Microvascular rarefaction, angiogenesis and hypertension

Transcription

1 Microvascular rarefaction, angiogenesis and hypertension Bernard I. Lévy PARRC Inserm U970 Institut des Vaisseaux et du Sang Hôpital Lariboisière, Paris.

2 Microcirculation ± 90% of the systemic resistance (arterioles < 150 µm) 100% of tissue perfusion and oxygenation (capillaries)

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5 Mean interstitial ph and po 2 as a function of the distance to the nearest blood vessel Permission obtained from Nature Publishing Group Helmlinger, G. et al. Nat. Med. 3, (1997). Jain, R. K. & Stylianopoulos, T. (2010) Delivering nanomedicine to solid tumors Nat. Rev. Clin. Oncol. doi: /nrclinonc

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7 ANGIOGENESIS Hypoxic Cells Mesodermic precursor Hematopoietic precursor VEGF Blood islands Ang2 Ang1 Hemangioblast VEGF VEGF Angioblast Primary capillary plexus Mature vascular network Vasculogenesis Angiogenesis Embryonic development Adult

8 ANGIOGENESIS Hypoxic Cells Ang1 Neoangiogenesis Mesodermic precursor Hematopoietic precursor Blood islands Ang2 + VEGF VEGF Hemangioblast Angioblast VEGF VEGF - VEGF Primary capillary plexus Mature vascular network Vasculogenesis Angiogenesis Vascular regression Embryonic development Adult

9 HYPOXIA : A MAJOR INDUCER OF NEO-VASCULARIZATION Decreased oxygen delivery or Increased oxygen consumption Decreased cellular oxygen concentration Increased HIF activities Increased expression of downstream genes Glycolytic Enzymes Anaerobic metabolism VEGF TGFß VEGFR-1 Angiopoietin 2 Tie1 Tie2 PDGF-B Angiogenesis NOS HO-1 Vasodilation EPO Erythropoïesis Tyrosine Hydroxylase Decrease in SNS activity

10 HYPOXIA : A MAJOR INDUCER OF NEO-VASCULARIZATION Decreased oxygen delivery or Increased oxygen consumption Decreased cellular oxygen concentration Increased HIF activities Increased expression of downstream genes Glycolytic Enzymes Anaerobic metabolism VEGF TGFß VEGFR-1 Angiopoietin 2 Tie1 Tie2 PDGF-B Angiogenesis NOS HO-1 Vasodilation EPO Erythropoïesis Tyrosine Hydroxylase Decrease in SNS activity

11 Diminution de l apport d O2 ou Augmentation de la consommation d O2 Activation de HIF Vasodilatation NO, HO Activité Sympathique Eryhtropoïèse EPO Angiogenèse VEGF TGFß VEGFR-1 Angiopoietin 2 Tie1 Tie2 PDGF-B Métabolisme anaérobie Enzymes glycolitiques

12 Diminution de l apport d O2 ou Augmentation de la consommation d O2 Eryhtropoïèse EPO Activation de HIF Angiogenèse VEGF TGFß VEGFR-1 Angiopoietin 2 Tie1 Tie2 PDGF-B Vasodilatation NO, HO Activité Sympathique Métabolisme anaérobie Enzymes glycolitiques

13 Two questions: 1- Does chronic hypoxia affect microvascular density in hypertensive rats? 2- Do changes in microvascular density modify resistance and then BP? Protocol: 5-week-old and maintained at 10% FIO2 for 8 weeks (Hypoxic groups). Normoxic controls (n=32)

14 Methods I: Hypoxic Chamber F I O 2 (10%) continuously controlled Duration: 8 weeks Standard temperature and humidity

15 Methods II: Doppler Echocardiography Non invasive BP (weekly) Cardiac Index (ml/min.cm 2 ): PA flow x 60 x π (PA Diam/2) 2 Body surface Total peripheral resistance (mmhg.min.cm2/mil): Mean arterial pressure Cardiac Index

16 Methods III: Angiogenesis Foot skin perfusion (Laser Doppler imaging) Capillary density Arteriole density Molecular mechanisms PCR, Western-blot (myocardium, quadriceps): VEGF, enos

