GO:0160024 Leydig cell proliferation: Hormonal Regulation, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0160024 (Leydig cell proliferation) describes the biological process by which Leydig cells, the testosterone-producing cells of the testis, increase in number through cell division.
• Leydig cell proliferation is primarily driven by luteinizing hormone (LH) and other gonadotrophins, with additional paracrine and autocrine inputs from testicular factors.
• Key molecular regulators include Ccnd1 (cyclin D1), Trps1, JAK1/STAT3 signaling, and neurotrophin-3, which control cell cycle entry and stem Leydig cell expansion.
• Stem Leydig cells (SLCs) are a self-renewing population that can proliferate and differentiate into mature Leydig cells, making them a target for regenerative studies.
• Dysregulated Leydig cell proliferation is linked to endocrine disruptor exposure, testicular dysfunction, and impaired spermatogenesis.
• Experimental models for studying this process include knockout mice, overexpression systems, and CRISPR-based editing of genes such as Trps1, Ccnd1, and Sdc2.
Description
Leydig cells are the primary source of testosterone in the male gonad, and their population size is dynamically regulated by proliferation, differentiation, and cell death. The Gene Ontology term GO:0160024, Leydig cell proliferation, captures the biological process by which these cells divide and expand their numbers. This process is essential for establishing adequate steroidogenic capacity during development, for maintaining testosterone production in adulthood, and for regenerating Leydig cells after injury or in aging. Understanding Leydig cell proliferation is therefore central to reproductive biology, endocrinology, and toxicology. Researchers study this process to uncover how hormones, growth factors, and environmental chemicals influence male fertility and endocrine health. The term is also relevant to stem cell biology, as stem Leydig cells (SLCs) can self-renew and give rise to proliferating progenitors that eventually differentiate into mature Leydig cells. Because Leydig cell proliferation is tightly controlled by a network of signaling pathways, it serves as a model for studying hormone-dependent tissue growth and regeneration.
Leydig cell proliferation At A Glance
| GO ID | GO:0160024 |
|---|---|
| GO term | Leydig cell proliferation |
| Ontology | biological_process |
| Synonym | None listed in QuickGO |
| Major function | Increase in Leydig cell number through cell division, supporting testosterone production and testicular function |
| Key regulators | Luteinizing hormone (LH), neurotrophin-3, oncostatin M, Trps1, Ccnd1, JAK1/STAT3 signaling |
| Cell types involved | Stem Leydig cells, immature Leydig cells, adult Leydig cells |
| Associated diseases | Testicular dysfunction, endocrine disruption, impaired spermatogenesis |
| Research models | Rodent models, knockout mice, overexpression systems, CRISPR editing |
What Is GO:0160024?
GO:0160024 (Leydig cell proliferation) is a biological process defined as the increase in the number of Leydig cells through cell division. This encompasses the proliferation of both stem Leydig cells and more differentiated Leydig cell progenitors, leading to expansion of the Leydig cell population in the testis. The process is regulated by endocrine hormones such as luteinizing hormone (LH) and by local testicular factors, and it is distinct from Leydig cell differentiation, which involves the acquisition of specialized steroidogenic functions.
Why Is Leydig cell proliferation Important in Cell Biology?
Leydig cell proliferation is fundamental to male reproductive health because it determines the size of the Leydig cell population and thus the capacity for testosterone production. Adequate Leydig cell numbers are required for spermatogenesis, secondary sexual characteristics, and overall metabolic homeostasis. Disruption of this process can lead to hypogonadism, infertility, and increased susceptibility to endocrine-related diseases. Moreover, understanding how Leydig cell proliferation is regulated provides insights into stem cell biology, tissue regeneration, and the effects of environmental toxicants on male fertility.
• Determines the number of testosterone-producing cells in the testis, directly affecting male fertility and secondary sexual characteristics.
• Plays a critical role in testicular development and pubertal maturation of the reproductive system.
• Involved in regeneration of Leydig cells after injury or in aging, with stem Leydig cells serving as a reservoir.
• Dysregulation is associated with testicular tumors, hypogonadism, and impaired spermatogenesis.
• Target of endocrine-disrupting chemicals such as bisphenol S, which can stimulate proliferation while inhibiting differentiation.
• Regulated by a complex interplay of gonadotrophins (LH) and local paracrine factors, making it a model for hormone-dependent tissue growth.
