Papers by Ebba BRAKENHIELM
European Heart Journal
Background Heart failure (HF) pathophysiology complicating cardiac amyloidosis (CA) is poorly exp... more Background Heart failure (HF) pathophysiology complicating cardiac amyloidosis (CA) is poorly explored due to the lack of relevant animal model. A recently transgenic mouse expressing an amyloidogenic variant of human apolipoprotein AII was developed that showed ubiquitous amyloid deposit but limited data on cardiac involvement. Purpose To investigate heart structure and function in transgenic mice expressing an amyloidogenic variant of human apolipoprotein AII Methods Seventy-nine mice ageing 2 to 3 months were included in this study as follow: amyloidosis group (n=44) and sham (i.e. genetic mutation without phenotypic expression, n=35). Both were serially imaged by echocardiography (Vevo3100 Fujifilm) and cardiac magnetic resonance imaging (CMR, Biospec 4.7 tesla), and invasively explored by left–sided catheterization (pressure-volume loop [PV loop], Millar Catheterization), before sacrifice and histological investigations. Results As soon as 2–3 months of age, the amyloidosis gro...
Oxidative Stress and Disease, 2005
Methods in molecular biology (Clifton, N.J.), 2008
Angiogenesis is required for the growth and expansion of both healthy and pathological tissues. T... more Angiogenesis is required for the growth and expansion of both healthy and pathological tissues. The plasticity of the adipose tissue is reflected by its remarkable ability to expand or to reduce in size throughout the adult lifespan. We, and others, have recently shown that expansion of fat mass is dependent on angiogenesis, and suppression of angiogenesis might provide a novel therapeutic approach for prevention and treatment of obesity. Here, we outline two technical procedures for assessment of angiogenesis in adipose tissues.
International journal of molecular imaging, 2011
The aim of this paper is to develop new optical bioprobes for the imaging of apoptosis. Procedure... more The aim of this paper is to develop new optical bioprobes for the imaging of apoptosis. Procedure. We developed quenched near-infrared probes which become fluorescent upon cleavage by caspase-3, the key regulatory enzyme of apoptosis. Results. Probes were shown to be selectively cleaved by recombinant caspase-3. Apoptosis of cultured endothelial cells was associated with an increased fluorescent signal for the cleaved probes, which colocalized with caspase-3 and was reduced by the addition of a caspase-3 inhibitor. Flow cytometry demonstrated a similar profile between the cleaved probes and annexin V. Ex vivo experiments showed that sections of hearts obtained from mice treated with the proapoptotic drug doxorubicin displayed an increase in the fluorescent signal for the cleaved probes, which was reduced by a caspase-3 inhibitor. Conclusion. We demonstrated the capacity of these novel probes to detect apoptosis by optical imaging in vitro and ex vivo.
Molecular Therapy, 2006
Introduction: Metastatic disease is a major cause of prostate cancer mortality. Lymph node involv... more Introduction: Metastatic disease is a major cause of prostate cancer mortality. Lymph node involvement is an important early prognostic indicator of patient survival. The extent of tumorassociated lymphangiogenesis can dictate lymphatic metastasis in many tumors. Limited experience on this issue in prostate cancer leads us to study tumor models, which recapitulate many of characteristics of the human disease including androgen regulation and PSA expression. Results: By applying in vivo bioluminescence imaging, we observed that prostate cancer xenografts display distinctive metastatic potentials. Whereas LAPC-4 and CWR22RV-1 tumors metastasized to lymph nodes and lungs, LAPC-9 tumors did not. Quantitative real-time PCR revealed that the expression of pro-lymphangiogenic factor, VEGF-C, was elevated in LAPC-4 and CWR22RV-1 compared to LAPC-9 tumors. Immunohistochemistry showed that LAPC-4 tumors contained patent intratumoral lymphatics, often filled with tumor cells. To examine the correlation of tumor lymphangiogenesis and metastasis, we over-expressed VEGF-C in the non-metastatic LAPC-9 model, and we downregulated lymphangiogenesis in CWR22RV-1 by expressing soluble VEGF-R3 to sequester VEGF-C. Recombinant lentiviral vectors were applied to express luciferase and vascular growth factor genes in the tumors. The effects of VEGF-C, VEGF-C C156S (a point mutant of VEGF-C that induces lymphangiogenesis but not angiogenesis), or VEGF-A were compared to control vector. While VEGF-A increased the number of blood vessels and the rate of growth, we observed limited enhancement of lymph node (signals 10-fold greater photons/s/cm 2 /sr over control) and lung metastasis. On the other hand, VEGF-C C156S and VEGF-C over-expression resulted in enhanced intratumoral lymphangiogenesis and significant dissemination to ipsilateral lymph nodes (200-to 1000-fold over control) and lungs (25-fold enhancement). The VEGF-C C156S tumors exhibited no increase in blood vessels. The expression of soluble VEGF-R3 in CWR22RV-1 resulted in a significant reduction in intratumoral vasculatures as well as metastasis to both regional lymph node and lung. The extent of metastasis in all tumor models assessed by optical imaging correlated well with immunocytochemical analyses of metastasis by cytokeratin marker and GFP. Conclusion: Bioluminescence imaging is a valuable tool to track metastasis in both the VEGF-C and VEGF-A expressing tumors. Our results indicate that tumor lymphangiogenesis is a key factor contributing to not only local regional lymph nodes but also to lungs in prostate cancer models. Inhibiting tumor lymphangiogenesis may be a promising therapeutic strategy to suppress the deadly consequence of systemic metastasis.
Journal of Clinical Investigation, 2007
Tumors produce multiple growth factors, but little is known about the interplay between various a... more Tumors produce multiple growth factors, but little is known about the interplay between various angiogenic factors in promoting tumor angiogenesis, growth, and metastasis. Here we show that 2 angiogenic factors frequently upregulated in tumors, PDGF-BB and FGF2, synergistically promote tumor angiogenesis and pulmonary metastasis. Simultaneous overexpression of PDGF-BB and FGF2 in murine fibrosarcomas led to the formation of highdensity primitive vascular plexuses, which were poorly coated with pericytes and VSMCs. Surprisingly, overexpression of PDGF-BB alone in tumor cells resulted in dissociation of VSMCs from tumor vessels and decreased recruitment of pericytes. In the absence of FGF2, capillary ECs lacked response to PDGF-BB. However, FGF2 triggers PDGFR-a and-b expression at the transcriptional level in ECs, which acquire hyperresponsiveness to PDGF-BB. Similarly, PDGF-BB-treated VSMCs become responsive to FGF2 stimulation via upregulation of FGF receptor 1 (FGFR1) promoter activity. These findings demonstrate that PDGF-BB and FGF2 reciprocally increase their EC and mural cell responses, leading to disorganized neovascularization and metastasis. Our data suggest that intervention of this non-VEGF reciprocal interaction loop for the tumor vasculature could be an important therapeutic target for the treatment of cancer and metastasis.
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Papers by Ebba BRAKENHIELM