GO:0014806 smooth muscle hyperplasia: Vascular Remodeling Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0014806 (smooth muscle hyperplasia) is defined as a process occurring in smooth muscle in which there is an increase in cell number by cell division, often leading to an increase in the size of an organ.
• Vascular smooth muscle cell (VSMC) phenotypic switching from a contractile to a synthetic/proliferative state is a central driver of neointimal hyperplasia after vessel injury [1,2,3].
• Multiple molecular regulators, including NEXN, Piezo1, ZFP36, PTPN14, TSPAN4, and Profilin-1, have been experimentally shown to control VSMC proliferation and neointimal hyperplasia in mouse models [1,3,4,5,6,8].
• Noncoding RNAs (microRNAs and long noncoding RNAs) are key post-transcriptional regulators of VSMC function and neointimal hyperplasia.
• Smooth muscle hyperplasia is not limited to vasculature; it also occurs in cutaneous lesions such as protein kinase C-fused blue naevi, where it is a diagnostic histopathologic feature.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models are powerful tools for dissecting causal gene function in smooth muscle hyperplasia research.
Description
Smooth muscle hyperplasia (GO:0014806) is a biological process defined as an increase in smooth muscle cell number through cell division, frequently resulting in enlargement of the affected organ [QuickGO]. This process is distinct from hypertrophy (cell enlargement) and is driven by the re-entry of normally quiescent smooth muscle cells into the cell cycle. In the vasculature, smooth muscle hyperplasia is a hallmark of neointimal hyperplasia, the pathological thickening of the arterial intima that occurs after angioplasty, stenting, or bypass grafting [1,2]. The phenotypic switching of vascular smooth muscle cells (VSMCs) from a differentiated, contractile state to a dedifferentiated, synthetic state is a prerequisite for their proliferation and migration, which together drive neointimal lesion formation [1,3,6]. Understanding the molecular mechanisms of smooth muscle hyperplasia is therefore critical for developing therapies to prevent restenosis and other proliferative vascular diseases. Beyond the vasculature, smooth muscle hyperplasia is also observed in certain cutaneous neoplasms, such as protein kinase C-fused blue naevi, where it serves as a diagnostic histopathologic clue. This article synthesizes authoritative GO annotations and verified PubMed literature to provide a research-grade overview of the genes, mechanisms, disease links, and experimental models relevant to GO:0014806.
smooth muscle hyperplasia At A Glance
| GO ID | GO:0014806 |
|---|---|
| GO term | smooth muscle hyperplasia |
| Ontology | biological_process |
| Synonym | None |
| Major function | Increase in smooth muscle cell number by cell division, often leading to organ enlargement |
| Cellular context | Smooth muscle cells, including vascular smooth muscle cells (VSMCs) |
| Associated diseases | Neointimal hyperplasia, restenosis, atherosclerosis, protein kinase C-fused blue naevi |
| Key regulators | NEXN, Piezo1, ZFP36, PTPN14, TSPAN4, Profilin-1, noncoding RNAs |
| Research models | Mouse carotid artery ligation/injury models, VSMC culture, CRISPR knockout/knock-in mice |
What Is GO:0014806?
According to the Gene Ontology, smooth muscle hyperplasia (GO:0014806) is a biological process, occurring in smooth muscle, in which there is an increase in cell number by cell division, often leading to an increase in the size of an organ. In simpler terms, it is the abnormal proliferation of smooth muscle cells, which can thicken the walls of hollow organs such as blood vessels, airways, or the gastrointestinal tract. This process is distinct from smooth muscle hypertrophy, which refers to an increase in cell size rather than cell number.
Why Is smooth muscle hyperplasia Important in Cell Biology?
Smooth muscle hyperplasia is a fundamental pathological process underlying numerous proliferative disorders, most notably neointimal hyperplasia and restenosis after vascular interventions [1,2]. It also contributes to airway remodeling in asthma and to certain cutaneous lesions. Because it involves a phenotypic switch of normally quiescent smooth muscle cells into a proliferative, synthetic state, it serves as a paradigm for studying cell-cycle re-entry, cytoskeletal remodeling, and mechanotransduction [3,6]. Elucidating its molecular drivers is essential for identifying therapeutic targets to limit pathological vascular remodeling.
• Neointimal hyperplasia after angioplasty or stenting is a major cause of restenosis and late stent failure [1,2].
• VSMC phenotypic switching is a key early event in atherosclerosis and plaque instability [1,3].
• Smooth muscle hyperplasia in the airway contributes to asthma-related airway remodeling.
