O lúpus eritematoso sistêmico (LES) é uma doença autoimune cuja fisiopatologia envolve mecanismos imunológicos, incluindo distúrbios nos processos de morte celular e nos mecanismos de eliminação de autoantígenos e de tolerância, acompanhados da formação de autoanticorpos patogênicos. Ele acomete principalmente mulheres jovens e a gestação nestas pacientes apresenta significativa morbimortalidade. Os achados clínicos e laboratoriais na nefrite lúpica são semelhantes àqueles encontrados em pacientes com pré-eclâmpsia (PE), especificamente hipertensão arterial, proteinúria e edema. Foi proposto o uso de fatores angiogênicos, como o fator de crescimento vascular endotelial (VEGF) e o fator de crescimento placentário (PlGF), e antiangiogênicos, como o receptor Fms-like tirosina quinase 1 solúvel (sFlt-1), para o diagnóstico diferencial entre estas duas condições, no entanto os dados disponíveis na literatura sobre estas citocinas em pacientes não gestantes com LES são inconsistentes. Este estudo foi desenhado para avaliar se existe diferença entre os níveis séricos de VEGF, PlGF e sFlt-1 em pacientes com LES com e sem atividade sistêmica da doença e se existe diferença nesses fatores quando comparamos pacientes com LES e mulheres saudáveis. Foram incluídas 54 mulheres com diagnóstico de LES em acompanhamento no ambulatório de Reumatologia do HUPE-UERJ, sem outra doença autoimune diagnosticada, e divididas de acordo com a atividade da doença. 30 pacientes tinham doença inativa (SLEDAI médio: 0,7) e 24 tinham doença ativa (SLEDAI médio: 11,6). 23 mulheres deste último grupo possuíam nefrite ativa, enquanto 20 das pacientes com doença em remissão já haviam apresentado nefrite ao longo da evolução do LES. O grupo controle foi formado por 34 mulheres hígidas atendidas no ambulatório de ginecologia da Policlínica Piquet Carneiro-UERJ. Considerando as três citocinas estudadas, as pacientes com LES apresentaram valores séricos médios superiores às mulheres do grupo controle (VEGF: 319,0 + 226,0 x 206,2 + 119,4, p=0,02; PlGF: 42,2 + 54,1 x 13,6 + 21,6, p=0,02; sFlt-1: 107,9 + 49,2 x 70,2 + 95,0, p=0,01). O grupo de pacientes com doença ativa também apresentou média superior ao controle nos três fatores (VEGF: 331,0 + 216,8 x 206,2 + 119,4, p=0,02; PlGF: 41,2 + 47,3 x 13,6 + 21,6, p=0,02; sFlt-1: 120,5 + 42,4 x 70,2 + 95,0, p=0,02), enquanto não foi encontrada diferença estatística entre o grupo de LES inativo e o controle. A média do sFlt-1 sérico foi maior nas pacientes com LES ativo do que a média das pacientes com a doença em remissão (120,5 + 54,9 x 97,8 + 42,4, p=0,02), mas não houve diferença significativa da média do VEGF e PlGF séricos entre os dois grupos. O melhor entendimento dos fatores angiogênicos e antiangiogênicos em pacientes com LES proporcionado por este estudo nos permite a análise dessas citocinas em gestantes com LES e, possivelmente, sua posterior aplicação como método diferencial entre nefrite lúpica e PE. / Systemic lupus erythematosus (SLE) is an autoimmune disease which pathophysiology involves immunological mechanisms including disturbances in the processes of cell death and mechanisms of elimination of autoantigens and tolerance, accompanied by formation of pathogenic autoantibodies. It mainly affects young women and pregnancy in these patients have significant morbidity and mortality. Clinical and laboratory findings in lupus nephritis are similar to those found in patients with preeclampsia (PE), specifically hypertension, proteinuria and edema. It has been proposed the use of angiogenic factors, such as vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), and antiangiogenic factors, as soluble Fms-like tyrosine kinase-1 (sFlt-1), for the differential diagnosis between these two conditions, however available data in the literature about these cytokines in non-pregnant SLE patients are inconsistent. This study was designed to evaluate whether there are differences between serum levels of VEGF, PlGF and sFlt-1 in SLE patients with and without systemic disease activity and whether there are differences in these factors when comparing SLE patients with healthy women. 