GO:0010987 negative regulation of high-density lipoprotein particle clearance: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0010987 describes any biological process that reduces the rate at which high-density lipoprotein (HDL) particles are removed from the circulation.
• HDL clearance is influenced by the charge and conformation of apolipoprotein A-I (APOA1), the major HDL structural protein.
• Inflammatory cytokines such as TNF-alpha and IL-6 downregulate key HDL-related genes and can accelerate HDL catabolism, thereby opposing negative regulation of clearance.
• microRNA-148a post-transcriptionally represses ABCA1 and LDLR, indirectly affecting circulating lipoprotein levels and HDL metabolism.
• Hepatic lipase activity, modulated by sphingomyelin in plasma lipoproteins, is a determinant of HDL remodeling and clearance.
• Experimental models for studying this process include Apoa1 knockout and human APOA1 knock-in mice, as well as cell-based assays using oxidized lipoproteins.
Description
High-density lipoprotein (HDL) particles are circulating complexes of apolipoproteins and lipids that mediate reverse cholesterol transport and exert anti-inflammatory and antioxidant functions. The concentration of HDL in plasma is determined by the balance between its production, remodeling, and clearance from the circulation. GO:0010987, negative regulation of high-density lipoprotein particle clearance, refers to any process that decreases the rate at which HDL particles are removed from the bloodstream. This term is distinct from positive regulation of HDL clearance and from general HDL metabolic processes. Understanding this regulatory node is important because delayed HDL clearance can elevate plasma HDL levels, which in some contexts may be protective, while in others may reflect dysfunctional HDL. Moreover, the same mechanisms that regulate HDL clearance can influence reverse cholesterol transport, immune modulation, and cardiovascular risk. Researchers studying atherosclerosis, inflammation, and lipid disorders therefore need precise tools to interrogate the genes and pathways that negatively regulate HDL particle clearance.
negative regulation of high-density lipoprotein particle clearance At A Glance
| GO ID | GO:0010987 |
|---|---|
| GO term | negative regulation of high-density lipoprotein particle clearance |
| Ontology | biological_process |
| Synonym | none |
| Major function | Decreases the rate of removal of HDL particles from the circulation, thereby modulating plasma HDL levels and reverse cholesterol transport. |
| Related processes | HDL remodeling, reverse cholesterol transport, inflammatory cytokine signaling, post-transcriptional regulation by microRNAs. |
| Key regulators | APOA1 conformation, ABCA1, LDLR, microRNA-148a, hepatic lipase, sphingomyelin. |
| Disease relevance | Cardiovascular disease, graft-versus-host disease, obesity-related lipid abnormalities. |
| Experimental models | Apoa1 knockout and human APOA1 transgenic mice, endothelial cell uptake assays, hepatic lipase activity assays. |
What Is GO:0010987?
GO:0010987 is a biological process term that encompasses any molecular event or pathway that reduces the rate of removal of high-density lipoprotein particles from the circulation. It includes changes in apolipoprotein conformation, receptor-mediated uptake, and extracellular remodeling that slow HDL catabolism. The term is defined by its outcome (decreased clearance) rather than by a specific molecular mechanism, and it can be applied to diverse cell types including hepatocytes, endothelial cells, and macrophages.
Why Is negative regulation of high-density lipoprotein particle clearance Important in Cell Biology?
Negative regulation of HDL particle clearance is a critical determinant of plasma HDL concentration and function. Because HDL mediates reverse cholesterol transport and has anti-inflammatory properties, understanding how its clearance is slowed or accelerated can reveal therapeutic strategies for cardiovascular disease, inflammatory conditions, and metabolic disorders. Moreover, the same pathways that regulate HDL clearance intersect with immune function and transplantation biology, as shown by the protective effect of HDL infusion in experimental graft-versus-host disease.
• Determines plasma HDL levels and thus cardiovascular risk profiles.
