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Zhong L, Zhang J, Yang J, Li B, Yi X, Speakman JR, Gao S, Li M. Chronic sleep fragmentation reduces left ventricular contractile function and alters gene expression related to innate immune response and circadian rhythm in the mouse heart. Gene 2024; 914:148420. [PMID: 38556117 DOI: 10.1016/j.gene.2024.148420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 03/11/2024] [Accepted: 03/27/2024] [Indexed: 04/02/2024]
Abstract
Sleep disorders have emerged as a widespread public health concern, primarily due to their association with an increased risk of developing cardiovascular diseases. Our previous research indicated a potential direct impact of insufficient sleep duration on cardiac remodeling in children and adolescents. Nevertheless, the underlying mechanisms behind the link between sleep fragmentation (SF) and cardiac abnormalities remain unclear. In this study, we aimed to investigate the effects of SF interventions at various life stages on cardiac structure and function, as well as to identify genes associated with SF-induced cardiac dysfunction. To achieve this, we established mouse models of chronic SF and two-week sleep recovery (SR). Our results revealed that chronic SF significantly compromised left ventricular contractile function across different life stages, leading to alterations in cardiac structure and ventricular remodeling, particularly during early life stages. Moreover, microarray analysis of mouse heart tissue identified two significant modules and nine hub genes (Ddx60, Irf9, Oasl2, Rnf213, Cmpk2, Stat2, Parp14, Gbp3, and Herc6) through protein-protein interaction analysis. Notably, the interactome predominantly involved innate immune responses. Importantly, all hub genes lost significance following SR. The second module primarily consisted of circadian clock genes, and real-time PCR validation demonstrated significant upregulation of Arntl, Dbp, and Cry1 after SF, while subsequent SR restored normal Arntl expression. Furthermore, the expression levels of four hub genes (Ddx60, Irf9, Oasl2, and Cmpk2) and three circadian clock genes (Arntl, Dbp, and Cry1) exhibited correlations with structural and functional echocardiographic parameters. Overall, our findings suggest that SF impairs left ventricular contractile function and ventricular remodeling during early life stages, and this may be mediated by modulation of the innate immune response and circadian rhythm. Importantly, our findings suggest that a short period of SR can alleviate the detrimental effects of SF on the cardiac immune response, while the influence of SF on circadian rhythm appears to be more persistent. These findings underscore the importance of good sleep for maintaining cardiac health, particularly during early life stages.
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Affiliation(s)
- Ling Zhong
- Department of Endocrinology, National Health Committee Key Laboratory of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Jie Zhang
- Department of Endocrinology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Jielin Yang
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Bo Li
- Department of Endocrinology, National Health Committee Key Laboratory of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Xinghao Yi
- Department of Endocrinology, National Health Committee Key Laboratory of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - John R Speakman
- Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Shan Gao
- Department of Endocrinology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
| | - Ming Li
- Department of Endocrinology, National Health Committee Key Laboratory of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.
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2
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Ouyang X, Matt A, Wang F, Gracheva E, Migunova E, Rajamani S, Dubrovsky EB, Zhou C. Attention LSTM U-Net model for Drosophila melanogaster heart tube segmentation in optical coherence microscopy images. BIOMEDICAL OPTICS EXPRESS 2024; 15:3639-3653. [PMID: 38867790 PMCID: PMC11166423 DOI: 10.1364/boe.523364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/22/2024] [Accepted: 04/28/2024] [Indexed: 06/14/2024]
Abstract
Optical coherence microscopy (OCM) imaging of the Drosophila melanogaster (fruit fly) heart tube has enabled the non-invasive characterization of fly heart physiology in vivo. OCM generates large volumes of data, making it necessary to automate image analysis. Deep-learning-based neural network models have been developed to improve the efficiency of fly heart image segmentation. However, image artifacts caused by sample motion or reflections reduce the accuracy of the analysis. To improve the precision and efficiency of image data analysis, we developed an Attention LSTM U-Net model (FlyNet3.0), which incorporates an attention learning mechanism to track the beating fly heart in OCM images. The new model has improved the intersection over union (IOU) compared to FlyNet2.0 + with reflection artifacts from 86% to 89% and with movement from 81% to 89%. We also extended the capabilities of OCM analysis through the introduction of an automated, in vivo heart wall thickness measurement method, which has been validated on a Drosophila model of cardiac hypertrophy. This work will enable the comprehensive, non-invasive characterization of fly heart physiology in a high-throughput manner.
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Affiliation(s)
- Xiangping Ouyang
- Department of Computer Science and Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Abigail Matt
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Fei Wang
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Elena Gracheva
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ekaterina Migunova
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Saathvika Rajamani
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | | | - Chao Zhou
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
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3
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Malhan D, Schoenrock B, Yalçin M, Blottner D, Relόgio A. Circadian regulation in aging: Implications for spaceflight and life on earth. Aging Cell 2023; 22:e13935. [PMID: 37493006 PMCID: PMC10497835 DOI: 10.1111/acel.13935] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/30/2023] [Accepted: 07/07/2023] [Indexed: 07/27/2023] Open
Abstract
Alterations in the circadian system are characteristic of aging on Earth. With the decline in physiological processes due to aging, several health concerns including vision loss, cardiovascular disorders, cognitive impairments, and muscle mass loss arise in elderly populations. Similar health risks are reported as "red flag" risks among astronauts during and after a long-term Space exploration journey. However, little is known about the common molecular alterations underlying terrestrial aging and space-related aging in astronauts, and controversial conclusions have been recently reported. In light of the regulatory role of the circadian clock in the maintenance of human health, we review here the overlapping role of the circadian clock both on aging on Earth and spaceflight with a focus on the four most affected systems: visual, cardiovascular, central nervous, and musculoskeletal systems. In this review, we briefly introduce the regulatory role of the circadian clock in specific cellular processes followed by alterations in those processes due to aging. We next summarize the known molecular alterations associated with spaceflight, highlighting involved clock-regulated genes in space flown Drosophila, nematodes, small mammals, and astronauts. Finally, we discuss common genes that are altered in terms of their expression due to aging on Earth and spaceflight. Altogether, the data elaborated in this review strengthen our hypothesis regarding the timely need to include circadian dysregulation as an emerging hallmark of aging on Earth and beyond.
