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1.
Mol Ther Nucleic Acids ; 34: 102068, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38034031

ABSTRACT

Dysfunction of endothelial cells (ECs) lining the inner surface of blood vessels are causative for a number of diseases. Hence, the ability to therapeutically modulate gene expression within ECs is of high therapeutic value in treating diseases such as those associated with lung edema. mRNAs formulated with lipid nanoparticles (LNPs) have emerged as a new drug modality to induce transient protein expression for modulating disease-relevant signal transduction pathways. In the study presented here, we tested the effect of a novel synthetic, nucleoside-modified mRNA encoding COMP-Ang1 (mRNA-76) formulated into a cationic LNP on attenuating inflammation-induced vascular leakage. After intravenous injection, the respective mRNA was found to be delivered almost exclusively to the ECs of the lung, while sparing other vascular beds and bypassing the liver. The mode of action of mRNA-76, such as its activation of the Tie2 signal transduction pathway, was tested by pharmacological studies in vitro and in vivo in respective mouse models. mRNA-76 was found to prevent lung vascular leakage/lung edema as well as neutrophil infiltration in a lipopolysaccharide-challenging model.

2.
Unfallchirurg ; 122(1): 76-78, 2019 Jan.
Article in German | MEDLINE | ID: mdl-30143823

ABSTRACT

This case report describes the osteosynthetic treatment and postoperative course of a fracture of the capitulum humeri and a concomitant fracture of the head of the radius with a follow-up over 3 months. Simultaneous fractures of the capitulum humeri and the head of the radius are rare injuries of the elbow. Due to the complex anatomical relationships this type of fracture poses a big challenge for treating traumatologists.


Subject(s)
Elbow Joint , Humeral Fractures , Radius Fractures , Fracture Fixation, Internal , Humans , Humerus , Radius
3.
Am J Respir Crit Care Med ; 198(2): 220-231, 2018 07 15.
Article in English | MEDLINE | ID: mdl-29447449

ABSTRACT

RATIONALE: During pneumonia, pathogen-host interaction evokes inflammation and lung barrier dysfunction. Tie2 activation by angiopoietin-1 reduces, whereas Tie2 blockade by angiopoietin-2 increases, inflammation and permeability during sepsis. The role of angiopoietin-1/-2 in pneumonia remains unidentified. OBJECTIVES: To investigate the prognostic and pathogenic impact of angiopoietins in regulating pulmonary vascular barrier function and inflammation in bacterial pneumonia. METHODS: Serum angiopoietin levels were quantified in pneumonia patients of two independent cohorts (n = 148, n = 395). Human postmortem lung tissue, pneumolysin- or angiopoietin-2-stimulated endothelial cells, isolated perfused and ventilated mouse lungs, and mice with pneumococcal pneumonia were investigated. MEASUREMENTS AND MAIN RESULTS: In patients with pneumonia, decreased serum angiopoietin-1 and increased angiopoietin-2 levels were observed as compared with healthy subjects. Higher angiopoietin-2 serum levels were found in patients with community-acquired pneumonia who died within 28 days of diagnosis compared with survivors. Receiver operating characteristic analysis revealed improved prognostic accuracy of CURB-65 for 28-day survival, intensive care treatment, and length of hospital stay if combined with angiopoietin-2 serum levels. In vitro, pneumolysin enhanced endothelial angiopoietin-2 release, angiopoietin-2 increased endothelial permeability, and angiopoietin-1 reduced pneumolysin-evoked endothelial permeability. Ventilated and perfused lungs of mice with angiopoietin-2 knockdown showed reduced permeability on pneumolysin stimulation. Increased pulmonary angiopoietin-2 and reduced angiopoietin-1 mRNA expression were observed in Streptococcus pneumoniae-infected mice. Finally, angiopoietin-1 therapy reduced inflammation and permeability in murine pneumonia. CONCLUSIONS: These data suggest a central role of angiopoietin-1/-2 in pneumonia-evoked inflammation and permeability. Increased angiopoietin-2 serum levels predicted mortality and length of hospital stay, and angiopoietin-1 may provide a therapeutic target for severe pneumonia.


