2
RESEARCH POSTER PRESENTATION DESIGN © 2011 www.PosterPresentations.com Villous Vascular Tree 3D Morphology of Ex Vivo Perfused Human Placental Cotyledon Objective Materials and Methods Introduction Marcel Chuecos, BS 1 , Kushal Gandhi, PhD 1 , James Maher, MD 1 , Andrey Bednov, PhD 1,2 , Daniela Pino, MD 1 , Guangchen J PhDi 3 , Lee David Moore, MD 1 , and Natalia Shlabritz-Loutsevitch, MD, PhD 1 1 Texas Tech University Health Sciences Center at the Permian Basin, Odessa, TX, USA. 2 University of Texas at the Permian Basin, Odessa, TX, USA. 3 Texas Tech University Health Sciences Center, Lubbock , TX, USA. Results Acknowledgements In human pregnancy, the first half of gestation is associated with the prevalence of branching angiogenesis, and the second half of gestation is marked by prevalence of non-branching angiogenesis. Some adverse maternal conditions, e.g pre-eclampsia are associated with excessive branching and decreased flow-mediated vasodilation. Mathematical models of placental oxygen exchange and consumption used different approaches to connect placental vascular structure and placental function, however, the physiological data is sparse. The aim of this study was to evaluate 3D vascular structure of ex-vivo perfused human placental cotyledon and compare vascular tree morphology with physiological parameters. Confocal images were generated in the Image Analysis Core Facility supported in part by TTUHSC. Authors are thankful to the director of the Core facility Dr. Petar Grozdanov for the support and expertise with confocal images. We acknowledge Dr. Amanda Howard, Regional Sales Engineer of Bitplane for the fantastic help with image analyses and Dr. Takaki (TTUHSC) for assistance with tissue preparation. Special thanks to the TTUHSC Clinical Research Institute for help with placenta collection. Authors are expressing their gratitude to TTUHSC-PB Regional Dean Dr. G Ventolini and UTPB Dean of art and sciences Dr. M. Zavada for the great support of this research. Discussion and Conclusion [email protected] Figure 1. Diagram of placenta perfusion methodology. Figure 3. Cartoon depiction of placenta perfusion vessel staining. Dashed box indicates cotyledon perfused. Black dots indicate blood vessels branching points. Figure 4. Variation in vascular tree morphology between cotyledons (upper panel) and within cotyledon (lower panel) of perfused human placenta (endothelium- specific DiI staining). Magnification 10X. Scale bar for all images: 300um. Figure 5. Vascular tracing with Imaris software. Orange circles indicate points of vascular branching. Figure 2. Pictures of placentas used for perfusion collected after delivery. PL3 PL2 PL1 Patient Gravidity Parity Pre-preg weight (kg) Height (cm) Gestational Age (wks.days) Maternal Age (Years) Race Prenatal medication other Drugs- Alcohol GD Beta Strept status Anaesthesia Delivery Apgar (1 minute) Apgar (5 minute) PT1 4 3 72.6 152 39.8 21 Caucasian Keflex. Zafran Yes No - Epidural C- section 7 9 PT2 3 2 83.9 165 39 37 Caucasian Glyburide. Fenofibrate No yes + Epidural C- section 7 8 PT3 1 0 89.5 162 40 20 N/A N/A No No + Epidural Vaginal 9 10 Table 1. Patient characteristics. Placenta Placenta Weight (g) Placenta Thickness (cm) Placenta Diameter (cm) Number of Cotyledons Cotyledon Weight (grams) (after perfusion) Fetal weight (grams) Fetal sex PL1 575 2.6 22 x 20 29 18.06 3540 F PL2 555 2.5 18 X 16.5 19 64.15 3460 F PL3 655 3 22 X 21 17 67.64 3470 M Table 2. Placenta characteristics. Authors Method Vasculature’s and villous branching Study’s endpoints Haeussner, E. et al. 2014. Sholl-analyses based Neuro- Lucida software and 3D reconstruction. 11.1 ± 5.140 7.1 ± 3.824 1.74 ± 1.019 Terminal distance ordering of branches Haeussner, E. et al. 2016. Sholl-analyses based Neuro- Lucida software and 3D reconstruction. CTR:1 x 10 5 um 3* EXP: 8 x 10 4 um 3* *Estimated from graphs. Intrauterine Growth Restriction Jirkovská, M. et al. 2012 Confocal microscopy, 3D reconstruction and immunohistochemistry. CTR: 0.027 ± 0.109 BP per villus EXP: 0.410 ± 0.202 BP per villus Diabetes Mellitus 1 Kato, Y. et al. 2016. Computational Model 2.22 – 6.02 bifurcation ratio Contraction of stem villi Mayhew, T. M. et al. 2004. Stereological analyses Branching Index: 0.28 ± 0.03 Intrauterine Growth Restriction Thunbo, MØ. et al. 2018. Computed topography angiography and 3D image segmentation. 