diabetes Archives - Sanford Burnham Prebys
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A new approach to restore insulin production in diabetes

AuthorSusan Gammon
Date

May 23, 2018

If you have diabetes, there is a strong chance you are either on insulin therapy now, or will be in the future. This holds true for people with Type 1 and Type 2 diabetes; both types lead to elevated blood glucose levels.

Insulin therapy maintains blood glucose at healthy levels to prevent the complications that come with diabetes, such as vision problems, kidney disease, neuropathy, heart disease—and the list goes on.

Insulin is usually administered under the skin using a syringe, insulin pen or insulin pump. But scientists are working to change that.

Fred Levine, MD, PhD, a scientist at SBP, has been working on methods to restore pancreatic beta cells—the cells that live in pancreatic islets and store and secrete insulin.

In Type 1 diabetes—an autoimmune disease—beta cells are destroyed by the immune system. In Type 2 diabetes, beta cells gradually lose their ability to produce insulin. “Regenerating insulin-producing beta cells could potentially free millions of patients from daily doses of insulin,” says Levine.

Levine’s initial work, published in two papers in Stem Cells and Cell Death and Disease, began with an observation that injuring the pancreas of diabetic mice causes alpha cells to convert to convert to insulin-producing beta cells. Alpha cells are also located in pancreatic islets but don’t normally produce insulin.

“There was a signal coming from the injured pancreas driving the conversion of alpha cells to beta cells—a process known as transdifferentiation—and we wanted to know what that signal was,” says Levine.

Levine’s next study found that the activation of PAR2, a receptor on alpha cells, was driving the transition to insulin-producing beta cells. That research was published in a later paper Cell Death and Disease.

“This was a good step toward understanding how to restore beta cells, and there are good drug candidates that can activate PAR2, so it could work in humans,” says Levine. “But there was still hurdle. The transdifferentiation process only occurs in the setting of profound beta cell deficiency—there had to be practically zero functional beta cells for alpha cells to convert.”

Most people with Type 2 diabetes and a smaller percentage with Type 1 have some, but not enough, functional beta cells. For these patients, activating PAR2 alone wouldn’t be a sufficient to treat diabetes. Levine’s group hypothesized that there must be an inhibitory signal coming from beta cells preventing the process.

In the latest study, published in Islets, Levine’s research team found that insulin is the inhibitory signal that prevents transdifferentiation.

“It makes sense that insulin inhibits transdifferentiation, because why would your body generate beta cells if you already had a significant number of cells producing insulin,” says Levine. “But biology isn’t perfect, hence the need for insulin therapy.”

“We were able to work around these obstacles and generate insulin-producing beta cells by using a combination of drugs, one that activates PAR2 (2fLI), and two that inhibit insulin secretion and action (diazoxide and S961). It’s a two element process—one which is positively acting on alpha cells and the other repressive of beta cells,” explains Levine.

“Our research offers the prospect of a straightforward pharmacological approach to regenerate insulin-producing cells to treat diabetes,” says Levine. “For Type 2 diabetes, we could potentially drive transdifferentiation in vivo by activating PAR2 and inhibiting insulin for a short term. It could result in restoration of long-term beta cell function.

“For Type 1 diabetes, we would still need to address the autoimmune aspect of the disorder, because new beta cells would continue to be attacked by the immune system,” adds Levine. “But as our understanding and ability to rein in the autoimmune system improves, the approach could be a much needed breakthrough for the disease.”

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SBP welcomes Congresswoman Susan Davis

AuthorSusan Gammon
Date

May 4, 2018

Susan Davis, U.S. Representative for California’s 53rd congressional district (D-San Diego), visited our Institute in April and met with several members of the faculty and SBP President Kristiina Vuori, MD, PhD  Davis, a strong advocate for increasing the NIH budget to advance scientific discoveries, has a long history of supporting initiatives on diabetes and cardiovascular health.

Davis was following up on an invitation for a tour of our campus from Chris Larson, PhD, vice president, drug discovery at SBP. Larson sits on the Board of Directors for the Southern California Chapter of the American Diabetes Association and meets regularly with Davis regarding issues related to diabetes care and research.

Pamela Itkin-Ansari, PhD, adjunct professor at SBP met with Davis and shared her research on implanting small encapsulation devices that contain pancreatic islet cells as an approach to treat type 1 (juvenile) diabetes. The work has now progressed to international clinical trials, which impressed Rep. Davis.

