Gingival tissue human beta-defensin levels in relation to infection and inflammation

Human β-defensins and their synthetic analogs: Natural defenders and prospective new drugs of oral health

As a family of cationic host defense peptides, human β-defensins (HBDs) are ubiquitous in the oral cavity and are mainly synthesized primarily by epithelial cells, serving as the primary barrier and aiming to prevent microbial invasion, inflammation, and disease while maintaining physiological homeostasis. In recent decades, there has been great interest in their biological functions, structure-activity relationships, mechanisms of action, and therapeutic potential in oral diseases. Meanwhile, researchers are dedicated to improving the properties of HBDs for clinical application. In this review, we first describe the classification, structural characteristics, functions, and mechanisms of HBDs. Next, we cover the role of HBDs and their synthetic analogs in oral diseases, including dental caries and pulp infections, periodontitis, peri-implantitis, fungal/viral infections and oral mucosal diseases, and oral squamous cell carcinoma. Finally, we discuss the limitations and challenges of clinical translation of HBDs and their synthetic analogs, including, but not limited to, stability, bioavailability, antimicrobial activity, resistance, and toxicity. Above all, this review summarizes the biological functions, mechanisms of action, and therapeutic potential of both natural HBDs and their synthetic analogs in oral diseases, as well as the challenges associated with clinical translation, thus providing substantial insights into the laboratory development and clinical application of HBDs in oral diseases.

Advances in periodontal biomarkers

Due to technologic advancements, periodontology has witnessed a boost in biomarker research over the past three decades. Indeed, with the aid of omics, our understanding of the healthy periodontium, pathogenesis of periodontal diseases, and healing after periodontal treatment has improved significantly. Yet, the traditional methods, periodontal probing and radiographies, remain the most common methods to diagnose periodontal disease and monitor treatment. Although these approaches can produce reliable diagnostic outcomes, they generally detect disease only after significant tissue degradation thus making treatment outcome highly uncertain. Accordingly, laboratories worldwide have collaborated with clinicians to design accurate, rapid and cost-effective biomarkers for periodontal disease diagnosis. Despite these efforts, biomarkers that can be widely used in early disease diagnosis and for treatment outcome prediction are far from daily use. The aim of this chapter is to give a general overview on periodontal health and diseases, and review recent advancements in periodontal biomarker research. A second aim will discuss the strengths and limitations of translating periodontal biomarker research to clinical practice. Genetic biomarkers of periodontitis are not discussed as the available confirmatory data is scarce.

Salivary Th17 cytokine, human β-defensin 1-3, and salivary scavenger and agglutinin levels in Crohn's disease

OBJECTIVES

Crohn's disease patients, who are prone to develop periodontal diseases, may carry genetic defects in their Th17 cytokine, human beta-defensin (hBD) 1-3, and salivary and scavenger agglutinin (SALSA) expressions. Biochemical composition of saliva reflects the oral consequences of systemic immune response modifications. Our aim was to evaluate the salivary Th17 cytokine, epithelial hBD 1-3, and SALSA levels in relation to Crohn's disease.

MATERIALS AND METHODS

This cross-sectional study included 42 Crohn's disease patients and 34 systemically healthy controls. Periodontal and dental indexes were measured, and stimulated saliva samples were collected. Salivary Th17 cytokine levels were analyzed by multiplex technique, and hBD 1-3 and SALSA levels by enzyme-linked immunosorbent assay.

RESULTS

There were 19 gingivitis and 11 initial periodontitis patients in the Crohn's disease group, and 15 gingivitis and 4 initial periodontitis in the control group. In comparison to controls, higher salivary Th17 cytokine levels were observed in Crohn's disease patients. No statistical difference was observed between Crohn's disease and control groups in terms of their salivary hBD 1-3 and SALSA levels. Based on the regression analysis, there is no independent association between Crohn's disease and salivary Th17 cytokine levels.

