University of Pittsburgh Pittsburgh Pennsylvania USA; Department of Cell Biology University of Pittsburgh Pittsburgh Pennsylvania USA

Renal Electrolyte Division Department of Medicine University of Pittsburgh Pittsburgh Pennsylvania USA; Department of Cell Biology University of Pittsburgh Pittsburgh Pennsylvania USA; Department of Pharmacology and Chemical Biology University of Pittsburgh Pittsburgh Pennsylvania USA

Section on Nephrology Department of Medicine Wake Forest University Winston Salem North Carolina USA; Department of Paediatrics and Inherited Metabolic Disorders 1st Faculty of Medicine Charles University Prague Czech Republic

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Nie M., Bal M.S., Yang Z., Liu J., Rivera C., Wenzel A., et al. Mucin-1 increases renal TRPV5 activity in vitro, and urinary level associates with calcium nephrolithiasis in patients. J. Am. Soc. Nephrol. 2016;27:3447–3458. PubMed PMC

Kim S.K. Identification of 613 new loci associated with heel bone mineral density and a polygenic risk score for bone mineral density, osteoporosis and fracture. PLoS One. 2018;13 PubMed PMC

Morris J.A., Kemp J.P., Youlten S.E., Laurent L., Logan J.G., Chai R.C., et al. An atlas of genetic influences on osteoporosis in humans and mice. Nat. Genet. 2019;51:258–266. PubMed PMC

Kemp J.P., Morris J.A., Medina-Gomez C., Forgetta V., Warrington N.M., Youlten S.E., et al. Identification of 153 new loci associated with heel bone mineral density and functional involvement of GPC6 in osteoporosis. Nat. Genet. 2017;49:1468–1475. PubMed PMC

Estrada K., Styrkarsdottir U., Evangelou E., Hsu Y.H., Duncan E.L., Ntzani E.E., et al. Genome-wide meta-analysis identifies 56 bone mineral density loci and reveals 14 loci associated with risk of fracture. Nat. Genet. 2012;44:491–501. PubMed PMC

Medina-Gomez C., Kemp J.P., Trajanoska K., Luan J., Chesi A., Ahluwalia T.S., et al. Life-course genome-wide association study meta-analysis of total body BMD and assessment of age-specific effects. Am. J. Hum. Genet. 2018;102:88–102. PubMed PMC

Watanabe K., Stringer S., Frei O., Umićević Mirkov M., de Leeuw C., Polderman T.J.C., et al. A global overview of pleiotropy and genetic architecture in complex traits. Nat. Genet. 2019;51:1339–1348. PubMed

Patton S., Gendler S.J., Spicer A.P. The epithelial mucin, MUC1, of milk, mammary gland and other tissues. Biochim. Biophys. Acta. 1995;1241:407–423. PubMed

Peng J.B., Suzuki Y., Gyimesi G., Hediger M.A. In: Calcium Entry Channels in Non-Excitable Cells. Kozak J.A., Putney J.W. Jr., editors. CRC Press/Taylor & Francis Group, LLC; Boca Raton, FL: 2018. TRPV5 and TRPV6 calcium-selective channels; pp. 241–274.

Lee J.W., Chou C.L., Knepper M.A. Deep sequencing in microdissected renal tubules identifies nephron segment-specific transcriptomes. J. Am. Soc. Nephrol. 2015;26:2669–2677. PubMed PMC

Nijenhuis T., Hoenderop J.G., van der Kemp A.W., Bindels R.J. Localization and regulation of the epithelial Ca2+ channel TRPV6 in the kidney. J. Am. Soc. Nephrol. 2003;14:2731–2740. PubMed

McAuley J.L., Linden S.K., Png C.W., King R.M., Pennington H.L., Gendler S.J., et al. MUC1 cell surface mucin is a critical element of the mucosal barrier to infection. J. Clin. Invest. 2007;117:2313–2324. PubMed PMC

Hoenderop J.G., van Leeuwen J.P., van der Eerden B.C., Kersten F.F., van der Kemp A.W., Merillat A.M., et al. Renal Ca2+ wasting, hyperabsorption, and reduced bone thickness in mice lacking TRPV5. J. Clin. Invest. 2003;112:1906–1914. PubMed PMC

Bianco S.D., Peng J.B., Takanaga H., Suzuki Y., Crescenzi A., Kos C.H., et al. Marked disturbance of calcium homeostasis in mice with targeted disruption of the Trpv6 calcium channel gene. J. Bone Miner. Res. 2007;22:274–285. PubMed PMC

Cha S.-K., Wu T., Huang C.-L. Protein kinase C inhibits caveolae-mediated endocytosis of TRPV5. Am. J. Physiol. Renal Physiol. 2008;294:F1212–F1221. PubMed

Yates A.J., Gutierrez G.E., Smolens P., Travis P.S., Katz M.S., Aufdemorte T.B., et al. Effects of a synthetic peptide of a parathyroid hormone-related protein on calcium homeostasis, renal tubular calcium reabsorption, and bone metabolism in vivo and in vitro in rodents. J. Clin. Invest. 1988;81:932–938. PubMed PMC

Bleyer A.J., Kidd K., Zivna M., Kmoch S. Autosomal dominant tubulointerstitial kidney disease. Adv. Chronic Kidney Dis. 2017;24:86–93. PubMed PMC

Brum A.M., van der Leije C.S., Schreuders-Koedam M., Chaibi S., van Leeuwen J.P., van der Eerden B.C. Mucin 1 (Muc1) deficiency in female mice leads to temporal skeletal changes during aging. JBMR Plus. 2018;2:341–350. PubMed PMC

Christou M.A., Ntritsos G., Markozannes G., Koskeridis F., Nikas S.N., Karasik D., et al. A genome-wide scan for pleiotropy between bone mineral density and nonbone phenotypes. Bone Res. 2020;8:26. PubMed PMC

