Bone and Intestinal Disease May Have Common Cause , source:PakTribune News Wire Service

Bone and Intestinal Disease May Have Common Cause
Thursday December 28, 2006 (0045 PST)

ISLAMABAD: In studies with mice, scientists have found evidence that osteoporosis-like bone disorders and inflammatory intestinal disorders are both caused by the abnormal regulation of a common protein.
Dr. Simon R. Carding from the University of Leeds in England and colleagues report their study in the December issue of the journal Immunity.
Autoimmune-related bone disease and intestinal inflammation are closely linked with the deregulation and the hyperactivation CD4 T cells, which are involved in the body`s defense system, or immune response, they report. "How these T cells are activated and mediate disease is not clear."
Mice that were genetically engineered to lack a key regulator of CD4 T cells have overactive T cells and spontaneously develop ulcerative colitis and the loss of bone cells, the scientists explain. Carding and colleagues` experiments indicate that this is caused by increased production of a protein called RANKL.
"We find that the hyperactive CD4 T cells produce too much of this protein, which then contributes to bone breakdown and bowel inflammation," Carding said.
Treating mice with osteoprotegerin, a protein that prevents RANKL from binding to its receptor, reversed this bone loss and improved colitis. "This study shows that some bone diseases and intestinal problems may share a common cause," Carding told.
"If similar mechanisms occur in humans, then osteoprotegerin might prove a useful treatment for intestinal disorders such as ulcerative colitis and Crohn`s disease," he said, which are both often accompanied by bone loss.
End.

A more tolerant immune system?? The future for autoimmune diseases?

Montana State University researchers have found a new way to fool the immune system into becoming more tolerant.David Pascual, MSU professor of veterinary molecular biology, said the process will let people tolerate instead of over-react to certain antigens. Antigens are foreign substances that cause the immune system to respond, but some immune systems respond too strongly.The discovery is good news for people with allergies, autoimmune diseases and inflammatory diseases like arthritis and multiple sclerosis, Pascual said. The discovery will let people use a nasal spray or take a pill to keep their bodies from overreacting to specific antigens. Their immune system will become non-responsive instead of producing allergic reactions or painful inflammations."We are pretty excited about it," said Pascual who noted that MSU has been working on the project for five years. The biotechnology is available now to companies or entrepreneurs that want to license it and develop it further.The key to the biotechnology is a protein that can be fused to a broad range of antigens, Pascual said. By fusing the protein to a specific antigen, researchers can target diseases. The approach is effective at extremely low doses, Pascual said. In some cases, tolerance is produced after only one dose.MS is one of many diseases that the new biotechnology could target. Becky Wiehe, regional program manager for the Montana Division, All America Chapter, National Multiple Sclerosis Society, said she is encouraged every time she hears about research projects that can help people with MS. She didn't used to hear such reports."There are many investigations in the research pipeline," Wiehe said. "That, to me, is exciting. It suggests we have new places to go, and we will get there."At least 1,600 Montanans have multiple sclerosis, and much about the neurological disease of the brain and spinal cord is a mystery, Wiehe continued. Common symptoms are fatigue, tingling, numbness, and inflammation of the nerve to the eye, but symptoms come and go unpredictably in many people. Montana also has a relatively high number of cases which are related, it seems, to genetic tendencies and the state's distance from the equator.MS becomes more common the farther you are from the equator, Wiehe said, theorizing that, "It might be a viral issue in colder climates."She added that Montana's level of MS is comparable to those in other states and countries along the 48th parallel. She said it might also reflect the large number of Montanans whose ancestors came from Scandinavia and Norway. Those areas have MS levels similar to Montana's . www.aarda.org

Systemic Lupus Erythematosus : Safety concern regarding Rituxan in systemic lupus erythematosus

The Food and Drug Administration (FDA) is alerting health care professionals and patients treated with Rituxan (rituximab) to reports of an emerging risk of a serious side effect in patients receiving or who have used Rituxan.
Read more
FDA recently learned that two patients who were treated with Rituxan for systemic lupus erythematosus (SLE) developed progressive multifocal leukoencephalopathy (PML), a fatal viral infection of the central nervous system. This side effect has been reported in patients as late as 12 months after their last dose of Rituxan.SLE is not an approved indication for Rituxan. Rituxan is approved only for the treatment of patients with non-Hodgkin's lymphoma and patients with rheumatoid arthritis whose disease no longer responds to other common treatments. "Rituxan is used in both approved and off-label settings, and therefore it is very important for prescribers as well as patients to be aware of these new reports of the risk of PML," said Dr. Steven Galson, director of FDA's Center for Drug Evaluation and Research. "Patients who are being treated or have been treated with Rituxan who experience any major changes in vision, balance, or coordination, or who experience confusion, should promptly call their doctor."

