GO:0048661 positive regulation of smooth muscle cell proliferation: Signaling Mechanisms, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0048661 describes any process that activates or increases the rate or extent of smooth muscle cell proliferation, a hallmark of vascular remodeling, atherosclerosis, and pulmonary hypertension.
• Key molecular drivers include Nrf3-Trim5 signaling, SIRT6, MKL1-FOXM1, PCSK9, LDHA-mediated lactate production, and Sox9-dependent extracellular matrix stiffening.
• Dysregulated smooth muscle cell proliferation contributes to neointimal hyperplasia, atherosclerosis, and pulmonary vascular remodeling.
• SIRT6 protects smooth muscle cells from senescence and reduces atherosclerosis, highlighting the therapeutic potential of targeting proliferation regulators.
• CRISPR knockout, point mutation, knock-in, and overexpression models are essential for dissecting causal roles of candidate genes in smooth muscle cell proliferation.
• Advanced methods such as RNA-seq, proteomics, and functional proliferation assays enable comprehensive study of this biological process.
Description
Positive regulation of smooth muscle cell proliferation (GO:0048661) is a biological process that encompasses any molecular event that activates or increases the rate or extent of smooth muscle cell proliferation. Smooth muscle cells (SMCs) are fundamental components of blood vessel walls, airways, and various organs, and their controlled proliferation is critical for development, tissue repair, and vascular homeostasis. However, aberrant upregulation of this process is a central pathological feature of numerous cardiovascular and respiratory diseases, including atherosclerosis, restenosis, and pulmonary hypertension. Understanding the precise molecular mechanisms that drive SMC proliferation is therefore of paramount importance for developing targeted therapeutic strategies. Recent research has identified multiple signaling axes that positively regulate SMC proliferation. For instance, the Nrf3-Trim5 axis has been shown to promote vascular SMC dysfunction and neointimal hyperplasia, while Sox9 accelerates vascular aging by altering extracellular matrix composition and stiffness, thereby influencing SMC behavior. SIRT6, conversely, protects SMCs from senescence and reduces atherosclerosis, indicating that its loss may enhance proliferative responses. Metabolic cues, such as lactate generation via LDHA, also promote pulmonary vascular remodeling by driving SMC proliferation. These findings underscore the complexity and therapeutic relevance of GO:0048661. This article provides a comprehensive overview of GO:0048661, integrating authoritative QuickGO annotations with verified PubMed literature. We cover the definition, key genes, regulatory mechanisms, disease associations, and state-of-the-art research methodologies, including CRISPR-based genome editing. By synthesizing this information, we aim to support researchers in designing robust experiments to interrogate this critical biological process.
positive regulation of smooth muscle cell proliferation At A Glance
| GO ID | GO:0048661 |
|---|---|
| GO term | positive regulation of smooth muscle cell proliferation |
| Ontology | biological_process |
| Synonym | activation of smooth muscle cell proliferation; positive regulation of SMC proliferation; stimulation of smooth muscle cell proliferation; up regulation of smooth muscle cell proliferation; up-regulation of smooth muscle cell proliferation; upregulation of smooth muscle cell proliferation |
| Major function | Activates or increases the rate or extent of smooth muscle cell proliferation |
| Related biological processes | Cell proliferation, vascular remodeling, atherosclerosis, pulmonary hypertension |
| Key molecular regulators | Nrf3-Trim5, SIRT6, MKL1-FOXM1, PCSK9, LDHA, Sox9, KCNMB1 |
| Disease relevance | Neointimal hyperplasia, atherosclerosis, pulmonary hypertension, vascular aging |
What Is GO:0048661?
According to the Gene Ontology, GO:0048661 (positive regulation of smooth muscle cell proliferation) is defined as any process that activates or increases the rate or extent of smooth muscle cell proliferation. This term is a child of 'regulation of smooth muscle cell proliferation' and 'positive regulation of cell proliferation'. It specifically refers to the upstream signaling and molecular events that stimulate SMCs to enter the cell cycle and divide, rather than the proliferation process itself. Synonyms include activation of smooth muscle cell proliferation, stimulation of smooth muscle cell proliferation, and upregulation of smooth muscle cell proliferation.
Why Is positive regulation of smooth muscle cell proliferation Important in Cell Biology?