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Affiliation(s)
- Deeksha Malhan
- Institute for Systems Medicine and Faculty of Human MedicineMSH Medical School HamburgHamburgGermany
| | - Britt Schoenrock
- Institute of Integrative NeuroanatomyCharité‐Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Müge Yalçin
- Institute for Systems Medicine and Faculty of Human MedicineMSH Medical School HamburgHamburgGermany
- Institute for Theoretical Biology (ITB)Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
- Molecular Cancer Research Center (MKFZ), Medical Department of Hematology, Oncology, and Tumour Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Dieter Blottner
- Institute of Integrative NeuroanatomyCharité‐Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
- Neuromuscular System and Neuromuscular SignalingBerlin Center of Space Medicine & Extreme EnvironmentsBerlinGermany
| | - Angela Relόgio
- Institute for Systems Medicine and Faculty of Human MedicineMSH Medical School HamburgHamburgGermany
- Institute for Theoretical Biology (ITB)Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
- Molecular Cancer Research Center (MKFZ), Medical Department of Hematology, Oncology, and Tumour Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
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4
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Migunova E, Rajamani S, Bonanni S, Wang F, Zhou C, Dubrovsky EB. Cardiac RNase Z edited via CRISPR-Cas9 drives heart hypertrophy in Drosophila. PLoS One 2023; 18:e0286214. [PMID: 37228086 PMCID: PMC10212119 DOI: 10.1371/journal.pone.0286214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 05/10/2023] [Indexed: 05/27/2023] Open
Abstract
Cardiomyopathy (CM) is a group of diseases distinguished by morphological and functional abnormalities in the myocardium. It is etiologically heterogeneous and may develop via cell autonomous and/or non-autonomous mechanisms. One of the most severe forms of CM has been linked to the deficiency of the ubiquitously expressed RNase Z endoribonuclease. RNase Z cleaves off the 3'-trailer of both nuclear and mitochondrial primary tRNA (pre-tRNA) transcripts. Cells mutant for RNase Z accumulate unprocessed pre-tRNA molecules. Patients carrying RNase Z variants with reduced enzymatic activity display a plethora of symptoms including muscular hypotonia, microcephaly and severe heart hypertrophy; still, they die primarily due to acute heart decompensation. Determining whether the underlying mechanism of heart malfunction is cell autonomous or not will provide an opportunity to develop novel strategies of more efficient treatments for these patients. In this study, we used CRISPR-TRiM technology to create Drosophila models that carry cardiomyopathy-linked alleles of RNase Z only in the cardiomyocytes. We found that this modification is sufficient for flies to develop heart hypertrophy and systolic dysfunction. These observations support the idea that the RNase Z linked CM is driven by cell autonomous mechanisms.
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Affiliation(s)
- Ekaterina Migunova
- Department of Biological Sciences, Fordham University, Bronx, NY, United States of America
| | - Saathvika Rajamani
- Department of Biological Sciences, Fordham University, Bronx, NY, United States of America
| | - Stefania Bonanni
- Department of Biological Sciences, Fordham University, Bronx, NY, United States of America
| | - Fei Wang
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States of America
| | - Chao Zhou
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States of America
| | - Edward B. Dubrovsky
- Department of Biological Sciences, Fordham University, Bronx, NY, United States of America
- Center for Cancer, Genetic Diseases, and Gene Regulation, Fordham University, Bronx, NY, United States of America
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5
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Faubert AC, Larina IV, Wang S. Open-source, highly efficient, post-acquisition synchronization for 4D dual-contrast imaging of the mouse embryonic heart over development with optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2023; 14:163-181. [PMID: 36698661 PMCID: PMC9842004 DOI: 10.1364/boe.475027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 05/28/2023]
Abstract
Dynamic imaging of the beating embryonic heart in 3D is critical for understanding cardiac development and defects. Optical coherence tomography (OCT) plays an important role in embryonic heart imaging with its unique imaging scale and label-free contrasts. In particular, 4D (3D + time) OCT imaging enabled biomechanical analysis of the developing heart in various animal models. While ultrafast OCT systems allow for direct volumetric imaging of the beating heart, the imaging speed remains limited, leading to an image quality inferior to that produced by post-acquisition synchronization. As OCT systems become increasingly available to a wide range of biomedical researchers, a more accessible 4D reconstruction method is required to enable the broader application of OCT in the dynamic, volumetric assessment of embryonic heartbeat. Here, we report an open-source, highly efficient, post-acquisition synchronization method for 4D cardiodynamic and hemodynamic imaging of the mouse embryonic heart. Relying on the difference between images to characterize heart wall movements, the method provides good sensitivity to the cardiac activity when aligning heartbeat phases, even at early stages when the heart wall occupies only a small number of pixels. The method works with a densely sampled single 3D data acquisition, which, unlike the B-M scans required by other methods, is readily available in most commercial OCT systems. Compared with an existing approach for the mouse embryonic heart, this method shows superior reconstruction quality. We present the robustness of the method through results from different embryos with distinct heart rates, ranging from 1.24 Hz to 2.13 Hz. Since the alignment process operates on a 1D signal, the method has a high efficiency, featuring sub-second alignment time while utilizing ∼100% of the original image files. This allows us to achieve repeated, dual-contrast imaging of mouse embryonic heart development. This new, open-source method could facilitate research using OCT to study early cardiogenesis.