54 women with SLE followed at outpatient clinic of Rheumatology HUPE - UERJ were included. They had no other autoimmune disease diagnosed and were divided according to disease activity. 30 patients had inactive disease (mean SLEDAI: 0.7), and 24 had active disease (mean SLEDAI: 11.6). 23 women in this latter group had active nephritis, while 20 patients with inactive disease had history of lupus nephritis. The control group consisted of 34 healthy women who attended the Gynecology outpatient clinic at Policlínica Piquet Carneiro - UERJ. Considering the three studied cytokines, the SLE patients had higher mean serum levels than the control group (VEGF: 319.0 + 226.0 x 206.2 + 119.4, p=0.02; PlGF: 42.2 + 54.1 x 13.6 + 21.6, p=0.02; sFlt-1: 107.9 + 49.2 x 70.2 + 95.0, p=0.01). The group of patients with active disease also had higher mean levels of all three factors than controls (VEGF: 331.0 + 216.8 x 206.2 + 119.4, p=0.02; PlGF: 41.2 + 47.3 x 13.6 + 21.6, p=0.02; sFlt-1: 120.5 + 42.4 x 70.2 + 95.0, p=0.02), whereas no statistical difference was found between the group with inactive SLE and the control group. The mean sFlt-1 levels were higher in patients with active SLE than the mean levels of patients with inactive disease (120.5 + 54.9 x 97.8 + 42.4, p=0.02), but there was no significant difference in mean serum of VEGF and PlGF levels between these two groups. A better understanding of angiogenic and antiangiogenic factors in patients with SLE provided by this study allows the analysis of these cytokines in pregnant woman with SLE and possibly their subsequent application as differential method between PE and lupus nephritis.

O lúpus eritematoso sistêmico (LES) é uma doença autoimune cuja fisiopatologia envolve mecanismos imunológicos, incluindo distúrbios nos processos de morte celular e nos mecanismos de eliminação de autoantígenos e de tolerância, acompanhados da formação de autoanticorpos patogênicos. Ele acomete principalmente mulheres jovens e a gestação nestas pacientes apresenta significativa morbimortalidade. Os achados clínicos e laboratoriais na nefrite lúpica são semelhantes àqueles encontrados em pacientes com pré-eclâmpsia (PE), especificamente hipertensão arterial, proteinúria e edema. Foi proposto o uso de fatores angiogênicos, como o fator de crescimento vascular endotelial (VEGF) e o fator de crescimento placentário (PlGF), e antiangiogênicos, como o receptor Fms-like tirosina quinase 1 solúvel (sFlt-1), para o diagnóstico diferencial entre estas duas condições, no entanto os dados disponíveis na literatura sobre estas citocinas em pacientes não gestantes com LES são inconsistentes. Este estudo foi desenhado para avaliar se existe diferença entre os níveis séricos de VEGF, PlGF e sFlt-1 em pacientes com LES com e sem atividade sistêmica da doença e se existe diferença nesses fatores quando comparamos pacientes com LES e mulheres saudáveis. Foram incluídas 54 mulheres com diagnóstico de LES em acompanhamento no ambulatório de Reumatologia do HUPE-UERJ, sem outra doença autoimune diagnosticada, e divididas de acordo com a atividade da doença. 30 pacientes tinham doença inativa (SLEDAI médio: 0,7) e 24 tinham doença ativa (SLEDAI médio: 11,6). 