scholarly journals β2-Adrenergic Receptors Increase Cardiac Fibroblast Proliferation Through the Gαs/ERK1/2-Dependent Secretion of Interleukin-6

2020 ◽  
Vol 21 (22) ◽  
pp. 8507
Author(s):  
Miles A. Tanner ◽  
Toby P. Thomas ◽  
Charles A. Maitz ◽  
Laurel A. Grisanti
Keyword(s):  
Adrenergic Receptors ◽  
Structural Integrity ◽  
Cytokine Production ◽  
Cardiac Fibroblasts ◽  
Cell Types ◽  
Fibroblast Proliferation ◽  
Primary Fibroblast ◽  
Disease States ◽  
Adult Mice

Fibroblasts are an important resident cell population in the heart involved in maintaining homeostasis and structure during normal conditions. They are also crucial in disease states for sensing signals and initiating the appropriate repair responses to maintain the structural integrity of the heart. This sentinel role of cardiac fibroblasts occurs, in part, through their ability to secrete cytokines. β-adrenergic receptors (βAR) are also critical regulators of cardiac function in the normal and diseased state and a major therapeutic target clinically. βAR are known to influence cytokine secretion in various cell types and they have been shown to be involved in cytokine production in the heart, but their role in regulating cytokine production in cardiac fibroblasts is not well understood. Thus, we hypothesized that βAR activation on cardiac fibroblasts modulates cytokine production to influence fibroblast function. Using primary fibroblast cultures from neonatal rats and adult mice, increased interleukin (IL)-6 expression and secretion occurred following β2AR activation. The use of pharmacological inhibitors and genetic manipulations showed that IL-6 elevations occurred through the Gαs-mediated activation of ERK1/2 and resulted in increased fibroblast proliferation. In vivo, a lack of β2AR resulted in increased infarct size following myocardial infarction and impaired wound closure in a murine dermal wound healing assay. These findings identify an important role for β2AR in regulating fibroblast proliferation through Gαs/ERK1/2-dependent alterations in IL-6 and may lead to the development of improved heart failure therapies through targeting fibrotic function of β2AR.

Abstract 421: Activated Cardiac Myofibroblasts Can Revert Back to Become Resident Fibroblasts Upon Injury Cessation

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Onur Kanisicak ◽  
Jason Karch ◽  
Hadi Khalil ◽  
Bryan Maliken ◽  
Jeffery D Molkentin
Keyword(s):  
Cardiac Fibroblasts ◽  
Cell Types ◽  
Lineage Tracing ◽  
Marker Genes ◽  
Fibrotic Response ◽  
Disease States ◽  
Unique Cell ◽  
Injury Recovery ◽  
Cardiac Myofibroblasts

Resident cardiac fibroblasts (CFs) are potential therapeutic targets in treating heart failure given the prominent role that fibrosis plays in this disorder. CFs directly convert to myofibroblasts (MFs) with injury where they mediate both adaptive wound healing after acute myocardial infarction as well as long-standing fibrosis during chronic disease states. However, the fate of activated MFs after injury recovery or when an infarction scar is stabilized remains poorly understood, in part because the field has lacked a definitive strategy for identifying and tracing MFs and CFs in vivo. To address this issue we recently generated a novel mouse model that permits lineage tracing of all MFs in the heart after injury or stress stimulation, which we used to address the fate of MFs after injury resolution. MFs were lineage traced with a tamoxifen inducible periostin allele knockin of the MerCreMer cDNA (PostnMCM), with a Rosa26-eGFP dependent reporter. PostnMCM x R26-eGFP mice were transiently injured with the combined infusion of angiotensin II and phenylephrine (Ang/PE) for 2 weeks, during which time tamoxifen was also given to trace all newly formed MFs. Mice were then allowed to “rest” for 2 weeks or longer with no Ang/PE as the fibrotic response regressed, and the fate of the eGFP + cells was assessed. The data show that immediately after 2 weeks of Ang/PE infusion nearly all the eGFP+ periostin lineage-traced myofibroblasts were αSMA positive and have an activated myofibroblast gene expression profile. However, when the fibrotic response regressed weeks later, a number of periostin-lineage traced eGFP+ cells were still present in the heart and these cells showed a phenotypic and molecular reversion back to CFs with a loss of myofibroblast marker genes. These results suggest that CFs are very unique cell types that can differentiate to MFs then back again to resident CFs.