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Affiliation(s)
- Andre C. Faubert
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Irina V. Larina
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shang Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
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6
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Roles of Drosophila fatty acid-binding protein in development and behavior. Biochem Biophys Res Commun 2022; 599:87-92. [PMID: 35176630 DOI: 10.1016/j.bbrc.2022.02.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 02/10/2022] [Indexed: 12/23/2022]
Abstract
Fatty acid-binding proteins (FABPs) are lipid chaperones that mediate the intracellular dynamics of the hydrophobic molecules that they physically bind to. FABPs are implicated in sleep and psychiatric disorders, as well as in various cellular processes, such as cell proliferation and survival. FABP is well conserved in insects, and Drosophila has one FABP ortholog, dFabp, in its genome. Although dFabp appears to be evolutionarily conserved in some brain functions, little is known about its development and physiological function. In the present study, we investigated the function of dFabp in Drosophila development and behavior. Knockdown or overexpression of dFabp in the developing brain, wing, and eye resulted in developmental defects, such as decreased survival, altered cell proliferation, and increased apoptosis. Glia-specific knockdown of dFabp affected neuronal development, and neuronal regulation of dFabp affected glial cell proliferation. Moreover, the behavioral phenotypes (circadian rhythm and locomotor activity) of flies with regulated dFabp expression in glia and flies with regulated dFabp expression in neurons were very similar. Collectively, our results suggest that dFabp is involved in the development of various tissues and brain functions to control behavior and is a mediator of neuron-glia interactions in the Drosophila nervous system.
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7
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Yildirim E, Curtis R, Hwangbo DS. Roles of peripheral clocks: lessons from the fly. FEBS Lett 2022; 596:263-293. [PMID: 34862983 PMCID: PMC8844272 DOI: 10.1002/1873-3468.14251] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 02/03/2023]
Abstract
To adapt to and anticipate rhythmic changes in the environment such as daily light-dark and temperature cycles, internal timekeeping mechanisms called biological clocks evolved in a diverse set of organisms, from unicellular bacteria to humans. These biological clocks play critical roles in organisms' fitness and survival by temporally aligning physiological and behavioral processes to the external cues. The central clock is located in a small subset of neurons in the brain and drives daily activity rhythms, whereas most peripheral tissues harbor their own clock systems, which generate metabolic and physiological rhythms. Since the discovery of Drosophila melanogaster clock mutants in the early 1970s, the fruit fly has become an extensively studied model organism to investigate the mechanism and functions of circadian clocks. In this review, we primarily focus on D. melanogaster to survey key discoveries and progresses made over the past two decades in our understanding of peripheral clocks. We discuss physiological roles and molecular mechanisms of peripheral clocks in several different peripheral tissues of the fly.
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Affiliation(s)
| | - Rachel Curtis
- Department of Biology, University of Louisville, Louisville, KY, USA
| | - Dae-Sung Hwangbo
- Department of Biology, University of Louisville, Louisville, KY, USA
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8
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Effects of an electric field on sleep quality and life span mediated by ultraviolet (UV)-A/blue light photoreceptor CRYPTOCHROME in Drosophila. Sci Rep 2021; 11:20543. [PMID: 34654874 PMCID: PMC8519966 DOI: 10.1038/s41598-021-99753-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 09/30/2021] [Indexed: 11/24/2022] Open
Abstract
Although electric fields (EF) exert beneficial effects on animal wound healing, differentiation, cancers and rheumatoid arthritis, the molecular mechanisms of these effects have remained unclear about a half century. Therefore, we aimed to elucidate the molecular mechanisms underlying EF effects in Drosophila melanogaster as a genetic animal model. Here we show that the sleep quality of wild type (WT) flies was improved by exposure to a 50-Hz (35 kV/m) constant electric field during the day time, but not during the night time. The effect was undetectable in cryptochrome mutant (cryb) flies. Exposure to a 50-Hz electric field under low nutrient conditions elongated the lifespan of male and female WT flies by ~ 18%, but not of several cry mutants and cry RNAi strains. Metabolome analysis indicated that the adenosine triphosphate (ATP) content was higher in intact WT than cry gene mutant strains exposed to an electric field. A putative magnetoreceptor protein and UV-A/blue light photoreceptor, CRYPTOCHROME (CRY) is involved in electric field (EF) receptors in animals. The present findings constitute hitherto unknown genetic evidence of a CRY-based system that is electric field sensitive in animals.