23 mulheres deste último grupo possuíam nefrite ativa, enquanto 20 das pacientes com doença em remissão já haviam apresentado nefrite ao longo da evolução do LES. O grupo controle foi formado por 34 mulheres hígidas atendidas no ambulatório de ginecologia da Policlínica Piquet Carneiro-UERJ. Considerando as três citocinas estudadas, as pacientes com LES apresentaram valores séricos médios superiores às mulheres do grupo controle (VEGF: 319,0 + 226,0 x 206,2 + 119,4, p=0,02; PlGF: 42,2 + 54,1 x 13,6 + 21,6, p=0,02; sFlt-1: 107,9 + 49,2 x 70,2 + 95,0, p=0,01). O grupo de pacientes com doença ativa também apresentou média superior ao controle nos três fatores (VEGF: 331,0 + 216,8 x 206,2 + 119,4, p=0,02; PlGF: 41,2 + 47,3 x 13,6 + 21,6, p=0,02; sFlt-1: 120,5 + 42,4 x 70,2 + 95,0, p=0,02), enquanto não foi encontrada diferença estatística entre o grupo de LES inativo e o controle. A média do sFlt-1 sérico foi maior nas pacientes com LES ativo do que a média das pacientes com a doença em remissão (120,5 + 54,9 x 97,8 + 42,4, p=0,02), mas não houve diferença significativa da média do VEGF e PlGF séricos entre os dois grupos. O melhor entendimento dos fatores angiogênicos e antiangiogênicos em pacientes com LES proporcionado por este estudo nos permite a análise dessas citocinas em gestantes com LES e, possivelmente, sua posterior aplicação como método diferencial entre nefrite lúpica e PE. / Systemic lupus erythematosus (SLE) is an autoimmune disease which pathophysiology involves immunological mechanisms including disturbances in the processes of cell death and mechanisms of elimination of autoantigens and tolerance, accompanied by formation of pathogenic autoantibodies. It mainly affects young women and pregnancy in these patients have significant morbidity and mortality. Clinical and laboratory findings in lupus nephritis are similar to those found in patients with preeclampsia (PE), specifically hypertension, proteinuria and edema. It has been proposed the use of angiogenic factors, such as vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), and antiangiogenic factors, as soluble Fms-like tyrosine kinase-1 (sFlt-1), for the differential diagnosis between these two conditions, however available data in the literature about these cytokines in non-pregnant SLE patients are inconsistent. This study was designed to evaluate whether there are differences between serum levels of VEGF, PlGF and sFlt-1 in SLE patients with and without systemic disease activity and whether there are differences in these factors when comparing SLE patients with healthy women. 54 women with SLE followed at outpatient clinic of Rheumatology HUPE - UERJ were included. They had no other autoimmune disease diagnosed and were divided according to disease activity. 30 patients had inactive disease (mean SLEDAI: 0.7), and 24 had active disease (mean SLEDAI: 11.6). 23 women in this latter group had active nephritis, while 20 patients with inactive disease had history of lupus nephritis. The control group consisted of 34 healthy women who attended the Gynecology outpatient clinic at Policlínica Piquet Carneiro - UERJ. Considering the three studied cytokines, the SLE patients had higher mean serum levels than the control group (VEGF: 319.0 + 226.0 x 206.2 + 119.4, p=0.02; PlGF: 42.2 + 54.1 x 13.6 + 21.6, p=0.02; sFlt-1: 107.9 + 49.2 x 70.2 + 95.0, p=0.01). The group of patients with active disease also had higher mean levels of all three factors than controls (VEGF: 331.0 + 216.8 x 206.2 + 119.4, p=0.02; PlGF: 41.2 + 47.3 x 13.6 + 21.6, p=0.02; sFlt-1: 120.5 + 42.4 x 70.2 + 95.0, p=0.02), whereas no statistical difference was found between the group with inactive SLE and the control group. The mean sFlt-1 levels were higher in patients with active SLE than the mean levels of patients with inactive disease (120.5 + 54.9 x 97.8 + 42.4, p=0.02), but there was no significant difference in mean serum of VEGF and PlGF levels between these two groups. A better understanding of angiogenic and antiangiogenic factors in patients with SLE provided by this study allows the analysis of these cytokines in pregnant woman with SLE and possibly their subsequent application as differential method between PE and lupus nephritis.