CONCLUSIONS

Crohn's disease does not relate to salivary antimicrobial hBD 1-3 or SALSA levels. While Crohn's disease patients have higher salivary Th17 cytokine levels in comparison to systemically healthy controls, an independent association between Crohn's disease and Th17 cytokine profile is still missing.

CLINICAL RELEVANCE

Diminished Th17 cytokine response in Crohn's disease, which might be related to genetic susceptibility, can be also visualized in saliva.

Local Defense Factors in Cleft-Affected Palate in Children before and during Milk Dentition Age: A Pilot Study

One of the most frequent congenital orofacial defects is the cleft lip and palate. Local tissue defense factors are known to be important in immune response and inflammatory and healing processes in the cleft tissue; however, they have only been researched in older children during mixed dentition. Thus, the aim of this study is to assess the distribution of LL-37, CD-163, IL-10, HBD-2, HBD-3, and HBD-4 in children before and during milk dentition. The unique and rare material of palate tissue was obtained from 13 patients during veloplastic surgeries during the time span of 20 years. Immunohistochemistry, light microscopy, semi-quantitative evaluation, and non-parametric statistical analysis were used. A significant decrease in HBD-3 and HBD-4 in the connective tissue was found, as well as several mutual statistically significant and strong correlations between HBD-2, HBD-3, HBD-4, and LL-37. Deficiency of HBD-3 and HBD-4 suggests promotion of chronic inflammation. The scarcity of HBD-4 could be connected to the different signaling pathways of dental pulp cells. Mutual correlations imply changes in the epithelial barrier, amplified healing efficiency, and increased antibacterial line of defense. Deprivation of changes in IL-10 quantity points to possible suppression of the factor. The presence of similar CD-163 immunoreactive substances produced by M2 macrophages was also observed.

Human β-defensins are correlated with the immune infiltration and regulated by vitamin D3 in periodontitis

OBJECTIVE

Exploring the correlation between human β-defensins (HBDs) and immune infiltration in periodontitis, and whether it is regulated by vitamin D3 .

BACKGROUND

The human body produces essential antimicrobial peptides called HBDs, which are associated with periodontitis. There is a strong link between periodontal tissue destruction and the immune cell infiltration. Moreover, vitamin D3 has been reported to regulate the expression of immune cell chemokines. However, the relationship between vitamin D3 , HBDs, and immune infiltration in periodontitis remains to be investigated.

METHODS

The Gene Expression Omnibus database was accessed to obtain transcriptomic information of gingival samples taken from periodontitis patients. The expression value of HBD-2 and HBD-3 was calculated. Additionally, using the online program ImmuCellAl, 10 immune cells were scored for immune infiltration in the high-HBDs-expression group and the low-HBDs-expression group, separately. After that, transcriptome sequencing was done based on human gingival fibroblasts that had received vitamin D3 treatment. Furthermore, hGFs were treated by vitamin D3 , tumor necrosis factor-α (TNF-α), and Porphyromonas gingivalis lipopolysaccharide (Pg-LPS). The expressions of HBD-2, HBD-3, interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) were detected. To seek the potential mechanism, CYP27A1 siRNA was employed to reduce the expression of CYP27A1, and nuclear factor-gene binding protein 65 (NF-κB p65) was examined.

RESULTS

In GSE10334, the expressions of HBD-2 and HBD-3 were down-regulated in periodontitis group. Meanwhile, monocyte, macrophage, and CD4_T cell were less infiltrated in low-HBD-2-expression group, while less Gamma-delta T-cell infiltration was found in low-HBD-3-expression group. Transcriptome sequencing found that 21 genes were significantly expressed, of which the function was enriched in response to bacterial origin and TNF signal pathway. Vitamin D3 could significantly up-regulate the expression of HBD-2 and HBD-3, which could be controlled by knocking down CYP27A1 mRNA expression. With prolonged vitamin D3 stimulation, the expression of HBD-2 and HBD-3 increased. TNF-α/Pg-LPS could significantly increase the expression of HBD-2, HBD-3, IL-8, MCP-1, and p65, all of which were reduced by vitamin D3 .