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9
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Migunova E, Theophilopoulos J, Mercadante M, Men J, Zhou C, Dubrovsky EB. ELAC2/RNaseZ-linked cardiac hypertrophy in Drosophila melanogaster. Dis Model Mech 2021; 14:271965. [PMID: 34338278 PMCID: PMC8419712 DOI: 10.1242/dmm.048931] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 07/20/2021] [Indexed: 12/16/2022] Open
Abstract
A severe form of infantile cardiomyopathy (CM) has been linked to mutations in ELAC2, a highly conserved human gene. It encodes Zinc phosphodiesterase ELAC protein 2 (ELAC2), which plays an essential role in the production of mature tRNAs. To establish a causal connection between ELAC2 variants and CM, here we used the Drosophila melanogaster model organism, which carries the ELAC2 homolog RNaseZ. Even though RNaseZ and ELAC2 have diverged in some of their biological functions, our study demonstrates the use of the fly model to study the mechanism of ELAC2-related pathology. We established transgenic lines harboring RNaseZ with CM-linked mutations in the background of endogenous RNaseZ knockout. Importantly, we found that the phenotype of these flies is consistent with the pathological features in human patients. Specifically, expression of CM-linked variants in flies caused heart hypertrophy and led to reduction in cardiac contractility associated with a rare form of CM. This study provides first experimental evidence for the pathogenicity of CM-causing mutations in the ELAC2 protein, and the foundation to improve our understanding and diagnosis of this rare infantile disease. This article has an associated First Person interview with the first author of the paper. Summary: A newly established Drosophila model recapitulates key features of human heart pathology linked to mutations in ELAC2, thus providing experimental evidence of the pathogenicity of ELAC2 variants.
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Affiliation(s)
- Ekaterina Migunova
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | | | - Marisa Mercadante
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Jing Men
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO 63105, USA.,Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Chao Zhou
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO 63105, USA
| | - Edward B Dubrovsky
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA.,Center for Cancer, Genetic diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
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10
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Li A, Tanzi RE. <p>Optogenetic Pacing: Current Insights and Future Potential</p>. RESEARCH REPORTS IN CLINICAL CARDIOLOGY 2020. [DOI: 10.2147/rrcc.s242650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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11
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Wang S, Larina IV. Live mechanistic assessment of localized cardiac pumping in mammalian tubular embryonic heart. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-19. [PMID: 32762173 PMCID: PMC7403774 DOI: 10.1117/1.jbo.25.8.086001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/23/2020] [Indexed: 06/01/2023]
Abstract
SIGNIFICANCE Understanding how the valveless embryonic heart pumps blood is essential to elucidate biomechanical cues regulating cardiogenesis, which is important for the advancement of congenital heart defects research. However, methods capable of embryonic cardiac pumping analysis remain limited, and assessing this highly dynamic process in mammalian embryos is challenging. New approaches are critically needed to address this hurdle. AIM We report an imaging-based approach for functional assessment of localized pumping dynamics in the early tubular embryonic mouse heart. APPROACH Four-dimensional optical coherence tomography was used to obtain structural and Doppler hemodynamic imaging of the beating heart in live mouse embryos at embryonic day 9.25. The pumping assessment was performed based on the volumetric blood flow rate, flow resistance within the heart tube, and pressure gradient induced by heart wall movements. The relation between the blood flow, the pressure gradient, and the resistance to flow were evaluated through temporal analyses and Granger causality test. RESULTS In the ventricles, our method revealed connections between the temporal profiles of pressure gradient and volumetric blood flow rate. Statistically significant causal relation from the pressure gradient to the blood flow was demonstrated. Our analysis also suggests that cardiac pumping in the early ventricles is a combination of suction and pushing. In contrast, in the outflow tract, where the conduction wave is slower than the blood flow, we did not find significant causal relation from pressure to flow, suggesting that, different from ventricular regions, the local active contraction of the outflow tract is unlikely to drive the flow in that region. CONCLUSIONS We present an imaging-based approach that enables localized assessment of pumping dynamics in the mouse tubular embryonic heart. This method creates a new opportunity for functional analysis of the pumping mechanism underlying the developing mammalian heart at early stages and could be useful for studying biomechanical changes in mutant embryonic hearts that model congenital heart defects.
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Affiliation(s)
- Shang Wang
- Stevens Institute of Technology, Department of Biomedical Engineering, Hoboken, New Jersey, USA
| | - Irina V. Larina
- Baylor College of Medicine, Department of Molecular Physiology and Biophysics, Houston, Texas, USA
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12
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Men J, Li A, Jerwick J, Li Z, Tanzi RE, Zhou C. Non-invasive red-light optogenetic control of Drosophila cardiac function. Commun Biol 2020; 3:336. [PMID: 32601302 PMCID: PMC7324573 DOI: 10.1038/s42003-020-1065-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 06/03/2020] [Indexed: 02/03/2023] Open
Abstract
Drosophila is a powerful genetic model system for cardiovascular studies. Recently, optogenetic pacing tools have been developed to control Drosophila heart rhythm noninvasively with blue light, which has a limited penetration depth. Here we developed both a red-light sensitive opsin expressing Drosophila system and an integrated red-light stimulation and optical coherence microscopy (OCM) imaging system. We demonstrated noninvasive control of Drosophila cardiac rhythms using a single light source, including simulated tachycardia in ReaChR-expressing flies and bradycardia and cardiac arrest in halorhodopsin (NpHR)-expressing flies at multiple developmental stages. By using red excitation light, we were able to pace flies at higher efficiency and with lower power than with equivalent blue light excitation systems. The recovery dynamics after red-light stimulation of NpHR flies were observed and quantified. The combination of red-light stimulation, OCM imaging, and transgenic Drosophila systems provides a promising and easily manipulated research platform for noninvasive cardiac optogenetic studies. Men et al. develop an optogenetic pacing tool to control Drosophila heart rhythm noninvasively with red light. Using optical coherence microscopy imaging, they demonstrate effective light-induced tachypacing, bradypacing, and restorable cardiac arrest in transgenic fly models. This study provides a user-friendly research platform for noninvasive cardiac optogenetic studies.