1.02 ± 1.73 vessel junctions per convex Fetal Growth Restriction Serov, A.S. et al. 2014 Mathematical Model 0.47 ± 0.06 villous density Oxygen Uptake y = -0.0018x + 0.3459 R² = 0.6673 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00 180.00 O 2 Consumption (ml/min/Kg Total Number of Branching Point per mm³ of cotyledon Correlation between placental cotyledon O 2 Consumption (ml/min/kg) and vascular branching. y = -0.0003x + 0.3078 R² = 0.5819 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.000 100.000 200.000 300.000 400.000 500.000 600.000 700.000 800.000 900.000 O 2 Consumption (ml/min/Kg Branching Points per mm³ of Vasculature Correlation between placental cotyledon O 2 Consumption (ml/min/kg) and volume of vasculature Placenta Fetal Input Pressure (mmHg) Maternal Input Pressure (mmHg) Fetal Flow (ml/min) Maternal Rate (ml/min) Fetal Leakage Absolute number of Branching Points (BP) Volume of Tissue (mm³) BP/Volume of tissue (mm³) Volume of Vasculature (mm³) - mean ± SEM BP/Volume of Vasculature (mm³) Volume of stem Villi Vasculature (mm³)* BP/Volume of Stem Villi Vasculature (mm³) PL1 35.15 33.88 4.8 15 11.12% 52 ± 20 1.21±0. 18 42.98 0.295 ± 0.105 176.271 0.0177 ± 0.00361 2.938E+03 PL2 26.81 62.11 4.8 15 8.30% 165 ± 53 1.04±.0 15 158.65 0.198 ± 0.060 833.333 0.0119 ± 0.00180 1.387E+04 PL3 33.19 32.4 4.5 15 13% 109 ± 26 1.23±0. 14 88.62 0.284 ± 0.039 383.803 0.0170 ± 0.00469 6.412E+03 At the end of perfusion experiment, each cotyledon was infused with 12 ml of 1,1’-Dioctadecyl-3,3,3’,3’-tetramethylindocarbocaninperchlorate (DiI, Cat No. 42364, Sigma-Aldrich; St. Louis, MO, USA) at the rate 6 ml/min, and subsequently with 12 ml of 4% paraformaldehyde at the same flow rate, using modified published protocol. Subsequently a portion of the cotyledon was fixed for 1-7 days in 4% paraformaldehyde (4.0 o C). All placental specimens were embedded in 4% agarose and sections with 300-400 μm thickness were cut with vibratome (The Vibratome Co., St. Louis, MO, USA). All fluorescent images were taken using the T1-E microscope with A1 confocal and STORM super- resolution modules (Nikon Instruments Melville NY, USA. Images were quantified using Image-Pro Premier software (Media Cybernetics, Inc, Rockville, MD. USA) and Imaris 9 (Bitplane, USA). Number of branching points was calculated using Imaris 9 algorithm. Details regarding methodology of estimation of placental oxygen consumption are in poster # F-162. Table 4. Published data and methods of estimation of placental villous branching. Fig.6 Villous tree structure with the emphasis on villous branching (Benirschke et al., 2006) The differences in the methodologies, applied for calculation of villous number and vascular branching points (Table 4) makes comparison between studies difficult. Our data is similar to published by Haeussner et al., 2016 with Neuro- Lucida analyses and 3D microvillous reconstruction. Despite differences in the absolute numbers, our data is in line with published by Jirkovska et al. 2012, regarding increased number of branching points in patients with diabetes. Mathematical models of the placental oxygen exchange, summarized by Serov (2015), include flow rate, membranes permeability and thickness, porosity, etc. Recent model, published by Lin et al. (2016) (Figure 7), demonstrated correlation between angle of villous tree/type of villi and oxygen uptake, demonstrating weak influence of number of branching points on the placental oxygen uptake. Our functional study showed association between number of branching points with the oxygen uptake. SGI Poster#F162 describes relationship between flow rate and oxygen uptake in the same model. Fig. 7. Flow streamlines (black lines) and normalised oxygen concentration field (colours) predicted for a placentome containing a villous tree with random branching angles correspond with the asymmetrical branching of the villous tree. (Lin et al., 2016) Ex vivo placental model could be used for testing mathematical computational algorithms linking placental structure and function. Table 3. Perfusion parameters and morphology of villous tree

