Abstract 1632: Tie2-Deficient Mice Exhibit Increased Susceptibility to Endothelial Apoptosis, Arteriolar Muscularization, and Pulmonary Arterial Hypertension in Response to Interleukin-6

Introduction: We have demonstrated downregulation in lung Tie2 receptor expression and activity in experimental models of PAH, implicating reduced Tie2 survival signaling in the pathogenesis of this disease. Therefore, we hypothesized that Tie2 deficiency would predispose to PAH due to increased endothelial cell (EC) apoptosis in response to environmental triggers. Methods: Adult male Tie2± or littermate WT mice received saline or interleukin-6 (IL-6) at a rate of 200ng/kg/day via subcutaneous injections for 1 or 2 weeks. Results: Significant elevation in RVSP (Fig.1 ) was observed in IL-6 treated Tie2± mice (31 ± 3mmHg) compared to saline-treated Tie2 ± mice (25 ± 1mmHg) and IL-6 treated WT mice (22 ± 1mmHg). Following 1 week of IL-6 treatment, increased pulmonary microvascular EC apoptosis was observed by TUNEL in Tie2± mice compared to WT (6.3 ± 0.3% vs. 0.9 ± 0.1%, respectively; p < 0.01). Furthermore, after 2 weeks, a significant increase in pulmonary microvascular muscularization by SMA staining (Fig.2 ) was seen in IL-6 treated Tie2±/mice compared to WT (36.4 ± 1.5% vs. 22.5 ± 1.1%, respectively; p < 0.01). Interestingly, Western blot analysis revealed a significant decrease in Angiopoietin-1 (Ang-1) level in the lung after 2 weeks of IL-6 treatment in Tie2± mice, and ELISA demonstrated a 60% decrease in Ang-1 secretion in vitro after incubation of pulmonary artery smooth muscle cells with IL-6 (p < 0.01). Conclusions: Tie2± mice demonstrated enhanced susceptibility to pulmonary EC apoptosis, increased muscularization, and PAH following chronic exposure to IL-6, supporting an important protective role for endogenous Tie2 signaling in the lung microvasculature. Figure 1. Increased RVSP in Tie2 +/+ mice following 2 weeks of IL-6 treatment (*P < 0.05 compared to Saline Tie2 +/+ ; † P < 0.01 compared to IL-6 WT) Figure 2. Increased pulmonary microvascular muscularization in Tie2 +/+ mice following 2 weeks of IL-6 treatment.

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Current Status of Putative Animal Sources of SARS-CoV-2 Infection in Humans: Wildlife, Domestic Animals and Pets

Microorganisms ◽

10.3390/microorganisms9040868 ◽

2021 ◽

Vol 9 (4) ◽

pp. 868

Author(s):

Max Maurin ◽

Florence Fenollar ◽

Oleg Mediannikov ◽

Bernard Davoust ◽

Christian Devaux ◽

...

Keyword(s):

Animal Species ◽

Biological Properties ◽

Experimental Models ◽

Current Data ◽

The Body ◽

Receptor Expression ◽

Current Status ◽

Susceptible Animal

SARS-CoV-2 is currently considered to have emerged from a bat coronavirus reservoir. However, the real natural cycle of this virus remains to be elucidated. Moreover, the COVID-19 pandemic has led to novel opportunities for SARS-CoV-2 transmission between humans and susceptible animal species. In silico and in vitro evaluation of the interactions between the SARS-CoV-2 spike protein and eucaryotic angiotensin-converting enzyme 2 (ACE2) receptor have tentatively predicted susceptibility to SARS-CoV-2 infection of several animal species. Although useful, these data do not always correlate with in vivo data obtained in experimental models or during natural infections. Other host biological properties may intervene such as the body temperature, level of receptor expression, co-receptor, restriction factors, and genetic background. The spread of SARS-CoV-2 also depends on the extent and duration of viral shedding in the infected host as well as population density and behaviour (group living and grooming). Overall, current data indicate that the most at-risk interactions between humans and animals for COVID-19 infection are those involving certain mustelids (such as minks and ferrets), rodents (such as hamsters), lagomorphs (especially rabbits), and felines (including cats). Therefore, special attention should be paid to the risk of SARS-CoV-2 infection associated with pets.

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The BMP Receptor 2 in Pulmonary Arterial Hypertension: When and Where the Animal Model Matches the Patient

Cells ◽

10.3390/cells9061422 ◽

2020 ◽

Vol 9 (6) ◽

pp. 1422 ◽

Cited By ~ 5

Author(s):

Chris Happé ◽

Kondababu Kurakula ◽

Xiao-Qing Sun ◽

Denielli da Silva Goncalves Bos ◽

Nina Rol ◽

...

