Salivary Gland Cells Research Articles

Transgenic mammalian salivary cells expressing ligninase as a proof-of-concept model for enhanced lignocellulose degradation to generate future resilient livestock

The major limitation in feed grade utility of cereal straws is the presence of the high amount of lignified fiber. Considering the limited ligninase availability in rumen, the current work is intended to establish the proof-of-concept for a recombinant ligninase expression in mammalian salivary gland cells so that it can be translated into generation of a live transgenic ruminant that can produce ligninase in its saliva for enhanced degradation of lignin. To verify the proof of concept the Sleeping Beauty transposon vector (pT2-RMCE) containing a ubiquitously active CAGGS promoter was used to express three different types of bacterial ligninases. Two of them are dye decolorizing peroxidase family (DyP1 and Dyp2) which belong to the category of heme peroxidases and one is laccase which belongs to a multi-copper oxidase (cotA). The vector was transfected into rat ParC10 salivary cell lines and the protein expressed by the engineered cells was harvested, purified to check the functionality on Kraft lignin degradation. Among the three, only DyP1 could be detected on Western blot and was also found to be functionally active. It can be concluded that mammalian salivary cells can be genetically engineered with appropriate ligninase gene to produce functional ligninase.

Alterations of CD8+ T cells in the blood and salivary glands of patients with primary Sjögren’s syndrome

ObjectiveTo identify the alterations of CD8+ T cells in blood and labial salivary glands (LSGs) of patients with Primary Sjögren’s syndrome (pSS).MethodsBlood samples from 24 pSS patients were assayed for CD38+ HLA-DR+ CD8+ (activated CD8+, aCD8+) T cells and serum IFN-γ and TNF-α, using flow cytometry and ELISA respectively, and compared with samples from 27 healthy controls. Immunohistochemistry was used to count CD8+ T cells in LSG tissues of 24 pSS patients and of 6 control patients with normal pathology.ResultspSS patients had more aCD8+ T cells than aCD4+ T cells (medians 33.13% vs. 9.43%, p < 0.0001), and had an increased level of aCD8+ T cells (medians 33.13% vs. 16.48%, p < 0.0001) and serum IFN-γ (medians 1026 pg/mL vs. 0.00 pg/mL, p < 0.0001) compared to the healthy controls. The levels of aCD8+ T cells and IFN-γ were both significant positively correlated with European League Against Rheumatism Sjögren’s Syndrome Disease Activity Index, IgG, anti-nuclear antibodies, rheumatoid factor. The LSGs focus score (FS) ≥1 group had more CD8+ T cell counts than 0≤ FS <1 group and control group (medians 256/mm2 vs. 126/mm2 and 256/mm2 vs. 64/mm2 respectively, both p < 0.05).ConclusionThe aCD8+ T cells and IFN-γ are positively correlated with each other, and predominantly elevated in the blood of pSS patients. In the LSG tissues of pSS, CD8+ T cell counts increase with severity of the lesions. CD8+ T cells may play crucial role in the pathogenesis of pSS.Key Points• Primary Sjögren’s syndrome (pSS) is a chronic and systemic autoimmune disease. pSS patients had elevated blood levels of CD38+HLA-DR+CD8+T cells and IFN-γ.• The CD38+HLA-DR+CD8+T cells positively correlated with disease parameters and serum IFN-γ.• The salivary glands of pSS patients had appreciable CD8+lymphocyte infiltration. CD8+T cells may play crucial role in the pathogenesis of pSS.

Rab26 controls secretory granule maturation and breakdown in Drosophila

At the onset of Drosophila metamorphosis, plenty of secretory glue granules are released from salivary gland cells and the glue is deposited on the ventral side of the forming (pre)pupa to attach it to a dry surface. Prior to this, a poorly understood maturation process takes place during which secretory granules gradually grow via homotypic fusions, and their contents are reorganized. Here we show that the small GTPase Rab26 localizes to immature (smaller, non-acidic) glue granules and its presence prevents vesicle acidification. Rab26 mutation accelerates the maturation, acidification and release of these secretory vesicles as well as the lysosomal breakdown (crinophagy) of residual, non-released glue granules. Strikingly, loss of Mon1, an activator of the late endosomal and lysosomal fusion factor Rab7, results in Rab26 remaining associated even with the large glue granules and a concomitant defect in glue release, similar to the effects of Rab26 overexpression. Our data thus identify Rab26 as a key regulator of secretory vesicle maturation that promotes early steps (vesicle growth) and inhibits later steps (lysosomal transport, acidification, content reorganization, release, and breakdown), which is counteracted by Mon1.