• Modulates reverse cholesterol transport and macrophage cholesterol efflux.
• Influenced by inflammatory cytokines, linking immune dysfunction to dyslipidemia.
• Relevant to graft-versus-host disease, where HDL infusion is protective in experimental models.
• Affected by genetic variants associated with obesity and serum lipid levels.
• Regulated post-transcriptionally by microRNA-148a via ABCA1 and LDLR.
• Involves apolipoprotein A-I charge and conformation as key determinants.
• Hepatic lipase activity and sphingomyelin content modulate HDL remodeling and clearance.
• Provides a target for CRISPR-based gene editing to dissect causal genes.
• Relevant to endothelial cell uptake of oxidized apolipoproteins in the brain.
What Happens During negative regulation of high-density lipoprotein particle clearance?
Modulation of APOA1 conformation and charge
In simple terms: The shape and electrical charge of the main HDL protein can change how long HDL stays in the blood.
Apolipoprotein A-I (APOA1) is the major structural and functional protein of HDL. Studies using reconstituted HDL have shown that the charge and conformation of APOA1 regulate the clearance of HDL particles in vivo. Negatively charged or conformationally altered APOA1 can slow the uptake of HDL by the liver and other tissues, thereby reducing the clearance rate. This represents a direct molecular mechanism for negative regulation of HDL particle clearance.
Post-transcriptional regulation by microRNAs
In simple terms: Small RNA molecules can dial down the production of proteins that help clear HDL.
MicroRNA-148a regulates the expression of LDL receptor (LDLR) and ABCA1, both of which influence circulating lipoprotein levels. By repressing these genes, microRNA-148a can indirectly reduce HDL clearance, contributing to negative regulation of HDL particle clearance. This highlights a layer of post-transcriptional control that can be targeted experimentally.
Inflammatory cytokine signaling
In simple terms: Inflammation can change how the body handles HDL, often making HDL disappear faster.
Inflammatory cytokines such as TNF-alpha and IL-6 regulate HDL metabolism and can establish links between immune dysfunction and cardiovascular disease. These cytokines often downregulate genes involved in HDL production and remodeling, and can accelerate HDL catabolism, thereby opposing negative regulation of clearance. Thus, the inflammatory milieu is a key contextual factor that determines whether HDL clearance is slowed or accelerated.
Role of hepatic lipase and sphingomyelin
In simple terms: Enzymes and lipids in the blood can remodel HDL and affect how quickly it is removed.
Hepatic lipase activity is regulated by sphingomyelin in plasma lipoproteins, and this enzyme plays a central role in HDL remodeling. Changes in sphingomyelin content can alter hepatic lipase activity, which in turn affects HDL particle size and clearance. Negative regulation of HDL clearance can therefore occur through modulation of hepatic lipase or its lipid environment.
Cellular uptake of oxidized apolipoproteins
In simple terms: Cells can take up damaged HDL proteins, which may slow or speed clearance depending on context.
Cerebral cortex endothelial cells can take up and clear oxidatively modified apolipoprotein E3, a process relevant to brain lipoprotein metabolism. Although this specifically involves APOE, similar mechanisms may apply to oxidized APOA1 and HDL particles. Negative regulation of HDL clearance could involve reduced cellular uptake of oxidized apolipoproteins, thereby prolonging HDL residence time.
Key Genes Involved in GO:0010987 negative regulation of high-density lipoprotein particle clearance
The following genes and proteins have been experimentally linked to the regulation of HDL particle clearance and related lipid metabolic pathways.