CONCLUSION

HBDs are correlated with immune infiltration in periodontitis. Vitamin D3 inhibits the expression of HBDs and chemokines induced by TNF-α/Pg-LPS, possibly through NF-κB pathway, in human gingival fibroblasts.

Localization and expression profiles of gingival monocyte chemoattractant protein-1-induced protein-1 (MCPIP-1) and mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT-1)

OBJECTIVES

The purposes of this study were to localize monocyte chemoattractant protein-1-induced protein-1 (MCPIP-1) and its suppressor mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT-1) in gingival tissues and to profile their protein expression levels in relation to the clinical inflammation, Porphyromonas gingivalis colonization, and interleukin (IL)-8 levels.

MATERIALS AND METHODS

Study samples were collected from two independent study populations: (1) Gingival tissues were collected from eight periodontally healthy individuals and eight periodontitis patients to localize MCPIP-1 and MALT-1 immunohistochemically, and (2) forty-one gingival tissue samples with marginal, mild, or moderate to severe inflammation were collected from 20 periodontitis patients to determine MCPIP-1 and MALT-1 levels using immunoblots, P. gingivalis levels with qPCR, P. gingivalis gingipain activities with fluorogenic substrates, and IL-8 levels with multiplex technique.

RESULTS

MCPIP-1 was detectable in the epithelium and in connective tissue, being especially prominent around the blood vessel walls in healthy periodontal tissues. MALT-1 was observed at all layers of gingival epithelium and especially around the accumulated inflammatory cells in connective tissue. No difference in gingival tissue MCPIP-1 and MALT-1 levels was observed in relation to the severity of gingival inflammation. MALT-1 levels were elevated (p = 0.023) with the increase in tissue P. gingivalis levels, and there was an association between MALT-1 and IL-8 levels (β = 0.054, p = 0.001).

CONCLUSIONS

Interactions of MALT-1 levels with gingival tissue P. gingivalis counts and IL-8 levels suggest that activation of MALT-1 can take part in P. gingivalis-regulated host immune responses.

CLINICAL RELEVANCE

Pharmacological targeting the crosstalk between immune response and MCPIP-1/MALT-1 may have benefits in periodontal treatment.

Human β-Defensins in Diagnosis of Head and Neck Cancers

Head and neck cancers are malignant growths with high death rates, which makes the early diagnosis of the affected patients of utmost importance. Over 90% of oral cavity cancers come from squamous cells, and the tongue, oral cavity, and salivary glands are the most common locations for oral squamous cell carcinoma lesions. Human β-defensins (hBDs), which are mainly produced by epithelial cells, are cationic peptides with a wide antimicrobial spectrum. In addition to their role in antimicrobial defense, these peptides also take part in the regulation of the immune response. Recent studies produced evidence that these small antimicrobial peptides are related to the gene and protein expression profiles of tumors. While the suppression of hBDs is a common finding in head and neck cancer studies, opposite findings were also presented. In the present narrative review, the aim will be to discuss the changes in the hBD expression profile during the onset and progression of head and neck cancers. The final aim will be to discuss the use of hBDs as diagnostic markers of head and neck cancers.

