Integrative mRNA/miRNA expression analysis in healing human gingiva

Oral mucosa: anti-inflammatory function, mechanisms, and applications

Large soft tissue injuries require several weeks to heal and frequently leave fibrotic scars that can negatively impact tissue function. However, the applicability of traditional skin and mucous membrane transplantation for the treatment of lesions in the ocular surface and urethra is limited owing to the unique locations and functions of these tissues. Oral mucosa has been widely used in the repair of such injuries owing to its reduced propensity for inducing an inflammatory response, angiogenesis, and scarring. Enhancing chronic wound healing while avoiding scar formation requires a broader understanding of the cellular and molecular pathways that drive wound repair in the oral mucosa. This review integrates current knowledge on the mechanisms underlying the resistance of the oral mucosa to inflammation and its application as a graft material, highlighting its challenges and potential advancements. The aim of this review is to offer insights into future therapeutic strategies for wound healing and related conditions.

Exosomes from adipose-derived stem cells accelerate wound healing by increasing the release of IL-33 from macrophages

BACKGROUND

Mesenchymal stem cell (MSC) -derived exosomes, especially adipose-derived mesenchymal stem cell exosomes (ADSC-Exos), have emerged as a promising alternative for skin damage repair with anti-inflammatory, angiogenic and cell proliferation effects while overcoming some of the limitations of MSC. However, the mechanism by which ADSC-Exos regulates inflammatory cells during wound healing remains unclear. This study investigated how ADSC-Exos regulate macrophages to promote wound healing.

METHODS

ADSC-Exos were isolated using ultracentrifugation, with subsequent quantification of exosomes particle number. To investigate their role in wound healing, the effects of ADSC-Exos on inflammation, angiogenesis, collagen deposition and macrophage polarization were evaluated through immunohistochemical staining, immunofluorescence and western blotting. Changes in gene expression associated with ADSC-Exos-induced macrophage polarization were analyzed using qPCR. RNA sequencing was performed to identify differentially expressed genes affected by ADSC-Exos. The critical role of IL-33 in the wound healing process was further confirmed using Il33-/- mice. Additionally, co-culture experiments were conducted to explore the effects of IL-33 on keratinocyte proliferation, collagen deposition and epithelialization.

RESULTS

ADSC-Exos inhibited the expression of TNF-α and IL-6, induced M2 macrophage polarization, promoted collagen deposition and angiogenesis, and accelerated wound healing. RNA sequencing identified IL-33 as a key mediator in this process. In Il33-/- mice, impaired wound healing and decreased M2 macrophage polarization were observed. The co-culture experiments showed that IL-33 enhanced keratinocyte function through activation of the Wnt/β-catenin signaling pathway. These findings highlight the therapeutic potential of ADSC-Exos in wound healing by modulating IL-33.

CONCLUSIONS

ADSC-Exos promote wound healing by regulating macrophage polarization and enhancing IL-33 release which drives keratinocyte proliferation, collagen deposition and epithelialization via the Wnt/β-catenin signaling pathway. These findings provide a mechanistic basis for the therapeutic potential of ADSC-Exos in tissue repair and regeneration.

Injectable hydrogel harnessing foreskin mesenchymal stem cell-derived extracellular vesicles for treatment of chronic diabetic skin wounds

Chronic skin wounds are a serious complication of diabetes with a high incidence rate, which can lead to disability or even death. Previous studies have shown that mesenchymal stem cells derived extracellular vesicles (EVs) have beneficial effects on wound healing. However, the human foreskin mesenchymal stem cell (FSMSCs)-derived extracellular vesicle (FM-EV) has not yet been isolated and characterized. Furthermore, the limited supply and short lifespan of EVs also hinder their practical use. In this study, we developed an injectable dual-physical cross-linking hydrogel (PSiW) with self-healing, adhesive, and antibacterial properties, using polyvinylpyrrolidone and silicotungstic acid to load FM-EV. The EVs were evenly distributed in the hydrogel and continuously released. In vivo and vitro tests demonstrated that the synergistic effect of EVs and hydrogel could significantly promote the repair of diabetic wounds by regulating macrophage polarization, promoting angiogenesis, and improving the microenvironment. Overall, the obtained EVs-loaded hydrogels developed in this work exhibited promising applicability for the repair of chronic skin wounds in diabetes patients.

The effect of smoking on clinical and biochemical early healing outcomes of coronally advanced flap with connective tissue graft: Prospective cohort study

BACKGROUND

This study aimed to determine the effects of smoking on early (≤3 months) clinical outcomes and relevant molecular biomarkers following root coverage surgery.

