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Siri-Angkul N, Kamp TJ. Cardiac L-type calcium channel regulation by Leucine-Rich Repeat-Containing Protein 10. Channels (Austin) 2024; 18:2355121. [PMID: 38762910 PMCID: PMC11110685 DOI: 10.1080/19336950.2024.2355121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 05/10/2024] [Indexed: 05/21/2024] Open
Abstract
L-type calcium channels (LTCCs), the major portal for Ca2+ entry into cardiomyocytes, are essential for excitation-contraction coupling and thus play a central role in regulating overall cardiac function. LTCC function is finely tuned by multiple signaling pathways and accessory proteins. Leucine-rich repeat-containing protein 10 (LRRC10) is a little studied cardiomyocyte-specific protein recently identified as a modulator of LTCCs. LRRC10 exerts a remarkable effect on LTCC function, more than doubling L-type Ca2+ current (ICa,L) amplitude in a heterologous expression system by altering the gating of the channels without changing their surface membrane expression. Genetic ablation of LRRC10 expression in mouse and zebrafish hearts leads to a significant reduction in ICa,L density and a slowly progressive dilated cardiomyopathy in mice. Rare sequence variants of LRRC10 have been identified in dilated cardiomyopathy and sudden unexplained nocturnal cardiac death syndrome, but these variants have not been clearly linked to disease. Nevertheless, the DCM-associated variant, I195T, converted LRRC10 from a ICa,L potentiator to a ICa,L suppressor, thus illustrating the wide dynamic range of LRRC10-mediated ICa,L regulation. This review focuses on the contemporary knowledge of LTCC modulation by LRRC10 and discusses potential directions for future investigations.
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Affiliation(s)
- Natthaphat Siri-Angkul
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA
| | - Timothy J Kamp
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA
- Stem Cell and Regenerative Medicine Center, University of Wisconsin - Madison, Madison, WI, USA
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Woon MT, Long PA, Reilly L, Evans JM, Keefe AM, Lea MR, Beglinger CJ, Balijepalli RC, Lee Y, Olson TM, Kamp TJ. Pediatric Dilated Cardiomyopathy-Associated LRRC10 (Leucine-Rich Repeat-Containing 10) Variant Reveals LRRC10 as an Auxiliary Subunit of Cardiac L-Type Ca 2+ Channels. J Am Heart Assoc 2018; 7:e006428. [PMID: 29431102 PMCID: PMC5850229 DOI: 10.1161/jaha.117.006428] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 11/10/2017] [Indexed: 12/30/2022]
Abstract
BACKGROUND Genetic causes of dilated cardiomyopathy (DCM) are incompletely understood. LRRC10 (leucine-rich repeat-containing 10) is a cardiac-specific protein of unknown function. Heterozygous mutations in LRRC10 have been suggested to cause DCM, and deletion of Lrrc10 in mice results in DCM. METHODS AND RESULTS Whole-exome sequencing was carried out on a patient who presented at 6 weeks of age with DCM and her unaffected parents, filtering for rare, deleterious, recessive, and de novo variants. Whole-exome sequencing followed by trio-based filtering identified a homozygous recessive variant in LRRC10, I195T. Coexpression of I195T LRRC10 with the L-type Ca2+ channel (Cav1.2, β2CN2, and α2δ subunits) in HEK293 cells resulted in a significant ≈0.5-fold decrease in ICa,L at 0 mV, in contrast to the ≈1.4-fold increase in ICa,L by coexpression of LRRC10 (n=9-12, P<0.05). Coexpression of LRRC10 or I195T LRRC10 did not alter the surface membrane expression of Cav1.2. LRRC10 coexpression with Cav1.2 in the absence of auxiliary β2CN2 and α2δ subunits revealed coassociation of Cav1.2 and LRRC10 and a hyperpolarizing shift in the voltage dependence of activation (n=6-9, P<0.05). Ventricular myocytes from Lrrc10-/- mice had significantly smaller ICa,L, and coimmunoprecipitation experiments confirmed association between LRRC10 and the Cav1.2 subunit in mouse hearts. CONCLUSIONS Examination of a patient with DCM revealed homozygosity for a previously unreported LRRC10 variant: I195T. Wild-type and I195T LRRC10 function as cardiac-specific subunits of L-type Ca2+ channels and exert dramatically different effects on channel gating, providing a potential link to DCM.
