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Sample records for adult mouse cardiomyocytes

  1. An improved isolation procedure for adult mouse cardiomyocytes.

    PubMed

    Pinz, Ilka; Zhu, Ming; Mende, Ulrike; Ingwall, Joanne S

    2011-09-01

    Isolated adult mouse cardiomyocytes are an important tool in cardiovascular research, but are challenging to prepare. Because the energy supply determines cell function and viability, we compared total creatine ([Cr]) and [ATP] in isolated cardiomyocytes with the intact mouse heart. Isolated myocytes suffered severe losses of Cr (-70%) and ATP (-53%). Myocytes were not able to replete [Cr] during a 5 h incubation period in medium supplemented with 1 mM Cr. In contrast, adding 20 mM Cr to the digestion buffers was sufficient to maintain normal [Cr]. Supplementing buffers with 5 mM of inosine (Ino) and adenosine (Ado) to prevent loss of cellular nucleosides partially protected against loss of ATP. To test whether maintaining [ATP] and [Cr] improves contractile function, myocytes were challenged by varying pacing rate from 0.5 to 10 Hz and by adding isoproterenol (Iso) at 5 and 10 Hz. All groups performed well up to 5 Hz, showing a positive cell shortening-frequency relationship; however, only 16% of myocytes isolated under standard conditions were able to sustain pacing with Iso challenge at 10 Hz. In contrast, 30-50% of the myocytes with normal Cr levels were able to contract and maintain low diastolic [Ca(2+)]. Cell yield also improved in Cr and the Cr/Ino/Ado-treated groups (85-90% vs. 70-75% rod shaped in untreated myocytes). These data suggest that viability and performance of isolated myocytes are improved when they are protected from the severe loss of Cr and ATP during the isolation, making them an even better research tool. PMID:21327944

  2. Female Adult Mouse Cardiomyocytes Are Protected Against Oxidative Stress

    PubMed Central

    Wang, Fangfei; He, Quan; Sun, Ying; Dai, Xiangguo; Yang, Xiao-Ping

    2010-01-01

    Premenopausal women have less cardiovascular disease and lower cardiovascular morbidity and mortality than men the same age. Our previous studies showed that female mice have lower mortality and better preserved cardiac function after myocardial infarction. However, the precise cellular and molecular mechanisms responsible for such a sex difference are not well established. Using cultured adult mouse cardiomyocytes (ACMs), we tested the hypothesis that the survival advantage of females stems from activated estrogen receptors (ER) and Akt survival signaling pathways. ACMs were isolated from male and female C57BL/6J mice and treated with hydrogen peroxide (H2O2, 100 μM) for 30 min. Cell survival was indicated by rod ratio (rod shaped cells/total cells) and cell death by lactate dehydrogenase (LDH) release and positive staining of Annexin-V (AV+, a marker for apoptosis) and propidium iodide (PI+, a marker for necrosis). In response to H2O2, female ACMs exhibited a higher rod ratio, lower LDH release and fewer AV+ and PI+ cells compared to males. Phospho-Akt was greater in females both at baseline and after H2O2 stimulation. The downstream molecule of Akt, phosphor-GSK-3β (inactivation), was also higher while caspase-3 activity was lower in females in response to H2O2. Bcl-2 did not differ between genders. ERα was the dominant isoform in females, whereas ERβ was low but similar in both genders. Our findings demonstrate that female ACMs have a greater survival advantage when challenged with oxidative stress-induced cell death. This may be attributable to activation of Akt and inhibition of GSK-3β and caspase-3 through an ERα-mediated mechanism. PMID:20212261

  3. Isolation and Culture of Adult Mouse Cardiomyocytes for Cell Signaling and in vitro Cardiac Hypertrophy

    PubMed Central

    Li, Daxiang; Wu, Jian; Bai, Yan; Zhao, Xiaochen; Liu, Lijun

    2014-01-01

    Technological advances have made genetically modified mice, including transgenic and gene knockout mice, an essential tool in many research fields. Adult cardiomyocytes are widely accepted as a good model for cardiac cellular physiology and pathophysiology, as well as for pharmaceutical intervention. Genetically modified mice preclude the need for complicated cardiomyocyte infection processes to generate the desired genotype, which are inefficient due to cardiomyocytes’ terminal differentiation. Isolation and culture of high quantity and quality functional cardiomyocytes will dramatically benefit cardiovascular research and provide an important tool for cell signaling transduction research and drug development. Here, we describe a well-established method for isolation of adult mouse cardiomyocytes that can be implemented with little training. The mouse heart is excised and cannulated to an isolated heart system, then perfused with a calcium-free and high potassium buffer followed by type II collagenase digestion in Langendorff retrograde perfusion mode. This protocol yields a consistent result for the collection of functional adult mouse cardiomyocytes from a variety of genetically modified mice. PMID:24894542

  4. Cardiomyocyte marker expression in a human lymphocyte cell line using mouse cardiomyocyte extract.

    PubMed

    Vojdani, Zahra; Tavakolinejad, Sima; Talaei-Khozani, Tahereh; Esmaeilpour, Tahereh; Rasooli, Manuchehr

    2011-03-01

    Cell transplantation shows potential for the treatment of cardiac diseases. Embryonic stem cells, cord blood and mesenchymal stem cells have been suggested as sources for transplantation therapy. Because of some technical limitations with the use of stem cells, transdifferentiation of fully differentiated cells is a potentially useful alternative. We investigated whether human peripheral blood cells could transdifferentiate into cardiomyocyte. Transdifferentiation was induced in a human B lymphocyte cell line (Raji). Cardiomyocyte extract was prepared from adult mouse cardiomyocytes. The cells were treated with 5-aza-2-deoxycytidine and trichostatin A, permeabilized with streptolysin O, and exposed to the mouse cardiomyocyte extract. They were cultured for 10 days, 3 weeks and 4 weeks. Cardiomyocyte markers were detected with immunohistochemistry and flow cytometry. Immunocytochemistry revealed that some cells expressed myosin heavy chain, α-actinin and cardiac troponin T after 3 and 4 weeks. Flow cytometry confirmed these data. In cells exposed to trichostatin A and 5-aza-2-deoxycytidine and permeabilized in the presence of the cardiomyocyte extract, troponin T expression was seen in 3.53% of the cells and 3.11% of them expressed α-actinin. After exposure to the cardiomyocyte extract, some permeabilized cells adhered to the plate loosely; however, the morphology did not change significantly, and they continued to show a rounded shape after 4 weeks. Our treated lymphocytes expressed cardiomyocyte markers. Our results suggest that lymphocytes may be useful in future research as a source of cells for reprogramming procedures. PMID:21547694

  5. Origin of Cardiomyocytes in the Adult Heart

    PubMed Central

    Leri, Annarosa; Rota, Marcello; Pasqualini, Francesco S.; Goichberg, Polina; Anversa, Piero

    2014-01-01

    This review article discusses the mechanisms of cardiomyogenesis in the adult heart. They include the reentry of cardiomyocytes into the cell cycle; dedifferentiation of preexisting cardiomyocytes which assume an immature replicating cell phenotype; transdifferentiation of hematopoietic stem cells into cardiomyocytes; and cardiomyocytes derived from activation and lineage specification of resident cardiac stem cells. The recognition of the origin of cardiomyocytes is of critical importance for the development of strategies capable of enhancing the growth response of the myocardium; in fact, cell therapy for the decompensated heart has to be based on the acquisition of this fundamental biological knowledge. PMID:25552694

  6. Epigenomic Reprogramming of Adult Cardiomyocyte-Derived Cardiac Progenitor Cells.

    PubMed

    Zhang, Yiqiang; Zhong, Jiang F; Qiu, Hongyu; MacLellan, W Robb; Marbán, Eduardo; Wang, Charles

    2015-01-01

    It has been believed that mammalian adult cardiomyocytes (ACMs) are terminally-differentiated and are unable to proliferate. Recently, using a bi-transgenic ACM fate mapping mouse model and an in vitro culture system, we demonstrated that adult mouse cardiomyocytes were able to dedifferentiate into cardiac progenitor-like cells (CPCs). However, little is known about the molecular basis of their intrinsic cellular plasticity. Here we integrate single-cell transcriptome and whole-genome DNA methylation analyses to unravel the molecular mechanisms underlying the dedifferentiation and cell cycle reentry of mouse ACMs. Compared to parental cardiomyocytes, dedifferentiated mouse cardiomyocyte-derived CPCs (mCPCs) display epigenomic reprogramming with many differentially-methylated regions, both hypermethylated and hypomethylated, across the entire genome. Correlated well with the methylome, our transcriptomic data showed that the genes encoding cardiac structure and function proteins are remarkably down-regulated in mCPCs, while those for cell cycle, proliferation, and stemness are significantly up-regulated. In addition, implantation of mCPCs into infarcted mouse myocardium improves cardiac function with augmented left ventricular ejection fraction. Our study demonstrates that the cellular plasticity of mammalian cardiomyocytes is the result of a well-orchestrated epigenomic reprogramming and a subsequent global transcriptomic alteration. PMID:26657817

  7. Epigenomic Reprogramming of Adult Cardiomyocyte-Derived Cardiac Progenitor Cells

    PubMed Central

    Zhang, Yiqiang; Zhong, Jiang F; Qiu, Hongyu; Robb MacLellan, W.; Marbán, Eduardo; Wang, Charles

    2015-01-01

    It has been believed that mammalian adult cardiomyocytes (ACMs) are terminally-differentiated and are unable to proliferate. Recently, using a bi-transgenic ACM fate mapping mouse model and an in vitro culture system, we demonstrated that adult mouse cardiomyocytes were able to dedifferentiate into cardiac progenitor-like cells (CPCs). However, little is known about the molecular basis of their intrinsic cellular plasticity. Here we integrate single-cell transcriptome and whole-genome DNA methylation analyses to unravel the molecular mechanisms underlying the dedifferentiation and cell cycle reentry of mouse ACMs. Compared to parental cardiomyocytes, dedifferentiated mouse cardiomyocyte-derived CPCs (mCPCs) display epigenomic reprogramming with many differentially-methylated regions, both hypermethylated and hypomethylated, across the entire genome. Correlated well with the methylome, our transcriptomic data showed that the genes encoding cardiac structure and function proteins are remarkably down-regulated in mCPCs, while those for cell cycle, proliferation, and stemness are significantly up-regulated. In addition, implantation of mCPCs into infarcted mouse myocardium improves cardiac function with augmented left ventricular ejection fraction. Our study demonstrates that the cellular plasticity of mammalian cardiomyocytes is the result of a well-orchestrated epigenomic reprogramming and a subsequent global transcriptomic alteration. PMID:26657817

  8. Isolation and Physiological Analysis of Mouse Cardiomyocytes

    PubMed Central

    Roth, Gretchen M.; Bader, David M.; Pfaltzgraff, Elise R.

    2014-01-01

    Cardiomyocytes, the workhorse cell of the heart, contain exquisitely organized cytoskeletal and contractile elements that generate the contractile force used to pump blood. Individual cardiomyocytes were first isolated over 40 years ago in order to better study the physiology and structure of heart muscle. Techniques have rapidly improved to include enzymatic digestion via coronary perfusion. More recently, analyzing the contractility and calcium flux of isolated myocytes has provided a vital tool in the cellular and sub-cellular analysis of heart failure. Echocardiography and EKGs provide information about the heart at an organ level only. Cardiomyocyte cell culture systems exist, but cells lack physiologically essential structures such as organized sarcomeres and t-tubules required for myocyte function within the heart. In the protocol presented here, cardiomyocytes are isolated via Langendorff perfusion. The heart is removed from the mouse, mounted via the aorta to a cannula, perfused with digestion enzymes, and cells are introduced to increasing calcium concentrations. Edge and sarcomere detection software is used to analyze contractility, and a calcium binding fluorescent dye is used to visualize calcium transients of electrically paced cardiomyocytes; increasing understanding of the role cellular changes play in heart dysfunction. Traditionally used to test drug effects on cardiomyocytes, we employ this system to compare myocytes from WT mice and mice with a mutation that causes dilated cardiomyopathy. This protocol is unique in its comparison of live cells from mice with known heart function and known genetics. Many experimental conditions are reliably compared, including genetic or environmental manipulation, infection, drug treatment, and more. Beyond physiologic data, isolated cardiomyocytes are easily fixed and stained for cytoskeletal elements. Isolating cardiomyocytes via perfusion is an extremely versatile method, useful in studying cellular changes

  9. Physiological contractility of cardiomyocytes in the wall of mouse and rat azygos vein

    PubMed Central

    Liu, Rong; Feng, Han-Zhong

    2014-01-01

    We recently demonstrated the abundant presence of cardiomyocytes in the wall of thoracic veins of adult mouse and rat. The highly differentiated morphology and myofilament protein contents of the venous cardiomyocytes suggested contractile functions. Here we further investigated the contractility of mouse and rat azygos venous rings compared with that of atrial strips and ventricular papillary muscle. 5-Bromo-4-chloro-indolyl-galactopyranoside (X-gal) staining of transgenic mouse vessels expressing lacZ under a cloned cardiac troponin T promoter demonstrated that the venous cardiomyocytes are discontinuous from atrial myocardium and aligned in the wall of thoracic veins perpendicular to the vessel axis. Histological sections displayed sarcomeric striations in the venous cardiomyocytes, which indicate an encirclement orientation of myofibrils in the vessel wall. Mechanical studies found that the rings of mouse and rat azygos vein produce strong cardiac type twitch contractions when stimulated with electrical pacing in contrast to the weak and slow smooth muscle contractions induced using 90 mM KCl. The twitch contraction and relaxation of mouse azygos veins further exhibited a cardiac type of β-adrenergic responses. Quantitative comparison showed that the contractions of venous cardiomyocytes are slightly slower than those of atrium muscle but significantly faster than those of ventricular papillary muscle. These novel findings indicate that the cardiomyocytes abundant in the wall of rodent thoracic veins possess fully differentiated cardiac muscle phenotype despite their anatomical and functional segregations from the heart. PMID:24477237

  10. Cardiomyocyte Marker Expression in Mouse Embryonic Fibroblasts by Cell-Free Cardiomyocyte Extract and Epigenetic Manipulation

    PubMed Central

    Talaei-Khozani, Tahereh; Heidari, Fatemeh; Esmaeilpour, Tahereh; Vojdani, Zahra; Mostafavi-Pour, Zohrah; Rohani, Leili

    2014-01-01

    Background: The regenerative capacity of the mammalian heart is quite limited. Recent reports have focused on reprogramming mesenchymal stem cells into cardiomyocytes. We investigated whether fibroblasts could transdifferentiate into myocardium. Methods: Mouse embryonic fibroblasts were treated with Trichostatin A (TSA) and 5-Aza-2-Deoxycytidine (5-aza-dC). The treated cells were permeabilized with streptolysin O and exposed to the mouse cardiomyocyte extract and cultured for 1, 10, and 21 days. Cardiomyocyte markers were detected by immunohistochemistry. Alkaline phosphatase activity and OCT4 were also detected in cells treated by chromatin-modifying agents. Results: The cells exposed to a combination of 5-aza-dC and TSA and permeabilized in the presence of the cardiomyocyte extract showed morphological changes. The cells were unable to express cardiomyocyte markers after 24 h. Immunocytochemical assays showed a notable degree of myosin heavy chain and α-actinin expressions after 10 days. The expression of the natriuretic factor and troponin T occurred after 21 days in these cells. The cells exposed to chromatin-modifying agents also expressed cardiomyocyte markers; however, the proportion of reprogrammed cells was clearly smaller than that in the cultures exposed to 5-aza-dC , TSA, and extract. Conclusion: It seems that the fibroblasts were able to eliminate the previous epigenetic markers and form new ones according to the factors existing in the extract. Since no beating was observed, at least up to 21 days, the cells may need an appropriate extracellular matrix for their function. PMID:24753644

  11. Analysis of Cardiomyocyte Development using Immunofluorescence in Embryonic Mouse Heart

    PubMed Central

    Wilsbacher, Lisa D.; Coughlin, Shaun R.

    2015-01-01

    During heart development, the generation of myocardial-specific structural and functional units including sarcomeres, contractile myofibrils, intercalated discs, and costameres requires the coordinated assembly of multiple components in time and space. Disruption in assembly of these components leads to developmental heart defects. Immunofluorescent staining techniques are used commonly in cultured cardiomyocytes to probe myofibril maturation, but this ex vivo approach is limited by the extent to which myocytes will fully differentiate in culture, lack of normal in vivo mechanical inputs, and absence of endocardial cues. Application of immunofluorescence techniques to the study of developing mouse heart is desirable but more technically challenging, and methods often lack sufficient sensitivity and resolution to visualize sarcomeres in the early stages of heart development. Here, we describe a robust and reproducible method to co-immunostain multiple proteins or to co-visualize a fluorescent protein with immunofluorescent staining in the embryonic mouse heart and use this method to analyze developing myofibrils, intercalated discs, and costameres. This method can be further applied to assess cardiomyocyte structural changes caused by mutations that lead to developmental heart defects. PMID:25866997

  12. Met signaling in cardiomyocytes is required for normal cardiac function in adult mice.

    PubMed

    Arechederra, María; Carmona, Rita; González-Nuñez, María; Gutiérrez-Uzquiza, Alvaro; Bragado, Paloma; Cruz-González, Ignacio; Cano, Elena; Guerrero, Carmen; Sánchez, Aránzazu; López-Novoa, José Miguel; Schneider, Michael D; Maina, Flavio; Muñoz-Chápuli, Ramón; Porras, Almudena

    2013-12-01

    Hepatocyte growth factor (HGF) and its receptor, Met, are key determinants of distinct developmental processes. Although HGF exerts cardio-protective effects in a number of cardiac pathologies, it remains unknown whether HGF/Met signaling is essential for myocardial development and/or physiological function in adulthood. We therefore investigated the requirement of HGF/Met signaling in cardiomyocyte for embryonic and postnatal heart development and function by conditional inactivation of the Met receptor in cardiomyocytes using the Cre-α-MHC mouse line (referred to as α-MHCMet-KO). Although α-MHCMet-KO mice showed normal heart development and were viable and fertile, by 6 months of age, males developed cardiomyocyte hypertrophy, associated with interstitial fibrosis. A significant upregulation in markers of myocardial damage, such as β-MHC and ANF, was also observed. By the age of 9 months, α-MHCMet-KO males displayed systolic cardiac dysfunction. Mechanistically, we provide evidence of a severe imbalance in the antioxidant defenses in α-MHCMet-KO hearts involving a reduced expression and activity of catalase and superoxide dismutase, with consequent reactive oxygen species accumulation. Similar anomalies were observed in females, although with a slower kinetics. We also found that Met signaling down-regulation leads to an increase in TGF-β production and a decrease in p38MAPK activation, which may contribute to phenotypic alterations displayed in α-MHCMet-KO mice. Consistently, we show that HGF acts through p38α to upregulate antioxidant enzymes in cardiomyocytes. Our results highlight that HGF/Met signaling in cardiomyocytes plays a physiological cardio-protective role in adult mice by acting as an endogenous regulator of heart function through oxidative stress control. PMID:23994610

  13. Oxidative Stress and Ca2+ Release Events in Mouse Cardiomyocytes

    PubMed Central

    Shirokova, Natalia; Kang, Chifei; Fernandez-Tenorio, Miguel; Wang, Wei; Wang, Qiongling; Wehrens, Xander H.T.; Niggli, Ernst

    2014-01-01

    Cellular oxidative stress, associated with a variety of common cardiac diseases, is well recognized to affect the function of several key proteins involved in Ca2+ signaling and excitation-contraction coupling, which are known to be exquisitely sensitive to reactive oxygen species. These include the Ca2+ release channels of the sarcoplasmic reticulum (ryanodine receptors or RyR2s) and the Ca2+/calmodulin-dependent protein kinase II (CaMKII). Oxidation of RyR2s was found to increase the open probability of the channel, whereas CaMKII can be activated independent of Ca2+ through oxidation. Here, we investigated how oxidative stress affects RyR2 function and SR Ca2+ signaling in situ, by analyzing Ca2+ sparks in permeabilized mouse cardiomyocytes under a broad range of oxidative conditions. The results show that with increasing oxidative stress Ca2+ spark duration is prolonged. In addition, long and very long-lasting (up to hundreds of milliseconds) localized Ca2+ release events started to appear, eventually leading to sarcoplasmic reticulum (SR) Ca2+ depletion. These changes of release duration could be prevented by the CaMKII inhibitor KN93 and did not occur in mice lacking the CaMKII-specific S2814 phosphorylation site on RyR2. The appearance of long-lasting Ca2+ release events was paralleled by an increase of RyR2 oxidation, but also by RyR-S2814 phosphorylation, and by CaMKII oxidation. Our results suggest that in a strongly oxidative environment oxidation-dependent activation of CaMKII leads to RyR2 phosphorylation and thereby contributes to the massive prolongation of SR Ca2+ release events. PMID:25517148

  14. Cardiomyocyte Regeneration in the mdx Mouse Model of Nonischemic Cardiomyopathy

    PubMed Central

    Laval, Steven; Owens, William Andrew

    2015-01-01

    Endogenous regeneration has been demonstrated in the mammalian heart after ischemic injury. However, approximately one-third of cases of heart failure are secondary to nonischemic heart disease and cardiac regeneration in these cases remains relatively unexplored. We, therefore, aimed at quantifying the rate of new cardiomyocyte formation at different stages of nonischemic cardiomyopathy. Six-, 12-, 29-, and 44-week-old mdx mice received a 7 day pulse of BrdU. Quantification of isolated cardiomyocyte nuclei was undertaken using cytometric analysis to exclude nondiploid nuclei. Between 6–7 and 12–13 weeks, there was a statistically significant increase in the number of BrdU-labeled nuclei in the mdx hearts compared with wild-type controls. This difference was lost by the 29–30 week time point, and a significant decrease in cardiomyocyte generation was observed in both the control and mdx hearts by 44–45 weeks. Immunohistochemical analysis demonstrated BrdU-labeled nuclei exclusively in mononucleated cardiomyocytes. This study demonstrates cardiomyocyte regeneration in a nonischemic model of mammalian cardiomyopathy, controlling for changes in nuclear ploidy, which is lost with age, and confirms a decrease in baseline rates of cardiomyocyte regeneration with aging. While not attempting to address the cellular source of regeneration, it confirms the potential utility of innate regeneration as a therapeutic target. PMID:25749191

  15. Targeting Pin1 Protects Mouse Cardiomyocytes from High-Dose Alcohol-Induced Apoptosis

    PubMed Central

    Wang, Yuehong; Li, Zizhuo; Zhang, Yu; Yang, Wei; Sun, Jiantao; Shan, Lina; Li, Weimin

    2016-01-01

    Long-term heavy alcohol consumption is considered to be one of the main causes of left ventricular dysfunction in alcoholic cardiomyopathy (ACM). As previously suggested, high-dose alcohol induces oxidation stress and apoptosis of cardiomyocytes. However, the underlying mechanisms are yet to be elucidated. In this study, we found that high-dose alcohol treatment stimulated expression and activity of Pin1 in mouse primary cardiomyocytes. While siRNA-mediated knockdown of Pin1 suppressed alcohol-induced mouse cardiomyocyte apoptosis, overexpression of Pin1 further upregulated the numbers of apoptotic mouse cardiomyocytes. We further demonstrated that Pin1 promotes mitochondria oxidative stress and loss of mitochondrial membrane potential but suppresses endothelial nitric oxide synthase (eNOS) expression in the presence of alcohol. Taken together, our results revealed a pivotal role of Pin1 in regulation of alcohol-induced mouse cardiomyocytes apoptosis by promoting reactive oxygen species (ROS) accumulation and repressing eNOS expression, which could be potential therapeutic targets for ACM. PMID:26697133

  16. Stable, Covalent Attachment of Laminin to Microposts Improves the Contractility of Mouse Neonatal Cardiomyocytes

    PubMed Central

    2015-01-01

    The mechanical output of contracting cardiomyocytes, the muscle cells of the heart, relates to healthy and disease states of the heart. Culturing cardiomyocytes on arrays of elastomeric microposts can enable inexpensive and high-throughput studies of heart disease at the single-cell level. However, cardiomyocytes weakly adhere to these microposts, which limits the possibility of using biomechanical assays of single cardiomyocytes to study heart disease. We hypothesized that a stable covalent attachment of laminin to the surface of microposts improves cardiomyocyte contractility. We cultured cells on polydimethylsiloxane microposts with laminin covalently bonded with the organosilanes 3-glycidoxypropyltrimethoxysilane and 3-aminopropyltriethoxysilane with glutaraldehyde. We measured displacement of microposts induced by the contractility of mouse neonatal cardiomyocytes, which attach better than mature cardiomyocytes to substrates. We observed time-dependent changes in contractile parameters such as micropost deformation, contractility rates, contraction and relaxation speeds, and the times of contractions. These parameters were affected by the density of laminin on microposts and by the stability of laminin binding to micropost surfaces. Organosilane-mediated binding resulted in higher laminin surface density and laminin binding stability. 3-glycidoxypropyltrimethoxysilane provided the highest laminin density but did not provide stable protein binding with time. Higher surface protein binding stability and strength were observed with 3-aminopropyltriethoxysilane with glutaraldehyde. In cultured cardiomyocytes, contractility rate, contraction speeds, and contraction time increased with higher laminin stability. Given these variations in contractile function, we conclude that binding of laminin to microposts via 3-aminopropyltriethoxysilane with glutaraldehyde improves contractility observed by an increase in beating rate and contraction speed as it occurs during the

  17. Fibroblast Growth Factor Receptor 1 Signaling in Adult Cardiomyocytes Increases Contractility and Results in a Hypertrophic Cardiomyopathy

    PubMed Central

    Cilvik, Sarah N.; Wang, Joy I.; Lavine, Kory J.; Uchida, Keita; Castro, Angela; Gierasch, Carolyn M.; Weinheimer, Carla J.; House, Stacey L.; Kovacs, Attila; Nichols, Colin G.; Ornitz, David M.

    2013-01-01

    Fibroblast growth factors (FGFs) and their receptors are highly conserved signaling molecules that have been implicated in postnatal cardiac remodeling. However, it is not known whether cardiomyocyte-expressed FGF receptors are necessary or sufficient for ventricular remodeling in the adult heart. To determine whether cardiomyocytes were competent to respond to an activated FGF receptor, and to determine if this signal would result in the development of hypertrophy, we engineered a doxycycline (DOX)-inducible, cardiomyocyte-specific, constitutively active FGF receptor mouse model (αMHC-rtTA, TRE-caFgfr1-myc). Echocardiographic and hemodynamic analysis indicated that acute expression of caFGFR1 rapidly and directly increased cardiac contractility, while chronic expression resulted in significant hypertrophy with preservation of systolic function. Subsequent histologic analysis showed increased cardiomyocyte cross-sectional area and regions of myocyte disarray and fibrosis, classic features of hypertrophic cardiomyopathy (HCM). Analysis of downstream pathways revealed a lack of clear activation of classical FGF-mediated signaling pathways, but did demonstrate a reduction in Serca2 expression and troponin I phosphorylation. Isolated ventricular myocytes showed enhanced contractility and reduced relaxation, an effect that was partially reversed by inhibition of actin-myosin interactions. We conclude that adult cardiomyocytes are competent to transduce FGF signaling and that FGF signaling is sufficient to promote increased cardiomyocyte contractility in vitro and in vivo through enhanced intrinsic actin-myosin interactions. Long-term, FGFR overexpression results in HCM with a dynamic outflow tract obstruction, and may serve as a unique model of HCM. PMID:24349409

  18. Rac1 modulates cardiomyocyte adhesion during mouse embryonic development

    SciTech Connect

    Abu-Issa, Radwan

    2015-01-24

    Highlights: • Conditional knockout of Rac1 using Nkx2.5 Cre line is lethal at E13.5. • The myocardium of the mutant is thin and disorganized. • The phenotype is not due to cardiomyocyte low proliferation or apoptosis. • The phenotype is due to specific defect in cardiomyocyte adhesion. - Abstract: Rac1, a member of the Rho subfamily of small GTPases, is involved in morphogenesis and differentiation of many cell types. Here we define a role of Rac1 in cardiac development by specifically deleting Rac1 in the pre-cardiac mesoderm using the Nkx2.5-Cre transgenic driver line. Rac1-conditional knockout embryos initiate heart development normally until embryonic day 11.5 (E11.5); their cardiac mesoderm is specified, and the heart tube is formed and looped. However, by E12.5-E13.5 the mutant hearts start failing and embryos develop edema and hemorrhage which is probably the cause for the lethality observed soon after. The hearts of Rac1-cKO embryos exhibit disorganized and thin myocardial walls and defects in outflow tract alignment. No significant differences of cardiomyocyte death or proliferation were found between developing control and mutant embryos. To uncover the role of Rac1 in the heart, E11.5 primary heart cells were cultured and analyzed in vitro. Rac1-deficient cardiomyocytes were less spread, round and loosely attached to the substrate and to each other implying that Rac1-mediated signaling is required for appropriate cell–cell and/or cellmatrix adhesion during cardiac development.

  19. Bone marrow stromal cells as an inducer for cardiomyocyte differentiation from mouse embryonic stem cells.

    PubMed

    Yue, Fengming; Johkura, Kohei; Tomotsune, Daihachiro; Shirasawa, Sakiko; Yokoyama, Tadayuki; Nagai, Mika; Sasaki, Katsunori

    2010-09-20

    Bone marrow stromal cells (BMSCs) secrete soluble factors and display varied cell-biological functions. To confirm the ability and efficiency of BMSCs to induce embryonic stem cells (ESCs) into cardiomyocytes, mouse embryoid bodies (EBs) were co-cultured with rat BMSCs. After about 10 days, areas of rhythmically contracting cells in more solid aggregates became evident with bundle-like structures formed along borders between EB outgrowth and BMSC layer. ESC-derived cardiomyocytes exhibited sarcomeric striations when stained with troponin I (Trop I), organized in separated bundles. Besides, the staining for connexin 43 was detected in cell-cell junctions, which demonstrated that ESC-derived cardiomyocytes were coupled by gap junction in culture. The related genes of cardiomyocytes were found in these beating and no-beating EBs co-cultured with BMSCs. In addition, an improved efficiency of cardiomyocyte differentiation from ESC-BMSC co-culture was found in the serum-free medium: 5-fold up-regulation in the number of beating area compared with the serum medium. Effective cardiac differentiation was also recognized in transfer filter assay and in condition medium obtained from BMSC culture. A clear increase in the expression of cardiac genes and TropI protein confirmed further cardiac differentiation by BMP4 and Retinoic Acid (RA) treatment. These results demonstrate that BMSCs can induce cardiomyocyte differentiation from ESCs through soluble factors and enhance it with BMP4 or RA treatment. Serum-free ESC-BMSC co-culture represents a defined in vitro model for identifying the cardiomyocyte-inducing activity from BMSCs and, in addition, a straightforward experimental system for assessing clinical applications. PMID:20801009

  20. Chrysin attenuates cardiomyocyte apoptosis and loss of intermediate filaments in a mouse model of mitoxantrone cardiotoxicity.

    PubMed

    Anghel, N; Cotoraci, C; Ivan, A; Suciu, M; Herman, H; Balta, C; Nicolescu, L; Olariu, T; Galajda, Z; Ardelean, A; Hermenean, A

    2015-12-01

    Chrysin (CHR) is a natural flavonoid and is present in high concentration in honey, propolis and many plant extracts. The aim of the present study was to evaluate the effects of CHR to reduce cardiomyocyte apoptosis and loss of intermediate filaments in a mouse model of mitoxantrone cardiotoxicity. Morphology of the cardiomyocytes was determined by optic and transmission electron microscopy and biochemistry methods. The expression of Bcl-2, Bax and Caspase-3 were assessed by immunofluorecence. Tunel assay was used to assess apoptosis in cardiomyocytes. In addition, the distribution of desmin protein was evaluated using immunohistochemistry. Our results show that MTX treatment significantly increased serum levels of creatine kinase isoenzyme (CK-MB), indicator of cardiac injury and withdrawn under CHR protection. Expression levels of Bcl-2 decreased, while those of Bax and caspase-3 increased following MTX treatment. 50 mg/kg of daily CHR intake reduced Bax and caspase-3 immunopositivity and restored Bcl-2 levels to a value comparable to the control. TUNEL (+) cardiomyocyte nuclei of MTX group showed typical signs of apoptosis which almost completely disappeared in response to 50 mg/kg CHR treatment. In parallel, an irregular distribution and a weak expression of desmin is associated with MTX induced cardiotoxic effects which was also restored by CHR treatment. In conclusion chrysin inhibits MTX-triggered cardiomyocyte apoptosis via multiple pathways, including decrease of the Bax/Bcl-2 ratio and caspase-3 expression along with preservation of the desmin disarray. PMID:26112963

  1. Effects of oxytocin on cardiomyocyte differentiation from mouse embryonic stem cells.

    PubMed

    Hatami, Leili; Valojerdi, Mojtaba Rezazadeh; Mowla, Seyed Javad

    2007-04-12

    This study sought to investigate the presence of oxytocin receptors and the possible biological role of oxytocin as an effective factor in the differentiation of embryonic stem cells (ESCs) into cardiomyocytes. Mouse ESCs were cultivated in hanging drops to form embryoid bodies (EBs). The EBs were then treated with and without oxytocin (experimental and control groups). Up to 30 days after plating, contraction and beating frequency were monitored and evaluated daily. The growth characteristics of the ESC-derived cardiomyocytes were assessed by cardioactive drugs, immunocytochemistry, transmission electron microscopy (TEM) and reverse transcription-polymerase chain reaction (RT-PCR). In the experimental group, the percentage of the EBs with spontaneous contraction was significantly increased from 17th day onward. The spontaneous beating frequency of each EB in both groups was also changed with cardioactive drugs such as Bay K, carbachol, isopernaline and phenylephrine. However, in the experimental group, changes with isopernaline were more pronounced at the early and intermediate stages of cardiomyocyte development. The beating cells of both groups, stained positive with anti alpha-actinin, desmin, cardiac troponin I and connexin antibodies, and revealed similar ultrastructural features. Oxytocin receptors were detected on the ESCs and derived-differentiated cells. In addition, cardiac-specific genes such as cardiac alpha- and beta-myosin heavy chain, myosin light chain-2v, and atrial natriuretic factor were also detected in the ESC-derived differentiated cells of both groups. In the experimental group, all the specific genes, with the exception of alpha-myosin heavy chain, were more pronounced at the early stage of cardiomyocyte development. In conclusion, oxytocin has receptors on undifferentiated ESCs and derived differentiated cells, and in spite of better improvement of the EBs with spontaneous contraction, it can only promote the early maturation of ESC

  2. Isolation, Culture, and Functional Characterization of Adult Mouse Cardiomyoctyes

    PubMed Central

    Graham, Evan Lee; Balla, Cristina; Franchino, Hannabeth; Melman, Yonathan

    2013-01-01

    The use of primary cardiomyocytes (CMs) in culture has provided a powerful complement to murine models of heart disease in advancing our understanding of heart disease. In particular, the ability to study ion homeostasis, ion channel function, cellular excitability and excitation-contraction coupling and their alterations in diseased conditions and by disease-causing mutations have led to significant insights into cardiac diseases. Furthermore, the lack of an adequate immortalized cell line to mimic adult CMs, and the limitations of neonatal CMs (which lack many of the structural and functional biomechanics characteristic of adult CMs) in culture have hampered our understanding of the complex interplay between signaling pathways, ion channels and contractile properties in the adult heart strengthening the importance of studying adult isolated cardiomyocytes. Here, we present methods for the isolation, culture, manipulation of gene expression by adenoviral-expressed proteins, and subsequent functional analysis of cardiomyocytes from the adult mouse. The use of these techniques will help to develop mechanistic insight into signaling pathways that regulate cellular excitability, Ca2+ dynamics and contractility and provide a much more physiologically relevant characterization of cardiovascular disease. PMID:24084584

  3. Arsenic trioxide alters the differentiation of mouse embryonic stem cell into cardiomyocytes.

    PubMed

    Rebuzzini, Paola; Cebral, Elisa; Fassina, Lorenzo; Alberto Redi, Carlo; Zuccotti, Maurizio; Garagna, Silvia

    2015-01-01

    Chronic arsenic exposure is associated with increased morbidity and mortality for cardiovascular diseases. Arsenic increases myocardial infarction mortality in young adulthood, suggesting that exposure during foetal life correlates with cardiac alterations emerging later. Here, we investigated the mechanisms of arsenic trioxide (ATO) cardiomyocytes disruption during their differentiation from mouse embryonic stem cells. Throughout 15 days of differentiation in the presence of ATO (0.1, 0.5, 1.0 μM) we analysed: the expression of i) marker genes of mesoderm (day 4), myofibrillogenic commitment (day 7) and post-natal-like cardiomyocytes (day 15); ii) sarcomeric proteins and their organisation; iii) Connexin 43 and iv) the kinematics contractile properties of syncytia. The higher the dose used, the earlier the stage of differentiation affected (mesoderm commitment, 1.0 μM). At 0.5 or 1.0 μM the expression of cardiomyocyte marker genes is altered. Even at 0.1 μM, ATO leads to reduction and skewed ratio of sarcomeric proteins and to a rarefied distribution of Connexin 43 cardiac junctions. These alterations contribute to the dysruption of the sarcomere and syncytium organisation and to the impairment of kinematic parameters of cardiomyocyte function. This study contributes insights into the mechanistic comprehension of cardiac diseases caused by in utero arsenic exposure. PMID:26447599

  4. Arsenic trioxide alters the differentiation of mouse embryonic stem cell into cardiomyocytes

    PubMed Central

    Rebuzzini, Paola; Cebral, Elisa; Fassina, Lorenzo; Alberto Redi, Carlo; Zuccotti, Maurizio; Garagna, Silvia

    2015-01-01

    Chronic arsenic exposure is associated with increased morbidity and mortality for cardiovascular diseases. Arsenic increases myocardial infarction mortality in young adulthood, suggesting that exposure during foetal life correlates with cardiac alterations emerging later. Here, we investigated the mechanisms of arsenic trioxide (ATO) cardiomyocytes disruption during their differentiation from mouse embryonic stem cells. Throughout 15 days of differentiation in the presence of ATO (0.1, 0.5, 1.0 μM) we analysed: the expression of i) marker genes of mesoderm (day 4), myofibrillogenic commitment (day 7) and post-natal-like cardiomyocytes (day 15); ii) sarcomeric proteins and their organisation; iii) Connexin 43 and iv) the kinematics contractile properties of syncytia. The higher the dose used, the earlier the stage of differentiation affected (mesoderm commitment, 1.0 μM). At 0.5 or 1.0 μM the expression of cardiomyocyte marker genes is altered. Even at 0.1 μM, ATO leads to reduction and skewed ratio of sarcomeric proteins and to a rarefied distribution of Connexin 43 cardiac junctions. These alterations contribute to the dysruption of the sarcomere and syncytium organisation and to the impairment of kinematic parameters of cardiomyocyte function. This study contributes insights into the mechanistic comprehension of cardiac diseases caused by in utero arsenic exposure. PMID:26447599

  5. Treprostinil potentiates the positive inotropic effect of catecholamines in adult rat ventricular cardiomyocytes

    PubMed Central

    Fontana, M; Olschewski, H; Olschewski, A; Schlüter, K-D

    2007-01-01

    Background and purpose: Prostanoids have been shown to improve exercise tolerance, hemodynamics and quality of life in patients with pulmonary arterial hypertension (PAH). We investigated whether treprostinil exerts direct contractile effects on cardiomyocytes that may explain partly the beneficial effects of these drugs. Experimental approach: Ventricular cardiomyocytes from adult rats were paced at a constant frequency of 0.5 to 2.0 Hz and cell shortening was monitored via a cell edge detection system. Twitch amplitudes, expressed as percent cell shortening of the diastolic cell length, and maximal contraction velocity, relaxation velocity, time to peak of contraction and time to reach 50% of relaxation were analyzed. Key results: Treprostinil (0.15 – 15 ng ml−1) slightly increased contractile dynamics of cardiomyocytes at clinically relevant concentrations. However, the drug significantly improved cell shortening of cardiomyocytes in the presence of isoprenaline, a β-adrenoceptor agonist. Treprostinil exerted this effect at all beating frequencies under investigation. Treprostinil mimicked this potentiating effect in a Langendorff preparation as well. The potentiating effect of treprostinil on isoprenaline-dependent cell shortening was no longer seen after phosphodiesterase inhibition. Long-term cultivation of cardiomyocytes with treprostinil did not modify load free cell shortening of these cells, but reduces the duration of contraction. Conclusions and implications: We conclude that the clinically used prostanoid treprostinil potentiates the positive inotropic effects of catecholamines in adult ventricular cardiomyocytes. This newly described effect may contribute to the beneficial clinical effects of prostanoids in patients with PAH. PMID:17533419

  6. Disassembly of myofibrils and potential imbalanced forces on Z-discs in cultured adult cardiomyocytes.

    PubMed

    Liu, Honghai; Qin, Wan; Wang, Zhonghai; Shao, Yonghong; Wang, Jingcai; Borg, Thomas K; Gao, Bruce Z; Xu, Meifeng

    2016-05-01

    Myofibrils are the main protein structures that generate force in the beating heart. Myofibril disassembly is related to many physiological and pathological processes. This study investigated, in a cultured rat adult cardiomyocyte model, the effect of force imbalance on myofibril disassembly. The imbalance of forces that were exerted on Z-discs was induced by the synergistic effect of broken intercalated discs and actin-myosin interaction. Cardiomyocytes with well-preserved intercalated discs were isolated from adult rat ventricles. The ultrastructure of cardiomyocyte was observed using a customized two-photon excitation fluorescence and second harmonic generation imaging system. The contraction of cardiomyocytes was recorded with a high-speed CCD camera, and the movement of cellular components was analyzed using a contractile imaging assay technique. The cardiomyocyte dynamic remodeling process was recorded using a time-lapse imaging system. The role of actin-myosin interaction in myofibril disassembly was investigated by incubating cardiomyocytes with blebbistatin (25 μM). Results demonstrated that the hierarchical disassembly process of myofibrils was initiated from cardiomyocyte free ends where intercalated discs had broken, during which the desmin network near the free cell ends was destroyed to release single myofibrils. Analysis of force (based on a schematic model of cardiomyocytes connected at intercalated discs) suggests that breaking of intercalated discs caused force imbalance on both sides of the Z-discs adjacent to the cell ends due to actin-myosin interaction. The damaged intercalated discs and actin-myosin interaction induced force imbalance on both sides of the Z-discs, which played an important role in the hierarchical disassembly of myofibrils. © 2016 Wiley Periodicals, Inc. PMID:27072949

  7. Towards regenerating the mammalian heart: challenges in evaluating experimentally induced adult mammalian cardiomyocyte proliferation.

    PubMed

    Zebrowski, David C; Becker, Robert; Engel, Felix B

    2016-05-01

    In recent years, there has been a dramatic increase in research aimed at regenerating the mammalian heart by promoting endogenous cardiomyocyte proliferation. Despite many encouraging successes, it remains unclear if we are any closer to achieving levels of mammalian cardiomyocyte proliferation for regeneration as seen during zebrafish regeneration. Furthermore, current cardiac regenerative approaches do not clarify whether the induced cardiomyocyte proliferation is an epiphenomena or responsible for the observed improvement in cardiac function. Moreover, due to the lack of standardized protocols to determine cardiomyocyte proliferation in vivo, it remains unclear if one mammalian regenerative factor is more effective than another. Here, we discuss current methods to identify and evaluate factors for the induction of cardiomyocyte proliferation and challenges therein. Addressing challenges in evaluating adult cardiomyocyte proliferation will assist in determining 1) which regenerative factors should be pursued in large animal studies; 2) if a particular level of cell cycle regulation presents a better therapeutic target than another (e.g., mitogenic receptors vs. cyclins); and 3) which combinatorial approaches offer the greatest likelihood of success. As more and more regenerative studies come to pass, progress will require a system that not only can evaluate efficacy in an objective manner but can also consolidate observations in a meaningful way. PMID:26921436

  8. AMPK activation by glucagon-like peptide-1 prevents NADPH oxidase activation induced by hyperglycemia in adult cardiomyocytes.

    PubMed

    Balteau, Magali; Van Steenbergen, Anne; Timmermans, Aurélie D; Dessy, Chantal; Behets-Wydemans, Gaetane; Tajeddine, Nicolas; Castanares-Zapatero, Diego; Gilon, Patrick; Vanoverschelde, Jean-Louis; Horman, Sandrine; Hue, Louis; Bertrand, Luc; Beauloye, Christophe

    2014-10-15

    Exposure of cardiomyocytes to high glucose concentrations (HG) stimulates reactive oxygen species (ROS) production by NADPH oxidase (NOX2). NOX2 activation is triggered by enhanced glucose transport through a sodium-glucose cotransporter (SGLT) but not by a stimulation of glucose metabolism. The aim of this work was to identify potential therapeutic approaches to counteract this glucotoxicity. In cultured adult rat cardiomyocytes incubated with 21 mM glucose (HG), AMP-activated protein kinase (AMPK) activation by A769662 or phenformin nearly suppressed ROS production. Interestingly, glucagon-like peptide 1 (GLP-1), a new antidiabetic drug, concomitantly induced AMPK activation and prevented the HG-mediated ROS production (maximal effect at 100 nM). α2-AMPK, the major isoform expressed in cardiomyocytes (but not α1-AMPK), was activated in response to GLP-1. Anti-ROS properties of AMPK activators were not related to changes in glucose uptake or glycolysis. Using in situ proximity ligation assay, we demonstrated that AMPK activation prevented the HG-induced p47phox translocation to caveolae, whatever the AMPK activators used. NOX2 activation by either α-methyl-d-glucopyranoside, a glucose analog transported through SGLT, or angiotensin II was also counteracted by GLP-1. The crucial role of AMPK in limiting HG-mediated NOX2 activation was demonstrated by overexpressing a constitutively active form of α2-AMPK using adenoviral infection. This overexpression prevented NOX2 activation in response to HG, whereas GLP-1 lost its protective action in α2-AMPK-deficient mouse cardiomyocytes. Under HG, the GLP-1/AMPK pathway inhibited PKC-β2 phosphorylation, a key element mediating p47phox translocation. In conclusion, GLP-1 induces α2-AMPK activation and blocks HG-induced p47phox translocation to the plasma membrane, thereby preventing glucotoxicity. PMID:25128166

  9. Cancer induces cardiomyocyte remodeling and hypoinnervation in the left ventricle of the mouse heart.

    PubMed

    Mühlfeld, Christian; Das, Suman Kumar; Heinzel, Frank R; Schmidt, Albrecht; Post, Heiner; Schauer, Silvia; Papadakis, Tamara; Kummer, Wolfgang; Hoefler, Gerald

    2011-01-01

    Cancer is often associated with cachexia, cardiovascular symptoms and autonomic dysregulation. We tested whether extracardiac cancer directly affects the innervation of left ventricular myocardium. Mice injected with Lewis lung carcinoma cells (tumor group, TG) or PBS (control group, CG) were analyzed after 21 days. Cardiac function (echocardiography), serum levels of TNF-α and Il-6 (ELISA), structural alterations of cardiomyocytes and their innervation (design-based stereology) and levels of innervation-related mRNA (quantitative RT-PCR) were analysed. The groups did not differ in various functional parameters. Serum levels of TNF-α and Il-6 were elevated in TG. The total length of axons in the left ventricle was reduced. The number of dense core vesicles per axon profile was reduced. Decreased myofibrillar volume, increased sarcoplasmic volume and increased volume of lipid droplets were indicative of metabolic alterations of TG cardiomyocytes. In the heart, the mRNA level of nerve growth factor was reduced whereas that of β1-adrenergic receptor was unchanged in TG. In the stellate ganglion of TG, mRNA levels of nerve growth factor and neuropeptide Y were decreased and that of tyrosine hydroxylase was increased. In summary, cancer induces a systemic pro-inflammatory state, a significant reduction in myocardial innervation and a catabolic phenotype of cardiomyocytes in the mouse. Reduced expression of nerve growth factor may account for the reduced myocardial innervation. PMID:21637823

  10. Ah receptor expression in cardiomyocytes protects adult female mice from heart dysfunction induced by TCDD exposure.

    PubMed

    Kurita, Hisaka; Carreira, Vinicius S; Fan, Yunxia; Jiang, Min; Naticchioni, Mindi; Koch, Sheryl; Rubinstein, Jack; Puga, Alvaro

    2016-04-29

    Epidemiological studies in humans and experimental work in rodents suggest that exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a persistent environmental toxicant, is associated with incidence of heart disease. Although TCDD toxicity depends by and large on the aryl hydrocarbon receptor (AHR), the role of the cardiac AHR in TCDD induced cardiovascular disease is not well defined. To determine whether the Ahr gene mediates disruption of heart function by TCDD, we generated a cardiomyocyte-specific Ahr knockout mouse by crossing Ahr(fx/fx) mice with βMhc:cre/+ mice, in which expression of Cre recombinase is driven by the promoter of the βMhc (myosin heavy chain-beta) gene. Starting at three months of age, mice with cardiomyocyte-specific Ahr ablation were exposed to 1μg/kg/week of TCDD or control vehicle by oral gavage for an additional three months. Relative to unexposed controls, TCDD-exposure induced cardiomyocyte Ahr-independent changes in males but not females, including a significant increase in body weight, blood pressure, and cardiac hypertrophy and a decrease in cardiac ejection fraction. TCDD exposure also induced cardiomyocyte Ahr-dependent changes in fibrosis and calcium signaling gene expression in both males and females. TCDD exposure appears to cause sexually dimorphic effects on heart function and induce fibrosis and changes in calcium signaling in both males and females through activation of the cardiomyocyte-specific Ahr. PMID:27163630

  11. Increased expression of estrogen-related receptor β during adaptation of adult cardiomyocytes to sustained hypoxia

    PubMed Central

    Cunningham, Kathryn F; Beeson, Gyda C; Beeson, Craig C; McDermott, Paul J

    2016-01-01

    Estrogen-related Receptors (ERR) are members of the steroid hormone receptor superfamily of transcription factors that regulate expression of genes required for energy metabolism including mitochondrial biogenesis, fatty acid oxidation and oxidative phosphorylation. While ERRα and EPPγ isoforms are known to share a wide array of target genes in the adult myocardium, the function of ERRβ has not been characterized in cardiomyocytes. The purpose of this study was to determine the role of ERRβ in regulating energy metabolism in adult cardiomyocytes in primary culture. Adult feline cardiomyocytes were electrically stimulated to contract in either hypoxia (0.5% O2) or normoxia (21% O2). As compared to baseline values measured in normoxia, ERRβ mRNA levels increased significantly after 8 hours of hypoxia and remained elevated over 24 h. Conversely, ERRβ mRNA decreased to normoxic levels after 4 hours of reoxygenation. Hypoxia increased expression of the α and β isoforms of Peroxisome Proliferator-Activated Receptor γ Coactivator-1 (PGC-1) mRNA by 6-fold and 3-fold, respectively. Knockdown of ERRβ expression via adenoviral-mediated delivery of ERRβ shRNA blocked hypoxia-induced increases in PGC-1β mRNA, but not PGC-1α mRNA. Loss of ERRβ had no effect on mtDNA content as measured after 24 h of hypoxia. To determine whether loss of ERRβ affected mitochondrial function, oxygen consumption rates (OCR) were measured in contracting versus quiescent cardiomyocytes in normoxia. OCR was significantly lower in contracting cardiomyocytes expressing ERRβ shRNA than scrambled shRNA controls. Maximal OCR also was reduced by ERRβ knockdown. In conclusion: 1) hypoxia increases in ERRβ mRNA expression in contracting cardiomyocytes; 2) ERRβ is required for induction of the PGC-1β isoform in response to hypoxia; 3) ERRβ expression is required to sustain OCR in normoxic conditions. PMID:27335690

  12. Adult progenitor cell transplantation influences contractile performance and calcium handling of recipient cardiomyocytes.

    PubMed

    Lee, Joon; Stagg, Mark A; Fukushima, Satsuki; Soppa, Gopal K R; Siedlecka, Urszula; Youssef, Samuel J; Suzuki, Ken; Yacoub, Magdi H; Terracciano, Cesare M N

    2009-04-01

    Adult progenitor cell transplantation has been proposed for the treatment of heart failure, but the mechanisms effecting functional improvements remain unknown. The aim of this study was to test the hypothesis that, in failing hearts treated with cell transplantation, the mechanical properties and excitation-contraction coupling of recipient cardiomyocytes are altered. Adult rats underwent coronary artery ligation, leading to myocardial infarction and chronic heart failure. After 3 wk, they received intramyocardial injections of either 10(7) green fluorescence protein (GFP)-positive bone marrow mononuclear cells or 5 x 10(6) GFP-positive skeletal myoblasts. Four weeks after injection, both cell types increased ejection fraction and reduced cardiomyocyte size. The contractility of isolated GFP-negative cardiomyocytes was monitored by sarcomere shortening assessment, Ca(2+) handling by indo-1 and fluo-4 fluorescence, and electrophysiology by patch-clamping techniques. Injection of either bone marrow cells or skeletal myoblasts normalized the impaired contractile performance and the prolonged time to peak of the Ca(2+) transient observed in failing cardiomyocytes. The smaller and slower L-type Ca(2+) current observed in heart failure normalized after skeletal myoblast, but not bone marrow cell, transplantation. Measurement of Ca(2+) sparks suggested a normalization of sarcoplasmic reticulum Ca(2+) leak after skeletal myoblast transplantation. The increased Ca(2+) wave frequency observed in failing myocytes was reduced by either bone marrow cells or skeletal myoblasts. In conclusion, the morphology, contractile performance, and excitation-contraction coupling of individual recipient cardiomyocytes are altered in failing hearts treated with adult progenitor cell transplantation. PMID:19181964

  13. Lipid emulsion rapidly restores contractility in stunned mouse cardiomyocytes: A comparison with therapeutic hypothermia

    PubMed Central

    Li, Jing; Fettiplace, Michael; Sy-Jou, Chen; Steinhorn, Benjamin; Shao, Zuohui; Zhu, Xiangdong; Li, Changqing; Harty, Shaun; Weinberg, Guy; Vanden Hoek, Terry L.

    2014-01-01

    Objective Cooling following cardiac arrest can improve survival significantly. However, delays in achieving target temperature may decrease the overall benefits of cooling. Here we test whether lipid emulsion, a clinically approved drug reported to exert cardioprotection, can rescue heart contractility in the setting of delayed cooling in stunned mouse cardiomyocytes. Design Cell culture study Setting Academic research laboratory Subjects Cardiomyocytes isolated from 1–2-day old C57BL6 mice Interventions Cardiomyocytes were exposed to 30 minutes of ischemia followed by 90 minutes reperfusion and 10 minutes isoproterenol with nine interventions: 1) no additional treatment; 2) intra-ischemic cooling at 32°C initiated 10 min prior to reperfusion; 3) delayed cooling started 20 minutes after reperfusion; 4) lipid emulsion + delayed cooling; 5) lipid emulsion (0.25%) administered at reperfusion; 6) lipid emulsion + intra-ischemic cooling; 7) delayed lipid emulsion; 8) lipid emulsion + delayed cooling + Akt inhibitor (API-2, 10 μM) and 9) lipid emulsion + delayed cooling + Erk inhibitor (U0126, 10 μM). Inhibitors were given to cells 1 h prior to ischemia. Measurements and Main Results Contractility was recorded by real-time phase-contrast imaging and analyzed with pulse image velocimetry in MATLAB. Ischemia diminished cell contraction. The cardioprotective effect of cooling was diminished when delayed but was rescued by lipid emulsion. Further, lipid emulsion on its own improved recovery of the contractility to an equal extent as intra-ischemic cooling. However, co-treatment of lipid emulsion and intra-ischemic cooling did not further improve the recovery compared to either treatment alone. Moreover, Akt and Erk inhibitors blocked lipid emulsion-induced protection. Conclusion Lipid emulsion improved contractility and rescued contractility in the context of delayed cooling. This protective effect required Akt and Erk signaling. Lipid emulsion might serve as a

  14. Heart valve cardiomyocytes of mouse embryos express the serotonin transporter SERT

    SciTech Connect

    Pavone, Luigi Michele Spina, Anna; Lo Muto, Roberta; Santoro, Dionea; Mastellone, Vincenzo; Avallone, Luigi

    2008-12-12

    Multiple evidence demonstrate a role for serotonin and its transporter SERT in heart valve development and disease. By utilizing a Cre/loxP system driven by SERT gene expression, we recently demonstrated a regionally restricted distribution of SERT-expressing cells in developing mouse heart. In order to characterize the cell types exhibiting SERT expression within the mouse heart valves at early developmental stages, in this study we performed immunohistochemistry for Islet1 (Isl1) and connexin-43 (Cx-43) on heart sections from SERT{sup Cre/+};ROSA26R embryos previously stained with X-gal. We observed the co-localization of LacZ staining with Isl1 labelling in the outflow tract, the right ventricle and the conal region of E11.5 mouse heart. Cx-43 labelled cells co-localized with LacZ stained cells in the forming atrioventricular valves. These results demonstrate the cardiomyocyte phenotype of SERT-expressing cells in heart valves of the developing mouse heart, thus suggesting an active role of SERT in early heart valve development.

  15. Mitochondrial pyruvate dehydrogenase phosphatase 1 regulates the early differentiation of cardiomyocytes from mouse embryonic stem cells.

    PubMed

    Heo, Hye Jin; Kim, Hyoung Kyu; Youm, Jae Boum; Cho, Sung Woo; Song, In-Sung; Lee, Sun Young; Ko, Tae Hee; Kim, Nari; Ko, Kyung Soo; Rhee, Byoung Doo; Han, Jin

    2016-01-01

    Mitochondria are crucial for maintaining the properties of embryonic stem cells (ESCs) and for regulating their subsequent differentiation into diverse cell lineages, including cardiomyocytes. However, mitochondrial regulators that manage the rate of differentiation or cell fate have been rarely identified. This study aimed to determine the potential mitochondrial factor that controls the differentiation of ESCs into cardiac myocytes. We induced cardiomyocyte differentiation from mouse ESCs (mESCs) and performed microarray assays to assess messenger RNA (mRNA) expression changes at differentiation day 8 (D8) compared with undifferentiated mESCs (D0). Among the differentially expressed genes, Pdp1 expression was significantly decreased (27-fold) on D8 compared to D0, which was accompanied by suppressed mitochondrial indices, including ATP levels, membrane potential, ROS and mitochondrial Ca(2+). Notably, Pdp1 overexpression significantly enhanced the mitochondrial indices and pyruvate dehydrogenase activity and reduced the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate compared to a mock control. In confirmation of this, a knockdown of the Pdp1 gene promoted the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate. In conclusion, our results suggest that mitochondrial PDP1 is a potential regulator that controls cardiac differentiation at an early differentiation stage in ESCs. PMID:27538372

  16. Krp1 (Sarcosin) promotes lateral fusion of myofibril assembly intermediates in cultured mouse cardiomyocytes

    SciTech Connect

    Greenberg, Cynthia C.; Connelly, Patricia S.; Daniels, Mathew P.; Horowits, Robert

    2008-03-10

    Krp1, also called sarcosin, is a cardiac and skeletal muscle kelch repeat protein hypothesized to promote the assembly of myofibrils, the contractile organelles of striated muscles, through interaction with N-RAP and actin. To elucidate its role, endogenous Krp1 was studied in primary embryonic mouse cardiomyocytes. While immunofluorescence showed punctate Krp1 distribution throughout the cell, detergent extraction revealed a significant pool of Krp1 associated with cytoskeletal elements. Reduction of Krp1 expression with siRNA resulted in specific inhibition of myofibril accumulation with no effect on cell spreading. Immunostaining analysis and electron microscopy revealed that cardiomyocytes lacking Krp1 contained sarcomeric proteins with longitudinal periodicities similar to mature myofibrils, but fibrils remained thin and separated. These thin myofibrils were degraded by a scission mechanism distinct from the myofibril disassembly pathway observed during cell division in the developing heart. The data are consistent with a model in which Krp1 promotes lateral fusion of adjacent thin fibrils into mature, wide myofibrils and contribute insight into mechanisms of myofibrillogenesis and disassembly.

  17. Mitochondrial pyruvate dehydrogenase phosphatase 1 regulates the early differentiation of cardiomyocytes from mouse embryonic stem cells

    PubMed Central

    Heo, Hye Jin; Kim, Hyoung Kyu; Youm, Jae Boum; Cho, Sung Woo; Song, In-Sung; Lee, Sun Young; Ko, Tae Hee; Kim, Nari; Ko, Kyung Soo; Rhee, Byoung Doo; Han, Jin

    2016-01-01

    Mitochondria are crucial for maintaining the properties of embryonic stem cells (ESCs) and for regulating their subsequent differentiation into diverse cell lineages, including cardiomyocytes. However, mitochondrial regulators that manage the rate of differentiation or cell fate have been rarely identified. This study aimed to determine the potential mitochondrial factor that controls the differentiation of ESCs into cardiac myocytes. We induced cardiomyocyte differentiation from mouse ESCs (mESCs) and performed microarray assays to assess messenger RNA (mRNA) expression changes at differentiation day 8 (D8) compared with undifferentiated mESCs (D0). Among the differentially expressed genes, Pdp1 expression was significantly decreased (27-fold) on D8 compared to D0, which was accompanied by suppressed mitochondrial indices, including ATP levels, membrane potential, ROS and mitochondrial Ca2+. Notably, Pdp1 overexpression significantly enhanced the mitochondrial indices and pyruvate dehydrogenase activity and reduced the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate compared to a mock control. In confirmation of this, a knockdown of the Pdp1 gene promoted the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate. In conclusion, our results suggest that mitochondrial PDP1 is a potential regulator that controls cardiac differentiation at an early differentiation stage in ESCs. PMID:27538372

  18. Effects of cerivastatin on adrenergic pathways, hypertrophic growth and TGFbeta expression in adult ventricular cardiomyocytes.

    PubMed

    Maxeiner, Hagen; Abdallah, Yaser; Kuhlmann, Christoph Rüdiger Wolfram; Schlüter, Klaus-Dieter; Wenzel, Sibylle

    2012-05-01

    The effects of statin treatment in the setting of heart failure have already been shown. Nevertheless, there is little knowledge about its influence on adrenergic pathways in cardiomyocytes. Therefore, this study investigated the impact of cerivastatin on adrenoceptor-mediated signalling pathways in isolated adult ventricular cardiomyocytes. It focused on two endpoints: hypertrophic growth and TGFbeta expression. Cultured cardiomyocytes were used to study rac activation (analysed by its translocation into the membrane fraction), ROS formation (H(2)DCF fluorescence) and hypertrophic growth ((14)C-phenylalanine incorporation). Alpha- and beta-adrenoceptor stimulation showed significant differences regarding rac activation, ROS formation, and p38 MAP kinase activation. Both alpha- and beta-adrenoceptor stimulation induced TGFbeta expression. Upon activation of alpha-adrenergic signalling - although ROS formation was not influenced by cerivastatin - TGFbeta expression decreased. Following beta stimulation, TGFbeta expression as well as rac and p38 MAP kinase activation were reduced after pre-treatment with cerivastatin. Statin treatment did not show any influence on hypertrophic growth. In summary, this study clearly demonstrates the ability of adrenoceptor stimulation to increase TGFbeta expression. One component of the beneficial effects of statin therapy on heart failure might therefore be due to a dominant reduction and inhibition of TGFbeta, which is involved in many pathophysiological processes in cardiomyocytes. PMID:22365145

  19. Morphological and molecular characterization of adult cardiomyocyte apoptosis during hypoxia and reoxygenation.

    PubMed

    Kang, P M; Haunstetter, A; Aoki, H; Usheva, A; Izumo, S

    2000-07-21

    Apoptosis has been implicated in ischemic heart disease, but its mechanism in cardiomyocytes has not been elucidated. In this study, we investigate the effects of hypoxia and reoxygenation in adult cardiomyocytes and the molecular mechanism involved in cardiomyocyte apoptosis. Morphologically, reoxygenation induced rounding up of the cells, appearance of membrane blebs that were filled with marginated mitochondria, and ultrastructural findings characteristic of apoptosis. Reoxygenation (18 hours of reoxygenation after 6 hours of hypoxia) and prolonged hypoxia (24 hours of hypoxia) resulted in a 59% and 51% decrease in cellular viability, respectively. During reoxygenation, cell death occurred predominantly via apoptosis associated with appearance of cytosolic cytochrome c and activation of caspase-3 and -9. However, nonapoptotic cell death predominated during prolonged hypoxia. Both caspase inhibition and Bcl-2 overexpression during reoxygenation significantly improved cellular viability through inhibition of apoptosis but had minimal effect on hypoxia-induced cell death. Bcl-2 overexpression blocked reoxygenation-induced cytochrome c release and activation of caspase -3 and -9, but caspase inhibition alone did not block cytochrome c release. These results suggest that apoptosis predominates in cardiomyocytes after reoxygenation through a mitochondrion-dependent apoptotic pathway, and Bcl-2 prevents reoxygenation-induced apoptosis by inhibiting cytochrome c release from the mitochondria and prevents activation of caspase-3 and -9. PMID:10903995

  20. Cardiomyogenic potential of c-kit+ expressing cells derived from neonatal and adult mouse hearts

    PubMed Central

    Zaruba, Marc-Michael; Soonpaa, Mark; Reuter, Sean; Field, Loren J.

    2010-01-01

    Summary Background c-kit is a receptor tyrosine kinase family member expressed in hematopoietic stem cells. c-kit is also transiently expressed in cardiomyocyte precursors during development, and in a rare cell population in the normal adult heart. Here, the cardiomyogenic potential of c-kit+ cells isolated from normal neonatal, normal adult and infarcted adult mouse hearts was evaluated. Methods and Results Magnetic activated cell sorting (MACS) was used to prepare c-kit+ cells from the hearts of ACT-EGFP/MHC-nLAC double transgenic mice. These animals exhibit widespread enhanced green fluorescent protein (EGFP) expression and cardiomyocyte-restricted nuclear β-galactosidase activity, thus permitting simultaneous tracking of cell survival and differentiation. A subset of the c-kit+ cells from double transgenic neonatal hearts acquired a cardiomyogenic phenotype when co-cultured with fetal cardiomyocytes (2.4% of all EGFP+ cells screened), but not when cultured alone or when co-cultured with mouse fibroblasts (0.03% and 0.05% of the EGFP+ cells screened, respectively). In contrast, c-kit+ cells from normal adult double transgenic hearts failed to undergo cardiomyogenic differentiation when co-cultured with non-transgenic fetal cardiomyocytes (>18,000 EGFP+ cells screened) or when transplanted into normal or infarcted adult mouse hearts (14 EGFP+ grafts examined). A single c-kit+ cell from an infarcted double transgenic adult heart was observed to acquire a cardiomyogenic phenotype in co-culture (>37,000 EGFP+ cells screened). Conclusions These data suggest that the ability of cardiac-resident c-kit+ cells to acquire a cardiomyogenic phenotype is subject to temporal limitations, or alternatively that the cardiomyogenic population is lost. Elucidation of the underlying molecular basis may permit robust cardiomyogenic induction in adult-derived cardiac c-kit+ cells. PMID:20421520

  1. Peptide-enhanced mRNA transfection in cultured mouse cardiac fibroblasts and direct reprogramming towards cardiomyocyte-like cells

    PubMed Central

    Lee, Kunwoo; Yu, Pengzhi; Lingampalli, Nithya; Kim, Hyun Jin; Tang, Richard; Murthy, Niren

    2015-01-01

    The treatment of myocardial infarction is a major challenge in medicine due to the inability of heart tissue to regenerate. Direct reprogramming of endogenous cardiac fibroblasts into functional cardiomyocytes via the delivery of transcription factor mRNAs has the potential to regenerate cardiac tissue and to treat heart failure. Even though mRNA delivery to cardiac fibroblasts has the therapeutic potential, mRNA transfection in cardiac fibroblasts has been challenging. Herein, we develop an efficient mRNA transfection in cultured mouse cardiac fibroblasts via a polyarginine-fused heart-targeting peptide and lipofectamine complex, termed C-Lipo and demonstrate the partial direct reprogramming of cardiac fibroblasts towards cardiomyocyte cells. C-Lipo enabled the mRNA-induced direct cardiac reprogramming due to its efficient transfection with low toxicity, which allowed for multiple transfections of Gata4, Mef2c, and Tbx5 (GMT) mRNAs for a period of 2 weeks. The induced cardiomyocyte-like cells had α-MHC promoter-driven GFP expression and striated cardiac muscle structure from α-actinin immunohistochemistry. GMT mRNA transfection of cultured mouse cardiac fibroblasts via C-Lipo significantly increased expression of the cardiomyocyte marker genes, Actc1, Actn2, Gja1, Hand2, and Tnnt2, after 2 weeks of transfection. Moreover, this study provides the first direct evidence that the stoichiometry of the GMT reprogramming factors influence the expression of cardiomyocyte marker genes. Our results demonstrate that mRNA delivery is a potential approach for cardiomyocyte generation. PMID:25834424

  2. Doxycycline Attenuates Protein Aggregation in Cardiomyocytes and Improves Survival of a Mouse Model of Cardiac Proteinopathy

    PubMed Central

    Zheng, Hanqiao; Tang, Mingxin; Zheng, Qingwen; Kumarapeli, Asangi R. K.; Horak, Kathleen M.; Tian, Zongwen; Wang, Xuejun

    2010-01-01

    Objective The goal of this preclinical study was to assess the therapeutic efficacy of doxycycline (Doxy) for desmin-related cardiomyopathy (DRC) and to elucidate the potential mechanisms involved. Background DRC, exemplifying cardiac proteinopathy, is characterized by intrasarcoplasmic protein aggregation and cardiac insufficiency. No effective treatment for DRC is presently available. Doxy was shown to attenuate aberrant intranuclear aggregation and toxicity of misfolded proteins in non-cardiac cells and animal models of other proteinopathies. Methods Mice and cultured neonatal rat cardiomyocytes with transgenic (TG) expression of a human DRC-linked missense mutant αB-crystallin (CryABR120G) were used for testing the effect of Doxy. Doxy was administered via drinking water (6 mg/ml) initiated at 8 or 16 weeks of age. Results Doxy treatment initiated at 16 weeks of age significantly delayed the premature death of CryABR120G TG mice, with a median lifespan of 30.4 weeks (placebo group 25 weeks, p<0.01). In another cohort of CryABR120G TG mice, Doxy treatment initiated at 8 weeks of age significantly attenuated cardiac hypertrophy in one month. Further investigation revealed that Doxy significantly reduced the abundance of CryAB-positive microscopic aggregates, detergent-resistant CryAB oligomers, and total ubiquitinated proteins in CryABR120G TG hearts. In cell culture, Doxy treatment dose-dependently suppressed the formation of both microscopic protein aggregates and detergent-resistant soluble CryABR120G oligomers, and reversed the upregulation of p62 protein induced by adenovirus-mediated CryABR120G expression. Conclusions Doxy suppresses CryABR120G induced aberrant protein aggregation in cardiomyocytes and prolongs CryABR120G based DRC mouse survival. PMID:20947000

  3. Effect of azelnidipine and amlodipine on single cell mechanics in mouse cardiomyocytes.

    PubMed

    Iribe, Gentaro; Kaihara, Keiko; Ito, Hiroshi; Naruse, Keiji

    2013-09-01

    Azelnidipine and amlodipine are dihydropyridine-type Ca(2+) channel blockers for the treatment of hypertension. Although these drugs have high vasoselectivity and small negative inotropic effects in vivo, little is known regarding their direct effects on cellular contractility without humoral regulation or the additive effects of these drugs with other antihypertensive drugs on myocardial contractility. To investigate the effects of Ca(2+) channel blockers on single cell mechanics, mouse cardiomyocytes were enzymatically isolated, and a pair of carbon fibers was attached to opposite cell-ends to stretch the cells. Cells were paced at 4 Hz superfused in normal Tyrode solution at 37°C. Cell length and active/passive force calculated from carbon fiber bending were recorded in 6 different preload conditions. Slopes of end-systolic force-length relation curves (maximum elastance) were measured as an index of contractility before and after drugs were administered. Azelnidipine at 10nM and 100 nM did not change maximum elastance, while amlodipine at 100 nM did decrease maximum elastance. The combination of RNH-6270 (active form of angiotensin II receptor blocker, olmesartan, 10nM) and either amlodipine (10nM) or azelnidipine (10nM) did not affect maximum elastance. Although both amlodipine and azelnidipine can be used safely at therapeutically relevant concentrations even in combination with olmesartan, the present results suggest that azelnidipine has a less negative inotropic action compared to amlodipine. PMID:23747592

  4. Dioxin Exposure Disrupts the Differentiation of Mouse Embryonic Stem Cells into Cardiomyocytes

    PubMed Central

    Wang, Ying; Fan, Yunxia; Puga, Alvaro

    2010-01-01

    Experimental exposure of fish, birds, and rodents to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin) causes multiple Ah receptor–mediated developmental abnormalities, an observation consistent with compelling evidence in human populations that TCDD exposure is responsible for a significant incidence of birth defects. To characterize molecular mechanisms that might explain the developmental effects of dioxin, we have studied the consequences of TCDD exposure on the differentiation of mouse embryonic stem (ES) cells in culture and on the expression of genes, including those coding for homeodomain containing transcription factors, with a role in progression of tissue differentiation and embryonic identity during development. We find that TCDD treatment causes expression changes in a number of homeobox genes concomitant with Ah receptor recruitment to the promoters of many of these genes, whether under naïve or dioxin-activated conditions. TCDD exposure also derails temporal expression trajectories of developmentally regulated genes in a wide diversity of differentiation pathways, including genes with functions in neural and cardiovascular development, self-renewal, hematopoiesis and mesenchymal lineage specification, and Notch and Wnt pathways. Among these, we find that TCDD represses the expression of the cardiac development–specific Nkx2.5 homeobox transcription factor, of cardiac troponin-T and of α- and β-myosin heavy chains, inhibiting the formation of beating cardiomyocytes, a characteristic phenotype of differentiating mouse ES cells in culture. These data identify potential pathways for dioxin to act as a developmental teratogen, possibly critical to cardiovascular development and disease, and provide molecular targets that may help us understand the molecular basis of Ah receptor–mediated developmental toxicity. PMID:20130022

  5. Defined MicroRNAs Induce Aspects of Maturation in Mouse and Human Embryonic-Stem-Cell-Derived Cardiomyocytes.

    PubMed

    Lee, Desy S; Chen, Jyh-Hong; Lundy, David J; Liu, Chung-Hung; Hwang, Shiaw-Min; Pabon, Lil; Shieh, Ru-Chi; Chen, Chien-Chang; Wu, Sheng-Nan; Yan, Yu-Ting; Lee, Sho-Tone; Chiang, Po-Min; Chien, Shu; Murry, Charles E; Hsieh, Patrick C H

    2015-09-29

    Pluripotent-cell-derived cardiomyocytes have great potential for use in research and medicine, but limitations in their maturity currently constrain their usefulness. Here, we report a method for improving features of maturation in murine and human embryonic-stem-cell-derived cardiomyocytes (m/hESC-CMs). We found that coculturing m/hESC-CMs with endothelial cells improves their maturity and upregulates several microRNAs. Delivering four of these microRNAs, miR-125b-5p, miR-199a-5p, miR-221, and miR-222 (miR-combo), to m/hESC-CMs resulted in improved sarcomere alignment and calcium handling, a more negative resting membrane potential, and increased expression of cardiomyocyte maturation markers. Although this could not fully phenocopy all adult cardiomyocyte characteristics, these effects persisted for two months following delivery of miR-combo. A luciferase assay demonstrated that all four miRNAs target ErbB4, and siRNA knockdown of ErbB4 partially recapitulated the effects of miR-combo. In summary, a combination of miRNAs induced via endothelial coculture improved ESC-CM maturity, in part through suppression of ErbB4 signaling. PMID:26365191

  6. Overexpression of a dominant-negative mutant of SIRT1 in mouse heart causes cardiomyocyte apoptosis and early-onset heart failure.

    PubMed

    Mu, WenLi; Zhang, QingJun; Tang, XiaoQiang; Fu, WenYan; Zheng, Wei; Lu, YunBiao; Li, HongLiang; Wei, YuSheng; Li, Li; She, ZhiGang; Chen, HouZao; Liu, DePei

    2014-09-01

    SIRT1, a mammalian ortholog of yeast silent information regulator 2 (Sir2), is an NAD(+)-dependent protein deacetylase that plays a critical role in the regulation of vascular function. The current study aims to investigate the functional significance of deacetylase activity of SIRT1 in heart. Here we show that the early postnatal hearts expressed the highest level of SIRT1 deacetylase activity compared to adult and aged hearts. We generated transgenic mice with cardiac-specific expression of a dominant-negative form of the human SIRT1 (SIRT1H363Y), which represses endogenous SIRT1 activity. The transgenic mice displayed dilated atrial and ventricular chambers, and died early in the postnatal period. Pathological, echocardiographic and molecular phenotype confirmed the presence of dilated cardiomyopathy. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling analysis revealed a greater abundance of apoptotic nuclei in the hearts of transgenic mice. Furthermore, we show that cardiomyocyte apoptosis caused by suppression of SIRT1 activity is, at least in part, due to increased p53 acetylation and upregulated Bax expression. These results indicate that dominant negative form of SIRT1 (SIRT1H363Y) overexpression in mouse hearts causes cardiomyocyte apoptosis and early-onset heart failure, suggesting a critical role of SIRT1 in preserving normal cardiac development during the early postnatal period. PMID:25104317

  7. [Proliferation of adult mammalian ventricular cardiomyocytes: a sporadic but feasible phenomenon].

    PubMed

    Vargas-González, Alvaro

    2014-01-01

    Proliferation of adult mammalian ventricular cardiomyocytes has been ruled out by some researchers, who have argued that these cells are terminally differentiated; however, this dogma has been rejected because other researchers have reported that these cells can present the processes necessary to proliferate, that is, DNA synthesis, mitosis and cytokinesis when the heart is damaged experimentally through pharmacological and surgical strategies or due to pathological conditions concerning the cardiovascular system. This review integrates some of the available works in the literature evaluating the DNA synthesis, mitosis and cytokinesis in these myocytes, when the myocardium is damaged, with the purpose of knowing if their proliferation can be considered as a feasible phenomenon. The review is concluded with a reflection about the perspectives of the knowledge generated in this area. PMID:24792902

  8. Mouse embryonic stem cells irradiated with γ-rays differentiate into cardiomyocytes but with altered contractile properties.

    PubMed

    Rebuzzini, Paola; Fassina, Lorenzo; Mulas, Francesca; Bellazzi, Riccardo; Redi, Carlo Alberto; Di Liberto, Riccardo; Magenes, Giovanni; Adjaye, James; Zuccotti, Maurizio; Garagna, Silvia

    2013-08-30

    Embryonic stem cells (ESCs) for their derivation from the inner cell mass of a blastocyst represent a valuable in vitro model to investigate the effects of ionizing radiation on early embryonic cellular response. Following irradiation, both human and mouse ESCs (mESCs) maintain their pluripotent status and the capacity to differentiate into embryoid bodies and to form teratomas. Although informative of the maintenance of a pluripotent status, these studies never investigated the capability of irradiated ESCs to form specific differentiated phenotypes. Here, for the first time, 5Gy-irradiated mESCs were differentiated into cardiomyocytes, thus allowing the analysis of the long-term effects of ionizing radiations on the differentiation potential of a pluripotent stem cell population. On treated mESCs, 96h after irradiation, a genome-wide expression analysis was first performed in order to determine whether the treatment influenced gene expression of the surviving mESCs. Microarrays analysis showed that only 186 genes were differentially expressed in treated mESCs compared to control cells; a quarter of these genes were involved in cellular differentiation, with three main gene networks emerging, including cardiogenesis. Based on these results, we differentiated irradiated mESCs into cardiomyocytes. On day 5, 8 and 12 of differentiation, treated cells showed a significant alteration (qRT-PCR) of the expression of marker genes (Gata-4, Nkx-2.5, Tnnc1 and Alpk3) when compared to control cells. At day 15 of differentiation, although the organization of sarcomeric α-actinin and troponin T proteins appeared similar in cardiomyocytes differentiated from either mock or treated cells, the video evaluation of the kinematics and dynamics of the beating cardiac syncytium evidenced altered contractile properties of cardiomyocytes derived from irradiated mESCs. This alteration correlated with significant reduction of Connexin 43 foci. Our results indicate that mESCs populations

  9. Calnexin silencing in mouse neonatal cardiomyocytes induces Ca2+ cycling defects, ER stress, and apoptosis.

    PubMed

    Bousette, Nicolas; Abbasi, Cynthia; Chis, Roxana; Gramolini, Anthony O

    2014-03-01

    Calnexin (CNX) is an endoplasmic reticulum (ER) quality control chaperone that has been implicated in ER stress. ER stress is a prominent pathological feature of various pathologic conditions, including cardiovascular diseases. However, the role of CNX and ER stress has not been studied in the heart. In the present study, we aimed to characterize the role of CNX in cardiomyocyte physiology with respect to ER stress, apoptosis, and cardiomyocyte Ca(2+) cycling. We demonstrated significantly decreased CNX mRNA and protein levels by LentiVector mediated transduction of targeting shRNAs. CNX silenced cardiomyocytes exhibited ER stress as evidenced by increased GRP78 and ATF6 protein levels, increased levels of spliced XBP1 mRNA, ASK-1, ERO1a, and CHOP mRNA levels. CNX silencing also led to significant activation of caspases-3 and -9. This activation of caspases was associated with hallmark morphological features of apoptosis including loss of sarcomeric organization and nuclear integrity. Ca(2+) imaging in live cells showed that CNX silencing resulted in Ca(2+) transients with significantly larger amplitudes but decreased frequency and Ca(2+) uptake rates in the basal state. Interestingly, 5 mM caffeine stimulated Ca(2+) transients were similar between control and CNX silenced cardiomyocytes. Finally, we demonstrated that CNX silencing induced the expression of the L-type voltage dependent calcium channel (CAV1.2) but reduced the expression of the sarcoplasmic reticulum ATPase (SERCA2a). In conclusion, this is the first study to demonstrate CNX has a specific role in cardiomyocyte viability and Ca(2+) cycling through its effects on ER stress, apoptosis and Ca(2+) channel expression. PMID:24037923

  10. No Evidence for Cardiomyocyte Number Expansion in Preadolescent Mice.

    PubMed

    Alkass, Kanar; Panula, Joni; Westman, Mattias; Wu, Ting-Di; Guerquin-Kern, Jean-Luc; Bergmann, Olaf

    2015-11-01

    The magnitude of cardiomyocyte generation in the adult heart has been heavily debated. A recent report suggests that during mouse preadolescence, cardiomyocyte proliferation leads to a 40% increase in the number of cardiomyocytes. Such an expansion would change our understanding of heart growth and have far-reaching implications for cardiac regeneration. Here, using design-based stereology, we found that cardiomyocyte proliferation accounted for 30% of postnatal DNA synthesis; however, we were unable to detect any changes in cardiomyocyte number after postnatal day 11. (15)N-thymidine and BrdU analyses provided no evidence for a proliferative peak in preadolescent mice. By contrast, cardiomyocyte multinucleation comprises 57% of postnatal DNA synthesis, followed by cardiomyocyte nuclear polyploidisation, contributing with 13% to DNA synthesis within the second and third postnatal weeks. We conclude that the majority of cardiomyocytes is set within the first postnatal week and that this event is followed by two waves of non-replicative DNA synthesis. This Matters Arising paper is in response to Naqvi et al. (2014), published in Cell. See also the associated Correspondence by Soonpaa et al. (2015), and the response by Naqvi et al. (2015), published in this issue. PMID:26544945

  11. The miR-17-92 cluster regulates FOG-2 expression and inhibits proliferation of mouse embryonic cardiomyocytes

    PubMed Central

    Xiang, Rui; Lei, Han; Chen, Mianzhi; Li, Qinwei; Sun, Huan; Ai, Jianzhong; Chen, Tielin; Wang, Honglian; Fang, Yin; Zhou, Qin

    2012-01-01

    MicroRNAs (miRNAs) have gradually been recognized as regulators of embryonic development; however, relatively few miRNAs have been identified that regulate cardiac development. A series of recent papers have established an essential role for the miRNA-17-92 (miR-17-92) cluster of miRNAs in the development of the heart. Previous research has shown that the Friend of Gata-2 (FOG-2) is critical for cardiac development. To investigate the possibility that the miR-17-92 cluster regulates FOG-2 expression and inhibits proliferation in mouse embryonic cardiomyocytes we initially used bioinformatics to analyze 3′ untranslated regions (3′UTR) of FOG-2 to predict the potential of miR-17-92 to target it. We used luciferase assays to demonstrate that miR-17-5p and miR-20a of miR-17-92 interact with the predicted target sites in the 3′UTR of FOG-2. Furthermore, RT-PCR and Western blot were used to demonstrate the post-transcriptional regulation of FOG-2 by miR-17-92 in embryonic cardiomyocytes from E12.5-day pregnant C57BL/6J mice. Finally, EdU cell assays together with the FOG-2 rescue strategy were employed to evaluate the effect of proliferation on embryonic cardiomyocytes. We first found that the miR-17-5p and miR-20a of miR-17-92 directly target the 3′UTR of FOG-2 and post-transcriptionally repress the expression of FOG-2. Moreover, our findings demonstrated that over-expression of miR-17-92 may inhibit cell proliferation via post-transcriptional repression of FOG-2 in embryonic cardiomyocytes. These results indicate that the miR-17-92 cluster regulates the expression of FOG-2 protein and suggest that the miR-17-92 cluster might play an important role in heart development. PMID:22267003

  12. NH2-terminal truncations of cardiac troponin I and cardiac troponin T produce distinct effects on contractility and calcium homeostasis in adult cardiomyocytes

    PubMed Central

    Wei, Hongguang

    2014-01-01

    Cardiac troponin I (TnI) has an NH2-terminal extension that is an adult heart-specific regulatory structure. Restrictive proteolytic truncation of the NH2-terminal extension of cardiac TnI occurs in normal hearts and is upregulated in cardiac adaptation to hemodynamic stress or β-adrenergic deficiency. NH2-terminal truncated cardiac TnI (cTnI-ND) alters the conformation of the core structure of cardiac TnI similarly to that produced by PKA phosphorylation of Ser23/24 in the NH2-terminal extension. At organ level, cTnI-ND enhances ventricular diastolic function. The NH2-terminal region of cardiac troponin T (TnT) is another regulatory structure that can be selectively cleaved via restrictive proteolysis. Structural variations in the NH2-terminal region of TnT also alter the molecular conformation and function. Transgenic mouse hearts expressing NH2-terminal truncated cardiac TnT (cTnT-ND) showed slower contractile velocity to prolong ventricular rapid-ejection time, resulting in higher stroke volume. Our present study compared the effects of cTnI-ND and cTnT-ND in cardiomyocytes isolated from transgenic mice on cellular morphology, contractility, and calcium kinetics. Resting cTnI-ND, but not cTnT-ND, cardiomyocytes had shorter length than wild-type cells with no change in sarcomere length. cTnI-ND, but not cTnT-ND, cardiomyocytes produced higher contractile amplitude and faster shortening and relengthening velocities in the absence of external load than wild-type controls. Although the baseline and peak levels of cytosolic Ca2+ were not changed, Ca2+ resequestration was faster in both cTnI-ND and cTnT-ND cardiomyocytes than in wild-type control. The distinct effects of cTnI-ND and cTnT-ND demonstrate their roles in selectively modulating diastolic or systolic functions of the heart. PMID:25518962

  13. Discontinuous thoracic venous cardiomyocytes and heart exhibit synchronized developmental switch of troponin isoforms

    PubMed Central

    Kracklauer, Martin P.; Feng, Han-Zhong; Jiang, Wenrui; Lin, Jenny L.-C.; Lin, Jim J.-C.; Jin, J.-P.

