Goblet cells are specialized columnar epithelial cells that function as unicellular exocrine glands, primarily responsible for secreting mucin to form a protective mucus layer on mucosal surfaces. Named for their distinctive goblet- or cup-like appearance, which arises from the accumulation of large mucin-filled granules compressing the nucleus to the cell base, they originate from pluripotent stem cells within the epithelium and exhibit a typical turnover of 3 to 7 days. These cells are essential for maintaining barrier integrity in various organs, particularly those exposed to environmental irritants or pathogens.[1][2]Structurally, goblet cells are polarized, with a narrow basal region containing the nucleus, Golgi apparatus, and rough endoplasmic reticulum for mucin synthesis, and a broad apical cytoplasm distended by secretory granules composed of highly glycosylated mucins suspended in electrolytes. In histological preparations, the unfixed granules appear clear, but fixation causes shrinkage, accentuating the goblet shape; they are often visualized using techniques like laser scanning confocal microscopy or histochemical stains such as Alcian blue for acidic mucins. Secretion occurs via exocytosis through two pathways: a constitutive low-level release and a stimulated response triggered by neural, hormonal, or irritant signals, such as acetylcholine or allergens, leading to rapid mucus expansion up to 500-fold upon hydration.[1][2]Goblet cells are distributed across multiple mucosal epithelia, with high density in the gastrointestinal tract—including the small intestinal villi, colonic surface epithelium, and crypts—and the respiratory airways from the nasal passages to the bronchi. They are also present in the conjunctiva and other sites like the urethra and vagina, though less abundantly in some regions such as the esophagus. Their prevalence increases distally in the gut, reflecting adaptive needs for lubrication and protection against microbial challenges.[1][2][3]In addition to mucus production, goblet cells contribute to innate and adaptive immunity by secreting antimicrobial peptides (e.g., RELM-β), cytokines (e.g., IL-13, IL-18), and chemokines (e.g., CCL20), while forming transient goblet cell-associated antigen passages (GAPs) to sample and deliver luminal antigens to underlying dendritic cells for immune tolerance or response. This multifaceted role supports intestinal homeostasis, wound repair via trefoil factor family peptides (TFF3), and defense against pathogens, with dysregulation linked to conditions like inflammatory bowel disease, asthma, and chronic obstructive pulmonary disease, where goblet cell hyperplasia or metaplasia exacerbates mucus hypersecretion.[3][1]
Anatomy and Morphology
Cellular Structure
Goblet cells are specialized epithelial cells characterized by their distinctive goblet-shaped morphology, resulting from the accumulation of mucin granules in the apical cytoplasm, which expands this region into a bulbous, cup-like structure while the basal portion remains narrow.[1][4] The nucleus is typically positioned at the base of the cell, compressed against the basement membrane, and appears flattened or elongated due to the overlying mucin-filled theca.[1][5] This theca consists primarily of membrane-bound secretory granules packed with mucins, giving the cell its namesake appearance under light microscopy.[4]At the ultrastructural level, goblet cells contain prominent organelles dedicated to mucin production, including abundant rough endoplasmic reticulum (rER) for initial protein synthesis and folding, a well-developed Golgi apparatus for glycosylation and packaging, and numerous secretory vesicles that store and transport mature mucin granules toward the apical surface.[1][4][5] The cytoskeleton, composed of intermediate filaments, microtubules, and microfilaments, supports the cell's structure and facilitates granule movement, though actin filaments play a relatively minor role compared to other epithelial cells.[1]The mucin composition varies by tissue type, with respiratory goblet cells predominantly expressing the gel-forming mucin MUC5AC and intestinal goblet cells synthesizing MUC2, the primary polymeric mucin in the gut.[1][4] Goblet cells exhibit variations in size and density across different epithelia; for instance, they are generally larger and more densely packed in the intestinal mucosa, particularly in the distal ileum and large intestine, compared to the sparser distribution in the proximal small intestine or airways.[4] In the colon, surface goblet cells tend to have less extensive mucin storage than those in the crypts.[5]
Tissue Distribution
