Einführung: Die Strategie der Kryokonservierung und Transplantation von ovariellem Gewebe bei malignomerkrankten Frauen zur Erhaltung der Fertilität beinhaltet die Problematik eines ausgeprägten ischämiebedingten Follikelverlustes. Fragestellung: Lässt sich durch die systemische bzw. lokale Applikation angiogeneseinduzierender Substanzen die (Neo-)Vaskularisation nach Transplantation verbessern bzw. der Follikel-Verlust reduzieren? Material und Methoden: A: Drei weiblichen Schafen wurden beide Ovarien explantiert, in 1 mm dicke Scheiben geschnitten und anschließend autolog heterotop in die Bauchwand retransplantiert. Bei einem Schaf wurde das ovarielle Gewebe im Rahmen der Transplantation lokal in eine VEGF (5 µg-)Fibrinkleber-Suspension eingebettet. Einem weiteren Schaf wurden über 2 Wochen nach Transplantation alle 2 Tage 150 IE/hMG systemisch appliziert. Das dritte Schaf blieb ohne Behandlung. Neun Monate später wurde das transplantierte Gewebe zur histologischen Analyse entnommen und das Follikelüberleben miteinander verglichen. B: Zwei weiteren Schafe wurden beide Ovarien explantiert, in entsprechende Scheiben präpariert, und in 20 immun-inkompetente Mäuse xenolog heterotop im Bereich des Rückens transplantiert. Zehn dieser Mäuse erhielten jeden 2. Tag 10 IE hMG systemisch beginnend ab dem Tag der Transplantation bis zur finalen Explantation. Die übrigen 10 Mäuse erhielten keine weitere spezifische Behandlung. Anschließend wurden jeweils 2 Mäuse beider Gruppen an Tag 2, 4, 6, 10 und 14 nach primärer Transplantation euthanasiert, das Transplantat entnommen und die Gefäßdichte in beiden Gruppen zu unterschiedlichen Zeitpunkten miteinander verglichen. Ergebnisse: A: Im Gegensatz zur Applikation von VEGF, welche im Vergleich zur Kontrolle keinen Effekt auf das Follikelüberleben hatte (12 vs. 7,4 %), konnte durch die Applikation von hMG das Follikelüberleben deutlich gesteigert werden (12 % vs. 29 %). B: Weiterhin ergab die Applikation von hMG im Vergleich zur Kontrollgruppe eine signifikant höhere mittlere Gefäßdichte pro mm2 zu sämtlichen untersuchten Zeitpunkten (Tag 2: 22 vs. 13 [p < 0,001], Tag 4: 22 vs. 13 [p < 0,001], Tag 6: 17 vs. 13 [p = 0,006], Tag 10: 28 vs. 12 [p < 0,001], bzw. Tag 14: 35 vs. 16 [p < 0,001]). Schlussfolgerungen: Der ausgeprägte ischämiebedingte Follikelverlust nach Transplantation von ovariellem Gewebe lässt sich durch die systemische Gabe von hMG, welches eine gesteigerte (Neo-)Vaskularisation induziert, deutlich reduzieren.
The effect of enoxaparin and fibroblast growth factor-1 (FGF-1) on post-infarction capillary density and regional myocardial blood flow (RMBF) was examined.New Zealand White rabbits received an intramyocardial injection of either physiological saline, FGF-1 + enoxaparin, FGF-1 or enoxaparin directly after ligation of the left anterior descending artery. RMBF and capillary density were investigated using fluorescent microspheres and histological examination.One week after infarction a significant difference in the number of capillaries could be demonstrated within the FGF-1 + enoxaparin group (p < 0.001 versus the control group), the FGF-1 group (p < 0.01) and the enoxaparin group (p < 0.05). Treatment with FGF-1 + enoxaparin resulted in a significantly increased number of capillaries compared to treatment with FGF-1 (p < 0.05) and enoxaparin (p < 0.05) alone. Additionally, all groups treated with FGF-1 and/or enoxaparin showed a significant increase of microvessel density in the treated ischemic border zone compared to the non-treated ischemic border zone (p < 0.001 for FGF-1 + enoxaparin, p < 0.01 for FGF-1, p < 0.05 for enoxaparin). RMBF was significantly increased within the FGF-1 + enoxaparin group compared to the control group (p < 0.05). Moreover, perfusion rates within the FGF-1 + enoxaparin-treated area did not significantly differ from the pre-infarction values.Treatment with either enoxaparin or FGF-1 or FGF-1 + enoxaparin resulted in increased microvessel growth. However, only the combination of enoxaparin with FGF-1 promotes capillary growth and RMBF. Thus, we conclude that enoxaparin enhances the angiogenic potential of intramyocardially injected FGF-1 in the acutely infarcted rabbit heart.
