scholarly journals Chamber-Specific Protein Expression during Direct Cardiac Reprogramming

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1513
Author(s):  
Zhentao Zhang ◽  
Jesse Villalpando ◽  
Wenhui Zhang ◽  
Young-Jae Nam
Keyword(s):  
Myocardial Infarction ◽  
Transcription Factors ◽  
Specific Protein ◽  
Heart Regeneration ◽  
Proof Of Concept ◽  
Major Fraction ◽  
Regenerative Approach ◽  
Inherent Advantage

Forced expression of core cardiogenic transcription factors can directly reprogram fibroblasts to induced cardiomyocyte-like cells (iCMs) in vitro and in vivo. This cardiac reprogramming approach provides a proof of concept for induced heart regeneration by converting a fibroblast fate to a cardiomyocyte fate. However, it remains elusive whether chamber-specific cardiomyocytes can be generated by cardiac reprogramming. Therefore, we assessed the ability of the cardiac reprogramming approach for chamber specification in vitro and in vivo. We found that in vivo cardiac reprogramming post-myocardial infarction exclusively induces a ventricular-like phenotype, while a major fraction of iCMs generated in vitro failed to determine their chamber identities. Our results suggest that in vivo cardiac reprogramming may have an inherent advantage of generating chamber-matched new cardiomyocytes as a potential heart regenerative approach.

scholarly journals Chamber Specification During Direct Cardiac Reprogramming

2021 ◽  
Author(s):  
Zhentao Zhang ◽  
Jesse Villalpando ◽  
Wenhui Zhang ◽  
Young-Jae Nam
Keyword(s):  
Myocardial Infarction ◽  
Transcription Factors ◽  
Post Myocardial Infarction ◽  
Heart Regeneration ◽  
Proof Of Concept ◽  
Major Fraction ◽  
Regenerative Approach ◽  
Inherent Advantage

Abstract Forced expression of core cardiogenic transcription factors can directly reprogram fibroblasts to induced cardiomyocyte-like cells (iCMs) in vitro and in vivo. This cardiac reprogramming approach provides a proof of concept for induced heart regeneration by converting a fibroblast fate to a cardiomyocyte fate. However, it remains elusive whether chamber-specific cardiomyocytes can be generated by cardiac reprogramming. Therefore, we assessed the ability of the cardiac reprogramming approach for chamber specification in vitro and in vivo. We found that in vivo cardiac reprogramming post-myocardial infarction exclusively generates ventricular-like iCMs, while a major fraction of iCMs generated in vitro fail to determine their chamber identities. Our results indicate that in vivo cardiac reprogramming may have an inherent advantage of generating chamber-matched new cardiomyocytes as a potential heart regenerative approach.

Specific Labeling of Protein Domains with Antibody Fragments

1981 ◽  
Vol 39 ◽  
pp. 416-417
Author(s):  
U. Aebi ◽  
L.E. Buhle ◽  
W.E. Fowler
Keyword(s):  
Image Processing ◽  
Specific Protein ◽  
Antibody Fragments ◽  
Supramolecular Organization ◽  
Two Dimensional ◽  
Ordered Structures ◽  
Virus Capsids ◽  
Processing Techniques

Many important supramolecular structures such as filaments, microtubules, virus capsids and certain membrane proteins and bacterial cell walls exist as ordered polymers or two-dimensional crystalline arrays in vivo. In several instances it has been possible to induce soluble proteins to form ordered polymers or two-dimensional crystalline arrays in vitro. In both cases a combination of electron microscopy of negatively stained specimens with analog or digital image processing techniques has proven extremely useful for elucidating the molecular and supramolecular organization of the constituent proteins. However from the reconstructed stain exclusion patterns it is often difficult to identify distinct stain excluding regions with specific protein subunits. To this end it has been demonstrated that in some cases this ambiguity can be resolved by a combination of stoichiometric labeling of the ordered structures with subunit-specific antibody fragments (e.g. Fab) and image processing of the electron micrographs recorded from labeled and unlabeled structures.