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Affiliation(s)
- Marites T Woon
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, WI
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
| | - Pamela A Long
- Mayo Graduate School, Molecular Pharmacology and Experimental Therapeutics Track, Mayo Clinic, Rochester, MN
| | - Louise Reilly
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, WI
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
| | - Jared M Evans
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN
| | - Alexis M Keefe
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, WI
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
| | - Martin R Lea
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, WI
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
| | - Carl J Beglinger
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, WI
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
| | - Ravi C Balijepalli
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, WI
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
| | - Youngsook Lee
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
| | - Timothy M Olson
- Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN
- Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, MN
| | - Timothy J Kamp
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, WI
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
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Diamante G, Menjivar-Cervantes N, Leung MS, Volz DC, Schlenk D. Contribution of G protein-coupled estrogen receptor 1 (GPER) to 17β-estradiol-induced developmental toxicity in zebrafish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 186:180-187. [PMID: 28284154 DOI: 10.1016/j.aquatox.2017.02.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 02/24/2017] [Accepted: 02/25/2017] [Indexed: 06/06/2023]
Abstract
Exposure to 17β-estradiol (E2) influences the regulation of multiple signaling pathways, and E2-mediated disruption of signaling events during early development can lead to malformations such as cardiac defects. In this study, we investigated the potential role of the G-protein estrogen receptor 1 (GPER) in E2-induced developmental toxicity. Zebrafish embryos were exposed to E2 from 2h post fertilization (hpf) to 76 hpf with subsequent transcriptional measurements of heart and neural crest derivatives expressed 2 (hand2), leucine rich repeat containing 10 (lrrc10), and gper at 12, 28 and 76 hpf. Alteration in the expression of lrrc10, hand2 and gper was observed at 12 hpf and 76 hpf, but not at 28 hpf. Expression of these genes was also altered after exposure to G1 (a GPER agonist) at 76 hpf. Expression of lrrc10, hand2 and gper all coincided with the formation of cardiac edema at 76 hpf as well as other developmental abnormalities. While co-exposure of G1 with G36 (a GPER antagonist) rescued G1-induced abnormalities and altered gene expression, co-exposure of E2 with G36, or ICI 182,780 (an estrogen receptor antagonist) did not rescue E2-induced cardiac deformities or gene expression. In addition, no effects on the concentrations of downstream ER and GPER signaling molecules (cAMP or calcium) were observed in embryo homogenates after E2 treatment. These data suggest that the impacts of E2 on embryonic development at this stage are complex and may involve multiple receptor and/or signaling pathways.
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Affiliation(s)
- Graciel Diamante
- Department of Environmental Sciences, University of California, Riverside, Riverside, CA 92507, United States.
| | - Norma Menjivar-Cervantes
- Department of Environmental Sciences, University of California, Riverside, Riverside, CA 92507, United States
| | - Man Sin Leung
- Department of Environmental Sciences, University of California, Riverside, Riverside, CA 92507, United States
| | - David C Volz
- Department of Environmental Sciences, University of California, Riverside, Riverside, CA 92507, United States
| | - Daniel Schlenk
- Department of Environmental Sciences, University of California, Riverside, Riverside, CA 92507, United States.
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Brody MJ, Lee Y. The Role of Leucine-Rich Repeat Containing Protein 10 (LRRC10) in Dilated Cardiomyopathy. Front Physiol 2016; 7:337. [PMID: 27536250 PMCID: PMC4971440 DOI: 10.3389/fphys.2016.00337] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 07/20/2016] [Indexed: 12/12/2022] Open
Abstract
Leucine-rich repeat containing protein 10 (LRRC10) is a cardiomyocyte-specific member of the Leucine-rich repeat containing (LRRC) protein superfamily with critical roles in cardiac function and disease pathogenesis. Recent studies have identified LRRC10 mutations in human idiopathic dilated cardiomyopathy (DCM) and Lrrc10 homozygous knockout mice develop DCM, strongly linking LRRC10 to the molecular etiology of DCM. LRRC10 localizes to the dyad region in cardiomyocytes where it can interact with actin and α-actinin at the Z-disc and associate with T-tubule components. Indeed, this region is becoming increasingly recognized as a signaling center in cardiomyocytes, not only for calcium cycling, excitation-contraction coupling, and calcium-sensitive hypertrophic signaling, but also as a nodal signaling hub where the myocyte can sense and respond to mechanical stress. Disruption of a wide range of critical structural and signaling molecules in cardiomyocytes confers susceptibility to cardiomyopathies in addition to the more classically studied mutations in sarcomeric proteins. However, the molecular mechanisms underlying DCM remain unclear. Here, we review what is known about the cardiomyocyte functions of LRRC10, lessons learned about LRRC10 and DCM from the Lrrc10 knockout mouse model, and discuss ongoing efforts to elucidate molecular mechanisms whereby mutation or absence of LRRC10 mediates cardiac disease.
