D M Ostrega studies how various factors influence insulin production and effectiveness in the body. In particular, they focus on the role of calpain proteins, which when blocked can lead to increased insulin release from the pancreas but reduced cell sensitivity to insulin. Their work also involves examining how specific genetic mutations, such as in the glucokinase gene, affect the body's response to high blood sugar. This research is important as it sheds light on potential pathways to better manage, or even prevent, conditions like type 2 diabetes.
Key findings
Blocking calpain proteins results in the pancreas releasing more insulin in response to high blood sugar, while making some cells less responsive to insulin's effects.
In glucokinase mutant mice, exposure to high blood sugar for 2-4 days led pancreatic cells to increase production of a faulty protein, improving their sugar-sensing ability despite the defect.
Normal pancreatic cells exposed to high blood sugar become less effective, indicating that prolonged hyperglycemia can damage healthy cells but may help defective ones adjust.
Frequently asked questions
Does D M Ostrega study diabetes?
Yes, D M Ostrega conducts research on insulin secretion and action related to type 2 diabetes.
What treatments has D M Ostrega researched?
While they primarily explore how insulin is produced and used by the body, their findings could inform treatments aimed at improving insulin sensitivity and secretion.
Is D M Ostrega's work relevant to patients with high blood sugar?
Yes, their research directly relates to how the body manages high blood sugar and could have implications for patients with diabetes.
Publications in plain English
Calpains play a role in insulin secretion and action.
Plain English Researchers found that blocking calpain proteins—which are found throughout the body—causes pancreases to release more insulin in response to high blood sugar, and simultaneously makes muscles and fat cells less responsive to insulin's signals. Since genetic variations in the calpain-10 gene are linked to type 2 diabetes, these results suggest that calpains are a key control point for how much insulin the body makes and how well cells use it.
Adaptation to hyperglycemia enhances insulin secretion in glucokinase mutant mice.
1998
Diabetes
Sreenan SK, Cockburn BN, Baldwin AC, Ostrega DM, Levisetti M +5 more
Plain English Researchers studied pancreatic cells from mice with a broken glucokinase gene (a gene that helps detect blood sugar) to see if exposing them to high blood sugar would improve their ability to make insulin. They found that cells from mutant mice actually recovered function when exposed to high sugar levels—they produced more insulin and better detected blood sugar changes—while normal cells exposed to the same high sugar levels became damaged and stopped working properly.
This matters because it explains why people with glucokinase gene mutations don't develop severe diabetes: their pancreatic cells adapt to high blood sugar instead of breaking down, and it suggests that having only one working copy of this gene actually provides protection against the cell damage that normally happens when blood sugar stays too high.
Plain English This study looked at how certain enzyme activities in the pancreas change as rats age, gain weight, and develop diabetes. Researchers found that, in obese rats with diabetes (ZDF and ZF), a specific enzyme called hexokinase (HK) was significantly more active—about 1.9 times greater in ZDF and 1.7 times greater in ZF compared to healthy rats. This increase may help maintain high insulin levels but does not explain why these diabetic rats fail to respond to rising glucose levels, which is crucial for managing diabetes.
Who this helps: This research benefits doctors and researchers working to understand diabetes and develop better treatments.
Plain English The study looked at how insulin production changes in someone who developed insulin-dependent diabetes (IDDM) over 13 months. Researchers found that even when blood sugar levels were normal, insulin secretion was reduced, and over time, the ability of the body to secrete insulin in response to sugar decreased significantly. This matters because it shows that insulin production starts to decline before diabetes is diagnosed, which could help in early detection and management of the disease.
Who this helps: This helps patients at risk of diabetes and doctors looking to identify early signs of the disease.
Plain English This study looked at how insulin is released in pulses by the pancreas of different types of rats, focusing on the role of glucose in this process. Researchers found that in healthy rats, insulin was released in shorter pulses (about every 7 minutes), while in diabetic Zucker rats, it happened much less frequently (about every 15 minutes). This is important because it shows that the way glucose influences insulin release is disrupted in diabetes, potentially leading to higher blood sugar levels.
Who this helps: This helps patients with diabetes by providing insights into how insulin regulation works and what might be going wrong in their bodies.
Hypoglycemia due to surreptitious injection of insulin. Identification of insulin species by high-performance liquid chromatography.
1991
Diabetes care
Given BD, Ostrega DM, Polonsky KS, Baldwin D, Kelley RI +1 more
Plain English Researchers studied patients who had low blood sugar due to undisclosed insulin injections, specifically looking at the type of insulin present in their bodies. They found that in three out of four patients, animal insulin was detected in their blood using a technique called high-performance liquid chromatography (HPLC). This method can help doctors confirm cases of low blood sugar caused by intentionally injecting insulin, which is important for proper diagnosis and treatment.
Who this helps: This helps doctors in accurately diagnosing patients experiencing unexplained low blood sugar episodes.