Effects of tertiary and quaternary derivatives of aminomethylenedioxyindenes on some experimental arrhythmias

1982 ◽  
Vol 60 (12) ◽  
pp. 1636-1642 ◽  
Author(s):  
Joseph J. Lynch ◽  
Ralf G. Rahwan ◽  
Richard J. Brumbaugh ◽  
Donald T. Witiak
Keyword(s):  
Cardiac Tissue ◽  
Metabolic Activation ◽  
Antiarrhythmic Activity ◽  
Cardiac Cells ◽  
Electrophysiological Properties ◽  
Calcium Dependent ◽  
Derivatives Of ◽  
Antiarrhythmic Effects

The 2-n-propyl- and 2-n-butyl-3-dimethylamino-5, 6-methylenedioxyindene hydrochlorides are intracellular calcium antagonists with coronary dilating and antiarrhythmic effects against ouabain- and calcium-induced arrhythmias. In the present study, pretreatment with these tertiary methylenedioxyindenes afforded significant protection against the calcium-dependent arrhythmias induced by chloroform in mice. On the other hand, their antiarrhythmic activity against aconitine- and metha-choline-induced arrhythmias in rats (in which calcium does not play a primary etiological role) was suggestive but not impressive. The quaternary derivative, 2-n-butyl-5, 6-methylenedioxy-3-trimethylammonium iodide, which was synthesized with the expectation of being devoid of antiarrhythmic activity owing to its exclusion from the intracellular compartment, unexpectedly demonstrated greater antiarrhythmic potency than the tertiary analogues against calcium-induced arrhythmias in rats and chloroform-induced arrhythmias in mice. Like the tertiary methylenedioxyindenes, the protective activity of the quaternary analogue against arrhythmias induced by aconitine or by methacholine in rats was suggestive but not impressive. Because of the relative inactivity of the quaternary methylenedioxyindene in vitro, it is proposed that its in vivo activity may be due either to metabolic activation or to concentration in cardiac tissue in sufficient quantity to allow diffusion into cardiac cells down a concentration gradient or to alter membrane electrophysiological properties to the extent of exerting antiarrhythmic activity.

scholarly journals Recapitulating Cardiac Structure and Function In Vitro from Simple to Complex Engineering

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 386
Author(s):  
Ana Santos ◽  
Yongjun Jang ◽  
Inwoo Son ◽  
Jongseong Kim ◽  
Yongdoo Park
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Computational Modeling ◽  
Cardiac Tissue ◽  
Cardiac Development ◽  
Heart Tissue ◽  
Cardiac Tissue Engineering ◽  
Cardiac Cells

Cardiac tissue engineering aims to generate in vivo-like functional tissue for the study of cardiac development, homeostasis, and regeneration. Since the heart is composed of various types of cells and extracellular matrix with a specific microenvironment, the fabrication of cardiac tissue in vitro requires integrating technologies of cardiac cells, biomaterials, fabrication, and computational modeling to model the complexity of heart tissue. Here, we review the recent progress of engineering techniques from simple to complex for fabricating matured cardiac tissue in vitro. Advancements in cardiomyocytes, extracellular matrix, geometry, and computational modeling will be discussed based on a technology perspective and their use for preparation of functional cardiac tissue. Since the heart is a very complex system at multiscale levels, an understanding of each technique and their interactions would be highly beneficial to the development of a fully functional heart in cardiac tissue engineering.

scholarly journals Monitoring contractility in single cardiomyocytes and whole hearts with bio-integrated microlasers

2019 ◽  
Author(s):  
Marcel Schubert ◽  
Lewis Woolfson ◽  
Isla RM Barnard ◽  
Andrew Morton ◽  
Becky Casement ◽  
...  
Keyword(s):  
Stem Cell ◽  
Single Molecule ◽  
Muscle Activation ◽  
Cardiac Tissue ◽  
Frequency Comb ◽  
Cardiac Cells ◽  
Optical Recording ◽  
Cardiac Contraction

