Vitamin D attenuates human gingival fibroblast inflammatory cytokine production following advanced glycation end product interaction with receptors for AGE

Mitochondrial dysfunction as a key player in aggravating periodontitis among diabetic patients: review of the current scope of knowledge

Periodontitis is a prevalent inflammatory disease that leads to significant periodontal tissue destruction and compromised dental health, with its severity exacerbated in individuals with Diabetes Mellitus (DM). This review explores the complex relationship between mitochondrial dysfunction and periodontitis in diabetic patients. Recent studies indicate that the excessive production of reactive oxygen species (ROS), primarily generated by dysfunctional mitochondrial electron transport chain (ETC) complexes, contributes to oxidative stress (OS) and subsequent periodontal tissue damage. The interplay between impaired mitochondrial biogenesis, apoptosis of periodontal cells, and ROS accumulation highlights a critical area of concern in understanding the pathophysiology of diabetic periodontitis. Furthermore, altered glycemic control due to inflammatory processes associated with periodontitis may perpetuate a cyclical detriment to oral and systemic health. This review aims to highlight the mechanistic roles of mitochondrial dysfunction in the aggravation of periodontitis among diabetic patients, emphasizing further research to identify potential therapeutic targets and improve treatment efficacy for this dual pathology.

Effects of D3K2 With Periodontal Therapy in Diabetes Mellitus and Stage I-II Periodontitis Patients

BACKGROUND

The aim of this study is to look into the clinical and biochemical outcomes of D3K2 supplementation in addition to nonsurgical periodontal treatment (NSPT) for patients suffering from diabetes mellitus (DM) and periodontitis.

METHODS

Thirty-eight participants with DM and periodontitis were randomized into two different groups. The test group provided NSPT with D3K2 whereas the control group received NSPT with placebo. Clinical periodontal parameters were recorded and serum and gingival crevicular fluid (GCF) were sampled at baseline and at the third and the sixth months after treatment. Glycated hemoglobin A1c (HbA1c), fasting blood glucose (FBG), 25(OH)D3, parathyroid hormone (PTH), calcium (Ca) and magnesium (Mg) values were determined in blood samples. GCF and serum interleukin (IL)-1β and IL-10 levels were analyzed using enzyme-linked immunosorbent assay.

RESULTS

All clinical periodontal parameters were importantly decreased at the third and sixth months after treatment compared to baseline in both groups. At the sixth month, 25(OH)D3 levels in the test group were observed to be statistically significantly higher than in the control group (p = 0.02). Serum IL-1β showed a statistically significant decrease at the sixth month compared to baseline and the third month in control group.

CONCLUSION

According to this study, there is limited additional benefit of D3K2 given with NSPT in individuals with DM and periodontitis.

Promotion of inflammatory response in mice with diabetes periodontitis: regulation of forkhead box protein M1 silencing to mediate activator protein-1 via reactive oxygen species production

Objective

Periodontitis, the sixth major complication of diabetes, has a mutually influential and mutually reinforcing relationship with diabetes. Forkhead box protein M1 (FOXM1) is essential for osteoclast differentiation, periodontitis, and diabetes. This study aims to investigate the potential action mechanisms and effects of FOXM1 on diabetes periodontitis.

Material and Methods

A model of mice with diabetes periodontitis was created. The pathological damage of periodontal tissues in the mandibles of mice was assessed through hematoxylin-eosin staining. The expression of bone resorption-related, cell proliferation transcription, inflammatory, and oxidative stress-related factors in mice with diabetes periodontitis was analyzed through Western blot and quantitative reverse transcription polymerase chain reaction. Oxidative stress level was examined through enzyme-linked immunosorbent assay. Furthermore, plasmids with FOXM1 silencing were constructed using short hairpin RNA. The activity of activator protein-1 (AP-1) binding was measured via electrophoretic mobility shift assay. Reactive oxygen species (ROS) expression was detected using a dichlorodihydrofluorescein diacetate probe.