Genotoxic and mutational potential of monocyclic terpenoids (carvacrol, carvone and thymol) in Drosophila melanogaster.

Genotoxicity and mutagenicity of monoterpene carvone along with the related monoterpene alcohols - carvacrol and thymol have been studied using Drosophila melanogaster as model system. The viability, pre-imaginal stage duration, level of dominant lethal mutations, unequal crossover in the Bar mutant of D. melanogaster and the influence of monocyclic terpenoids on the multiplication of the nuclear genome in salivary gland cells were investigated. The compounds tested after oral administration (0.02% in 1,2-propylene glycol) influence the degree of chromosome polyteny in salivary gland cells of D. melanogaster larvae. Among the terpenoids examined, carvacrol exhibited the most significant impact on imago lifespan, frequency of dominant lethal mutations, unequal crossover in the Bar mutant when added to the culture medium. Oral administration of terpenoids increases the average level of chromosome polyteny with the highest value for carvacrol - 1178C compared to control (776C). The conceivable mechanism of action for monocyclic terpenoids associated with the impact on juvenile hormone activity is debated.

Relative Biological Effectiveness Values of Spot-scanning Proton Beam Therapy at Shonan Kamakura General Hospital.

This study aimed to confirm the relative biological effectiveness (RBE) values of the proton beam therapy (PBT) system installed in Shonan Kamakura General Hospital. Clonogenic cell-survival assays were performed with a human salivary gland (HSG) cell line, a human tongue squamous-cell carcinoma cell line (SAS), and a human osteosarcoma cell line (MG-63). Cells were irradiated with proton beams and X-rays with different doses (1.8, 3.6, 5.5, and 7.3 Gy for proton beams, and 2, 4, 6, and 8 Gy for X-rays). Proton beam irradiation used spot-scanning methods and three different depths (at the proximal, center, and distal sides of the spread-out Bragg peak). RBE values were obtained from a comparison of the dose that resulted in a surviving fraction of 10% (D10). D10 of proton beams at the proximal, center, and distal sides and X-rays in HSG were 4.71, 4.71, 4.51, and 5.25 Gy, respectively; those in SAS were 5.08, 5.04, 5.01, and 5.59 Gy, respectively; and those in MG-63 were 5.36, 5.42, 5.12, and 6.06 Gy, respectively. The RBE10 values at the proximal, center, and distal sides in HSG were 1.11, 1.11, and 1.16 respectively; those in SAS were 1.10, 1.11, and 1.12, respectively; and those in MG-63 were 1.13, 1.12, and 1.18, respectively. RBE10 values of 1.10-1.18 were confirmed by in vitro experiments using the PBT system. These results are considered acceptable for clinical use in terms of therapeutic efficacy and safety.

P63 as an Ideal Diagnostic Marker for Pleomorphic Adenoma: An Immunohistochemical Study

Introduction: Pleomorphic Adenoma (PA) histopathologically represents a heterogeneous lesion with a varying proportion of epithelial and mesenchymal components. Due to its morphological diversity, a diagnostic dilemma often arises when identifying its various patterns. This diverse morphology is considered to be a function of the neoplastic myoepithelium. Tumor protein 63 (p63) is expressed in stratified epithelia and in the basal cells of salivary glands. Aim: To investigate the immunoreactivity of p63 as a reliable myoepithelial marker in PA. Materials and Methods: A cross-sectional study was performed in the Department of Oral and Maxillofacial Pathology at PGIDS, Rohtak, Haryana, India. The duration of the study was 14 months, from March 2015 to April 2016. A total of 15 tissue blocks of histopathologically diagnosed cases of PA were included from departmental archives and subjected to Immunohistochemistry (IHC) using a monoclonal p63 antibody. The myoepithelium was classified as myoepithelial-like (abluminal and spindled), modified myoepithelium (myxoid and chondroid), and transformed myoepithelium (solid epithelioid, squamous, and basaloid cribriform). IHC for p63 was assessed in each myoepithelial component, as well as in non neoplastic Myoepithelial Cells (MEC) and inner tubular epithelial cells. Only nuclear staining for p63 was considered positive. The obtained data were subjected to statistical analysis, and the Chi-square test was applied. Results: The PA samples subjected to IHC showed 100% p63 reactivity. Transformed MEC, abluminal, and modified MEC revealed variable immunostaining with a significant difference (p=0.049). There was no immunostaining in luminal/inner layer cells in all cases of PA. p63 was also expressed in the nuclei of MEC of acini and intercalated ducts of normal salivary gland tissue. Conclusion: p63 is a sensitive and specific myoepithelial marker to identify MEC in PA. Additionally, the expression of MECassociated markers in acini and intercalated ducts of normal salivary glands has confirmed their role in the histogenesis of this tumour.

