Objective
The objective of this research is to define how an enzyme called ceramide synthase-2 (CERS2) controls insulin-producing beta-cell health by producing specialized protective fats called very-long-chain sphingolipids. By experimentally reducing CERS2 to understand its regulatory role and then boosting it under stress conditions, we will determine whether this enzyme can help beta-cells survive the metabolic and inflammatory challenges encountered in type 1 diabetes (T1D). Beta-cells in people with T1D face a double challenge: they are attacked by the immune system while simultaneously struggling with internal metabolic dysfunction and stress. We focus on understanding one critical aspect of this metabolic dysfunction, the production of very-long-chain sphingolipids, which are essential fat molecules that help beta-cells maintain their structure, package insulin correctly, and potentially resist stress. This project has two main goals. First, we will reduce CERS2 levels specifically in human beta-cells to understand what goes wrong when production of these protective fats decreases. We will then measure three key outcomes: changes in the beta-cells’ fat composition, their ability to release insulin in response to sugar, and the activation of stress-response genes. Second, we will increase CERS2 levels in human beta-cells and expose them to the types of inflammatory signals and cellular stress that occur during diabetes development. We will then assess whether boosting these protective fats helps the cells maintain normal insulin secretion and survive these challenges. By using beta-cells obtained from human organ donors and advanced molecular analysis techniques, this research will provide critical insights into whether manipulating this fat-production pathway could represent a new strategy to strengthen beta-cells against the metabolic and immune attacks that destroy them in T1D.
Background Rationale
Type 1 diabetes (T1D) occurs when the immune system mistakenly attacks and destroys the insulin-producing beta-cells in the pancreas. While the immune attack is the primary driver of T1D, beta-cells themselves have underlying vulnerabilities that accelerate their destruction. Understanding and addressing these vulnerabilities represents an important complementary approach to immune-focused therapies. One critical but understudied vulnerability involves how beta-cells process and use fats. Beta-cells require specialized fats called sphingolipids to build their membranes, package insulin into tiny storage vesicles, and protect themselves from stress. Scientists have traditionally viewed one type of these fats, ceramides, as uniformly harmful when they accumulate. However, recent research reveals that ceramides are a diverse family with different chain lengths, and these different forms may have opposite effects on beta-cell health. An enzyme called ceramide synthase-2 (CERS2) produces very-long-chain versions of these fats (called very-long-chain sphingolipids or VLCSLs), which appear to protect beta-cells, while shorter versions are harmful. When we experimentally reduced CERS2 in human beta-cells, they lost their protective very-long-chain fats, showed impaired insulin secretion, and activated stress-response genes. This mirrors what happens in people with T1D. Pancreatic tissue from individuals recently diagnosed with T1D shows reduced CERS2 and severely depleted VLCSLs, and people carrying genetic variants that reduce CERS2 function have higher diabetes risk. Furthermore, studies in diabetic mice show that increasing VLCSLs can prevent autoimmune diabetes, suggesting these protective fats interact with the immune system to preserve beta-cells. Since human beta-cells differ fundamentally from mouse beta-cells in how they handle fats and respond to stress, understanding this pathway in actual human-cells is essential for developing therapies. Most current T1D treatments focus solely on controlling the immune system, but few aim to strengthen the beta-cells themselves. This research addresses that critical gap.
Description of Project
Type 1 diabetes (T1D) occurs when the immune system attacks and destroys insulin-producing beta-cells in the pancreas. While immune dysfunction drives the disease, the beta-cells themselves have underlying metabolic weaknesses that make them more vulnerable to this attack. Most current therapies focus on controlling the immune response, but few approaches strengthen the beta-cells to help them survive. Our research focuses on a previously overlooked aspect of beta-cell health: specialized fats called sphingolipids. These molecules act like protective building blocks in beta-cell membranes and are essential for packaging and releasing insulin properly. A specific enzyme called ceramide synthase-2 (CERS2) produces a very-long-chain form of these sphingolipids. We found that when CERS2 levels drop, beta cells lose their ability to secrete insulin effectively and may become more susceptible to stress and immune attack. Importantly, pancreatic tissue from people newly diagnosed with T1D shows reduced CERS2 and depleted very-long-chain sphingolipids. This project will test whether manipulating CERS2 levels can protect human beta cells from the metabolic and inflammatory stresses that occur in diabetes. Using human beta-cells obtained from organ donors, we will apply cutting-edge techniques to either reduce or increase CERS2 levels. We will then examine how these changes affect insulin production and release, fat composition, and the cells’ ability to withstand inflammatory signals like those present in T1D. By understanding how these specialized fats regulate human beta-cell function and survival, we aim to identify new strategies to fortify beta-cells against the combined metabolic and immune challenges that drive their destruction in T1D.
