institut de myologie, myology, Pitié-Salpêtrière, paris

Morphological Unit

N_RomeroTeam leader: Dr Norma Beatriz ROMERO, PH, AP-HP

The Risler Pavilion Laboratory is dedicated in particular to the morphological identification and characterisation of genetic neuromuscular diseases in the adult and child.

This laboratory is recognised for the scientific value of its work, its experience in human muscle biopsy analysis and its mastery of morphological techniques. Several fundamental and complementary activities are also carried out:

  • Histo-enzymological analyses of frozen muscle sections
  • Immunocytochemical analyses using specific antibodies directed against different muscle cell proteins : (dystrophin, sarcoglycans, dystroglycans, dysferlin, caveolin, collagen, desmin, myotilin, myosin etc.)
  • Ultrastructural analyses by electron microscopy
  • Western blot analysis
  • MND diagnosis
  • Centre for reference for neuromuscular disease diagnosis
  • Designing or participating in research programmes necessitating this expertise
  • Training

 

Team members

Dr Norma Beatriz ROMERO (MD, PhD), Team leader, Hospital Practitioner
Dr Teresinha EVANGELISTA (MD), Hospital Practitioner, researcher
Mme Favienne LEVY-BORSATO, Secretary
Mme Emmanuelle LACENE, Clinical Research Assistant
Mme Mai Thao BUI, Research Technician
M Guy BROCHIER (PhD), Research Technician Assistant
Mme Angéline MADELAINE, Laboratory Technician
Melle Anais CHANUT, Laboratory Technician
Mme Clémence LABASSE, Research Technician
Mme Maud BEUVIN, Laboratory Assistant
Pr Michel FARDEAU, Volunteer Consultant

 

Contact

01 42 16 22 42
01 42 16 22 43

 

Diagnosis of NMD

We analyse muscle biopsies in our laboratory, with the precise aim of diagnosing muscle pathologies. Some muscle samples from the laboratory’s collection are re-analysed using new tools resulting from advanced research methods.

This activity is very directly linked with the concrete needs of patients.

Requests come either from the Pitié-Salpêtrière Hospital Group:  the Neuromuscular Pathology consultation of the Institute of Myology at the Salpêtrière (Prof Bertrand Fontaine), the Internal Medicine department of Dr Olivier Benveniste, or from hospitals outside the Pitié-Salpêtrière Group (Necker-Children’s, Robert Debré, Val de Grâce, Institute of Childcare and Rothschild in Paris, Raymond Poincaré in Garches, Central Hospitals of Poissy, Montreuil etc).
 

Reference centre for diagnosis of NMD

In our capacity as a Centre of Expertise of Neuromuscular Pathology, we are asked to respond to requests from other centres in France and abroad.

We are frequently approached to:

  • give a second opinion about examinations already carried out elsewhere ; we regularly receive biopsy sections in cases of diagnosis difficulties (about sixty cases a year).
  • complete the analyses of muscle samples taken by other laboratories in Paris or the provinces. These samples are analysed using specialist techniques, not available in all laboratories.
  • help different French and foreign laboratories (by taking samples for research).

 

Participation in research projects

The aim of this work is to contribute to the characterisation of new or as yet unidentified neuromuscular diseases (in collaboration with : M. Bitoun, G. Bonne, D. Hantaï, A. Ferreiro, F. Leturcq, P. Richard, J. Lunardi, N. Monnier, J. Laporte, V. Biancalana, A. Oldfors, F. Muntoni, N. Clarke, N. Laing, C.Wallgren-Pettersson, AL Taratuto etc)
. The goal of this work is to contribute at the characterisation of new or not yet identified neuromuscular diseases (in collaborations).

To be mentioned here:

  • The first protocol of gene therapy done in humans. This phase I essay of clinical research, without any direct benefit for the patients, has been performed using a plasmid with total cDNA of dystrophin in patients with disease of Duchenne or Becker. The principal investigators were Pr Michel Fardeau (Institut de myologie) and Pr Serge Herson (Internal medicine CHUPS). This essay has been performed in collaboration with the Transgene collaboration.

 

  • The immunocytochemical, histo-enzymological and ultrastructural analyses of abnormalities associated with congenital myopathies, in particular core myopathies (Central Core Disease (CCD), Multi-minicore), correlated with molecular studies, allows to bring precisions at the clinical entities which are not yet well defined or differentiated. In the domain of congenital myopathies with cores, we have also contributed to the clinical and morphological characterisation of patients with CCD linked or not-linked with the gene RYR1.

 

  • In the domain of congenital myopathies, we have also contributed at the study of nemalin myopathies (NM) with the identification of one of the first children with a severe form of NM, which was associated at a mutation stop of the gene ACTA1 and at the study of myopathies with congenital fiber type disproportion (CFTD) linked at the gene TPM3.
  • Thanks to the immunocytochemical study with antibodies against alpha- and beta-dystroglycan, collagen VI and perlecan, which we have systematically introduced in our laboratory, it has been possible to perform a reclassification of multiple muscular dystrophies of at that time unknown origin. In this domain, we have contributed to the identification of congenital muscular dystrophy associated at collagen 6, as well as to the study of muscular dystrophies with deficiency in alpha-dystroglycan, linked or not-linked at the gene FKRP.
  • A first clinical and morphological analysis of a large series of patients with a congenital myopathy of the centronuclear type (CNM) has been performed. This work has contributed in an important way to linkage analyses on the autosomal dominant form of CNM and to the identification of the causal gene DNM2 that encodes Dynamine 2. Next, we have described the selectivity of the muscular affection in patients with a DNM2 mutation by a clinical and muscle imaging study. Later, we have identified the severe clinical and sporadic forms associated with DNM2.
Next, we concentrated our interest on the histopathological analysis of patients in whom a mutation in DNM2 had been excluded. These patients make up a heterogeneous group with as common characteristic a variable number of fibres with internalized nuclei. This work has led to a classification in several subgroups of patients based on the morphological aspects observed at the muscular biopsy, as well as the mode of transmission and the clinical presentation.