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Affiliation(s)
- Matthew J Brody
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center Cincinnati, OH, USA
| | - Youngsook Lee
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Madison, WI, USA
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QU XINKAI, YUAN FANG, LI RUOGU, XU LEI, JING WEIFENG, LIU HUA, XU YINGJIA, ZHANG MIN, LIU XU, FANG WEIYI, YANG YIQING, QIU XINGBIAO. Prevalence and spectrum of LRRC10 mutations associated with idiopathic dilated cardiomyopathy. Mol Med Rep 2015; 12:3718-3724. [DOI: 10.3892/mmr.2015.3843] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 05/01/2015] [Indexed: 11/06/2022] Open
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Brody MJ, Cho E, Mysliwiec MR, Kim TG, Carlson CD, Lee KH, Lee Y. Lrrc10 is a novel cardiac-specific target gene of Nkx2-5 and GATA4. J Mol Cell Cardiol 2013; 62:237-46. [PMID: 23751912 PMCID: PMC3940241 DOI: 10.1016/j.yjmcc.2013.05.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 05/11/2013] [Accepted: 05/30/2013] [Indexed: 10/26/2022]
Abstract
Cardiac gene expression is precisely regulated and its perturbation causes developmental defects and heart disease. Leucine-rich repeat containing 10 (Lrrc10) is a cardiac-specific factor that is crucial for proper cardiac development and deletion of Lrrc10 in mice results in dilated cardiomyopathy. However, the mechanisms regulating Lrrc10 expression in cardiomyocytes remain unknown. Therefore, we set out to determine trans-acting factors and cis-elements critical for mediating Lrrc10 expression. We identify Lrrc10 as a transcriptional target of Nkx2-5 and GATA4. The Lrrc10 promoter region contains two highly conserved cardiac regulatory elements, which are functional in cardiomyocytes but not in fibroblasts. In vivo, Nkx2-5 and GATA4 endogenously occupy the proximal and distal cardiac regulatory elements of Lrrc10 in the heart. Moreover, embryonic hearts of Nkx2-5 knockout mice have dramatically reduced expression of Lrrc10. These data demonstrate the importance of Nkx2-5 and GATA4 in regulation of Lrrc10 expression in vivo. The proximal cardiac regulatory element located at around -200bp is synergistically activated by Nkx2-5 and GATA4 while the distal cardiac regulatory element present around -3kb requires SRF in addition to Nkx2-5 and GATA4 for synergistic activation. Mutational analyses identify a pair of adjacent Nkx2-5 and GATA binding sites within the proximal cardiac regulatory element that are necessary to induce expression of Lrrc10. In contrast, only the GATA site is functional in the distal regulatory element. Taken together, our data demonstrate that the transcription factors Nkx2-5 and GATA4 cooperatively regulate cardiac-specific expression of Lrrc10.
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Affiliation(s)
- Matthew J. Brody
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, WI 53706, USA
- Molecular and Environmental Toxicology Center, University of Wisconsin-Madison, WI 53706, USA
| | - Eunjin Cho
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, WI 53706, USA
- Molecular and Cellular Pharmacology, University of Wisconsin-Madison, WI 53706, USA
| | - Matthew R. Mysliwiec
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, WI 53706, USA
| | - Tae-gyun Kim
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, WI 53706, USA
| | - Clayton D. Carlson
- Department of Biochemistry and the Genome Center of Wisconsin, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Kyu-Ho Lee
- Department of Pediatrics, Division of Pediatric Cardiology, Children’s Hospital, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Youngsook Lee
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, WI 53706, USA
- Molecular and Environmental Toxicology Center, University of Wisconsin-Madison, WI 53706, USA
- Molecular and Cellular Pharmacology, University of Wisconsin-Madison, WI 53706, USA
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Ablation of the cardiac-specific gene leucine-rich repeat containing 10 (Lrrc10) results in dilated cardiomyopathy. PLoS One 2012; 7:e51621. [PMID: 23236519 PMCID: PMC3517560 DOI: 10.1371/journal.pone.0051621] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 11/02/2012] [Indexed: 01/06/2023] Open
Abstract
Leucine-rich repeat containing 10 (LRRC10) is a cardiac-specific protein exclusively expressed in embryonic and adult cardiomyocytes. However, the role of LRRC10 in mammalian cardiac physiology remains unknown. To determine if LRRC10 is critical for cardiac function, Lrrc10-null (Lrrc10−/−) mice were analyzed. Lrrc10−/− mice exhibit prenatal systolic dysfunction and dilated cardiomyopathy in postnatal life. Importantly, Lrrc10−/− mice have diminished cardiac performance in utero, prior to ventricular dilation observed in young adults. We demonstrate that LRRC10 endogenously interacts with α-actinin and α-actin in the heart and all actin isoforms in vitro. Gene expression profiling of embryonic Lrrc10−/− hearts identified pathways and transcripts involved in regulation of the actin cytoskeleton to be significantly upregulated, implicating dysregulation of the actin cytoskeleton as an early defective molecular signal in the absence of LRRC10. In contrast, microarray analyses of adult Lrrc10−/− hearts identified upregulation of oxidative phosphorylation and cardiac muscle contraction pathways during the progression of dilated cardiomyopathy. Analyses of hypertrophic signal transduction pathways indicate increased active forms of Akt and PKCε in adult Lrrc10−/− hearts. Taken together, our data demonstrate that LRRC10 is essential for proper mammalian cardiac function. We identify Lrrc10 as a novel dilated cardiomyopathy candidate gene and the Lrrc10−/− mouse model as a unique system to investigate pediatric cardiomyopathy.
