Zebra Fish And Muscular Dystrophy

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Zebra Fish and Muscular Dystrophy

TRANSCRIPT:

BLANCH : The body's muscles are used in virtually everything we do, whether it's taking a walk to stretch our legs or even just sitting on a park bench, which is why the effects of muscular dystrophy where the muscles literally waste away are so devastating.

But sufferers are being offered new hope from a most unlikely source, the humble zebra fish. For ABC TV's science and technology program Catalyst, Maryanne Demasi reports.

MARYANNE DEMASI : Muscle damage occurs as a normal part of life. Weight lifting or over-stretching can induce small tears in our muscle fibres, which gradually repair over time.

The problem is our ability to do this diminishes with age.

In common genetic diseases like muscular dystrophy, excessive muscle damage can leave sufferers crippled.

ASSOCIATE PROFESSOR PETER CURRIE : Individuals with muscular dystrophy undergo cycles of muscle degeneration. So what actually happens is the muscles themselves tear themselves apart upon contraction.

The disease is inevitably fatal and usually in late teens and early 20's these individuals will die from either respiratory or cardiac failure.

MARYANNE DEMASI : To help in the fight against this devastating disease, researchers believe these tranquil creatures hold the key.

Most of you would recognise these as Zebra fish - because they're commonly found in many home aquariums.

Now, they may look completely different to us, but we're more closely related than you think.

ASSOCIATE PROFESSOR PETER CURRIE : Humans are basically modified fish, so there's nothing clearer in the fossil records than the fact that we evolved from fish.

The muscles of a fish form nearly the entirety of the body-weight of a fish and they have an amazing ability to grow this muscle and it struck me that this process to make muscle must be kind of special and important in a fish and worth studying.

MARYANNE DEMASI : Peter studies their embryos to better understand the repair of human muscle.

ASSOCIATE PROFESSOR PETER CURRIE : I just fell in love with the embryo when I looked down the microscope, it's a beautifully totally optically clear embryo, rapidly developing and the orchestration of the cell movements and behaviours are just spectacular - so it was love at first sight.

MARYANNE DEMASI : He compared healthy embryos to those bred with muscular dystrophy.

MARYANNE DEMASI & ASSOCIATE PROFESSOR PETTER CURRIE : This is a dish with embryos. I'm just going to peel the egg case away from a normal embryo and what you can see is that that embryo swims around quite freely.

MARYANNE DEMASI : Oh yeah.

ASSOCIATE PROFESSOR PETER CURRIE : So now if I dissect an embryo that is mutant and doesn't have any normal muscle - you can see that embryo now fails to swim properly when released from its egg casing.

MARYANNE DEMASI : When you look closer at the muscle fibres of a zebrafish with muscular dystrophy, it's no wonder they can't swim - their muscles are literally tearing apart.

MARYANNE DEMASI : So is that what actually happens in humans with muscular dystrophy? They can't move their muscles?

ASSOCIATE PROFESSOR PETER CURRIE : Yes, a similar muscle breakdown occurs in humans and in this fish down the dish that you see there.

MARYANNE DEMASI : Peter predicted these embryos with muscular dystrophy would soon die - but to his surprise something incredible happened.

The muscles were regenerating at an amazing rate and the fish were surviving much longer than expected. He discovered the muscle's "stem cells" were the key.

ASSOCIATE PROFESSOR PETER CURRIE : Well this was the real eureka moment and the real excitement that we had we found that the stem cell populations were dividing and growing much quicker than they were in the human situation

MARYANNE DEMASI : So this might be why the zebra fish with muscular dystrophy were living longer than expected?

ASSOCIATE PROFESSOR PETER CURRIE : Exactly.

MARYANNE DEMASI : Learning how the zebra fish regenerate muscle so efficiently, will help us understand how humans can repair muscle better....and one day, may lead to a cure for muscular dystrophy.

ASSOCIATE PROFESSOR PETER CURRIE : So its quite an amazing fact I think to ponder that these little fish swimming in the tank could one day affect therapeutic strategies for a whole host of muscle wasting diseases.

BLANCH : Associate Professor Peter Currie from the Victor Chang Institute in Sydney with new research that may offer hope for those suffering from muscular dystrophy.