Subject(s)
Angiopoietin-1/therapeutic use , Angiopoietin-2/therapeutic use , Endothelial Cells/drug effects , Host-Pathogen Interactions/drug effects , Inflammation/physiopathology , Lung/drug effects , Pneumonia, Pneumococcal/drug therapy , Pneumonia, Pneumococcal/physiopathology , Angiopoietin-1/blood , Angiopoietin-2/blood , Humans , Prognosis
4.
Surg J (N Y) ; 3(3): e143-e144, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28890932

ABSTRACT

Isolated biceps femoris rupture is a rare injury associated with limitation in the function of the knee. We present a 65-year-old man who sustained an isolated complete rupture of the tendon of the biceps femoris. The diagnostic was reached after clinical examination and magnetic resonance imaging of the affected knee. This case was treated with a surgical tendon reconstruction. The outcome was good and the patient was able to walk normally again without limitation, even if he did not comply with our recommendation.

5.
Clin Rheumatol ; 34(4): 673-81, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25630309

ABSTRACT

Tocilizumab (TCZ) and tumour necrosis factor inhibitors (TNFi) are recommended for the treatment of rheumatoid arthritis (RA) in patients with inadequate response (IR) to prior disease-modifying antirheumatic drugs (DMARDs). This retrospective analysis assessed the efficacy of TCZ and TNFi, alone or in combination with DMARDs, in 1603 patients with IR to previous treatment with either DMARDs (DMARD-IR) and/or TNFi (TNFi-IR), initiating treatment with TCZ or a TNFi, managed in routine clinical practice. Patients were grouped according to treatment history and treatment initiated: DMARD-IR patients initiating treatment with TCZ + DMARD (DMARD-IR TCZ) or TNFi + DMARD (DMARD-IR TNFi), DMARD-IR and/or TNFi-IR patients initiating treatment with TCZ monotherapy (TCZ mono) or TNFi monotherapy (TNFi mono), and TNFi-IR patients initiating treatment with TCZ + DMARD (TNFi-IR TCZ) or TNFi + DMARD (TNFi-IR TNFi). Patients initiating treatment with TCZ generally had more severe disease and longer disease duration compared with the corresponding TNFi group. Significantly more patients achieved remission (DAS28 ESR <2.6) in the TCZ groups compared with corresponding TNFi groups (DMARD-IR, TCZ 44.0 % vs. TNFi 29.6 %; monotherapy, TCZ 37.2 % vs. TNFi 30.2 %; TNF-IR, TCZ 41.3 % vs. TNFi 19.2 %; p < 0.001 for all comparisons). More patients achieved moderate-good responses (EULAR criteria) in the TCZ treatment groups (79-85 %) compared with TNFi treatment groups (65-81 %). Patient-reported outcomes showed greater improvements in TCZ compared with TNFi groups. In patients with inadequate response to DMARDs and/or TNFi treated in routine clinical practice, TCZ in combination with DMARDs or as monotherapy resulted in significantly more patients achieving remission and more marked improvements in patient-reported outcomes compared with TNF inhibitors.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Arthritis, Rheumatoid/drug therapy , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Adult , Aged , Antirheumatic Agents/therapeutic use , Female , Humans , Male , Middle Aged , Retrospective Studies , Severity of Illness Index , Surveys and Questionnaires , Treatment Outcome
6.
J Clin Oncol ; 32(36): 4141-8, 2014 Dec 20.
Article in English | MEDLINE | ID: mdl-25403217

ABSTRACT

PURPOSE: Atu027 is a novel liposomal RNA interference therapeutic that includes a short-interfering RNA (siRNA), which silences expression of protein kinase N3 in the vascular endothelium. Atu027 has previously been shown to inhibit local tumor invasion as well as lymph node and pulmonary metastasis in mouse cancer models. This first-in-human study aimed to assess the safety, tolerability, and pharmacokinetics of Atu027 while evaluating therapeutic effects on both primary tumors and metastatic lesions. PATIENTS AND METHODS: Thirty-four patients with advanced solid tumors received 10 escalating doses of Atu027 without premedication, as one single followed by eight intravenous infusions twice per week during a 28-day cycle. Response was monitored by computed tomography/magnetic resonance imaging at baseline, at the end of treatment (EoT), and at final follow-up (EoS), and was assessed according to RECIST. RESULTS: Atu027 was well tolerated up to dose levels of 0.336 mg/kg; most adverse events (AEs) were low-grade toxicities (grade 1 or 2). No maximum tolerated dose was reached. Plasma levels of siRNA strands and lipids were dose proportional, peaking during 4-hour infusion. Disease stabilization was achieved in 41% of patients at EoT (n = 14 of 34 treated patients); eight patients had stable disease at EoS, and some experienced complete or partial regression of metastases. sFLT1 (soluble variant of vascular endothelial growth factor receptor-1) decreased from pretreatment levels in most patients after dose levels 04 to 10. CONCLUSION: Atu027 was safe in patients with advanced solid tumors, with 41% of patients having stable disease for at least 8 weeks. In view of these results, further clinical trials have been initiated, and sFLT1 will be investigated as a potential biomarker.