Goblet cells are predominantly located in the pseudostratified columnar epithelium lining the respiratory tract, where they serve as primary secretory cells in the superficial epithelium of large airways.[1] They are also abundant in the simple columnar epithelium of the gastrointestinal tract, particularly along the length of the small and large intestines, with their proportion increasing caudally from approximately 4% of epithelial cells in the duodenum to 16% in the colon.[6] In the ocular surface, goblet cells are present in the conjunctival epithelium, especially in the fornix and bulbar regions, where they occur singly in humans or in clusters in rodents.[7]Density variations exist across these sites, reflecting functional adaptations to local protective needs. In the small intestine, goblet cells are interspersed at a relatively high density, typically comprising about 10-15% of the epithelial population or roughly 1 per 6-12 enterocytes, facilitating robust mucus coverage over absorptive surfaces.[6] Goblet cells are absent or exceedingly rare in keratinized epithelia such as the skin and in non-mucosal tissues like the kidney, which lack the wet, secretory environments that support their development. They are also absent from the normal gastric mucosa.[2][8]The distribution of goblet cells demonstrates evolutionary conservation across vertebrates, from jawless fish like hagfish to mammals, underscoring their fundamental role in mucosal protection against pathogens and environmental insults.[9] This conservation highlights their presence in epithelial linings exposed to external interfaces, such as respiratory, gastrointestinal, and ocular surfaces, across diverse species.[10]
Physiology and Development
Mucus Production Mechanisms
Goblet cells synthesize mucus primarily through the production of mucin glycoproteins, such as MUC5AC in airways and MUC2 in the intestine. The process begins with transcription of mucin genes in the nucleus, followed by translation of the mucin precursor proteins on ribosomes and co-translational insertion into the rough endoplasmic reticulum (ER), where N-linked glycosylation and disulfide bond formation occur to dimerize the monomers.[11] These dimers are then transported to the Golgi apparatus in an ATP-dependent manner, where extensive O-linked glycosylation adds oligosaccharide chains to proline-threonine-serine (PTS) domains, resulting in large, heavily glycosylated molecules exceeding megadalton sizes.[11] In the trans-Golgi network, the mucins oligomerize, condense, and are packaged into secretory granules, stabilized by low pH and high calcium concentrations to prevent premature expansion.[5]Mucus secretion from goblet cells is triggered by diverse stimuli, including neural, hormonal, and irritant signals. Neural stimulation, often via vagal nerves releasing acetylcholine, activates muscarinic receptors to induce rapid granule exocytosis in intestinal and airway goblet cells.[5] Hormonal factors like vasoactive intestinal peptide (VIP) bind to VPAC receptors on goblet cells, promoting glycoconjugate secretion through cyclic AMP-mediated pathways in ocular and colonic tissues.[12] Irritant-induced secretion involves transient receptor potential vanilloid 1 (TRPV1) channels, which respond to capsaicin or inflammatory signals, enhancing mucin production and release while influencing goblet cell differentiation and glycosylation.[13]Goblet cells exhibit two main types of secretion: constitutive basal release, which maintains steady-state mucus layers through low-level calcium oscillations, and stimulated secretion, characterized by compound exocytosis of multiple granules in response to elevated intracellular calcium.[11] The latter is energy-dependent, relying on ATP hydrolysis for vesicle trafficking and SNARE complex assembly, alongside calcium influx from ER stores via IP3 receptors or ryanodine receptors, which triggers synaptobrevin-2-mediated fusion of granules with the apical plasmamembrane.[11] Upon release, mucin polymers undergo rapid hydration and entanglement, facilitated by bicarbonate-induced pH neutralization and calcium chelation, expanding over 1,000-fold to form a viscoelastic gel that provides a dynamic barrier.[5]
Embryonic and Cellular Differentiation
Goblet cells in the gastrointestinal (GI) tract originate from the endodermal germ layer during embryonic development, as the endoderm forms the epithelial lining of the primitive gut tube.[14] In contrast, goblet cells within the respiratory tract epithelium derive from foregut endoderm, which buds to form the lung primordium and subsequent airway structures.[15] Goblet cells in the ocular conjunctiva, however, arise from surface ectoderm, contributing to the stratified squamous epithelium that lines the eye's protective surfaces.[16] These distinct embryonic origins reflect the specialized roles of goblet cells in mucosal barriers across different organ systems.Differentiation of goblet cells from intestinal stem cells occurs primarily in the crypts of Lieberkühn, where leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5)-positive stem cells give rise to progenitor populations that commit to secretory lineages.