Virus a possible cause of type 1 diabetes

23 04 2015

Researchers have found a virus in the pancreas of patients with type 1 diabetes. The discovery may offer the potential for both treatment and a vaccine.

 

The dark patches are viral components in the insulin-producing cells in the islets of Langerhans. Photo: DiViD.

Type 1 diabetes affects children and adolescents. The pancreas stops producing insulin. High blood glucose levels can lead to serious complications such as heart attack, stroke, vision loss, kidney failure and foot amputation.

Daily treatment involving multiple finger-prick blood tests to monitor glucose levels, four to six insulin injections or the use of an insulin pump, all put a great strain on the patient.

Unlike type 2 diabetes, it is not possible to regulate this form of diabetes by exercise or changes in diet. Only 29 per cent of patients achieve the recommended treatment goals that prevent complications.

For many years it has been suspected that a virus is a possible cause of type 1 diabetes. A new study has found a virus present in the pancreas of individuals who have recently been diagnosed with this type of diabetes.

The study was headed by Professor Knut Dahl-Jørgensen at the Faculty of Medicine, UiO, in collaboration with Lars Krogvold, research fellow at UiO and consultant paediatrician at Oslo University Hospital.

 

Professor Knut Dahl-Jørgensen at the University of Oslo heads the research group which is behind the discovery of a virus in the pancreas. Photo: UiO.

Common virus in an uncommon place

The researchers identified viral components in the insulin-producing cells in the islets of Langerhans.

The islets of Langerhans are hormone-producing groups of cells in the pancreas.

The virus that has been detected is in the group of enteroviruses.

Professor Dahl-Jørgensen explains:

“This is a type of virus that occurs frequently among the population. It can cause colds and stomach bugs but also serious infections in the brain and heart, for example”.

Enterovirus is normally found in the intestines and respiratory tract. In individuals with a genetic predisposition the virus has the ability to cause chronic infections.

“It is this type of infection that we have now identified in the insulin-producing cells in the pancreas”, says Dahl-Jørgensen.

 

Lars Krogvold, consultant paediatrician at OUS and research fellow at UiO. Photo: Private.

Vaccine and treatment

The next step will be to try to develop a vaccine.

The work will be done in an EU project in collaboration with two pharmaceutical companies which specialize in developing vaccines. The project will be headed by collaborative partners in Finland.

Lars Krogvold explains, “Producing new vaccines is a very slow business and extremely expensive. We have to make sure the vaccine is both safe and effective for patients and that adverse effects are minimized”.

The process usually takes more than five years, Krogvold adds.

New drugs to treat viral infections are constantly being developed. The hope is to start a project based on patients with newly diagnosed diabetes.

If those plans are realized, as early as next year patients could be participating in a clinical trial to test a combination of a new drug and a well-known drug.

“Our hope is that this can stop the destruction of the insulin-producing cells, and preserve the body’s residual insulin production capability. That will lessen the seriousness of the disease.

Insulin-producing cells have the ability to regenerate, so if we are very lucky some patients may be able to stop insulin therapy completely”, says Krogvold.

 

New research based on existing theory

An increase in the number of cases of type 1 diabetes was discovered in Norway after a viral epidemic. The number of new cases of type 1 diabetes is highest in the autumn and winter, when we have most virus infections.

Some years ago, researchers found a virus in the pancreas of a child who died of diabetes. Since then, signs of the virus have been identified in the blood of diabetes patients with greater frequency than in healthy individuals.

 

Earlier lack of evidence

“A virus consists of genetic material surrounded by a protein shell or capsid. We have detected specific proteins from the capsid by immunostaining tissue samples using special antibodies aimed at these proteins. Most importantly, we have also found the genetic material RNA, which is exclusively specific for this type of virus. In addition, changes have been found in genes that are involved in fighting viruses”, says Krogvold.

““Hitherto there were only indirect indications that a virus could trigger type 1 diabetes. We had no evidence to show that the virus is actually in the insulin-producing cells. To be able to say with certainty that diabetes is caused by a virus, the virus must be identified in the morbid cells, which is what we have done. We also have to show that antiviral treatment or vaccines help to remove it.”.

“If this is possible, we may be able to stop the process at an early stage and prevent the disease having such a serious progression, or preferably prevent it from arising in the first place”, says Dahl-Jørgensen in conclusion.

 

Reference

Lars Krogvold, et al. Detection of a low-grade enteroviral infection in the islets of Langerhans of living patients newly diagnosed with type 1 diabetes. American Diabetes Association, November 2014.

By Thomas Olafsen, information officer at UiO.