• Protein kinase C-fused blue naevi exhibit smooth muscle hyperplasia as a diagnostic histopathologic feature.
• Noncoding RNAs regulate VSMC proliferation and migration, offering potential therapeutic targets.
• Mechanotransduction via Piezo1 controls VSMC phenotypic switch and neointimal hyperplasia.
• m6A RNA modification of Profilin-1 drives VSMC phenotype switching and neointimal hyperplasia.
• PTPN14 amplifies PDGFRβ signaling to aggravate neointimal hyperplasia.
• ZFP36 deletion in smooth muscle promotes neointimal hyperplasia in mice.
• TSPAN4 regulates VSMC phenotypic switching via TPM1-mediated cytoskeletal organization.
What Happens During smooth muscle hyperplasia?
Initiation: Phenotypic Switching of Smooth Muscle Cells
In simple terms: Smooth muscle cells change from a quiet, contracting state to a growing, migrating state.
The first step in smooth muscle hyperplasia is the phenotypic switch of differentiated, contractile smooth muscle cells into a synthetic, proliferative phenotype. This switch is characterized by downregulation of contractile markers such as MYH11, ACTA2, and CNN1, and upregulation of synthetic markers and cell-cycle genes [1,3,6]. In vascular smooth muscle cells (VSMCs), this process is triggered by injury, growth factors, and mechanical stress, and is essential for neointimal hyperplasia [1,2].
Proliferation: Cell Division and Increase in Cell Number
In simple terms: The switched cells start dividing rapidly, increasing their numbers.
Once switched to a synthetic phenotype, smooth muscle cells re-enter the cell cycle and proliferate. This proliferation is driven by growth factor signaling pathways, including PDGFRβ, and is modulated by cytoskeletal reorganization [5,6]. The increase in cell number is the defining feature of hyperplasia (GO:0014806). Key regulators include NEXN, which when lost promotes VSMC proliferation and neointimal hyperplasia, and Piezo1, a mechanosensitive ion channel essential for the phenotypic switch and subsequent hyperplasia.
Migration: Cells Move to Form Neointima
In simple terms: The dividing cells travel from the middle layer of the vessel to the inner layer, building up a thick lesion.
Proliferating smooth muscle cells migrate from the media to the intima, where they accumulate and form the neointimal lesion. This migration requires dynamic reorganization of the actin cytoskeleton, regulated by proteins such as TSPAN4 and TPM1. Noncoding RNAs also modulate VSMC migration and neointimal hyperplasia.
Matrix Remodeling and Lesion Maturation
In simple terms: The cells deposit new matrix proteins, making the lesion more stable and thick.
As smooth muscle cells accumulate in the intima, they secrete extracellular matrix components, leading to further thickening of the vessel wall. This matrix remodeling is influenced by signaling pathways such as PDGFRβ, which is amplified by PTPN14 to aggravate neointimal hyperplasia. The resulting lesion can narrow the vessel lumen, causing restenosis.
Resolution and Therapeutic Targeting
In simple terms: Understanding how to stop or reverse this process is key to treating diseases.
Smooth muscle hyperplasia is not always irreversible; interventions targeting key regulators can attenuate lesion formation. For example, deletion of ZFP36 in smooth muscle promotes neointimal hyperplasia, suggesting that ZFP36 is protective. Conversely, inhibition of PTPN14 or Piezo1 reduces hyperplasia [3,5]. These findings highlight potential therapeutic targets for restenosis and other proliferative vascular diseases.