Polymer stent coatings may not be suitable for drug elution because of inherent proinflammatory effects. A previous study suggested a beneficial effect of a stent eluting tacrolimus from a nanoporous ceramic aluminum oxide coating in a rabbit restenosis model. We investigated whether this stent is effective in preventing in-stent restenosis in a porcine restenosis model. Thirty-four juvenile swine underwent balloon overstretch injury and were subjected to implantation of either stainless steel (bare) stents, bare stents coated with nanoporous aluminum oxide alone, and coated stents eluting 50 and 180 mug of tacrolimus (FK506). In-stent restenosis was quantified at 1 and 3 months after stent placement by histomorphometry. A significant increase of neointimal hyperplasia was noted with the stents coated with aluminum oxide alone compared with bare stents (2.92 +/- 1.02 and 1.38 +/- 0.51 mm(2), respectively; P < 0.02). In all arteries containing coated stents, particle debris was found in the media and neointima, resulting in augmented vascular inflammation. In the group of stents coated with aluminum oxide, FK506 elution at a dose 180 mug reduced neointimal hyperplasia vs. no drug elution (1.66 +/- 0.49 vs. 2.92 +/- 1.02 mm(2); 180 mug vs. ceramic alone; P < 0.03). At a dose of 50 mug stent-based delivery of FK506, no reduction of neointimal hyperplasia was found (2.88 +/- 1.31 and 2.92 +/- 1.02 mm(2), respectively; P = NS; FK506 vs. ceramic alone). In summary, particle debris shed from a drug-eluting aluminum oxide coating of a stainless steel stent counteracts potential antiproliferative effects of stent-based tacrolimus delivery in a porcine model of restenosis. We propose that stent coatings eluting drugs need to be routinely tested for being tightly anchored into the stent surface. Alternatively, omission of any coating used as a drug reservoir may eliminate inflammatory particle debris after placement of drug-eluting stents.
Abstract Despite advances in the treatment of breast cancer, it is still the second leading cause of cancer-related death in women worldwide. A large number of patients develop recurrence and die of advanced metastatic disease. More than 70% of metastatic breast cancers (mBC) express androgen receptor (AR) representing a potential target for anti-hormone therapies. AR is suggested to directly interact with an associated transcription factor (ARaTF) in breast cancer, however the functional role of ARaTF and its interaction with AR remains to be elucidated. We find that AR expression highly correlates with ARaTF in patients. To study its functional role driving tumorigenesis and metastatic outgrowth, we utilize patient-derived xenograft cell lines derived from liquid biopsies of mBC patients which reflect the highly heterogenous disease. Using genetically manipulated PDX cell models, we demonstrate that repression of ARaTF significantly reduces tumor growth of AR positive (AR+) BC cells in vivo. Notably, we observe the opposite phenotype in an AR negative cell model suggesting a tumor suppressive function when AR is not present. Mechanistically, we find that ARaTF regulates key metabolic processes: (1) Pharmacological inhibition of AR or silencing of ARaTF restricts mitochondrial respiration activity resulting in decreased energy production. (2) We also find that ARaTF positively regulates genes encoding enzymes involved in de novo fatty acid biosynthesis in AR+ BC. We further observe upregulation of the CD36 fatty acid transporter facilitating fatty acid uptake as compensatory pathway upon downregulation of ARaTF. Finally, abolishing CD36 expression in AR+ BC cells significantly reduces cell viability upon ARaTF downregulation. These findings suggest that lipid and energy metabolism are transcriptionally regulated by ARaTF facilitating cell survival in nutrient-depleted environments and thus facilitating metastatic outgrowth. These findings provide knowledge about the functional role of ARaTF regulating the lipogenic metabolic profile of AR+ breast cancer, and might help to identify patients who benefit from an anti-androgen treatment. Citation Format: Sarah-Jane Neuberth, Corinna Schumacher, Marteinn Thor Snaebjörnsson, Roberto Würth, Franziska Maria Zickgraf, Ornella Kossi, Felix Geist, Andrea Geist, Vera Thiel, Jonas Schwickert, Mattia Falcone, Massimo Saini, Almut Schulze, Andreas Trumpp, Martin R. Sprick. An androgen receptor-associated transcription factor regulates fatty acid metabolism driving tumor growth in androgen receptor-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 652.