[17] Key transcription factors, such as SAM pointed domain-containing ETS transcription factor (SPDEF) and Krüppel-like factor 4 (KLF4), drive this terminal differentiation by promoting goblet cell maturation and mucin gene expression while suppressing proliferative signals in progenitors.[18] Inhibition of the Notch signaling pathway plays a pivotal role in biasing progenitors toward the goblet cell fate over absorptive enterocytes; for instance, blockade of Notch components like γ-secretase leads to rapid conversion of crypt cells into post-mitotic goblet cells through upregulation of secretory transcription factors such as atonal bHLH transcription factor 1 (ATOH1).[19][20]Postnatal maturation of gut goblet cells is significantly influenced by environmental factors, including the gut microbiota and dietary components, which refine their density, mucin composition, and secretory capacity.[21] Neonatal colonization by commensal microbes primes goblet cell development by modulating stem cell niches and enhancing epithelial differentiation during the pre-weaning period, with disruptions leading to immature mucus layers.[21] Dietary shifts, such as the introduction of solid foods, further promote goblet cell expansion and functional adaptation in the intestine.[22]Recent research highlights the plasticity of goblet cells, demonstrating their potential for transdifferentiation with other secretory cells like Paneth cells in response to niche signals. In the intestinal epithelium, goblet and Paneth cells share a common progenitor with overlapping transcriptomes, enabling phenotypic interconversion driven by local antimicrobial demands and signaling cues such as Wnt pathway modulation.[23] This "shapeshifting" capability, observed in 2025 studies (as of June 2025) using lineage tracing, underscores how environmental and niche factors dynamically regulate secretory cell identities without altering core lineage commitment.[24]
Functions
Barrier and Lubrication Roles
Goblet cells secrete gel-forming mucins, primarily MUC2 in the intestines, that polymerize to form a stratified mucus layer consisting of an inner firmly adherent layer and an outer loosely adherent layer. The inner layer, anchored to the epithelial surface by goblet cell interactions, is typically 50 μm thick in mice and up to 200 μm in humans, creating a sterile barrier that excludes pathogens larger than 0.5 μm in diameter by its dense, net-like structure. This layer traps and immobilizes microorganisms, preventing their adhesion to the epithelium, while the outer layer, which expands through proteolytic processing and expansion of the inner layer, facilitates the transport of trapped particles away from the mucosa. In the intestinal tract, this dual-layer organization aids peristalsis by providing lubrication that reduces friction between the epithelial surface and luminal contents, enabling efficient propulsion of digesta without tissue damage.In the airways, goblet cells produce mucins such as MUC5AC and MUC5B, which form a low-viscosity gel layer atop the periciliary layer (approximately 5-7 μm thick), with the overall mucusgel reaching 2-5 μm in the trachea under normal conditions. This mucus configuration minimizes shear stress and friction during ciliary beating, allowing coordinated metachronal waves to propel the gel toward the oropharynx at rates of 5-20 mm/min, and supports cough clearance by enabling rapid mucus mobilization during expiratory flows exceeding 200 L/min. The lubricative properties of airway mucus, derived from its hydrated mucin network, thus protect the ciliated epithelium from mechanical injury while maintaining efficient mucociliary transport.Goblet cells in the stomach, often referred to as surface mucous cells, secrete a bicarbonate-rich mucus layer that establishes a pH gradient, buffering the acidic luminal environment (pH 1-3) to near-neutral values at the epithelial surface and preventing acid diffusion to the mucosa. This protective mechanism relies on the mucus trapping secreted bicarbonate from adjacent cells, maintaining a stable diffusion barrier approximately 200-500 μm thick in the gastric pits and surface epithelium.Beyond mechanical protection, goblet cell-derived mucus maintains hydration on exposed mucosal surfaces, such as the ocular conjunctiva and respiratory epithelium, by forming a highly hydrated gel that retains water through hydrophilic mucin domains, preventing desiccation and stabilizing the tear film or airway surface liquid. In the conjunctiva, this hydration layer, renewed by continuous goblet cell secretion, supports tear stability and protects against evaporative loss in the interblink interval.The mucus layers exhibit dynamic turnover, with the intestinal inner layer renewed approximately every hour through basal goblet cell secretion in the distal colon, ensuring rapid replacement to sustain barrier integrity against constant luminal challenges. In airways, turnover aligns with clearance rates, with goblet cells responding to stimuli to replenish the thin gel layer within minutes to hours.
