Review of genes potentially related to hyposecretion in male non-obese diabetic (NOD) mice, a Sjögren's syndrome model

Quantitative Changes in the Proteome of Chronically Inflamed Lacrimal Glands From a Sjögren's Disease Animal Model

Purpose

The lacrimal gland (LG) is the major source of aqueous tears, and insufficient LG secretion leads to aqueous-deficient dry eye (ADDE) disease. To provide a foundational description of LG's protein expression patterns, we prepared protein extracts of LGs from a wild-type and an ADDE mouse model and analyzed the proteome by quantitative mass spectrometry.

Methods

LGs were isolated from an ADDE mouse model, male non-obese diabetic (NOD) mice and control wild-type BALB/c mice (n = 6 each). Protein samples were prepared in urea-based lysis buffer and protein concentrations determined by the BCA method. The equivalent of 200 µg protein were tryptically digested and analyzed by nanoflow liquid chromatography tandem mass spectrometry (LC-MS/MS). Proteins were identified and quantified using the PEAKS X bioinformatics suite. Downstream differential protein expression analysis was performed using the MS-DAP R package. Selected significantly differentially expressed and detected proteins were subjected to spatial expression analysis using immunohistochemistry.

Results

Cumulatively, the LC-MS/MS-based proteomics analyses of the murine LG samples identified a total of 31,932 peptide sequences resulting in 2617 protein identifications at a 1% false discovery rate at the peptide and protein level. Principal component analysis (PCA) and hierarchical cluster analysis revealed a separation of NOD and BALB/c samples. Overall, protein diversity was consistently higher in NOD samples. After applying global peptide filter criteria and peptide-to-protein rollup, 1750 remaining proteins were subjected to differential expression analysis using the MSqRob algorithm, which identified 580 proteins with statistically significant expression differences. Data are available via ProteomeXchange with identifier PXD060937. At the cellular level, the up- and downregulation of select proteins were confirmed by immunohistochemistry.

Conclusions

Our data suggest that chronic inflammation leads to significant alterations in the LG proteome. Ongoing studies aim to identify potentially unique, inflammation-induced proteins that could be amenable to pharmacological modulation.

SHED-Derived Exosomes Ameliorate Sjögren's Syndrome-Induced Hyposalivation by Suppressing Th1 Cell Response via the miR-29a-3p/T-bet Axis

Background: Sjögren's syndrome (SS), an autoimmune disease, was characterized by sicca syndrome and systemic manifestations, presenting significant treatment challenges. Exosomes, naturally derived nanoparticles containing bioactive molecules, have garnered interest in regenerative medicine. The present study aimed to elucidate the immunoregulatory properties and mechanism of exosomes obtained from the stem cells derived from human exfoliated deciduous teeth (SHED-exos) in SS-induced sialadenitis. Methods: SHED-exo nanoparticles were injected into submandibular glands (SMGs) of 14-week-old nonobese diabetic (NOD) mice, a classic animal model of SS. At 21 weeks, the saliva flow rate (SFR) was measured. Lymphocyte proportions were examined via flow cytometry. Inflammatory cytokine levels were examined by the Quantibody mouse Th1/Th2/Th17 array and ELISA. miR-29a-3p expression and its regulatory effect on T-bet was detected using FISH and luciferase reporter gene assay, respectively. Results: SHED-exos injected into SMGs increased SFR, reduced lymphocytic infiltration, and decreased inflammatory cytokine levels in serum, SMG tissues, and saliva. Mechanistically, SHED-exos suppressed the Th1 proportion in spleen lymphocytes in NOD mice. Exosomal miR-29a-3p targeted and suppressed T-bet expression, which is a Th1-specific transcription factor. In vitro, SHED-exos (but not miR-29a-3p-inhibited exosomes) decreased the level of Th1 differentiation and IFN-γ and TNF-α production. Furthermore, SHED-exos (but not miR-29a-3p-inhibited exosomes) blocked the increase in IFN-γ and TNF-α production induced by T-bet overexpression. In vivo, miR-29a-3p-inhibited exosomes neither increase saliva secretion in NOD mice nor decrease lymphocytic infiltration, T-bet expression, and IFN-γ and TNF-α levels in SMGs. Conclusion: SHED-exos suppress Th1 cell differentiation and response through the miR-29a-3p/T-bet axis, contributing to amelioration of SS-induced hyposalivation.