Clinical Trials in Thrombosis: Secondary Prevention of Myocardial Infarction

1976 ◽  
Vol 35 (01) ◽  
pp. 049-056 ◽  
Author(s):  
Christian R Klimt ◽  
P. H Doub ◽  
Nancy H Doub
Keyword(s):  
Myocardial Infarction ◽  
Secondary Prevention ◽  
Case Control ◽  
Therapeutic Effects ◽  
Case Control Studies ◽  
Definitive Answer ◽  
Inhibition Of Platelet Aggregation ◽  
Prospective Trials

SummaryNumerous in vivo and in vitro experiments, investigating the inhibition of platelet aggregation and the prevention of experimentally-induced thrombosis, suggest that anti-platelet drugs, such as aspirin or the combination of aspirin and dipyridamole or sulfinpyrazone, may be effective anti-thrombotic agents in man. Since 1971, seven randomized prospective trials and two case-control studies have been referenced in the literature or are currently being conducted, which evaluate the effects of aspirin, sulfinpyrazone, or dipyridamole in combination with aspirin in the secondary prevention of myocardial infarction. A critical review of these trials indicates a range of evidence from no difference to a favorable trend that antiplatelet drugs may serve as anti-thrombotic agents in man. To date, a definitive answer concerning the therapeutic effects of these drugs in the secondary prevention of coronary heart disease is not available.

Subnuclear compartmentalization of sequence-specific transcription factors and regulation of eukaryotic gene expression

2005 ◽  
Vol 83 (4) ◽  
pp. 535-547 ◽  
Author(s):  
Gareth N Corry ◽  
D Alan Underhill
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Transcriptional Activation ◽  
Current Knowledge ◽  
Nuclear Architecture ◽  
Subnuclear Localization ◽  
Modular Structures

To date, the majority of the research regarding eukaryotic transcription factors has focused on characterizing their function primarily through in vitro methods. These studies have revealed that transcription factors are essentially modular structures, containing separate regions that participate in such activities as DNA binding, protein–protein interaction, and transcriptional activation or repression. To fully comprehend the behavior of a given transcription factor, however, these domains must be analyzed in the context of the entire protein, and in certain cases the context of a multiprotein complex. Furthermore, it must be appreciated that transcription factors function in the nucleus, where they must contend with a variety of factors, including the nuclear architecture, chromatin domains, chromosome territories, and cell-cycle-associated processes. Recent examinations of transcription factors in the nucleus have clarified the behavior of these proteins in vivo and have increased our understanding of how gene expression is regulated in eukaryotes. Here, we review the current knowledge regarding sequence-specific transcription factor compartmentalization within the nucleus and discuss its impact on the regulation of such processes as activation or repression of gene expression and interaction with coregulatory factors.Key words: transcription, subnuclear localization, chromatin, gene expression, nuclear architecture.

scholarly journals Myocardial fibrosis reversion via rhACE2-electrospun fibrous patch for ventricular remodeling prevention

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Zeping Qiu ◽  
Jingwen Zhao ◽  
Fanyi Huang ◽  
Luhan Bao ◽  
Yanjia Chen ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Myocardial Fibrosis ◽  
Ventricular Remodeling ◽  
Cardiac Fibroblasts ◽  
Cost Effective ◽  
Intramyocardial Injection ◽  
Undesirable Consequence ◽  
Adverse Remodeling

AbstractMyocardial fibrosis and ventricular remodeling were the key pathology factors causing undesirable consequence after myocardial infarction. However, an efficient therapeutic method remains unclear, partly due to difficulty in continuously preventing neurohormonal overactivation and potential disadvantages of cell therapy for clinical practice. In this study, a rhACE2-electrospun fibrous patch with sustained releasing of rhACE2 to shape an induction transformation niche in situ was introduced, through micro-sol electrospinning technologies. A durable releasing pattern of rhACE2 encapsulated in hyaluronic acid (HA)—poly(L-lactic acid) (PLLA) core-shell structure was observed. By multiple in vitro studies, the rhACE2 patch demonstrated effectiveness in reducing cardiomyocytes apoptosis under hypoxia stress and inhibiting cardiac fibroblasts proliferation, which gave evidence for its in vivo efficacy. For striking mice myocardial infarction experiments, a successful prevention of adverse ventricular remodeling has been demonstrated, reflecting by improved ejection fraction, normal ventricle structure and less fibrosis. The rhACE2 patch niche showed clear superiority in long term function and structure preservation after ischemia compared with intramyocardial injection. Thus, the micro-sol electrospun rhACE2 fibrous patch niche was proved to be efficient, cost-effective and easy-to-use in preventing ventricular adverse remodeling.

scholarly journals Novel Identified Circular Transcript of RCAN2, circ-RCAN2, Shows Deviated Expression Pattern in Pig Reperfused Infarcted Myocardium and Hypoxic Porcine Cardiac Progenitor Cells In Vitro