Einleitung: Die Dysbalance proangiogener (Placental Growth Factor = PlGF) und antiangiogener Faktoren (soluble fms-like tyrosine kinase 1 = sFlt-1) gilt heute als pathophysiologische Grundlage bei der Entstehung einer Präeklampsie (PE), eines HELLP-Syndroms (Haemolysis, Elevated Liver enzymes, Low Platelets) oder einer intrauterinen Wachstumsretardierung (IUGR). Der sFlt1/PlGF-Quotient, ein sensitiver und robuster diagnostischer Marker, ist bereits Wochen vor der Krankheitsmanifestation erhöht. Ziel dieser Studie war es, die Wertigkeit des sFlt1/PlGFQuotienten als prädiktiven Faktor bei Risikopatientinnen zu untersuchen. Patienten und Methode: In diese prospektive Studie wurden 68 Patientinnen mit einer Einlingsschwangerschaft und mindestens einem Risikofaktor für das Auftreten einer PE, eines HELLP-Syndrom oder einer IUGR im Schwangerschaftsverlauf eingeschlossen. Die Patientinnen wurden je nach Verlauf der Schwangerschaft in eine Gruppe mit Symptomen (Fallgruppe) und eine Gruppe ohne Symptome (Kontrollgruppe) für eine der oben genannten Erkrankungen unterteilt. Der sFlt1/PlGF-Quotient wurde bei der Aufnahme in die Studie und im weiteren Schwangerschaftsverlauf bestimmt. Ergebnisse: Eine PE, ein HELLP-Syndrom oder eine IUGR trat bei 41 % der Risikopatientinnen auf… Der absolute Wert des sFlt-1/PlGF-Quotienten war nur bei der Gruppe mit Symptomen auf ≥ 85 erhöht und zeigte sich in der 25 + 0-31 + 0 SSW (p = 0,005) und ab der 35 + 0 SSW (p = 0,044) als prädiktiver Faktor für eine PE, ein HELLP-Syndrom oder eine IUGR. Ab 7–10 Wochen vor der Entbindung war, in der Fallgruppe stärker als in der Kontrollgruppe, ein Anstieg des sFlt1/PlGFQuotienten zu beobachten. Dieser war 0–2 Wochen vor der Entbindung bei beiden Gruppen (Kontrollgruppe (MW ± SA 66,9 ± 134) vs. Fallgruppe (MW ± SA 393,3 ± 147,4, p = 0,021) am ,stärksten und zeigte sich ebenfalls als prädiktiver Faktor für eine der genannten Schwangerschaftserkrankungen (p = 0,025). Schlussfolgerung: Bei Risikoschwangeren kann der sFlt1/ PlGF-Quotient für die Einschätzung des individuellen Risikos für eine PE, ein HELLP-Syndrom oder eine IUGR im Schwangerschaftsverlauf genutzt werden. Wiederholte Messungen des Quotienten versprechen eine risikoangepasste Betreuung dieser Patientinnen.:1. BIBLIOGRAFISCHE BESCHREIBUNG 2 2. EINFÜHRUNG 3 2.1. Allgemeines 3 2.2. Klassifikationen 3 2.3. Risikofaktoren 5 2.4. Neue molekulare Erkenntnisse: angiogene Faktoren 6 2.5. Klinische Studien 7 2.6. Differentialdiagnostik anhand angiogener Faktoren 11 2.7. Die Methode für die automatisierte Messung 12 2.8. Die Bedeutung der Dopplersonografie 12 2.9. Weitere Marker und First-Trimester-Screening 13 2.10. Prävention 14 3. PUBLIKATIONSMANUSKRIPT Die Wertigkeit des sFlt-1/PlGF-Quotienten als Prädiktionsparameter bei Schwangeren mit erhöhtem Präeklamsierisiko......................................................15 4. ZUSAMMENFASSUNG DER ARBEIT 22 5. ANLAGEN 27 5.1. Literaturverzeichnis 27 5.2. Erklärung über die eigenständige Abfassung der Arbeit 332 5.3. Lebenslauf 33 5.4. Danksagung 35 / Background: A dysbalance of proangiogenic [placental growth factor (PlGF)] and antiangiogenic [soluble fms-like tyrosine kinase 1 (sFlt-1)] proteins is known to cause the symptoms of preeclampsia (PE), HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) or intrauterine growth restriction (IUGR). An increased sFlt-1/ PlGF ratio ≥ 85 is considered a reliable diagnostic marker. Altered sFlt1 and PlGF concentrations can be detected several weeks prior to the onset of clinical symptoms. In this study we analysed the role of the sFlt1/PlGF ratio as a predictive marker for preeclampsia in a high-risk patient group. Patients and materials: We prospectively included 68 singleton pregnancies with at least one risk factor for PE, HELLP syndrome or IUGR. During the study the patients were divided into one group with symptoms (patient group) and one group without symptoms (control group) for the above-mentioned diseases. The sFlt1/PlGF ratios were measured on admission and during the course of pregnancy. Results: During pregnancy 41 % of patients developed