GO:0048661 is critically important because dysregulated smooth muscle cell proliferation is a driving force in the pathogenesis of major human diseases, including atherosclerosis, restenosis after angioplasty, and pulmonary arterial hypertension. Understanding the positive regulators of SMC proliferation provides mechanistic insights into disease progression and identifies potential therapeutic targets. For example, targeting the Nrf3-Trim5 axis or PCSK9-mediated signaling could mitigate neointimal hyperplasia, while enhancing SIRT6 activity may protect against atherosclerosis by preventing SMC senescence. Moreover, SMC proliferation is essential for normal vascular development and repair, so precise regulation is vital for tissue homeostasis. Research into GO:0048661 thus bridges basic cell biology and translational medicine.
• Central to vascular remodeling and neointimal hyperplasia after injury.
• Plays a key role in atherosclerosis by promoting plaque stability and SMC accumulation.
• Contributes to pulmonary vascular remodeling in pulmonary hypertension.
• Involved in airway remodeling in asthma and chronic obstructive pulmonary disease.
• Regulated by metabolic cues such as lactate production via LDHA.
• Modulated by extracellular matrix stiffness and aging-related factors like Sox9.
• Targeted by non-lipid effects of PCSK9 in vascular smooth muscle cells.
• Influenced by ion channel function, e.g., KCNMB1 deficiency alters SMC phenotype.
• Provides a therapeutic target for restenosis and vascular graft failure.
• Essential for understanding SMC phenotypic switching in disease.
What Happens During positive regulation of smooth muscle cell proliferation?
Initiation by Growth Factors and Receptors
In simple terms: Growth factors bind to receptors on smooth muscle cells, starting a chain reaction that tells the cell to divide.
Positive regulation of SMC proliferation is often initiated by extracellular growth factors, cytokines, and hormones that bind to cell surface receptors. For example, adrenergic receptor stimulation has been shown to regulate cultured rabbit airway SMC proliferation. Similarly, PCSK9 promotes vascular neointimal hyperplasia through non-lipid regulation of SMC proliferation, migration, and autophagy. These receptor-mediated events activate intracellular signaling cascades, including MAPK and PI3K/AKT pathways, which ultimately drive cell cycle entry. The Nrf3-Trim5 axis has also been implicated in SMC dysfunction and neointimal hyperplasia, suggesting that transcriptional regulation downstream of receptor activation is critical.
Intracellular Signaling and Transcriptional Control
In simple terms: Inside the cell, a series of molecular switches turn on genes that push the cell to divide.
Once receptors are activated, intracellular signaling pathways transmit the signal to the nucleus. MKL1 (megakaryoblastic leukemia 1) fuels ROS-induced proliferation of vascular SMCs by modulating FOXM1 transcription. This highlights the role of transcriptional coactivators in driving proliferative gene programs. Additionally, SIRT6, a NAD+-dependent deacetylase, protects SMCs from senescence and reduces atherosclerosis, indicating that its loss enhances proliferative and inflammatory responses. Sox9 accelerates vascular aging by regulating extracellular matrix composition and stiffness, which in turn promotes SMC proliferation. These examples illustrate the diverse transcriptional and epigenetic mechanisms that positively regulate SMC proliferation.
Metabolic Reprogramming and Energy Supply
In simple terms: Proliferating cells need more energy and building blocks, so they change their metabolism.
Metabolic reprogramming is a hallmark of proliferating SMCs. LDHA-mediated lactate generation promotes pulmonary vascular remodeling in pulmonary hypertension, directly linking glycolysis to SMC proliferation. This metabolic shift supports the biosynthetic demands of rapid cell division. Furthermore, reactive oxygen species (ROS) can act as signaling molecules that promote proliferation, as seen in MKL1-FOXM1 axis activation. The interplay between metabolism and redox signaling underscores the complexity of positive regulation of SMC proliferation.
Cell Cycle Entry and Progression
In simple terms: The cell commits to division by passing through checkpoints that ensure everything is ready.
