scholarly journals A Novel Ex vivo Culture Method for the Embryonic Mouse Heart

Author(s):  
Laura A. Dyer ◽  
Cam Patterson
2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Haruko Nakano ◽  
Xiaoqian Liu ◽  
Armin Arshi ◽  
Ben van Handel ◽  
Rajkumar Sasidharan ◽  
...  

The circulatory system is the first functional organ system that develops during mammalian life. Accumulating evidences suggest that cardiac and endocardial cells can arise from a single common progenitor cell during mammalian cardiogenesis. Notably, these early cardiac progenitors express multiple hematopoietic transcription factors, consistent with previous reports. Indeed, a close relationship among cardiac, endocardial and hematopoietic lineages has been suggested in fly, zebrafish, and embryonic stem cell in vitro differentiation models. However, it is unclear when, where and how this hematopoietic gene program is in operation during in vivo mammalian cardiogenesis. Hematopoietic colony assay suggests that mouse heart explants generate myeloids and erythroids in the absence of circulation, suggesting that the heart tube is a de novo site for the definitive hematopoiesis. Lineage tracing revealed that putative cardiac-derived Nkx2-5+/Isl1+ endocardial cells give rise to CD41+ hematopoietic progenitors that contribute to definitive hematopoiesis in vivo and ex vivo during embryogenesis earlier than in the AGM region. Furthermore, Nkx2-5 and Isl1 are both required for the hemogenic activity of the endocardium. Together, identification of Nkx2-5/Isl1-dependent hemogenic endocardial cells (1) adds hematopoietic component in the cardiogenesis lineage tree, (2) changes the long-held dogma that AGM is the only major source of definitive hematopoiesis in the embryo proper, and (3) represents phylogenetically conserved fundamental mechanism of cardio-vasculo-hematopoietic differentiation pathway during the development of circulatory system.


Author(s):  
Laurent Dembele ◽  
Nouhoum Diallo ◽  
Fanta Sogore ◽  
Bintou Diarra ◽  
Fatoumata I. Ballo ◽  
...  

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Gentian Lluri ◽  
Xiaoqian Liu ◽  
Atsushi N

Objective: We examined whether the hematopoietic cells induce the coronary artery formation using genetically modified mouse models of hematopoietic ablation in vivo and ex vivo . Methods: As a model of for hematopoietic cell deficient animals, we used Runx1 (a transcription factor required for definitive hematopoiesis) knockout embryos and Vav1-cre; R26-DTA embryos, which ablates 2/3 of CD45+ hematopoietic cells. The coronary growth and the hematopoietic cells were evaluated in whole-mount, section and ex vivo explant culture. Results: The developing coronary endothelial cells form blood-island-like structure at around E12.5 in the subepicardial region. Interestingly, however, the histological analyses suggest that the first Ter119+ and CD45+ blood cells appear in the subendocardial area at E10.5, even before the formation of coronary channels. These initial hematopoietic cells in the heart are not likely derived from the epicardium, as the sorted epicardial cells yielded no hematopoietic cell in colony formation assay. These observations raised a question whether these heart-resident hematopoietic cells rather play an inductive role during coronary formation. To examine this possibility, we analyzed two hematopoietic ablation models. Both Runx1 knockout embryos and Vav1-cre; R26-DTA embryos revealed disorganized, hypoplastic microvasculature of coronary vessels on section and whole-mount stainings. Furthermore, coronary explant experiments showed that the mouse heart explants from Runx1 knockout embryos and Vav1-cre; R26-DTA embryos exhibited impaired coronary formation ex vivo. Conclusion: Hematopoietic cells are not merely transported via coronary vessels, but substantially involved in the induction of the coronary vessels during cardiogenesis.


2004 ◽  
Vol 286 (4) ◽  
pp. H1461-H1470 ◽  
Author(s):  
Maya Khairallah ◽  
François Labarthe ◽  
Bertrand Bouchard ◽  
Gawiyou Danialou ◽  
Basil J. Petrof ◽  
...  