2021 ◽  
Vol 22 (3) ◽  
pp. 1390
Author(s):  
Julia Mester-Tonczar ◽  
Patrick Einzinger ◽  
Johannes Winkler ◽  
Nina Kastner ◽  
Andreas Spannbauer ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Progenitor Cells ◽  
Regulatory Networks ◽  
Circular Rnas ◽  
Cardiac Progenitor Cells ◽  
Tissue Samples ◽  
Healthy Myocardium ◽  
Acute Mi

Circular RNAs (circRNAs) are crucial in gene regulatory networks and disease development, yet circRNA expression in myocardial infarction (MI) is poorly understood. Here, we harvested myocardium samples from domestic pigs 3 days after closed-chest reperfused MI or sham surgery. Cardiac circRNAs were identified by RNA-sequencing of rRNA-depleted RNA from infarcted and healthy myocardium tissue samples. Bioinformatics analysis was performed using the CIRIfull and KNIFE algorithms, and circRNAs identified with both algorithms were subjected to differential expression (DE) analysis and validation by qPCR. Circ-RCAN2 and circ-C12orf29 expressions were significantly downregulated in infarcted tissue compared to healthy pig heart. Sanger sequencing was performed to identify the backsplice junctions of circular transcripts. Finally, we compared the expressions of circ-C12orf29 and circ-RCAN2 between porcine cardiac progenitor cells (pCPCs) that were incubated in a hypoxia chamber for different time periods versus normoxic pCPCs. Circ-C12orf29 did not show significant DE in vitro, whereas circ-RCAN2 exhibited significant ischemia-time-dependent upregulation in hypoxic pCPCs. Overall, our results revealed novel cardiac circRNAs with DE patterns in pCPCs, and in infarcted and healthy myocardium. Circ-RCAN2 exhibited differential regulation by myocardial infarction in vivo and by hypoxia in vitro. These results will improve our understanding of circRNA regulation during acute MI.

scholarly journals Regulation of sarcomagenesis by the empty spiracles homeobox genes EMX1 and EMX2

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Manuel Pedro Jimenez-García ◽  
Antonio Lucena-Cacace ◽  
Daniel Otero-Albiol ◽  
Amancio Carnero
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Transcription Factors ◽  
Neural Crest ◽  
Tumor Suppressors ◽  
Homeobox Genes ◽  
Neuronal Cell ◽  
Cell Gene Expression

AbstractThe EMX (Empty Spiracles Homeobox) genes EMX1 and EMX2 are two homeodomain gene members of the EMX family of transcription factors involved in the regulation of various biological processes, such as cell proliferation, migration, and differentiation, during brain development and neural crest migration. They play a role in the specification of positional identity, the proliferation of neural stem cells, and the differentiation of certain neuronal cell phenotypes. In general, they act as transcription factors in early embryogenesis and neuroembryogenesis from metazoans to higher vertebrates. The EMX1 and EMX2’s potential as tumor suppressor genes has been suggested in some cancers. Our work showed that EMX1/EMX2 act as tumor suppressors in sarcomas by repressing the activity of stem cell regulatory genes (OCT4, SOX2, KLF4, MYC, NANOG, NES, and PROM1). EMX protein downregulation, therefore, induced the malignance and stemness of cells both in vitro and in vivo. In murine knockout (KO) models lacking Emx genes, 3MC-induced sarcomas were more aggressive and infiltrative, had a greater capacity for tumor self-renewal, and had higher stem cell gene expression and nestin expression than those in wild-type models. These results showing that EMX genes acted as stemness regulators were reproduced in different subtypes of sarcoma. Therefore, it is possible that the EMX genes could have a generalized behavior regulating proliferation of neural crest-derived progenitors. Together, these results indicate that the EMX1 and EMX2 genes negatively regulate these tumor-altering populations or cancer stem cells, acting as tumor suppressors in sarcoma.

scholarly journals Adropin-based dual treatment enhances the therapeutic potential of mesenchymal stem cells in rat myocardial infarction

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
HuiYa Li ◽  
DanQing Hu ◽  
Guilin Chen ◽  
DeDong Zheng ◽  
ShuMei Li ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Therapeutic Potential ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Paracrine Factors ◽  
Dual Treatment

