Salivary Gland Function Research Articles

Interleukin-22 Exerts Detrimental Effects on Salivary Gland Integrity and Function.

Interleukin-22 (IL-22) affects epithelial tissue function and integrity in a context-dependent manner. IL-22 levels are elevated in salivary glands of Sjögren's syndrome (SS) patients, but its role in the pathogenesis of this disease remains unclear. The objective of this study is to elucidate the impact of IL-22 on salivary gland tissue integrity and function in murine models. We showed that IL-22 levels in sera and salivary glands increased progressively in female non-obese diabetic (NOD) mice, accompanying the development of SS. Administration of IL-22 to the submandibular glands of NOD mice prior to the disease onset reduced salivary secretion and induced caspase-3 activation in salivary gland tissues, which were accompanied by alterations in multiple genes controlling tissue integrity and inflammation. Similarly, IL-22 administration to submandibular glands of C57BL/6 mice also induced hyposalivation and caspase-3 activation, whereas blockade of endogenous IL-22 in C57BL/6 mice treated with anti-CD3 antibody mitigated hyposalivation and caspase-3 activation. Finally, IL-22 treatment reduced the number of viable C57BL/6 mouse submandibular gland epithelial cells cultured in vitro, indicating a direct impact of this cytokine on these cells. We conclude that IL-22 exerts a detrimental impact on salivary gland tissues.

Can Superficial Parotid Sparing Alone Reduce Xerostomia? A Retrospective Study Correlating Type of Tobacco Use, Chronic Xerostomia and Parotid Sparing

<h3>Purpose/Objective(s)</h3> Head and neck cancer is one of the most common cancers in India. Tobacco chewing is the most widespread form of tobacco consumption. Majority of the patients present in locally advanced stage and achieving parotid sparing with IMRT in these patients can be challenging. We aimed to correlate the incidence of chronic xerostomia with the type of tobacco use and parotid volumes. <h3>Materials/Methods</h3> Patients with squamous carcinomas of head and neck region treated with conventionally fractionated curative-intent radiotherapy (bilateral neck) to a dose of 60-70 Gy between June 2017 and March 2020 were included in the study. The superficial and deep lobes of parotid were contoured retrospectively and the dosimetric data along with physician-assessed Radiation Therapy Oncology Group (RTOG) xerostomia toxicity grades at one year were retrieved. The individual, superficial and deep lobe parotids were considered spared if the mean dose was less than 26Gy. Patients were divided into five groups: Group 1 constituted bilateral parotid-spared, Group 2 of contralateral parotid-spared, Group 3 of contralateral superficial parotid-spared, Group 4 of bilateral superficial parotid-spared, and Group 5 where no sparing could be achieved. The groups were compared using chi-square test. <h3>Results</h3> 174 patients were included in the study. The median age was 59 years (IRQ 20 - 89). Chewing (40%), followed by smoking (35%) were the most frequent forms of tobacco consumption. The most common subsite was oropharynx (30.5%) followed by hypopharynx (26.4%), and about 83% had locally advanced disease. The mean bilateral parotid volume was 55.9 cc (18-130 cc). Tobacco chewers had significantly smaller mean parotid (53cc vs 60cc, p=0.02) and submandibular gland volumes (6cc vs 14cc, p<0.001) as compared to smokers. Bilateral or contralateral parotid sparing was achieved in 62.7%, bilateral or contralateral superficial lobe in 27.6%, and no sparing in 9.8% of patients. At one year, grade 0/I xerostomia was reported by 89.5%, and ≥grade II xerostomia in 11.5%. The grade of xerostomia was similar in smokers and chewers (p=0.95). The ipsilateral (26.5 Gy vs 37.8 Gy, p <0.001) and contralateral (23.3 Gy vs 34.1 Gy, p <0.001) superficial parotid mean dose in patients with grade 0/I and ≥grade II xerostomia was significantly different. Patients with bilateral or contralateral superficial lobe sparing had lower rates of grade II/III xerostomia compared to no sparing group (p<0.001). <h3>Conclusion</h3> Tobacco chewers have smaller parotid and submandibular glands compared to smokers. This did not impact the sparing of glands or the severity of xerostomia. Contralateral or bilateral superficial parotid sparing translated into superior salivary gland function at 1 year.