Meyer T.E., Verwoert G.C., Hwang S.J., Glazer N.L., Smith A.V., van Rooij F.J., et al. Genome-wide association studies of serum magnesium, potassium, and sodium concentrations identify six loci influencing serum magnesium levels. PLoS Genet. 2010;6 PubMed PMC

Liu Y., El-Achkar T.M., Wu X.-R. Tamm-Horsfall protein regulates circulating and renal cytokines by affecting glomerular filtration rate and acting as a urinary cytokine trap. J. Biol. Chem. 2012;287:16365–16378. PubMed PMC

Duarte C.G. Effects of ethacrynic acid and furosemide on urinary calcium, phosphate and magnesium. Metabolism. 1968;17:867–876. PubMed

Rejnmark L., Vestergaard P., Heickendorff L., Andreasen F., Mosekilde L. Effects of long-term treatment with loop diuretics on bone mineral density, calcitropic hormones and bone turnover. J. Intern. Med. 2005;257:176–184. PubMed

Dumic J., Dabelic S., Flögel M. Galectin-3: an open-ended story. Biochim. Biophys. Acta. 2006;1760:616–635. PubMed

Shan M., Gentile M., Yeiser J.R., Walland A.C., Bornstein V.U., Chen K., et al. Mucus enhances gut homeostasis and oral tolerance by delivering immunoregulatory signals. Science. 2013;342:447–453. PubMed PMC

Poland P.A., Rondanino C., Kinlough C.L., Heimburg-Molinaro J., Arthur C.M., Stowell S.R., et al. Identification and characterization of endogenous galectins expressed in Madin Darby canine kidney cells. J. Biol. Chem. 2011;286:6780–6790. PubMed PMC

Lim H., Yu C.Y., Jou T.S. Galectin-8 regulates targeting of Gp135/podocalyxin and lumen formation at the apical surface of renal epithelial cells. FASEB J. 2017;31:4917–4927. PubMed

Wolf M.T., Wu X.-R., Huang C.-L. Uromodulin upregulates TRPV5 by impairing caveolin-mediated endocytosis. Kidney Int. 2013;84:130–137. PubMed PMC

Lang T., Hansson G.C., Samuelsson T. Gel-forming mucins appeared early in metazoan evolution. Proc. Natl. Acad. Sci. U. S. A. 2007;104:16209–16214. PubMed PMC

Duraisamy S., Kufe T., Ramasamy S., Kufe D. Evolution of the human MUC1 oncoprotein. Int. J. Oncol. 2007;31:671–677. PubMed

Peng J.-B. TRPV5 and TRPV6 in transcellular Ca 2+ transport: regulation, gene duplication, and polymorphisms in African populations. Adv. Exp. Med. Biol. 2011;704:239–275. PubMed

Kinlough C.L., Poland P.A., Gendler S.J., Mattila P.E., Mo D., Weisz O.A., et al. Core-glycosylated mucin-like repeats from MUC1 are an apical targeting signal. J. Biol. Chem. 2011;286:39072–39081. PubMed PMC

Hanisch F.G., Kinlough C.L., Staubach S., Hughey R.P. MUC1 membrane trafficking: protocols for assessing biosynthetic delivery, endocytosis, recycling, and release through exosomes. Methods Mol. Biol. 2012;842:123–140. PubMed

Croce M.V., Isla-Larrain M., Remes-Lenicov F., Colussi A.G., Lacunza E., Kim K.C., et al. MUC1 cytoplasmic tail detection using CT33 polyclonal and CT2 monoclonal antibodies in breast and colorectal tissue. Histol. Histopathol. 2006;21:849–855. PubMed

Montalbetti N., Carattino M.D. Acid-sensing ion channels modulate bladder nociception. Am. J. Physiol. Renal Physiol. 2021;321:F587–F599. PubMed PMC

Montalbetti N., Rooney J.G., Marciszyn A.L., Carattino M.D. ASIC3 fine-tunes bladder sensory signaling. Am. J. Physiol. Renal Physiol. 2018;315:F870–F879. PubMed PMC

Kovacs G., Montalbetti N., Franz M.C., Graeter S., Simonin A., Hediger M.A. Human TRPV5 and TRPV6: key players in cadmium and zinc toxicity. Cell Calcium. 2013;54:276–286. PubMed

Kovacs G., Montalbetti N., Simonin A., Danko T., Balazs B., Zsembery A., et al. Inhibition of the human epithelial calcium channel TRPV6 by 2-aminoethoxydiphenyl borate (2-APB) Cell Calcium. 2012;52:468–480. PubMed

Spicer A.P., Rowse G.J., Lidner T.K., Gendler S.J. Delayed mammary tumor progression in Muc-1 null mice. J. Biol. Chem. 1995;270:30093–30101. PubMed

Bouley R., Pastor-Soler N., Cohen O., McLaughlin M., Breton S., Brown D. Stimulation of AQP2 membrane insertion in renal epithelial cells in vitro and in vivo by the cGMP phosphodiesterase inhibitor sildenafil citrate (viagra) Am. J. Physiol. Renal Physiol. 2005;288:F1103–F1112. PubMed

Al-bataineh M.M., Gong F., Marciszyn A.L., Myerburg M.M., Pastor-Soler N.M. Regulation of proximal tubule vacuolar H(+)-ATPase by PKA and AMP-activated protein kinase. Am. J. Physiol. Renal Physiol. 2014;306:F981–F995. PubMed PMC

Schindelin J., Arganda-Carreras I., Frise E., Kaynig V., Longair M., Pietzsch T., et al. Fiji: an open-source platform for biological-image analysis. Nat. Methods. 2012;9:676–682. PubMed PMC