Published Dec 5, 2014 01:51 PM – Last modified Mar 23, 2015 12:58 PM

 

 

Med.uio.no [en línea] Oslo (NOR): med.uio.no, 23 de abril de 2015 [ref. 05 de diciembre de 2014] Disponible en Internet: http://www.med.uio.no/klinmed/english/research/news-and-events/news/2014/virus-possible-cause-of-type-1-diabetes.html

 



Simple and strong predictor of diabetes risk found

17 11 2014

McMaster University researchers have discovered a simple way to predict an adult’s future risk of developing Type 2 diabetes.

The study, published in the journal Diabetologia, found that the blood glycaemia level at one hour after drinking a glucose solution of 75 grams beats every known Type 2 diabetes prediction model published to date.

From left: David Meyre, associate professor, Department of Clinical Epidemiology and Biostatistics, and Akram Alyass, a PhD student in computational science at McMaster

 

“Having the one-hour plasma glucose (1h-PG) information alone is sufficient to identify people who are more at risk for developing Type 2 diabetes in the future,” said David Meyre, the paper’s senior author and an associate professor in the Department of Clinical Epidemiology and Biostatistics at McMaster’s Michael G. DeGroote School of Medicine. “Only 30% of non-diabetic middle-aged adults in the study displayed a high 1h-PG (higher than 8.9 mmol/l), but they accounted for 75% of all future diabetic cases”.

“This measurement, known as one-hour plasma glucose (1h-PG), may help to identify high-risk subjects in the general population for inclusion in Type 2 diabetes prevention programs.”

He added that such prevention programs, if applied on a global scale, may save billions of dollars and improve the lives of millions of people.

This is important as the prevalence of Type 2 Diabetes has more than doubled globally over the past 30 years, and the rate of death among patients with diabetes is about twice as high as among those without it. Problems related to the disease include blindness, heart attacks, kidney disease and infections leading to amputations.

Meyre added: “Applying mass screening programs in populations and enrolling people at risk in a simple and inexpensive lifestyle modification program, in cooperation with the family doctor, may prevent up to half of future Type 2 diabetes cases.

“Another exciting perspective worth investigating is whether 1h-PG predicts future complications of Type 2 diabetes.”

Using new mathematical methods to capture data on nearly 5,000 northern Europeans from two independent longitudinal studies, the researchers found that 1h-PG alone outperformed the popular but more complicated prediction models based on multiple clinical risk factors, including age, sex, body mass index and family history of diabetes.

The research team, which included colleagues from McMaster and universities in Lund, Sweden, and Helsinki, Finland, wrote that the value of the 1h-PG for Type 2 diabetes prediction in multi-ethnic longitudinal studies still needs to be assessed because the rate of the disease varies by ethnicity. However, they are fairly confident in the transferability of their results to other populations.

“Colleagues from the University of Texas recently reported that one-hour plasma glucose was predictive of future Type 2 diabetes risk in Mexican Americans and this is encouraging,” said Akram Alyass, the study’s first author and a PhD student in computational science at McMaster.

The study was funded by several research foundations, hospitals and universities in Finland and Sweden. Meyre holds a Canada Research Chair in Genetic Epidemiology.

 

Study article: Modelling of OGTT curve identifies 1 h plasma glucose level as a strong predictor of incident type 2 diabetes: results from two prospective cohorts (Diabetologia)


 

Fhs.mcmaster.ca [en línea] Hamilton, ON (CAN): fhs.mcmaster.ca, 17 de noviembre de 2014 [ref. 14 de octubre de 2014] Disponible en Internet: http://fhs.mcmaster.ca/main/news/news_2014/predictor_of_diabetes_risk_study.html



Some saturated fatty acids may present a bigger risk to diabetes than others

14 08 2014

The relationship between saturated fat and type 2 diabetes may be more complex than previously thought, according to the results of a large international study published today in the journal Lancet Diabetes and Endocrinology. The study found that saturated fatty acids can be associated with both an increased and decreased risk of developing the disease, depending on the type of fatty acids present in the blood.

The results add to the growing debate around the health consequences of fat, and could partially explain evidence from recent studies that suggests some foods high in saturated fats, such as dairy products, could actually lower the risk of type 2 diabetes.

 

Saturated fat is typically found in foods with a high proportion of animal fat, such as butter, cheese and red meat, and in fried foods. It is made up of chains of individual fat molecules (fatty acids) that vary in length, depending on how many carbon atoms they contain. These saturated fatty acids have long been considered detrimental to health, and current recommendations suggest they should make up no more than 10 per cent of the calories we eat. However, the role of saturated fat in type 2 diabetes risk is unclear.

 

Our findings provide strong evidence that individual saturated fatty acids are not all the same

-Nita Forouhi

 

In the EPIC-InterAct Study, which was funded mainly by the European Commission under its Framework 6 programme, a team of researchers led by the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge set out to examine the relationship between blood levels of nine different saturated fatty acids and the risk of developing type 2 diabetes in later life.