A preclinical model to investigate normal tissue damage following fractionated radiotherapy to the head and neck.

Radiotherapy (RT) of head and neck (H&N) cancer is known to cause both early- and late-occurring toxicities. To better appraise normal tissue responses and their dependence on treatment parameters such as radiation field and type, as well as dose and fractionation scheme, a preclinical model with relevant endpoints is required. 12-week old female C57BL/6J mice were irradiated with 100 or 180kV X-rays to total doses ranging from 30 to 85Gy, given in 10 fractions over 5days. The radiation field covered the oral cavity, swallowing structures and salivary glands. Monte Carlo simulations were employed to estimate tissue dose distribution. The follow-up period was 35days, in order to study the early radiation-induced effects. Baseline and post irradiation investigations included macroscopic and microscopic examinations of the skin, lips, salivary glands and oral mucosa. Saliva sampling was performed to assess the salivary gland function following radiation exposure. A dose dependent radiation dermatitis in the skin was observed for doses above 30Gy. Oral mucositis in the tongue appeared as ulcerations on the ventral surface of the tongue for doses of 75-85Gy. The irradiated mice showed significantly reduced saliva production compared to controls. In summary, a preclinical model to investigate a broad panel of normal tissue responses following fractionated irradiation of the H&N region was established. The optimal dose to study early radiation-induced effects was found to be around 75Gy, as this was the highest tolerated dose that gave acute effects similar to that observed in cancer patients.

Low-dose interleukin-2 can improve salivary secretion but not lymphocyte infiltration of salivary glands in a murine model of Sjögren’s syndrome

Introduction/aimEffects of low-dose interleukin-2 (IL-2) on the exocrine glandular glands of Sjögren’s syndrome are unknown. The aim of this study was to investigate the effects of low-dose IL-2 on salivary gland structure and function in a murine model of Sjögren’s syndrome.Materials and methodsNon-obese diabetic/Ltj (NOD) mice were used as the animal model of Sjögren’s syndrome, and low-dose IL-2 or phosphate buffered saline was administered subcutaneously from 5 weeks of age, while ICR mice were used as controls. Some mice were sacrificed at 9 weeks of age, while the other mice that continued to receive treatment were sacrificed at 23 weeks. We determined the salivary flow rate of mice every 3 weeks during the intervention. After the mice were sacrificed, one submandibular gland was removed for pathological evaluation, while the other submandibular gland was used to measure the levels of 25 cytokines by Luminex technology. Cervical lymph nodes and spleens were examined by flow cytometry for the proportions of CD8+ T cells and Treg cells.ResultsThe results showed that the salivary flow rate of NOD mice was slower than that of control-group mice, and there were more pathological changes in the submandibular gland. The levels of many cytokines in the submandibular gland were elevated. The proportion of CD8+ T cells in the cervical lymph nodes and spleens was increased; however, the proportion of Treg cells was decreased. After treatment with IL-2, the exocrine function of the salivary glands of mice was improved. IL-2 also promoted the proliferation of Treg cells in the cervical lymph nodes and spleens, but it did not alter the extent of lymphocyte infiltration in the submandibular gland. The levels of cytokines in the submandibular glands, as well as the proportion of CD8+ T cells in the cervical lymph nodes and spleens, were unchanged significantly after IL-2 treatment.ConclusionOur results demonstrate that treatment with low-dose IL-2 improves the secretory function of the exocrine glands of mice with Sjögren’s syndrome, but it does not reverse the structural damage of the exocrine glands.

Sci-Seq of Human Fetal Salivary Tissue Introduces Human Transcriptional Paradigms and a Novel Cell Population.