METHODS

Eighteen smokers and 18 nonsmokers, status biochemically verified, with RT1 gingival recession defects were recruited and completed study procedures. All patients received coronally advanced flap plus connective tissue graft. Baseline and 3 month recession depth (RD), recession width (RW), keratinized tissue width (KTW), clinical attachment level (CAL), and gingival phenotype (GP) were recorded. Root coverage (RC) percentage and complete root coverage (CRC) were calculated. Recipient (gingival crevicular fluid) and donor (wound fluid) site VEGF-A, HIF-1α, 8-OHdG, and ANG levels were determined.

RESULTS

There were no significant intergroup differences for any baseline or postoperative clinical parameters (P > 0.05), except for whole mouth gingival index (increased in nonsmokers at 3 months; P < 0.05). Compared to baseline, RD, RW, CAL, KTW, and GP significantly improved postoperatively, without significant intergroup differences. There were no significant intergroup differences for RC (smokers = 83%, nonsmokers = 91%, P = 0.069), CRC (smokers = 50%, nonsmokers = 72%, P = 0.177), and CAL gain (P = 0.193). The four biomarker levels significantly increased postoperatively (day 7; P ≤ 0.042) in both groups and returned to baseline (day 28) without significant intergroup differences (P > 0.05). Similarly, donor site parameters were not different between groups. Strong correlations, consistent over time, were found between biomarkers implicated in angiogenesis (VEGF-A, HIF-1α, and ANG).

CONCLUSIONS

The early (3 month) clinical and molecular changes after root coverage surgery utilizing a coronally advanced flap plus connective tissue graft are similar between smokers and nonsmokers.

Skin treatment with non-thermal plasma modulates the immune system through miR-223-3p and its target genes

Non-thermal plasma, a partially ionized gas, holds significant potential for clinical applications, including wound-healing support, oral therapies, and anti-tumour treatments. While its applications showed promising outcomes, the underlying molecular mechanisms remain incompletely understood. We thus apply non-thermal plasma to mouse auricular skin and conducted non-coding RNA sequencing, as well as single-cell blood sequencing. In a time-series analysis (five timepoints spanning 2 hours), we compare the expression of microRNAs in the plasma-treated left ears to the unexposed right ears of the same mice as well as to the ears of unexposed control mice. Our findings indicate specific effects in the treated ears for a set of five miRNAs: mmu-miR-144-5p, mmu-miR-144-3p, mmu-miR-142a-5p, mmu-miR-223-3p, and mmu-miR-451a. Interestingly, mmu-miR-223-3p also exhibits an increase over time in the right non-treated ear of the exposed mice, suggesting systemic effects. Notably, this miRNA, along with mmu-miR-142a-5p and mmu-miR-144-3p, regulates genes and pathways associated with wound healing and tissue regeneration (namely ErbB, FoxO, Hippo, and PI3K-Akt signalling). This co-regulation is particularly remarkable considering the significant seed dissimilarities among the miRNAs. Finally, single-cell sequencing of PBMCs reveals the downregulation of 12 from 15 target genes in B-cells, Cd4+ and Cd8+ T-cells. Collectively, our data provide evidence for a systemic effect of non-thermal plasma.

Mural cell composition and functional analysis in the healing process of human gingiva from periodontal intrabony defects

OBJECTIVE

To evaluate the composition and function of mural cell populations in human gingival tissues DESIGN: A cross-sectional study was conducted on seven periodontitis (stage Ⅲ) patients. Gingival tissues were collected two months after scaling and root planing and divided into 3 groups: 1, h_h group (horizontal bone resorption, residual pocket depth ≤3 mm); 2, v_h group (vertical bone resorption >4 mm, residual pocket depth ≤3 mm); 3, v_i group (vertical bone resorption >4 mm, residual pocket depth ≥6 mm). Single-cell RNA sequencing (10X genomics) and subsequent bioinformatics analysis were performed. Protein expression of selected genes was confirmed by histological staining.

RESULTS

Two mural cell clusters, RGS5⁺THY1⁺ and ACTA2⁺MYH11⁺ subpopulations, were identified and confirmed by histological staining and cross-validation with three different single-cell RNA sequencing datasets in the GEO database. RGS5⁺THY1⁺ cluster in perivascular areas possessed cellular protrusions and exhibited immunomodulatory and synthetic phenotypes. In contrast, the ACTA2⁺MYH11⁺ cluster strictly distributed around vessel walls was characterized by a contractile phenotype. Mural cells closely interacted with endothelial cells through PDGF and NOTCH3 signaling. Mural cell loss was detected in the v_i group and in hopeless periodontal teeth, which might be caused by tumor necrosis factor-alpha induced apoptosis.