Results

Treatment with the ROS inhibitor N-acetylcysteine ameliorated the degree of bone destruction, attenuated the inflammatory response, and mitigated oxidative stress in mice with diabetes periodontitis. Short hairpin-FOXM1 reduced the levels of FOXM1, increased the levels of C-Jun proto-oncogene and AP-1, enhanced AP-1 binding activity, and increased ROS production in the macrophage cells. sh-FOXM1 increased the mRNA and protein levels of tartrate-resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR), and nuclear factor-activated T-cell c1 (NFATc1). By contrast, JUN-small interfering RNA decreased the mRNA and protein expression of TRAP, OSCAR, and NFATc1. The silencing of FOXM1-regulated ROS production mediated AP-1 activation to promote macrophage osteoclast differentiation.

Conclusion

FOXM1 plays a key role in diabetes periodontitis, and this study provides theoretical support for the clinical prevention and treatment of diabetes periodontitis in humans.

Identification and Validation of Aging- and Endoplasmic Reticulum Stress-Related Genes in Periodontitis Using a Competing Endogenous RNA Network

Periodontitis is a multifactorial chronic inflammatory disease that destroy periodontium. Apart from microbial infection and host immune responses, emerging evidence shows aging and endoplasmic reticulum stress (ER stress) play a key role in periodontitis pathogenesis. The aim of this study is to identify aging-related genes (ARGs) and endoplasmic reticulum stress-related genes (ERGs) in periodontitis. Data were obtained from the Gene Expression Omnibus (GEO), Human Ageing Genomic Resources (HAGR) and GeneCards databases to identify differentially expressed mRNAs/miRNAs/lncRNAs (DEmRNAs/DEmiRNAs/DElncRNAs), ARGs and ERGs, respectively. We used the MultiMiR database for the reverse prediction of miRNAs and predicted miRNA-lncRNA interactions using the STARBase database. Afterwards, we constructed a mRNA-miRNA-lncRNA ceRNA network. A total of 10 hub genes, namely LCK, LYN, CXCL8, IL6, HCK, IL1B, BTK, CXCL12, GNAI1 and FCER1G, and 5 DEmRNAs-ARGs-ERGs were then discovered. Further, weighted gene co-expression network analysis (WGCNA) and single sample gene set enrichment analysis (ssGSEA) were performed to explore co-expression modules and immune infiltration respectively. Finally, we used transmission electron microscope (TEM), inverted fluorescence microscopy, quantitative real-time polymerase chain reaction (qRT-PCR) and Western Blot to verify the bioinformatic results in periodontal ligament stem cells (PDLSCs) infected with Porphyromonas gingivalis (P. gingivalis). The experimental results broadly confirmed the accuracy of bioinformatic analysis. The present study established an aging- and ER stress-related ceRNA network in periodontitis, contributing to a deeper understanding of the pathogenesis of periodontitis.

A literature review of bioactive substances for the treatment of periodontitis: In vitro, in vivo and clinical studies

Periodontitis is a common chronic inflammatory disease of the supporting tissues of the tooth that involves a complex interaction of microorganisms and various cell lines around the infected site. To prevent and treat this disease, several options are available, such as scaling, root planning, antibiotic treatment, and dental surgeries, depending on the stage of the disease. However, these treatments can have various side effects, including additional inflammatory responses, chronic wounds, and the need for secondary surgery. Consequently, numerous studies have focused on developing new therapeutic agents for more effective periodontitis treatment. This review explores the latest trends in bioactive substances with therapeutic effects for periodontitis using various search engines. Therefore, this study aimed to suggest effective directions for therapeutic approaches. Additionally, we provide a summary of the current applications and underlying mechanisms of bioactive substances, which can serve as a reference for the development of periodontitis treatments.

Diabetes mellitus promotes susceptibility to periodontitis-novel insight into the molecular mechanisms

Diabetes mellitus is a main risk factor for periodontitis, but until now, the underlying molecular mechanisms remain unclear. Diabetes can increase the pathogenicity of the periodontal microbiota and the inflammatory/host immune response of the periodontium. Hyperglycemia induces reactive oxygen species (ROS) production and enhances oxidative stress (OS), exacerbating periodontal tissue destruction. Furthermore, the alveolar bone resorption damage and the epigenetic changes in periodontal tissue induced by diabetes may also contribute to periodontitis. We will review the latest clinical data on the evidence of diabetes promoting the susceptibility of periodontitis from epidemiological, molecular mechanistic, and potential therapeutic targets and discuss the possible molecular mechanistic targets, focusing in particular on novel data on inflammatory/host immune response and OS. Understanding the intertwined pathogenesis of diabetes mellitus and periodontitis can explain the cross-interference between endocrine metabolic and inflammatory diseases better, provide a theoretical basis for new systemic holistic treatment, and promote interprofessional collaboration between endocrine physicians and dentists.

