What are glandular epithelial cells?
Just as a building relies on its plumbing system for water supply and sanitation, the human body depends on the glandular epithelial cells to manage the flow and distribution of essential secretions. Glandular epithelial cells form the inner lining of most of the endocrine and exocrine glands. They play a crucial role in the production and secretion of various bodily fluids and molecules such as sweat, saliva, breast milk, hormones etc. (1). Glandular epithelial cells are arranged in the form of glands and are classified as unicellular or multicellular on the basis of the number of cells that make up the gland. For example, the secretory glands present in the gastrointestinal tract are made up of a single type of cells known as the enteroendocrine cells. whereas the adrenal glands are composed of multiple cell types which make up the adrenal cortex and medulla region that release specific substances and regulate several important functions of the human body (2).
Glandular epithelial cells also possess the ability to communicate with adjacent cell types via the communicating junctions (gap junctions) present in the basement membrane (basal layer) of a tissue. These junctions aid in creating sync and coordination between neighboring cells by creating channels that allow the passage of small molecules and ions between neighboring cells to perform and maintain vital body functions such as homeostasis and regulation of cell growth and proliferation (3).
Formation of glandular epithelial cells
Glandular epithelium (epithelial cell layer) is formed during embryonic development when epithelial budding occurs in the connective tissue. The budding extends into the underlying connective tissue forming a channel called a duct. These ducts may or may not elongate depending on their fate of differentiating into exocrine or endocrine glands. Exocrine glands release their products directly onto the epithelial surface with the help of ducts. They are further classified as unicellular and multicellular. The unicellular glands are located sporadically in the mucous membranes of small and large intestines (e.g., goblet cells). The multicellular glands form an inner lining of the abdominal cavity and chest. Moreover, multicellular glands (mammary glands) vary in their form as tubular (alveolar glands), coiled (sweat glands) and branched depending on their branching and secretory units. Endocrine glands are ductless glands which release their secretions (hormones) directly into the bloodstream. Some common examples of endocrine glands are the pituitary gland and thyroid gland (4).
Considering the importance of glandular morphogenesis in hormone production, cellular proliferation and recognition, scientists have developed methods to generate human endometrial glandular epithelia in vitro. With the correct combination of extracellular matrix, cell culture media and growth factors, researchers have been able to replicate the glandular and organoid structures in vitro. These in vitro tissue/glandular models can be used to investigate the conditions/diseases associated with glandular epithelia (5).
The clinical significance of glandular epithelial cells
Glandular epithelial cells play a governing role in maintaining the physiological functions of the human body. The diversity of glandular epithelial cells allows it the flexibility and adaptability to activate or inhibit the release of secretory substances in response to signals and stimuli generated as a result of complex cellular and tissue-level interactions. For example, the liver, being an exocrine gland, secretes bile, which is temporarily stored in the gallbladder, which is then released through the pancreatic duct into the duodenum. Even the slightest impediment in this process can lead to cholecystitis, inflammation and dysfunction of the gallbladder. Similarly, decreased lacrimal and salivary gland functions are the common etiologies of Sjögren syndrome, which is an autoimmune disorder associated with rheumatoid arthritis. Any abnormality in the secretory activity of thyroid glands can lead to hypo- or hyperthyroidism. Endometriosis, a disorder of the uterus, has been an area of prolonged research with respect to glandular epithelium. The glandular epithelium present within the endometrial tissue (inner lining of the uterus) houses cancer associated mutations which is often identified as the cause of ovarian cancers (6). Recent studies using in vitro models of endometriosis have demonstrated that stage-specific embryonic antigen-1 (SSEA-1) (7) expression in basal epithelial cells marks disease progression, while stimulator of interferon gene (STING) (8) levels reflect inflammatory density within the epithelium. These biomarkers offer promising starting points for characterizing endometriosis pathogenesis and clinical staging. Overall, analyzing the performance of glandular epithelial cells through cytopathology, biopsy and molecular markers can provide crucial information for the development of effective and efficient diagnostic tools for a wide range of conditions (9).