Key Genes Involved in GO:0014806 smooth muscle hyperplasia
The following genes and proteins have been experimentally implicated in the regulation of smooth muscle hyperplasia, particularly in vascular smooth muscle cells and neointimal hyperplasia models.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NEXN | Regulates VSMC phenotypic switching; loss promotes neointimal hyperplasia | Knockout mouse models show increased neointimal formation |
| Piezo1 | Mechanosensitive ion channel essential for VSMC phenotypic switch | Smooth muscle-specific knockout reduces neointimal hyperplasia |
| ZFP36 | RNA-binding protein; deletion promotes neointimal hyperplasia | Smooth muscle ZFP36 knockout mice develop exacerbated lesions |
| PTPN14 | Tyrosine phosphatase that boosts PDGFRβ signaling | Knockdown or inhibition attenuates neointimal hyperplasia |
| TSPAN4 | Tetraspanin regulating cytoskeletal organization via TPM1 | Knockdown impairs VSMC phenotypic switching and intimal hyperplasia |
| PFN1 (Profilin-1) | Actin-binding protein; m6A modification drives phenotype switching | m6A modification of PFN1 activates p-ANXA2/STAT3 pathway |
| TPM1 | Tropomyosin 1; target of TSPAN4 for cytoskeletal organization | Regulates VSMC phenotypic switching and intimal hyperplasia |
| PDGFRβ | Receptor tyrosine kinase driving VSMC proliferation | Signaling amplified by PTPN14 in neointimal hyperplasia |
| ANXA2 | Annexin A2; phosphorylated form activates STAT3 | Downstream of PFN1 m6A modification in VSMC phenotype switching |
| STAT3 | Transcription factor promoting proliferation | Activated by p-ANXA2 in VSMC phenotype switching |
| MYH11 | Smooth muscle myosin heavy chain; contractile marker | Downregulated during phenotypic switching [1,3] |
| ACTA2 | Alpha smooth muscle actin; contractile marker | Downregulated during phenotypic switching [1,3] |
| CNN1 | Calponin 1; contractile marker | Downregulated during phenotypic switching [1,3] |
| miRNAs (e.g., miR-21, miR-145) | Noncoding RNAs regulating VSMC function | Modulate neointimal hyperplasia |
| lncRNAs (e.g., MALAT1, H19) | Long noncoding RNAs regulating VSMC function | Modulate neointimal hyperplasia |
How Is smooth muscle hyperplasia Regulated?
Smooth muscle hyperplasia is regulated at multiple levels, including transcriptional, post-transcriptional, and post-translational mechanisms. Noncoding RNAs, such as microRNAs and long noncoding RNAs, play critical roles in modulating VSMC proliferation and migration during neointimal hyperplasia. The m6A RNA modification of Profilin-1 mRNA enhances its stability and translation, driving VSMC phenotype switching via the p-ANXA2/STAT3 pathway. Protein tyrosine phosphatases, such as PTPN14, regulate PDGFRβ signaling strength and duration, thereby controlling VSMC proliferation. RNA-binding proteins like ZFP36 influence the stability of mRNAs encoding pro-proliferative factors. Mechanotransduction via Piezo1 channels links hemodynamic forces to VSMC phenotypic switching. Additionally, cytoskeletal regulators such as NEXN and TSPAN4 modulate the actin cytoskeleton to control VSMC contractility and proliferation [1,6].
smooth muscle hyperplasia and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NEXN | Neointimal hyperplasia; loss promotes VSMC proliferation | Smooth muscle-specific knockout mouse; carotid artery ligation injury |
| Piezo1 | Neointimal hyperplasia; mechanotransduction | Inducible smooth muscle-specific knockout mouse |
| PTPN14 | Neointimal hyperplasia; PDGFRβ signaling | VSMC-specific knockout or pharmacological inhibition in mouse |
| PFN1 | Neointimal hyperplasia; m6A modification | VSMC-specific overexpression or m6A reader knockout |
| ZFP36 | Neointimal hyperplasia; mRNA stability | Smooth muscle-specific knockout mouse |
Neointimal Hyperplasia and Restenosis
Neointimal hyperplasia is the pathological thickening of the arterial intima due to smooth muscle cell proliferation and migration, and is the primary cause of restenosis after percutaneous coronary intervention or bypass surgery [1,2]. Multiple genes have been shown to drive this process in mouse models, including Piezo1, PTPN14, and Profilin-1 [3,5,8]. Conversely, NEXN and ZFP36 appear protective, as their loss exacerbates lesion formation [1,4].
Atherosclerosis
Smooth muscle hyperplasia contributes to atherosclerotic plaque progression and stability. VSMC phenotypic switching from contractile to synthetic states is a hallmark of advanced plaques, and genes such as TSPAN4 and NEXN regulate this switch [1,6]. Noncoding RNAs also influence VSMC behavior in atherosclerosis.
Cutaneous Smooth Muscle Hyperplasia
Smooth muscle hyperplasia is a histopathologic feature of protein kinase C-fused blue naevi, a distinct subset of blue naevi. A case series of 12 patients reported smooth muscle hyperplasia in these lesions, highlighting its diagnostic relevance beyond the vasculature.