PE, HELLP syndrome or IUGR. An increase of the absolute value of the sFlt1/PlGF ratio ≥ 85 was only observed in the patient group and was found to be a predictive factor for PE, HELLP syndrome or IUGR at 25 + 0 to 31 + 0 weeks of gestation (p = 0.005) and after 35 + 0 weeks of gestation (p = 0.044). Alterations of the sFlt1/PlGF ratio were observed in all patients but were higher in the patient group from 7–10 weeks prior to delivery and with the highest peak 0–2 weeks prior to delivery. Compared to the control group (mean ± SD 66.9 ± 134) absolute values of sFlt1/PlGF ratio were signifi cantly (p = 0.021) increased 0–2 weeks prior to delivery in the patient group (mean ± SD 393.3 ± 147.4). An increase of the sFlt1/PlGF ratio ≥ 85 0–2 weeks before delivery has shown to be predictive for one of the mentioned diseases (p = 0.025).Conclusions: In high-risk patients the sFlt1/PlGF ratio can be used for an individual risk assessment with regard to PE, HELLP syndrome or IUGR. Serial measurements permit a risk-adapted prenatal care of these patients.:1. BIBLIOGRAFISCHE BESCHREIBUNG 2 2. EINFÜHRUNG 3 2.1. Allgemeines 3 2.2. Klassifikationen 3 2.3. Risikofaktoren 5 2.4. Neue molekulare Erkenntnisse: angiogene Faktoren 6 2.5. Klinische Studien 7 2.6. Differentialdiagnostik anhand angiogener Faktoren 11 2.7. Die Methode für die automatisierte Messung 12 2.8. Die Bedeutung der Dopplersonografie 12 2.9. Weitere Marker und First-Trimester-Screening 13 2.10. Prävention 14 3. PUBLIKATIONSMANUSKRIPT Die Wertigkeit des sFlt-1/PlGF-Quotienten als Prädiktionsparameter bei Schwangeren mit erhöhtem Präeklamsierisiko......................................................15 4. ZUSAMMENFASSUNG DER ARBEIT 22 5. ANLAGEN 27 5.1. Literaturverzeichnis 27 5.2. Erklärung über die eigenständige Abfassung der Arbeit 332 5.3. Lebenslauf 33 5.4. Danksagung 35

Einleitung: Die Dysbalance proangiogener (Placental Growth Factor = PlGF) und antiangiogener Faktoren (soluble fms-like tyrosine kinase 1 = sFlt-1) gilt heute als pathophysiologische Grundlage bei der Entstehung einer Präeklampsie (PE), eines HELLP-Syndroms (Haemolysis, Elevated Liver enzymes, Low Platelets) oder einer intrauterinen Wachstumsretardierung (IUGR). Der sFlt1/PlGF-Quotient, ein sensitiver und robuster diagnostischer Marker, ist bereits Wochen vor der Krankheitsmanifestation erhöht. Ziel dieser Studie war es, die Wertigkeit des sFlt1/PlGFQuotienten als prädiktiven Faktor bei Risikopatientinnen zu untersuchen. Patienten und Methode: In diese prospektive Studie wurden 68 Patientinnen mit einer Einlingsschwangerschaft und mindestens einem Risikofaktor für das Auftreten einer PE, eines HELLP-Syndrom oder einer IUGR im Schwangerschaftsverlauf eingeschlossen. Die Patientinnen wurden je nach Verlauf der Schwangerschaft in eine Gruppe mit Symptomen (Fallgruppe) und eine Gruppe ohne Symptome (Kontrollgruppe) für eine der oben genannten Erkrankungen unterteilt. Der sFlt1/PlGF-Quotient wurde bei der Aufnahme in die Studie und im weiteren Schwangerschaftsverlauf bestimmt. Ergebnisse: Eine PE, ein HELLP-Syndrom oder eine IUGR trat bei 41 % der Risikopatientinnen auf. Der absolute Wert des sFlt-1/PlGF-Quotienten war nur bei der Gruppe mit Symptomen auf ≥ 85 erhöht und zeigte sich in der 25 + 0-31 + 0 SSW (p = 0,005) und ab der 35 + 0 SSW (p = 0,044) als prädiktiver Faktor für eine PE, ein HELLP-Syndrom oder eine IUGR. Ab 7–10 Wochen vor der Entbindung war, in der Fallgruppe stärker als in der Kontrollgruppe, ein Anstieg des sFlt1/PlGFQuotienten zu beobachten. Dieser war 0–2 Wochen vor der Entbindung bei beiden Gruppen (Kontrollgruppe (MW ± SA 66,9 ± 134) vs. Fallgruppe (MW ± SA 393,3 ± 147,4, p = 0,021) am stärksten und zeigte sich ebenfalls als prädiktiver Faktor für eine der genannten Schwangerschaftserkrankungen (p = 0,025). Schlussfolgerung: Bei Risikoschwangeren kann der sFlt1/PlGF-Quotient für die Einschätzung des individuellen Risikos für eine PE, ein HELLP-Syndrom oder eine IUGR im Schwangerschaftsverlauf genutzt werden. Wiederholte Messungen des Quotienten versprechen eine risikoangepasste Betreuung dieser Patientinnen.