    2012-01-01

    Cardiomyocyte-like cells have been reported in thoracic veins of rodents and other mammals, but their differentiation state and relationship to the muscle mass in the heart remain to be characterized. Here we investigated the distribution, ultrastructure, and the expression and developmental regulation of myofilament proteins in mouse and rat pulmonary and azygos venous cardiomyocytes. Tracing cardiomyocytes in transgenic mouse tissues with a lacZ reporter gene driven by cloned rat cardiac troponin T promoter demonstrated scattered distribution of cardiomyocytes discontinuous from the atrial sleeves. The longitudinal axis of venous cardiomyocytes is perpendicular to that of the vessel. These cells contain typical sarcomere structures and intercalated discs as shown in electron microscopic images and express cardiac isoforms of troponin T, troponin I and myosin. The expression of troponin I isoform genes and the alternative splicing of cardiac troponin T in thoracic venous cardiomyocytes are regulated during postnatal development in a precise synchrony with that in the heart. Nonetheless, the patterns of cardiac troponin T splicing in adult rat thoracic venous cardiomyocytes are slightly but clearly distinct from those in the atrial and ventricular muscles. The data indicate that mouse and rat thoracic venous cardiomyocytes residing in extra-cardiac tissue possess a physiologically differentiated state and an intrinsically preset developmental clock, which are apparently independent of the very different hemodynamic environments and functional features of the vessels and heart. PMID:23176202

  14. Differential Expression Levels of Integrin α6 Enable the Selective Identification and Isolation of Atrial and Ventricular Cardiomyocytes

    PubMed Central

    Wiencierz, Anne Maria; Kernbach, Manuel; Ecklebe, Josephine; Monnerat, Gustavo; Tomiuk, Stefan; Raulf, Alexandra; Christalla, Peter; Malan, Daniela; Hesse, Michael; Bosio, Andreas; Fleischmann, Bernd K.; Eckardt, Dominik

    2015-01-01

    Rationale Central questions such as cardiomyocyte subtype emergence during cardiogenesis or the availability of cardiomyocyte subtypes for cell replacement therapy require selective identification and purification of atrial and ventricular cardiomyocytes. However, current methodologies do not allow for a transgene-free selective isolation of atrial or ventricular cardiomyocytes due to the lack of subtype specific cell surface markers. Methods and Results In order to develop cell surface marker-based isolation procedures for cardiomyocyte subtypes, we performed an antibody-based screening on embryonic mouse hearts. Our data indicate that atrial and ventricular cardiomyocytes are characterized by differential expression of integrin α6 (ITGA6) throughout development and in the adult heart. We discovered that the expression level of this surface marker correlates with the intracellular subtype-specific expression of MLC-2a and MLC-2v on the single cell level and thereby enables the discrimination of cardiomyocyte subtypes by flow cytometry. Based on the differential expression of ITGA6 in atria and ventricles during cardiogenesis, we developed purification protocols for atrial and ventricular cardiomyocytes from mouse hearts. Atrial and ventricular identities of sorted cells were confirmed by expression profiling and patch clamp analysis. Conclusion Here, we introduce a non-genetic, antibody-based approach to specifically isolate highly pure and viable atrial and ventricular cardiomyocytes from mouse hearts of various developmental stages. This will facilitate in-depth characterization of the individual cellular subsets and support translational research applications. PMID:26618511

  15. 1,5-Disubstituted benzimidazoles that direct cardiomyocyte differentiation from mouse embryonic stem cells

    PubMed Central

    Okolotowicz, Karl J.; Bushway, Paul; Lanier, Marion; Gilley, Cynthia; Cynthia, Mark; Cashman, John R.

    2016-01-01

    Cardiomyopathy is the leading cause of death worldwide. Despite progress in medical treatments, heart transplantation is one of the only current options for those with infarcted heart muscle. Stem cell differentiation technology may afford cell-based therapeutics that may lead to the generation of new, healthy heart muscle cells from undifferentiated stem cells. Our approach is to use small molecules to stimulate stem cell differentiation. Herein, we describe a novel class of 1,5-disubstituted benzimidazoles that induce differentiation of stem cells into cardiac cells. We report on the evaluation in vitro for cardiomyocyte differentiation and describe structure–activity relationship results that led to molecules with drug-like properties. The results of this study show the promise of small molecules to direct stem cell lineage commitment, to probe signaling pathways and to develop compounds for the stimulation of stem cells to repair damaged heart tissue. PMID:26278027

  16. Proteomics Unveils Fibroblast-Cardiomyocyte Lactate Shuttle and Hexokinase Paradox in Mouse Muscles.

    PubMed

    Rakus, Dariusz; Gizak, Agnieszka; Wiśniewski, Jacek R

    2016-08-01

    Quantitative mapping, given in biochemically interpretable units such as mol per mg of total protein, of tissue-specific proteomes is prerequisite for the analysis of any process in cells. We applied label- and standard-free proteomics to characterize three types of striated muscles: white, red, and cardiac muscle. The analysis presented here uncovers several unexpected and novel features of striated muscles. In addition to differences in protein expression levels, the three muscle types substantially differ in their patterns of basic metabolic pathways and isoforms of regulatory proteins. Importantly, some of the conclusions drawn on the basis of our results, such as the potential existence of a "fibroblast-cardiomyocyte lactate shuttle" and the "hexokinase paradox" point to the necessity of reinterpretation of some basic aspects of striated muscle metabolism. The data presented here constitute a powerful database and a resource for future studies of muscle physiology and for the design of pharmaceutics for the treatment of muscular disorders. PMID:27302655

  17. Beta-adrenoceptor subtype dependence of chronotropy in mouse embryonic stem cell-derived cardiomyocytes.

    PubMed

    Ali, N N; Xu, X; Brito-Martins, M; Poole-Wilson, P A; Harding, S E; Fuller, S J

    2004-11-01

    Cardiomyocytes derived from embryonic stem cells (ESCM) have potential both as an experimental model for investigating cardiac physiology and as a source for tissue repair. For both reasons it is important to characterise the responses of these cells, and one of the key modulators of contraction is the beta-adrenergic system. We therefore undertook a detailed study of the response of the spontaneous beating rate of ESCM to beta-adrenoceptor (betaAR) stimulation. Embryoid bodies (EBs) were generated from murine ES line E14Tg2a by the hanging drop method, followed by plating. Spontaneously beating areas were seen starting from 9-14 days after differentiation: the experiments described here were performed on EBs between developmental day 19 and 48. Beating cell layers were seeded with charcoal to allow tracking of movement by a video-edge detection system. Experiments were performed in physiological medium containing 1 mM Ca2+ at 37 degrees C. Isoprenaline (Iso) increased beating rate with an EC50 value of 52 nM. Iso (0.3 microM) increased basal rate from 67 +/- 7 beats per minute (bpm) to 138 +/- 18 bpm, P < 0.001, n = 22. At earlier developmental time points the response to Iso was not maintained through 5 min exposure; this spontaneous desensitisation only being observed before day 36. A repeat application of Iso after a wash period of 20 min produced reproducible effects on beating rate. Subtype dependence of the betaAR response was determined by comparing an initial response with a second in the presence of selective beta1- or beta2AR antagonists. In the presence of the specific beta1AR-blocker CGP 20712A (300 nM) the increase in rate with Iso was reduced from 207 +/- 42% of basal to 128 +/- 13%, P < 0.01. With the beta2AR-blocker ICI 118,551 (50 nM) there was no significant change in Iso response. Exposure to the muscarinic agonist, carbachol (10 microM), inhibited the increase in frequency mediated by isoprenaline, but had mixed stimulatory and inhibitory

  18. Telomerase expression confers cardioprotection in the adult mouse heart after acute myocardial infarction

    PubMed Central

    Serrano, Rosa; Tejera, Agueda; Ayuso, Eduard; Jimenez, Veronica; Formentini, Ivan; Bobadilla, Maria; Mizrahi, Jacques; de Martino, Alba; Gomez, Gonzalo; Pisano, David; Mulero, Francisca; Wollert, Kai C.; Bosch, Fatima; Blasco, Maria A.

    2016-01-01

    Coronary heart disease is one of the main causes of death in the developed world, and treatment success remains modest, with high mortality rates within 1 year after myocardial infarction (MI). Thus, new therapeutic targets and effective treatments are necessary. Short telomeres are risk factors for age-associated diseases, including heart disease. Here we address the potential of telomerase (Tert) activation in prevention of heart failure after MI in adult mice. We use adeno-associated viruses for cardiac-specific Tert expression. We find that upon MI, hearts expressing Tert show attenuated cardiac dilation, improved ventricular function and smaller infarct scars concomitant with increased mouse survival by 17% compared with controls. Furthermore, Tert treatment results in elongated telomeres, increased numbers of Ki67 and pH3-positive cardiomyocytes and a gene expression switch towards a regeneration signature of neonatal mice. Our work suggests telomerase activation could be a therapeutic strategy to prevent heart failure after MI. PMID:25519492

  19. Hypoxia-induced preconditioning in adult stimulated cardiomyocytes is mediated by the opening and trafficking of sarcolemmal KATP channels

    PubMed Central

    Budas, Grant R.; Jovanovic, Sofija; Crawford, Russell M.; Jovanovic, Aleksandar

    2007-01-01

    The opening of sarcolemmal and mitochondrial ATP-sensitive K+ (KATP) channels in the heart is believed to mediate ischemic preconditioning, a phenomenon whereby brief periods of ischemia/reperfusion protect the heart against myocardial infarction. Here, we have applied digital epifluorescent microscopy, immunoprecipitation and Western blotting, perforated patch clamp electrophysiology, and immunofluorescence/laser confocal microscopy to examine the involvement of KATP channels in cardioprotection afforded by preconditioning. We have shown that adult, stimulated-to-beat, guinea-pig cardiomyocytes survived in sustained hypoxia for ∼17 min. An episode of 5-min-long hypoxia/5-min-long reoxygenation before sustained hypoxia dramatically increased the duration of cellular survival. Experiments with different antagonists of KATP channels, applied at different times during the experimental protocol, suggested that the opening of sarcolemmal KATP channels at the beginning of sustained hypoxia mediate preconditioning. This conclusion was supported by perforated patch clamp experiments that revealed activation of sarcolemmal KATP channels by preconditioning. Immunoprecipitation and Western blotting as well as immunofluorescence and laser confocal microscopy showed that the preconditioning is associated with the increase in KATP channel proteins in sarcolemma. Inhibition of trafficking of KATP channel subunits prevented preconditioning without affecting sensitivity of cardiomyocytes to hypoxia in the absence of preconditioning. We conclude that the preconditioning is mediated by the activation and trafficking of sarcolemmal KATP channels. PMID:15084521

  20. In situ calibration of nucleoplasmic versus cytoplasmic Ca²+ concentration in adult cardiomyocytes.

    PubMed

    Ljubojević, Senka; Walther, Stefanie; Asgarzoei, Mojib; Sedej, Simon; Pieske, Burkert; Kockskämper, Jens

    2011-05-18

    Quantification of subcellularly resolved Ca²⁺ signals in cardiomyocytes is essential for understanding Ca²⁺ fluxes in excitation-contraction and excitation-transcription coupling. The properties of fluorescent indicators in intracellular compartments may differ, thus affecting the translation of Ca²⁺-dependent fluorescence changes into [Ca²⁺] changes. Therefore, we determined the in situ characteristics of a frequently used Ca²⁺ indicator, Fluo-4, and a ratiometric Ca²⁺ indicator, Asante Calcium Red, and evaluated their use for reporting and quantifying cytoplasmic and nucleoplasmic Ca²⁺ signals in isolated cardiomyocytes. Ca²⁺ calibration curves revealed significant differences in the apparent Ca²⁺ dissociation constants of Fluo-4 and Asante Calcium Red between cytoplasm and nucleoplasm. These parameters were used for transformation of fluorescence into nucleoplasmic and cytoplasmic [Ca²⁺]. Resting and diastolic [Ca²⁺] were always higher in the nucleoplasm. Systolic [Ca²⁺] was usually higher in the cytoplasm, but some cells (15%) exhibited higher systolic [Ca²⁺] in the nucleoplasm. Ca²⁺ store depletion or blockade of Ca²⁺ leak pathways eliminated the resting [Ca²⁺] gradient between nucleoplasm and cytoplasm, whereas inhibition of inositol 1,4,5-trisphosphate receptors by 2-APB reversed it. The results suggest the presence of significant nucleoplasmic-to-cytoplasmic [Ca²⁺] gradients in resting myocytes and during the cardiac cycle. Nucleoplasmic [Ca²⁺] in cardiomyocytes may be regulated via two mechanisms: diffusion from the cytoplasm and active Ca²⁺ release via inositol 1,4,5-trisphosphate receptors from perinuclear Ca²⁺ stores. PMID:21575569

  1. Modulation of intracellular calcium waves and triggered activities by mitochondrial ca flux in mouse cardiomyocytes.

    PubMed

    Zhao, Zhenghang; Gordan, Richard; Wen, Hairuo; Fefelova, Nadezhda; Zang, Wei-Jin; Xie, Lai-Hua

    2013-01-01

    Recent studies have suggested that mitochondria may play important roles in the Ca(2+) homeostasis of cardiac myocytes. However, it is still unclear if mitochondrial Ca(2+) flux can regulate the generation of Ca(2+) waves (CaWs) and triggered activities in cardiac myocytes. In the present study, intracellular/cytosolic Ca(2+) (Cai (2+)) was imaged in Fluo-4-AM loaded mouse ventricular myocytes. Spontaneous sarcoplasmic reticulum (SR) Ca(2+) release and CaWs were induced in the presence of high (4 mM) external Ca(2+) (Cao (2+)). The protonophore carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP) reversibly raised basal Cai (2+) levels even after depletion of SR Ca(2+) in the absence of Cao (2+) , suggesting Ca(2+) release from mitochondria. FCCP at 0.01 - 0.1 µM partially depolarized the mitochondrial membrane potential (Δψ m ) and increased the frequency and amplitude of CaWs in a dose-dependent manner. Simultaneous recording of cell membrane potentials showed the augmentation of delayed afterdepolarization amplitudes and frequencies, and induction of triggered action potentials. The effect of FCCP on CaWs was mimicked by antimycin A (an electron transport chain inhibitor disrupting Δψ m ) or Ru360 (a mitochondrial Ca(2+) uniporter inhibitor), but not by oligomycin (an ATP synthase inhibitor) or iodoacetic acid (a glycolytic inhibitor), excluding the contribution of intracellular ATP levels. The effects of FCCP on CaWs were counteracted by the mitochondrial permeability transition pore blocker cyclosporine A, or the mitochondrial Ca(2+) uniporter activator kaempferol. Our results suggest that mitochondrial Ca(2+) release and uptake exquisitely control the local Ca(2+) level in the micro-domain near SR ryanodine receptors and play an important role in regulation of intracellular CaWs and arrhythmogenesis. PMID:24348912

  2. Hippo signaling impedes adult heart regeneration

    PubMed Central

    Heallen, Todd; Morikawa, Yuka; Leach, John; Tao, Ge; Willerson, James T.; Johnson, Randy L.; Martin, James F.

    2013-01-01

    Heart failure due to cardiomyocyte loss after ischemic heart disease is the leading cause of death in the United States in large part because heart muscle regenerates poorly. The endogenous mechanisms preventing mammalian cardiomyocyte regeneration are poorly understood. Hippo signaling, an ancient organ size control pathway, is a kinase cascade that inhibits developing cardiomyocyte proliferation but it has not been studied postnatally or in fully mature adult cardiomyocytes. Here, we investigated Hippo signaling in adult cardiomyocyte renewal and regeneration. We found that unstressed Hippo-deficient adult mouse cardiomyocytes re-enter the cell cycle and undergo cytokinesis. Moreover, Hippo deficiency enhances cardiomyocyte regeneration with functional recovery after adult myocardial infarction as well as after postnatal day eight (P8) cardiac apex resection and P8 myocardial infarction. In damaged hearts, Hippo mutant cardiomyocytes also have elevated proliferation. Our findings reveal that Hippo signaling is an endogenous repressor of adult cardiomyocyte renewal and regeneration. Targeting the Hippo pathway in human disease might be beneficial for the treatment of heart disease. PMID:24255096

  3. Two inhibitory systems and CKIs regulate cell cycle exit of mammalian cardiomyocytes after birth.

    PubMed

    Tane, Shoji; Okayama, Hitomi; Ikenishi, Aiko; Amemiya, Yuki; Nakayama, Keiichi I; Takeuchi, Takashi

    2015-10-16

    Mammalian cardiomyocytes actively proliferate during embryonic stages, following which they exit their cell cycle after birth, and the exit is maintained. Previously, we showed that two inhibitory systems (the G1-phase inhibitory system: repression of cyclin D1 expression; the M-phase inhibitory system: inhibition of CDK1 activation) maintain the cell cycle exit of mouse adult cardiomyocytes. We also showed that two CDK inhibitors (CKIs), p21(Cip1) and p27(Kip1), regulate the cell cycle exit in a portion of postnatal cardiomyocytes. It remains unknown whether the two inhibitory systems are involved in the cell cycle exit of postnatal cardiomyocytes and whether p21(Cip1) and p27(Kip1) also inhibit entry to M-phase. Here, we showed that more than 40% of cardiomyocytes entered an additional cell cycle by induction of cyclin D1 expression at postnatal stages, but M-phase entry was inhibited in the majority of cardiomyocytes. Marked cell cycle progression and endoreplication were observed in cardiomyocytes of p21(Cip1) knockout mice at 4 weeks of age. In addition, tri- and tetranucleated cardiomyocytes increased significantly in p21(Cip1) knockout mice. These data showed that the G1-phase inhibitory system and two CKIs (p21(Cip1) and p27(Kip1)) inhibit entry to an additional cell cycle in postnatal cardiomyocytes, and that the M-phase inhibitory system and p21(Cip1) inhibit M-phase entry of cardiomyocytes which have entered the additional cell cycle. PMID:26363457

  4. Enrichment of live unlabelled cardiomyocytes from heterogeneous cell populations using manipulation of cell settling velocity by magnetic field

    PubMed Central

    Sofla, Aarash; Cirkovic, Bojana; Hsieh, Anne; Miklas, Jason W.; Filipovic, Nenad; Radisic, Milica

    2013-01-01

    The majority of available cardiomyocyte markers are intercellular proteins, limiting our ability to enrich live cardiomyocytes from heterogeneous cell preparations in the absence of genetic labeling. Here, we describe enrichment of live cardiomyocytes from the hearts of adult mice in a label-free microfluidic approach. The separation device consisted of a vertical column (15 mm long, 700 μm diameter), placed between permanent magnets resulting in a field strength of 1.23 T. To concentrate the field at the column wall, the column was wrapped with 69 μm diameter nickel wire. Before passing the cells through the column, the cardiomyocytes in the cell suspension had been rendered paramagnetic by treatment of the adult mouse heart cell preparation with sodium nitrite (2.5 mM) for 20 min on ice. The cell suspension was loaded into the vertical column from the top and upon settling, the non-myocytes were removed by the upward flow from the column. The cardiomyocytes were then collected from the column by applying a higher flow rate (144 μl/min). We found that by applying a separation flow rate of 4.2 μl/min in the first step, we can enrich live adult cardiomyocytes to 93% ± 2% in a label-free manner. The cardiomyocytes maintained viability immediately after separation and upon 24 h in culture. PMID:24404002

  5. [Desmin content and transversal stiffness of the left ventricle mouse cardiomyocytes and skeletal muscle fibers after a 30-day space flight on board "BION-M1" biosatellite].

    PubMed

    Ogneva, I V; Maximova, M V; Larina, I M

    2014-01-01

    The aim of this study was to determine the transversal stiffness of the cortical cytoskeleton and the cytoskeletal protein desmin content in the left ventricle cardiomyocytes, fibers of the mouse soleus and tibialis anterior muscle after a 30-day space flight on board the "BION-M1" biosatellite (Russia, 2013). The dissection was made after 13-16.5 h after landing. The transversal stiffness was measured in relaxed and calcium activated state by, atomic force microscopy. The desmin content was estimated by western blotting, and the expression level of desmin-coding gene was detected using real-time PCR. The results indicate that, the transversal stiffness of the left ventricle cardiomyocytes and fibers of the soleus muscle in relaxed and activated states did not differ from the control. The transversal stiffness of the tibialis muscle fibers in relaxed and activated state was increased in the mice group after space flight. At the same time, in all types of studied tissues the desmin content and the expression level of desmin-coding gene did not differ from the control level. PMID:25730983

  6. Three-Dimensional Adult Cardiac Extracellular Matrix Promotes Maturation of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

    PubMed

    Fong, Ashley H; Romero-López, Mónica; Heylman, Christopher M; Keating, Mark; Tran, David; Sobrino, Agua; Tran, Anh Q; Pham, Hiep H; Fimbres, Cristhian; Gershon, Paul D; Botvinick, Elliot L; George, Steven C; Hughes, Christopher C W

    2016-08-01

    Pluripotent stem cell-derived cardiomyocytes (CMs) have great potential in the development of new therapies for cardiovascular disease. In particular, human induced pluripotent stem cells (iPSCs) may prove especially advantageous due to their pluripotency, their self-renewal potential, and their ability to create patient-specific cell lines. Unfortunately, pluripotent stem cell-derived CMs are immature, with characteristics more closely resembling fetal CMs than adult CMs, and this immaturity has limited their use in drug screening and cell-based therapies. Extracellular matrix (ECM) influences cellular behavior and maturation, as does the geometry of the environment-two-dimensional (2D) versus three-dimensional (3D). We therefore tested the hypothesis that native cardiac ECM and 3D cultures might enhance the maturation of iPSC-derived CMs in vitro. We demonstrate that maturation of iPSC-derived CMs was enhanced when cells were seeded into a 3D cardiac ECM scaffold, compared with 2D culture. 3D cardiac ECM promoted increased expression of calcium-handling genes, Junctin, CaV1.2, NCX1, HCN4, SERCA2a, Triadin, and CASQ2. Consistent with this, we find that iPSC-derived CMs in 3D adult cardiac ECM show increased calcium signaling (amplitude) and kinetics (maximum upstroke and downstroke) compared with cells in 2D. Cells in 3D culture were also more responsive to caffeine, likely reflecting an increased availability of calcium in the sarcoplasmic reticulum. Taken together, these studies provide novel strategies for maturing iPSC-derived CMs that may have applications in drug screening and transplantation therapies to treat heart disease. PMID:27392582

  7. Ginsenoside Rb3 protects cardiomyocytes against ischemia-reperfusion injury via the inhibition of JNK-mediated NF-κB pathway: a mouse cardiomyocyte model.

    PubMed

    Ma, Lijia; Liu, Huimin; Xie, Zulong; Yang, Shuang; Xu, Wei; Hou, Jingbo; Yu, Bo

    2014-01-01

    Ginsenoside Rb3 is extracted from the plant Panax ginseng and plays important roles in cardiovascular diseases, including myocardial ischemia-reperfusion (I/R) injury. NF-κB is an important transcription factor involved in I/R injury. However, the underlying mechanism of ginsenoside Rb3 in myocardial I/R injury remains poorly understood. In the current study, a model of myocardial I/R injury was induced via oxygen and glucose deprivation (OGD) followed by reperfusion (OGD-Rep) in mouse cardiac myoblast H9c2 cells. Our data demonstrate that ginsenoside Rb3 suppresses OGD-Rep-induced cell apoptosis by the suppression of ROS generation. By detecting the NF-κB signaling pathway, we discover that the protective effect of ginsenoside Rb3 on the OGD-Rep injury is closely related to the inhibition of NF-κB activity. Ginsenoside Rb3 inhibits the upregulation of phospho-IκB-α and nuclear translocation of NF-κB subunit p65 which are induced by ORD-Rep injury. In addition, the extract also inhibits the OGD-Rep-induced increase in the expression of inflammation-related factors, such as IL-6, TNF-α, monocyte chemotactic protein-1 (MCP-1), MMP-2 and MMP-9. However, LPS treatment alleviates the protective roles of ginsenoside Rb3 and activates the NF-κB pathway. Finally, the upstream factors of NF-κB were analyzed, including the Akt/Foxo3a and MAPK signaling pathways. We find that ginsenoside Rb3 pretreatment only decreases the phosphorylation of JNK induced by OGD-Rep injury, an indicator of the MAPK pathway. Importantly, an inhibitor of phospho-JNK, SP600125, protects against OGD-Rep induced apoptosis and inhibited NF-κB signaling pathway, similar to the roles of ginsenoside Rb3. Taken together, our results demonstrate that the protective effect of ginsenoside Rb3 on the OGD-Rep injury is attributed to the inhibition of JNK-mediated NF-κB activation, suggesting that ginsenoside Rb3 has the potential to serve as a novel therapeutic agent for myocardial I/R injury. PMID

  8. Ginsenoside Rb3 Protects Cardiomyocytes against Ischemia-Reperfusion Injury via the Inhibition of JNK-Mediated NF-κB Pathway: A Mouse Cardiomyocyte Model

    PubMed Central

    Xie, Zulong; Yang, Shuang; Xu, Wei; Hou, Jingbo; Yu, Bo

    2014-01-01

    Ginsenoside Rb3 is extracted from the plant Panax ginseng and plays important roles in cardiovascular diseases, including myocardial ischemia-reperfusion (I/R) injury. NF-κB is an important transcription factor involved in I/R injury. However, the underlying mechanism of ginsenoside Rb3 in myocardial I/R injury remains poorly understood. In the current study, a model of myocardial I/R injury was induced via oxygen and glucose deprivation (OGD) followed by reperfusion (OGD-Rep) in mouse cardiac myoblast H9c2 cells. Our data demonstrate that ginsenoside Rb3 suppresses OGD-Rep-induced cell apoptosis by the suppression of ROS generation. By detecting the NF-κB signaling pathway, we discover that the protective effect of ginsenoside Rb3 on the OGD-Rep injury is closely related to the inhibition of NF-κB activity. Ginsenoside Rb3 inhibits the upregulation of phospho-IκB-α and nuclear translocation of NF-κB subunit p65 which are induced by ORD-Rep injury. In addition, the extract also inhibits the OGD-Rep-induced increase in the expression of inflammation-related factors, such as IL-6, TNF-α, monocyte chemotactic protein-1 (MCP-1), MMP-2 and MMP-9. However, LPS treatment alleviates the protective roles of ginsenoside Rb3 and activates the NF-κB pathway. Finally, the upstream factors of NF-κB were analyzed, including the Akt/Foxo3a and MAPK signaling pathways. We find that ginsenoside Rb3 pretreatment only decreases the phosphorylation of JNK induced by OGD-Rep injury, an indicator of the MAPK pathway. Importantly, an inhibitor of phospho-JNK, SP600125, protects against OGD-Rep induced apoptosis and inhibited NF-κB signaling pathway, similar to the roles of ginsenoside Rb3. Taken together, our results demonstrate that the protective effect of ginsenoside Rb3 on the OGD-Rep injury is attributed to the inhibition of JNK-mediated NF-κB activation, suggesting that ginsenoside Rb3 has the potential to serve as a novel therapeutic agent for myocardial I/R injury. PMID

  9. Histomorphological Phenotyping of the Adult Mouse Brain.

    PubMed

    Mikhaleva, Anna; Kannan, Meghna; Wagner, Christel; Yalcin, Binnaz

    2016-01-01

    This article describes a series of standard operating procedures for morphological phenotyping of the mouse brain using basic histology. Many histological studies of the mouse brain use qualitative approaches based on what the human eye can detect. Consequently, some phenotypic information may be missed. Here we describe a quantitative approach for the assessment of brain morphology that is simple and robust. A total of 78 measurements are made throughout the brain at specific and well-defined regions, including the cortex, the hippocampus, and the cerebellum. Experimental design and timeline considerations, including strain background effects, the importance of sectioning quality, measurement variability, and efforts to correct human errors are discussed. © 2016 by John Wiley & Sons, Inc. PMID:27584555

  10. Maternal High-Salt Intake During Pregnancy Reprogrammed Renin–Angiotensin System-Mediated Cardiomyocyte Apoptosis in the Adult Offspring Heart

    PubMed Central

    Lv, Juanxiu; Zhang, Peiwen; Zhang, Yujuan; Kuang, Hanzhe; Cao, Li; Wu, Conglong; Jiang, Lin; Li, Dawei; Mao, Caiping

    2014-01-01

    Aims: Excess salt intake during pregnancy may alter fetal organ structures and functions leading to increased risks in the development of cardiovascular diseases in later life. The present study determined whether and how the prenatal high-salt (HS) diets affect renin–angiotensin system (RAS) that may mediate cardiac cell death. Methods and Results: Angiotensin II receptors, AT1 and AT2, protein expression was increased in the myocardium of the offspring exposed to prenatal HS; apoptotic cells appeared in the myocardium of the adult offspring. Mitochondrion was isolated in cell experiments, and the data showed cardiomyocyte apoptosis requiring cytochrome C release. Pretreating H9C2 cells with AT2 agonist CGP42112A induced cell apoptosis in DNA fragments and activated caspase 3. CGP42112A increased mitochondrion cytochrome C release and apoptosis in the cells. Conclusion: Both in vitro and in vivo study demonstrated that cardiomyocyte apoptosis was related to AT2 activation. Prenatal HS diets may reprogram RAS that mediates apoptosis in the offspring myocardium, and AT2 may contribute to cardiomyocyte apoptosis via the cytochrome C release pathway. PMID:23690339

  11. Requirement of IP3 receptor 3 (IP3R3) in nitric oxide induced cardiomyocyte differentiation of mouse embryonic stem cells.

    PubMed

    Wei, Wenjie; Huang, Wei; Yue, Jianbo

    2016-08-01

    Nitric oxide (NO) markedly induces cardiomyocyte (CM) differentiation of embryonic stem (ES) cells. Here we examined the role of the Ca(2+) signaling in the NO-induced CM differentiation of mouse ES cells. We found that NO induced intracellular Ca(2+) increases in ES cells in a dose-dependent manner, and application of IP3 pathway antagonists not only significantly inhibited this induced Ca(2+) increase but also abolished NO-induced CM differentiation of ES cells. Subsequently, all 3 types of inositol 1, 4, 5-trisphosphate (IP3) receptors (IP3Rs) in mouse ES cells were individually or triply knocked down. Interestingly, only knockdown of type 3 IP3R (IP3R3) or triple-knockdown of three types of IP3Rs significantly inhibited the NO-induced Ca(2+) increases. Consistently, IP3R3 knockdown blocked the NO-induced CM differentiation of ES cells. CMs derived from IP3R3 knockdown ES cells also showed both structural and functional defects. In summary, our results indicate that the IP3R3-Ca(2+) pathway is required for NO-induced CM differentiation of ES cells. PMID:27349290

  12. ATM localization and gene expression in the adult mouse eye

    PubMed Central

    Leemput, Julia; Masson, Christel; Bigot, Karine; Errachid, Abdelmounaim; Dansault, Anouk; Provost, Alexandra; Gadin, Stéphanie; Aoufouchi, Said; Menasche, Maurice

    2009-01-01

    Purpose High levels of metabolism and oxygen consumption in most adult murine ocular compartments, combined with exposure to light and ultraviolet (UV) radiation, are major sources of oxidative stress, causing DNA damage in ocular cells. Of all mammalian body cells, photoreceptor cells consume the largest amount of oxygen and generate the highest levels of oxidative damage. The accumulation of such damage throughout life is a major factor of aging tissues. Several multiprotein complexes have recently been identified as the major sensors and mediators involved in the maintenance of DNA integrity. The activity of these complexes initially seemed to be restricted to dividing cells, given their ultimate role in major cell cycle checkpoints. However, it was later established that they are also active in post-mitotic cells. Recent findings demonstrate that the DNA damage response (DDR) is essential for the development, maintenance, and normal functioning of the adult central nervous system. One major molecular factor in the DDR is the protein, ataxia telangiectasia mutated (ATM). It is required for the rapid induction of cellular responses to DNA double-strand breaks. These cytotoxic DNA lesions may be caused by oxidative damage. To understand how ATM prevents oxidative stress and participates in the maintenance of genomic integrity and cell viability of the adult retina, we determined the ATM expression patterns and studied its localization in the adult mouse eye. Methods Atm gene expression was analyzed by RT–PCR experiments and its localization by in situ hybridization on adult mouse ocular and cerebellar tissue sections. ATM protein expression was determined by western blot analysis of proteins homogenates extracted from several mouse tissues and its localization by immunohistochemistry experiments performed on adult mouse ocular and cerebellar tissue sections. In addition, subcellular localization was realized by confocal microscopy imaging of ocular tissue

  13. Human induced pluripotent stem cell‐derived versus adult cardiomyocytes: an in silico electrophysiological study on effects of ionic current block

    PubMed Central

    Paci, M; Hyttinen, J; Rodriguez, B

    2015-01-01

    Background and Purpose Two new technologies are likely to revolutionize cardiac safety and drug development: in vitro experiments on human‐induced pluripotent stem cell‐derived cardiomyocytes (hiPSC‐CMs) and in silico human adult ventricular cardiomyocyte (hAdultV‐CM) models. Their combination was recently proposed as a potential replacement for the present hERG‐based QT study for pharmacological safety assessments. Here, we systematically compared in silico the effects of selective ionic current block on hiPSC‐CM and hAdultV‐CM action potentials (APs), to identify similarities/differences and to illustrate the potential of computational models as supportive tools for evaluating new in vitro technologies. Experimental Approach In silico AP models of ventricular‐like and atrial‐like hiPSC‐CMs and hAdultV‐CM were used to simulate the main effects of four degrees of block of the main cardiac transmembrane currents. Key Results Qualitatively, hiPSC‐CM and hAdultV‐CM APs showed similar responses to current block, consistent with results from experiments. However, quantitatively, hiPSC‐CMs were more sensitive to block of (i) L‐type Ca2+ currents due to the overexpression of the Na+/Ca2+ exchanger (leading to shorter APs) and (ii) the inward rectifier K+ current due to reduced repolarization reserve (inducing diastolic potential depolarization and repolarization failure). Conclusions and Implications In silico hiPSC‐CMs and hAdultV‐CMs exhibit a similar response to selective current blocks. However, overall hiPSC‐CMs show greater sensitivity to block, which may facilitate in vitro identification of drug‐induced effects. Extrapolation of drug effects from hiPSC‐CM to hAdultV‐CM and pro‐arrhythmic risk assessment can be facilitated by in silico predictions using biophysically‐based computational models. PMID:26276951

  14. A Comprehensive Atlas of the Adult Mouse Penis

    PubMed Central

    Phillips, Tiffany R.; Wright, David K.; Gradie, Paul E.; Johnston, Leigh A.; Pask, Andrew J.

    2016-01-01

    Mice are routinely used to study the development of the external genitalia and, in particular, the process of male urethral closure. This is because misplacement of the male penile urethra, or hypospadias, is amongst the most common birth defects reported in humans. While mice present a tractable model to study penile development, several structures differ between mice and humans, and there is a lack of consensus in the literature on their annotation and developmental origins. Defining the ontology of the mouse prepuce is especially important for the relevance and interpretation of mouse models of hypospadias to human conditions. We have developed a detailed annotation of the adult mouse penis that addresses these differences and enables an accurate comparison of murine and human hypospadias phenotypes. Through MRI data, gross morphology and section histology, we define the origin of the mouse external and internal prepuces, their relationship to the single human foreskin as well as provide a comprehensive view of the various structures of the mouse penis and their associated muscle attachments within the body. These data are combined to annotate structures in a novel 3D adult penis atlas that can be downloaded, viewed at any angle, and manipulated to examine the relationship of various structures. PMID:26112156

  15. Inositol-1,4,5-trisphosphate-mediated spontaneous activity in mouse embryonic stem cell-derived cardiomyocytes.

    PubMed

    Kapur, Nidhi; Banach, Kathrin

    2007-06-15

    Embryonic stem cell-derived cardiomyocytes (ESdCs) have been proposed as a source for cardiac cell-replacement therapy. The aim of this study was to determine the Ca2+-handling mechanisms that determine the frequency and duration of spontaneous Ca2+ transients in single ESdCs. With laser scanning confocal microscopy using the Ca2+-sensitive dye Fluo-4/AM, we determined that spontaneous Ca2+ transients in ESdCs at the onset of beating (day 9) depend on Ca2+ entry across the plasma membrane (50%) whereas Ca2+-induced Ca2+ release is the major contributor to Ca2+ transients in ESdCs after 16 days (72%). Likewise, Ca2+ extrusion in 9-day-old ESdCs depends on Na+-Ca2+ exchange (50.0+/-8%) whereas Ca2+ reuptake by the sarco(endo)plasmic Ca2+ ATPase (72+/-5%) dominates in further differentiated cells. Spontaneous Ca2+ transients were suppressed by the inositol-1,4,5-trisphosphate (IP3) receptor (IP3R) blocker 2-aminoethoxydiphenyl borate (2-APB) and the phospholipase C blocker U73122 but continued in the presence of caffeine. Stimulation of IP3 production by phenylephrine or endothelin-1 had a positive chronotropic effect that could be reversed by U73122 and 2-APB. The presence of Ca2+-free solution and block of L-type Ca2+ channels by nifedipine also resulted in a cessation of spontaneous activity. Overall, IP3R-mediated Ca2+ release in ESdCs is translated into a depolarization of the plasma membrane and a whole-cell Ca2+ transient is subsequently induced by voltage-dependent Ca2+ influx. Although ryanodine receptor-mediated Ca2+ release amplifies the IP3R-induced trigger for the Ca2+ transients and modulates its frequencies, it is not a prerequisite for spontaneous activity. The results of this study offer important insight into the role of IP3R-mediated Ca2+ release for pacemaker activity in differentiating cardiomyocytes. PMID:17379641

  16. Secretory products of guinea pig epicardial fat induce insulin resistance and impair primary adult rat cardiomyocyte function

    PubMed Central

    Greulich, Sabrina; de Wiza, Daniella Herzfeld; Preilowski, Sebastian; Ding, Zhaoping; Mueller, Heidi; Langin, Dominique; Jaquet, Kornelia; Ouwens, D Margriet; Eckel, Juergen

    2011-01-01

    Abstract Epicardial adipose tissue (EAT) has been implicated in the development of heart disease. Nonetheless, the crosstalk between factors secreted from EAT and cardiomyocytes has not been studied. Here, we examined the effect of factors secreted from EAT on contractile function and insulin signalling in primary rat cardiomocytes. EAT and subcutaneous adipose tissue (SAT) were isolated from guinea pigs fed a high-fat (HFD) or standard diet. HFD feeding for 6 months induced glucose intolerance, and decreased fractional shortening and ejection fraction (all P < 0.05). Conditioned media (CM) generated from EAT and SAT explants were subjected to cytokine profiling using antibody arrays, or incubated with cardiomyocytes to assess the effects on insulin action and contractile function. Eleven factors were differentially secreted by EAT when compared to SAT. Furthermore, secretion of 30 factors by EAT was affected by HFD feeding. Most prominently, activin A-immunoreactivity was 6.4-fold higher in CM from HFD versus standard diet-fed animals and, 2-fold higher in EAT versus SAT. In cardiomyocytes, CM from EAT of HFD-fed animals increased SMAD2-phosphorylation, a marker for activin A-signalling, decreased sarcoplasmic-endoplasmic reticulum calcium ATPase 2a expression, and reduced insulin-mediated phosphorylation of Akt-Ser473 versus CM from SAT and standard diet-fed animals. Finally, CM from EAT of HFD-fed animals as compared to CM from the other groups markedly reduced sarcomere shortening and cytosolic Ca2+ fluxes in cardiomyocytes. These data provide evidence for an interaction between factors secreted from EAT and cardiomyocyte function. PMID:21143387

  17. Downregulation of RACK1 is associated with cardiomyocyte apoptosis after myocardial ischemia/reperfusion injury in adult rats.

    PubMed

    Qian, Long; Shi, Jiahai; Zhang, Chi; Lu, Jiawei; Lu, Xiaoning; Wu, Kunpeng; Yang, Chen; Yan, Daliang; Zhang, Chao; You, Qingsheng; Liu, Xiaojuan

    2016-03-01

    The receptor for activated C kinase 1 (RACK1) is a multifaceted scaffolding protein that mediates the shuttling of activated protein kinase C (PKC) to cellular membranes. In addition, RACK1 could decrease cell apoptosis in a variety of disease models. However, the function of RACK1 in cardiomyocyte apoptosis after myocardial ischemia/reperfusion (I/R) is unknown. In this study, male Sprague-Dawley rats were anesthetized and subjected to myocardial I/R insult consisting of 30 min left anterior descending coronary artery (LAD) occlusion followed by reperfusion for 1, 2, 4, 6, 8, 12, and 24 h. The expression of RACK1 was decreased after myocardial I/R and was associated with cardiomyocyte apoptosis. To further verify the relationship between RACK1 and cardiomyocyte apoptosis, H9c2 cardiomyocytes were cultured under hypoxia for 6 h, then maintained in the regular incubator to reoxygenation. After H9c2 cells were transfected with Flag-RACK1 to overexpress RACK1, RACK1 expression was upregulated in hypoxia/reoxygenation (H/R) 4 h group accompanied with the decrease of cleaved caspase-3 and the increase of Bcl-2 expression. Terminal transferase-mediated biotin dUTP nick end labeling (TUNEL) assay showed that RACK1 overexpression inhibited H9c2 cell apoptosis induced by H/R treatment. Our data suggested that RACK1 might suppress cardiomyocyte apoptosis after I/R, providing a novel molecular target for the therapy of ischemia heart disease. PMID:26659395

  18. Optical microscopy imaging for the diagnosis of the pharmacological reaction of mouse embryonic stem cell-derived cardiomyocytes (mESC-CMs).

    PubMed

    Ikeuchi, Tomohiko; Espulgar, Wilfred; Shimizu, Eiichi; Saito, Masato; Lee, Jong-Kook; Dou, Xiaoming; Yamaguchi, Yoshinori; Tamiya, Eiichi

    2015-10-01

    Quantitative diagnosis of pharmacological chronotropic reactions on mouse embryonic stem cell-derived cardiomyocytes (mESC-CMs) was successfully performed by utilizing derivative imaging analysis of videos recorded with a microscope camera at 30 Hz frame rate and 680 × 510 pixel resolution. The imaging analysis algorithm, developed in our lab, generated the contractile profile of the cells which was exploited for drug effect profiling. Six drugs such as isoproterenol (0.01-1 μM), quinidine (2-200 μM), propranolol (0.03-30 μM), verapamil (0.01-1 μM), sotalol (1-100 μM), and acetylsalicylic acid (0.1-10 μM) were administered and the quantitative medication effect was determined. Among the negative chronotropic agents administered, verapamil was found to be the most potent while sotalol was found to be the least potent at the micromolar level. Simultaneous measurement of the field potential and contractile motion in the verapamil effect test showed a coherent result. Moreover, this approach can provide insights into the contraction-relaxation conditions which are not available in the common electrophysiological approach. With these findings, it is expected that this study can aid in providing a simple and reliable in vitro mESC-CM-based screening platform for cardiovascular effect profiling of candidate drugs. PMID:26309911

  19. Assessment of developmental cardiotoxic effects of some commonly used phytochemicals in mouse embryonic D3 stem cell differentiation and chick embryonic cardiomyocyte micromass culture models.

    PubMed

    Mohammed, Omar J; McAlpine, Roseanna; Chiewhatpong, Phasawee; Latif, Muhammad Liaque; Pratten, Margaret K

    2016-09-01

    Pregnant women often use herbal medicines to alleviate symptoms of pregnancy. The active phytochemicals eugenol (from holy basil) and α-bisabolol (from chamomile) are recommended to promote calmness and reduce stress. There is evidence that both eugenol and α-bisabolol possess pro-apoptotic and anti-proliferative effects and induce reactive oxygen species. The potential effect was examined by monitoring cardiomyocyte contractile activity (differentiation), cell activity, protein content and ROS production for mouse D3 embryonic stem cell and ‎chick embryonic micromass culture. The results showed that eugenol (0.01-80μM) demonstrated effects on cell activity (both systems) and ROS production (stem cell system only), as well as decreasing the contractile activity and protein content at high concentrations in both systems. Additionally, α-bisabolol (0.01-80μM) at high concentrations decreased the contractile activity and cell activity and in the stem cell system induced ROS production and decreased protein content. The results suggest only low concentrations should be ingested in pregnancy.‎. PMID:27105832

  20. Prolactin Stimulates Precursor Cells in the Adult Mouse Hippocampus

    PubMed Central

    Walker, Tara L.; Vukovic, Jana; Koudijs, Margaretha M.; Blackmore, Daniel G.; Mackay, Eirinn W.; Sykes, Alex M.; Overall, Rupert W.; Hamlin, Adam S.; Bartlett, Perry F.

    2012-01-01

    In the search for ways to combat degenerative neurological disorders, neurogenesis-stimulating factors are proving to be a promising area of research. In this study, we show that the hormonal factor prolactin (PRL) can activate a pool of latent precursor cells in the adult mouse hippocampus. Using an in vitro neurosphere assay, we found that the addition of exogenous PRL to primary adult hippocampal cells resulted in an approximate 50% increase in neurosphere number. In addition, direct infusion of PRL into the adult dentate gyrus also resulted in a significant increase in neurosphere number. Together these data indicate that exogenous PRL can increase hippocampal precursor numbers both in vitro and in vivo. Conversely, PRL null mice showed a significant reduction (approximately 80%) in the number of hippocampal-derived neurospheres. Interestingly, no deficit in precursor proliferation was observed in vivo, indicating that in this situation other niche factors can compensate for a loss in PRL. The PRL loss resulted in learning and memory deficits in the PRL null mice, as indicated by significant deficits in the standard behavioral tests requiring input from the hippocampus. This behavioral deficit was rescued by direct infusion of recombinant PRL into the hippocampus, indicating that a lack of PRL in the adult mouse hippocampus can be correlated with impaired learning and memory. PMID:22973440

  1. Endothelial-Cardiomyocyte Interactions in Cardiac Development and Repair

    PubMed Central

    Hsieh, Patrick C.H.; Davis, Michael E.; Lisowski, Laura K.; Lee, Richard T.

    2009-01-01

    Communication between endothelial cells and cardiomyocytes regulates not only early cardiac development but also adult cardiomyocyte function, including the contractile state. In the normal mammalian myocardium, each cardiomyocyte is surrounded by an intricate network of capillaries and is next to endothelial cells. Cardiomyocytes depend on endothelial cells not only for oxygenated blood supply but also for local protective signals that promote cardiomyocyte organization and survival. While endothelial cells direct cardiomyocytes, cardiomyocytes reciprocally secrete factors that impact endothelial cell function. Understanding how endothelial cells communicate with cardiomyocytes will be critical for cardiac regeneration, in which the ultimate goal is not simply to improve systolic function transiently but to establish new myocardium that is both structurally and functionally normal in the long term. PMID:16460266

  2. Inhibition of ErbB2 by receptor tyrosine kinase inhibitors causes myofibrillar structural damage without cell death in adult rat cardiomyocytes

    SciTech Connect

    Pentassuglia, Laura; Graf, Michael; Lane, Heidi; Kuramochi, Yukio; Cote, Gregory; Timolati, Francesco; Sawyer, Douglas B.; Zuppinger, Christian; Suter, Thomas M.

    2009-04-15

    Inhibition of ErbB2 (HER2) with monoclonal antibodies, an effective therapy in some forms of breast cancer, is associated with cardiotoxicity, the pathophysiology of which is poorly understood. Recent data suggest, that dual inhibition of ErbB1 (EGFR) and ErbB2 signaling is more efficient in cancer therapy, however, cardiac safety of this therapeutic approach is unknown. We therefore tested an ErbB1-(CGP059326) and an ErbB1/ErbB2-(PKI166) tyrosine kinase inhibitor in an in-vitro system of adult rat ventricular cardiomyocytes and assessed their effects on 1. cell viability, 2. myofibrillar structure, 3. contractile function, and 4. MAPK- and Akt-signaling alone or in combination with Doxorubicin. Neither CGP nor PKI induced cardiomyocyte necrosis or apoptosis. PKI but not CGP caused myofibrillar structural damage that was additive to that induced by Doxorubicin at clinically relevant doses. These changes were associated with an inhibition of excitation-contraction coupling. PKI but not CGP decreased p-Erk1/2, suggesting a role for this MAP-kinase signaling pathway in the maintenance of myofibrils. These data indicate that the ErbB2 signaling pathway is critical for the maintenance of myofibrillar structure and function. Clinical studies using ErbB2-targeted inhibitors for the treatment of cancer should be designed to include careful monitoring for cardiac dysfunction.

  3. Adult mouse brain gene expression patterns bear an embryologic imprint

    PubMed Central

    Zapala, Matthew A.; Hovatta, Iiris; Ellison, Julie A.; Wodicka, Lisa; Del Rio, Jo A.; Tennant, Richard; Tynan, Wendy; Broide, Ron S.; Helton, Rob; Stoveken, Barbara S.; Winrow, Christopher; Lockhart, Daniel J.; Reilly, John F.; Young, Warren G.; Bloom, Floyd E.; Lockhart, David J.; Barlow, Carrolee

    2005-01-01

    The current model to explain the organization of the mammalian nervous system is based on studies of anatomy, embryology, and evolution. To further investigate the molecular organization of the adult mammalian brain, we have built a gene expression-based brain map. We measured gene expression patterns for 24 neural tissues covering the mouse central nervous system and found, surprisingly, that the adult brain bears a transcriptional “imprint” consistent with both embryological origins and classic evolutionary relationships. Embryonic cellular position along the anterior–posterior axis of the neural tube was shown to be closely associated with, and possibly a determinant of, the gene expression patterns in adult structures. We also observed a significant number of embryonic patterning and homeobox genes with region-specific expression in the adult nervous system. The relationships between global expression patterns for different anatomical regions and the nature of the observed region-specific genes suggest that the adult brain retains a degree of overall gene expression established during embryogenesis that is important for regional specificity and the functional relationships between regions in the adult. The complete collection of extensively annotated gene expression data along with data mining and visualization tools have been made available on a publicly accessible web site (www.barlow-lockhart-brainmapnimhgrant.org). PMID:16002470

  4. Cardiomyocytes induce endothelial cells to trans-differentiate into cardiac muscle: implications for myocardium regeneration.

    PubMed

    Condorelli, G; Borello, U; De Angelis, L; Latronico, M; Sirabella, D; Coletta, M; Galli, R; Balconi, G; Follenzi, A; Frati, G; Cusella De Angelis, M G; Gioglio, L; Amuchastegui, S; Adorini, L; Naldini, L; Vescovi, A; Dejana, E; Cossu, G

    2001-09-11

    The concept of tissue-restricted differentiation of postnatal stem cells has been challenged by recent evidence showing pluripotency for hematopoietic, mesenchymal, and neural stem cells. Furthermore, rare but well documented examples exist of already differentiated cells in developing mammals that change fate and trans-differentiate into another cell type. Here, we report that endothelial cells, either freshly isolated from embryonic vessels or established as homogeneous cells in culture, differentiate into beating cardiomyocytes and express cardiac markers when cocultured with neonatal rat cardiomyocytes or when injected into postischemic adult mouse heart. Human umbilical vein endothelial cells also differentiate into cardiomyocytes under similar experimental conditions and transiently coexpress von Willebrand factor and sarcomeric myosin. In contrast, neural stem cells, which efficiently differentiate into skeletal muscle, differentiate into cardiomyocytes at a low rate. Fibroblast growth factor 2 and bone morphogenetic protein 4, which activate cardiac differentiation in embryonic cells, do not activate cardiogenesis in endothelial cells or stimulate trans-differentiation in coculture, suggesting that different signaling molecules are responsible for cardiac induction during embryogenesis and in successive periods of development. The fact that endothelial cells can generate cardiomyocytes sheds additional light on the plasticity of endothelial cells during development and opens perspectives for cell autologous replacement therapies. PMID:11535818

  5. Cardiomyocytes induce endothelial cells to trans-differentiate into cardiac muscle: Implications for myocardium regeneration

    PubMed Central

    Condorelli, G.; Borello, U.; De Angelis, L.; Latronico, M.; Sirabella, D.; Coletta, M.; Galli, R.; Balconi, G.; Follenzi, A.; Frati, G.; Cusella De Angelis, M. G.; Gioglio, L.; Amuchastegui, S.; Adorini, L.; Naldini, L.; Vescovi, A.; Dejana, E.; Cossu, G.

    2001-01-01

    The concept of tissue-restricted differentiation of postnatal stem cells has been challenged by recent evidence showing pluripotency for hematopoietic, mesenchymal, and neural stem cells. Furthermore, rare but well documented examples exist of already differentiated cells in developing mammals that change fate and trans-differentiate into another cell type. Here, we report that endothelial cells, either freshly isolated from embryonic vessels or established as homogenous cells in culture, differentiate into beating cardiomyocytes and express cardiac markers when cocultured with neonatal rat cardiomyocytes or when injected into postischemic adult mouse heart. Human umbilical vein endothelial cells also differentiate into cardiomyocytes under similar experimental conditions and transiently coexpress von Willebrand factor and sarcomeric myosin. In contrast, neural stem cells, which efficiently differentiate into skeletal muscle, differentiate into cardiomyocytes at a low rate. Fibroblast growth factor 2 and bone morphogenetic protein 4, which activate cardiac differentiation in embryonic cells, do not activate cardiogenesis in endothelial cells or stimulate trans-differentiation in coculture, suggesting that different signaling molecules are responsible for cardiac induction during embryogenesis and in successive periods of development. The fact that endothelial cells can generate cardiomyocytes sheds additional light on the plasticity of endothelial cells during development and opens perspectives for cell autologous replacement therapies. PMID:11535818

  6. Evidence for Cardiomyocyte Renewal in Humans

    SciTech Connect

    Bergmann, O; Bhardwaj, R D; Bernard, S; Zdunek, S; Barnabe-Heider, F; Walsh, S; Zupicich, J; Alkass, K; Buchholz, B A; Druid, H; Jovinge, S; Frisen, J

    2008-10-14

    It has been difficult to establish whether we are limited to the heart muscle cells we are born with or if cardiomyocytes are generated also later in life. We have taken advantage of the integration of {sup 14}C, generated by nuclear bomb tests during the Cold War, into DNA to establish the age of cardiomyocytes in humans. We report that cardiomyocytes renew, with a gradual decrease from 1% turning over annually at the age of 20 to 0.3% at the age of 75. Less than 50% of cardiomyocytes are exchanged during a normal lifespan. The capacity to generate cardiomyocytes in the adult human heart suggests that it may be rational to work towards the development of therapeutic strategies aiming to stimulate this process in cardiac pathologies.

  7. Mechanical Testing of Mouse Carotid Arteries: from Newborn to Adult

    PubMed Central

    Amin, Mazyar; Le, Victoria P.; Wagenseil, Jessica E.

    2012-01-01

    The large conducting arteries in vertebrates are composed of a specialized extracellular matrix designed to provide pulse dampening and reduce the work performed by the heart. The mix of matrix proteins determines the passive mechanical properties of the arterial wall1. When the matrix proteins are altered in development, aging, disease or injury, the arterial wall remodels, changing the mechanical properties and leading to subsequent cardiac adaptation2. In normal development, the remodeling leads to a functional cardiac and cardiovascular system optimized for the needs of the adult organism. In disease, the remodeling often leads to a negative feedback cycle that can cause cardiac failure and death. By quantifying passive arterial mechanical properties in development and disease, we can begin to understand the normal remodeling process to recreate it in tissue engineering and the pathological remodeling process to test disease treatments. Mice are useful models for studying passive arterial mechanics in development and disease. They have a relatively short lifespan (mature adults by 3 months and aged adults by 2 years), so developmental3 and aging studies4 can be carried out over a limited time course. The advances in mouse genetics provide numerous genotypes and phenotypes to study changes in arterial mechanics with disease progression5 and disease treatment6. Mice can also be manipulated experimentally to study the effects of changes in hemodynamic parameters on the arterial remodeling process7. One drawback of the mouse model, especially for examining young ages, is the size of the arteries. We describe a method for passive mechanical testing of carotid arteries from mice aged 3 days to adult (approximately 90 days). We adapt a commercial myograph system to mount the arteries and perform multiple pressure or axial stretch protocols on each specimen. We discuss suitable protocols for each age, the necessary measurements and provide example data. We also include

  8. Single-cell transcriptome and epigenomic reprogramming of cardiomyocyte-derived cardiac progenitor cells.

    PubMed

    Chen, Xin; Chakravarty, Tushar; Zhang, Yiqiang; Li, Xiaojin; Zhong, Jiang F; Wang, Charles

    2016-01-01

    The molecular basis underlying the dedifferentiation of mammalian adult cardiomyocytes (ACMs) into myocyte-derived cardiac progenitor cells (mCPCs) during cardiac tissue regeneration is poorly understood. We present data integrating single-cell transcriptome and whole-genome DNA methylome analyses of mouse mCPCs to understand the epigenomic reprogramming governing their intrinsic cellular plasticity. Compared to parental cardiomyocytes, mCPCs display epigenomic reprogramming with many differentially-methylated regions, both hypermethylated and hypomethylated, across the entire genome. Correlating well with the methylome, our single-cell transcriptomic data show that the genes encoding cardiac structure and function proteins are remarkably down-regulated in mCPCs, while those for cell cycle, proliferation, and stemness are significantly up-regulated. In addition, implanting mCPCs into infarcted mouse myocardium improves cardiac function with augmented left ventricular ejection fraction. This dataset suggests that the cellular plasticity of mammalian cardiomyocytes is the result of a well-orchestrated epigenomic reprogramming and a subsequent global transcriptomic alteration. Understanding cardiomyocyte epigenomic reprogramming may enable the design of future clinical therapies that induce cardiac regeneration, and prevent heart failure. PMID:27622691

  9. Exploration and visualization of connectivity in the adult mouse brain.

    PubMed

    Feng, David; Lau, Chris; Ng, Lydia; Li, Yang; Kuan, Leonard; Sunkin, Susan M; Dang, Chinh; Hawrylycz, Michael

    2015-02-01

    The Allen Mouse Brain Connectivity Atlas is a mesoscale whole brain axonal projection atlas of the C57Bl/6J mouse brain. All data were aligned to a common template in 3D space to generate a comprehensive and quantitative database of inter-areal and cell-type-specific projections. A suite of computational tools were developed to search and visualize the projection labeling experiments, available at http://connectivity.brain-map.org. We present three use cases illustrating how these publicly-available tools can be used to perform analyses of long range brain region connectivity. The use cases make extensive use of advanced visualization tools integrated with the atlas including projection density histograms, 3D computed anterograde and retrograde projection paths, and multi-specimen projection composites. These tools offer convenient access to detailed axonal projection information in the adult mouse brain and the ability to perform data analysis and visualization of projection fields and neuroanatomy in an integrated manner. PMID:25637033

  10. Differential Apoptosis Radiosensitivity of Neural Progenitors in Adult Mouse Hippocampus.

    PubMed

    Li, Yu-Qing; Cheng, Zoey; Wong, Shun

    2016-01-01

    Mammalian tissue-specific stem cells and progenitors demonstrate differential DNA damage response. Neural progenitors in dentate gyrus of the hippocampus are known to undergo apoptosis after irradiation. Using a mouse model of hippocampal neuronal development, we characterized the apoptosis sensitivity of the different neural progenitor subpopulations in adult mouse dentate gyrus after irradiation. Two different bromodeoxyuridine incorporation paradigms were used for cell fate mapping. We identified two apoptosis sensitive neural progenitor subpopulations after irradiation. The first represented non-proliferative and non-newborn neuroblasts and immature neurons that expressed doublecortin, calretinin or both. The second consisted of proliferative intermediate neural progenitors. The putative radial glia-like neural stem cells or type-1 cells, regardless of proliferation status, were apoptosis resistant after irradiation. There was no evidence of radiation-induced apoptosis in the absence of the Trp53 (p53) gene but absence of Cdkn1a (p21) did not alter the apoptotic response. Upregulation of nuclear p53 was observed in neuroblasts after irradiation. We conclude that adult hippocampal neural progenitors may demonstrate differential p53-dependent apoptosis sensitivity after irradiation. PMID:27331809

  11. Differential Apoptosis Radiosensitivity of Neural Progenitors in Adult Mouse Hippocampus

    PubMed Central

    Li, Yu-Qing; Cheng, Zoey; Wong, Shun

    2016-01-01

    Mammalian tissue-specific stem cells and progenitors demonstrate differential DNA damage response. Neural progenitors in dentate gyrus of the hippocampus are known to undergo apoptosis after irradiation. Using a mouse model of hippocampal neuronal development, we characterized the apoptosis sensitivity of the different neural progenitor subpopulations in adult mouse dentate gyrus after irradiation. Two different bromodeoxyuridine incorporation paradigms were used for cell fate mapping. We identified two apoptosis sensitive neural progenitor subpopulations after irradiation. The first represented non-proliferative and non-newborn neuroblasts and immature neurons that expressed doublecortin, calretinin or both. The second consisted of proliferative intermediate neural progenitors. The putative radial glia-like neural stem cells or type-1 cells, regardless of proliferation status, were apoptosis resistant after irradiation. There was no evidence of radiation-induced apoptosis in the absence of the Trp53 (p53) gene but absence of Cdkn1a (p21) did not alter the apoptotic response. Upregulation of nuclear p53 was observed in neuroblasts after irradiation. We conclude that adult hippocampal neural progenitors may demonstrate differential p53-dependent apoptosis sensitivity after irradiation. PMID:27331809

  12. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    PubMed Central

    Webb, Carol F.; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-01-01

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. PMID:26111446

  13. Over-expression of FK506-binding protein FKBP12.6 alters excitation–contraction coupling in adult rabbit cardiomyocytes

    PubMed Central

    Loughrey, C M; Seidler, T; Miller, S L W; Prestle, J; MacEachern, K E; Reynolds, D F; Hasenfuss, G; Smith, G L

    2004-01-01

    This study investigated the function of FK506-binding protein (FKBP12.6) using adenoviral-mediated gene transfer to over-express FKBP12.6 (Ad-FKBP12.6) in adult rabbit ventricular cardiomyocytes. Infection with a β-galactosidase-expressing adenovirus (Ad-LacZ) was used as a control. Peak-systolic intracellular [Ca2+] (measured with Fura-2) was higher in the Ad-FKBP12.6 group compared to Ad-LacZ (1 Hz field stimulation at 37°C). The amplitude of caffeine-induced Ca2+ release was also greater, indicating a higher SR Ca2+ content in the Ad-FKBP12.6 group. Voltage clamp experiments indicated that FKBP12.6 over-expression did not change L-type Ca2+ current amplitude or Ca2+ efflux rates via the Na+ –Ca2+ exchanger. Ca2+ transients comparable to those after Ad-FKBP12.6 transfection could be obtained by enhancing SR Ca2+ content of Ad-LacZ infected cells with periods of high frequency stimulation. Line-scan confocal microscopy (Fluo-3 fluorescence) of intact cardiomyocytes stimulated at 0.5 Hz (20−21°C) revealed a higher degree of synchronicity of SR Ca2+ release and fewer non-responsive Ca2+ release sites in the Ad-FKBP12.6 group compared to control. Ca2+ spark morphology was measured in β-escin-permeabilized cardiomyocytes at a free [Ca2+]i of 150 nm. The average values of the spark parameters (amplitude, duration, width and frequency) were reduced in the Ad-FKBP12.6 group. Increasing [Ca2+]i to 400 nm caused coherent propagating Ca2+ waves in the Ad-FKBP12.6 group but only limited Ca2+ release events were recorded in the control group. These data indicate that FKBP12.6 over-expression enhances Ca2+ transient amplitude predominately by increasing SR Ca2+ content. Moreover, there is also evidence that FKBP12.6 can enhance the coupling between SR Ca2+ release sites independently of SR content. PMID:14966299

  14. Na+/Ca2+ exchanger overexpression impairs frequency- and ouabain-dependent cell shortening in adult rat cardiomyocytes.

    PubMed

    Bölck, Birgit; Münch, Götz; Mackenstein, Peter; Hellmich, Martin; Hirsch, Ingo; Reuter, Hannes; Hattebuhr, Nadja; Weig, Hans-Jörg; Ungerer, Martin; Brixius, Klara; Schwinger, Robert H G

    2004-10-01

    The Na(+)/Ca(2+) exchanger (NCX) may influence cardiac function depending on its predominant mode of action, forward mode or reverse mode, during the contraction-relaxation cycle. The intracellular Na(+) concentration ([Na(+)](i)) and the duration of the action potential as well as the level of NCX protein expression regulate the mode of action of NCX. [Na(+)](i) and NCX expression have been reported to be increased in human heart failure. Nevertheless, the consequences of altered NCX expression in heart failure are still a matter of discussion. We aimed to characterize the influence of NCX expression on intracellular Ca(2+) transport in rat cardiomyocytes by adenoviral-mediated gene transfer. A five- to ninefold (dose dependent) overexpression of NCX protein was achieved after 48 h by somatic gene transfer (Ad.NCX.GFP) versus control (Ad.GFP). NCX activity, determined by Na(+) gradient-dependent (45)Ca(2+)-uptake, was significantly increased. The protein expressions of sarco(endo)plasmic reticulum Ca(2+)-ATPase, phospholamban, and calsequestrin were unaffected by NCX overexpression. Fractional shortening (FS) of isolated cardiomyocytes was significantly increased at low stimulation rates in Ad.NCX.GFP. After a step-wise enhancing frequency of stimulation to 3.0 Hz, FS remained unaffected in Ad.GFP cells but declined in Ad.NCX.GFP cells. The positive inotropic effect of the cardiac glycoside ouabain was less effective in Ad.NCX.GFP cells, whereas the positive inotropic effect of beta-adrenergic stimulation remained unchanged. In conclusion, NCX overexpression results in a reduced cell shortening at higher stimulation frequencies as well as after inhibition of sarcolemmal Na(+)-K(+)-ATPase, i.e., in conditions with enhanced [Na(+)](i). At low stimulation rates, increased NCX expression enhances both intracellular systolic Ca(2+) and contraction amplitude. PMID:15165985

  15. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    SciTech Connect

    Webb, Carol F.; Ratliff, Michelle L.; Powell, Rebecca; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-08-07

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.

  16. A state of reversible compensated ventricular dysfunction precedes pathological remodelling in response to cardiomyocyte-specific activity of angiotensin II type-1 receptor in mice

    PubMed Central

    Frentzou, Georgia A.; Drinkhill, Mark J.; Turner, Neil A.; Ball, Stephen G.; Ainscough, Justin F. X.

    2015-01-01

    ABSTRACT Cardiac dysfunction is commonly associated with high-blood-pressure-induced cardiomyocyte hypertrophy, in response to aberrant renin-angiotensin system (RAS) activity. Ensuing pathological remodelling promotes cardiomyocyte death and cardiac fibroblast activation, leading to cardiac fibrosis. The initiating cellular mechanisms that underlie this progressive disease are poorly understood. We previously reported a conditional mouse model in which a human angiotensin II type-I receptor transgene (HART) was expressed in differentiated cardiomyocytes after they had fully matured, but not during development. Twelve-month-old HART mice exhibited ventricular dysfunction and cardiomyocyte hypertrophy with interstitial fibrosis following full receptor stimulation, without affecting blood pressure. Here, we show that chronic HART activity in young adult mice causes ventricular dysfunction without hypertrophy, fibrosis or cardiomyocyte death. Dysfunction correlated with reduced expression of pro-hypertrophy markers and increased expression of pro-angiogenic markers in the cardiomyocytes experiencing increased receptor load. This stimulates responsive changes in closely associated non-myocyte cells, including the downregulation of pro-angiogenic genes, a dampened inflammatory response and upregulation of Tgfβ. Importantly, this state of compensated dysfunction was reversible. Furthermore, increased stimulation of the receptors on the cardiomyocytes caused a switch in the secondary response from the non-myocyte cells. Progressive cardiac remodelling was stimulated through hypertrophy and death of individual cardiomyocytes, with infiltration, proliferation and activation of fibroblast and inflammatory cells, leading to increased angiogenic and inflammatory signalling. Together, these data demonstrate that a state of pre-hypertrophic compensated dysfunction can exist in affected individuals before common markers of heart disease are detectable. The data also suggest that

  17. An anatomic gene expression atlas of the adult mouse brain.

    PubMed

    Ng, Lydia; Bernard, Amy; Lau, Chris; Overly, Caroline C; Dong, Hong-Wei; Kuan, Chihchau; Pathak, Sayan; Sunkin, Susan M; Dang, Chinh; Bohland, Jason W; Bokil, Hemant; Mitra, Partha P; Puelles, Luis; Hohmann, John; Anderson, David J; Lein, Ed S; Jones, Allan R; Hawrylycz, Michael

    2009-03-01

    Studying gene expression provides a powerful means of understanding structure-function relationships in the nervous system. The availability of genome-scale in situ hybridization datasets enables new possibilities for understanding brain organization based on gene expression patterns. The Anatomic Gene Expression Atlas (AGEA) is a new relational atlas revealing the genetic architecture of the adult C57Bl/6J mouse brain based on spatial correlations across expression data for thousands of genes in the Allen Brain Atlas (ABA). The AGEA includes three discovery tools for examining neuroanatomical relationships and boundaries: (1) three-dimensional expression-based correlation maps, (2) a hierarchical transcriptome-based parcellation of the brain and (3) a facility to retrieve from the ABA specific genes showing enriched expression in local correlated domains. The utility of this atlas is illustrated by analysis of genetic organization in the thalamus, striatum and cerebral cortex. The AGEA is a publicly accessible online computational tool integrated with the ABA (http://mouse.brain-map.org/agea). PMID:19219037

  18. Function of GATA Factors in the Adult Mouse Liver

    PubMed Central

    Zheng, Rena; Rebolledo-Jaramillo, Boris; Zong, Yiwei; Wang, Liqing; Russo, Pierre; Hancock, Wayne; Stanger, Ben Z.; Hardison, Ross C.; Blobel, Gerd A.

    2013-01-01

    GATA transcription factors and their Friend of Gata (FOG) cofactors control the development of diverse tissues. GATA4 and GATA6 are essential for the expansion of the embryonic liver bud, but their expression patterns and functions in the adult liver are unclear. We characterized the expression of GATA and FOG factors in whole mouse liver and purified hepatocytes. GATA4, GATA6, and FOG1 are the most prominently expressed family members in whole liver and hepatocytes. GATA4 chromatin immunoprecipitation followed by high throughput sequencing (ChIP-seq) identified 4409 occupied sites, associated with genes enriched in ontologies related to liver function, including lipid and glucose metabolism. However, hepatocyte-specific excision of Gata4 had little impact on gross liver architecture and function, even under conditions of regenerative stress, and, despite the large number of GATA4 occupied genes, resulted in relatively few changes in gene expression. To address possible redundancy between GATA4 and GATA6, both factors were conditionally excised. Surprisingly, combined Gata4,6 loss did not exacerbate the phenotype resulting from Gata4 loss alone. This points to the presence of an unusually robust transcriptional network in adult hepatocytes that ensures the maintenance of liver function. PMID:24367609

  19. Changes in tetrahydrobiopterin levels in endothelial cells and adult cardiomyocytes induced by LPS and hydrogen peroxide--a role for GFRP?

    PubMed

    Kalivendi, Shasi; Hatakeyama, Kazuyuki; Whitsett, Jennifer; Konorev, Eugene; Kalyanaraman, B; Vásquez-Vivar, Jeannette

    2005-02-15

    Alterations in tetrahydrobiopterin (BH4) levels have significant consequences in vascular pathophysiology. However, the mechanisms regulating BH4 remain poorly understood. The activity of GTP cyclohydrolase I (GTPCH-I), the first enzyme in BH4 biosynthesis, is controlled by protein levels, posttranslational modifications and interaction with GTPCH-I feedback regulatory protein (GFRP). This work examined the correlation between GTPCH-I protein levels and activity and changes in BH4 in human endothelial cells (HAECs) and adult rat cardiomyocytes (ARCM). Changes in BH4 were stimulated with LPS in HAECs and ARCM, and with hydrogen peroxide in HAECs only. Biopterin production by HAECs and ARCM were attained with concentrations of LPS >1 microg/ml and responses were nonlinear with respect to LPS concentrations. Western blot analysis demonstrated that induction of biopterin synthesis in HAECs and ARCM by LPS does not entail augmentation of constitutive GTPCH-I protein levels. However, LPS diminished GFRP mRNA, suggesting that disruption of GTPCH-I:GFRP complex enhances de novo biopterin synthesis. Conversely, treatment with hydrogen peroxide increased GTPCH-I and GFRP mRNA levels in HAECs while depleting BH4 and GSH, which was counteracted by catalase. This indicates that GFRP may override increases in GTPCH-I protein inhibiting enzyme activity. This conclusion is further supported by depletion of biopterin in cells transiently transfected with GFRP. Thus, allosteric regulation of GTPCH-I activity in the cardiovascular system maybe an important mechanism regulating BH4 levels through GFRP signaling. PMID:15649650

  20. Rigid microenvironments promote cardiac differentiation of mouse and human embryonic stem cells

    NASA Astrophysics Data System (ADS)

    Arshi, Armin; Nakashima, Yasuhiro; Nakano, Haruko; Eaimkhong, Sarayoot; Evseenko, Denis; Reed, Jason; Stieg, Adam Z.; Gimzewski, James K.; Nakano, Atsushi

    2013-04-01

    While adult heart muscle is the least regenerative of tissues, embryonic cardiomyocytes are proliferative, with embryonic stem (ES) cells providing an endless reservoir. In addition to secreted factors and cell-cell interactions, the extracellular microenvironment has been shown to play an important role in stem cell lineage specification, and understanding how scaffold elasticity influences cardiac differentiation is crucial to cardiac tissue engineering. Though previous studies have analyzed the role of matrix elasticity on the function of differentiated cardiomyocytes, whether it affects the induction of cardiomyocytes from pluripotent stem cells is poorly understood. Here, we examine the role of matrix rigidity on cardiac differentiation using mouse and human ES cells. Culture on polydimethylsiloxane (PDMS) substrates of varied monomer-to-crosslinker ratios revealed that rigid extracellular matrices promote a higher yield of de novo cardiomyocytes from undifferentiated ES cells. Using a genetically modified ES system that allows us to purify differentiated cardiomyocytes by drug selection, we demonstrate that rigid environments induce higher cardiac troponin T expression, beating rate of foci, and expression ratio of adult α- to fetal β- myosin heavy chain in a purified cardiac population. M-mode and mechanical interferometry image analyses demonstrate that these ES-derived cardiomyocytes display functional maturity and synchronization of beating when co-cultured with neonatal cardiomyocytes harvested from a developing embryo. Together, these data identify matrix stiffness as an independent factor that instructs not only the maturation of already differentiated cardiomyocytes but also the induction and proliferation of cardiomyocytes from undifferentiated progenitors. Manipulation of the stiffness will help direct the production of functional cardiomyocytes en masse from stem cells for regenerative medicine purposes.

  1. Rigid microenvironments promote cardiac differentiation of mouse and human embryonic stem cells

    PubMed Central

    Arshi, Armin; Nakashima, Yasuhiro; Nakano, Haruko; Eaimkhong, Sarayoot; Evseenko, Denis; Reed, Jason; Stieg, Adam Z.; Gimzewski, James K.; Nakano, Atsushi

    2013-01-01

    While adult heart muscle is the least regenerative of tissues, embryonic cardiomyocytes are proliferative, with embryonic stem (ES) cells providing an endless reservoir. In addition to secreted factors and cell-cell interactions, the extracellular microenvironment has been shown to play an important role in stem cell lineage specification, and understanding how scaffold elasticity influences cardiac differentiation is crucial to cardiac tissue engineering. Though previous studies have analyzed the role of the matrix elasticity on the function of differentiated cardiomyocytes, whether it affects the induction of cardiomyocytes from pluripotent stem cells is poorly understood. Here, we examined the role of matrix rigidity on the cardiac differentiation using mouse and human ES cells. Culture on polydimethylsiloxane (PDMS) substrates of varied monomer-to-crosslinker ratios revealed that rigid extracellular matrices promote a higher yield of de novo cardiomyocytes from undifferentiated ES cells. Using an genetically modified ES system that allows us to purify differentiated cardiomyocytes by drug selection, we demonstrate that rigid environments induce higher cardiac troponin T expression, beating rate of foci, and expression ratio of adult α- to fetal β- myosin heavy chain in a purified cardiac population. M-mode and mechanical interferometry image analyses demonstrate that these ES-derived cardiomyocytes display functional maturity and synchronization of beating when co-cultured with neonatal cardiomyocytes harvested from a developing embryo. Together, these data identify matrix stiffness as an independent factor that instructs not only the maturation of the already differentiated cardiomyocytes but also the induction and proliferation of cardiomyocytes from undifferentiated progenitors. Manipulation of the stiffness will help direct the production of functional cardiomyocytes en masse from stem cells for regenerative medicine purposes. PMID:24311969

  2. Rigid microenvironments promote cardiac differentiation of mouse and human embryonic stem cells.

    PubMed

    Arshi, Armin; Nakashima, Yasuhiro; Nakano, Haruko; Eaimkhong, Sarayoot; Evseenko, Denis; Reed, Jason; Stieg, Adam Z; Gimzewski, James K; Nakano, Atsushi

    2013-08-01

    While adult heart muscle is the least regenerative of tissues, embryonic cardiomyocytes are proliferative, with embryonic stem (ES) cells providing an endless reservoir. In addition to secreted factors and cell-cell interactions, the extracellular microenvironment has been shown to play an important role in stem cell lineage specification, and understanding how scaffold elasticity influences cardiac differentiation is crucial to cardiac tissue engineering. Though previous studies have analyzed the role of the matrix elasticity on the function of differentiated cardiomyocytes, whether it affects the induction of cardiomyocytes from pluripotent stem cells is poorly understood. Here, we examined the role of matrix rigidity on the cardiac differentiation using mouse and human ES cells. Culture on polydimethylsiloxane (PDMS) substrates of varied monomer-to-crosslinker ratios revealed that rigid extracellular matrices promote a higher yield of de novo cardiomyocytes from undifferentiated ES cells. Using an genetically modified ES system that allows us to purify differentiated cardiomyocytes by drug selection, we demonstrate that rigid environments induce higher cardiac troponin T expression, beating rate of foci, and expression ratio of adult α- to fetal β- myosin heavy chain in a purified cardiac population. M-mode and mechanical interferometry image analyses demonstrate that these ES-derived cardiomyocytes display functional maturity and synchronization of beating when co-cultured with neonatal cardiomyocytes harvested from a developing embryo. Together, these data identify matrix stiffness as an independent factor that instructs not only the maturation of the already differentiated cardiomyocytes but also the induction and proliferation of cardiomyocytes from undifferentiated progenitors. Manipulation of the stiffness will help direct the production of functional cardiomyocytes en masse from stem cells for regenerative medicine purposes. PMID:24311969

  3. Dynamic DNA methylation orchestrates cardiomyocyte development, maturation and disease.

    PubMed

    Gilsbach, Ralf; Preissl, Sebastian; Grüning, Björn A; Schnick, Tilman; Burger, Lukas; Benes, Vladimir; Würch, Andreas; Bönisch, Ulrike; Günther, Stefan; Backofen, Rolf; Fleischmann, Bernd K; Schübeler, Dirk; Hein, Lutz

    2014-01-01

    The heart is a highly specialized organ with essential function for the organism throughout life. The significance of DNA methylation in shaping the phenotype of the heart remains only partially known. Here we generate and analyse DNA methylomes from highly purified cardiomyocytes of neonatal, adult healthy and adult failing hearts. We identify large genomic regions that are differentially methylated during cardiomyocyte development and maturation. Demethylation of cardiomyocyte gene bodies correlates strongly with increased gene expression. Silencing of demethylated genes is characterized by the polycomb mark H3K27me3 or by DNA methylation. De novo methylation by DNA methyltransferases 3A/B causes repression of fetal cardiac genes, including essential components of the cardiac sarcomere. Failing cardiomyocytes partially resemble neonatal methylation patterns. This study establishes DNA methylation as a highly dynamic process during postnatal growth of cardiomyocytes and their adaptation to pathological stress in a process tightly linked to gene regulation and activity. PMID:25335909

  4. Dynamic DNA methylation orchestrates cardiomyocyte development, maturation and disease

    PubMed Central

    Gilsbach, Ralf; Preissl, Sebastian; Grüning, Björn A.; Schnick, Tilman; Burger, Lukas; Benes, Vladimir; Würch, Andreas; Bönisch, Ulrike; Günther, Stefan; Backofen, Rolf; Fleischmann, Bernd K.; Schübeler, Dirk; Hein, Lutz

    2014-01-01

    The heart is a highly specialized organ with essential function for the organism throughout life. The significance of DNA methylation in shaping the phenotype of the heart remains only partially known. Here we generate and analyse DNA methylomes from highly purified cardiomyocytes of neonatal, adult healthy and adult failing hearts. We identify large genomic regions that are differentially methylated during cardiomyocyte development and maturation. Demethylation of cardiomyocyte gene bodies correlates strongly with increased gene expression. Silencing of demethylated genes is characterized by the polycomb mark H3K27me3 or by DNA methylation. De novo methylation by DNA methyltransferases 3A/B causes repression of fetal cardiac genes, including essential components of the cardiac sarcomere. Failing cardiomyocytes partially resemble neonatal methylation patterns. This study establishes DNA methylation as a highly dynamic process during postnatal growth of cardiomyocytes and their adaptation to pathological stress in a process tightly linked to gene regulation and activity. PMID:25335909

  5. Advances and techniques to measure cGMP in intact cardiomyocytes.

    PubMed

    Götz, Konrad R; Nikolaev, Viacheslav O

    2013-01-01

    Förster resonance energy transfer (FRET)-based biosensors are powerful tools for real-time monitoring of signaling events in intact cells using fluorescence microscopy. Here, we describe a highly sensitive method which allows FRET-based measurements of the second messenger cGMP in adult mouse ventricular myocytes. Such measurements have been challenging before, primarily due to relatively low cGMP concentrations in cardiomyocytes and limited sensitivity of the available biosensors. With our new technique, one can reliably measure dynamic changes in cGMP upon stimulation of myocytes with natriuretic peptides and other physiological and pharmacological ligands. PMID:23709029

  6. MiR-21 Protected Cardiomyocytes against Doxorubicin-Induced Apoptosis by Targeting BTG2

    PubMed Central

    Tong, Zhongyi; Jiang, Bimei; Wu, Yanyang; Liu, Yanjuan; Li, Yuanbin; Gao, Min; Jiang, Yu; Lv, Qinglan; Xiao, Xianzhong

    2015-01-01

    Doxorubicin (DOX) is an anthracycline drug with a wide spectrum of antineoplastic activities. However, it causes cardiac cytotoxicity, and this limits its clinical applications. MicroRNA-21 (miR-21) plays a vital role in regulating cell proliferation and apoptosis. While miR-21 is preferentially expressed in adult cardiomyocytes and involved in cardiac development and heart disease, little is known regarding its biological functions in responding to DOX-induced cardiac cytotoxicity. In this study, the effects of DOX on mouse cardiac function and the expression of miR-21 were examined in both mouse heart tissues and rat H9C2 cardiomyocytes. The results showed that the cardiac functions were more aggravated in chronic DOX injury mice compared with acute DOX-injury mice; DOX treatment significantly increased miR-21 expression in both mouse heart tissue and H9C2 cells. Over-expression of miR-21 attenuated DOX-induced apoptosis in cardiamyocytes whereas knocking down its expression increased DOX-induced apoptosis. These gain- and loss- of function experiments showed that B cell translocation gene 2 (BTG2) was a target of miR-21. The expression of BTG2 was significantly decreased both in myocardium and H9C2 cells treated with DOX. The present study has revealed that miR-21 protects mouse myocardium and H9C2 cells against DOX-induced cardiotoxicity probably by targeting BTG2. PMID:26132560

  7. Members Only: Hypoxia-Induced Cell-Cycle Activation in Cardiomyocytes.

    PubMed

    Sharma, Arun; Wu, Sean M

    2015-09-01

    A low level of cardiomyocyte turnover occurs in the adult mammalian heart, but the source of these new cells remains unknown. Kimura et al., 2015 utilized a novel hypoxia-induced fate mapping system to identify a rare population of adult cardiomyocytes undergoing cell-cycle entry and expansion in healthy adult hearts and following ischemic injury. PMID:26331604

  8. Building and re-building the heart by cardiomyocyte proliferation.

    PubMed

    Foglia, Matthew J; Poss, Kenneth D

    2016-03-01

    The adult human heart does not regenerate significant amounts of lost tissue after injury. Rather than making new, functional muscle, human hearts are prone to scarring and hypertrophy, which can often lead to fatal arrhythmias and heart failure. The most-cited basis of this ineffective cardiac regeneration in mammals is the low proliferative capacity of adult cardiomyocytes. However, mammalian cardiomyocytes can avidly proliferate during fetal and neonatal development, and both adult zebrafish and neonatal mice can regenerate cardiac muscle after injury, suggesting that latent regenerative potential exists. Dissecting the cellular and molecular mechanisms that promote cardiomyocyte proliferation throughout life, deciphering why proliferative capacity normally dissipates in adult mammals, and deriving means to boost this capacity are primary goals in cardiovascular research. Here, we review our current understanding of how cardiomyocyte proliferation is regulated during heart development and regeneration. PMID:26932668

  9. Novel fluorescence resonance energy transfer-based reporter reveals differential calcineurin activation in neonatal and adult cardiomyocytes.