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Fan X, Yang Q, Wang Y, Zhang Y, Wang J, Yuan J, Li Y, Wang Y, Deng Y, Yuan W, Mo X, Wan Y, Ocorr K, Yang X, Wu X. Cloning and characterization of the cardiac-specific Lrrc10 promoter. BMB Rep 2011; 44:123-8. [PMID: 21345312 DOI: 10.5483/bmbrep.2011.44.2.123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leucine-rich repeat containing protein 10 (LRRC10) is characterized as a cardiac-specific gene, suggesting a role in heart development and disease. A severe cardiac morphogenic defect in zebrafish morphants was recently reported but a contradictory result was found in mice, suggesting a more complicated molecular mechanism exists during mouse embryonic development. To elucidate how LRRC10 is regulated, we analyzed the 5'enhancer region approximately 3 kilo bases (kb) upstream of the Lrrc10 start site using luciferase reporter gene assays. Our characterization of the Lrrc10 promoter indicates it possesses complicated cis-and trans-acting elements. We show that GATA4 and MEF2C could both increase transcriptional activity of Lrrc10 promoter individually but that they do not act synergistically, suggesting that there exists a more complex regulation pattern. Surprisingly, knockout of Gata4 and Mef2c binding sites in the 5'enhancer region (-2,894/-2,889) didn't change the transcriptional activity of the Lrrc10 promoter and the likely GATA4 binding site identified was located in a region only 100 base pair (bp) upstream of the promoter. Our data provides insight into the molecular regulation of Lrrc10 expression, which probably also contributes to its tissue-specific expression.
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Affiliation(s)
- Xiongwei Fan
- The Center for Heart Development, Key Lab of MOE for Development Biology and Protein Chemistry, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China
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Effective and steady differentiation of a clonal derivative of P19CL6 embryonal carcinoma cell line into beating cardiomyocytes. J Biomed Biotechnol 2010; 2010:380561. [PMID: 20368798 PMCID: PMC2846686 DOI: 10.1155/2010/380561] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 12/01/2009] [Accepted: 12/25/2009] [Indexed: 02/05/2023] Open
Abstract
The P19CL6 cell line is a useful model to study cardiac differentiation in vitro. However, large variations were noticed in the differentiation rates among previous reports as well as our individual experiments. To overcome the unstable differentiation, we established P19CL6-A1, a new clonal derivative of P19CL6 that could differentiate into cardiomyocytes more efficiently and stably than the parent using the double stimulation with 5-Aza and DMSO based on the previous report. We also introduced a new software, Visorhythm, that can analyze the temporal variations in the beating rhythms and can chart correlograms displaying the oscillated rhythms. Using P19CL6-A1-derived cardiomyocytes and the software, we demonstrated that the correlograms could clearly display the enhancement of beating rates by cardiotonic reagents. These indicate that a combination of P19CL6-A1 and Visorhythm is a useful tool that can provide invaluable assistance in inotropic drug discovery, drug screening, and toxicity testing.
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Manuylov NL, Manuylova E, Avdoshina V, Tevosian S. Serdin1/Lrrc10 is dispensable for mouse development. Genesis 2008; 46:441-6. [PMID: 18781631 DOI: 10.1002/dvg.20422] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have previously identified Serdin1/Lrrc10 as a cardiac-specific message that is expressed early in murine heart development and encodes a novel leucine-rich protein. A high degree of evolutionary conservation with respect to protein sequence, cardiac-specific expression, and cis-regulatory elements suggested that LRRC10 has an important and conserved function in cardiac development. Recently, the zebrafish lrrc10 knockdown models were described with a dramatic early defect in heart looping which supported the notion that Serdin1/Lrrc10 is likely to be essential for heart development in all vertebrates. To determine Lrrc10 function in mammalian cardiac development, we have disrupted the Lrrc10 gene in mice. We report here that, in striking contrast to the zebrafish lrrc10 knockdown, Lrrc10-null mice develop normally and exhibit no discernable phenotype.