Multiple pathologies and non-pathological factors can disrupt the function of the non-regenerative human salivary gland including cancer and cancer therapeutics, autoimmune diseases, infections, pharmaceutical side effects, and traumatic injury. Despite the wide range of pathologies, no therapeutic or regenerative approaches exist to address salivary gland loss, likely due to significant gaps in our understanding of salivary gland development. Moreover, identifying the tissue of origin when diagnosing salivary carcinomas requires an understanding of human fetal development. Using computational tools, we identify developmental branchpoints, a novel stem cell-like population, and key signaling pathways in the human developing salivary glands by analyzing our human fetal single-cell sequencing data. Trajectory and transcriptional analysis suggest that the earliest progenitors yield excretory duct and myoepithelial cells and a transitional population that will yield later ductal cell types. Importantly, this single-cell analysis revealed a previously undescribed population of stem cell-like cells that are derived from SD and expresses high levels of genes associated with stem cell-like function. We have observed these rare cells, not in a single niche location but dispersed within the developing duct at later developmental stages. Our studies introduce new human-specific developmental paradigms for the salivary gland and lay the groundwork for the development of translational human therapeutics.

Soluble epoxide hydrolase inhibitor, t-AUCB, improves salivary gland function by ameliorating endothelial injury

AimsInhibitor of soluble epoxide hydrolase (t-AUCB) has been used in the experimental therapy of hypertension. This study aimed to investigate whether the secretion of submandibular glands (SMGs) altered in renal hypertensive rats, and to explore whether t-AUCB could improve the salivary secretion. Main methods2-kidney 1-clip Sprague-Dawley rats were used as renal hypertensive animals. t-AUCB treatment was given for 1 week after 8 weeks modeling. Blood pressure, blood perfusion and the secretion of SMGs, and endothelium-dependent relaxation of external maxillary artery were measured to investigate the effects of t-AUCB on the vascular tone and the secretion of SMGs in renal hypertensive rats. SMGs were collected for histological evaluation and the internal arteries were dissected for primary endothelial cells culture. Key findingsThe blood perfusion and flow rate of SMGs in the renal hypertensive rats were significantly lower than those in the controls. Endothelium-dependent relaxation of the external maxillary artery and AMPK/Akt/eNOS signaling was impaired in hypertensive rats. The glandular morphology and the concentration of salivary ions did not change obviously. t-AUCB treatment ameliorated the secretion of SMGs, the blood perfusion, and the dysfunction of endothelium-dependent relaxation of the external maxillary artery by activating the AMPK/Akt/eNOS pathway in hypertensive rats. Significancet-AUCB increases the blood perfusion through ameliorating dysfunction of endothelium-dependent relaxation of SMGs arteries and thus improves the hyposecretion of SMGs in hypertensive rats.

Role of quiescent cells in the homeostatic maintenance of the adult submandibular salivary gland

SummaryStem/progenitor cells are required for maintenance of salivary gland (SG) function and serve as untapped reservoirs to create functional cells. Despite recent advancements in the identification of stem/progenitor pools, in the submandibular gland (SMG), a knowledge gap remains. Furthermore, the contribution to adult SMG homeostasis of stem/progenitor cells originating from embryonic development is unclear. Here, we employ an H2B-GFP embryonic and adult pulse-and-chase system to characterize potential SMG stem/progenitor cells (SGSCs) based on quiescence at different stages. Phenotypical profiling of quiescent cells in the SMG revealed that label-retaining cells (LRCs) of embryonic or adult origin co-localized with CK8+ ductal or vimentin + mesenchymal, but not with CK5+ or CK14 + stem/progenitor cells. These SMG LRCs failed to self-renew in vitro while non-label retaining cells displayed differentiation and long-term expansion potential as organoids. Collectively, our data suggest that an active cycling population of cells is responsible for SMG homeostasis with organoid forming potential.

Impairment of salivary function in juvenile idiopathic oligoarticular arthritis is a sign of early onset disease.

Recent evidences of the presence of reduced stimulated salivary flow rate and altered saliva composition in oligoarticular juvenile idiopathic arthritis (o-JIA) suggest a specific damage to the salivary glands. The aim of this cross-sectional study was to investigate whether reduced salivary flow rate could be related to age and gender at disease onset in o-JIA. A total of 57 Caucasian patients (41 females and 16 males) aged 5 to 16 years affected by o-JIA were consecutively enrolled in the study. Information on medication intake, dietary and oral hygiene habits were gathered through a standardised questionnaire. All patients underwent oral and sialometry examination. Early onset disease would seem to be associated with salivary glands impairment. Regular dental and salivary gland function assessments may be highly recommended in o-JIA patients considering that saliva collection is a non-invasive and inexpensive procedure.