Type 1 Diabetes May Be Caused By Disruption of Link Between Nerve Cells and Beta Cells

New York, NY, December 15, 2006 — Researchers in Canada have found evidence in mice that the autoimmune attack causing type 1 diabetes may be triggered by abnormal nerve endings in the pancreatic beta cells. The scientists found that in mice that usually develop type 1 diabetes spontaneously, removing these defective nerve endings prevented the mice from contracting the disease. The study was led by Hans Michael Dosch, a scientist at the Hospital for Sick Children in Toronto, and published in the latest issue of the journal Cell.The researchers identified a “control circuit” between islet cells and the sensory nerves surrounding them. The nerve cells normally produce a neuron-peptide that keeps this circuit functioning. But since defective neurons can’t produce the substance, the circuit is disrupted. This led to inflammation around the islets and eventually to their destruction—and type 1 diabetes in the mice. Conversely, the researchers found that infusing the animals with the neuron-peptide actually reversed early diabetes.This is an intriguing finding that could lead to increased focus on the role nerve cells play in the initiation of type 1 diabetes. It has long been assumed that the misguided autoimmune attack that causes type 1 diabetes is aimed at pancreatic beta cells from the very beginning. But the new findings suggest that the connection between nerve cells and beta cells is where the disease process begins. (The new research is preliminary and was conducted in mice, so it is far from certain whether human type 1 diabetes is triggered by the same events.)If research in humans supports these findings, it could provide a possible new therapeutic target for diabetes prevention and a strategy for diagnostic tests to detect diabetes risk earlier. It also could offer a way to produce conditions that allow beta cell regeneration. And it would shed light on a possible link between type 1 diabetes and autoimmune attacks on nervous tissue.Although JDRF did not fund the new study in Cell, it supported earlier research by Dr. Dosch into a possible connection between nerve cells and type 1 diabetes. In 2003, Dr. Dosch and colleagues found that the autoimmune destruction in type 1 diabetes was not limited to beta cells, but destroyed nerve cells as well. JDRF funded that research, which was published in Nature Medicine, and the human islets used were provided by a JDRF research center in Pittsburgh.

DENDRITIC CELLS OFFER NEW THERAPEUTIC TARGET FOR DRUGS TO TREAT MS AND OTHER AUTOIMMUNE DISEASE

Scientists at the Johns Hopkins Kimmel Cancer Center have found that a gene pathway linked to a deadly form of leukemia may provide a new way to treat autoimmune diseases, including multiple sclerosis. Their tests in cell cultures and mice suggest that blocking the pathway by interfering with a blood cell growth gene, known as FLT3, targets an immune system cell often ignored in favor of T-cell targets in standard therapies.
FLT3, which controls the development of healthy blood cells, was identified as a treatment target in patients with acute myeloid leukemia, a blood cell cancer, several years ago by the same Johns Hopkins investigators. In the current work, the Hopkins team has confirmed that the gene is activated in dendritic cells, whose role is to distribute "look here" information about unwanted foreign invaders to soldiering T-cells.
"Someday, using a drug to block FLT3 gene signaling could stop dendritic cells from triggering harmful responses against a patient's own body," says Donald Small, M.D., Ph.D., professor at the Johns Hopkins Kimmel Cancer Center, whose findings appear in the November 15 issue of the Proceedings of the National Academy of Sciences. Preliminary clinical tests in people with autoimmune diseases with just such a drug could begin in the next year, Small said.
A characteristic of autoimmune diseases is that patients' immune T-cells mistake normal cells in the body for foreign ones. Current therapies, such as steroids, are designed to suppress T-cell responses. But the Hopkins investigators believe that targeting dendritic cells may stop the faulty immune response at a higher "upstream" level since T-cells frequently receive their information from dendritic cells.
Testing their idea, Small and his Hopkins colleague Katherine Whartenby used an experimental compound called CEP-701, already known to block actions of the growth-promoting FLT3 gene, on human dendritic cells and in mice engineered to mimic multiple sclerosis, a disease that causes T-cells to destroy the myelin protein sheath around nerves in the central nervous system. The drug had a similar effect on dendritic cells, causing most of them to die. In the mouse model, investigators found that more of the myelin sheath was preserved in mice treated with CEP-701 than those not treated.
Small cautions that massive die-off of dendritic cells poses a possible risk of immune system suppression, a condition that could leave patients vulnerable to infections or other diseases. "But our studies show that though many dendritic cells were destroyed, some still remained," he said.
Their tests also revealed that mice infected with a potent bacterium survived after treatment with CEP-701. This research was funded by the National Institutes of Health.
Additional authors include Peter A. Calabresi, Erin McCadden, Bao Nguyen, David Kardian, Tianhong Wang, Claudio Mosse and Drew M. Pardoll from Johns Hopkins.
Whartenby, K. et al, Inhibition of FLT3 signaling targets DCs to ameliorate autoimmune disease, PNAS 102:46:16741-16746.
# # #