Immune Modulation
Goblet cells in the intestinal epithelium facilitate antigen sampling by forming goblet cell-associated passages (GAPs), which enable the delivery of low-molecular-weight luminal antigens directly to CD103+ dendritic cells in the lamina propria.[25] This process allows for selective transport of antigens without disrupting the epithelial barrier, promoting immune surveillance and tolerance to harmless environmental antigens.[25] GAP formation is dynamically regulated, with goblet cells responding to microbial cues to open these passages transiently.[26]Beyond sampling, goblet cells contribute to oral tolerance by incorporating antigens into the mucus layer, where they are trapped and presented in an immunoregulatory context that favors the differentiation of regulatory T cells (Tregs). Mucus-embedded antigens, particularly those derived from food or commensals, deliver signals such as TGF-β and retinoic acid to underlying immune cells, enhancing Treg induction and suppressing inflammatory responses. This mechanism is essential for maintaining gut homeostasis and preventing aberrant immune activation against benign luminal contents.Goblet cells also secrete trefoil factor family (TFF) peptides like TFF3, which support epithelial repair.[27] These peptides are co-secreted with mucins to reinforce innate defenses in the mucus gel.[27] Additionally, goblet cells are highly responsive to cytokines such as IL-13, which stimulates mucin production and goblet cell hyperplasia to amplify immune modulation during type 2 responses.[28]Through the glycans on secreted mucins, goblet cells selectively nourish beneficial microbiota, such as Akkermansia muciniphila, which degrade specific glycan structures for energy while strengthening the mucus barrier.[29] This mutualistic interaction promotes microbial diversity and limits pathogen colonization by favoring mucin-utilizing symbionts.[29]Recent studies have revealed sex-specific roles for goblet cells in intestinal immune homeostasis, with females exhibiting distinct goblet cell maturation and mucus production patterns that influence susceptibility to inflammation.[30] In female mice, disruptions in goblet cell function lead to altered crypt architecture and impaired barrier integrity.[30] These differences underscore the need for sex-tailored approaches in understanding mucosal immune responses.[30]
Pathophysiology
Hyperplasia and Metaplasia
Goblet cell metaplasia involves the transformation of other epithelial cell types, such as club cells (formerly known as Clara cells) in the lungs, into goblet-like cells that produce mucin, primarily driven by signaling from interleukin-13 (IL-13) and interleukin-4 (IL-4).[31] These cytokines bind to the IL-4 receptor alpha (IL-4Rα), activating downstream pathways that promote transdifferentiation and mucingene expression, such as MUC5AC, in response to chronic stimuli like allergens.[32] This process is distinct from hyperplasia, as it alters cell identity rather than increasing cell numbers.Goblet cell hyperplasia, an increase in goblet cell numbers, is mediated by upregulation through the signal transducer and activator of transcription 6 (STAT6) pathway, particularly in allergic conditions where IL-13 and IL-4 signaling activates STAT6 to induce mucin production and epithelial remodeling.[33] This mechanism contributes to excessive mucus secretion, which is predominant in the airways during asthma, where allergen exposure leads to thickened mucus plugs obstructing airflow. In the gut during inflammatory bowel disease (IBD), such as Crohn's disease, goblet cell depletion is more characteristic, contributing to impaired mucus barrier and exacerbating inflammation, though hyperplasia may occur in regenerative responses to injury.[34]These changes exhibit potential reversibility; for instance, eliminating IL-13 signaling can regress established goblet cell metaplasia, allowing affected cells to transition back to ciliated or other epithelial phenotypes upon removal of stimuli like allergens.[35] Targeting IL-13 signaling has shown potential in reversing metaplasia in preclinical models of airway disease.[36] In contrast, age-related alterations show a decline in goblet cell numbers and mucin content, particularly in the human colon, which may impair mucosal barrier functions in the elderly.[37]
Involvement in Infections and Inflammation