Salivary Human β-Defensin 1-3 and Human α-Defensin-1 Levels in Relation to the Extent of Periodontal Disease and Tooth Loss in the Elderly

The oral innate immune response may diminish with aging. In the present study, the aim was to examine human β-defensin (hBD) 1-3 and human neutrophil peptide (HNP)-1 levels in the saliva of an elderly population to establish the extent of periodontal disease and tooth loss. A total of 175 individuals aged ≥ 65 years were divided into five groups based on the number of teeth with a pocket depth ≥ 4 mm as follows: 17 pocket-free individuals (Control), 55 individuals having 1-6 pocket teeth (PerioA), 33 individuals having 7-13 pocket teeth (PerioB), 29 individuals having at least 14 pocket teeth (PerioC), and 41 edentulous individuals. Their salivary defensin levels were measured with ELISA kits. The salivary HNP-1 levels were significantly higher in the Perio groups (PerioB: p < 0.001 and PerioC: p < 0.001) in comparison to the Control. The associations between salivary HNP-1 levels and the number of pocket teeth remained significant after adjustments for age, gender, level of education, and number of teeth. The salivary HNP and hBD levels differed in terms of their correlation to the extent of periodontal disease and tooth loss in the elderly.

Baseline interleukin-10, CD163, and tumor necrosis factor-like weak inducer of apoptosis (TWEAK) gingival tissue levels in relation to clinical periodontal treatment outcomes: A 12-week follow-up study

BACKGROUND

The aim of this study was to examine the relationship between healing response after non-surgical periodontal treatment and baseline gingival tissue levels of M2 macrophage activation-related proteins CD163, interleukin (IL)-10, interferon (IFN)-γ, and tumor necrosis factor-like weak inducer of apoptosis (TWEAK), and the CD163/TWEAK ratio.

METHODS

Eighty-eight gingival tissue samples from 44 Stage III/IV, Grade C periodontitis patients (18 smokers) and 41 tissue samples from 41 periodontally healthy participants (18 smokers) were evaluated. Clinical parameters were recorded in periodontally healthy individuals at baseline and in periodontitis patients at pre-treatment and 2, 6, and 12 weeks following therapy. IL-10, IFN-γ, CD163, and TWEAK levels were analyzed with Luminex technique.

RESULTS

Tissue levels (median, 1^st -3^rd quartile) of IL-10 (pg/ng protein), CD163 (pg/μg protein) and TWEAK (pg/μg protein) were as follows: IL-10 periodontitis: 2.08, 0.86-5.32 and periodontally healthy: 5.22, 3.20-10.25; CD163 periodontitis: 8.85, 4.92-14.06 and periodontally healthy: 18.36, 12.51-34.02; TWEAK periodontitis: 0.08, 0.05-0.11 and periodontally healthy: 0.16, 0.12-0.21. IL-10, CD163, and TWEAK levels were higher (P < 0.001) in periodontally healthy tissues than in periodontitis tissues. Pocket closure at 12 weeks was associated with elevated baseline gingival CD163 levels (P = 0.047) and CD163/TWEAK ratio (P = 0.001). Elevated baseline gingival CD163/TWEAK ratio was associated with pocket reduction at 6 (P = 0.022) and 12 weeks (P = 0.002).

CONCLUSION

Associations of pocket closure with pre-treatment gingival tissue CD163 levels and CD163/TWEAK ratio indicate that baseline M2 macrophage activation profile may play a role in periodontal wound healing.

Serum, saliva, and gingival tissue human β-defensin levels in relation to retinoic acid use

BACKGROUND

Retinoic acid is an active derivative of vitamin A and regulates the differentiation, proliferation, and antimicrobial peptide expression profiles of human cells. The aim of the present study was to analyze the effect of systemic retinoic acid use on serum, saliva, and gingival tissue levels of human β-defensin (hBD)-1, hBD-2, and hBD-3.

METHODS

A total of 69 participants (34 systemic retinoic acid users and 35 healthy controls) were enrolled in this study. Plaque index, probing pocket depth, bleeding on probing (BOP), and clinical attachment loss were measured. Saliva and serum hBD-1, hBD-2, and hBD-3 levels were quantified by enzyme-linked immunosorbent assay. Gingival tissue hBD-1, hBD-2, and hBD-3 levels were determined by immunohistochemistry. A univariate general linear model was used in adjusted comparisons of hBD1, hBD-2, and hBD-3. P values of < 0.05 were considered statistically significant.