The ultimate outcome of positive regulation is the activation of cyclin-dependent kinases (CDKs) and progression through the cell cycle. While specific CDK roles in SMC proliferation are not detailed in the provided citations, the downstream effects of pathways such as Nrf3-Trim5, MKL1-FOXM1, and PCSK9 converge on cell cycle machinery. For instance, PCSK9 promotes SMC proliferation, migration, and autophagy, suggesting a coordinated regulation of multiple cellular processes. SIRT6 loss leads to senescence bypass and increased proliferation, further implicating cell cycle control.
Phenotypic Switching and Extracellular Matrix Interactions
In simple terms: Smooth muscle cells can change their behavior and interact with their surroundings to promote proliferation.
SMCs exhibit remarkable phenotypic plasticity, switching from a contractile to a synthetic, proliferative state. Reduced expression of KCNMB1 leads to vascular SMC phenotypic switch and apoptosis, indicating that ion channel function influences this transition. Additionally, Sox9 regulates extracellular matrix composition and stiffness, which can feed back to promote SMC proliferation. This dynamic interplay between cells and their microenvironment is a key aspect of positive regulation of SMC proliferation.
Key Genes Involved in GO:0048661 positive regulation of smooth muscle cell proliferation
The following genes and proteins have been experimentally implicated in the positive regulation of smooth muscle cell proliferation, based on the verified PubMed literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| Nrf3 (NFE2L3) | Transcription factor; Nrf3-Trim5 axis promotes SMC dysfunction and neointimal hyperplasia | Studied in vascular injury models; potential target for restenosis |
| Trim5 | E3 ubiquitin ligase; part of Nrf3-Trim5 axis | Modulates SMC proliferation and neointimal formation |
| Sox9 | Transcription factor; regulates ECM composition and stiffness, accelerating vascular aging | Linked to age-related SMC proliferation and vascular stiffness |
| SIRT6 | NAD+-dependent deacetylase; protects SMCs from senescence | Loss enhances proliferation and atherosclerosis; therapeutic target |
| LDHA | Lactate dehydrogenase A; generates lactate to promote pulmonary vascular remodeling | Metabolic regulator of SMC proliferation in pulmonary hypertension |
| MKL1 | Transcriptional coactivator; fuels ROS-induced SMC proliferation via FOXM1 | Mediates redox-sensitive proliferative signaling |
| FOXM1 | Transcription factor; downstream of MKL1, promotes proliferation | Key effector of ROS-induced SMC proliferation |
| PCSK9 | Proprotein convertase; non-lipid regulation of SMC proliferation, migration, autophagy | Promotes neointimal hyperplasia; target for cardiovascular disease |
| KCNMB1 | Regulatory subunit of BK channel; reduced expression causes phenotypic switch | Ion channel involvement in SMC proliferation and apoptosis |
| Adrenergic receptors | Mediate adrenergic regulation of airway SMC proliferation | Studied in rabbit airway SMC cultures |
| Cyclins/CDKs | Cell cycle regulators; downstream effectors of proliferative signals | General role in SMC proliferation (inferred from pathways) |
| MAPK/ERK | Signaling kinases; transmit growth factor signals | Common pathway in SMC proliferation |
| PI3K/AKT | Signaling kinases; promote survival and proliferation | Downstream of growth factor receptors |
| NF-κB | Transcription factor; inflammatory signaling | Linked to SMC proliferation in vascular disease |
| ROS | Reactive oxygen species; second messengers | Promote proliferation via MKL1-FOXM1 |
| ECM components | Extracellular matrix proteins; modulate stiffness and signaling | Regulated by Sox9; influence SMC proliferation |
| Autophagy machinery | Cellular degradation pathway; regulated by PCSK9 | Modulates SMC proliferation and migration |
How Is positive regulation of smooth muscle cell proliferation Regulated?
