First transgenic mouse created to mimic Parkinson’s earliest symptoms

Washington, May 4 (ANI): Researchers have created the first transgenic mouse to display the earliest signs of Parkinson’s disease using the genetic mutation that is characteristic of human forms of the disease.

The mouse model, which expresses the same mutant proteins as human Parkinson’s patients, also displays early signs of constipation and other gastrointestinal problems that are a common harbinger of the disease in humans.

Thus, researchers at University of California, San Francisco (UCSF) have said that these animals could serve as a means of investigating therapies for reversing the neurological dysfunction of the disease at its earliest stages.

For a long time, researchers have suspected that the neurological component of Parkinson’s, which causes tremors and stiffness among other symptoms, is actually a late-stage effect of a larger, systemic problem, says Dr. Robert L. Nussbaum, senior author on the paper.

“This new model validates that theory by mimicking what we know to be the genetic pathway leading to Parkinson’s, while also displaying the earliest symptoms that occur in humans. This will give us an important tool in identifying an early intervention for this devastating disease,” said Nussbaum.

The UCSF mouse model is the first to display the full gastrointestinal symptoms as well, and is consistent with the progression of the disease in humans.

The study has been published in the latest issue of the journal, ‘Human Molecular Genetics’. (ANI)

Stem cell transplantation may correct rare genetic disorder in kids

Washington, Sep 18 (ANI): Scripps Research Institute scientists have offered new hope for parents whose children suffer from the rare genetic disorder ‘cystinosis’ by showing through an experiment on mice that stem cell transplantation can successfully correct the defect.

“After meeting the children who suffer from this disease, like an 18-year-old who has already had three kidney transplants, and the families who are desperately searching for help, our team is committed to moving toward a cure for cystinosis, a lysosomal storage disorder. This study is an important step toward that goal,” said principal investigator Stephanie Cherqui.

In the study, the researchers used bone marrow stem cell transplantation to address symptoms of cystinosis in a mouse model.

The procedure virtually halted the cystine accumulation responsible for the disease, and the cascade of cell death that follows.

Cystine is a by-product of the break down of cellular components the body no longer needs in the cell’s “housekeeping” organelles, called lysosomes.

Normally, cystine is shunted out of cells, but in cystinosis a gene defect of the lysosomal cystine transporter causes it to build up, forming crystals that are especially damaging to the kidneys and eyes.

Cystinosis is a rare but devastating disease affecting children as young as six months, who begin to suffer renal dysfunction, which grows progressively worse with time. Other symptoms include diabetes, muscular disease, neurological dysfunction, and retinopathy.

The only available drug to treat cystinosis, cysteamine, while slowing the progression of kidney degradation, does not prevent it, and end-stage kidney failure is inevitable.

In the new study, the researchers found that transplanted bone marrow stem cells carrying the normal lysosomal cystine transporter gene abundantly engrafted into every tissue of the experimental mice.

This led to an average drop in cystine levels of about 80 percent in every organ.

Not only it prevented kidney dysfunction, there was less deposition of cystine crystals in the cornea, less bone demineralization, and an improvement in motor function.

“The results really surprised and encouraged us. Because the defect is present in every cell of the body, we did not expect a bone marrow stem cell transplant to be so widespread and effective,” says Cherqui.

Cherqui said that adult bone marrow stem cell therapy is particularly well suited as a potential treatment for cystinosis because these cells target all types of tissues.

In addition, stem cells reside in the bone marrow for the duration of a patient’s life, becoming active as needed, a particular benefit for a progressive disease like cystinosis.

The study has been published in the journal Blood. (ANI)

Cats’ central nervous system can repair on its own

Washington, Mar 31 (ANI): While analysing a mysterious neurological affliction in cats, scientists have found that their central nervous system has a unique ability to repair itself and restore function.

Researchers from the University of Wisconsin-Madison have revealed that myelin restoration in cats can lead to functional recovery.

Myelin is a fatty insulator of nerve fibres that degrades in a host of human central nervous system disorders, the most common of which is multiple sclerosis.

“The fundamental point of the study is that it proves unequivocally that extensive remyelination can lead to recovery from a severe neurological disorder. It indicates the profound ability of the central nervous system to repair itself,” said Ian Duncan, the UW-Madison neuroscientist who led the research.

The finding paves the way for strategies to re-establish myelin as a therapy for treating a range of severe neurological diseases linked with the loss or damage of myelin, but where the nerves themselves remain intact.

The researchers started the study after getting intrigued by a mysterious affliction of pregnant cats that had developed severe neurological dysfunction-including movement disorders, vision loss and paralysis-via diets that had been irradiated

Taken off the diet, the cats recovered slowly, but eventually all lost functions were restored.

“After being on the diet for three to four months, the pregnant cats started to develop progressive neurological disease. Cats put back on a normal diet recovered. It’s a very puzzling demyelinating disease,” said Duncan.

Duncan said that the afflicted cats were shown to have severe and widely-distributed demyelination of the central nervous system.

Although the neurological symptoms exhibited by the cats were similar to those experienced by humans with demyelination disorders, the disease was not close to the known myelin-related diseases of humans.n cats removed from the diet, recovery was slow, but all of the previously demyelinated axons became remyelinated.

However, Duncan noted that the restored myelin sheaths were not as thick as healthy myelin.

“It’s not normal, but from a physiological standpoint, the thin myelin membrane restores function. It’s doing what it is supposed to do,” he said.

“The key thing is that it absolutely confirms the notion that remyelinating strategies are clinically important,” he added.

The study has been published in the Proceedings of the National Academy of Sciences. (ANI)