RESULTS

Reduced salivary levels of hBD-2 (P = 0.042), but not hBD-1 or hBD-3, were detected in systemic retinoic acid users compared to non-user controls. There was a significant difference in the adjusted (for BOP%) salivary hBD-2 concentrations between retinoic acid and control groups (P = 0.031). No difference was observed in serum or tissue levels of hBD-1, hBD-2, or hBD-3 between the two study groups.

CONCLUSION

Systemic retinoic acid use was associated with suppressed salivary hBD-2 level, which was independent of gingival inflammation.

KEY FINDINGS

Systemic retinoic acid use associates with suppressed salivary hBD-2 levels.

Toll-like receptor-1, -2, and -6 genotypes in relation to salivary human beta-defensin-1, -2, -3 and human neutrophilic peptide-1

AIM

To examine whether functional gene polymorphisms of toll-like receptor (TLR)1, TLR2, and TLR6 are related to the salivary concentrations of human beta-defensins (hBDs)-1, -2, -3, and human neutrophilic peptide (HNP)-1.

MATERIALS AND METHODS

Polymorphisms of TLR1 (rs5743618), TLR2 (rs5743708), and TLR6 (rs5743810) were genotyped by PCR-based pyrosequencing from the salivary samples of 230 adults. Salivary hBD-1, -2, -3, and HNP-1 concentrations were measured using enzyme-linked immunosorbent assay. General and periodontal health examinations, including panoramic radiography, were available for all participants.

RESULTS

The genotype frequencies for wild types and variant types were as follows: 66.5% and 33.5% for TLR1, 95.5% and 4.5% for TLR2, and 25.1% and 74.9% for TLR6, respectively. The TLR2 heterozygote variant group exhibited higher salivary hBD-2 concentrations than the TLR2 wild-type group (p = .038). On the contrary, elevated hBD-2 concentrations were detected in the TLR6 wild-type group compared with the TLR6 heterozygote and homozygote variant group (p = .028). The associations between TLR6 genotypes and salivary hBD-2 concentrations remained significant after adjusting them for periodontal status, age, and smoking.

CONCLUSION

hBD-2 concentrations in saliva are related to TLR2 and TLR6 polymorphisms, but only the TLR6 genotype seems to exhibit an independent association with the salivary hBD-2 concentrations.

Alternative Antibiotics in Dentistry: Antimicrobial Peptides

The rise of antibiotic resistant bacteria due to overuse and misuse of antibiotics in medicine and dentistry is a growing concern. New approaches are needed to combat antibiotic resistant (AR) bacterial infections. There are a number of methods available and in development to address AR infections. Dentists conventionally use chemicals such as chlorohexidine and calcium hydroxide to kill oral bacteria, with many groups recently developing more biocompatible antimicrobial peptides (AMPs) for use in the oral cavity. AMPs are promising candidates in the treatment of (oral) infections. Also known as host defense peptides, AMPs have been isolated from animals across all kingdoms of life and play an integral role in the innate immunity of both prokaryotic and eukaryotic organisms by responding to pathogens. Despite progress over the last four decades, there are only a few AMPs approved for clinical use. This review summarizes an Introduction to Oral Microbiome and Oral Infections, Traditional Antibiotics and Alternatives & Antimicrobial Peptides. There is a focus on cationic AMP characteristics and mechanisms of actions, and an overview of animal-derived natural and synthetic AMPs, as well as observed microbial resistance.

Beneficial Effect of Edoxaban on Preventing Atrial Fibrillation and Coagulation by Reducing Inflammation via HBG1/HBD Biomarkers

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia. The effectiveness and mechanism of edoxaban in preventing stroke after atrial fibrillation remain unclear.