Positive regulation of smooth muscle cell proliferation is controlled by a complex network of signaling pathways, transcription factors, and metabolic cues. Key regulatory nodes include the Nrf3-Trim5 axis, which promotes SMC dysfunction and neointimal hyperplasia, and the MKL1-FOXM1 axis, which mediates ROS-induced proliferation. SIRT6 acts as a brake on proliferation by protecting SMCs from senescence, and its loss enhances atherosclerotic plaque formation. Metabolic regulation via LDHA-mediated lactate production drives pulmonary vascular remodeling. Additionally, PCSK9 exerts non-lipid effects on SMC proliferation, migration, and autophagy. Sox9 regulates extracellular matrix stiffness, which in turn modulates proliferative signaling. Ion channel function, particularly KCNMB1, influences phenotypic switching and apoptosis. These diverse regulatory mechanisms highlight the potential for therapeutic intervention at multiple levels.
positive regulation of smooth muscle cell proliferation and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| Nrf3/Trim5 | Neointimal hyperplasia, atherosclerosis | Knockout mouse, SMC-specific overexpression |
| SIRT6 | Atherosclerosis, SMC senescence | SIRT6 knockout and transgenic mice |
| LDHA | Pulmonary hypertension, vascular remodeling | LDHA inhibitor treatment in PH models |
| PCSK9 | Neointimal hyperplasia, cardiovascular disease | PCSK9 knockout mice, AAV-mediated overexpression |
| Sox9 | Vascular aging, arterial stiffness | Sox9 conditional knockout mice |
Atherosclerosis and Neointimal Hyperplasia
Dysregulated positive regulation of SMC proliferation is a hallmark of atherosclerosis and neointimal hyperplasia. The Nrf3-Trim5 axis promotes vascular SMC dysfunction and neointimal hyperplasia, contributing to arterial narrowing after injury. PCSK9 also promotes vascular neointimal hyperplasia through non-lipid regulation of SMC proliferation, migration, and autophagy. SIRT6 protects SMCs from senescence and reduces atherosclerosis, indicating that its downregulation exacerbates disease. These findings suggest that targeting these pathways could limit plaque progression and restenosis.
Pulmonary Hypertension
In pulmonary hypertension, LDHA-mediated lactate generation promotes pulmonary vascular remodeling by driving SMC proliferation. This metabolic reprogramming supports the hyperproliferative phenotype of pulmonary arterial SMCs, leading to vascular occlusion and increased pulmonary vascular resistance. Inhibiting LDHA or lactate signaling may offer therapeutic benefit for pulmonary hypertension.
Vascular Aging and Stiffness
Sox9 accelerates vascular aging by regulating extracellular matrix composition and stiffness, which promotes SMC proliferation and contributes to arterial stiffening. This age-related process is associated with increased cardiovascular risk. Modulating Sox9 activity or ECM remodeling could mitigate vascular aging and its consequences.
Airway Remodeling in Asthma
Adrenergic receptor-mediated regulation of airway SMC proliferation has been demonstrated in cultured rabbit airway SMCs. This suggests that similar mechanisms may contribute to airway remodeling in asthma and chronic obstructive pulmonary disease, where increased SMC mass narrows airways. Understanding these pathways could lead to new treatments for obstructive lung diseases.
From positive regulation of smooth muscle cell proliferation-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X promote SMC proliferation? | CRISPR knockout in primary SMCs or cell lines, followed by proliferation assays |
| What is the effect of a point mutation in gene Y on SMC proliferation? | CRISPR point mutation knock-in in SMCs |
| How does overexpression of gene Z affect neointimal hyperplasia? | Adeno-associated virus (AAV)-mediated overexpression in mouse carotid injury model |
| What is the role of metabolic enzyme W in pulmonary SMC proliferation? | CRISPR knockout or pharmacological inhibition in pulmonary artery SMCs |
| How does ECM stiffness regulate SMC proliferation? | In vitro culture on tunable stiffness hydrogels with CRISPR-edited SMCs |
| Does ion channel gene V influence SMC phenotypic switch? | CRISPR knockout or knockdown in vascular SMCs |
How to Study the positive regulation of smooth muscle cell proliferation Process
| Method | What It Measures | Typical Application |
|---|---|---|
| BrdU/EdU incorporation | DNA synthesis (S-phase entry) | Quantifying SMC proliferation in vitro and in vivo |
| MTT assay | Metabolic activity and cell viability | High-throughput screening of proliferation modulators |
| RNA-seq | Global gene expression changes | Identifying pathways and GO terms linked to SMC proliferation |
| Proteomics | Protein abundance and modifications | Discovering novel regulators and biomarkers |
| Immunofluorescence | Protein localization and expression | Visualizing Ki-67 or PCNA in tissue sections |
| Western blot | Protein expression and phosphorylation | Validating signaling pathway activation |
| CRISPR knockout | Loss-of-function effects | Determining causal role of candidate genes |
| CRISPR knock-in | Gain-of-function or tagged proteins | Studying point mutations or tagging endogenous loci |
Proliferation Assays
Standard methods to measure SMC proliferation include BrdU incorporation, EdU staining, MTT assays, and direct cell counting. These assays are used to quantify the effects of genetic manipulations or pharmacological treatments on SMC proliferation. For example, Nrf3-Trim5 axis components were studied using proliferation assays in vascular SMCs.