• Relevant to stem cell research, as stem Leydig cells can be isolated and manipulated for regenerative therapies.
• Provides a window into the mechanisms of cell cycle control, including cyclin D1 and transcription factors like Trps1.
• Important for understanding sex differences in endocrine function and disease susceptibility.
• Offers potential therapeutic targets for male infertility and androgen deficiency.
What Happens During Leydig cell proliferation?
Activation of Stem Leydig Cells
In simple terms: Stem Leydig cells are dormant cells that can wake up and start dividing when needed.
Stem Leydig cells (SLCs) are a self-renewing population residing in the testicular interstitium. Upon appropriate stimuli, such as luteinizing hormone (LH) or neurotrophin-3, these cells re-enter the cell cycle and proliferate, expanding the progenitor pool. This step is crucial for both developmental establishment of the Leydig cell population and for regeneration after injury.
Hormonal Stimulation by Luteinizing Hormone
In simple terms: Luteinizing hormone acts like a key that unlocks the division of Leydig cells.
Luteinizing hormone (LH), secreted by the pituitary, binds to its receptor on Leydig cells and activates signaling cascades that promote proliferation and differentiation. LH regulates testosterone production, Leydig cell proliferation, differentiation, and circadian rhythm during spermatogenesis. The dynamic interplay between gonadotrophins and testicular factors controls the balance between proliferation and differentiation.
Paracrine and Autocrine Regulation
In simple terms: Cells in the testis talk to each other to control Leydig cell growth.
Beyond LH, local factors produced by Leydig cells and other testicular cells modulate proliferation. For example, oncostatin M stimulates immature Leydig cell proliferation but inhibits maturation through JAK1/STAT3 signaling and induction of oxidative stress. Neurotrophin-3 promotes stem Leydig cell proliferation during regeneration in rats. These paracrine and autocrine loops fine-tune the proliferative response.
Cell Cycle Entry and Progression
In simple terms: The cell cycle is the engine that drives cell division, and specific proteins control it.
Proliferation requires entry into the cell cycle, which is governed by cyclins and cyclin-dependent kinases. Trps1 targets Ccnd1 (cyclin D1) to regulate mouse Leydig cell proliferation. Cyclin D1 promotes progression through the G1 phase, and its expression is modulated by hormonal and local signals. Disruption of these regulators can lead to uncontrolled proliferation or failure to expand the Leydig cell pool.
Differentiation Versus Proliferation Balance
In simple terms: Leydig cells can either multiply or mature, and the body decides which is needed.
Proliferation and differentiation are often inversely regulated. For instance, bisphenol S stimulates Leydig cell proliferation but inhibits differentiation in pubertal male rats. Similarly, oncostatin M promotes proliferation while inhibiting maturation. This balance ensures that sufficient numbers of functional Leydig cells are produced without excessive accumulation of immature cells.
Key Genes Involved in GO:0160024 Leydig cell proliferation
The following genes and proteins have been experimentally implicated in the regulation of Leydig cell proliferation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| Lhcgr | Receptor for luteinizing hormone; mediates LH signaling | Knockout models show impaired Leydig cell proliferation and testosterone production |
| Ccnd1 | Cyclin D1; promotes cell cycle progression | Target of Trps1; regulates Leydig cell proliferation in mice |
| Trps1 | Transcription factor; represses Ccnd1 | Knockdown increases Leydig cell proliferation; potential therapeutic target |
| Jak1 | Janus kinase 1; mediates cytokine signaling | Involved in oncostatin M-induced proliferation via JAK1/STAT3 |
| Stat3 | Signal transducer and activator of transcription 3 | Mediates oncostatin M effects on Leydig cell proliferation and oxidative stress |
| Ntf3 | Neurotrophin-3; growth factor | Stimulates stem Leydig cell proliferation during regeneration |
| Osm | Oncostatin M; cytokine | Stimulates immature Leydig cell proliferation but inhibits maturation |
| Ptn | Pleiotrophin; growth factor | From Leydig cells, activates SDC2 and modulates spermatogonial stem cell proliferation |
| Sdc2 | Syndecan-2; cell surface proteoglycan | Mediates PTN signaling in testicular cells |
| Gfra1 | GDNF family receptor alpha 1 | Involved in PTN/SDC2 signaling affecting spermatogonial stem cells |
| Esr1 | Estrogen receptor alpha | May mediate estrogenic effects on Leydig cell proliferation |
| Esr2 | Estrogen receptor beta | Potential role in endocrine disruption of Leydig cells |
| Ar | Androgen receptor | Androgens can feedback regulate Leydig cell proliferation |
| Insl3 | Insulin-like 3 | Marker of Leydig cell differentiation; may influence proliferation |
| Cyp11a1 | Cholesterol side-chain cleavage enzyme | Steroidogenic marker; differentiation status affects proliferation |
| Hsd3b1 | 3-beta-hydroxysteroid dehydrogenase | Steroidogenic enzyme; linked to Leydig cell maturation |
| Pcna | Proliferating cell nuclear antigen | Marker of cell proliferation used in studies |
| Mki67 | Ki-67; proliferation marker | Commonly used to assess Leydig cell proliferation |
How Is Leydig cell proliferation Regulated?