| Gene | Major Role | Research Relevance |
|---|---|---|
| APOA1 | Major structural protein of HDL; charge and conformation regulate clearance | Target for knock-in and point mutation studies to dissect clearance mechanisms |
| ABCA1 | Cholesterol efflux pump; influences HDL biogenesis and indirectly clearance | microRNA-148a target; knockout models show altered HDL levels |
| LDLR | Receptor for LDL and other lipoproteins; affects circulating lipoprotein levels | Post-transcriptionally regulated by microRNA-148a; relevant to HDL clearance |
| MIR148A | microRNA that represses ABCA1 and LDLR | Overexpression and knockout models to study post-transcriptional control |
| LIPC | Hepatic lipase; remodels HDL and affects clearance | Enzyme activity assays and knockout models |
| APOE | Apolipoprotein involved in lipoprotein clearance; oxidized forms taken up by endothelial cells | Relevant to brain lipoprotein metabolism and neurodegeneration |
| TNF | Pro-inflammatory cytokine that regulates HDL metabolism | Inflammation models to study HDL clearance |
| IL6 | Pro-inflammatory cytokine linked to HDL regulation | Inflammation models to study HDL clearance |
| SCARB1 | Scavenger receptor BI; mediates selective HDL cholesterol uptake | Candidate for negative regulation of HDL clearance |
| CETP | Cholesteryl ester transfer protein; remodels HDL | Modulates HDL size and clearance |
| PLTP | Phospholipid transfer protein; affects HDL remodeling | Potential regulator of HDL clearance |
| LCAT | Lecithin-cholesterol acyltransferase; esterifies cholesterol on HDL | Affects HDL maturation and clearance |
| SR-BI | Alternative name for SCARB1; mediates HDL uptake | Knockout models show altered HDL clearance |
| ABCG1 | Cholesterol efflux pump to HDL | Indirectly affects HDL clearance |
| NR1H3 | Liver X receptor alpha; regulates ABCA1 and ABCG1 | Transcription factor controlling HDL-related genes |
| NR1H2 | Liver X receptor beta; regulates lipid metabolism | Potential regulator of HDL clearance |
| PPARA | Peroxisome proliferator-activated receptor alpha; regulates lipid metabolism | Inflammation and lipid crosstalk |
| PPARG | Peroxisome proliferator-activated receptor gamma; regulates lipid metabolism | Inflammation and lipid crosstalk |
How Is negative regulation of high-density lipoprotein particle clearance Regulated?
The process of negative regulation of HDL particle clearance is itself regulated at multiple levels. Inflammatory cytokines such as TNF-alpha and IL-6 can downregulate HDL-related genes and accelerate catabolism, thereby opposing negative regulation. Post-transcriptional control by microRNA-148a represses ABCA1 and LDLR, indirectly slowing HDL clearance. Hepatic lipase activity, modulated by sphingomyelin, is another key regulatory node. Additionally, the charge and conformation of APOA1 directly determine whether HDL particles are cleared rapidly or slowly.
negative regulation of high-density lipoprotein particle clearance and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| APOA1 | Cardiovascular disease; HDL deficiency | Apoa1 knockout and human APOA1 knock-in mice |
| ABCA1 | Tangier disease; HDL deficiency | Abca1 knockout mice and cell models |
| LDLR | Familial hypercholesterolemia | Ldlr knockout mice |
| MIR148A | Dyslipidemia; obesity-related traits | miR-148a transgenic and knockout mice |
| APOE | Alzheimer's disease; brain lipoprotein metabolism | Apoe knockout and human APOE knock-in mice |
Cardiovascular disease and inflammation
Inflammatory cytokines establish links between immune dysfunction and cardiovascular disease by regulating HDL metabolism. Negative regulation of HDL clearance can be disrupted in chronic inflammatory states, leading to altered HDL levels and function. Understanding this axis may inform therapies for atherosclerosis and related disorders.
Graft-versus-host disease
HDL infusion protects from acute graft-versus-host disease in experimental allogeneic hematopoietic cell transplantation. This suggests that modulating HDL clearance and availability could have immunomodulatory therapeutic benefits.
Obesity and metabolic syndrome
Genetic association studies have explored the relationship between obesity and serum lipid levels, including HDL. Variants in genes affecting HDL clearance may contribute to obesity-related dyslipidemia.