    PubMed

    Bazzazi, Hojjat; Sang, Lingjie; Dick, Ivy E; Joshi-Mukherjee, Rosy; Yang, Wanjun; Yue, David T

    2015-09-01

    Novel fluorescence resonance energy transfer-based genetically encoded reporters of calcineurin are constructed by fusing the two subunits of calcineurin with P2A-based linkers retaining the expected native conformation of calcineurin. Calcineurin reporters display robust responses to calcium transients in HEK293 cells. The sensor responses are correlated with NFATc1 translocation dynamics in HEK293 cells. The sensors are uniformly distributed in neonatal myocytes and respond efficiently to single electrically evoked calcium transients and show cumulative activation at frequencies of 0.5 and 1 Hz. In adult myocytes, the calcineurin sensors appear to be localized to the cardiac z-lines, and respond to cumulative calcium transients at frequencies of 0.5 and 1 Hz. The phosphatase calcineurin is a central component of many calcium signalling pathways, relaying calcium signals from the plasma membrane to the nucleus. It has critical functions in a multitude of systems, including immune, cardiac and neuronal. Given the widespread importance of calcineurin in both normal and pathological conditions, new tools that elucidate the spatiotemporal dynamics of calcineurin activity would be invaluable. Here we develop two separate genetically encoded fluorescence resonance energy transfer (FRET)-based sensors of calcineurin activation, DuoCaN and UniCaN. Both sensors showcase a large dynamic range and rapid response kinetics, differing primarily in the linker structure between the FRET pairs. Both sensors were calibrated in HEK293 cells and their responses correlated well with NFAT translocation to the nucleus, validating the biological relevance of the sensor readout. The sensors were subsequently expressed in neonatal rat ventricular myocytes and acutely isolated adult guinea pig ventricular myocytes. Both sensors demonstrated robust responses in myocytes and revealed kinetic differences in calcineurin activation during changes in pacing rate for neonatal versus adult myocytes

  10. Developmental alterations in centrosome integrity contribute to the post-mitotic state of mammalian cardiomyocytes.

    PubMed

    Zebrowski, David C; Vergarajauregui, Silvia; Wu, Chi-Chung; Piatkowski, Tanja; Becker, Robert; Leone, Marina; Hirth, Sofia; Ricciardi, Filomena; Falk, Nathalie; Giessl, Andreas; Just, Steffen; Braun, Thomas; Weidinger, Gilbert; Engel, Felix B

    2015-01-01

    Mammalian cardiomyocytes become post-mitotic shortly after birth. Understanding how this occurs is highly relevant to cardiac regenerative therapy. Yet, how cardiomyocytes achieve and maintain a post-mitotic state is unknown. Here, we show that cardiomyocyte centrosome integrity is lost shortly after birth. This is coupled with relocalization of various centrosome proteins to the nuclear envelope. Consequently, postnatal cardiomyocytes are unable to undergo ciliogenesis and the nuclear envelope adopts the function as cellular microtubule organizing center. Loss of centrosome integrity is associated with, and can promote, cardiomyocyte G0/G1 cell cycle arrest suggesting that centrosome disassembly is developmentally utilized to achieve the post-mitotic state in mammalian cardiomyocytes. Adult cardiomyocytes of zebrafish and newt, which are able to proliferate, maintain centrosome integrity. Collectively, our data provide a novel mechanism underlying the post-mitotic state of mammalian cardiomyocytes as well as a potential explanation for why zebrafish and newts, but not mammals, can regenerate their heart. PMID:26247711

  11. DNA hydroxymethylation controls cardiomyocyte gene expression in development and hypertrophy

    PubMed Central

    Greco, Carolina M.; Kunderfranco, Paolo; Rubino, Marcello; Larcher, Veronica; Carullo, Pierluigi; Anselmo, Achille; Kurz, Kerstin; Carell, Thomas; Angius, Andrea; Latronico, Michael V. G.; Papait, Roberto; Condorelli, Gianluigi

    2016-01-01

    Methylation at 5-cytosine (5-mC) is a fundamental epigenetic DNA modification associated recently with cardiac disease. In contrast, the role of 5-hydroxymethylcytosine (5-hmC)—5-mC's oxidation product—in cardiac biology and disease is unknown. Here we assess the hydroxymethylome in embryonic, neonatal, adult and hypertrophic mouse cardiomyocytes, showing that dynamic modulation of hydroxymethylated DNA is associated with specific transcriptional networks during heart development and failure. DNA hydroxymethylation marks the body of highly expressed genes as well as distal regulatory regions with enhanced activity. Moreover, pathological hypertrophy is characterized by a shift towards a neonatal 5-hmC distribution pattern. We also show that the ten-eleven translocation 2 (TET2) enzyme regulates the expression of key cardiac genes, such as Myh7, through 5-hmC deposition on the gene body and at enhancers. Thus, we provide a genome-wide analysis of 5-hmC in the cardiomyocyte and suggest a role for this epigenetic modification in heart development and disease. PMID:27489048

  12. DNA hydroxymethylation controls cardiomyocyte gene expression in development and hypertrophy.

    PubMed

    Greco, Carolina M; Kunderfranco, Paolo; Rubino, Marcello; Larcher, Veronica; Carullo, Pierluigi; Anselmo, Achille; Kurz, Kerstin; Carell, Thomas; Angius, Andrea; Latronico, Michael V G; Papait, Roberto; Condorelli, Gianluigi

    2016-01-01

    Methylation at 5-cytosine (5-mC) is a fundamental epigenetic DNA modification associated recently with cardiac disease. In contrast, the role of 5-hydroxymethylcytosine (5-hmC)-5-mC's oxidation product-in cardiac biology and disease is unknown. Here we assess the hydroxymethylome in embryonic, neonatal, adult and hypertrophic mouse cardiomyocytes, showing that dynamic modulation of hydroxymethylated DNA is associated with specific transcriptional networks during heart development and failure. DNA hydroxymethylation marks the body of highly expressed genes as well as distal regulatory regions with enhanced activity. Moreover, pathological hypertrophy is characterized by a shift towards a neonatal 5-hmC distribution pattern. We also show that the ten-eleven translocation 2 (TET2) enzyme regulates the expression of key cardiac genes, such as Myh7, through 5-hmC deposition on the gene body and at enhancers. Thus, we provide a genome-wide analysis of 5-hmC in the cardiomyocyte and suggest a role for this epigenetic modification in heart development and disease. PMID:27489048

  13. Knockout of SRC-1 and SRC-3 in Mice Decreases Cardiomyocyte Proliferation and Causes a Noncompaction Cardiomyopathy Phenotype

    PubMed Central

    Chen, Xian; Qin, Li; Liu, Zhaoliang; Liao, Lan; Martin, James F.; Xu, Jianming

    2015-01-01

    Noncompaction cardiomyopathy (NCC) is a congenital heart disease that causes ventricular dysfunction and high mortality rate in children. The mechanisms responsible for NCC are still unknown. The steroid receptor coactivator-1 (SRC-1) and SRC-3 are transcriptional coactivators for nuclear hormone receptors and certain other transcription factors that regulate many genes in development and organ function. However, the roles of SRC-1/3 in heart morphogenesis, function and NCC occurrence are unknown. This study aims to examine the spatial and temporal expression patterns of SRC-1/3 in the heart and investigate the specific roles of SRC-1/3 in heart development, function and NCC occurrence. Immunochemical analysis detected SRC-1/3 expressions in the proliferating cardiomyocytes of mouse heart at prenatal and neonatal stages, while these expressions disappeared within two weeks after birth. Through generating and characterizing mouse lines with global or cardiomyocyte-specific knockouts of SRC-1/3, we found ablation of SRC-1/3 in the myocardial lineage resulted in prominent trabeculae, deep intertrabecular recesses and thin ventricular wall and septum. These developmental defects caused a failure of trabecular compaction, decreased internal ventricular dimension, reduced cardiac ejection fraction and output and led to a high rate of postnatal mortality. Collectively, these structural and functional abnormalities closely simulate the phenotype of NCC patients. Further molecular analysis of cardiomyocytes in vivo and in vitro revealed that SRC-1/3 directly up-regulate cyclin E2, cyclin B1 and myocardin to promote cardiomyocyte proliferation and differentiation. In conclusion, SRC-1/3 are required for cardiomyocyte proliferation and differentiation at earlier developmental stages, and their dysfunction causes NCC-like abnormalities in the hearts of newborn and adult mice. PMID:26221073

  14. Cerebellar stem cells do not produce neurons and astrocytes in adult mouse

    SciTech Connect

    Su, Xin; Guan, Wuqiang; Yu, Yong-Chun; Fu, Yinghui

    2014-07-18

    Highlights: • No new neurons and astrocytes are generated in adult mouse cerebellum. • Very few mash1{sup +} or nestin{sup +} stem cells exist, and most of them are quiescent. • Cell proliferation rate is diversified among cerebellar regions and decreases over time. - Abstract: Although previous studies implied that cerebellar stem cells exist in some adult mammals, little is known about whether these stem cells can produce new neurons and astrocytes. In this study by bromodeoxyuridine (BrdU) intraperitoneal (i.p.) injection, we found that there are abundant BrdU{sup +} cells in adult mouse cerebellum, and their quantity and density decreases significantly over time. We also found cell proliferation rate is diversified in different cerebellar regions. Among these BrdU{sup +} cells, very few are mash1{sup +} or nestin{sup +} stem cells, and the vast majority of cerebellar stem cells are quiescent. Data obtained by in vivo retrovirus injection indicate that stem cells do not produce neurons and astrocytes in adult mouse cerebellum. Instead, some cells labeled by retrovirus are Iba1{sup +} microglia. These results indicate that very few stem cells exist in adult mouse cerebellum, and none of these stem cells contribute to neurogenesis and astrogenesis under physiological condition.

  15. Acute inflammation stimulates a regenerative response in the neonatal mouse heart

    PubMed Central

    Han, Chunyong; Nie, Yu; Lian, Hong; Liu, Rui; He, Feng; Huang, Huihui; Hu, Shengshou

    2015-01-01

    Cardiac injury in neonatal 1-day-old mice stimulates a regenerative response characterized by reactive cardiomyocyte proliferation, which is distinguished from the fibrotic repair process in adults. Acute inflammation occurs immediately after heart injury and has generally been believed to exert a negative effect on heart regeneration by promoting scar formation in adults; however, little is known about the role of acute inflammation in the cardiac regenerative response in neonatal mice. Here, we show that acute inflammation induced cardiomyocyte proliferation after apical intramyocardial microinjection of immunogenic zymosan A particles into the neonatal mouse heart. We also found that cardiac injury-induced regenerative response was suspended after immunosuppression in neonatal mice, and that cardiomyocytes could not be reactivated to proliferate after neonatal heart injury in the absence of interleukin-6 (IL-6). Furthermore, cardiomyocyte-specific deletion of signal transducer and activator of transcription 3 (STAT3), the major downstream effector of IL-6 signaling, decreased reactive cardiomyocyte proliferation after apical resection. Our results indicate that acute inflammation stimulates the regenerative response in neonatal mouse heart, and suggest that modulation of inflammatory signals might have important implications in cardiac regenerative medicine. PMID:26358185

  16. Transcriptional Landscape of Cardiomyocyte Maturation

    PubMed Central

    Uosaki, Hideki; Cahan, Patrick; Lee, Dong I.; Wang, Songnan; Miyamoto, Matthew; Fernandez, Laviel; Kass, David A.; Kwon, Chulan

    2015-01-01

    SUMMARY Decades of progress in developmental cardiology has advanced our understanding of the early aspects of heart development, including cardiomyocyte (CM) differentiation. However, control of CM maturation which is subsequently required to generate adult myocytes, remains elusive. Here, we analyzed over 200 microarray datasets from early embryonic to adult hearts and identified a large number of genes whose expression shifts gradually and continuously during maturation. We generated an atlas of integrated gene expression, biological pathways, transcriptional regulators, and gene regulatory networks (GRNs), which show discrete sets of key transcriptional regulators and pathways activated or suppressed during CM maturation. We developed a GRN-based program named MatStatCM that indexes CM maturation status. MatStatCM reveals that pluripotent stem cell-derived CMs mature early in culture, but are arrested at the late embryonic stage with aberrant regulation of key transcription factors. Our study provides a foundation for understanding CM maturation. PMID:26586429

  17. Conversion of human fibroblasts into functional cardiomyocytes by small molecules.

    PubMed

    Cao, Nan; Huang, Yu; Zheng, Jiashun; Spencer, C Ian; Zhang, Yu; Fu, Ji-Dong; Nie, Baoming; Xie, Min; Zhang, Mingliang; Wang, Haixia; Ma, Tianhua; Xu, Tao; Shi, Guilai; Srivastava, Deepak; Ding, Sheng

    2016-06-01

    Reprogramming somatic fibroblasts into alternative lineages would provide a promising source of cells for regenerative therapy. However, transdifferentiating human cells into specific homogeneous, functional cell types is challenging. Here we show that cardiomyocyte-like cells can be generated by treating human fibroblasts with a combination of nine compounds that we term 9C. The chemically induced cardiomyocyte-like cells uniformly contracted and resembled human cardiomyocytes in their transcriptome, epigenetic, and electrophysiological properties. 9C treatment of human fibroblasts resulted in a more open-chromatin conformation at key heart developmental genes, enabling their promoters and enhancers to bind effectors of major cardiogenic signals. When transplanted into infarcted mouse hearts, 9C-treated fibroblasts were efficiently converted to chemically induced cardiomyocyte-like cells. This pharmacological approach to lineage-specific reprogramming may have many important therapeutic implications after further optimization to generate mature cardiac cells. PMID:27127239

  18. Localization of PPAR isotypes in the adult mouse and human brain

    PubMed Central

    Warden, Anna; Truitt, Jay; Merriman, Morgan; Ponomareva, Olga; Jameson, Kelly; Ferguson, Laura B.; Mayfield, R. Dayne; Harris, R. Adron

    2016-01-01

    Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that act as ligand-activated transcription factors. PPAR agonists have well-documented anti-inflammatory and neuroprotective roles in the central nervous system. Recent evidence suggests that PPAR agonists are attractive therapeutic agents for treating neurodegenerative diseases as well as addiction. However, the distribution of PPAR mRNA and protein in brain regions associated with these conditions (i.e. prefrontal cortex, nucleus accumbens, amygdala, ventral tegmental area) is not well defined. Moreover, the cell type specificity of PPARs in mouse and human brain tissue has yet to be investigated. We utilized quantitative PCR and double immunofluorescence microscopy to determine that both PPAR mRNA and protein are expressed ubiquitously throughout the adult mouse brain. We found that PPARs have unique cell type specificities that are consistent between species. PPARα was the only isotype to colocalize with all cell types in both adult mouse and adult human brain tissue. Overall, we observed a strong neuronal signature, which raises the possibility that PPAR agonists may be targeting neurons rather than glia to produce neuroprotection. Our results fill critical gaps in PPAR distribution and define novel cell type specificity profiles in the adult mouse and human brain. PMID:27283430

  19. Effects of Shenqi Fuzheng injection on Fas/FasL protein expression levels in the cardiomyocytes of a mouse model of viral myocarditis

    PubMed Central

    WU, TIANMIN; CHEN, JINSHUI; FAN, LIUFANG; XIE, WENYAN; XU, CHANGSHENG; WANG, HUAJUN

    2016-01-01

    The aim of the present study was to examine the effects of Shenqi Fuzheng injection (SFI) on Fas and FasL protein expression levels in the cardiomyocytes of mice with viral myocarditis (VMC) and to explore the underlying anti-apoptotic mechanisms. A total of 120 male BALB/c mice were randomly divided into five groups as follows: Blank control group, model group, ribavirin group, low-dose SFI group and high-dose SFI group. The VMC model was established by the injection of coxsackievirus group B type 3 and saline, ribavirin or SFI was administered 30 min later. Cardiac samples were harvested from mice in each group on days 3, 10 and 30. Apoptosis of cardiac cells was examined using terminal deoxynucleotidyl transferase dUTP nick-end labeling, and Fas and FasL protein expression levels were detected using immunohistochemistry. Myocardial apoptosis and Fas/FasL protein expression levels were significantly increased in the model group, as compared with the blank group (P<0.01), whereas the apoptotic index (AI) and Fas/FasL protein expression levels of cardiac cells in the high-dose SFI group were significantly decreased compared with those in the model group on day 10 (acute phase; P<0.01). The AI and Fas/FasL protein expression levels of cardiac cells in the low- and high-dose SFI groups were also significantly decreased on day 30 (chronic phase; P<0.01); however, no differences between the high- and low-dose groups were detected. In conclusion, SFI relieves VMC via the downregulation of Fas and FasL protein expression and the inhibition of cell apoptosis. PMID:27168814

  20. Challenges measuring cardiomyocyte renewal

    PubMed Central

    Soonpaa, Mark H.; Rubart, Michael; Field, Loren J.

    2012-01-01

    Interventions to effect therapeutic cardiomyocyte renewal have received considerable interest of late. Such interventions, if successful, could give rise to myocardial regeneration in diseased hearts. Regenerative interventions fall into two broad categories, namely approaches based on promoting renewal of pre-existing cardiomyocytes and approaches based on cardiomyogenic stem cell activity. The latter category can be further subdivided into approaches promoting differentiation of endogenous cardiomyogenic stem cells, approaches wherein cardiomyogenic stem cells are harvested, amplified or enriched ex vivo, and subsequently engrafted into the heart, and approaches wherein an exogenous stem cell is induced to differentiate in vitro, and the resulting cardiomyocytes are engrafted into the heart. There is disagreement in the literature regarding the degree to which cardiomyocyte renewal occurs in the normal and injured heart, the mechanism(s) by which this occurs, and the degree to which therapeutic interventions can enhance regenerative growth. This review discusses several caveats which are encountered when attempting to measure cardiomyocyte renewal in vivo which likely contribute, at least in part, to the disagreement regarding the levels at which this occurs in normal, injured and treated hearts. PMID:23142641

  1. In vivo reprogramming of murine cardiac fibroblasts into induced cardiomyocytes

    PubMed Central

    Qian, Li; Huang, Yu; Spencer, C. Ian; Foley, Amy; Vedantham, Vasanth; Liu, Lei; Conway, Simon J.; Fu, Ji-dong; Srivastava, Deepak

    2012-01-01

    SUMMARY The reprogramming of adult cells into pluripotent cells or directly into alternative adult cell types holds great promise for regenerative medicine. We reported that cardiac fibroblasts, which represent 50% of the cells in the mammalian heart, can be directly reprogrammed to adult cardiomyocyte-like cells in vitro by the addition of Gata4, Mef2c and Tbx5 (GMT). Here, we use genetic lineage-tracing to show that resident non-myocytes in the murine heart can be reprogrammed into cardiomyocyte-like cells in vivo by local delivery of GMT after coronary ligation. Induced cardiomyocytes became bi-nucleate, assembled sarcomeres and had cardiomyocyte-like gene expression. Analysis of single cells revealed ventricular cardiomyocyte-like action potentials, beating upon electrical stimulation, and evidence of electrical coupling. In vivo delivery of GMT decreased infarct size and modestly attenuated cardiac dysfunction up to 3 months after coronary ligation. Delivery of the pro-angiogenic and fibroblast activating peptide, Thymosin β4, along with GMT, resulted in further improvements in scar area and cardiac function. These findings demonstrate that cardiac fibroblasts can be reprogrammed into cardiomyocyte-like cells in their native environment for potential regenerative purposes. PMID:22522929

  2. Serial transplantation reveals the stem-cell-like regenerative potential of adult mouse hepatocytes.

    PubMed Central

    Overturf, K.; al-Dhalimy, M.; Ou, C. N.; Finegold, M.; Grompe, M.

    1997-01-01

    Previous work has shown that adult mouse hepatocytes can divide at least 18 times in vivo. To test whether this represents the upper limit of their regenerative capacity, we performed serial transplantation of hepatocytes in the fumarylacetoacetate hydrolase deficiency murine model of liver repopulation. Hepatocytes from adult donors were serially transplanted in limiting numbers six times and resulted in complete repopulation during each cycle. This corresponds to a minimal number of 69 cell doublings or a 7.3 x 10(20)-fold expansion. No evidence for abnormal liver function or altered hepatic architecture was found in repopulated animals. We conclude that a fraction of adult mouse hepatocytes have growth potential similar to that of hematopoietic stem cells. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:9358753

  3. Cardiomyocyte glucagon receptor signaling modulates outcomes in mice with experimental myocardial infarction

    PubMed Central

    Ali, Safina; Ussher, John R.; Baggio, Laurie L.; Kabir, M. Golam; Charron, Maureen J.; Ilkayeva, Olga; Newgard, Christopher B.; Drucker, Daniel J.

    2014-01-01

    Objective Glucagon is a hormone with metabolic actions that maintains normoglycemia during the fasting state. Strategies enabling either inhibition or activation of glucagon receptor (Gcgr) signaling are being explored for the treatment of diabetes or obesity. However, the cardiovascular consequences of manipulating glucagon action are poorly understood. Methods We assessed infarct size and the following outcomes following left anterior descending (LAD) coronary artery ligation; cardiac gene and protein expression, acylcarnitine profiles, and cardiomyocyte survival in normoglycemic non-obese wildtype mice, and in newly generated mice with selective inactivation of the cardiomyocyte Gcgr. Complementary experiments analyzed Gcgr signaling and cell survival in cardiomyocyte cultures and cell lines, in the presence or absence of exogenous glucagon. Results Exogenous glucagon administration directly impaired recovery of ventricular pressure in ischemic mouse hearts ex vivo, and increased mortality from myocardial infarction after LAD coronary artery ligation in mice in a p38 MAPK-dependent manner. In contrast, cardiomyocyte-specific reduction of glucagon action in adult GcgrCM−/− mice significantly improved survival, and reduced hypertrophy and infarct size following myocardial infarction. Metabolic profiling of hearts from GcgrCM−/− mice revealed a marked reduction in long chain acylcarnitines in both aerobic and ischemic hearts, and following high fat feeding, consistent with an essential role for Gcgr signaling in the control of cardiac fatty acid utilization. Conclusions Activation or reduction of cardiac Gcgr signaling in the ischemic heart produces substantial cardiac phenotypes, findings with implications for therapeutic strategies designed to augment or inhibit Gcgr signaling for the treatment of metabolic disorders. PMID:25685700

  4. A comprehensive transcriptomic analysis of infant and adult mouse ovary.

    PubMed

    Pan, Linlin; Gong, Wei; Zhou, Yuanyuan; Li, Xiaonuan; Yu, Jun; Hu, Songnian

    2014-10-01

    Ovary development is a complex process involving numerous genes. A well-developed ovary is essential for females to keep fertility and reproduce offspring. In order to gain a better insight into the molecular mechanisms related to the process of mammalian ovary development, we performed a comparative transcriptomic analysis on ovaries isolated from infant and adult mice by using next-generation sequencing technology (SOLiD). We identified 15,454 and 16,646 transcriptionally active genes at the infant and adult stage, respectively. Among these genes, we also identified 7021 differentially expressed genes. Our analysis suggests that, in general, the adult ovary has a higher level of transcriptomic activity. However, it appears that genes related to primordial follicle development, such as those encoding Figla and Nobox, are more active in the infant ovary, whereas expression of genes vital for follicle development, such as Gdf9, Bmp4 and Bmp15, is upregulated in the adult. These data suggest a dynamic shift in gene expression during ovary development and it is apparent that these changes function to facilitate follicle maturation, when additional functional gene studies are considered. Furthermore, our investigation has also revealed several important functional pathways, such as apoptosis, MAPK and steroid biosynthesis, that appear to be much more active in the adult ovary compared to those of the infant. These findings will provide a solid foundation for future studies on ovary development in mice and other mammals and help to expand our understanding of the complex molecular and cellular events that occur during postnatal ovary development. PMID:25251848

  5. Simple non-invasive analysis of embryonic stem cell-derived cardiomyocytes beating in vitro

    NASA Astrophysics Data System (ADS)

    Radaszkiewicz, Katarzyna Anna; Sýkorová, Dominika; Karas, Pavel; Kudová, Jana; Kohút, Lukáš; Binó, Lucia; Večeřa, Josef; Víteček, Jan; Kubala, Lukáš; Pacherník, Jiří

    2016-02-01

    The analysis of digital video output enables the non-invasive screening of various active biological processes. For the monitoring and computing of the beating parameters of cardiomyocytes in vitro, CB Analyser (cardiomyocyte beating analyser) software was developed. This software is based on image analysis of the video recording of beating cardiomyocytes. CB Analyser was tested using cardiomyocytes derived from mouse embryonic stem cells at different stages of cardiomyogenesis. We observed that during differentiation (from day 18), the beat peak width decreased, which corresponded to the increased speed of an individual pulse. However, the beating frequency did not change. Further, the effects of epinephrine modulating mature cardiomyocyte functions were tested to validate the CB Analyser analysis. In conclusion, data show that CB Analyser is a useful tool for evaluating the functions of both developing and mature cardiomyocytes under various conditions in vitro.

  6. Controllable Expansion of Primary Cardiomyocytes by Reversible Immortalization

    PubMed Central

    Zhang, Yue; Nuglozeh, Edem; Touré, Fatouma; Schmidt, Ann Marie

    2009-01-01

    Abstract Cardiac tissue engineering will remain only a prospect unless large numbers of therapeutic cells can be provided, either from small samples of cardiac cells or from stem cell sources. In contrast to most adult cells, cardiomyocytes are terminally differentiated and cannot be expanded in culture. We explored the feasibility of enabling the in vitro expansion of primary neonatal rat cardiomyocytes by lentivector-mediated cell immortalization, and then reverting the phenotype of the expanded cells back to the cardiomyocyte state. Primary rat cardiomyocytes were transduced with simian virus 40 large T antigen (TAg), or with Bmi-1 followed by the human telomerase reverse transcriptase (hTERT) gene; the cells were expanded; and the transduced genes were removed by adenoviral vector expressing Cre recombinase. The TAg gene was more efficient in cell transduction than the Bmi-1/hTERT gene, based on the rate of cell proliferation. Immortalized cells exhibited the morphological features of dedifferentiation (increased vimentin expression, and reduced expression of troponin I and Nkx2.5) along with the continued expression of cardiac markers (α-actin, connexin-43, and calcium transients). After the immortalization was reversed, cells returned to their differentiated state. This strategy for controlled expansion of primary cardiomyocytes by gene transfer has potential for providing large amounts of a patient's own cardiomyocytes for cell therapy, and the cardiomyocytes derived by this method could be a useful cellular model by which to study cardiogenesis. PMID:19708763

  7. Microscopic heat pulses induce contraction of cardiomyocytes without calcium transients

    SciTech Connect

    Oyama, Kotaro; Mizuno, Akari; Shintani, Seine A.; Itoh, Hideki; Serizawa, Takahiro; Fukuda, Norio; Suzuki, Madoka

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Infra-red laser beam generates microscopic heat pulses. Black-Right-Pointing-Pointer Heat pulses induce contraction of cardiomyocytes. Black-Right-Pointing-Pointer Ca{sup 2+} transients during the contraction were not detected. Black-Right-Pointing-Pointer Skinned cardiomyocytes in free Ca{sup 2+} solution also contracted. Black-Right-Pointing-Pointer Heat pulses regulated the contractions without Ca{sup 2+} dynamics. -- Abstract: It was recently demonstrated that laser irradiation can control the beating of cardiomyocytes and hearts, however, the precise mechanism remains to be clarified. Among the effects induced by laser irradiation on biological tissues, temperature change is one possible effect which can alter physiological functions. Therefore, we investigated the mechanism by which heat pulses, produced by infra-red laser light under an optical microscope, induce contractions of cardiomyocytes. Here we show that microscopic heat pulses induce contraction of rat adult cardiomyocytes. The temperature increase, {Delta}T, required for inducing contraction of cardiomyocytes was dependent upon the ambient temperature; that is, {Delta}T at physiological temperature was lower than that at room temperature. Ca{sup 2+} transients, which are usually coupled to contraction, were not detected. We confirmed that the contractions of skinned cardiomyocytes were induced by the heat pulses even in free Ca{sup 2+} solution. This heat pulse-induced Ca{sup 2+}-decoupled contraction technique has the potential to stimulate heart and skeletal muscles in a manner different from the conventional electrical stimulations.

  8. A mouse model for adult cardiac-specific gene deletion with CRISPR/Cas9.

    PubMed

    Carroll, Kelli J; Makarewich, Catherine A; McAnally, John; Anderson, Douglas M; Zentilin, Lorena; Liu, Ning; Giacca, Mauro; Bassel-Duby, Rhonda; Olson, Eric N

    2016-01-12

    Clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas)9 genomic editing has revolutionized the generation of mutant animals by simplifying the creation of null alleles in virtually any organism. However, most current approaches with this method require zygote injection, making it difficult to assess the adult, tissue-specific functions of genes that are widely expressed or which cause embryonic lethality when mutated. Here, we describe the generation of cardiac-specific Cas9 transgenic mice, which express high levels of Cas9 in the heart, but display no overt defects. In proof-of-concept experiments, we used Adeno-Associated Virus 9 (AAV9) to deliver single-guide RNA (sgRNA) that targets the Myh6 locus exclusively in cardiomyocytes. Intraperitoneal injection of postnatal cardiac-Cas9 transgenic mice with AAV9 encoding sgRNA against Myh6 resulted in robust editing of the Myh6 locus. These mice displayed severe cardiomyopathy and loss of cardiac function, with elevation of several markers of heart failure, confirming the effectiveness of this method of adult cardiac gene deletion. Mice with cardiac-specific expression of Cas9 provide a tool that will allow rapid and accurate deletion of genes following a single injection of AAV9-sgRNAs, thereby circumventing embryonic lethality. This method will be useful for disease modeling and provides a means of rapidly editing genes of interest in the heart. PMID:26719419

  9. Mouse matriptase-2: identification, characterization and comparative mRNA expression analysis with mouse hepsin in adult and embryonic tissues.

    PubMed Central

    Hooper, John D; Campagnolo, Luisa; Goodarzi, Goodarz; Truong, Tony N; Stuhlmann, Heidi; Quigley, James P

    2003-01-01

    We report the identification and characterization of mouse matriptase-2 (m-matriptase-2), an 811-amino-acid protein composed of an N-terminal cytoplasmic domain, a membrane-spanning domain, two CUB (complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domains, three LDLR (low-density-lipoprotein receptor class A) domains and a C-terminal serine-protease domain. All m-matriptase-2 protein domain boundaries corresponded with intron/exon junctions of the encoding gene, which spans approx. 29 kb and comprises 18 exons. Matriptase-2 is highly conserved in human, mouse and rat, with the rat matriptase-2 gene ( r-maltriptase-2 ) predicted to encode transmembrane and soluble isoforms. Western-blot analysis indicated that m-matriptase-2 migrates close to its theoretical molecular mass of 91 kDa, and immunofluorescence analysis was consistent with the proposed surface membrane localization of this protein. Reverse-transcription PCR and in-situ -hybridization analysis indicated that m-matriptase-2 expression overlaps with the distribution of mouse hepsin (m-hepsin, a cell-surface serine protease identified in hepatoma cells) in adult tissues and during embryonic development. In adult tissues both are expressed at highest levels in liver, kidney and uterus. During embryogenesis m-matriptase-2 expression peaked between days 12.5 and 15.5. m-hepsin expression was biphasic, with peaks at day 7.5 to 8.5 and again between days 12.5 and 15.5. In situ hybridization of embryonic tissues indicated abundant expression of both m-matriptase-2 and m-hepsin in the developing liver and at lower levels in developing pharyngo-tympanic tubes. While m-hepsin was detected in the residual embryonic yolk sac and with lower intensity in lung, heart, gastrointestinal tract, developing kidney tubules and epithelium of the oral cavity, m-matriptase-2 was absent in these tissues, but strongly expressed within the nasal cavity by olfactory epithelial

  10. High-resolution gene expression atlases for adult and developing mouse brain and spinal cord.

    PubMed

    Henry, Alex M; Hohmann, John G

    2012-10-01

    Knowledge of the structure, genetics, circuits, and physiological properties of the mammalian brain in both normal and pathological states is ever increasing as research labs worldwide probe the various aspects of brain function. Until recently, however, comprehensive cataloging of gene expression across the central nervous system has been lacking. The Allen Institute for Brain Science, as part of its mission to propel neuroscience research, has completed several large gene-mapping projects in mouse, nonhuman primate, and human brain, producing informative online public resources and tools. Here we present the Allen Mouse Brain Atlas, covering ~20,000 genes throughout the adult mouse brain; the Allen Developing Mouse Brain Atlas, detailing expression of approximately 2,000 important developmental genes across seven embryonic and postnatal stages of brain growth; and the Allen Spinal Cord Atlas, revealing expression for ~20,000 genes in the adult and neonatal mouse spinal cords. Integrated data-mining tools, including reference atlases, informatics analyses, and 3-D viewers, are described. For these massive-scale projects, high-throughput industrial techniques were developed to standardize and reliably repeat experimental goals. To verify consistency and accuracy, a detailed analysis of the 1,000 most viewed genes for the adult mouse brain (according to website page views) was performed by comparing our data with peer-reviewed literature and other databases. We show that our data are highly consistent with independent sources and provide a comprehensive compendium of information and tools used by thousands of researchers each month. All data and tools are freely available via the Allen Brain Atlas portal (www.brain-map.org). PMID:22832508

  11. Hair cell replacement in adult mouse utricles after targeted ablation of hair cells with diphtheria toxin.

    PubMed

    Golub, Justin S; Tong, Ling; Ngyuen, Tot B; Hume, Cliff R; Palmiter, Richard D; Rubel, Edwin W; Stone, Jennifer S

    2012-10-24

    We developed a transgenic mouse to permit conditional and selective ablation of hair cells in the adult mouse utricle by inserting the human diphtheria toxin receptor (DTR) gene into the Pou4f3 gene, which encodes a hair cell-specific transcription factor. In adult wild-type mice, administration of diphtheria toxin (DT) caused no significant hair cell loss. In adult Pou4f3(+/DTR) mice, DT treatment reduced hair cell numbers to 6% of normal by 14 days post-DT. Remaining hair cells were located primarily in the lateral extrastriola. Over time, hair cell numbers increased in these regions, reaching 17% of untreated Pou4f3(+/DTR) mice by 60 days post-DT. Replacement hair cells were morphologically distinct, with multiple cytoplasmic processes, and displayed evidence for active mechanotransduction channels and synapses characteristic of type II hair cells. Three lines of evidence suggest replacement hair cells were derived via direct (nonmitotic) transdifferentiation of supporting cells: new hair cells did not incorporate BrdU, supporting cells upregulated the pro-hair cell gene Atoh1, and supporting cell numbers decreased over time. This study introduces a new method for efficient conditional hair cell ablation in adult mouse utricles and demonstrates that hair cells are spontaneously regenerated in vivo in regions where there may be ongoing hair cell turnover. PMID:23100430

  12. Akt1/protein kinase B enhances transcriptional reprogramming of fibroblasts to functional cardiomyocytes

    PubMed Central

    Zhou, Huanyu; Dickson, Matthew E.; Kim, Min Soo; Bassel-Duby, Rhonda; Olson, Eric N.

    2015-01-01

    Conversion of fibroblasts to functional cardiomyocytes represents a potential approach for restoring cardiac function after myocardial injury, but the technique thus far has been slow and inefficient. To improve the efficiency of reprogramming fibroblasts to cardiac-like myocytes (iCMs) by cardiac transcription factors [Gata4, Hand2, Mef2c, and Tbx5 (GHMT)], we screened 192 protein kinases and discovered that Akt/protein kinase B dramatically accelerates and amplifies this process in three different types of fibroblasts (mouse embryo, adult cardiac, and tail tip). Approximately 50% of reprogrammed mouse embryo fibroblasts displayed spontaneous beating after 3 wk of induction by Akt plus GHMT. Furthermore, addition of Akt1 to GHMT evoked a more mature cardiac phenotype for iCMs, as seen by enhanced polynucleation, cellular hypertrophy, gene expression, and metabolic reprogramming. Insulin-like growth factor 1 (IGF1) and phosphoinositol 3-kinase (PI3K) acted upstream of Akt whereas the mitochondrial target of rapamycin complex 1 (mTORC1) and forkhead box o3 (Foxo3a) acted downstream of Akt to influence fibroblast-to-cardiomyocyte reprogramming. These findings provide insights into the molecular basis of cardiac reprogramming and represent an important step toward further application of this technique. PMID:26354121

  13. Whole Mount Dissection and Immunofluorescence of the Adult Mouse Cochlea.

    PubMed

    Montgomery, Scott C; Cox, Brandon C

    2016-01-01

    The organ of Corti, housed in the cochlea of the inner ear, contains mechanosensory hair cells and surrounding supporting cells which are organized in a spiral shape and have a tonotopic gradient for sound detection. The mouse cochlea is approximately 6 mm long and often divided into three turns (apex, middle, and base) for analysis. To investigate cell loss, cell division, or mosaic gene expression, the whole mount or surface preparation of the cochlea is useful. This dissection method allows visualization of all cells within the organ of Corti when combined with immunostaining and confocal microscopy to image cells at different planes in the z-axis. Multiple optical cross-sections can also be obtained from these z-stack images. In addition, the whole mount dissection method can be used for scanning electron microscopy, although a different fixation method is needed. Here, we present a method to isolate the organ of Corti as three intact cochlear turns (apex, middle, and base). This method can be used for mice ranging from one week of age through adulthood and differs from the technique used for neonatal samples where calcification of the cochlea is incomplete. A slightly modified version can be used for dissection of the rat cochlea. We also demonstrate a procedure for immunostaining with fluorescently tagged antibodies. PMID:26779585

  14. Adult mouse cortical cell taxonomy revealed by single cell transcriptomics.

    PubMed

    Tasic, Bosiljka; Menon, Vilas; Nguyen, Thuc Nghi; Kim, Tae Kyung; Jarsky, Tim; Yao, Zizhen; Levi, Boaz; Gray, Lucas T; Sorensen, Staci A; Dolbeare, Tim; Bertagnolli, Darren; Goldy, Jeff; Shapovalova, Nadiya; Parry, Sheana; Lee, Changkyu; Smith, Kimberly; Bernard, Amy; Madisen, Linda; Sunkin, Susan M; Hawrylycz, Michael; Koch, Christof; Zeng, Hongkui

    2016-02-01

    Nervous systems are composed of various cell types, but the extent of cell type diversity is poorly understood. We constructed a cellular taxonomy of one cortical region, primary visual cortex, in adult mice on the basis of single-cell RNA sequencing. We identified 49 transcriptomic cell types, including 23 GABAergic, 19 glutamatergic and 7 non-neuronal types. We also analyzed cell type-specific mRNA processing and characterized genetic access to these transcriptomic types by many transgenic Cre lines. Finally, we found that some of our transcriptomic cell types displayed specific and differential electrophysiological and axon projection properties, thereby confirming that the single-cell transcriptomic signatures can be associated with specific cellular properties. PMID:26727548

  15. Adult Mouse Cortical Cell Taxonomy by Single Cell Transcriptomics

    PubMed Central

    Tasic, Bosiljka; Menon, Vilas; Nguyen, Thuc Nghi; Kim, Tae Kyung; Jarsky, Tim; Yao, Zizhen; Levi, Boaz; Gray, Lucas T.; Sorensen, Staci A.; Dolbeare, Tim; Bertagnolli, Darren; Goldy, Jeff; Shapovalova, Nadiya; Parry, Sheana; Lee, Changkyu; Smith, Kimberly; Bernard, Amy; Madisen, Linda; Sunkin, Susan M.; Hawrylycz, Michael; Koch, Christof; Zeng, Hongkui

    2016-01-01

    Nervous systems are composed of various cell types, but the extent of cell type diversity is poorly understood. Here, we construct a cellular taxonomy of one cortical region, primary visual cortex, in adult mice based on single cell RNA-sequencing. We identify 49 transcriptomic cell types including 23 GABAergic, 19 glutamatergic and seven non-neuronal types. We also analyze cell-type specific mRNA processing and characterize genetic access to these transcriptomic types by many transgenic Cre lines. Finally, we show that some of our transcriptomic cell types display specific and differential electrophysiological and axon projection properties, thereby confirming that the single cell transcriptomic signatures can be associated with specific cellular properties. PMID:26727548

  16. Retinoic acid receptor beta2 and neurite outgrowth in the adult mouse spinal cord in vitro.

    PubMed

    Corcoran, Jonathan; So, Po-Lin; Barber, Robert D; Vincent, Karen J; Mazarakis, Nicholas D; Mitrophanous, Kyriacos A; Kingsman, Susan M; Maden, Malcolm

    2002-10-01

    Retinoic acid, acting through the nuclear retinoic acid receptor beta2 (RARbeta2), stimulates neurite outgrowth from peripheral nervous system tissue that has the capacity to regenerate neurites, namely, embryonic and adult dorsal root ganglia. Similarly, in central nervous system tissue that can regenerate, namely, embryonic mouse spinal cord, retinoic acid also stimulates neurite outgrowth and RARbeta2 is upregulated. By contrast, in the adult mouse spinal cord, which cannot regenerate, no such upregulation of RARbeta2 by retinoic acid is observed and no neurites are extended in vitro. To test our hypothesis that the upregulation of RARbeta2 is crucial to neurite regeneration, we have transduced adult mouse or rat spinal cord in vitro with a minimal equine infectious anaemia virus vector expressing RARbeta2. After transduction, prolific neurite outgrowth occurs. Outgrowth does not occur when the cord is transduced with a different isoform of RARbeta nor does it occur following treatment with nerve growth factor. These data demonstrate that RARbeta2 is involved in neurite outgrowth, at least in vitro, and that this gene may in the future be of some therapeutic use. PMID:12235288

  17. Subretinal delivery and electroporation in pigmented and nonpigmented adult mouse eyes

    PubMed Central

    Nickerson, John M.; Goodman, Penny; Chrenek, Micah A.; Johnson, Christiana J.; Berglin, Lennart; Redmond, T. Michael.; Boatright, Jeffrey H.

    2013-01-01

    Subretinal injection offers one of the best ways to deliver many classes of drugs, reagents, cells and treatments to the photoreceptor, Müller, and retinal pigment epithelium (RPE) cells of the retina. Agents delivered to this space are placed within microns of the intended target cell, accumulating to high concentrations because there is no dilution due to transport processes or diffusion. Dilution in the interphotoreceptor space (IPS) is minimal because the IPS volume is only 10-20 microliters in the human eye and less than 1 microliter in the mouse eye. For gene delivery purposes, we wished to transfect the cells adjacent to the IPS in adult mouse eyes. Others transfect these cells in neonatal rats to study the development of the retina. In both neonates and adults, electroporation is found to be effective Here we describe the optimization of electroporation conditions for RPE cells in the adult mouse eye with naked plasmids. However, both techniques, subretinal injection and electroporation, present some technical challenges that require skill on the part of the surgeon to prevent untoward damage to the eye. Here we describe methods that we have used for the past ten years (1). PMID:22688698

  18. Early origins of heart disease: low birth weight and determinants of cardiomyocyte endowment.

    PubMed

    Botting, K J; Wang, K C W; Padhee, M; McMillen, I C; Summers-Pearce, B; Rattanatray, L; Cutri, N; Posterino, G S; Brooks, D A; Morrison, J L

    2012-09-01

    1. World-wide epidemiological and experimental animal studies demonstrate that adversity in fetal life, resulting in intrauterine growth restriction, programmes the offspring for a greater susceptibility to ischaemic heart disease and heart failure in adult life. 2. After cardiogenesis, cardiomyocyte endowment is determined by a range of hormones and signalling pathways that regulate cardiomyocyte proliferation, apoptosis and the timing of multinucleation/terminal differentiation. 3. The small fetus may have reduced cardiomyocyte endowment owing to the impact of a suboptimal intrauterine environment on the signalling pathways that regulate cardiomyocyte proliferation, apoptosis and the timing of terminal differentiation. PMID:22126336

  19. Stem cell niches in the adult mouse heart

    PubMed Central

    Urbanek, Konrad; Cesselli, Daniela; Rota, Marcello; Nascimbene, Angelo; De Angelis, Antonella; Hosoda, Toru; Bearzi, Claudia; Boni, Alessandro; Bolli, Roberto; Kajstura, Jan; Anversa, Piero; Leri, Annarosa

    2006-01-01

    Cardiac stem cells (CSCs) have been identified in the adult heart, but the microenvironment that protects the slow-cycling, undifferentiated, and self-renewing CSCs remains to be determined. We report that the myocardium possesses interstitial structures with the architectural organization of stem cell niches that harbor long-term BrdU-retaining cells. The recognition of long-term label-retaining cells provides functional evidence of resident CSCs in the myocardium, indicating that the heart is an organ regulated by a stem cell compartment. Cardiac niches contain CSCs and lineage-committed cells, which are connected to supporting cells represented by myocytes and fibroblasts. Connexins and cadherins form gap and adherens junctions at the interface of CSCs–lineage-committed cells and supporting cells. The undifferentiated state of CSCs is coupled with the expression of α4-integrin, which colocalizes with the α2-chain of laminin and fibronectin. CSCs divide symmetrically and asymmetrically, but asymmetric division predominates, and the replicating CSC gives rise to one daughter CSC and one daughter committed cell. By this mechanism of growth kinetics, the pool of primitive CSCs is preserved, and a myocyte progeny is generated together with endothelial and smooth muscle cells. Thus, CSCs regulate myocyte turnover that is heterogeneous across the heart, faster at the apex and atria, and slower at the base–midregion of the ventricle. PMID:16754876

  20. Aldosterone-induced cardiomyocyte growth, and fibroblast migration and proliferation are mediated by TRAF3IP2.

    PubMed

    Somanna, Naveen K; Yariswamy, Manjunath; Garagliano, Joseph M; Siebenlist, Ulrich; Mummidi, Srinivas; Valente, Anthony J; Chandrasekar, Bysani

    2015-10-01

    Sustained activation of the Renin-Angiotensin-Aldosterone System (RAAS) contributes to the pathogenesis of heart failure. Aldosterone (Aldo) is known to induce both myocardial hypertrophy and fibrosis through oxidative stress and proinflammatory pathways. Here we have investigated whether Aldo-mediated cardiomycocyte hypertrophy is dependent on TRAF3IP2, an upstream regulator of IKK and JNK. We also investigated whether the pro-mitogenic and pro-migratory effects of Aldo on cardiac fibroblasts are also mediated by TRAF3IP2. Aldo induced both superoxide and hydrogen peroxide in isolated adult mouse cardiomyocytes (CM), and upregulated TRAF3IP2 expression in part via the mineralocorticoid receptor and oxidative stress. Silencing TRAF3IP2 blunted Aldo-induced IKKβ, p65, JNK, and c-Jun activation, IL-18, IL-6 and CT-1 upregulation, and cardiomyocyte hypertrophy. In isolated adult mouse cardiac fibroblasts (CF), Aldo stimulated TRAF3IP2-dependent IL-18 and IL-6 production, CTGF, collagen I and III expression, MMP2 activation, and proliferation and migration. These in vitro results suggest that TRAF3IP2 may play a causal role in Aldo-induced adverse cardiac remodeling in vivo, and identify TRAF3IP2 as a potential therapeutic target in hypertensive heart disease. PMID:26148936

  1. Rapid and efficient gene delivery into the adult mouse brain via focal electroporation

    PubMed Central

    Nomura, Tadashi; Nishimura, Yusuke; Gotoh, Hitoshi; Ono, Katsuhiko

    2016-01-01

    In vivo gene delivery is required for studying the cellular and molecular mechanisms of various biological events. Virus-mediated gene transfer or generation of transgenic animals is widely used; however, these methods are time-consuming and expensive. Here we show an improved electroporation technique for acute gene delivery into the adult mouse brain. Using a syringe-based microelectrode, local DNA injection and the application of electric current can be performed simultaneously; this allows rapid and efficient gene transduction of adult non-neuronal cells. Combining this technique with various expression vectors that carry specific promoters resulted in targeted gene expression in astrocytic cells. Our results constitute a powerful strategy for the genetic manipulation of adult brains in a spatio-temporally controlled manner. PMID:27430903

  2. Oligodendrocyte heterogeneity in the mouse juvenile and adult central nervous system.

    PubMed

    Marques, Sueli; Zeisel, Amit; Codeluppi, Simone; van Bruggen, David; Mendanha Falcão, Ana; Xiao, Lin; Li, Huiliang; Häring, Martin; Hochgerner, Hannah; Romanov, Roman A; Gyllborg, Daniel; Muñoz-Manchado, Ana B; La Manno, Gioele; Lönnerberg, Peter; Floriddia, Elisa M; Rezayee, Fatemah; Ernfors, Patrik; Arenas, Ernest; Hjerling-Leffler, Jens; Harkany, Tibor; Richardson, William D; Linnarsson, Sten; Castelo-Branco, Gonçalo

    2016-06-10

    Oligodendrocytes have been considered as a functionally homogeneous population in the central nervous system (CNS). We performed single-cell RNA sequencing on 5072 cells of the oligodendrocyte lineage from 10 regions of the mouse juvenile and adult CNS. Thirteen distinct populations were identified, 12 of which represent a continuum from Pdgfra(+) oligodendrocyte precursor cells (OPCs) to distinct mature oligodendrocytes. Initial stages of differentiation were similar across the juvenile CNS, whereas subsets of mature oligodendrocytes were enriched in specific regions in the adult brain. Newly formed oligodendrocytes were detected in the adult CNS and were responsive to complex motor learning. A second Pdgfra(+) population, distinct from OPCs, was found along vessels. Our study reveals the dynamics of oligodendrocyte differentiation and maturation, uncoupling them at a transcriptional level and highlighting oligodendrocyte heterogeneity in the CNS. PMID:27284195

  3. Neural stem/progenitor cell properties of glial cells in the adult mouse auditory nerve

    PubMed Central

    Lang, Hainan; Xing, Yazhi; Brown, LaShardai N.; Samuvel, Devadoss J.; Panganiban, Clarisse H.; Havens, Luke T.; Balasubramanian, Sundaravadivel; Wegner, Michael; Krug, Edward L.; Barth, Jeremy L.

    2015-01-01

    The auditory nerve is the primary conveyor of hearing information from sensory hair cells to the brain. It has been believed that loss of the auditory nerve is irreversible in the adult mammalian ear, resulting in sensorineural hearing loss. We examined the regenerative potential of the auditory nerve in a mouse model of auditory neuropathy. Following neuronal degeneration, quiescent glial cells converted to an activated state showing a decrease in nuclear chromatin condensation, altered histone deacetylase expression and up-regulation of numerous genes associated with neurogenesis or development. Neurosphere formation assays showed that adult auditory nerves contain neural stem/progenitor cells (NSPs) that were within a Sox2-positive glial population. Production of neurospheres from auditory nerve cells was stimulated by acute neuronal injury and hypoxic conditioning. These results demonstrate that a subset of glial cells in the adult auditory nerve exhibit several characteristics of NSPs and are therefore potential targets for promoting auditory nerve regeneration. PMID:26307538

  4. Rapid and efficient gene delivery into the adult mouse brain via focal electroporation.

    PubMed

    Nomura, Tadashi; Nishimura, Yusuke; Gotoh, Hitoshi; Ono, Katsuhiko

    2016-01-01

    In vivo gene delivery is required for studying the cellular and molecular mechanisms of various biological events. Virus-mediated gene transfer or generation of transgenic animals is widely used; however, these methods are time-consuming and expensive. Here we show an improved electroporation technique for acute gene delivery into the adult mouse brain. Using a syringe-based microelectrode, local DNA injection and the application of electric current can be performed simultaneously; this allows rapid and efficient gene transduction of adult non-neuronal cells. Combining this technique with various expression vectors that carry specific promoters resulted in targeted gene expression in astrocytic cells. Our results constitute a powerful strategy for the genetic manipulation of adult brains in a spatio-temporally controlled manner. PMID:27430903

  5. Histology and Ultrastructure of Transitional Changes in Skin Morphology in the Juvenile and Adult Four-Striped Mouse (Rhabdomys pumilio)

    PubMed Central

    Stewart, Eranée; Ajao, Moyosore Salihu

    2013-01-01

    The four-striped mouse has a grey to brown coloured coat with four characteristic dark stripes interspersed with three lighter stripes running along its back. The histological differences in the skin of the juvenile and adult mouse were investigated by Haematoxylin and Eosin and Masson Trichrome staining, while melanocytes in the skin were studied through melanin-specific Ferro-ferricyanide staining. The ultrastructure of the juvenile skin, hair follicles, and melanocytes was also explored. In both the juvenile and adult four-striped mouse, pigment-containing cells were observed in the dermis and were homogeneously dispersed throughout this layer. Apart from these cells, the histology of the skin of the adult four-striped mouse was similar to normal mammalian skin. In the juvenile four-striped mouse, abundant hair follicles of varying sizes were observed in the dermis and hypodermis, while hair follicles of similar size were only present in the dermis of adult four-striped mouse. Ultrastructural analysis of juvenile hair follicles revealed that the arrangement and differentiation of cellular layers were typical of a mammal. This study therefore provides unique transition pattern in the four-striped mouse skin morphology different from the textbook description of the normal mammalian skin. PMID:24288469

  6. Kinetics and genomic profiling of adult human and mouse β-cell maturation.

    PubMed

    Szabat, Marta; Pourghaderi, Poya; Soukhatcheva, Galina; Verchere, C Bruce; Warnock, Garth L; Piret, James M; Johnson, James D

    2011-01-01

    Diabetes is a multifactorial metabolic disorder defined by the loss of functional pancreatic insulin-producing β-cells. The functional maturation and dedifferentiation of adult β-cells is central to diabetes pathogenesis and to β-cell replacement therapy for the treatment of diabetes. Despite its importance, the dynamics and mechanisms of adult β-cell maturation remain poorly understood. Using a novel Pdx1/Ins1 dual fluorescent reporter lentiviral vector, we previously found that individual adult human and mouse β-cells exist in at least two differentiation states distinguishable by the activation of the rat Ins1 promoter and performed the first real-time imaging of the maturation of individual cultured β-cells. Our previous study focused on transformed (MIN6) β-cells as a model to investigatethe kinetics of β-cell maturation. In the present study, we investigated the kinetics of the maturation process in primary human and mouse β-cells and performed gene expression profiling. Gene expression profiling of FACS purified immature Pdx1 (+) /Ins1 (low) cells and mature Pdx1 (high) /Ins1 (high ) cells from cultures of human islets, mouse islets and MIN6 cells revealed that Pdx1 (+) /Ins1 (low) cells are enriched for multiple genes associated with β-cell development/progenitor cells, proliferation, apoptosis, as well as genes coding for other islet cell hormones such as glucagon. We also demonstrated that the heterogeneity in β-cell maturation states previously observed in vitro, can also be found in vivo. Collectively, these experiments contribute to the understanding of maturation, dedifferentiation and plasticity of adult pancreatic β-cells. The results have significant implications for islet regeneration and for in vitro generation of functional β-cells to treat diabetes. PMID:21633187

  7. Sertoli Cells Maintain Leydig Cell Number and Peritubular Myoid Cell Activity in the Adult Mouse Testis

    PubMed Central

    Monteiro, Ana; Milne, Laura; Cruickshanks, Lyndsey; Jeffrey, Nathan; Guillou, Florian; Freeman, Tom C.; Mitchell, Rod T.; Smith, Lee B.

    2014-01-01

    The Sertoli cells are critical regulators of testis differentiation and development. In the adult, however, their known function is restricted largely to maintenance of spermatogenesis. To determine whether the Sertoli cells regulate other aspects of adult testis biology we have used a novel transgenic mouse model in which Amh-Cre induces expression of the receptor for Diphtheria toxin (iDTR) specifically within Sertoli cells. This causes controlled, cell-specific and acute ablation of the Sertoli cell population in the adult animal following Diphtheria toxin injection. Results show that Sertoli cell ablation leads to rapid loss of all germ cell populations. In addition, adult Leydig cell numbers decline by 75% with the remaining cells concentrated around the rete and in the sub-capsular region. In the absence of Sertoli cells, peritubular myoid cell activity is reduced but the cells retain an ability to exclude immune cells from the seminiferous tubules. These data demonstrate that, in addition to support of spermatogenesis, Sertoli cells are required in the adult testis both for retention of the normal adult Leydig cell population and for support of normal peritubular myoid cell function. This has implications for our understanding of male reproductive disorders and wider androgen-related conditions affecting male health. PMID:25144714

  8. Light Scattering Properties Vary across Different Regions of the Adult Mouse Brain

    PubMed Central

    Stubblefield, Elizabeth A.; Felsen, Gidon

    2013-01-01

    Recently developed optogenetic tools provide powerful approaches to optically excite or inhibit neural activity. In a typical in-vivo experiment, light is delivered to deep nuclei via an implanted optical fiber. Light intensity attenuates with increasing distance from the fiber tip, determining the volume of tissue in which optogenetic proteins can successfully be activated. However, whether and how this volume of effective light intensity varies as a function of brain region or wavelength has not been systematically studied. The goal of this study was to measure and compare how light scatters in different areas of the mouse brain. We delivered different wavelengths of light via optical fibers to acute slices of mouse brainstem, midbrain and forebrain tissue. We measured light intensity as a function of distance from the fiber tip, and used the data to model the spread of light in specific regions of the mouse brain. We found substantial differences in effective attenuation coefficients among different brain areas, which lead to substantial differences in light intensity demands for optogenetic experiments. The use of light of different wavelengths additionally changes how light illuminates a given brain area. We created a brain atlas of effective attenuation coefficients of the adult mouse brain, and integrated our data into an application that can be used to estimate light scattering as well as required light intensity for optogenetic manipulation within a given volume of tissue. PMID:23874433

  9. Redox regulation of cardiomyocyte cell cycling via an ERK1/2 and c-Myc-dependent activation of cyclin D2 transcription

    PubMed Central

    Murray, Thomas V.A.; Smyrnias, Ioannis; Schnelle, Moritz; Mistry, Rajesh K.; Zhang, Min; Beretta, Matteo; Martin, Daniel; Anilkumar, Narayana; de Silva, Shana M.; Shah, Ajay M.; Brewer, Alison C.

    2015-01-01

    Adult mammalian cardiomyocytes have a very limited capacity to proliferate, and consequently the loss of cells after cardiac stress promotes heart failure. Recent evidence suggests that administration of hydrogen peroxide (H2O2), can regulate redox-dependent signalling pathway(s) to promote cardiomyocyte proliferation in vitro, but the potential relevance of such a pathway in vivo has not been tested. We have generated a transgenic (Tg) mouse model in which the H2O2-generating enzyme, NADPH oxidase 4 (Nox4), is overexpressed within the postnatal cardiomyocytes, and observed that the hearts of 1–3 week old Tg mice pups are larger in comparison to wild type (Wt) littermate controls. We demonstrate that the cardiomyocytes of Tg mouse pups have increased cell cycling capacity in vivo as determined by incorporation of 5-bromo-2′-deoxyuridine. Further, microarray analyses of the transcriptome of these Tg mouse hearts suggested that the expression of cyclin D2 is significantly increased. We investigated the molecular mechanisms which underlie this more proliferative phenotype in isolated neonatal rat cardiomyocytes (NRCs) in vitro, and demonstrate that Nox4 overexpression mediates an H2O2-dependent activation of the ERK1/2 signalling pathway, which in turn phosphorylates and activates the transcription factor c-myc. This results in a significant increase in cyclin D2 expression, which we show to be mediated, at least in part, by cis-acting c-myc binding sites within the proximal cyclin D2 promoter. Overexpression of Nox4 in NRCs results in an increase in their proliferative capacity that is ablated by the silencing of cyclin D2. We further demonstrate activation of the ERK1/2 signalling pathway, increased phosphorylation of c-myc and significantly increased expression of cyclin D2 protein in the Nox4 Tg hearts. We suggest that this pathway acts to maintain the proliferative capacity of cardiomyocytes in Nox4 Tg pups in vivo and so delays their exit from the cell

  10. Genetics of Cardiac Developmental Disorders: Cardiomyocyte Proliferation and Growth and Relevance to Heart Failure.

    PubMed

    Wilsbacher, Lisa; McNally, Elizabeth M

    2016-05-23

    Cardiac developmental disorders represent the most common of human birth defects, and anomalies in cardiomyocyte proliferation drive many of these disorders. This review highlights the molecular mechanisms of prenatal cardiac growth. Trabeculation represents the initial ventricular growth phase and is necessary for embryonic survival. Later in development, the bulk of the ventricular wall derives from the compaction process, yet the arrest of this process can still be compatible with life. Cardiomyocyte proliferation and growth form the basis of both trabeculation and compaction, and mouse models indicate that cardiomyocyte interactions with the surrounding environment are critical for these proliferative processes. The human genetics of left ventricular noncompaction cardiomyopathy suggest that cardiomyocyte cell-autonomous mechanisms contribute to the compaction process. Understanding the determinants of prenatal or early postnatal cardiomyocyte proliferation and growth provides critical information that identifies risk factors for cardiovascular disease, including heart failure and its associated complications of arrhythmias and thromboembolic events. PMID:26925501

  11. Ultrastructural analysis of adult mouse neocortex comparing aldehyde perfusion with cryo fixation

    PubMed Central

    Korogod, Natalya; Petersen, Carl CH; Knott, Graham W

    2015-01-01

    Analysis of brain ultrastructure using electron microscopy typically relies on chemical fixation. However, this is known to cause significant tissue distortion including a reduction in the extracellular space. Cryo fixation is thought to give a truer representation of biological structures, and here we use rapid, high-pressure freezing on adult mouse neocortex to quantify the extent to which these two fixation methods differ in terms of their preservation of the different cellular compartments, and the arrangement of membranes at the synapse and around blood vessels. As well as preserving a physiological extracellular space, cryo fixation reveals larger numbers of docked synaptic vesicles, a smaller glial volume, and a less intimate glial coverage of synapses and blood vessels compared to chemical fixation. The ultrastructure of mouse neocortex therefore differs significantly comparing cryo and chemical fixation conditions. DOI: http://dx.doi.org/10.7554/eLife.05793.001 PMID:26259873

  12. Ultrastructural analysis of adult mouse neocortex comparing aldehyde perfusion with cryo fixation.

    PubMed

    Korogod, Natalya; Petersen, Carl C H; Knott, Graham W

    2015-01-01

    Analysis of brain ultrastructure using electron microscopy typically relies on chemical fixation. However, this is known to cause significant tissue distortion including a reduction in the extracellular space. Cryo fixation is thought to give a truer representation of biological structures, and here we use rapid, high-pressure freezing on adult mouse neocortex to quantify the extent to which these two fixation methods differ in terms of their preservation of the different cellular compartments, and the arrangement of membranes at the synapse and around blood vessels. As well as preserving a physiological extracellular space, cryo fixation reveals larger numbers of docked synaptic vesicles, a smaller glial volume, and a less intimate glial coverage of synapses and blood vessels compared to chemical fixation. The ultrastructure of mouse neocortex therefore differs significantly comparing cryo and chemical fixation conditions. PMID:26259873

  13. ChIP-Seq analysis of the adult male mouse brain after developmental exposure to arsenic.

    PubMed

    Tyler, Christina R; Weber, Jessica A; Labrecque, Matthew; Hessinger, Justin M; Edwards, Jeremy S; Allan, Andrea M

    2015-12-01

    Exposure to the common environmental contaminant arsenic impacts the epigenetic landscape, including DNA methylation and histone modifications, of several cell types. Developmental arsenic exposure (DAE) increases acetylation and methylation of histone proteins and the protein expression of several chromatin-modifying enzymes in the dentate gyrus (DG) subregion of the adult male mouse brain [26]. To complement and support these data, ChIP-Seq analysis of DNA associated with trimethylation of histone 3 lysine 4 (H3K4me3) derived from the adult male DG after DAE was performed. DAE induced differential H3K4me3 enrichment on genes in pathways associated with cellular development and growth, cell death and survival, and neurological disorders, particularly as they relate to cancer, in the adult male brain. Comparison of H3K4me3 enrichment in controls revealed mechanisms that are potentially lacking in arsenic-exposed animals, including neurotransmission, neuronal growth and development, hormonal regulation, protein synthesis, and cellular homeostasis. New pathways impacted by arsenic include cytoskeleton organization, cell signaling, and potential disruption of immune function and warrant further investigation using this DAE paradigm in the mouse brain. PMID:26543888

  14. Survival of glucose phosphate isomerase null somatic cells and germ cells in adult mouse chimaeras.

    PubMed

    Keighren, Margaret A; Flockhart, Jean H; West, John D

    2016-01-01

    The mouse Gpi1 gene encodes the glycolytic enzyme glucose phosphate isomerase. Homozygous Gpi1(-/-) null mouse embryos die but a previous study showed that some homozygous Gpi1(-/-) null cells survived when combined with wild-type cells in fetal chimaeras. One adult female Gpi1(-/-)↔Gpi1(c/c) chimaera with functional Gpi1(-/-) null oocytes was also identified in a preliminary study. The aims were to characterise the survival of Gpi1(-/-) null cells in adult Gpi1(-/-)↔Gpi1(c/c) chimaeras and determine if Gpi1(-/-) null germ cells are functional. Analysis of adult Gpi1(-/-)↔Gpi1(c/c) chimaeras with pigment and a reiterated transgenic lineage marker showed that low numbers of homozygous Gpi1(-/-) null cells could survive in many tissues of adult chimaeras, including oocytes. Breeding experiments confirmed that Gpi1(-/-) null oocytes in one female Gpi1(-/-)↔Gpi1(c/c) chimaera were functional and provided preliminary evidence that one male putative Gpi1(-/-)↔Gpi1(c/c) chimaera produced functional spermatozoa from homozygous Gpi1(-/-) null germ cells. Although the male chimaera was almost certainly Gpi1(-/-)↔Gpi1(c/c), this part of the study is considered preliminary because only blood was typed for GPI. Gpi1(-/-) null germ cells should survive in a chimaeric testis if they are supported by wild-type Sertoli cells. It is also feasible that spermatozoa could bypass a block at GPI, but not blocks at some later steps in glycolysis, by using fructose, rather than glucose, as the substrate for glycolysis. Although chimaera analysis proved inefficient for studying the fate of Gpi1(-/-) null germ cells, it successfully identified functional Gpi1(-/-) null oocytes and revealed that some Gpi1(-/-) null cells could survive in many adult tissues. PMID:27103217

  15. Cardiomyocyte death in doxorubicin-induced cardiotoxicity

    PubMed Central

    Zhang, Yi-Wei; Shi, Jianjian; Li, Yuan-Jian; Wei, Lei

    2009-01-01

    SUMMARY Doxorubicin (DOX) is one of the most widely used and successful antitumor drugs, but its cumulative and dose-dependent cardiac toxicity has been the major concern of oncologists in cancer therapeutic practice for decades. With the increasing population of cancer survivals, there is a growing need to develop preventive strategies and effective therapies against DOX-induced cardiotoxicity, in particular, the late onset cardiomyopathy. Although intensive investigations on the DOX-induced cardiotoxicity have been continued for decades, the underlying mechanisms responsible for DOX-induced cardiotoxicity have not been completely elucidated. A rapidly expanding body of evidence supports that cardiomyocyte death by apoptosis and necrosis is a primary mechanism of DOX-induced cardiomyopathy and other types of cell death, such as autophagy and senescence/aging, may participate in this process. In this review, we will focus on the current understanding of molecular mechanisms underlying DOX-induced cardiomyocyte death, including the major primary mechanism of excess production of reactive oxygen species (ROS) and other recently discovered ROS-independent mechanisms. Different sensitivity to DOX-induced cell death signals between adult and young cardiomyocytes will also be discussed. PMID:19866340

  16. Glucocorticoid signaling in the heart: A cardiomyocyte perspective.

    PubMed

    Oakley, Robert H; Cidlowski, John A

    2015-09-01

    Heart failure is one of the leading causes of death in the Western world. Glucocorticoids are primary stress hormones that regulate a vast array of biological processes, and synthetic derivatives of these steroids have been mainstays in the clinic for the last half century. Abnormal levels of glucocorticoids are known to negatively impact the cardiovascular system; however, surprisingly little is known about the direct role of glucocorticoid signaling in the heart. The actions of glucocorticoids are mediated classically by the glucocorticoid receptor (GR). In certain cells, such as cardiomyocytes, glucocorticoid occupancy and activation of the mineralocorticoid receptor (MR) may also contribute to the observed response. Recently, there has been a surge of reports investigating the in vivo function of glucocorticoid signaling in the heart using transgenic mice that specifically target GR or MR in cardiomyocytes. Results from these studies suggest that GR signaling in cardiomyocytes is critical for the normal development and function of the heart. In contrast, MR signaling in cardiomyocytes participates in the development and progression of cardiac disease. In the following review, we discuss these genetic mouse models and the new insights they are providing into the direct role cardiomyocyte glucocorticoid signaling plays in heart physiology and pathophysiology. This article is part of a Special Issue entitled 'Steroid Perspectives'. PMID:25804222

  17. Profilin modulates sarcomeric organization and mediates cardiomyocyte hypertrophy

    PubMed Central

    Kooij, Viola; Viswanathan, Meera C.; Lee, Dong I.; Rainer, Peter P.; Schmidt, William; Kronert, William A.; Harding, Sian E.; Kass, David A.; Bernstein, Sanford I.; Van Eyk, Jennifer E.; Cammarato, Anthony

    2016-01-01

    Aims Heart failure is often preceded by cardiac hypertrophy, which is characterized by increased cell size, altered protein abundance, and actin cytoskeletal reorganization. Profilin is a well-conserved, ubiquitously expressed, multifunctional actin-binding protein, and its role in cardiomyocytes is largely unknown. Given its involvement in vascular hypertrophy, we aimed to test the hypothesis that profilin-1 is a key mediator of cardiomyocyte-specific hypertrophic remodelling. Methods and results Profilin-1 was elevated in multiple mouse models of hypertrophy, and a cardiomyocyte-specific increase of profilin in Drosophila resulted in significantly larger heart tube dimensions. Moreover, adenovirus-mediated overexpression of profilin-1 in neonatal rat ventricular myocytes (NRVMs) induced a hypertrophic response, measured by increased myocyte size and gene expression. Profilin-1 silencing suppressed the response in NRVMs stimulated with phenylephrine or endothelin-1. Mechanistically, we found that profilin-1 regulates hypertrophy, in part, through activation of the ERK1/2 signalling cascade. Confocal microscopy showed that profilin localized to the Z-line of Drosophila myofibrils under normal conditions and accumulated near the M-line when overexpressed. Elevated profilin levels resulted in elongated sarcomeres, myofibrillar disorganization, and sarcomeric disarray, which correlated with impaired muscle function. Conclusion Our results identify novel roles for profilin as an important mediator of cardiomyocyte hypertrophy. We show that overexpression of profilin is sufficient to induce cardiomyocyte hypertrophy and sarcomeric remodelling, and silencing of profilin attenuates the hypertrophic response. PMID:26956799

  18. Cathepsin B-dependent motor neuron death after nerve injury in the adult mouse

    SciTech Connect

    Sun, Li; Wu, Zhou; Baba, Masashi; Peters, Christoph; Uchiyama, Yasuo; Nakanishi, Hiroshi

    2010-08-27

    Research highlights: {yields} Cathepsin B (CB), a lysosomal cysteine protease, is expressed in neuron and glia. {yields} CB increased in hypogrossal nucleus neurons after nerve injury in adult mice. {yields} CB-deficiency significantly increased the mean survival ratio of injured neurons. {yields} Thus, CB plays a critical role in axotomy-induced neuronal death in adult mice. -- Abstract: There are significant differences in the rate of neuronal death after peripheral nerve injury between species. The rate of neuronal death of motor neurons after nerve injury in the adult rats is very low, whereas that in adult mice is relatively high. However, the understanding of the mechanism underlying axotomy-induced motor neuron death in adult mice is limited. Cathepsin B (CB), a typical cysteine lysosomal protease, has been implicated in three major morphologically distinct pathways of cell death; apoptosis, necrosis and autophagic cell death. The possible involvement of CB in the neuronal death of hypogrossal nucleus (HGN) neurons after nerve injury in adult mice was thus examined. Quantitative analyses showed the mean survival ratio of HGN neurons in CB-deficient (CB-/-) adult mice after nerve injury was significantly greater than that in the wild-type mice. At the same time, proliferation of microglia in the injured side of the HGN of CB-/- adult mice was markedly reduced compared with that in the wild-type mice. On the injured side of the HGN in the wild-type adult mice, both pro- and mature forms of CB markedly increased in accordance with the increase in the membrane-bound form of LC3 (LC3-II), a marker protein of autophagy. Furthermore, the increase in CB preceded an increase in the expression of Noxa, a major executor for axotomy-induced motor neuron death in the adult mouse. Conversely, expression of neither Noxa or LC3-II was observed in the HGN of adult CB-/- mice after nerve injury. These observations strongly suggest that CB plays a critical role in axotomy

  19. Regrowth of Serotonin Axons in the Adult Mouse Brain Following Injury.

    PubMed

    Jin, Yunju; Dougherty, Sarah E; Wood, Kevin; Sun, Landy; Cudmore, Robert H; Abdalla, Aya; Kannan, Geetha; Pletnikov, Mikhail; Hashemi, Parastoo; Linden, David J

    2016-08-17

    It is widely believed that damaged axons in the adult mammalian brain have little capacity to regrow, thereby impeding functional recovery after injury. Studies using fixed tissue have suggested that serotonin neurons might be a notable exception, but remain inconclusive. We have employed in vivo two-photon microscopy to produce time-lapse images of serotonin axons in the neocortex of the adult mouse. Serotonin axons undergo massive retrograde degeneration following amphetamine treatment and subsequent slow recovery of axonal density, which is dominated by new growth with little contribution from local sprouting. A stab injury that transects serotonin axons running in the neocortex is followed by local regression of cut serotonin axons and followed by regrowth from cut ends into and across the stab rift zone. Regrowing serotonin axons do not follow the pathways left by degenerated axons. The regrown axons release serotonin and their regrowth is correlated with recovery in behavioral tests. PMID:27499084

  20. Postnatal telomere dysfunction induces cardiomyocyte cell-cycle arrest through p21 activation.

    PubMed

    Aix, Esther; Gutiérrez-Gutiérrez, Óscar; Sánchez-Ferrer, Carlota; Aguado, Tania; Flores, Ignacio

    2016-06-01

    The molecular mechanisms that drive mammalian cardiomyocytes out of the cell cycle soon after birth remain largely unknown. Here, we identify telomere dysfunction as a critical physiological signal for cardiomyocyte cell-cycle arrest. We show that telomerase activity and cardiomyocyte telomere length decrease sharply in wild-type mouse hearts after birth, resulting in cardiomyocytes with dysfunctional telomeres and anaphase bridges and positive for the cell-cycle arrest protein p21. We further show that premature telomere dysfunction pushes cardiomyocytes out of the cell cycle. Cardiomyocytes from telomerase-deficient mice with dysfunctional telomeres (G3 Terc(-/-)) show precocious development of anaphase-bridge formation, p21 up-regulation, and binucleation. In line with these findings, the cardiomyocyte proliferative response after cardiac injury was lost in G3 Terc(-/-) newborns but rescued in G3 Terc(-/-)/p21(-/-) mice. These results reveal telomere dysfunction as a crucial signal for cardiomyocyte cell-cycle arrest after birth and suggest interventions to augment the regeneration capacity of mammalian hearts. PMID:27241915

  1. Expression of Quaking RNA-Binding Protein in the Adult and Developing Mouse Retina

    PubMed Central

    Aono, Kentaro; Kawashima, Togo; Inoue, Kiyoshi; Ku, Li; Feng, Yue; Koike, Chieko

    2016-01-01

    Quaking (QKI), which belongs to the STAR family of KH domain-containing RNA-binding proteins, functions in pre-mRNA splicing, microRNA regulation, and formation of circular RNA. QKI plays critical roles in myelinogenesis in the central and peripheral nervous systems and has been implicated neuron-glia fate decision in the brain; however, neither the expression nor function of QKI in the neural retina is known. Here we report the expression of QKI RNA-binding protein in the developing and mature mouse retina. QKI was strongly expressed by Müller glial cells in both the developing and adult retina. Intriguingly, during development, QKI was expressed in early differentiating neurons, such as the horizontal and amacrine cells, and subsequently in later differentiating bipolar cells, but not in photoreceptors. Neuronal expression was uniformly weak in the adult. Among QKI isoforms (5, 6, and 7), QKI-5 was the predominantly expressed isoform in the adult retina. To study the function of QKI in the mouse retina, we examined quakingviable(qkv) mice, which have a dysmyelination phenotype that results from deficiency of QKI expression and reduced numbers of mature oligodendrocytes. In homozygous qkv mutant mice (qkv/qkv), the optic nerve expression levels of QKI-6 and 7, but not QKI-5 were reduced. In the retina of the mutant homozygote, QKI-5 levels were unchanged, and QKI-6 and 7 levels, already low, were also unaffected. We conclude that QKI is expressed in developing and adult Müller glia. QKI is additionally expressed in progenitors and in differentiating neurons during retinal development, but expression weakened or diminished during maturation. Among QKI isoforms, we found that QKI-5 predominated in the adult mouse retina. Since Müller glial cells are thought to share properties with retinal progenitor cells, our data suggest that QKI may contribute to maintaining retinal progenitors prior to differentiation into neurons. On the other hand, the expression of QKI in

  2. Deficiency in the mouse mitochondrial adenine nucleotide translocator isoform 2 gene is associated with cardiac noncompaction.