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Affiliation(s)
- Jing Men
- Department of Bioengineering, Lehigh University, Bethlehem, PA, 18015, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63105, USA
| | - Airong Li
- Genetics and Aging Research Unit, McCance Center for Brain Health, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Jason Jerwick
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63105, USA.,Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, 18015, USA
| | - Zilong Li
- Genetics and Aging Research Unit, McCance Center for Brain Health, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, McCance Center for Brain Health, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Chao Zhou
- Department of Bioengineering, Lehigh University, Bethlehem, PA, 18015, USA. .,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63105, USA. .,Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, 18015, USA.
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13
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Wang S, Larina IV, Larin KV. Label-free optical imaging in developmental biology [Invited]. BIOMEDICAL OPTICS EXPRESS 2020; 11:2017-2040. [PMID: 32341864 PMCID: PMC7173889 DOI: 10.1364/boe.381359] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/30/2020] [Accepted: 02/25/2020] [Indexed: 05/03/2023]
Abstract
Application of optical imaging in developmental biology marks an exciting frontier in biomedical optics. Optical resolution and imaging depth allow for investigation of growing embryos at subcellular, cellular, and whole organism levels, while the complexity and variety of embryonic processes set multiple challenges stimulating the development of various live dynamic embryonic imaging approaches. Among other optical methods, label-free optical techniques attract an increasing interest as they allow investigation of developmental mechanisms without application of exogenous markers or fluorescent reporters. There has been a boost in development of label-free optical imaging techniques for studying embryonic development in animal models over the last decade, which revealed new information about early development and created new areas for investigation. Here, we review the recent progress in label-free optical embryonic imaging, discuss specific applications, and comment on future developments at the interface of photonics, engineering, and developmental biology.
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Affiliation(s)
- Shang Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, 1 Castle Point Terrace, Hoboken, NJ 07030, USA
| | - Irina V. Larina
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Kirill V. Larin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, TX 77204, USA
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14
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Duan L, Qin X, He Y, Sang X, Pan J, Xu T, Men J, Tanzi RE, Li A, Ma Y, Zhou C. Segmentation of Drosophila heart in optical coherence microscopy images using convolutional neural networks. JOURNAL OF BIOPHOTONICS 2018; 11:e201800146. [PMID: 29992766 PMCID: PMC6289629 DOI: 10.1002/jbio.201800146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/08/2018] [Indexed: 05/06/2023]
Abstract
Convolutional neural networks (CNNs) are powerful tools for image segmentation and classification. Here, we use this method to identify and mark the heart region of Drosophila at different developmental stages in the cross-sectional images acquired by a custom optical coherence microscopy (OCM) system. With our well-trained CNN model, the heart regions through multiple heartbeat cycles can be marked with an intersection over union of ~86%. Various morphological and dynamical cardiac parameters can be quantified accurately with automatically segmented heart regions. This study demonstrates an efficient heart segmentation method to analyze OCM images of the beating heart in Drosophila.
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Affiliation(s)
- Lian Duan
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, USA
| | - Xi Qin
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, USA
| | - Yuanhao He
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, USA
| | - Xialin Sang
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, USA
- Department of Electrical Engineering and Computer Science, Hainan University, Haikou, China
| | - Jinda Pan
- School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Tao Xu
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, USA
- State Key Laboratory of Software Engineering, Wuhan University, Wuhan, China
| | - Jing Men
- Department of Bioengineering, Lehigh University, Bethlehem, PA, USA
| | - Rudolph E. Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, USA
| | - Airong Li
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, USA
| | - Yutao Ma
- State Key Laboratory of Software Engineering, Wuhan University, Wuhan, China
| | - Chao Zhou
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, USA
- Department of Bioengineering, Lehigh University, Bethlehem, PA, USA
- Correspondence: Chao Zhou, Department of Electrical and Computer Engineering, Lehigh University, 19 Memorial Drive West, 18015, Bethlehem, PA, USA
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15
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Grishina OA, Wang S, Larina IV. Speckle variance optical coherence tomography of blood flow in the beating mouse embryonic heart. JOURNAL OF BIOPHOTONICS 2017; 10:735-743. [PMID: 28417585 PMCID: PMC5565627 DOI: 10.1002/jbio.201600293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/25/2017] [Accepted: 01/31/2017] [Indexed: 05/19/2023]
Abstract
Efficient separation of blood and cardiac wall in the beating embryonic heart is essential and critical for experiment-based computational modelling and analysis of early-stage cardiac biomechanics. Although speckle variance optical coherence tomography (SV-OCT) relying on calculation of intensity variance over consecutively acquired frames is a powerful approach for segmentation of fluid flow from static tissue, application of this method in the beating embryonic heart remains challenging because moving structures generate SV signal indistinguishable from the blood. Here, we demonstrate a modified four-dimensional SV-OCT approach that effectively separates the blood flow from the dynamic heart wall in the beating mouse embryonic heart. The method takes advantage of the periodic motion of the cardiac wall and is based on calculation of the SV signal over the frames corresponding to the same phase of the heartbeat cycle. Through comparison with Doppler OCT imaging, we validate this speckle-based approach and show advantages in its insensitiveness to the flow direction and velocity as well as reduced influence from the heart wall movement. This approach has a potential in variety of applications relying on visualization and segmentation of blood flow in periodically moving structures, such as mechanical simulation studies and finite element modelling. Picture: Four-dimensional speckle variance OCT imaging shows the blood flow inside the beating heart of an E8.5 mouse embryo.
