Abstract 316: Cell-Matrix Contacts Regulate Age-Associated Cardiac Function

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Ayla O Sessions ◽  
Gaurav Kaushik ◽  
Anthony Cammarato ◽  
Adam Engler
Keyword(s):  
Cardiac Function ◽  
Collagen Iv ◽  
Cardiac Performance ◽  
Model Organisms ◽  
Mechanical Function ◽  
Heart Tube ◽  
Cell Matrix ◽  
Intercalated Discs ◽  
Ecm Proteins ◽  
Ventral Muscle

An increased deposition of ECM is observed in all advanced age heart failure patients. Therefore, it is necessary to investigate the effect of extracellular remodeling on mechanical function in genetically tractable, rapidly aging, and simple model organisms such as Drosophila melanogaster . The bilayered design of the Drosophila heart-tube makes it an easier model in which to study the interplay between ECM and cardiomyocytes as they regulate contraction. Here we present data from two common wildtype strains of Drosophila exhibiting different aging profiles in terms of cytoskeletal and ECM regulation and remodeling. Using a recently developed nanoindentation method to measure cardiomyocyte stiffness of intact Drosophila hearts, we have found that while yellow-white ( yw ) flies show midline stiffening at the intercalated discs (ICD) presenting a clear diastolic dysfunction with age, the white-1118 ( w1118 ) flies exhibit no ICD stiffening, but show an increase in thickness of the ECM layer between the ventral muscle (VM) and cardiomyocytes (CM). Paired with increased expression of ECM proteins, the w1118 Drosophila line may provide a good model for exploring the effect of cell-ECM contacts on regulating cardiac function with age. Knock-down of integral ECM genes LamininA and Viking (Collagen IV) result in no effect on cardiac performance in juvenile flies but causes a decrease in underlying cardiomyocyte stiffness and an increase in the contractile irregularity of heart beats. This suggests that the cell-ECM contacts in the basement membrane are intimately tied to coupling of the cardiomyocytes of the Drosophila heart-tube, which may have larger implications for elderly patients suffering from myocardial fibrosis and experiencing cardiomyocyte decoupling and resultant arrhythmias.

Abstract 371: Down Regulation of ECM Genes Laminin and Collagen IV Lead to Preserved Cardiac Function With Age and Increased Lifespan in Drosophila

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Ayla O Sessions
Keyword(s):  
Diastolic Dysfunction ◽  
High Speed ◽  
Current Model ◽  
Collagen Iv ◽  
Model Systems ◽  
Model Organisms ◽  
Heart Tube ◽  
Ecm Remodeling ◽  
Intercalated Discs ◽  
And Performance

Increased deposition of extracellular matrix (ECM) is observed in all advanced age heart failure patients, but current model systems are complex and slow to age. To investigate the effect of extracellular remodeling on mechanical function in genetically tractable, rapidly aging, and simple model organisms, we employed Drosophila melanogaster, which has a simple trilayered heart tube. We found that two common wildtype strains of Drosophila, i.e. yellow-white (yw) and white-1118 (w1118), exhibit different cytoskeletal and ECM remodeling with age. Using a recently developed nanoindentation method to measure cardiomyocyte stiffness and high speed optical imaging to assess contractility of intact Drosophila hearts, we found that yw flies had stiffer intercalated discs (ICD) and exhibited diastolic dysfunction with age. On the other hand, w1118 flies had a shorter lifespan compared to yw, did not exhibit ICD stiffening, had a less severe diastolic dysfunction, and showed an increase in ECM layer thickness between ventral muscle (VM) and cardiomyocyte (CM) layers of the heart tube. To modulate ECM and assess its effect in the aged w1118 flies, we knocked-down ECM genes LamininA and Viking (homologous to Collagen IV). Both ECM KD genotypes exhibited diastolic dilation with increased fractional shortening at adult (1wk) and aged (5wk) time points. The LamininA KD resulted in decreased cardiomyocyte stiffness correlating with increased relaxation velocities in adult flies and preservation of shortening and relaxation velocities in aged flies over controls. However, both the LamininA and Collagen IV KD flies experienced a basal increase in the decoupling of their cardiomyocytes as determined by heart period variance and % fibrillar heart-beats. These conductance issues were not enough to counteract the increased cardiac output and performance with age, and the Collagen IV KD outlived controls by 1.5 weeks median survival and the LamininA KD by 3 weeks. This suggests that the cell-ECM contacts in the basement membrane are intimately tied not only to the coupling of the cardiomyocytes of the Drosophila heart tube but also to cytoskeletal remodeling, but perhaps different ECM proteins have different mechanisms for interacting with the cardiomyocyte cytoskeleton.