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Affiliation(s)
- Nikolay L Manuylov
- Department of Genetics, Dartmouth Medical School, Hanover, New Hampshire, USA
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Kim KH, Kim TG, Micales BK, Lyons GE, Lee Y. Dynamic expression patterns of leucine-rich repeat containing protein 10 in the heart. Dev Dyn 2007; 236:2225-34. [PMID: 17626279 PMCID: PMC2002521 DOI: 10.1002/dvdy.21225] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Leucine-rich repeat containing protein 10 (LRRC10) is a heart-specific factor whose function remains unknown. Examination of the intracellular location of the gene products is a critical step in determining the biological functions of the protein. Our expression analyses in mice indicate that LRRC10 is exclusively expressed from the precardiac region in early embryos to the adult heart. LRRC10 expression is markedly elevated upon birth, suggesting its role in the embryonic as well as adult hearts. Of interest, LRRC10 exhibits dynamic intracellular expression patterns in cardiomyocytes. Cardiomyocytes from embryos and newborns show diffuse cytoplasmic and nuclear staining of LRRC10. In contrast, striking striations are observed in adult cardiomyocytes, which are colocalized with the markers for the Z-line, sarcoplasmic reticulum (SR), and transverse (T)-tubule by double immunostaining. Further investigation by electron micrographs places LRRC10 in a diad region where the SR interacts with the T-tubule that locates along the Z-line.
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Affiliation(s)
- Ki-Hyun Kim
- Department of Anatomy, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53706, USA
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Kim KH, Antkiewicz DS, Yan L, Eliceiri KW, Heideman W, Peterson RE, Lee Y. Lrrc10 is required for early heart development and function in zebrafish. Dev Biol 2007; 308:494-506. [PMID: 17601532 PMCID: PMC2048587 DOI: 10.1016/j.ydbio.2007.06.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 05/15/2007] [Accepted: 06/06/2007] [Indexed: 11/15/2022]
Abstract
Leucine-rich Repeat Containing protein 10 (LRRC10) has recently been identified as a cardiac-specific factor in mice. However, the function of this factor remains to be elucidated. In this study, we investigated the developmental roles of Lrrc10 using zebrafish as an animal model. Knockdown of Lrrc10 in zebrafish embryos (morphants) using morpholinos caused severe cardiac morphogenic defects including a cardiac looping failure accompanied by a large pericardial edema, and embryonic lethality between day 6 and 7 post fertilization. The Lrrc10 morphants exhibited cardiac functional defects as evidenced by a decrease in ejection fraction and cardiac output. Further investigations into the underlying mechanisms of the cardiac defects revealed that the number of cardiomyocyte was reduced in the morphants. Expression of two cardiac genes was deregulated in the morphants including an increase in atrial natriuretic factor, a hallmark for cardiac hypertrophy and failure, and a decrease in cardiac myosin light chain 2, an essential protein for cardiac contractility in zebrafish. Moreover, a reduced fluorescence intensity from NADH in the morphant heart was observed in live zebrafish embryos as compared to control. Taken together, the present study demonstrates that Lrrc10 is necessary for normal cardiac development and cardiac function in zebrafish embryos, which will enhance our understanding of congenital heart defects and heart disease.
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Affiliation(s)
- Ki-Hyun Kim
- Department of Anatomy, School of Medicine and Public Health, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA
| | - Dagmara S. Antkiewicz
- Molecular and Environmental Toxicology Center, School of Pharmacy, University of Wisconsin, Madison, WI 53705, USA
| | - Long Yan
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53706, USA
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin, Madison, WI 53706, USA
| | - Kevin W. Eliceiri
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin, Madison, WI 53706, USA
| | - Warren Heideman
- Molecular and Environmental Toxicology Center, School of Pharmacy, University of Wisconsin, Madison, WI 53705, USA
| | - Richard E. Peterson
- Molecular and Environmental Toxicology Center, School of Pharmacy, University of Wisconsin, Madison, WI 53705, USA
| | - Youngsook Lee
- Department of Anatomy, School of Medicine and Public Health, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA
- Corresponding author. Fax: +1 608 262 7306., E-mail address: (Y. Lee)
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