In Vivo Generation of SSA/Ro Antigen-Specific Regulatory T Cells Improves Experimental Sjögren's Syndrome in Mice.

Sjögren's syndrome (SS) is a systemic autoimmune disease, and T cells play an important role in the initiation and perpetuation of the disease. In this study, we developed an immunotherapy for NOD/LtJ mice with SS-like symptoms by combining a transient depletion of CD4+ T cells with the administration of autoantigen-specific peptide Ro480. NOD/LtJ mice were treated with single anti-CD4 monoclonal antibody (mAb) followed 2 days later by a series of 6 intraperitoneal injections of Ro480-494 every other day. Salivary flow rates were determined pre- and posttreatment once a week. Mice were euthanized 6 weeks after the initial anti-CD4 mAb treatment, salivary glands (SGs) were collected for analyses of histologic disease scores and inflammatory cell infiltration, polymerase chain reaction determination of genes was conducted, and flow cytometry analysis including major histocompatibility complex class II tetramer staining of immune cells was performed. In addition, adoptive transfer of Treg cells was administrated to investigate the function of the newly generating Treg cells in vivo. The combination of anti-CD4 mAb with autoantigen-specific peptide Ro480 generated SSA/Ro antigen-specific Treg cells in vivo, which can suppress interferon-γ production of CD4+ T cells and inflammation infiltration in SGs and maintain the function of SGs. Our findings provide a new approach to generating antigen-specific Treg cells in vivo for SS treatment, which may have implications for potential therapy for patients with SS.

Ascorbic acid induces salivary gland function through TET2/acetylcholine receptor signaling in aging SAMP1/Klotho (-/-) mice.

Aging affects salivary gland function and alters saliva production and excretion. This study aimed to investigate whether ascorbic acid can be used to treat salivary gland dysfunction in an extensive aging mouse model of SAMP1/Klotho-/- mice. In our previous study, we found that ascorbic acid biosynthesis was disrupted in the salivary glands of SAMP1/Klotho (-/-) mice subjected to metabolomic profiling analysis. In SAMP1/Klotho -/- mice, daily supplementation with ascorbic acid (100 mg/kg for 18 days) significantly increased saliva secretion compared with the control. The expression of salivary gland functional markers (α-amylase, ZO-1, and Aqua5) is upregulated. Additionally, acetylcholine and/or beta-adrenergic receptors (M1AchR, M3AchR, and Adrb1) were increased by ascorbic acid in the salivary glands of aging mice, and treatment with ascorbic acid upregulated the expression of acetylcholine receptors through the DNA demethylation protein TET2. These results suggest that ascorbic acid could overcome the lack caused by dysfunction of ascorbic acid biosynthesis and induce the recovery of salivary gland function.

Effect of vitamin E and supragingival scaling on salivary gland function in patients with differentiated thyroid cancer treated with 131I.

The aim of this study was to evaluate the effect of vitamin E and supragingival scaling with vitamin C on the salivary glands of patients with differentiated thyroid carcinoma after 131I treatment. A total of 89 prospective patients with differentiated thyroid carcinoma were enrolled and randomly divided into the following groups: vitamin E group (n = 30, group A), vitamin C group (n = 30, group B) and supragingival scaling with vitamin C group (n = 29, group C). Using functional indices (e.g. maximum uptake fraction, uptake index, excretion fraction, secretion time and excretion rate), changes in the salivary gland functions before and a month after 131I treatment were assessed by dynamic imaging of salivary gland. We compared the before and after 131I therapy results of the three groups. In group A (P < 0.05), the excretion fraction and excretion rate of the left parotid gland were significantly higher, and the uptake index of the bilateral submandibular glands was significantly lower. No significant changes in salivary gland functional parameters were observed in group B (P > 0.05). The uptake index of the bilateral parotid glands and the excretion rate of the left parotid gland were significantly higher in group C (P < 0.05). The degree of serum amylase level reduction decreased significantly in group C (P < 0.05). Vitamin E showed a protective effect on parotid excretion function in patients with differentiated thyroid carcinoma who underwent 131I treatment. Supragingival scaling may be a promising radiation protector because it is associated with a protective effect on the salivary gland functions.