institut de myologie, myology, Pitié-Salpêtrière, paris

  • We have also identified a group of CNM patients that presented a curious morphological feature characterized by the presence of a variable number of fibers « en collerettes » or “dark necklace” fibres (DNF). These dark necklaces are situated a few micrometers of the sarcolemma and have been observed in the two types of fibres. The dark necklaces are colored by HE, GT, PAS, NADH-TR, SDH and COX, but they are not stained by myofibrillar ATPase. Some nuclei are aligned with the dark necklace. The ultrastructural analysis showed that the dark necklace consists of myofibrils with a small diameter, which are surrounded by mitochondria and sarcotubular structures. The immunohistochemical analysis has shown an intense staining with the anti-SERCA1 and SERCA2 antibodies, bot not with the other proteins of the sarcoplasmic reticulum (calsequestrin, the ryanodin receptor, triadin), and the T-tubule (dihydropyridin receptor-alpha1subunit). We have observed a moderate reaction with the anti-desmin and alphaB-crystallin antibodies, but less with anti-myotilin. Clinically, it is sporadic cases, with symptoms that started in the first decennium of their lives, with a proximal weakness of the lower limbs and a slowly progressive evolution. The genetic analysis has permetted to exclude mutations in the genes DNM2, hJumpy and BIN. The analysis of the gene MTM is currently performed. The mechanism of this defect in the organisation of the sarcoplasm still has to be elucidated.
  • We are studying the clinical, immunohistochemical and ultrastructural characteristics in patients with myofibrillar myopathy (MFM). The ultrastructural findings in 19 patients with different genetically-proven MFMs (9 desmin, 5 alpha-B-crystallin, 3 ZASP, 2 myotilin) were analyzed. In one patient with a ZASP mutation, we additionally performed an immuno-electron microscopic (EM) study, using antibodies against desmin, alpha-B-crystallin, ZASP and myotilin. The ultrastructural findings in desminopathies and alpha-B-crystallinopathies were very similar and consisted of electrondense granulofilamentous accumulations and sandwich formations. They differed in the presence of early apoptotic nuclear changes in alpha-B-crystallinopathies. ZASPopathies were characterized by filamentous bundles (labeled with the myotilin antibody on immunoEM), and floccular accumulations of thin filamentous material. Tubulofilamentous inclusions in sarcoplasm and myonuclei in combination with filamentous bundles were characteristic for myotilinopathies. We conclude from this study that MFMs ultrastructural findings can direct diagnostic efforts towards the causal gene mutated, and that EM should be included in the diagnostic workup of MFMs. The immunohistochemical study involves 15 patients with a genetically-proven MFM (7 desmin, 3 alpha-B-crystallin, 3 ZASP, 2 myotilin) in whom we used 23 antibodies including several novel antibodies against distinct Z-disc and M-line proteins. This study is performed in collaboration with Dieter O. Fürst and Peter F.M. van der Ven of the Institute for Cell Biology, Department of Molecular Cell Biology, University of Bonn, Bonn (Germany) and with Rudolf Kley of the Neurologische Univ.-Klinik Bergmannsheil, Ruhr-Universität Bochum, Bochum (Germany). The results of this study are currently being analyzed.

 

Training

Teams working on the study of muscular diseases have expressed an interest in following up or improving their training in muscular biopsy analysis (example: Study group Meetings in Myology organised at the Institute of Myology etc).

For several years now, we have received physicians for training courses in the diagnosis of muscular diseases and/or postdoctoral trainings, and technicians for training in sampling techniques and the processing of biopsies. Last years, we received Michele Roccella (Palerme), Pierre-Yves Jeannet, (Lausanne), Haffed Haddad (Tunis), Simona Gambelli (Sienne), Muriel Herasse (Paris), Fabiana Lubieniecki (Buenos Aires), Soledad Monges (Buenos Aires) et  Javier Linzoain (Córdoba). In 2008, we will welcome Felipe Andreinolo, neuropathologist of Brasil (Sao Paulo) and  Jorge Bevilacqua, neurologist of Chili (Santiago)

The Risler Pavilion now has a specially adapted and equipped meeting room for up to 15 people in order to bring together physicians and scientists with an interest in Neuromuscular Pathology. Several regular meetings are held there:

  • Meetings to compare genetic/morphologic/pathological/clinical results (monday) with the regular participation of Dr F. Leturcq,  Dr S. Quijano, Dr P. Laforet, Dr G. Bonne, Dr R. Ben Yaou, Dr P. Richard, Dr A. Behin, Dr T. Stojkovic, Dr T. Evangelista, Dr C. Métay.
  • Patient record discussion meetings (Thursday), between the physicians of the consultation of the Institute of Myology (Dr P. Laforet, Dr A. Behin, Dr T. Stojkovic, Dr T. Evangelista, Dr G. Bassez) and the physicians of the Internal Medicine department (Dr O. Benveniste).
  • Metabolic diseases meetings (Friday) with the participation of  the biologists of the laboratory of Prof B.Hainque.

Although the laboratory of the Risler Pavilion is integrated within the hospital, it collaborates with other inter- and/or extra-hospital partners : the neuromuscular pathology consultation of the Babinski Building, the Raymond Escourolle Neuropathology Laboratory, the Tissue Bank for Research, the Internal Medicine department, the Cardiology department, the Immunology department, the Federation of Neurology and the CNRS and Inserm Research Units.

 

Key publications