Off-Target Deletion of Conditional Dbc1 Allele in the Foxp3YFP-Cre Mouse Line under Specific Setting

The Cre-LoxP conditional knockout strategy has been used extensively to study gene function in a specific cell-type. In this study, the authors tried to engineer mice in which the Dbc1 gene is conditionally knocked out in Treg cells. Unexpectedly, the conditional Dbc1 allele was completely deleted with a low frequency in some Foxp3YFP-Cre mice harboring floxed Dbc1 allele under specific settings. It was found that the germline recombination of floxed Dbc1 allele, which caused Dbc1 knock out mice, occurred in the male Foxp3YFP-Cre mice harboring floxed Dbc1 allele. Even though the authors documented that Foxp3 is expressed in the testis, the germline recombination was not caused by the germline expression of Cre, which was driven by the Foxp3 promoter. The germline recombination may be caused by the unspecific expression of Cre recombinase in the fetus, in which the floxed Dbc1 allele of some stem cells with development potential to germ cells may be recombined. Additionally, this study found that the floxed Dbc1 allele was recombined in non-T cells of some Foxp3Cre Dbc1fl mice, which need to be characterized. Our results also suggest that using male mice with a low frequency of recombined gene allele can reduce the risk of having full knock out mice.

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3-Iodothyronamine Induces Diverse Signaling Effects at Different Aminergic and Non-Aminergic G-Protein Coupled Receptors

Experimental and Clinical Endocrinology & Diabetes ◽

10.1055/a-1022-1554 ◽

2019 ◽

Vol 128 (06/07) ◽

pp. 395-400 ◽

Cited By ~ 3

Author(s):

Heike Biebermann ◽

Gunnar Kleinau

Keyword(s):

Body Temperature ◽

G Protein ◽

Intracellular Signaling ◽

Serotonin Receptor ◽

Fine Tuning ◽

Specific Cell ◽

Knock Out ◽

Alpha2 Adrenoceptor ◽

Knock Out Mice ◽

G Protein Coupled

AbstractThe thyroid hormone metabolite 3-iodothyronamine (3-T1AM) exerts diverse physiological reactions such as a decrease of body temperature, and negative inotropic and chronotropic effects. This observed pleomorphic effect in physiology can be barely explained by interaction with only one target protein such as the trace-amine receptor 1 (TAAR1), a class A G-protein coupled receptor (GPCR). Moreover, Taar1 knock-out mice still react to 3-T1AM through physiological responses with a rapid decrease in body temperature. These facts propelled our group and others to search for further targets for this molecule.The group of TAARs evolved early in evolution and, according to sequence similarities, they are closely related to adrenoceptors and other aminergic receptors. Therefore, several of these receptors were characterized by their potential to interplay with 3-T1AM. Indeed, 3-T1AM acts as a positive allosteric modulator on the beta2-adrenoceptor (ADRB2) and as a biased agonist on the serotonin receptor 1B (5HT1b) and the alpha2-adrenoceptor (ADRA2A). In addition, 3-T1AM was reported to be a weak antagonist at a non-aminergic muscarinic receptor (M3).These findings impressively reflect that such trace amines can unselectively and simultaneously function at different receptors expressed by one cell or at different tissues. In conclusion, the role of 3-T1AM is hypothesized to concert the fine-tuning of specific cell reactions by the accentuation of certain pathways dependent on distinct receptors. 3-T1AM acts as a regulator of signals by blocking, modulating, or inducing simultaneously distinct intracellular signaling cascades via different GPCRs.

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Intercalated disc protein Xinβ is required for Hippo-YAP signaling in the heart

Nature Communications ◽

10.1038/s41467-020-18379-8 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Haipeng Guo ◽

Yao Wei Lu ◽

Zhiqiang Lin ◽

Zhan-Peng Huang ◽

Jianming Liu ◽

...

Keyword(s):

Cardiovascular Diseases ◽

Cardiac Function ◽

Heart Development ◽

Genetic Interaction ◽

Specific Cell ◽

Cardiomyocyte Proliferation ◽

Intercalated Disc ◽

Knock Out ◽

Genes Encoding ◽

Knock Out Mice

Abstract Intercalated discs (ICD), specific cell-to-cell contacts that connect adjacent cardiomyocytes, ensure mechanical and electrochemical coupling during contraction of the heart. Mutations in genes encoding ICD components are linked to cardiovascular diseases. Here, we show that loss of Xinβ, a newly-identified component of ICDs, results in cardiomyocyte proliferation defects and cardiomyopathy. We uncovered a role for Xinβ in signaling via the Hippo-YAP pathway by recruiting NF2 to the ICD to modulate cardiac function. In Xinβ mutant hearts levels of phosphorylated NF2 are substantially reduced, suggesting an impairment of Hippo-YAP signaling. Cardiac-specific overexpression of YAP rescues cardiac defects in Xinβ knock-out mice—indicating a functional and genetic interaction between Xinβ and YAP. Our study reveals a molecular mechanism by which cardiac-expressed intercalated disc protein Xinβ modulates Hippo-YAP signaling to control heart development and cardiac function in a tissue specific manner. Consequently, this pathway may represent a therapeutic target for the treatment of cardiovascular diseases.

