Neuraxial dysraphism in EPAS1-associated syndrome due to improper mesenchymal transition

ObjectiveTo investigate the effect of somatic, postzygotic, gain-of-function mutation of Endothelial Per-Arnt-Sim (PAS) domain protein 1 (EPAS1) encoding hypoxia-inducible factor-2α (HIF-2α) on posterior fossa development and spinal dysraphism in EPAS1 gain-of-function syndrome, which consists of multiple paragangliomas, somatostatinoma, and polycythemia.MethodsPatients referred to our institution for evaluation of new, recurrent, and/or metastatic paragangliomas/pheochromocytoma were confirmed for EPAS1 gain-of-function syndrome by identification of the EPAS1 gain-of-function mutation in resected tumors and/or circulating leukocytes. The posterior fossa, its contents, and the spine were evaluated retrospectively on available MRI and CT images of the head and neck performed for tumor staging and restaging. The transgenic mouse model underwent Microfil vascular perfusion and subsequent intact ex vivo 14T MRI and micro-CT as well as gross dissection, histology, and immunohistochemistry to assess the role of EPAS1 in identified malformations.ResultsAll 8 patients with EPAS1 gain-of-function syndrome demonstrated incidental posterior fossa malformations—one Dandy-Walker variant and 7 Chiari malformations without syringomyelia. These findings were not associated with a small posterior fossa; rather, the posterior fossa volume exceeded that of its neural contents. Seven of 8 patients demonstrated spinal dysraphism; 4 of 8 demonstrated abnormal vertebral segmentation. The mouse model similarly demonstrated features of neuraxial dysraphism, including cervical myelomeningocele and spinal dysraphism, and cerebellar tonsil displacement through the foramen magnum. Histology and immunohistochemistry demonstrated incomplete mesenchymal transition in the mutant but not the control mouse.ConclusionsThis study characterized posterior fossa and spinal malformations seen in EPAS1 gain-of-function syndrome and suggests that gain-of-function mutation in HIF-2α results in improper mesenchymal transition.

Download Full-text

IL-6 trans-signaling drives a STAT3-dependent pathway that leads to structural alterations of the peritoneal membrane

AJP Renal Physiology ◽

10.1152/ajprenal.00319.2019 ◽

2020 ◽

Vol 318 (2) ◽

pp. F338-F353 ◽

Cited By ~ 1

Author(s):

Xiaoxiao Yang ◽

Hao Yan ◽

Na Jiang ◽

Zanzhe Yu ◽

Jiangzi Yuan ◽

...

Keyword(s):

Mouse Model ◽

Ex Vivo ◽

Umbilical Vein ◽

Inflammatory Factor ◽

Peritoneal Membrane ◽

Peritoneal Fibrosis ◽

Mesenchymal Transition ◽

Structural Alterations ◽

Peritoneal Mesothelial Cells ◽

Junction Molecules

IL-6 is a vital inflammatory factor in the peritoneal cavity of patients undergoing peritoneal dialysis (PD). The present study examined the effect of IL-6 trans-signaling on structural alterations of the peritoneal membrane. We investigated whether the epithelial-to-mesenchymal transition (EMT) process of human peritoneal mesothelial cells (HPMCs) and the production of proangiogenic factors were controlled by IL-6 trans-signaling. Its role in the peritoneal alterations was detected in a mouse model. The morphology of HPMCs and levels of cytokines in PD effluent were also explored. Stimulation of HPMCs with the IL-6 and soluble IL-6 receptor complex (IL-6/S) promoted the EMT process of HPMCs depending on the STAT3 pathway. In a coculture system of HPMCs and human umbilical vein endothelial cells, IL-6/S mediated the production of VEGF and angiopoietins so as to downregulate the expression of endothelial junction molecules and finally affect vascular permeability. Daily intraperitoneal injection of high glucose-based dialysis fluid induced peritoneal fibrosis, angiogenesis, and macrophage infiltration in a mouse model, accompanied by phosphorylation of STAT3. Blockade of IL-6 trans-signaling prevented these peritoneum alterations. The fibroblast-like appearance of HPMCs ex vivo was upregulated in patients undergoing prevalent PD accompanied by increasing levels of IL-6, VEGF, and angiopoietin-2 in the PD effluent. Taken together, these findings identified a critical link between IL-6 trans-signaling and structural alterations of the peritoneal membrane, and it might be a potential target for the treatment of patients undergoing PD who have developed peritoneal alterations.