Neurodegeneration and brain lipoprotein metabolism
Cerebral cortex endothelial cells take up and clear oxidatively modified apolipoprotein E3, linking lipoprotein clearance to brain physiology. Dysregulation of this process may contribute to neurodegeneration.
From negative regulation of high-density lipoprotein particle clearance-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does APOA1 charge affect HDL clearance? | Point mutation knock-in of APOA1 in mice |
| Does loss of ABCA1 alter HDL clearance? | ABCA1 knockout cell lines and mice |
| Does microRNA-148a regulate HDL clearance? | miR-148a overexpression and knockout models |
| Does hepatic lipase modulate HDL clearance? | LIPC knockout mice and enzyme activity assays |
| Does inflammation affect HDL clearance? | TNF-alpha or IL-6 treated cell and mouse models |
| Does HDL infusion protect against GVHD? | Experimental allogeneic hematopoietic cell transplantation in mice |
How to Study the negative regulation of high-density lipoprotein particle clearance Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Reconstituted HDL clearance assay | Rate of HDL removal from circulation | In vivo testing of APOA1 variants |
| qPCR / RNA-seq | Expression of HDL-related genes | Assessing inflammatory or microRNA effects |
| Hepatic lipase activity assay | Enzyme activity in plasma | Studying HDL remodeling |
| Cellular uptake assay | Uptake of oxidized apolipoproteins | Endothelial cell biology |
| Western blot | Protein levels of ABCA1, APOA1 | Validating gene knockdown or overexpression |
| Lipid profile analysis | Plasma HDL, LDL, triglyceride levels | Phenotyping animal models |
| Flow cytometry | HDL binding to cells | Receptor interaction studies |
| CRISPR knockout screening | Identify genes regulating HDL clearance | Functional genomics |
Lipoprotein clearance assays
Reconstituted HDL particles can be injected into animal models to measure clearance rates, as demonstrated by Braschi et al.. This method directly assesses the effect of APOA1 charge and conformation on HDL removal.
Gene expression analysis
Quantitative PCR and RNA-seq can measure the expression of HDL-related genes such as ABCA1, LDLR, and APOA1 in response to inflammatory cytokines or microRNA modulation.
Enzyme activity assays
Hepatic lipase activity can be measured in plasma or tissue samples to assess its role in HDL remodeling and clearance.
Cellular uptake studies
Endothelial cells can be incubated with oxidized apolipoproteins to measure uptake and clearance, as shown for APOE3 in cerebral cortex endothelial cells.
How CRISPR Can Be Used to Study GO:0010987 negative regulation of high-density lipoprotein particle clearance
Knockout
CRISPR knockout of candidate genes such as ABCA1, LDLR, or LIPC can be used to determine their causal role in negative regulation of HDL particle clearance. Knockout cell lines and mice can be generated to measure changes in HDL clearance rates.
Point Mutation
Point mutations in APOA1 can be introduced to alter its charge or conformation, allowing precise testing of how these properties affect HDL clearance. This approach is ideal for dissecting structure-function relationships.
Knock-in
Knock-in of human APOA1 or other human lipoprotein genes into mouse models can humanize the system and enable testing of human-specific variants. This is particularly useful for translational studies.
Overexpression
Overexpression of microRNA-148a or other regulatory factors can be achieved via CRISPR activation or lentiviral delivery to study their impact on HDL clearance. Overexpression models help identify gain-of-function effects.
How EDITGENE Supports negative regulation of high-density lipoprotein particle clearance Research
Researchers studying negative regulation of high-density lipoprotein particle clearance-related genes often need to determine whether a candidate gene is causally involved in slowing HDL removal or whether it is merely a bystander. This requires precise genetic models that can isolate the effect of a single gene or mutation on HDL clearance rates. EDITGENE provides a comprehensive suite of CRISPR-based services to generate such models efficiently.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of high-density lipoprotein particle clearance research.