scholarly journals Gastric Hyperplasia and Increased Proliferative Responses of Lymphocytes in Mice Lacking the COOH-terminal Ankyrin Domain of NF-κB2

1997 ◽  
Vol 186 (7) ◽  
pp. 999-1014 ◽  
Author(s):  
Hideaki Ishikawa ◽  
Daniel Carrasco ◽  
Estefania Claudio ◽  
Rolf-Peter Ryseck ◽  
Rodrigo Bravo
Keyword(s):  
T Cells ◽  
Lymphocyte Proliferation ◽  
Cytokine Production ◽  
Cell Types ◽  
Homozygous Deletion ◽  
Binding Activity ◽  
Activated T Cells ◽  
Physiological Relevance

The nfkb2 gene encodes the p100 precursor which produces the p52 protein after proteolytic cleavage of its COOH-terminal domain. Although the p52 product can act as an alternative subunit of NF-κB, the p100 precursor is believed to function as an inhibitor of Rel/NF-κB activity by cytoplasmic retention of Rel/NF-κB complexes, like other members of the IκB family. However, the physiological relevance of the p100 precursor as an IκB molecule has not been understood. To assess the role of the precursor in vivo, we generated, by gene targeting, mice lacking p100 but still containing a functional p52 protein. Mice with a homozygous deletion of the COOH-terminal ankyrin repeats of NF-κB2 (p100−/−) had marked gastric hyperplasia, resulting in early postnatal death. p100−/− animals also presented histopathological alterations of hematopoietic tissues, enlarged lymph nodes, increased lymphocyte proliferation in response to several stimuli, and enhanced cytokine production in activated T cells. Dramatic induction of nuclear κB–binding activity composed of p52-containing complexes was found in all tissues examined and also in stimulated lymphocytes. Thus, the p100 precursor is essential for the proper regulation of p52-containing Rel/NF-κB complexes in various cell types and its absence cannot be efficiently compensated for by other IκB proteins.

scholarly journals Inhibition of mTOR during a postnatal critical sensitive window rescues deficits in GABAergic PV cell connectivity and social behavior caused by loss of TSC1

2020 ◽  
Author(s):  
Mayukh Choudhury ◽  
Clara A. Amegandjin ◽  
Vidya Jadhav ◽  
Josianne Nunes Carriço ◽  
Ariane Quintal ◽  
...  
Keyword(s):  
Social Behavior ◽  
Time Course ◽  
Cell Types ◽  
Developmental Time ◽  
Adult Mice ◽  
Mtorc1 Signaling ◽  
Pv Cell ◽  
Mechanistic Basis

ABSTRACTMutations in regulators of the Mechanistic Target Of Rapamycin Complex 1 (mTORC1), such as Tsc1/2, lead to neurodevelopmental disorders associated with autism, intellectual disabilities and epilepsy. Whereas the effects of mTORC1 signaling dysfunction within diverse cell types are likely critical for the onset of the diverse neurological symptoms associated with mutations in mTORC1 regulators, they are not well understood. In particular, the effects of mTORC1 dys-regulation in specific types of inhibitory interneurons are unclear.Here, we showed that Tsc1 haploinsufficiency in parvalbumin (PV)-positive GABAergic interneurons either in cortical organotypic cultures or in vivo caused a premature increase in their perisomatic innervations, followed by a striking loss in adult mice. This effects were accompanied by alterations of AMPK-dependent autophagy in pre-adolescent but not adult mice. PV cell-restricted Tsc1 mutant mice showed deficits in social behavior. Treatment with the mTOR inhibitor Rapamycin restricted to the third postnatal week was sufficient to permanently rescue deficits in both PV cell innervation and social behavior in adult conditional haploinsufficient mice. All together, these findings identify a novel role of Tsc1-mTORC1 signaling in the regulation of the developmental time course and maintenance of cortical PV cell connectivity and provide a mechanistic basis for the targeted rescue of autism-related behaviors in disorders associated with deregulated mTORC1 signaling.

