title: HL-1 cells: a cardiac muscle cell line that contracts and retains phenotypic characteristics of the adult cardiomyocyte.
abstract: We have derived a cardiac muscle cell line, designated HL-1, from the AT-1 mouse atrial cardiomyocyte tumor lineage. HL-1 cells can be serially passaged, yet they maintain the ability to contract and retain differentiated cardiac morphological, biochemical, and electrophysiological properties. Ultrastructural characteristics typical of embryonic atrial cardiac muscle cells were found consistently in the cultured HL-1 cells. Reverse transcriptase-PCR-based analyses confirmed a pattern of gene expression similar to that of adult atrial myocytes, including expression of alpha-cardiac myosin heavy chain, alpha-cardiac actin, and connexin43. They also express the gene for atrial natriuretic factor. Immunohistochemical staining of the HL-1 cells indicated that the distribution of the cardiac-specific markers desmin, sarcomeric myosin, and atrial natriuretic factor was similar to that of cultured atrial cardiomyocytes. A delayed rectifier potassium current (IKr) was the most prominent outward current in HL-1 cells. The activating currents displayed inward rectification and deactivating current tails were voltage-dependent, saturated at >>+20 mV, and were highly sensitive to dofetilide (IC50 of 46.9 nM). Specific binding of [3H]dofetilide was saturable and fit a one-site binding isotherm with a Kd of 140 +/- 60 nM and a Bmax of 118 fmol per 10(5) cells. HL-1 cells represent a cardiac myocyte cell line that can be repeatedly passaged and yet maintain a cardiac-specific phenotype.
authors.affiliation: Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, New Orleans, LA 70112, USA. wclayc@lsumc.edu
authors.forename: W C
authors.initials: WC
authors.lastname: Claycomb
authors.forename: N A
authors.initials: NA
authors.lastname: Lanson
authors.forename: B S
authors.initials: BS
authors.lastname: Stallworth
authors.forename: D B
authors.initials: DB
authors.lastname: Egeland
authors.forename: J B
authors.initials: JB
authors.lastname: Delcarpio
authors.forename: A
authors.initials: A
authors.lastname: Bahinski
authors.forename: N J
authors.initials: NJ
authors.lastname: Izzo
mesh_terms: D000818:Animals; D016275:Atrial Function; D009320:Atrial Natriuretic Factor / Q000096:biosynthesis; D002454:Cell Differentiation; D018031:Connexin 43 / Q000096:biosynthesis; D004553:Electric Conductivity; D005260:Female; D015870:Gene Expression; D006325:Heart Atria / Q000166:cytology*; D006338:Heart Neoplasms; D051379:Mice; D008810:Mice, Inbred C57BL; D009124:Muscle Proteins / Q000096:biosynthesis; D009200:Myocardial Contraction; D009206:Myocardium / Q000166:cytology*; D010627:Phenethylamines / Q000378:metabolism; D010641:Phenotype; D013449:Sulfonamides / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D018031:Connexin 43; D009124:Muscle Proteins; D010627:Phenethylamines; D013449:Sulfonamides; D009320:Atrial Natriuretic Factor; C063533:dofetilide