    PubMed

    Kokoszka, Jason E; Waymire, Katrina G; Flierl, Adrian; Sweeney, Katelyn M; Angelin, Alessia; MacGregor, Grant R; Wallace, Douglas C

    2016-08-01

    The mouse fetal and adult hearts express two adenine nucleotide translocator (ANT) isoform genes. The predominant isoform is the heart-muscle-brain ANT-isoform gene 1 (Ant1) while the other is the systemic Ant2 gene. Genetic inactivation of the Ant1 gene does not impair fetal development but results in hypertrophic cardiomyopathy in postnatal mice. Using a knockin X-linked Ant2 allele in which exons 3 and 4 are flanked by loxP sites combined in males with a protamine 1 promoter driven Cre recombinase we created females heterozygous for a null Ant2 allele. Crossing the heterozygous females with the Ant2(fl), PrmCre(+) males resulted in male and female ANT2-null embryos. These fetuses proved to be embryonic lethal by day E14.5 in association with cardiac developmental failure, immature cardiomyocytes having swollen mitochondria, cardiomyocyte hyperproliferation, and cardiac failure due to hypertrabeculation/noncompaction. ANTs have two main functions, mitochondrial-cytosol ATP/ADP exchange and modulation of the mitochondrial permeability transition pore (mtPTP). Previous studies imply that ANT2 biases the mtPTP toward closed while ANT1 biases the mtPTP toward open. It has been reported that immature cardiomyocytes have a constitutively opened mtPTP, the closure of which signals the maturation of cardiomyocytes. Therefore, we hypothesize that the developmental toxicity of the Ant2 null mutation may be the result of biasing the cardiomyocyte mtPTP to remain open thus impairing cardiomyocyte maturation and resulting in cardiomyocyte hyperproliferation and failure of trabecular maturation. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. PMID:27048932

  3. Distribution of EphA5 receptor protein in the developing and adult mouse nervous system

    PubMed Central

    Cooper, Margaret A.; Crockett, David P.; Nowakowski, Richard S.; Gale, Nicholas W.; Zhou, Renping

    2009-01-01

    The EphA5 receptor tyrosine kinase plays key roles in axon guidance during development. However, the presence of EphA5 protein in the nervous system has not been fully characterized. To better examine EphA5 localization, mutant mice, in which the EphA5 cytoplasmic domain was replaced with β-galactosidase, were analyzed for both temporal and regional changes in the distribution of EphA5 protein in the developing and adult nervous system. During embryonic development, high levels of EphA5 protein were found in the retina, olfactory bulb, cerebral neocortex, hippocampus, pretectum, tectum, cranial nerve nuclei, and the spinal cord. Variations in intensity were observed as development proceeded. Staining of pretectal nuclei, tectal nuclei, and other areas of the mesencephalon became more diffuse after maturity whereas the cerebral neocortex gained more robust intensity. In the adult, receptor protein continued to be detected in many areas including the olfactory nuclei, neocortex, piriform cortex, induseum griseum, hippocampus, thalamus, amygdala, hypothalamus and septum. In addition, EphA5 protein was found in the claustrum, stria terminalis, barrel cortex, striatal patches, and along discrete axon tracts within the corpus callosum of the adult. These observations suggest that EphA5 function is not limited to the developing mouse brain and may play a role in synaptic plasticity in the adult. PMID:19326470

  4. Sexually dimorphic effect of in vitro fertilization (IVF) on adult mouse fat and liver metabolomes.

    PubMed

    Feuer, Sky K; Donjacour, Annemarie; Simbulan, Rhodel K; Lin, Wingka; Liu, Xiaowei; Maltepe, Emin; Rinaudo, Paolo F

    2014-11-01

    The preimplantation embryo is particularly vulnerable to environmental perturbation, such that nutritional and in vitro stresses restricted exclusively to this stage may alter growth and affect long-term metabolic health. This is particularly relevant to the over 5 million children conceived by in vitro fertilization (IVF). We previously reported that even optimized IVF conditions reprogram mouse postnatal growth, fat deposition, and glucose homeostasis in a sexually dimorphic fashion. To more clearly interrogate the metabolic changes associated with IVF in adulthood, we used nontargeted mass spectrometry to globally profile adult IVF- and in vivo-conceived liver and gonadal adipose tissues. There was a sex- and tissue-specific effect of IVF on adult metabolite signatures indicative of metabolic reprogramming and oxidative stress and reflective of the observed phenotypes. Additionally, we observed a striking effect of IVF on adult sexual dimorphism. Male-female differences in metabolite concentration were exaggerated in hepatic IVF tissue and significantly reduced in IVF adipose tissue, with the majority of changes affecting amino acid and lipid metabolites. We also observed female-specific changes in markers of oxidative stress and adipogenesis, including reduced glutathione, cysteine glutathione disulfide, ophthalmate, urate, and corticosterone. In summary, embryo manipulation and early developmental experiences can affect adult patterns of sexual dimorphism and metabolic physiology. PMID:25211591

  5. Molecular mechanisms of cardiomyocyte regeneration and therapeutic outlook.

    PubMed

    Germani, Antonia; Di Rocco, Giuliana; Limana, Federica; Martelli, Fabio; Capogrossi, Maurizio C

    2007-03-01

    Differently from some lower vertebrates, which can completely regenerate their heart, in higher vertebrates cardiac injury generally leads to progressive failure. Induction of cycle re-entry in terminally differentiated cardiomyocytes and stem-cell transplantation are strategies to increase the regenerative potential of the heart. As experimental and clinical studies progress, demonstrating that adult stem-cell administration has a favorable impact on myocardial function, the identification of cardiac stem cells suggests that some endogenous repair mechanisms actually exist in the mammalian heart. However, a deeper understanding of the mechanism that drives cardiomyocyte proliferation and stem-cell-mediated cardiac repair is required to translate such strategies into effective therapies. PMID:17257896

  6. Establishment of Leptin-Responsive Cell Lines from Adult Mouse Hypothalamus

    PubMed Central

    Iwakura, Hiroshi; Dote, Katsuko; Bando, Mika; Koyama, Hiroyuki; Hosoda, Kiminori; Kangawa, Kenji; Nakao, Kazuwa

    2016-01-01

    Leptin resistance is considered to be the primary cause of obesity. However, the cause of leptin resistance remains incompletely understood, and there is currently no cure for the leptin-resistant state. In order to identify novel drug-target molecules that could overcome leptin resistance, it would be useful to develop in vitro assay systems for evaluating leptin resistance. In this study, we established immortalized adult mouse hypothalamus—derived cell lines, termed adult mouse hypothalamus (AMH) cells, by developing transgenic mice in which SV40 Tag was overexpressed in chromogranin A—positive cells in a tamoxifen-dependent manner. In order to obtain leptin-responsive clones, we selected clones based on the phosphorylation levels of STAT3 induced by leptin. The selected clones were fairly responsive to leptin in terms of STAT3, ERK, and Akt phosphorylation and induction of c-Fos mRNA induction. Pretreatment with leptin, insulin, and palmitate attenuated the c-Fos mRNA response to leptin, suggesting that certain aspects of leptin resistance might be reconstituted in this cellular model. These cell lines are useful tools for understanding the molecular nature of the signal disturbance in the leptin-resistant state and for identifying potential target molecules for drugs that relieve leptin resistance, although they have drawbacks including de-differentiated nature and lack of long-time stability. PMID:26849804

  7. Caspase-Mediated Apoptosis in Sensory Neurons of Cultured Dorsal Root Ganglia in Adult Mouse

    PubMed Central

    Momeni, Hamid Reza; Soleimani Mehranjani, Malek; Shariatzadeh, Mohammad Ali; Haddadi, Mahnaz

    2013-01-01

    Objective: Sensory neurons in dorsal root ganglia (DRG) undergo apoptosis after peripheral nerve injury. The aim of this study was to investigate sensory neuron death and the mechanism involved in the death of these neurons in cultured DRG. Materials and Methods: In this experimental study, L5 DRG from adult mouse were dissected and incubated in culture medium for 24, 48, 72 and 96 hours. Freshly dissected and cultured DRG were then fixed and sectioned using a cryostat. Morphological and biochemical features of apoptosis were investigated using fluorescent staining (Propidium iodide and Hoechst 33342) and the terminal Deoxynucleotide transferase dUTP nick end labeling (TUNEL) method respectively. To study the role of caspases, general caspase inhibitor (Z-VAD.fmk, 100 μM) and immunohistochemistry for activated caspase-3 were used. Results: After 24, 48, 72 and 96 hours in culture, sensory neurons not only displayed morphological features of apoptosis but also they appeared TUNEL positive. The application of Z-VAD.fmk inhibited apoptosis in these neurons over the same time period. In addition, intense activated caspase-3 immunoreactivity was found both in the cytoplasm and the nuclei of these neurons after 24 and 48 hours. Conclusion: Results of the present study show caspase-dependent apoptosis in the sensory neurons of cultured DRG from adult mouse. PMID:24027661

  8. The electrophysiological development of cardiomyocytes.

    PubMed

    Liu, Jie; Laksman, Zachary; Backx, Peter H

    2016-01-15

    The generation of human cardiomyocytes (CMs) from human pluripotent stem cells (hPSCs) has become an important resource for modeling human cardiac disease and for drug screening, and also holds significant potential for cardiac regeneration. Many challenges remain to be overcome however, before innovation in this field can translate into a change in the morbidity and mortality associated with heart disease. Of particular importance for the future application of this technology is an improved understanding of the electrophysiologic characteristics of CMs, so that better protocols can be developed and optimized for generating hPSC-CMs. Many different cell culture protocols are currently utilized to generate CMs from hPSCs and all appear to yield relatively “developmentally” immature CMs with highly heterogeneous electrical properties. These hPSC-CMs are characterized by spontaneous beating at highly variable rates with a broad range of depolarization-repolarization patterns, suggestive of mixed populations containing atrial, ventricular and nodal cells. Many recent studies have attempted to introduce approaches to promote maturation and to create cells with specific functional properties. In this review, we summarize the studies in which the electrical properties of CMs derived from stem cells have been examined. In order to place this information in a useful context, we also review the electrical properties of CMs as they transition from the developing embryo to the adult human heart. The signal pathways involved in the regulation of ion channel expression during development are also briefly considered. PMID:26788696

  9. Cardiac regenerative potential of cardiosphere-derived cells from adult dog hearts

    PubMed Central

    Hensley, Michael Taylor; de Andrade, James; Keene, Bruce; Meurs, Kathryn; Tang, Junnan; Wang, Zegen; Caranasos, Thomas G; Piedrahita, Jorge; Li, Tao-Sheng; Cheng, Ke

    2015-01-01

    The regenerative potential of cardiosphere-derived cells (CDCs) for ischaemic heart disease has been demonstrated in mice, rats, pigs and a recently completed clinical trial. The regenerative potential of CDCs from dog hearts has yet to be tested. Here, we show that canine CDCs can be produced from adult dog hearts. These cells display similar phenotypes in comparison to previously studied CDCs derived from rodents and human beings. Canine CDCs can differentiate into cardiomyocytes, smooth muscle cells and endothelial cells in vitro. In addition, conditioned media from canine CDCs promote angiogenesis but inhibit cardiomyocyte death. In a doxorubicin-induced mouse model of dilated cardiomyopathy (DCM), intravenous infusion of canine CDCs improves cardiac function and decreases cardiac fibrosis. Histology revealed that injected canine CDCs engraft in the mouse heart and increase capillary density. Out study demonstrates the regenerative potential of canine CDCs in a mouse model of DCM. PMID:25854418

  10. Isolation of Cardiomyocytes and Cardiofibroblasts for Ex Vivo Analysis.

    PubMed

    Mbogo, George Williams; Nedeva, Christina; Puthalakath, Hamsa

    2016-01-01

    Heart failure (HF) is a common clinical endpoint to several underlying causes including aging, hypertension, stress, and cardiomyopathy. It is characterized by a significant decline in the cardiac output. Cardiomyocytes are terminally differentiated cells and therefore, apoptotic death due to beta adrenergic (β-AR) signaling contributes to high attrition rate of these cells. Past treatments of HF offer some survival benefit to patients (e.g., the beta blockers), but at the expense of blocking the compensatory beta-adrenergic signaling in surviving cells. One prerequisite for developing new therapeutics is to be able to grow cardiomyocytes ex vivo, and test their apoptotic response to drugs. Here we describe methods for isolation and culturing of neonatal and adult calcium tolerant cardiomyocytes. Similarly, cardiofibroblasts can also be isolated using the same protocol and subsequently, immortalized with SV40 T-Antigen for ex vivo studies. PMID:27108436

  11. Determinants of cardiomyocyte development in long-term primary culture.

    PubMed

    Piper, H M; Jacobson, S L; Schwartz, P

    1988-09-01

    The influence of cell attachment to substrates and of medium composition on development of cardiomyocytes from adult rats in cultures up to 9 days old was investigated. Cardiomyocytes prevented from attaching to a culture substratum deteriorated within 3 days in medium 199 (M199) with or without fetal calf serum (FCS). Rapid attachment during the first 4 h after plating could be attained equally well on FCS or laminin coated surfaces. In M199 without FCS, attached cardiomyocytes on FCS coated dishes were able to retain their overall elongated morphology, but the number of cells remaining attached constantly decreased during the first 9 days in serum free culture. Attached on laminin the rate of loss from serum free cultures was lower. In the presence of 20% FCS, attached cardiomyocytes spread extensively after day 3, both on FCS and on laminin coated dishes. In serum containing media many cells pass through a spherical intermediate state before spreading extensively. Almost all cardiomyocytes cultured with 20% FCS on untreated tissue culture plastic gradually become spherical before attaching. With 20% FCS in culture media, the number of cells remaining in culture after 9 days was similar whether cells were rapidly attached to FCS treated or laminin coated substrata, or were plated on culture plastic, i.e., 52, 63, and 45% of the maximal number attached on day 1. By day 9 in all three culture types cells were spread and were beating spontaneously. These results indicate that adult cardiomyocytes do not establish in a stable morphological state in long-term cultures, in other than a surface attached spread cell form. For this stability the presence of yet unidentified components of fetal calf serum is required. PMID:3230587

  12. Survival of glucose phosphate isomerase null somatic cells and germ cells in adult mouse chimaeras

    PubMed Central

    Keighren, Margaret A.; Flockhart, Jean H.

    2016-01-01

    ABSTRACT The mouse Gpi1 gene encodes the glycolytic enzyme glucose phosphate isomerase. Homozygous Gpi1−/− null mouse embryos die but a previous study showed that some homozygous Gpi1−/− null cells survived when combined with wild-type cells in fetal chimaeras. One adult female Gpi1−/−↔Gpi1c/c chimaera with functional Gpi1−/− null oocytes was also identified in a preliminary study. The aims were to characterise the survival of Gpi1−/− null cells in adult Gpi1−/−↔Gpi1c/c chimaeras and determine if Gpi1−/− null germ cells are functional. Analysis of adult Gpi1−/−↔Gpi1c/c chimaeras with pigment and a reiterated transgenic lineage marker showed that low numbers of homozygous Gpi1−/− null cells could survive in many tissues of adult chimaeras, including oocytes. Breeding experiments confirmed that Gpi1−/− null oocytes in one female Gpi1−/−↔Gpi1c/c chimaera were functional and provided preliminary evidence that one male putative Gpi1−/−↔Gpi1c/c chimaera produced functional spermatozoa from homozygous Gpi1−/− null germ cells. Although the male chimaera was almost certainly Gpi1−/−↔Gpi1c/c, this part of the study is considered preliminary because only blood was typed for GPI. Gpi1−/− null germ cells should survive in a chimaeric testis if they are supported by wild-type Sertoli cells. It is also feasible that spermatozoa could bypass a block at GPI, but not blocks at some later steps in glycolysis, by using fructose, rather than glucose, as the substrate for glycolysis. Although chimaera analysis proved inefficient for studying the fate of Gpi1−/− null germ cells, it successfully identified functional Gpi1−/− null oocytes and revealed that some Gpi1−/− null cells could survive in many adult tissues. PMID:27103217

  13. Localization and regulation of PML bodies in the adult mouse brain.

    PubMed

    Hall, Małgorzata H; Magalska, Adriana; Malinowska, Monika; Ruszczycki, Błażej; Czaban, Iwona; Patel, Satyam; Ambrożek-Latecka, Magdalena; Zołocińska, Ewa; Broszkiewicz, Hanna; Parobczak, Kamil; Nair, Rajeevkumar R; Rylski, Marcin; Pawlak, Robert; Bramham, Clive R; Wilczyński, Grzegorz M

    2016-06-01

    PML is a tumor suppressor protein involved in the pathogenesis of promyelocytic leukemia. In non-neuronal cells, PML is a principal component of characteristic nuclear bodies. In the brain, PML has been implicated in the control of embryonic neurogenesis, and in certain physiological and pathological phenomena in the adult brain. Yet, the cellular and subcellular localization of the PML protein in the brain, including its presence in the nuclear bodies, has not been investigated comprehensively. Because the formation of PML bodies appears to be a key aspect in the function of the PML protein, we investigated the presence of these structures and their anatomical distribution, throughout the adult mouse brain. We found that PML is broadly expressed across the gray matter, with the highest levels in the cerebral and cerebellar cortices. In the cerebral cortex PML is present exclusively in neurons, in which it forms well-defined nuclear inclusions containing SUMO-1, SUMO 2/3, but not Daxx. At the ultrastructural level, the appearance of neuronal PML bodies differs from the classic one, i.e., the solitary structure with more or less distinctive capsule. Rather, neuronal PML bodies have the form of small PML protein aggregates located in the close vicinity of chromatin threads. The number, size, and signal intensity of neuronal PML bodies are dynamically influenced by immobilization stress and seizures. Our study indicates that PML bodies are broadly involved in activity-dependent nuclear phenomena in adult neurons. PMID:25956166

  14. Clonal identification of multipotent precursors from adult mouse pancreas that generate neural and pancreatic lineages.

    PubMed

    Seaberg, Raewyn M; Smukler, Simon R; Kieffer, Timothy J; Enikolopov, Grigori; Asghar, Zeenat; Wheeler, Michael B; Korbutt, Gregory; van der Kooy, Derek

    2004-09-01

    The clonal isolation of putative adult pancreatic precursors has been an elusive goal of researchers seeking to develop cell replacement strategies for diabetes. We report the clonal identification of multipotent precursor cells from the adult mouse pancreas. The application of a serum-free, colony-forming assay to pancreatic cells enabled the identification of precursors from pancreatic islet and ductal populations. These cells proliferate in vitro to form clonal colonies that coexpress neural and pancreatic precursor markers. Upon differentiation, individual clonal colonies produce distinct populations of neurons and glial cells, pancreatic endocrine beta-, alpha- and delta-cells, and pancreatic exocrine and stellate cells. Moreover, the newly generated beta-like cells demonstrate glucose-dependent Ca(2+) responsiveness and insulin release. Pancreas colonies do not express markers of embryonic stem cells, nor genes suggestive of mesodermal or neural crest origins. These cells represent a previously unidentified adult intrinsic pancreatic precursor population and are a promising candidate for cell-based therapeutic strategies. PMID:15322557

  15. Growth Arrest Specific 1 (GAS1) Is Abundantly Expressed in the Adult Mouse Central Nervous System

    PubMed Central

    Zarco, Natanael; Bautista, Elizabeth; Cuéllar, Manola; Vergara, Paula; Flores-Rodriguez, Paola; Aguilar-Roblero, Raúl

    2013-01-01

    Growth arrest specific 1 (GAS1) is a pleiotropic protein that induces apoptosis and cell arrest in different tumors, but it is also involved in the development of the nervous system and other tissues and organs. This dual ability is likely caused by its capacity to interact both by inhibiting the intracellular signaling cascade induced by glial cell-line derived neurotrophic factor and by facilitating the activity of the sonic hedgehog pathway. The presence of GAS1 mRNA has been described in adult mouse brain, and here we corroborated this observation. We then proceeded to determine the distribution of the protein in the adult central nervous system (CNS). We detected, by western blot analysis, expression of GAS1 in olfactory bulb, caudate-putamen, cerebral cortex, hippocampus, mesencephalon, medulla oblongata, cerebellum, and cervical spinal cord. To more carefully map the expression of GAS1, we performed double-label immunohistochemistry and noticed expression of GAS1 in neurons in all brain areas examined. We also observed expression of GAS1 in astroglial cells, albeit the pattern of expression was more restricted than that seen in neurons. Briefly, in the present article, we report the widespread distribution and cellular localization of the GAS1 native protein in adult mammalian CNS. PMID:23813868

  16. Abca7 deletion does not affect adult neurogenesis in the mouse

    PubMed Central

    Li, Hongyun; Karl, Tim; Garner, Brett

    2016-01-01

    ATP-binding cassette transporter A7 (ABCA7) is highly expressed in the brain. Recent genome-wide association studies (GWAS) have identified ABCA7 single nucleotide polymorphisms (SNPs) that increase Alzheimer's disease (AD) risk, however, the mechanisms by which ABCA7 may control AD risk remain to be fully elucidated. Based on previous research suggesting that certain ABC transporters may play a role in the regulation of neurogenesis, we conducted a study of cell proliferation and neurogenic potential using cellular bromodeoxyuridine (BrdU) incorporation and doublecortin (DCX) immunostaining in adult Abca7 deficient mice and wild-type-like (WT) littermates. In the present study counting of BrdU-positive and DCX-positive cells in an established adult neurogenesis site in the dentate gyrus (DG) indicated there were no significant differences when WT and Abca7 deficient mice were compared. We also measured the area occupied by immunohistochemical staining for BrdU and DCX in the DG and the subventricular zone (SVZ) of the same mice and this confirmed that ABCA7 does not play a significant role in the regulation of cell proliferation or neurogenesis in the adult mouse. PMID:26792809

  17. Characterization of neural stem cells and their progeny in the sensory circumventricular organs of adult mouse.

    PubMed

    Furube, Eriko; Morita, Mitsuhiro; Miyata, Seiji

    2015-11-01

    Although evidence has accumulated that neurogenesis and gliogenesis occur in the subventricular zone (SVZ) and subgranular zone (SGZ) of adult mammalian brains, recent studies indicate the presence of neural stem cells (NSCs) in adult brains, particularly the circumventricular regions. In the present study, we aimed to determine characterization of NSCs and their progenitor cells in the sensory circumventricular organs (CVOs), including organum vasculosum of the lamina terminalis, subfornical organ, and area postrema of adult mouse. There were two types of NSCs: tanycyte-like ependymal cells and astrocyte-like cells. Astrocyte-like NSCs proliferated slowly and oligodendrocyte progenitor cells (OPCs) and neural progenitor cells (NPCs) actively divided. Molecular marker protein expression of NSCs and their progenitor cells were similar to those reported in the SVZ and SGZ, except that astrocyte-like NSCs expressed S100β. These circumventricular NSCs possessed the capacity to give rise to oligodendrocytes and sparse numbers of neurons and astrocytes in the sensory CVOs and adjacent brain regions. The inhibition of vascular endothelial growth factor (VEGF) signaling by using a VEGF receptor-associated tyrosine kinase inhibitor AZD2171 largely suppressed basal proliferation of OPCs. A single systemic administration of lipopolysaccharide attenuated proliferation of OPCs and induced remarkable proliferation of microglia. The present study indicates that sensory circumventricular NSCs provide new neurons and glial cells in the sensory CVOs and adjacent brain regions. PMID:25994374

  18. Abca7 deletion does not affect adult neurogenesis in the mouse.

    PubMed

    Li, Hongyun; Karl, Tim; Garner, Brett

    2016-01-01

    ATP-binding cassette transporter A7 (ABCA7) is highly expressed in the brain. Recent genome-wide association studies (GWAS) have identified ABCA7 single nucleotide polymorphisms (SNPs) that increase Alzheimer's disease (AD) risk, however, the mechanisms by which ABCA7 may control AD risk remain to be fully elucidated. Based on previous research suggesting that certain ABC transporters may play a role in the regulation of neurogenesis, we conducted a study of cell proliferation and neurogenic potential using cellular bromodeoxyuridine (BrdU) incorporation and doublecortin (DCX) immunostaining in adult Abca7 deficient mice and wild-type-like (WT) littermates. In the present study counting of BrdU-positive and DCX-positive cells in an established adult neurogenesis site in the dentate gyrus (DG) indicated there were no significant differences when WT and Abca7 deficient mice were compared. We also measured the area occupied by immunohistochemical staining for BrdU and DCX in the DG and the subventricular zone (SVZ) of the same mice and this confirmed that ABCA7 does not play a significant role in the regulation of cell proliferation or neurogenesis in the adult mouse. PMID:26792809

  19. Developmental alterations in centrosome integrity contribute to the post-mitotic state of mammalian cardiomyocytes

    PubMed Central

    Zebrowski, David C; Vergarajauregui, Silvia; Wu, Chi-Chung; Piatkowski, Tanja; Becker, Robert; Leone, Marina; Hirth, Sofia; Ricciardi, Filomena; Falk, Nathalie; Giessl, Andreas; Just, Steffen; Braun, Thomas; Weidinger, Gilbert; Engel, Felix B

    2015-01-01

    Mammalian cardiomyocytes become post-mitotic shortly after birth. Understanding how this occurs is highly relevant to cardiac regenerative therapy. Yet, how cardiomyocytes achieve and maintain a post-mitotic state is unknown. Here, we show that cardiomyocyte centrosome integrity is lost shortly after birth. This is coupled with relocalization of various centrosome proteins to the nuclear envelope. Consequently, postnatal cardiomyocytes are unable to undergo ciliogenesis and the nuclear envelope adopts the function as cellular microtubule organizing center. Loss of centrosome integrity is associated with, and can promote, cardiomyocyte G0/G1 cell cycle arrest suggesting that centrosome disassembly is developmentally utilized to achieve the post-mitotic state in mammalian cardiomyocytes. Adult cardiomyocytes of zebrafish and newt, which are able to proliferate, maintain centrosome integrity. Collectively, our data provide a novel mechanism underlying the post-mitotic state of mammalian cardiomyocytes as well as a potential explanation for why zebrafish and newts, but not mammals, can regenerate their heart. DOI: http://dx.doi.org/10.7554/eLife.05563.001 PMID:26247711

  20. From pluripotency to distinct cardiomyocyte subtypes.

    PubMed

    David, Robert; Franz, Wolfgang-Michael

    2012-06-01

    Differentiated adult cardiomyocytes (CMs) lack significant regenerative potential, which is one reason why degenerative heart diseases are the leading cause of death in the western world. For future cardiac repair, stem cell-based therapeutic strategies may become alternatives to donor heart transplantation. The principle of reprogramming adult terminally differentiated cells (iPSC) had a major impact on stem cell biology. One can now generate autologous pluripotent cells that highly resemble embryonic stem cells (ESC) and that are ethically inoffensive as opposed to human ESC. Yet, due to genetic and epigenetic aberrations arising during the full reprogramming process, it is questionable whether iPSC will enter the clinic in the near future. Therefore, the recent achievement of directly reprogramming fibroblasts into cardiomyocytes via a milder approach, thereby avoiding an initial pluripotent state, may become of great importance. In addition, various clinical scenarios will depend on the availability of specific cardiac cellular subtypes, for which a first step was achieved via our own programming approach to achieve cardiovascular cell subtypes. In this review, we discuss recent progress in the cardiovascular stem cell field addressing the above mentioned aspects. PMID:22689787

  1. MEF2D deficiency in neonatal cardiomyocytes triggers cell cycle re-entry and programmed cell death in vitro.

    PubMed

    Estrella, Nelsa L; Clark, Amanda L; Desjardins, Cody A; Nocco, Sarah E; Naya, Francisco J

    2015-10-01

    The cardiomyocyte cell cycle is a poorly understood process. Mammalian cardiomyocytes permanently withdraw from the cell cycle shortly after birth but can re-enter the cell cycle and proliferate when subjected to injury within a brief temporal window in the neonatal period. Thus, investigating the mechanisms of cell cycle regulation in neonatal cardiomyocytes may provide critical insight into the molecular events that prevent adult myocytes from proliferating in response to injury or stress. MEF2D is a key transcriptional mediator of pathological remodeling in the adult heart downstream of various stress-promoting insults. However, the specific gene programs regulated by MEF2D in cardiomyocytes are unknown. By performing genome-wide transcriptome analysis using MEF2D-depleted neonatal cardiomyocytes, we found a significant impairment in the cell cycle, characterized by the up-regulation of numerous positive cell cycle regulators. Expression of Pten, the primary negative regulator of PI3K/Akt, was significantly reduced in MEF2D-deficient cardiomyocytes and found to be a direct target gene of MEF2D. Consistent with these findings mutant cardiomyocytes showed activation of the PI3K/Akt survival pathway. Paradoxically, prolonged deficiency of MEF2D in neonatal cardiomyocytes did not trigger proliferation but instead resulted in programmed cell death, which is likely mediated by the E2F transcription factor. These results demonstrate a critical role for MEF2D in cell cycle regulation of post-mitotic, neonatal cardiomyocytes in vitro. PMID:26294766

  2. A mouse model of adult-onset anaemia due to erythropoietin deficiency.

    PubMed

    Yamazaki, Shun; Souma, Tomokazu; Hirano, Ikuo; Pan, Xiaoqing; Minegishi, Naoko; Suzuki, Norio; Yamamoto, Masayuki

    2013-01-01

    Erythropoietin regulates erythropoiesis in a hypoxia-inducible manner. Here we generate inherited super-anaemic mice (ISAM) as a mouse model of adult-onset anaemia caused by erythropoietin deficiency. ISAM express erythropoietin in the liver but lack erythropoietin production in the kidney. Around weaning age, when the major erythropoietin-producing organ switches from the liver to the kidney, ISAM develop anaemia due to erythropoietin deficiency, which is curable by administration of recombinant erythropoietin. In ISAM severe chronic anaemia enhances transgenic green fluorescent protein and Cre expression driven by the complete erythropoietin-gene regulatory regions, which facilitates efficient labelling of renal erythropoietin-producing cells. We show that the majority of cortical and outer medullary fibroblasts have the innate potential to produce erythropoietin, and also reveal a new set of erythropoietin target genes. ISAM are a useful tool for the evaluation of erythropoiesis-stimulating agents and to trace the dynamics of erythropoietin-producing cells. PMID:23727690

  3. Brain-derived neurotrophic factor prevents dendritic retraction of adult mouse retinal ganglion cells.

    PubMed

    Binley, Kate E; Ng, Wai S; Barde, Yves-Alain; Song, Bing; Morgan, James E

    2016-08-01

    We used cultured adult mouse retinae as a model system to follow and quantify the retraction of dendrites using diolistic labelling of retinal ganglion cells (RGCs) following explantation. Cell death was monitored in parallel by nuclear staining as 'labelling' with RGC and apoptotic markers was inconsistent and exceedingly difficult to quantify reliably. Nuclear staining allowed us to delineate a lengthy time window during which dendrite retraction can be monitored in the absence of RGC death. The addition of brain-derived neurotrophic factor (BDNF) produced a marked reduction in dendritic degeneration, even when application was delayed for 3 days after retinal explantation. These results suggest that the delayed addition of trophic factors may be functionally beneficial before the loss of cell bodies in the course of conditions such as glaucoma. PMID:27285957

  4. Isolation and Culture of Dental Epithelial Stem Cells from the Adult Mouse Incisor

    PubMed Central

    Chavez, Miquella G.; Hu, Jimmy; Seidel, Kerstin; Li, Chunying; Jheon, Andrew; Naveau, Adrien; Horst, Orapin; Klein, Ophir D.

    2014-01-01

    Understanding the cellular and molecular mechanisms that underlie tooth regeneration and renewal has become a topic of great interest1-4, and the mouse incisor provides a model for these processes. This remarkable organ grows continuously throughout the animal's life and generates all the necessary cell types from active pools of adult stem cells housed in the labial (toward the lip) and lingual (toward the tongue) cervical loop (CL) regions. Only the dental stem cells from the labial CL give rise to ameloblasts that generate enamel, the outer covering of teeth, on the labial surface. This asymmetric enamel formation allows abrasion at the incisor tip, and progenitors and stem cells in the proximal incisor ensure that the dental tissues are constantly replenished. The ability to isolate and grow these progenitor or stem cells in vitro allows their expansion and opens doors to numerous experiments not achievable in vivo, such as high throughput testing of potential stem cell regulatory factors. Here, we describe and demonstrate a reliable and consistent method to culture cells from the labial CL of the mouse incisor. PMID:24834972

  5. Hormonal regulation of epidermal growth factor and protease in the submandibular gland of the adult mouse.

    PubMed

    Gresik, E W; Schenkein, I; van der Noen, H; Barka, T

    1981-09-01

    The structure of the granular convoluted tubules of the mouse submandibular gland is influenced by androgens, adrenal steroids, and thyroid hormones. We wished to investigate the effects of variations in hormonal status on the quantitative and qualitative distribution of two secretory products of these tubules, epidermal growth factor (EGF) and protease. The effects of the thyroid and adrenal glands on EGF content and protease activity of the submandibular glands of adult female mice were studied by RIAs (EGF), enzyme assays (protease), and immunocytochemical methods. In animals rendered chronically hypothyroid by propylthiouracil (4 months) or in animals which were adrenalectomized and ovariectomized (3 weeks), protease activity and EGF levels were reduced by 81-97%. The administration of testosterone induced these polypeptides even in hypothyroid animals. Daily administration of L-T4 (T4; 1 micrograms/g BW) for 7 days increased EGF and protease activity 3.6-fold in intact mice and reversed the effect of hypothyroidism. EGF and protease were also induced by T4 in adrenalectomized and ovariectomized mice, although to a lesser degree than in intact animals. Immunocytochemical stainings of submandibular glands indicated that the number of granular convoluted tubule cells immunoreactive for EGF correlated with the levels of EGF determined by RIAs. With respect to immunostaining for protease, such a correlation was not observed. The data indicate multihormonal regulation of EGF and protease in the mouse submandibular gland. PMID:7021131

  6. Meis1 Is Required for Adult Mouse Erythropoiesis, Megakaryopoiesis and Hematopoietic Stem Cell Expansion.

    PubMed

    Miller, Michelle Erin; Rosten, Patty; Lemieux, Madeleine E; Lai, Courteney; Humphries, R Keith

    2016-01-01

    Meis1 is recognized as an important transcriptional regulator in hematopoietic development and is strongly implicated in the pathogenesis of leukemia, both as a Hox transcription factor co-factor and independently. Despite the emerging recognition of Meis1's importance in the context of both normal and leukemic hematopoiesis, there is not yet a full understanding of Meis1's functions and the relevant pathways and genes mediating its functions. Recently, several conditional mouse models for Meis1 have been established. These models highlight a critical role for Meis1 in adult mouse hematopoietic stem cells (HSCs) and implicate reactive oxygen species (ROS) as a mediator of Meis1 function in this compartment. There are, however, several reported differences between these studies in terms of downstream progenitor populations impacted and effectors of function. In this study, we describe further characterization of a conditional knockout model based on mice carrying a loxP-flanked exon 8 of Meis1 which we crossed onto the inducible Cre localization/expression strains, B6;129-Gt(ROSA)26Sor(tm1(Cre/ERT)Nat)/J or B6.Cg-Tg(Mx1-Cre)1Cgn/J. Findings obtained from these two inducible Meis1 knockout models confirm and extend previous reports of the essential role of Meis1 in adult HSC maintenance and expansion and provide new evidence that highlights key roles of Meis1 in both megakaryopoiesis and erythropoiesis. Gene expression analyses point to a number of candidate genes involved in Meis1's role in hematopoiesis. Our data additionally support recent evidence of a role of Meis1 in ROS regulation. PMID:26986211

  7. Meis1 Is Required for Adult Mouse Erythropoiesis, Megakaryopoiesis and Hematopoietic Stem Cell Expansion

    PubMed Central

    Miller, Michelle Erin; Rosten, Patty; Lemieux, Madeleine E.; Lai, Courteney; Humphries, R. Keith

    2016-01-01

    Meis1 is recognized as an important transcriptional regulator in hematopoietic development and is strongly implicated in the pathogenesis of leukemia, both as a Hox transcription factor co-factor and independently. Despite the emerging recognition of Meis1’s importance in the context of both normal and leukemic hematopoiesis, there is not yet a full understanding of Meis1’s functions and the relevant pathways and genes mediating its functions. Recently, several conditional mouse models for Meis1 have been established. These models highlight a critical role for Meis1 in adult mouse hematopoietic stem cells (HSCs) and implicate reactive oxygen species (ROS) as a mediator of Meis1 function in this compartment. There are, however, several reported differences between these studies in terms of downstream progenitor populations impacted and effectors of function. In this study, we describe further characterization of a conditional knockout model based on mice carrying a loxP-flanked exon 8 of Meis1 which we crossed onto the inducible Cre localization/expression strains, B6;129-Gt(ROSA)26Sortm1(Cre/ERT)Nat/J or B6.Cg-Tg(Mx1-Cre)1Cgn/J. Findings obtained from these two inducible Meis1 knockout models confirm and extend previous reports of the essential role of Meis1 in adult HSC maintenance and expansion and provide new evidence that highlights key roles of Meis1 in both megakaryopoiesis and erythropoiesis. Gene expression analyses point to a number of candidate genes involved in Meis1’s role in hematopoiesis. Our data additionally support recent evidence of a role of Meis1 in ROS regulation. PMID:26986211

  8. Generation of a novel mouse model that recapitulates early and adult onset glycogenosis type IV.

    PubMed

    Akman, H Orhan; Sheiko, Tatiana; Tay, Stacey K H; Finegold, Milton J; Dimauro, Salvatore; Craigen, William J

    2011-11-15

    Glycogen storage disease type IV (GSD IV) is a rare autosomal recessive disorder caused by deficiency of the glycogen branching enzyme (GBE). The diagnostic feature of the disease is the accumulation of a poorly branched form of glycogen known as polyglucosan (PG). The disease is clinically heterogeneous, with variable tissue involvement and age of disease onset. Absence of enzyme activity is lethal in utero or in infancy affecting primarily muscle and liver. However, residual enzyme activity (5-20%) leads to juvenile or adult onset of a disorder that primarily affects muscle as well as central and peripheral nervous system. Here, we describe two mouse models of GSD IV that reflect this spectrum of disease. Homologous recombination was used to insert flippase recognition target recombination sites around exon 7 of the Gbe1 gene and a phosphoglycerate kinase-Neomycin cassette within intron 7, leading to a reduced synthesis of GBE. Mice bearing this mutation (Gbe1(neo/neo)) exhibit a phenotype similar to juvenile onset GSD IV, with wide spread accumulation of PG. Meanwhile, FLPe-mediated homozygous deletion of exon 7 completely eliminated GBE activity (Gbe1(-/-)), leading to a phenotype of lethal early onset GSD IV, with significant in utero accumulation of PG. Adult mice with residual GBE exhibit progressive neuromuscular dysfunction and die prematurely. Differently from muscle, PG in liver is a degradable source of glucose and readily depleted by fasting, emphasizing that there are structural and regulatory differences in glycogen metabolism among tissues. Both mouse models recapitulate typical histological and physiological features of two human variants of branching enzyme deficiency. PMID:21856731

  9. Cardiomyocyte proliferation in cardiac development and regeneration: a guide to methodologies and interpretations.

    PubMed

    Leone, Marina; Magadum, Ajit; Engel, Felix B

    2015-10-01

    The newt and the zebrafish have the ability to regenerate many of their tissues and organs including the heart. Thus, a major goal in experimental medicine is to elucidate the molecular mechanisms underlying the regenerative capacity of these species. A wide variety of experiments have demonstrated that naturally occurring heart regeneration relies on cardiomyocyte proliferation. Thus, major efforts have been invested to induce proliferation of mammalian cardiomyocytes in order to improve cardiac function after injury or to protect the heart from further functional deterioration. In this review, we describe and analyze methods currently used to evaluate cardiomyocyte proliferation. In addition, we summarize the literature on naturally occurring heart regeneration. Our analysis highlights that newt and zebrafish heart regeneration relies on factors that are also utilized in cardiomyocyte proliferation during mammalian fetal development. Most of these factors have, however, failed to induce adult mammalian cardiomyocyte proliferation. Finally, our analysis of mammalian neonatal heart regeneration indicates experiments that could resolve conflicting results in the literature, such as binucleation assays and clonal analysis. Collectively, cardiac regeneration based on cardiomyocyte proliferation is a promising approach for improving adult human cardiac function after injury, but it is important to elucidate the mechanisms arresting mammalian cardiomyocyte proliferation after birth and to utilize better assays to determine formation of new muscle mass. PMID:26342071

  10. A brain-specific gene cluster isolated from the region of the mouse obesity locus is expressed in the adult hypothalamus and during mouse development

    SciTech Connect

    Laig-Webster, M.; Lim, M.E.; Chehab, F.F.

    1994-09-01

    The molecular defect underlying an autosomal recessive form of genetic obesity in a classical mouse model C57 BL/6J-ob/ob has not yet been elucidated. Whereas metabolic and physiological disturbances such as diabetes and hypertension are associated with obesity, the site of expression and the nature of the primary lesion responsible for this cascade of events remains elusive. Our efforts aimed at the positional cloning of the ob gene by YAC contig mapping and gene identification have resulted in the cloning of a brain-specific gene cluster from the ob critical region. The expression of this gene cluster is remarkably complex owing to the multitude of brain-specific mRNA transcripts detected on Northern blots. cDNA cloning of these transcripts suggests that they are expressed from different genes as well as by alternate splicing mechanisms. Furthermore, the genomic organization of the cluster appears to consist of at least two identical promoters displaying CpG islands characteristic of housekeeping genes, yet clearly involving tissue-specific expression. Sense and anti-sense synthetic RNA probes were derived from a common DNA sequence on 3 cDNA clones and hybridized to 8-16 days mouse embryonic stages and mouse adult brain sections. Expression in development was noticeable as of the 11th day of gestation and confined to the central nervous system mainly in the telencephalon and spinal cord. Coronal and sagittal sections of the adult mouse brain showed expression only in 3 different regions of the brain stem. In situ hybridization to mouse hypothalamus sections revealed the presence of a localized and specialized group of cells expressing high levels of mRNA, suggesting that this gene cluster may also be involved in the regulation of hypothalamic activities. The hypothalamus has long been hypothesized as a primary candidate tissue for the expression of the obesity gene mainly because of its well-established role in the regulation of energy metabolism and food intake.

  11. Establishment of a tamoxifen-inducible Cre-driver mouse strain for widespread and temporal genetic modification in adult mice.

    PubMed

    Ichise, Hirotake; Hori, Akiko; Shiozawa, Seiji; Kondo, Saki; Kanegae, Yumi; Saito, Izumu; Ichise, Taeko; Yoshida, Nobuaki

    2016-07-29

    Temporal genetic modification of mice using the ligand-inducible Cre/loxP system is an important technique that allows the bypass of embryonic lethal phenotypes and access to adult phenotypes. In this study, we generated a tamoxifen-inducible Cre-driver mouse strain for the purpose of widespread and temporal Cre recombination. The new line, named CM32, expresses the GFPneo-fusion gene in a wide variety of tissues before FLP recombination and tamoxifen-inducible Cre after FLP recombination. Using FLP-recombined CM32 mice (CM32Δ mice) and Cre reporter mouse lines, we evaluated the efficiency of Cre recombination with and without tamoxifen administration to adult mice, and found tamoxifen-dependent induction of Cre recombination in a variety of adult tissues. In addition, we demonstrated that conditional activation of an oncogene could be achieved in adults using CM32Δ mice. CM32Δ;T26 mice, which harbored a Cre recombination-driven, SV40 large T antigen-expressing transgene, were viable and fertile. No overt phenotype was found in the mice up to 3 months after birth. Although they displayed pineoblastomas (pinealoblastomas) and/or thymic enlargement due to background Cre recombination by 6 months after birth, they developed epidermal hyperplasia when administered tamoxifen. Collectively, our results suggest that the CM32Δ transgenic mouse line can be applied to the assessment of adult phenotypes in mice with loxP-flanked transgenes. PMID:26923756

  12. Lumican deficiency results in cardiomyocyte hypertrophy with altered collagen assembly.

    PubMed

    Dupuis, Loren E; Berger, Matthew G; Feldman, Samuel; Doucette, Lorna; Fowlkes, Vennece; Chakravarti, Shukti; Thibaudeau, Sarah; Alcala, Nicolas E; Bradshaw, Amy D; Kern, Christine B

    2015-07-01

    The ability of the heart to adapt to increased stress is dependent on the modification of its extracellular matrix (ECM) architecture that is established during postnatal development as cardiomyocytes differentiate, a process that is poorly understood. We hypothesized that the small leucine-rich proteoglycan (SLRP) lumican (LUM), which binds collagen and facilitates collagen assembly in other tissues, may play a critical role in establishing the postnatal murine myocardial ECM. Although previous studies suggest that LUM deficient mice (lum(-/-)) exhibit skin anomalies consistent with Ehlers-Danlos syndrome, lum(-/-) hearts have not been evaluated. These studies show that LUM was immunolocalized to non-cardiomyocytes of the cardiac ventricles and its expression increased throughout development. Lumican deficiency resulted in significant (50%) perinatal death and further examination of the lum(-/-) neonatal hearts revealed an increase in myocardial tissue without a significant increase in cell proliferation. However cardiomyocytes from surviving postnatal day 0 (P0), 1 month (1 mo) and adult (4 mo) lum(-/-) hearts were significantly larger than their wild type (WT) littermates. Immunohistochemistry revealed that the increased cardiomyocyte size in the lum(-/-) hearts correlated with alteration of the cardiomyocyte pericellular ECM components collagenα1(I) and the class I SLRP decorin (DCN). Western blot analysis demonstrated that the ratio of glycosaminoglycan (GAG) decorated DCN to core DCN was reduced in P0 and 1 mo lum(-/-) hearts. There was also a reduction in the β and γ forms of collagenα1(I) in lum(-/-) hearts. While the total insoluble collagen content was significantly reduced, the fibril size was increased in lum(-/-) hearts, indicating that LUM may play a role in collagen fiber stability and lateral fibril assembly. These results suggest that LUM controls cardiomyocyte growth by regulating the pericellular ECM and also indicates that LUM may coordinate

  13. Notch2 is required for maintaining sustentacular cell function in the adult mouse main olfactory epithelium

    PubMed Central

    Rodriguez, Steve; Sickles, Heather M.; DeLeonardis, Chris; Alcaraz, Ana; Gridley, Thomas; Lin, David M.

    2008-01-01

    Notch receptors are expressed in neurons and glia in the adult nervous system, but why this expression persists is not well-understood. Here we examine the role of the Notch pathway in the postnatal mouse main olfactory system, and show evidence consistent with a model where Notch2 is required for maintaining sustentacular cell function. In the absence of Notch2, the laminar nature of these glial-like cells is disrupted. Hes1, Hey1, and Six1, which are downstream effectors of the Notch pathway, are down-regulated, and cytochrome P450 and Glutathione S-transferase (GST) expression by sustentacular cells is reduced. Functional levels of GST activity are also reduced. These disruptions are associated with increased olfactory sensory neuron degeneration. Surprisingly, expression of Notch3 is also down-regulated. This suggests the existence of a feedback loop where expression of Notch3 is initially independent of Notch2, but requires Notch2 for maintained expression. While the Notch pathway has previously been shown to be important for promoting gliogenesis during development, this is the first demonstration that the persistent expression of Notch receptors is required for maintaining glial function in adult. PMID:18155189

  14. Inhibition of Notch activity promotes nonmitotic regeneration of hair cells in the adult mouse utricles.

    PubMed

    Lin, Vincent; Golub, Justin S; Nguyen, Tot Bui; Hume, Clifford R; Oesterle, Elizabeth C; Stone, Jennifer S

    2011-10-26

    The capacity of adult mammals to regenerate sensory hair cells is not well defined. To explore early steps in this process, we examined reactivation of a transiently expressed developmental gene, Atoh1, in adult mouse utricles after neomycin-induced hair cell death in culture. Using an adenoviral reporter for Atoh1 enhancer, we found that Atoh1 transcription is activated in some hair cell progenitors (supporting cells) 3 d after neomycin treatment. By 18 d after neomycin, the number of cells with Atoh1 transcriptional activity increased significantly, but few cells acquired hair cell features (i.e., accumulated ATOH1 or myosin VIIa protein or developed stereocilia). Treatment with DAPT, an inhibitor of γ-secretase, reduced notch pathway activity, enhanced Atoh1 transcriptional activity, and dramatically increased the number of Atoh1-expressing cells with hair cell features, but only in the striolar/juxtastriolar region. Similar effects were seen with TAPI-1, an inhibitor of another enzyme required for notch activity (TACE). Division of supporting cells was rare in any control or DAPT-treated utricles. This study shows that mature mammals have a natural capacity to initiate vestibular hair cell regeneration and suggests that regional notch activity is a significant inhibitor of direct transdifferentiation of supporting cells into hair cells following damage. PMID:22031879

  15. Comparative transcriptome profiling of the injured zebrafish and mouse hearts identifies miRNA-dependent repair pathways

    PubMed Central

    Crippa, Stefania; Nemir, Mohamed; Ounzain, Samir; Ibberson, Mark; Berthonneche, Corinne; Sarre, Alexandre; Boisset, Gaëlle; Maison, Damien; Harshman, Keith; Xenarios, Ioannis; Diviani, Dario; Schorderet, Daniel; Pedrazzini, Thierry

    2016-01-01

    Aims The adult mammalian heart has poor regenerative capacity. In contrast, the zebrafish heart retains a robust capacity for regeneration into adulthood. These distinct responses are consequences of a differential utilization of evolutionary-conserved gene regulatory networks in the damaged heart. To systematically identify miRNA-dependent networks controlling cardiac repair following injury, we performed comparative gene and miRNA profiling of the cardiac transcriptome in adult mice and zebrafish. Methods and results Using an integrated approach, we show that 45 miRNA-dependent networks, involved in critical biological pathways, are differentially modulated in the injured zebrafish vs. mouse hearts. We study, more particularly, the miR-26a-dependent response. Therefore, miR-26a is down-regulated in the fish heart after injury, whereas its expression remains constant in the mouse heart. Targets of miR-26a involve activators of the cell cycle and Ezh2, a component of the polycomb repressive complex 2 (PRC2). Importantly, PRC2 exerts repressive functions on negative regulators of the cell cycle. In cultured neonatal cardiomyocytes, inhibition of miR-26a stimulates, therefore, cardiomyocyte proliferation. Accordingly, miR-26a knockdown prolongs the proliferative window of cardiomyocytes in the post-natal mouse heart. Conclusions This novel strategy identifies a series of miRNAs and associated pathways, in particular miR-26a, which represent attractive therapeutic targets for inducing repair in the injured heart. PMID:26857418

  16. Stroke Increases Neural Stem Cells and Angiogenesis in the Neurogenic Niche of the Adult Mouse

    PubMed Central

    Zhang, Rui Lan; Chopp, Michael; Roberts, Cynthia; Liu, Xianshuang; Wei, Min; Nejad-Davarani, Siamak P.; Wang, Xinli; Zhang, Zheng Gang

    2014-01-01

    The unique cellular and vascular architecture of the adult ventricular-subventricular zone (V/SVZ) neurogenic niche plays an important role in regulating neural stem cell function. However, the in vivo identification of neural stem cells and their relationship to blood vessels within this niche in response to stroke remain largely unknown. Using whole-mount preparation of the lateral ventricle wall, we examined the architecture of neural stem cells and blood vessels in the V/SVZ of adult mouse over the course of 3 months after onset of focal cerebral ischemia. Stroke substantially increased the number of glial fibrillary acidic protein (GFAP) positive neural stem cells that are in contact with the cerebrospinal fluid (CSF) via their apical processes at the center of pinwheel structures formed by ependymal cells residing in the lateral ventricle. Long basal processes of these cells extended to blood vessels beneath the ependymal layer. Moreover, stroke increased V/SVZ endothelial cell proliferation from 2% in non-ischemic mice to 12 and 15% at 7 and 14 days after stroke, respectively. Vascular volume in the V/SVZ was augmented from 3% of the total volume prior to stroke to 6% at 90 days after stroke. Stroke-increased angiogenesis was closely associated with neuroblasts that expanded to nearly encompass the entire lateral ventricular wall in the V/SVZ. These data indicate that stroke induces long-term alterations of the neural stem cell and vascular architecture of the adult V/SVZ neurogenic niche. These post-stroke structural changes may provide insight into neural stem cell mediation of stroke-induced neurogenesis through the interaction of neural stem cells with proteins in the CSF and their sub-ependymal neurovascular interaction. PMID:25437857

  17. Temporal profiles of synaptic plasticity-related signals in adult mouse hippocampus with methotrexate treatment.

    PubMed

    Yang, Miyoung; Kim, Juhwan; Kim, Sung-Ho; Kim, Joong-Sun; Shin, Taekyun; Moon, Changjong

    2012-07-25

    Methotrexate, which is used to treat many malignancies and autoimmune diseases, affects brain functions including hippocampal-dependent memory function. However, the precise mechanisms underlying methotrexate-induced hippocampal dysfunction are poorly understood. To evaluate temporal changes in synaptic plasticity-related signals, the expression and activity of N-methyl-D-aspartic acid receptor 1, calcium/calmodulin-dependent protein kinase II, extracellular signal-regulated kinase 1/2, cAMP responsive element-binding protein, glutamate receptor 1, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor were examined in the hippocampi of adult C57BL/6 mice after methotrexate (40 mg/kg) intraperitoneal injection. Western blot analysis showed biphasic changes in synaptic plasticity-related signals in adult hippocampi following methotrexate treatment. N-methyl-D-aspartic acid receptor 1, calcium/calmodulin-dependent protein kinase II, and glutamate receptor 1 were acutely activated during the early phase (1 day post-injection), while extracellular signal-regulated kinase 1/2 and cAMP responsive element-binding protein activation showed biphasic increases during the early (1 day post-injection) and late phases (7-14 days post-injection). Brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor expression increased significantly during the late phase (7-14 days post-injection). Therefore, methotrexate treatment affects synaptic plasticity-related signals in the adult mouse hippocampus, suggesting that changes in synaptic plasticity-related signals may be associated with neuronal survival and plasticity-related cellular remodeling. PMID:25657706

  18. Expression of Npas4 mRNA in Telencephalic Areas of Adult and Postnatal Mouse Brain

    PubMed Central

    Damborsky, Joanne C.; Slaton, G. Simona; Winzer-Serhan, Ursula H.

    2015-01-01

    The transcription factor neuronal PAS domain-containing protein 4 (Npas4) is an inducible immediate early gene which regulates the formation of inhibitory synapses, and could have a significant regulatory role during cortical circuit formation. However, little is known about basal Npas4 mRNA expression during postnatal development. Here, postnatal and adult mouse brain sections were processed for isotopic in situ hybridization using an Npas4 specific cRNA antisense probe. In adults, Npas4 mRNA was found in the telencephalon with very restricted or no expression in diencephalon or mesencephalon. In most telencephalic areas, including the anterior olfactory nucleus (AON), piriform cortex, neocortex, hippocampus, dorsal caudate putamen (CPu), septum and basolateral amygdala nucleus (BLA), basal Npas4 expression was detected in scattered cells which exhibited strong hybridization signal. In embryonic and neonatal brain sections, Npas4 mRNA expression signals were very low. Starting at postnatal day 5 (P5), transcripts for Npas4 were detected in the AON, CPu and piriform cortex. At P8, additional Npas4 hybridization was found in CA1 and CA3 pyramidal layer, and in primary motor cortex. By P13, robust mRNA expression was located in layers IV and VI of all sensory cortices, frontal cortex and cingulate cortex. After onset of expression, postnatal spatial mRNA distribution was similar to that in adults, with the exception of the CPu, where Npas4 transcripts became gradually restricted to the most dorsal part. In conclusion, the spatial distribution of Npas4 mRNA is mostly restricted to telencephalic areas, and the temporal expression increases with developmental age during postnatal development, which seem to correlate with the onset of activity-driven excitatory transmission. PMID:26633966

  19. How to make a cardiomyocyte.

    PubMed

    Später, Daniela; Hansson, Emil M; Zangi, Lior; Chien, Kenneth R

    2014-12-01

    During development, cardiogenesis is orchestrated by a family of heart progenitors that build distinct regions of the heart. Each region contains diverse cell types that assemble to form the complex structures of the individual cardiac compartments. Cardiomyocytes are the main cell type found in the heart and ensure contraction of the chambers and efficient blood flow throughout the body. Injury to the cardiac muscle often leads to heart failure due to the loss of a large number of cardiomyocytes and its limited intrinsic capacity to regenerate the damaged tissue, making it one of the leading causes of morbidity and mortality worldwide. In this Primer we discuss how insights into the molecular and cellular framework underlying cardiac development can be used to guide the in vitro specification of cardiomyocytes, whether by directed differentiation of pluripotent stem cells or via direct lineage conversion. Additional strategies to generate cardiomyocytes in situ, such as reactivation of endogenous cardiac progenitors and induction of cardiomyocyte proliferation, will also be discussed. PMID:25406392

  20. Doublecortin (DCX) is not Essential for Survival and Differentiation of Newborn Neurons in the Adult Mouse Dentate Gyrus

    PubMed Central

    Dhaliwal, Jagroop; Xi, Yanwei; Bruel-Jungerman, Elodie; Germain, Johanne; Francis, Fiona; Lagace, Diane C.

    2016-01-01

    In the adult brain, expression of the microtubule-associated protein Doublecortin (DCX) is associated with neural progenitor cells (NPCs) that give rise to new neurons in the dentate gyrus. Many studies quantify the number of DCX-expressing cells as a proxy for the level of adult neurogenesis, yet no study has determined the effect of removing DCX from adult hippocampal NPCs. Here, we use a retroviral and inducible mouse transgenic approach to either knockdown or knockout DCX from adult NPCs in the dentate gyrus and examine how this affects cell survival and neuronal maturation. Our results demonstrate that shRNA-mediated knockdown of DCX or Cre-mediated recombination in floxed DCX mice does not alter hippocampal neurogenesis and does not change the neuronal fate of the NPCs. Together these findings show that the survival and maturation of adult-generated hippocampal neurons does not require DCX. PMID:26793044

  1. High yield extraction of pure spinal motor neurons, astrocytes and microglia from single embryo and adult mouse spinal cord

    PubMed Central

    Beaudet, Marie-Josée; Yang, Qiurui; Cadau, Sébastien; Blais, Mathieu; Bellenfant, Sabrina; Gros-Louis, François; Berthod, François

    2015-01-01

    Extraction of mouse spinal motor neurons from transgenic mouse embryos recapitulating some aspects of neurodegenerative diseases like amyotrophic lateral sclerosis has met with limited success. Furthermore, extraction and long-term culture of adult mouse spinal motor neurons and glia remain also challenging. We present here a protocol designed to extract and purify high yields of motor neurons and glia from individual spinal cords collected on embryos and adult (5-month-old) normal or transgenic mice. This method is based on mild digestion of tissue followed by gradient density separation allowing to obtain two millions motor neurons over 92% pure from one E14.5 single embryo and more than 30,000 from an adult mouse. These cells can be cultured more than 14 days in vitro at a density of 100,000 cells/cm2 to maintain optimal viability. Functional astrocytes and microglia and small gamma motor neurons can be purified at the same time. This protocol will be a powerful and reliable method to obtain motor neurons and glia to better understand mechanisms underlying spinal cord diseases. PMID:26577180

  2. Rhythmic Ganglion Cell Activity in Bleached and Blind Adult Mouse Retinas

    PubMed Central

    Menzler, Jacob; Channappa, Lakshmi; Zeck, Guenther

    2014-01-01

    In retinitis pigmentosa – a degenerative disease which often leads to incurable blindness- the loss of photoreceptors deprives the retina from a continuous excitatory input, the so-called dark current. In rodent models of this disease this deprivation leads to oscillatory electrical activity in the remaining circuitry, which is reflected in the rhythmic spiking of retinal ganglion cells (RGCs). It remained unclear, however, if the rhythmic RGC activity is attributed to circuit alterations occurring during photoreceptor degeneration or if rhythmic activity is an intrinsic property of healthy retinal circuitry which is masked by the photoreceptor’s dark current. Here we tested these hypotheses by inducing and analysing oscillatory activity in adult healthy (C57/Bl6) and blind mouse retinas (rd10 and rd1). Rhythmic RGC activity in healthy retinas was detected upon partial photoreceptor bleaching using an extracellular high-density multi-transistor-array. The mean fundamental spiking frequency in bleached retinas was 4.3 Hz; close to the RGC rhythm detected in blind rd10 mouse retinas (6.5 Hz). Crosscorrelation analysis of neighbouring wild-type and rd10 RGCs (separation distance <200 µm) reveals synchrony among homologous RGC types and a constant phase shift (∼70 msec) among heterologous cell types (ON versus OFF). The rhythmic RGC spiking in these retinas is driven by a network of presynaptic neurons. The inhibition of glutamatergic ganglion cell input or the inhibition of gap junctional coupling abolished the rhythmic pattern. In rd10 and rd1 retinas the presynaptic network leads to local field potentials, whereas in bleached retinas additional pharmacological disinhibition is required to achieve detectable field potentials. Our results demonstrate that photoreceptor bleaching unmasks oscillatory activity in healthy retinas which shares many features with the functional phenotype detected in rd10 retinas. The quantitative physiological differences advance the

  3. Adult Plasticity in the Subcortical Auditory Pathway of the Maternal Mouse

    PubMed Central

    Miranda, Jason A.; Shepard, Kathryn N.; McClintock, Shannon K.; Liu, Robert C.

    2014-01-01

    Subcortical auditory nuclei were traditionally viewed as non-plastic in adulthood so that acoustic information could be stably conveyed to higher auditory areas. Studies in a variety of species, including humans, now suggest that prolonged acoustic training can drive long-lasting brainstem plasticity. The neurobiological mechanisms for such changes are not well understood in natural behavioral contexts due to a relative dearth of in vivo animal models in which to study this. Here, we demonstrate in a mouse model that a natural life experience with increased demands on the auditory system – motherhood – is associated with improved temporal processing in the subcortical auditory pathway. We measured the auditory brainstem response to test whether mothers and pup-naïve virgin mice differed in temporal responses to both broadband and tone stimuli, including ultrasonic frequencies found in mouse pup vocalizations. Mothers had shorter latencies for early ABR peaks, indicating plasticity in the auditory nerve and the cochlear nucleus. Shorter interpeak latency between waves IV and V also suggest plasticity in the inferior colliculus. Hormone manipulations revealed that these cannot be explained solely by estrogen levels experienced during pregnancy and parturition in mothers. In contrast, we found that pup-care experience, independent of pregnancy and parturition, contributes to shortening auditory brainstem response latencies. These results suggest that acoustic experience in the maternal context imparts plasticity on early auditory processing that lasts beyond pup weaning. In addition to establishing an animal model for exploring adult auditory brainstem plasticity in a neuroethological context, our results have broader implications for models of perceptual, behavioral and neural changes that arise during maternity, where subcortical sensorineural plasticity has not previously been considered. PMID:24992362

  4. Quantitative Expression Profile of Distinct Functional Regions in the Adult Mouse Brain

    PubMed Central

    Nagano, Mamoru; Uno, Kenichiro D.; Tsujino, Kaori; Hanashima, Carina; Shigeyoshi, Yasufumi; Ueda, Hiroki R.

    2011-01-01

    The adult mammalian brain is composed of distinct regions with specialized roles including regulation of circadian clocks, feeding, sleep/awake, and seasonal rhythms. To find quantitative differences of expression among such various brain regions, we conducted the BrainStars (B*) project, in which we profiled the genome-wide expression of ∼50 small brain regions, including sensory centers, and centers for motion, time, memory, fear, and feeding. To avoid confounds from temporal differences in gene expression, we sampled each region every 4 hours for 24 hours, and pooled the samples for DNA-microarray assays. Therefore, we focused on spatial differences in gene expression. We used informatics to identify candidate genes with expression changes showing high or low expression in specific regions. We also identified candidate genes with stable expression across brain regions that can be used as new internal control genes, and ligand-receptor interactions of neurohormones and neurotransmitters. Through these analyses, we found 8,159 multi-state genes, 2,212 regional marker gene candidates for 44 small brain regions, 915 internal control gene candidates, and 23,864 inferred ligand-receptor interactions. We also found that these sets include well-known genes as well as novel candidate genes that might be related to specific functions in brain regions. We used our findings to develop an integrated database (http://brainstars.org/) for exploring genome-wide expression in the adult mouse brain, and have made this database openly accessible. These new resources will help accelerate the functional analysis of the mammalian brain and the elucidation of its regulatory network systems. PMID:21858037

  5. Role of oxidative stress in rabies virus infection of adult mouse dorsal root ganglion neurons.

    PubMed

    Jackson, Alan C; Kammouni, Wafa; Zherebitskaya, Elena; Fernyhough, Paul

    2010-05-01

    Rabies virus infection of dorsal root ganglia (DRG) was studied in vitro with cultured adult mouse DRG neurons. Recent in vivo studies of transgenic mice that express the yellow fluorescent protein indicate that neuronal process degeneration, involving both dendrites and axons, occurs in mice infected with the challenge virus standard (CVS) strain of rabies virus by footpad inoculation. Because of the similarities of the morphological changes in experimental rabies and in diabetic neuropathy and other diseases, we hypothesize that neuronal process degeneration occurs as a result of oxidative stress. DRG neurons were cultured from adult ICR mice. Two days after plating, they were infected with CVS. Immunostaining was evaluated with CVS- and mock-infected cultures for neuron specific beta-tubulin, rabies virus antigen, and amino acid adducts of 4-hydroxy-2-nonenal (4-HNE) (marker of lipid peroxidation and hence oxidative stress). Neuronal viability (by trypan blue exclusion), terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining, and axonal growth were also assessed with the cultures. CVS infected 33 to 54% of cultured DRG neurons. Levels of neuronal viability and TUNEL staining were similar in CVS- and mock-infected DRG neurons. There were significantly more 4-HNE-labeled puncta at 2 and 3 days postinfection in CVS-infected cultures than in mock-infected cultures, and axonal outgrowth was reduced at these time points in CVS infection. Axonal swellings with 4-HNE-labeled puncta were also associated with aggregations of actively respiring mitochondria. We have found evidence that rabies virus infection in vitro causes axonal injury of DRG neurons through oxidative stress. Oxidative stress may be important in vivo in rabies and may explain previous observations of the degeneration of neuronal processes. PMID:20181692

  6. Adult mouse model of early hepatocellular carcinoma promoted by alcoholic liver disease

    PubMed Central

    Ambade, Aditya; Satishchandran, Abhishek; Gyongyosi, Benedek; Lowe, Patrick; Szabo, Gyongyi

    2016-01-01

    AIM: To establish a mouse model of alcohol-driven hepatocellular carcinoma (HCC) that develops in livers with alcoholic liver disease (ALD). METHODS: Adult C57BL/6 male mice received multiple doses of chemical carcinogen diethyl nitrosamine (DEN) followed by 7 wk of 4% Lieber-DeCarli diet. Serum alanine aminotransferase (ALT), alpha fetoprotein (AFP) and liver Cyp2e1 were assessed. Expression of F4/80, CD68 for macrophages and Ly6G, MPO, E-selectin for neutrophils was measured. Macrophage polarization was determined by IL-1β/iNOS (M1) and Arg-1/IL-10/CD163/CD206 (M2) expression. Liver steatosis and fibrosis were measured by oil-red-O and Sirius red staining respectively. HCC development was monitored by magnetic resonance imaging, confirmed by histology. Cellular proliferation was assessed by proliferating cell nuclear antigen (PCNA). RESULTS: Alcohol-DEN mice showed higher ALTs than pair fed-DEN mice throughout the alcohol feeding without weight gain. Alcohol feeding resulted in increased ALT, liver steatosis and inflammation compared to pair-fed controls. Alcohol-DEN mice had reduced steatosis and increased fibrosis indicating advanced liver disease. Molecular characterization showed highest levels of both neutrophil and macrophage markers in alcohol-DEN livers. Importantly, M2 macrophages were predominantly higher in alcohol-DEN livers. Magnetic resonance imaging revealed increased numbers of intrahepatic cysts and liver histology confirmed the presence of early HCC in alcohol-DEN mice compared to all other groups. This correlated with increased serum alpha-fetoprotein, a marker of HCC, in alcohol-DEN mice. PCNA immunostaining revealed significantly increased hepatocyte proliferation in livers from alcohol-DEN compared to pair fed-DEN or alcohol-fed mice. CONCLUSION: We describe a new 12-wk HCC model in adult mice that develops in livers with alcoholic hepatitis and defines ALD as co-factor in HCC. PMID:27122661

  7. Isolation of high-purity myenteric plexus from adult human and mouse gastrointestinal tract

    PubMed Central

    Grundmann, David; Klotz, Markus; Rabe, Holger; Glanemann, Matthias; Schäfer, Karl-Herbert

    2015-01-01

    The enteric nervous system (ENS) orchestrates a broad range of important gastrointestinal functions such as intestinal motility and gastric secretion. The ENS can be affected by environmental factors, diet and disease. Changes due to these alterations are often hard to evaluate in detail when whole gut samples are used. Analyses based on pure ENS tissue can more effectively reflect the ongoing changes during pathological processes. Here, we present an optimized approach for the isolation of pure myenteric plexus (MP) from adult mouse and human. To do so, muscle tissue was individually digested with a purified collagenase. After incubation and a gentle mechanical disruption step, MP networks could be collected with anatomical integrity. These tissues could be stored and used either for immediate genomic, proteomic or in vitro approaches, and enteric neurospheres could be generated and differentiated. In a pilot experiment, the influence of bacterial lipopolysaccharide on human MP was analyzed using 2-dimensional gel electrophoresis. The method also allows investigation of factors that are secreted by myenteric tissue in vitro. The isolation of pure MP in large amounts allows new analytical approaches that can provide a new perspective in evaluating changes of the ENS in experimental models, human disease and aging. PMID:25791532

  8. Expression of slow skeletal TnI in adult mouse hearts confers metabolic protection to ischemia

    PubMed Central

    Pound, Kayla M.; Arteaga, Grace M.; Fasano, Mathew; Wilder, Tanganyika; Fischer, Susan K.; Warren, Chad M.; Wende, Adam R.; Farjah, Mariam; Abel, E. Dale; Solaro, R. John; Lewandowski, E. Douglas

    2011-01-01

    Changes in metabolic and myofilament phenotypes coincide in developing hearts. Posttranslational modification of sarcomere proteins influences contractility, affecting the energetic cost of contraction. However, metabolic adaptations to sarcomeric phenotypes are not well understood, particularly during pathophysiological stress. This study explored metabolic adaptations to expression of the fetal, slow skeletal muscle troponin I (ssTnI). Hearts expressing ssTnI exhibited no significant ATP loss during 5 minutes of global ischemia, while non-transgenic littermates (NTG) showed continual ATP loss. At 7 min ischemia TG-ssTnI hearts retained 80±12% of ATP vs. 49±6% in NTG (P<0.05). Hearts expressing ssTnI also had increased AMPK phosphorylation. The mechanism of ATP preservation was augmented glycolysis. Glycolytic end products (lactate and alanine) were 38% higher in TG-ssTnI than NTG at 2 min and 27% higher at 5 min. This additional glycolysis was supported exclusively by exogenous glucose, and not glycogen. Thus, expression of a fetal myofilament protein in adult mouse hearts induced elevated anaerobic ATP production during ischemia via metabolic adaptations consistent with the resistance to hypoxia of fetal hearts. The general findings hold important relevance to both our current understanding of the association between metabolic and contractile phenotypes and the potential for invoking cardioprotective mechanisms against ischemic stress. PMID:21640727

  9. MicroRNA Clusters in the Adult Mouse Heart: Age-Associated Changes

    PubMed Central

    Zhang, Xiaomin; Azhar, Gohar; Williams, Emmanuel D.; Rogers, Steven C.; Wei, Jeanne Y.

    2015-01-01

    The microRNAs and microRNA clusters have been implicated in normal cardiac development and also disease, including cardiac hypertrophy, cardiomyopathy, heart failure, and arrhythmias. Since a microRNA cluster has from two to dozens of microRNAs, the expression of a microRNA cluster could have a substantial impact on its target genes. In the present study, the configuration and distribution of microRNA clusters in the mouse genome were examined at various inter-microRNA distances. Three important microRNA clusters that are significantly impacted during adult cardiac aging, the miR-17-92, miR-106a-363, and miR-106b-25, were also examined in terms of their genomic location, RNA transcript character, sequence homology, and their relationship with the corresponding microRNA families. Multiple microRNAs derived from the three clusters potentially target various protein components of the cdc42-SRF signaling pathway, which regulates cytoskeleton dynamics associated with cardiac structure and function. The data indicate that aging impacted the expression of both guide and passenger strands of the microRNA clusters; nutrient stress also affected the expression of the three microRNA clusters. The miR-17-92, miR-106a-363, and miR-106b-25 clusters are likely to impact the Cdc42-SRF signaling pathway and thereby affect cardiac morphology and function during pathological conditions and the aging process. PMID:26221604

  10. Aryl Hydrocarbon Receptor Activity of Tryptophan Metabolites in Young Adult Mouse Colonocytes.

    PubMed

    Cheng, Yating; Jin, Un-Ho; Allred, Clint D; Jayaraman, Arul; Chapkin, Robert S; Safe, Stephen

    2015-10-01

    The tryptophan microbiota metabolites indole-3-acetate, indole-3-aldehyde, indole, and tryptamine are aryl hydrocarbon receptor (AhR) ligands, and in this study we investigated their AhR agonist and antagonist activities in nontransformed young adult mouse colonocyte (YAMC) cells. Using Cyp1a1 mRNA as an Ah-responsive end point, we observed that the tryptophan metabolites were weak AhR agonists and partial antagonists in YAMC cells, and the pattern of activity was different from that previously observed in CaCo2 colon cancer cells. However, expansion of the end points to other Ah-responsive genes including the Cyp1b1, the AhR repressor (Ahrr), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible poly(ADP-ribose) polymerase (TiParp) revealed a highly complex pattern of AhR agonist/antagonist activities that were both ligand- and gene-dependent. For example, the magnitude of induction of Cyp1b1 mRNA was similar for TCDD, tryptamine, and indole-3-acetate, whereas lower induction was observed for indole and indole-3-aldehyde was inactive. These results suggest that the tryptophan metabolites identified in microbiota are selective AhR modulators. PMID:25873348

  11. Neurotoxic effects of ochratoxin A on the subventricular zone of adult mouse brain.

    PubMed

    Paradells, Sara; Rocamonde, Brenda; Llinares, Cristina; Herranz-Pérez, Vicente; Jimenez, Misericordia; Garcia-Verdugo, Jose Manuel; Zipancic, Ivan; Soria, Jose Miguel; Garcia-Esparza, Ma Angeles

    2015-07-01

    Ochratoxin A (OTA), a mycotoxin that was discovered as a secondary metabolite of the fungal species Aspergillus and Penicillium, is a common contaminant in food and animal feed. This mycotoxin has been described as teratogenic, carcinogenic, genotoxic, immunotoxic and has been proven a potent neurotoxin. Other authors have previously reported the effects of OTA in different structures of the central nervous system as well as in some neurogenic regions. However, the impact of OTA exposure in the subventricular zone (SVZ) has not been assessed yet. To elucidate whether OTA affects neural precursors of the mouse SVZ we investigated, in vitro and in vivo, the effects of OTA exposure on the SVZ and on the neural precursors obtained from this neurogenic niche. In this work, we prove the cumulative effect of OTA exposure on proliferation, differentiation and depletion of neural stem cells cultured from the SVZ. In addition, we corroborated these results in vivo by immunohistochemistry and electron microscopy. As a result, we found a significant alteration in the proliferation process, which was evidenced by a decrease in the number of 5-bromo-2-deoxyuridine-positive cells and glial cells, as well as, a significant decrease in the number of neuroblasts in the SVZ. To summarize, in this study we demonstrate how OTA could be a threat to the developing and the adult SVZ through its impact in cell viability, proliferation and differentiation in a dose-dependent manner. PMID:25256750

  12. Adult pallium transcriptomes surprise in not reflecting predicted homologies across diverse chicken and mouse pallial sectors

    PubMed Central

    Belgard, T. Grant; Montiel, Juan F.; Wang, Wei Zhi; García-Moreno, Fernando; Ponting, Chris P.; Molnár, Zoltán

    2013-01-01

    The thorniest problem in comparative neurobiology is the identification of the particular brain region of birds and reptiles that corresponds to the mammalian neocortex [Butler AB, Reiner A, Karten HJ (2011) Ann N Y Acad Sci 1225:14–27; Wang Y, Brzozowska-Prechtl A, Karten HJ (2010) Proc Natl Acad Sci USA 107(28):12676–12681]. We explored which genes are actively transcribed in the regions of controversial ancestry in a representative bird (chicken) and mammal (mouse) at adult stages. We conducted four analyses comparing the expression patterns of their 5,130 most highly expressed one-to-one orthologous genes that considered global patterns of expression specificity, strong gene markers, and coexpression networks. Our study demonstrates transcriptomic divergence, plausible convergence, and, in two exceptional cases, conservation between specialized avian and mammalian telencephalic regions. This large-scale study potentially resolves the complex relationship between developmental homology and functional characteristics on the molecular level and settles long-standing evolutionary debates. PMID:23878249

  13. Adult pallium transcriptomes surprise in not reflecting predicted homologies across diverse chicken and mouse pallial sectors.

    PubMed

    Belgard, T Grant; Montiel, Juan F; Wang, Wei Zhi; García-Moreno, Fernando; Margulies, Elliott H; Ponting, Chris P; Molnár, Zoltán

    2013-08-01

    The thorniest problem in comparative neurobiology is the identification of the particular brain region of birds and reptiles that corresponds to the mammalian neocortex [Butler AB, Reiner A, Karten HJ (2011) Ann N Y Acad Sci 1225:14-27; Wang Y, Brzozowska-Prechtl A, Karten HJ (2010) Proc Natl Acad Sci USA 107(28):12676-12681]. We explored which genes are actively transcribed in the regions of controversial ancestry in a representative bird (chicken) and mammal (mouse) at adult stages. We conducted four analyses comparing the expression patterns of their 5,130 most highly expressed one-to-one orthologous genes that considered global patterns of expression specificity, strong gene markers, and coexpression networks. Our study demonstrates transcriptomic divergence, plausible convergence, and, in two exceptional cases, conservation between specialized avian and mammalian telencephalic regions. This large-scale study potentially resolves the complex relationship between developmental homology and functional characteristics on the molecular level and settles long-standing evolutionary debates. PMID:23878249

  14. Absent in Melanoma 2 (AIM2) limits pro-inflammatory cytokine transcription in cardiomyocytes by inhibiting STAT1 phosphorylation.

    PubMed

    Furrer, Antonia; Hottiger, Michael O; Valaperti, Alan

    2016-06-01

    Interferon (IFN)-γ is highly upregulated during heart inflammation and enhances the production of pro-inflammatory cytokines. Absent in Melanoma 2 (AIM2) is an IFN-inducible protein implicated as a component of the inflammasome. Here we seek to determine the role of AIM2 during inflammation in cardiac cells. We found that the presence of AIM2, but not of the other inflammasome components Nod-like receptor (NLR) NLRP3 or NLRC4, specifically limited the transcription of the pro-inflammatory cytokines interleukin (IL)-6, IP-10, and tumor necrosis factor (TNF)-α in HL-1 mouse cardiomyocytes stimulated with IFN-γ and lipopolysaccharides (LPS). Similarly, AIM2 reduced pro-inflammatory cytokine transcription in primary mouse neonatal cardiomyocytes (MNC), but not in primary mouse neonatal cardiac fibroblasts (MNF). Interestingly, AIM2-dependent reduction of pro-inflammatory cytokines in cardiomyocytes was independent of Caspase-1. Mechanistically, AIM2 reduced pro-inflammatory cytokine transcription in cardiomyocytes by interacting with and inhibiting the phosphorylation of STAT1. In AIM2-depleted cardiomyocytes, increased STAT1 phosphorylation enhanced the NF-κB pathway by promoting NF-κB p65 phosphorylation and acetylation. These results show for the first time that AIM2 plays an important anti-inflammatory, yet inflammasome-independent function in cardiomyocytes. Our findings will help to further understand how the various heart cell types differently react to inflammatory stimuli. PMID:27148820

  15. IGF-2R-mediated signaling results in hypertrophy of cultured cardiomyocytes from fetal sheep.

    PubMed

    Wang, Kimberley C W; Brooks, Doug A; Botting, Kimberley J; Morrison, Janna L

    2012-06-01

    Activation of the insulin-like growth factor-1 receptor (IGF-1R) is known to play a role in cardiomyocyte hypertrophy. While IGF-2R is understood to be a clearance receptor for IGF-2, there is also evidence that it may play a role in the induction of pathological cardiomyocyte hypertrophy. It is not known whether IGF-2R activates cardiomyocyte hypertrophy during growth of the fetal heart. Fetal sheep hearts (125 ± 0.4 days gestation) were dissected, and the cardiomyocytes isolated from the left and right ventricles for culturing. Cultured cardiomyocytes were treated with either LONG R(3)IGF-1, an IGF-1R agonist; picropodophyllin, an IGF-1R autophosphorylation inhibitor; U0126, an inhibitor of extracellular signal-regulated protein kinase (ERK); Leu(27)IGF-2, an IGF-2R agonist; Gö6976, a protein kinase C inhibitor; KN-93, an inhibitor of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII); or KN-92, an L-type calcium channel inhibitor and negative control for KN-93. The cross-sectional area of cultured cardiomyocytes was determined relative to control cardiomyocytes treated with serum-free culture medium. IGF-1R and IGF-2R activation each resulted in ERK signaling, but IGF-2R activation alone induced CaMKII signaling, resulting in hypertrophy of cardiomyocytes in the late gestation sheep fetus. These data suggest that changes in the intrauterine environment that result in increased cardiac IGF-2R may also lead to cardiomyocyte hypertrophy in the fetus and potentially an increased risk of cardiovascular disease in adult life. PMID:22441800

  16. Innervating sympathetic neurons regulate heart size and the timing of cardiomyocyte cell cycle withdrawal.

    PubMed

    Kreipke, R E; Birren, S J

    2015-12-01

    Sympathetic drive to the heart is a key modulator of cardiac function and interactions between heart tissue and innervating sympathetic fibres are established early in development. Significant innervation takes place during postnatal heart development, a period when cardiomyocytes undergo a rapid transition from proliferative to hypertrophic growth. The question of whether these innervating sympathetic fibres play a role in regulating the modes of cardiomyocyte growth was investigated using 6-hydroxydopamine (6-OHDA) to abolish early sympathetic innervation of the heart. Postnatal chemical sympathectomy resulted in rats with smaller hearts, indicating that heart growth is regulated by innervating sympathetic fibres during the postnatal period. In vitro experiments showed that sympathetic interactions resulted in delays in markers of cardiomyocyte maturation, suggesting that changes in the timing of the transition from hyperplastic to hypertrophic growth of cardiomyocytes could underlie changes in heart size in the sympathectomized animals. There was also an increase in the expression of Meis1, which has been linked to cardiomyocyte cell cycle withdrawal, suggesting that sympathetic signalling suppresses cell cycle withdrawal. This signalling involves β-adrenergic activation, which was necessary for sympathetic regulation of cardiomyocyte proliferation and hypertrophy. The effect of β-adrenergic signalling on cardiomyocyte hypertrophy underwent a developmental transition. While young postnatal cardiomyocytes responded to isoproterenol (isoprenaline) with a decrease in cell size, mature cardiomyocytes showed an increase in cell size in response to the drug. Together, these results suggest that early sympathetic effects on proliferation modulate a key transition between proliferative and hypertrophic growth of the heart and contribute to the sympathetic regulation of adult heart size. PMID:26420487

  17. Time-lapse imaging of neuroblast migration in acute slices of the adult mouse forebrain.

    PubMed

    Khlghatyan, Jivan; Saghatelyan, Armen

    2012-01-01

    the stationary and migratory phases is crucial for the unambiguous interpretation of results. We also performed multiple z-step acquisitions to monitor neuroblasts migration in 3D. Wide-field fluorescent imaging has been used extensively to visualize neuronal migration. Here, we describe detailed protocol for labeling neuroblasts, performing real-time video-imaging of neuroblast migration in acute slices of the adult mouse forebrain, and analyzing cell migration. While the described protocol exemplified the migration of neuroblasts in the adult RMS, it can also be used to follow cell migration in embryonic and early postnatal brains. PMID:23007608

  18. Regression of Copper-Deficient Heart Hypertrophy: Reduction in the Size of Hypertrophic Cardiomyocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary copper deficiency causes cardiac hypertrophy and its transition to heart failure in a mouse model. Copper repletion results in a rapid regression of cardiac hypertrophy and prevention of heart failure. The present study was undertaken to understand dynamic changes of cardiomyocytes in the hy...

  19. Cardiomyocytes display low mitochondrial priming and are highly resistant toward cytotoxic T-cell killing.

    PubMed

    Zheng, Xiang; Halle, Stephan; Yu, Kai; Mishra, Pooja; Scherr, Michaela; Pietzsch, Stefan; Willenzon, Stefanie; Janssen, Anika; Boelter, Jasmin; Hilfiker-Kleiner, Denise; Eder, Matthias; Förster, Reinhold

    2016-06-01

    Following heart transplantation, alloimmune responses can cause graft rejection by damaging donor vascular and parenchymal cells. However, it remains unclear whether cardiomyocytes are also directly killed by immune cells. Here, we used two-photon microscopy to investigate how graft-specific effector CD8(+) T cells interact with cardiomyocytes in a mouse heart transplantation model. Surprisingly, we observed that CD8(+) T cells are completely impaired in killing cardiomyocytes. Even after virus-mediated preactivation, antigen-specific CD8(+) T cells largely fail to lyse these cells although both cell types engage in dynamic interactions. Furthermore, we established a two-photon microscopy-based assay using intact myocardium to determine the susceptibility of cardiomyocytes to undergo apoptosis. This feature, also known as mitochondrial priming reveals an unexpected weak predisposition of cardiomyocytes to undergo apoptosis in situ. These observations together with the early exhaustion phenotype of graft-infiltrating specific T cells provide an explanation why cardiomyocytes are largely protected from direct CD8(+) T-cell-mediated killing. PMID:26970349

  20. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections.

    PubMed

    Bensley, Jonathan Guy; De Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-01-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4',6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2-10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections. PMID:27048757

  1. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections

    NASA Astrophysics Data System (ADS)

    Bensley, Jonathan Guy; de Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-04-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4‧,6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2–10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections.

  2. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections

    PubMed Central

    Bensley, Jonathan Guy; De Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-01-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4′,6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2–10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections. PMID:27048757

  3. PAX6 MiniPromoters drive restricted expression from rAAV in the adult mouse retina.

    PubMed

    Hickmott, Jack W; Chen, Chih-Yu; Arenillas, David J; Korecki, Andrea J; Lam, Siu Ling; Molday, Laurie L; Bonaguro, Russell J; Zhou, Michelle; Chou, Alice Y; Mathelier, Anthony; Boye, Sanford L; Hauswirth, William W; Molday, Robert S; Wasserman, Wyeth W; Simpson, Elizabeth M

    2016-01-01

    Current gene therapies predominantly use small, strong, and readily available ubiquitous promoters. However, as the field matures, the availability of small, cell-specific promoters would be greatly beneficial. Here we design seven small promoters from the human paired box 6 (PAX6) gene and test them in the adult mouse retina using recombinant adeno-associated virus. We chose the retina due to previous successes in gene therapy for blindness, and the PAX6 gene since it is: well studied; known to be driven by discrete regulatory regions; expressed in therapeutically interesting retinal cell types; and mutated in the vision-loss disorder aniridia, which is in need of improved therapy. At the PAX6 locus, 31 regulatory regions were bioinformatically predicted, and nine regulatory regions were constructed into seven MiniPromoters. Driving Emerald GFP, these MiniPromoters were packaged into recombinant adeno-associated virus, and injected intravitreally into postnatal day 14 mice. Four MiniPromoters drove consistent retinal expression in the adult mouse, driving expression in combinations of cell-types that endogenously express Pax6: ganglion, amacrine, horizontal, and Müller glia. Two PAX6-MiniPromoters drive expression in three of the four cell types that express PAX6 in the adult mouse retina. Combined, they capture all four cell types, making them potential tools for research, and PAX6-gene therapy for aniridia. PMID:27556059

  4. PAX6 MiniPromoters drive restricted expression from rAAV in the adult mouse retina

    PubMed Central

    Hickmott, Jack W; Chen, Chih-yu; Arenillas, David J; Korecki, Andrea J; Lam, Siu Ling; Molday, Laurie L; Bonaguro, Russell J; Zhou, Michelle; Chou, Alice Y; Mathelier, Anthony; Boye, Sanford L; Hauswirth, William W; Molday, Robert S; Wasserman, Wyeth W; Simpson, Elizabeth M

    2016-01-01

    Current gene therapies predominantly use small, strong, and readily available ubiquitous promoters. However, as the field matures, the availability of small, cell-specific promoters would be greatly beneficial. Here we design seven small promoters from the human paired box 6 (PAX6) gene and test them in the adult mouse retina using recombinant adeno-associated virus. We chose the retina due to previous successes in gene therapy for blindness, and the PAX6 gene since it is: well studied; known to be driven by discrete regulatory regions; expressed in therapeutically interesting retinal cell types; and mutated in the vision-loss disorder aniridia, which is in need of improved therapy. At the PAX6 locus, 31 regulatory regions were bioinformatically predicted, and nine regulatory regions were constructed into seven MiniPromoters. Driving Emerald GFP, these MiniPromoters were packaged into recombinant adeno-associated virus, and injected intravitreally into postnatal day 14 mice. Four MiniPromoters drove consistent retinal expression in the adult mouse, driving expression in combinations of cell-types that endogenously express Pax6: ganglion, amacrine, horizontal, and Müller glia. Two PAX6-MiniPromoters drive expression in three of the four cell types that express PAX6 in the adult mouse retina. Combined, they capture all four cell types, making them potential tools for research, and PAX6-gene therapy for aniridia. PMID:27556059

  5. Dynamic expression of TrkB receptor protein on proliferating and maturing cells in the adult mouse dentate gyrus

    PubMed Central

    Donovan, Michael H.; Yamaguchi, Masahiro; Eisch, Amelia J.