As a teenager, Davis worked as a counselor at a camp for diabetic children—most of whom have type 1 diabetes.  The experience led to a lifelong interest in improving the health and welfare of diabetic patients, both type 1 and type 2.

“Congresswoman Davis’ visit went really well,” says Larson, who organized a tour of the Prebys Center, showcasing the high-throughput drug discovery capabilities of the facility. “She was especially keen to learn how our automated technology can screen hundreds of thousands of chemical compounds to find future drugs.

“It was an honor to host Congresswoman Davis, and she and her staff are most welcome to visit anytime,” says Larson.

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Are artificial sweeteners bad for your health?

AuthorJessica Moore
Date

October 25, 2016

These days, we’re fighting a war on sugar, and it might seem like we’re winning. Low-calorie, artificial sweeteners are added to 15% of the volume of foods and beverages purchased in the United States.1 And they’re in all sorts of products labeled “light” or “no added sugar,” from soda to yogurt to protein bars. By replacing sugar, they’re meant to help consumers take in fewer calories. But epidemiological data suggest they may do the opposite, elevating the risk of health problems like type 2 diabetes and cardiovascular disease. 

“Artificial sweeteners were approved for consumption by the U.S. Food and Drug Administration because they’re non-toxic and don’t cause cancer at the recommended daily intake,” said George Kyriazis, PhD, assistant professor in the Integrative Metabolism Program, who recently presented evidence of their possible health risks during a public lecture at the University of Central Florida. “But we’re only now figuring out whether and how they may affect metabolism.”

The potential impact of artificial sweeteners, including sucralose, aspartame, saccharin and acesulfame potassium, on American health could be huge. In large studies following the same group of people over 10-20 years, those who drank at least one artificially sweetened beverage every day were 40% to 60% more likely to develop type 2 diabetes or suffer a heart attack or stroke as those who didn’t.2 The jump in relative risk is roughly the same as that with one or more regular sugary sodas.

Why is consumption of low-calorie sweeteners associated with all these problems if they’re not metabolized by our cells? Kyriazis thinks a potential mechanism lies in their ability to activate sweet taste receptors, the focus of his research. Sweet taste receptors, despite their name, are actually found in many organs, including the intestine and pancreas, where they regulate sugar uptake and secretion of sugar-regulating hormones, respectively.

Kyriazis has shown that sweet taste receptors are essential for artificial sweeteners to wreak havoc on metabolism. For example, adding saccharin to the water of normal mice for a few months causes them to become pre-diabetic, but mice lacking sweet taste receptors are protected from this condition. Whether this is also true in humans is unknown, but Kyriazis is leading a proof-of-concept clinical study at the Translational Research Institute for Metabolism and Diabetes at Florida Hospital that will begin recruiting soon.

“We will give healthy participants an FDA-approved food additive that inhibits sweet taste receptors and see if it can prevent any of the anticipated negative metabolic effects of saccharin consumption,” Kyriazis explained. “These studies could further our understanding of the role of sweet taste receptors in metabolic disease, which will help determine their validity as a target for future drug development.”

 

References:

  1. Ng SW, Slining MM, Popkin BM. Use of caloric and noncaloric sweeteners in US consumer packaged foods, 2005–2009. J Acad Nutr Diet 2012.
  2. Swithers SE. Artificial sweeteners produce the counterintuitive effect of inducing metabolic derangements. Trends Endocrinol Metab 2013. Table 1, refs 25, 26, 30.
Institute News

The science of crowdfunding

Authorkcusato
Date

March 3, 2016

He doesn’t need money to produce an album. He’s not raising funds to start a new business in his hometown. And he’s not asking for cash because he’s a famous rapper who suddenly finds himself “bankrupt.” He is a young scientist who needs money to conduct research aimed to save lives, so he is turning to crowdfunding.

Joseph Lancman, PhD, is a scientist in the organogenesis lab of Duc Dong, PhD, at Sanford Burnham Prebys Medical Discovery Institute (SBP) in La Jolla. Lancman’s crowdfunding site just went live on Diabetes Research Connection (DRC), a San Diego-based company that created a platform to connect donors directly with early-career scientists. In the next 90 days, Lancman hopes to generate $50,000 for his research project that may provide the scientific breakthrough needed to find a cure for type 1 diabetes. Watch his video here.