Methods: The expressions of HBG1 and HBD in red blood cells were tested in AF. Sixty C57B/6J mice were randomly divided into the following groups: the control (CON) group, atrial fibrillation (AF) group, AF + edoxaban group, and AF + rivaroxaban group. H&E staining assay and reticular fiber staining were performed. Myocardial fibrosis was evaluated by the Masson staining assay, Sirius red staining assay, and immunohistochemical assay for the expressions of α-SMA and COL1A1. ELISA and RT-PCR assay were performed for the detection of inflammatory parameters (TNF-α, IL-1β, IL-6, and IL-10). Blood lipids were detected by using the Beckman automatic biochemical analyzer. Furthermore, four items of coagulation were detected, and molecular docking among HBG1, HBD, and MASP1 (Xa) was performed by PyMOL 2.1 software. The BP neural network model, cubic spline interpolation, and support vector machine model were constructed to predict prothrombin time based on HBG1 and HBD expressions. COIP assay was performed to construct the interaction between HBG1 and HBD. The functional enrichment analysis was performed by DAVID and Metascape tools.

Results: The expressions of HBG1 and HBD in red blood cells of the patients with atrial fibrillation were decreased. The results showed a lower level of hemoglobin in red blood cells with HBG1-siRNA and HBG1-siRNA. Compared with the AF group, the collagen fiber percentage in the AF + edoxaban group was decreased (p < 0.05). After using edoxaban, the expressions of TNF-α, IL-1β, IL-6, and IL-10 were significantly decreased (p < 0.05). The LDL-C, TC, and TG levels were downregulated in the AF + edoxaban group. The PT and APTT levels in the AF + edoxaban group were more increasing than in the AF mice (p < 0.05). Compared with the AF group, the expressions of HBG1 and HBD were downregulated in the AF + edoxaban group (p < 0.05). HBG1 protein matched well with HBD and MASP1(Xa) protein surfaces. There exists a significant interaction between HBG1, HBD, and PT via the BP neural network and support vector machine. Enrichment analysis showed that HBG1 and HBD were mainly enriched in blood coagulation.

Conclusion: Edoxaban could prevent atrial fibrillation and coagulation by reducing inflammation, lipids, and fibrosis via HBG1/HBD biomarkers effectively, and the effect was superior to that of rivaroxaban.

Salivary levels of hBDs in children and adolescents with type 1 diabetes mellitus and gingivitis

OBJECTIVES

Type 1 diabetes mellitus (T1DM), a chronic autoimmune disease characterized by insulin deficiency, is related to periodontal diseases in children and adolescents. Our aim was to profile salivary human beta-defensin (hBD)-2 and hBD-3 concentrations in relation to periodontal and T1DM status in children and adolescent populations.

MATERIAL AND METHODS

Unstimulated saliva samples were collected from 66 participants including periodontally healthy T1DM patients (T1DM + C; n = 18), T1DM patients with gingivitis (T1DM + G; n = 20), systemically and periodontally healthy individuals (SH + C: n = 15), and systemically healthy gingivitis patients (SH + G; n = 13). Full mouth plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded. Salivary hBD-2 and hBD-3 concentrations were evaluated by sandwich ELISA method. A p value of < 0.05 was considered statistically significant.

RESULTS

Salivary hBD-3 concentrations were lower in T1DM groups in comparison to systemically healthy counterparts (SH + G vs. T1DM + G; p < 0.001 and SH + C vs. T1DM + C; p < 0.001). Salivary hBD-2 levels did not differ between related groups. The difference in hBD-3 concentrations between T1DM and control groups was still significant (p = 0.008) after being adjusted for PI%, BOP%, and age.

CONCLUSION

In the limits of study, T1DM patients were found to have decreased salivary hBD-3 concentrations, regardless of their gingival inflammatory status.

CLINICAL RELEVANCE

Altered salivary hBD-3 concentration can partly explain why diabetic children are more prone to periodontal diseases.