    2008-01-01

    Brain-derived neurotrophic factor (BDNF) is implicated in regulation of adult hippocampal neurogenesis, presumably via its primary receptor, TrkB, but controversy exists about how BDNF affects neurogenesis (e.g. proliferation vs. survival/differentiation). This controversy arises, in part, due to the lack of information about if and when TrkB is expressed on adult neural precursors in vivo. Using multiple methods to analyze proliferating and maturing cells in the adult mouse subgranular zone (SGZ), we find that the proportion of proliferating cells that are TrkB-IR is low and it remains low for at least one week following BrdU labeling, but increases as neuroblasts mature. Use of the nestin-GFP transgenic mouse revealed the likelihood of being TrkB-IR increased with presumed maturity of the cell type. Stem-like cells, which rarely divide, were likely to express TrkB. However, early progenitors and late progenitors, which are still in the cell cycle had rare TrkB expression. Immature neuroblasts, however, were more likely to express TrkB, especially as their morphology became more mature. Taken together, these findings emphasize that expression of TrkB protein is closely linked to progression towards neuronal maturity. This provides evidence that maturing cells but not proliferating cells in the adult mouse SGZ have the molecular machinery necessary to respond directly to BDNF. Furthermore, these findings lay critical groundwork for further exploration of the role of BDNF-TrkB signaling in regulation of adult hippocampal neurogenesis. PMID:18240316

  6. Dual transcriptional activator and repressor roles of TBX20 regulate adult cardiac structure and function

    PubMed Central

    Sakabe, Noboru J.; Aneas, Ivy; Shen, Tao; Shokri, Leila; Park, Soo-Young; Bulyk, Martha L.; Evans, Sylvia M.; Nobrega, Marcelo A.

    2012-01-01

    The ongoing requirement in adult heart for transcription factors with key roles in cardiac development is not well understood. We recently demonstrated that TBX20, a transcriptional regulator required for cardiac development, has key roles in the maintenance of functional and structural phenotypes in adult mouse heart. Conditional ablation of Tbx20 in adult cardiomyocytes leads to a rapid onset and progression of heart failure, with prominent conduction and contractility phenotypes that lead to death. Here we describe a more comprehensive molecular characterization of the functions of TBX20 in adult mouse heart. Coupling genome-wide chromatin immunoprecipitation and transcriptome analyses (RNA-Seq), we identified a subset of genes that change expression in Tbx20 adult cardiomyocyte-specific knockout hearts which are direct downstream targets of TBX20. This analysis revealed a dual role for TBX20 as both a transcriptional activator and a repressor, and that each of these functions regulates genes with very specialized and distinct molecular roles. We also show how TBX20 binds to its targets genome-wide in a context-dependent manner, using various cohorts of co-factors to either promote or repress distinct genetic programs within adult heart. Our integrative approach has uncovered several novel aspects of TBX20 and T-box protein function within adult heart. Sequencing data accession number (http://www.ncbi.nlm.nih.gov/geo): GSE30943. PMID:22328084

  7. Hepatocyte nuclear factor 4α is required for cell differentiation and homeostasis in the adult mouse gastric epithelium.

    PubMed

    Moore, Benjamin D; Khurana, Shradha S; Huh, Won Jae; Mills, Jason C

    2016-08-01

    We have previously shown that the sequential transcription factors Xbp1→Mist1 (Bhlha15) govern the ultrastructural maturation of the secretory apparatus in enzyme-secreting zymogenic chief cells (ZCs) in the gastric unit. Here we sought to identify transcriptional regulators upstream of X-box binding protein 1 (XBP1) and MIST1. We used immunohistochemistry to characterize Hnf4α(flox/flox) adult mouse stomachs after tamoxifen-induced deletion of Hnf4α We used qRT-PCR, Western blotting, and chromatin immunoprecipitation to define the molecular interaction between hepatocyte nuclear factor 4 alpha (HNF4α) and Xbp1 in mouse stomach and human gastric cells. We show that HNF4α protein is expressed in pit (foveolar) cells, mucous neck cells, and zymogenic chief cells (ZCs) of the corpus gastric unit. Loss of HNF4α in adult mouse stomach led to reduced ZC size and ER content, phenocopying previously characterized effects of Xbp1 deletion. However, HNF4α(Δ/Δ) stomachs also exhibited additional phenotypes including increased proliferation in the isthmal stem cell zone and altered mucous neck cell migration, indicating a role of HNF4α in progenitor cells as well as in ZCs. HNF4α directly occupies the Xbp1 promoter locus in mouse stomach, and forced HNF4α expression increased abundance of XBP1 mRNA in human gastric cancer cells. Finally, as expected, loss of HNF4α caused decreased Xbp1 and Mist1 expression in mouse stomachs. We show that HNF4α regulates homeostatic proliferation in the gastric epithelium and is both necessary and sufficient for the upstream regulation of the Xbp1→Mist1 axis in maintenance of ZC secretory architecture. PMID:27340127

  8. Maternal diet-induced obesity programs cardiovascular dysfunction in adult male mouse offspring independent of current body weight.

    PubMed

    Blackmore, Heather L; Niu, Youguo; Fernandez-Twinn, Denise S; Tarry-Adkins, Jane L; Giussani, Dino A; Ozanne, Susan E

    2014-10-01

    Obese pregnancies are not only associated with adverse consequences for the mother but also the long-term health of her child. Human studies have shown that individuals from obese mothers are at increased risk of premature death from cardiovascular disease (CVD), but are unable to define causality. This study aimed to determine causality using a mouse model of maternal diet-induced obesity. Obesity was induced in female C57BL/6 mice by feeding a diet rich in simple sugars and saturated fat 6 weeks prior to pregnancy and throughout pregnancy and lactation. Control females were fed laboratory chow. Male offspring from both groups were weaned onto chow and studied at 3, 5, 8, and 12 weeks of age for gross cardiac morphometry using stereology, cardiomyocyte cell area by histology, and cardiac fetal gene expression using qRT-PCR. Cardiac function was assessed by isolated Langendorff technology at 12 weeks of age and hearts were analyzed at the protein level for the expression of the β1 adrenergic receptor, muscarinic type-2 acetylcholine receptor, and proteins involved in cardiac contraction. Offspring from obese mothers develop pathologic cardiac hypertrophy associated with re-expression of cardiac fetal genes. By young adulthood these offspring developed severe systolic and diastolic dysfunction and cardiac sympathetic dominance. Importantly, cardiac dysfunction occurred in the absence of any change in corresponding body weight and despite the offspring eating a healthy low-fat diet. These findings provide a causal link to explain human observations relating maternal obesity with premature death from CVD in her offspring. PMID:25051449

  9. Virus-Specific Immunity in Neonatal and Adult Mouse Rotavirus Infection

    PubMed Central

    Sheridan, J. F.; Eydelloth, R. S.; Vonderfecht, S. L.; Aurelian, L.

    1983-01-01

    Mouse rotavirus (epizootic diarrhea of infant mice) was used as a model to study the role of virus-specific immunity in infection and diarrheal disease. The distribution of viral antigen in intestinal tissues was determined by immunofluorescent staining with anti-simian rotavirus (SA-11) serum. The location and proportion of antigen-positive cells appeared to vary as a function of time postinfection and age of the animal at the time of infection. In animals infected at 1 and 7 days of age, antigen-positive cells (5 to 25%) were first detected (1 day postinfection) in the proximal segment of the small intestine, and infection progressed to the middle and distal segments. At 10 days postinfection, virus-infected cells were no longer observed in the proximal segment. In animals infected at 21 days of age (disease-free), a significantly lower proportion of cells were antigen positive (2 to 5%), and they were restricted to the middle and distal segments of the small intestine. Infection, defined according to the presence of virus and viral antigens in intestinal tissues and by seroconversion in the immunoglobulin M (IgM) isotype as determined by enzyme-linked immunosorbent assay with SA-11 antigen, was observed for all age groups (neonatal to adult), even in the presence of virus-specific serum or intestinal immunoglobulins. On the other hand, diarrheal disease was not detected in neonatal mice (1 to 3 days old) positive for passively acquired virus-specific intestinal IgG. The presence of virus-specific IgA in the intestinal tract at the time of infection did not protect from subsequent diarrheal disease. Virus-specific, cell-mediated immunity, determined by a delayed-type hypersensitivity response, did not develop in neonatal mice infected at 5 and 12 days of age. Reinfection of adult mice was associated with suppression of virus-specific delayed-type hypersensitivity and a significant decrease in the titers of the virus-specific serum IgG and IgA. Images PMID:6299952

  10. Hes3 expression in the adult mouse brain is regulated during demyelination and remyelination.

    PubMed

    Toutouna, Louiza; Nikolakopoulou, Polyxeni; Poser, Steven W; Masjkur, Jimmy; Arps-Forker, Carina; Troullinaki, Maria; Grossklaus, Sylvia; Bosak, Viktoria; Friedrich, Ulrike; Ziemssen, Tjalf; Bornstein, Stefan R; Chavakis, Triantafyllos; Androutsellis-Theotokis, Andreas

    2016-07-01

    Hes3 is a component of the STAT3-Ser/Hes3 Signaling Axis controlling the growth and survival of neural stem cells and other plastic cells. Pharmacological activation of this pathway promotes neuronal rescue and behavioral recovery in models of ischemic stroke and Parkinson's disease. Here we provide initial observations implicating Hes3 in the cuprizone model of demyelination and remyelination. We focus on the subpial motor cortex of mice because we detected high Hes3 expression. This area is of interest as it is impacted both in human demyelinating diseases and in the cuprizone model. We report that Hes3 expression is reduced at peak demyelination and is partially restored within 1 week after cuprizone withdrawal. This raises the possibility of Hes3 involvement in demyelination/remyelination that may warrant additional research. Supporting a possible role of Hes3 in the maintenance of oligodendrocyte markers, a Hes3 null mouse strain shows lower levels of myelin basic protein in undamaged adult mice, compared to wild-type controls. We also present a novel method for culturing the established oligodendrocyte progenitor cell line oli-neu in a manner that maintains Hes3 expression as well as its self-renewal and differentiation potential, offering an experimental tool to study Hes3. Based upon this approach, we identify a Janus kinase inhibitor and dbcAMP as powerful inducers of Hes3 gene expression. We provide a new biomarker and cell culture method that may be of interest in demyelination/remyelination research. PMID:27018293

  11. Selective expression of prion protein in peripheral tissues of the adult mouse.

    PubMed

    Ford, M J; Burton, L J; Morris, R J; Hall, S M

    2002-01-01

    The level of expression of normal cellular prion protein, PrP(c) (cellular prion protein), controls both the rate and the route of neuroinvasive infection, from peripheral entry portal to the CNS. Paradoxically, an overview of the distribution of PrP(c) within tissues outside the CNS is lacking. We have used novel antibodies that recognise cellular prion protein in glutaraldehyde-fixed tissue (in order to optimise immunohistochemical labelling of this conformationally labile protein), in combination with in situ hybridisation, to examine the expression of PrP(c) in peripheral tissues of the adult mouse. We found that although prion protein is expressed in many tissues, it is expressed at high levels only in discrete subpopulations of cells. Prominent amongst these are elements of the "hardwired neuroimmune network" that integrate the body's immune defence and neuroendocrine systems under CNS control. These prion protein-expressing elements include small diameter afferent nerves in the skin and the lamina propria of the aerodigestive tract, sympathetic ganglia and nerves, antigen presenting and processing cells (both follicular and non-follicular dendritic cells) and sub-populations of lymphocytes particularly in skin, gut- and bronchus-associated lymphoid tissues. Prion protein is also expressed in the parasympathetic and enteric nervous systems, in the dispersed neuroendocrine system, and in peripheral nervous system axons and their associated Schwann cells. This selective expression of cellular prion protein provides a variety of alternative routes for the propagation and transport of prion infection entering from peripheral sites, either naturally (via the aerodigestive tract or abraded skin) or experimentally (by intraperitoneal injection) to the brain. Key regulatory cells that express prion protein, and in particular enteroendocrine cells in the mucosal wall of the gut, and dendritic cells that convey pathogens from epithelial layers to secondary lymphoid

  12. Effect of Cyanotoxins on the Hypothalamic–Pituitary–Gonadal Axis in Male Adult Mouse

    PubMed Central

    Xu, Huajun

    2014-01-01

    Background Microcystins LR (MC-LR) are hepatotoxic cyanotoxins that have been shown to induce reproductive toxicity, and Hypothalamic–Pituitary–Gonadal Axis (HPG) is responsible for the control of reproductive functions. However, few studies have been performed to evaluate the effects of MC-LR on HPG axis. This study aimed to investigate the MC-LR-induced toxicity in the reproductive system of mouse and focus on the HPG axis. Methods Adult male C57BL/6 mice were exposed to various concentrations of MC-LR (0, 3.75, 7.50, 15.00 and 30.00 µg/kg body weight per day) for 1 to 14 days, and it was found that exposure to different concentrations of MC-LR significantly disturbed sperm production in the mice testes in a dose- and time-dependent manner. To elucidate the associated possible mechanisms, the serum levels of testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were assessed. Meanwhile, PCR assays were employed to detect alterations in a series of genes involved in HPG axis, such as FSH, LH, gonadotropin-releasing hormone (GnRH) and their complement receptors. Furthermore, the effect of MC-LR on the viability and testosterone production of Leydig cells were tested in vitro. Results: MC-LR significantly impaired the spermatogenesis of mice possibly through the direct or indirect inhibition of GnRH synthesis at the hypothalamic level, which resulted in reduction of serum levels of LH that lead to suppression of testosterone production in the testis of mice. Conclusions MC-LR may be a GnRH toxin that would disrupt the reproductive system of mice. PMID:25375936

  13. Brief Isoflurane Anesthesia Produces Prominent Phosphoproteomic Changes in the Adult Mouse Hippocampus.

    PubMed

    Kohtala, Samuel; Theilmann, Wiebke; Suomi, Tomi; Wigren, Henna-Kaisa; Porkka-Heiskanen, Tarja; Elo, Laura L; Rokka, Anne; Rantamäki, Tomi

    2016-06-15

    Anesthetics are widely used in medical practice and experimental research, yet the neurobiological basis governing their effects remains obscure. We have here used quantitative phosphoproteomics to investigate the protein phosphorylation changes produced by a 30 min isoflurane anesthesia in the adult mouse hippocampus. Altogether 318 phosphorylation alterations in total of 237 proteins between sham and isoflurane anesthesia were identified. Many of the hit proteins represent primary pharmacological targets of anesthetics. However, findings also enlighten the role of several other proteins-implicated in various biological processes including neuronal excitability, brain energy homeostasis, synaptic plasticity and transmission, and microtubule function-as putative (secondary) targets of anesthetics. In particular, isoflurane increases glycogen synthase kinase-3β (GSK3β) phosphorylation at the inhibitory Ser(9) residue and regulates the phosphorylation of multiple proteins downstream and upstream of this promiscuous kinase that regulate diverse biological functions. Along with confirmatory Western blot data for GSK3β and p44/42-MAPK (mitogen-activated protein kinase; reduced phosphorylation of the activation loop), we observed increased phosphorylation of microtubule-associated protein 2 (MAP2) on residues (Thr(1620,1623)) that have been shown to render its dissociation from microtubules and alterations in microtubule stability. We further demonstrate that diverse anesthetics (sevoflurane, urethane, ketamine) produce essentially similar phosphorylation changes on GSK3β, p44/p42-MAPK, and MAP2 as observed with isoflurane. Altogether our study demonstrates the potential of quantitative phosphoproteomics to study the mechanisms of anesthetics (and other drugs) in the mammalian brain and reveals how already a relatively brief anesthesia produces pronounced phosphorylation changes in multiple proteins in the central nervous system. PMID:27074656

  14. Bergmann glia are patterned into topographic molecular zones in the developing and adult mouse cerebellum

    PubMed Central

    Reeber, Stacey L.; Arancillo, Marife K. V.; Sillitoe, Roy V.

    2015-01-01

    Cerebellar circuits are patterned into an array of topographic parasagittal domains called zones. Zones are best revealed by gene expression, circuit anatomy, and cellular degeneration patterns. Thus far, the study of zones has been focused heavily on how neurons are organized. Because of this, detailed neuronal patterning maps have been established for Purkinje cells, granule cells, Golgi cells, unipolar brush cells, and also for the terminal field organization of climbing fiber and mossy fiber afferents. In comparison, however, it remains poorly understood if glial cells are also organized into zones. We have identified an Npy-Gfp BAC transgenic mouse line (Tau-Sapphire Green fluorescent protein (Gfp) is under the control of the neuropeptide Y (Npy) gene regulatory elements) that can be used to label Bergmann glial cells with Golgi-like resolution. In these adult transgenic mice we found that Npy-Gfp expression was localized to Bergmann glia mainly in lobules VI/VII and IX/X. Using double immunofluorescence, we show that in these lobules, Npy-Gfp expression in the Bergmann glia overlaps with the pattern of the small heat shock protein HSP25, a Purkinje cell marker for zones located in lobules VI/VII and IX/X. Developmental analysis starting from the day of birth showed that HSP25 and Npy-Gfp expression follow a similar program of spatial and temporal patterning. However, loss of Npy signaling did not alter the patterning of Purkinje cell zones. We conclude that Bergmann glial cells are zonally organized and their patterns are restricted by boundaries that also confine cerebellar neurons into a topographic circuit map. PMID:24906823

  15. Designer Self-Assembling Peptide Nanofiber Scaffolds for Adult Mouse Neural Stem Cell 3-Dimensional Cultures

    PubMed Central

    Gelain, Fabrizio; Bottai, Daniele; Vescovi, Angleo; Zhang, Shuguang

    2006-01-01

    Biomedical researchers have become increasingly aware of the limitations of conventional 2-dimensional tissue cell culture systems, including coated Petri dishes, multi-well plates and slides, to fully address many critical issues in cell biology, cancer biology and neurobiology, such as the 3-D microenvironment, 3-D gradient diffusion, 3-D cell migration and 3-D cell-cell contact interactions. In order to fully understand how cells behave in the 3-D body, it is important to develop a well-controlled 3-D cell culture system where every single ingredient is known. Here we report the development of a 3-D cell culture system using a designer peptide nanofiber scaffold with mouse adult neural stem cells. We attached several functional motifs, including cell adhesion, differentiation and bone marrow homing motifs, to a self-assembling peptide RADA16 (Ac-RADARADARADARADA-COHN2). These functionalized peptides undergo self-assembly into a nanofiber structure similar to Matrigel. During cell culture, the cells were fully embedded in the 3-D environment of the scaffold. Two of the peptide scaffolds containing bone marrow homing motifs significantly enhanced the neural cell survival without extra soluble growth and neurotrophic factors to the routine cell culture media. In these designer scaffolds, the cell populations with β-Tubulin+, GFAP+ and Nestin+ markers are similar to those found in cell populations cultured on Matrigel. The gene expression profiling array experiments showed selective gene expression, possibly involved in neural stem cell adhesion and differentiation. Because the synthetic peptides are intrinsically pure and a number of desired function cellular motifs are easy to incorporate, these designer peptide nanofiber scaffolds provide a promising controlled 3-D culture system for diverse tissue cells, and are useful as well for general molecular and cell biology. PMID:17205123

  16. Reproducible expansion and characterization of mouse neural stem/progenitor cells in adherent cultures derived from the adult subventricular zone

    PubMed Central

    Theus, Michelle H.; Ricard, Jerome; Liebl, Daniel J.

    2012-01-01

    Endogenous neural stem/progenitor cells (NSPCs) residing in the subventricular zone (SVZ) of the adult mouse forebrain have been shown to enhance their neurogenic potential in response to CNS injury. Mechanisms involved in regulating adult neurogenesis under naïve or stressed conditions can be studied using a monolayer cell-culture system of the nestin-expressing NSPC lineage to analyze proliferation, survival and differentiation. Here, we describe a protocol for the expansion of NSPCs for studies aimed at understanding the functional role of NSPCs in maintaining adult neurogenic processes. In this unit, we outline in detail the procedures for: (1) isolation, maintenance and culture of the NSPC component of the SVZ niche from the lateral wall of the lateral ventricle; (2) characterization of NSPC functions by examining proliferation, survival and differentiation; and (3) efficient siRNA transfection methods in 96-well format. PMID:22415840

  17. Cardiomyocyte specific deletion of PP2A causes cardiac hypertrophy

    PubMed Central

    Li, Lei; Fang, Chao; Xu, Di; Xu, Yidan; Fu, Heling; Li, Jianmin

    2016-01-01

    Cardiac hypertrophy is a common pathological alteration in heart disease, which has been reported to be connected with serine/threonine protein phosphatases that control the dephosphorylation of a variety of cardiac proteins. Herein, we generated protein phosphatase type 2A knockout expressing a tamoxifen-inducible Cre recombinase protein fused to two mutant estrogen-receptor ligand-binding domains (MerCreMer) under the control of the a-myosin heavy chain promoter. Cardiac function of mice was determined by echocardiography. Decrease in PP2A activity leads to increased cardiomyocyte hypertrophy and fibrosis. Loss of PP2ACα leads to the heart failure, including the changes of EF, FS, LV, ANP and BNP. On the molecular level, knockout mice shows increased expression of B55a and B56e at 60 days after tamoxifen injection. Additionally, the regulation of the Akt/GSK3β/β-catenin pathway is severely disturbed in knockout mice. In conclusion, cardiomyocyte specific deletion of PP2A gene causes the cardiac hypertrophy. We will use the knockout mice to generate a type of cardiomyocyte hypertrophy mouse model with myocardial fibrosis. PMID:27186301

  18. Leukemia Inhibitory Factor Enhances Endogenous Cardiomyocyte Regeneration after Myocardial Infarction

    PubMed Central

    Kanda, Masato; Nagai, Toshio; Takahashi, Toshinao; Liu, Mei Lan; Kondou, Naomichi; Naito, Atsuhiko T.; Akazawa, Hiroshi; Sashida, Goro; Iwama, Atsushi; Komuro, Issei; Kobayashi, Yoshio

    2016-01-01

    Cardiac stem cells or precursor cells regenerate cardiomyocytes; however, the mechanism underlying this effect remains unclear. We generated CreLacZ mice in which more than 99.9% of the cardiomyocytes in the left ventricular field were positive for 5-bromo-4-chloro-3-indolyl-β-d-galactoside (X-gal) staining immediately after tamoxifen injection. Three months after myocardial infarction (MI), the MI mice had more X-gal-negative (newly generated) cells than the control mice (3.04 ± 0.38/mm2, MI; 0.47 ± 0.16/mm2, sham; p < 0.05). The cardiac side population (CSP) cell fraction contained label-retaining cells, which differentiated into X-gal-negative cardiomyocytes after MI. We injected a leukemia inhibitory factor (LIF)-expression construct at the time of MI and identified a significant functional improvement in the LIF-treated group. At 1 month after MI, in the MI border and scar area, the LIF-injected mice had 31.41 ± 5.83 X-gal-negative cardiomyocytes/mm2, whereas the control mice had 12.34 ± 2.56 X-gal-negative cardiomyocytes/mm2 (p < 0.05). Using 5-ethynyl-2'-deoxyurinide (EdU) administration after MI, the percentages of EdU-positive CSP cells in the LIF-treated and control mice were 29.4 ± 2.7% and 10.6 ± 3.7%, respectively, which suggests that LIF influenced CSP proliferation. Moreover, LIF activated the Janus kinase (JAK)signal transducer and activator of transcription (STAT), mitogen-activated protein kinase/extracellular signal-regulated (MEK)extracellular signal-regulated kinase (ERK), and phosphatidylinositol 3-kinase (PI3K)–AKT pathways in CSPs in vivo and in vitro. The enhanced green fluorescent protein (EGFP)-bone marrow-chimeric CreLacZ mouse results indicated that LIF did not stimulate cardiogenesis via circulating bone marrow-derived cells during the 4 weeks following MI. Thus, LIF stimulates, in part, stem cell-derived cardiomyocyte regeneration by activating cardiac stem or precursor cells. This approach may represent a novel therapeutic

  19. Disruption of Ah Receptor Signaling during Mouse Development Leads to Abnormal Cardiac Structure and Function in the Adult.

    PubMed

    Carreira, Vinicius S; Fan, Yunxia; Kurita, Hisaka; Wang, Qin; Ko, Chia-I; Naticchioni, Mindi; Jiang, Min; Koch, Sheryl; Zhang, Xiang; Biesiada, Jacek; Medvedovic, Mario; Xia, Ying; Rubinstein, Jack; Puga, Alvaro

    2015-01-01

    The Developmental Origins of Health and Disease (DOHaD) Theory proposes that the environment encountered during fetal life and infancy permanently shapes tissue physiology and homeostasis such that damage resulting from maternal stress, poor nutrition or exposure to environmental agents may be at the heart of adult onset disease. Interference with endogenous developmental functions of the aryl hydrocarbon receptor (AHR), either by gene ablation or by exposure in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent AHR ligand, causes structural, molecular and functional cardiac abnormalities and altered heart physiology in mouse embryos. To test if embryonic effects progress into an adult phenotype, we investigated whether Ahr ablation or TCDD exposure in utero resulted in cardiac abnormalities in adult mice long after removal of the agent. Ten-months old adult Ahr-/- and in utero TCDD-exposed Ahr+/+ mice showed sexually dimorphic abnormal cardiovascular phenotypes characterized by echocardiographic findings of hypertrophy, ventricular dilation and increased heart weight, resting heart rate and systolic and mean blood pressure, and decreased exercise tolerance. Underlying these effects, genes in signaling networks related to cardiac hypertrophy and mitochondrial function were differentially expressed. Cardiac dysfunction in mouse embryos resulting from AHR signaling disruption seems to progress into abnormal cardiac structure and function that predispose adults to cardiac disease, but while embryonic dysfunction is equally robust in males and females, the adult abnormalities are more prevalent in females, with the highest severity in Ahr-/- females. The findings reported here underscore the conclusion that AHR signaling in the developing heart is one potential target of environmental factors associated with cardiovascular disease. PMID:26555816

  20. Disruption of Ah Receptor Signaling during Mouse Development Leads to Abnormal Cardiac Structure and Function in the Adult

    PubMed Central

    Carreira, Vinicius S.; Fan, Yunxia; Kurita, Hisaka; Wang, Qin; Ko, Chia-I; Naticchioni, Mindi; Jiang, Min; Koch, Sheryl; Zhang, Xiang; Biesiada, Jacek; Medvedovic, Mario; Xia, Ying; Rubinstein, Jack; Puga, Alvaro

    2015-01-01

    The Developmental Origins of Health and Disease (DOHaD) Theory proposes that the environment encountered during fetal life and infancy permanently shapes tissue physiology and homeostasis such that damage resulting from maternal stress, poor nutrition or exposure to environmental agents may be at the heart of adult onset disease. Interference with endogenous developmental functions of the aryl hydrocarbon receptor (AHR), either by gene ablation or by exposure in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent AHR ligand, causes structural, molecular and functional cardiac abnormalities and altered heart physiology in mouse embryos. To test if embryonic effects progress into an adult phenotype, we investigated whether Ahr ablation or TCDD exposure in utero resulted in cardiac abnormalities in adult mice long after removal of the agent. Ten-months old adult Ahr-/- and in utero TCDD-exposed Ahr+/+ mice showed sexually dimorphic abnormal cardiovascular phenotypes characterized by echocardiographic findings of hypertrophy, ventricular dilation and increased heart weight, resting heart rate and systolic and mean blood pressure, and decreased exercise tolerance. Underlying these effects, genes in signaling networks related to cardiac hypertrophy and mitochondrial function were differentially expressed. Cardiac dysfunction in mouse embryos resulting from AHR signaling disruption seems to progress into abnormal cardiac structure and function that predispose adults to cardiac disease, but while embryonic dysfunction is equally robust in males and females, the adult abnormalities are more prevalent in females, with the highest severity in Ahr-/- females. The findings reported here underscore the conclusion that AHR signaling in the developing heart is one potential target of environmental factors associated with cardiovascular disease. PMID:26555816

  1. Comprehensive Analysis of Neonatal versus Adult Unilateral Decortication in a Mouse Model Using Behavioral, Neuroanatomical, and DNA Microarray Approaches

    PubMed Central

    Yoshikawa, Akira; Nakamachi, Tomoya; Shibato, Junko; Rakwal, Randeep; Shioda, Seiji

    2014-01-01

    Previously, studying the development, especially of corticospinal neurons, it was concluded that the main compensatory mechanism after unilateral brain injury in rat at the neonatal stage was due in part to non-lesioned ipsilateral corticospinal neurons that escaped selection by axonal elimination or neuronal apoptosis. However, previous results suggesting compensatory mechanism in neonate brain were not correlated with high functional recovery. Therefore, what is the difference among neonate and adult in the context of functional recovery and potential mechanism(s) therein? Here, we utilized a brain unilateral decortication mouse model and compared motor functional recovery mechanism post-neonatal brain hemisuction (NBH) with adult brain hemisuction (ABH). Three analyses were performed: (1) Quantitative behavioral analysis of forelimb movements using ladder walking test; (2) neuroanatomical retrograde tracing analysis of unlesioned side corticospinal neurons; and (3) differential global gene expressions profiling in unlesioned-side neocortex (rostral from bregma) in NBH and ABH on a 8 × 60 K mouse whole genome Agilent DNA chip. Behavioral data confirmed higher recovery ability in NBH over ABH is related to non-lesional frontal neocortex including rostral caudal forelimb area. A first inventory of differentially expressed genes genome-wide in the NBH and ABH mouse model is provided as a resource for the scientific community. PMID:25490135

  2. ZLN005 protects cardiomyocytes against high glucose-induced cytotoxicity by promoting SIRT1 expression and autophagy.

    PubMed

    Li, Wenju; Li, Xiaoli; Wang, Bin; Chen, Yan; Xiao, Aiping; Zeng, Di; Ou, Dongbo; Yan, Song; Li, Wei; Zheng, Qiangsun

    2016-07-01

    Diabetic cardiomyopathy increases the risk for the development of heart failure independent of coronary artery disease and hypertension. Either type 1 or type 2 diabetes is often accompanied by varying degrees of hyperglycemia, which has been proven to induce myocardial apoptosis in animal models. Recently, a novel small molecule, ZLN005, has been reported to show antidiabetic efficacy in a mouse model, possibly by induction of PGC-1α expression. In this study, we investigated whether ZLN005 protects cardiomyocytes against high glucose-induced cytotoxicity and the mechanisms involved. Neonatal mouse cardiomyocytes were incubated with media containing 5.5 or 33mM glucose for 24h in the presence or absence of ZLN005. ZLN005 treatment led to ameliorated cardiomyocyte oxidative injury, enhanced cell viability, and reduced apoptosis in the high glucose environment. Western blot analysis revealed that high glucose suppressed cardiomyocyte autophagy, whereas ZLN005 increased the expression of autophagy marker proteins ATG5, beclin1, and LC3 II/LC3 I; this increase was accompanied by increased expression of SIRT1. Furthermore, EX527, a SIRT1-specific inhibitor, weakened the protective effects of ZLN005 on cardiomyocytes subjected to high glucose. Taken together, these results suggest that ZLN005 suppresses high glucose-induced cardiomyocyte injury by promoting SIRT1 expression and autophagy. PMID:27208585

  3. Fibroblast growth factor 10 alters the balance between goblet and Paneth cells in the adult mouse small intestine.

    PubMed

    Al Alam, Denise; Danopoulos, Soula; Schall, Kathy; Sala, Frederic G; Almohazey, Dana; Fernandez, G Esteban; Georgia, Senta; Frey, Mark R; Ford, Henri R; Grikscheit, Tracy; Bellusci, Saverio

    2015-04-15

    Intestinal epithelial cell renewal relies on the right balance of epithelial cell migration, proliferation, differentiation, and apoptosis. Intestinal epithelial cells consist of absorptive and secretory lineage. The latter is comprised of goblet, Paneth, and enteroendocrine cells. Fibroblast growth factor 10 (FGF10) plays a central role in epithelial cell proliferation, survival, and differentiation in several organs. The expression pattern of FGF10 and its receptors in both human and mouse intestine and their role in small intestine have yet to be investigated. First, we analyzed the expression of FGF10, FGFR1, and FGFR2, in the human ileum and throughout the adult mouse small intestine. We found that FGF10, FGFR1b, and FGFR2b are expressed in the human ileum as well as in the mouse small intestine. We then used transgenic mouse models to overexpress Fgf10 and a soluble form of Fgfr2b, to study the impact of gain or loss of Fgf signaling in the adult small intestine. We demonstrated that overexpression of Fgf10 in vivo and in vitro induces goblet cell differentiation while decreasing Paneth cells. Moreover, FGF10 decreases stem cell markers such as Lgr5, Lrig1, Hopx, Ascl2, and Sox9. FGF10 inhibited Hes1 expression in vitro, suggesting that FGF10 induces goblet cell differentiation likely through the inhibition of Notch signaling. Interestingly, Fgf10 overexpression for 3 days in vivo and in vitro increased the number of Mmp7/Muc2 double-positive cells, suggesting that goblet cells replace Paneth cells. Further studies are needed to determine the mechanism by which Fgf10 alters cell differentiation in the small intestine. PMID:25721301

  4. Herpesvirus-mediated delivery of a genetically encoded fluorescent Ca(2+) sensor to canine cardiomyocytes.

    PubMed

    Prorok, János; Kovács, Péter P; Kristóf, Attila A; Nagy, Norbert; Tombácz, Dóra; Tóth, Judit S; Ordög, Balázs; Jost, Norbert; Virág, László; Papp, Julius G; Varró, András; Tóth, András; Boldogkoi, Zsolt

    2009-01-01

    We report the development and application of a pseudorabies virus-based system for delivery of troponeon, a fluorescent Ca(2+) sensor to adult canine cardiomyocytes. The efficacy of transduction was assessed by calculating the ratio of fluorescently labelled and nonlabelled cells in cell culture. Interaction of the virus vector with electrophysiological properties of cardiomyocytes was evaluated by the analysis of transient outward current (I(to)), kinetics of the intracellular Ca(2+) transients, and cell shortening. Functionality of transferred troponeon was verified by FRET analysis. We demonstrated that the transfer efficiency of troponeon to cultured adult cardiac myocytes was virtually 100%. We showed that even after four days neither the amplitude nor the kinetics of the I(to) current was significantly changed and no major shifts occurred in parameters of [Ca(2+)](i) transients. Furthermore, we demonstrated that infection of cardiomyocytes with the virus did not affect the morphology, viability, and physiological attributes of cells. PMID:19636419

  5. Ultrastructural maturation of human bone marrow mesenchymal stem cells-derived cardiomyocytes under alternative induction of 5-azacytidine.

    PubMed

    Piryaei, Abbas; Soleimani, Masoud; Heidari, Mohammad Hassan; Saheli, Mona; Rohani, Razieh; Almasieh, Mohammadali

    2015-05-01

    Adult cardiomyocytes lack the ability to proliferate and are unable to repair damaged heart tissue, therefore differentiation of stem cells to cardiomyocytes represents an exceptional opportunity to study cardiomyocytes in vitro and potentially provides a valuable source for replacing damaged tissue. However, characteristic maturity of the in vitro differentiated cardiomyocytes and methods to achieve it are yet to be optimized. In this study, differentiation of human bone marrow-mesenchymal stem cells (hBM-MSCs) into cardiomyocytes is accomplished and the process investigated ultrastructurally. The hBM-MSCs were alternatively treated with 5 μM of 5-azacytidine (5-aza) for 8 weeks resulting in differentiation to cardiomyocytes. Expressions of cardiomyocyte-specific genes [cardiac α-actinin, cardiac β-myosin heavy chain (MHC) and connexin-43] and proteins (cardiac α-actinin, cardiac troponin and connexin-43) were confirmed in a time-dependent manner from the first to the fifth weeks post-induction. Ultrastructural maturation of hBM-MSCs-derived cardiomyocyte (MSCs-CM) corresponded with increase in number and organization of myofilaments in cells over time. Starting from week five, organized myofibrils along with developing sarcomeres were detectable. Later on, MSCs-CM were characterized by the presence of sarcoplasmic reticulum, T-tubules and diads as cardiomyocytes connected to each other by intercalated disc-like structures. Here, we showed the potential of hBM-MSCs as a source for the production of cardiomyocytes and confirmed mature ultrastructural characteristics of these cells using our alternative incubation method. PMID:25573851

  6. Dataset of integrin-linked kinase protein: Protein interactions in cardiomyocytes identified by mass spectrometry.

    PubMed

    Traister, Alexandra; Lu, Mingliang; Coles, John G; Maynes, Jason T

    2016-06-01

    Using hearts from mice overexpressing integrin linked kinase (ILK) behind the cardiac specific promoter αMHC, we have performed immunoprecipitation and mass spectrometry to identify novel ILK protein:protein interactions that regulate cardiomyocyte activity and calcium flux. Integrin linked kinase complexes were captured from mouse heart lysates using a commercial antibody, with subsequent liquid chromatography tandem mass spectral analysis. Interacting partners were identified using the MASCOT server, and important interactions verified using reverse immunoprecipitation and mass spectrometry. All ILK interacting proteins were identified in a non-biased manner, and are stored in the ProteomeXchange Consortium via the PRIDE partner repository (reference ID PRIDE: PXD001053). The functional role of identified ILK interactions in cardiomyocyte function and arrhythmia were subsequently confirmed in human iPSC-cardiomyocytes. PMID:27408918

  7. Isolation and Assessment of Single Long-Term Reconstituting Hematopoietic Stem Cells from Adult Mouse Bone Marrow.

    PubMed

    Kent, David G; Dykstra, Brad J; Eaves, Connie J

    2016-01-01

    Hematopoietic stem cells with long-term repopulating activity can now be routinely obtained at purities of 40% to 50% from suspensions of adult mouse bone marrow. Here we describe robust protocols for both their isolation as CD45(+) EPCR(+) CD150(+) CD48(-) (ESLAM) cells using multiparameter cell sorting and for tracking their clonal growth and differentiation activity in irradiated mice transplanted with single ESLAM cells. The simplicity of these procedures makes them attractive for characterizing the molecular and biological properties of individual hematopoietic stem cells with unprecedented power and precision. © 2016 by John Wiley & Sons, Inc. PMID:27532815

  8. Lumican Deficiency Results In Cardiomyocyte Hypertrophy With Altered Collagen Assembly

    PubMed Central

    Dupuis, Loren E.; Berger, Matthew G.; Feldman, Samuel; Doucette, Lorna; Fowlkes, Vennece; Chakravarti, Shukti; Thibaudeau, Sarah; Alcala, Nicolas E.; Bradshaw, Amy D.; Kern, Christine B.

    2015-01-01

    The ability of the heart to adapt to increased stress is dependent on modification of its extracellular matrix (ECM) architecture that is established during postnatal development as cardiomyocytes differentiate, a process that is poorly understood. We hypothesized that the small leucine-rich proteoglycan (SLRP) lumican (LUM), which binds collagen and facilitates collagen assembly in other tissues, may play a critical role in establishing the postnatal murine myocardial ECM. Although previous studies suggest LUM deficient mice (lum−/−) exhibit skin anomalies consistent with Ehlers-Danlos syndrome, lum−/− hearts have not been evaluated. These studies show LUM was immunolocalized to non-cardiomyocytes of the cardiac ventricles and its expression increased throughout development. Lumican deficiency resulted in significant (50%) perinatal death and further examination of the lum−/− neonatal hearts revealed an increase in myocardial tissue without a significant increase in cell proliferation. However cardiomyocytes from surviving postnatal day 0 (P0), 1 month (1 mo) and adult (4 mo) lum−/− hearts were significantly larger than their wild type (WT) littermates. Immunohistochemistry revealed that the increased cardiomyocyte size in the lum−/− hearts correlated with alteration of the cardiomyocyte pericellular ECM components collagenα1(I) and the class I SLRP decorin (DCN). Western blot analysis demonstrated that the ratio of glycosaminoglycan (GAG) decorated DCN to core DCN was reduced in P0 and 1 mo lum−/− hearts. There was also a reduction in the β and γ forms of collagenα1(I) in lum−/− hearts. While the total insoluble collagen content was significantly reduced, the fibril size was increased in lum−/− hearts, indicating LUM may play a role in collagen fiber stability and lateral fibril assembly. These results suggest that LUM controls cardiomyocyte growth by regulating the pericellular ECM and also indicates that LUM may coordinate

  9. Neuregulin stimulation of cardiomyocyte regeneration in mice and human myocardium reveals a therapeutic window.

    PubMed

    Polizzotti, Brian D; Ganapathy, Balakrishnan; Walsh, Stuart; Choudhury, Sangita; Ammanamanchi, Niyatie; Bennett, David G; dos Remedios, Cristobal G; Haubner, Bernhard J; Penninger, Josef M; Kühn, Bernhard

    2015-04-01

    Therapies developed for adult patients with heart failure have been shown to be ineffective in pediatric clinical trials, leading to the recognition that new pediatric-specific therapies for heart failure must be developed. Administration of the recombinant growth factor neuregulin-1 (rNRG1) stimulates regeneration of heart muscle cells (cardiomyocytes) in adult mice. Because proliferation-competent cardiomyocytes are more abundant in growing mammals, we hypothesized that administration of rNRG1 during the neonatal period might be more effective than in adulthood. If so, neonatal rNRG1 delivery could be a new therapeutic strategy for treating heart failure in pediatric patients. To evaluate the effectiveness of rNRG1 administration in cardiac regeneration, newborn mice were subjected to cryoinjury, which induced myocardial dysfunction and scar formation and decreased cardiomyocyte cell cycle activity. Early administration of rNRG1 to mice from birth to 34 days of age improved myocardial function and reduced the prevalence of transmural scars. In contrast, administration of rNRG1 from 4 to 34 days of age only transiently improved myocardial function. The mechanisms of early administration involved cardiomyocyte protection (38%) and proliferation (62%). We also assessed the ability of rNRG1 to stimulate cardiomyocyte proliferation in intact cultured myocardium from pediatric patients. rNRG1 induced cardiomyocyte proliferation in myocardium from infants with heart disease who were less than 6 months of age. Our results identify an effective time period within which to execute rNRG1 clinical trials in pediatric patients for the stimulation of cardiomyocyte regeneration. PMID:25834111

  10. New model for cardiomyocyte sheet transplantation using a virus-cell fusion technique

    PubMed Central

    Takahashi, Yuto; Tomotsune, Daihachiro; Takizawa, Sakiko; Yue, Fengming; Nagai, Mika; Yokoyama, Tadayuki; Hirashima, Kanji; Sasaki, Katsunori

    2015-01-01

    AIM: To facilitate close contacts between transplanted cardiomyocytes and host skeletal muscle using cell fusion mediated by hemagglutinating virus of Japan envelope (HVJ-E) and tissue maceration. METHODS: Cardiomyocytes (1.5 × 106) from fetal rats were first cultured. After proliferation, some cells were used for fusion with adult muscle fibers using HVJ-E. Other cells were used to create cardiomyocyte sheets (area: about 3.5 cm2 including 2.1 × 106 cells), which were then treated with Nile blue, separated, and transplanted between the latissimus dorsi and intercostal muscles of adult rats with four combinations of HVJ-E and/or NaOH maceration: G1: HVJ-E(+), NaOH(+), Cardiomyocytes(+); G2: HVJ-E(-), NaOH(+), Cardiomyocytes(+); G3: HVJ-E(+), NaOH(-), Cardiomyocytes(+); G4: HVJ-E(-), NaOH(-), Cardiomyocytes(-). At 1 and 2 wk after transplantation, the four groups were compared by detection of beating domains, motion images using moving target analysis software, action potentials, gene expression of MLC-2v and Mesp1 by reverse transcription-polymerase chain reaction, hematoxylin-eosin staining, and immunostaining for cardiac troponin and skeletal myosin. RESULTS: In vitro cardiomyocytes were fused with skeletal muscle fibers using HVJ-E. Cardiomyocyte sheets remained in the primary transplanted sites for 2 wk. Although beating domains were detected in G1, G2, and G3 rats, G1 rats prevailed in the number, size, motion image amplitudes, and action potential compared with G2 and G3 rats. Close contacts were only found in G1 rats. At 1 wk after transplantation, the cardiomyocyte sheets showed adhesion at various points to the myoblast layer in the latissimus dorsi muscle. At 2 wk after transplantation, close contacts were seen over a broad area. Part of the skeletal muscle sarcoplasma seemed to project into the myocardiocyte plasma and some nuclei appeared to share both sarcoplasmas. CONCLUSION: The present results show that close contacts were acquired and facilitated

  11. Copper reverses cardiomyocyte hypertrophy through vascular endothelial growth factor-mediated reduction in the cell size.

    PubMed

    Zhou, Yang; Jiang, Youchun; Kang, Y James

    2008-07-01

    Previous studies have shown that dietary copper supplementation reversed heart hypertrophy induced by pressure overload in a mouse model. The present study was undertaken to understand the cellular basis of copper-induced regression of cardiac hypertrophy. Primary cultures of neonatal rat cardiomyocytes were treated with phenylephrine (PE) at a final concentration of 100 microM in cultures for 48 h to induce cellular hypertrophy. The hypertrophied cardiomyocytes were exposed to copper sulfate at a final concentration of 5 microM in cultures for additional 24 h. This copper treatment reduced the size of the hypertrophied cardiomyocytes, as measured by flow cytometry, protein content in cells, cell volume and cardiomyocyte hypertrophy markers including beta-myosin heavy chain protein, skeletal alpha-actin, and atrial natriuretic peptide. Cell cycle analysis and cell sorting of p-histone-3 labeled cardiomyocytes indicated that cell division was not involved in the copper-induced regression of cardiomyocyte hypertrophy. Copper also inhibited PE-induced apoptosis, determined by a TUNEL assay. Because copper stimulates vascular endothelial growth factor (VEGF) production through activation of hypoxia-inducible transcription factor, an anti-VEGF antibody at a final concentration of 2 ng/ml in cultures was used and shown to blunt copper-induced regression of cell hypertrophy. Conversely, VEGF alone at a final concentration of 0.2 microg/ml reversed cell hypertrophy as the same as copper did. This study demonstrates that both copper and VEGF reduce the size of hypertrophied cardiomyocytes, and copper regression of cardiac hypertrophy is VEGF-dependent. PMID:18495151

  12. Induced Pluripotent Stem Cell-Derived Cardiac Progenitors Differentiate to Cardiomyocytes and Form Biosynthetic Tissues

    PubMed Central

    Chakraborty, Syandan; Chellapan, Malathi; Bursac, Nenad; Leong, Kam W.

    2013-01-01

    The mammalian heart has little capacity to regenerate, and following injury the myocardium is replaced by non-contractile scar tissue. Consequently, increased wall stress and workload on the remaining myocardium leads to chamber dilation, dysfunction, and heart failure. Cell-based therapy with an autologous, epigenetically reprogrammed, and cardiac-committed progenitor cell source could potentially reverse this process by replacing the damaged myocardium with functional tissue. However, it is unclear whether cardiac progenitor cell-derived cardiomyocytes are capable of attaining levels of structural and functional maturity comparable to that of terminally-fated cardiomyocytes. Here, we first describe the derivation of mouse induced pluripotent stem (iPS) cells, which once differentiated allow for the enrichment of Nkx2-5(+) cardiac progenitors, and the cardiomyocyte-specific expression of the red fluorescent protein. We show that the cardiac progenitors are multipotent and capable of differentiating into endothelial cells, smooth muscle cells and cardiomyocytes. Moreover, cardiac progenitor selection corresponds to cKit(+) cell enrichment, while cardiomyocyte cell-lineage commitment is concomitant with dual expression of either cKit/Flk1 or cKit/Sca-1. We proceed to show that the cardiac progenitor-derived cardiomyocytes are capable of forming electrically and mechanically coupled large-scale 2D cell cultures with mature electrophysiological properties. Finally, we examine the cell progenitors’ ability to form electromechanically coherent macroscopic tissues, using a physiologically relevant 3D culture model and demonstrate that following long-term culture the cardiomyocytes align, and form robust electromechanical connections throughout the volume of the biosynthetic tissue construct. We conclude that the iPS cell-derived cardiac progenitors are a robust cell source for tissue engineering applications and a 3D culture platform for pharmacological screening and

  13. miR-218 Involvement in Cardiomyocyte Hypertrophy Is Likely through Targeting REST

    PubMed Central

    Liu, Jing-Jing; Zhao, Cui-Mei; Li, Zhi-Gang; Wang, Yu-Mei; Miao, Wei; Wu, Xiu-Juan; Wang, Wen-Jing; Liu, Chang; Wang, Duo; Wang, Kang; Li, Li; Peng, Lu-Ying

    2016-01-01

    MicroRNAs (miRNAs) have been identified as key players in cardiomyocyte hypertrophy, which is associated with significant risks of heart failure. However, many microRNAs are still not recognized for their functions in pathophysiological processes. In this study, we evaluated effects of miR-218 in cardiomyocyte hypertrophy using both in vitro and in vivo models. We found that miR-218 was evidently downregulated in a transverse aortic constriction (TAC) mouse model. Overexpression of miR-218 is sufficient to reduce hypertrophy, whereas the suppression of miR-218 aggravates hypertrophy in primary cardiomyocytes induced by isoprenaline (ISO). In addition, we identified RE1-silencing transcription factor (REST) as a novel target of miR-218; it negatively regulated the expression of REST in hypertrophic cardiomyocytes and the TAC model. These results showed that miR-218 plays a crucial role in cardiomyocyte hypertrophy, likely via targeting REST, suggesting a potential candidate target for interfering hypertrophy. PMID:27258257

  14. Glucocorticoids promote structural and functional maturation of foetal cardiomyocytes: a role for PGC-1α

    PubMed Central

    Rog-Zielinska, E A; Craig, M-A; Manning, J R; Richardson, R V; Gowans, G J; Dunbar, D R; Gharbi, K; Kenyon, C J; Holmes, M C; Hardie, D G; Smith, G L; Chapman, K E

    2015-01-01

    Glucocorticoid levels rise dramatically in late gestation to mature foetal organs in readiness for postnatal life. Immature heart function may compromise survival. Cardiomyocyte glucocorticoid receptor (GR) is required for the structural and functional maturation of the foetal heart in vivo, yet the molecular mechanisms are largely unknown. Here we asked if GR activation in foetal cardiomyocytes in vitro elicits similar maturational changes. We show that physiologically relevant glucocorticoid levels improve contractility of primary-mouse-foetal cardiomyocytes, promote Z-disc assembly and the appearance of mature myofibrils, and increase mitochondrial activity. Genes induced in vitro mimic those induced in vivo and include PGC-1α, a critical regulator of cardiac mitochondrial capacity. SiRNA-mediated abrogation of the glucocorticoid induction of PGC-1α in vitro abolished the effect of glucocorticoid on myofibril structure and mitochondrial oxygen consumption. Using RNA sequencing we identified a number of transcriptional regulators, including PGC-1α, induced as primary targets of GR in foetal cardiomyocytes. These data demonstrate that PGC-1α is a key mediator of glucocorticoid-induced maturation of foetal cardiomyocyte structure and identify other candidate transcriptional regulators that may play critical roles in the transition of the foetal to neonatal heart. PMID:25361084

  15. Blockage of VIP during mouse embryogenesis modifies adult behavior and results in permanent changes in brain chemistry.

    PubMed

    Hill, Joanna M; Hauser, Janet M; Sheppard, Lia M; Abebe, Daniel; Spivak-Pohis, Irit; Kushnir, Michal; Deitch, Iris; Gozes, Illana

    2007-01-01

    Vasoactive intestinal peptide (VIP) regulates growth and development during the early postimplantation period of mouse embryogenesis. Blockage of VIP with a VIP antagonist during this period results in growth restriction, microcephaly, and developmental delays. Similar treatment of neonatal rodents also causes developmental delays and impaired diurnal rhythms, and the adult brains of these animals exhibit neuronal dystrophy and increased VIP binding. These data suggest that blockage of VIP during the development of the nervous system can result in permanent changes to the brain. In the current study, pregnant mice were treated with a VIP antagonist during embryonic days 8 through 10. The adult male offspring were examined in tests of novelty, paired activity, and social recognition. Brain tissue was examined for several measures of chemistry and gene expression of VIP and related compounds. Glial cells from the cortex of treated newborn mice were plated with neurons and examined for VIP binding and their ability to enhance neuronal survival. Treated adult male mice exhibited increased anxiety-like behavior and deficits in social behavior. Brain tissue exhibited regionally specific changes in VIP chemistry and a trend toward increased gene expression of VIP and related compounds that reached statistical significance in the VIP receptor, VPAC-1, in the female cortex. When compared to control astrocytes, astrocytes from treated cerebral cortex produced further increases in neuronal survival with excess synaptic connections and reduced VIP binding. In conclusion, impaired VIP activity during mouse embryogenesis resulted in permanent changes to both adult brain chemistry/cell biology and behavior with aspects of autism-like social deficits. PMID:17726225

  16. Caffeine exposure alters cardiac gene expression in embryonic cardiomyocytes

    PubMed Central

    Fang, Xiefan; Mei, Wenbin; Barbazuk, William B.; Rivkees, Scott A.

    2014-01-01

    Previous studies demonstrated that in utero caffeine treatment at embryonic day (E) 8.5 alters DNA methylation patterns, gene expression, and cardiac function in adult mice. To provide insight into the mechanisms, we examined cardiac gene and microRNA (miRNA) expression in cardiomyocytes shortly after exposure to physiologically relevant doses of caffeine. In HL-1 and primary embryonic cardiomyocytes, caffeine treatment for 48 h significantly altered the expression of cardiac structural genes (Myh6, Myh7, Myh7b, Tnni3), hormonal genes (Anp and BnP), cardiac transcription factors (Gata4, Mef2c, Mef2d, Nfatc1), and microRNAs (miRNAs; miR208a, miR208b, miR499). In addition, expressions of these genes were significantly altered in embryonic hearts exposed to in utero caffeine. For in utero experiments, pregnant CD-1 dams were treated with 20–60 mg/kg of caffeine, which resulted in maternal circulation levels of 37.3–65.3 μM 2 h after treatment. RNA sequencing was performed on embryonic ventricles treated with vehicle or 20 mg/kg of caffeine daily from E6.5-9.5. Differential expression (DE) analysis revealed that 124 genes and 849 transcripts were significantly altered, and differential exon usage (DEU) analysis identified 597 exons that were changed in response to prenatal caffeine exposure. Among the DE genes identified by RNA sequencing were several cardiac structural genes and genes that control DNA methylation and histone modification. Pathway analysis revealed that pathways related to cardiovascular development and diseases were significantly affected by caffeine. In addition, global cardiac DNA methylation was reduced in caffeine-treated cardiomyocytes. Collectively, these data demonstrate that caffeine exposure alters gene expression and DNA methylation in embryonic cardiomyocytes. PMID:25354728

  17. Direct reprogramming of human fibroblasts toward a cardiomyocyte-like state.

    PubMed

    Fu, Ji-Dong; Stone, Nicole R; Liu, Lei; Spencer, C Ian; Qian, Li; Hayashi, Yohei; Delgado-Olguin, Paul; Ding, Sheng; Bruneau, Benoit G; Srivastava, Deepak

    2013-01-01

    Direct reprogramming of adult somatic cells into alternative cell types has been shown for several lineages. We previously showed that GATA4, MEF2C, and TBX5 (GMT) directly reprogrammed nonmyocyte mouse heart cells into induced cardiomyocyte-like cells (iCMs) in vitro and in vivo. However, GMT alone appears insufficient in human fibroblasts, at least in vitro. Here, we show that GMT plus ESRRG and MESP1 induced global cardiac gene-expression and phenotypic shifts in human fibroblasts derived from embryonic stem cells, fetal heart, and neonatal skin. Adding Myocardin and ZFPM2 enhanced reprogramming, including sarcomere formation, calcium transients, and action potentials, although the efficiency remained low. Human iCM reprogramming was epigenetically stable. Furthermore, we found that transforming growth factor β signaling was important for, and improved the efficiency of, human iCM reprogramming. These findings demonstrate that human fibroblasts can be directly reprogrammed toward the cardiac lineage, and lay the foundation for future refinements in vitro and in vivo. PMID:24319660

  18. Direct Reprogramming of Human Fibroblasts toward a Cardiomyocyte-like State

    PubMed Central

    Fu, Ji-Dong; Stone, Nicole R.; Liu, Lei; Spencer, C. Ian; Qian, Li; Hayashi, Yohei; Delgado-Olguin, Paul; Ding, Sheng; Bruneau, Benoit G.; Srivastava, Deepak

    2013-01-01

    Summary Direct reprogramming of adult somatic cells into alternative cell types has been shown for several lineages. We previously showed that GATA4, MEF2C, and TBX5 (GMT) directly reprogrammed nonmyocyte mouse heart cells into induced cardiomyocyte-like cells (iCMs) in vitro and in vivo. However, GMT alone appears insufficient in human fibroblasts, at least in vitro. Here, we show that GMT plus ESRRG and MESP1 induced global cardiac gene-expression and phenotypic shifts in human fibroblasts derived from embryonic stem cells, fetal heart, and neonatal skin. Adding Myocardin and ZFPM2 enhanced reprogramming, including sarcomere formation, calcium transients, and action potentials, although the efficiency remained low. Human iCM reprogramming was epigenetically stable. Furthermore, we found that transforming growth factor β signaling was important for, and improved the efficiency of, human iCM reprogramming. These findings demonstrate that human fibroblasts can be directly reprogrammed toward the cardiac lineage, and lay the foundation for future refinements in vitro and in vivo. PMID:24319660

  19. The Satellite Cell in Male and Female, Developing and Adult Mouse Muscle: Distinct Stem Cells for Growth and Regeneration

    PubMed Central

    Neal, Alice; Boldrin, Luisa; Morgan, Jennifer Elizabeth

    2012-01-01

    Satellite cells are myogenic cells found between the basal lamina and the sarcolemma of the muscle fibre. Satellite cells are the source of new myofibres; as such, satellite cell transplantation holds promise as a treatment for muscular dystrophies. We have investigated age and sex differences between mouse satellite cells in vitro and assessed the importance of these factors as mediators of donor cell engraftment in an in vivo model of satellite cell transplantation. We found that satellite cell numbers are increased in growing compared to adult and in male compared to female adult mice. We saw no difference in the expression of the myogenic regulatory factors between male and female mice, but distinct profiles were observed according to developmental stage. We show that, in contrast to adult mice, the majority of satellite cells from two week old mice are proliferating to facilitate myofibre growth; however a small proportion of these cells are quiescent and not contributing to this growth programme. Despite observed changes in satellite cell populations, there is no difference in engraftment efficiency either between satellite cells derived from adult or pre-weaned donor mice, male or female donor cells, or between male and female host muscle environments. We suggest there exist two distinct satellite cell populations: one for muscle growth and maintenance and one for muscle regeneration. PMID:22662253

  20. Chronic serotonin-norepinephrine reuptake transporter inhibition modifies basal respiratory output in adult mouse in vitro and in vivo

    PubMed Central

    Warren, Kelly A.; Solomon, Irene C.

    2012-01-01

    Respiratory disturbances are a common feature of panic disorder and present as breathing irregularity, hyperventilation, and increased sensitivity to carbon dioxide. Common therapeutic interventions, such as tricyclic (TCA) and selective serotonin reuptake inhibitor (SSRI) antidepressants, have been shown to ameliorate not only the psychological components of panic disorder but also the respiratory disturbances. These drugs are also prescribed for generalized anxiety and depressive disorders, neither of which are characterized by respiratory disturbances, and previous studies have demonstrated that TCAs and SSRIs exert effects on basal respiratory activity in animal models without panic disorder symptoms. Whether serotonin-norepinephrine reuptake inhibitors (SNRIs) have similar effects on respiratory activity remains to be determined. Therefore, the current study was designed to investigate the effects of chronic administration of the SNRI antidepressant venlafaxine (VHCL) on basal respiratory output. For these experiments, we recorded phrenic nerve discharge in an in vitro arterially-perfused adult mouse preparation and diaphragm electromyogram (EMG) activity in an in vivo urethane-anesthetized adult mouse preparation. We found that following 28-d VHCL administration, basal respiratory burst frequency was markedly reduced due to an increase in expiratory duration (TE), and the inspiratory duty cycle (TI/Ttot) was significantly shortened. In addition, post-inspiratory and spurious expiratory discharges were seen in vitro. Based on our observations, we suggest that drugs capable of simultaneously blocking both 5-HT and NE reuptake transporters have the potential to influence the respiratory control network in patients using SNRI therapy. PMID:22871263

  1. PPARγ mRNA in the adult mouse hypothalamus: distribution and regulation in response to dietary challenges

    PubMed Central

    Liu, Yang; Huang, Ying; Lee, Syann; Bookout, Angie L.; Castorena, Carlos M.; Wu, Hua; Gautron, Laurent

    2015-01-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcription factor that was originally identified as a regulator of peroxisome proliferation and adipocyte differentiation. Emerging evidence suggests that functional PPARγ signaling also occurs within the hypothalamus. However, the exact distribution and identities of PPARγ-expressing hypothalamic cells remains under debate. The present study systematically mapped PPARγ mRNA expression in the adult mouse brain using in situ hybridization histochemistry. PPARγ mRNA was found to be expressed at high levels outside the hypothalamus including the neocortex, the olfactory bulb, the organ of the vasculosum of the lamina terminalis (VOLT), and the subfornical organ. Within the hypothalamus, PPARγ was present at moderate levels in the suprachiasmatic nucleus (SCh) and the ependymal of the 3rd ventricle. In all examined feeding-related hypothalamic nuclei, PPARγ was expressed at very low levels that were close to the limit of detection. Using qPCR techniques, we demonstrated that PPARγ mRNA expression was upregulated in the SCh in response to fasting. Double in situ hybridization further demonstrated that PPARγ was primarily expressed in neurons rather than glia. Collectively, our observations provide a comprehensive map of PPARγ distribution in the intact adult mouse hypothalamus. PMID:26388745

  2. Targeted deletion of Vglut2 expression in the embryonal telencephalon promotes an anxiolytic phenotype of the adult mouse

    PubMed Central

    Nordenankar, Karin; Bergfors, Assar

    2015-01-01

    Background Anxiety is a natural emotion experienced by all individuals. However, when anxiety becomes excessive, it contributes to the substantial group of anxiety disorders that affect one in three people and thus are among the most common psychiatric disorders. Anxiolysis, the reduction of anxiety, is mediated via several large groups of therapeutical compounds, but the relief is often only temporary, and increased knowledge of the neurobiology underlying anxiety is needed in order to improve future therapies. Aim We previously demonstrated that mice lacking forebrain expression of the Vesicular glutamate transporter 2 (Vglut2) from adolescence showed a strong anxiolytic behaviour as adults. In the current study, we wished to analyse if removal of Vglut2 expression already from mid-gestation of the mouse embryo would give rise to similar anxiolysis in the adult mouse. Methods We produced transgenic mice lacking Vglut2 from mid-gestation and analysed their affective behaviour, including anxiety, when they had reached adulthood. Results The transgenic mice lacking Vglut2 expression from mid-gestation showed certain signs of anxiolytic behaviour, but this phenotype was not as prominent as when Vglut2 was removed during adolescence. Conclusion Our results suggest that both embryonal and adolescent forebrain expression of Vglut2 normally contributes to balancing the level of anxiety. As the neurobiological basis for anxiety is similar across species, our results in mice may help improve the current understanding of the neurocircuitry of anxiety, and hence anxiolysis, also in humans. PMID:25857802

  3. Activation of CB1 inhibits NGF-induced sensitization of TRPV1 in adult mouse afferent neurons

    PubMed Central

    Wang, Zun-Yi; McDowell, Thomas; Wang, Peiqing; Alvarez, Roxanne; Gomez, Timothy; Bjorling, Dale E.

    2015-01-01

    Transient receptor potential vanilloid 1 (TRPV1)-containing afferent neurons convey nociceptive signals and play an essential role in pain sensation. Exposure to nerve growth factor (NGF) rapidly increases TRPV1 activity (sensitization). In the present study, we investigated whether treatment with the selective cannabinoid receptor 1 (CB1) agonist arachidonyl-2'-chloroethylamide (ACEA) affects NGF-induced sensitization of TRPV1 in adult mouse dorsal root ganglion (DRG) afferent neurons. We found that CB1, NGF receptor tyrosine kinase A (trkA), and TRPV1 are present in cultured adult mouse small- to medium-sized afferent neurons and treatment with NGF (100 ng/ml) for 30 minutes significantly increased the number of neurons that responded to capsaicin (as indicated by increased intracellular Ca2+ concentration). Pretreatment with the CB1 agonist ACEA (10 nM) inhibited the NGF-induced response, and this effect of ACEA was reversed by a selective CB1 antagonist. Further, pretreatment with ACEA inhibited NGF-induced phosphorylation of AKT. Blocking PI3 kinase activity also attenuated the NGF-induced increase in the number of neurons that responded to capsaicin. Our results indicate that the analgesic effect of CB1 activation may in part be due to inhibition of NGF-induced sensitization of TRPV1 and also that the effect of CB1 activation is at least partly mediated by attenuation of NGF-induced increased PI3 signaling. PMID:25088915

  4. A Novel Procedure for Rapid Imaging of Adult Mouse Brains with MicroCT Using Iodine-Based Contrast

    PubMed Central

    Anderson, Ryan; Maga, A. Murat

    2015-01-01

    High-resolution Magnetic Resonance Imaging (MRI) has been the primary modality for obtaining 3D cross-sectional anatomical information in animals for soft tissue, particularly brain. However, costs associated with MRI can be considerably high for large phenotypic screens for gross differences in the structure of the brain due to pathology and/or experimental manipulations. MicroCT (mCT), especially benchtop mCT, is becoming a common laboratory equipment with throughput rates equal or faster than any form of high-resolution MRI at lower costs. Here we explore adapting previously developed contrast based mCT to image adult mouse brains in-situ. We show that 2% weight per volume (w/v) iodine-potassium iodide solution can be successfully used to image adult mouse brains within 48 hours post-mortem when a structural support matrix is used. We demonstrate that hydrogel can be effectively used as a perfusant which limits the tissue shrinkage due to iodine. PMID:26571123

  5. Genetic manipulation of adult-born hippocampal neurons rescues memory in a mouse model of Alzheimer's disease.

    PubMed

    Richetin, Kevin; Leclerc, Clémence; Toni, Nicolas; Gallopin, Thierry; Pech, Stéphane; Roybon, Laurent; Rampon, Claire

    2015-02-01

    In adult mammals, neural progenitors located in the dentate gyrus retain their ability to generate neurons and glia throughout lifetime. In rodents, increased production of new granule neurons is associated with improved memory capacities, while decreased hippocampal neurogenesis results in impaired memory performance in several memory tasks. In mouse models of Alzheimer's disease, neurogenesis is impaired and the granule neurons that are generated fail to integrate existing networks. Thus, enhancing neurogenesis should improve functional plasticity in the hippocampus and restore cognitive deficits in these mice. Here, we performed a screen of transcription factors that could potentially enhance adult hippocampal neurogenesis. We identified Neurod1 as a robust neuronal determinant with the capability to direct hippocampal progenitors towards an exclusive granule neuron fate. Importantly, Neurod1 also accelerated neuronal maturation and functional integration of new neurons during the period of their maturation when they contribute to memory processes. When tested in an APPxPS1 mouse model of Alzheimer's disease, directed expression of Neurod1 in cycling hippocampal progenitors conspicuously reduced dendritic spine density deficits on new hippocampal neurons, to the same level as that observed in healthy age-matched control animals. Remarkably, this population of highly connected new neurons was sufficient to restore spatial memory in these diseased mice. Collectively our findings demonstrate that endogenous neural stem cells of the diseased brain can be manipulated to become new neurons that could allow cognitive improvement. PMID:25518958

  6. A mouse model for juvenile doxorubicin-induced cardiac dysfunction.

    PubMed

    Zhu, Wuqiang; Shou, Weinian; Payne, R Mark; Caldwell, Randall; Field, Loren J

    2008-11-01

    Doxorubicin (DOX) is a potent antitumor agent. DOX can also induce cardiotoxicity, and high cumulative doses are associated with recalcitrant heart failure. Children are particularly sensitive to DOX-induced heart failure. The ability to genetically modify mice makes them an ideal experimental system to study the molecular basis of DOX-induced cardiotoxicity. However, most mouse DOX studies rely on acute drug administration in adult animals, which typically are analyzed within 1 wk. Here, we describe a juvenile mouse model of chronic DOX-induced cardiac dysfunction. DOX treatment was initiated at 2 wk of age and continued for a period of 5 wk (25 mg/kg cumulative dose). This resulted in a decline in cardiac systolic function, which was accompanied by marked atrophy of the heart, low levels of cardiomyocyte apoptosis, and decreased growth velocity. Other animals were allowed to recover for 13 wk after the final DOX injection. Cardiac systolic function improved during this recovery period but remained depressed compared with the saline injected controls, despite the reversal of cardiac atrophy. Interestingly, increased levels of cardiomyocyte apoptosis and concomitant myocardial fibrosis were observed after DOX withdrawal. These data suggest that different mechanisms contribute to cardiac dysfunction during the treatment and recovery phases. PMID:18614963

  7. Extracellular mtDNA activates NF-κB via toll-like receptor 9 and induces cell death in cardiomyocytes.

    PubMed

    Bliksøen, Marte; Mariero, Lars Henrik; Torp, May Kristin; Baysa, Anton; Ytrehus, Kirsti; Haugen, Fred; Seljeflot, Ingebjørg; Vaage, Jarle; Valen, Guro; Stensløkken, Kåre-Olav

    2016-07-01

    Acute myocardial infarction (AMI) causes sterile inflammation, which exacerbates tissue injury. Elevated levels of circulating mitochondrial DNA (mtDNA) have been associated with AMI. We hypothesized that mtDNA triggers an innate immune response via TLR9 and NF-κB activation, causing cardiomyocyte injury. Murine cardiomyocytes express TLR9 mRNA and protein and were able to internalize fluorescently labeled mouse mtDNA. Incubation of human embryonic kidney cells with serum from AMI patients containing naturally elevated levels of mtDNA induced TLR9-dependent NF-κB activity. This effect was mimicked by isolated mtDNA. mtDNA activated NF-κB in reporter mice both in vivo and in isolated cardiomyocytes. Moreover, incubation of isolated cardiomyocytes with mtDNA induced cell death after 4 and 24 h. Laser confocal microscopy showed that incubation of cardiomyocytes with mtDNA accelerated mitochondrial depolarization induced by reactive oxygen species. In contrast to mtDNA, isolated total DNA did not activate NF-κB nor induce cell death. In conclusion, mtDNA can induce TLR9-dependent NF-κB activation in reporter cells and activate NF-κB in cardiomyocytes. In cardiomyocytes, mtDNA causes mitochondrial dysfunction and death. Endogenous mtDNA in the extracellular space is a danger signal with direct detrimental effects on cardiomyocytes. PMID:27164906

  8. A physiologically based pharmacokinetic model for atrazine and its main metabolites in the adult male C57BL/6 mouse

    SciTech Connect

    Lin Zhoumeng; Fisher, Jeffrey W.; Ross, Matthew K.; Filipov, Nikolay M.

    2011-02-15

    Atrazine (ATR) is a chlorotriazine herbicide that is widely used and relatively persistent in the environment. In laboratory rodents, excessive exposure to ATR is detrimental to the reproductive, immune, and nervous systems. To better understand the toxicokinetics of ATR and to fill the need for a mouse model, a physiologically based pharmacokinetic (PBPK) model for ATR and its main chlorotriazine metabolites (Cl-TRIs) desethyl atrazine (DE), desisopropyl atrazine (DIP), and didealkyl atrazine (DACT) was developed for the adult male C57BL/6 mouse. Taking advantage of all relevant and recently made available mouse-specific data, a flow-limited PBPK model was constructed. The ATR and DACT sub-models included blood, brain, liver, kidney, richly and slowly perfused tissue compartments, as well as plasma protein binding and red blood cell binding, whereas the DE and DIP sub-models were constructed as simple five-compartment models. The model adequately simulated plasma levels of ATR and Cl-TRIs and urinary dosimetry of Cl-TRIs at four single oral dose levels (250, 125, 25, and 5 mg/kg). Additionally, the model adequately described the dose dependency of brain and liver ATR and DACT concentrations. Cumulative urinary DACT amounts were accurately predicted across a wide dose range, suggesting the model's potential use for extrapolation to human exposures by performing reverse dosimetry. The model was validated using previously reported data for plasma ATR and DACT in mice and rats. Overall, besides being the first mouse PBPK model for ATR and its Cl-TRIs, this model, by analogy, provides insights into tissue dosimetry for rats. The model could be used in tissue dosimetry prediction and as an aid in the exposure assessment to this widely used herbicide.

  9. MicroRNAs and Their Targets Are Differentially Regulated in Adult and Neonatal Mouse CD8+ T Cells.

    PubMed

    Wissink, Erin M; Smith, Norah L; Spektor, Roman; Rudd, Brian D; Grimson, Andrew

    2015-11-01

    Immunological memory, which protects organisms from re-infection, is a hallmark of the mammalian adaptive immune system and the underlying principle of vaccination. In early life, however, mice and other mammals are deficient at generating memory CD8+ T cells, which protect organisms from intracellular pathogens. The molecular basis that differentiates adult and neonatal CD8+ T cells is unknown. MicroRNAs (miRNAs) are both developmentally regulated and required for normal adult CD8+ T cell functions. We used next-generation sequencing to identify mouse miRNAs that are differentially regulated in adult and neonatal CD8+ T cells, which may contribute to the impaired development of neonatal memory cells. The miRNA profiles of adult and neonatal cells were surprisingly similar during infection; however, we observed large differences prior to infection. In particular, miR-29 and miR-130 have significant differential expression between adult and neonatal cells before infection. Importantly, using RNA-Seq, we detected reciprocal changes in expression of messenger RNA targets for both miR-29 and miR-130. Moreover, targets that we validated include Eomes and Tbx21, key genes that regulate the formation of memory CD8+ T cells. Notably, age-dependent changes in miR-29 and miR-130 are conserved in human CD8+ T cells, further suggesting that these developmental differences are biologically relevant. Together, these results demonstrate that miR-29 and miR-130 are likely important regulators of memory CD8+ T cell formation and suggest that neonatal cells are committed to a short-lived effector cell fate prior to infection. PMID:26416483

  10. MicroRNAs and Their Targets Are Differentially Regulated in Adult and Neonatal Mouse CD8+ T Cells

    PubMed Central

    Wissink, Erin M.; Smith, Norah L.; Spektor, Roman; Rudd, Brian D.; Grimson, Andrew

    2015-01-01

    Immunological memory, which protects organisms from re-infection, is a hallmark of the mammalian adaptive immune system and the underlying principle of vaccination. In early life, however, mice and other mammals are deficient at generating memory CD8+ T cells, which protect organisms from intracellular pathogens. The molecular basis that differentiates adult and neonatal CD8+ T cells is unknown. MicroRNAs (miRNAs) are both developmentally regulated and required for normal adult CD8+ T cell functions. We used next-generation sequencing to identify mouse miRNAs that are differentially regulated in adult and neonatal CD8+ T cells, which may contribute to the impaired development of neonatal memory cells. The miRNA profiles of adult and neonatal cells were surprisingly similar during infection; however, we observed large differences prior to infection. In particular, miR-29 and miR-130 have significant differential expression between adult and neonatal cells before infection. Importantly, using RNA-Seq, we detected reciprocal changes in expression of messenger RNA targets for both miR-29 and miR-130. Moreover, targets that we validated include Eomes and Tbx21, key genes that regulate the formation of memory CD8+ T cells. Notably, age-dependent changes in miR-29 and miR-130 are conserved in human CD8+ T cells, further suggesting that these developmental differences are biologically relevant. Together, these results demonstrate that miR-29 and miR-130 are likely important regulators of memory CD8+ T cell formation and suggest that neonatal cells are committed to a short-lived effector cell fate prior to infection. PMID:26416483

  11. O-GlcNAcylation Negatively Regulates Cardiomyogenic Fate in Adult Mouse Cardiac Mesenchymal Stromal Cells.

    PubMed

    Zafir, Ayesha; Bradley, James A; Long, Bethany W; Muthusamy, Senthilkumar; Li, Qianhong; Hill, Bradford G; Wysoczynski, Marcin; Prabhu, Sumanth D; Bhatnagar, Aruni; Bolli, Roberto; Jones, Steven P

    2015-01-01

    In both preclinical and clinical studies, cell transplantation of several cell types is used to promote repair of damaged organs and tissues. Nevertheless, despite the widespread use of such strategies, there remains little understanding of how the efficacy of cell therapy is regulated. We showed previously that augmentation of a unique, metabolically derived stress signal (i.e., O-GlcNAc) improves survival of cardiac mesenchymal stromal cells; however, it is not known whether enhancing O-GlcNAcylation affects lineage commitment or other aspects of cell competency. In this study, we assessed the role of O-GlcNAc in differentiation of cardiac mesenchymal stromal cells. Exposure of these cells to routine differentiation protocols in culture increased markers of the cardiomyogenic lineage such as Nkx2.5 and connexin 40, and augmented the abundance of transcripts associated with endothelial and fibroblast cell fates. Differentiation significantly decreased the abundance of O-GlcNAcylated proteins. To determine if O-GlcNAc is involved in stromal cell differentiation, O-GlcNAcylation was increased pharmacologically during the differentiation protocol. Although elevated O-GlcNAc levels did not significantly affect fibroblast and endothelial marker expression, acquisition of cardiomyocyte markers was limited. In addition, increasing O-GlcNAcylation further elevated smooth muscle actin expression. In addition to lineage commitment, we also evaluated proliferation and migration, and found that increasing O-GlcNAcylation did not significantly affect either; however, we found that O-GlcNAc transferase--the protein responsible for adding O-GlcNAc to proteins--is at least partially required for maintaining cellular proliferative and migratory capacities. We conclude that O-GlcNAcylation contributes significantly to cardiac mesenchymal stromal cell lineage and function. O-GlcNAcylation and pathological conditions that may affect O-GlcNAc levels (such as diabetes) should be

  12. Chronic hemodynamic unloading regulates the morphologic development of newborn mouse hearts transplanted into the ear of isogeneic adult mice.

    PubMed Central

    Rossi, M. A.

    1992-01-01

    The morphologic development of newborn mouse hearts transplanted into the pinna of the ears of isogeneic adult mice was assessed in comparison to in situ ventricular myocardium of recipients. The grafted hearts became vascularized from the auricular artery at the base of the ear, and although these preparations appeared not to be intrinsically innervated, most of them showed grossly visible pulsatile activity. Since they were not subjected to hemodynamic load due to working against a pressure gradient, this technique provided an interesting experimental model for studies on the growth of chronically unloaded tissue. The ultrastructure of the myocardium from neonatal mouse hearts, which were fixed immediately after dissection, revealed no differences in comparison to previously published observations. By 2 months, there was virtually no change in the myocardial cell size as compared with newborn mouse cardiac tissue. The heterotopic hearts showed a mature ultrastructural appearance, with parallel bands of myofibrils alternating with rows of mitochondria and differentiated intercalated discs comparable to in situ myocardium. The interstitial space was widened due to fibrous tissue, with activated fibroblasts and a few mononuclear cells. In contrast, by 6 months after transplantation, the heterotopic myocardium showed a dispersion of the measured cell diameter of myocytes, with atrophy of a certain population of cells and hypertrophy in others; nevertheless, the mean cell diameter was similar to that observed in 2-month grafts. The myocytes showed significant dissociation from each other in fibrous tissue and a cellular infiltrate composed predominantly of mononuclear cells, and greater variability of the parallel arrangement of cells. They often contained myofibrils coursing in different directions rather than in parallel. Normal-sized or predominantly atrophic degenerated myocytes, characterized by a wide variety of ultrastructural alterations, were present. By 12

  13. Repair of liver mediated by adult mouse liver neuro-glia antigen 2-positive progenitor cell transplantation in a mouse model of cirrhosis

    PubMed Central

    Zhang, Hongyu; Siegel, Christopher T.; Shuai, Ling; Lai, Jiejuan; Zeng, Linli; Zhang, Yujun; Lai, Xiangdong; Bie, Ping; Bai, Lianhua

    2016-01-01

    NG2-expressing cells are a population of periportal vascular stem/progenitors (MLpvNG2+ cells) that were isolated from healthy adult mouse liver by using a “Percoll-Plate-Wait” procedure. We demonstrated that isolated cells are able to restore liver function after transplantation into a cirrhotic liver, and co-localized with the pericyte marker (immunohistochemistry: PDGFR-β) and CK19. Cells were positive for: stem cell (Sca-1, CD133, Dlk) and liver stem cell markers (EpCAM, CD14, CD24, CD49f); and negative for: hematopoietic (CD34, CD45) and endothelial markers (CD31, vWf, von Willebrand factor). Cells were transplanted (1 × 106 cells) in mice with diethylnitrosamine-induced cirrhosis at week 6. Cells showed increased hepatic associated gene expression of alpha-fetoprotein (AFP), Albumin (Alb), Glucose-6-phosphatase (G6Pc), SRY (sex determining region Y)-box 9 (Sox9), hepatic nuclear factors (HNF1a, HNF1β, HNF3β, HNF4α, HNF6, Epithelial cell adhesion molecule (EpCAM), Leucine-rich repeated-containing G-protein coupled receptor 5-positive (Lgr5) and Tyrosine aminotransferase (TAT). Cells showed decreased fibrogenesis, hepatic stellate cell infiltration, Kupffer cells and inflammatory cytokines. Liver function markers improved. In a cirrhotic liver environment, cells could differentiate into hepatic lineages. In addition, grafted MLpvNG2+ cells could mobilize endogenous stem/progenitors to participate in liver repair. These results suggest that MLpvNG2+ cells may be novel adult liver progenitors that participate in liver regeneration. PMID:26905303

  14. Repair of liver mediated by adult mouse liver neuro-glia antigen 2-positive progenitor cell transplantation in a mouse model of cirrhosis.

    PubMed

    Zhang, Hongyu; Siegel, Christopher T; Shuai, Ling; Lai, Jiejuan; Zeng, Linli; Zhang, Yujun; Lai, Xiangdong; Bie, Ping; Bai, Lianhua

    2016-01-01

    NG2-expressing cells are a population of periportal vascular stem/progenitors (MLpvNG2(+) cells) that were isolated from healthy adult mouse liver by using a "Percoll-Plate-Wait" procedure. We demonstrated that isolated cells are able to restore liver function after transplantation into a cirrhotic liver, and co-localized with the pericyte marker (immunohistochemistry: PDGFR-β) and CK19. Cells were positive for: stem cell (Sca-1, CD133, Dlk) and liver stem cell markers (EpCAM, CD14, CD24, CD49f); and negative for: hematopoietic (CD34, CD45) and endothelial markers (CD31, vWf, von Willebrand factor). Cells were transplanted (1 × 10(6) cells) in mice with diethylnitrosamine-induced cirrhosis at week 6. Cells showed increased hepatic associated gene expression of alpha-fetoprotein (AFP), Albumin (Alb), Glucose-6-phosphatase (G6Pc), SRY (sex determining region Y)-box 9 (Sox9), hepatic nuclear factors (HNF1a, HNF1β, HNF3β, HNF4α, HNF6, Epithelial cell adhesion molecule (EpCAM), Leucine-rich repeated-containing G-protein coupled receptor 5-positive (Lgr5) and Tyrosine aminotransferase (TAT). Cells showed decreased fibrogenesis, hepatic stellate cell infiltration, Kupffer cells and inflammatory cytokines. Liver function markers improved. In a cirrhotic liver environment, cells could differentiate into hepatic lineages. In addition, grafted MLpvNG2(+) cells could mobilize endogenous stem/progenitors to participate in liver repair. These results suggest that MLpvNG2(+) cells may be novel adult liver progenitors that participate in liver regeneration. PMID:26905303

  15. Protein Quality Control and Degradation in Cardiomyocytes

    PubMed Central

    Wang, Xuejun; Su, Huabo; Ranek, Mark J.

    2008-01-01

    The heart is constantly under stress and cardiomyocytes face enormous challenges to correctly fold nascent polypeptides and keep mature proteins from denaturing. To meet the challenge, cardiomyocytes have developed multi-layered protein quality control (PQC) mechanisms which are carried out primarily by chaperones and ubiquitin-proteasome system mediated proteolysis. Autophagy may also participate in PQC in cardiomyocytes, especially under pathological conditions. Cardiac PQC often becomes inadequate in heart disease, which may play an important role in the development of congestive heart failure. PMID:18495153

  16. Daily rhythms of core temperature and locomotor activity indicate different adaptive strategies to cold exposure in adult and aged mouse lemurs acclimated to a summer-like photoperiod.