The availability of genetically modified mice requires the development of methods to assess heart function and metabolism in the intact beating organ. With the use of radioactive substrates and ex vivo perfusion of the mouse heart in the working mode, previous studies have documented glucose and fatty acid oxidation pathways. This study was aimed at characterizing the metabolism of other potentially important exogenous carbohydrate sources, namely, lactate and pyruvate. This was achieved by using 13C-labeling methods. The mouse heart perfusion setup and buffer composition were optimized to reproduce conditions close to the in vivo milieu in terms of workload, cardiac functions, and substrate-hormone supply to the heart (11 mM glucose, 0.8 nM insulin, 50 μM carnitine, 1.5 mM lactate, 0.2 mM pyruvate, 5 nM epinephrine, 0.7 mM oleate, and 3% albumin). The use of three differentially 13C-labeled carbohydrates and a 13C-labeled long-chain fatty acid allowed the quantitative assessment of the metabolic origin and fate of tissue pyruvate as well as the relative contribution of substrates feeding acetyl-CoA (pyruvate and fatty acids) and oxaloacetate (pyruvate) for mitochondrial citrate synthesis. Beyond concurring with the notion that the mouse heart preferentially uses fatty acids for energy production (63.5 ± 3.9%) and regulates its fuel selection according to the Randle cycle, our study reports for the first time in the mouse heart the following findings. First, exogenous lactate is the major carbohydrate contributing to pyruvate formation (42.0 ± 2.3%). Second, lactate and pyruvate are constantly being taken up and released by the heart, supporting the concept of compartmentation of lactate and glucose metabolism. Finally, mitochondrial anaplerotic pyruvate carboxylation and citrate efflux represent 4.9 ± 1.8 and 0.8 ± 0.1%, respectively, of the citric acid cycle flux and are modulated by substrate supply. The described 13C-labeling strategy combined with an experimental setup that enables continuous monitoring of physiological parameters offers a unique model to clarify the link between metabolic alterations, cardiac dysfunction, and disease development.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ricardo Romero-Moreno ◽  
Kimberly J. Curtis ◽  
Thomas R. Coughlin ◽  
Maria Cristina Miranda-Vergara ◽  
Shourik Dutta ◽  
...  

Abstract Bone is one of the most common sites for metastasis across cancers. Cancer cells that travel through the vasculature and invade new tissues can remain in a non-proliferative dormant state for years before colonizing the metastatic site. Switching from dormancy to colonization is the rate-limiting step of bone metastasis. Here we develop an ex vivo co-culture method to grow cancer cells in mouse bones to assess cancer cell proliferation using healthy or cancer-primed bones. Profiling soluble factors from conditioned media identifies the chemokine CXCL5 as a candidate to induce metastatic colonization. Additional studies using CXCL5 recombinant protein suggest that CXCL5 is sufficient to promote breast cancer cell proliferation and colonization in bone, while inhibition of its receptor CXCR2 with an antagonist blocks proliferation of metastatic cancer cells. This study suggests that CXCL5 and CXCR2 inhibitors may have efficacy in treating metastatic bone tumors dependent on the CXCL5/CXCR2 axis.


2008 ◽  
Vol 237 (9) ◽  
pp. 2304-2314 ◽  
Author(s):  
Jennifer Slough ◽  
Laura Cooney ◽  
Martina Brueckner

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sasha V. Siegel ◽  
Lia Chappell ◽  
Jessica B. Hostetler ◽  
Chanaki Amaratunga ◽  
Seila Suon ◽  
...  

Abstract Plasmodium vivax gene regulation remains difficult to study due to the lack of a robust in vitro culture method, low parasite densities in peripheral circulation and asynchronous parasite development. We adapted an RNA-seq protocol “DAFT-seq” to sequence the transcriptome of four P. vivax field isolates that were cultured for a short period ex vivo before using a density gradient for schizont enrichment. Transcription was detected from 78% of the PvP01 reference genome, despite being schizont-enriched samples. This extensive data was used to define thousands of 5′ and 3′ untranslated regions, some of which overlapped with neighbouring transcripts, and to improve the gene models of 352 genes, including identifying 20 novel gene transcripts. This dataset has also significantly increased the known amount of heterogeneity between P. vivax schizont transcriptomes from individual patients. The majority of genes found to be differentially expressed between the isolates lack Plasmodium falciparum homologs and are predicted to be involved in host-parasite interactions, with an enrichment in reticulocyte binding proteins, merozoite surface proteins and exported proteins with unknown function. An improved understanding of the diversity within P. vivax transcriptomes will be essential for the prioritisation of novel vaccine targets.


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