Joint efficacy of the three biomarkers SNCA, GYPB and HBG1 for atrial fibrillation and stroke: Analysis via the support vector machine neural network

Atrial fibrillation (AF) is the most common type of persistent arrhythmia. Although its incidence has been increasing, the pathogenesis of AF in stroke remains unclear. In this study, a total of 30 participants were recruited, including 10 controls, 10 patients with AF and 10 patients with AF and stroke (AF + STROKE). Differentially expressed genes (DEGs) were identified, and functional annotation of DEGs, comparative toxicogenomic database analysis associated with cardiovascular diseases, and predictions of miRNAs of hub genes were performed. Using RT‐qPCR, biological process and support vector machine neural networks, numerous DEGs were found to be related to AF. HBG1, SNCA and GYPB were found to be upregulated in the AF group. Higher expression of hub genes in AF and AF + STROKE groups was detected via RT‐PCR. Upon training the biological process neural network of SNCA and GYPB for HBG1, only small differences were detected. Based on the support vector machine, the predicted value of SNCA and GYPB for HBG1 was 0.9893. Expression of the hub genes of HBG1, SNCA and GYPB might therefore be significantly correlated to AF. These genes are involved in the incidence of AF complicated by stroke, and may serve as targets for early diagnosis and treatment.

Gingipain-Responsive Thermosensitive Hydrogel Loaded with SDF-1 Facilitates In Situ Periodontal Tissue Regeneration

Existing local drug delivery systems for periodontitis suffer from poor antibacterial effect and unsatisfied periodontal regeneration. In this study, a smart gingipain-responsive hydrogel (PEGPD@SDF-1) was synthesized as an environmentally sensitive carrier for on-demand drug delivery. The PEGPD@SDF-1 hydrogel was synthesized from polyethylene glycol diacrylate (PEG-DA) based scaffolds, dithiothreitol (DTT), and a novel designed functional peptide module (FPM) via Michael-type addition reaction, and the hydrogel was further loaded with stromal cell derived factor-1 (SDF-1). The FPM exhibiting a structure of anchor peptide-short antimicrobial peptide (SAMP)-anchor peptide could be cleaved by gingipain specifically, and the SAMP was released out of the hydrogel for antibacterial effect in response to gingipain. The hydrogel properties were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), swelling ratio analysis, degradation evaluation, and release curve description of the SAMP and SDF-1. Results in vitro indicated the PEGPD@SDF-1 hydrogel exhibited preferable biocompatibility and could promote the proliferation, migration, and osteogenic differentiation of periodontal ligament stem cells (PDLSCs). Antibacterial testing demonstrated that the PEGPD@SDF-1 hydrogel released the SAMP stressfully in response to gingipain stimulation, thereby strongly inhibiting the growth of Porphyromonas gingivalis. Furthermore, the study in vivo indicated that the PEGPD@SDF-1 hydrogel inhibited P. gingivalis reproduction, created a low-inflammatory environment, facilitated the recruitment of CD90+/CD34- stromal cells, and induced osteogenesis. Taken together, these results suggest that the gingipain-responsive PEGPD@SDF-1 hydrogel could facilitate in situ periodontal tissue regeneration and is a promising candidate for the on-demand local drug delivery system for periodontitis.

Regulation of hBD-2, hBD-3, hCAP18/LL37, and Proinflammatory Cytokine Secretion by Human Milk Oligosaccharides in an Organotypic Oral Mucosal Model