Download Full-text

Gain of function in the mouse model of a recurrent mutation p53N236Spromotes the formation of double minute chromosomes and the oncogenic potential of p19ARF

Molecular Carcinogenesis ◽

10.1002/mc.22737 ◽

2017 ◽

Vol 57 (2) ◽

pp. 147-158 ◽

Cited By ~ 3

Author(s):

Lanjun Zhao ◽

Boyuan Wang ◽

Xilong Zhao ◽

Xiaoming Wu ◽

Qiushi Zhang ◽

...

Keyword(s):

Mouse Model ◽

Recurrent Mutation ◽

Gain Of Function ◽

Oncogenic Potential ◽

Double Minute ◽

Double Minute Chromosomes

Download Full-text

Ex vivo culture of human CD34+ cord blood cells with thrombopoietin (TPO) accelerates platelet engraftment in a NOD/SCID mouse model

Experimental Hematology ◽

10.1016/j.exphem.2006.04.009 ◽

2006 ◽

Vol 34 (7) ◽

pp. 943-950 ◽

Cited By ~ 27

Author(s):

Yvette van Hensbergen ◽

Laurus F. Schipper ◽

Anneke Brand ◽

Manon C. Slot ◽

Mick Welling ◽

...

Keyword(s):

Mouse Model ◽

Cord Blood ◽

Blood Cells ◽

Scid Mouse ◽

Ex Vivo ◽

Human Cd34 ◽

Scid Mouse Model ◽

Cord Blood Cells ◽

Ex Vivo Culture

Download Full-text

Corticosteroids alter alveolar macrophage control of Lichtheimia corymbifera spores in an ex vivo mouse model

Medical Mycology ◽

10.1093/mmy/myaa104 ◽

2020 ◽

Author(s):

Kévin Brunet ◽

François Arrivé ◽

Jean-Philippe Martellosio ◽

Isabelle Lamarche ◽

Sandrine Marchand ◽

...

Keyword(s):

Mouse Model ◽

Alveolar Macrophage ◽

Oxidative Burst ◽

Ex Vivo ◽

Fungal Growth ◽

Invasive Infection ◽

Ex Vivo Model ◽

Lichtheimia Corymbifera ◽

The Impact

Abstract Alveolar macrophages (AM) are the first-line lung defense against Mucorales in pulmonary mucormycosis. Since corticosteroid use is a known risk factor for mucormycosis, the aim of this study was to describe the role of corticosteroids on AM capacities to control Lichtheimia corymbifera spore growth using a new ex vivo model. An in vivo mouse model was developed to determine the acetate cortisone dose able to trigger pulmonary invasive infection. Then, in the ex vivo model, male BALB/c mice were pretreated with the corticosteroid regimen triggering invasive infection, before AM collection through bronchoalveolar lavage. AMs from corticosteroid-treated mice and untreated control AMs were then exposed to L. corymbifera spores in vitro (ratio 1:5). AM control of fungal growth, adherence/phagocytosis, and oxidative burst were assessed using optical densities by spectrophotometer, flow cytometry, and 2', 7'-dichlorofluoresceine diacetate fluorescence, respectively. Cortisone acetate at 500 mg/kg, at D-3 and at D0, led to pulmonary invasive infection at D3. Co-incubated spores and AMs from corticosteroid-treated mice had significantly higher absorbance (fungal growth) than co-incubated spores and control AMs, at 24 h (P = .025), 36 h (P = .004), and 48 h (P = .001). Colocalization of spores with AMs from corticosteroid-treated mice was significantly lower than for control AMs (7.6 ± 1.9% vs 22.3 ± 5.8%; P = .003), reflecting spore adherence and phagocytosis inhibition. Finally, oxidative burst was significantly increased when control AMs were incubated with spores (P = 0.029), while corticosteroids hampered oxidative burst from treated AMs (P = 0.321). Corticosteroids enhanced fungal growth of L. corymbifera through AM phagocytosis inhibition and burst oxidative decrease in our ex vivo model. Lay Summary The aim of this study was to describe the impact of corticosteroids on alveolar macrophage (AM) capacities to control Mucorales growth in a new murine ex vivo model. Corticosteroids enhanced fungal growth of L. corymbifera through AM phagocytosis inhibition and burst oxidative decrease.