Goblet cells serve as entry points for respiratory viruses due to their expression of viral receptors and position in the mucosal epithelium. In nasal mucosa, goblet cells express ACE2 and TMPRSS2, facilitating SARS-CoV-2 attachment and entry, alongside ciliated cells which often serve as primary targets in early infection, as shown in single-cell analyses of human nasal epithelia.[38][39] This tropism allows the virus to replicate in airway cells, leading to altered mucus production that impairs mucociliary clearance.Bacterial pathogens interact with goblet cells by disrupting their integrity, often eliciting strong inflammatory responses. For instance, Acinetobacter baumannii adheres to and degrades goblet cell mucins in bronchial epithelium, as revealed by transcriptomic profiling in differentiated human airway models. This breakdown activates early proinflammatory pathways, including NF-κB signaling and cytokine release (e.g., IL-6 and IL-8), exacerbating lunginflammation.[40] The 2025 transcriptomics data highlight how A. baumannii induces goblet cell loss within hours of exposure, compromising the mucus barrier and promoting bacterial persistence in the airways.[40]In the gastrointestinal tract, goblet cells contribute to barrier dysfunction during inflammatory bowel disease (IBD) through mechanical mechanisms. Under inflammatory conditions, goblet cell expansion and secretion exert compressive stress on adjacent enterocytes, fracturing tight junctions and increasing permeability. A 2025 in vivo imaging study in mouse models of colitis showed that this mechanical breaching allows luminal contents, including bacteria, to penetrate the epithelium, fueling chronic inflammation in IBD. These dynamics highlight goblet cells' dual role in maintaining and inadvertently compromising gut integrity during disease flares.Neural regulation modulates goblet cell responses in gastrointestinal infections via neurotransmitters like serotonin (5-HT). Enterochromaffin cells release 5-HT, which acts on 5-HT4 receptors on goblet cells to stimulate mucus secretion, enhancing barrier protection against pathogens.[41] Recent 2025 reviews of enteric nervous system interactions emphasize that this 5-HT-mediated pathway accelerates mucin release during GI infections, coordinating with immune signals to trap invaders, though dysregulation can lead to excessive secretion.[42]Goblet cell mucus secretion provides initial protection against infections by trapping microbes and limiting their access to epithelial surfaces, but hypersecretion can become detrimental by causing obstruction and impaired clearance. In viral infections, adequate goblet cell-derived mucus shields nasal epithelia from SARS-CoV-2 entry, reducing pathogenesis; however, insufficient or dysregulated secretion permits viral dissemination and secondary bacterial superinfections.[38] Similarly, in bacterial challenges, early mucus hypersecretion aids defense, yet prolonged inflammation from goblet cell disruption leads to barrier failure and tissue damage, as seen in airway and gut models. This balance underscores goblet cells' context-dependent contributions to host defense versus pathology.[40]
Clinical Aspects
Associated Diseases and Neoplasms
Goblet cell hyperplasia is a prominent feature in allergic asthma, where it contributes to excessive mucus production and the formation of airway mucus plugs that obstruct airflow and exacerbate symptoms. In asthmatic airways, the epithelium exhibits increased numbers of MUC5AC-expressing goblet cells, leading to mucin-rich plugs formed by acute degranulation in remodeled tissues.[43] This hyperplasia is driven by inflammatory signals such as IL-13, resulting in persistent mucus hypersecretion that correlates with disease severity and fatal outcomes.[44]In cystic fibrosis, goblet cell dysfunction impairs mucociliary clearance through altered exocytosis and dehydrated mucus secretion, promoting chronic airway obstruction and infections. Defective CFTR-mediated chloride transport reduces airway surface liquid volume, causing goblet cells to release hyperviscous MUC5AC and MUC5B mucins that fail to clear effectively.[45] This leads to retained mucus bundles and ectopic granule retention in goblet cells, exacerbating the cycle of inflammation and bacterial colonization characteristic of the disease.[46]Goblet cell carcinoids, now classified as goblet cell adenocarcinomas, represent rare neuroendocrine neoplasms primarily arising in the appendix, characterized by dual glandular and neuroendocrine differentiation with prominent mucin production. These tumors, accounting for 14-19% of appendiceal neuroendocrine neoplasms, often present with appendicitis and exhibit aggressive behavior due to their amphicrine nature, involving signet-ring-like cells secreting mucins.[47] Incidence is low at 0.01-0.05 per 100,000, but they carry a risk of metastasis, particularly in higher-grade variants.[48]In ulcerative colitis, goblet cell metaplasia and hypermucinous proliferations in the colonic mucosa are associated with an elevated risk of dysplasia and colorectal neoplasia. These changes, including abnormal mucin overproduction by epithelial cells, reflect chronic inflammation and correlate with refractory disease in 10-15% of patients, serving as precursors to malignant transformation.[49] Specifically, goblet cell-deficient dysplasia linked to metaplasia acts as a high-risk marker for aggressive colorectal cancers in inflammatory bowel disease.