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Schistosoma Japonicum infection in Treg-specific USP21 knock-out mice

10.1101/2020.03.09.983502 ◽

2020 ◽

Author(s):

Youxiang Zhang ◽

Guina Xu ◽

Baoxin Zhang ◽

Shan Zhang ◽

Yangyang Li ◽

...

Keyword(s):

T Cells ◽

Schistosoma Japonicum ◽

Treg Cells ◽

Immune Homeostasis ◽

Mice Model ◽

Knock Out ◽

Specific Protease ◽

Knock Out Mice ◽

And Control ◽

Further Development

AbstractUSP21, an E3 de-ubiquitin enzyme playing vital roles in physiological activities, is important for Treg cells to maintain immune homeostasis and control immune tolerance. To understand its diverse functions and potential mechanism is essential for disease development. We, using the USP21 gene-conditional knock-out mice model of Schistosoma Japonicum infection, found more cercariae developed into adults, and more eggs deposited in the liver in KO mice. However, immunohistochemistry showed the degree and the area of egg granuloma and liver fibrosis were both reduced. This suggested knock-out USP21 did affect the immunoregulation between schistosomes and the host. In KO mice the content of IFN-gamma and IL-4, and the expression of anti-SEA IgG and anti-SWAP IgG both increased in the liver, spleen and blood by flow cytometry, while the content of IL-10, lL-17A, IL-23, IL-9 and the expression of USP21 and anti-SEA IgM decreased. This indicated USP21-knockout-Tregs promoted both Th1-type and Th2-type immunity and inhibited other immunities during schistosomes infection, which disordered the host immunity. This study revealed the immunomodulatory of USP21 and preliminarily suggests it might be essential to regulate the complex immune network between the host and schistosomes. USP21 provides a new possible target for schistosomiasis treatment in the future.Author summarySchistosomiasis is a common neglected tropical disease that affects more than 230 million people worldwide. Therefore, the study on the mechanism of immune interaction between schistosomas and the host is not only helpful for the understanding of immune homeostasis, but also helpful for the further development of the treatment of schistosomiasis. Ubiquitin Specific Protease 21(USP21) has been shown to be involved in the regulation of many biological processes, such as maintaining immune homeostasis and regulating cell growth. Here, we observed that the specific deletion of USP21 led to the decrease of mice’s ability to resist schistosomes infection and promoted the survival of schistosomes. It was also proved that unstable regulatory T cells would produce polarization phenomenon and promote differentiation to helper T cells, which would lead to disorder of immune response in mice. However, this process reduced the serious immune pathological damage caused by egg granuloma. Our findings reveal that USP21 may be an important molecule regulating immune interaction between Schistosoma japonicum and the host.

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ovoD co-selection: a method for enriching CRISPR/Cas9-edited alleles in Drosophila

10.1101/310854 ◽

2018 ◽

Author(s):

Ben Ewen-Campen ◽

Norbert Perrimon

Keyword(s):

Genome Editing ◽

Germ Cells ◽

Low Frequency ◽

Nonhomologous End Joining ◽

Selection Strategy ◽

End Joining ◽

Knock Out ◽

Homology Directed Repair ◽

Promising Strategy ◽

Dominant Female

ABSTRACTScreening for successful CRISPR/Cas9 editing events remains a time consuming technical bottleneck in the field of Drosophila genome editing. This step can be particularly laborious for events that do not cause a visible phenotype, or those which occur at relatively low frequency. A promising strategy to enrich for desired CRISPR events is to co-select for an independent CRISPR event that produces an easily detectable phenotype. Here, we describe a simple negative co-selection strategy involving CRISPR-editing of a dominant female sterile allele, ovoD1. In this system (“ovoD co-selection”), the only functional germ cells in injected females are those that have been edited at the ovoD1 locus, and thus 100% of the offspring of these flies have undergone editing of at least one locus. We demonstrate that ovoD co-selection can be used to enrich for knock-out mutagenesis via nonhomologous end-joining (NHEJ), and for knock-in alleles via homology-directed repair (HDR). Altogether, our results demonstrate that ovoD co-selection reduces the amount of screening necessary to isolate desired CRISPR events in Drosophila.

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