Download Full-text

A novel mouse model based on intersectional genetics enables unambiguous in vivo discrimination between plasmacytoid and other dendritic cells and their comparative characterization

10.1101/2022.01.07.475382 ◽

2022 ◽

Author(s):

Michael Valente ◽

Nils Collinet ◽

Thien-Phong Vu Manh ◽

Karima Naciri ◽

Gilles Bessou ◽

...

Keyword(s):

Dendritic Cells ◽

Steady State ◽

Mouse Model ◽

Single Cell ◽

Ex Vivo ◽

High Specificity ◽

Type I ◽

Specific Expression ◽

Physiological Functions

Plasmacytoid dendritic cells (pDC) were identified about 20 years ago, based on their unique ability to rapidly produce copious amounts of all subsets of type I and type III interferon (IFN-I/III) upon virus sensing, while being refractory to infection. Yet, the identity and physiological functions of pDC are still a matter of debate, in a large part due to their lack of specific expression of any single cell surface marker or gene that would allow to track them in tissues and to target them in vivo with high specificity and penetrance. Indeed, recent studies showed that previous methods that were used to identify or deplete pDC also targeted other cell types, including pDC-like cells and transitional DC (tDC) that were proposed to be responsible for all the antigen presentation ability previously attributed to steady state pDC. Hence, improving our understanding of the nature and in vivo choreography of pDC physiological functions requires the development of novel tools to unambiguously identify and track these cells, including in comparison to pDC-like cells and tDC. Here, we report successful generation of a pDC-reporter mouse model, by using an intersectional genetic strategy based on the unique co-expression of Siglech and Pacsin1 in pDC. This pDC-Tomato mouse strain allows specific ex vivo and in situ detection of pDC. Breeding them with Zbtb46GFP mice allowed side-by-side purification and transcriptional profiling by single cell RNA sequencing of bona fide pDC, pDC-like cells and tDC, in comparison to type 1 and 2 conventional DC (cDC1 and cDC2), both at steady state and during a viral infection, revealing diverging activation patterns of pDC-like cells and tDC. Finally, by breeding pDC-Tomato mice with Ifnb1EYFP mice, we determined the choreography of pDC recruitment to the micro-anatomical sites of viral replication in the spleen, with initially similar but later divergent behaviors of the pDC that engaged or not into IFN-I production. Our novel pDC-Tomato mouse model, and newly identified gene modules specific to combinations of DC types and activations states, will constitute valuable resources for a deeper understanding of the functional division of labor between DC types and its molecular regulation at homeostasis and during viral infections.

Download Full-text

Abstract 16485: The Nitroxyl Donor 1-Nitrosocyclohexyl Acetate Limits Cardiac Superoxide Upregulation and Diastolic Dysfunction in a Mouse Model of Diabetic Cardiomyopathy

Circulation ◽

10.1161/circ.130.suppl_2.16485 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Rebecca H Ritchie ◽

Nga Cao ◽

Yung George Wong ◽

Sarah Rosli ◽

Helen Kiriazis ◽

...