The aims were to investigate oxidative stress (I), angiogenesis (II) and inflammation (III-IV) in healthy women during pregnancy and postpartum. Oxidative stress was estimated by measurement of 8-iso-PGF2α and the antioxidants α- and γ-tocopherol. The angiogenic factors PlGF, VEGF-A and the antiangiogenic factor sFlt1 were measured to estimate angiogenesis. PTX3, IL-6, TNF-α and a PGF2α metabolite were measured to estimate inflammation. Out of 52 included women, 15 had minor pregnancy complications and 37 were classified as normal. In study III data from all 52 women were used. For the other studies (I, II and IV) only data from the 37 women with normal pregnancy were used. Pregnancy was associated with increased levels of 8-iso-PGF2α with advancing gestational age. The median postpartum value corresponded to values observed in early gestation and a significant decrease was observed from late pregnancy to postpartum. Lipid-adjusted α- and γ-tocopherol levels decreased with advancing gestational age (I). PlGF increased from early pregnancy until weeks 29–30 and thereafter decreased until week 40. sFlt1 levels were relatively constant until weeks 29–30, when they increased, reaching a peak at weeks 39–40. Postpartum levels were low. The sFlt1:PlGF ratio decreased from weeks 9–12, was constantly low from weeks 19–20 to 37–38 and then increased to weeks 39–40. VEGF-A was detectable in only 8 % of the samples during pregnancy and in 64 % postpartum (II). There was a continuous increase of PTX3 as pregnancy progressed. The increase was most evident after week 31 with the highest levels just before delivery (III). IL-6 increased throughout pregnancy and remained high postpartum. No change in TNF-α could be seen with advancing gestational age or postpartum. The PGF2α metabolite levels increased throughout pregnancy and decreased postpartum (IV). In conclusion, normal pregnancy is associated with mild oxidative stress and inflammation. This might have physiological effects for normal pregnancy development. By delineating how these mediators of oxidative stress, angiogenesis and inflammation fluctuate throughout normal pregnancy and postpartum, we have established a reference for studies of these factors in pregnancy complications.

Due to the high metabolic demand and low capacity for energy storage of the brain, neurons are vitally reliant on a constant oxygen supply. Under chronic mild hypoxic conditions (10% oxygen), angiogenesis is induced in the brain in an attempt to restore tissue oxygen tension to normal levels. In brain hypoxia, vascular endothelial growth factor (VEGF) plays a critical role in angiogenesis; however, the role of its homolog placental growth factor (PlGF) is unknown. Using PlGF knockout (PlGF-/-) mice exposed to whole body hypoxia (10% oxygen) for 7, 14 and 21-days, we show that PlGF-/- animals exhibit a delay in the angiogenic response of the brain to hypoxia. PlGF-/- microvessels had a significant increase in fibrinogen accumulation and extravasation, which correlated with disruption of the tight-junction protein claudin-5. These vessels displayed large lumens, were surrounded by reactive astrocytes, lacked mural cell coverage and endothelial VEGF expression, and regressed after 21 days of hypoxia. The lack of PlGF, in combination with reduced VEGF expression levels observed in the brain of PlGF-/- animals during the first 5 days of hypoxia, is likely the cause of the delayed angiogenic response and the prothrombotic phenotype of these mice. In vitro studies conducted to analyze mechanisms involved in the impaired angiogenic phenotype and enhanced astrocytic reactivity to hypoxia of PlGF-/- animals indicated that: i) PlGF-/- mouse brain endothelial cells exhibit alterations in intracellular signaling pathways associated with sprouting (ERK1/2) and vessel branching morphogenesis (GSK-3β) and ii) PlGF-/- astrocytes overexpress VEGF receptor-2 (VEGFR-2) which through activation of the ERK1/2 signaling pathway leads to a more proliferative astrocytic phenotype. These astrocytes were more resistant to oxygen and glucose deprivation (OGD) than PlGF+/+ astrocytes, a characteristic that was shown to be independent of the classical antiapoptotic VEGFR-2-dependent PI3K/Akt pathway. The findings presented in this thesis demonstrated a critical role of PlGF in vascular remodeling in the hypoxic brain.