Abstract 92: Platelet Derived Growth Factor Receptor Alpha Signaling is Required for Cardiac Fibroblast Survival and Proliferation

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Malina J Ivey ◽  
Michelle D Tallquist
Keyword(s):  
Preliminary Data ◽  
Cardiac Fibrosis ◽  
Heart Function ◽  
Cardiac Fibroblasts ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Fibroblast Proliferation ◽  
Artery Ligation ◽  
Developing Heart ◽  
Factor Receptor Alpha

Cardiac fibrosis contributes significantly to heart disease and is a hallmark of decreased cardiac function. Currently, there are no treatments that attenuate fibrosis, but identification of signaling pathways required for fibroblast function would provide some potential targets. PDGFRα is a receptor tyrosine kinase that is required for fibroblast formation in the developing heart, and preliminary data indicates that it is also required for maintenance of resident fibroblasts and expansion of activated fibroblasts after injury. Preliminary experiments demonstrate that loss of PDGFRα expression in adult cardiac fibroblasts results in 50% reduction in the number of the resident fibroblasts by 4 days after gene deletion. This was further validated using an independent fibroblast marker, collagen1a1GFP. Based on the low basal level of fibroblast proliferation, we hypothesize that PDGFRα signaling is essential for fibroblast survival and that fibroblasts undergo rapid turnover in the absence of PDGFRα signaling. Future studies will determine the exact mechanism of this loss. We have also begun to elucidate which PDGFRα downstream signals promote fibroblast maintenance. Using a PDGFRα-dependent-PI3K-deficient mouse model, preliminary data indicates that PDGFRα-dependent PI3K signaling is essential for cell survival. We are also investigating the role of PDGFRα signaling after myocardial infarction. Using recently described genetic tools to follow fibroblasts after injury, we have determined that fibroblasts reach their peak of proliferation within a week after permanent left anterior descending artery ligation. This injury-induced proliferation is reduced by 50% after deletion of PDGFRα. Therefore, we have demonstrated that PDGFRα has a role in fibroblast maintenance in the healthy heart, as well as a role in fibroblast proliferation after injury. Our studies will continue to illuminate additional roles for PDGFRα in the fibroblast, as well as the implications of fibroblast loss on other cell types and overall heart function.

Cytokine-mediated PGE2expression in human colonic fibroblasts

1998 ◽  
Vol 275 (4) ◽  
pp. C988-C994 ◽  
Author(s):  
Edward C. Kim ◽  
Yingting Zhu ◽  
Valerie Andersen ◽  
Daniela Sciaky ◽  
H. James Cao ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Lines ◽  
Shape Change ◽  
Cell Types ◽  
Mrna Levels ◽  
Primary Fibroblast ◽  
Fibroblast Cultures ◽  
Epithelial Cell Lines ◽  
Factor Α

We investigated prostanoid biogenesis in human colonic fibroblasts (CCD-18Co and 5 primary fibroblast cultures) and epithelial cell lines (NCM460, T84, HT-29, and LS 174T) and the effect of PGE2 on fibroblast morphology. Cytokine-stimulated PGE2production was measured. PGH synthase-1 and -2 (PGHS-1 and -2) protein and mRNA expression were evaluated. Basal PGE2 levels were low in all cell types (0.15–6.47 ng/mg protein). Treatment for 24 h with interleukin-1β (IL-1β; 10 ng/ml) or tumor necrosis factor-α (50 ng/ml), respectively, elicited maximal 25- and 6-fold inductions of PGE2 synthesis in CCD-18Co cultures and similar results in primary fibroblast cultures; maximal inductions with IL-1β in colonic epithelial cell lines were from zero to fivefold. Treatment of CCD-18Co fibroblasts with IL-1β caused maximal 21- and 53-fold increases, respectively, in PGHS-2 protein and mRNA levels without altering PGHS-1 expression. PGE2 (0.1 μmol/l) elicited a dramatic shape change in selected fibroblasts. Colonic fibroblasts are potentially important as cytokine targets and a source of and target for colonic prostanoids in vivo.