Anticipated Outcome
We anticipate this research will demonstrate that the enzyme, ceramide synthase-2 (CERS2), and the protective fats it produces play a crucial role in maintaining human beta-cell health and that manipulating this pathway can influence how well beta-cells function and survive under diabetic conditions. In the first part of our study, when we reduce CERS2 levels in human beta-cells, we expect to see a cascade of problems, including depletion of protective very-long-chain fats, accumulation of harmful shorter-chain fats, impaired insulin release in response to sugar, and activation of cellular stress responses. Using advanced imaging techniques, we anticipate finding that these cells have fewer properly formed insulin storage granules and damaged internal structures. Through single-cell genetic analysis, we expect to identify shifts in beta-cell populations toward less functional, more stress-sensitive states, with genes involved in insulin packaging and release turned down and stress-response genes turned up. These findings would establish that loss of CERS2 and its protective fats directly causes beta-cell dysfunction. In the second part, when we increase CERS2 levels and then expose beta-cells to inflammatory signals and cellular stresses similar to those in diabetes, we anticipate that cells with elevated CERS2 will maintain higher levels of protective fats, preserve their insulin-releasing ability, and show reduced activation of stress pathways compared to normal cells. We expect these protected cells to maintain properly formed insulin granules and healthy internal structures even under stress. Together, these outcomes would provide strong evidence that manipulating the CERS2 pathway can protect human beta-cells from both metabolic and inflammatory challenges. This would establish proof-of-concept for a fundamentally new therapeutic approach, using fat-metabolism targets to fortify beta-cells against the stresses that drive their failure in type 1 diabetes. This approach could potentially complement existing immune-directed therapies to preserve beta-cell function.
Relevance to T1D
This research directly addresses a critical unmet need in type 1 diabetes (T1D) care: protecting the insulin-producing beta-cells themselves. While current disease-modifying therapies focus primarily on controlling the immune attack that causes T1D, they do little to strengthen beta-cells or help them withstand the metabolic and inflammatory stresses that accelerate their destruction. Our work targets this gap by identifying and testing a beta-cell-intrinsic pathway that could be manipulated to enhance stress resilience. The relevance of CERS2 and very-long-chain sphingolipids to T1D is supported by multiple lines of evidence. Pancreatic tissue from people newly diagnosed with T1D shows marked reductions in CERS2 expression and dramatic depletion (over 75%) of very-long-chain sphingolipids in insulin-containing cells. Genetic studies reveal that people carrying variants that reduce CERS2 function have increased risk of developing diabetes, and some T1D patients develop antibodies against sulfatide, a critical very-long-chain sphingolipid found in insulin granules. Importantly, animal studies demonstrate that increasing very-long-chain sphingolipids can prevent autoimmune diabetes, indicating these molecules interact with the immune system to preserve beta-cell mass. This research is particularly valuable because it uses actual human beta-cells rather than relying solely on animal models. Human and rodent beta-cells differ fundamentally in how they metabolize fats and respond to stress, making human-based studies essential for developing clinically relevant therapies. By defining exactly how very-long-chain sphingolipids regulate human beta-cell function, insulin secretion, and stress resilience, this work could identify new therapeutic targets for preserving beta-cell health. Our goal aligns with Breakthrough T1D's strategic vision of combining immune modulation with approaches that protect and preserve beta-cell function. If successful, this research could lead to sphingolipid-targeted interventions that preserve functional beta-cell mass in people with or at risk for T1D. Potential interventions include drugs that boost CERS2 activity, or cell-engineering strategies for beta-cell replacement therapies. These approaches would complement existing immunotherapies by directly strengthening beta-cell resilience.