Sappanone A Aggrandises Ionising Radiation-induced Damage in Oral Epithelial Cells.

To analyse the role played by Sappanone A, a bioactive ingredient isolated from the heartwood of Caesalpinia sappan, in the regulation of oral epithelial cell viability under radiation. Cell viability of human oral keratinocytes (HOKs) and mouse salivary gland cells under ionising radiation was analysed. Expression of Ki67 was measured by immunohistochemical staining. Fragmentation of deoxyribonucleic acid (DNA) was measured by comet assay. Cell death was analysed using trypan blue exclusion assay. Cell viability was measured using a Cell Counting Kit 8 (CCK8; Abcam, Cambridge, UK) assay. Sappanone A decreased cell viability of HOK cells and mouse salivary gland cells under ionising radiation. In addition, Sappanone A enhanced radiation-induced genomic DNA fragmentation, accompanied by impaired homologous recombination and non-homologous end joining DNA repair. Mechanistic evaluation revealed that Sappanone A counteracted radiation-induced inosine monophosphate dehydrogenase 2 (IMPDH2) activation, and that this effect could be abolished by reconstituted expression of a Sappanone A-binding defective IMPDH2 mutant. The present study highlights a novel role played by Sappanone A in the modulation of radiosensitivity of oral epithelial cells.

Expression of CFTR, a hallmark gene of ionocytes, is downregulated in salivary glands of Sjögren’s syndrome patients

IntroductionThe autoimmune exocrinopathy, Sjögren’s syndrome (SjS), is associated with secretory defects in salivary glands. The cystic fibrosis transmembrane conductance regulator (CFTR) of the chloride channel is a master regulator of fluid secretion, but its role in SjS has not been investigated. Our research found a link between CFTR and SjS at the genetic and protein levels, as well as through clinical data.MethodsWe used single-cell RNA sequencing to identify the presence of CFTR in glandular epithelial cells of the human salivary gland (scRNA-seq) and confirmed the difference using immunofluorescence tests in labial glands and clinical data statistics from 44 non-SjS and 36 SjS patients.ResultsThe changes of CFTR expression in salivary glands of SjS patients was assessed at both mRNA and protein levels. According to the scRNA-seq analyses, CFTR was the hallmark gene of ionocytes. We firstly identified that SjS had a lower level of CFTR expression in the labial glands than non-SjS at mRNA level.Using immunofluorescence assays, we also found that CFTR expression was decreased in SjS patients compared to non-SjS. The results of the clinical statistics revealed that CFTR expression was adversely correlated with feelings of dry mouth, lymphocyte infiltration in the labial glands, and certain autoantibodies in serum (antinuclear antibody, anti-Ro/SSA, and anti-La/SSB antibodies).ConclusionThose findings above proved an obviously downregulated expression of CFTR in salivary glands of SjS patients and its clinical significance. Dysfunction in CFTR or ionocytes may contribute to SjS pathogenesis and represents a promising therapeutic target.

A novel cell-based transplantation method using a Rho kinase inhibitor and a specific catheter device for the treatment of salivary gland damage after head and neck radiotherapy