AbstractCardiac regeneration and stem cell therapies depend critically on the ability to locally resolve the contractile properties of heart tissue1,2. Current regeneration approaches explore the growth of cardiac tissue in vitro and the injection of stem cell-derived cardiomyocytes3–6 (CMs) but scientists struggle with low engraftment rates and marginal mechanical improvements, leaving the estimated 26 million patients suffering from heart failure worldwide without effective therapy7–9. One impediment to further progress is the limited ability to functionally monitor injected cells as currently available techniques and probes lack speed and sensitivity as well as single cell specificity. Here, we introduce microscopic whispering gallery mode (WGM) lasers into beating cardiomyocytes to realize all-optical recording of transient cardiac contraction profiles with cellular resolution. The brilliant emission and high spectral sensitivity of microlasers to local changes in refractive index enable long-term tracking of individual cardiac cells, monitoring of drug administration, and accurate measurements of organ scale contractility in live zebrafish. Our study reveals changes in sarcomeric protein density as underlying factor to cardiac contraction which is of fundamental importance for understanding the mechano-biology of cardiac muscle activation. The ability to non-invasively assess functional properties of transplanted cells and engineered cardiac tissue will stimulate the development of novel translational approaches and the in vivo monitoring of physiological parameters more broadly. Likewise, the use of implanted microlasers as cardiac sensors is poised to inspire the adaptation of the most advanced optical tools known to the microresonator community, like quantum-enhanced single-molecule biosensing or frequency comb spectroscopy10.

scholarly journals The Future of Direct Cardiac Reprogramming: Any GMT Cocktail Variety?

2020 ◽  
Vol 21 (21) ◽  
pp. 7950
Author(s):  
Leyre López-Muneta ◽  
Josu Miranda-Arrubla ◽  
Xonia Carvajal-Vergara
Keyword(s):  
Transcription Factors ◽  
Cardiac Tissue ◽  
Sendai Virus ◽  
Direct Conversion ◽  
Myocardial Cell ◽  
Cardiac Cells ◽  
Human Cells ◽  
A Cell

Direct cardiac reprogramming has emerged as a novel therapeutic approach to treat and regenerate injured hearts through the direct conversion of fibroblasts into cardiac cells. Most studies have focused on the reprogramming of fibroblasts into induced cardiomyocytes (iCMs). The first study in which this technology was described, showed that at least a combination of three transcription factors, GATA4, MEF2C and TBX5 (GMT cocktail), was required for the reprogramming into iCMs in vitro using mouse cells. However, this was later demonstrated to be insufficient for the reprogramming of human cells and additional factors were required. Thereafter, most studies have focused on implementing reprogramming efficiency and obtaining fully reprogrammed and functional iCMs, by the incorporation of other transcription factors, microRNAs or small molecules to the original GMT cocktail. In this respect, great advances have been made in recent years. However, there is still no consensus on which of these GMT-based varieties is best, and robust and highly reproducible protocols are still urgently required, especially in the case of human cells. On the other hand, apart from CMs, other cells such as endothelial and smooth muscle cells to form new blood vessels will be fundamental for the correct reconstruction of damaged cardiac tissue. With this aim, several studies have centered on the direct reprogramming of fibroblasts into induced cardiac progenitor cells (iCPCs) able to give rise to all myocardial cell lineages. Especially interesting are reports in which multipotent and highly expandable mouse iCPCs have been obtained, suggesting that clinically relevant amounts of these cells could be created. However, as of yet, this has not been achieved with human iCPCs, and exactly what stage of maturity is appropriate for a cell therapy product remains an open question. Nonetheless, the major concern in regenerative medicine is the poor retention, survival, and engraftment of transplanted cells in the cardiac tissue. To circumvent this issue, several cell pre-conditioning approaches are currently being explored. As an alternative to cell injection, in vivo reprogramming may face fewer barriers for its translation to the clinic. This approach has achieved better results in terms of efficiency and iCMs maturity in mouse models, indicating that the heart environment can favor this process. In this context, in recent years some studies have focused on the development of safer delivery systems such as Sendai virus, Adenovirus, chemical cocktails or nanoparticles. This article provides an in-depth review of the in vitro and in vivo cardiac reprograming technology used in mouse and human cells to obtain iCMs and iCPCs, and discusses what challenges still lie ahead and what hurdles are to be overcome before results from this field can be transferred to the clinical settings.

scholarly journals Engineering Biomaterials to Guide Heart Cells for Matured Cardiac Tissue

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 925
Author(s):  
Yongjun Jang ◽  
Yongdoo Park ◽  
Jongseong Kim
Keyword(s):  
Cardiac Tissue ◽  
Structural Integrity ◽  
Cardiac Cells ◽  
Heart Cells ◽  
Cardiac Tissues ◽  
Main Components ◽  
2D And 3D ◽  
Suitable Environment