“We recently discovered a way to reprogram cells and change their identity without removing them from the body,” Lancman said. “We believe this breakthrough will have great implications for people with degenerative diseases, like diabetes.”

As many as three million Americans have type 1 diabetes.  Millions of children and adults struggle with this disease, yet funding has decreased dramatically for research. In fact, the head of the National Institutes of Health (NIH)  said last year that young scientists in this country now face the worst funding in 50 years.

So, if you are a young scientist with a great idea, where do you go? Alberto Hayek, MD, co-founder and president of the DRC and world-renowned diabetes expert, says some go away. “Due to the limited funding available, scientists just starting out in their career are forced to leave the field of diabetes and go to fields that have more funding. We are giving scientists the funding needed to test and validate research that departs from conventional thinking,” Hayek said.

Dong says his lab heard about DRC from others in the field. “The DRC is committed to funding innovative projects that may not be considered mainstream approaches. The crowdfunding model itself is highly innovative, by making sure that 100% of donations will go directly into specific labs and projects chosen by the individual donors,” Dong said.

And it works. Since DRC launched its platform in 2014, six research projects from all over the country have been 100% funded. Every dollar of the money raised goes directly to the scientist. The power to fund projects has been given to the people.

Lancman has a total of 90 days to make it happen. He needs 5,000 people to donate $10 each in order to reach his goal. He’s excited to be able to continue to work towards a cure for diabetes, and allow people to live full lives without painful daily insulin injections.

Come on, social media.

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SBP’s Sheila Collins’ diabetes research featured in Orlando Sentinel

Authorsgammon
Date

December 21, 2015

“Obesity has reached epidemic proportions in the United States. Over 60 percent of the population can be classified as overweight or obese, placing them at risk for a large number of chronic diseases, including insulin resistance, cardiovascular disease, and type 2 diabetes,” says Sheila Collins, PhD, professor at SBP’s Lake Nona campus.

“There is a critical need for novel approaches to treating obesity—in particular, agents acting to increase energy expenditure would be valuable.”

Read the article in the Orlando Sentinel by Naseem S. Miller about how Collins is studying hormones produced by the heart to prevent obesity and possibly the myriad of disorders that come with it.

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Can your heart prevent diabetes?

AuthorGuest Blogger
Date

November 19, 2015

This article was written by guest blogger Crystal Woodard, PhD

Can your heart prevent diabetes? Being overweight or obese is currently deemed the single best predictor of type 2 diabetes. With the prevalence of obesity on the rise, estimates suggest that one in three American adults could have type 2 diabetes by 2050. Weight loss is key to preventing this epidemic. At SBP, scientists are investigating how hormones released by the heart may help the body burn more calories to prevent obesity and type 2 diabetes.

What color is your fat? All fat is not created equal. Excess weight is held in energy-storing fat cells called white adipose tissue as well as energy-burning fat cells called brown adipose tissue. Increasing a person’s brown fat could improve the risks associated with obesity.

Two compounds released by the heart in response to high blood pressure—human atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP)—have been found to play a direct role in “browning” white adipose tissue. By browning, white fat starts to burn more calories, mimicking what occurs in brown fat. Sheila Collins, PhD, professor in the Integrative Metabolism Program and her research team, are investigating how these natriuretic peptides activate fat browning with the goal of tapping into the process to help promote weight loss and prevent diabetes.

In collaboration with Dr. Richard Pratley at the Florida Hospital – SBP Translational Research Institute for Metabolism and Diabetes, the teams are conducting clinical trials with obese and lean volunteers to test whether BNP can increase energy expenditure and improve glucose tolerance. Since recombinant human BNP is an FDA-approved drug prescribed for acute heart failure patients, the costs, and development and approval times for using BNP for these conditions may be reduced.

How does BNP work? Investigators in Italy almost 20 years ago discovered that binding sites for BNP, called natriuretic peptide receptors (NPRs), were expressed in human adipose tissue. The natriuretic peptide ‘signaling’ receptor, NPRA, binds the natriuretic peptides, while the natriuretic peptide ‘clearance’ receptor, NPRC, removes them from circulation. Since then, several studies have reported that BNP levels are lower in the blood of obese patients compared to their lean counterparts. Additional research suggests BNP can lead to increased release of adiponectin, an insulin-sensitizing hormone produced by fat cells and that low levels of BNP in the bloodstream might contribute to insulin resistance.