    PubMed

    Terrien, Jeremy; Zizzari, Philippe; Epelbaum, Jacques; Perret, Martine; Aujard, Fabienne

    2009-07-01

    Daily variations in core temperature (Tc) within the normothermic range imply thermoregulatory processes that are essential for optimal function and survival. Higher susceptibility towards cold exposure in older animals suggests that these processes are disturbed with age. In the mouse lemur, a long-day breeder, we tested whether aging affected circadian rhythmicity of Tc, locomotor activity (LA), and energy balance under long-day conditions when exposed to cold. Adult (N = 7) and aged (N = 5) mouse lemurs acclimated to LD14/10 were exposed to 10-day periods at 25 and 12 degrees C. Tc and LA rhythms were recorded by telemetry, and caloric intake (CI), body mass changes, and plasma IGF-1 were measured. During exposure to 25 degrees C, both adult and aged mouse lemurs exhibited strong daily variations in Tc. Aged animals exhibited lower levels of nocturnal LA and nocturnal and diurnal Tc levels in comparison to adults. Body mass and IGF-1 levels remained unchanged with aging. Under cold exposure, torpor bout occurrence was never observed whatever the age category. Adult and aged mouse lemurs maintained their Tc in the normothermic range and a positive energy balance. All animals exhibited increase in CI and decrease in IGF-1 in response to cold. The decrease in IGF-1 was delayed in aged mouse lemurs compared to adults. Moreover, both adult and aged animals responded to cold exposure by increasing their diurnal LA compared to those under Ta = 25 degrees C. However, aged animals exhibited a strong decrease in nocturnal LA and Tc, whereas cold effects were only slight in adults. The temporal organization and amplitude of the daily phase of low Tc were particularly well preserved under cold exposure in both age groups. Sexually active mouse lemurs exposed to cold thus seemed to prevent torpor exhibition and temporal disorganization of daily rhythms of Tc, even during aging. However, although energy balance was not impaired with age in mouse lemurs after cold exposure

  17. CLARITY and PACT-based imaging of adult zebrafish and mouse for whole-animal analysis of infections.

    PubMed

    Cronan, Mark R; Rosenberg, Allison F; Oehlers, Stefan H; Saelens, Joseph W; Sisk, Dana M; Jurcic Smith, Kristen L; Lee, Sunhee; Tobin, David M

    2015-12-01

    Visualization of infection and the associated host response has been challenging in adult vertebrates. Owing to their transparency, zebrafish larvae have been used to directly observe infection in vivo; however, such larvae have not yet developed a functional adaptive immune system. Cells involved in adaptive immunity mature later and have therefore been difficult to access optically in intact animals. Thus, the study of many aspects of vertebrate infection requires dissection of adult organs or ex vivo isolation of immune cells. Recently, CLARITY and PACT (passive clarity technique) methodologies have enabled clearing and direct visualization of dissected organs. Here, we show that these techniques can be applied to image host-pathogen interactions directly in whole animals. CLARITY and PACT-based clearing of whole adult zebrafish and Mycobacterium tuberculosis-infected mouse lungs enables imaging of mycobacterial granulomas deep within tissue to a depth of more than 1 mm. Using established transgenic lines, we were able to image normal and pathogenic structures and their surrounding host context at high resolution. We identified the three-dimensional organization of granuloma-associated angiogenesis, an important feature of mycobacterial infection, and characterized the induction of the cytokine tumor necrosis factor (TNF) within the granuloma using an established fluorescent reporter line. We observed heterogeneity in TNF induction within granuloma macrophages, consistent with an evolving view of the tuberculous granuloma as a non-uniform, heterogeneous structure. Broad application of this technique will enable new understanding of host-pathogen interactions in situ. PMID:26449262

  18. CLARITY and PACT-based imaging of adult zebrafish and mouse for whole-animal analysis of infections

    PubMed Central

    Cronan, Mark R.; Rosenberg, Allison F.; Oehlers, Stefan H.; Saelens, Joseph W.; Sisk, Dana M.; Jurcic Smith, Kristen L.; Lee, Sunhee; Tobin, David M.

    2015-01-01

    ABSTRACT Visualization of infection and the associated host response has been challenging in adult vertebrates. Owing to their transparency, zebrafish larvae have been used to directly observe infection in vivo; however, such larvae have not yet developed a functional adaptive immune system. Cells involved in adaptive immunity mature later and have therefore been difficult to access optically in intact animals. Thus, the study of many aspects of vertebrate infection requires dissection of adult organs or ex vivo isolation of immune cells. Recently, CLARITY and PACT (passive clarity technique) methodologies have enabled clearing and direct visualization of dissected organs. Here, we show that these techniques can be applied to image host-pathogen interactions directly in whole animals. CLARITY and PACT-based clearing of whole adult zebrafish and Mycobacterium tuberculosis-infected mouse lungs enables imaging of mycobacterial granulomas deep within tissue to a depth of more than 1 mm. Using established transgenic lines, we were able to image normal and pathogenic structures and their surrounding host context at high resolution. We identified the three-dimensional organization of granuloma-associated angiogenesis, an important feature of mycobacterial infection, and characterized the induction of the cytokine tumor necrosis factor (TNF) within the granuloma using an established fluorescent reporter line. We observed heterogeneity in TNF induction within granuloma macrophages, consistent with an evolving view of the tuberculous granuloma as a non-uniform, heterogeneous structure. Broad application of this technique will enable new understanding of host-pathogen interactions in situ. PMID:26449262

  19. Modifications of perineuronal nets and remodelling of excitatory and inhibitory afferents during vestibular compensation in the adult mouse.

    PubMed

    Faralli, Alessio; Dagna, Federico; Albera, Andrea; Bekku, Yoko; Oohashi, Toshitaka; Albera, Roberto; Rossi, Ferdinando; Carulli, Daniela

    2016-07-01

    Perineuronal nets (PNNs) are aggregates of extracellular matrix molecules surrounding several types of neurons in the adult CNS, which contribute to stabilising neuronal connections. Interestingly, a reduction of PNN number and staining intensity has been observed in conditions associated with plasticity in the adult brain. However, it is not known whether spontaneous PNN changes are functional to plasticity and repair after injury. To address this issue, we investigated PNN expression in the vestibular nuclei of the adult mouse during vestibular compensation, namely the resolution of motor deficits resulting from a unilateral peripheral vestibular lesion. After unilateral labyrinthectomy, we found that PNN number and staining intensity were strongly attenuated in the lateral vestibular nucleus on both sides, in parallel with remodelling of excitatory and inhibitory afferents. Moreover, PNNs were completely restored when vestibular deficits of the mice were abated. Interestingly, in mice with genetically reduced PNNs, vestibular compensation was accelerated. Overall, these results strongly suggest that temporal tuning of PNN expression may be crucial for vestibular compensation. PMID:26264050

  20. Status epilepticus stimulates NDEL1 expression via the CREB/CRE pathway in the adult mouse brain.

    PubMed

    Choi, Yun-Sik; Lee, Boyoung; Hansen, Katelin F; Aten, Sydney; Horning, Paul; Wheaton, Kelin L; Impey, Soren; Hoyt, Kari R; Obrietan, Karl

    2016-09-01

    Nuclear distribution element-like 1 (NDEL1/NUDEL) is a mammalian homolog of the Aspergillus nidulans nuclear distribution molecule NudE. NDEL1 plays a critical role in neuronal migration, neurite outgrowth and neuronal positioning during brain development; however within the adult central nervous system, limited information is available regarding NDEL1 expression and functions. Here, the goal was to examine inducible NDEL1 expression in the adult mouse forebrain. Immunolabeling revealed NDEL1 within the forebrain, including the cortex and hippocampus, as well as the midbrain and hypothalamus. Expression was principally localized to perikarya. Using a combination of immunolabeling and RNA seq profiling, we detected a marked and long-lasting upregulation of NDEL1 expression within the hippocampus following a pilocarpine-evoked repetitive seizure paradigm. Chromatin immunoprecipitation (ChIP) analysis identified a cAMP response element-binding protein (CREB) binding site within the CpG island proximal to the NDEL1 gene, and in vivo transgenic repression of CREB led to a marked downregulation of seizure-evoked NDEL1 expression. Together these data indicate that NDEL1 is inducibly expressed in the adult nervous system, and that signaling via the CREB/CRE transcriptional pathway is likely involved. The role of NDEL1 in neuronal migration and neurite outgrowth during development raises the interesting prospect that inducible NDEL1 in the mature nervous system could contribute to the well-characterized structural and functional plasticity resulting from repetitive seizure activity. PMID:27298008

  1. Immaturity of human stem-cell-derived cardiomyocytes in culture: fatal flaw or soluble problem?

    PubMed

    Veerman, Christiaan C; Kosmidis, Georgios; Mummery, Christine L; Casini, Simona; Verkerk, Arie O; Bellin, Milena

    2015-05-01

    Cardiomyocytes from human pluripotent stem cells (hPSC-CMs) are increasingly used to model cardiac disease, test drug efficacy and for safety pharmacology. Nevertheless, a major hurdle to more extensive use is their immaturity and similarity to fetal rather than adult cardiomyocytes. Here, we provide an overview of the strategies currently being used to increase maturation in culture, which include prolongation of time in culture, exposure to electrical stimulation, application of mechanical strain, growth in three-dimensional tissue configuration, addition of non-cardiomyocytes, use of hormones and small molecules, and alteration of the extracellular environment. By comparing the outcomes of these studies, we identify the approaches most likely to improve functional maturation of hPSC-CMs in terms of their electrophysiology and excitation-contraction coupling. PMID:25583389

  2. The case for induced pluripotent stem cell-derived cardiomyocytes in pharmacological screening

    PubMed Central

    Khan, Jaffar M; Lyon, Alexander R; Harding, Sian E

    2013-01-01

    The current drug screening models are deficient, particularly in detecting cardiac side effects. Human stem cell-derived cardiomyocytes could aid both early cardiotoxicity detection and novel drug discovery. Work over the last decade has generated human embryonic stem cells as potentially accurate sources of human cardiomyocytes, but ethical constraints and poor efficacy in establishing cell lines limit their use. Induced pluripotent stem cells do not require the use of human embryos and have the added advantage of producing patient-specific cardiomyocytes, allowing both generic and disease- and patient-specific pharmacological screening, as well as drug development through disease modelling. A critical question is whether sufficient standards have been achieved in the reliable and reproducible generation of ‘adult-like’ cardiomyocytes from human fibroblast tissue to progress from validation to safe use in practice and drug discovery. This review will highlight the need for a new experimental system, assess the validity of human induced pluripotent stem cell-derived cardiomyocytes and explore what the future may hold for their use in pharmacology. LINKED ARTICLES This article is part of a themed section on Regenerative Medicine and Pharmacology: A Look to the Future. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue-2 PMID:22845396

  3. 'Advanced' generation lentiviruses as efficient vectors for cardiomyocyte gene transduction in vitro and in vivo.

    PubMed

    Bonci, D; Cittadini, A; Latronico, M V G; Borello, U; Aycock, J K; Drusco, A; Innocenzi, A; Follenzi, A; Lavitrano, M; Monti, M G; Ross, J; Naldini, L; Peschle, C; Cossu, G; Condorelli, G

    2003-04-01

    Efficient gene transduction in cardiomyocytes is a task that can be accomplished only by viral vectors. Up to now, the most commonly used vectors for this purpose have been adenoviral-derived ones. Recently, it has been demonstrated that lentiviral vectors can transduce growth-arrested cells, such as hematopoietic stem cells. Moreover, a modified form of lentiviral vector (the 'advanced' generation), containing an mRNA-stabilizer sequence and a nuclear import sequence, has been shown to significantly improve gene transduction in growth-arrested cells as compared to the third-generation vector. Therefore, we tested whether the 'advanced' generation lentivirus is capable of infecting and transducing cardiomyocytes both in vitro and in vivo, comparing efficacy in vitro against the third-generation of the same vector. Here we report that 'advanced' generation lentiviral vectors infected most (>80%) cardiomyocytes in culture, as demonstrated by immunofluorescence and FACS analyses: in contrast the percentage of cardiomyocytes infected by third-generation lentivirus was three- to four-fold lower. Moreover, 'advanced' generation lentivirus was also capable of infecting and inducing stable gene expression in adult myocardium in vivo. Thus, 'advanced' generation lentiviral vectors can be used for both in vitro and in vivo gene expression studies in the cardiomyocyte. PMID:12692591

  4. Oncostatin M-induced cardiomyocyte dedifferentiation regulates the progression of diabetic cardiomyopathy through B-Raf/Mek/Erk signaling pathway.

    PubMed

    Zhang, Xiaotian; Ma, Sai; Zhang, Ran; Li, Shuang; Zhu, Di; Han, Dong; Li, Xiujuan; Li, Congye; Yan, Wei; Sun, Dongdong; Xu, Bin; Wang, Yabin; Cao, Feng

    2016-03-01

    It has been reported that oncostatin M (OSM) could initiate cardiomyocyte dedifferentiation both in vivo and in vitro. OSM-induced cardiomyocyte dedifferentiation might be a new target for the treatment of diabetic cardiomyopathy (DCM). This study was designed to determine the role of OSM in cardiomyocyte dedifferentiation and the progression of DCM. A mouse DCM model was established to evaluate the effects of OSM in vivo. Echocardiography was applied to determine cardiac function. Sirius red staining was used to detect fibrosis area. Transmission electron microscopy was used to evaluate mitochondria impairment. Real-time polymerase chain reaction and western blot analysis were performed to detect relative mRNA expressions and cardiomyocyte dedifferentiation-related protein expressions, respectively. OSM treatment induced similar impaired cardiac function and cardiac ultrastructure impairment to those detected in DCM mice. The expressions of dedifferentiation markers of cardiomyocyte (Runx1, and α-SM-actin) were up-regulated in the OSM-treated mice compared with those in the control group. To further demonstrate the important role of OSM, OSM receptor knockout (Oβ(ko)) mice were used. In Oβ(ko) mice, cardiomyocytes dedifferentiation markers of c-kit, Runx1, and atrial natriuretic peptide were down-regulated, with attenuated DCM injury and abrogated OSM/B-Raf/Mek/Erk signaling pathway. In conclusion, OSM-induced cardiomyocyte dedifferentiation plays a crucial role in the progression of DCM. The mechanism of OSM-induced cardiomyocyte dedifferentiation is associated with B-Raf/Mek/Erk signaling pathway through the OSM receptor Oβ. PMID:26837420

  5. Role of Mitochondrial fission and fusion in cardiomyocyte contractility

    PubMed Central

    Givvimani, S; Pushpakumar, SB; Metreveli, N; Veeranki, S; Kundu, S; Tyagi, SC

    2015-01-01

    Background Mitochondria constitute 30% of cell volume and are engaged in two dynamic processes called fusion and fission, regulated by Drp-1(Dynamin related protein) and mitofusin 2 (Mfn2). Previously, we showed that Drp-1 inhibition ameliorates cardiovascular dysfunction following pressure overload in aortic banding model and myocardial infarction. As dynamic organelles, mitochondria are capable of changing their morphology in response to stress. However, whether such changes can alter their function and in turn cellular function is unknown. Further, a direct role of fission and fusion in cardiomyocyte contractility has not yet been studied. In this study, we hypothesize that disrupted fission and fusion balance by increased Drp-1 and decreased Mfn2 expression in cardiomyocytes affect their contractility through alterations in the calcium and potassium concentrations. Methods To verify this, we used freshly isolated ventricular myocytes from wild type mouse and transfected them with either siRNA to Drp-1 or Mfn2. Myocyte contractility studies were performed by IonOptix using a myopacer. Intracellular calcium and potassium measurements were done using flow cytometry. Immunocytochemistry (ICC) was done to evaluate live cell mitochondria and its membrane potential. Protein expression was done by Western blot and Immunocytochemistry. Results We found that silencing mitochondrial fission increased the myocyte contractility, while fusion inhibition decreased contractility with simultaneous changes in calcium and potassium. Also, we observed that increase in fission prompted decrease in Serca-2a and increase in cytochrome c leading to mitophagy. Conclusion Our results suggested that regulating mitochondrial fission and fusion have direct effects on overall cardiomyocyte contractility and thus function. PMID:25841124

  6. Different tumours induced by benzo(a)pyrene and its 7,8-dihydrodiol injected into adult mouse salivary gland.

    PubMed Central

    Wigley, C. B.; Amos, J.; Brookes, P.

    1978-01-01

    A comparison has been made between the carcinogenic activities of benzo(a)pyrene and the proposed proximate carcinogen, benzo(a)pyrene 7,8-dihydrodiol, in the adult C57BL mouse submandibular salivary gland. In preliminary studies using a range of doses, the dihydrodiol was slightly less active than the parent hydrocarbon in this system. There was a difference in the type of tumour induced by the 2 compounds. Benzo(a)pyrene induced tumours of the salivary glands at the site of injection, whereas the dihydrodiol induced malignant lymphosarcomas, particularly of the thymus, which were often metastatic to other orgnas. Possible reasons for the different sites of action of the 2 compounds are discussed. PMID:580763

  7. RUNX1B Expression Is Highly Heterogeneous and Distinguishes Megakaryocytic and Erythroid Lineage Fate in Adult Mouse Hematopoiesis

    PubMed Central

    Draper, Julia E.; Sroczynska, Patrycja; Tsoulaki, Olga; Leong, Hui Sun; Fadlullah, Muhammad Z. H.; Miller, Crispin; Kouskoff, Valerie; Lacaud, Georges

    2016-01-01

    The Core Binding Factor (CBF) protein RUNX1 is a master regulator of definitive hematopoiesis, crucial for hematopoietic stem cell (HSC) emergence during ontogeny. RUNX1 also plays vital roles in adult mice, in regulating the correct specification of numerous blood lineages. Akin to the other mammalian Runx genes, Runx1 has two promoters P1 (distal) and P2 (proximal) which generate distinct protein isoforms. The activities and specific relevance of these two promoters in adult hematopoiesis remain to be fully elucidated. Utilizing a dual reporter mouse model we demonstrate that the distal P1 promoter is broadly active in adult hematopoietic stem and progenitor cell (HSPC) populations. By contrast the activity of the proximal P2 promoter is more restricted and its upregulation, in both the immature Lineage- Sca1high cKithigh (LSK) and bipotential Pre-Megakaryocytic/Erythroid Progenitor (PreMegE) populations, coincides with a loss of erythroid (Ery) specification. Accordingly the PreMegE population can be prospectively separated into “pro-erythroid” and “pro-megakaryocyte” populations based on Runx1 P2 activity. Comparative gene expression analyses between Runx1 P2+ and P2- populations indicated that levels of CD34 expression could substitute for P2 activity to distinguish these two cell populations in wild type (WT) bone marrow (BM). Prospective isolation of these two populations will enable the further investigation of molecular mechanisms involved in megakaryocytic/erythroid (Mk/Ery) cell fate decisions. Having characterized the extensive activity of P1, we utilized a P1-GFP homozygous mouse model to analyze the impact of the complete absence of Runx1 P1 expression in adult mice and observed strong defects in the T cell lineage. Finally, we investigated how the leukemic fusion protein AML1-ETO9a might influence Runx1 promoter usage. Short-term AML1-ETO9a induction in BM resulted in preferential P2 upregulation, suggesting its expression may be important to

  8. Mouse Models of Human T Lymphotropic Virus Type-1–Associated Adult T-Cell Leukemia/Lymphoma

    PubMed Central

    Zimmerman, B.; Niewiesk, S.; Lairmore, M. D.

    2011-01-01

    Human T-lymphotropic virus type-1 (HTLV-1), the first human retrovirus discovered, is the causative agent of adult T-cell leukemia/lymphoma (ATL) and a number of lymphocyte-mediated inflammatory conditions including HTLV-1–associated myelopathy/tropical spastic paraparesis. Development of animal models to study the pathogenesis of HTLV-1–associated diseases has been problematic. Mechanisms of early infection and cell-to-cell transmission can be studied in rabbits and nonhuman primates, but lesion development and reagents are limited in these species. The mouse provides a cost-effective, highly reproducible model in which to study factors related to lymphoma development and the preclinical efficacy of potential therapies against ATL. The ability to manipulate transgenic mice has provided important insight into viral genes responsible for lymphocyte transformation. Expansion of various strains of immunodeficient mice has accelerated the testing of drugs and targeted therapy against ATL. This review compares various mouse models to illustrate recent advances in the understanding of HTLV-1–associated ATL development and how improvements in these models are critical to the future development of targeted therapies against this aggressive T-cell lymphoma. PMID:20442421

  9. Genomic structure, promoter identification, and chromosomal mapping of a mouse nuclear orphan receptor expressed in embryos and adult testes

    SciTech Connect

    Lee, C.H.; Wei, Li-Na; Copeland, N.G.; Gilbert, D.J.; Jenkins, N.A.

    1995-11-01

    We have isolated and characterized overlapping genomic clones containing the complete transcribed region of a newly isolated mouse cDNA encoding an orphan receptor expressed specifically in midgestation embryos and adult testis. This gene spans a distance of more than 50 kb and is organized into 13 exons. The transcription initiation site is located at the 158th nucleotide upstream from the translation initiation codon. All the exon/intron junction sequences follow the GT/AG rule. Based upon Northern blot analysis and the size of the transcribed region of the gene, its transcript was determined to be approximately 2.5 kb. Within approximately 500 hp upstream from the transcription initiation site, several immune response regulatory elements were identified but no TATA box was located. This gene was mapped to the distal region of mouse chromosome 10 and its locus has been designated Tr2-11. Immunohistochemical studies show that the Tr2-11 protein is present mainly in advanced germ cell populations of mature testes and that Tr2-11 gene expression is dramatically decreased in vitamin A-depleted animals. 23 refs., 7 figs.

  10. DNA microarray-based experimental strategy for trustworthy expression profiling of the hippocampal genes by astaxanthin supplementation in adult mouse

    PubMed Central

    Yook, Jang Soo; Shibato, Junko; Rakwal, Randeep; Soya, Hideaki

    2015-01-01

    Naturally occurring astaxantin (ASX) is one of the noticeable carotenoid and dietary supplement, which has strong antioxidant and anti-inflammatory properties, and neuroprotective effects in the brain through crossing the blood–brain barrier. Specially, we are interested in the role of ASX as a brain food. Although ASX has been suggested to have potential benefit to the brain function, the underlying molecular mechanisms and events mediating such effect remain unknown. Here we examined molecular factors in the hippocampus of adult mouse fed ASX diets (0.1% and 0.5% doses) using DNA microarray (Agilent 4 × 44 K whole mouse genome chip) analysis. In this study, we described in detail our experimental workflow and protocol, and validated quality controls with the housekeeping gene expression (Gapdh and Beta-actin) on the dye-swap based approach to advocate our microarray data, which have been uploaded to Gene Expression Omnibus (accession number GSE62197) as a gene resource for the scientific community. This data will also form an important basis for further detailed experiments and bioinformatics analysis with an aim to unravel the potential molecular pathways or mechanisms underlying the positive effects of ASX supplementation on the brain, in particular the hippocampus. PMID:26981356

  11. Taurine in drinking water recovers learning and memory in the adult APP/PS1 mouse model of Alzheimer's disease

    PubMed Central

    Kim, Hye Yun; Kim, Hyunjin V.; Yoon, Jin H.; Kang, Bo Ram; Cho, Soo Min; Lee, Sejin; Kim, Ji Yoon; Kim, Joo Won; Cho, Yakdol; Woo, Jiwan; Kim, YoungSoo

    2014-01-01

    Alzheimer's disease (AD) is a lethal progressive neurological disorder affecting the memory. Recently, US Food and Drug Administration mitigated the standard for drug approval, allowing symptomatic drugs that only improve cognitive deficits to be allowed to accelerate on to clinical trials. Our study focuses on taurine, an endogenous amino acid found in high concentrations in humans. It has demonstrated neuroprotective properties against many forms of dementia. In this study, we assessed cognitively enhancing property of taurine in transgenic mouse model of AD. We orally administered taurine via drinking water to adult APP/PS1 transgenic mouse model for 6 weeks. Taurine treatment rescued cognitive deficits in APP/PS1 mice up to the age-matching wild-type mice in Y-maze and passive avoidance tests without modifying the behaviours of cognitively normal mice. In the cortex of APP/PS1 mice, taurine slightly decreased insoluble fraction of Aβ. While the exact mechanism of taurine in AD has not yet been ascertained, our results suggest that taurine can aid cognitive impairment and may inhibit Aβ-related damages. PMID:25502280

  12. DNA microarray-based experimental strategy for trustworthy expression profiling of the hippocampal genes by astaxanthin supplementation in adult mouse.

    PubMed

    Yook, Jang Soo; Shibato, Junko; Rakwal, Randeep; Soya, Hideaki

    2016-03-01

    Naturally occurring astaxantin (ASX) is one of the noticeable carotenoid and dietary supplement, which has strong antioxidant and anti-inflammatory properties, and neuroprotective effects in the brain through crossing the blood-brain barrier. Specially, we are interested in the role of ASX as a brain food. Although ASX has been suggested to have potential benefit to the brain function, the underlying molecular mechanisms and events mediating such effect remain unknown. Here we examined molecular factors in the hippocampus of adult mouse fed ASX diets (0.1% and 0.5% doses) using DNA microarray (Agilent 4 × 44 K whole mouse genome chip) analysis. In this study, we described in detail our experimental workflow and protocol, and validated quality controls with the housekeeping gene expression (Gapdh and Beta-actin) on the dye-swap based approach to advocate our microarray data, which have been uploaded to Gene Expression Omnibus (accession number GSE62197) as a gene resource for the scientific community. This data will also form an important basis for further detailed experiments and bioinformatics analysis with an aim to unravel the potential molecular pathways or mechanisms underlying the positive effects of ASX supplementation on the brain, in particular the hippocampus. PMID:26981356

  13. PPARβ/δ and PPARγ maintain undifferentiated phenotypes of mouse adult neural precursor cells from the subventricular zone

    PubMed Central

    Bernal, Carolina; Araya, Claudia; Palma, Verónica; Bronfman, Miguel

    2015-01-01

    The subventricular zone (SVZ) is one of the main niches of neural stem cells in the adult mammalian brain. Stem and precursor cells in this region are the source for neurogenesis and oligodendrogesis, mainly in the olfactory bulb and corpus callosum, respectively. The identification of the molecular components regulating the decision of these cells to differentiate or maintain an undifferentiated state is important in order to understand the modulation of neurogenic processes in physiological and pathological conditions. PPARs are a group of transcription factors, activated by lipid ligands, with important functions in cellular differentiation and proliferation in several tissues. In this work, we demonstrate that mouse adult neural precursor cells (NPCs), in situ and in vitro, express PPARβ/δ and PPARγ. Pharmacological activation of both PPARs isoforms induces proliferation and maintenance of the undifferentiated phenotype. Congruently, inhibition of PPARβ/δ and PPARγ results in a decrease of proliferation and loss of the undifferentiated phenotype. Interestingly, PPARγ regulates the level of EGFR in adult NPCs, concurrent with it is function described in embryonic NPCs. Furthermore, we describe for the first time that PPARβ/δ regulates SOX2 level in adult NPCs, probably through a direct transcriptional regulation, as we identified two putative PPAR response elements in the promoter region of Sox2. EGFR and SOX2 are key players in neural stem/precursor cells self-renewal. Finally, rosiglitazone, a PPARγ ligand, increases PPARβ/δ level, suggesting a possible cooperation between these two PPARs in the control of cell fate behavior. Our work contributes to the understanding of the molecular mechanisms associated to neural cell fate decision and places PPARβ/δ and PPARγ as interesting new targets of modulation of mammalian brain homeostasis. PMID:25852474

  14. PPARβ/δ and PPARγ maintain undifferentiated phenotypes of mouse adult neural precursor cells from the subventricular zone.

    PubMed

    Bernal, Carolina; Araya, Claudia; Palma, Verónica; Bronfman, Miguel

    2015-01-01

    The subventricular zone (SVZ) is one of the main niches of neural stem cells in the adult mammalian brain. Stem and precursor cells in this region are the source for neurogenesis and oligodendrogesis, mainly in the olfactory bulb and corpus callosum, respectively. The identification of the molecular components regulating the decision of these cells to differentiate or maintain an undifferentiated state is important in order to understand the modulation of neurogenic processes in physiological and pathological conditions. PPARs are a group of transcription factors, activated by lipid ligands, with important functions in cellular differentiation and proliferation in several tissues. In this work, we demonstrate that mouse adult neural precursor cells (NPCs), in situ and in vitro, express PPARβ/δ and PPARγ. Pharmacological activation of both PPARs isoforms induces proliferation and maintenance of the undifferentiated phenotype. Congruently, inhibition of PPARβ/δ and PPARγ results in a decrease of proliferation and loss of the undifferentiated phenotype. Interestingly, PPARγ regulates the level of EGFR in adult NPCs, concurrent with it is function described in embryonic NPCs. Furthermore, we describe for the first time that PPARβ/δ regulates SOX2 level in adult NPCs, probably through a direct transcriptional regulation, as we identified two putative PPAR response elements in the promoter region of Sox2. EGFR and SOX2 are key players in neural stem/precursor cells self-renewal. Finally, rosiglitazone, a PPARγ ligand, increases PPARβ/δ level, suggesting a possible cooperation between these two PPARs in the control of cell fate behavior. Our work contributes to the understanding of the molecular mechanisms associated to neural cell fate decision and places PPARβ/δ and PPARγ as interesting new targets of modulation of mammalian brain homeostasis. PMID:25852474

  15. A comparison of the multiple oocyte maturation gene expression patterns between the newborn and adult mouse ovary

    PubMed Central

    Bahmanpour, Soghra; Talaei Khozani, Tahereh; Zarei fard, Nehleh; Jaberipour, Mansoureh; Hosseini, Ahmah; Esmaeilpour, Tahereh

    2013-01-01

    Background: The interaction between follicular cells and oocyte leads to a change in gene expression involved in oocyte maturation processes. Objective: The purpose of this study was to quantify the expression of more common genes involved in follicular growth and oocyte developmental competence. Materials and Methods: In this experimental study, the expression of genes was evaluated with qRT-PCR assay in female BALB/c mice pups at 3-day of pre-pubertal and 8 week old virgin adult ovaries. The tissue was prepared by H&E staining for normal morphological appearance. The data were calculated with the 2-∆Ct formula and assessed using non-parametric two-tailed Mann-Whitney test. The p<0.05 was considered as significant. Results: The data showed a significant increase in the level of Stra8 and GDF9 in adult compared with newborn mice ovaries (p=0.049). In contrast, a significant decrease in the level of Mvh, REC8, SCP1, SCP3, and ZP2 was observed in adult mice ovaries compared to those in the newborn mice ovaries (all p=0.049 except SCP1: p=0.046). There was no significant difference in the level of OCT4 and Cx37 expression between adult and newborn mice ovaries. Conclusion: The modifications in gene expression patterns coordinate the follicular developmental processes. Furthermore, the findings showed higher expression level of premeiotic gene (Stra8) and lower level of meiotic entry markers (SCP1, SCP3, and REC8) in juvenile than newborn mouse ovaries. This article extracted from Ph.D. thesis. (Nehleh Zarei fard) PMID:24639702

  16. The channel opening rate of adult- and fetal-type mouse muscle nicotinic receptors activated by acetylcholine

    PubMed Central

    Maconochie, David J; Steinbach, Joe Henry

    1998-01-01

    In this paper, we examine acetylcholine (ACh)-induced currents in quail fibroblast cell lines expressing either the fetal (Q-F18) or the adult (Q-A33) complement of nicotinic acetylcholine receptor subunits derived from mouse skeletal muscle. Pulses of ACh were applied to outside-out patches of cell membrane by means of a fast perfusion system, at concentrations from 100 nM to 10 mM. We obtained current records with intracellular potentials of -60 and +40 mV. The goal of this study was to estimate the channel opening rate.By fitting sums of exponentials to averaged responses, we estimated the rate of development of the current on the application of acetylcholine. The rate constant of the predominant exponential component (the on-rate) ranges over 3 orders of magnitude, from around 100 s−1 (fetal) at low concentrations of ACh to over 100 000 s−1 (fetal and adult) at the highest concentrations.We establish that our measurement of the on-rate is not limited by technical constraints, and can therefore be related to the rate constants of a kinetic scheme. Our observations are consistent with a model having a rate-limiting channel opening step with a forwards rate constant (β) of 80 000 s−1 on average for adult receptors and 60 000 s−1 for fetal receptors, and a minimum opening to closing ratio (β/α) of around 33 (adult) or 50 (fetal). The channel opening rate, β, varies from around 30 000 s−1 to well over 100 000 s−1 for different patches. The large variation cannot all be ascribed to errors of measurement, but indicates patch to patch variation. PMID:9481672

  17. Half-Logistic Function Model for First Half of Descending Phase of Cardiomyocyte Cytoplasmic Ca2+ Concentration ([Ca2+]i)-Time Curve (CaTCIII) in Isolated Aequorin-Injected Mouse Left Ventricular Papillary Muscle

    PubMed Central

    Mizuno, Ju; Otsuji, Mikiya; Yokoyama, Takeshi; Arita, Hideko; Hanaoka, Kazuo

    2016-01-01

    Background Myocardial contraction and relaxation are regulated by increases and decreases in cytoplasmic calcium concentration ([Ca2+]i). In previous studies, we found that a half-logistic (h-L) function, which represents a half-curve of a symmetrical sigmoid logistic function with a boundary at the inflection point, curve-fits the first half of the ascending phase and the second half of the descending phase of the [Ca2+]i transient curve better than a mono-exponential (m-E) function. In the present study, we investigated the potential application of an h-L function to analyse the first half of the descending phase of CaTC (CaTCIII). Methods The [Ca2+]i was measured using the Ca2+-sensitive aequorin, which was microinjected into 15 isolated mouse left ventricular (LV) papillary muscles. The observed CaTCIII data in the interval from the point corresponding to the peak [Ca2+]i to the point corresponding to dCa/dtmin was curve-fitted using the h-L and m-E function equations by the least-squares method. Results The mean correlation coefficient (r) values of the h-L and m-E function best curve-fits for 11 CaTCIIIs were 0.9986 and 0.9982, respectively. The Z transformation of h-L r (3.64 ± 0.45) was larger than that of m-E r (3.50 ± 0.33) (p < 0.05). Conclusions The h-L function can evaluate most CaTCIIIs more accurately than the m-E function in isolated aequorin-injected mouse LV papillary muscle. The three calculated h-L parameters i.e., amplitude constant, time constant, and non-zero asymptote, are more reliable indices than m-E for evaluating the magnitude and time course of the change in the decrease in [Ca2+]i. PMID:27122933

  18. Cardiomyocyte ultrastructural damage in β-thalassaemic mice

    PubMed Central

    Sanyear, Chanita; Butthep, Punnee; Nithipongvanich, Ramaneeya; Sirankapracha, Pornpan; Winichagoon, Pranee; Fucharoen, Suthat; Svasti, Saovaros

    2013-01-01

    β-thalassaemia is a hereditary anaemia resulting from the absence or reduction in β-globin chain production. Heart complications related to iron overload are the most serious cause of death in these patients. In this report cardiac pathology of β-thalassaemic mice was evaluated by light and electron microscopy. The study was carried out in thalassaemic mice carrying human β-thalassaemia mutation, IVSII-654 (654), transgenic mice carrying human βE-globin transgene insertion (E4), thalassaemic mice with human βE-globin transgene insertion (654/E4) and homozygous thalassaemic mice rescued by the human βE-globin transgene (R), which is generated by cross-breeding between the 654 and E4 mice. Histology showed iron deposition in cardiac myocytes of 654 and R mice, but the ultrastructural damage was observed only in the R mice when compared with the wild type, 654, E4 and 654/E4 mice. Histopathological changes in the cardiomyocytes of the R mice included mitochondrial swelling, loss of myofilaments and the presence of lipofuscin, related to the increased level of tissue iron content. The progressive ultrastructural pathology in R mice cardiomyocytes is consistent with the ultrastructural pathology previously studied in patients with thalassaemia. Thus, this R thalassaemic mouse model is suitable for in vivo pathophysiological study of thalassaemic heart. PMID:24020406

  19. BRG1 and BRM SWI/SNF ATPases redundantly maintain cardiomyocyte homeostasis by regulating cardiomyocyte mitophagy and mitochondrial dynamics in vivo.

    PubMed

    Bultman, Scott J; Holley, Darcy Wood; G de Ridder, Gustaaf; Pizzo, Salvatore V; Sidorova, Tatiana N; Murray, Katherine T; Jensen, Brian C; Wang, Zhongjing; Bevilacqua, Ariana; Chen, Xin; Quintana, Megan T; Tannu, Manasi; Rosson, Gary B; Pandya, Kumar; Willis, Monte S

    2016-01-01

    There has been an increasing recognition that mitochondrial perturbations play a central role in human heart failure. Mitochondrial networks, whose function is to maintain the regulation of mitochondrial biogenesis, autophagy ('mitophagy') and mitochondrial fusion/fission, are new potential therapeutic targets. Yet our understanding of the molecular underpinning of these processes is just emerging. We recently identified a role of the SWI/SNF ATP-dependent chromatin remodeling complexes in the metabolic homeostasis of the adult cardiomyocyte using cardiomyocyte-specific and inducible deletion of the SWI/SNF ATPases BRG1 and BRM in adult mice (Brg1/Brm double mutant mice). To build upon these observations in early altered metabolism, the present study looks at the subsequent alterations in mitochondrial quality control mechanisms in the impaired adult cardiomyocyte. We identified that Brg1/Brm double-mutant mice exhibited increased mitochondrial biogenesis, increases in 'mitophagy', and alterations in mitochondrial fission and fusion that led to small, fragmented mitochondria. Mechanistically, increases in the autophagy and mitophagy-regulated proteins Beclin1 and Bnip3 were identified, paralleling changes seen in human heart failure. Evidence for perturbed cardiac mitochondrial dynamics included decreased mitochondria size, reduced numbers of mitochondria, and an altered expression of genes regulating fusion (Mfn1, Opa1) and fission (Drp1). We also identified cardiac protein amyloid accumulation (aggregated fibrils) during disease progression along with an increase in pre-amyloid oligomers and an upregulated unfolded protein response including increased GRP78, CHOP, and IRE-1 signaling. Together, these findings described a role for BRG1 and BRM in mitochondrial quality control, by regulating mitochondrial number, mitophagy, and mitochondrial dynamics not previously recognized in the adult cardiomyocyte. As critical to the pathogenesis of heart failure, epigenetic

  20. Expression of the Argonaute protein PiwiL2 and piRNAs in adult mouse mesenchymal stem cells

    SciTech Connect

    Wu, Qiuling; Ma, Qi; Shehadeh, Lina A.; Wilson, Amber; Xia, Linghui; Yu, Hong; Webster, Keith A.

    2010-06-11

    Piwi (P-element-induced wimpy testis) first discovered in Drosophila is a member of the Argonaute family of micro-RNA binding proteins with essential roles in germ-cell development. The murine homologue of PiwiL2, also known as Mili is selectively expressed in the testes, and mice bearing targeted mutations of the PiwiL2 gene are male-sterile. PiwiL2 proteins are thought to protect the germ line genome by suppressing retrotransposons, stabilizing heterochromatin structure, and regulating target genes during meiosis and mitosis. Here, we report that PiwiL2 and associated piRNAs (piRs) may play similar roles in adult mouse mesenchymal stem cells. We found that PiwiL2 is expressed in the cytoplasm of metaphase mesenchymal stem cells from the bone marrow of adult and aged mice. Knockdown of PiwiL2 with a specific siRNA enhanced cell proliferation, significantly increased the number of cells in G1/S and G2/M cell cycle phases and was associated with increased expression of cell cycle genes CCND1, CDK8, microtubule regulation genes, and decreased expression of tumor suppressors Cables 1, LATS, and Cxxc4. The results suggest broader roles for Piwi in genome surveillance beyond the germ line and a possible role in regulating the cell cycle of mesenchymal stem cells.

  1. Regulation of neonatal and adult mammalian heart regeneration by the miR-15 family

    PubMed Central

    Porrello, Enzo R.; Mahmoud, Ahmed I.; Simpson, Emma; Johnson, Brett A.; Grinsfelder, David; Canseco, Diana; Mammen, Pradeep P.; Rothermel, Beverly A.; Olson, Eric N.; Sadek, Hesham A.

    2013-01-01

    We recently identified a brief time period during postnatal development when the mammalian heart retains significant regenerative potential after amputation of the ventricular apex. However, one major unresolved question is whether the neonatal mouse heart can also regenerate in response to myocardial ischemia, the most common antecedent of heart failure in humans. Here, we induced ischemic myocardial infarction (MI) in 1-d-old mice and found that this results in extensive myocardial necrosis and systolic dysfunction. Remarkably, the neonatal heart mounted a robust regenerative response, through proliferation of preexisting cardiomyocytes, resulting in full functional recovery within 21 d. Moreover, we show that the miR-15 family of microRNAs modulates neonatal heart regeneration through inhibition of postnatal cardiomyocyte proliferation. Finally, we demonstrate that inhibition of the miR-15 family from an early postnatal age until adulthood increases myocyte proliferation in the adult heart and improves left ventricular systolic function after adult MI. We conclude that the neonatal mammalian heart can regenerate after myocardial infarction through proliferation of preexisting cardiomyocytes and that the miR-15 family contributes to postnatal loss of cardiac regenerative capacity. PMID:23248315

  2. Detyrosinated microtubules buckle and bear load in contracting cardiomyocytes.

    PubMed

    Robison, Patrick; Caporizzo, Matthew A; Ahmadzadeh, Hossein; Bogush, Alexey I; Chen, Christina Yingxian; Margulies, Kenneth B; Shenoy, Vivek B; Prosser, Benjamin L

    2016-04-22

    The microtubule (MT) cytoskeleton can transmit mechanical signals and resist compression in contracting cardiomyocytes. How MTs perform these roles remains unclear because of difficulties in observing MTs during the rapid contractile cycle. Here, we used high spatial and temporal resolution imaging to characterize MT behavior in beating mouse myocytes. MTs deformed under contractile load into sinusoidal buckles, a behavior dependent on posttranslational "detyrosination" of α-tubulin. Detyrosinated MTs associated with desmin at force-generating sarcomeres. When detyrosination was reduced, MTs uncoupled from sarcomeres and buckled less during contraction, which allowed sarcomeres to shorten and stretch with less resistance. Conversely, increased detyrosination promoted MT buckling, stiffened the myocyte, and correlated with impaired function in cardiomyopathy. Thus, detyrosinated MTs represent tunable, compression-resistant elements that may impair cardiac function in disease. PMID:27102488

  3. Cholesterol Depletion Alters Cardiomyocyte Subcellular Signaling and Increases Contractility

    PubMed Central

    McIntosh, Victoria J.; Abou Samra, Abdul B.; Mohammad, Ramzi M.; Lasley, Robert D.

    2016-01-01

    Membrane cholesterol levels play an important factor in regulating cell function. Sarcolemmal cholesterol is concentrated in lipid rafts and caveolae, which are flask-shaped invaginations of the plasma membrane. The scaffolding protein caveolin permits the enrichment of cholesterol in caveolae, and caveolin interactions with numerous proteins regulate their function. The purpose of this study was to determine whether acute reductions in cardiomyocyte cholesterol levels alter subcellular protein kinase activation, intracellular Ca2+ and contractility. Methods: Ventricular myocytes, isolated from adult Sprague Dawley rats, were treated with the cholesterol reducing agent methyl-β-cyclodextrin (MβCD, 5 mM, 1 hr, room temperature). Total cellular cholesterol levels, caveolin-3 localization, subcellular, ERK and p38 mitogen activated protein kinase (MAPK) signaling, contractility, and [Ca2+]i were assessed. Results: Treatment with MβCD reduced cholesterol levels by ~45 and shifted caveolin-3 from cytoskeleton and triton-insoluble fractions to the triton-soluble fraction, and increased ERK isoform phosphorylation in cytoskeletal, cytosolic, triton-soluble and triton-insoluble membrane fractions without altering their subcellular distributions. In contrast the primary effect of MβCD was on p38 subcellular distribution of p38α with little effect on p38 phosphorylation. Cholesterol depletion increased cardiomyocyte twitch amplitude and the rates of shortening and relaxation in conjunction with increased diastolic and systolic [Ca2+]i. Conclusions: These results indicate that acute reductions in membrane cholesterol levels differentially modulate basal cardiomyocyte subcellular MAPK signaling, as well as increasing [Ca2+]i and contractility. PMID:27441649

  4. The Bulk of Autotaxin Activity Is Dispensable for Adult Mouse Life.

    PubMed

    Katsifa, Aggeliki; Kaffe, Eleanna; Nikolaidou-Katsaridou, Nefeli; Economides, Aris N; Newbigging, Susan; McKerlie, Colin; Aidinis, Vassilis

    2015-01-01

    Autotaxin (ATX, Enpp2) is a secreted lysophospholipase D catalysing the production of lysophosphatidic acid, a pleiotropic growth factor-like lysophospholipid. Increased ATX expression has been detected in a number of chronic inflammatory diseases and different types of cancer, while genetic interventions have proven a role for ATX in disease pathogenesis. Therefore, ATX has emerged as a potential drug target and a large number of ATX inhibitors have been developed exhibiting promising therapeutic potential. However, the embryonic lethality of ATX null mice and the ubiquitous expression of ATX and LPA receptors in adult life question the suitability of ATX as a drug target. Here we show that inducible, ubiquitous genetic deletion of ATX in adult mice, as well as long-term potent pharmacologic inhibition, are well tolerated, alleviating potential toxicity concerns of ATX therapeutic targeting. PMID:26569406

  5. The Bulk of Autotaxin Activity Is Dispensable for Adult Mouse Life

    PubMed Central

    Katsifa, Aggeliki; Kaffe, Eleanna; Nikolaidou-Katsaridou, Nefeli; Economides, Aris N.; Newbigging, Susan; McKerlie, Colin; Aidinis, Vassilis

    2015-01-01

    Autotaxin (ATX, Enpp2) is a secreted lysophospholipase D catalysing the production of lysophosphatidic acid, a pleiotropic growth factor-like lysophospholipid. Increased ATX expression has been detected in a number of chronic inflammatory diseases and different types of cancer, while genetic interventions have proven a role for ATX in disease pathogenesis. Therefore, ATX has emerged as a potential drug target and a large number of ATX inhibitors have been developed exhibiting promising therapeutic potential. However, the embryonic lethality of ATX null mice and the ubiquitous expression of ATX and LPA receptors in adult life question the suitability of ATX as a drug target. Here we show that inducible, ubiquitous genetic deletion of ATX in adult mice, as well as long-term potent pharmacologic inhibition, are well tolerated, alleviating potential toxicity concerns of ATX therapeutic targeting. PMID:26569406

  6. Roles of Wnt Signaling in the Neurogenic Niche of the Adult Mouse Ventricular-Subventricular Zone.

    PubMed

    Hirota, Yuki; Sawada, Masato; Huang, Shih-Hui; Ogino, Takashi; Ohata, Shinya; Kubo, Akiharu; Sawamoto, Kazunobu

    2016-02-01

    In many animal species, the production of new neurons (neurogenesis) occurs throughout life, in a specialized germinal region called the ventricular-subventricular zone (V-SVZ). In this region, neural stem cells undergo self-renewal and generate neural progenitor cells and new neurons. In the olfactory system, the new neurons migrate rostrally toward the olfactory bulb, where they differentiate into mature interneurons. V-SVZ-derived new neurons can also migrate toward sites of brain injury, where they contribute to neural regeneration. Recent studies indicate that two major branches of the Wnt signaling pathway, the Wnt/β-catenin and Wnt/planar cell polarity pathways, play essential roles in various facets of adult neurogenesis. Here, we review the Wnt signaling-mediated regulation of adult neurogenesis in the V-SVZ under physiological and pathological conditions. PMID:26572545

  7. Variable partial unilateral ureteral obstruction and its release in the neonatal and adult mouse.

    PubMed

    Thornhill, Barbara A; Chevalier, Robert L

    2012-01-01

    Obstructive nephropathy is the most important cause of renal failure in children. Unilateral ureteral obstruction (UUO) in the neonatal mouse provides a useful model to investigate the response of the developing kidney to urine flow obstruction. Creation of reversible variable partial UUO (compared to complete UUO) more closely approximates congenital lesions, and permits the study of recovery following release of the obstruction. Implementation of this technique requires the appropriate optical, surgical, and anesthetic equipment, as well as adaptations appropriate to the very small animals undergoing surgical procedures. Care of the pups must include minimizing trauma to delicate tissues, close monitoring of anesthesia and body temperature, and ensuring acceptance of the pups by the mother. It is important to document the severity and patency of the partial UUO by ureteral measurement and pelvic injection of India ink. Finally, removal of kidneys for histologic examination should be accomplished with gentle handling and processing. PMID:22639278

  8. DNA delivery in adult mouse eyes: An update with corneal endothelium outcomes

    PubMed Central

    Nickerson, John M.; Getz, Shannon E.; Sellers, Jana T.; Chrenek, Micah A.; Goodman, Penny; Bernal, Christiana J.; Boatright, Jeffrey H.

    2014-01-01

    Ocular injection (intravitreal, subretinal, or into the anterior space) is an efficient approach to deliver many classes of drugs, cells, and other treatments to various cell types of the eye. In particular, subretinal injection is efficient since delivered agents accumulate as there is no dilution due to transport processes or diffusion and because the volume of the interphotoreceptor space (IPS) is minimal (10–20 microliters in the human eye, less than 1 microliter in the mouse eye). We previously reported methods using subretinal injection and electroporation to deliver DNA to photoreceptor and retinal pigment epithelium (RPE) cells in retinas of live mice(1–3). Here we detail further optimization of that approach and additionally report its use in delivering DNA expression plasmids to the corneal endothelium. PMID:24510822

  9. Characterization and isolation of immature neurons of the adult mouse piriform cortex.

    PubMed

    Rubio, A; Belles, M; Belenguer, G; Vidueira, S; Fariñas, I; Nacher, J

    2016-07-01

    Physiological studies indicate that the piriform or primary olfactory cortex of adult mammals exhibits a high degree of synaptic plasticity. Interestingly, a subpopulation of cells in the layer II of the adult piriform cortex expresses neurodevelopmental markers, such as the polysialylated form of neural cell adhesion molecule (PSA-NCAM) or doublecortin (DCX). This study analyzes the nature, origin, and potential function of these poorly understood cells in mice. As previously described in rats, most of the PSA-NCAM expressing cells in layer II could be morphologically classified as tangled cells and only a small proportion of larger cells could be considered semilunar-pyramidal transitional neurons. Most were also immunoreactive for DCX, confirming their immature nature. In agreement with this, detection of PSA-NCAM combined with that of different cell lineage-specific antigens revealed that most PSA-NCAM positive cells did not co-express markers of glial cells or mature neurons. Their time of origin was evaluated by birthdating experiments with halogenated nucleosides performed at different developmental stages and in adulthood. We found that virtually all cells in this paleocortical region, including PSA-NCAM-positive cells, are born during fetal development. In addition, proliferation analyses in adult mice revealed that very few cells were cycling in layer II of the piriform cortex and that none of them was PSA-NCAM-positive. Moreover, we have established conditions to isolate and culture these immature neurons in the adult piriform cortex layer II. We find that although they can survive under certain conditions, they do not proliferate in vitro either. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 748-763, 2016. PMID:26487449

  10. A lacZ reporter gene expression atlas for 313 adult KOMP mutant mouse lines.

    PubMed

    West, David B; Pasumarthi, Ravi K; Baridon, Brian; Djan, Esi; Trainor, Amanda; Griffey, Stephen M; Engelhard, Eric K; Rapp, Jared; Li, Bowen; de Jong, Pieter J; Lloyd, K C Kent

    2015-04-01

    Expression of the bacterial beta-galactosidase reporter gene (lacZ) in the vector used for the Knockout Mouse Project (KOMP) is driven by the endogenous promoter of the target gene. In tissues from KOMP mice, histochemical staining for LacZ enzyme activity can be used to determine gene expression patterns. With this technique, we have produced a comprehensive resource of gene expression using both whole mount (WM) and frozen section (FS) LacZ staining in 313 unique KOMP mutant mouse lines. Of these, ∼ 80% of mutants showed specific staining in one or more tissues, while ∼ 20% showed no specific staining, ∼ 13% had staining in only one tissue, and ∼ 25% had staining in >6 tissues. The highest frequency of specific staining occurred in the brain (∼ 50%), male gonads (42%), and kidney (39%). The WM method was useful for rapidly identifying whole organ and some substructure staining, while the FS method often revealed substructure and cellular staining specificity. Both staining methods had >90% repeatability in biological replicates. Nonspecific LacZ staining occurs in some tissues due to the presence of bacteria or endogenous enzyme activity. However, this can be effectively distinguished from reporter gene activity by the combination of the WM and FS methods. After careful annotation, LacZ staining patterns in a high percentage of mutants revealed a unique structure-function not previously reported for many of these genes. The validation of methods for LacZ staining, annotation, and expression analysis reported here provides unique insights into the function of genes for which little is currently known. PMID:25591789

  11. Genistein exposure inhibits growth and alters steroidogenesis in adult mouse antral follicles.

    PubMed

    Patel, Shreya; Peretz, Jackye; Pan, Yuan-Xiang; Helferich, William G; Flaws, Jodi A

    2016-02-15

    Genistein is a naturally occurring isoflavone phytoestrogen commonly found in plant products such as soybeans, lentils, and chickpeas. Genistein, like other phytoestrogens, has the potential to mimic, enhance, or impair the estradiol biosynthesis pathway, thereby potentially altering ovarian follicle growth. Previous studies have inconsistently indicated that genistein exposure may alter granulosa cell proliferation and hormone production, but no studies have examined the effects of genistein on intact antral follicles. Thus, this study was designed to test the hypothesis that genistein exposure inhibits follicle growth and steroidogenesis in intact antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice were cultured with vehicle (dimethyl sulfoxide; DMSO) or genistein (6.0 and 36μM) for 18-96h. Every 24h, follicle diameters were measured to assess growth. At the end of each culture period, the media were pooled to measure hormone levels, and the cultured follicles were collected to measure expression of cell cycle regulators and steroidogenic enzymes. The results indicate that genistein (36μM) inhibits growth of mouse antral follicles. Additionally, genistein (6.0 and 36μM) increases progesterone, testosterone, and dehydroepiandrosterone (DHEA) levels, but decreases estrone and estradiol levels. The results also indicate that genistein alters the expression of steroidogenic enzymes at 24, 72 and 96h, and the expression of cell cycle regulators at 18h. These data indicate that genistein exposure inhibits antral follicle growth by inhibiting the cell cycle, alters sex steroid hormone levels, and dysregulates steroidogenic enzymes in cultured mouse antral follicles. PMID:26792615

  12. A lacZ reporter gene expression atlas for 313 adult KOMP mutant mouse lines

    PubMed Central

    Pasumarthi, Ravi K.; Baridon, Brian; Djan, Esi; Trainor, Amanda; Griffey, Stephen M.; Engelhard, Eric K.; Rapp, Jared; Li, Bowen; de Jong, Pieter J.; Lloyd, K.C. Kent

    2015-01-01

    Expression of the bacterial beta-galactosidase reporter gene (lacZ) in the vector used for the Knockout Mouse Project (KOMP) is driven by the endogenous promoter of the target gene. In tissues from KOMP mice, histochemical staining for LacZ enzyme activity can be used to determine gene expression patterns. With this technique, we have produced a comprehensive resource of gene expression using both whole mount (WM) and frozen section (FS) LacZ staining in 313 unique KOMP mutant mouse lines. Of these, ∼80% of mutants showed specific staining in one or more tissues, while ∼20% showed no specific staining, ∼13% had staining in only one tissue, and ∼25% had staining in >6 tissues. The highest frequency of specific staining occurred in the brain (∼50%), male gonads (42%), and kidney (39%). The WM method was useful for rapidly identifying whole organ and some substructure staining, while the FS method often revealed substructure and cellular staining specificity. Both staining methods had >90% repeatability in biological replicates. Nonspecific LacZ staining occurs in some tissues due to the presence of bacteria or endogenous enzyme activity. However, this can be effectively distinguished from reporter gene activity by the combination of the WM and FS methods. After careful annotation, LacZ staining patterns in a high percentage of mutants revealed a unique structure-function not previously reported for many of these genes. The validation of methods for LacZ staining, annotation, and expression analysis reported here provides unique insights into the function of genes for which little is currently known. PMID:25591789

  13. Polyclonal origin and hair induction ability of dermal papillae in neonatal and adult mouse back skin

    PubMed Central

    Collins, Charlotte A.; Jensen, Kim B.; MacRae, Elizabeth J.; Mansfield, William; Watt, Fiona M.

    2012-01-01

    Hair follicle development and growth are regulated by Wnt signalling and depend on interactions between epidermal cells and a population of fibroblasts at the base of the follicle, known as the dermal papilla (DP). DP cells have a distinct gene expression signature from non-DP dermal fibroblasts. However, their origins are largely unknown. By generating chimeric mice and performing skin reconstitution assays we show that, irrespective of whether DP form during development, are induced by epidermal Wnt activation in adult skin or assemble from disaggregated cells, they are polyclonal in origin. While fibroblast proliferation is necessary for hair follicle formation in skin reconstitution assays, mitotically inhibited cells readily contribute to DP. Although new hair follicles do not usually develop in adult skin, adult dermal fibroblasts are competent to contribute to DP during hair follicle neogenesis, irrespective of whether they originate from skin in the resting or growth phase of the hair cycle or skin with β-catenin-induced ectopic follicles. We propose that during skin reconstitution fibroblasts may be induced to become DP cells by interactions with hair follicle epidermal cells, rather than being derived from a distinct subpopulation of cells. PMID:22537489

  14. Adult neurogenesis and specific replacement of interneuron subtypes in the mouse main olfactory bulb

    PubMed Central

    Bagley, Joshua; LaRocca, Greg; Jimenez, Daniel A; Urban, Nathaniel N

    2007-01-01

    Background New neurons are generated in the adult brain from stem cells found in the subventricular zone (SVZ). These cells proliferate in the SVZ, generating neuroblasts which then migrate to the main olfactory bulb (MOB), ending their migration in the glomerular layer (GLL) and the granule cell layer (GCL) of the MOB. Neuronal populations in these layers undergo turnover throughout life, but whether all neuronal subtypes found in these areas are replaced and when neurons begin to express subtype-specific markers is not known. Results Here we use BrdU injections and immunohistochemistry against (calretinin, calbindin, N-copein, tyrosine hydroxylase and GABA) and show that adult-generated neurons express markers of all major subtypes of neurons in the GLL and GCL. Moreover, the fractions of new neurons that express subtype-specific markers at 40 and 75 days post BrdU injection are very similar to the fractions of all neurons expressing these markers. We also show that many neurons in the glomerular layer do not express NeuN, but are readily and specifically labeled by the fluorescent nissl stain Neurotrace. Conclusion The expression of neuronal subtype-specific markers by new neurons in the GLL and GCL changes rapidly during the period from 14–40 days after BrdU injection before reaching adult levels. This period may represent a critical window for cell fate specification similar to that observed for neuronal survival. PMID:17996088

  15. Polyclonal origin and hair induction ability of dermal papillae in neonatal and adult mouse back skin.

    PubMed

    Collins, Charlotte A; Jensen, Kim B; MacRae, Elizabeth J; Mansfield, William; Watt, Fiona M

    2012-06-15

    Hair follicle development and growth are regulated by Wnt signalling and depend on interactions between epidermal cells and a population of fibroblasts at the base of the follicle, known as the dermal papilla (DP). DP cells have a distinct gene expression signature from non-DP dermal fibroblasts. However, their origins are largely unknown. By generating chimeric mice and performing skin reconstitution assays we show that, irrespective of whether DP form during development, are induced by epidermal Wnt activation in adult skin or assemble from disaggregated cells, they are polyclonal in origin. While fibroblast proliferation is necessary for hair follicle formation in skin reconstitution assays, mitotically inhibited cells readily contribute to DP. Although new hair follicles do not usually develop in adult skin, adult dermal fibroblasts are competent to contribute to DP during hair follicle neogenesis, irrespective of whether they originate from skin in the resting or growth phase of the hair cycle or skin with β-catenin-induced ectopic follicles. We propose that during skin reconstitution fibroblasts may be induced to become DP cells by interactions with hair follicle epidermal cells, rather than being derived from a distinct subpopulation of cells. PMID:22537489

  16. Wnt-dependent de novo hair follicle regeneration in adult mouse skin after wounding.

    PubMed

    Ito, Mayumi; Yang, Zaixin; Andl, Thomas; Cui, Chunhua; Kim, Noori; Millar, Sarah E; Cotsarelis, George

    2007-05-17

    The mammalian hair follicle is a complex 'mini-organ' thought to form only during development; loss of an adult follicle is considered permanent. However, the possibility that hair follicles develop de novo following wounding was raised in studies on rabbits, mice and even humans fifty years ago. Subsequently, these observations were generally discounted because definitive evidence for follicular neogenesis was not presented. Here we show that, after wounding, hair follicles form de novo in genetically normal adult mice. The regenerated hair follicles establish a stem cell population, express known molecular markers of follicle differentiation, produce a hair shaft and progress through all stages of the hair follicle cycle. Lineage analysis demonstrated that the nascent follicles arise from epithelial cells outside of the hair follicle stem cell niche, suggesting that epidermal cells in the wound assume a hair follicle stem cell phenotype. Inhibition of Wnt signalling after re-epithelialization completely abrogates this wounding-induced folliculogenesis, whereas overexpression of Wnt ligand in the epidermis increases the number of regenerated hair follicles. These remarkable regenerative capabilities of the adult support the notion that wounding induces an embryonic phenotype in skin, and that this provides a window for manipulation of hair follicle neogenesis by Wnt proteins. These findings suggest treatments for wounds, hair loss and other degenerative skin disorders. PMID:17507982

  17. Promotion of Cortical Neurogenesis from the Neural Stem Cells in the Adult Mouse Subcallosal Zone.

    PubMed

    Kim, Joo Yeon; Choi, Kyuhyun; Shaker, Mohammed R; Lee, Ju-Hyun; Lee, Boram; Lee, Eunsoo; Park, Jae-Yong; Lim, Mi-Sun; Park, Chang-Hwan; Shin, Ki Soon; Kim, Hyun; Geum, Dongho; Sun, Woong

    2016-04-01

    Neurogenesis occurs spontaneously in the subventricular zone (SVZ) of the lateral ventricle in adult rodent brain, but it has long been debated whether there is sufficient adult neurogenesis in human SVZ. Subcallosal zone (SCZ), a posterior continuum of SVZ closely associated with posterior regions of cortical white matter, has also been reported to contain adult neural stem cells (aNSCs) in both rodents and humans. However, little is known whether SCZ-derived aNSC (SCZ-aNSCs) can produce cortical neurons following brain injury. We found that SCZ-aNSCs exhibited limited neuronal differentiation potential in culture and after transplantation in mice. Neuroblasts derived from SCZ initially migrated toward injured cortex regions following brain injury, but later exhibited apoptosis. Overexpression of anti-apoptotic bcl-xL in the SCZ by retroviral infection rescued neuroblasts from cell death in the injured cortex, but neuronal maturation was still limited, resulting in atrophy. In combination with Bcl-xL, infusion of brain-derived neurotropic factor rescued atrophy, and importantly, a subset of such SCZ-aNSCs differentiated and attained morphological and physiological characteristics of mature, excitatory neurons. These results suggest that the combination of anti-apoptotic and neurotrophic factors might enable the use of aNSCs derived from the SCZ in cortical neurogenesis for neural replacement therapy. Stem Cells 2016;34:888-901. PMID:26701067

  18. Simultaneous Assessment of Cardiomyocyte DNA Synthesis and Ploidy: A Method to Assist Quantification of Cardiomyocyte Regeneration and Turnover.

    PubMed

    Richardson, Gavin D

    2016-01-01

    Although it is accepted that the heart has a limited potential to regenerate cardiomyocytes following injury and that low levels of cardiomyocyte turnover occur during normal ageing, quantification of these events remains challenging. This is in part due to the rarity of the process and the fact that multiple cellular sources contribute to myocardial maintenance. Furthermore, DNA duplication within cardiomyocytes often leads to a polyploid cardiomyocyte and only rarely leads to new cardiomyocytes by cellular division. In order to accurately quantify cardiomyocyte turnover discrimination between these processes is essential. The protocol described here employs long term nucleoside labeling in order to label all nuclei which have arisen as a result of DNA replication and cardiomyocyte nuclei identified by utilizing nuclei isolation and subsequent PCM1 immunolabeling. Together this allows the accurate and sensitive identification of the nucleoside labeling of the cardiomyocyte nuclei population. Furthermore, 4',6-diamidino-2-phenylindole labeling and analysis of nuclei ploidy, enables the discrimination of neo-cardiomyocyte nuclei from nuclei which have incorporated nucleoside during polyploidization. Although this method cannot control for cardiomyocyte binucleation, it allows a rapid and robust quantification of neo-cardiomyocyte nuclei while accounting for polyploidization. This method has a number of downstream applications including assessing the potential therapeutics to enhance cardiomyocyte regeneration or investigating the effects of cardiac disease on cardiomyocyte turnover and ploidy. This technique is also compatible with additional downstream immunohistological techniques, allowing quantification of nucleoside incorporation in all cardiac cell types. PMID:27285379

  19. Simultaneous Assessment of Cardiomyocyte DNA Synthesis and Ploidy: A Method to Assist Quantification of Cardiomyocyte Regeneration and Turnover

    PubMed Central

    Richardson, Gavin D.

    2016-01-01

    Although it is accepted that the heart has a limited potential to regenerate cardiomyocytes following injury and that low levels of cardiomyocyte turnover occur during normal ageing, quantification of these events remains challenging. This is in part due to the rarity of the process and the fact that multiple cellular sources contribute to myocardial maintenance. Furthermore, DNA duplication within cardiomyocytes often leads to a polyploid cardiomyocyte and only rarely leads to new cardiomyocytes by cellular division. In order to accurately quantify cardiomyocyte turnover discrimination between these processes is essential. The protocol described here employs long term nucleoside labeling in order to label all nuclei which have arisen as a result of DNA replication and cardiomyocyte nuclei identified by utilizing nuclei isolation and subsequent PCM1 immunolabeling. Together this allows the accurate and sensitive identification of the nucleoside labeling of the cardiomyocyte nuclei population. Furthermore, 4′,6-diamidino-2-phenylindole labeling and analysis of nuclei ploidy, enables the discrimination of neo-cardiomyocyte nuclei from nuclei which have incorporated nucleoside during polyploidization. Although this method cannot control for cardiomyocyte binucleation, it allows a rapid and robust quantification of neo-cardiomyocyte nuclei while accounting for polyploidization. This method has a number of downstream applications including assessing the potential therapeutics to enhance cardiomyocyte regeneration or investigating the effects of cardiac disease on cardiomyocyte turnover and ploidy. This technique is also compatible with additional downstream immunohistological techniques, allowing quantification of nucleoside incorporation in all cardiac cell types. PMID:27285379

  20. Role of cardiomyocyte circadian clock in myocardial metabolic adaptation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marked circadian rhythmicities in cardiovascular physiology and pathophysiology exist. The cardiomyocyte circadian clock has recently been linked to circadian rhythms in myocardial gene expression, metabolism, and contractile function. For instance, the cardiomyocyte circadian clock is essential f...

  1. RyR2 Modulates a Ca2+-Activated K+ Current in Mouse Cardiac Myocytes

    PubMed Central

    Mu, Yong-hui; Zhao, Wen-chao; Duan, Ping; Chen, Yun; Zhao, Wei-da; Wang, Qian; Tu, Hui-yin; Zhang, Qian

    2014-01-01

    In cardiomyocytes, Ca2+ entry through voltage-dependent Ca2+ channels (VDCCs) binds to and activates RyR2 channels, resulting in subsequent Ca2+ release from the sarcoplasmic reticulum (SR) and cardiac contraction. Previous research has documented the molecular coupling of small-conductance Ca2+-activated K+ channels (SK channels) to VDCCs in mouse cardiac muscle. Little is known regarding the role of RyRs-sensitive Ca2+ release in the SK channels in cardiac muscle. In this study, using whole-cell patch clamp techniques, we observed that a Ca2+-activated K+ current (IK,Ca) recorded from isolated adult C57B/L mouse atrial myocytes was significantly decreased by ryanodine, an inhibitor of ryanodine receptor type 2 (RyR2), or by the co-application of ryanodine and thapsigargin, an inhibitor of the sarcoplasmic reticulum calcium ATPase (SERCA) (p<0.05, p<0.01, respectively). The activation of RyR2 by caffeine increased the IK,Ca in the cardiac cells (p<0.05, p<0.01, respectively). We further analyzed the effect of RyR2 knockdown on IK,Ca and Ca2+ in isolated adult mouse cardiomyocytes using a whole-cell patch clamp technique and confocal imaging. RyR2 knockdown in mouse atrial cells transduced with lentivirus-mediated small hairpin interference RNA (shRNA) exhibited a significant decrease in IK,Ca (p<0.05) and [Ca2+]i fluorescence intensity (p<0.01). An immunoprecipitated complex of SK2 and RyR2 was identified in native cardiac tissue by co-immunoprecipitation assays. Our findings indicate that RyR2-mediated Ca2+ release is responsible for the activation and modulation of SK channels in cardiac myocytes. PMID:24747296

  2. Odour enrichment increases adult-born dopaminergic neurons in the mouse olfactory bulb.

    PubMed

    Bonzano, Sara; Bovetti, Serena; Fasolo, Aldo; Peretto, Paolo; De Marchis, Silvia

    2014-11-01

    The olfactory bulb (OB) is the first brain region involved in the processing of olfactory information. In adult mice, the OB is highly plastic, undergoing cellular/molecular dynamic changes that are modulated by sensory experience. Odour deprivation induces down-regulation of tyrosine hydroxylase (TH) expression in OB dopaminergic interneurons located in the glomerular layer (GL), resulting in decreased dopamine in the OB. Although the effect of sensory deprivation is well established, little is known about the influence of odour enrichment on dopaminergic cells. Here we report that prolonged odour enrichment on C57BL/6J strain mice selectively increases TH-immunopositive cells in the GL by nearly 20%. Following odour enrichment on TH-green fluorescent protein (GFP) transgenic mice, in which GFP identified both mature TH-positive cells and putative immature dopaminergic cells expressing TH mRNA but not TH protein, we found a similar 20% increase in GFP-expressing cells, with no changes in the ratio between TH-positive and TH-negative cells. These data suggest that enriched conditions induce an expansion in the whole dopaminergic lineage. Accordingly, by using 5-bromo-2-deoxyuridine injections to label adult-generated cells in the GL of TH-GFP mice, we found an increase in the percentage of 5-bromo-2-deoxyuridine-positive dopaminergic cells in enriched compared with control conditions, whereas no differences were found for calretinin- and calbindin-positive subtypes. Strikingly, the fraction of newborn cells among the dopaminergic population doubled in enriched conditions. On the whole, our results demonstrate that odour enrichment drives increased integration of adult-generated dopaminergic cells that could be critical to adapt the OB circuits to the environmental incoming information. PMID:25216299

  3. Characterizing Newly Repopulated Microglia in the Adult Mouse: Impacts on Animal Behavior, Cell Morphology, and Neuroinflammation

    PubMed Central

    Elmore, Monica R. P.; Lee, Rafael J.; West, Brian L.; Green, Kim N.

    2015-01-01

    Microglia are the primary immune cell in the brain and are postulated to play important roles outside of immunity. Administration of the dual colony-stimulating factor 1 receptor (CSF1R)/c-Kit kinase inhibitor, PLX3397, to adult mice results in the elimination of ~99% of microglia, which remain eliminated for as long as treatment continues. Upon removal of the inhibitor, microglia rapidly repopulate the entire adult brain, stemming from a central nervous system (CNS) resident progenitor cell. Using this method of microglial elimination and repopulation, the role of microglia in both healthy and diseased states can be explored. Here, we examine the responsiveness of newly repopulated microglia to an inflammatory stimulus, as well as determine the impact of these cells on behavior, cognition, and neuroinflammation. Two month-old wild-type mice were placed on either control or PLX3397 diet for 21 d to eliminate microglia. PLX3397 diet was then removed in a subset of animals to allow microglia to repopulate and behavioral testing conducted beginning at 14 d repopulation. Finally, inflammatory profiling of the microglia-repopulated brain in response to lipopolysaccharide (LPS; 0.25 mg/kg) or phosphate buffered saline (PBS) was determined 21 d after inhibitor removal using quantitative real time polymerase chain reaction (RT-PCR), as well as detailed analyses of microglial morphologies. We find mice with repopulated microglia to perform similarly to controls by measures of behavior, cognition, and motor function. Compared to control/resident microglia, repopulated microglia had larger cell bodies and less complex branching in their processes, which resolved over time after inhibitor removal. Inflammatory profiling revealed that the mRNA gene expression of repopulated microglia was similar to normal resident microglia and that these new cells appear functional and responsive to LPS. Overall, these data demonstrate that newly repopulated microglia function similarly to the

  4. Activation of calcium-sensing receptor increases TRPC3 expression in rat cardiomyocytes

    SciTech Connect

    Feng, Shan-Li; Sun, Ming-Rui; Li, Ting-Ting; Yin, Xin; Xu, Chang-Qing; Sun, Yi-Hua

    2011-03-11

    Research highlights: {yields} Calcium-sensing receptor (CaR) activation stimulates TRP channels. {yields} CaR promoted transient receptor potential C3 (TRPC3) expression. {yields} Adult rat ventricular myocytes display capacitative calcium entry (CCE), which was operated by TRPCs. {yields} TRPC channels activation induced by CaR activator sustained the increased [Ca{sup 2+}]{sub i} to evoke cardiomyocytes apoptosis. -- Abstract: Transient receptor potential (TRP) channels are expressed in cardiomyocytes, which gate a type of influx of extracellular calcium, the capacitative calcium entry. TRP channels play a role in mediating Ca{sup 2+} overload in the heart. Calcium-sensing receptors (CaR) are also expressed in rat cardiac tissue and promote the apoptosis of cardiomyocytes by Ca{sup 2+} overload. However, data about the link between CaR and TRP channels in rat heart are few. In this study, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting were used to examine the expression of the TRP canonical proteins TRPC1 and TRPC3 in adult and neonatal rat cardiomyocytes. Laser scan confocal microscopy was used to detect intracellular [Ca{sup 2+}]{sub i} levels in isolated adult rat ventricular myocytes. The results showed that, in adult rat cardiomyocytes, the depletion of Ca{sup 2+} stores in the endoplasmic/sarcoplasmic reticulum (ER/SR) by thapsigargin induced a transient increase in [Ca{sup 2+}]{sub i} in the absence of [Ca{sup 2+}]{sub o} and the subsequent restoration of [Ca{sup 2+}]{sub o} sustained the increased [Ca{sup 2+}]{sub i} for a few minutes, whereas, the persisting elevation of [Ca{sup 2+}]{sub i} was reduced in the presence of the TRPC inhibitor SKF96365. The stimulation of CaR by its activator gadolinium chloride (GdCl{sub 3}) or spermine also resulted in the same effect and the duration of [Ca{sup 2+}]{sub i} increase was also shortened in the absence of [Ca{sup 2+}]{sub o}. In adult and neonatal rat cardiomyocytes, GdCl{sub 3

  5. Differential genomic imprinting regulates paracrine and autocrine roles of IGF2 in mouse adult neurogenesis

    PubMed Central

    Ferrón, S. R.; Radford, E. J.; Domingo-Muelas, A.; Kleine, I.; Ramme, A.; Gray, D.; Sandovici, I.; Constancia, M.; Ward, A.; Menheniott, T. R.; Ferguson-Smith, A. C.

    2015-01-01

    Genomic imprinting is implicated in the control of gene dosage in neurogenic niches. Here we address the importance of Igf2 imprinting for murine adult neurogenesis in the subventricular zone (SVZ) and in the subgranular zone (SGZ) of the hippocampus in vivo. In the SVZ, paracrine IGF2 is a cerebrospinal fluid and endothelial-derived neurogenic factor requiring biallelic expression, with mutants having reduced activation of the stem cell pool and impaired olfactory bulb neurogenesis. In contrast, Igf2 is imprinted in the hippocampus acting as an autocrine factor expressed in neural stem cells (NSCs) solely from the paternal allele. Conditional mutagenesis of Igf2 in blood vessels confirms that endothelial-derived IGF2 contributes to NSC maintenance in SVZ but not in the SGZ, and that this is regulated by the biallelic expression of IGF2 in the vascular compartment. Our findings indicate that a regulatory decision to imprint or not is a functionally important mechanism of transcriptional dosage control in adult neurogenesis. PMID:26369386

  6. Differential genomic imprinting regulates paracrine and autocrine roles of IGF2 in mouse adult neurogenesis.

    PubMed

    Ferrón, S R; Radford, E J; Domingo-Muelas, A; Kleine, I; Ramme, A; Gray, D; Sandovici, I; Constancia, M; Ward, A; Menheniott, T R; Ferguson-Smith, A C

    2015-01-01

    Genomic imprinting is implicated in the control of gene dosage in neurogenic niches. Here we address the importance of Igf2 imprinting for murine adult neurogenesis in the subventricular zone (SVZ) and in the subgranular zone (SGZ) of the hippocampus in vivo. In the SVZ, paracrine IGF2 is a cerebrospinal fluid and endothelial-derived neurogenic factor requiring biallelic expression, with mutants having reduced activation of the stem cell pool and impaired olfactory bulb neurogenesis. In contrast, Igf2 is imprinted in the hippocampus acting as an autocrine factor expressed in neural stem cells (NSCs) solely from the paternal allele. Conditional mutagenesis of Igf2 in blood vessels confirms that endothelial-derived IGF2 contributes to NSC maintenance in SVZ but not in the SGZ, and that this is regulated by the biallelic expression of IGF2 in the vascular compartment. Our findings indicate that a regulatory decision to imprint or not is a functionally important mechanism of transcriptional dosage control in adult neurogenesis. PMID:26369386

  7. Negative elongation factor controls energy homeostasis in cardiomyocytes.

    PubMed

    Pan, Haihui; Qin, Kunhua; Guo, Zhanyong; Ma, Yonggang; April, Craig; Gao, Xiaoli; Andrews, Thomas G; Bokov, Alex; Zhang, Jianhua; Chen, Yidong; Weintraub, Susan T; Fan, Jian-Bing; Wang, Degeng; Hu, Yanfen; Aune, Gregory J; Lindsey, Merry L; Li, Rong

    2014-04-10

    Negative elongation factor (NELF) is known to enforce promoter-proximal pausing of RNA polymerase II (Pol II), a pervasive phenomenon observed across multicellular genomes. However, the physiological impact of NELF on tissue homeostasis remains unclear. Here, we show that whole-body conditional deletion of the B subunit of NELF (NELF-B) in adult mice results in cardiomyopathy and impaired response to cardiac stress. Tissue-specific knockout of NELF-B confirms its cell-autonomous function in cardiomyocytes. NELF directly supports transcription of those genes encoding rate-limiting enzymes in fatty acid oxidation (FAO) and the tricarboxylic acid (TCA) cycle. NELF also shares extensively transcriptional target genes with peroxisome proliferator-activated receptor α (PPARα), a master regulator of energy metabolism in the myocardium. Mechanistically, NELF helps stabilize the transcription initiation complex at the metabolism-related genes. Our findings strongly indicate that NELF is part of the PPARα-mediated transcription regulatory network that maintains metabolic homeostasis in cardiomyocytes. PMID:24656816

  8. Finding the rhythm of sudden cardiac death: new opportunities using induced pluripotent stem cell-derived cardiomyocytes.

    PubMed

    Sallam, Karim; Li, Yingxin; Sager, Philip T; Houser, Steven R; Wu, Joseph C

    2015-06-01

    Sudden cardiac death is a common cause of death in patients with structural heart disease, genetic mutations, or acquired disorders affecting cardiac ion channels. A wide range of platforms exist to model and study disorders associated with sudden cardiac death. Human clinical studies are cumbersome and are thwarted by the extent of investigation that can be performed on human subjects. Animal models are limited by their degree of homology to human cardiac electrophysiology, including ion channel expression. Most commonly used cellular models are cellular transfection models, which are able to mimic the expression of a single-ion channel offering incomplete insight into changes of the action potential profile. Induced pluripotent stem cell-derived cardiomyocytes resemble, but are not identical, adult human cardiomyocytes and provide a new platform for studying arrhythmic disorders leading to sudden cardiac death. A variety of platforms exist to phenotype cellular models, including conventional and automated patch clamp, multielectrode array, and computational modeling. Induced pluripotent stem cell-derived cardiomyocytes have been used to study long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and other hereditary cardiac disorders. Although induced pluripotent stem cell-derived cardiomyocytes are distinct from adult cardiomyocytes, they provide a robust platform to advance the science and clinical care of sudden cardiac death. PMID:26044252

  9. Cardiomyocyte degeneration with calpain deficiency reveals a critical role in protein homeostasis.

    PubMed

    Galvez, Anita S; Diwan, Abhinav; Odley, Amy M; Hahn, Harvey S; Osinska, Hanna; Melendez, Jaime G; Robbins, Jeffrey; Lynch, Roy A; Marreez, Yehia; Dorn, Gerald W

    2007-04-13

    Regulating the balance between synthesis and proteasomal degradation of cellular proteins is essential for tissue growth and maintenance, but the critical pathways regulating protein ubiquitination and degradation are incompletely defined. Although participation of calpain calcium-activated proteases in post-necrotic myocardial autolysis is well characterized, their importance in homeostatic turnover of normal cardiac tissue is controversial. Hence, we evaluated the consequences of physiologic calpain (calcium-activated protease) activity in cultured cardiomyocytes and unstressed mouse hearts. Comparison of in vitro proteolytic activities of cardiac-expressed calpains 1 and 2 revealed calpain 1, but not calpain 2, activity at physiological calcium concentrations. Physiological calpain 1 activation was evident in adenoviral transfected cultured cardiomyocytes as proteolysis of specific substrates, generally increased protein ubiquitination, and accelerated protein turnover, that were each inhibited by coexpression of the inhibitor protein calpastatin. Conditional forced expression of calpain 1, but not calpain 2, in mouse hearts demonstrated substrate-specific proteolytic activity under basal conditions, with hyperubiquitination of cardiac proteins and increased 26S proteasome activity. Loss of myocardial calpain activity by forced expression of calpastatin diminished ubiquitination of 1 or more specific myocardial proteins, without affecting overall ubiquitination or proteasome activity, and resulted in a progressive dilated cardiomyopathy characterized by accumulation of intracellular protein aggregates, formation of autophagosomes, and degeneration of sarcomeres. Thus, calpain 1 is upstream of, and necessary for, ubiquitination and proteasomal degradation of a subset of myocardial proteins whose abnormal accumulation produces autophagosomes and degeneration of cardiomyocytes with functional decompensation. PMID:17332428

  10. Store-operated calcium entry is present in HL-1 cardiomyocytes and contributes to resting calcium.

    PubMed

    Touchberry, Chad D; Elmore, Chris J; Nguyen, Tien M; Andresen, Jon J; Zhao, Xiaoli; Orange, Matthew; Weisleder, Noah; Brotto, Marco; Claycomb, William C; Wacker, Michael J

    2011-12-01

    Store-operated Ca(2+) entry (SOCE) has recently been shown to be of physiological and pathological importance in the heart, particularly during cardiac hypertrophy. However, measuring changes in intracellular Ca(2+) during SOCE is very difficult to study in adult primary cardiomyocytes. As a result there is a need for a stable and reliable in vitro model of SOCE which can be used to test cardiac drugs and investigate the role of SOCE in cardiac pathology. HL-1 cells are the only immortal cardiomyocyte cell line available that continuously divides and spontaneously contracts while maintaining phenotypic characteristics of the adult cardiomyocyte. To date the role of SOCE has not yet been investigated in the HL-1 cardiac cell line. We report for the first time that these cells expressed stromal interaction molecule 1 (STIM1) and the Ca(2+) release-activated Ca(2+) (CRAC) channel Orai1, which are essential components of the SOCE machinery. In addition, SOCE was tightly coupled to sarcoplasmic reticulum (SR)-Ca(2+) release in HL-1 cells, and such response was not impaired in the presence of voltage dependent Ca(2+) channels (L-type and T-type channels) or reverse mode Na(+)/Ca(2+) exchanger (NCX) inhibitors. We were able to abolish the SOCE response with known SOCE inhibitors (BTP-2 and SKF-96365) and by targeted knockdown of Orai1 with RNAi. In addition, knockdown of Orai1 resulted in lower baseline Ca(2+) and an attenuated response to thapsigargin (TG) and caffeine, indicating that SOCE may play a role in Ca(2+) homeostasis during unstressed conditions in cardiomyocytes. Currently, there is little knowledge about SOCE in cardiomyocytes, and the present results suggest that HL-1 cells will be of great utility in investigating the role of SOCE in the heart. PMID:22079292

  11. Cre recombinase-regulated Endothelin1 transgenic mouse lines: novel tools for analysis of embryonic and adult disorders

    PubMed Central

    Tavares, Andre L.P.; Clouthier, David E.

    2015-01-01

    Endothelin-1 (EDN1) influences both craniofacial and cardiovascular development and a number of adult physiological conditions by binding to one or both of the known endothelin receptors, thus initiating multiple signaling cascades. Animal models containing both conventional and conditional loss of the Edn1 gene have been used to dissect EDN1 function in both embryos and adults. However, while transgenic Edn1 over-expression or targeted genomic insertion of Edn1 has been performed to understand how elevated levels of Edn1 result in or exacerbate disease states, an animal model in which Edn1 over-expression can be achieved in a spatiotemporal-specific manner has not been reported. Here we describe the creation of Edn1 conditional over-expression transgenic mouse lines in which the chicken β-actin promoter and an Edn1 cDNA are separated by a strong stop sequence flanked by loxP sites. In the presence of Cre, the stop cassette is removed, leading to Edn1 expression. Using the Wnt1-Cre strain, in which Cre expression is targeted to the Wnt1-expressing domain of the central nervous system (CNS) from which neural crest cells (NCCs) arise, we show that stable CBA-Edn1 transgenic lines with varying EDN1 protein levels develop defects in NCC-derived tissues of the face, though the severity differs between lines. We also show that Edn1 expression can be achieved in other embryonic tissues utilizing other Cre strains, with this expression also resulting in developmental defects. CBA-Edn1 transgenic mice will be useful in investigating diverse aspects of EDN1-mediated-development and disease, including understanding how NCCs achieve and maintain a positional and functional identity and how aberrant EDN1 levels can lead to multiple physiological changes and diseases. PMID:25725491

  12. The Cardiomyocyte Molecular Clock Regulates the Circadian Expression of Kcnh2 and Contributes to Ventricular Repolarization

    PubMed Central

    Schroder, Elizabeth A.; Burgess, Don E.; Zhang, Xiping; Lefta, Mellani; Smith, Jennifer L.; Patwardhan, Abhijit; Bartos, Daniel C.; Elayi, Claude S.; Esser, Karyn A.; Delisle, Brian P.