 

The researchers looked at 12,403 people who developed type 2 diabetes from among a group of 340,234 adults across eight European countries. Using a sophisticated method of high-speed blood analysis, developed especially for the project by researchers at MRC Human Nutrition Research, they determined the proportion of each of the nine fatty acids in blood samples from the study participants and related this with later incidence of type 2 diabetes.

 

They found that saturated fatty acids with an even number of carbon atoms in their chain (14, 16 and 18 carbon atoms) were associated with a higher risk of type 2 diabetes, while saturated fatty acids with an odd number (15 and 17) were associated with a lower risk.

 

Lead scientist Dr Nita Forouhi, from the MRC Epidemiology Unit at the University of Cambridge, said: “Our findings provide strong evidence that individual saturated fatty acids are not all the same. The challenge we face now is to work out how the levels of these fatty acids in our blood correspond to the different foods we eat.

 

“These odd-chain saturated fatty acids are well-established markers of eating dairy fats, which is consistent with several recent studies, including our own, that have indicated a protective effect against type 2 diabetes from eating yoghurt and other dairy products. In contrast, the situation for even-chain saturated fatty acids is more complex. As well as being consumed in fatty diets, these blood fatty acids can also be made within the body through a process which is stimulated by the intake of carbohydrates and alcohol.”

 

The authors therefore conclude that it is too early to make any direct dietary recommendations on the basis of this work.

 

Professor David Lomas, Chair of the MRC’s Population and Systems Medicine Board, added: “Type 2 diabetes has serious consequences for health and healthcare costs, and its numbers are rising in all world regions. Identifying new ways to not only treat, but prevent the condition are therefore vital. This research arising from 26 research institutions across Europe is an example of the power of international collaboration to generate larger and more reliable studies. By combining large-scale population data with advanced laboratory analysis, this research has delivered a compelling case to look more closely at the contribution of individual components of fat to health and disease.”

 

 

 

Cam.ac.uk [en línea] Cambridge (UK): cam.ac.uk, 14 de agosto de 2014 [ref. 06 de agosto de 2014] Disponible en Internet: http://www.cam.ac.uk/research/news/some-saturated-fatty-acids-may-present-a-bigger-risk-to-diabetes-than-others



Regeneran tejido del tiroides con células madre embrionarias de ratones

28 02 2013

A partir de células pluripotentes de embriones de roedores, un equipo científico ha logrado crear in vitro folículos tiroideos que, una vez trasplantados, han demostrado ser funcionales. Los resultados, publicados en Nature, podrán servir para aplicar la medicina regenerativa al tratamiento del hipotiroidismo.

 

Tinción de yodo (verde) expresado por los folículos tiroideos obtenidos in vitro a partir de células madre embrionarias de ratón. Imagen: S. Costagliola

Tinción de yodo (verde) expresado por los folículos tiroideos obtenidos in vitro a partir de células madre embrionarias de ratón. Imagen: S. Costagliola

Un grupo de investigadores de centros belgas y estadounidenses ha logrado por primera vez convertir células madre embrionarias de ratones en células del tiroides y formar con ellas tejidos que, una vez trasplantados en roedores, fueron capaces de cumplir su misión de regular los niveles hormonales del animal.

Lo más relevante del estudio es que “las células foliculares derivadas de las células madre embrionarias generaron tejido del tiroides capaz de recuperar los déficits hormonales de los animales”.

Se abre así una vía a la aplicación de tecnologías basadas en células madre para tratar el hipotiroidismo –la enfermedad endocrina congénita más común en humanos, que afecta a uno de cada 2.000 recién nacidos–, un área de estudio que, hasta el momento, ha recibido poca atención por parte de la medicina regenerativa.

La principal función de la glándula tiroidea es metabolizar yodo sintetizando hormonas que regulan el crecimiento, desarrollo y metabolismo de casi todos los tejidos.

En el caso de los mamíferos, esta glándula se compone de dos tipos de células endocrinas: las células foliculares tiroideas –que segregan dos hormonas, la tiroxina y la triyodotironina– y las células C, que segregan calcitonina.

Sabine Costagliola, de la Universidad Libre de Bruselas, y sus colegas crearon un protocolo con el que generar células foliculares del tiroides a partir de células madre embrionarias, gracias a la sobreexpresión de solo dos factores de transcripción –proteínas que participan en la expresión de los genes–.

En el paso siguiente aplicaron a las nuevas células foliculares un tratamiento con hormona tirotrofina –un fármaco utilizado para tratar el cáncer de tiroides–. La tirotrofina estimuló a las células a formar tejidos tridimensionales, es decir, se obtuvieron folículos creados in vitro.