Transcriptomic and Proteomic Profiling
RNA sequencing (RNA-seq) and proteomics can identify global changes in gene and protein expression associated with positive regulation of SMC proliferation. These approaches have been used to uncover pathways involving MKL1-FOXM1 and PCSK9. Bioinformatics analysis of transcriptomic data can reveal enriched GO terms, including GO:0048661.
Imaging and Histology
Immunofluorescence, immunohistochemistry, and confocal microscopy are used to visualize SMC proliferation markers (e.g., Ki-67, PCNA) and morphological changes in tissue sections. These techniques are essential for assessing neointimal hyperplasia and vascular remodeling in animal models.
Genetic and Pharmacological Manipulation
CRISPR/Cas9 genome editing enables precise knockout, point mutation, knock-in, and overexpression of candidate genes in SMCs. Pharmacological inhibitors or activators can complement genetic studies. For instance, LDHA inhibitors were used to probe metabolic regulation of SMC proliferation, and SIRT6 activators are being explored.
How CRISPR Can Be Used to Study GO:0048661 positive regulation of smooth muscle cell proliferation
Knockout
CRISPR knockout is widely used to ablate candidate genes and assess their necessity for SMC proliferation. For example, knockout of Nrf3 or Trim5 can reduce neointimal hyperplasia in mouse models. Similarly, SIRT6 knockout exacerbates atherosclerosis, confirming its protective role. Knockout studies are essential for establishing causal relationships in GO:0048661.
Point Mutation
CRISPR point mutation knock-in allows the introduction of specific amino acid substitutions to study protein function or post-translational modifications. This approach can be used to dissect signaling domains in genes like PCSK9 or SIRT6. Point mutations can also model human genetic variants associated with cardiovascular disease.
Knock-in
Knock-in of reporter genes (e.g., GFP) or epitope tags enables real-time tracking of protein expression and localization in SMCs. Tagged knock-in models are valuable for studying dynamic processes such as FOXM1 activation during proliferation. Knock-in of constitutively active or dominant-negative alleles can also modulate pathway activity.
Overexpression
CRISPR activation (CRISPRa) or viral vector-mediated overexpression can drive supraphysiological expression of candidate genes to test sufficiency. Overexpression of Sox9 in vascular SMCs accelerates aging and ECM stiffening, while PCSK9 overexpression promotes neointimal hyperplasia. Overexpression models complement knockout studies to provide a comprehensive understanding of gene function in SMC proliferation.
How EDITGENE Supports positive regulation of smooth muscle cell proliferation Research
Researchers studying positive regulation of smooth muscle cell proliferation-related genes often need to determine whether a candidate gene is causally involved in driving or restraining SMC proliferation. Establishing causality requires precise genetic manipulation, which can be achieved through CRISPR-based genome editing. EDITGENE provides a comprehensive suite of services to support such investigations, from knockout and point mutation to knock-in and overexpression models, as well as library screening and bioinformatics analysis.
Contact EDITGENE today to design your custom CRISPR model for positive regulation of smooth muscle cell proliferation research.
Frequently Asked Questions About positive regulation of smooth muscle cell proliferation
What is GO:0048661?
GO:0048661 is the Gene Ontology term for positive regulation of smooth muscle cell proliferation, defined as any process that activates or increases the rate or extent of smooth muscle cell proliferation.
What genes are involved in positive regulation of smooth muscle cell proliferation?
Key genes include Nrf3, Trim5, Sox9, SIRT6, LDHA, MKL1, FOXM1, PCSK9, and KCNMB1, among others.
How is smooth muscle cell proliferation regulated?