Keyword(s):

Pulmonary Arterial Hypertension ◽

Animal Models ◽

Arterial Hypertension ◽

Transforming Growth Factor ◽

Experimental Models ◽

Receptor Expression ◽

Rat Models ◽

Downstream Signaling ◽

Pulmonary Arterial ◽

Expression And Activity

Background: Mutations in bone morphogenetic protein receptor type II (BMPR2) are leading to the development of hereditary pulmonary arterial hypertension (PAH). In non-hereditary forms of PAH, perturbations in the transforming growth factor-β (TGF-β)/BMP-axis are believed to cause deficient BMPR2 signaling by changes in receptor expression, the activity of the receptor and/or downstream signaling. To date, BMPR2 expression and its activity in the lungs of patients with non-hereditary PAH is poorly characterized. In recent decades, different animal models have been used to understand the role of BMPR2 signaling in PAH pathophysiology. Specifically, the monocrotaline (MCT) and Sugen–Hypoxia (SuHx) models are extensively used in interventional studies to examine if restoring BMPR2 signaling results in PAH disease reversal. While PAH is assumed to develop in patients over months or years, pulmonary hypertension in experimental animal models develops in days or weeks. It is therefore likely that modifications in BMP and TGF-β signaling in these models do not fully recapitulate those in patients. In order to determine the translational potential of the MCT and SuHx models, we analyzed the BMPR2 expression and activity in the lungs of rats with experimentally induced PAH and compared this to the BMPR2 expression and activity in the lungs of PAH patients. Methods: the BMPR2 expression was analyzed by Western blot analysis and immunofluorescence (IF) microscopy to determine the quantity and localization of the receptor in the lung tissue from normal control subjects and patients with hereditary or idiopathic PAH, as well as in the lungs of control rats and rats with MCT or SuHx-induced PAH. The activation of the BMP pathway was analyzed by determining the level and localization of phosphorylated Smad1/5/8 (pSmad 1/5/8), a downstream mediator of canonical BMPR2 signaling. Results: While BMPR2 and pSmad 1/5/8 expression levels were unaltered in whole lung lysates/homogenates from patients with hereditary and idiopathic PAH, IF analysis showed that BMPR2 and pSmad 1/5/8 levels were markedly decreased in the pulmonary vessels of both PAH patient groups. Whole lung BMPR2 expression was variable in the two PAH rat models, while in both experimental models the expression of BMPR2 in the lung vasculature was increased. However, in the human PAH lungs, the expression of pSmad 1/5/8 was downregulated in the lung vasculature of both experimental models. Conclusion: BMPR2 receptor expression and downstream signaling is reduced in the lung vasculature of patients with idiopathic and hereditary PAH, which cannot be appreciated when using human whole lung lysates. Despite increased BMPR2 expression in the lung vasculature, the MCT and SuHx rat models did develop PAH and impaired downstream BMPR2-Smad signaling similar to our findings in the human lung.

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gamma-Interferon in multiple myeloma: inhibition of interleukin-6 (IL- 6)-dependent myeloma cell growth and downregulation of IL-6-receptor expression in vitro

Blood ◽

10.1182/blood.v81.11.3076.bloodjournal81113076 ◽

1993 ◽

Vol 81 (11) ◽

pp. 3076-3082 ◽

Cited By ~ 1

Author(s):

M Portier ◽

XG Zhang ◽

E Caron ◽

ZY Lu ◽

R Bataille ◽

...

Keyword(s):

Multiple Myeloma ◽

Cell Growth ◽

Interleukin 6 ◽

Plasma Cells ◽

Myeloma Cell ◽

Gamma Interferon ◽

Receptor Expression ◽

Endogenous Production ◽

Spontaneous Proliferation

In multiple myeloma, malignant plasma cells from most patients with active disease proliferate spontaneously when cultured for 5 days in vitro. This spontaneous proliferation is related to the endogenous production of interleukin-6 (IL-6), the major myeloma-cell growth factor. A 50% inhibitory dose (100 U/mL) of human recombinant gamma- interferon (hr gamma-IFN) blocked the proliferation of myeloma cells almost completely in all 19 patients analyzed. This inhibition was not caused by suppression of endogenous IL-6 production and was also observed in the presence of an excess of hrIL-6. hr gamma-IFN was also completely inhibitory in four human myeloma cell lines (HMCL) whose growth is totally dependent on the addition of exogenous hrIL-6. This inhibition was associated with a 47% to 73% decrease in membrane IL-6- binding gp80 protein as well as with a 90% decrease in the amount of gp80 mRNA in HMCL. These results are in line with recent reports indicating that gamma-IFN inhibited several IL-6-dependent biologic processes. They suggest a need to reconsider why previous preliminary clinical trials failed to demonstrate a beneficial effect of gamma-IFN in multiple myeloma.