Leydig cell proliferation is regulated by a complex network of endocrine, paracrine, and autocrine signals. Luteinizing hormone (LH) is a primary endocrine regulator, activating the LH receptor (LHCGR) and downstream signaling pathways that promote both proliferation and differentiation. Local factors such as neurotrophin-3 and oncostatin M modulate proliferation in a context-dependent manner. Intracellular signaling cascades, including JAK1/STAT3 and cyclin D1-dependent cell cycle progression, are critical nodes. Additionally, environmental endocrine disruptors like bisphenol S can dysregulate these pathways, leading to altered proliferation and differentiation. The balance between proliferation and differentiation is also influenced by steroidogenic feedback and androgen receptor signaling.
Leydig cell proliferation and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| Trps1 | Leydig cell proliferation dysregulation | Knockout or overexpression in mouse Leydig cell lines |
| Ccnd1 | Cell cycle control in Leydig cells | Conditional knockout mice |
| Jak1/Stat3 | Oncostatin M-mediated proliferation and oxidative stress | In vitro Leydig cell culture with inhibitors |
| Ntf3 | Stem Leydig cell regeneration | Rat model of Leydig cell regeneration |
| Ptn/Sdc2 | Spermatogonial stem cell proliferation | Human spermatogonial stem cell culture |
Testicular Dysfunction and Infertility
Disrupted Leydig cell proliferation can lead to inadequate testosterone production, impaired spermatogenesis, and male infertility. Endocrine-disrupting chemicals such as bisphenol S stimulate Leydig cell proliferation while inhibiting differentiation, resulting in a population of immature, dysfunctional cells and reduced fertility in animal models. Similarly, alterations in LH signaling or local growth factors can compromise Leydig cell regeneration and function.
Endocrine Disruption and Environmental Toxicity
Exposure to environmental chemicals can perturb Leydig cell proliferation. Bisphenol S, a common substitute for bisphenol A, has been shown to stimulate Leydig cell proliferation but inhibit differentiation in pubertal male rats through multiple mechanisms, including oxidative stress and altered hormone signaling. This highlights the sensitivity of Leydig cell proliferation to xenobiotics and its relevance to reproductive toxicology.
Leydig Cell Tumors and Hyperplasia
While not directly studied in the provided citations, dysregulated Leydig cell proliferation is a hallmark of Leydig cell tumors and hyperplasia. The molecular pathways controlling normal proliferation, such as cyclin D1 and Trps1, may be co-opted in neoplastic growth. Further research is needed to establish direct links, but the role of these regulators in cell cycle control suggests potential involvement.
Regenerative Failure and Aging
The decline in Leydig cell number and function with aging may be related to impaired proliferation of stem Leydig cells. Neurotrophin-3 has been shown to stimulate stem Leydig cell proliferation during regeneration in rats, suggesting that boosting this pathway could counteract age-related declines. Understanding the mechanisms of stem Leydig cell proliferation is therefore relevant to developing therapies for androgen deficiency in aging men.