Subject(s)
Neoplasms/drug therapy , Protein Kinase C/antagonists & inhibitors , RNA, Small Interfering/therapeutic use , Adult , Aged , Aged, 80 and over , Complement System Proteins/analysis , Cytokines/blood , Female , Humans , Liposomes , Male , Middle Aged , Prospective Studies , Protein Kinase C/genetics , RNA, Small Interfering/adverse effects , RNA, Small Interfering/pharmacokinetics
7.
Crit Care Med ; 42(10): e654-62, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25083983

ABSTRACT

OBJECTIVE: Angiopoietin-2, a protein secreted by stimulated endothelium and an antagonist of the endothelium-stabilizing receptor Tie2, contributes to the pathophysiology of septic multiple organ dysfunction. We tested the therapeutic potential of a pulmonary-endothelium-specific RNA interference-based angiopoietin-2 targeting strategy in sepsis. DESIGN: Laboratory and animal research. SETTINGS: Research laboratories of the Medical School Hannover, Department of Nephrology and Hypertension, Hannover and Silence Therapeutics GmbH, Berlin. SUBJECTS: C57Bl/6 mice. INTERVENTIONS: Lung-endothelium-specific angiopoietin-2 small interfering RNA was administered both before and after sepsis induction (cecal ligation and puncture or lipopolysaccharides) intravenously. MEASUREMENTS AND MAIN RESULTS: Angiopoietin-2 small interfering RNA was highly specific and reduced angiopoietin-2 expression in the septic murine lungs up to 73.8% (p = 0.01) and enhanced the phosphorylation of Tie2 both in control and septic animals. Angiopoietin-2 small interfering RNA reduced pulmonary interleukin-6 transcription, intercellular adhesion molecule expression, neutrophil infiltration, and vascular leakage. Manifestations of sepsis were also attenuated in distant organs, including the kidney, where renal function was improved without affecting local angiopoietin-2 production. Finally, angiopoietin-2 small interfering RNA ameliorated the severity of illness and improved survival in cecal ligation and puncture, both as a pretreatment and as a rescue intervention. CONCLUSION: The Tie2 antagonist angiopoietin-2 represents a promising target against sepsis-associated multiple organ dysfunction. A novel RNA interference therapeutic approach targeting gene expression in the pulmonary endothelium could be a clinically relevant pharmacological strategy to reduce injurious angiopoietin-2 synthesis.


Subject(s)
Angiopoietin-2/physiology , Lung/metabolism , Multiple Organ Failure/etiology , RNA Interference/physiology , Sepsis/complications , Angiopoietin-2/metabolism , Animals , Disease Models, Animal , Inflammation/etiology , Inflammation/metabolism , Inflammation/physiopathology , Mice , Mice, Inbred C57BL , Multiple Organ Failure/metabolism , Multiple Organ Failure/physiopathology , RNA, Small Interfering/metabolism , Receptor, TIE-2/metabolism , Sepsis/metabolism , Sepsis/mortality , Sepsis/physiopathology
8.
Mol Ther ; 22(4): 811-20, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24390281

ABSTRACT

Posttranscriptional gene silencing by RNA interference can be therapeutically exploited to inhibit pathophysiological gene expression. However, in contrast to the established effectiveness of RNAi in vitro, safe and effective delivery of siRNAs to specific organs and cell types in vivo remains the major hurdle. Here, we report the development and in vivo characterization of a novel siRNA delivery system (DACC lipoplex) suitable for modulating target gene expression specifically in the lung vasculature. Systemic administration of DACC in mice delivered siRNA cargo functionally to the lung pulmonary endothelium. A single dose of DACC lipoplexes administered by bolus injection or by infusion was sufficient to specifically silence genes expressed in pulmonary endothelial cells such as CD31, Tie-2, VE-cadherin, or BMP-R2. When tested in a mouse model for lung cancer, repeated treatment with DACC/siRNA(CD31) reduced formation of lung metastases and increased life span in a mouse model of experimental lung metastasis.