    2015-01-01

    Background Sudden Cardiac Death (SCD) follows a diurnal variation. Data suggest the timing of SCD is influenced by circadian (~24 hour) changes in neurohumoral and cardiomyocyte-specific regulation of the heart’s electrical properties. Objective The basic helix-loop-helix transcription factors BMAL1 and CLOCK coordinate the circadian expression of select genes. We tested whether Bmal1 expression in cardiomyocytes contributes to K+ channel expression and diurnal changes in ventricular repolarization. Methods We utilized transgenic mice that allow for the inducible cardiomyocyte-specific deletion of Bmal1 (iCSΔBmal1−/−). We used quantitative PCR, voltage-clamping, promoter-reporter bioluminescence assays, and electrocardiographic (ECG) telemetry. Results Although several K+ channel gene transcripts were downregulated in iCSΔBmal1−/− mouse hearts, only Kcnh2 exhibited a robust circadian pattern of expression that was disrupted in iCSΔBmal1−/− hearts. Kcnh2 underlies the rapidly activating delayed-rectifier K+ current (IKr), and IKr recorded from iCSΔBmal1−/− ventricular cardiomyocytes was ~50% compared to control myocytes. Promoter-reporter assays demonstrated that the human Kcnh2 promoter is transactivated by the co-expression of BMAL1 and CLOCK. ECG analysis showed iCSΔBmal1−/− mice developed a prolongation in the heart rate corrected QT (QTc) interval during the light (resting)-phase. This was secondary to an augmented circadian rhythm in the uncorrected QT interval without a corresponding change in the RR interval. Conclusion The molecular clock in the heart regulates the circadian expression of Kcnh2, modifies K+ channel gene expression and is important for normal ventricular repolarization. Disruption of the cardiomyocyte circadian clock mechanism likely unmasks diurnal changes in ventricular repolarization that could contribute to an increased risk of cardiac arrhythmias/SCD. PMID:25701773

  13. Hyper sensitive protein detection by Tandem-HTRF reveals Cyclin D1 dynamics in adult mouse

    PubMed Central

    Zampieri, Alexandre; Champagne, Julien; Auzemery, Baptiste; Fuentes, Ivanna; Maurel, Benjamin; Bienvenu, Frédéric

    2015-01-01

    We present here a novel method for the semi-quantitative detection of low abundance proteins in solution that is both fast and simple. It is based on Homogenous Time Resolved Förster Resonance Energy Transfer (HTRF), between a lanthanide labeled donor antibody and a d2 or XL665 labeled acceptor antibody that are both raised against different epitopes of the same target. This novel approach we termed “Tandem-HTRF”, can specifically reveal rare polypeptides from only a few microliters of cellular lysate within one hour in a 384-well plate format. Using this sensitive approach, we observed surprisingly that the core cell cycle regulator Cyclin D1 is sustained in fully developed adult organs and harbors an unexpected expression pattern affected by environmental challenge. Thus our method, Tandem-HTRF offers a promising way to investigate subtle variations in the dynamics of sparse proteins from limited biological material. PMID:26503526

  14. Gestational ketogenic diet programs brain structure and susceptibility to depression & anxiety in the adult mouse offspring

    PubMed Central

    Sussman, Dafna; Germann, Jurgen; Henkelman, Mark

    2015-01-01

    Introduction The ketogenic diet (KD) has seen an increase in popularity for clinical and non-clinical purposes, leading to rise in concern about the diet's impact on following generations. The KD is known to have a neurological effect, suggesting that exposure to it during prenatal brain development may alter neuro-anatomy. Studies have also indicated that the KD has an anti-depressant effect on the consumer. However, it is unclear whether any neuro-anatomical and/or behavioral changes would occur in the offspring and persist into adulthood. Methods To fill this knowledge gap we assessed the brain morphology and behavior of 8-week-old young-adult CD-1 mice, who were exposed to the KD in utero, and were fed only a standard-diet (SD) in postnatal life. Standardized neuro-behavior tests included the Open-Field, Forced-Swim, and Exercise Wheel tests, and were followed by post-mortem Magnetic Resonance Imaging (MRI) to assess brain anatomy. Results The adult KD offspring exhibit reduced susceptibility to anxiety and depression, and elevated physical activity level when compared with controls exposed to the SD both in utero and postnatally. Many neuro-anatomical differences exist between the KD offspring and controls, including, for example, a cerebellar volumetric enlargement by 4.8%, a hypothalamic reduction by 1.39%, and a corpus callosum reduction by 4.77%, as computed relative to total brain volume. Conclusions These results suggest that prenatal exposure to the KD programs the offspring neuro-anatomy and influences their behavior in adulthood. PMID:25642385

  15. Synaptic pathology and therapeutic repair in adult retinoschisis mouse by AAV-RS1 transfer

    PubMed Central

    Ou, Jingxing; Vijayasarathy, Camasamudram; Ziccardi, Lucia; Chen, Shan; Zeng, Yong; Marangoni, Dario; Pope, Jodie G.; Bush, Ronald A.; Wu, Zhijian; Li, Wei; Sieving, Paul A.

    2015-01-01

    Strategies aimed at invoking synaptic plasticity have therapeutic potential for several neurological conditions. The human retinal synaptic disease X-linked retinoschisis (XLRS) is characterized by impaired visual signal transmission through the retina and progressive visual acuity loss, and mice lacking retinoschisin (RS1) recapitulate human disease. Here, we demonstrate that restoration of RS1 via retina-specific delivery of adeno-associated virus type 8-RS1 (AAV8-RS1) vector rescues molecular pathology at the photoreceptor–depolarizing bipolar cell (photoreceptor-DBC) synapse and restores function in adult Rs1-KO animals. Initial development of the photoreceptor-DBC synapse was normal in the Rs1-KO retina; however, the metabotropic glutamate receptor 6/transient receptor potential melastatin subfamily M member 1–signaling (mGluR6/TRPM1-signaling) cascade was not properly maintained. Specifically, the TRPM1 channel and G proteins Gαo, Gβ5, and RGS11 were progressively lost from postsynaptic DBC dendritic tips, whereas the mGluR6 receptor and RGS7 maintained proper synaptic position. This postsynaptic disruption differed from other murine night-blindness models with an electronegative electroretinogram response, which is also characteristic of murine and human XLRS disease. Upon AAV8-RS1 gene transfer to the retina of adult XLRS mice, TRPM1 and the signaling molecules returned to their proper dendritic tip location, and the DBC resting membrane potential was restored. These findings provide insight into the molecular plasticity of a critical synapse in the visual system and demonstrate potential therapeutic avenues for some diseases involving synaptic pathology. PMID:26098217

  16. Synaptic pathology and therapeutic repair in adult retinoschisis mouse by AAV-RS1 transfer.

    PubMed

    Ou, Jingxing; Vijayasarathy, Camasamudram; Ziccardi, Lucia; Chen, Shan; Zeng, Yong; Marangoni, Dario; Pope, Jodie G; Bush, Ronald A; Wu, Zhijian; Li, Wei; Sieving, Paul A

    2015-07-01

    Strategies aimed at invoking synaptic plasticity have therapeutic potential for several neurological conditions. The human retinal synaptic disease X-linked retinoschisis (XLRS) is characterized by impaired visual signal transmission through the retina and progressive visual acuity loss, and mice lacking retinoschisin (RS1) recapitulate human disease. Here, we demonstrate that restoration of RS1 via retina-specific delivery of adeno-associated virus type 8-RS1 (AAV8-RS1) vector rescues molecular pathology at the photoreceptor-depolarizing bipolar cell (photoreceptor-DBC) synapse and restores function in adult Rs1-KO animals. Initial development of the photoreceptor-DBC synapse was normal in the Rs1-KO retina; however, the metabotropic glutamate receptor 6/transient receptor potential melastatin subfamily M member 1-signaling (mGluR6/TRPM1-signaling) cascade was not properly maintained. Specifically, the TRPM1 channel and G proteins Gαo, Gβ5, and RGS11 were progressively lost from postsynaptic DBC dendritic tips, whereas the mGluR6 receptor and RGS7 maintained proper synaptic position. This postsynaptic disruption differed from other murine night-blindness models with an electronegative electroretinogram response, which is also characteristic of murine and human XLRS disease. Upon AAV8-RS1 gene transfer to the retina of adult XLRS mice, TRPM1 and the signaling molecules returned to their proper dendritic tip location, and the DBC resting membrane potential was restored. These findings provide insight into the molecular plasticity of a critical synapse in the visual system and demonstrate potential therapeutic avenues for some diseases involving synaptic pathology. PMID:26098217

  17. MRI signature in a novel mouse model of genetically induced adult oligodendrocyte cell death.

    PubMed

    Mueggler, Thomas; Pohl, Hartmut; Baltes, Christof; Riethmacher, Dieter; Suter, Ueli; Rudin, Markus

    2012-01-16

    Two general pathological processes contribute to multiple sclerosis (MS): acute inflammation and degeneration. While magnetic resonance imaging (MRI) is highly sensitive in detecting abnormalities related to acute inflammation both clinically and in animal models of experimental autoimmune encephalomyelitis (EAE), the correlation of these readouts with acute and future disabilities has been found rather weak. This illustrates the need for imaging techniques addressing neurodegenerative processes associated with MS. In the present work we evaluated the sensitivity of different MRI techniques (T(2) mapping, macrophage tracking based on labeling cells in vivo by ultrasmall particles of iron oxide (USPIO), diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI)) to detect histopathological changes in a novel animal model making use of intrinsic, temporally and spatially controlled triggering of oligodendrocyte cell death. This mouse model allows studying the MRI signature associated to neurodegenerative processes of MS in the absence of adaptive inflammatory components that appear to be foremost in the EAE models. Our results revealed pronounced T(2) hyperintensities in brain stem and cerebellar structures, which we attribute to structural alteration of white matter by pronounced vacuolation. Brain areas were found devoid of significant macrophage infiltration in line with the absence of a peripheral inflammatory response. The significant decrease in diffusion anisotropy derived from DTI measures in these structures is mainly caused by a pronounced decrease in diffusivity parallel to the fiber indicative of axonal damage. Triggering of oligodendrocyte ablation did not translate into a significant increase in radial diffusivity. Only minor decreases in MT ratio have been observed, which is attributed to inefficient removal of myelin debris. PMID:21945466

  18. Comparative Analysis of the Expression Profile of Wnk1 and Wnk1/Hsn2 Splice Variants in Developing and Adult Mouse Tissues

    PubMed Central

    Shekarabi, Masoud; Lafrenière, Ron G.; Gaudet, Rébecca; Laganière, Janet; Marcinkiewicz, Martin M.; Dion, Patrick A.; Rouleau, Guy A.

    2013-01-01

    The With No lysine (K) family of serine/threonine kinase (WNK) defines a small family of kinases with significant roles in ion homeostasis. WNK1 has been shown to have different isoforms due to what seems to be largely tissue specific splicing. Here, we used two distinct in situ hybridization riboprobes on developing and adult mouse tissues to make a comparative analysis of Wnk1 and its sensory associated splice isoform, Wnk1/Hsn2. The hybridization signals in developing mouse tissues, which were prepared at embryonic day e10.5 and e12.5, revealed a homogenous expression profile with both probes. At e15.5 and in the newborn mouse, the two probes revealed different expression profiles with prominent signals in nervous system tissues and also other tissues such as kidney, thymus and testis. In adult mouse tissues, the two expression profiles appeared even more restricted to the nervous tissues, kidney, thymus and testis, with no detectable signal in the other tissues. Throughout the nervous system, sensory tissues, as well as in Cornu Ammonis 1 (CA1), CA2 and CA3 areas of the hippocampus, were strongly labeled with both probes. Hybridization signals were also strongly detected in Schwann and supporting satellite cells. Our results show that the expression profiles of Wnk1 isoforms change during the development, and that the expression of the Wnk1 splice variant containing the Hsn2 exon is prominent during developing and in adult mouse tissues, suggesting its important role in the development and maintenance of the nervous system. PMID:23451271

  19. Enhanced Adult Neurogenesis Increases Brain Stiffness: In Vivo Magnetic Resonance Elastography in a Mouse Model of Dopamine Depletion

    PubMed Central

    Klein, Charlotte; Hain, Elisabeth G.; Braun, Juergen; Riek, Kerstin; Mueller, Susanne

    2014-01-01

    The mechanical network of the brain is a major contributor to neural health and has been recognized by in vivo magnetic resonance elastography (MRE) to be highly responsive to diseases. However, until now only brain softening was observed and no mechanism was known that reverses the common decrement of neural elasticity during aging or disease. We used MRE in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP) mouse model for dopaminergic neurodegeneration as observed in Parkinson’s disease (PD) to study the mechanical response of the brain on adult hippocampal neurogenesis as a robust correlate of neuronal plasticity in healthy and injured brain. We observed a steep transient rise in elasticity within the hippocampal region of up to over 50% six days after MPTP treatment correlating with increased neuronal density in the dentate gyrus, which could not be detected in healthy controls. Our results provide the first indication that new neurons reactively generated following neurodegeneration substantially contribute to the mechanical scaffold of the brain. Diagnostic neuroimaging may thus target on regions of the brain displaying symptomatically elevated elasticity values for the detection of neuronal plasticity following neurodegeneration. PMID:24667730

  20. Expression Atlas of the Deubiquitinating Enzymes in the Adult Mouse Retina, Their Evolutionary Diversification and Phenotypic Roles

    PubMed Central

    Esquerdo, Mariona; Grau-Bové, Xavier; Garanto, Alejandro; Toulis, Vasileios; Garcia-Monclús, Sílvia; Millo, Erica; López-Iniesta, Ma José; Abad-Morales, Víctor; Ruiz-Trillo, Iñaki; Marfany, Gemma

    2016-01-01

    Ubiquitination is a relevant cell regulatory mechanism to determine protein fate and function. Most data has focused on the role of ubiquitin as a tag molecule to target substrates to proteasome degradation, and on its impact in the control of cell cycle, protein homeostasis and cancer. Only recently, systematic assays have pointed to the relevance of the ubiquitin pathway in the development and differentiation of tissues and organs, and its implication in hereditary diseases. Moreover, although the activity and composition of ubiquitin ligases has been largely addressed, the role of the deubiquitinating enzymes (DUBs) in specific tissues, such as the retina, remains mainly unknown. In this work, we undertook a systematic analysis of the transcriptional levels of DUB genes in the adult mouse retina by RT-qPCR and analyzed the expression pattern by in situ hybridization and fluorescent immunohistochemistry, thus providing a unique spatial reference map of retinal DUB expression. We also performed a systematic phylogenetic analysis to understand the origin and the presence/absence of DUB genes in the genomes of diverse animal taxa that represent most of the known animal diversity. The expression landscape obtained supports the potential subfunctionalization of paralogs in those families that expanded in vertebrates. Overall, our results constitute a reference framework for further characterization of the DUB roles in the retina and suggest new candidates for inherited retinal disorders. PMID:26934049

  1. Astrocytic adaptation during cerebral angiogenesis follows the new vessel formation induced through chronic hypoxia in adult mouse cortex

    NASA Astrophysics Data System (ADS)

    Masamoto, Kazuto; Kanno, Iwao

    2014-03-01

    We examined longitudinal changes of the neuro-glia-vascular unit during cerebral angiogenesis induced through chronic hypoxia in the adult mouse cortex. Tie2-GFP mice in which the vascular endothelial cells expressed green fluorescent proteins (GFP) were exposed to chronic hypoxia, while the spatiotemporal developments of the cortical capillary sprouts and the neighboring astrocytic remodeling were characterized with repeated two-photon microscopy. The capillary sprouts appeared at early phases of the hypoxia adaptation (1-2 weeks), while the morphological changes of the astrocytic soma and processes were not detected in this phase. In the later phases of the hypoxia adaptation (> 2 weeks), the capillary sprouts created a new connection with existing capillaries, and its neighboring astrocytes extended their processes to the newly-formed vessels. The findings show that morphological adaptation of the astrocytes follow the capillary development during the hypoxia adaptation, which indicate that the newly-formed vessels provoke cellular interactions with the neighboring astrocytes to strengthen the functional blood-brain barrier.

  2. An In Vitro Adult Mouse Muscle-nerve Preparation for Studying the Firing Properties of Muscle Afferents

    PubMed Central

    Franco, Joy A.; Kloefkorn, Heidi E.; Hochman, Shawn; Wilkinson, Katherine A.

    2014-01-01

    Muscle sensory neurons innervating muscle spindles and Golgi tendon organs encode length and force changes essential to proprioception. Additional afferent fibers monitor other characteristics of the muscle environment, including metabolite buildup, temperature, and nociceptive stimuli. Overall, abnormal activation of sensory neurons can lead to movement disorders or chronic pain syndromes. We describe the isolation of the extensor digitorum longus (EDL) muscle and nerve for in vitro study of stretch-evoked afferent responses in the adult mouse. Sensory activity is recorded from the nerve with a suction electrode and individual afferents can be analyzed using spike sorting software. In vitro preparations allow for well controlled studies on sensory afferents without the potential confounds of anesthesia or altered muscle perfusion. Here we describe a protocol to identify and test the response of muscle spindle afferents to stretch. Importantly, this preparation also supports the study of other subtypes of muscle afferents, response properties following drug application and the incorporation of powerful genetic approaches and disease models in mice. PMID:25285602

  3. Sexually Dimorphic Patterns of Episomal rAAV Genome Persistence in the Adult Mouse Liver and Correlation With Hepatocellular Proliferation

    PubMed Central

    Dane, Allison P; Cunningham, Sharon C; Graf, Nicole S; Alexander, Ian E

    2009-01-01

    Recombinant adeno-associated virus vectors (rAAVs) show exceptional promise for liver-targeted gene therapy, with phenotype correction in small and large animal disease models being reported with increasing frequency. Success in humans, however, remains a considerable challenge that demands greater understanding of host–vector interactions, notably those governing the efficiency of initial gene transfer and subsequent long-term persistence of gene expression. In this study, we examined long-term enhanced green fluorescent protein (eGFP) expression and vector genome persistence in the mouse liver after rAAV2/8-mediated gene transfer in early adulthood. Two intriguing findings emerged of considerable scientific and clinical interest. First, adult female and male mice showed distinctly different patterns of persistence of eGFP expression across the hepatic lobule after exhibiting similar patterns initially. Female mice retained a predominantly perivenous pattern of expression, whereas male mice underwent inversion of this pattern with preferential loss of perivenous expression and relative retention of periportal expression. Second, these changing patterns of expression correlated with sexually dimorphic patterns of genome persistence that appear linked both spatially and temporally to underlying hepatocellular proliferation. Observation of the equivalent phenomenon in man could have significant implications for the long-term therapeutic efficacy of rAAV-mediated gene transfer, particularly in the context of correction of liver functions showing metabolic zonation. PMID:19568224

  4. Selective depression of nociceptive responses of dorsal horn neurones by SNC 80 in a perfused hindquarter preparation of adult mouse.

    PubMed

    Cao, C Q; Hong, Y G; Dray, A; Perkins, M N

    2001-01-01

    -nociceptive dorsal horn neurones were not inhibited by SNC 80 at a dose of up to 10 microM (n=5). These data demonstrate that delta-opioid receptor modulate nociceptive, but not non-nociceptive, transmission in spinal dorsal horn neurones of the adult mouse. The potentiation of neuronal activity by HS 378 may reflect an autoregulatory role of the endogenous delta-opioid in nociceptive transmission in mouse. PMID:11731107

  5. Dysferlin deficiency blunts β-adrenergic-dependent lusitropic function of mouse heart.

    PubMed

    Wei, Bin; Wei, Hongguang; Jin, J-P

    2015-12-01

    Dysferlin is a cell membrane bound protein with a role in the repair of skeletal and cardiac muscle cells. Deficiency of dysferlin leads to limb-girdle muscular dystrophy 2B (LGMD2B) and Miyoshi myopathy. In cardiac muscle, dysferlin is located at the intercalated disc and transverse tubule membranes. Loss of dysferlin causes death of cardiomyocytes, notably in ageing hearts, leading to dilated cardiomyopathy and heart failure in LGM2B patients. To understand the primary pathogenesis and pathophysiology of dysferlin cardiomyopathy, we studied cardiac phenotypes of young adult dysferlin knockout mice and found early myocardial hypertrophy with largely compensated baseline cardiac function. Cardiomyocytes isolated from dysferlin-deficient mice showed normal shortening and re-lengthening velocities in the absence of external load with normal peak systolic Ca(2+) but slower Ca(2+) re-sequestration than wild-type controls. The effects of isoproterenol on relaxation velocity, left ventricular systolic pressure and stroke volume were blunted in dysferlin-deficient mouse hearts compared with that in wild-type hearts. Young dysferlin-deficient mouse hearts expressed normal isoforms of myofilament proteins whereas the phosphorylation of ventricular myosin light chain 2 was significantly increased, implying a molecular response to the impaired lusitropic function. These early phenotypes of diastolic cardiac dysfunction and blunted lusitropic response of cardiac muscle to β-adrenergic stimulation indicate a novel pathogenic mechanism of dysferlin cardiomyopathy. PMID:26415898

  6. Build a Better Mouse: Directly-Observed Issues in Computer Use for Adults with SMI

    PubMed Central

    Black, Anne C.; Serowik, Kristin L.; Schensul, Jean J.; Bowen, Anne M.; Rosen, Marc I.

    2014-01-01

    Integrating information technology into healthcare has the potential to bring treatment to hard-to-reach people. Individuals with serious mental illness (SMI), however, may derive limited benefit from these advances in care because of lack of computer ownership and experience. To date, conclusions about the computer skills and attitudes of adults with SMI have been based primarily on self-report. In the current study, 28 psychiatric outpatients with co-occurring cocaine use were interviewed about their computer use and opinions, and 25 were then directly observed using task analysis and think aloud methods as they navigated a multi-component health informational website. Participants reported low rates of computer ownership and use, and negative attitudes towards computers. Self-reported computer skills were higher than demonstrated in the task analysis. However, some participants spontaneously expressed more positive attitudes and greater computer self-efficacy after navigating the website. Implications for increasing access to computer-based health information are discussed. PMID:22711454

  7. Reconstruction of the nigrostriatal dopamine pathway in the adult mouse brain.

    PubMed

    Thompson, Lachlan H; Grealish, Shane; Kirik, Deniz; Björklund, Anders

    2009-08-01

    Transplants of fetal dopamine neurons can be used to restore dopamine neurotransmission in animal models of Parkinson's disease, as well as in patients with advanced Parkinson's disease. In these studies the cells are placed in the striatum rather than in the substantia nigra where they normally reside, which may limit their ability to achieve full restoration of motor function. Using a microtransplantation approach, which allows precise placement of small cell deposits directly into the host substantia nigra, and fetal donor cells that express green fluorescent protein under the control of the tyrosine hydroxylase promoter, we show that dopamine neuroblasts implanted into the substantia nigra of adult mice are capable of generating a new nigrostriatal pathway with an outgrowth pattern that matches the anatomy of the intrinsic system. This target-directed regrowth was closely aligned with the intrinsic striatonigral fibre projection and further enhanced by over-expression of glial cell line-derived neurotrophic factor in the striatal target. Results from testing of amphetamine-induced rotational behaviour suggest, moreover, that dopamine neurons implanted into the substantia nigra are also capable of integrating into the host circuitry at the functional level. PMID:19674082

  8. Impaired adult hippocampal neurogenesis and cognitive ability in a mouse model of intrastriatal hemorrhage.

    PubMed

    Yang, Yuan; Zhang, Meikui; Kang, Xiaoni; Jiang, Chen; Zhang, Huan; Wang, Pei; Li, Jingjing

    2015-07-10

    Thrombin released by hematoma is an important mediator of the secondary injury of intracerebral hemorrhage (ICH), however, the effect of thrombin on adult neurogenesis and cognitive ability remains elusive. In this study, intrastriatal injection of 0.05 U thrombin didn't affect the neurogenesis at the subgranular zone (SGZ), which was distal to the injection site. 0.1 U thrombin increased the 5-bromo-2-deoxyuridine(+) (BrdU(+), S-phase proliferating cells)/doublecortin(+) (DCX(+), immature neurons) double labelled neurons, but decreased BrdU(+)/NeuN(+) double labelled mature neurons. Higher doses of thrombin (1 U, 2 U, and 5 U) significantly decreased the BrdU(+)/DCX(+) and BrdU(+)/NeuN(+) double labelled cells. After 1 U thrombin injection, cell apoptosis was found at the dentate gyrus of hippocampus at 3-24 h, but not 5 d post-injury. Thrombin infusion (1 U) induced spatial memory deficits in Morris water maze test; whereas, hirudin, the thrombin antagonist, significantly reversed both neurogenesis loss and spatial learning and memory impairment. In conclusion, at least at short term (5 days) after striatum ICH, the effect of high dose of thrombin on neurogenesis of SGZ, and the spatial learning and memory ability, is detrimental. PMID:26021875

  9. Acute inflammation alters adult hippocampal neurogenesis in a multiple sclerosis mouse model.

    PubMed

    Giannakopoulou, A; Grigoriadis, N; Bekiari, C; Lourbopoulos, A; Dori, I; Tsingotjidou, A S; Michaloudi, H; Papadopoulos, G C

    2013-07-01

    Neural precursor cells (NPCs) located in the subgranular zone (SGZ) of the dentate gyrus (DG) give rise to thousands of new cells every day, mainly hippocampal neurons, which are integrated into existing neuronal circuits. Aging and chronic degenerative disorders have been shown to impair hippocampal neurogenesis, but the consequence of inflammation is somewhat controversial. The present study demonstrates that the inflammatory environment prevailing in the brain of experimental autoimmune encephalomyelitis (EAE) mice enhances the proliferation of NPCs in SGZ of the dorsal DG and alters the proportion between radial glial cells and newborn neuroblasts. The injection protocol of the cell cycle marker bromodeoxyuridine and the immunohistochemical techniques that were employed revealed that the proliferation of NPCs is increased approximately twofold in the SGZ of the dorsal DG of EAE mice, at the acute phase of the disease. However, although EAE animals exhibited significant higher percentage of newborn radial-glia-like NPCs, the mean percentage of newborn neuroblasts rather was decreased, indicating that the robust NPCs proliferation is not followed by a proportional production of newborn neurons. Significant positive correlations were detected between the number of proliferating cells in the SGZ and the clinical score or degree of brain inflammation of diseased animals. Finally, enhanced neuroproliferation in the acute phase of EAE was not found to trigger compensatory apoptotic mechanisms. The possible causes of altered neurogenesis observed in this study emphasize the need to understand more precisely the mechanisms regulating adult neurogenesis under both normal and pathological conditions. PMID:23606574

  10. Build a better mouse: directly-observed issues in computer use for adults with SMI.

    PubMed

    Black, Anne C; Serowik, Kristin L; Schensul, Jean J; Bowen, Anne M; Rosen, Marc I

    2013-03-01

    Integrating information technology into healthcare has the potential to bring treatment to hard-to-reach people. Individuals with serious mental illness (SMI), however, may derive limited benefit from these advances in care because of lack of computer ownership and experience. To date, conclusions about the computer skills and attitudes of adults with SMI have been based primarily on self-report. In the current study, 28 psychiatric outpatients with co-occurring cocaine use were interviewed about their computer use and opinions, and 25 were then directly observed using task analysis and think aloud methods as they navigated a multi-component health informational website. Participants reported low rates of computer ownership and use, and negative attitudes towards computers. Self-reported computer skills were higher than demonstrated in the task analysis. However, some participants spontaneously expressed more positive attitudes and greater computer self-efficacy after navigating the website. Implications for increasing access to computer-based health information are discussed. PMID:22711454

  11. Mechanochemotransduction During Cardiomyocyte Contraction Is Mediated by Localized Nitric Oxide Signaling

    PubMed Central

    Jian, Zhong; Han, Huilan; Zhang, Tieqiao; Puglisi, Jose; Izu, Leighton T.; Shaw, John A.; Onofiok, Ekama; Erickson, Jeffery R.; Chen, Yi-Je; Horvath, Balazs; Shimkunas, Rafael; Xiao, Wenwu; Li, Yuanpei; Pan, Tingrui; Chan, James; Banyasz, Tamas; Tardiff, Jil C.; Chiamvimonvat, Nipavan; Bers, Donald M.; Lam, Kit S.; Chen-Izu, Ye

    2014-01-01

    Cardiomyocytes contract against a mechanical load during each heartbeat, and excessive mechanical stress leads to heart diseases. Using a cell-in-gel system that imposes an afterload during cardiomyocyte contraction, we found that nitric oxide synthase (NOS) was involved in transducing mechanical load to alter Ca2+ dynamics. In mouse ventricular myocytes, afterload increased the systolic Ca2+ transient, which enhanced contractility to counter mechanical load, but also caused spontaneous Ca2+ sparks during diastole that could be arrhythmogenic. The increases in the Ca2+ transient and sparks were attributable to increased ryanodine receptor (RyR) sensitivity because the amount of Ca2+ in the sarcoplasmic reticulum load was unchanged. Either pharmacological inhibition or genetic deletion of nNOS (or NOS1), but not of eNOS (or NOS3), prevented afterload-induced Ca2+ sparks. This differential effect may arise from localized NO signaling, arising from the proximity of nNOS to RyR, as determined by super-resolution imaging. Ca2+-calmodulin–dependent protein kinase II (CaMKII) and nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) also contributed to afterload-induced Ca2+ sparks. Cardiomyocytes from a mouse model of familial hypertrophic cardiomyopathy exhibited enhanced mechanotransduction and frequent arrhythmogenic Ca2+ sparks. Inhibiting nNOS and CaMKII, but not NOX2, in cardiomyocytes from this model eliminated the Ca2+ sparks, suggesting mechanotransduction activated nNOS and CaMKII independently from NOX2. Thus, our data identify nNOS, CaMKII, and NOX2 as key mediators in mechanochemotransduction during cardiac contraction, which provides new therapeutic targets for treating mechanical stress–induced Ca2+ dysregulation, arrhythmias, and cardiomyopathy. PMID:24643800

  12. Response of olfactory axons to loss of synaptic targets in the adult mouse

    PubMed Central

    Ardiles, Yona; de la Puente, Rafael; Toledo, Rafael; Isgor, Ceylan; Guthrie, Kathleen

    2007-01-01

    Glomerular convergence has been proposed to rely on interactions between like olfactory axons, however topographic targeting is influenced by guidance molecules encountered in the olfactory bulb. Disruption of these cues during development misdirects sensory axons, however little is known about the role of bulb-derived signals in later life, as new axons arise during turnover of the olfactory sensory neuron (OSN) population. To evaluate the contribution of bulb neurons in maintaining topographic projections in adults, we ablated them with N-methyl-D-aspartate (NMDA) in P2-IRES-tauLacZ mice and examined how sensory axons responded to loss of their postsynaptic partners. NMDA lesion eliminated bulb neurons without damage to sensory axons or olfactory ensheathing glia. P2 axons contained within glomeruli at the time of lesion maintained convergence at these locations; there was no evidence of compensatory growth into the remnant tissue. Delayed apoptosis of OSNs in the target-deprived epithelium led to declines in P2 neuron number as well as the gradual atrophy, and in some cases complete loss, of P2 glomeruli in lesioned bulbs by three weeks. Increased cell proliferation in the epithelium partially restored the OSN population, and by eight weeks, new P2 axons distributed within diverse locations in the bulb remnant and within the anterior olfactory nucleus. Prior studies have suggested that initial development of olfactory topography does not rely on synapse formation with target neurons, however the present data demonstrate that continued maintenance of the sensory map requires the presence of sufficient numbers and/or types of available bulbar synaptic targets. PMID:17674970

  13. Functional improvement of damaged adult mouse muscle by implantation of primary myoblasts.

    PubMed Central

    Irintchev, A; Langer, M; Zweyer, M; Theisen, R; Wernig, A

    1997-01-01

    1. Myoblasts from expanded primary cultures were implanted into cryodamaged soleus muscles of adult BALB/c mice. One to four months later isometric tension recordings were performed in vitro, and the male donor cells implanted into female hosts were traced on histological sections using a Y-chromosome-specific probe. The muscles were either mildly or severely cryodamaged, which led to reductions in tetanic muscle force to 33% (n = 9 muscles, 9 animals) and 70% (n = 11) of normal, respectively. Reduced forces resulted from deficits in regeneration of muscle tissue as judged from the reduced desmin-positive cross-sectional areas (34 and 66% of control, respectively). 2. Implantation of 10(6) myogenic cells into severely cryodamaged muscles more than doubled muscle tetanic force (to 70% of normal, n = 14), as well as specific force (to 66% of normal). Absolute and relative amount of desmin-positive muscle cross-sectional areas were significantly increased indicating improved microarchitecture and less fibrosis. Newly formed muscle tissue was fully innervated since the tetanic forces resulting from direct and indirect (nerve-evoked) stimulation were equal. Endplates were found on numerous Y-positive muscle fibres. 3. As judged from their position under basal laminae of muscle fibres and the expression of M-cadherin, donor-derived cells contributed to the pool of satellite cells on small- and large-diameter muscle fibres. 4. Myoblast implantation after mild cryodamage and in undamaged muscles had little or no functional or structural effects; in both preparations only a few Y-positive muscle nuclei were detected. It is concluded that myoblasts from expanded primary cultures-unlike permanent cell lines-significantly contribute to muscle regeneration only when previous muscle damage is extensive and loss of host satellite cells is severe. Images Figure 1 Figure 2 Figure 3 PMID:9161990

  14. INTRINSIC CIRCADIAN RHYTHMS IN THE CARDIOMYOCYTE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cardiomyocyte possesses a fully functional circadian clock. Circadian clocks are a set of proteins that generate self-sustained transcriptional positive and negative feedback loops with a free-running period of 24 hours. These intracellular molecular mechanisms confer the selective advantage of ...

  15. Isolation and Cryopreservation of Neonatal Rat Cardiomyocytes

    PubMed Central

    Vandergriff, Adam C.; Hensley, Michael Taylor; Cheng, Ke

    2016-01-01

    Cell culture has become increasingly important in cardiac research, but due to the limited proliferation of cardiomyocytes, culturing cardiomyocytes is difficult and time consuming. The most commonly used cells are neonatal rat cardiomyocytes (NRCMs), which require isolation every time cells are needed. The birth of the rats can be unpredictable. Cryopreservation is proposed to allow for cells to be stored until needed, yet freezing/thawing methods for primary cardiomyocytes are challenging due to the sensitivity of the cells. Using the proper cryoprotectant, dimethyl sulfoxide (DMSO), cryopreservation was achieved. By slowly extracting the DMSO while thawing the cells, cultures were obtained with viable NRCMs. NRCM phenotype was verified using immunocytochemistry staining for α-sarcomeric actinin. In addition, cells also showed spontaneous contraction after several days in culture. Cell viability after thawing was acceptable at 40–60%. In spite of this, the methods outlined allow one to easily cryopreserve and thaw NRCMs. This gives researchers a greater amount of flexibility in planning experiments as well as reducing the use of animals. PMID:25938862

  16. Expression and Regulation of the Fkbp5 Gene in the Adult Mouse Brain

    PubMed Central

    Scharf, Sebastian H.; Liebl, Claudia; Binder, Elisabeth B.

    2011-01-01

    Background Chronic stress has been found to be a major risk factor for various human pathologies. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, which is tightly regulated via, among others, the glucocorticoid receptor (GR). The activity of the GR is modulated by a variety of proteins, including the co-chaperone FK506 binding protein 51 (FKBP5). Although FKBP5 has been associated with risk for affective disorders and has been implicated in GR sensitivity, previous studies focused mainly on peripheral blood, while information about basal distribution and induction in the central nervous system are sparse. Methodology/Principal Findings In the present study, we describe the basal expression pattern of Fkbp5 mRNA in the brain of adult male mice and show the induction of Fkbp5 mRNA via dexamethasone treatment or different stress paradigms. We could show that Fkbp5 is often, but not exclusively, expressed in regions also known for GR expression, for example the hippocampus. Furthermore, we were able to induce Fkbp5 expression via dexamethasone in the CA1 and DG subregions of the hippocampus, the paraventricular nucleus (PVN) and the central amygdala (CeA). Increase of Fkbp5 mRNA was also found after restrained stress and 24 hours of food deprivation in the PVN and the CeA, while in the hippocampus only food deprivation caused an increase in Fkbp5 mRNA. Conclusions/Significance Interestingly, regions with a low basal expression showed higher increase in Fkbp5 mRNA following induction than regions with high basal expression, supporting the hypothesis that GR sensitivity is, at least partly, mediated via Fkbp5. In addition, this also supports the use of Fkbp5 gene expression as a marker for GR sensitivity. In summary, we were able to give an overview of the basal expression of fkbp5 mRNA as well as to extend the findings of induction of Fkbp5 and its regulatory influence on GR sensitivity from peripheral blood to the brain. PMID:21347384

  17. Protection of Cardiomyocytes from Ischemic/Hypoxic Cell Death via Drbp1 and pMe2GlyDH in Cardio-specific ARC Transgenic Mice*

    PubMed Central

    Pyo, Jong-Ok; Nah, Jihoon; Kim, Hyo-Jin; Chang, Jae-Woong; Song, Young-Wha; Yang, Dong-Kwon; Jo, Dong-Gyu; Kim, Hyung-Ryong; Chae, Han-Jung; Chae, Soo-Wan; Hwang, Seung-Yong; Kim, Seung-Jun; Kim, Hyo-Joon; Cho, Chunghee; Oh, Chang-Gyu; Park, Woo Jin; Jung, Yong-Keun

    2008-01-01

    The ischemic death of cardiomyocytes is associated in heart disease and heart failure. However, the molecular mechanism underlying ischemic cell death is not well defined. To examine the function of apoptosis repressor with a caspase recruitment domain (ARC) in the ischemic/hypoxic damage of cardiomyocytes, we generated cardio-specific ARC transgenic mice using a mouse α-myosin heavy chain promoter. Compared with the control, the hearts of ARC transgenic mice showed a 3-fold overexpression of ARC. Langendoff preparation showed that the hearts isolated from ARC transgenic mice exhibited improved recovery of contractile performance during reperfusion. The cardiomyocytes cultured from neonatal ARC transgenic mice were significantly resistant to hypoxic cell death. Furthermore, the ARC C-terminal calcium-binding domain was as potent to protect cardiomyocytes from hypoxic cell death as ARC. Genome-wide RNA expression profiling uncovered a list of genes whose expression was changed (>2-fold) in ARC transgenic mice. Among them, expressional regulation of developmentally regulated RNA-binding protein 1 (Drbp1) or the dimethylglycine dehydrogenase precursor (pMe2GlyDH) affected hypoxic death of cardiomyocytes. These results suggest that ARC may protect cardiomyocytes from hypoxic cell death by regulating its downstream, Drbp1 and pMe2GlyDH, shedding new insights into the protection of heart from hypoxic damages. PMID:18782777

  18. Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure.

    PubMed

    Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C; van Meer, Berend; Ward-van Oostwaard, Dorien; Passier, Robert; Tertoolen, Leon G J; Mummery, Christine L; Casini, Simona

    2015-11-27

    One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation. PMID:26456652

  19. Heme Oxygenase-1/Carbon Monoxide System and Embryonic Stem Cell Differentiation and Maturation into Cardiomyocytes

    PubMed Central

    Suliman, Hagir B.; Zobi, Fabio

    2016-01-01

    Abstract Aims: The differentiation of embryonic stem (ES) cells into energetically efficient cardiomyocytes contributes to functional cardiac repair and is envisioned to ameliorate progressive degenerative cardiac diseases. Advanced cell maturation strategies are therefore needed to create abundant mature cardiomyocytes. In this study, we tested whether the redox-sensitive heme oxygenase-1/carbon monoxide (HO-1/CO) system, operating through mitochondrial biogenesis, acts as a mechanism for ES cell differentiation and cardiomyocyte maturation. Results: Manipulation of HO-1/CO to enhance mitochondrial biogenesis demonstrates a direct pathway to ES cell differentiation and maturation into beating cardiomyocytes that express adult structural markers. Targeted HO-1/CO interventions up- and downregulate specific cardiogenic transcription factors, transcription factor Gata4, homeobox protein Nkx-2.5, heart- and neural crest derivatives-expressed protein 1, and MEF2C. HO-1/CO overexpression increases cardiac gene expression for myosin regulatory light chain 2, atrial isoform, MLC2v, ANP, MHC-β, and sarcomere α-actinin and the major mitochondrial fusion regulators, mitofusin 2 and MICOS complex subunit Mic60. This promotes structural mitochondrial network expansion and maturation, thereby supporting energy provision for beating embryoid bodies. These effects are prevented by silencing HO-1 and by mitochondrial reactive oxygen species scavenging, while disruption of mitochondrial biogenesis and mitochondrial DNA depletion by loss of mitochondrial transcription factor A compromise infrastructure. This leads to failure of cardiomyocyte differentiation and maturation and contractile dysfunction. Innovation: The capacity to augment cardiomyogenesis via a defined mitochondrial pathway has unique therapeutic potential for targeting ES cell maturation in cardiac disease. Conclusion: Our findings establish the HO-1/CO system and redox regulation of mitochondrial biogenesis as

  20. Correlation between expression of CatSper family and sperm profiles in the adult mouse testis following Iranian Kerack abuse.

    PubMed

    Amini, M; Shirinbayan, P; Behnam, B; Roghani, M; Farhoudian, A; Joghataei, M T; Koruji, M

    2014-05-01

    Illicit drug use can be an important cause of male infertility. The aim of this study was to investigate the effects of an Iranian illicit drug, Kerack, on sperm parameters, testicular structure and CatSper genes expression of mice. In this study, 25 male mice were divided into five groups consisting of control, sham and three experimental groups. All animal in experimental groups were addicted to Kerack for 7 days. These experimental groups include experimental I which was given Kerack at a dose of 5 mg/kg, experimental II, 35 mg/kg and experimental III, 70 mg/kg, intraperitoneally twice a day for a period of 35 days. Mice were then sacrificed and spermatozoas were removed from cauda epididymis and analyzed for count, motility, morphology (normal/abnormal) and viability. Right testes were removed, weighed and processed for light microscopic studies whereas left testes removed were subjected to total mRNA extraction for using in real-time PCR (RT-PCR). The results were analyzed by performing anova (Tukey's tests) and Pearson correlation coefficient. Sperm parameters and seminiferous epithelium thickness were decreased in experimental groups (dose-dependently) vs. sham and control groups (p < 0.05). RT-PCR results showed that CatSper 2, 3, 4 genes expressions were reduced with 35 and 70 mg/kg injected Kerack when compared with control testes (p ≤ 0.05). However, CatSper1 expression was only reduced with high dose injected Kerack (70 mg/kg) in comparison to control testes (p ≤ 0.05). This study shows the deleterious effects of Kerack used in Iran on testis structure and sperm parameters in general, and particularly sperm morphology in adult mouse. It could down-regulate the expression of CatSper genes, resulting in depression of sperm motility. PMID:24619711

  1. Oral Immunization with Cholera Toxin Provides Protection against Campylobacter jejuni in an Adult Mouse Intestinal Colonization Model

    PubMed Central

    Albert, M. John; Mustafa, Abu Salim; Islam, Anjum; Haridas, Shilpa

    2013-01-01

    ABSTRACT Immunity to Campylobacter jejuni, a major diarrheal pathogen, is largely Penner serotype specific. For broad protection, a vaccine should be based on a common antigen(s) present in all strains. In our previous study (M. J. Albert, S. Haridas, D. Steer, G. S. Dhaunsi, A. I. Smith, and B. Adler, Infect. Immun. 75:3070–3073, 2007), we demonstrated that antibody to cholera toxin (CT) cross-reacted with the major outer membrane proteins (MOMPs) of all Campylobacter jejuni strains tested. In the current study, we investigated whether immunization with CT protects against intestinal colonization by C. jejuni in an adult mouse model and whether the nontoxic subunit of CT (CT-B) is the portion mediating cross-reaction. Mice were orally immunized with CT and later challenged with C. jejuni strains (48, 75, and 111) of different serotypes. Control animals were immunized with phosphate-buffered saline. Fecal shedding of challenge organisms was studied daily for 9 days. Serum and fecal antibody responses were studied by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. The cross-reactivity of rabbit CT-B antibody to MOMP was studied by immunoblotting. The reactivity of 21 overlapping 30-mer oligopeptides (based on MOMP’s sequence) against rabbit CT antibody was tested by ELISA. Test animals produced antibodies to CT and MMP in serum and feces and showed resistance to colonization, the vaccine efficacies being 49% (for strain 48), 37% (for strain 75), and 34% (for strain 111) (P, ≤0.05 to ≤0.001). One peptide corresponding to a variable region of MOMP showed significant reactivity. CT-B antibody cross-reacted with MOMP. Since CT-B is a component of oral cholera vaccines, it might be possible to control C. jejuni diarrhea with these vaccines. PMID:23653448

  2. Early Social Enrichment Rescues Adult Behavioral and Brain Abnormalities in a Mouse Model of Fragile X Syndrome

    PubMed Central

    Oddi, Diego; Subashi, Enejda; Middei, Silvia; Bellocchio, Luigi; Lemaire-Mayo, Valerie; Guzmán, Manuel; Crusio, Wim E; D'Amato, Francesca R; Pietropaolo, Susanna

    2015-01-01

    Converging lines of evidence support the use of environmental stimulation to ameliorate the symptoms of a variety of neurodevelopmental disorders. Applying these interventions at very early ages is critical to achieve a marked reduction of the pathological phenotypes. Here we evaluated the impact of early social enrichment in Fmr1-KO mice, a genetic mouse model of fragile X syndrome (FXS), a major developmental disorder and the most frequent monogenic cause of autism. Enrichment was achieved by providing male KO pups and their WT littermates with enhanced social stimulation, housing them from birth until weaning with the mother and an additional nonlactating female. At adulthood they were tested for locomotor, social, and cognitive abilities; furthermore, dendritic alterations were assessed in the hippocampus and amygdala, two brain regions known to be involved in the control of the examined behaviors and affected by spine pathology in Fmr1-KOs. Enrichment rescued the behavioral FXS-like deficits displayed in adulthood by Fmr1-KO mice, that is, hyperactivity, reduced social interactions, and cognitive deficits. Early social enrichment also eliminated the abnormalities shown by adult KO mice in the morphology of hippocampal and amygdala dendritic spines, namely an enhanced density of immature vs mature types. Importantly, enrichment did not induce neurobehavioral changes in WT mice, thus supporting specific effects on FXS-like pathology. These findings show that early environmental stimulation has profound and long-term beneficial effects on the pathological FXS phenotype, thereby encouraging the use of nonpharmacological interventions for the treatment of this and perhaps other neurodevelopmental diseases. PMID:25348604

  3. The transformation of synaptic to system plasticity in motor output from the sacral cord of the adult mouse.

    PubMed

    Jiang, Mingchen C; Elbasiouny, Sherif M; Collins, William F; Heckman, C J

    2015-09-01

    Synaptic plasticity is fundamental in shaping the output of neural networks. The transformation of synaptic plasticity at the cellular level into plasticity at the system level involves multiple factors, including behavior of local networks of interneurons. Here we investigate the synaptic to system transformation for plasticity in motor output in an in vitro preparation of the adult mouse spinal cord. System plasticity was assessed from compound action potentials (APs) in spinal ventral roots, which were generated simultaneously by the axons of many motoneurons (MNs). Synaptic plasticity was assessed from intracellular recordings of MNs. A computer model of the MN pool was used to identify the middle steps in the transformation from synaptic to system behavior. Two input systems that converge on the same MN pool were studied: one sensory and one descending. The two synaptic input systems generated very different motor outputs, with sensory stimulation consistently evoking short-term depression (STD) whereas descending stimulation had bimodal plasticity: STD at low frequencies but short-term facilitation (STF) at high frequencies. Intracellular and pharmacological studies revealed contributions from monosynaptic excitation and stimulus time-locked inhibition but also considerable asynchronous excitation sustained from local network activity. The computer simulations showed that STD in the monosynaptic excitatory input was the primary driver of the system STD in the sensory input whereas network excitation underlies the bimodal plasticity in the descending system. These results provide insight on the roles of plasticity in the monosynaptic and polysynaptic inputs converging on the same MN pool to overall motor plasticity. PMID:26203107

  4. Adult siRNA-induced knockdown of mGlu7 receptors reduces anxiety in the mouse.

    PubMed

    O'Connor, Richard M; Thakker, Deepak R; Schmutz, Markus; van der Putten, Herman; Hoyer, Daniel; Flor, Peter J; Cryan, John F

    2013-09-01

    Our knowledge regarding the molecular pathophysiology underlying anxiety disorders remains incomplete. Increasing evidence points to a role of glutamate in anxiety. The group III metabotropic glutamate receptors (mGlu4, mGlu6, mGlu7 and mGlu8 receptors) remain the least investigated glutamate receptor subtypes partially due to a delay in the development of specific pharmacological tools. Early work using knockout animals and pharmacological tools aimed at investigating the role of mGlu7 receptor in the pathophysiology of anxiety disorders has yielded exciting yet not always consistent results. To further investigate the role this receptor plays in anxiety-like behaviour, we knocked down mGlu7 receptor mRNA levels in the adult mouse brain using siRNA delivered via an osmotic minipump. This reduced anxiety-like behaviour in the light-dark box coupled with an attenuation of stress-induced hyperthermia (SIH) and a reduction of the acoustic startle response (ASRs) in the fear-potentiated startle paradigm (FPS). These effects on anxiety-like behaviour were independent of any impairment of locomotor activity and surprisingly, no behavioural changes were observed in the forced swim test (FST), which is in contrast to mGlu7 receptor knockout animals. Furthermore, the previously reported epilepsy-prone phenotype seen in mGlu7 receptor knockout animals was not observed following siRNA-induced knockdown of the receptor. These data suggest targeting mGlu7 receptors with selective antagonist drugs may be an effective and safe strategy for the treatment of anxiety disorders. PMID:23603202

  5. Spatiotemporally Regulated Ablation of Klf4 in Adult Mouse Corneal Epithelial Cells Results in Altered Epithelial Cell Identity and Disrupted Homeostasis

    PubMed Central

    Delp, Emili E.; Swamynathan, Sudha; Kao, Winston W.; Swamynathan, Shivalingappa K.

    2015-01-01

    Purpose. In previous studies, conditional disruption of Klf4 in the developing mouse ocular surface from embryonic day 10 resulted in corneal epithelial fragility, stromal edema, and loss of conjunctival goblet cells, revealing the importance of Klf4 in ocular surface maturation. Here, we use spatiotemporally regulated ablation of Klf4 to investigate its functions in maintenance of adult corneal epithelial homeostasis. Methods. Expression of Cre was induced in ternary transgenic (Klf4LoxP/LoxP/Krt12rtTA/rtTA/Tet-O-Cre) mouse corneal epithelium by doxycycline administered through intraperitoneal injections and drinking water, to generate corneal epithelium–specific deletion of Klf4 (Klf4Δ/ΔCE). Corneal epithelial barrier function was tested by fluorescein staining. Expression of selected Klf4-target genes was determined by quantitative PCR (QPCR), immunoblotting, and immunofluorescent staining. Results. Klf4 was efficiently ablated within 5 days of doxycycline administration in adult Klf4Δ/ΔCE corneal epithelium. The Klf4Δ/ΔCE corneal epithelial barrier function was disrupted, and the basal cells were swollen and rounded after 15 days of doxycycline treatment. Increased numbers of cell layers and Ki67-positive proliferating cells suggested deregulated Klf4Δ/ΔCE corneal epithelial homeostasis. Expression of tight junction proteins ZO-1 and occludin, desmosomal Dsg and Dsp, basement membrane laminin-332, and corneal epithelial–specific keratin-12 was decreased, while that of matrix metalloproteinase Mmp9 and noncorneal keratin-17 increased, suggesting altered Klf4Δ/ΔCE corneal epithelial cell identity. Conclusions. Ablation of Klf4 in the adult mouse corneas resulted in the absence of characteristic corneal epithelial cell differentiation, disrupted barrier function, and squamous metaplasia, revealing that Klf4 is essential for maintenance of the adult corneal epithelial cell identity and homeostasis. PMID:26047041

  6. Analysis of cardiomyocyte movement in the developing murine heart

    SciTech Connect

    Hashimoto, Hisayuki; Yuasa, Shinsuke; Tabata, Hidenori; Tohyama, Shugo; Seki, Tomohisa; Egashira, Toru; Hayashiji, Nozomi; Hattori, Fumiyuki; Kusumoto, Dai; Kunitomi, Akira; Takei, Makoto; Kashimura, Shin; Yozu, Gakuto; Shimojima, Masaya; Motoda, Chikaaki; Muraoka, Naoto; Nakajima, Kazunori; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Fukuda, Keiichi

    2015-09-04

    The precise assemblage of several types of cardiac precursors controls heart organogenesis. The cardiac precursors show dynamic movement during early development and then form the complicated heart structure. However, cardiomyocyte movements inside the newly organized mammalian heart remain unclear. We previously established the method of ex vivo time-lapse imaging of the murine heart to study cardiomyocyte behavior by using the Fucci (fluorescent ubiquitination-based cell cycle indicator) system, which can effectively label individual G1, S/G2/M, and G1/S-transition phase nuclei in living cardiomyocytes as red, green, and yellow, respectively. Global analysis of gene expression in Fucci green positive ventricular cardiomyocytes confirmed that cell cycle regulatory genes expressed in G1/S, S, G2/M, and M phase transitions were upregulated. Interestingly, pathway analysis revealed that many genes related to the cell cycle were significantly upregulated in the Fucci green positive ventricular cardiomyocytes, while only a small number of genes related to cell motility were upregulated. Time-lapse imaging showed that murine proliferating cardiomyocytes did not exhibit dynamic movement inside the heart, but stayed on site after entering the cell cycle. - Highlights: • We directly visualized cardiomyocyte movement inside the developing murine heart. • Cell cycle related genes were upregulated in the proliferating cardiomyocytes. • Time-lapse imaging revealed that proliferating murine cardiomyocytes stayed in place. • Murine ventricular cardiomyocytes proliferate on site during development.

  7. A new genus and species of demodecid mites from the tongue of a house mouse Mus musculus: description of adult and immature stages with data on parasitism.

    PubMed

    Izdebska, J N; Rolbiecki, L

    2016-06-01

    The study of the parasitofauna of the house mouse Mus musculus (Rodentia: Muridae) Linnaeus is particularly important owing to its multiple relationships with humans - as a cosmopolitan, synanthropic rodent, bred for pets, food for other animals or laboratory animal. This article proposes and describes a new genus and species of the parasitic mite based on adult and immature stages from the house mouse. Glossicodex musculi gen. n., sp. n. is a medium-sized demodecid mite (adult stages on average 199 µm in length) found in mouse tissue of the tongue. It is characterized by two large, hooked claws on each tarsus of the legs; the legs are relatively massive, consisting of large, non-overlapping segments. The palps consist of three slender, clearly separated, relatively narrow segments, wherein their coxal segments are also quite narrow and spaced. Also, segments of the palps of larva and nymphs are clearly isolated, and on the terminal segment, trident claws that resemble legs' claws can be found. On the ventral side, in immature stages, triangular scuta, topped with sclerotized spur, can be also observed. Glossicodex musculi was noted in 10.8% of mice with a mean infection intensity of 2.2 parasites per host. PMID:26991770

  8. Spatial Distribution of Maxi-Anion Channel on Cardiomyocytes Detected by Smart-Patch Technique☆

    PubMed Central

    Dutta, Amal K.; Korchev, Yuri E.; Shevchuk, Andrew I.; Hayashi, Seiji; Okada, Yasunobu; Sabirov, Ravshan Z.

    2008-01-01

    Spatial distribution of maxi-anion channels in rat cardiomyocytes were studied by applying the recently developed patch clamp technique under scanning ion conductance microscopy, called the “smart-patch” technique. In primary-cultured neonatal cells, the channel was found to be unevenly distributed over the cell surface with significantly lower channel activity in cellular extensions compared with the other parts. Local ATP release, detected using a PC12 cell-based biosensor technique, also exhibited a similar pattern. The maxi-anion channel activity could not be detected in freshly isolated adult cardiomyocytes by the conventional patch-clamp with 2-MΩ pipettes. However, when fine-tipped 15–20 MΩ pipettes were targeted to only Z-line areas, we observed, for the first time, the maxi-anion events. Smart-patching different regions of the cell surface, we found that the channel activity was maximal at the openings of T-tubules and along Z-lines, but was significantly decreased in the scallop crest area. Thus, it is concluded that maxi-anion channels are concentrated at the openings of T-tubules and along Z-lines in adult cardiomyocytes. This study showed that the smart-patch technique provides a powerful method to detect a unitary event of channels that are localized at some specific site in the narrow region. PMID:18024498

  9. Cardiomyocytes mediate anti-angiogenesis in type 2 diabetic rats through the exosomal transfer of miR-320 into endothelial cells.

    PubMed

    Wang, Xiaohong; Huang, Wei; Liu, Guansheng; Cai, Wenfeng; Millard, Ronald W; Wang, Yigang; Chang, Jiang; Peng, Tianqing; Fan, Guo-Chang

    2014-09-01

    Exosomes, nano-vesicles naturally released from living cells, have been well recognized to play critical roles in mediating cell-to-cell communication. Given that diabetic hearts exhibit insufficient angiogenesis, it is significant to test whether diabetic cardiomyocyte-derived exosomes possess any capacity in regulating angiogenesis. In this study, we first observed that both proliferation and migration of mouse cardiac endothelial cells (MCECs) were inhibited when co-cultured with cardiomyocytes isolated from adult Goto-Kakizaki (GK) rats, a commonly used animal model of type 2 diabetes. However, GK-myocyte-mediated anti-angiogenic effects were negated upon addition of GW4869, an inhibitor of exosome formation/release, into the co-cultures. Next, exosomes were purified from the myocyte culture supernatants by differential centrifugation. While exosomes derived from GK myocytes (GK-exosomes) displayed similar size and molecular markers (CD63 and CD81) to those originated from the control Wistar rat myocytes (WT-exosomes), their regulatory role in angiogenesis is opposite. We observed that the MCEC proliferation, migration and tube-like formation were inhibited by GK-exosomes, but were promoted by WT-exosomes. Mechanistically, we found that GK-exosomes encapsulated higher levels of miR-320 and lower levels of miR-126 compared to WT-exosomes. Furthermore, GK-exosomes were effectively taken up by MCECs and delivered miR-320. In addition, transportation of miR-320 from myocytes to MCECs could be blocked by GW4869. Importantly, the exosomal miR-320 functionally down-regulated its target genes (IGF-1, Hsp20 and Ets2) in recipient MCECs, and overexpression of miR-320 inhibited MCEC migration and tube formation. GK exosome-mediated inhibitory effects on angiogenesis were removed by knockdown of miR-320. Together, these data indicate that cardiomyocytes exert an anti-angiogenic function in type 2 diabetic rats through exosomal transfer of miR-320 into endothelial cells

  10. Adiponectin Modulates Oxidative Stress-Induced Autophagy in Cardiomyocytes

    PubMed Central

    Essick, Eric E.; Wilson, Richard M.; Pimentel, David R.; Shimano, Masayuki; Baid, Simoni; Ouchi, Noriyuki; Sam, Flora

    2013-01-01

    Diastolic heart failure (HF) i.e., “HF with preserved ejection fraction” (HF-preserved EF) accounts for up to 50% of all HF presentations; however there have been no therapeutic advances. This stems in part from an incomplete understanding about HF-preserved EF. Hypertension is the major cause of HF-preserved EF whilst HF-preserved EF is also highly associated with obesity. Similarly, excessive reactive oxygen species (ROS), i.e., oxidative stress occurs in hypertension and obesity, sensitizing the heart to the renin-angiotensin-aldosterone system, inducing autophagic type-II programmed cell death and accelerating the propensity to adverse cardiac remodeling, diastolic dysfunction and HF. Adiponectin (APN), an adipokine, mediates cardioprotective actions but it is unknown if APN modulates cardiomyocyte autophagy. We tested the hypothesis that APN ameliorates oxidative stress-induced autophagy in cardiomyocytes. Isolated adult rat ventricular myocytes were pretreated with recombinant APN (30µg/mL) followed by 1mM hydrogen peroxide (H2O2) exposure. Wild type (WT) and APN-deficient (APN-KO) mice were infused with angiotensin (Ang)-II (3.2mg/kg/d) for 14 days to induced oxidative stress. Autophagy-related proteins, mTOR, AMPK and ERK expression were measured. H2O2 induced LC3I to LC3II conversion by a factor of 3.4±1.0 which was abrogated by pre-treatment with APN by 44.5±10%. However, neither H2O2 nor APN affected ATG5, ATG7, or Beclin-1 expression. H2O2 increased phospho-AMPK by 49±6.0%, whilst pretreatment with APN decreased phospho-AMPK by 26±4%. H2O2 decreased phospho-mTOR by 36±13%, which was restored by APN. ERK inhibition demonstrated that the ERK-mTOR pathway is involved in H2O2-induced autophagy. Chronic Ang-II infusion significantly increased myocardial LC3II/I protein expression ratio in APN-KO vs. WT mice. These data suggest that excessive ROS caused cardiomyocyte autophagy which was ameliorated by APN by inhibiting an H2O2-induced AMPK

  11. Follistatin-like 5 is expressed in restricted areas of the adult mouse brain: Implications for its function in the olfactory system.

    PubMed

    Masuda, Tomoyuki; Sakuma, Chie; Nagaoka, Atsuko; Yamagishi, Toshiyuki; Ueda, Shuichi; Nagase, Takahiro; Yaginuma, Hiroyuki

    2014-02-01

    Follistatin-like 5 (Fstl5), a member of the follistatin family of genes, encodes a secretory glycoprotein. Previous studies revealed that other members of this family including Fstl1 and Fstl3 play an essential role in development, homeostasis, and congenital disorders. However, the in vivo function of Fstl5 is poorly understood. To gain insight into the function of Fstl5 in the mouse central nervous system, we examined the Fstl5 expression pattern in the adult mouse brain. The results of in situ hybridization analysis showed a highly restricted pattern of Fstl5, namely, with localization in the olfactory system, hippocampal CA3 area and granular cell layer of the cerebellum. Restricted expression in the olfactory system suggests a possible role for Fstl5 in maintaining odor perception. PMID:24588779

  12. Atorvastatin protects cardiomyocytes from oxidative stress by inhibiting LOX-1 expression and cardiomyocyte apoptosis.

    PubMed

    Zhang, Lei; Cheng, Linfang; Wang, Qiqi; Zhou, Dongchen; Wu, Zhigang; Shen, Ling; Zhang, Li; Zhu, Jianhua

    2015-03-01

    Coronary artery disease (CAD) is a major health problem worldwide. The most severe form of CAD is acute coronary syndrome (ACS). Recent studies have demonstrated the beneficial role of atorvastatin in ACS; however, the mechanisms underlying this effect have not been fully clarified. Growing evidence indicates that activation of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) plays an important role in oxidative stress-induced cardiomyocyte apoptosis during ACS. In this study, we examined whether atorvastatin inhibits H2O2-induced LOX-1 expression and H9c2 cardiomyocyte apoptosis, and investigated the underlying signaling pathway. Treatment of H9c2 cardiomyocytes with H2O2 resulted in elevated expression of LOX-1 mRNA and protein, as well as increased caspase-3 and -9 protein expression and cell apoptosis. H2O2-induced LOX-1 expression, caspase protein expression, and cardiomyocyte apoptosis were attenuated by pretreatment with atorvastatin. Atorvastatin activated H2O2-inhibited phosphorylation of Akt in a concentration-dependent manner. The Akt inhibitor, LY294002, inhibited the effect of atorvastatin on inducing Akt phosphorylation and on suppressing H2O2-mediated caspase up-regulation and cell apoptosis. These findings indicate that atorvastatin protects cardiomyocyte from oxidative stress via inhibition of LOX-1 expression and apoptosis, and that activation of H2O2-inhibited phosphorylation of Akt may play an important role in the protective function of atorvastatin. PMID:25630653

  13. Electrophysiological and contractile function of cardiomyocytes derived from human embryonic stem cells

    PubMed Central

    Blazeski, Adriana; Zhu, Renjun; Hunter, David W.; Weinberg, Seth H.; Boheler, Kenneth R.; Zambidis, Elias T.; Tung, Leslie

    2013-01-01

    Human embryonic stem cells have emerged as the prototypical source from which cardiomyocytes can be derived for use in drug discovery and cell therapy. However, such applications require that these cardiomyocytes (hESC-CMs) faithfully recapitulate the physiology of adult cells, especially in relation to their electrophysiological and contractile function. We review what is known about the electrophysiology of hESC-CMs in terms of beating rate, action potential characteristics, ionic currents, and cellular coupling as well as their contractility in terms of calcium cycling and contraction. We also discuss the heterogeneity in cellular phenotypes that arises from variability in cardiac differentiation, maturation, and culture conditions, and summarize present strategies that have been implemented to reduce this heterogeneity. Finally, we present original electrophysiological data from optical maps of hESC-CM clusters. PMID:22958937

  14. Cardiomyocyte proliferation vs progenitor cells in myocardial regeneration: The debate continues

    PubMed Central

    Malliaras, Konstantinos; Terrovitis, John

    2013-01-01

    In recent years, several landmark studies have provided compelling evidence that cardiomyogenesis occurs in the adult mammalian heart. However, the rate of new cardiomyocyte formation is inadequate for complete restoration of the normal mass of myocardial tissue, should a significant myocardial injury occur, such as myocardial infarction. The cellular origin of postnatal cardiomyogenesis in mammals remains a controversial issue and two mechanisms seem to be participating, proliferation of pre-existing cardiomyocytes and myogenic differentiation of progenitor cells. We will discuss the relative importance of these two processes in different settings, such as normal ageing and post-myocardial injury, as well as the strengths and limitations of the existing experimental methodologies used in the relevant studies. Further clarification of the mechanisms underlying cardiomyogenesis in mammals will open the way for their therapeutic exploitation in the clinical field, with the scope of myocardial regeneration. PMID:24689031

  15. Elastic interactions synchronize beating in cardiomyocytes.

    PubMed

    Cohen, Ohad; Safran, Samuel A

    2016-07-13

    Motivated by recent experimental results, we study theoretically the synchronization of the beating phase and frequency of two nearby cardiomyocyte cells. Each cell is represented as an oscillating force dipole in an infinite, viscoelastic medium and the propagation of the elastic signal within the medium is predicted. We examine the steady-state beating of two nearby cells, and show that elastic interactions result in forces that synchronize the phase and frequency of beating in a manner that depends on their mutual orientation. The theory predicts both in-phase and anti-phase steady-state beating depending on the relative cell orientations, as well as how synchronized beating varies with substrate elasticity and the inter-cell distance. These results suggest how mechanics plays a role in cardiac efficiency, and may be relevant for the design of cardiomyocyte based micro devices and other biomedical applications. PMID:27352146

  16. Characterizing functional stem cell–cardiomyocyte interactions

    PubMed Central

    Bursac, Nenad; Kirkton, Robert D; McSpadden, Luke C; Liau, Brian

    2010-01-01

    Despite the progress in traditional pharmacological and organ transplantation therapies, heart failure still afflicts 5.3 million Americans. Since June 2000, stem cell-based approaches for the prevention and treatment of heart failure have been pursued in clinics with great excitement; however, the exact mechanisms of how transplanted cells improve heart function remain elusive. One of the main difficulties in answering these questions is the limited ability to directly access and study interactions between implanted cells and host cardiomyocytes in situ. With the growing number of candidate cell types for potential clinical use, it is becoming increasingly more important to establish standardized, well-controlled in vitro and in situ assays to compare the efficacy and safety of different stem cells in cardiac repair. This article describes recent innovative methodologies to characterize direct functional interactions between stem cells and cardiomyocytes, aimed to facilitate the rational design of future cell-based therapies for heart disease. PMID:20017697

  17. Assessment of the cellular and electrophysiological response of cardiomyocytes to radiation

    NASA Astrophysics Data System (ADS)

    Helm, Alexander; Ritter, Sylvia; Durante, Marco; Friess, Johannes; Thielemann, Christiane; Mr; Frank, Simon

    Cardiac disease is considered as a late effect resulting from an exposure during long-term space missions. Yet, the underlying mechanisms and the impact of radiation quality and dose are not well understood. To address this topic, we used cardiomyocytes derived from mouse embryonic stem cells (mESC) as a model system. This model has already been successfully used for cardiotoxicity screening of new drugs. Both, the cellular and electrophysiological response to X-ray irradiation were examined. Cellular endpoints such as the induction of micronuclei, apoptosis, number of binucleated cells and expression of connexin43 (Cx 43) were analyzed by standard techniques. For electrophysiological studies a microelectrode array (MEA) was used allowing non-invasive recordings of electrical signals such as signal amplitude and shape, beat rate and conduction velocity. Data analysis was performed using the MATLAB based software DrCell. As a first approach, cardiomyocytes were generated by differentiation of mESC via the formation of embryoid bodies. However, the system proved to be unsuitable due to large intra- and inter-sample variations. In consecutive experiments we used commercially available Cor.At cells, i.e. a pure culture of mESC derived cardiomyocytes. For the analysis of cellular and electrophysiological endpoints Cor.At cells were seeded onto chamber slides or MEA chips, respectively. Irradiation with 0.5 and 2 Gy X-rays (250 kV, 16 mA) was performed two days after seeding. At that time cardiomyocytes are electrically coupled through gap junctions and form a spontaneously beating network. Samples were examined up to four days after exposure. Analysis of the electrophysiological data revealed only minor differences between controls and X-irradiated samples indicating the functionality of cardiomyocytes is not within the dose range examined. Currently, further experiments are performed to statistically verify this finding. Additionally, the expression of Cx 43, a major

  18. Data on the gene expression of cardiomyocyte exposed to hypothermia.

    PubMed

    Zhang, Jian; Xue, Xiaodong; Xu, Yinli; Zhang, Yuji; Li, Zhi; Wang, Huishan

    2016-09-01

    Hypothermia is widely used in neurosurgery and cardiac surgeries. However, little is known about the underlying molecular mechanisms. We previously reported that the transcriptome responses of cardiomyocyte exposed to hypothermia, "The transcriptome responses of cardiomyocyte exposed to hypothermia" [4]. Herein, we provide the hypothermia inhibited proliferation of cardiomyocyte cells in vitro and the details of transcription factors in regulation of differentially expressed genes. PMID:27274530

  19. Culture and establishment of self-renewing human and mouse adult liver and pancreas 3D organoids and their genetic manipulation.

    PubMed

    Broutier, Laura; Andersson-Rolf, Amanda; Hindley, Christopher J; Boj, Sylvia F; Clevers, Hans; Koo, Bon-Kyoung; Huch, Meritxell

    2016-09-01

    Adult somatic tissues have proven difficult to expand in vitro, largely because of the complexity of recreating appropriate environmental signals in culture. We have overcome this problem recently and developed culture conditions for adult stem cells that allow the long-term expansion of adult primary tissues from small intestine, stomach, liver and pancreas into self-assembling 3D structures that we have termed 'organoids'. We provide a detailed protocol that describes how to grow adult mouse and human liver and pancreas organoids, from cell isolation and long-term expansion to genetic manipulation in vitro. Liver and pancreas cells grow in a gel-based extracellular matrix (ECM) and a defined medium. The cells can self-organize into organoids that self-renew in vitro while retaining their tissue-of-origin commitment, genetic stability and potential to differentiate into functional cells in vitro (hepatocytes) and in vivo (hepatocytes and endocrine cells). Genetic modification of these organoids opens up avenues for the manipulation of adult stem cells in vitro, which could facilitate the study of human biology and allow gene correction for regenerative medicine purposes. The complete protocol takes 1-4 weeks to generate self-renewing 3D organoids and to perform genetic manipulation experiments. Personnel with basic scientific training can conduct this protocol. PMID:27560176

  20. Glyceraldehyde-3-Phosphate Dehydrogenase Interacts with Proapoptotic Kinase Mst1 to Promote Cardiomyocyte Apoptosis

    PubMed Central

    You, Bei; Huang, Shengdong; Qin, Qing; Yi, Bing; Yuan, Yang; Xu, Zhiyun; Sun, Jianxin

    2013-01-01

    Mammalian sterile 20-like kinase 1 (Mst1) is a critical component of the Hippo signaling pathway, which regulates a variety of biological processes ranging from cell contact inhibition, organ size control, apoptosis and tumor suppression in mammals. Mst1 plays essential roles in the heart disease since its activation causes cardiomyocyte apoptosis and dilated cardiomyopathy. However, the mechanism underlying Mst1 activation in the heart remains unknown. In a yeast two-hybrid screen of a human heart cDNA library with Mst1 as bait, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was identified as an Mst1-interacting protein. The interaction of GAPDH with Mst1 was confirmed by co-immunoprecipitation in both co-transfected HEK293 cells and mouse heart homogenates, in which GAPDH interacted with the kinase domain of Mst1, whereas the C-terminal catalytic domain of GAPDH mediated its interaction with Mst1. Moreover, interaction of Mst1 with GAPDH caused a robust phosphorylation of GAPDH and markedly increased the Mst1 activity in cells. Chelerythrine, a potent inducer of apoptosis, substantially increased the nuclear translocation and interaction of GAPDH and Mst1 in cardiomyocytes. Overexpression of GAPDH significantly augmented the Mst1 mediated apoptosis, whereas knockdown of GAPDH markedly attenuated the Mst1 activation and cardiomyocyte apoptosis in response to either chelerythrine or hypoxia/reoxygenation. These findings reveal a novel function of GAPDH in Mst1 activation and cardiomyocyte apoptosis and suggest that disruption of GAPDH interaction with Mst1 may prevent apoptosis related heart diseases such as heart failure and ischemic heart disease. PMID:23527007

  1. Regulation of the Cardiomyocyte Population in the Developing Heart

    PubMed Central

    Thornburg, Kent; Jonker, Sonnet; O’Tierney, Perrie; Chattergoon, Natasha; Louey, Samantha; Faber, Job; Giraud, George

    2011-01-01

    During fetal life the myocardium expands through replication of cardiomyocytes. In sheep, cardiomyocytes begin the process of becoming terminally differentiated at about 100 gestation days out of 145 days term. In this final step of development, cardiomyocytes become binucleated and stop dividing. The number of cells at birth is important in determining the number of cardiomyocytes for life. Therefore, the regulation of cardiomyocyte growth in the womb is critical to long term disease outcome. Growth factors that stimulate proliferation of fetal cardiomyocytes include angiotensin II, cortisol and insulin-like growth factor-1. Increased ventricular wall stress leads to short term increases in proliferation but longer term loss of cardiomyocyte generative capacity. Two normally circulating hormones have been identified that suppress proliferation: atrial natriuretic peptide (ANP) and tri-iodo-L-thyronine (T3). Atrial natriuretic peptide signals through the NPRA receptor that serves as a guanylate cyclase and signals through cGMP. ANP powerfully suppresses mitotic activity in cardiomyocytes in the presence of angiotensin II in culture. Addition of a cGMP analogue has the same effect as ANP. ANP suppresses both the extracellular receptor kinases and the phosphoinositol 3 kinase pathways. T3 also suppresses increased mitotic activity of stimulated cardiomyocytes but does so by increasing the cell cycle suppressant, p21, and decreasing the cell cycle activator, cyclin D1. PMID:21147149

  2. Direct Cardiomyocyte Reprogramming: A New Direction for Cardiovascular Regenerative Medicine

    PubMed Central

    Yi, B. Alexander; Mummery, Christine L.; Chien, Kenneth R.

    2013-01-01

    The past few years have seen unexpected new developments in direct cardiomyocyte reprogramming. Direct cardiomyocyte reprogramming potentially offers an entirely novel approach to cardiovascular regenerative medicine by converting cardiac fibroblasts into functional cardiomyocytes in situ. There is much to be learned, however, about the mechanisms of direct reprogramming in order that the process can be made more efficient. Early efforts have suggested that this new technology can be technically challenging. Moreover, new methods of inducing heart reprogramming will need to be developed before this approach can be translated to the bedside. Despite this, direct cardiomyocyte reprogramming may lead to new therapeutic options for sufferers of heart disease. PMID:24003244

  3. Cardiac RNA induces inflammatory responses in cardiomyocytes and immune cells via Toll-like receptor 7 signaling.

    PubMed

    Feng, Yan; Chen, Hongliang; Cai, Jiayan; Zou, Lin; Yan, Dan; Xu, Ganqiong; Li, Dan; Chao, Wei

    2015-10-30

    We have recently reported that extracellular RNA (exRNA) released from necrotic cells induces cytokine production in cardiomyocytes and immune cells and contributes to myocardial ischemia/reperfusion injury. However, the signaling mechanism by which exRNA exhibits its pro-inflammatory effect is unknown. Here we hypothesize that exRNA directly induces inflammation through specific Toll-like receptors (TLRs). To test the hypothesis, we treated rat neonatal cardiomyocytes, mouse bone marrow-derived macrophages (BMDM), or mouse neutrophils with RNA (2.5-10 μg/ml) isolated from rat cardiomyocytes or the hearts from mouse, rat, and human. We found that cellular RNA induced production of several cytokines such as macrophage inflammatory protein-2 (MIP-2), ILs, TNFα, and the effect was completely diminished by RNase, but not DNase. The RNA-induced cytokine production was partially inhibited in cells treated with TLR7 antagonist or genetically deficient in TLR7. Deletion of myeloid differentiation primary response protein 88 (MyD88), a downstream adapter of TLRs including TLR7, abolished the RNA-induced MIP-2 production. Surprisingly, genetic deletion of TLR3 had no impact on the RNA-induced MIP-2 response. Importantly, extracellular RNA released from damaged cardiomyocytes also induced cytokine production. Finally, mice treated with 50 μg of RNA intraperitoneal injection exhibited acute peritonitis as evidenced by marked neutrophil and monocyte migration into the peritoneal space. Together, these data demonstrate that exRNA of cardiac origin exhibits a potent pro-inflammatory property in vitro and in vivo and that exRNA induces cytokine production through TLR7-MyD88 signaling. PMID:26363072

  4. Dose of Phenobarbital and Age of Treatment at Early Life are Two Key Factors for the Persistent Induction of Cytochrome P450 Enzymes in Adult Mouse Liver.

    PubMed

    Tien, Yun-Chen; Liu, Ke; Pope, Chad; Wang, Pengcheng; Ma, Xiaochao; Zhong, Xiao-bo

    2015-12-01

    Drug treatment of neonates and infants and its long-term consequences on drug responses have emerged in recent years as a major challenge for health care professionals. In the current study, we use phenobarbital as a model drug and mouse as an in vivo model to demonstrate that the dose of phenobarbital and age of treatment are two key factors for the persistent induction of gene expression and consequential increases of enzyme activities of Cyp2b, Cyp2c, and Cyp3a in adult livers. We show that phenobarbital treatment at early life of day 5 after birth with a low dose (<100 mg/kg) does not change expression and enzyme activities of Cyp2b, Cyp2c, and Cyp3a in adult mouse liver, whereas phenobarbital treatment with a high dose (>200 mg/kg) significantly increases expression and enzyme activities of these P450s in adult liver. We also demonstrate that phenobarbital treatment before day 10 after birth, but not at later ages, significantly increases mRNAs, proteins, and enzyme activities of the tested P450s. Such persistent induction of P450 gene expression and enzyme activities in adult livers by phenobarbital treatment only occurs within a sensitive age window early in life. The persistent induction in gene expression and enzyme activities is higher in female mice than in male mice for Cyp2b10 but not for Cyp2c29 and Cyp3a11. These results will stimulate studies to evaluate the long-term impacts of drug treatment with different doses at neonatal and infant ages on drug metabolism, therapeutic efficacy, and drug-induced toxicity throughout the rest of life. PMID:26400395

  5. Epicardial FSTL1 reconstitution regenerates the adult mammalian heart

    PubMed Central

    Wei, Ke; Serpooshan, Vahid; Hurtado, Cecilia; Diez-Cuñado, Marta; Zhao, Mingming; Maruyama, Sonomi; Zhu, Wenhong; Fajardo, Giovanni; Noseda, Michela; Nakamura, Kazuto; Tian, Xueying; Liu, Qiaozhen; Wang, Andrew; Matsuura, Yuka; Bushway, Paul; Cai, Wenqing; Savchenko, Alex; Mahmoudi, Morteza; Schneider, Michael D.; van den Hoff, Maurice J. B.; Butte, Manish J.; Yang, Phillip C.; Walsh, Kenneth; Zhou, Bin; Bernstein, Daniel; Mercola, Mark; Ruiz-Lozano, Pilar

    2016-01-01

    The elucidation of factors that activate the regeneration of the adult mammalian heart is of major scientific and therapeutic importance. Here we found that epicardial cells contain a potent cardiogenic activity identified as follistatin-like 1 (Fstl1). Epicardial Fstl1 declines following myocardial infarction and is replaced by myocardial expression. Myocardial Fstl1 does not promote regeneration, either basally or upon transgenic overexpression. Application of the human Fstl1 protein (FSTL1) via an epicardial patch stimulates cell cycle entry and division of pre-existing cardiomyocytes, improving cardiac function and survival in mouse and swine models of myocardial infarction. The data suggest that the loss of epicardial FSTL1 is a maladaptive response to injury, and that its restoration would be an effective way to reverse myocardial death and remodelling following myocardial infarction in humans. PMID:26375005

  6. Epicardial FSTL1 reconstitution regenerates the adult mammalian heart.

    PubMed

    Wei, Ke; Serpooshan, Vahid; Hurtado, Cecilia; Diez-Cuñado, Marta; Zhao, Mingming; Maruyama, Sonomi; Zhu, Wenhong; Fajardo, Giovanni; Noseda, Michela; Nakamura, Kazuto; Tian, Xueying; Liu, Qiaozhen; Wang, Andrew; Matsuura, Yuka; Bushway, Paul; Cai, Wenqing; Savchenko, Alex; Mahmoudi, Morteza; Schneider, Michael D; van den Hoff, Maurice J B; Butte, Manish J; Yang, Phillip C; Walsh, Kenneth; Zhou, Bin; Bernstein, Daniel; Mercola, Mark; Ruiz-Lozano, Pilar

    2015-09-24

    The elucidation of factors that activate the regeneration of the adult mammalian heart is of major scientific and therapeutic importance. Here we found that epicardial cells contain a potent cardiogenic activity identified as follistatin-like 1 (Fstl1). Epicardial Fstl1 declines following myocardial infarction and is replaced by myocardial expression. Myocardial Fstl1 does not promote regeneration, either basally or upon transgenic overexpression. Application of the human Fstl1 protein (FSTL1) via an epicardial patch stimulates cell cycle entry and division of pre-existing cardiomyocytes, improving cardiac function and survival in mouse and swine models of myocardial infarction. The data suggest that the loss of epicardial FSTL1 is a maladaptive response to injury, and that its restoration would be an effective way to reverse myocardial death and remodelling following myocardial infarction in humans. PMID:26375005

  7. Aza-induced cardiomyocyte differentiation of P19 EC-cells by epigenetic co-regulation and ERK signaling.

    PubMed

    Abbey, Deepti; Seshagiri, Polani B

    2013-09-10

    Stem cells in cell based therapy for cardiac injury is being potentially considered. However, genetic regulatory networks involved in cardiac differentiation are not clearly understood. Among stem cell differentiation models, mouse P19 embryonic carcinoma (EC) cells, are employed for studying (epi)genetic regulation of cardiomyocyte differentiation. Here, we comprehensively assessed cardiogenic differentiation potential of 5-azacytidine (Aza) on P19 EC-cells, associated gene expression profiles and the changes in DNA methylation, histone acetylation and activated-ERK signaling status during differentiation. Initial exposure of Aza to cultured EC-cells leads to an efficient (55%) differentiation to cardiomyocyte-rich embryoid bodies with a threefold (16.8%) increase in the cTnI+ cardiomyocytes. Expression levels of cardiac-specific gene markers i.e., Isl-1, BMP-2, GATA-4, and α-MHC were up-regulated following Aza induction, accompanied by differential changes in their methylation status particularly that of BMP-2 and α-MHC. Additionally, increases in the levels of acetylated-H3 and pERK were observed during Aza-induced cardiac differentiation. These studies demonstrate that Aza is a potent cardiac inducer when treated during the initial phase of differentiation of mouse P19 EC-cells and its effect is brought about epigenetically and co-ordinatedly by hypo-methylation and histone acetylation-mediated hyper-expression of cardiogenesis-associated genes and involving activation of ERK signaling. PMID:23747406

  8. Micropost arrays for measuring stem cell-derived cardiomyocyte contractility.

    PubMed

    Beussman, Kevin M; Rodriguez, Marita L; Leonard, Andrea; Taparia, Nikita; Thompson, Curtis R; Sniadecki, Nathan J

    2016-02-01

    Stem cell-derived cardiomyocytes have the potential to be used to study heart disease and maturation, screen drug treatments, and restore heart function. Here, we discuss the procedures involved in using micropost arrays to measure the contractile forces generated by stem cell-derived cardiomyocytes. Cardiomyocyte contractility is needed for the heart to pump blood, so measuring the contractile forces of cardiomyocytes is a straightforward way to assess their function. Microfabrication and soft lithography techniques are utilized to create identical arrays of flexible, silicone microposts from a common master. Micropost arrays are functionalized with extracellular matrix protein to allow cardiomyocytes to adhere to the tips of the microposts. Live imaging is used to capture videos of the deflection of microposts caused by the contraction of the cardiomyocytes. Image analysis code provides an accurate means to quantify these deflections. The contractile forces produced by a beating cardiomyocyte are calculated by modeling the microposts as cantilever beams. We have used this assay to assess techniques for improving the maturation and contractile function of stem cell-derived cardiomyocytes. PMID:26344757

  9. Cardiomyocyte Circadian Oscillations Are Cell-Autonomous, Amplified by β-Adrenergic Signaling, and Synchronized in Cardiac Ventricle Tissue

    PubMed Central

    Welsh, David K.