According to Collins, “Early studies proposed that increased clearance is responsible for the lower peptide levels observed in obese individuals in comparison to lean individuals; however, there are no definitive studies to actually prove this or not. Important efforts are currently underway to understand how NPRs are regulated and how the peptides can be best used for their fat-burning capacity.”

Dr. Sheila Collins is a professor at Sanford Burnham Prebys Medical Discovery Institute (SBP) in Lake Nona, Fla. and a recipient of an American Diabetes Association research award. Dr. Richard Pratley is a senior investigator at the Florida Hospital – SBP Translational Research Institute, Medical Director of the Florida Hospital Diabetes Institute, and adjunct professor at SBP in Lake Nona. This post was written by Crystal Woodard, PhD, a post-doctoral fellow in Dr. Collins’s lab.

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Is there a type 3 diabetes?

AuthorGuest Blogger
Date

November 10, 2015

This article was written by guest blogger Jessica Frisch-Daiello, PhD

People with type 2 diabetes are twice as likely to develop Alzheimer’s disease—a type of dementia affecting behavior, memory, and cognitive functions. According to the Centers for Disease Control and Prevention, in 2013 Alzheimer’s ranked sixth and diabetes was seventh as the leading causes of death in the United States. Recent studies are suggesting a link between insulin resistance in the brain and Alzheimer’s disease, prompting some researchers to consider a new classification for the disease: type 3 diabetes.

People with diabetes can’t effectively break down blood sugar. Either their bodies don’t produce enough insulin (type 1 diabetes) or their bodies become desensitized to insulin (type 2 diabetes).

The exact mechanisms between insulin resistance and Alzheimer’s disease are not well understood and research is on-going. However, studies suggest that insulin resistance in the brain leads to the formation of two pathological hallmarks of Alzheimer’s disease—the formation of tau tangles and the build-up of clusters of beta amyloid peptides called plaques in the brain. The degree of insulin resistance is correlated with the amount of plaques deposited between nerve cells. Plaques create a blockade that inhibits cell-to-cell signaling in the brain. Additionally, insulin dysfunction has also been shown to affect the formation of tau tangles by mediating the activity of an important enzyme in the body, GSK-3β (glycogen synthase kinase 3).

Juan Pablo Palavicini, PhD, an SBP postdoctoral fellow in the lab of Xianlin Han, PhD, is studying the role of a particular class of molecules found in the body that might give more clues to the mechanisms connecting these two seemingly disparate diseases. According to Palavicini, “We have found that a specific lipid class called sulfatide is severely deficient in the brains of both Alzheimer’s disease patients and type 2 diabetics. Moreover, our research shows that when sulfatide is removed, there is a dramatic change in insulin levels, beta amyloid peptides, and tau tangles. We are currently exploring therapeutic techniques to restore sulfatide content as a treatment for both diseases.”

Sulfatide serves many functions in the body, including aiding neural plasticity and memory. It also plays a role in insulin secretion. A change in the expression of sulfatide has been associated with a number of conditions, including Alzheimer’s disease, Parkinson’s disease, and diabetes.

Given the association between Alzheimer’s disease and diabetes, it is important for people to incorporate healthy habits in everyday life. Both the American Diabetes Association and the Alzheimer’s Association say that daily exercise, social interaction, and a diet emphasizing fruits, vegetables, and whole grains may reduce the risk of developing, or slowing the progression of, these diseases.

Dr. Palavicini and Dr. Han are pursuing this research as part of a mentor-based postdoctoral fellowship awarded by the American Diabetes Association. This article was written by Dr. Jessica Frisch-Daiello, a postdoctoral associate in Dr. Han’s laboratory at SBP.

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The Diabetes Story: Will new treatments lead to novel weight loss drugs?

AuthorGuest Blogger
Date

November 3, 2015

Written by Jing Ping Lu, PhD

November is American Diabetes Month. Throughout the month, we will be highlighting our research contributions to this increasingly prevalent disease.