Subject(s)
Dipeptides/administration & dosage , Gene Transfer Techniques , Genetic Therapy , Lung Neoplasms/genetics , Phosphatidylethanolamines/administration & dosage , Polyethylene Glycols/administration & dosage , RNA, Small Interfering/administration & dosage , Animals , Disease Models, Animal , Endothelium/metabolism , Humans , Lung/metabolism , Lung/pathology , Lung Neoplasms/pathology , Lung Neoplasms/therapy , Mice , RNA, Small Interfering/genetics
9.
Clin Rheumatol ; 32(9): 1347-55, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23703358

ABSTRACT

This study aims to investigate the use of biological disease-modifying antirheumatic drugs (bDMARDs) as monotherapy in patients with rheumatoid arthritis (RA) in "real world" clinical settings and to compare tumor necrosis factor (TNF) inhibitors and tocilizumab monotherapy in terms of efficacy and patient and clinician satisfaction with treatment. This study made use of a retrospective, cohort-19 based study including included data from 254 patients (TNF inhibitors n = 128; tocilizumab n = 126) managed in 30 centers throughout Germany. Efficacy of monotherapy and patient and physician overall satisfaction with treatment were assessed at baseline, 3, and 6 months of monotherapy using a range of measures including Disease Activity Score 28 joint (DAS28), swollen joint count (SJC) and tender joint count (TJC), and visual analogue scales (VAS). Between 18 and 41 % of patients treated with bDMARDs received the agent as monotherapy. Intolerance to DMARDs, contraindications for combination therapy, and comorbidities were the most common reasons for introduction of bDMARD monotherapy. Mean DAS28 (erythrocyte sedimentation rate, ESR) was significantly lower at 3 and 6 months following tocilizumab vs. TNF inhibitors (p ≤ 0.001). Joint counts improved from baseline to month 6 in both groups (SJC -5.1 vs. -3.7 and TJC -5.6 vs. -5.1, for tocilizumab and TNF inhibitors, respectively). Patient as well as physician satisfaction (VAS 100 mm scale) was significantly higher for tocilizumab vs. TNF inhibitors (75.3 vs. 66.8; p = 0.001 and 74.9 vs. 67.1, p = 0.003, respectively). Significantly more patients remained on tocilizumab monotherapy vs. TNF-inhibitor monotherapy (89.7 vs. 75.8 %; p < 0.01). Monotherapy with bDMARDs is common in routine clinical practice. Tocilizumab monotherapy appeared to be superior over TNF-inhibitor monotherapy with respect to DAS28 and drug adherence.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Antirheumatic Agents/therapeutic use , Arthritis, Rheumatoid/drug therapy , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Adult , Aged , Blood Sedimentation , Female , Germany , Humans , Male , Medication Adherence , Middle Aged , Patient Satisfaction , Retrospective Studies , Severity of Illness Index , Treatment Outcome
10.
Eur J Cell Biol ; 91(9): 694-705, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22609186

ABSTRACT

Several pathways are involved in the control of endothelial cell morphology, endothelial permeability and function in order to maintain vascular homeostasis. Here we report that protein kinase N3 (PKN3) appears to play a pivotal role in maintaining endothelial cell morphology, cell-cell junctions and motility. An RNAi-based cell biological approach in cultured human endothelial cells (HUVEC) revealed that knockdown of PKN3 expression gave rise to cells with divergent cell morphology, impaired locomotion, disturbed adherens junctions (AJ) integrity and irregular actin organization. Notably, knockdown of PKN3 cells led to improper stress fiber formation and marked adhesiveness of intercellular adherens junctions when cells became stimulated with the pro-inflammatory cytokine TNF-α. Moreover, TNF-α-induced ICAM-1 expression on the cell surface was reduced in cells with suppressed PKN3 expression. Finally, loss-of-function for PKN3 appeared to affect Pyk2 phosphorylation in endothelial cells. These observations suggest that PKN3 can be considered a novel protein implicated in remodeling the actin-adherens junction, possibly by linking ICAM-1-signaling with actin/AJ dynamics. We propose that loss of PKN3 function and concomitant aberrations in actin rearrangement may attenuate pro-inflammatory activation of endothelial cells.