Radiotherapy (RT) for head and neck cancer results in irreversible damage to salivary glands (SGs) and decreases saliva production, leading to a dry mouth. To date, there are no satisfactory therapies to solve this problem. We recently established a novel culturing method using a Rho kinase inhibitor (RI), Y-27632, that maintained cellular morphology and function for a prolonged period of time. In the present study, we investigated whether cell-based transplantation using our culturing method ameliorated the dysfunction of irradiated SGs. First, rat SG cells were cultured in a medium with RI. Cells were characterized by morphological findings and mRNA expression analysis. We also assessed features of SG cells in three-dimensional (3-D) culture by scanning electron microscopy and immunohistochemistry (IHC). The RI-containing medium led to higher cell proliferation of rat SG cells with preservation of cell morphology and higher alpha-amylase (AMY) expression in both 2-D and 3-D culture systems. To establish the atrophic-SG models, external RT at a dose of 15 Gy was delivered to the head and neck fields of nude rats. The SG cells derived from GFP-rats were cultured in medium with RI, after which they were transplanted into the submandibular glands of atrophic-SG rats using a catheter placed into Wharton's duct. IHC and salivary flow rate (SFR) analyses were measured 12 weeks after the transplantation. Following transplantation, donor cells (GFP-SG cells) were primarily located in the ductal region of the SG, and AMY expression in SGs and the SFR were increased in the SG cell transplantation group compared with the control. Those data indicated that cell-based therapy using RI-treated SG cells could restore salivary hypofunction of irradiated SGs by direct integration of the donor cells in the duct of SGs. We propose that these data support future clinical plans in which SG cells would be excised from the labial minor SGs of the patients with head and neck cancers prior to RT, cultured during RT, and auto-transplanted into SGs using a catheter into the Wharton's duct. We believe that our culturing and transplantation methods can be applied to SG cells, constituting a therapeutic approach for the treatment of patients with dry mouth after not only RT but also aging and Sjögren's syndrome.

Hydrogels for Salivary Gland Tissue Engineering.

Mimicking the complex architecture of salivary glands (SGs) outside their native niche is challenging due their multicellular and highly branched organization. However, significant progress has been made to recapitulate the gland structure and function using several in vitro and ex vivo models. Hydrogels are polymers with the potential to retain a large volume of water inside their three-dimensional structure, thus simulating extracellular matrix properties that are essential for the cell and tissue integrity. Hydrogel-based culture of SG cells has seen a tremendous success in terms of developing platforms for cell expansion, building an artificial gland, and for use in transplantation to rescue loss of SG function. Both natural and synthetic hydrogels have been used widely in SG tissue engineering applications owing to their properties that support the proliferation, reorganization, and polarization of SG epithelial cells. While recent improvements in hydrogel properties are essential to establish more sophisticated models, the emphasis should still be made towards supporting factors such as mechanotransduction and associated signaling cues. In this concise review, we discuss considerations of an ideal hydrogel-based biomaterial for SG engineering and their associated signaling pathways. We also discuss the current advances made in natural and synthetic hydrogels for SG tissue engineering applications.

Dose response modelling of secretory cell loss in salivary glands using PSMA PET

Background and purposeXerostomia remains a common side effect of radiotherapy (RT) for patients with head and neck (H&N) cancer despite advancements in treatment planning and delivery. Secretory salivary gland cells express the prostate-specific membrane antigen (PSMA), and show significant uptake on PET scans using 68Ga/18F-PSMA-ligands. We aimed to objectively quantify the dose–response of salivary glands to RT using PSMA PET. Methods and materials28H&N cancer patients received RT with 70 Gy in 35 fractions over 7 weeks. PSMA PET/CT was acquired at baseline (BL), during treatment (DT) and at 1-&6-months post-treatment (PT1M/PT6M). Dose, BL- PT1M- and PT6M-SUV were extracted for every voxel inside each parotid (PG) and submandibular (SMG) gland. The PT1M/6M data was analysed using a generalised linear mixed effects model.Patient-reported xerostomia and DT-PSMA loss was also analysed. ResultsDose had a relative effect on BL SUV. For a population average gland (BL-SUV of 10), every 1 Gy increment, decreased the PT1M/PT6M-SUV by 1.6 %/1.6 % for PGs and by 0.9 %/1.8 % for SMGs. TD50 of the population curves was 26.5/31.3 Gy for PGs, and 22.9/27.8 Gy for SMGs at PT1M /PT6M. PSMA loss correlated well with patient-reported xerostomia at DT/PT1M (Spearman’s ρ = -0.64, −0.50). ConclusionA strong relationship was demonstrated between radiation dose and loss of secretory cells in salivary glands derived using PSMA PET/CT. The population curve could potentially be used as a dose planning objective, by maximising the predicted post-treatment SUV. BL scans could be used to further tailor this to individual patients.