From Leydig cell proliferation-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate Leydig cell proliferation in vivo? | Knockout mouse (e.g., Trps1, Ccnd1) |
| What is the effect of a point mutation in a signaling domain? | Point-mutation knock-in mouse (e.g., Lhcgr) |
| Can a reporter gene track Leydig cell proliferation? | Knock-in of fluorescent reporter (e.g., Ki67-GFP) |
| Does overexpression of a growth factor increase proliferation? | Transgenic overexpression (e.g., Ntf3) |
| What are the transcriptomic changes during proliferation? | RNA-seq of isolated Leydig cells |
| Can CRISPR screen identify novel regulators? | CRISPR library screening in Leydig cell lines |
How to Study the Leydig cell proliferation Process
| Method | What It Measures | Typical Application |
|---|---|---|
| BrdU/EdU incorporation | DNA synthesis (S phase) | Quantifying proliferation in cultured Leydig cells |
| Ki-67 immunostaining | Cells in active cell cycle | Assessing proliferation in testis sections |
| RNA-seq | Global gene expression | Identifying pathways altered during proliferation |
| CRISPR library screen | Genes required for proliferation | High-throughput discovery of regulators |
| Western blot | Protein expression and phosphorylation | Validating signaling pathways (e.g., STAT3) |
| Reporter gene assay | Transcriptional activity | Studying promoter regulation (e.g., Ccnd1) |
| Flow cytometry | Cell cycle distribution | Analyzing proliferation vs. quiescence |
| Hormone measurement | Testosterone levels | Correlating proliferation with function |
In Vivo Models and Hormonal Manipulation
Rodent models are widely used to study Leydig cell proliferation. Hormonal manipulations, such as hypophysectomy or LH administration, can alter proliferation rates. Regeneration models, such as ethylene dimethanesulfonate (EDS) treatment in rats, allow study of stem Leydig cell proliferation. These models provide physiological context but require careful interpretation due to systemic effects.
In Vitro Leydig Cell Culture
Primary Leydig cells or cell lines (e.g., MA-10, TM3) can be cultured and treated with hormones, growth factors, or chemicals to assess proliferation. Oncostatin M and neurotrophin-3 have been tested in such systems. Proliferation is typically measured by BrdU or EdU incorporation, MTT assays, or Ki-67 staining.
Molecular and Genomic Approaches
RNA-seq and proteomics can identify global changes in gene expression during Leydig cell proliferation. For example, transcriptomic analysis of stem Leydig cells has revealed key pathways. CRISPR screens can systematically identify genes required for proliferation. These methods are powerful for discovering novel regulators.
Imaging and Histology
Immunohistochemistry for proliferation markers (e.g., PCNA, Ki-67) allows visualization of dividing Leydig cells in tissue sections. Confocal imaging of fluorescent reporters can track proliferation dynamics in live cells. These techniques are essential for validating in vitro findings in vivo.
How CRISPR Can Be Used to Study GO:0160024 Leydig cell proliferation
Knockout
CRISPR knockout of genes such as Trps1 or Ccnd1 in Leydig cell lines or mouse models can reveal their essential roles in proliferation. For example, Trps1 knockout increases Ccnd1 expression and proliferation, demonstrating its repressive function. Knockout models are valuable for establishing causality.
Point Mutation
Introducing point mutations in key signaling domains, such as the LH receptor (Lhcgr) or STAT3, can dissect specific phosphorylation sites or binding interfaces required for proliferation. This approach is useful for understanding how subtle genetic changes affect Leydig cell proliferation.
Knock-in
Knock-in of reporter genes (e.g., fluorescent proteins) under the control of proliferation markers like Ki-67 allows real-time tracking of Leydig cell proliferation in vivo. Knock-in of tagged proteins can also facilitate biochemical studies of protein interactions.
Overexpression
CRISPR activation (CRISPRa) or transgenic overexpression of growth factors such as neurotrophin-3 can boost Leydig cell proliferation. Overexpression models help identify sufficiency of a gene to drive proliferation and can be used to test therapeutic potential.
How EDITGENE Supports Leydig cell proliferation Research
Researchers studying Leydig cell proliferation-related genes often need to determine whether a candidate gene is causally involved in the process. This requires precise genetic manipulation, such as knockout, point mutation, knock-in, or overexpression, followed by functional assays. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate such studies, from cell model generation to high-throughput screening and bioinformatics analysis.
Contact EDITGENE today to design your custom CRISPR model for Leydig cell proliferation research.
Frequently Asked Questions About Leydig cell proliferation
What is Leydig cell proliferation?
Leydig cell proliferation is the biological process by which Leydig cells, the testosterone-producing cells of the testis, increase in number through cell division. It is essential for testicular development, testosterone production, and regeneration.