Derivation of Human Salivary Epithelial Progenitors from Pluripotent Stem Cells via Activation of RA and Wnt Signaling.

Derivation of salivary gland epithelial progenitors (SGEPs) from human pluripotent stem cells (hPSCs) has great potential in developmental biology and regenerative medicine. At present, no efficient method is available to generate salivary gland cells from hPSCs. Here, we described for the first time a robust protocol for direct differentiation of hPSCs into SGEPs by mimicking retinoic acid and Wnt signaling. These hPSC-derived SGEPs expressed SOX9, KRT5, and KRT19, important progenitor markers of developing salivary glands. CD24 and α-SMA positive cells, capable of restoring the functions of injured salivary glands, were also present in SGEP cultures. Importantly, RNA-sequencing revealed that the SGEPs resembled the transcript profiles of human fetal submandibular glands. Therefore, we provided an efficient protocol to induce hPSCs differentiation into SGEPs. Our study provides a foundation for generating functional hPSCs derived salivary gland acinar cells and three-dimensional organoids, potentially serving as new models for basic study and future translational research.

Ascorbic acid alleviates oxidative stress and improves major salivary glands’ structure and function in diabetic rats: A histological and immunohistochemical study

Diabetes Mellitus and the associated hyperglycemia trigger oxidative damage to tissues and organs. DM is obviously related to the salivary glands’ dysfunction. Ascorbic acid is a powerful dietary antioxidant. In this study, we investigated the ascorbic acid’s putative potential to conserve the structure and function of the major salivary glands in diabetic patients. Adult male albino rats (n = 24) were equally divided into four groups: Group I (control, only distilled water), Group II (ascorbic acid 200 mg/Kg/day), Group III (experimentally-induced diabetes by single intraperitoneal injection of streptozotocin 60 mg/kg), and Group IV (ascorbic acid after one week of diabetes induction). Blood glucose level was assessed. After eight weeks, samples from the salivary glands were processed for histopathological and immunohistochemical examination. Group III showed degenerative changes in the salivary glands and increased collagen deposition, whereas the glycoprotein content and antiapoptotic activity decreased. Group IV showed marked histologic and functional improvement. Although further research is required to fully understand its mode of action, ascorbic acid is advised as an adjuvant medication for diabetes to keep the integrity of major salivary glands.

Imaging Activated-T-Lymphocytes in the Salivary Glands of Patients with Sjögren's Syndrome by 99mTc-Interleukin-2: Diagnostic and Therapeutic Implications.

Background: Sjögren’s syndrome (SS) is a progressive autoimmune disease characterized by local mononuclear cell infiltration of the salivary and lachrymal glands. Labial biopsy demonstrates local infiltration by Th1 cells that produce pro-inflammatory cytokines, such as interleukin-2 (IL2). The aim of this study was to assess the utility of 99mTc-labelled-IL2 (99mTc-IL2) in evaluating in vivo the extent and severity of lympho-mononuclear cell infiltration in the salivary glands of patients with SS. Methods: We investigated 48 patients with primary SS and 27 control subjects using 99mTc-IL2 scintigraphy. Furthermore, in a subgroup of 30 patients, we also performed 99mTc-pertechnetate scintigraphy (99mTcO4−) for evaluation of the salivary gland function. Results: 99mTc-IL2 uptake in the salivary glands of SS patients was higher than in the control subjects (1.30 ± 0.16 vs. 0.83 ± 0.08 for parotids and 1.36 ± 0.15 vs. 1.16 ± 0.07 for submandibular glands; p < 0.0001). The salivary gland uptake of 99mTc-IL2 in patients with a longer history of disease was lower compared with the recently diagnosed patients. A significant direct correlation was found between the uptake of 99mTc-IL2 and histology. Conclusions: 99mTc-IL2 scintigraphy showed that the degree of lymphocytic infiltration of major salivary glands is variable in patients with different disease durations. Patients with a high 99mTc-IL2 uptake could be efficiently treated with immuno-modulatory drugs and the efficacy of treatment could be followed-up by 99mTc-IL2 scintigraphy.