Frequently Asked Questions About negative regulation of high-density lipoprotein particle clearance
What is GO:0010987?
GO:0010987 is a Gene Ontology biological process term for negative regulation of high-density lipoprotein particle clearance, meaning any process that slows the removal of HDL particles from the circulation.
What genes are involved in negative regulation of HDL clearance?
Key genes include APOA1, ABCA1, LDLR, MIR148A, LIPC, and APOE, among others.
How does APOA1 affect HDL clearance?
The charge and conformation of APOA1 regulate the clearance of reconstituted HDL in vivo.
What role does microRNA-148a play in HDL metabolism?
MicroRNA-148a represses ABCA1 and LDLR, thereby influencing circulating lipoprotein levels and indirectly HDL clearance.
How do inflammatory cytokines affect HDL clearance?
Inflammatory cytokines such as TNF-alpha and IL-6 regulate HDL metabolism and can accelerate HDL catabolism, opposing negative regulation of clearance.
What is the link between HDL clearance and graft-versus-host disease?
HDL infusion protects from acute graft-versus-host disease in experimental allogeneic hematopoietic cell transplantation.
Can CRISPR be used to study HDL clearance?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models can be used to dissect genes regulating HDL clearance.
What experimental models exist for HDL clearance?
Models include Apoa1 knockout and human APOA1 transgenic mice, endothelial cell uptake assays, and hepatic lipase activity assays.
How is hepatic lipase involved in HDL clearance?
Hepatic lipase activity, regulated by sphingomyelin in plasma lipoproteins, remodels HDL and affects its clearance.
What diseases are associated with dysregulated HDL clearance?
Cardiovascular disease, graft-versus-host disease, obesity-related dyslipidemia, and neurodegeneration have been linked to altered HDL clearance.
Conclusion
GO:0010987, negative regulation of high-density lipoprotein particle clearance, is a biologically important process that controls plasma HDL levels and function. It is regulated by apolipoprotein conformation, microRNAs, inflammatory cytokines, and enzymes such as hepatic lipase. Dysregulation of this process is implicated in cardiovascular disease, graft-versus-host disease, obesity, and neurodegeneration. CRISPR-based models offer powerful tools to dissect the causal genes and pathways involved, and EDITGENE provides end-to-end services to support such research.
References
- 1. Haas MJ et al.. 2010. Regulation of high-density lipoprotein by inflammatory cytokines: establishing links between immune dysfunction and cardiovascular disease.. Diabetes Metab Res Rev 26(2):90-9 PMID: 20047197
- 2. Chagué C et al.. 2022. High-density lipoprotein infusion protects from acute graft-versus-host disease in experimental allogeneic hematopoietic cell transplantation.. Am J Transplant 22(5):1350-1361 PMID: 35038785
- 3. Braschi S et al.. 1999. Apolipoprotein A-I charge and conformation regulate the clearance of reconstituted high density lipoprotein in vivo.. J Lipid Res 40(3):522-32 PMID: 10064741
- 4. Ke J et al.. 2022. Exploring the Genetic Association between Obesity and Serum Lipid Levels Using Bivariate Methods.. Twin Res Hum Genet 25(6):234-244 PMID: 36606461
- 5. Cruz S et al.. 2019. Cellular Uptake and Clearance of Oxidatively-modified Apolipoprotein E3 by Cerebral Cortex Endothelial Cells.. Int J Mol Sci 20(18) PMID: 31533203
- 7. Yang P et al.. 2015. Regulation of hepatic lipase activity by sphingomyelin in plasma lipoproteins.. Biochim Biophys Acta 1851(10):1327-36 PMID: 26193433
- 8. Goedeke L et al.. 2015. MicroRNA-148a regulates LDL receptor and ABCA1 expression to control circulating lipoprotein levels.. Nat Med 21(11):1280-9 PMID: 26437365