Villous Vascular Tree 3D Morphology of Ex Vivo Perfused Human Placental Cotyledon · 2018-06-11 · of ex-vivo perfused human placental cotyledon and compare vascular tree morphology

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  • RESEARCH POSTER PRESENTATION DESIGN © 2011

    www.PosterPresentations.com

    Villous Vascular Tree 3D Morphology of Ex Vivo Perfused Human Placental Cotyledon

    Objective

    Materials and Methods

    Introduction

    Marcel Chuecos, BS1, Kushal Gandhi, PhD1, James Maher, MD1, Andrey Bednov, PhD1,2, Daniela Pino, MD1, Guangchen J PhDi3, Lee David Moore, MD1,and Natalia Shlabritz-Loutsevitch, MD, PhD1

    1Texas Tech University Health Sciences Center at the Permian Basin, Odessa, TX, USA. 2University of Texas at the Permian Basin, Odessa, TX, USA. 3Texas Tech University Health Sciences Center, Lubbock , TX, USA.

    Results

    Acknowledgements

    In human pregnancy, the first half of gestation isassociated with the prevalence of branching angiogenesis,and the second half of gestation is marked by prevalenceof non-branching angiogenesis. Some adverse maternalconditions, e.g pre-eclampsia are associated withexcessive branching and decreased flow-mediatedvasodilation. Mathematical models of placental oxygenexchange and consumption used different approaches toconnect placental vascular structure and placentalfunction, however, the physiological data is sparse.

    The aim of this study was to evaluate 3D vascular structureof ex-vivo perfused human placental cotyledon andcompare vascular tree morphology with physiologicalparameters.

    Confocal images were generated in the Image Analysis Core Facility supported in part by TTUHSC. Authors arethankful to the director of the Core facility Dr. Petar Grozdanov for the support and expertise with confocal images.We acknowledge Dr. Amanda Howard, Regional Sales Engineer of Bitplane for the fantastic help with image analysesand Dr. Takaki (TTUHSC) for assistance with tissue preparation. Special thanks to the TTUHSC Clinical ResearchInstitute for help with placenta collection. Authors are expressing their gratitude to TTUHSC-PB RegionalDean Dr. G Ventolini and UTPB Dean of art and sciences Dr. M. Zavada for the great support of this research.

    Discussion and Conclusion

    [email protected]

    Figure 1. Diagram of placenta perfusion methodology.

    Figure 3. Cartoon depiction of placenta perfusion vessel staining. Dashed box indicates cotyledon perfused.Black dots indicate blood vessels branching points.

    Figure 4. Variation in vascular tree morphology between cotyledons (upper panel) and within cotyledon(lower panel) of perfused human placenta (endothelium- specific DiI staining). Magnification 10X. Scale barfor all images: 300um.

    Figure 5. Vascular tracing with Imaris software. Orange circles indicatepoints of vascular branching.

    Figure 2. Pictures of placentas usedfor perfusion collected afterdelivery.