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Apoptosis signal-regulating kinase 1 inhibition in in vivo and in vitro models of pulmonary hypertension

Pulmonary Circulation ◽

10.1177/2045894020922810 ◽

2020 ◽

Vol 10 (2) ◽

pp. 204589402092281 ◽

Cited By ~ 1

Author(s):

Kathryn S. Wilson ◽

Hanna Buist ◽

Kornelija Suveizdyte ◽

John T. Liles ◽

Grant R. Budas ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Smooth Muscle ◽

Pulmonary Arterial Hypertension ◽

Pulmonary Artery ◽

Arterial Hypertension ◽

Mitogen Activated Protein ◽

Pulmonary Arterial ◽

Pulmonary Artery Smooth Muscle

Pulmonary arterial hypertension, group 1 of the pulmonary hypertension disease family, involves pulmonary vascular remodelling, right ventricular dysfunction and cardiac failure. Oxidative stress, through activation of mitogen-activated protein kinases is implicated in these changes. Inhibition of apoptosis signal-regulating kinase 1, an apical mitogen-activated protein kinase, prevented pulmonary arterial hypertension developing in rodent models. Here, we investigate apoptosis signal-regulating kinase 1 in pulmonary arterial hypertension by examining the impact that its inhibition has on the molecular and cellular signalling in established disease. Apoptosis signal-regulating kinase 1 inhibition was investigated in in vivo pulmonary arterial hypertension and in vitro pulmonary hypertension models. In the in vivo model, male Sprague Dawley rats received a single subcutaneous injection of Sugen SU5416 (20 mg/kg) prior to two weeks of hypobaric hypoxia (380 mmHg) followed by three weeks normoxia (Sugen/hypoxic), then animals were either maintained for three weeks on control chow or one containing apoptosis signal-regulating kinase 1 inhibitor (100 mg/kg/day). Cardiovascular measurements were carried out. In the in vitro model, primary cultures of rat pulmonary artery fibroblasts and rat pulmonary artery smooth muscle cells were maintained in hypoxia (5% O2) and investigated for proliferation, migration and molecular signalling in the presence or absence of apoptosis signal-regulating kinase 1 inhibitor. Sugen/hypoxic animals displayed significant pulmonary arterial hypertension compared to normoxic controls at eight weeks. Apoptosis signal-regulating kinase 1 inhibitor decreased right ventricular systolic pressure to control levels and reduced muscularised vessels in lung tissue. Apoptosis signal-regulating kinase 1 inhibition was found to prevent hypoxia-induced proliferation, migration and cytokine release in rat pulmonary artery fibroblasts and also prevented rat pulmonary artery fibroblast-induced rat pulmonary artery smooth muscle cell migration and proliferation. Apoptosis signal-regulating kinase 1 inhibition reversed pulmonary arterial hypertension in the Sugen/hypoxic rat model. These effects may be a result of intrinsic changes in the signalling of adventitial fibroblast.

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Novel Approaches to Treat Experimental Pulmonary Arterial Hypertension: A Review

Journal of Biomedicine and Biotechnology ◽

10.1155/2010/702836 ◽

2010 ◽

Vol 2010 ◽

pp. 1-11 ◽

Cited By ~ 20

Author(s):

S. Umar ◽

P. Steendijk ◽

D. L. Ypey ◽

D. E. Atsma ◽

E. E. van der Wall ◽

...

Keyword(s):

Pulmonary Arterial Hypertension ◽

Arterial Hypertension ◽

Treatment Options ◽

Experimental Models ◽

Homogeneous Groups ◽

Emerging Trends ◽

Animal Data ◽

Life Threatening ◽

Pulmonary Arterial

Background. Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by an increase in pulmonary artery pressure leading to right ventricular (RV) hypertrophy, RV failure, and ultimately death. Current treatments can improve symptoms and reduce severity of the hemodynamic disorder but gradual deterioration in their condition often necessitates a lung transplant.Methods and Results. In experimental models of PAH, particularly the model of monocrotaline-induced pulmonary hypertension, efficacious treatment options tested so far include a spectrum of pharmacologic agents with actions such as anti-mitogenic, proendothelial function, proangiogenic, antiinflammatory and antioxidative. Emerging trends in PAH treatment are gene and cell therapy and their combination, like (progenitor) cells enriched with eNOS or VEGF gene. More animal data should be collected to investigate optimal cell type, in vitro cell transduction, route of administration, and number of cells to inject. Several recently discovered and experimentally tested interventions bear potential for therapeutic purposes in humans or have been shown already to be effective in PAH patients leading to improved life expectation and better quality of life.Conclusion. Since many patients remain symptomatic despite therapy, we should encourage research in animal models of PAH and implement promising treatments in homogeneous groups of PAH patients.

