Na+,K+-ATPase as a Target for Treatment of Tissue Fibrosis

Myofibroblast activation is a critical process in the pathogenesis of tissue fibrosis accounting for 45% of all deaths. No effective therapies are available for the treatment of fibrotic diseases. We focus our mini-review on recent data showing that cardiotonic steroids (CTS) that are known as potent inhibitors of Na+,K+-ATPase affect myofibroblast differentiation in a cell type-specific manner. In cultured human lung fibroblasts (HLF), epithelial cells, and cancer-associated fibroblasts, CTS blocked myofibroblast differentiation triggered by profibrotic cytokine TGF-β. In contrast, in the absence of TGF-β, CTS augmented myofibroblast differentiation of cultured cardiac fibroblasts. The cell type-specific action of CTS in myofibroblast differentiation is consistent with data obtained in in vivo studies. Thus, infusion of ouabain via osmotic mini-pumps attenuated the development of lung fibrosis in bleomycintreated mice, whereas marinobufagenin stimulated renal and cardiac fibrosis in rats with experimental renal injury. In TGF-β-treated HLF, suppression of myofibroblast differentiation by ouabain is mediated by elevation of the [Na+]i/[K+]i ratio and is accompanied by upregulation of cyclooxygenase COX-2 and downregulation of TGF-β receptor TGFBR2. Augmented expression of COX-2 is abolished by inhibition of Na+/Ca2+ exchanger, suggesting a key role of [Ca2+]i-mediated signaling. What is the relative impact in tissue fibrosis of [Na+]i,[K+]iindependent signaling documented in several types of CTS-treated cells? Do the different conformational transitions of Na+,K+-ATPase α1 subunit in the presence of ouabain and marinobufagenin contribute to their distinct involvement in myofibroblast differentiation? Additional experiments should be done to answer these questions and to develop novel pharmacological approaches for the treatment of fibrosis-related disorders.

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Abstract P153: Role of Nonreceptor Tyrosine Kinases in Cardiac Fibrosis in a Mouse Model of Pressure Overload Hypertrophy

Circulation Research ◽

10.1161/res.109.suppl_1.ap153 ◽

2011 ◽

Vol 109 (suppl_1) ◽

Author(s):

Sundaravadivel Balasubramanian ◽

Harinath Kasiganesan ◽

Lakeya Quinones ◽

Yuhua Zhang ◽

Amy Bradshaw ◽

...

Keyword(s):

Tyrosine Kinases ◽

Cardiac Fibrosis ◽

Cardiac Fibroblasts ◽

Heart Diseases ◽

Pressure Overload ◽

In Vivo Studies ◽

Survival Pathways ◽

And Function ◽

Nonreceptor Tyrosine Kinases

During prolonged hypertrophic insult to the myocardium, while the function of cardiomyocytes needs to be protected, the hyperactivation of cardiac fibroblasts has to be curbed to prevent fibrosis. Previously, we showed that integrin-mediated non-receptor tyrosine kinase (NRTK) activation is required for normal functioning of both cardiac fibroblasts and cardiomyocytes. We hypothesized that inhibition of NRTKs in cardiac fibroblasts without affecting cardiomyocytes would be beneficial to the stressed myocardium. Our initial studies using kinase inactive forms of Src, Pyk2 and FAK expressed adenovirally in isolated primary cardiac fibroblasts showed that the pro-fibrotic signaling events as studied by fibronectin and collagen deposition are downregulated. Our in vivo studies in mouse transverse aortic constriction (TAC) model suggest that dasatinib, a multikinase NRTK inhibitor administration via a peritoneally implanted mini-osmotic pump is able to preserve ventricular geometry and function and reduce the accumulation of fibrotic extracellular matrix (ECM) proteins upon 4 wk pressure overload. Data obtained from cell culture experiments with kinase inactive NRTKs and dasatinib suggest that NRTK inhibition is able to reduce the proliferation, migration and mitogenic signaling in cardiac fibroblasts without affecting the cell survival pathways in cardiomyocytes. These data indicate that NRTKs play a significant pro-fibrotic role in cardiac fibroblasts and curbing the activity of NRTKs could be a potential therapeutic approach to treat fibrosis in hypertrophic heart diseases.

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The double face of miR-320: cardiomyocytes-derived miR-320 deteriorated while fibroblasts-derived miR-320 protected against heart failure induced by transverse aortic constriction

Signal Transduction and Targeted Therapy ◽

10.1038/s41392-020-00445-8 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Xudong Zhang ◽

Shuai Yuan ◽

Huaping Li ◽

Jiabing Zhan ◽

Feng Wang ◽

...