Effects of whey and soy protein supplementation on inflammatory cytokines in older adults: a systematic review and meta-analysis

BACKGROUND AND AIMS

Low-grade inflammation is a mediator of muscle proteostasis. This study aimed to investigate the effects of isolated whey and soy proteins on inflammatory markers.

METHODS

We conducted a systematic literature search of randomised controlled trials (RCT) through MEDLINE, Web of Science, Scopus and Cochrane Library databases from inception until September 2021. To determine the effectiveness of isolated proteins on circulating levels of C-reactive protein (CRP), IL-6 and TNF-α, a meta-analysis using a random-effects model was used to calculate the pooled effects (CRD42021252603).

RESULTS

Thirty-one RCT met the inclusion criteria and were included in the systematic review and meta-analysis. A significant reduction of circulating IL-6 levels following whey protein [Mean Difference (MD): -0·79, 95 % CI: -1·15, -0·42, I² = 96 %] and TNF-α levels following soy protein supplementation (MD: -0·16, 95 % CI: -0·26, -0·05, I² = 68 %) was observed. The addition of soy isoflavones exerted a further decline in circulating TNF-α levels (MD: -0·20, 95 % CI: -0·31, -0·08, I² = 34 %). According to subgroup analysis, whey protein led to a statistically significant decrease in circulating IL-6 levels in individuals with sarcopenia and pre-frailty (MD: -0·98, 95 % CI: -1·56, -0·39, I² = 0 %). These findings may be dependent on participant characteristics and treatment duration.

CONCLUSIONS

These data support that whey and soy protein supplementation elicit anti-inflammatory effects by reducing circulating IL-6 and TNF-α levels, respectively. This effect may be enhanced by soy isoflavones and may be more prominent in individuals with sarcopenia.

Phytocannabinoids regulate inflammation in IL-1β-stimulated human gingival fibroblasts

OBJECTIVES

Billions of individuals worldwide suffer from periodontal disease, an inflammatory disease that results in hard-tissue and soft-tissue destruction. A viable therapeutic option to treat periodontal disease may be via cannabinoids that exert immunomodulatory effects, and the endocannabinoid system (ECS) is readily present in periodontal tissues that exhibit cannabinoid type 1 and 2 receptors (CB1R and CB2R). Phytocannabinoids (pCBs), which are a part of a heterogeneous group of molecules acting on cannabinoid receptors (CBR) derived from the cannabis plants, have been attributed to a wide variety of effects including anti-inflammatory activity and some pro-inflammatory effects depending on the cell type. Thus, this study aims to examine the effects of pCBs on primary human gingival fibroblasts (HGFs) in IL-1β stimulated (simulated periodontal disease) HGFs.

MATERIALS AND METHODS

Human gingival fibroblasts (HGFs) obtained from ATCC were cultured per the manufacturer's recommendation. The functional activity of cannabinoid receptors was measured using ACTOne (cAMP)-based CB1R and CB2R assay. The effects of three pCBs (0.1-10 μg/ml or 10^-4.5 -10^-6.5  M) on cell viability were assessed using the CCK-8 cellular dehydrogenase assay. IL-1β (1 ng/ml) was added an hour before the treatment to stimulate inflammation in the HGFs before the addition of cannabinoid ligands. After 24-h incubation, the production of INF-γ, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and TNF-α was measured using Mesoscale Discovery (MSD) Human Pro-Inflammatory kit. To measure prostaglandin E 2 levels (PGE2), Cisbio HTRF PGE2 assay kit was used per the manufacturer's recommendation to measure after 24-h incubation. The data were analyzed using GraphPad Prism 6.0. The analytes for each group were compared using a one-way ANOVA test with Bonferroni's correction.