Function of salivary glands in patients with terminal chronic renal failure before and after renal transplantation

BACKGROUND: This study was based on the lack of literature data about the state of the function of the salivary glands in patients who underwent kidney transplantation.&#x0D; AIM: To compare the state of the salivary glands and oral hygiene in patients with chronic renal insufficiency before and after kidney transplantation.&#x0D; MATERIAL AND METHODS: The salivary glands of 50 patients with terminal chronic renal failure were assessed.&#x0D; RESULTS: Severe impairment of salivary gland function was found in this group of patients, and xerostomia led to changes in the qualitative and quantitative indices of mixed saliva. After kidney transplantation, the salivary gland function improved, but did not fully recover to normal levels. The hygienic state of the oral cavity was improved.&#x0D; CONCLUSION: After kidney transplantation, patients require follow-up observation and preventive therapy of the salivary glands to improve and restore their function.

Comparison of Objective Measures of Trismus and Salivation With Patient-Reported Outcomes Following Treatment for Head and Neck Cancer

Xerostomia and reduced mouth opening are negatively associated with quality of life after radiation therapy (RT) for head and neck cancer. Studies comparing objective measures of function with patient-reported outcomes (PROs) have not revealed a clear association. To determine how much of the variation in PROs is explained by objective measures of salivary gland and oral cavity functions (salivary flow and maximal interincisal opening). This cross-sectional study at a single academic cancer center evaluated 112 patients who underwent RT for head and neck cancer between January 2016 and March 2021. Measurements of pre-RT and post-RT saliva and a complete PROs scale within 6 months of the post-RT measurement were analyzed using pairwise associations. Three independently scored PRO scales from the validated FACE-Q Head and Neck Cancer Module were evaluated: eating and drinking, eating distress, and salivation. Three objective measures were analyzed: maximal interincisal opening, stimulated salivary flow, and unstimulated salivary flow. Univariable linear regression models were performed for each PRO against each objective measure, and coefficients of determination (R2) and 95% CIs were reported. The patient cohort comprised 86 men (77%). Median age was 61 years (IQR, 53-68 years), 89 patients (80%) were White, and 61 patients (54%) were current or former smokers. Unstimulated saliva accounted for only a small portion of variation on the salivation scale (R2 = 14.0%). The remaining associations were even smaller (R2 = 5.0%-10.0%). No upper 95% CI bound included an R2 of 30%, suggesting that objective measurements do not explain a high level of the variation in PROs. In this cross-sectional study, objective measurements of salivary flow and mouth opening explained only a small fraction of variation in PROs. These findings suggest that factors other than objective function, including patient adaptation, are the dominant influence on PROs in this population. Patient-reported outcomes should be integrated into head and neck cancer clinical care and research. Additional research is required to evaluate which clinicopathological factors influence PROs for salivation, eating and drinking, and eating distress.

Lymphoepithelial lesions in the salivary glands of primary Sjögren's syndrome patients: the perfect storm?

In patients with primary Sjögren's syndrome (pSS), inflamed salivary gland (SG) tissue may contain lymphoepithelial lesions (LELs). LELs are histopathological phenomena whereby B cells are present in hyperplastic ductal epithelium of the SG. Despite the potential role of LELs in pSS pathogenesis, studies on their formation, detection, and prevalence in benign lesions (not complicated with lymphoma) are scarce. Recent evidence however shows that LELs are present in approximately half of the patients with pSS, both in minor and major SGs. Migration of a small number of B cells into the epithelium appears to be a critical initial step in LEL formation. These intra-epithelial B cells are proliferative, exhibit an innate-like phenotype, and may be linked to MALT lymphoma development. Alongside intra-epithelial B cells, the hyperplastic epithelial partner in LELs also engages in the local immune reaction. Epithelial cells are a source of cytokines and chemokines, with CXCL10 in particular playing a potential role in LEL formation. Importantly, LELs also have a negative impact on the maintenance of SG homeostasis by SG progenitor cell (SGPC) populations, likely due to dysregulation of SGPC lineage commitment or induction of plasticity. In conclusion, LEL formation mirrors a perfect storm of B and epithelial cell interaction culminating in increased risk of B cell derailment and SGPC dysregulation in pSS patients. We therefore argue that attenuation of LEL formation is an important treatment goal to preserve SG function and prevent B cell derailment in pSS.