Disturbed natural killer cell homeostasis in the salivary gland enhances autoimmune pathology via IFN-γ in a mouse model of primary Sjögren’s syndrome

Innate lymphoid cells (ILCs), including natural killer (NK) cells, ILC1, ILC2, lymphoid tissue-inducer (LTi) cells, and ILC3 cell, play a key role in various immune responses. Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by chronic inflammation of exocrine glands, such as the lacrimal and salivary glands (SGs). The role of NK cells among ILCs in the pathogenesis of pSS is still unclear. In this study, the characteristics and subsets of NK cells in the salivary gland (SG) tissue were analyzed using a murine model of pSS. Multiple phenotypes and cytotoxic signature of the SG NK cells in control and pSS model mice were evaluated by flow cytometric analysis. Intracellular expression of interferon-γ (IFN-γ) among T cells and NK cells from the SG tissues was compared by in vitro experiments. In addition, pathological analysis was performed using anti-asialo-GM1 (ASGM1) antibody (Ab)-injected pSS model mice. The number of conventional NK (cNK) cells in the SG of pSS model mice significantly increased compared with that in control mice at 6 weeks of age. The production level of IFN-γ was significantly higher in SG NK cells than in SG T cells. The depletion of NK cells by ASGM1 Ab altered the ratio of tissue resident NK (rNK) cells to cNK cells, which inhibited the injury to SG cells with the recovery of saliva secretion in pSS model mice. The results indicate that SG cNK cells may enhance the autoreactive response in the target organ by upregulating of IFN-γ, whereas SG rNK cells protect target cells against T cell cytotoxicity. Therefore, the activation process and multiple functions of NK cells in the target organ could be helpful to develop potential markers for determining autoimmune disease activity and target molecules for incurable immune disorders.

Cell-derived vesicles from adipose-derived mesenchymal stem cells ameliorate irradiation-induced salivary gland cell damage.

IntroductionSalivary gland (SG) damage is commonly caused by aging, irradiation, and some medications, and currently, no damage modifying agent is available. However, cell therapy based on mesenchymal stem cells (MSCs) has been proposed as a therapeutic modality for irradiated SGs. Therefore, we administered cell-derived vesicles (CDVs) of adipose-derived mesenchymal stem cells (ADMSCs) to irradiated SG cells to investigate their radioprotective effects in vitro.MethodsThe artificial CDVs were obtained from ADMSC by tangential flow filtration (TFF) purification and ultracentrifugation. Cultured human SG epithelial cells were exposed to 2, 5 or 15 Gy of 4 MV X-rays produced by a linear accelerator. The effects of ADMSC-CDVs on SG epithelial cells damaged by irradiation were tested by proliferation activity, transepithelial electrical resistance (TEER), and amylase activity.ResultsExposure to penetrating radiation inhibited the proliferation of SG epithelial cells, but the radiation intensity required to reduce the proliferation of human submandibular gland epithelial cells (hSMGECs) was greater than required for other SG cells. ADMSC-CDVs restored the proliferative ability of SG epithelial cells reduced by irradiation, and the proliferation capacities of irradiated human parotid gland epithelial cells (hPGECs) and human sublingual gland epithelial cells (hSLGECs) were increased by administering ADMSC-CDVs to non-irradiated SG epithelial cells. Furthermore, amylase activity in irradiated hPGECs, hSMGECs, and hSLGECs was lower than in non-irradiated controls. However, amylase ability was restored in all by ADMSC-CDV treatment. Also, TEER was diminished by irradiation in hPGECs, hSMGECs, and hSLGECs and restored by ADMSC-CDV administration.ConclusionOverall, our findings demonstrate that ADMSC-CDVs have potent radioprotective effects on irradiated SG cells.