What genes are involved in Leydig cell proliferation?
Key genes include Lhcgr (LH receptor), Ccnd1 (cyclin D1), Trps1, Jak1, Stat3, Ntf3 (neurotrophin-3), and Osm (oncostatin M), among others.
How is Leydig cell proliferation regulated?
It is regulated by luteinizing hormone (LH) and local paracrine factors such as neurotrophin-3 and oncostatin M, which activate signaling pathways like JAK1/STAT3 and cyclin D1.
What is the role of stem Leydig cells in proliferation?
Stem Leydig cells are a self-renewing population that can proliferate and differentiate into mature Leydig cells, contributing to regeneration after injury.
Which diseases are associated with abnormal Leydig cell proliferation?
Abnormal proliferation is linked to testicular dysfunction, infertility, and endocrine disruption. For example, bisphenol S stimulates proliferation but inhibits differentiation, impairing fertility.
What research models are used to study Leydig cell proliferation?
Common models include knockout mice, transgenic overexpression, primary Leydig cell culture, and CRISPR-edited cell lines.
How does luteinizing hormone affect Leydig cell proliferation?
LH binds to its receptor on Leydig cells and activates signaling cascades that promote both proliferation and differentiation, as well as testosterone production.
What is the role of Trps1 in Leydig cell proliferation?
Trps1 is a transcription factor that represses Ccnd1 (cyclin D1). Knockdown of Trps1 increases Leydig cell proliferation, indicating its role as a negative regulator.
Can environmental chemicals affect Leydig cell proliferation?
Yes, endocrine-disrupting chemicals like bisphenol S can stimulate Leydig cell proliferation while inhibiting differentiation, leading to dysfunctional Leydig cells.
How can CRISPR be used to study Leydig cell proliferation?
CRISPR can create knockout, point mutation, knock-in, or overexpression models in Leydig cells to test the function of specific genes in proliferation.
Conclusion
GO:0160024 (Leydig cell proliferation) is a critical biological process that determines the size and function of the Leydig cell population, with direct implications for male fertility and endocrine health. Research has identified key hormonal and local regulators, including LH, neurotrophin-3, oncostatin M, and cell cycle proteins like cyclin D1 and Trps1. Dysregulation of this process by genetic or environmental factors can lead to testicular dysfunction and infertility. Continued investigation using advanced CRISPR models and multi-omics approaches will further unravel the mechanisms controlling Leydig cell proliferation and may yield new therapeutic strategies for reproductive disorders.
References
- 1. Chen H et al.. 2017. Leydig cell stem cells: Identification, proliferation and differentiation.. Mol Cell Endocrinol 445:65-73 PMID: 27743991
- 2. Lei T et al.. 2025. Luteinizing Hormone Regulates Testosterone Production, Leydig Cell Proliferation, Differentiation, and Circadian Rhythm During Spermatogenesis.. Int J Mol Sci 26(8) PMID: 40332028
- 3. Sriraman V et al.. 2005. Hormonal regulation of Leydig cell proliferation and differentiation in rodent testis: a dynamic interplay between gonadotrophins and testicular factors.. Reprod Biomed Online 11(4):507-18 PMID: 16274617
- 4. Zhao X et al.. 2024. PTN from Leydig cells activates SDC2 and modulates human spermatogonial stem cell proliferation and survival via GFRA1.. Biol Res 57(1):66 PMID: 39285301
- 5. Yu Y et al.. 2020. Neurotrophin-3 stimulates stem Leydig cell proliferation during regeneration in rats.. J Cell Mol Med 24(23):13679-13689 PMID: 33090725
- 6. Sun J et al.. 2021. Trps1 targets Ccnd1 to regulate mouse Leydig cell proliferation.. Andrology 9(6):1923-1933 PMID: 34185441
- 7. Tian L et al.. 2022. Oncostatin M stimulates immature Leydig cell proliferation but inhibits its maturation and function in rats through JAK1/STAT3 signaling and induction of oxidative stress in vitro.. Andrology 10(2):354-366 PMID: 34516050
- 8. Pan P et al.. 2023. Bisphenol S stimulates Leydig cell proliferation but inhibits differentiation in pubertal male rats through multiple mechanisms.. Environ Toxicol 38(10):2361-2376 PMID: 37357847