From smooth muscle hyperplasia-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a candidate gene promote smooth muscle hyperplasia? | Smooth muscle-specific knockout mouse (e.g., Cre-loxP) [1,3,4] |
| Does a specific point mutation in a gene affect VSMC proliferation? | Knock-in mouse expressing mutant allele via CRISPR |
| Does overexpression of a gene drive neointimal hyperplasia? | Transgenic mouse with smooth muscle-specific overexpression |
| Where and when is a protein expressed during hyperplasia? | Tagged knock-in mouse (e.g., GFP or HA tag) |
| What is the role of a noncoding RNA in VSMC function? | Knockout or overexpression of miRNA/lncRNA in VSMC |
| Can a drug target reduce neointimal hyperplasia? | Pharmacological inhibition in mouse injury model |
How to Study the smooth muscle hyperplasia Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Carotid artery ligation injury model | Neointimal hyperplasia in vivo | Assessing gene function in VSMC proliferation [1,3] |
| Immunofluorescence | Protein expression and localization | Detecting contractile markers and proliferation [1,6] |
| RNA-seq | Transcriptome changes | Identifying genes involved in phenotypic switching [1,6] |
| Proteomics | Protein abundance and modifications | Quantifying signaling changes |
| EdU/BrdU incorporation | DNA synthesis and proliferation | Measuring VSMC proliferation in vitro and in vivo |
| Transwell migration assay | Cell migration | Assessing VSMC migration |
| Western blot | Protein expression and phosphorylation | Validating signaling pathways [5,8] |
| qRT-PCR | mRNA expression | Quantifying contractile and synthetic markers [1,4] |
Lineage Tracing and Genetic Fate Mapping
Lineage tracing using inducible Cre recombinase under smooth muscle-specific promoters (e.g., Myh11-CreERT2) allows researchers to track the fate of smooth muscle cells during hyperplasia. This method has been used to demonstrate that VSMCs migrate and proliferate to form neointimal lesions [1,3].
RNA Sequencing and Transcriptomics
Bulk or single-cell RNA sequencing of smooth muscle cells isolated from injured vessels can identify genes and pathways differentially expressed during phenotypic switching and hyperplasia. This approach has revealed the downregulation of contractile markers and upregulation of synthetic genes [1,6].
Proteomics and Phosphoproteomics
Mass spectrometry-based proteomics can quantify changes in protein abundance and phosphorylation during smooth muscle hyperplasia. For example, phosphoproteomics has been used to identify PDGFRβ signaling components regulated by PTPN14.
Imaging and Histology
Immunohistochemistry and immunofluorescence for contractile markers (e.g., ACTA2, MYH11) and proliferation markers (e.g., Ki67) are standard methods to assess smooth muscle hyperplasia in tissue sections. These techniques have been used to characterize neointimal lesions in mouse models [1,3,4].
How CRISPR Can Be Used to Study GO:0014806 smooth muscle hyperplasia
Knockout
CRISPR-Cas9 knockout of candidate genes in vascular smooth muscle cells or in mouse models is a powerful approach to determine loss-of-function effects on smooth muscle hyperplasia. For example, smooth muscle-specific knockout of Piezo1 or ZFP36 has been used to demonstrate their roles in neointimal hyperplasia [3,4]. EDITGENE provides custom knockout cell lines and mouse models to accelerate this research.
Point Mutation
CRISPR-mediated point mutations can mimic human disease-associated variants or disrupt specific phosphorylation sites. For instance, mutating the m6A site in Profilin-1 mRNA could test its role in VSMC phenotype switching. EDITGENE offers precise point-mutation services in smooth muscle cell lines and primary cells.
Knock-in
Knock-in of reporter genes (e.g., GFP) or epitope tags (e.g., HA) allows visualization and purification of endogenous proteins. Tagging TSPAN4 or NEXN in smooth muscle cells can reveal their dynamic localization during hyperplasia [1,6]. EDITGENE provides knock-in services for endogenous tagging and reporter expression.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression can drive sustained expression of candidate genes to test sufficiency in promoting smooth muscle hyperplasia. Overexpression of PTPN14 or Profilin-1 has been shown to aggravate neointimal hyperplasia [5,8]. EDITGENE offers overexpression cell models and in vivo delivery.
How EDITGENE Supports smooth muscle hyperplasia Research
Researchers studying smooth muscle hyperplasia-related genes often need to determine whether a candidate gene is causally involved in VSMC phenotypic switching, proliferation, and neointimal lesion formation. EDITGENE provides a comprehensive suite of CRISPR-based services to enable these investigations, from gene knockout to precise point mutations and overexpression models.
Contact EDITGENE today to design your custom CRISPR model for smooth muscle hyperplasia research.
Frequently Asked Questions About smooth muscle hyperplasia
What is smooth muscle hyperplasia (GO:0014806)?
Smooth muscle hyperplasia (GO:0014806) is a biological process defined as an increase in smooth muscle cell number by cell division, often leading to an increase in the size of an organ. It is distinct from hypertrophy, which involves cell enlargement.