    PL3

    PL2

    PL1Patient Gravidity Parity

    Pre-pregweight

    (kg)

    Height (cm)

    Gestational Age

    (wks.days)

    Maternal Age

    (Years)Race

    Prenatal medication

    other

    Drugs-Alcohol

    GD Beta

    Streptstatus

    Anaesthesia DeliveryApgar

    (1 minute)Apgar

    (5 minute)

    PT1 4 3 72.6 152 39.8 21 Caucasian Keflex. Zafran

    Yes No - Epidural C-section

    7 9

    PT2 3 2 83.9 165 39 37 Caucasian Glyburide. Fenofibrate

    No yes + Epidural C-section

    7 8

    PT3 1 0 89.5 162 40 20 N/A N/A No No + Epidural Vaginal 9 10

    Table 1. Patient characteristics.

    Placenta Placenta Weight (g)Placenta

    Thickness (cm)Placenta Diameter (cm) Number of Cotyledons

    Cotyledon Weight (grams) (after

    perfusion)Fetal weight (grams) Fetal sex

    PL1 575 2.6 22 x 20 29 18.06 3540 FPL2 555 2.5 18 X 16.5 19 64.15 3460 FPL3 655 3 22 X 21 17 67.64 3470 M

    Table 2. Placenta characteristics.

    Authors MethodVasculature’s

    and villousbranching

    Study’s endpoints

    Haeussner, E. et al. 2014.

    Sholl-analyses based Neuro-Lucida software and 3D

    reconstruction.

    11.1 ± 5.140 7.1 ± 3.824

    1.74 ± 1.019

    Terminal distance ordering of branches

    Haeussner, E. et al. 2016.

    Sholl-analyses based Neuro-Lucida software and 3D

    reconstruction.

    CTR:1 x 105 um3*

    EXP: 8 x 104 um3* *Estimated from graphs.

    Intrauterine Growth Restriction

    Jirkovská, M. et al. 2012

    Confocal microscopy, 3D reconstruction and

    immunohistochemistry.

    CTR: 0.027 ± 0.109 BP per villus

    EXP: 0.410 ± 0.202 BP per villus

    Diabetes Mellitus 1

    Kato, Y. et al. 2016.

    Computational Model2.22 – 6.02

    bifurcation ratioContraction of stem villi

    Mayhew, T. M. et al. 2004.

    Stereological analysesBranching Index:

    0.28 ± 0.03Intrauterine Growth

    Restriction

    Thunbo, MØ. et al. 2018.

    Computed topography angiography and 3D image

    segmentation.

    1.02 ± 1.73 vessel junctions per convex Fetal Growth Restriction

    Serov, A.S. et al. 2014

    Mathematical Model0.47 ± 0.06 villous

    densityOxygen Uptake

    y = -0.0018x + 0.3459R² = 0.6673

    0

    0.05

    0.1

    0.15

    0.2

    0.25

    0.3

    0.35

    0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00 180.00

    O2

    Cons

    umpt

    ion

    (ml/

    min

    /Kg

    Total Number of Branching Point per mm³ of cotyledon

    Correlation between placental cotyledon O2 Consumption (ml/min/kg) and vascular branching.

    y = -0.0003x + 0.3078R² = 0.5819

    0

    0.05

    0.1

    0.15

    0.2

    0.25

    0.3

    0.35

    0.000 100.000 200.000 300.000 400.000 500.000 600.000 700.000 800.000 900.000

    O2

    Cons

    umpt

    ion

    (ml/

    min

    /Kg

    Branching Points per mm³ of Vasculature

    Correlation between placental cotyledon O2 Consumption (ml/min/kg) and volume of vasculature

    PlacentaFetal Input Pressure (mmHg)

    MaternalInput

    Pressure(mmHg)

    Fetal Flow

    (ml/min)

    MaternalRate

    (ml/min)

    Fetal Leakage

    Absolutenumber of Branching Points (BP)

    Volume of

    Tissue(mm³)

    BP/Volume of tissue (mm³)

    Volume of Vasculature

    (mm³) - mean ± SEM

    BP/Volume of Vasculature

    (mm³)

    Volume of stem Villi

    Vasculature (mm³)*

    BP/Volume of Stem Villi Vasculature

    (mm³)

    PL1 35.15 33.88 4.8 15 11.12% 52 ± 201.21±0.