scholarly journals Genetic neuroscience of mammalian learning and memory

2003 ◽  
Vol 358 (1432) ◽  
pp. 787-795 ◽  
Author(s):  
Susumu Tonegawa ◽  
Kazu Nakazawa ◽  
Matthew A. Wilson
Keyword(s):  
Cell Types ◽  
Genetically Engineered ◽  
Mouse Strains ◽  
Cellular Mechanisms ◽  
Genetic Manipulations ◽  
Adult Mice ◽  
Multiple Levels ◽  
Primary Research Interest

Our primary research interest is to understand the molecular and cellular mechanisms on neuronal circuitry underlying the acquisition, consolidation and retrieval of hippocampus-dependent memory in rodents. We study these problems by producing genetically engineered (i.e. spatially targeted and/or temporally restricted) mice and analysing these mice by multifaceted methods including molecular and cellular biology, in vitro and in vivo physiology and behavioural studies. We attempt to identify deficits at each of the multiple levels of complexity in specific brain areas or cell types and deduce those deficits that underlie specific learning or memory. We will review our recent studies on the acquisition, consolidation and recall of memories that have been conducted with mouse strains in which genetic manipulations were targeted to specific types of cells in the hippocampus or forebrain of young adult mice.

scholarly journals Exogenous Heat-Killed Escherichia coli Improves Alveolar Macrophage Activity and Reduces Pneumocystis carinii Lung Burden in Infant Mice

2007 ◽  
Vol 75 (7) ◽  
pp. 3382-3393 ◽  
Author(s):  
Kerry M. Empey ◽  
Melissa Hollifield ◽  
Beth A. Garvy
Keyword(s):  
Escherichia Coli ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Cytokine Production ◽  
Pneumocystis Carinii ◽  
Effector Cells ◽  
Macrophage Activity ◽  
Adult Mice

ABSTRACT Pneumocystis carinii is an opportunistic fungal pathogen that causes life-threatening pneumonia in immunocompromised individuals. Infants appear to be particularly susceptible to Pneumocystis pulmonary infections. We have previously demonstrated that there is approximately a 3-week delay in the clearance of Pneumocystis organisms from pup mouse lungs compared to that in adults. We have further shown that there is approximately a 1-week delay in alveolar macrophage activation in pups versus adult mice. Alveolar macrophages are the primary effector cells responsible for the killing and clearance of Pneumocystis, suggesting that pup alveolar macrophages may be involved in the delayed clearance of this organism. Alveolar macrophages cultured in vitro with Pneumocystis alone demonstrate little to no activation, as indicated by a lack of cytokine production. However, when cultured with lipopolysaccharide (LPS) or zymosan, cytokine production was markedly increased, suggesting that pup alveolar macrophages are specifically unresponsive to Pneumocystis organisms rather than being intrinsically unable to become activated. Furthermore, pup mice treated with aerosolized, heat-killed Escherichia coli in vivo were able to clear Pneumocystis more efficiently than were control mice. Together, these data suggest that while pup alveolar macrophages are unresponsive to P. carinii f. sp. muris organisms, they are capable of activation by heat-killed E. coli in vivo, as well as LPS and zymosan in vitro. The lack of response of pup mice to P. carinii f. sp. muris may reflect protective mechanisms specific to the developing pup lung, but ultimately it results in insufficient clearance of Pneumocystis organisms.

STAT5 promotes multilineage hematolymphoid development in vivo through effects on early hematopoietic progenitor cells

Blood ◽  
2002 ◽  
Vol 99 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Jonathan W. Snow ◽  
Ninan Abraham ◽  
Melissa C. Ma ◽  
Nancy W. Abbey ◽  
Brian Herndier ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Blood Cell ◽  
Progenitor Cells ◽  
Cell Types ◽  
Hematopoietic Stem ◽  
Signal Transducers ◽  
Adult Mice ◽  
Colony Forming Units ◽  
Proliferation Activity