Keyword(s):

Heart Failure ◽

Signaling Pathway ◽

Cardiac Fibrosis ◽

Cell Types ◽

Transverse Aortic Constriction ◽

Cell Type ◽

Aortic Constriction ◽

Cell Type Specific ◽

Pathway Analyses

AbstractMicroRNAs (miRNAs) are aberrantly expressed in the pathophysiologic process of heart failure (HF). However, the functions of a certain miRNA in different cardiac cell types during HF are scarcely reported, which might be covered by the globe effects of it on the heart. In the current study, Langendorff system was applied to isolate cardiomyocytes (CMs) and cardiac fibroblasts (CFs) from transverse aortic constriction (TAC)-induced mice. Slight increase of miR-320 expression was observed in the whole heart tissue of TAC mice. Interestingly, miR-320 was significantly elevated in CMs but decreased in CFs from TAC mice at different time points. Then, recombinant adeno-associated virus 9 with cell-type-specific promoters were used to manipulate miR-320 expressions in vivo. Both in vitro and in vivo experiments showed the miR-320 overexpression in CMs exacerbated cardiac dysfunction, whereas overexpression of miR-320 in CFs alleviated cardiac fibrosis and hypertrophy. Mechanically, downstream signaling pathway analyses revealed that miR-320 might induce various effects via targeting PLEKHM3 and IFITM1 in CMs and CFs, respectively. Moreover, miR-320 mediated effects could be abolished by PLEKHM3 re-expression in CMs or IFITM1 re-expression in CFs. Interestingly, miR-320 treated CFs were able to indirectly affect CMs function, but not vice versa. Meanwhile, upstream signaling pathway analyses showed that miR-320 expression and decay rate were rigorously manipulated by Ago2, which was regulated by a cluster of cell-type-specific TFs distinctively expressed in CMs and CFs, respectively. Together, we demonstrated that miR-320 functioned differently in various cell types of the heart during the progression of HF.

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Beneficial effects of spermidine on cardiovascular health and longevity suggest a cell type-specific import of polyamines by cardiomyocytes

Biochemical Society Transactions ◽

10.1042/bst20180622 ◽

2018 ◽

Vol 47 (1) ◽

pp. 265-272 ◽

Cited By ~ 3

Author(s):

Bengt-Olof Nilsson ◽

Lo Persson

Keyword(s):

Cardiovascular Health ◽

In Vivo Studies ◽

Special Focus ◽

Cell Type ◽

Excitable Cells ◽

Beneficial Effects ◽

A Cell ◽

Cell Type Specific ◽

Stimulation Of

Abstract Recent and exciting in vivo studies show that supplementation with the polyamine spermidine (Spd) is cardioprotective and prolongs lifespan in both mice and humans. The mechanisms behind Spd-induced cardioprotection are supposed to involve Spd-evoked stimulation of autophagy, mitophagy and mitochondrial respiration and improved the mechano-elastical function of cardiomyocytes. Although cellular uptake of Spd was not characterized, these results suggest that Spd is imported by the cardiomyocytes and acts intracellularly. In the light of these new and thrilling data, we discuss in the present review cellular polyamine import with a special focus on mechanisms that may be relevant for Spd uptake by electrically excitable cells such as cardiomyocytes.

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Mechanoregulation of cardiac myofibroblast differentiation: implications for cardiac fibrosis and therapy

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00299.2015 ◽

2015 ◽

Vol 309 (4) ◽

pp. H532-H542 ◽

Cited By ~ 31

Author(s):

Kar Wey Yong ◽

YuHui Li ◽

GuoYou Huang ◽

Tian Jian Lu ◽

Wan Kamarul Zaman Wan Safwani ◽

...

Keyword(s):

Cardiac Fibrosis ◽

Cardiac Fibroblasts ◽

Three Dimensional ◽

Myofibroblast Differentiation ◽

Matrix Stiffness ◽

Extracellular Matrix Stiffness ◽

Mechanical Microenvironment

Cardiac myofibroblast differentiation, as one of the most important cellular responses to heart injury, plays a critical role in cardiac remodeling and failure. While biochemical cues for this have been extensively investigated, the role of mechanical cues, e.g., extracellular matrix stiffness and mechanical strain, has also been found to mediate cardiac myofibroblast differentiation. Cardiac fibroblasts in vivo are typically subjected to a specific spatiotemporally changed mechanical microenvironment. When exposed to abnormal mechanical conditions (e.g., increased extracellular matrix stiffness or strain), cardiac fibroblasts can undergo myofibroblast differentiation. To date, the impact of mechanical cues on cardiac myofibroblast differentiation has been studied both in vitro and in vivo. Most of the related in vitro research into this has been mainly undertaken in two-dimensional cell culture systems, although a few three-dimensional studies that exist revealed an important role of dimensionality. However, despite remarkable advances, the comprehensive mechanisms for mechanoregulation of cardiac myofibroblast differentiation remain elusive. In this review, we introduce important parameters for evaluating cardiac myofibroblast differentiation and then discuss the development of both in vitro (two and three dimensional) and in vivo studies on mechanoregulation of cardiac myofibroblast differentiation. An understanding of the development of cardiac myofibroblast differentiation in response to changing mechanical microenvironment will underlie potential targets for future therapy of cardiac fibrosis and failure.

