1. MOLECULAR CLASSIFICATION OF AIS PATIENTS: TOWARD NEW EMERGING CONCEPTS IN MOLECULAR MEDICINE TO TREAT ADOLESCENT IDIOPATHIC SCOLIOSIS
B. Azeddine, H. Labelle, B. Poitras, CH. Rivard, and A. Moreau.
Bone Molecular Genetics and Musculoskeletal Malformations Laboratory, Research Centre, Hôpital Sainte-Justine
POES, 06 mai 2005

2. Adolescent idiopathic scoliosis
Definition: «  Idiopathic scoliosis is a three-dimensional deformity of the spine with lateral curvature combined with vertebral rotation, which affect mostly girls. »
It’s etiology is still unknown

3. Tissues & systems targeted by melatonin action and affected in AIS
Postural control defect (CNS)
AIS patient
Equilibrium & vestibular dysfonction
Proprioception dysfonction
Platelet abnomalities
Increased calmodulin level
Osteopenia
Reduced muscle spindles
Muscle fibers abnormalities
Abnormal muscular tone
GH secretion
NOVEL HYPOTHESIS
Melatonin signaling dysfunction in AIS
Mel   i
GTP AC
MT1-2
ATP Gi
GDP
AMPc
First unifying concept supporting
the multiplicity of disorders
associated with AIS

4. Aims
The goals of this study were to assess the possibility to establish a molecular classification of AIS patients and to demonstrate the feasibility to correct this melatonin signaling defect using therapeutic compounds

5. Materials and methods AIS CTRL Patients number Total 62 22 7 8 55 14
Clinical data of scoliotic patients and control subjects
AIS
CTRL
Patients number
Total 62 22 7 8 55 14
Mean age (year)
boys
girls
16,4 15
14,7 16
Mean Cobb’s angle
thoracic
double
thoracolumbar
lumbar
50,9°
53°-48°
49,9°
47,1°
51,9°
60°-30°
53°
no scoliosis
76,5°

6. Percentage of cAMP inhibition
Melatonin signaling dysfunction in osteoblasts isolated from AIS patients
300
250
200
150
Percentage of cAMP inhibition
per 100,000 cells
GR 1 (n=13)
100
GR 2 (n=25)
GR 3 (n=16) 50
CTRL (n=4) F
-11 -9 -7 -5
Melatonin concentration (M)
Moreau et al., Spine 2004; 29:

7. Phosphorylation of Gi proteins is increased in osteoblasts derived from AIS patients
Melatonin
Vanadate
Genistein
Control
Inactive form
60kDa
Ctrl
Active form
43kDa
60kDa
1003
43kDa
60kDa
1007
43kDa

8. Search for regulators involved in Gi protein phosphorylation
TKs
Rack1 P
TPs Y
PKCδ
activation P Gi S
inactivation

9. Abnormal interactions between MT2 melatonin receptor subtype and PKCδ occur in AIS cells
Patients
Gender
Age (years)
Curve pattern
Cobb's angle
Pain
Group
# 1056 F 18
right thoracic 34
Yes 2
# 1084 F 12
right thoracic 70 No 3
# 1138 F 14
right thoracic 58 No 1

10. Rack1 interactions with PKCδ are affected in AIS cells
Patients
Gender
Age (years)
Curve pattern
Cobb's angle
Pain
Group
# 1056 F 18
right thoracic 34
Yes 2
# 1084 F 12
right thoracic 70 No 3
# 1138 F 14
right thoracic 58 No 1

11. Screening for therapeutic compounds that could rescue melatonin signaling dysfunction in AIS
120
100 80
Control
% cAMP 60
Compound B 40 20
Compound A F
-11 -9 -7 -5
melatonin concentration [M]
Patient #1004

12. Summary
Increased phosphorylation of Gi proteins could be at the origin of the melatonin signaling defect in AIS although such dysfunction may involve more than one gene.
Functional assays offer the mean to identify for the first time children at risk of progression without the knowledge of specific mutations.
Such dysfunction could be rescued in some patients using therapeutic compounds and may offer innovative approaches to prevent or stop spinal deformities.

13. X The future of scoliosis treatments Scoliosis Early detection
25˚- 40˚
Identification of patients
with a risk of progression
45˚+, progressive
Surgery
Prior the clinical manifestations
1. Goal: To prevent scoliosis using pharmacotherapies and/or braces
Functional & molecular classification of patients already diagnosed
2. Goal: To stop the progression of scoliotic deformities
Development of new generation of braces
Use of a tailored pharmacotherapy (selection of specific drugs)
Identification of biochemical/molecular markers

14. Bone Molecular Genetics and Musculoskeletal Malformations Laboratory
Acknowledgements
Bone Molecular Genetics and Musculoskeletal Malformations Laboratory
Collaborators
University of Milan, Italy
Dr Debora Angeloni
Prof Franco Fraschini
Hôpital Sainte-Justine
Dr Hubert Labelle
Dr Benoît Poitras
Dr Charles-Hilaire Rivard
Dr Guy Grimard
Dr Gilles Chabot
Julie Joncas
Dr Florina Moldovan
Dr. Moreau’s team
Dr Alain Moreau
Hugo Boulanger
Catherine Chassaing
Ginette Lacroix
Virginie Landreville
Kareen Letellier
Isabelle Turgeon
Dr Da Shen Wang
Montreal’s Children Hospital
Dr Jean Ouellette
Dr Vincent Arlet