17 Hypoxia reduced SBP in SBP (mmhg) *** *** *** ** Normoxic Hypoxic Normoxic Hypoxic Age (w)

18 Hypoxia decreased total peripheral resistance Control Hypoxia Control Hypoxia MBP (mm Hg) 130 ± ± ± ± 8 CI (ml/ min.cm 2 ) TPRi 0.24 ± ± ± ± 0.02 ** 563 ± ± ± ± 49 *** Means ± SEM **

19 Hypoxia increased foot skin perfusion in s Skin perfusion (Laser Doppler) *** 500 Nx Hx

20 Nx Hypoxia did not affect angiographic score (larger arteries) Angiographic Score Hx Strain Oxygen Strain & Oxygen p= p= p=0.3112

21 Hypoxia increased capillary density in heart from Nx Capillary density in hypoxic animals *** % of Nx Hx 0-5

22 Hypoxia increased capillary density in skeletal muscle Nx 25 Capillary density hypoxic vs. normoxic animals *** 20 Hx % of Nx ***

23 A) Quadriceps B) Heart mrna VEGF * * ** * 0 N H N H 0 N H N H FLK * * ** * 0 N H N H 0 N H N H

24 Hypoxia increases VEGF in skeletal muscle from Nx Hyx Nx Hyx Nx Hyx Nx Hyx VEGF enos Actin Actin VEGF *** enos Strain Oxygen Strain & Oxygen p= p= p= Strain Oxygen Strain & Oxygen p= p= p=0.5819

25 Leg Heart Capillar density (number/mm 2 ) * *** Capillar density (number/mm 2 ) *** *** ** 0 N H N H 0 N H N H N H N H N H N H VEGF VEGF FLK-1 FLK-1 enos enos Actin Actin

26 Hypoxia increases VEGF in heart of Nx Hyx Nx Hyx Nx Hyx Nx Hyx VEGF enos Actin P-eNOS VEGF ** enos Actin P-eNOS

27 Heart VEGF VEGF FLK-1 enos Actin N H N H ** * N H N H * * N H N H * N H N H Flk-1 enos

28 Quadriceps VEGF VEGF FLK-1 enos Actin N H N H VEGF ** ** N H N H Flk ** ** N H N H enos N H N H Flk-1 enos

29 SBP (mmhg) Hypoxic chamber - 10% O ** * Hyx + anti-vegf ** Hyx Weeks % of hypoxic VEGF neutralizing antibody: 3mg/kg - i.p, twice a week * * Arterioles Leg Heart Hyx Capillaries * Hyx + anti-vegf

30 Chronic hypoxia 1- Prevents or corrects HT in the 2- Results in proliferation of neo-capillaries in the skeletal and cardiac muscle 3- Significant decrease in TPR in the s 4- Increases skin perfusion 5- Mediated by VEGF and VEGF-R1 both increased in tissues Vilar J et al. Circulation Research. 2008;103:

31 Clinical relevance? Mice based medicine?

32 Hypertension and high altitude Epidemiological data in human Baibas N et al. Residence in mountainous compared with lowland areas in relation to total and coronary mortality. A study in rural Greece. J Epidemiol Community Health Lei S et al. Geographical differences in blood pressure of male youth aged years in China. Blood Press Ruiz L et al. Altitude and hypertension Mayo Clin Proc Mortimer EA et al. Reduction in mortality from coronary heart disease in men residing at high altitude N Engl J Med. 1977

33 Faeh D, Gutzwiller F, Bopp M; Swiss National Cohort Study Group. Lower mortality from coronary heart disease and stroke at higher altitudes in Switzerland. Circulation Aug 11;120(6): Mortality data from 1990 to 2000, sociodemographic information, and places of birth and residence (40 to 84 years; living at altitudes of 259 to 1960 m) were obtained from the Swiss National Cohort. Longitudinal, census-based record linkage study. The 1.64 million German Swiss residents born in Switzerland provided 14.5 million person-years. Mortality from coronary heart disease ( 22% per 1000 m) and stroke ( 12% per 1000 m) significantly decreased with increasing altitude