[50]Recent research highlights the role of MUC2-overproducing goblet-like cells in colorectal cancer tumorigenesis, where these cells contribute to altered mucus barriers that facilitate microbial dysbiosis and tumor progression. In 2025 studies using tumorigenic human goblet-like cell models, upregulated MUC2 production was shown to modulate the tumor microenvironment, promoting invasion through glycoprotein changes like A33 expression associated with colon cancer.[51] This mucin dysregulation underscores goblet cell plasticity in driving neoplastic growth.The GOBLET trial, a phase 1/2 study initiated in 2025, evaluates pelareorep in combination therapies for metastatic pancreatic cancer, addressing neoplasms where goblet cell-derived mucins may influence tumor biology and therapeutic response. Early safety data from cohort 5 indicate acceptable tolerability with mFOLFIRINOX and atezolizumab in first-line metastatic pancreatic ductal adenocarcinoma, with ongoing enrollment to assess efficacy.[52]
Diagnostic and Therapeutic Approaches
Diagnosis of goblet cell abnormalities primarily relies on histopathological examination of tissue biopsies, where Alcian blue/periodic acid-Schiff (PAS) staining is used to identify mucin-producing goblet cells by highlighting acid and neutral mucins in blue and magenta, respectively.[53][54] This combined stain is routinely recommended for esophageal and gastric biopsies to detect intestinal metaplasia characterized by goblet cell presence, improving diagnostic accuracy in conditions like Barrett's esophagus.[55] For colonic assessment, endoscopy allows direct visualization and biopsy collection to evaluate goblet cell density and mucin production in the gastrointestinal mucosa.[56] In airway pathologies, bronchoscopy facilitates the procurement of endobronchial biopsies to assess goblet cell hyperplasia, with larger bronchoscopes preferred for optimal sampling in children and adults.[57][58]Therapeutic strategies targeting goblet cell dysfunction focus on reducing mucus hypersecretion and modulating underlying inflammation. Mucolytics such as N-acetylcysteine (NAC) are employed to break down mucus viscosity and inhibit goblet cell hyperplasia by acting as both a mucolytic and mucoregulator, particularly in chronic obstructive pulmonary disease (COPD) and post-infectious conditions.[59]Oral or inhaled NAC has demonstrated efficacy in decreasing inflammatory markers and mucus production in smokers and COPD patients, correlating with reduced goblet cell activity.[60] For asthma involving goblet cell-mediated mucus overproduction, monoclonal antibodies targeting interleukin-13 (IL-13), such as lebrikizumab, block IL-13 signaling to prevent goblet cell hyperplasia and excessive mucin secretion, showing improved lung function in uncontrolled cases.[61][36]Emerging approaches aim to restore goblet cell function through microbiota modulation and genetic interventions. In the gut, short-chain fatty acids like butyrate, derived from microbiota metabolism, promote goblet cell differentiation and mucus layer repair by enhancing mucin gene expression in epithelial cells, offering potential for therapies in inflammatory bowel disease.[62] Neonatal microbiota colonization further primes goblet cell maturation in the colon, suggesting probiotic or dietary interventions could restore barrier integrity post-dysbiosis.[21] For cystic fibrosis (CF), where CFTR defects impair goblet cell exocytosis and mucin hydration, gene therapy targets airway epithelial cells, including goblet cells, to correct mucin abnormalities and improve mucus clearance, though challenges like the impermeable mucus barrier persist.[46][63]Clinical trials evaluating combination therapies, such as the GOBLET study, assess pelareorep (an oncolytic virus) with atezolizumab (anti-PD-L1 immunotherapy) and chemotherapy in advanced gastrointestinal cancers, showing preliminary safety and tumor responses as of 2025.[64] The study expands to multiple cohorts, aiming to enhance anti-tumor immunity in immunologically cold tumors.[65]
History and Research
Discovery and Early Studies
Goblet cells were first identified in 1837 by anatomist Jakob Henle during his microscopic examination of the small intestine's epithelial lining, where he described distinctive flask-shaped cells interspersed among the columnar epithelium. Henle's observations, detailed in his work Symbolae ad anatomiam villorum intestinalium, marked the initial recognition of these structures as integral components of the mucosal surface, though their function remained unclear at the time.[66]Advancements in microscopy during the mid-19th century further elucidated their characteristics. In 1857, Franz Leydig extended the description to the respiratory tract, noting similar cells in the tracheal epithelium and proposing their involvement in mucussecretion based on their cytoplasmic content.