Por último, cuando se trasplantaron los folículos en ratones con hipotiroidismo, los animales recuperaron sus niveles hormonales, lo que implica que los tejidos tiroideos derivados de las células madre cumplieron con su función.

 

Referencia bibliográfica:

Francesco Antonica, Dominika Figini Kasprzyk, Robert Opitz, Michelina Iacovino, Xiao-Hui Liao, Alexandra Mihaela Dumitrescu, Samuel Refetoff, Kathelijne Peremans, Mario Manto, Michael Kyba, Sabine Costagliola. “Generation of functional thyroid from embryonic stem cells”. Nature. doi:10.1038/nature11525. Vol. 490. 10 de octubre de 2012.

 

 

Agenciasinc.es [en línea] Madrid (ESP): agenciasinc.es, 28 de febrero de 2013 [ref. 10 de octubre de 2012] Disponible en Internet: http://www.agenciasinc.es/Noticias/Regeneran-tejido-del-tiroides-con-celulas-madre-embrionarias-de-ratones



Weight Loss Surgery May Not Combat Diabetes Long-Term

17 12 2012

Weight loss surgery, which in recent years has been seen as an increasingly attractive option for treating Type 2 diabetes, may not be as effective against the disease as it was initially thought to be, according to a new report. The study found that many obese Type 2 diabetics who undergo gastric bypass surgery do not experience a remission of their disease, and of those that do, about a third redevelop diabetes within five years of their operation.

Stuart Bradford

Stuart Bradford

The findings contrast with the growing perception that surgery is essentially a cure for Type II diabetes. Earlier this year, two widely publicized studies reported that surgery worked better than drugs, diet and exercise in causing a remission of Type 2 diabetes in overweight people whose blood sugar was out of control, leading some experts to call for greater use of surgery in treating the disease. But the studies were small and relatively short, lasting under two years.

The latest study, published in the journal Obesity Surgery, tracked thousands of diabetics who had gastric bypass surgery for more than a decade. It found that many people whose diabetes at first went away were likely to have it return. While weight regain is a common problem among those who undergo bariatric surgery, regaining lost weight did not appear to be the cause of diabetes relapse. Instead, the study found that people whose diabetes was most severe or in its later stages when they had surgery were more likely to have a relapse, regardless of whether they regained weight.

“Some people are under the impression that you have surgery and you’re cured,” said Dr. Vivian Fonseca, the president for medicine and science for the American Diabetes Association, who was not involved in the study. “There have been a lot of claims about how wonderful surgery is for diabetes, and I think this offers a more realistic picture.”

The findings suggest that weight loss surgery may be most effective for treating diabetes in those whose disease is not very advanced. “What we’re learning is that not all diabetic patients do as well as others,” said Dr. David E. Arterburn, the lead author of the study and an associate investigator at the Group Health Research Institute in Seattle. “Those who are early in diabetes seem to do the best, which makes a case for potentially earlier intervention.”

One of the strengths of the new study was that it involved thousands of patients enrolled in three large health plans in California and Minnesota, allowing detailed tracking over many years. All told, 4,434 adult diabetics were followed between 1995 and 2008. All were obese, and all underwent Roux-en-Y operations, the most popular type of gastric bypass procedure.

After surgery, about 68 percent of patients experienced a complete remission of their diabetes. But within five years, 35 percent of those patients had it return. Taken together, that means that most of the subjects in the study, about 56 percent — a figure that includes those whose disease never remitted — had no long-lasting remission of diabetes after surgery.

The researchers found that three factors were particularly good predictors of who was likely to have a relapse of diabetes. If patients, before surgery, had a relatively long duration of diabetes, had poor control of their blood sugar, or were taking insulin, then they were least likely to benefit from gastric bypass. A patient’s weight, either before or after surgery, was not correlated with their likelihood of remission or relapse.

In Type 2 diabetes, the beta cells that produce insulin in the pancreas tend to wear out as the disease progresses, which may explain why some people benefit less from surgery. “If someone is too far advanced in their diabetes, where their pancreas is frankly toward the latter stages of being able to produce insulin, then even after losing a bunch of weight their body may not be able to produce enough insulin to control their blood sugar,” Dr. Arterburn said.

Nonetheless, he said it might be the case that obese diabetics, even those whose disease is advanced, can still benefit from gastric surgery, at least as far as their quality of life and their risk factors for heart disease and other complications are concerned.

“It’s not a surefire cure for everyone,” he said. “But almost universally, patients lose weight after weight loss surgery, and that in and of itself may have so many health benefits.”

 

Well.blogs.nytimes.com [en línea] New York (USA): well.blogs.nytimes.com, 17 de diciembre de 2012 [ref. 28 de noviembre de 2012] Disponible en Internet: http://well.blogs.nytimes.com/2012/11/28/weight-loss-surgery-may-not-combat-diabetes-long-term/?ref=health