The extracellular matrix (ECM) is needed to maintain the structural integrity of tissues and to mediate cellular dynamics. Its main components are fibrous proteins and glycosaminoglycans, which provide a suitable environment for biological functions. Thus, biomaterials with ECM-like properties have been extensively developed by modulating their key components and properties. In the field of cardiac tissue engineering, the use of biomaterials offers several advantages in that biophysical and biochemical cues can be designed to mediate cardiac cells, which is critical for maturation and regeneration. This suggests that understanding biomaterials and their use in vivo and in vitro is beneficial in terms of advancing cardiac engineering. The current review provides an overview of both natural and synthetic biomaterials and their use in cardiac engineering. In addition, we focus on different strategies to recapitulate the cardiac tissue in 2D and 3D approaches, which is an important step for the maturation of cardiac tissues toward regeneration of the adult heart.

scholarly journals Artemisinin-Resistant Mutants of Toxoplasma gondii Have Altered Calcium Homeostasis

2007 ◽  
Vol 51 (11) ◽  
pp. 3816-3823 ◽  
Author(s):  
Kisaburo Nagamune ◽  
Silvia N. J. Moreno ◽  
L. David Sibley
Keyword(s):  
Toxoplasma Gondii ◽  
Mechanism Of Action ◽  
Calcium Homeostasis ◽  
Apicomplexan Parasites ◽  
Calcium Dependent ◽  
Molecular Alterations ◽  
Derivatives Of ◽  
Important Drug

ABSTRACT Artemisinin is a plant sesquiterpene lactone that has become an important drug for combating malaria, especially in regions where resistance to other drugs is widespread. While the mechanism of action is debated, artemisinin has been reported to inhibit the sarcoplasmic endoplasmic reticulum Ca2+ ATPase (SERCA) in the malaria parasite. Artemisinin is also effective against Toxoplasma in vitro and in vivo, although it is less potent and, hence, is generally not used therapeutically to treat toxoplasmosis. To explore the mechanism of action, we generated chemically derived mutants of Toxoplasma gondii that were resistant to growth inhibition by this compound in vitro. Three artemisinin-resistant (ARTr) mutant clones that differed in their sensitivities in vitro by three- to fivefold compared with that of the wild-type parasites were obtained. ARTr mutants were cross-resistant to other derivatives of artemisinin, the most potent of which was artemisone. Resistance was not due to molecular alterations or differences in the expression of SERCA or other putative targets, such as proteins that code for multidrug resistance or translationally controlled tumor protein. ARTr mutants were resistant to the induction of protein secretion from micronemes, a calcium-dependent process that is triggered by artemisinin. ARTr mutants were not cross-resistant to secretion induced by thapsigargin but were more sensitive and were unable to regulate cytoslic calcium following treatment with this compound. These studies implicate calcium homeostasis in the mechanism of action of artemisinins against apicomplexan parasites.

Derivatives of Deoxypodophyllotoxin Induce Apoptosis Through Bcl-2/Bax Proteins Expression

2020 ◽  
Vol 20 ◽  
Author(s):  
Ya-Nan Li ◽  
Ni Ning ◽  
Lei Song ◽  
Yun Geng ◽  
Jun-Ting Fan ◽  
...  
Keyword(s):  
Annexin V ◽  
Mtt Method ◽  
Anthriscus Sylvestris ◽  
Anti Tumor Activity ◽  
Derivatives Of ◽  
Toxicity In Vitro ◽  
Ht 29 ◽  
Mcf 7

Background: Deoxypodophyllotoxin, isolated from theTraditional Chinese Medicine Anthriscus sylvestris, is well-known because of its significant antitumor activity with strong toxicity in vitro and in vivo. Objective: In this article, we synthesized a series of deoxypodophyllotoxin derivatives, and evaluated their antitumor effectiveness.Methods:The anti tumor activity of deoxypodophyllotoxin derivatives was investigated by the MTT method. Apoptosis percentage was measured by flow cytometer analysis using Annexin-V-FITC. Results: The derivatives revealed obvious cytotoxicity in the MTT assay by decreasing the number of late cancer cells. The decrease of Bcl-2/Bax could be observed in MCF-7, HepG2, HT-29 andMG-63 using Annexin V-FITC. The ratio of Bcl-2/Bax in the administration group was decreased, which was determined by the ELISA kit. Conclusion: The derivatives of deoxypodophyllotoxin could induce apoptosis in tumor cell lines by influencing Bcl-2/Bax.

scholarly journals “Empowering” Cardiac Cells via Stem Cell Derived Mitochondrial Transplantation- Does Age Matter?

