GPR146 and Cholesterol Metabolism

Not Applicable

Not yet recruiting

• Conditions: Healthy Participants

• Registration Number: NCT07142317
• Lead Sponsor: Maastricht University Medical Center

Brief Summary

Blood cholesterol balance is regulated by an interplay between the small intestine and the liver. Recently, a new protein (cholesin) was discovered, which is secreted by intestinal cells after dietary cholesterol intake. Cholesin travels to the liver and binds to the GPR146 receptor. This inhibits cholesterol production in the liver. Because plant sterols lower blood cholesterol levels by reducing cholesterol absorption in the intestine, the investigators would like to understand the effects of plant sterols on GPR146. The investigator hypothesis is that the production of the GPR146 gene differs after adding plant sterols to a high-cholesterol diet compared to eating a high-cholesterol and low-cholesterol diet. The main objective of this study is to investigate whether the expression of the GPR146 gene in the blood of adults differs between three meals with different levels of cholesterol intake. The secondary objective of the study is to examine changes in the expression of cholesin, the LDL receptor (LDLR), and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) genes in the blood after these meals. Furthermore, changes in the expression of these genes, all of which play an important role in cholesterol metabolism, will be examined in intestinal cells.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-08
• Study First Submitted: 2025-08-19
• Study First Submitted QC: 2025-08-19
• Study First Posted: 2025-08-26
• Last Update Submitted: 2025-09-25
• Study Start: 2025-10-01
• Last Update Posted: 2025-10-01
• Primary Completion: 2026-09
• Study Completion: 2026-12-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 23

Inclusion Criteria

• Men and women, aged between 18-70 years
• BMI between 18.5-25.0 kg/m2
• Fasting serum total cholesterol (TC) <8.0 mmol/L and fasting serum triacylglycerol (TAG) <3 mmol/L
• Fasting plasma glucose (FBG) <7 mmol/L
• Systolic blood pressure <160 mmHg and diastolic blood pressure <100 mmHg
• Stable body weight (weight gain or loss of <3 kg in the past three months)
• Willingness to give up being a blood donor from 8 weeks before the start of the study, during the study, and for 4 weeks after completion of the study
• No difficult venipuncture as evidenced during the screening visit

Exclusion Criteria

• Allergy or intolerance to any of the components of the study meal
• Familial hypercholesterolemia
• History of gastrointestinal surgery, including bariatric procedures such as sleeve gastrectomy, gastric bypass, gastric band, gastric balloon, or other major gastrointestinal surgeries that may affect digestion or absorption
• Current smokers
• Diabetic patients
• Pregnant and breastfeeding women
• Abuse of drugs
• More than 10 alcoholic consumptions per week for women and 14 for men
• Not willing to stop the use of products or dietary supplements known to interfere with the main outcomes as judged by the principal investigator for at least 1 week before the start of the study
• Use of medications to treat or affect blood pressure, lipid, or glucose metabolism
• Use of an investigational product within another biomedical intervention trial within the previous 1 month
• Severe medical conditions that might interfere with the study, such as: epilepsy, asthma, kidney failure or renal insufficiency, chronic obstructive pulmonary disease, inflammatory bowel diseases, autoinflammatory diseases, and rheumatoid arthritis
• Active cardiovascular disease, such as congestive heart failure, or a cardiovascular event, such as an acute myocardial infarction or a cerebrovascular accident

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
The postprandial changes in GPR146 gene expression in peripheral blood mononuclear cells (PBMCs) after three dietary conditions.	At baseline (fasting; before the meal) and at 360 minutes (6-hours) postprandial	The gene expression levels will be determined by messenger RNA (mRNA) quantification using the real-time reverse transcription polymerase chain reaction (RT-qPCR) method in PBMCs and reported as fold change (increase or decrease) relative to baseline.

Secondary Outcome Measures

Name	Time	Method
The postprandial changes in C7orf50, HMGCR, and LDLR gene expressions in peripheral blood mononuclear cells (PBMCs) after three dietary conditions.	At baseline (fasting; before the meal) and at 360 minutes (6-hours) postprandial	The gene expression levels will be determined by messenger RNA (mRNA) quantification using the real-time reverse transcription polymerase chain reaction (RT-qPCR) method in PBMCs and reported as fold change (increase or decrease) relative to baseline
The postprandial changes in GPR146 and LDLR protein expressions in peripheral blood mononuclear cells after three dietary conditions.	At baseline (fasting; before the meal) and at 360 minutes (6-hours) postprandial	The protein expression levels will be measured by fluorescence-activated cell sorting (FACS) analysis and reported as percentage of marker-positive cells and/or fold change in mean fluorescence intensity from baseline.

Trial Locations

Locations (1)

Maastricht University; 🇳🇱 Maastricht, Limburg, Netherlands