MRC Mouse Network Models for Disorders of Bone and Cartilage Presentation on behalf of Bone and Cartilage Consortium: Professor R V Thakker May Professor.

MRC Mouse Network

Models for Disorders of Bone and Cartilage

Presentation on behalf of Bone and Cartilage Consortium:

Professor R V ThakkerMay Professor of Medicine

University of Oxford

First meeting of MRC Mouse Network,Harwell, UK

13th January 2012

Aims

1. To establish mouse models of bone and cartilage disorders e.g. osteoporosis, osteoarthritis, skeletal trauma, chondrocalcinosis, Paget’s disease, and skeletal dysplasia

2. To use these models for: elucidating the underlying biological mechanisms, facilitating translational research, and development of biomarkers

3. To evaluate translation of findings to the human population level by comparison to large scale GWAS data sets (GEFOS and TREAT-OA)

Why is this important?

Disorders of bone and mineral homeostasis:

• Osteoporosis• Osteoarthritis• Skeletal trauma• Chondrocalcinosis• Gout• Paget’s disease

These disorders are very common, and a major burden on the health services

Effective treatments and prevention strategies are required

ENDOCRINOLOGY

R ThakkerG WilliamsD Bassett

RHEUMATOLOGY

M BrownM FeldmanS RalstonT Vincent

ORTHOPAEDICS

J Nanchahal

HUMANGENETICS

Rivadeneira Uitterlinden

Group

VETERINARY SURGERY

A Goodship

MOUSE GENETICS

S BrownR Cox

P Potter

BASIC SCIENCE

A BoydeP CroucherJ EdwardsN HorwoodA Pitsillides

T Skerry

ENGINEERING / MATERIAL SCIENCE

H Gupta

ConsortiumMembers

Bone Phenotyping• Primary Screen

- Performed at MRC Harwell

- Bone & cartilage screen fits within primary screens for other systems

- Development, growth, biochemistry, body composition, whole body X-ray, DEXA – for bone mineral density

• Intermediate high resolution secondary screen- Faxitron – high throughput quantative analysis of bone mineral

content

- Micro CT – high throughput quantitative analysis of structure, mineralization and static morphometry

• Detailed and bespoke secondary screening- Back scattered electron scanning electron microscopy (BSE-

SEM)

- Quantitative BSE-SEM

- Bone histology & histomorphometry

- Con-focal microscopy

- Mechanical testing

- Nanomechanical (synchroton X-ray scattering)

- Primary bone cell culture

- Longitudinal studies

Collection, fixation, storage and distribution of skeletal elements between laboratories & multiple analyses per

sample upholds principles of 3Rs and economy

From Williams & Bassett






content



SEM)








Lpk/+

WT

Lpk: Spondyloepiphyseal Dysplasia CongenitaWT

WT

Lpk/+

Lpk/+

Proliferatingchondrocytes

Hypertrophicchondrocytes

Lpk/+

Humerus Ulna

WT

- WT Ser1386Pro - WT Ser1386Pro

cell lysates supernatants

Antibody: anti c-Mmyc• Dominant mutant

• Disproportionately shortened humerus and secondary osteoarthritis

• Flattened epyphyses and disorganized growth plate

• Due to Ser1386Pro Col2a1 mutation ; in C-propeptide domain

• ER retention of mutant Col2a1 Esapa et al, JBMR, 2012, in press






content



SEM)








Faxitron: deiodinase mutants have increased bone mineral

Bassett et al, 2010, PNAS






content



SEM)








Adult D2KO and D1/D2KO mice have brittle bones

Biomechanical characteristics and strength properties determined by destructive 3 point bend testing

16w

Yieldload

Maximumload

Fracture load

D2KO

WT

Stiffness

* *

**

*

Bassett et al, 2010, PNAS






content



SEM)








B C DD T = 0 sT = 240 s Wild type Hpr

1 week

4 weeks

7 weeks

10 weeks

16 weeks

Mineral coating

Collagen fibril

d

l

b

L

i. Wild-type ii. Hpr

f/f0 vs. l/L for d = 7 nm

l/L0.0 0.2 0.4 0.6 0.8 1.0 1.2

f/f0

0.01

0.1

1

10

100

d = 7 nm1 week4 weeks7 weeks10 weeks16 weeksWild-typeHprModel predictionsExperimental valuesRegression line for Experimental values

Karunaratne et al, JBMR, 2012, in press

1 week old mice scapula

10 weeks old wild type mice scapula

10 weeks old Hpr mice scapula

Mineral particle orientated along the muscle force direction

Mineral particles are randomly orientated due to the low muscle forces and less activity levels in 1 week old mice

Due to the disturbed local mechanical and structural environment mineral particles are randomly orientated

WT

HPR

Disruption of muscle stress-mediated mineral orientation at the nanoscale in the flat scapular bones of rahictic mice (HPR)

Karunaratne et al, in preparation

Summary – Phenotyping by Bone & Cartilage Consortium

• Primary Screen- Performed at MRC Harwell




content



SEM)








MRC Mouse Network Models for Disorders of Bone and Cartilage Presentation on behalf of Bone and Cartilage Consortium: Professor R V Thakker May Professor.

Documents

disorders of bone

behalf of bone

mouse models of bone

primary screens

quantitative bsesem

body xray

electron microscopy

cartilage disorders