RESULTS

Cannabidivarin (CBVN or CBDV) (EC₅₀  = 12 nM) and cannabigerol (CBG) (EC₅₀  = 30 nM) exhibited agonist activity on CB2R with intermediate efficacy. Cannabidiol (CBD) did not exhibit activation of the CB2R, and the CB1R activation was not observed with any of the pCBs. Cytotoxicity results showed that concentrations of 2.50 μg/ml or greater for the pCBs were toxic except for CBVN. Lower concentrations of CBD and CBG (0.1-0.75 μg/ml), and CBVN at 2.50 μg/ml exhibited significant effects on HGF proliferation. In IL-1β-stimulated HGFs, prostaglandin E2 (PGE2) production was significantly suppressed only by CBG and CBVN. CBD and CBG treatment alone did, however, elevate PGE2 production significantly compared to control. IL-1β stimulation resulted in a robust increase in the production of all cytokines tested. Treatment of IL-β-stimulated HGF with the three pCBs (1 μg/ml) significantly reduced INF-ɣ, TNF-α, and IL-2. The significant suppression of IL-4 was seen with CBD and CBVN, while only CBVN exerted suppression of IL-13. The three pCBs significantly increased IL-6, IL-10, and IL-12 levels, while none of the pCBs reduced the expression of IL-8 in IL-1β-stimulated HGF.

CONCLUSION

The effective inhibition of IL-1β-stimulated production of PGE2 and cytokines by the pCB in HGFs suggests that targeting the endocannabinoid system may lead to the development of therapeutic strategies for periodontal therapy. However, each pCB has its unique anti-inflammatory profile, in which certain pro-inflammatory activities are also exhibited. The pCBs alone or in combination may benefit and aid in improving public oral health.

Impact of Metal Particles Released during Ultrasonic Scaling of Titanium Surfaces on Human Gingival Fibroblasts

PURPOSE

Metal particles found in tissues around dental implants have been proposed to play a pathogenic role in peri-implantitis. Ultrasonic scaling has been suggested as a mechanism by which these particles can be inadvertently released into surrounding tissues. Furthermore, risk factors like diabetes can result in exacerbation of this inflammatory condition. The current study aimed to analyze metal particles released from titanium surfaces during ultrasonic scaling and their impact on pro-inflammatory cytokine production by human gingival fibroblasts.

METHODS

Metal particles generated from ultrasonic scaling of titanium discs using two different tips (metal and poly-etheretherketone tips) were characterized using scanning electron microscopy and elemental analysis. Endotoxin levels and Human gingival fibroblast viability, in the presence commercial and ultrasonically generated particles were determined. Fibroblasts, cultured in high or low glucose growth medium, were incubated with commercial titanium particles or ultrasonically generated particles in the presence or absence of interluekin-1β. Interleukin 6 and interleukin 8 production were then quantified using Enzyme linked immunosorbent assay.

RESULTS

Analysis of particles after scaling of titanium discs showed significant levels of titanium particles. Commercial titanium particles and generated particles had no effect of fibroblast viability. Endotoxin levels of all particles were too low to stimulate HGF cells. IL-1β significantly stimulated IL-6 and IL-8 production. However, commercial, and generated particles generally had no significant effect on IL- 6 and IL-8 production.

CONCLUSION

Our study concluded that particles generated during ultrasonic scaling had no significant effect on viability of HGF cells and cytokine production.

Vitamin D and Its Role in Oral Diseases Development. Scoping Review

Vitamin D is a fat-soluble secosteroid that plays a significant role in the whole body, including the maxillofacial region. The discovery of its receptors in many cells and organs made it possible to reveal the participation of vitamin D not only in the regulation of calcium phosphate metabolism, but also in immune processes, in providing anti-inflammatory and antimicrobial effects, slowing down cell proliferation and stimulating differentiation. In this literature review, we demonstrate the association between low vitamin D levels and the development of recurrent aphthous stomatitis, the course and response to treatment of squamous cell carcinoma of the oral cavity, the severity of periodontal diseases, and the processes of osseointegration and bone remodeling during dental implantation and guided tissue regeneration. The aim of our article was to demonstate a possible connection between vitamin D level and the oral diseases that can be presented at an oral surgery appointment, which will help clinicians to reduce the risk of early dental implant failure, ensure favorable outcomes of augmentative operations, as well as decrease the destructive effects of severe periodontitis and other conditions throug knowledge and timely lab tests and endocrinologist prescriptions.