Due to the high metabolic demand and low capacity for energy storage of the brain, neurons are vitally reliant on a constant oxygen supply. Under chronic mild hypoxic conditions (10% oxygen), angiogenesis is induced in the brain in an attempt to restore tissue oxygen tension to normal levels. In brain hypoxia, vascular endothelial growth factor (VEGF) plays a critical role in angiogenesis; however, the role of its homolog placental growth factor (PlGF) is unknown. Using PlGF knockout (PlGF-/-) mice exposed to whole body hypoxia (10% oxygen) for 7, 14 and 21-days, we show that PlGF-/- animals exhibit a delay in the angiogenic response of the brain to hypoxia. PlGF-/- microvessels had a significant increase in fibrinogen accumulation and extravasation, which correlated with disruption of the tight-junction protein claudin-5. These vessels displayed large lumens, were surrounded by reactive astrocytes, lacked mural cell coverage and endothelial VEGF expression, and regressed after 21 days of hypoxia. The lack of PlGF, in combination with reduced VEGF expression levels observed in the brain of PlGF-/- animals during the first 5 days of hypoxia, is likely the cause of the delayed angiogenic response and the prothrombotic phenotype of these mice. In vitro studies conducted to analyze mechanisms involved in the impaired angiogenic phenotype and enhanced astrocytic reactivity to hypoxia of PlGF-/- animals indicated that: i) PlGF-/- mouse brain endothelial cells exhibit alterations in intracellular signaling pathways associated with sprouting (ERK1/2) and vessel branching morphogenesis (GSK-3β) and ii) PlGF-/- astrocytes overexpress VEGF receptor-2 (VEGFR-2) which through activation of the ERK1/2 signaling pathway leads to a more proliferative astrocytic phenotype. These astrocytes were more resistant to oxygen and glucose deprivation (OGD) than PlGF+/+ astrocytes, a characteristic that was shown to be independent of the classical antiapoptotic VEGFR-2-dependent PI3K/Akt pathway. The findings presented in this thesis demonstrated a critical role of PlGF in vascular remodeling in the hypoxic brain.

Due to the high metabolic demand and low capacity for energy storage of the brain, neurons are vitally reliant on a constant oxygen supply. Under chronic mild hypoxic conditions (10% oxygen), angiogenesis is induced in the brain in an attempt to restore tissue oxygen tension to normal levels. In brain hypoxia, vascular endothelial growth factor (VEGF) plays a critical role in angiogenesis; however, the role of its homolog placental growth factor (PlGF) is unknown. Using PlGF knockout (PlGF-/-) mice exposed to whole body hypoxia (10% oxygen) for 7, 14 and 21-days, we show that PlGF-/- animals exhibit a delay in the angiogenic response of the brain to hypoxia. PlGF-/- microvessels had a significant increase in fibrinogen accumulation and extravasation, which correlated with disruption of the tight-junction protein claudin-5. These vessels displayed large lumens, were surrounded by reactive astrocytes, lacked mural cell coverage and endothelial VEGF expression, and regressed after 21 days of hypoxia. The lack of PlGF, in combination with reduced VEGF expression levels observed in the brain of PlGF-/- animals during the first 5 days of hypoxia, is likely the cause of the delayed angiogenic response and the prothrombotic phenotype of these mice. In vitro studies conducted to analyze mechanisms involved in the impaired angiogenic phenotype and enhanced astrocytic reactivity to hypoxia of PlGF-/- animals indicated that: i) PlGF-/- mouse brain endothelial cells exhibit alterations in intracellular signaling pathways associated with sprouting (ERK1/2) and vessel branching morphogenesis (GSK-3β) and ii) PlGF-/- astrocytes overexpress VEGF receptor-2 (VEGFR-2) which through activation of the ERK1/2 signaling pathway leads to a more proliferative astrocytic phenotype. These astrocytes were more resistant to oxygen and glucose deprivation (OGD) than PlGF+/+ astrocytes, a characteristic that was shown to be independent of the classical antiapoptotic VEGFR-2-dependent PI3K/Akt pathway. The findings presented in this thesis demonstrated a critical role of PlGF in vascular remodeling in the hypoxic brain.