The growing epidemic of diabetes presents significant challenges for health care. It ranks 7th among the leading causes of death, and about one tenth of all health care dollars are spent on diabetes and its complications. According to the American Diabetes Association, 29.1 million Americans have been diagnosed with this metabolic disorder, and 1.4 million new cases were reported in 2013. With these statistics, the burden diabetes has on the health care system will continue to rise.

Opportunities to research the disease have also increased with the growing diabetic population. One particular area of emphasis is in understanding how glucose—a type of sugar—is broken down, or metabolized, in diabetic patients. Glucose is the major energy source our body uses to carry out activities. Glucose levels in the blood are kept constant by a hormone called insulin. After eating, the glucose level in the blood rises and signals insulin release. Insulin is like a key that opens up the locks on our cells so that glucose can enter. Glucose can then be stored in the form of glycogen and used later for energy. If our body does not make enough insulin, or insulin is not well recognized by the cell, then glucose levels will build up in the blood stream causing diabetes and other long-term complications.

Treating Diabetes Diabetic treatments are primarily developed to lower the amount of blood glucose by restoring the secretion of insulin or enhancing how well insulin works to promote the entry of glucose into cells. Another hormone called glucagon-like-peptide-1(GLP-1) has been shown to increase glucose-dependent stimulation of insulin release, and GLP-1 based drugs are used to treat diabetes. Julio Ayala, PhD, and his research team are working on projects that utilize GLP-1 based drugs to stimulate insulin secretion. These drugs come in two categories, GLP-1 analogs that mimic the action of GLP-1 and dipeptidyl peptidase 4 (DPP-4) inhibitors that prevent the breakdown of GLP-1 made in the body. Although both drugs can effectively lower glucose levels, one promotes weight loss while the other does not.

A new avenue for weight loss? Preliminary research performed in Ayala’s lab confirmed that the two drugs have different effects on food intake. “Interestingly, when targeted to specific regions in the brain, GLP-1 analogs reduce food intake to a greater degree than does native (natural) GLP-1. This may partly explain why GLP-1 analogs promote weight loss while DPP-4 inhibitors that increase native GLP-1 levels do not,” Ayala explained. “This leads us to speculate that even though both drugs bind to the same receptor in the feeding centers of the brain, they activate different molecular mechanisms in cells of the brain and this eventually results in different effects on food intake, and therefore, weight loss.”

As Ayala’s team continues to explore the mechanism of action, they hope to identify the critical steps that lead to the reduction in food intake. “Obesity is a leading risk factor for developing Type 2 diabetes. If we can discover the steps that GLP-1 analogs engage to promote weight loss, then drugs can be designed to specifically target these steps. This would provide a new avenue for designing drugs to treat obesity,” Ayala added, “and that could deliver a greater benefit to diabetes patients and contribute to decreasing the rise in Type 2 diabetes. We are excited to see the possibilities.”

Dr. Julio Ayala is an assistant professor at Sanford Burnham Prebys Medical Discovery Research Institute in Lake Nona, Fla and a recipient of an American Diabetes Association research award.

This post was written by Jing Ping Lu, PhD, a post-doctoral associate in Dr. Rastinejad’s lab in Lake Nona.

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Potential drug targets could improve treatment of vascular disease in diabetic patients

Authorsgammon
Date

July 15, 2015

The newly discovered role of a vascular protein in diabetes-induced hardening of the arteries could lead to better treatments that reduce the risk of heart attack, stroke, and death, according to research spearheaded by SBP investigators. The study, published recently in Circulation Research, reveals that a receptor called LRP6 inhibits molecular signals that drive diet-induced hardening of the arteries, also known as arteriosclerosis. Continue reading “Potential drug targets could improve treatment of vascular disease in diabetic patients”

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Protecting pancreatic cells from stress could hold promise for treating diabetes

Authorsgammon
Date

April 21, 2015

 

Type 2 diabetes is a chronic disease that affects about eight percent of adults worldwide, significantly increasing the risk of heart disease and stroke. This disease interferes with the body’s ability to make or use a hormone called insulin, which is produced by beta cells in the pancreas. These cells eventually fail in many patients with type 2 diabetes, making insulin replacement therapy a necessity for survival. However, this treatment is imprecise, onerous and often promotes weight gain, highlighting the strong need for better treatment options. Continue reading “Protecting pancreatic cells from stress could hold promise for treating diabetes”