Human milk oligosaccharides (HMOs), the third largest solid fraction in human milk, can modulate inflammation through Toll-like receptor signaling, but little is known about their immunomodulatory potential in the oral cavity. In this study, we determined whether the HMOs 2′-fucosyllactose (2′-FL) and 3-fucosyllactose (3-FL) regulate human-beta defensin (hBD)-2 and -3, cathelicidin (hCAP18/LL-37), and cytokine responses in human gingival cells using a three-dimensional oral mucosal culture model. The model was incubated with 0.1% or 1% 2′-FL and 3-FL, alone and in combination, for 5 or 24 h, and hBD-2, hBD-3, and hCAP18/LL-37 were analyzed by immunohistochemistry. The expression profiles of interleukin (IL)-1, IL-1RA, IL-8, and monocyte chemoattractant protein (MCP)-1 were determined by LUMINEX immunoassay. The combination of 1% 2′-FL and 1% 3-FL, and 1% 3-FL alone, for 24 h upregulated hBD-2 protein expression significantly (p < 0.001 and p = 0.016, respectively). No changes in the other antimicrobial peptides or proinflammatory cytokines were observed. Thus, 3-FL, alone and in combination with 2′-FL, stimulates oral mucosal secretion of hBD-2, without effecting a proinflammatory response when studied in an oral mucosal culture model.

Elevated Baseline Salivary Protease Activity May Predict the Steadiness of Gingival Inflammation During Periodontal Healing: A 12-Week Follow-Up Study on Adults

Aim was to profile salivary total protease, Porphyromonas gingivalis gingipain, and neutrophil elastase activities in relation to the resolution of periodontal inflammation, salivary macrophage-derived chemokine (MDC), and macrophage inflammatory protein-1α concentrations. Nonsurgical periodontal treatment was performed in 24 periodontitis patients in a prospective interventional study design. Periodontal clinical parameters were recorded, and stimulated saliva samples were collected at baseline and 2, 6, and 12 weeks after treatment. Salivary total protease and gingipain activities were determined using fluorogenic substrates, elastase activity by chromogenic substrates, and cytokine concentrations by Luminex immunoassay. For statistical analyses, generalized linear mixed models for repeated measures were used. Salivary total protease activity elevated, while gingival inflammation and plaque accumulation decreased 2 and 6 weeks after periodontal therapy. Salivary MDC concentration was elevated 12 weeks after periodontal treatment. Patients with elevated protease activities at baseline in comparison to patients with low baseline total protease activities, had higher levels of gingival inflammation before and after periodontal treatment. In conclusion, elevations in salivary total protease activity seem to be part of periodontal healing at its early phases. Higher levels of salivary total protease activities before periodontal treatment may predict the severity and steadiness of unresolved gingival inflammation.

The Change of Interleukin-6 Level-Related Genes and Pathways Induced by Exercise in Sedentary Individuals

Sedentary behavior increases the risk of many chronic disorders, in addition, these chronic diseases are associated with elevated markers interleukin-6 (IL-6). Increasing evidence indicates that physical activity can prevent chronic inflammatory disease. However, the effect of exercise on sedentary individuals with disparate basal serum IL-6 level was not well elucidated. In this study, the gene expression profile of GES12384 was downloaded from the Gene Expression Omnibus (GEO) database. This data set contained 12 sedentary middle-aged men (6 high IL-6 and 6 low IL-6 level), and their blood samples were taken in the pre-exercise period and at the end of 24 weeks of exercise. The differentially expressed genes (DEGs) of 24 weeks group were identified, followed by functional enrichment analysis. Subsequently, protein-protein interaction (PPI) network and transcription factors (TFs)-DEGs network were constructed. A total of 193 DEGs were identified between high and low IL-6 level in the 24 weeks group. Functional enrichment analysis showed that DEGs were mainly involved in African trypanosomiasis pathway. PPI network revealed that the hub genes included C-C motif chemokine receptor 7 (CCR7), hemoglobin subunit delta (HBD), and interferon gamma (IFNG). Subnetworks analysis indicated that these genes were relevant to immune response, and participated in African trypanosomiasis pathway. The TF targets network found that myocyte enhancer factor 2A (MEF2A) was a key regulatory factor. In conclusion, the inflammation-related genes (CCR7, HBD, and IFNG) in sedentary individuals could be affected by exercise, and the identified DEGs and TFs in this study promoted our understanding of exercise inhibited the development of chronic disease. [Figure: see text].