Subject(s)
Actins/metabolism , Adherens Junctions/metabolism , Endothelial Cells/metabolism , Protein Kinase C/deficiency , Protein Kinase C/metabolism , Cells, Cultured , Endothelial Cells/cytology , Humans , Intercellular Adhesion Molecule-1/metabolism , Signal Transduction
12.
Clin Cancer Res ; 16(22): 5469-80, 2010 Nov 15.
Article in English | MEDLINE | ID: mdl-21062934

ABSTRACT

PURPOSE: Atu027, a novel RNA interference therapeutic, has been shown to inhibit lymph node metastasis in orthotopic prostate cancer mouse models. The aim of this study is to elucidate the pharmacologic activity of Atu027 in inhibiting hematogenous metastasis to the target organ lung in four different preclinical mouse models. EXPERIMENTAL DESIGN: Atu027 compared with vehicle or control small interfering RNA lipoplexes was tested in two experimental lung metastasis models (Lewis lung carcinoma, B16V) and spontaneous metastasis mouse models (MDA-MB-435, MDA-MB-231, mammary fat pad). Different dosing schedules (repeated low volume tail vein injections) were applied to obtain insight into effective Atu027 treatment. Primary tumor growth and lung metastasis were measured, and tissues were analyzed by immunohistochemistry and histology. In vitro studies in human umbilical vein endothelial cells were carried out to provide an insight into molecular changes on depletion of PKN3, in support of efficacy results. RESULTS: Intravenous administration of Atu027 prevents pulmonary metastasis. In particular, formation of spontaneous lung metastasis was significantly inhibited in animals with large tumor grafts as well as in mice with resected primary mammary fat pad tumors. In addition, we provide evidence that an increase in VE-cadherin protein levels as a downstream result of PKN3 target gene inhibition may change endothelial function, resulting in reduced colonization and micrometastasis formation. CONCLUSION: Atu027 can be considered as a potent drug for preventing lung metastasis formation, which might be suitable for preventing hematogenous metastasis in addition to standard cancer therapy.


Subject(s)
Carcinoma, Lewis Lung/prevention & control , Carcinoma, Lewis Lung/secondary , Disease Models, Animal , Lung Neoplasms/prevention & control , Lung Neoplasms/secondary , RNA Interference , RNA, Small Interfering/therapeutic use , Animals , Dose-Response Relationship, Drug , Drug Administration Schedule , Endothelial Cells/drug effects , Endothelial Cells/enzymology , Endothelial Cells/metabolism , Humans , Injections, Intravenous , Mice , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Xenograft Model Antitumor Assays
13.
Pulm Pharmacol Ther ; 23(4): 334-44, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20362688

ABSTRACT

The ability of synthetic small interfering RNA (siRNA) to silence gene expression makes it a useful tool in biomedical research. However, effective and non-toxic functional siRNA delivery to mouse lungs in vivo is still a key challenge, and regulation of constitutively expressed genes is poorly characterized. Following in vitro validation of siRNA molecules, naked, stabilized siRNA (AtuRNAi) was applied intranasally (i.n.) by droplets or intratracheally (i.t.) by MicroSprayer in female C57BL/6 mice. Distribution of Cy3-tagged siRNAs was examined. Pulmonary expression of ubiquitously (lamin B1) or cell-specific (E-cadherin, VE-cadherin), constitutive genes was analysed by TaqMan-realtime-PCR. Further, formulated lipoplex-siRNA, which has enhanced transfection efficiency, was applied i.t. or intravenously (i.v.). Single i.t. as compared to i.n. application of unformulated siRNA resulted in higher delivery efficiency and homogenous pulmonary distribution. After inhalation of target-specific siRNA, reduction of epithelial E-cadherin by 21%, but no significant reduction of endothelial VE-cadherin or ubiquitously expressed lamin B1 was observed. Pharmacokinetic analysis revealed rapid transfer of intact siRNA molecules into the vascular system and accumulation in the kidneys, calling lung specificity into question. I.t. application of lipoplex-siRNA evoked inflammation. In contrast, i.v. application of lipoplex-siRNA specifically reduced expression of VE-cadherin mRNA by about 50% in lungs without evoking lung cellular influx. In conclusion, sufficient pulmonary distribution of aerosolized siRNA was attained in mice by MicroSprayer, however development of appropriate siRNA carriers is highly desirable to improve lung-specific functional inhalative siRNA delivery. Pulmonary knockdown of constitutive endothelial targets by 50% was achieved by i.v. application of lipoplex-siRNA.