Abstract 426: Laminin Downregulation Facilitates Cardiomyocyte Coupling in situ to Increase Contractile Function

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Ayla Sessions ◽  
Gaurav Kaushik ◽  
Adam Engler
Keyword(s):  
Basement Membrane ◽  
Contractile Function ◽  
Current Model ◽  
Model Systems ◽  
Model Organisms ◽  
Muscle Physiology ◽  
Heart Tube ◽  
Age Related ◽  
New Evidence

Aging is associated with extensive remodeling of the heart, including basement membrane extracellular matrix (ECM) components that surround cardiomyocytes. Remodeling is thought to contribute to impaired cardiac mechanotransduction, but the contribution of specific basement membrane ECM components to age-related cardiac remodeling is unclear, owing to current model systems being complex and slow to age. To investigate the effect of basement membrane remodeling on mechanical function in genetically tractable, rapidly aging, and simple model organisms, we employed Drosophila melanogaster, which has a simple trilayered heart tube composed of only basement membrane ECM. We observed differential regulation of collagens between laboratory Drosophila strains , i.e. yellow-white ( yw ) and white-1118 ( w 1118 ), leading to changes in muscle physiology, which were linked to severity of dysfunction with age. Therefore, we sought to understand the extent to which basement membrane ECM modulates lateral cardiomyocyte coupling and contractile function during aging. Cardiac-restricted knockdown of ECM genes Pericardin , Laminin A , and Viking in Drosophila prevented age-associated heart tube restriction and increased contractility, even under viscous load. Most notably, reduction of Laminin A expression decreased levels of other genes that co-assemble in ECM, leading to overall preservation of contractile velocity and extension of median organismal lifespan by 3 weeks or 39%. These data provide new evidence of a direct link between basement membrane ECM homeostasis, contractility, and maintenance of lifespan.

Abstract 47: Loss of the Cardio Protection Inferred by S-nitrosylation of GRK2 At Cysteine 340 Leads to Decreased Cardiac Performance and a Hypertensive Phenotype With Aging

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Christopher J Traynham ◽  
Ancai Yuan ◽  
Erhe Gao ◽  
Walter Koch
Keyword(s):  
Cardiac Hypertrophy ◽  
Cardiac Function ◽  
Ischemia Reperfusion ◽  
Cardiac Performance ◽  
Heart Weight ◽  
Cardiac Phenotype ◽  
Cardio Protection ◽  
G Protein Coupled ◽  
Global Population