    1842.98 0.295 ± 0.105 176.271

    0.0177 ±0.00361

    2.938E+03

    PL2 26.81 62.11 4.8 15 8.30% 165 ± 531.04±.0

    15158.65 0.198 ± 0.060 833.333

    0.0119 ±0.00180

    1.387E+04

    PL3 33.19 32.4 4.5 15 13% 109 ± 261.23±0.

    1488.62 0.284 ± 0.039 383.803

    0.0170 ±0.00469

    6.412E+03

    At the end of perfusion experiment, each cotyledon was infused with 12 ml of 1,1’-Dioctadecyl-3,3,3’,3’-tetramethylindocarbocaninperchlorate (DiI, Cat No. 42364, Sigma-Aldrich; St. Louis, MO, USA) at the rate 6 ml/min, and subsequently with 12 ml of 4% paraformaldehyde at the same flow rate, using modified published protocol. Subsequently a portion of the cotyledon was fixed for 1-7 days in 4% paraformaldehyde (4.0oC). All placental specimens were embedded in 4% agarose and sections with 300-400 μm thickness were cut with vibratome (The Vibratome Co., St. Louis, MO, USA). All fluorescent images were taken using the T1-E microscope with A1 confocal and STORM super-resolution modules (Nikon Instruments Melville NY, USA. Images were quantified using Image-Pro Premier software (Media Cybernetics, Inc, Rockville, MD. USA) and Imaris 9 (Bitplane, USA). Number of branching points was calculated using Imaris 9 algorithm. Details regarding methodology of estimation of placental oxygen consumption are in poster # F-162.

    Table 4. Published data and methods of estimation of placental villous branching.

    Fig.6 Villous tree structure with the emphasis on villous branching (Benirschke et al., 2006)

    The differences in the methodologies, applied for calculation of villous numberand vascular branching points (Table 4) makes comparison between studiesdifficult. Our data is similar to published by Haeussner et al., 2016 with Neuro-Lucida analyses and 3D microvillous reconstruction. Despite differences in theabsolute numbers, our data is in line with published by Jirkovska et al. 2012,regarding increased number of branching points in patients with diabetes.Mathematical models of the placental oxygen exchange, summarized by Serov(2015), include flow rate, membranes permeability and thickness, porosity, etc.Recent model, published by Lin et al. (2016) (Figure 7), demonstratedcorrelation between angle of villous tree/type of villi and oxygen uptake,demonstrating weak influence of number of branching points on the placentaloxygen uptake. Our functional study showed association between number ofbranching points with the oxygen uptake. SGI Poster#F162 describesrelationship between flow rate and oxygen uptake in the same model.

    Fig. 7. Flow streamlines (black lines) and normalised oxygen concentration field (colours) predicted for a placentome containing a villous tree with random branching angles correspond with the asymmetrical branching of the villous tree. (Lin et al., 2016)

    Ex vivo placental model could be used for testing mathematical computational algorithms linking placental structure and function.

    Table 3. Perfusion parameters and morphology of villous tree

  • RESEARCH POSTER PRESENTATION DESIGN © 2011

    www.PosterPresentations.com

    Table 1. Structural variability (number of branching points) in ex vivo perfused human placenta. Number of branching points mean ± SEM Sections of cotyledon A B C D

    PL1 91 34 31 N.A 52 ± 20 PL2 285 205 135 36 165 ± 53 PL3 183 74 105 75 109 ± 26

    Table 1. Structural variability (number of branching points) in ex vivo perfused human placenta.

    Number of branching points

    mean ± SEM

    Sections of cotyledon

    A

    B

    C

    D

    PL1

    91

    34

    31

    N.A

    52 ± 20

    PL2

    285

    205

    135

    36

    165 ± 53

    PL3

    183

    74

    105

    75

    109 ± 26

    Villous Vascular Tree 3D Morphology of Ex Vivo Perfused �Human Placental CotyledonSlide Number 2