Subject(s)
Gene Expression Regulation , Gene Silencing , Gene Transfer Techniques , RNA, Small Interfering/administration & dosage , Administration, Intranasal , Animals , Antigens, CD/genetics , Cadherins/genetics , Female , Gene Targeting/methods , Inflammation/genetics , Lamin Type B/genetics , Lung/metabolism , Lung/pathology , Mice , Mice, Inbred C57BL , Polymerase Chain Reaction , RNA, Messenger/metabolism , RNA, Small Interfering/pharmacokinetics , Tissue Distribution , Trachea
14.
Microvasc Res ; 80(2): 286-93, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20144624

ABSTRACT

RNA interference (RNAi) has become an indispensable tool for loss of function analysis in today's basic cell biological research, and is currently being utilized for developing novel therapeutic methods. Systemic administration of synthetic small interfering RNA (siRNA) into the bloodstream is a feasible route for targeting the vascular endothelium or peripheral blood cells. The vascular endothelium can be considered an organ by itself, involved in many pathophysiological processes. Here, we aim to summarize current strategies of using RNAi for analysis of gene function in endothelial (in vitro loss-of-function analysis) and of exploiting RNAi for therapeutic purposes in order to suppress disrupted gene expression ("RNAi therapeutics"). With respect to the latter, we will summarize recent experimental concepts as well as ongoing therapeutic applications of RNAi mediated suppression of gene expression modulating angiogenic processes in cancer and retinopathies. We will further discuss the opportunities, prospects, challenges and potential fallbacks as well as the present strategies for the realization of "RNAi therapeutics" in combating vascular diseases.


Subject(s)
Endothelium, Vascular/cytology , Gene Silencing , Genetic Therapy/methods , RNA Interference/physiology , RNA, Small Interfering/therapeutic use , Vascular Diseases/therapy , Endothelial Cells/cytology , Gene Expression Regulation , Gene Targeting , Humans , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/genetics , Vascular Diseases/genetics
15.
Exp Cell Res ; 315(13): 2165-80, 2009 Aug 01.
Article in English | MEDLINE | ID: mdl-19409380

ABSTRACT

RNAi mediated loss of Drp1 function changes mitochondrial morphology in cultured HeLa and HUVEC cells by shifting the balance of mitochondrial fission and fusion towards unopposed fusion. Over time, inhibition of Drp1 expression results in the formation of a highly branched mitochondrial network along with "bulge"-like structures. These changes in mitochondrial morphology are accompanied by a reduction in levels of Mitofusin 1 (Mfn1) and 2 (Mfn2) and a modified proteolytic processing of OPA1 isoforms, resulting in the inhibition of cell proliferation. In addition, our data imply that bulge formation is driven by Mfn1 action along with particular proteolytic short-OPA1 (s-OPA1) variants: Loss of Mfn2 in the absence of Drp1 results in an increase of Mfn1 levels along with processed s-OPA1-isoforms, thereby enhancing continuous "fusion" and bulge formation. Moreover, bulge formation might reflect s-OPA1 mitochondrial membrane remodeling activity, resulting in the compartmentalization of cytochrome c deposits. The proteins Yme1L and PHB2 appeared not associated with the observed enhanced OPA1 proteolysis upon RNAi of Drp1, suggesting the existence of other OPA1 processing controlling proteins. Taken together, Drp1 appears to affect the activity of the mitochondrial fusion machinery by unbalancing the protein levels of mitofusins and OPA1.


Subject(s)
GTP Phosphohydrolases/metabolism , Microtubule-Associated Proteins/metabolism , Mitochondrial Membranes , Mitochondrial Proteins/metabolism , Animals , Dynamins , GTP Phosphohydrolases/genetics , Gene Knockdown Techniques , HeLa Cells , Humans , Isoenzymes/genetics , Isoenzymes/metabolism , Membrane Fusion/physiology , Membrane Proteins/genetics , Membrane Proteins/metabolism , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Microtubule-Associated Proteins/genetics , Mitochondria/metabolism , Mitochondria/ultrastructure , Mitochondrial Membrane Transport Proteins , Mitochondrial Membranes/metabolism , Mitochondrial Membranes/ultrastructure , Mitochondrial Proteins/genetics , Prohibitins , RNA Interference , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism
16.
Cancer Res ; 68(23): 9788-98, 2008 Dec 01.
Article in English | MEDLINE | ID: mdl-19047158

ABSTRACT

We have previously described a small interfering RNA (siRNA) delivery system (AtuPLEX) for RNA interference (RNAi) in the vasculature of mice. Here we report preclinical data for Atu027, a siRNA-lipoplex directed against protein kinase N3 (PKN3), currently under development for the treatment of advanced solid cancer. In vitro studies revealed that Atu027-mediated inhibition of PKN3 function in primary endothelial cells impaired tube formation on extracellular matrix and cell migration, but is not essential for proliferation. Systemic administration of Atu027 by repeated bolus injections or infusions in mice, rats, and nonhuman primates results in specific, RNAi-mediated silencing of PKN3 expression. We show the efficacy of Atu027 in orthotopic mouse models for prostate and pancreatic cancers with significant inhibition of tumor growth and lymph node metastasis formation. The tumor vasculature of Atu027-treated animals showed a specific reduction in lymph vessel density but no significant changes in microvascular density.


