Removing a protein called PIGR from immune cells significantly reduces fatty plaque buildup in arteries, according to a 2026 research study. Scientists found that mice without PIGR in their immune cells developed much smaller atherosclerotic plaques despite eating an unhealthy diet, and this protection occurred without changes in blood cholesterol levels. This discovery suggests a completely new way to fight heart disease by controlling immune cell behavior rather than just lowering cholesterol, though human testing is still years away.
Scientists have discovered that a specific protein called PIGR plays an important role in heart disease development. When researchers removed this protein from immune cells in mice, the animals developed much smaller fatty deposits in their arteries—a key sign of heart disease prevention. According to Gram Research analysis, this finding could eventually lead to new treatments for atherosclerosis, a condition where arteries become clogged with fatty buildup. The study shows that targeting PIGR in immune cells might be a promising way to protect hearts without needing to change cholesterol levels, opening up entirely new approaches to preventing heart attacks and strokes.
Key Statistics
A 2026 research study found that mice lacking the PIGR protein in immune cells developed significantly reduced fatty plaques in their arteries compared to normal mice, with dramatically fewer immune cells infiltrating the plaque tissue.
According to research reviewed by Gram, PIGR expression increased during the development of human immune cells into macrophages in laboratory studies, and PIGR was found colocalized with macrophages in actual human atherosclerotic plaques.
The protective effect of PIGR deficiency in immune cells occurred independently of changes in blood lipid levels or antibody levels, suggesting a novel mechanism distinct from traditional cholesterol-lowering approaches to heart disease prevention.
The Quick Take
- What they studied: Whether a protein called PIGR found in immune cells contributes to the buildup of fatty deposits in arteries (atherosclerosis)
- Who participated: Laboratory mice genetically modified to develop heart disease, plus human immune cells grown in the lab to study how they behave
- Key finding: Mice without the PIGR protein in their immune cells developed significantly smaller fatty plaques in their arteries compared to normal mice, even when eating an unhealthy diet
- What it means for you: This research suggests a new target for heart disease treatment, but it’s still in early stages. Don’t expect new medications immediately—scientists need to do more research to understand exactly how this works and whether it’s safe for humans
The Research Details
Researchers used mice that were genetically engineered to develop heart disease naturally. They performed bone marrow transplants, replacing the blood-forming cells in sick mice with cells from mice that lacked the PIGR protein. This allowed them to test whether removing PIGR specifically from immune cells (rather than from the whole body) would reduce heart disease. They fed the mice an unhealthy diet for 10 weeks to speed up atherosclerosis development, then examined the fatty deposits in their arteries.
The team also studied human immune cells in laboratory dishes, watching how PIGR levels changed as these cells developed into macrophages—a type of immune cell that plays a major role in heart disease. They looked at real human atherosclerotic plaques under a microscope to see where PIGR was located and which cells contained it.
This approach is powerful because it isolates the effect of PIGR in immune cells specifically, rather than looking at the whole-body effects. This helps researchers understand which cells and proteins are most important for preventing heart disease.
Understanding which proteins drive heart disease is crucial for developing new treatments. Most current heart disease medications focus on lowering cholesterol, but this research suggests that controlling immune cell behavior through PIGR might offer a completely different approach. By using bone marrow transplants, the researchers could pinpoint exactly which cells matter most, making their findings more reliable and actionable for drug development.
The study used well-established laboratory techniques and mouse models that are standard in cardiovascular research. The findings are specific and measurable—researchers could directly count and measure the fatty plaques in arteries. However, the sample size wasn’t specified in the abstract, and all work was done in mice and human cells in dishes, not in living humans. Results in mice don’t always translate to humans, so more research is needed before clinical applications.
What the Results Show
Mice lacking the PIGR protein in their immune cells showed dramatically reduced fatty plaque buildup in their aortic sinuses (the base of the main artery leaving the heart) compared to normal mice. The plaques were significantly smaller, suggesting that PIGR in immune cells actively promotes atherosclerosis development.
When researchers examined the plaques under a microscope, they found far fewer macrophages—immune cells that normally accumulate in fatty deposits and contribute to plaque growth. This suggests that PIGR helps immune cells infiltrate and damage artery walls. Interestingly, other plaque components like smooth muscle cells and collagen (structural proteins) remained unchanged, meaning PIGR specifically affects immune cell behavior rather than overall plaque structure.
The protective effect occurred without any changes in blood cholesterol levels or antibody levels, which was surprising. This means PIGR works through a different mechanism than traditional cholesterol-lowering approaches, potentially offering a new therapeutic angle.
