Cadherin-2 also known as Neural cadherin (N-cadherin), is a protein that in humans is encoded by the CDH2gene.[5][6][7] CDH2 has also been designated as CD325 (cluster of differentiation 325).
Cadherin-2 is a transmembraneprotein expressed in multiple tissues and functions to mediate cell–cell adhesion. In cardiac muscle, Cadherin-2 is an integral component in adherens junctions residing at intercalated discs, which function to mechanically and electrically couple adjacent cardiomyocytes. Alterations in expression and integrity of Cadherin-2 has been observed in various forms of disease, including human dilated cardiomyopathy. Variants in CDH2 have also been identified to cause a syndromic neurodevelopmental disorder.[8]
Cadherin-2 is widely expressed in the embryo post-implantation, showing high levels in the mesoderm with sustained expression through adulthood.[15] Cadherin-2 mutation during development has the most significant effect on cell adhesion in the primitive heart; dissociated myocytes and abnormal heart tube development occur.[16] Cadherin-2 plays a role in the development of the vertebrate heart at the transition of epithelial cells to trabecular and compact myocardial cell layer formation.[17] An additional study showed that myocytes expressing a dominant negative Cadherin-2 mutant showed significant abnormalities in myocyte distribution and migration towards the endocardium, resulting in defects in trabecular formation within the myocardium.[18][19]
Mouse models employing transgenesis have highlighted the function of N-cadherin in cardiac muscle. Mice with altered expression of N-cadherin and/or E-cadherin showed a dilated cardiomyopathy phenotype, likely due to malfunction of intercalated discs.[27] In agreement with this, mice with ablation of N-cadherin in adult hearts via a cardiac-specific tamoxifen-inducible Cre N-cadherin transgene showed disrupted assembly of intercalated discs, dilated cardiomyopathy, impaired cardiac function, decreased sarcomere length, increased Z-line thickness, decreases in connexin 43, and a loss in muscular tension. Mice died within two months of transgene expression, mainly due to spontaneous Ventricular tachycardia.[28] Further analysis of N-cadherin knockout mice revealed that the arrhythmias were likely due to ion channel remodeling and aberrant Kv1.5 channel function. These animals showed a prolonged action potential duration, reduced density of inward rectifier potassium channel and decreased expression of Kv1.5, KCNE2 and cortactin combined with disrupted actincytoskeleton at the sarcolemma.[29]
Role in neurons
In neural cells, at certain central nervous system synapses, presynaptic to postsynaptic adhesion is mediated at least in part by Cadherin-2.[30] N-cadherins interact with catenins to play an important role in learning and memory (For full article see Cadherin-catenin complex in learning and memory). Loss of N-cadherin is also associated with attention-deficit hyperactivity disorder in humans, and impaired synaptic functioning. [31]
Role in cancer metastasis
Cadherin-2 is commonly found in cancer cells and provides a mechanism for transendothelial migration. When a cancer cell adheres to the endothelial cells of a blood vessel it up-regulates the src kinase pathway, which phosphorylates beta-catenins attached to both Cadherin-2 (this protein) and E-cadherins. This causes the intercellular connection between two adjacent endothelial cells to fail and allows the cancer cell to slip through.[32]
One study investigating genetic underpinnings of obsessive-compulsive disorder and Tourette disorder found that while CDH2 variants are likely not disease-causing as single entities, they may confer risk when examined as part of a panel of related cell–cell adhesion genes.[33] Further studies in larger cohorts will be required to unequivocally determine this.
In human dilated cardiomyopathy, it was shown that Cadherin-2 expression was enhanced and arranged in a disarrayed fashion, suggesting that disorganization of Cadherin-2 protein in heart disease may be a component of remodeling.[34]
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"UniProt". www.uniprot.org. Retrieved 26 August 2022.
^Walsh FS, Barton CH, Putt W, Moore SE, Kelsell D, Spurr N, Goodfellow PN (September 1990). "N-cadherin gene maps to human chromosome 18 and is not linked to the E-cadherin gene". Journal of Neurochemistry. 55 (3): 805–12. doi:10.1111/j.1471-4159.1990.tb04563.x. PMID2384753. S2CID29840435.
^Buxton RS, Magee AI (June 1992). "Structure and interactions of desmosomal and other cadherins". Seminars in Cell Biology. 3 (3): 157–67. doi:10.1016/s1043-4682(10)80012-1. PMID1623205.