What genes are involved in smooth muscle hyperplasia?
Key genes experimentally implicated include NEXN, Piezo1, ZFP36, PTPN14, TSPAN4, Profilin-1 (PFN1), and noncoding RNAs such as microRNAs and lncRNAs [1,2,3,4,5,6,8].
How does smooth muscle hyperplasia cause restenosis?
After vascular injury, smooth muscle cells switch to a synthetic phenotype, proliferate, and migrate to the intima, forming a neointimal lesion that narrows the vessel lumen and causes restenosis [1,2].
What is the role of Piezo1 in smooth muscle hyperplasia?
Piezo1 is a mechanosensitive ion channel essential for VSMC phenotypic switching; its deletion reduces neointimal hyperplasia in mice.
How is smooth muscle hyperplasia regulated by noncoding RNAs?
MicroRNAs and long noncoding RNAs modulate VSMC proliferation, migration, and phenotypic switching, thereby influencing neointimal hyperplasia.
What experimental models are used to study smooth muscle hyperplasia?
Common models include mouse carotid artery ligation injury, VSMC culture, and genetically modified mice (knockout, knock-in, transgenic) [1,3,4,5,6,8].
Can CRISPR be used to study smooth muscle hyperplasia?
Yes, CRISPR-Cas9 knockout, point mutation, knock-in, and overexpression models are widely used to dissect gene function in VSMC biology and neointimal hyperplasia [1,3,4,5,6,8].
What is the link between smooth muscle hyperplasia and cancer?
Smooth muscle hyperplasia is not a cancer, but it shares features with tumorigenesis such as increased proliferation. It is observed in benign lesions like protein kinase C-fused blue naevi.
What is the difference between smooth muscle hyperplasia and hypertrophy?
Hyperplasia is an increase in cell number, while hypertrophy is an increase in cell size. GO:0014806 specifically refers to hyperplasia.
How can EDITGENE help with smooth muscle hyperplasia research?
EDITGENE provides CRISPR knockout, point mutation, knock-in, overexpression, library screening, and bioinformatics services to study genes involved in smooth muscle hyperplasia.
Conclusion
Smooth muscle hyperplasia (GO:0014806) is a critical biological process underlying neointimal hyperplasia, restenosis, and other proliferative disorders. Recent research has identified numerous molecular regulators, including NEXN, Piezo1, ZFP36, PTPN14, TSPAN4, and Profilin-1, that control VSMC phenotypic switching and proliferation [1,3,4,5,6,8]. Noncoding RNAs add another layer of regulation. Understanding these mechanisms is essential for developing targeted therapies. EDITGENE offers comprehensive CRISPR services to accelerate discovery in this field.
References
- 1. Lin Z et al.. 2025. NEXN regulates vascular smooth muscle cell phenotypic switching and neointimal hyperplasia.. JCI Insight 10(13) PMID: 40440261
- 2. Maguire EM et al.. 2020. Noncoding RNAs in vascular smooth muscle cell function and neointimal hyperplasia.. FEBS J 287(24):5260-5283 PMID: 32367680
- 3. Zhang FR et al.. 2025. Smooth muscle cell Piezo1 is essential for phenotypic switch and neointimal hyperplasia.. Br J Pharmacol 182(9):2031-2048 PMID: 39900041
- 4. Wang L et al.. 2025. Deletion of smooth muscle ZFP36 promotes neointimal hyperplasia in mice.. Acta Pharmacol Sin 46(5):1317-1328 PMID: 39890944
- 5. Ma Q et al.. 2024. PTPN14 aggravates neointimal hyperplasia via boosting PDGFRβ signaling in smooth muscle cells.. Nat Commun 15(1):7398 PMID: 39191789
- 6. Li S et al.. 2025. TSPAN4 controls vascular smooth muscle cell phenotypic switching and intimal hyperplasia by targeting TPM1-regulated cytoskeletal organization.. Clin Sci (Lond) 139(19):1145-1161 PMID: 41004162
- 7. Goutas D et al.. 2024. Smooth muscle hyperplasia in protein kinase C-fused blue naevi: Report of 12 cases.. Histopathology 85(2):347-352 PMID: 38747196
- 8. Gao XF et al.. 2024. m(6)A Modification of Profilin-1 in Vascular Smooth Muscle Cells Drives Phenotype Switching and Neointimal Hyperplasia via Activation of the p-ANXA2/STAT3 Pathway.. Arterioscler Thromb Vasc Biol 44(12):2543-2559 PMID: 39508106