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Trypanosoma cruziglutathione-binding proteins: immunogenicity during human and experimental Chagas' disease

Parasitology ◽

10.1017/s0031182000060832 ◽

1992 ◽

Vol 104 (1) ◽

pp. 87-98 ◽

Cited By ~ 14

Author(s):

B. Plumas-Marty ◽

C. Verwaerde ◽

M. Loyens ◽

P. Velge ◽

A. Taibi ◽

...

Keyword(s):

Binding Proteins ◽

Developmental Stages ◽

Protective Role ◽

Experimental Models ◽

Transferase Activity ◽

Glutathione S Transferase ◽

Electron Microscopic ◽

New Class ◽

Defensive Role

SUMMARYFollowing purification by affinity chromatography, three glutathione-binding proteins (TcGBP) of 45, 30, and 25 kDa were co-purified fromTrypanosoma cruziepimastigotes. Using 1-chloro-2,4 dinitrobenzene as substrate, a glutathione S-transferase activity of 70 nmol/min/mg of proteins was detected in the GSH binding fraction. An increased expression of TcGBP and total GST activity was observed upon incubation of parasites with phenobarbital, which is an inducer of GST synthesis. Immunofluorescence and electron microscopic experiments demonstrated that TcGBP were expressed by all developmental stages of the parasite, including infective forms. The expression of these proteins by intracellular dividing amastigotes could be in favour of a potential defensive role of these molecules against host attack. Results obtained by immunoprecipitation ofin vitrotranslation products using anti-TcGBP antisera suggested that these three polypeptides are not glycosylated. In addition, antibodies directed against the TcGBP were found in a high proportion ofT. cruzi-infected chronic chagasic patients' sera and in sera of chronically infected BALB/c mice. In contrast, acute chagasic patients' sera and acute-phase mouse sera were found to be poorly reactive with these proteins. Our results identify a new class of potential target antigens, which may be essential for the development ofT. cruziin its host. Their protective role in experimental models deserves to be investigated.

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gamma-Interferon in multiple myeloma: inhibition of interleukin-6 (IL- 6)-dependent myeloma cell growth and downregulation of IL-6-receptor expression in vitro

Blood ◽

10.1182/blood.v81.11.3076.3076 ◽

1993 ◽

Vol 81 (11) ◽

pp. 3076-3082 ◽

Cited By ~ 60

Author(s):

M Portier ◽

XG Zhang ◽

E Caron ◽

ZY Lu ◽

R Bataille ◽

...

Keyword(s):

Multiple Myeloma ◽

Cell Growth ◽

Interleukin 6 ◽

Plasma Cells ◽

Myeloma Cell ◽

Gamma Interferon ◽

Receptor Expression ◽

Endogenous Production ◽

Spontaneous Proliferation

Abstract In multiple myeloma, malignant plasma cells from most patients with active disease proliferate spontaneously when cultured for 5 days in vitro. This spontaneous proliferation is related to the endogenous production of interleukin-6 (IL-6), the major myeloma-cell growth factor. A 50% inhibitory dose (100 U/mL) of human recombinant gamma- interferon (hr gamma-IFN) blocked the proliferation of myeloma cells almost completely in all 19 patients analyzed. This inhibition was not caused by suppression of endogenous IL-6 production and was also observed in the presence of an excess of hrIL-6. hr gamma-IFN was also completely inhibitory in four human myeloma cell lines (HMCL) whose growth is totally dependent on the addition of exogenous hrIL-6. This inhibition was associated with a 47% to 73% decrease in membrane IL-6- binding gp80 protein as well as with a 90% decrease in the amount of gp80 mRNA in HMCL. These results are in line with recent reports indicating that gamma-IFN inhibited several IL-6-dependent biologic processes. They suggest a need to reconsider why previous preliminary clinical trials failed to demonstrate a beneficial effect of gamma-IFN in multiple myeloma.

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