Oral biosciences: The annual review 2023

BACKGROUND

The Journal of Oral Biosciences is dedicated to advancing and disseminating fundamental knowledge with regard to every aspect of oral biosciences. This review features review articles in the fields of "bone regeneration," "periodontitis," "periodontal diseases," "salivary glands," "sleep bruxism," and "Sjögren's syndrome."

HIGHLIGHT

This review focuses on human demineralized dentin and cementum matrices for bone regeneration, oxidized low-density lipoprotein in periodontal disease and systemic conditions, the relationship between inflammatory mediators in migraine and periodontitis, phosphoinositide signaling molecules in the salivary glands, and the pathophysiologies of sleep bruxism and Sjögren's syndrome.

CONCLUSION

The review articles featured in the Journal of Oral Biosciences have broadened the knowledge of readers regarding various aspects of oral biosciences. The current editorial review discusses the findings and significance of these review articles.

What is the impact of e-cigarettes on periodontal stem cells as revealed by transcriptomic analyses?

DESIGN

The research used an in vitro cell exposure model and multi-omics integration of transcriptome and epigenome profiling to compare the molecular effects of e-cigarettes and tobacco smoke on dental stem cells.

AIM

The study aimed to compare the effects of e-cigarette and tobacco smoke on periodontal stem cells using a multi-omics approach to understand gene regulation.

METHODS

This research studied primary human gingival mesenchymal stem cells (GMSCs) and periodontal ligament stem cells (PDLSCs) obtained from healthy donors. The cells were subjected to tobacco smoke, e-cigarette aerosol (both tobacco and menthol flavors), e-cigarette liquid (both tobacco and menthol flavors), or untreated conditions using an in vitro exposure system. RNA sequencing and bioinformatics analysis were used to profile the transcriptome and identify differential gene expression. Additionally, chromatin immunoprecipitation sequencing (ChIP-seq) was used to conduct genome-wide histone modification mapping for H3K27me3. Transcriptome profiling was combined with histone modification characterization to understand gene regulatory mechanisms. The study compared the effects of smoke versus e-cigarette, aerosol versus liquid exposure, and tobacco versus menthol flavor on gene expression and epigenetic landscapes in the two oral stem cell populations.

RESULTS

The use of tobacco smoke caused damage to the DNA and nucleus in GMSCs, as well as mitochondrial dysfunction in PDLSCs. Regarding e-cigarettes, the aerosol and liquid affected non-coding RNA expression differently. The chemokine CXCL2 was found to be downregulated by aerosol but upregulated by liquid in GMSCs. An integrative analysis revealed that the upregulation of CXCL2 caused by e-liquid involved reduced H3K27me3 and activation of distal enhancers. On the other hand, aerosol exposure maintained H3K27me3 levels, while direct e-liquid exposure resulted in genome-wide reductions in H3K27me3, particularly in enhancer regions. Overall, the specific delivery methods and components of e-cigarettes caused unique changes in the transcriptome and epigenome of oral stem cells.

CONCLUSIONS

E-cigarettes affect oral stem cells differently than tobacco smoke. Their aerosol and liquid have varying impacts on gene expression and regulatory landscapes in oral cells. Multi-omics approaches are important to understanding the molecular changes caused by e-cigarette components. This can help with toxicological assessments and determine their impact on periodontal health. Transcriptome and epigenome profiling are powerful tools to examine the unique molecular mechanisms involved in cellular responses to e-cigarettes.