Subject(s)
Pancreatic Neoplasms/therapy , Prostatic Neoplasms/therapy , Protein Kinase C/antagonists & inhibitors , Protein Kinase C/genetics , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/genetics , Animals , Cell Growth Processes/physiology , Disease Progression , Endothelial Cells/drug effects , Endothelial Cells/enzymology , HeLa Cells , Humans , Liposomes/administration & dosage , Lymphatic Metastasis , Macaca fascicularis , Male , Mice , Mice, SCID , Neovascularization, Pathologic/enzymology , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/pathology , Neovascularization, Pathologic/therapy , Pancreatic Neoplasms/enzymology , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Prostatic Neoplasms/enzymology , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , RNA Interference , Rats , Transfection/methods
17.
Microvasc Res ; 76(1): 31-41, 2008 May.
Article in English | MEDLINE | ID: mdl-18455200

ABSTRACT

Liposomally formulated siRNA can be used for RNAi applications in vivo. Intravenous bolus administration of lipoplexed siRNA has been shown to reduce gene expression in the vascular endothelium. Here, we applied immunofluorescence staining for different endothelial markers (PECAM-1, CD34, laminin) on paraffin sections to compare the respective expression pattern with the intracellular localization of intravenously administered, fluorescently labeled siRNA (siRNA-Cy3-lipoplex). By confocal microscopy, lipoplexed siRNA-Cy3 was detected inside vascular endothelial cells in vivo, which where identified with co-staining of endothelial markers. Consequently, the finding of intracellular siRNA uptake by vascular endothelial cells correlated with RNAi based specific protein reduction in situ as revealed by PECAM-1 specific immunofluorescence staining in lung tissue sections. Therefore, by using a cell biological approach these in situ data emphasize the functional uptake of liposomal siRNA molecules in vascular endothelial cells of different mouse tissues as indicated in our previous molecular study.


Subject(s)
Endothelial Cells/metabolism , Intracellular Space/metabolism , RNA, Small Interfering/metabolism , Animals , Antigens, CD/genetics , Antigens, CD34/analysis , Cadherins/genetics , Carbocyanines/chemistry , Endothelial Cells/chemistry , Endothelium, Lymphatic/chemistry , Endothelium, Lymphatic/cytology , Endothelium, Lymphatic/metabolism , Fluorescent Antibody Technique , Gene Expression , Glycoproteins/analysis , Immunohistochemistry , Intracellular Space/chemistry , Laminin/analysis , Liposomes , Liver/chemistry , Liver/cytology , Liver/metabolism , Lung/chemistry , Lung/cytology , Lung/metabolism , Membrane Transport Proteins , Mice , Mice, Inbred C57BL , Mice, Nude , Myocardium/chemistry , Myocardium/cytology , Myocardium/metabolism , PTEN Phosphohydrolase/genetics , Platelet Endothelial Cell Adhesion Molecule-1/analysis , Platelet Endothelial Cell Adhesion Molecule-1/genetics , Platelet Endothelial Cell Adhesion Molecule-1/metabolism , Pulmonary Alveoli/chemistry , Pulmonary Alveoli/cytology , Pulmonary Alveoli/metabolism , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/chemistry , Vascular Endothelial Growth Factor Receptor-2/genetics
18.
J Cell Sci ; 118(Pt 14): 3049-59, 2005 Jul 15.
Article in English | MEDLINE | ID: mdl-15985469

ABSTRACT

Mitochondria are dynamic organelles that change morphology by controlled fission and fusion events. Mitochondrial fission is regulated by a conserved protein complex assembled at the outer membrane. Human MTP18 is a novel nuclear-encoded mitochondrial membrane protein, implicated in controlling mitochondrial fission. Upon overexpression of MTP18, mitochondrial morphology was altered from filamentous to punctate structures suggesting excessive mitochondrial fission. Mitochondrial fragmentation was blocked in cells coexpressing either the mitochondrial fusion protein Mfn1 or Drp1(K38A), a dominant negative version of the fission protein Drp1. Also, a loss-of function of endogenous MTP18 by RNA interference (RNAi) resulted in highly fused mitochondria. Moreover, MTP18 appears to be required for mitochondrial fission because it is blocked after overexpression of hFis1 in cells with RNAi-mediated MTP18 knockdown. In conclusion, we propose that MTP18 functions as an essential intramitochondrial component of the mitochondrial division apparatus, contributing to the maintenance of mitochondrial morphology.