The transcription factor signal transducers and activators of transcription 5 (STAT5) is activated by numerous cytokines that orchestrate blood cell development. Multilineage peripheral blood cytopenias were observed in adult mice lacking both isoforms of STAT5 (STAT5A and STAT5B) as well as accelerated rates of apoptosis in the bone marrow. Although the hematopoietic stem cell (HSC) population was preserved in a number of these mice, the post-HSC progenitor populations were diminished and a marked reduction in functional progenitors (spleen colony-forming units) was detected. Competitive bone marrow transplantation studies in vivo revealed a profound impairment of repopulation potential of STAT5-null HSCs, leading to complete lack of contribution to the myeloid, erythroid, and lymphoid lineages. These abnormalities were associated with heightened proliferation activity in the HSC fraction, suggesting the action of homeostatic mechanisms to maintain sufficient levels of diverse blood cell types for viability. Thus, STAT5 normally sustains the robust hematopoietic reserve that contributes to host viability through crucial survival effects on early progenitor cells.

Cardiac fibroblasts: friend or foe?

2006 ◽  
Vol 291 (3) ◽  
pp. H1015-H1026 ◽  
Author(s):  
Troy A. Baudino ◽  
Wayne Carver ◽  
Wayne Giles ◽  
Thomas K. Borg
Keyword(s):  
Cardiac Function ◽  
Cardiac Fibroblasts ◽  
Cell Types ◽  
Dynamic Interaction ◽  
Normal Function ◽  
Complex Signals ◽  
Stage Of Development ◽  
Electrical Stimuli

Cardiac function is determined by the dynamic interaction of various cell types and the extracellular matrix that composes the heart. This interaction varies with the stage of development and the degree and duration of mechanical, chemical, and electrical signals between the various cell types and the ECM. Understanding how these complex signals interact at the molecular, cellular, and organ levels is critical to understanding the function of the heart under a variety of physiological and pathophysiological conditions. Quantitative approaches, both in vivo and in vitro, are essential to understand the dynamic interaction of mechanical, chemical, and electrical stimuli that govern cardiac function. The fibroblast can thus be a friend in normal function or a foe in pathophysiological conditions.

Effects of the JNK inhibitor anthra[1,9-cd]pyrazol-6(2H)-one (SP-600125) on soluble guanylyl cyclase α1gene regulation and cGMP synthesis

2005 ◽  
Vol 289 (4) ◽  
pp. C778-C784 ◽  
Author(s):  
Joshua S. Krumenacker ◽  
Alexander Kots ◽  
Ferid Murad
Keyword(s):  
Pc12 Cells ◽  
Guanylyl Cyclase ◽  
Soluble Guanylyl Cyclase ◽  
Fetal Lung ◽  
Cell Types ◽  
Mrna Levels ◽  
Disease States ◽  
Jun Kinase ◽  
Constitutively Active

The decreased expression of the nitric oxide (NO) receptor, soluble guanylyl cyclase (sGC), occurs in response to multiple stimuli in vivo and in cell culture and correlates with various disease states such as hypertension, inflammation, and neurodegenerative disorders. The ability to understand and modulate sGC expression and cGMP levels in any of these conditions could be a valuable therapeutic tool. We demonstrate herein that the c-Jun NH2-terminal kinase JNK II inhibitor anthra[1,9- cd]pyrazol-6(2 H)-one (SP-600125) completely blocked the decreased expression of sGCα1-subunit mRNA by nerve growth factor (NGF) in PC12 cells. Inhibitors of the ERK and p38 MAPK pathways, PD-98059 and SB-203580, had no effect. SP-600125 also inhibited the NGF-mediated decrease in the expression of sGCα1protein as well as sGC activity in PC12 cells. Other experiments revealed that decreased sGCα1mRNA expression through a cAMP-mediated pathway, using forskolin, was not blocked by SP-600125. We also demonstrate that TNF-α/IL-1β stimulation of rat fetal lung (RFL-6) fibroblast cells resulted in sGCα1mRNA inhibition, which was blocked by SP-600125. Expression of a constitutively active JNKK2-JNK1 fusion protein in RFL-6 cells caused endogenous sGCα1mRNA levels to decrease, while a constitutively active ERK2 protein had no effect. Collectively, these data demonstrate that SP-600125 may influence the intracellular levels of the sGCα1-subunit in certain cell types and may implicate a role for c-Jun kinase in the regulation of sGCα1expression.

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