    2016-01-01

    Circadian clocks impact vital cardiac parameters such as blood pressure and heart rate, and adverse cardiac events such as myocardial infarction and sudden cardiac death. In mammals, the central circadian pacemaker, located in the suprachiasmatic nucleus of the hypothalamus, synchronizes cellular circadian clocks in the heart and many other tissues throughout the body. Cardiac ventricle explants maintain autonomous contractions and robust circadian oscillations of clock gene expression in culture. In the present study, we examined the relationship between intrinsic myocardial function and circadian rhythms in cultures from mouse heart. We cultured ventricular explants or dispersed cardiomyocytes from neonatal mice expressing a PER2::LUC bioluminescent reporter of circadian clock gene expression. We found that isoproterenol, a β-adrenoceptor agonist known to increase heart rate and contractility, also amplifies PER2 circadian rhythms in ventricular explants. We found robust, cell-autonomous PER2 circadian rhythms in dispersed cardiomyocytes. Single-cell rhythms were initially synchronized in ventricular explants but desynchronized in dispersed cells. In addition, we developed a method for long-term, simultaneous monitoring of clock gene expression, contraction rate, and basal intracellular Ca2+ level in cardiomyocytes using PER2::LUC in combination with GCaMP3, a genetically encoded fluorescent Ca2+ reporter. In contrast to robust PER2 circadian rhythms in cardiomyocytes, we detected no rhythms in contraction rate and only weak rhythms in basal Ca2+ level. In summary, we found that PER2 circadian rhythms of cardiomyocytes are cell-autonomous, amplified by adrenergic signaling, and synchronized by intercellular communication in ventricle explants, but we detected no robust circadian rhythms in contraction rate or basal Ca2+. PMID:27459195

  10. Overexpression of myocardin induces partial transdifferentiation of human‐induced pluripotent stem cell‐derived mesenchymal stem cells into cardiomyocytes

    PubMed Central

    Zhang, Jiao; Ho, Jenny Chung‐Yee; Chan, Yau‐Chi; Lian, Qizhou; Siu, Chung‐Wah; Tse, Hung‐Fat

    2014-01-01

    Abstract Mesenchymal stem cells (MSCs) derived from human‐induced pluripotent stem cells (iPSCs) show superior proliferative capacity and therapeutic potential than those derived from bone marrow (BM). Ectopic expression of myocardin further improved the therapeutic potential of BM‐MSCs in a mouse model of myocardial infarction. The aim was of this study was to assess whether forced myocardin expression in iPSC‐MSCs could further enhance their transdifferentiation to cardiomyocytes and improve their electrophysiological properties for cardiac regeneration. Myocardin was overexpressed in iPSC‐MSCs using viral vectors (adenovirus or lentivirus). The expression of smooth muscle cell and cardiomyocyte markers, and ion channel genes was examined by reverse transcription‐polymerase chain reaction (RT‐PCR), immunofluorescence staining and patch clamp. The conduction velocity of the neonatal rat ventricular cardiomyocytes cocultured with iPSC‐MSC monolayer was measured by multielectrode arrays recording plate. Myocardin induced the expression of α‐MHC, GATA4, α‐actinin, cardiac MHC, MYH11, calponin, and SM α‐actin, but not cTnT, β‐MHC, and MLC2v in iPSC‐MSCs. Overexpression of myocardin in iPSC‐MSC enhanced the expression of SCN9A and CACNA1C, but reduced that of KCa3.1 and Kir2.2 in iPSC‐MSCs. Moreover, BKCa, IKir, ICl, Ito and INa.TTX were detected in iPSC‐MSC with myocardin overexpression; while only BKCa, IKir, ICl, IKDR, and IKCa were noted in iPSC‐MSC transfected with green florescence protein. Furthermore, the conduction velocity of iPSC‐MSC was significantly increased after myocardin overexpression. Overexpression of myocardin in iPSC‐MSCs resulted in partial transdifferentiation into cardiomyocytes phenotype and improved the electrical conduction during integration with mature cardiomyocytes. PMID:24744906

  11. ATROPHIC CARDIOMYOCYTE SIGNALING IN HYPERTENSIVE HEART DISEASE

    PubMed Central

    Kamalov, German; Zhao, Wenyuan; Zhao, Tieqiang; Sun, Yao; Ahokas, Robert A.; Marion, Tony N.; Darazi, Fahed Al; Gerling, Ivan C.; Bhattacharya, Syamal K.; Weber, Karl T.

    2013-01-01

    Cardinal pathologic features of hypertensive heart disease (HHD) include not only hypertrophied cardiomyocytes and foci of scattered microscopic scarring, a footprint of prior necrosis, but also small myocytes ensnared by fibrillar collagen where disuse atrophy with protein degradation would be predicted. Whether atrophic signaling is concordant with the appearance of HHD and involves oxidative and endoplasmic reticulum (ER) stress remains unexplored. Herein, we examine these possibilities focusing on the left ventricle (LV) and cardiomyocytes harvested from hypertensive rats receiving 4 wks aldosterone/salt treatment (ALDOST) alone or together with ZnSO4, a nonvasoactive antioxidant, with the potential to attenuate atrophy and optimize hypertrophy. Compared to untreated age-/sex-/strain-matched controls, ALDOST was accompanied by: a) LV hypertrophy with preserved systolic function; b) concordant cardiomyocyte atrophy (<1000 μm2) found at sites bordering on fibrosis where they were re-expressing β-myosin heavy chain; and c) upregulation of ubiquitin ligases, MuRF1 and atrogin-1, and elevated 8-isoprostane and unfolded protein ER response with mRNA upregulation of stress markers. ZnSO4 cotreatment reduced lipid peroxidation, fibrosis and the number of atrophic myocytes, together with a further increase in cell area and width of atrophied and hypertrophied myocytes, and improved systolic function, but did not attenuate elevated blood pressure. We conclude that atrophic signaling, concordant with hypertrophy, occurs in the presence of a reparative fibrosis and induction of oxidative and ER stress at sites of scarring where myocytes are atrophied. ZnSO4 cotreatment in HHD with ALDOST attenuates the number of atrophic myocytes, optimizes size of atrophied and hypertrophied myocytes, and improves systolic function. PMID:24084216

  12. Atrophic cardiomyocyte signaling in hypertensive heart disease.

    PubMed

    Kamalov, German; Zhao, Wenyuan; Zhao, Tieqiang; Sun, Yao; Ahokas, Robert A; Marion, Tony N; Al Darazi, Fahed; Gerling, Ivan C; Bhattacharya, Syamal K; Weber, Karl T

    2013-12-01

    Cardinal pathological features of hypertensive heart disease (HHD) include not only hypertrophied cardiomyocytes and foci of scattered microscopic scarring, a footprint of prior necrosis, but also small myocytes ensnared by fibrillar collagen where disuse atrophy with protein degradation would be predicted. Whether atrophic signaling is concordant with the appearance of HHD and involves oxidative and endoplasmic reticulum (ER) stress remains unexplored. Herein, we examine these possibilities focusing on the left ventricle and cardiomyocytes harvested from hypertensive rats receiving 4 weeks aldosterone/salt treatment (ALDOST) alone or together with ZnSO₄, a nonvasoactive antioxidant, with the potential to attenuate atrophy and optimize hypertrophy. Compared with untreated age-/sex-/strain-matched controls, ALDOST was accompanied by (1) left ventricle hypertrophy with preserved systolic function; (2) concordant cardiomyocyte atrophy (<1000 μm²) found at sites bordering on fibrosis where they were reexpressing β-myosin heavy chain; and (3) upregulation of ubiquitin ligases, muscle RING-finger protein-1 and atrogin-1, and elevated 8-isoprostane and unfolded protein ER response with messenger RNA upregulation of stress markers. ZnSO₄ cotreatment reduced lipid peroxidation, fibrosis, and the number of atrophic myocytes, together with a further increase in cell area and width of atrophied and hypertrophied myocytes, and improved systolic function but did not attenuate elevated blood pressure. We conclude that atrophic signaling, concordant with hypertrophy, occurs in the presence of a reparative fibrosis and induction of oxidative and ER stress at sites of scarring where myocytes are atrophied. ZnSO₄ cotreatment in HHD with ALDOST attenuates the number of atrophic myocytes, optimizes size of atrophied and hypertrophied myocytes, and improves systolic function. PMID:24084216

  13. Acoustical sensing of cardiomyocyte cluster beating

    SciTech Connect

    Tymchenko, Nina; Kunze, Angelika; Dahlenborg, Kerstin; Svedhem, Sofia; Steel, Daniella

    2013-06-14

    Highlights: •An example of the application of QCM-D to live cell studies. •Detection of human pluripotent stem cell-derived cardiomyocyte cluster beating. •Clusters were studied in a thin liquid film and in a large liquid volume. •The QCM-D beating profile provides an individual fingerprint of the hPS-CMCs. -- Abstract: Spontaneously beating human pluripotent stem cell-derived cardiomyocytes clusters (CMCs) represent an excellent in vitro tool for studies of human cardiomyocyte function and for pharmacological cardiac safety assessment. Such testing typically requires highly trained operators, precision plating, or large cell quantities, and there is a demand for real-time, label-free monitoring of small cell quantities, especially rare cells and tissue-like structures. Array formats based on sensing of electrical or optical properties of cells are being developed and in use by the pharmaceutical industry. A potential alternative to these techniques is represented by the quartz crystal microbalance with dissipation monitoring (QCM-D) technique, which is an acoustic surface sensitive technique that measures changes in mass and viscoelastic properties close to the sensor surface (from nm to μm). There is an increasing number of studies where QCM-D has successfully been applied to monitor properties of cells and cellular processes. In the present study, we show that spontaneous beating of CMCs on QCM-D sensors can be clearly detected, both in the frequency and the dissipation signals. Beating rates in the range of 66–168 bpm for CMCs were detected and confirmed by simultaneous light microscopy. The QCM-D beating profile was found to provide individual fingerprints of the hPS-CMCs. The presented results point towards acoustical assays for evaluation cardiotoxicity.

  14. Mouse genetic differences in voluntary wheel running, adult hippocampal neurogenesis and learning on the multi-strain-adapted plus water maze

    PubMed Central

    Merritt, Jennifer; Rhodes, Justin S.

    2014-01-01

    Moderate levels of aerobic exercise broadly enhance cognition throughout the lifespan. One hypothesized contributing mechanism is increased adult hippocampal neurogenesis. Recently, we measured the effects of voluntary wheel running on adult hippocampal neurogenesis in 12 different mouse strains, and found increased neurogenesis in all strains, ranging from 2 to 5 fold depending on the strain. The purpose of this study was to determine the extent to which increased neurogenesis from wheel running is associated with enhanced performance on the water maze for 5 of the 12 strains, chosen based on their levels of neurogenesis observed in the previous study (C57BL/6J, 129S1/SvImJ, B6129SF1/J, DBA/2J, and B6D2F1/J). Mice were housed with or without a running wheels for 30 days then tested for learning and memory on the plus water maze, adapted for multiple strains, and rotarod test of motor performance. The first 10 days, animals were injected with BrdU to label dividing cells. After behavioral testing animals were euthanized to measure adult hippocampal neurogenesis using standard methods. Levels of neurogenesis depended on strain but all mice had a similar increase in neurogenesis in response to exercise. All mice acquired the water maze but performance depended on strain. Exercise improved water maze performance in all strains to a similar degree. Rotarod performance depended on strain. Exercise improved rotarod performance only in DBA/2J and B6D2F1/J mice. Taken together, results demonstrate that despite different levels of neurogenesis, memory performance and motor coordination in these mouse strains, all strains have the capacity to increase neurogenesis and improve learning on the water maze through voluntary wheel running. PMID:25435316

  15. Induction of Human iPSC-Derived Cardiomyocyte Proliferation Revealed by Combinatorial Screening in High Density Microbioreactor Arrays

    PubMed Central

    Titmarsh, Drew M.; Glass, Nick R.; Mills, Richard J.; Hidalgo, Alejandro; Wolvetang, Ernst J.; Porrello, Enzo R.; Hudson, James E.; Cooper-White, Justin J.

    2016-01-01

    Inducing cardiomyocyte proliferation in post-mitotic adult heart tissue is attracting significant attention as a therapeutic strategy to regenerate the heart after injury. Model animal screens have identified several candidate signalling pathways, however, it remains unclear as to what extent these pathways can be exploited, either individually or in combination, in the human system. The advent of human cardiac cells from directed differentiation of human pluripotent stem cells (hPSCs) now provides the ability to interrogate human cardiac biology in vitro, but it remains difficult with existing culture formats to simply and rapidly elucidate signalling pathway penetrance and interplay. To facilitate high-throughput combinatorial screening of candidate biologicals or factors driving relevant molecular pathways, we developed a high-density microbioreactor array (HDMA) – a microfluidic cell culture array containing 8100 culture chambers. We used HDMAs to combinatorially screen Wnt, Hedgehog, IGF and FGF pathway agonists. The Wnt activator CHIR99021 was identified as the most potent molecular inducer of human cardiomyocyte proliferation, inducing cell cycle activity marked by Ki67, and an increase in cardiomyocyte numbers compared to controls. The combination of human cardiomyocytes with the HDMA provides a versatile and rapid tool for stratifying combinations of factors for heart regeneration. PMID:27097795

  16. Induction of Human iPSC-Derived Cardiomyocyte Proliferation Revealed by Combinatorial Screening in High Density Microbioreactor Arrays.

    PubMed

    Titmarsh, Drew M; Glass, Nick R; Mills, Richard J; Hidalgo, Alejandro; Wolvetang, Ernst J; Porrello, Enzo R; Hudson, James E; Cooper-White, Justin J

    2016-01-01

    Inducing cardiomyocyte proliferation in post-mitotic adult heart tissue is attracting significant attention as a therapeutic strategy to regenerate the heart after injury. Model animal screens have identified several candidate signalling pathways, however, it remains unclear as to what extent these pathways can be exploited, either individually or in combination, in the human system. The advent of human cardiac cells from directed differentiation of human pluripotent stem cells (hPSCs) now provides the ability to interrogate human cardiac biology in vitro, but it remains difficult with existing culture formats to simply and rapidly elucidate signalling pathway penetrance and interplay. To facilitate high-throughput combinatorial screening of candidate biologicals or factors driving relevant molecular pathways, we developed a high-density microbioreactor array (HDMA) - a microfluidic cell culture array containing 8100 culture chambers. We used HDMAs to combinatorially screen Wnt, Hedgehog, IGF and FGF pathway agonists. The Wnt activator CHIR99021 was identified as the most potent molecular inducer of human cardiomyocyte proliferation, inducing cell cycle activity marked by Ki67, and an increase in cardiomyocyte numbers compared to controls. The combination of human cardiomyocytes with the HDMA provides a versatile and rapid tool for stratifying combinations of factors for heart regeneration. PMID:27097795

  17. Nop2 is expressed during proliferation of neural stem cells and in adult mouse and human brain.

    PubMed

    Kosi, Nina; Alić, Ivan; Kolačević, Matea; Vrsaljko, Nina; Jovanov Milošević, Nataša; Sobol, Margarita; Philimonenko, Anatoly; Hozák, Pavel; Gajović, Srećko; Pochet, Roland; Mitrečić, Dinko

    2015-02-01

    The nucleolar protein 2 gene encodes a protein specific for the nucleolus. It is assumed that it plays a role in the synthesis of ribosomes and regulation of the cell cycle. Due to its link to cell proliferation, higher expression of Nop2 indicates a worse tumor prognosis. In this work we used Nop2(gt1gaj) gene trap mouse strain. While lethality of homozygous animals suggested a vital role of this gene, heterozygous animals allowed the detection of expression of Nop2 in various tissues, including mouse brain. Histochemistry, immunohistochemistry and immunoelectron microscopy techniques, applied to a mature mouse brain, human brain and on mouse neural stem cells revealed expression of Nop2 in differentiating cells, including astrocytes, as well as in mature neurons. Nop2 was detected in various regions of mouse and human brain, mostly in large pyramidal neurons. In the human, Nop2 was strongly expressed in supragranular and infragranular layers of the somatosensory cortex and in layer III of the cingulate cortex. Also, Nop2 was detected in CA1 and the subiculum of the hippocampus. Subcellular analyses revealed predominant location of Nop2 within the dense fibrillar component of the nucleolus. To test if Nop2 expression correlates to cell proliferation occurring during tissue regeneration, we induced strokes in mice by middle cerebral artery occlusion. Two weeks after stroke, the number of Nop2/nestin double positive cells in the region affected by ischemia and the periventricular zone substantially increased. Our findings suggest a newly discovered role of Nop2 in both mature neurons and in cells possibly involved in the regeneration of nervous tissue. PMID:25481415

  18. HENMT1 and piRNA Stability Are Required for Adult Male Germ Cell Transposon Repression and to Define the Spermatogenic Program in the Mouse.

    PubMed

    Lim, Shu Ly; Qu, Zhi Peng; Kortschak, R Daniel; Lawrence, David M; Geoghegan, Joel; Hempfling, Anna-Lena; Bergmann, Martin; Goodnow, Christopher C; Ormandy, Christopher J; Wong, Lee; Mann, Jeff; Scott, Hamish S; Jamsai, Duangporn; Adelson, David L; O'Bryan, Moira K

    2015-10-01

    piRNAs are critical for transposable element (TE) repression and germ cell survival during the early phases of spermatogenesis, however, their role in adult germ cells and the relative importance of piRNA methylation is poorly defined in mammals. Using a mouse model of HEN methyltransferase 1 (HENMT1) loss-of-function, RNA-Seq and a range of RNA assays we show that HENMT1 is required for the 2' O-methylation of mammalian piRNAs. HENMT1 loss leads to piRNA instability, reduced piRNA bulk and length, and ultimately male sterility characterized by a germ cell arrest at the elongating germ cell phase of spermatogenesis. HENMT1 loss-of-function, and the concomitant loss of piRNAs, resulted in TE de-repression in adult meiotic and haploid germ cells, and the precocious, and selective, expression of many haploid-transcripts in meiotic cells. Precocious expression was associated with a more active chromatin state in meiotic cells, elevated levels of DNA damage and a catastrophic deregulation of the haploid germ cell gene expression. Collectively these results define a critical role for HENMT1 and piRNAs in the maintenance of TE repression in adult germ cells and setting the spermatogenic program. PMID:26496356

  19. HENMT1 and piRNA Stability Are Required for Adult Male Germ Cell Transposon Repression and to Define the Spermatogenic Program in the Mouse

    PubMed Central

    Lim, Shu Ly; Geoghegan, Joel; Hempfling, Anna-Lena; Bergmann, Martin; Goodnow, Christopher C.; Ormandy, Christopher J.; Wong, Lee; Mann, Jeff; Scott, Hamish S.; Jamsai, Duangporn; Adelson, David L.

    2015-01-01

    piRNAs are critical for transposable element (TE) repression and germ cell survival during the early phases of spermatogenesis, however, their role in adult germ cells and the relative importance of piRNA methylation is poorly defined in mammals. Using a mouse model of HEN methyltransferase 1 (HENMT1) loss-of-function, RNA-Seq and a range of RNA assays we show that HENMT1 is required for the 2’ O-methylation of mammalian piRNAs. HENMT1 loss leads to piRNA instability, reduced piRNA bulk and length, and ultimately male sterility characterized by a germ cell arrest at the elongating germ cell phase of spermatogenesis. HENMT1 loss-of-function, and the concomitant loss of piRNAs, resulted in TE de-repression in adult meiotic and haploid germ cells, and the precocious, and selective, expression of many haploid-transcripts in meiotic cells. Precocious expression was associated with a more active chromatin state in meiotic cells, elevated levels of DNA damage and a catastrophic deregulation of the haploid germ cell gene expression. Collectively these results define a critical role for HENMT1 and piRNAs in the maintenance of TE repression in adult germ cells and setting the spermatogenic program. PMID:26496356

  20. Characterization of Np95 expression in mouse brain from embryo to adult: A novel marker for proliferating neural stem/precursor cells

    PubMed Central

    Murao, Naoya; Matsuda, Taito; Noguchi, Hirofumi; Koseki, Haruhiko; Namihira, Masakazu; Nakashima, Kinichi

    2014-01-01

    Nuclear protein 95 KDa (Np95, also known as UHRF1 or ICBP90) plays an important role in maintaining DNA methylation of newly synthesized DNA strands by recruiting DNA methyltransferase 1 (DNMT1) during cell division. In addition, Np95 participates in chromatin remodeling by interacting with histone modification enzymes such as histone deacetylases. However, its expression pattern and function in the brain have not been analyzed extensively. We here investigated the expression pattern of Np95 in the mouse brain, from developmental to adult stages. In the fetal brain, Np95 is abundantly expressed at the midgestational stage, when a large number of neural stem/precursor cells (NS/PCs) exist. Interestingly, Np95 is expressed specifically in NS/PCs but not in differentiated cells such as neurons or glial cells. Furthermore, we demonstrate that Np95 is preferentially expressed in type 2a cells, which are highly proliferative NS/PCs in the dentate gyrus of the adult hippocampus. Moreover, the number of Np95-expressing cells increases in response to kainic acid administration or to voluntary running, which are known to enhance the proliferation of adult NS/PCs. These results suggest that Np95 participates in the process of proliferation and differentiation of NS/PCs, and that it should be a useful novel marker for proliferating NS/PCs, facilitating the analysis of the complex behavior of NS/PCs in the brain.

  1. Protease-activated receptor-1 negatively regulates proliferation of neural stem/progenitor cells derived from the hippocampal dentate gyrus of the adult mouse.

    PubMed

    Tanaka, Masayuki; Yoneyama, Masanori; Shiba, Tatsuo; Yamaguchi, Taro; Ogita, Kiyokazu

    2016-07-01

    Thrombin-activated protease-activated receptor (PAR)-1 regulates the proliferation of neural cells following brain injury. To elucidate the involvement of PAR-1 in the neurogenesis that occurs in the adult hippocampus, we examined whether PAR-1 regulated the proliferation of neural stem/progenitor cells (NPCs) derived from the murine hippocampal dentate gyrus. NPC cultures expressed PAR-1 protein and mRNA encoding all subtypes of PAR. Direct exposure of the cells to thrombin dramatically attenuated the cell proliferation without causing cell damage. This thrombin-induced attenuation was almost completely abolished by the PAR antagonist RWJ 56110, as well as by dabigatran and 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), which are selective and non-selective thrombin inhibitors, respectively. Expectedly, the PAR-1 agonist peptide (AP) SFLLR-NH2 also attenuated the cell proliferation. The cell proliferation was not affected by the PAR-1 negative control peptide RLLFT-NH2, which is an inactive peptide for PAR-1. Independently, we determined the effect of in vivo treatment with AEBSF or AP on hippocampal neurogenesis in the adult mouse. The administration of AEBSF, but not that of AP, significantly increased the number of newly-generated cells in the hippocampal subgranular zone. These data suggest that PAR-1 negatively regulated adult neurogenesis in the hippocampus by inhibiting the proliferative activity of the NPCs. PMID:27426918

  2. Long-term treatment with L-DOPA or pramipexole affects adult neurogenesis and corresponding non-motor behavior in a mouse model of Parkinson's disease.

    PubMed

    Chiu, W-H; Depboylu, C; Hermanns, G; Maurer, L; Windolph, A; Oertel, W H; Ries, V; Höglinger, G U

    2015-08-01

    Non-motor symptoms such as hyposmia and depression are often observed in Parkinson's disease (PD) and can precede the onset of motor symptoms for years. The underlying pathological alterations in the brain are not fully understood so far. Dysregulation of adult neurogenesis in the dentate gyrus of the hippocampus and the olfactory bulb has been recently suggested to be implicated in non-motor symptoms of PD. However, there is so far no direct evidence to support the relationship of non-motor symptoms and the modulation of adult neurogenesis following dopamine depletion and/or dopamine replacement. In this study, we investigated the long-term effects of l-DOPA and pramipexole, a dopamine agonist, in a mouse model of bilateral intranigral 6-OHDA lesion, in order to assess the impact of adult neurogenesis on non-motor behavior. We found that l-DOPA and pramipexole can normalize decreased neurogenesis in the hippocampal dentate gyrus and the periglomerular layer of the olfactory bulb caused by a 6-OHDA lesion. Interestingly, pramipexole showed an antidepressant and anxiolytic effect in the forced swim test and social interaction test. However, there was no significant change in learning and memory function after dopamine depletion and dopamine replacement, respectively. PMID:25839898

  3. Acoustical sensing of cardiomyocyte cluster beating.

    PubMed

    Tymchenko, Nina; Kunze, Angelika; Dahlenborg, Kerstin; Svedhem, Sofia; Steel, Daniella

    2013-06-14

    Spontaneously beating human pluripotent stem cell-derived cardiomyocytes clusters (CMCs) represent an excellent in vitro tool for studies of human cardiomyocyte function and for pharmacological cardiac safety assessment. Such testing typically requires highly trained operators, precision plating, or large cell quantities, and there is a demand for real-time, label-free monitoring of small cell quantities, especially rare cells and tissue-like structures. Array formats based on sensing of electrical or optical properties of cells are being developed and in use by the pharmaceutical industry. A potential alternative to these techniques is represented by the quartz crystal microbalance with dissipation monitoring (QCM-D) technique, which is an acoustic surface sensitive technique that measures changes in mass and viscoelastic properties close to the sensor surface (from nm to μm). There is an increasing number of studies where QCM-D has successfully been applied to monitor properties of cells and cellular processes. In the present study, we show that spontaneous beating of CMCs on QCM-D sensors can be clearly detected, both in the frequency and the dissipation signals. Beating rates in the range of 66-168 bpm for CMCs were detected and confirmed by simultaneous light microscopy. The QCM-D beating profile was found to provide individual fingerprints of the hPS-CMCs. The presented results point towards acoustical assays for evaluation cardiotoxicity. PMID:23643814

  4. The transcriptome responses of cardiomyocyte exposed to hypothermia.

    PubMed

    Zhang, Jian; Xue, Xiaodong; Xu, Yinli; Zhang, Yuji; Li, Zhi; Wang, Huishan

    2016-06-01

    Hypothermia has positive and negative consequences on the body. Hypothermia depresses myocardial contraction, conduction, and metabolic rate in the heart. However, little is known about the underlying molecular mechanisms. Herein, we compared the gene expression of human adult ventricular cardiomyocytes (AC16) under hypothermia to find differences between different temperatures, and elucidate the candidate genes that may play important roles in the response to hypothermia. A total of 2413 differentially expressed genes (DEGs) were identified by microarray hybridization, which provided abundant data for further analysis. Gene Ontology (GO) enrichment analysis revealed that genes related to transcription, and protein and lipid metabolism were significantly enriched. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEGs were significantly enriched in TGF-β pathway and cytokine-cytokine receptor interaction, which may play important roles in changes affected by hypothermia. A set of transcription factors (TFs) (CPBP, Churchill, NF-AT1, GKLF, SRY, ZNF333, ING4, myogenin, DRI1 and CRX) was recognized to be the functional layer of key nodes, which mapped the signal of hypothermia to transcriptome. The identified DEGs, pathways and predicted TFs could facilitate further investigations of the detailed molecular mechanisms. PMID:27039159

  5. Transcriptome analyses of adult mouse brain reveal enrichment of lncRNAs in specific brain regions and neuronal populations

    PubMed Central

    Kadakkuzha, Beena M.; Liu, Xin-An; McCrate, Jennifer; Shankar, Gautam; Rizzo, Valerio; Afinogenova, Alina; Young, Brandon; Fallahi, Mohammad; Carvalloza, Anthony C.; Raveendra, Bindu; Puthanveettil, Sathyanarayanan V.

    2015-01-01

    Despite the importance of the long non-coding RNAs (lncRNAs) in regulating biological functions, the expression profiles of lncRNAs in the sub-regions of the mammalian brain and neuronal populations remain largely uncharacterized. By analyzing RNASeq datasets, we demonstrate region specific enrichment of populations of lncRNAs and mRNAs in the mouse hippocampus and pre-frontal cortex (PFC), the two major regions of the brain involved in memory storage and neuropsychiatric disorders. We identified 2759 lncRNAs and 17,859 mRNAs in the hippocampus and 2561 lncRNAs and 17,464 mRNAs expressed in the PFC. The lncRNAs identified correspond to ~14% of the transcriptome of the hippocampus and PFC and ~70% of the lncRNAs annotated in the mouse genome (NCBIM37) and are localized along the chromosomes as varying numbers of clusters. Importantly, we also found that a few of the tested lncRNA-mRNA pairs that share a genomic locus display specific co-expression in a region-specific manner. Furthermore, we find that sub-regions of the brain and specific neuronal populations have characteristic lncRNA expression signatures. These results reveal an unexpected complexity of the lncRNA expression in the mouse brain. PMID:25798087

  6. On-Going Frontal Alpha Rhythms Are Dominant in Passive State and Desynchronize in Active State in Adult Gray Mouse Lemurs

    PubMed Central

    Rahman, Anisur; Lamberty, Yves; Bordet, Regis; Richardson, Jill C.; Forloni, Gianluigi; Drinkenburg, Wilhelmus; Lopez, Susanna; Aujard, Fabienne; Babiloni, Claudio; Pifferi, Fabien

    2015-01-01

    The gray mouse lemur (Microcebus murinus) is considered a useful primate model for translational research. In the framework of IMI PharmaCog project (Grant Agreement n°115009, www.pharmacog.org), we tested the hypothesis that spectral electroencephalographic (EEG) markers of motor and locomotor activity in gray mouse lemurs reflect typical movement-related desynchronization of alpha rhythms (about 8–12 Hz) in humans. To this aim, EEG (bipolar electrodes in frontal cortex) and electromyographic (EMG; bipolar electrodes sutured in neck muscles) data were recorded in 13 male adult (about 3 years) lemurs. Artifact-free EEG segments during active state (gross movements, exploratory movements or locomotor activity) and awake passive state (no sleep) were selected on the basis of instrumental measures of animal behavior, and were used as an input for EEG power density analysis. Results showed a clear peak of EEG power density at alpha range (7–9 Hz) during passive state. During active state, there was a reduction in alpha power density (8–12 Hz) and an increase of power density at slow frequencies (1–4 Hz). Relative EMG activity was related to EEG power density at 2–4 Hz (positive correlation) and at 8–12 Hz (negative correlation). These results suggest for the first time that the primate gray mouse lemurs and humans may share basic neurophysiologic mechanisms of synchronization of frontal alpha rhythms in awake passive state and their desynchronization during motor and locomotor activity. These EEG markers may be an ideal experimental model for translational basic (motor science) and applied (pharmacological and non-pharmacological interventions) research in Neurophysiology. PMID:26618512

  7. On-Going Frontal Alpha Rhythms Are Dominant in Passive State and Desynchronize in Active State in Adult Gray Mouse Lemurs.

    PubMed

    Infarinato, Francesco; Rahman, Anisur; Del Percio, Claudio; Lamberty, Yves; Bordet, Regis; Richardson, Jill C; Forloni, Gianluigi; Drinkenburg, Wilhelmus; Lopez, Susanna; Aujard, Fabienne; Babiloni, Claudio; Pifferi, Fabien

    2015-01-01

    The gray mouse lemur (Microcebus murinus) is considered a useful primate model for translational research. In the framework of IMI PharmaCog project (Grant Agreement n°115009, www.pharmacog.org), we tested the hypothesis that spectral electroencephalographic (EEG) markers of motor and locomotor activity in gray mouse lemurs reflect typical movement-related desynchronization of alpha rhythms (about 8-12 Hz) in humans. To this aim, EEG (bipolar electrodes in frontal cortex) and electromyographic (EMG; bipolar electrodes sutured in neck muscles) data were recorded in 13 male adult (about 3 years) lemurs. Artifact-free EEG segments during active state (gross movements, exploratory movements or locomotor activity) and awake passive state (no sleep) were selected on the basis of instrumental measures of animal behavior, and were used as an input for EEG power density analysis. Results showed a clear peak of EEG power density at alpha range (7-9 Hz) during passive state. During active state, there was a reduction in alpha power density (8-12 Hz) and an increase of power density at slow frequencies (1-4 Hz). Relative EMG activity was related to EEG power density at 2-4 Hz (positive correlation) and at 8-12 Hz (negative correlation). These results suggest for the first time that the primate gray mouse lemurs and humans may share basic neurophysiologic mechanisms of synchronization of frontal alpha rhythms in awake passive state and their desynchronization during motor and locomotor activity. These EEG markers may be an ideal experimental model for translational basic (motor science) and applied (pharmacological and non-pharmacological interventions) research in Neurophysiology. PMID:26618512

  8. Electrical stimulation of primary neonatal rat ventricular cardiomyocytes using pacemakers.

    PubMed

    Martherus, Ruben S R M; Zeijlemaker, Volkert A; Ayoubi, Torik A Y

    2010-01-01

    The study of gene regulation in cardiac myocytes requires a reliable in vitro model. However, monolayer cultures used for this purpose are typically not exposed to electrical stimulation, though this has been shown to strongly affect cardiomyocyte gene expression. Based on pacemakers for clinical use, we developed an easy-to-use portable system that allows the user to perform electro-stimulation of cardiomyocyte cultures in standard tissue incubators without the need for bulky equipment. In addition, we present a refined protocol for culturing high-purity cardiomyocyte cultures with excellent contractile properties for a wide variety of applications. PMID:20078430

  9. Mouse adenovirus type 1 causes a fatal hemorrhagic encephalomyelitis in adult C57BL/6 but not BALB/c mice.

    PubMed Central

    Guida, J D; Fejer, G; Pirofski, L A; Brosnan, C F; Horwitz, M S

    1995-01-01

    Mouse adenovirus type 1 (MAV-1) produces a lethal disease in newborn or suckling mice characterized by infectious virus and viral lesions in multiple organs. Previous reports of MAV-1 infection of adult mice generally described serologic evidence of infection without morbidity or mortality. However, our current results demonstrate that MAV-1 causes a fatal illness in adult C57BL/6(B6) mice (50% lethal dose, [LD50], 10(3.0) PFU) but not in adult BALB/c mice at all of the doses tested (LD50, > or = 10(5.0) PFU). Adult (BALB/c x B6)F1 mice were intermediately susceptible (LD50, 10(4.5) PFU). Clinically, the sensitive B6 mice showed symptoms of acute central nervous system (CNS) disease, including tremors, seizures, ataxia, and paralysis. Light microscopic examination of CNS tissue from the B6 animals revealed petechial hemorrhages, edema, neovascularization, and mild inflammation in the brain and spinal cord. Analysis by electron microscopy showed evidence of inflammation, such as activated microglia, as well as swollen astrocytic endfeet and perivascular lipid deposition indicative of blood-brain barrier dysfunction. Outside of the CNS, the only significant pathological findings were foci of cytolysis in the splenic white pulp. Assessment of viral replication from multiple tissues was performed by using RNase protection assays with an antisense MAV-1 early region 1a probe. The greatest amounts of viral mRNA in MAV-1-infected B6 animals were located in the brain and spinal cord. Less viral message was detected in the spleen, lungs, and heart. No viral mRNA was detected in BALB/c mouse tissue, with the exception of low levels in the heart. Viral titers of organ tissues were also determined and were concordant with RNase protection findings on the brain and spinal cord but failed to demonstrate significant infectious virus in additional organs. Our experiments demonstrate that MAV-1 has a striking tropism for the CNS that is strain dependent, and this provides an

  10. Adult mouse motor units develop almost all of their force in the subprimary range: a new all-or-none strategy for force recruitment?

    PubMed

    Manuel, Marin; Heckman, C J

    2011-10-19

    Classical studies of the mammalian neuromuscular system have shown an impressive adaptation match between the intrinsic properties of motoneurons and the contractile properties of their motor units. In these studies, the rate at which motoneurons start to fire repetitively corresponds to the rate at which individual twitches start to sum, and the firing rate increases linearly with the amount of excitation ("primary range") up to the point where the motor unit develops its maximal force. This allows for the gradation of the force produced by a motor unit by rate modulation. In adult mouse motoneurons, however, we recently described a regime of firing ("subprimary range") that appears at lower excitation than what is required for the primary range, a finding that might challenge the classical conception. To investigate the force production of mouse motor units, we simultaneously recorded, for the first time, the motoneuron discharge elicited by intracellular ramps of current and the force developed by its motor unit. We showed that the motor unit developed nearly its maximal force during the subprimary range. This was found to be the case regardless of the input resistance of the motoneuron, the contraction speed, or the tetanic force of the motor unit. Our work suggests that force modulation in small mammals mainly relies on the number of motor units that are recruited rather than on rate modulation of individual motor units. PMID:22016552

  11. Glial cell line-derived neurotrophic factor alters the growth characteristics and genomic imprinting of mouse multipotent adult germline stem cells

    SciTech Connect

    Jung, Yoon Hee

    2010-03-10

    This study evaluated the essentiality of glial cell line-derived neurotrophic factor (GDNF) for in vitro culture of established mouse multipotent adult germline stem (maGS) cell lines by culturing them in the presence of GDNF, leukemia inhibitory factor (LIF) or both. We show that, in the absence of LIF, GDNF slows the proliferation of maGS cells and result in smaller sized colonies without any change in distribution of cells to different cell-cycle stages, expression of pluripotency genes and in vitro differentiation potential. Furthermore, in the absence of LIF, GDNF increased the expression of male germ-line genes and repopulated the empty seminiferous tubule of W/W{sup v} mutant mouse without the formation of teratoma. GDNF also altered the genomic imprinting of Igf2, Peg1, and H19 genes but had no effect on DNA methylation of Oct4, Nanog and Stra8 genes. However, these effects of GDNF were masked in the presence of LIF. GDNF also did not interfere with the multipotency of maGS cells if they are cultured in the presence of LIF. In conclusion, our results suggest that, in the absence of LIF, GDNF alters the growth characteristics of maGS cells and partially impart them some of the germline stem (GS) cell-like characteristics.

  12. Systems Genetics Analysis of a Recombinant Inbred Mouse Cell Culture Panel Reveals Wnt Pathway Member Lrp6 as a Regulator of Adult Hippocampal Precursor Cell Proliferation.

    PubMed

    Kannan, Suresh; Nicola, Zeina; Overall, Rupert W; Ichwan, Muhammad; Ramírez-Rodríguez, Gerardo; N Grzyb, Anna; Patone, Giannino; Saar, Kathrin; Hübner, Norbert; Kempermann, Gerd

    2016-03-01

    In much animal research, genetic variation is rather avoided than used as a powerful tool to identify key regulatory genes in complex phenotypes. Adult hippocampal neurogenesis is one such highly complex polygenic trait, for which the understanding of the molecular basis is fragmented and incomplete, and for which novel genetic approaches are needed. In this study, we aimed at marrying the power of the BXD panel, a mouse genetic reference population, with the flexibility of a cell culture model of adult neural precursor proliferation and differentiation. We established adult-derived hippocampal precursor cell cultures from 20 strains of the BXD panel, including the parental strains C57BL/6J and DBA/2J. The rates of cell proliferation and neuronal differentiation were measured, and transcriptional profiles were obtained from proliferating cultures. Together with the published genotypes of all lines, these data allowed a novel systems genetics analysis combining quantitative trait locus analysis with transcript expression correlation at a cellular level to identify genes linked with the differences in proliferation. In a proof-of-principle analysis, we identified Lrp6, the gene encoding the coreceptor to Frizzled in the Wnt pathway, as a potential negative regulator of precursor proliferation. Overexpression and siRNA silencing confirmed the regulatory role of Lrp6. As well as adding to our knowledge of the pathway surrounding Wnt in adult hippocampal neurogenesis, this finding allows the new appreciation of a negative regulator within this system. In addition, the resource and associated methodology will allow the integration of regulatory mechanisms at a systems level. Stem Cells 2016;34:674-684. PMID:26840599

  13. Specific Distribution of the Autophagic Protein GABARAPL1/GEC1 in the Developing and Adult Mouse Brain and Identification of Neuronal Populations Expressing GABARAPL1/GEC1

    PubMed Central

    Le Grand, Jaclyn Nicole; Bon, Karine; Fraichard, Annick; Zhang, Jianhua; Jouvenot, Michèle; Risold, Pierre-Yves; Boyer-Guittaut, Michaël; Delage-Mourroux, Régis

    2013-01-01

    Macroautophagy is a highly conserved cellular degradation process, regulated by autophagy-related (atg) factors, in which a double membrane autophagosome engulfs cytoplasmic components to target them for degradation. In yeast, the Atg8 protein is indispensable for autophagosome formation. In mammals, this is complicated by the presence of six Atg8 homologues grouped into the GABARAP and MAP1LC3 subfamilies. Although these proteins share a high similarity, their transcript expression, regulation and protein interactions differ, suggesting they may display individual properties and specific functions. GABARAPL1/GEC1 is a member of the GABARAP subfamily and its mRNA is the most highly expressed Atg8 homologue in the central nervous system. Consequently, we performed an in depth study of GABARAPL1 distribution in the developing and adult murine brain. Our results show that GABARAPL1 brain expression is visible as early as embryonic day 11 and progressively increases to a maximum level in the adult. Immunohistochemical staining was detected in both fibers and immature neurons in embryos but was restrained to neurons in adult tissue. By E17, intense punctate-like structures were visible and these accumulated in cortical primary neurons treated with the autophagosome/lysosome fusion inhibitor Bafilomycin A1 (Baf A1), suggesting that they represent autophagosomes. Finally, GABARAPL1 expression was particularly intense in motoneurons in the embryo and in neurons involved in somatomotor and neuroendocrine functions in the adult, particularly in the substantia nigra pars compacta, a region affected in Parkinson's disease. Our study of cerebral GABARAPL1 protein expression provides insight into its role in the development and homeostasis of the mouse brain. PMID:23690988

  14. Measuring fast calcium fluxes in cardiomyocytes.

    PubMed

    Golebiewska, Urszula; Scarlata, Suzanne

    2011-01-01

    Cardiomyocytes have multiple Ca(2+) fluxes of varying duration that work together to optimize function (1,2). Changes in Ca(2+) activity in response to extracellular agents is predominantly regulated by the phospholipase Cβ- Gα(q;) pathway localized on the plasma membrane which is stimulated by agents such as acetylcholine (3,4). We have recently found that plasma membrane protein domains called caveolae(5,6) can entrap activated Gα(q;)(7). This entrapment has the effect of stabilizing the activated state of Gα(q;) and resulting in prolonged Ca(2+) signals in cardiomyocytes and other cell types(8). We uncovered this surprising result by measuring dynamic calcium responses on a fast scale in living cardiomyocytes. Briefly, cells are loaded with a fluorescent Ca(2+) indicator. In our studies, we used Ca(2+) Green (Invitrogen, Inc.) which exhibits an increase in fluorescence emission intensity upon binding of calcium ions. The fluorescence intensity is then recorded for using a line-scan mode of a laser scanning confocal microscope. This method allows rapid acquisition of the time course of fluorescence intensity in pixels along a selected line, producing several hundreds of time traces on the microsecond time scale. These very fast traces are transferred into excel and then into Sigmaplot for analysis, and are compared to traces obtained for electronic noise, free dye, and other controls. To dissect Ca(2+) responses of different flux rates, we performed a histogram analysis that binned pixel intensities with time. Binning allows us to group over 500 traces of scans and visualize the compiled results spatially and temporally on a single plot. Thus, the slow Ca(2+) waves that are difficult to discern when the scans are overlaid due to different peak placement and noise, can be readily seen in the binned histograms. Very fast fluxes in the time scale of the measurement show a narrow distribution of intensities in the very short time bins whereas longer Ca(2+) waves

  15. Mechanical Stretch Inhibits MicroRNA499 via p53 to Regulate Calcineurin-A Expression in Rat Cardiomyocytes

    PubMed Central

    Chua, Su-Kiat; Wang, Bao-Wei; Lien, Li-Ming; Lo, Huey-Ming; Chiu, Chiung-Zuan; Shyu, Kou-Gi

    2016-01-01

    Background MicroRNAs play an important role in cardiac remodeling. MicroRNA 499 (miR499) is highly enriched in cardiomyocytes and targets the gene for Calcineurin A (CnA), which is associated with mitochondrial fission and apoptosis. The mechanism regulating miR499 in stretched cardiomyocytes and in volume overloaded heart is unclear. We sought to investigate the mechanism regulating miR499 and CnA in stretched cardiomyocytes and in volume overload-induced heart failure. Methods & Results Rat cardiomyocytes grown on a flexible membrane base were stretched via vacuum to 20% of maximum elongation at 60 cycles/min. An in vivo model of volume overload with aorta-caval shunt in adult rats was used to study miR499 expression. Mechanical stretch downregulated miR499 expression, and enhanced the expression of CnA protein and mRNA after 12 hours of stretch. Expression of CnA and calcineurin activity was suppressed with miR499 overexpression; whereas, expression of dephosphorylated dynamin-related protein 1 (Drp1) was suppressed with miR499 overexpression and CnA siRNA. Adding p53 siRNA reversed the downregulation of miR499 when stretched. A gel shift assay and promoter-activity assay demonstrated that stretch increased p53 DNA binding activity but decreased miR499 promoter activity. When the miR499 promoter p53-binding site was mutated, the inhibition of miR499 promoter activity with stretch was reversed. The in vivo aorta-caval shunt also showed downregulated myocardial miR499 and overexpression of miR499 suppressed CnA and cellular apoptosis. Conclusion The miR499-controlled apoptotic pathway involving CnA and Drp1 in stretched cardiomyocytes may be regulated by p53 through the transcriptional regulation of miR499. PMID:26859150

  16. Newborn Hypoxia/Anoxia Inhibits Cardiomyocyte Proliferation and Decreases Cardiomyocyte Endowment in the Developing Heart: Role of Endothelin-1

    PubMed Central

    Paradis, Alexandra N.; Gay, Maresha S.; Wilson, Christopher G.; Zhang, Lubo

    2015-01-01

    In the developing heart, cardiomyocytes undergo terminal differentiation during a critical window around birth. Hypoxia is a major stress to preterm infants, yet its effect on the development and maturation of the heart remains unknown. We tested the hypothesis in a rat model that newborn anoxia accelerates cardiomyocyte terminal differentiation and results in reduced cardiomyocyte endowment in the developing heart via an endothelin-1-dependent mechanism. Newborn rats were exposed to anoxia twice daily from postnatal day 1 to 3, and hearts were isolated and studied at postnatal day 4 (P4), 7 (P7), and 14 (P14). Anoxia significantly increased HIF-1α protein expression and pre-proET-1 mRNA abundance in P4 neonatal hearts. Cardiomyocyte proliferation was significantly decreased by anoxia in P4 and P7, resulting in a significant reduction of cardiomyocyte number per heart weight in the P14 neonates. Furthermore, the expression of cyclin D2 was significantly decreased due to anoxia, while p27 expression was increased. Anoxia has no significant effect on cardiomyocyte binucleation or myocyte size. Consistently, prenatal hypoxia significantly decreased cardiomyocyte proliferation but had no effect on binucleation in the fetal heart. Newborn administration of PD156707, an ETA-receptor antagonist, significantly increased cardiomyocyte proliferation at P4 and cell size at P7, resulting in an increase in the heart to body weight ratio in P7 neonates. In addition, PD156707 abrogated the anoxia-mediated effects. The results suggest that hypoxia and anoxia via activation of endothelin-1 at the critical window of heart development inhibits cardiomyocyte proliferation and decreases myocyte endowment in the developing heart, which may negatively impact cardiac function later in life. PMID:25692855

  17. Uniform Action Potential Repolarization within the Sarcolemma of In Situ Ventricular Cardiomyocytes

    PubMed Central

    Bu, Guixue; Adams, Heather; Berbari, Edward J.; Rubart, Michael

    2009-01-01

    Previous studies have speculated, based on indirect evidence, that the action potential at the transverse (t)-tubules is longer than at the surface membrane in mammalian ventricular cardiomyocytes. To date, no technique has enabled recording of electrical activity selectively at the t-tubules to directly examine this hypothesis. We used confocal line-scan imaging in conjunction with the fast response voltage-sensitive dyes ANNINE-6 and ANNINE-6plus to resolve action potential-related changes in fractional dye fluorescence (ΔF/F) at the t-tubule and surface membranes of in situ mouse ventricular cardiomyocytes. Peak ΔF/F during action potential phase 0 depolarization averaged −21% for both dyes. The shape and time course of optical action potentials measured with the water-soluble ANNINE-6plus were indistinguishable from those of action potentials recorded with intracellular microelectrodes in the absence of the dye. In contrast, optical action potentials measured with the water-insoluble ANNINE-6 were significantly prolonged compared to the electrical recordings obtained from dye-free hearts, suggesting electrophysiological effects of ANNINE-6 and/or its solvents. With either dye, the kinetics of action potential-dependent changes in ΔF/F during repolarization were found to be similar at the t-tubular and surface membranes. This study provides what to our knowledge are the first direct measurements of t-tubule electrical activity in ventricular cardiomyocytes, which support the concept that action potential duration is uniform throughout the sarcolemma of individual cells. PMID:19289075

  18. O-GlcNAcylation, Novel Post-Translational Modification Linking Myocardial Metabolism and Cardiomyocyte Circadian Clock*

    PubMed Central

    Durgan, David J.; Pat, Betty M.; Laczy, Boglarka; Bradley, Jerry A.; Tsai, Ju-Yun; Grenett, Maximiliano H.; Ratcliffe, William F.; Brewer, Rachel A.; Nagendran, Jeevan; Villegas-Montoya, Carolina; Zou, Chenhang; Zou, Luyun; Johnson, Russell L.; Dyck, Jason R. B.; Bray, Molly S.; Gamble, Karen L.; Chatham, John C.; Young, Martin E.

    2011-01-01

    The cardiomyocyte circadian clock directly regulates multiple myocardial functions in a time-of-day-dependent manner, including gene expression, metabolism, contractility, and ischemic tolerance. These same biological processes are also directly influenced by modification of proteins by monosaccharides of O-linked β-N-acetylglucosamine (O-GlcNAc). Because the circadian clock and protein O-GlcNAcylation have common regulatory roles in the heart, we hypothesized that a relationship exists between the two. We report that total cardiac protein O-GlcNAc levels exhibit a diurnal variation in mouse hearts, peaking during the active/awake phase. Genetic ablation of the circadian clock specifically in cardiomyocytes in vivo abolishes diurnal variations in cardiac O-GlcNAc levels. These time-of-day-dependent variations appear to be mediated by clock-dependent regulation of O-GlcNAc transferase and O-GlcNAcase protein levels, glucose metabolism/uptake, and glutamine synthesis in an NAD-independent manner. We also identify the clock component Bmal1 as an O-GlcNAc-modified protein. Increasing protein O-GlcNAcylation (through pharmacological inhibition of O-GlcNAcase) results in diminished Per2 protein levels, time-of-day-dependent induction of bmal1 gene expression, and phase advances in the suprachiasmatic nucleus clock. Collectively, these data suggest that the cardiomyocyte circadian clock increases protein O-GlcNAcylation in the heart during the active/awake phase through coordinated regulation of the hexosamine biosynthetic pathway and that protein O-GlcNAcylation in turn influences the timing of the circadian clock. PMID:22069332

  19. The α11 integrin mediates fibroblast-extracellular matrix-cardiomyocyte interactions in health and disease.

    PubMed

    Civitarese, Robert A; Talior-Volodarsky, Ilana; Desjardins, Jean-Francois; Kabir, Golam; Switzer, Jennifer; Mitchell, Melissa; Kapus, Andras; McCulloch, Christopher A; Gullberg, Donald; Connelly, Kim A

    2016-07-01

    Excessive cardiac interstitial fibrosis impairs normal cardiac function. We have shown that the α11β1 (α11) integrin mediates fibrotic responses to glycated collagen in rat myocardium by a pathway involving transforming growth factor-β. Little is known of the role of the α11 integrin in the developing mammalian heart. Therefore, we examined the impact of deletion of the α11 integrin in wild-type mice and in mice treated with streptozotocin (STZ) to elucidate the role of the α11 integrin in normal cardiac homeostasis and in the pathogenesis of diabetes-related fibrosis. As anticipated, cardiac fibrosis was reduced in α11 integrin knockout mice (α11(-/-); C57BL/6 background) treated with STZ compared with STZ-treated wild-type mice (P < 0.05). Unexpectedly, diastolic function was impaired in both vehicle and STZ-treated α11(-/-) mice, as shown by the decreased minimum rate of pressure change and prolonged time constant of relaxation in association with increased end-diastolic pressure (all P < 0.05 compared with wild-type mice). Accordingly, we examined the phenotype of untreated α11(-/-) mice, which demonstrated a reduced cardiomyocyte cross-sectional cell area and myofibril thickness (all P < 0.05 compared with wild-type mice) and impaired myofibril arrangement. Immunostaining for desmin and connexin 43 showed abnormal intermediate filament organization at intercalated disks and impaired gap-junction development. Overall, deletion of the α11 integrin attenuates cardiac fibrosis in the mammalian mouse heart and reduces ECM formation as a result of diabetes. Furthermore, α11 integrin deletion impairs cardiac function and alters cardiomyocyte morphology. These findings shed further light on the poorly understood interaction between the fibroblast-cardiomyocyte and the ECM. PMID:27199132

  20. Optogenetic Control of Cardiomyocytes via Viral Delivery

    PubMed Central

    Ambrosi, Christina M.; Entcheva, Emilia

    2014-01-01

    Optogenetics is an emerging technology for the manipulation and control of excitable tissues, such as the brain and heart. As this technique requires the genetic modification of cells in order to inscribe light sensitivity, for cardiac applications, here we describe the process through which neonatal rat ventricular myocytes are virally infected in vitro with channelrhodopsin-2 (ChR2). We also describe in detail the procedure for quantitatively determining the optimal viral dosage, including instructions for patterning gene expression in multicellular cardiomyocyte preparations (cardiac syncytia) to simulate potential in vivo transgene distributions. Finally, we address optical actuation of ChR2-transduced cells and means to measure their functional response to light. PMID:25070340

  1. Calcium and mitochondrial metabolism in ceramide-induced cardiomyocyte death

    PubMed Central

    Parra, Valentina; Moraga, Francisco; Kuzmicic, Jovan; López-Crisosto, Camila; Troncoso, Rodrigo; Torrealba, Natalia; Criollo, Alfredo; Díaz-Elizondo, Jessica; Rothermel, Beverly A.; Quest, Andrew F.G.; Lavandero, Sergio

    2014-01-01

    Ceramides are important intermediates in the biosynthesis and degradation of sphingolipids that regulatenumerous cellular processes, including cell cycle progression, cell growth, differentiation and death. In cardiomyocytes, ceramides induce apoptosis by decreasing mitochondrial membrane potential and promoting cytochrome-c release. Ca2+ overload is a common feature of all types of cell death. The aim of this study was to determine the effect of ceramides on cytoplasmic Ca2+ levels, mitochondrial function and cardiomyocyte death. Our data show that C2-ceramide induces apoptosis and necrosis in cultured cardiomyocytes by a mechanism involving increased Ca2+ influx, mitochondrial network fragmentation and loss of the mitochondrial Ca2+ buffer capacity. These biochemical events increase cytosolic Ca2+ levels and trigger cardiomyocyte death via the activation of calpains. PMID:23602992

  2. Calcium and mitochondrial metabolism in ceramide-induced cardiomyocyte death.

    PubMed

    Parra, Valentina; Moraga, Francisco; Kuzmicic, Jovan; López-Crisosto, Camila; Troncoso, Rodrigo; Torrealba, Natalia; Criollo, Alfredo; Díaz-Elizondo, Jessica; Rothermel, Beverly A; Quest, Andrew F G; Lavandero, Sergio

    2013-08-01

    Ceramides are important intermediates in the biosynthesis and degradation of sphingolipids that regulate numerous cellular processes, including cell cycle progression, cell growth, differentiation and death. In cardiomyocytes, ceramides induce apoptosis by decreasing mitochondrial membrane potential and promoting cytochrome-c release. Ca(2+) overload is a common feature of all types of cell death. The aim of this study was to determine the effect of ceramides on cytoplasmic Ca(2+) levels, mitochondrial function and cardiomyocyte death. Our data show that C2-ceramide induces apoptosis and necrosis in cultured cardiomyocytes by a mechanism involving increased Ca(2+) influx, mitochondrial network fragmentation and loss of the mitochondrial Ca(2+) buffer capacity. These biochemical events increase cytosolic Ca(2+) levels and trigger cardiomyocyte death via the activation of calpains. PMID:23602992

  3. Endocrine and other physiologic modulators of perinatal cardiomyocyte endowment.

    PubMed

    Jonker, S S; Louey, S

    2016-01-01

    Immature contractile cardiomyocytes proliferate to rapidly increase cell number, establishing cardiomyocyte endowment in the perinatal period. Developmental changes in cellular maturation, size and attrition further contribute to cardiac anatomy. These physiological processes occur concomitant with a changing hormonal environment as the fetus prepares itself for the transition to extrauterine life. There are complex interactions between endocrine, hemodynamic and nutritional regulators of cardiac development. Birth has been long assumed to be the trigger for major differences between the fetal and postnatal cardiomyocyte growth patterns, but investigations in normally growing sheep and rodents suggest this may not be entirely true; in sheep, these differences are initiated before birth, while in rodents they occur after birth. The aim of this review is to draw together our understanding of the temporal regulation of these signals and cardiomyocyte responses relative to birth. Further, we consider how these dynamics are altered in stressed and suboptimal intrauterine environments. PMID:26432905

  4. Cardiomyocyte-Specific Ablation of Med1 Subunit of the Mediator Complex Causes Lethal Dilated Cardiomyopathy in Mice

    PubMed Central

    Jia, Yuzhi; Chang, Hsiang-Chun; Schipma, Matthew J.; Liu, Jing; Shete, Varsha; Liu, Ning; Sato, Tatsuya; Thorp, Edward B.; Barger, Philip M.; Zhu, Yi-Jun; Viswakarma, Navin; Kanwar, Yashpal S.; Ardehali, Hossein; Thimmapaya, Bayar; Reddy, Janardan K.

    2016-01-01

    Mediator, an evolutionarily conserved multi-protein complex consisting of about 30 subunits, is a key component of the polymerase II mediated gene transcription. Germline deletion of the Mediator subunit 1 (Med1) of the Mediator in mice results in mid-gestational embryonic lethality with developmental impairment of multiple organs including heart. Here we show that cardiomyocyte-specific deletion of Med1 in mice (csMed1-/-) during late gestational and early postnatal development by intercrossing Med1fl/fl mice to α-MyHC-Cre transgenic mice results in lethality within 10 days after weaning due to dilated cardiomyopathy-related ventricular dilation and heart failure. The csMed1-/- mouse heart manifests mitochondrial damage, increased apoptosis and interstitial fibrosis. Global gene expression analysis revealed that loss of Med1 in heart down-regulates more than 200 genes including Acadm, Cacna1s, Atp2a2, Ryr2, Pde1c, Pln, PGC1α, and PGC1β that are critical for calcium signaling, cardiac muscle contraction, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy and peroxisome proliferator-activated receptor regulated energy metabolism. Many genes essential for oxidative phosphorylation and proper mitochondrial function such as genes coding for the succinate dehydrogenase subunits of the mitochondrial complex II are also down-regulated in csMed1-/- heart contributing to myocardial injury. Data also showed up-regulation of about 180 genes including Tgfb2, Ace, Atf3, Ctgf, Angpt14, Col9a2, Wisp2, Nppa, Nppb, and Actn1 that are linked to cardiac muscle contraction, cardiac hypertrophy, cardiac fibrosis and myocardial injury. Furthermore, we demonstrate that cardiac specific deletion of Med1 in adult mice using tamoxifen-inducible Cre approach (TmcsMed1-/-), results in rapid development of cardiomyopathy and death within 4 weeks. We found that the key findings of the csMed1-/- studies described above are highly reproducible in TmcsMed1-/- mouse heart

  5. RE1 silencing transcription factor/neuron-restrictive silencing factor regulates expansion of adult mouse subventricular zone-derived neural stem/progenitor cells in vitro.

    PubMed

    Soldati, Chiara; Caramanica, Pasquale; Burney, Matthew J; Toselli, Camilla; Bithell, Angela; Augusti-Tocco, Gabriella; Stanton, Lawrence W; Biagioni, Stefano; Buckley, Noel J; Cacci, Emanuele

    2015-08-01

    Adult neural stem cell (aNSC) activity is tuned by external stimuli through the recruitment of transcription factors. This study examines the RE1 silencing transcription factor (REST) in neural stem/progenitor cells isolated from the subventricular zone of adult mouse brain and provides the first extensive characterization of REST-mediated control of the cellular and molecular properties. This study shows that REST knockdown affects the capacity of progenitor cells to generate neurospheres, reduces cell proliferation, and triggers cell differentiation despite the presence of growth factors. Genome- and transcriptome-wide analyses show that REST binding sites are significantly enriched in genes associated with synaptic transmission and nervous system development and function. Seeking candidate regulators of aNSC function, this study identifies a member of the bone morphogenetic protein (BMP) family, BMP6, the mRNA and protein of which increased after REST knockdown. The results of this study extend previous findings, demonstrating a reciprocal control of REST expression by BMPs. Administration of exogenous BMP6 inhibits aNSC proliferation and induces the expression of the astrocytic marker glial fibrillary acidic protein, highlighting its antimitogenic and prodifferentiative effects. This study suggests that BMP6 produced in a REST-regulated manner together with other signals can contribute to regulation of NSC maintenance and fate. PMID:25691247

  6. Cocaine-induced loss of white matter proteins in the adult mouse nucleus accumbens is attenuated by administration of a β-lactam antibiotic during cocaine withdrawal.

    PubMed

    Kovalevich, Jane; Corley, Gladys; Yen, William; Rawls, Scott M; Langford, Dianne

    2012-12-01

    We report significantly decreased white matter protein levels in the nucleus accumbens in an adult mouse model of chronic cocaine abuse. Previous studies from human cocaine abuse patients show disruption of white matter and myelin loss, thus supporting our observations. Understanding the neuropathological mechanisms for white matter disruption in cocaine abuse patients is complicated by polydrug use and other comorbid factors, hindering the development of effective therapeutic strategies to ameliorate damage or compliment rehabilitation programs. In this context, our data further demonstrate that cocaine-induced loss of white matter proteins is absent in mice treated with the β-lactam antibiotic, ceftriaxone, during cocaine withdrawal. Other studies report that ceftriaxone, a glutamate transporter subtype-1 activator, is neuroprotective in murine models of multiple sclerosis, thereby demonstrating potential therapeutic properties for diseases with white matter loss. Cocaine-induced white matter abnormalities likely contribute to the cognitive, motor, and psychological deficits commonly afflicting cocaine abusers, yet the underlying mechanisms responsible for these changes remain unknown. Our observations describe an adult animal model for the study of cocaine-induced myelin loss for the first time, and highlight a potential pharmacological intervention to ameliorate cocaine-induced white matter loss. PMID:23031254

  7. Isoform-Specific Modulation of Inflammation Induced by Adenoviral Mediated Delivery of Platelet-Derived Growth Factors in the Adult Mouse Heart

    PubMed Central

    Ylä-Herttuala, Seppo; Betsholtz, Christer; Andrae, Johanna

    2016-01-01

    Platelet-derived growth factors (PDGFs) are key regulators of mesenchymal cells in vertebrate development. To what extent PDGFs also exert beneficial homeostatic or reparative roles in adult organs, as opposed to adverse fibrogenic responses in pathology, are unclear. PDGF signaling plays critical roles during heart development, during which forced overexpression of PDGFs induces detrimental cardiac fibrosis; other studies have implicated PDGF signaling in post-infarct myocardial repair. Different PDGFs may exert different effects mediated through the two PDGF receptors (PDGFRα and PDGFRβ) in different cell types. Here, we assessed responses induced by five known PDGF isoforms in the adult mouse heart in the context of adenovirus vector-mediated inflammation. Our results show that different PDGFs have different, in some cases even opposing, effects. Strikingly, whereas the major PDGFRα agonists (PDGF-A and -C) decreased the amount of scar tissue and increased the numbers of PDGFRα-positive fibroblasts, PDGFRβ agonists either induced large scars with extensive inflammation (PDGF-B) or dampened the adenovirus-induced inflammation and produced a small and dense scar (PDGF-D). These results provide evidence for PDGF isoform-specific inflammation-modulating functions that may have therapeutic implications. They also illustrate a surprising complexity in the PDGF-mediated pathophysiological responses. PMID:27513343

  8. Cocaine-Induced Loss of White Matter Proteins in the Adult Mouse Nucleus Accumbens Is Attenuated by Administration of a β-Lactam Antibiotic during Cocaine Withdrawal

    PubMed Central

    Kovalevich, Jane; Corley, Gladys; Yen, William; Rawls, Scott M.; Langford, Dianne

    2013-01-01

    We report significantly decreased white matter protein levels in the nucleus accumbens in an adult mouse model of chronic cocaine abuse. Previous studies from human cocaine abuse patients show disruption of white matter and myelin loss, thus supporting our observations. Understanding the neuropathological mechanisms for white matter disruption in cocaine abuse patients is complicated by polydrug use and other comorbid factors, hindering the development of effective therapeutic strategies to ameliorate damage or compliment rehabilitation programs. In this context, our data further demonstrate that cocaine-induced loss of white matter proteins is absent in mice treated with the β-lactam antibiotic, ceftriaxone, during cocaine withdrawal. Other studies report that ceftriaxone, a glutamate transporter subtype-1 activator, is neuroprotective in murine models of multiple sclerosis, thereby demonstrating potential therapeutic properties for diseases with white matter loss. Cocaine-induced white matter abnormalities likely contribute to the cognitive, motor, and psychological deficits commonly afflicting cocaine abusers, yet the underlying mechanisms responsible for these changes remain unknown. Our observations describe an adult animal model for the study of cocaine-induced myelin loss for the first time, and highlight a potential pharmacological intervention to ameliorate cocaine-induced white matter loss. PMID:23031254

  9. Effects of maternal L-tryptophan depletion and corticosterone administration on neurobehavioral adjustments in mouse dams and their adolescent and adult daughters.

    PubMed

    Zoratto, Francesca; Berry, Alessandra; Anzidei, Francesca; Fiore, Marco; Alleva, Enrico; Laviola, Giovanni; Macrì, Simone

    2011-08-01

    Major depressive disorder (MDD), a pathology characterized by mood and neurovegetative disturbances, depends on a multi-factorial contribution of individual predisposition (e.g., diminished serotonergic transmission) and environmental factors (e.g., neonatal abuse or neglect). Despite its female-biased prevalence, MDD basic research has mainly focused on male rodents. Most of present models of depression are also devalued due to the fact that they typically address only one of the aforementioned pathogenetic factors. In this paper we first describe the basic principles behind mouse model development and evaluation and then articulate that current models of depression are intrinsically devalued due to poor construct and/or external validity. We then report a first attempt to overcome this limitation through the design of a mouse model in which the genetic and the environmental components of early risk factors for depression are mimicked together. Environmental stress is mimicked through the supplementation of corticosterone in the maternal drinking water while biological predisposition is mimicked through maternal access to an L-tryptophan (the serotonin precursor) deficient diet during the first week of lactation. CD1 dams and their offspring exposed to the L-tryptophan deficient diet (T) and to corticosterone (80mg/l; C) were compared to animal facility reared (AFR) subjects. T and C mice served as intermediate reference groups. Adolescent TC offspring, compared to AFR mice, showed decreased time spent floating in the forced-swim test and increased time spent in the open sectors of an elevated 0-maze. Adult TC offspring showed reduced preference for novelty, decreased breakpoints in the progressive ratio operant procedure and major alterations in central BDNF levels and altered HPA regulation. The route of administration and the possibility to control the independent variables predisposing to depressive-like symptoms disclose novel avenues towards the development

  10. Isolation and Mechanical Measurements of Myofibrils from Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

    PubMed

    Pioner, Josè Manuel; Racca, Alice W; Klaiman, Jordan M; Yang, Kai-Chun; Guan, Xuan; Pabon, Lil; Muskheli, Veronica; Zaunbrecher, Rebecca; Macadangdang, Jesse; Jeong, Mark Y; Mack, David L; Childers, Martin K; Kim, Deok-Ho; Tesi, Chiara; Poggesi, Corrado; Murry, Charles E; Regnier, Michael

    2016-06-14

    Tension production and contractile properties are poorly characterized aspects of excitation-contraction coupling of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Previous approaches have been limited due to the small size and structural immaturity of early-stage hiPSC-CMs. We developed a substrate nanopatterning approach to produce hiPSC-CMs in culture with adult-like dimensions, T-tubule-like structures, and aligned myofibrils. We then isolated myofibrils from hiPSC-CMs and measured the tension and kinetics of activation and relaxation using a custom-built apparatus with fast solution switching. The contractile properties and ultrastructure of myofibrils more closely resembled human fetal myofibrils of similar gestational age than adult preparations. We also demonstrated the ability to study the development of contractile dysfunction of myofibrils from a patient-derived hiPSC-CM cell line carrying the familial cardiomyopathy MYH7 mutation (E848G). These methods can bring new insights to understanding cardiomyocyte maturation and developmental mechanical dysfunction of hiPSC-CMs with cardiomyopathic mutations. PMID:27161364

  11. Targeted homozygous deletion of M-band titin in cardiomyocytes prevents sarcomere formation.

    PubMed

    Musa, Hanny; Meek, Stephen; Gautel, Mathias; Peddie, Dianna; Smith, Andrew J H; Peckham, Michelle

    2006-10-15

    Titin, a multifunctional protein that stretches from the Z-disk to the M-band in heart and skeletal muscle, contains a kinase domain, phosphorylation sites and multiple binding sites for structural and signalling proteins in the M-band. To determine whether this region is crucial for normal sarcomere development, we created mouse embryonic stem cell (ES) lines in which either one or both alleles contained a targeted deletion of the entire M-band-coding region, leaving Z-disk-binding and myosin-filament-binding sites intact. ES cells were differentiated into cardiomyocytes, and myofibrillogenesis investigated by immunofluorescence microscopy. Surprisingly, deletion of one allele did not markedly affect differentiation into cardiomyocytes, suggesting that a single intact copy of the titin gene is sufficient for normal myofibrillogenesis. By contrast, deletion of both alleles resulted in a failure of differentiation beyond an early stage of myofibrillogenesis. Sarcomeric myosin remained in non-striated structures, Z-disk proteins, such as alpha-actinin, were mainly found in primitive dot-like structures on actin stress fibres, M-band-associated proteins (myomesin, obscurin, Nbr1, p62 and MURF2) remained punctate. These results show that integration of the M-band region of titin is required for myosin filament assembly, M-band formation and maturation of the Z-disk. PMID:17038546

  12. [Ophiopogonin D protects cardiomyocytes against doxorubicin-induced injury through suppressing endoplasmic reticulum stress].

    PubMed

    Meng, Chen; Yuan, Cai-Hua; Zhang, Chen-Chen; Wen, Ming-Da; Gao, Yan-Hong; Ding, Xiao-Yu; Zhang, Ying-Yu; Zhang, Zhao

    2014-08-01

    This study aimed to examine whether ophiopogonin D (OP-D) is capable of protecting cardiomyocytes against DOX-induced injury and the mechanisms involved. H9c2 cells were cultured. MTT assay was used to evaluate cell viability and toxicity. Mito-tracker as fluorescence probe was used to measure ROS content raised from mitochondria. The mRNA and protein expression of ATF6alpha, GRP78 and CHOP were analyzed using real-time PCR and Western blotting, respectively. The results showed that a significant endoplasmic reticulum stress (ERS) was induced upon exposure of H9c2 cells to DOX as indicated by the increase in the expression of ERS related proteins, which was paralleled with the accumulation of reactive oxygen species (ROS) and decrease in the viability of H9c2 cells. Whereas, DOX-induced ROS accumulation and up-regulation of ERS related proteins were partially abolished by pretreatment with OP-D. Consequently, a DOX-induced ERS was mitigated by application of OP-D. Similarly, DOX-induced decrease in cell viability was partially attenuated by either inhibiting CHOP or pretreatment with N-acetylcysteine (NAC), an antioxidant. Moreover, cardiac ultrastructural abnormalities seen in mouse receiving DOX injections were obviously ameliorated by pretreatment of OP-D. Taken together, the present study proved that OP-D protects cardiomyocytes against DOX-induced injury, at least in part, through reducing ROS accumulation and alleviating ERS. PMID:25322552

  13. Depletion of lamina-associated polypeptide 1 from cardiomyocytes causes cardiac dysfunction in mice

    PubMed Central

    Shin, Ji-Yeon; Le Dour, Caroline; Sera, Fusako; Iwata, Shinichi; Homma, Shunichi; Joseph, Leroy C; Morrow, John P; Dauer, William T; Worman, Howard J

    2014-01-01

    We previously showed that striated muscle-selective depletion of lamina-associated polypeptide 1 (LAP1), an integral inner nuclear membrane protein, leads to profound muscular dystrophy with premature death in mice. As LAP1 is also depleted in hearts of these mice, we examined their cardiac phenotype. Striated muscle-selective LAP1 knockout mice display ventricular systolic dysfunction with abnormal induction of genes encoding cardiomyopathy related proteins. To eliminate possible confounding effects due to skeletal muscle pathology, we generated a new mouse line in which LAP1 is deleted in a cardiomyocyte-selective manner. These mice had no skeletal muscle pathology and appeared overtly normal at 20 weeks of age. However, cardiac echocardiography revealed that they developed left ventricular systolic dysfunction and cardiac gene expression analysis revealed abnormal induction of cardiomyopathy-related genes. Our results demonstrate that LAP1 expression in cardiomyocytes is required for normal left ventricular function, consistent with a report of cardiomyopathy in a human subject with mutation in the gene encoding LAP1. PMID:24859316

  14. Cyclic stretch of Embryonic Cardiomyocytes Increases Proliferation, Growth, and Expression While Repressing Tgf-β Signaling

    PubMed Central

    Banerjee, Indroneal; Carrion, Katrina; Serrano, Ricardo; Dyo, Jeffrey; Sasik, Roman; Lund, Sean; Willems, Erik; Aceves, Seema; Meili, Rudolph; Mercola, Mark; Chen, Ju; Zambon, Alexander; Hardiman, Gary; Doherty, Taylor A; Lange, Stephan; del Álamo, Juan C.; Nigam, Vishal

    2014-01-01

    Perturbed biomechanical stimuli are thought to be critical for the pathogenesis of a number of congenital heart defects, including Hypoplastic Left Heart Syndrome (HLHS). While embryonic cardiomyocytes experience biomechanical stretch every heart beat, their molecular responses to biomechanical stimuli during heart development are poorly understood. We hypothesized that biomechanical stimuli activate specific signaling pathways that impact proliferation, gene expression and myocyte contraction. The objective of this study was to expose embryonic mouse cardiomyocytes (EMCM) to cyclic stretch and examine key molecular and phenotypic responses. Analysis of RNA-Sequencing data demonstrated that gene ontology groups associated with myofibril and cardiac development were significantly modulated. Stretch increased EMCM proliferation, size, cardiac gene expression, and myofibril protein levels. Stretch also repressed several components belonging to the Transforming Growth Factor-β (Tgf-β) signaling pathway. EMCMs undergoing cyclic stretch had decreased Tgf-β expression, protein levels, and signaling. Furthermore, treatment of EMCMs with a Tgf-β inhibitor resulted in increased EMCM size. Functionally, Tgf-β signaling repressed EMCM proliferation and contractile function, as assayed via dynamic monolayer force microscopy (DMFM). Taken together, these data support the hypothesis that biomechanical stimuli play a vital role in normal cardiac development and for cardiac pathology, including HLHS. PMID:25446186

  15. Transcriptional and Functional Profiling of Human Embryonic Stem Cell-Derived Cardiomyocytes

    PubMed Central

    Xie, Xiaoyan; Fu, Ji-Dong; Drukker, Micha; Lee, Andrew; Li, Ronald A.; Gambhir, Sanjiv S.; Weissman, Irving L.; Robbins, Robert C.; Wu, Joseph C.

    2008-01-01

    Human embryonic stem cells (hESCs) can serve as a potentially limitless source of cells that may enable regeneration of diseased tissue and organs. Here we investigate the use of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) in promoting recovery from cardiac ischemia reperfusion injury in a mouse model. Using microarrays, we have described the hESC-CM transcriptome within the spectrum of changes that occur between undifferentiated hESCs and fetal heart cells. The hESC-CMs expressed cardiomyocyte genes at levels similar to those found in 20-week fetal heart cells, making this population a good source of potential replacement cells in vivo. Echocardiographic studies showed significant improvement in heart function by 8 weeks after transplantation. Finally, we demonstrate long-term engraftment of hESC-CMs by using molecular imaging to track cellular localization, survival, and proliferation in vivo. Taken together, global gene expression profiling of hESC differentiation enables a systems-based analysis of the biological processes, networks, and genes that drive hESC fate decisions, and studies such as this will serve as the foundation for future clinical applications of stem cell therapies. PMID:18941512

  16. MMI-0100 inhibits cardiac fibrosis in myocardial infarction by direct actions on cardiomyocytes and fibroblasts via MK2 inhibition

    PubMed Central

    Xu, Lei; Yates, Cecelia C.; Lockyer, Pamela; Xie, Liang; Bevilacqua, Ariana; He, Jun; Lander, Cynthia; Patterson, Cam; Willis, Monte

    2014-01-01

    The cell-permeant peptide inhibitor of MAPKAP kinase 2 (MK2), MMI-0100, inhibits MK2 and downstream fibrosis and inflammation. Recent studies have demonstrated that MMI-0100 reduces intimal hyperplasia in a mouse vein graft model, pulmonary fibrosis in a murine bleomycin-induced model and development of adhesions in conjunction with abdominal surgery. MK2 is critical to the pathogenesis of ischemic heart injury as MK2 −/− mice are resistant to ischemic remodeling. Therefore, we tested the hypothesis that inhibiting MK2 with MMI-0100 would protect the heart after acute myocardial infarction (AMI) in vivo. AMI was induced by placing a permanent LAD coronary ligation. When MMI-0100 peptide was given 30 minutes after permanent LAD coronary artery ligation, the resulting fibrosis was reduced/prevented ~50% at a 2 week time point, with a corresponding improvement in cardiac function and decrease in left ventricular dilation. In cultured cardiomyocytes and fibroblasts, MMI-0100 inhibited MK2 to reduce cardiomyocyte caspase 3/7 activity, while enhancing primary cardiac fibroblast caspase 3/7 activity, which may explain MMI-0100’s salvage of cardiac function and anti-fibrotic effects in vivo. These findings suggest that therapeutic inhibition of MK2 after acute MI, using rationally-designed cell-permeant peptides, inhibits cardiac fibrosis and maintains cardiac function by mechanisms that involve inhibiting cardiomyocyte apoptosis, while enhancing primary cardiac fibroblast cell death. PMID:25257914

  17. Coupling primary and stem cell–derived cardiomyocytes in an in vitro model of cardiac cell therapy

    PubMed Central

    Aratyn-Schaus, Yvonne; Pasqualini, Francesco S.; Yuan, Hongyan; McCain, Megan L.; Ye, George J.C.; Sheehy, Sean P.; Campbell, Patrick H.

    2016-01-01

    The efficacy of cardiac cell therapy depends on the integration of existing and newly formed cardiomyocytes. Here, we developed a minimal in vitro model of this interface by engineering two cell microtissues (μtissues) containing mouse cardiomyocytes, representing spared myocardium after injury, and cardiomyocytes generated from embryonic and induced pluripotent stem cells, to model newly formed cells. We demonstrated that weaker stem cell–derived myocytes coupled with stronger myocytes to support synchronous contraction, but this arrangement required focal adhesion-like structures near the cell–cell junction that degrade force transmission between cells. Moreover, we developed a computational model of μtissue mechanics to demonstrate that a reduction in isometric tension is sufficient to impair force transmission across the cell–cell boundary. Together, our in vitro and in silico results suggest that mechanotransductive mechanisms may contribute to the modest functional benefits observed in cell-therapy studies by regulating the amount of contractile force effectively transmitted at the junction between newly formed and spared myocytes. PMID:26858266

  18. Coupling primary and stem cell-derived cardiomyocytes in an in vitro model of cardiac cell therapy.

    PubMed

    Aratyn-Schaus, Yvonne; Pasqualini, Francesco S; Yuan, Hongyan; McCain, Megan L; Ye, George J C; Sheehy, Sean P; Campbell, Patrick H; Parker, Kevin Kit

    2016-02-15

    The efficacy of cardiac cell therapy depends on the integration of existing and newly formed cardiomyocytes. Here, we developed a minimal in vitro model of this interface by engineering two cell microtissues (μtissues) containing mouse cardiomyocytes, representing spared myocardium after injury, and cardiomyocytes generated from embryonic and induced pluripotent stem cells, to model newly formed cells. We demonstrated that weaker stem cell-derived myocytes coupled with stronger myocytes to support synchronous contraction, but this arrangement required focal adhesion-like structures near the cell-cell junction that degrade force transmission between cells. Moreover, we developed a computational model of μtissue mechanics to demonstrate that a reduction in isometric tension is sufficient to impair force transmission across the cell-cell boundary. Together, our in vitro and in silico results suggest that mechanotransductive mechanisms may contribute to the modest functional benefits observed in cell-therapy studies by regulating the amount of contractile force effectively transmitted at the junction between newly formed and spared myocytes. PMID:26858266

  19. Plakophilin-2 loss promotes TGF-β1/p38 MAPK-dependent fibrotic gene expression in cardiomyocytes.

    PubMed

    Dubash, Adi D; Kam, Chen Y; Aguado, Brian A; Patel, Dipal M; Delmar, Mario; Shea, Lonnie D; Green, Kathleen J

    2016-02-15

    Members of the desmosome protein family are integral components of the cardiac area composita, a mixed junctional complex responsible for electromechanical coupling between cardiomyocytes. In this study, we provide evidence that loss of the desmosomal armadillo protein Plakophilin-2 (PKP2) in cardiomyocytes elevates transforming growth factor β1 (TGF-β1) and p38 mitogen-activated protein kinase (MAPK) signaling, which together coordinate a transcriptional program that results in increased expression of profibrotic genes. Importantly, we demonstrate that expression of Desmoplakin (DP) is lost upon PKP2 knockdown and that restoration of DP expression rescues the activation of this TGF-β1/p38 MAPK transcriptional cascade. Tissues from PKP2 heterozygous and DP conditional knockout mouse models also exhibit elevated TGF-β1/p38 MAPK signaling and induction of fibrotic gene expression in vivo. These data therefore identify PKP2 and DP as central players in coordination of desmosome-dependent TGF-β1/p38 MAPK signaling in cardiomyocytes, pathways known to play a role in different types of cardiac disease, such as arrhythmogenic or hypertrophic cardiomyopathy. PMID:26858265

  20. Analysis of cardiomyocyte movement in the developing murine heart.

    PubMed

    Hashimoto, Hisayuki; Yuasa, Shinsuke; Tabata, Hidenori; Tohyama, Shugo; Seki, Tomohisa; Egashira, Toru; Hayashiji, Nozomi; Hattori, Fumiyuki; Kusumoto, Dai; Kunitomi, Akira; Takei, Makoto; Kashimura, Shin; Yozu, Gakuto; Shimojima, Masaya; Motoda, Chikaaki; Muraoka, Naoto; Nakajima, Kazunori; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Fukuda, Keiichi

    2015-09-01

    The precise assemblage of several types of cardiac precursors controls heart organogenesis. The cardiac precursors show dynamic movement during early development and then form the complicated heart structure. However, cardiomyocyte movements inside the newly organized mammalian heart remain unclear. We previously established the method of ex vivo time-lapse imaging of the murine heart to study cardiomyocyte behavior by using the Fucci (fluorescent ubiquitination-based cell cycle indicator) system, which can effectively label individual G1, S/G2/M, and G1/S-transition phase nuclei in living cardiomyocytes as red, green, and yellow, respectively. Global analysis of gene expression in Fucci green positive ventricular cardiomyocytes confirmed that cell cycle regulatory genes expressed in G1/S, S, G2/M, and M phase transitions were upregulated. Interestingly, pathway analysis revealed that many genes related to the cell cycle were significantly upregulated in the Fucci green positive ventricular cardiomyocytes, while only a small number of genes related to cell motility were upregulated. Time-lapse imaging showed that murine proliferating cardiomyocytes did not exhibit dynamic movement inside the heart, but stayed on site after entering the cell cycle. PMID:26168730