2021 ◽  
Vol 22 (4) ◽  
pp. 1824
Author(s):  
Matthias Mietsch ◽  
Rabea Hinkel
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Treatment Strategies ◽  
Cardiac Cells ◽  
Aging Effects ◽  
Beneficial Effects ◽  
Micro Rnas ◽  
New Treatment

With cardiovascular diseases affecting millions of patients, new treatment strategies are urgently needed. The use of stem cell based approaches has been investigated during the last decades and promising effects have been achieved. However, the beneficial effect of stem cells has been found to being partly due to paracrine functions by alterations of their microenvironment and so an interesting field of research, the “stem- less” approaches has emerged over the last years using or altering the microenvironment, for example, via deletion of senescent cells, application of micro RNAs or by modifying the cellular energy metabolism via targeting mitochondria. Using autologous muscle-derived mitochondria for transplantations into the affected tissues has resulted in promising reports of improvements of cardiac functions in vitro and in vivo. However, since the targeted treatment group represents mainly elderly or otherwise sick patients, it is unclear whether and to what extent autologous mitochondria would exert their beneficial effects in these cases. Stem cells might represent better sources for mitochondria and could enhance the effect of mitochondrial transplantations. Therefore in this review we aim to provide an overview on aging effects of stem cells and mitochondria which might be important for mitochondrial transplantation and to give an overview on the current state in this field together with considerations worthwhile for further investigations.

scholarly journals Two Drosophila Innexins Are Expressed in Overlapping Domains and Cooperate to Form Gap-Junction Channels

2000 ◽  
Vol 11 (7) ◽  
pp. 2459-2470 ◽  
Author(s):  
Lucy A. Stebbings ◽  
Martin G. Todman ◽  
Pauline Phelan ◽  
Jonathan P. Bacon ◽  
Jane A. Davies
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Ectopic Expression ◽  
In Vivo Studies ◽  
Electrophysiological Properties ◽  
Gap Junction Channels ◽  
Overlapping Domains ◽  
In Vitro Data

Members of the innexin protein family are structural components of invertebrate gap junctions and are analogous to vertebrate connexins. Here we investigate two Drosophila innexin genes,Dm-inx2 and Dm-inx3 and show that they are expressed in overlapping domains throughout embryogenesis, most notably in epidermal cells bordering each segment. We also explore the gap-junction–forming capabilities of the encoded proteins. In pairedXenopus oocytes, the injection of Dm-inx2mRNA results in the formation of voltage-sensitive channels in only ∼ 40% of cell pairs. In contrast, Dm-Inx3 never forms channels. Crucially, when both mRNAs are coexpressed, functional channels are formed reliably, and the electrophysiological properties of these channels distinguish them from those formed by Dm-Inx2 alone. We relate these in vitro data to in vivo studies. Ectopic expression ofDm-inx2 in vivo has limited effects on the viability ofDrosophila, and animals ectopically expressingDm-inx3 are unaffected. However, ectopic expression of both transcripts together severely reduces viability, presumably because of the formation of inappropriate gap junctions. We conclude that Dm-Inx2 and Dm-Inx3, which are expressed in overlapping domains during embryogenesis, can form oligomeric gap-junction channels.

Synthesis, in vitro and in vivo antitumor activity of symmetrical bis-Schiff base derivatives of isatin

2014 ◽  
Vol 74 ◽  
pp. 742-750 ◽  
Author(s):  
Chengyuan Liang ◽  
Juan Xia ◽  
Dong Lei ◽  
Xiang Li ◽  
Qizheng Yao ◽  
...  
Keyword(s):  
Schiff Base ◽  
Antitumor Activity ◽  
Schiff Base Derivatives ◽  
In Vivo Antitumor Activity ◽  
Derivatives Of

Synthesis, characterization and in vitro and in vivo anticancer activity of Pt(iv) derivatives of [Pt(1S,2S-DACH)(5,6-dimethyl-1,10-phenanthroline)]

2017 ◽  
Vol 46 (21) ◽  
pp. 7005-7019 ◽  
Author(s):  
Benjamin W. J. Harper ◽  
Emanuele Petruzzella ◽  
Roman Sirota ◽  
Fernanda Fabiola Faccioli ◽  
Janice R. Aldrich-Wright ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Biological Evaluation ◽  
Synthesis And Biological Evaluation ◽  
Derivatives Of

Synthesis and biological evaluation in vitro and in vivo of functionalized Pt(iv) derivatives of Pt56MeSS.

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