Due to the high metabolic demand and low capacity for energy storage of the brain, neurons are vitally reliant on a constant oxygen supply. Under chronic mild hypoxic conditions (10% oxygen), angiogenesis is induced in the brain in an attempt to restore tissue oxygen tension to normal levels. In brain hypoxia, vascular endothelial growth factor (VEGF) plays a critical role in angiogenesis; however, the role of its homolog placental growth factor (PlGF) is unknown. Using PlGF knockout (PlGF-/-) mice exposed to whole body hypoxia (10% oxygen) for 7, 14 and 21-days, we show that PlGF-/- animals exhibit a delay in the angiogenic response of the brain to hypoxia. PlGF-/- microvessels had a significant increase in fibrinogen accumulation and extravasation, which correlated with disruption of the tight-junction protein claudin-5. These vessels displayed large lumens, were surrounded by reactive astrocytes, lacked mural cell coverage and endothelial VEGF expression, and regressed after 21 days of hypoxia. The lack of PlGF, in combination with reduced VEGF expression levels observed in the brain of PlGF-/- animals during the first 5 days of hypoxia, is likely the cause of the delayed angiogenic response and the prothrombotic phenotype of these mice. In vitro studies conducted to analyze mechanisms involved in the impaired angiogenic phenotype and enhanced astrocytic reactivity to hypoxia of PlGF-/- animals indicated that: i) PlGF-/- mouse brain endothelial cells exhibit alterations in intracellular signaling pathways associated with sprouting (ERK1/2) and vessel branching morphogenesis (GSK-3β) and ii) PlGF-/- astrocytes overexpress VEGF receptor-2 (VEGFR-2) which through activation of the ERK1/2 signaling pathway leads to a more proliferative astrocytic phenotype. These astrocytes were more resistant to oxygen and glucose deprivation (OGD) than PlGF+/+ astrocytes, a characteristic that was shown to be independent of the classical antiapoptotic VEGFR-2-dependent PI3K/Akt pathway. The findings presented in this thesis demonstrated a critical role of PlGF in vascular remodeling in the hypoxic brain.

Short summary: Background: High cardiovascular risk in patients with chronic kidney disease is partly due to mineral dysbalance, microinflammation and oxidative stress. CKD patients accumulate traditional and non-traditional CV risk factors. FGF23, MMPs and PlGF belong among these non-traditional biomarkers of CV risk. FGF23 is a phosphaturic hormone and inhibitor of calcitriol synthesis. It is associated with vascular calcifications. Matrix-metalloproteinases (e.g. MMP-2, MMP-9) are proteolytic, proinflammatory enzymes, contributing to myocardial remodelation. Placental growth factor (PlGF) is a proangiogenic cytokine that is associated with LV hypertrophy in animal model. Plasmatic FGF23, MMPs and PlGF are elevated in CKD. Aim: We aimed to describe dynamic changes between several novel biomarkers of CV risk (FGF23, MMP-2, MMP-9 and PlGF) in CKD stages 1-5, to describe their mutual correlations and possible association with traditional CV risk markers. We studied possible association of laboratory and echocardiographic parameters in patients with CKD stages 2-4. Methods: In a cross-sectional study we evaluated 80 patiens with CKD 1-5 and 44 healthy controls. In a prospective study we evaluated echocardiographic and laboratory parameters in 62 patients with CKD 2-4 for an average study period of 36±10...