Keyword(s):

Heart Failure ◽

Mouse Model ◽

Diastolic Dysfunction ◽

Diabetic Cardiomyopathy ◽

Ex Vivo ◽

Systolic Function ◽

Left Ventricular ◽

Cardiomyocyte Hypertrophy ◽

Lv Diastolic Dysfunction ◽

The Impact

Nitroxyl (HNO), a redox congener of NO•, is a novel regulator of cardiovascular function combining vasodilator and positive inotropic properties. Our previous studies have demonstrated these properties occur concomitantly in the intact heart; HNO moreover also exhibits antihypertrophic and superoxide-suppressing actions. HNO donors may thus offer favorable actions in heart failure. The impact of chronic HNO donor administration has however yet to be reported in this context. We tested the hypothesis that the HNO donor 1-nitrosocyclohexyl acetate (1-NCA) limits cardiomyocyte hypertrophy and left ventricular (LV) diastolic dysfunction in a mouse model of diabetic cardiomyopathy in vivo. Male 6 week-old FVB/N mice received either streptozotocin (55 mg/kg/day i.p. for 5 days, n=17), to induce type 1 diabetes, or citrate vehicle (n=16). After 4 weeks of hyperglycemia, mice were allocated to 1-NCA therapy (83mg/kg/day i.p.) or vehicle, and followed for a further 4 weeks. As shown in the table, blood glucose was unaffected by 1-NCA. LV diastolic dysfunction was evident in diabetic mice, measured as echocardiography-derived A wave velocity, deceleration time and E:A ratio; LV systolic function was preserved. Diabetes-induced diastolic dysfunction was accompanied by increased LV cardiomyocyte size, hypertrophic and pro-fibrotic gene expression, and upregulation of LV superoxide. These characteristics of diabetic cardiomyopathy were largely prevented by 1-NCA treatment. Selectivity of 1-NCA as a donor of HNO versus NO• was demonstrated by the sensitivity of the coronary vasodilation response of 1-NCA to the HNO scavenger L-cysteine (4mM), but not to the NO• scavenger hydroxocobalamin (50μM), in the normal rat heart ex vivo (n=3-7). Collectively, our studies provide the first evidence that HNO donors may represent a promising new strategy for the treatment of diabetic cardiomyopathy, and implies their therapeutic efficacy in settings of chronic heart failure.

Download Full-text

Lipocalin 2 induces the epithelial–mesenchymal transition in stressed endometrial epithelial cells: possible correlation with endometriosis development in a mouse model

Reproduction ◽

10.1530/rep-13-0236 ◽

2014 ◽

Vol 147 (2) ◽

pp. 179-187 ◽

Cited By ~ 17

Author(s):

Chi-Jr Liao ◽

Pei-Tzu Li ◽

Ying-Chu Lee ◽

Sheng-Hsiang Li ◽

Sin Tak Chu

Keyword(s):

Epithelial Cells ◽

Mouse Model ◽

Epithelial Mesenchymal Transition ◽

Migration And Invasion ◽

Lipocalin 2 ◽

Mesenchymal Transition ◽

Endometrial Cells ◽

Cellular Microenvironments ◽

And Migration ◽

Endometrial Epithelial Cells

Lipocalin 2 (LCN2) is an induced stressor that promotes the epithelial–mesenchymal transition (EMT). We previously demonstrated that the development of endometriosis in mice correlates with the secretion of LCN2 in the uterus. Here, we sought to clarify the relationship between LCN2 and EMT in endometrial epithelial cells and to determine whether LCN2 plays a role in endometriosis. Antibodies that functionally inhibit LCN2 slowed the growth of ectopic endometrial tissue in a mouse model of endometriosis, suggesting that LCN2 promotes the formation of endometriotic lesions. Using nutrient deprivation as a stressor, LCN2 expression was induced in cultured primary endometrial epithelial cells. As LCN2 levels increased, the cells transitioned from a round to a spindle-like morphology and dispersed. Immunochemical analyses revealed decreased levels of cytokeratin and increased levels of fibronectin in these endometrial cells, adhesive changes that correlate with induction of cell migration and invasion.Lcn2knockdown also indicated that LCN2 promotes EMT and migration of endometrial epithelial cells. Our results suggest that stressful cellular microenvironments cause uterine tissues to secrete LCN2 and that this results in EMT of endometrial epithelial cells, which may correlate with the development of ectopic endometriosis. These findings shed light on the role of LCN2 in the pathology of endometrial disorders.

Download Full-text