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Affiliation(s)
| | | | - Irina V. Larina
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, 77030, USA
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16
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Klassen MP, Peters CJ, Zhou S, Williams HH, Jan LY, Jan YN. Age-dependent diastolic heart failure in an in vivo Drosophila model. eLife 2017; 6. [PMID: 28328397 PMCID: PMC5362267 DOI: 10.7554/elife.20851] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 02/11/2017] [Indexed: 12/13/2022] Open
Abstract
While the signals and complexes that coordinate the heartbeat are well established, how the heart maintains its electromechanical rhythm over a lifetime remains an open question with significant implications to human health. Reasoning that this homeostatic challenge confronts all pulsatile organs, we developed a high resolution imaging and analysis toolset for measuring cardiac function in intact, unanesthetized Drosophila melanogaster. We demonstrate that, as in humans, normal aging primarily manifests as defects in relaxation (diastole) while preserving contractile performance. Using this approach, we discovered that a pair of two-pore potassium channel (K2P) subunits, largely dispensable early in life, are necessary for terminating contraction (systole) in aged animals, where their loss culminates in fibrillatory cardiac arrest. As the pumping function of its heart is acutely dispensable for survival, Drosophila represents a uniquely accessible model for understanding the signaling networks maintaining cardiac performance during normal aging.
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Affiliation(s)
- Matthew P Klassen
- Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Christian J Peters
- Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Shiwei Zhou
- Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Hannah H Williams
- Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Lily Yeh Jan
- Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States.,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Yuh Nung Jan
- Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
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17
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Arthaut LD, Jourdan N, Mteyrek A, Procopio M, El-Esawi M, d’Harlingue A, Bouchet PE, Witczak J, Ritz T, Klarsfeld A, Birman S, Usselman RJ, Hoecker U, Martino CF, Ahmad M. Blue-light induced accumulation of reactive oxygen species is a consequence of the Drosophila cryptochrome photocycle. PLoS One 2017; 12:e0171836. [PMID: 28296892 PMCID: PMC5351967 DOI: 10.1371/journal.pone.0171836] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 01/26/2017] [Indexed: 01/03/2023] Open
Abstract
Cryptochromes are evolutionarily conserved blue-light absorbing flavoproteins which participate in many important cellular processes including in entrainment of the circadian clock in plants, Drosophila and humans. Drosophila melanogaster cryptochrome (DmCry) absorbs light through a flavin (FAD) cofactor that undergoes photoreduction to the anionic radical (FAD•-) redox state both in vitro and in vivo. However, recent efforts to link this photoconversion to the initiation of a biological response have remained controversial. Here, we show by kinetic modeling of the DmCry photocycle that the fluence dependence, quantum yield, and half-life of flavin redox state interconversion are consistent with the anionic radical (FAD•-) as the signaling state in vivo. We show by fluorescence detection techniques that illumination of purified DmCry results in enzymatic conversion of molecular oxygen (O2) to reactive oxygen species (ROS). We extend these observations in living cells to demonstrate transient formation of superoxide (O2•-), and accumulation of hydrogen peroxide (H2O2) in the nucleus of insect cell cultures upon DmCry illumination. These results define the kinetic parameters of the Drosophila cryptochrome photocycle and support light-driven electron transfer to the flavin in DmCry signaling. They furthermore raise the intriguing possibility that light-dependent formation of ROS as a byproduct of the cryptochrome photocycle may contribute to its signaling role.
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Affiliation(s)
- Louis-David Arthaut
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
- Department of Biomedical Engineering, Florida Institute of Technology, Melbourne, Florida, United States of America
| | | | - Ali Mteyrek
- GCRN team, Brain Plasticity Unit, UMR 8249 CNRS/ESPCI Paris, PSL Research University, Paris, France
| | - Maria Procopio
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
- Department of Physics and Astronomy, University of California, Irvine, California, United States of America
| | - Mohamed El-Esawi
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
- Botany Department, Faculty of Science, Tanta University, Tanta, Egypt
| | | | | | - Jacques Witczak
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
| | - Thorsten Ritz
- Department of Physics and Astronomy, University of California, Irvine, California, United States of America
| | - André Klarsfeld
- GCRN team, Brain Plasticity Unit, UMR 8249 CNRS/ESPCI Paris, PSL Research University, Paris, France
| | - Serge Birman
- GCRN team, Brain Plasticity Unit, UMR 8249 CNRS/ESPCI Paris, PSL Research University, Paris, France
| | - Robert J. Usselman
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Carlos F. Martino
- Department of Biomedical Engineering, Florida Institute of Technology, Melbourne, Florida, United States of America
| | - Margaret Ahmad
- UMR CNRS 8256 (B2A), IBPS, Université Paris VI, Paris, France
- Department of Biology, Xavier University, Cincinnati, Ohio, United States of America
- * E-mail:
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18
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Wang S, Garcia MD, Lopez AL, Overbeek PA, Larin KV, Larina IV. Dynamic imaging and quantitative analysis of cranial neural tube closure in the mouse embryo using optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2017; 8:407-419. [PMID: 28101427 PMCID: PMC5231309 DOI: 10.1364/boe.8.000407] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 12/14/2016] [Indexed: 05/18/2023]
Abstract
Neural tube closure is a critical feature of central nervous system morphogenesis during embryonic development. Failure of this process leads to neural tube defects, one of the most common forms of human congenital defects. Although molecular and genetic studies in model organisms have provided insights into the genes and proteins that are required for normal neural tube development, complications associated with live imaging of neural tube closure in mammals limit efficient morphological analyses. Here, we report the use of optical coherence tomography (OCT) for dynamic imaging and quantitative assessment of cranial neural tube closure in live mouse embryos in culture. Through time-lapse imaging, we captured two neural tube closure mechanisms in different cranial regions, zipper-like closure of the hindbrain region and button-like closure of the midbrain region. We also used OCT imaging for phenotypic characterization of a neural tube defect in a mouse mutant. These results suggest that the described approach is a useful tool for live dynamic analysis of normal neural tube closure and neural tube defects in the mouse model.