IFT140+/K14+ cells function as stem/progenitor cells in salivary glands

Stem/progenitor cells are important for salivary gland development, homeostasis maintenance, and regeneration following injury. Keratin-14+ (K14+) cells have been recognized as bona fide salivary gland stem/progenitor cells. However, K14 is also expressed in terminally differentiated myoepithelial cells; therefore, more accurate molecular markers for identifying salivary stem/progenitor cells are required. The intraflagellar transport (IFT) protein IFT140 is a core component of the IFT system that functions in signaling transduction through the primary cilia. It is reportedly expressed in mesenchymal stem cells and plays a role in bone formation. In this study, we demonstrated that IFT140 was intensively expressed in K14+ stem/progenitor cells during the developmental period and early regeneration stage following ligation-induced injuries in murine submandibular glands. In addition, we demonstrated that IFT140+/ K14+ could self-renew and differentiate into granular duct cells at the developmental stage in vivo. The conditional deletion of Ift140 from K14+ cells caused abnormal epithelial structure and function during salivary gland development and inhibited regeneration. IFT140 partly coordinated the function of K14+ stem/progenitor cells by modulating ciliary membrane trafficking. Our investigation identified a combined marker, IFT140+/K14+, for salivary gland stem/progenitor cells and elucidated the essential role of IFT140 and cilia in regulating salivary stem/progenitor cell differentiation and gland regeneration.

Mitochondrial double-stranded RNAs as a pivotal mediator in the pathogenesis of Sjӧgren’s syndrome

Sjӧgren’s syndrome (SS) is a systemic autoimmune disease that targets the exocrine glands, resulting in impaired saliva and tear secretion. To date, type I interferons (I-IFNs) are increasingly recognized as pivotal mediators in SS, but their endogenous drivers have not been elucidated. Here, we investigate the role of mitochondrial double-stranded RNAs (mt-dsRNAs) in regulating I-IFNs and other glandular phenotypes of SS. We find that mt-dsRNAs are elevated in the saliva and tears of SS patients (n = 73 for saliva and n = 16 for tears) and in salivary glands of non-obese diabetic mice with salivary dysfunction. Using the in-house-developed 3D culture of immortalized human salivary gland cells, we show that stimulation by exogenous dsRNAs increase mt-dsRNAs, activate the innate immune system, trigger I-IFNs, and promote glandular phenotypes. These responses are mediated via the Janus kinase 1 (JAK1)/signal transducer and activator of transcription (STAT) pathway. Indeed, a small chemical inhibitor of JAK1 attenuates mtRNA elevation and immune activation. We further show that muscarinic receptor ligand acetylcholine ameliorates autoimmune characteristics by preventing mt-dsRNA-mediated immune activation. Last, direct suppression of mt-dsRNAs reverses the glandular phenotypes of SS. Altogether, our study underscores the significance of mt-dsRNA upregulation in the pathogenesis of SS and suggests mt-dsRNAs as propagators of a pseudo-viral signal in the SS target tissue.

Detection and characterization of rice orange leaf phytoplasma infection in rice and Recilia dorsalis

Phytoplasmas are small bacterial parasites that lack cell walls and are transmitted in a persistent-propagative manner by insect vectors. However, detailed multiplication patterns and movements of phytoplasmas within host plant and insect vector remain elusive. In this study, a specific antibody against the immunodominant membrane protein (Imp) of rice orange leaf phytoplasma (ROLP) was generated and subjected to the frozen section immune gold labeling assay, immune gold labeling microscopy, and immune fluorescence labeling assay to investigate how ROLP enters, propagates, and spreads in rice and its leafhopper vector Recilia dorsalis at the ultrastructural level. During acquisition and transmission by insect vectors, ROLPs could squeeze and penetrate the multiple membrane/tissue barriers such as microvilli, apical plasmalemma, and basal lamina in the intestines or salivary glands by endocytosis- and exocytosis-like mechanism. Furthermore, ROLP infection is restricted to the type IV and V cells of salivary glands. In contrast to the classical binary fission used by most bacteria, electron microscopy reveals that ROLP exploits an asymmetrical budding strategy to replicate in plant hosts and insect vectors. In this process, a cellular protrusion of ROLP forms a bud to reproduce the offspring by fission at the junction between the bud and the ROLP main body. These results clarify the infection characteristics of ROLP in rice and R. dorsalis, which will help guide the formulation of ROLP prevention and control strategies.

Adenoid cystic carcinoma of trachea presenting as a medical emergency- A case report

Adenoid cystic carcinoma is a chief histologic type of malignancy of minor salivary glands. Primary malignant Tracheal neoplasms are rare &amp;#60;0.1%, with Adenoid Cystic Carcinoma being very rare. It arises from mucous secreting cells of salivary glands and upper respiratory tract. After Squamous Cell Carcinoma it is second most common Primary tracheal malignancy. Diagnosis can be done by Computed Tomography or Magnetic Resonance Imaging. But histopathology remains gold standard of diagnosis.