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The deficiency of miR-214-3p exacerbates cardiac fibrosis via miR-214-3p/NLRC5 axis

Clinical Science ◽

10.1042/cs20190203 ◽

2019 ◽

Vol 133 (17) ◽

pp. 1845-1856 ◽

Cited By ~ 6

Author(s):

Kun Yang ◽

Jiaran Shi ◽

Zhujun Hu ◽

Xiaosheng Hu

Keyword(s):

Cardiac Fibrosis ◽

Cardiac Fibroblasts ◽

Conditional Knockout ◽

In Vivo Studies ◽

Sham Operation ◽

Pathological Feature ◽

Important Regulator

Abstract Cardiac fibrosis is a common pathological feature of many cardiovascular diseases. The regulatory mechanisms of miRNAs in cardiac fibrosis are still unknown. Previous studies on miR-214-3p in cardiac fibroblasts reached contradictory conclusions. Thus the role of miR-214-3p in cardiac fibrosis deserves further exploration. Using a combination of in vitro and in vivo studies, we identified miR-214-3p as an important regulator of cardiac fibrosis, and the proliferation and activation of cardiac fibroblasts. We demonstrated that the expression of miR-214-3p is down-regulated in TGF-β1-treated myofibroblasts and transverse aortic constriction (TAC)-induced murine model. Additionally, miR-214-3pflox/flox/FSP1-cre mice and miR-214-3pwt/wt/FSP1-cre mice were subjected to TAC operation or sham operation, and the conditional knockout of miR-214-3p in cardiac fibroblasts aggravates TAC-induced cardiac fibrosis. In vitro, our results indicate that miR-214-3p is an important repressor for fibroblasts proliferation and fibroblast-to-myofibroblast transition by functionally targeting NOD-like receptor family CARD domain containing 5 (NLRC5). In conclusion, our findings show that the deficiency of miR-214-3p exacerbates cardiac fibrosis and reveal a novel miR-214-3p/NLRC5 axis in the regulation of cardiac fibrosis.

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ITag-RNA Allows in Vivo Cell-Type Specific Transcriptional Characterization and Tracking of Circulating Transcripts

SSRN Electronic Journal ◽

10.2139/ssrn.3229487 ◽

2018 ◽

Author(s):

J. Darr ◽

M. Lassi ◽

R. Gerlini ◽

F. Scheid ◽

M. Hrabě de Angelis ◽

...

Keyword(s):

Cell Type ◽

Cell Type Specific

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Differential pial and penetrating arterial responses examined by optogenetic activation of astrocytes and neurons

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x211010355 ◽

2021 ◽

pp. 0271678X2110103

Author(s):

Nao Hatakeyama ◽

Miyuki Unekawa ◽

Juri Murata ◽

Yutaka Tomita ◽

Norihiro Suzuki ◽

...

Keyword(s):

Cortical Neurons ◽

Acetylcholine Receptors ◽

Step Function ◽

Muscarinic Acetylcholine Receptors ◽

Cell Type ◽

Function Type ◽

Neuron Activation ◽

Cell Type Specific ◽

Arterial Responses

A variety of brain cells participates in neurovascular coupling by transmitting and modulating vasoactive signals. The present study aimed to probe cell type-dependent cerebrovascular (i.e., pial and penetrating arterial) responses with optogenetics in the cortex of anesthetized mice. Two lines of the transgenic mice expressing a step function type of light-gated cation channel (channelrhodopsine-2; ChR2) in either cortical neurons (muscarinic acetylcholine receptors) or astrocytes (Mlc1-positive) were used in the experiments. Photo-activation of ChR2-expressing astrocytes resulted in a widespread increase in cerebral blood flow (CBF), extending to the nonstimulated periphery. In contrast, photo-activation of ChR2-expressing neurons led to a relatively localized increase in CBF. The differences in the spatial extent of the CBF responses are potentially explained by differences in the involvement of the vascular compartments. In vivo imaging of the cerebrovascular responses revealed that ChR2-expressing astrocyte activation led to the dilation of both pial and penetrating arteries, whereas ChR2-expressing neuron activation predominantly caused dilation of the penetrating arterioles. Pharmacological studies showed that cell type-specific signaling mechanisms participate in the optogenetically induced cerebrovascular responses. In conclusion, pial and penetrating arterial vasodilation were differentially evoked by ChR2-expressing astrocytes and neurons.

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