^Forbes MS, Sperelakis N (1985). "Intercalated discs of mammalian heart: a review of structure and function". Tissue & Cell. 17 (5): 605–48. doi:10.1016/0040-8166(85)90001-1. PMID3904080.
^Zuppinger C, Schaub MC, Eppenberger HM (April 2000). "Dynamics of early contact formation in cultured adult rat cardiomyocytes studied by N-cadherin fused to green fluorescent protein". Journal of Molecular and Cellular Cardiology. 32 (4): 539–55. doi:10.1006/jmcc.1999.1086. PMID10756112.
^Dou JP, Jiao B, Sheng JJ, Yu ZB (October 2014). "[Dynamic assembly of intercalated disc during postnatal development in the rat myocardium]". Sheng Li Xue Bao. 66 (5): 569–74. PMID25332002.
^Goncharova EJ, Kam Z, Geiger B (January 1992). "The involvement of adherens junction components in myofibrillogenesis in cultured cardiac myocytes". Development. 114 (1): 173–83. doi:10.1242/dev.114.1.173. PMID1576958.
^Hertig CM, Eppenberger-Eberhardt M, Koch S, Eppenberger HM (January 1996). "N-cadherin in adult rat cardiomyocytes in culture. I. Functional role of N-cadherin and impairment of cell-cell contact by a truncated N-cadherin mutant". Journal of Cell Science. 109 ( Pt 1) (1): 1–10. doi:10.1242/jcs.109.1.1. PMID8834785.
^Ferreira-Cornwell MC, Luo Y, Narula N, Lenox JM, Lieberman M, Radice GL (April 2002). "Remodeling the intercalated disc leads to cardiomyopathy in mice misexpressing cadherins in the heart". Journal of Cell Science. 115 (Pt 8): 1623–34. doi:10.1242/jcs.115.8.1623. PMID11950881.
^Tsipis A, Athanassiadou AM, Athanassiadou P, Kavantzas N, Agrogiannis G, Patsouris E (September 2010). "Apoptosis-related factors p53, bcl-2 and the defects of force transmission in dilated cardiomyopathy". Pathology, Research and Practice. 206 (9): 625–30. doi:10.1016/j.prp.2010.05.007. PMID20591580.
Cavallaro U (December 2004). "N-cadherin as an invasion promoter: a novel target for antitumor therapy?". Current Opinion in Investigational Drugs. 5 (12): 1274–8. PMID15648948.
Salomon D, Ayalon O, Patel-King R, Hynes RO, Geiger B (May 1992). "Extrajunctional distribution of N-cadherin in cultured human endothelial cells". Journal of Cell Science. 102 ( Pt 1) (1): 7–17. doi:10.1242/jcs.102.1.7. PMID1500442.
Walsh FS, Barton CH, Putt W, Moore SE, Kelsell D, Spurr N, Goodfellow PN (September 1990). "N-cadherin gene maps to human chromosome 18 and is not linked to the E-cadherin gene". Journal of Neurochemistry. 55 (3): 805–12. doi:10.1111/j.1471-4159.1990.tb04563.x. PMID2384753. S2CID29840435.
Wallis J, Fox MF, Walsh FS (July 1994). "Structure of the human N-cadherin gene: YAC analysis and fine chromosomal mapping to 18q11.2". Genomics. 22 (1): 172–9. doi:10.1006/geno.1994.1358. PMID7959764.
Matsuyoshi N, Imamura S (June 1997). "Multiple cadherins are expressed in human fibroblasts". Biochemical and Biophysical Research Communications. 235 (2): 355–8. doi:10.1006/bbrc.1997.6707. PMID9199196.
Gaidar YA, Lepekhin EA, Sheichetova GA, Witt M (February 1998). "Distribution of N-cadherin and NCAM in neurons and endocrine cells of the human embryonic and fetal gastroenteropancreatic system". Acta Histochemica. 100 (1): 83–97. doi:10.1016/s0065-1281(98)80008-1. PMID9542583.
Kremmidiotis G, Baker E, Crawford J, Eyre HJ, Nahmias J, Callen DF (May 1998). "Localization of human cadherin genes to chromosome regions exhibiting cancer-related loss of heterozygosity". Genomics. 49 (3): 467–71. doi:10.1006/geno.1998.5281. PMID9615235.