In the next 35 years, the global population of individuals above 60 years of age will double to approximately 2 billion. In the aged population, cardiovascular diseases are known to occur at a higher prevalence ultimately leading to increased mortality. G protein-coupled receptors (GPCRs) have been identified as vital regulators of cardiac function. GPCR kinases (GRKs) are important in cardiac GPCR regulation through desensitization of these receptors. GRK2 is highly expressed in the heart, and has been widely characterized due to its upregulation in heart failure. Studies from our lab have shown that elevated GRK2 levels in ischemia-reperfusion (I/R) injury result in a pro-death phenotype. Interestingly, cardio-protection can be inferred via S-nitrosylation of GRK2 at cysteine 340. Further, we have generated a knock-in GRK2 340S mouse, in which cysteine 340 was mutated to block dynamic GRK2 S-nitrosylation. GRK2 340S mice are more susceptible to I/R injury. Given that GRK2 340S mice are more susceptible to oxidative stress, and there is a nitroso-redox imbalance in senescence, it is possible that these mice are more likely to exhibit decreased cardiac performance as they age. Therefore, we hypothesize that with age GRK2 340S knockin mice will develop an overall worsened cardiac phenotype compared to control wild-type (WT) mice. To test this hypothesis, 340S and WT mice were aged for a year, and cardiac function was evaluated via echocardiography. Aged 340S mice exhibited significantly decreased ejection fraction and fraction shortening relative to aged WT controls. Prior to tissue harvesting, in-vivo hemodynamics was conducted via Millar catheterization. At baseline, aged 340S mice exhibited increased systolic blood pressure compared to aged WT mice. At the conclusion of this protocol, mice were sacrificed and heart weight (HW), body weight (BW), and tibia length (TL) measured to evaluate cardiac hypertrophy. Aged 340S mice exhibited significantly increased HW/BW and HW/TL ratios, indicative of cardiac hypertrophy, relative to aged WT controls. Taken together, these data suggest that with age, loss of the cardio protection inferred by S-nitrosylation of GRK2 at leads to decreased cardiac performance, and an overall worsened cardiac phenotype.

scholarly journals Decreased uterine vascularization and uterine arterial expansive remodeling with reduced matrix metalloproteinase-2 and -9 in hypertensive pregnancy

2020 ◽  
Vol 318 (1) ◽  
pp. H165-H180 ◽  
Author(s):  
Chen Lin ◽  
Hong He ◽  
Ning Cui ◽  
Zongli Ren ◽  
Minglin Zhu ◽  
...  
Keyword(s):  
Proteolytic Enzymes ◽  
Gelatin Zymography ◽  
Collagen Iv ◽  
Intraluminal Pressure ◽  
Matrix Metalloproteinase 2 ◽  
Trophoblast Invasion ◽  
Related Disorder ◽  
Uterine Arteries ◽  
Ecm Proteins ◽  
Placental Ischemia

Normal pregnancy involves extensive remodeling of uterine and spiral arteries and matrix metalloproteinases (MMPs)-mediated proteolysis of extracellular matrix (ECM). Preeclampsia is characterized by hypertension in pregnancy (HTN-Preg) and intrauterine growth restriction (IUGR) with unclear mechanisms. Initial faulty placentation and reduced uterine perfusion pressure (RUPP) could release cytoactive factors and trigger an incessant cycle of suppressed trophoblast invasion of spiral arteries, further RUPP, and progressive placental ischemia leading to HTN-Preg and IUGR; however, the extent and depth of uterine vascularization and the proteolytic enzymes and ECM proteins involved are unclear. We hypothesized that HTN-Preg involves decreased uterine vascularization and arterial remodeling by MMPs and accumulation of ECM collagen. Blood pressure (BP) and fetal parameters were measured in normal Preg rats and RUPP rat model, and the uteri were assessed for vascularity, MMP levels, and collagen deposition. On gestational day 19, BP was higher, and the uterus weight, litter size, and pup weight were reduced in RUPP vs. Preg rats. Histology of uterine tissue sections showed reduced number (5.75 ± 0.95 vs. 11.50 ± 0.87) and size (0.05 ± 0.01 vs. 0.12 ± 0.02 mm2) of uterine spiral arterioles in RUPP vs. Preg rats. Immunohistochemistry showed localization of endothelial cell marker cluster of differentiation 31 (CD31) and smooth muscle marker α-actin in uterine arteriolar wall and confirmed decreased number/size of uterine arterioles in RUPP rats. The cytotrophoblast marker cytokeratin-7 showed less staining and invasion of spiral arteries in the deep decidua of RUPP vs. Preg rats. Uterine arteries showed less expansion in response to increases in intraluminal pressure in RUPP vs. Preg rats. Western blot analysis, gelatin zymography, and immunohistochemistry showed decreases in MMP-2 and MMP-9 and increases in the MMP substrate collagen-IV in uterus and uterine arteries of RUPP vs. those in Preg rats. The results suggest decreased number, size and expansiveness of spiral and uterine arteries with decreased MMP-2 and MMP-9 and increased collagen-IV in HTN-Preg. Decreased uterine vascularization and uterine arterial expansive remodeling by MMPs could be contributing mechanisms to uteroplacental ischemia in HTN-Preg and preeclampsia. NEW & NOTEWORTHY Preeclampsia is a pregnancy-related disorder in which initial inadequate placentation and RUPP cause the release of cytoactive factors and trigger a ceaseless cycle of suppressed trophoblast invasion of spiral arteries, further RUPP, and progressive placental ischemia leading to HTN-Preg and IUGR; however, the extent/depth of uterine vascularization and the driving proteolytic enzymes and ECM proteins are unclear. This study shows decreased number, size, and expansiveness of uterine spiral arteries, with decreased MMP-2 and MMP-9 and increased collagen-IV in HTN-Preg rats. The decreased uterine vascularization and uterine arterial expansive remodeling by MMPs could contribute to progressive uteroplacental ischemia in HTN-Preg and preeclampsia.