Human immune cells grown in the laboratory showed increasing PIGR levels as they developed into macrophages, suggesting this protein becomes more important as immune cells mature. In actual human atherosclerotic plaques, PIGR was found specifically in the inner lining of arteries where plaques form, and it colocalized with macrophages—meaning it was present in the same cells that cause damage. These observations in human tissue support the mouse findings and suggest the mechanism is relevant to real human heart disease.
This research builds on earlier work from the same group showing that mice completely lacking PIGR throughout their entire bodies had reduced atherosclerosis. The new study goes further by proving that the immune cell component is the critical part. Previous research has shown that macrophages are central to atherosclerosis, and this work identifies PIGR as a specific protein that controls macrophage behavior in this context. The finding that PIGR works independently of cholesterol levels distinguishes it from most current heart disease research.
The study was conducted entirely in mice and laboratory-grown human cells, not in living humans. Mouse models don’t always behave the same way as human bodies, so results may not translate directly. The specific sample size wasn’t provided in the abstract, making it difficult to assess statistical power. The researchers acknowledge that the exact molecular mechanisms—the step-by-step biological processes—remain unclear. Long-term effects and safety considerations haven’t been evaluated. Additionally, the study only looked at one type of mouse model of heart disease, so results might differ in other genetic backgrounds or disease conditions.
The Bottom Line
This research is too preliminary for any clinical recommendations. It’s a basic science discovery that identifies a new target, not a tested treatment. People concerned about heart disease should continue following established prevention strategies: maintain healthy cholesterol levels, exercise regularly, eat a heart-healthy diet, and work with their doctors on proven interventions. This research may eventually lead to new medications, but that’s years away.
Cardiologists and researchers studying atherosclerosis should pay close attention to this work as it opens a new research direction. People with family histories of early heart disease might eventually benefit if this leads to new treatments. People currently managing heart disease should not change their treatment based on this research—it’s not yet applicable to human medicine. Pharmaceutical companies may be interested in developing PIGR-targeting drugs.
This is very early-stage research. Typically, moving from mouse studies to human clinical trials takes 5-10 years or more. Even if promising drugs are developed, they would need extensive safety testing before becoming available. Realistic timeline for potential new treatments: 7-15 years minimum.
Frequently Asked Questions
What is PIGR and why does it matter for heart disease?
PIGR is a protein found on immune cells that helps them move through the body. Research shows that when PIGR is removed from immune cells, fatty plaques in arteries shrink significantly, suggesting this protein actively promotes heart disease development and could be a new treatment target.
Can I get a PIGR-blocking drug to prevent heart disease?
Not yet. This is early-stage research in mice and laboratory cells. Developing a safe, effective human medication typically takes 7-15 years from basic research. Current proven prevention methods—exercise, healthy diet, and cholesterol management—remain your best options now.
Does this mean cholesterol doesn’t matter for heart disease anymore?
No. This research identifies an additional mechanism beyond cholesterol that contributes to heart disease. Cholesterol remains critically important for heart health. This discovery suggests future treatments might work alongside cholesterol management, not replace it.
How is this different from current heart disease treatments?
Most heart medications target cholesterol levels. This research targets immune cell behavior through a different protein pathway. If developed into a drug, it could offer a complementary approach that works through a completely different mechanism, potentially helping people who don’t respond well to current treatments.
Will this research lead to a cure for heart disease?
This identifies one important piece of the heart disease puzzle, not a complete solution. Heart disease involves multiple biological processes. This discovery may eventually contribute to better prevention or treatment, but a single cure is unlikely given the disease’s complexity.
Want to Apply This Research?
- Track cardiovascular risk factors that are currently modifiable: weekly exercise minutes, daily steps, blood pressure readings, and dietary choices (servings of fruits/vegetables, sodium intake). As new treatments emerge from research like this, users can monitor how their markers respond.
- Users can log their current heart disease prevention activities and set goals for the modifiable factors that research shows matter: exercise frequency, diet quality, and stress management. The app could send reminders about these proven interventions while noting that new research may offer additional options in the future.
- Establish a baseline of current cardiovascular health metrics and track them monthly. As this research progresses toward human trials, users interested in PIGR-targeted therapies can follow the research timeline through the app’s news feed, ensuring they’re informed if clinical trials become available in their area.
This research is preliminary laboratory work in mice and human cells, not human clinical trials. The findings have not been tested in living humans and should not influence current medical treatment decisions. Anyone with concerns about heart disease should consult their healthcare provider about proven prevention and treatment strategies. This article is for educational purposes only and does not constitute medical advice. Do not change any heart disease medications or prevention strategies based on this research.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.