AbstractBoth weak survival ability of stem cells and hostile microenvironment are dual dilemma for cell therapy. Adropin, a bioactive substance, has been demonstrated to be cytoprotective. We therefore hypothesized that adropin may produce dual protective effects on the therapeutic potential of stem cells in myocardial infarction by employing an adropin-based dual treatment of promoting stem cell survival in vitro and modifying microenvironment in vivo. In the current study, adropin (25 ng/ml) in vitro reduced hydrogen peroxide-induced apoptosis in rat bone marrow mesenchymal stem cells (MSCs) and improved MSCs survival with increased phosphorylation of Akt and extracellular regulated protein kinases (ERK) l/2. Adropin-induced cytoprotection was blocked by the inhibitors of Akt and ERK1/2. The left main coronary artery of rats was ligated for 3 or 28 days to induce myocardial infarction. Bromodeoxyuridine (BrdU)-labeled MSCs, which were in vitro pretreated with adropin, were in vivo intramyocardially injected after ischemia, following an intravenous injection of 0.2 mg/kg adropin (dual treatment). Compared with MSCs transplantation alone, the dual treatment with adropin reported a higher level of interleukin-10, a lower level of tumor necrosis factor-α and interleukin-1β in plasma at day 3, and higher left ventricular ejection fraction and expression of paracrine factors at day 28, with less myocardial fibrosis and higher capillary density, and produced more surviving BrdU-positive cells at day 3 and 28. In conclusion, our data evidence that adropin-based dual treatment may enhance the therapeutic potential of MSCs to repair myocardium through paracrine mechanism via the pro-survival pathways.

scholarly journals An integrated framework for quantifying immune-tumour interactions in a 3D co-culture model

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gheed Al-Hity ◽  
FengWei Yang ◽  
Eduard Campillo-Funollet ◽  
Andrew E. Greenstein ◽  
Hazel Hunt ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Cell ◽  
In Vitro Models ◽  
Proof Of Concept ◽  
Culture Model ◽  
Spheroid Growth ◽  
Confocal Images ◽  
Cancer Spheroids

AbstractInvestigational in vitro models that reflect the complexity of the interaction between the immune system and tumours are limited and difficult to establish. Herein, we present a platform to study the tumour-immune interaction using a co-culture between cancer spheroids and activated immune cells. An algorithm was developed for analysis of confocal images of the co-culture to evaluate the following quantitatively; immune cell infiltration, spheroid roundness and spheroid growth. As a proof of concept, the effect of the glucocorticoid stress hormone, cortisol was tested on 66CL4 co-culture model. Results were comparable to 66CL4 syngeneic in vivo mouse model undergoing psychological stress. Furthermore, administration of glucocorticoid receptor antagonists demonstrated the use of this model to determine the effect of treatments on the immune-tumour interplay. In conclusion, we provide a method of quantifying the interaction between the immune system and cancer, which can become a screening tool in immunotherapy design.

scholarly journals Preclinical Development of Autologous Hematopoietic Stem Cell-Based Gene Therapy for Immune Deficiencies: A Journey from Mouse Cage to Bed Side

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 549
Author(s):  
Laura Garcia-Perez ◽  
Anita Ordas ◽  
Kirsten Canté-Barrett ◽  
Pauline Meij ◽  
Karin Pike-Overzet ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Severe Combined Immunodeficiency ◽  
Good Manufacturing Practice ◽  
Proof Of Concept ◽  
Preclinical Development ◽  
Hematopoietic Stem ◽  
Immune Deficiencies ◽  
Suitable Vector

Recent clinical trials using patient’s own corrected hematopoietic stem cells (HSCs), such as for primary immunodeficiencies (Adenosine deaminase (ADA) deficiency, X-linked Severe Combined Immunodeficiency (SCID), X-linked chronic granulomatous disease (CGD), Wiskott–Aldrich Syndrome (WAS)), have yielded promising results in the clinic; endorsing gene therapy to become standard therapy for a number of diseases. However, the journey to achieve such a successful therapy is not easy, and several challenges have to be overcome. In this review, we will address several different challenges in the development of gene therapy for immune deficiencies using our own experience with Recombinase-activating gene 1 (RAG1) SCID as an example. We will discuss product development (targeting of the therapeutic cells and choice of a suitable vector and delivery method), the proof-of-concept (in vitro and in vivo efficacy, toxicology, and safety), and the final release steps to the clinic (scaling up, good manufacturing practice (GMP) procedures/protocols and regulatory hurdles).

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