Matricellular proteins as modulators of wound healing and the foreign body response

2003 ◽  
Vol 90 (12) ◽  
pp. 986-992 ◽  
Author(s):  
Themis Kyriakides ◽  
Paul Bornstein
Keyword(s):  
Wound Healing ◽  
Foreign Body ◽  
Tissue Repair ◽  
Foreign Body Response ◽  
Matricellular Proteins ◽  
Cell Matrix ◽  
Ecm Proteins ◽  
Matrix Interactions ◽  
Cell Matrix Interactions ◽  
Body Response

SummaryMatricellular proteins form a group of extracellular matrix (ECM) proteins that do not subserve a primary structural role, but rather function as modulators of cell-matrix interactions (1). Members of the group, including thrombospondin (TSP) -1, TSP-2, SPARC, tenascin (TN)-C, and osteopontin (OPN), have been shown to participate in a number of processes related to tissue repair. Specifically, studies in knockout mice have indicated that a deficiency in one or more of these proteins can alter the course of wound healing. More recently, TSP1, TSP2, and SPARC have also been implicated in the foreign body response, an unusual reaction to injury that occurs after the implantation of biomaterials. This review will focus on the roles of these proteins in the response to injury in mice and will show how studies of this pathophysiological process can elucidate some of the intrinsic properties of these matricellular proteins.

Abstract 13672: High Frequency Echocardiography and Speckle Tracking Based Strain Analysis Revealed Delayed Functional Recovery After Myocardial Cryoinjury in Adult Zebrafish

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Selina Hein ◽  
Lorenz Lehmann ◽  
Hugo A Katus ◽  
David Hassel
Keyword(s):  
Cardiac Function ◽  
Temporal Resolution ◽  
High Frequency ◽  
Speckle Tracking ◽  
Strain Analysis ◽  
Cardiac Performance ◽  
Response To Treatment ◽  
Adult Zebrafish ◽  
Cardiovascular Research ◽  
Larval Stages