Innervation of the human minor salivary glands; immunohistochemical study for neurochemical substances

Distributions of choline acetyltransferase (ChAT), vasoactive intestinal polypeptide (VIP), dopamine β-hydroxylase (DBH), tyrosine hydroxylase (TH), neuropeptide Y (NPY) and the transient receptor potential cation channel subfamily V member 2 (TRPV2) were examined in the human minor salivary glands. ChAT-, VIP- and DBH-immunoreactive (-IR) nerve fibers were detected within nerve bundles and close to blood vessels and ducts in the salivary glands. Periacinar nerve fibers were commonly immunoreactive for ChAT in the Ebner’s gland but infrequently in other salivary glands. Periacinar VIP-IR nerve fibers were numerous in the palatal gland, moderate in the lingual gland and relatively rare in the labial and Ebner’s glands. Some TH-, NPY- and TRPV2-IR nerve fibers were also present around blood vessels and glandular acini in the palatal, lingual and Ebner’s glands. Neuronal cells in the vicinity of Ebner’s and lingual glands were immunoreactive for ChAT, VIP, TH and TRPV2. By confocal laser scanning microscopy, VIP- and ChAT-IR varicosities were located in the vicinity of myoepithelial and acinar cells in the minor salivary glands. The human minor salivary glands are probably innervated by parasympathetic and sympathetic nerves. Neurotransmitters including neuropeptides in these nerves are thought to be correlated to vasodilation and/or salivary secretion. Acetylcholine and VIP may regulate secretion of the saliva and its components in the salivary glands.

Cytotoxic CD8+ T cells may be drivers of tissue destruction in Sjögren’s syndrome

Sjögren’s syndrome is a chronic autoimmune disorder whose pathogenesis is poorly understood and that lacks effective therapies. Detailed quantitative and spatial analyses of tissues affected by Sjögren’s syndrome were undertaken, including the quantitation of the frequency of selected cell–cell interactions in the disease milieu. Quantitative analyses of CD4+ T cell subsets and of CD8+ T cells in the labial salivary glands from untreated patients with primary Sjögren’s syndrome revealed that activated CD8+ cytotoxic T cells (CD8+CTLs) were the most prominent T cells in these infiltrates. An accumulation of apoptotic glandular epithelial cells, mainly ductal and acinar cells, was observed, consistent with the impaired salivary secretion often observed in patients with this disease. FasL expressing activated CD8+ T cells were seen to accumulate around Fas expressing apoptotic epithelial cells. Quantitative analyses of apoptotic cell types and of conjugates between cytotoxic T cells and epithelial cells undergoing apoptosis suggest that Sjögren’s syndrome is primarily driven by CD8+CTL mediated execution of epithelial cells mainly represented by ductal and acinar cells.

HCG11 inhibits salivary adenoid cystic carcinoma by upregulating EphA2 via binding to miR-1297

Ephrin receptor A2 (EphA2) was reported to be related to the tumorigenesis of salivary adenoid cystic carcinoma (SACC), which is a rare malignancy accounting for less than 1% of all oral and maxillofacial tumors. This research aimed to assess the molecular mechanisms of EphA2 in SACC. The expression of long non-coding RNA human leukocyte antigen complex group 11 (HCG11), microRNA-1297 (miR-1297), and EphA2 in SACC cell lines compared with normal human salivary gland (HSG) cell line was measured by reverse transcription-quantitative polymerase chain reaction. EphA2 protein level was detected by western blot. 5-ethynyl-2'-deoxyuridine (EdU), colony formation, Transwell, and wounding healing experiments were applied to evaluate SACC cell proliferation, migration, and invasion. The relationship among HCG11, miR-1297, and EphA2 was confirmed by luciferase reporter, RNA pulldown, and RNA immunoprecipitation experiments. HCG11 and EphA2 were downregulated while miR-1297 was upregulated in SACC cells. EphA2 overexpression suppressed SACC cell proliferation, migration, and invasion. HCG11 bound to miR-1297 to reduce the inhibition of miR-1297 on EphA2 expression. EphA2 knockdown reversed the suppression of HCG11 overexpression on SACC cell phenotypes. This study identified the HCG11/miR-1297/EphA2 regulatory axis in SACC, which might provide novel therapeutic targets for SACC.