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Affiliation(s)
- Shang Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
- Equal Contribution
| | - Monica D. Garcia
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
- Equal Contribution
| | - Andrew L. Lopez
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Paul A. Overbeek
- Department of Molecular & Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Kirill V. Larin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
- Interdisciplinary Laboratory of Biophotonics, Tomsk State University, Tomsk, Russia
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd., Houston, TX 77204, USA
| | - Irina V. Larina
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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19
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Men J, Jerwick J, Wu P, Chen M, Alex A, Ma Y, Tanzi RE, Li A, Zhou C. Drosophila Preparation and Longitudinal Imaging of Heart Function In Vivo Using Optical Coherence Microscopy (OCM). J Vis Exp 2016. [PMID: 28060288 DOI: 10.3791/55002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Longitudinal study of the heartbeat in small animals contributes to understanding structural and functional changes during heart development. Optical coherence microscopy (OCM) has been demonstrated to be capable of imaging small animal hearts with high spatial resolution and ultrahigh imaging speed. The high image contrast and noninvasive properties make OCM ideal for performing longitudinal studies without requiring tissue dissections or staining. Drosophila has been widely used as a model organism in cardiac developmental studies due to its high number of orthologous human disease genes, its similarity of molecular mechanisms and genetic pathways with vertebrates, its short life cycle, and its low culture cost. Here, the experimental protocols are described for the preparation of Drosophila and optical imaging of the heartbeat with a custom OCM system throughout the life cycle of the specimen. By following the steps provided in this report, transverse M-mode and 3D OCM images can be acquired to conduct longitudinal studies of the Drosophila cardiac morphology and function. The en face and axial sectional OCM images and the heart rate (HR) and cardiac activity period (CAP) histograms, were also shown to analyze the heart structural changes and to quantify the heart dynamics during Drosophila metamorphosis, combined with the videos constructed with M-mode images to trace cardiac activity intuitively. Due to the genetic similarity between Drosophila and vertebrates, longitudinal study of heart morphology and dynamics in fruit flies could help reveal the origins of human heart diseases. The protocol here would provide an effective method to perform a wide range of studies to understand the mechanisms of cardiac diseases in humans.
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Affiliation(s)
- Jing Men
- Bioengineering Program, Lehigh University; Center for Photonics and Nanoelectronics, Lehigh University
| | - Jason Jerwick
- Center for Photonics and Nanoelectronics, Lehigh University; Department of Electrical and Computer Engineering, Lehigh University
| | - Penghe Wu
- Bioengineering Program, Lehigh University; Center for Photonics and Nanoelectronics, Lehigh University
| | - Mingming Chen
- Department of Electrical and Computer Engineering, Lehigh University; State Key Laboratory of Software Engineering, Wuhan University
| | - Aneesh Alex
- Center for Photonics and Nanoelectronics, Lehigh University; Department of Electrical and Computer Engineering, Lehigh University
| | - Yutao Ma
- State Key Laboratory of Software Engineering, Wuhan University
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School
| | - Airong Li
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School
| | - Chao Zhou
- Bioengineering Program, Lehigh University; Center for Photonics and Nanoelectronics, Lehigh University; Department of Electrical and Computer Engineering, Lehigh University;
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20
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Men J, Huang Y, Solanki J, Zeng X, Alex A, Jerwick J, Zhang Z, Tanzi RE, Li A, Zhou C. Optical Coherence Tomography for Brain Imaging and Developmental Biology. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2016; 22:6803213. [PMID: 27721647 PMCID: PMC5049888 DOI: 10.1109/jstqe.2015.2513667] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT) is a promising research tool for brain imaging and developmental biology. Serving as a three-dimensional optical biopsy technique, OCT provides volumetric reconstruction of brain tissues and embryonic structures with micrometer resolution and video rate imaging speed. Functional OCT enables label-free monitoring of hemodynamic and metabolic changes in the brain in vitro and in vivo in animal models. Due to its non-invasiveness nature, OCT enables longitudinal imaging of developing specimens in vivo without potential damage from surgical operation, tissue fixation and processing, and staining with exogenous contrast agents. In this paper, various OCT applications in brain imaging and developmental biology are reviewed, with a particular focus on imaging heart development. In addition, we report findings on the effects of a circadian gene (Clock) and high-fat-diet on heart development in Drosophila melanogaster. These findings contribute to our understanding of the fundamental mechanisms connecting circadian genes and obesity to heart development and cardiac diseases.