Subject(s)
Mitochondria/physiology , Mitochondrial Proteins/physiology , Animals , COS Cells , Cells, Cultured , Chlorocebus aethiops , Dynamins , Endopeptidase K , GTP Phosphohydrolases/metabolism , GTP Phosphohydrolases/physiology , HeLa Cells , Humans , Intracellular Membranes/metabolism , Membrane Proteins , Microtubule-Associated Proteins/metabolism , Microtubule-Associated Proteins/physiology , Mitochondria/metabolism , Mitochondrial Proteins/antagonists & inhibitors , Mitochondrial Proteins/biosynthesis , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , RNA Interference , Subcellular Fractions/metabolism , Transfection
19.
Stat Methods Med Res ; 14(2): 129-46, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15807148

ABSTRACT

The evaluation of diagnostic agents or imaging procedures is governed by the same scientific and regulatory rules as that of other medical products. Receiver operating characteristic (ROC) curves, and especially the area under these ROC curves, are indices for the accuracy of a diagnostic test for continuous as well as ordinal data. The methodology of multivariate rank statistics for the nonparametric Behrens-Fisher problem is used to evaluate the accuracy of a diagnostic test in a complex factorial design with repeated measurements. Hypotheses are formulated by means of relative treatment effects and are tested by a multivariate extension of the Mann-Whitney statistic in a heteroscedastic model. The application of this method is demonstrated by the analysis of a data set from a diagnostic clinical trial.


Subject(s)
Diagnostic Tests, Routine/statistics & numerical data , Statistics, Nonparametric , Biometry , Clinical Trials as Topic/statistics & numerical data , Confidence Intervals , Contrast Media , Humans , Models, Statistical , Multivariate Analysis , Polysaccharides , ROC Curve , Thrombosis/diagnostic imaging , Ultrasonography, Doppler, Color/statistics & numerical data
20.
Oncogene ; 24(7): 1138-49, 2005 Feb 10.
Article in English | MEDLINE | ID: mdl-15592522

ABSTRACT

Cancer cells frequently evade apoptosis during tumorigenesis by acquiring mutations in apoptotic regulators. Chronic activation of the PI 3-kinase-Akt pathway through loss of the tumor suppressor PTEN is one mechanism by which these cells can gain increased protection against apoptosis. We report here that REDD1 (RTP801) can act as a transcriptional downstream target of PI 3-kinase signaling in human prostate cancer cells (PC-3). REDD1 expression is markedly reduced in PC-3 cells treated with LY294002 (LY) or Rapamycin and strongly induced under hypoxic conditions in a hypoxia-inducible factor-1 (HIF-1)-dependent manner. Loss of function studies employing antisense molecules or RNA interference indicate that REDD1 is essential for invasive growth of prostate cancer cells in vitro and in vivo. Reduced REDD1 levels can sensitize cells towards apoptosis, whereas elevated levels of REDD1 induced by hypoxia or overexpression desensitize cells to apoptotic stimuli. Taken together our data designate REDD1 as a novel target for therapeutic intervention in prostate cancer.


Subject(s)
Phosphatidylinositol 3-Kinases/physiology , Prostatic Neoplasms/metabolism , Transcription Factors/physiology , Apoptosis , Cell Hypoxia , Cell Line, Tumor , Chromones/pharmacology , Cobalt/pharmacology , Dimethyl Sulfoxide/pharmacology , Gene Expression/genetics , Humans , Hypoxia-Inducible Factor 1, alpha Subunit , Male , Morpholines/pharmacology , Neoplasm Invasiveness/genetics , Phosphatidylinositol 3-Kinases/genetics , Phosphoinositide-3 Kinase Inhibitors , Prostatic Neoplasms/genetics , Prostatic Neoplasms/immunology , RNA, Antisense/genetics , Signal Transduction , Sirolimus/pharmacology , Transcription Factors/analysis , Transcription Factors/genetics , Up-Regulation
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