Protalex Lead Compound, PRTX-100, Inhibits Platelet Phagocytosis In Vitro

Data Presented at American Society of Hematology Conference

NEW HOPE, Pa.--(BUSINESS WIRE)--Protalex, Inc. (OTCBB: PRTX) announced today that it has unveiled pre-clinical data showing that PRTX-100, the company’s lead compound in development for various autoimmune disorders, inhibits the phagocytosis (ingestion) of platelets in vitro. The data from the study entitled, PRTX-100 Inhibits Platelet Phagocytosis In Vitro, were presented Saturday, December 9, 2006, by Chris Yatko, Research Scientist at Protalex, at the American Society of Hematology’s 48th Annual Meeting and Exposition in Orlando, Florida. Platelet phagocytosis is the effector limb of Idiopathic Thrombocytopenic Purpura (ITP), a rare blood-clotting disorder. As such, the results of the study indicate the potential of PRTX-100 for the treatment of patients with ITP.
“Prevention of platelet phagocytosis is an important step in the treatment of ITP. This study confirms our belief that PRTX-100 may be a promising therapy for this indication and we look forward to continued development of this compound,” said Steven H. Kane, President and Chief Executive Officer of Protalex.
About Idiopathic Thrombocytopenic Purpura (ITP)
ITP is an autoimmune disease in which platelets are misidentified as foreign objects by the immune system and are subsequently targeted for elimination. Normal proteins found on the surface of the platelets act as antigens in ITP-affected patients, thus signaling the body’s white blood cells to remove the platelets from the bloodstream. As a result, patients with ITP have an abnormally low platelet count, ranging from zero (most severe) to about 100,000 per cu/ml of blood (milder case). A healthy person usually has a platelet count of between 150,000 and 400,000 per cu/ml of blood. A count of 30,000 is generally considered safe (i.e., protecting against spontaneous bleeding). Patients with ITP therefore often bruise easily, suffer from bleeding gums as well as nosebleeds, gingival, gastrointestinal, and/or central nervous system bleeding.
Two types of ITP exist: (1) Acute ITP, usually lasting less than six months and mainly occurring in children, typically caused by a viral infection (often not requiring treatment and not recurring), and; (2) Chronic ITP, which is longer-term and chiefly affects adults, specifically women over 40 years of age.
According to the Platelet Disorder Support Association, ITP currently affects approximately 200,000 people in the U.S., with women suffering from the disorder at a rate about 3 times greater than men. About 50% of new cases occur in children and roughly 30,000 new cases occur annually. At present, there is no known cure and only a limited number of treatments are available, including chemotherapy, various biologics, hormones, small molecule immunosuppressants or splenectomy. Corticosteroids are currently the standard first-line therapy, however, these are associated with significant short- and long-term side effects, including swelling of the face, neck, and/or shoulders, fluid retention, heartburn, osteoporosis, premature atherosclerosis, cataracts, glucose intolerance, thinning of the skin and increased risk of infections, among others.
About PRTX-100
PRTX-100 is a highly-purified form of Staphylococcal Protein A. PRTX-100 binds directly to monocytes and a subset of B-cells that are involved in the development and progression of various autoimmune diseases, enabling the compound to modulate the function of these cells and restore the balance of the immune system.