Optimizing Soluble Cues for Salivary Gland Tissue Mimetics Using a Design of Experiments (DoE) Approach.

The development of therapies to prevent or treat salivary gland dysfunction has been limited by a lack of functional in vitro models. Specifically, critical markers of salivary gland secretory phenotype downregulate rapidly ex vivo. Here, we utilize a salivary gland tissue chip model to conduct a design of experiments (DoE) approach to test combinations of seven soluble cues that were previously shown to maintain or improve salivary gland cell function. This approach uses statistical techniques to improve efficiency and accuracy of combinations of factors. The DoE-designed culture conditions improve markers of salivary gland function. Data show that the EGFR inhibitor, EKI-785, maintains relative mRNA expression of Mist1, a key acinar cell transcription factor, while FGF10 and neurturin promote mRNA expression of Aqp5 and Tmem16a, channel proteins involved in secretion. Mist1 mRNA expression correlates with increased secretory function, including calcium signaling and mucin (PAS-AB) staining. Overall, this study demonstrates that media conditions can be efficiently optimized to support secretory function in vitro using a DoE approach.

Effect of lymphotoxin blockage on different stages of Sjogren's syndrome in an animal model

AbstractBackgroundLymphotoxin (LT) is an important mediator in Sjogren's syndrome (SS), both in patients and in animal models. Deletion of the LT alpha gene prevented the development of disease manifestations in the interelukin alpha transgenic mouse (IL14αTG) mouse model of SS.AimsThe current study was designed to evaluate the use of LT inhibitors at different stages of the disease in IL14αTG mice.Materials and MethodsIL14αTG mice were treated with anti‐LTa monoclonal antibody, LTb receptor‐immunoglobulin fusion protein (LTBR‐Ig) or isotype control during different stages of disease and analysis of salivary gland function, immunoglobulins, autoantibodies and histology of internal organs performed.Results and DiscussionThe inhibitors were very effective in maintaining salivary gland function and preventing infiltration of the glands with lymphocytes when used in the early stages of the disease. Blocking LT at later stages of the disease did not recover salivary gland function but was still effective in limiting extra glandular manifestations including eye disease and tumor development. Some differences were noted in the effectiveness of anti‐LTα versus LTBR‐Ig in limiting particular disease manifestations.ConclusionLT inhibitors deserve further investigation in the management of SS at whatever stage is identified.

A MZB Cell Activation Profile Present in the Lacrimal Glands of Sjögren's Syndrome-Susceptible C57BL/6.NOD-Aec1Aec2 Mice Defined by Global RNA Transcriptomic Analyses.

The C57BL/6.NOD-Aec1Aec2 mouse has been extensively studied to define the underlying cellular and molecular basis for the onset and development of Sjögren’s syndrome (SS), a human systemic autoimmune disease characterized clinically as the loss of normal lacrimal and salivary gland functions leading respectively to dry eye and dry mouth pathologies. While an overwhelming majority of SS studies in both humans and rodent models have long focused primarily on pathophysiological events and the potential role of T lymphocytes in these events, recent studies in our murine models have indicated that marginal zone B (MZB) lymphocytes are critical for both development and onset of SS disease. Although migration and function of MZB cells are difficult to study in vivo and in vitro, we have carried out ex vivo investigations that use temporal global RNA transcriptomic analyses to track early cellular and molecular events in these exocrine glands of C57BL/6.NOD-Aec1Aec2 mice. In the present report, genome-wide transcriptome analyses of lacrimal glands indicate that genes and gene-sets temporally upregulated during early onset of disease define the Notch2/NF-kβ14 and Type1 interferon signal transduction pathways, as well as identify chemokines, especially Cxcl13, and Rho-GTPases, including DOCK molecules, in the cellular migration of immune cells to the lacrimal glands. We discuss how the current results compare with our recently published salivary gland data obtained from similar studies carried out in our C57BL/6.NOD-Aec1Aec2 mice, pointing out both similarities and differences in the etiopathogeneses underlying the autoimmune response within the two glands. Overall, this study uses the power of transcriptomic analyses to identify temporal molecular bioprocesses activated during the preclinical covert pathogenic stage(s) of SS disease and how these findings may impact future intervention therapies as the disease within the two exocrine glands may not be identical.