[67] This insight was corroborated and refined by Max Johann Sigismund Schultze in the 1860s, who employed vital staining techniques—such as with alkaline solutions—to selectively highlight the mucin within these cells, confirming their role as specialized mucus producers in the intestinal epithelium.[68] Schultze's work, particularly in 1867, also introduced the term "goblet cells" (Becherzellen in German) to reflect their characteristic cup- or goblet-like morphology when filled with secretory granules.[68]Early functional studies built on these morphological insights by connecting goblet cells to broader glandular secretion processes. In 1868, Rudolf Heidenhain investigated salivary and mucous gland physiology, linking the cellular mechanisms of goblet-like cells to the production and release of viscous secretions that lubricate epithelial surfaces.[69] By the late 19th century, the term "goblet cell" gained widespread adoption in histological literature, emphasizing their secretory apparatus and distribution in both gastrointestinal and respiratory mucosae.[70]Initial clinical associations emerged around the turn of the 20th century, when pathologists observed hyperplasia of goblet cells contributing to excessive mucus production in conditions like asthma. Postmortem examinations from the early 1900s revealed desquamated epithelial cells, including goblet cells, embedded in airway mucus plugs, highlighting their role in obstructive pathology.[71] These findings laid the groundwork for understanding goblet cell dysregulation in inflammatory diseases.[44]
Recent Advances
Advances in single-cell RNA sequencing (scRNA-seq) since the 2010s have unveiled significant heterogeneity among goblet cells, identifying distinct subpopulations with varying transcriptional profiles across intestinal and airway epithelia. For instance, scRNA-seq analyses of the human colon have revealed intercrypt goblet cells that differ from crypt-based ones in gene expression related to mucus production and immune modulation.[72] Similarly, studies of the distal lung and small intestine have highlighted goblet cell clusters exhibiting diverse markers for secretory functions and responses to environmental cues, challenging the view of goblet cells as a uniform population.[73][74] These findings, extending into airway epithelia, underscore goblet cell diversity in barrier maintenance and pathogen sensing.[75]Recent research has demonstrated the plasticity of goblet cells, particularly their potential for transdifferentiation into Paneth cells driven by niche signals in the intestinal crypts. A 2025 study in Cell Stem Cell showed that Lgr5+ intestinal stem cells generate secretory lineages, including goblet and Paneth cells, with epigenetic and phenotypic plasticity modulated by Wnt and Notch signaling from the niche, allowing adaptive shifts in cell fate under stress.[76] This plasticity enables goblet cells to convert fates in response to inflammatory or regenerative cues, highlighting their role in dynamic epithelial homeostasis.[77]In infection contexts, goblet cells have emerged as key players in viral tropism and bacterial pathogenesis. A 2025 investigation identified goblet cells in nasal and intestinal mucosae as determinants of viral entry and spread, where their mucus shields against pathogens but can also serve as initial infection sites, influencing disease severity in respiratory viruses like SARS-CoV-2.[78] For bacterial infections, transcriptomic analysis revealed that Acinetobacter baumannii rapidly induces goblet cell breakdown in human bronchial epithelia, triggering robust inflammatory responses and epithelial barrier disruption within hours of exposure.[79]Aging and sex-specific differences further illuminate goblet cell functions. A 2024 study documented an age-related decline in goblet cell numbers and mucin content in the human colon, correlating with thinner mucus layers and increased vulnerability to inflammation in the elderly.[37] In 2025 research, female-specific roles were delineated in the intestine, where flavin-containing monooxygenase 5 (FMO5) regulates goblet cell maturation and mucus barrier integrity exclusively in females, leading to sex-dimorphic susceptibility to colitis upon disruption.[80]Therapeutic innovations targeting goblet cells include MUC2-focused models for cancer and neural modulation of secretion. In 2025, MUC2-producing goblet-like tumorigenic cell lines were developed to model colorectal cancer progression, demonstrating how mucin barriers suppress tumor invasion and immune evasion, offering targets for mucin-enhancing therapies.[51] Concurrently, studies on neural control revealed that enteric neurons regulate goblet cell mucus secretion in the gastrointestinal tract via acetylcholine and neuropeptide signaling, providing avenues for neuromodulatory treatments in disorders like inflammatory bowel disease.[81]