34 Lower mortality at higher altitude did not appear to depend on variations in classic cardiovascular disease risk factors or in sociodemographic characteristics but rather could result from physiological adaptations to altitude or differences in climate. Our findings not only substantiate the concept of a protective effect of altitude on cardiovascular disease mortality but also suggest a dose-dependent and sustained effect. Circulation Aug 11;120:

35 > 900 clinical studies > 20 B dollars in anti-angiogenic research

36 PlGF

37 Inhibi on of VEGF pathway in oncology An -VEGF-R1 An bodies An -VEGF An bodies Soluble VEGF Receptors Aptamers An -VEGF-R2 An bodies Adapted from Ferrara & Kerbel, Nature, 2005 mab = monoclonal An body nib= tyrosine Kinase

38 Targeted Therapies

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40 A link between VEGF blockade in patients and capillary density? and BP? and endothelial function?

41 SBP evolution SBP (mmhg) p< Baseline 6 months Mourad JJ. Ann Oncol ;19:927

42 DBP evolution 95 p< DBP (mmhg) Baseline 6 months Mourad JJ. Ann Oncol ;19:927

43 Videocapillaroscopy X mm 1.2 mm Capillary density is the mean of 4 fields measurements in a selected 3 by 3 mm area of the middle third of the phalanx

44 Skin Capillary density 130 p< Capillary density per field (after venous congestion) Baseline 6 months 40

45 Results N=18 Baseline 6 months P (student paired test) SBP (mmhg) 129 ± ± DBP (mmhg) 75 ± 7 82 ± Basal capillary density (cap/mm 2 ) Maximal capillary density (cap/mm 2 ) 84 ± ± ± ± No significant change in weight, serum creatinine, or other biological parameters occured during the follow-up. Mourad JJ. Ann Oncol ;19:927

46 Bevacizumab dose-dependent effect on capillary density Reduction in capillary density Change in capillary density ( n/ mm2) R 2 = 0,43 p=0,008 R²=0.43 ; p= Cum ulative dose of bevacizum ab Mourad JJ. Ann Oncol ;19:927

47 Before treatment Baseline Ach1 Ach2 Ach3 Heat At 6 months Baseline Ach1 Ach2 Ach3 Heat

48 Laser doppler flowmetry 1200 Ach1 Ach2 Ach3 Heat 1000 ** Baseline * 6 months ANOVA : P<0.005 vs. baseline

49 P<0.01 P<0.01 Clin Cancer Res 2008

50 Summary and Conclusion BP seems to be (also) controlled by microvascular density Chronic hypoxia modifies the capillary density and tissue perfusion VEGF is necessary for the maintenance of an adapted microcirculatory network in adults Variations in BP & capillary density could be early markers of efficacy of anti-angiogenic treatments.

51 Grade 2-3 bevacizumab-related HT P< 0.04 No HT Scartozzi M et al; Ann Oncology 2009

52 Blood pressure as a potential biomarker of the efficacy of angiogenesis inhibition. Lévy BI. Ann Oncol. 2009;20:200-3

53 n= 632 patients (317 with NSCLC; 315 with CRC) Nakaya A et al. Retrospective analysis of bevacizumab-induced hypertension and clinical outcome in patients with colorectal cancer and lung cancer. Cancer Med 2016; April 16. DOI: /cam4.701,

54 NSCLC Nakaya A et al. Cancer Med 2016

55 CRC Nakaya A et al. Cancer Med 2016

56 Horsley L et al. Is the Toxicity Of Anti-Angiogenic Drugs Predictive Of Outcome? A Review of Hypertension and Proteinuria as Biomarkers of Response to Anti-Angiogenic Therapy. Expert Opin Drug Metab Toxicol. 2012;8:

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61 Inserm U970 Paris Cardiovascular Research HEGP Team2 -Angiogenesis: C Loinard C Cochain JJ Mourad Y Zouggari M Duriez J Vilar B Lévy JS Silvestre

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63 Thank You!