Zebrafish is a widespread used model in cardiovascular research, and recently adult zebrafish, as a more human relevant model compared to larval stages, became particularly valuable to study heart regeneration. While cardiac performance in larval stages can be easily assessed using transillumination microscopy, methods to reliably assess cardiac function in adult zebrafish are largely missing. Here, we developed the first standardized protocol to reliably assess cardiac function in adult zebrafish using high frequency echocardiography and speckle-tracking algorithms. Respecting distinct anatomic characteristics in zebrafish, we defined three examination planes according to standards in human echocardiography. Further, by combining conventional echocardiographic measurements with modern speckle tracking based strain analysis we are able to measure myocardial performance in extremely high spatial and temporal resolution. Thereby we were able to attain high quality B-Mode imaging and PW-Doppler signals allowing distinct detection of changes in chronotropy, inotropy and, for the first time in adult zebrafish, in dromotropy in response to treatment with Atenolol and Isoproterenol. Additionally, we employed zebrafish that underwent cardiac cryoinjury to longitudinally follow functional cardiac regeneration. High-resolution speckle-tracking strain analysis allowed us to demarcate injured myocardial regions and demonstrate that functional healing extends beyond 30-45 days post injury (dpi) as previously implied by conventional methodologies. Specifically, we found delayed restitution of cardiac displacement and re-synchronization of injured and non-injured myocardium beyond 60 dpi until 120 dpi. In summary, our protocol enables highly reproducible and high throughput measurements of cardiac performance in adult zebrafish in a high spatio-temporal resolution. Thereby, our protocol represents a valuable novel tool for functional cardiac assessment and to detect changes in cardiac function in response to gene mutation or myocardial injury and might lead to further insights into cardiac physiology and disease.

Collagen IV synthesis is restricted to the enteroendocrine pathway during multilineage differentiation of human colorectal epithelial stem cells

2001 ◽  
Vol 114 (11) ◽  
pp. 2055-2064
Author(s):  
Susan C. Kirkland ◽  
Karen Henderson
Keyword(s):  
Stem Cells ◽  
Epithelial Cells ◽  
Collagen Iv ◽  
Model System ◽  
Enteroendocrine Cells ◽  
Multilineage Differentiation ◽  
Epithelial Stem Cells ◽  
Enteroendocrine Cell ◽  
Cell Matrix

The human large intestine is lined by a rapidly renewing epithelial monolayer where cell loss is precisely balanced with cell production. The continuous supply of new cells is produced by undifferentiated multipotent stem cells via a coordinated program of proliferation and differentiation yielding three epithelial lineages: absorptive, goblet and enteroendocrine. Cell-matrix interactions have been suggested to be regulators of the multilineage differentiation program of the colorectal crypt but the expression of matrix proteins or their receptors does not appear to have the subtlety expected for this task. We have developed an in vitro model system of intestinal epithelial stem cells to facilitate the direct analysis of stem cells undergoing lineage commitment and differentiation. Using this culture system, we can now directly investigate the role of cell-matrix signalling in stem-cell decisions. In this study, collagen-IV synthesis has been followed in monolayers of multipotent cells that have been induced to differentiate into absorptive, goblet and enteroendocrine cells. Our experiments demonstrate that commitment to the enteroendocrine lineage is specifically accompanied by the expression of type-IV collagen that remains enteroendocrine-cell associated. Undifferentiated cells, absorptive cells and goblet cells do not express collagen IV. To confirm that the differential lineage-specific expression of collagen IV observed in the model system was representative of the in vivo situation, collagen-IV synthesis was analysed in isolated human colorectal crypts and tissue sections using immunocytochemistry and in situ hybridisation. These studies confirmed the in vitro findings, in that implementation of the enteroendocrine differentiation program involves synthesis and accumulation of a collagen-IV matrix. Thus, human colorectal enteroendocrine cells are unique in the colorectal crypt in that they assemble a cell-associated collagen-IV-rich matrix not observed on other colorectal epithelial cells. This study provides the first evidence for differential matrix synthesis between colorectal epithelial lineages in human colorectal epithelium. The specialised pericellular environment of the enteroendocrine cells might explain some of the unique phenotypic characteristics of this cell lineage. Furthermore, these findings suggest a potential mechanism whereby individual epithelial cells could modulate their cell-matrix signalling even while rapidly migrating in heterogeneous sheets over a shared basement membrane.