CONCLUSIONS

Gingival mural cells can be classified into two distinct clusters according to their gene signatures and cell morphology. The loss of mural cells may indicate periodontitis progression.

miRNA-encapsulated abiotic materials and biovectors for cutaneous and oral wound healing: Biogenesis, mechanisms, and delivery nanocarriers

MicroRNAs (miRNAs) as therapeutic agents have attracted increasing interest in the past decade owing to their significant effectiveness in treating a wide array of ailments. These polymerases II-derived noncoding RNAs act through post-transcriptional controlling of different proteins and their allied pathways. Like other areas of medicine, researchers have utilized miRNAs for managing acute and chronic wounds. The increase in the number of patients suffering from either under-healing or over-healing wound demonstrates the limited efficacy of the current wound healing strategies and dictates the demands for simpler approaches with greater efficacy. Various miRNA can be designed to induce pathway beneficial for wound healing. However, the proper design of miRNA and its delivery system for wound healing applications are still challenging due to their limited stability and intracellular delivery. Therefore, new miRNAs are required to be identified and their delivery strategy needs to be optimized. In this review, we discuss the diverse roles of miRNAs in various stages of wound healing and provide an insight on the most recent findings in the nanotechnology and biomaterials field, which might offer opportunities for the development of new strategies for this chronic condition. We also highlight the advances in biomaterials and delivery systems, emphasizing their challenges and resolutions for miRNA-based wound healing. We further review various biovectors (e.g., adenovirus and lentivirus) and abiotic materials such as organic and inorganic nanomaterials, along with dendrimers and scaffolds, as the delivery systems for miRNA-based wound healing. Finally, challenges and opportunities for translation of miRNA-based strategies into clinical applications are discussed.

Complement factor D as a predictor of Achilles tendon healing and long-term patient outcomes

Dense connective tissue healing, such as tendon, is protracted leading to highly variable and unsatisfactory patient outcomes. Biomarkers prognostic of long-term clinical outcomes is, however, unknown. The present study was designed to investigate the proteomic profile of healing, identify potential biomarkers, and assess their association with the patient's long-term outcomes after ATR. Quantitative mass spectrometry analysis demonstrated 1423 proteins in healing and contralateral healthy Achilles tendons of 28 ATR patients. Comparing healing at 2 weeks and healthy protein profiles, we identified 821 overlapping, 390 upregulated, and 17 downregulated proteins. Upregulated proteins are related mainly to extracellular matrix organization and metabolism, while downregulated pathways were associated with exocytosis in immune modulation and thrombosis formation. Further proteomic profiling in relation to validated patient outcomes revealed the downregulated pro-inflammatory complement factor D (CFD) as the most reliable predictive biomarker of successful tendon healing. Our finding showed a comprehensive proteomic landscape and bioinformatics on human connective tissue, indicating subtype-specific and shared biological processes and proteins in healing and healthy Achilles tendons, as well as in tendons related to good and poor patient outcomes. Inflammatory protein CFD and serpin family B member 1 were finally identified as potential predictive biomarkers of effective healing outcomes when combined the proteomic profiles with a validated clinical database. Following the future elucidation of the mechanisms associated with the identified biomarkers as predictors of good outcomes, our findings could lead to improved prognostic accuracy and development of targeted treatments, thus improving the long-term healing outcomes for all patients.

miR-223-3p alleviates TGF-β-induced epithelial-mesenchymal transition and extracellular matrix deposition by targeting SP3 in endometrial epithelial cells

Intrauterine adhesion (IUA) is the clinical manifestation of endometrial fibrosis. The dysregulation of microRNAs (miRNAs) has been confirmed to implicate in a diversity of human diseases, including IUA. Nevertheless, the specific function of miR-223-3p in IUA remains to be clarified. Reverse transcription quantitative polymerase chain reaction analysis displayed the downregulation of miR-223-3p in IUA tissues and endometrial epithelial cells (EECs). Results from wound healing assay, Transwell assay and western blotting showed that TGF-β facilitated the migration and invasion of EECs and induced epithelial-mesenchymal transition (EMT) process as well as extracellular matrix (ECM) deposition. Overexpression of miR-223-3p in EECs was shown to suppress the effects induced by TGF-β. Bioinformatics analysis and luciferase reporter assay revealed the binding relation between miR-223-3p and SP3. SP3 was highly expressed in IUA and its expression was inversely correlated with miR-223-3p expression in IUA tissue samples. Additionally, upregulation of SP3 reversed the influence of miR-223-3p on the phenotypes of EECs. In conclusion, miR-223-3p alleviates TGF-β-induced cell migration, invasion, EMT process and ECM deposition in EECs by targeting SP3.