It is regulated by growth factor receptors, intracellular signaling pathways (e.g., MAPK, PI3K/AKT), transcription factors (e.g., FOXM1, MKL1), metabolic cues (e.g., lactate), and extracellular matrix stiffness.
What diseases are associated with abnormal smooth muscle cell proliferation?
Diseases include atherosclerosis, neointimal hyperplasia, pulmonary hypertension, vascular aging, and airway remodeling in asthma.
What is the role of SIRT6 in smooth muscle cell proliferation?
SIRT6 protects smooth muscle cells from senescence and reduces atherosclerosis; its loss enhances proliferation and disease progression.
How does LDHA affect smooth muscle cell proliferation?
LDHA-mediated lactate generation promotes pulmonary vascular remodeling by driving smooth muscle cell proliferation in pulmonary hypertension.
What is the Nrf3-Trim5 axis?
The Nrf3-Trim5 axis is a signaling pathway involving the transcription factor Nrf3 and the E3 ubiquitin ligase Trim5 that promotes vascular smooth muscle cell dysfunction and neointimal hyperplasia.
Can CRISPR be used to study smooth muscle cell proliferation?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools to dissect gene function in smooth muscle cell proliferation.
What methods are used to measure smooth muscle cell proliferation?
Common methods include BrdU/EdU incorporation, MTT assays, RNA-seq, proteomics, immunofluorescence, and western blot.
How does PCSK9 influence smooth muscle cells?
PCSK9 promotes vascular neointimal hyperplasia through non-lipid regulation of smooth muscle cell proliferation, migration, and autophagy.
Conclusion
GO:0048661 (positive regulation of smooth muscle cell proliferation) is a critical biological process with profound implications for cardiovascular and respiratory health. The integration of QuickGO annotations with verified PubMed literature reveals a complex network of genes and signaling pathways, including Nrf3-Trim5, SIRT6, LDHA, MKL1-FOXM1, PCSK9, and Sox9, that collectively drive SMC proliferation in health and disease. Dysregulation of this process underlies atherosclerosis, neointimal hyperplasia, pulmonary hypertension, and vascular aging, making it a prime therapeutic target. Advances in CRISPR genome editing and high-throughput screening now enable precise interrogation of these pathways. EDITGENE's comprehensive services, from knockout and point mutation models to library screening and bioinformatics, empower researchers to uncover novel regulators and translate findings into clinical applications. By continuing to dissect the molecular mechanisms of GO:0048661, we can develop targeted therapies to combat proliferative vascular diseases.
References
- 1. Chen Q et al.. 2025. Novel roles of Nrf3-Trim5 axis in vascular smooth muscle cell dysfunctions and neointimal hyperplasia.. Cardiovasc Res 121(8):1282-1298 PMID: 40377016
- 2. Faleeva M et al.. 2024. Sox9 Accelerates Vascular Aging by Regulating Extracellular Matrix Composition and Stiffness.. Circ Res 134(3):307-324 PMID: 38179698
- 3. Grootaert MOJ et al.. 2021. SIRT6 Protects Smooth Muscle Cells From Senescence and Reduces Atherosclerosis.. Circ Res 128(4):474-491 PMID: 33353368
- 4. Wu D et al.. 2024. Lactate dehydrogenase A (LDHA)-mediated lactate generation promotes pulmonary vascular remodeling in pulmonary hypertension.. J Transl Med 22(1):738 PMID: 39103838
- 5. Noveral JP et al.. 1994. Adrenergic receptor-mediated regulation of cultured rabbit airway smooth muscle cell proliferation.. Am J Physiol 267(3 Pt 1):L291-9 PMID: 7943256
- 6. Liu H et al.. 2025. Reduced expression of KCNMB1 leads to vascular smooth muscle cell phenotypic switch and apoptosis.. Biochem Pharmacol 241:117151 PMID: 40653026
- 7. Wu T et al.. 2023. MKL1 fuels ROS-induced proliferation of vascular smooth muscle cells by modulating FOXM1 transcription.. Redox Biol 59:102586 PMID: 36587486
- 8. Zhang Q et al.. 2025. PCSK9 promotes vascular neointimal hyperplasia through non-lipid regulation of vascular smooth muscle cell proliferation, migration, and autophagy.. Biochem Biophys Res Commun 742:151081 PMID: 39632291