Maximum cardiac performance of rainbow trout (Oncorhynchus mykiss) at temperatures approaching their upper lethal limit

1996 ◽  
Vol 199 (3) ◽  
pp. 663-672 ◽  
Author(s):  
A Farrell ◽  
A Gamperl ◽  
J Hicks ◽  
H Shiels ◽  
K Jain
Keyword(s):  
Heart Rate ◽  
Rainbow Trout ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Cardiac Performance ◽  
Preferred Temperature ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Lethal Limit ◽  
Q10 Values

Numerous studies have examined the effect of temperature on in vivo and in situ cardiovascular function in trout. However, little information exists on cardiac function at temperatures near the trout's upper lethal limit. This study measured routine and maximum in situ cardiac performance in rainbow trout (Oncorhynchus mykiss) following acclimation to 15, 18 and 22 °C, under conditions of tonic (30 nmol l-1), intermediate (60 nmol l-1) and maximal (200 nmol l-1) adrenergic stimulation. Heart rate increased significantly with both temperature and adrenaline concentration. The Q10 values for heart rate ranged from 1.28 at 30 nmol l-1 adrenaline to 1.36 at 200 nmol l-1 adrenaline. In contrast to heart rate, maximum stroke volume declined by approximately 20 % (from 1.0 to 0.8 ml kg-1) as temperature increased from 15 to 22 °C. This decrease was not alleviated by maximally stimulating the heart with 200 nmol l-1 adrenaline. Because of the equal and opposite effects of increasing temperature on heart rate and stroke volume, maximum cardiac output did not increase between 15 and 22 °C. Maximum power output decreased (by approximately 10-15 %) at all adrenaline concentrations as temperature increased. This reduction reflected a poorer pressure-generating ability at temperatures above 15 °C. These results, in combination with earlier work, suggest (1) that peak cardiac performance occurs around the trout's preferred temperature and well below its upper lethal limit; (2) that the diminished cardiac function concomitant with acclimation to high temperatures was associated with inotropic failure; (3) that Q10 values for cardiac rate functions, other than heart rate per se, have a limited predictive value at temperatures above the trout's preferred temperature; and (4) that heart rate is a poor indicator of cardiac function at temperatures above 15 °C.

Modification of alterations in cardiac function and sarcoplasmic reticulum by vanadate in ischemic-reperfused rat hearts

2005 ◽  
Vol 99 (3) ◽  
pp. 999-1005 ◽  
Author(s):  
Satoshi Takeda ◽  
Seibu Mochizuki ◽  
Harjot K. Saini ◽  
Vijayan Elimban ◽  
Naranjan S. Dhalla
Keyword(s):  
Superoxide Dismutase ◽  
Sarcoplasmic Reticulum ◽  
Cardiac Function ◽  
Diastolic Pressure ◽  
Ischemia Reperfusion ◽  
Cardiac Performance ◽  
Sr Protein ◽  
Release Channel ◽  
Beneficial Effects ◽  
Rat Hearts

To study the cardioprotective effects of vanadate on ischemia-reperfusion (I/R) injury, isolated rat hearts perfused at constant flow were subjected to global ischemia for 30 min followed by reperfusion for 30 min. In this experimental model, I/R markedly decreased ventricular developed pressure and increased end-diastolic pressure. Pretreatment of hearts with 4 μM vanadate attenuated I/R-induced cardiac dysfunction. The reduction in sarcoplasmic reticulum (SR) Ca2+ uptake and Ca2+ release, as well as SR protein contents for Ca2+-pump ATPase and Ca2+-release channel, was also prevented by vanadate. Pretreatment of hearts with an antioxidant mixture containing superoxide dismutase + catalase exerted effects similar to those of vanadate in I/R hearts. Postischemic treatment of hearts with vanadate or superoxide dismutase + catalase also had beneficial effects on I/R-induced changes in cardiac performance and SR function. Alterations in cardiac function and SR Ca2+ transport due to an oxyradical-generating system (xanthine + xanthine oxidase) or an oxidant (H2O2) were attenuated by treatment with vanadate. These results suggest that vanadate may exert beneficial effects on cardiac performance and SR function in I/R hearts because of its antioxidant action.

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