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Affiliation(s)
- Jing Men
- Department of Electrical and Computer Engineering, Center for Photonics and Nanoelectronics, and Bioengineering Program, Lehigh University, Bethlehem, PA, USA, 18015
| | - Yongyang Huang
- Department of Electrical and Computer Engineering, Center for Photonics and Nanoelectronics, and Bioengineering Program, Lehigh University, Bethlehem, PA, USA, 18015
| | - Jitendra Solanki
- Department of Electrical and Computer Engineering, Center for Photonics and Nanoelectronics, and Bioengineering Program, Lehigh University, Bethlehem, PA, USA, 18015
| | - Xianxu Zeng
- Department of Electrical and Computer Engineering, Center for Photonics and Nanoelectronics, and Bioengineering Program, Lehigh University, Bethlehem, PA, USA, 18015
- Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P.R. China, 450000
| | - Aneesh Alex
- Department of Electrical and Computer Engineering, Center for Photonics and Nanoelectronics, and Bioengineering Program, Lehigh University, Bethlehem, PA, USA, 18015
| | - Jason Jerwick
- Department of Electrical and Computer Engineering, Center for Photonics and Nanoelectronics, and Bioengineering Program, Lehigh University, Bethlehem, PA, USA, 18015
| | - Zhan Zhang
- Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P.R. China, 450000
| | - Rudolph E. Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA, 02129
| | - Airong Li
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA, 02129
| | - Chao Zhou
- Department of Electrical and Computer Engineering, Center for Photonics and Nanoelectronics, and Bioengineering Program, Lehigh University, Bethlehem, PA, USA, 18015
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21
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Takeda N, Maemura K. Circadian clock and the onset of cardiovascular events. Hypertens Res 2016; 39:383-90. [PMID: 26888119 DOI: 10.1038/hr.2016.9] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 01/11/2016] [Accepted: 01/12/2016] [Indexed: 02/07/2023]
Abstract
The onset of cardiovascular diseases often shows time-of-day variation. Acute myocardial infarction or ventricular arrhythmia such as ventricular tachycardia occurs mainly in the early morning. Multiple biochemical and physiological parameters show circadian rhythm, which may account for the diurnal variation of cardiovascular events. These include the variations in blood pressure, activity of the autonomic nervous system and renin-angiotensin axis, coagulation cascade, vascular tone and the intracellular metabolism of cardiomyocytes. Importantly, the molecular clock system seems to underlie the circadian variation of these parameters. The center of the biological clock, also known as the central clock, exists in the suprachiasmatic nucleus. In contrast, the molecular clock system is also activated in each cell of the peripheral organs and constitute the peripheral clock. The biological clock system is currently considered to have a beneficial role in maintaining the homeostasis of each organ. Discoordination, however, between the peripheral clock and external environment could potentially underlie the development of cardiovascular events. Therefore, understanding the molecular and cellular pathways by which cardiovascular events occur in a diurnal oscillatory pattern will help the establishment of a novel therapeutic approach to the management of cardiovascular disorders.
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Affiliation(s)
- Norihiko Takeda
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Koji Maemura
- Department of Cardiovascular Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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22
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Alex A, Li A, Tanzi RE, Zhou C. Optogenetic pacing in Drosophila melanogaster. SCIENCE ADVANCES 2015; 1:e1500639. [PMID: 26601299 PMCID: PMC4646813 DOI: 10.1126/sciadv.1500639] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 08/12/2015] [Indexed: 05/19/2023]
Abstract
Electrical stimulation is currently the gold standard for cardiac pacing. However, it is invasive and nonspecific for cardiac tissues. We recently developed a noninvasive cardiac pacing technique using optogenetic tools, which are widely used in neuroscience. Optogenetic pacing of the heart provides high spatial and temporal precisions, is specific for cardiac tissues, avoids artifacts associated with electrical stimulation, and therefore promises to be a powerful tool in basic cardiac research. We demonstrated optogenetic control of heart rhythm in a well-established model organism, Drosophila melanogaster. We developed transgenic flies expressing a light-gated cation channel, channelrhodopsin-2 (ChR2), specifically in their hearts and demonstrated successful optogenetic pacing of ChR2-expressing Drosophila at different developmental stages, including the larva, pupa, and adult stages. A high-speed and ultrahigh-resolution optical coherence microscopy imaging system that is capable of providing images at a rate of 130 frames/s with axial and transverse resolutions of 1.5 and 3.9 μm, respectively, was used to noninvasively monitor Drosophila cardiac function and its response to pacing stimulation. The development of a noninvasive integrated optical pacing and imaging system provides a novel platform for performing research studies in developmental cardiology.
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Affiliation(s)
- Aneesh Alex
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
- Center for Photonics and Nanoelectronics, Lehigh University, Bethlehem, PA 18015, USA
| | - Airong Li
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA
| | - Rudolph E. Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA
- Corresponding author. E-mail: (R.E.T.); (C.Z.)
| | - Chao Zhou
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
- Center for Photonics and Nanoelectronics, Lehigh University, Bethlehem, PA 18015, USA
- Bioengineering Program, Lehigh University, Bethlehem, PA 18015, USA
- Corresponding author. E-mail: (R.E.T.); (C.Z.)
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