Doxorubicin causes a chronic cardiomyopathy in which reactive oxygen species (ROS) accumulate over time and are associated with genetic and functional lesions of mitochondria. Dexrazoxane is a cardioprotective iron chelator that interferes with ROS production. We aim to analyze the effects of dexrazoxane on mitochondria in the prevention of doxorubicin-induced chronic myocardial lesions.Wistar rats (11 weeks of age) were injected with intravenous doxorubicin (0.8 mg kg(-1) weekly for 7 weeks) with or without simultaneous dexrazoxane (8 mg kg(-1)). Animals were killed at 48 weeks. Cardiomyopathy was scored clinically and histologically and cardiac mitochondria were analyzed.Compared to control rats receiving saline, rats treated with doxorubicin alone developed a clinical, macroscopic, histological and ultrastructural cardiomyopathy with low cytochrome c-oxidase (COX) activity (26% of controls). The expression of the mtDNA-encoded COX II subunit was reduced (64% of controls). Myocardia exhibited a high production of ROS (malondialdehyde 338% and superoxide 787% of controls). Mitochondria were depleted of mitochondrial DNA (mtDNA copy number 46% of controls) and contained elevated levels of mtDNA deletions. Dexrazoxane co-administration prevented all these effects of doxorubicin on mitochondria, except that hearts co-exposed to doxorubicin and dexrazoxane had a slightly lower mtDNA content (81% of controls) and mtDNA deletions at low frequency.Dexrazoxane prevented doxorubicin induced late-onset cardiomyopathy and also protected the cardiac mitochondria from acquired ultrastructural, genetic and functional damage.
Neutrophils are of great importance for the host's defense against invading organisms. Granulocyte colony-stimulating factor (G-CSF) has been used to augment both the neutrophil number and function, and its prophylactic administration has proved beneficial in animal models of sepsis. However, pretreatment with G-CSF is not practical under clinical conditions. We therefore investigated the effect of recombinant human (rh)G-CSF, administered only after infection, on the survival rate as well as the hemodynamic and cytokine response of the animals.Chronically catheterized conscious pigs were challenged with Pseudomonas aeruginosa (8 x 10(7) colony-forming units kg(-1) x h(-1) for 120 h (control group, n = 10). Animals in the G-CSF group (n = 7) also received rhG-CSF (5 microg kg(-1) x day(-1)), the first dose being given 3 h after beginning bacterial infusion.The mortality rate was 50% (5/10) and 29% (2/7) in the control and G-CSF groups, respectively (p = NS, control vs. G-CSF group). Fever, severe pulmonary hypertension, and a hyperdynamic response were recorded in all of the animals. In spite of a prompt and significant recovery from the initial leukopenia (p < .05 vs. control group), the animals of the G-CSF group showed no significant differences in the parameters investigated from those of the controls. Compared with the survivors, the interleukin-1 receptor antagonist was markedly elevated in all nonsurvivors after 6 h of sepsis (p < .05).These data suggest that treatment with rhG-CSF after the onset of bacterial sepsis might not significantly improve the chances of survival for non-neutropenic patients.