Recognizing and appreciating the labs working in this space
- Bonfanti Lab. The Francis Crick Institute, London, UK. https://www.crick.ac.uk/research/labs/paola-bonfanti , Twitter:@TheCrick , Instagram: @thefranciscrickinstitute
- Macara Lab. Vanderbilt University, Nashville, Tennessee, USA. https://lab.vanderbilt.edu/macara-lab/ , Twitter: @VanderbiiltU , Instagram: @vanderbiltu
- Mark LaBarge Lab. Department of Population Sciences at the Beckman Research Institute at City of Hope National Medical Center. California, USA. https://www.cityofhope.org/research/beckman-research-institute/population-sciences/mark-labarge-lab#paragraph-283481 , Twitter: @cityofhope , Instagram: @cityofhope
- The Ana Soto Lab. Tufts University, Boston, Massachusetts, USA. https://gsbs.tufts.edu/faculty-research/ana-soto-lab , Twitter: @TuftsGSBS , Instagram: @tuftsuniversity
- Bissell Lab. Lawrence Berkeley National Laboratory. California, USA. https://www2.lbl.gov/LBL-Programs/lifesciences/BissellLab/main.html
- Foxman Lab. Yale School of Medicine, Connecticut, USA. https://medicine.yale.edu/lab/foxman/ , Twitter: @EllenFoxman
- The Chung Lab. Louisiana State University, Louisiana, USA. https://faculty.lsu.edu/seyeonchunglab/index.php , Twitter: @seyeon_chung
- Aleksandra Tata, Assistant Professor in Surgery. Duke University, North Carolina, USA. https://medschool.duke.edu/profile/aleksandra-tata
- Crislyn D’Souza-Schorey, Morris Pollard Collegiate Professor of Biological Sciences. University of Notre Dame, Indiana, USA. , https://harpercancer.nd.edu/people/crislyn-dsouza-schorey/ , Twitter: @dsouzalab
References
- https://www.osmosis.org/answers/glandular-epithelium
- Rehfeld, A., Nylander, M., & Karnov, K. (2017). Glandular Epithelium and Glands. In Compendium of Histology (pp. 101–120). Springer International Publishing. https://doi.org/10.1007/978-3-319-41873-5_6
- Kurn H, Daly DT. Histology, Epithelial Cell. [Updated 2023 Feb 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559063/
- https://openstax.org/books/anatomy-and-physiology/pages/4-2-epithelial-tissue
- Rinehart, C. A., Jr, Lyn-Cook, B. D., & Kaufman, D. G. (1988). Gland formation from human endometrial epithelial cells in vitro. In vitro cellular & developmental biology : journal of the Tissue Culture Association, 24(10), 1037–1041. https://doi.org/10.1007/BF02620878
- Wang, Y., Nicholes, K., & Shih, I. M. (2020). The Origin and Pathogenesis of Endometriosis. Annual review of pathology, 15, 71–95. https://doi.org/10.1146/annurev-pathmechdis-012419-032654
- Valentijn, A. J., Palial, K., Al-Lamee, H., Tempest, N., Drury, J., Von Zglinicki, T., Saretzki, G., Murray, P., Gargett, C. E., & Hapangama, D. K. (2013). SSEA-1 isolates human endometrial basal glandular epithelial cells: phenotypic and functional characterization and implications in the pathogenesis of endometriosis. Human reproduction (Oxford, England), 28(10), 2695–2708. https://doi.org/10.1093/humrep/det285
- Gołąbek-Grenda, A., & Olejnik, A. (2022). In vitro modeling of endometriosis and endometriotic microenvironment — Challenges and recent advances. Cellular signalling, 97, 110375. https://doi.org/10.1016/j.cellsig.2022.110375
- Freeman, S. C., Malik, A., & Basit, H. (2025). Physiology, Exocrine Gland. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK542322
About the author:
DR. SURUCHI PODDAR
Content Editor The League of Extraordinary Cell Types, Sci-Illustrate Stories
Dr. Poddar received a PhD in Biomedical Engineering from Indian Institute of Technology-Banaras Hindu University (IIT-BHU), Varanasi, India. She started her career as a postdoctoral researcher in 2020 with the Nanoscience Technology Center at the University of Central Florida, Orlando where she worked on a multi-organ human-on-a-chip system. Currently she is working on solid-state nanopore technology at Wake Forest University, North Carolina. When not working, she enjoys watching movies, cooking food and exploring new places, restaurants, attractions.
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Bruna received her Bachelor’s degree in Biological Sciences and her Master’s in Cellular and Molecular Biology from the University of Tuscia, Italy. She then pursued a PhD in Molecular Biology at the Max Planck Institute for Biology of Aging in Cologne, Germany.
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Dr. Petretto received his Ph.D. in Biochemistry at the University of Fribourg, Switzerland, focusing on the behavior of matter at nanoscopic scales and the stability of colloidal systems. Using molecular dynamics simulations, he explored the delicate interaction among particles, interfaces, and solvents.
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The League of Extraordinary Cell types
The team at Sci-Illustrate and Endosymbiont bring to you an exciting series where we dive deep into the wondrous cell types in our body, that make our hearts tick ❤.