Advanced glycosylation end products inhibit the proliferation of bone-marrow stromal cells through activating MAPK pathway

BACKGROUND

The purpose of present study was to explore the mechanism of nuclear factor-kappa B (NF-κB), phosphatidylinositol 3-kinase (PI3K)/protein kinase B(PKB/Akt) and mitogen-activated protein kinase (MAPK) signaling pathways after intervention of advanced glycosylation end products (AGEs) on rat bone-marrow stromal cells (BMSCs).

METHODS

Prepare and identify AGEs. BMSCs were isolated from 16 SD rats and cultured with different concentration of AGEs. Cell viability was detected by cell counting kit-8 (CCK-8). BMSCs were cultured with AGEs (0.25 mg/ml) for 30 min, 12 h, 24 h, 72 h and 120 h. In addition, BMSCs were cultured with AGEs, AGEs + JNK inhibitor and AGEs + P38 inhibitor for 24 h and 48 h, respectively. Western blotting and RT-PCR were used to determine the protein and mRNA expression levels, respectively.

RESULTS

Cell viability of BMSCs was significantly correlated with concentration and effect time of AGEs (P < 0.05), and the most appropriate concentration was 0.25 mg/ml. AGEs stimulation significantly increased the protein expression levels of NF-κB p65, JNK, p38 (P < 0.05), decreased IκB (P < 0.05), but had no effect on the protein expression of Akt in BMSCs (P > 0.05). At the mRNA level, JNK and p38 inhibitors significantly reduced the levels of NF-κB p65, p38 and JNK, increased IκB (P > 0.05), but had no effect on Akt in BMSCs (P > 0.05). At the protein level, JNK and p38 inhibitors notably decreased the expression of NF-κB p65, p38, p-JNK, P-IκB and JNK (P < 0.001), and increased IκB (P < 0.05).

CONCLUSION

Advanced glycosylation end products can inhibit the proliferation of bone-marrow stromal cells through activating MAPK pathway.

Vitamin D3 and Dental Mesenchymal Stromal Cells

Vitamin D3 is a hormone involved in the regulation of bone metabolism, mineral homeostasis, and immune response. Almost all dental tissues contain resident mesenchymal stromal cells (MSCs), which are largely similar to bone marrow-derived MSCs. In this narrative review, we summarized the current findings concerning the physiological effects of vitamin D3 on dental MSCs. The existing literature suggests that dental MSCs possess the ability to convert vitamin D3 into 25(OH)D3 and subsequently to the biologically active 1,25(OH)2D3. The vitamin D3 metabolites 25(OH)D3 and 1,25(OH)2D3 stimulate osteogenic differentiation and diminish the inflammatory response of dental MSCs. In addition, 1,25(OH)2D3 influences the immunomodulatory properties of MSCs in different dental tissues. Thus, dental MSCs are both producers and targets of 1,25(OH)2D3 and might regulate the local vitamin D3-dependent processes in an autocrine/paracrine manner. The local vitamin D3 metabolism is assumed to play an essential role in the local physiological processes, but the mechanisms of its regulation in dental MSCs are mostly unknown. The alteration of the local vitamin D3 metabolism may unravel novel therapeutic modalities for the treatment of periodontitis as well as new strategies for dental tissue regeneration.

Vitamin D as A Protector of Arterial Health: Potential Role in Peripheral Arterial Disease Formation

Atherosclerotic occlusive diseases and aneurysms that affect large and medium-sized arteries outside the cardiac and cerebral circulation are collectively known as peripheral arterial disease (PAD). With a rise in the rate of aging population worldwide, the number of people diagnosed with PAD is rapidly increasing. The micronutrient vitamin D is an important steroid hormone that acts on many crucial cellular mechanisms. Experimental studies suggest that optimal levels of vitamin D have beneficial effects on the heart and blood vessels; however, high vitamin D concentrations have been implicated in promoting vascular calcification and arterial stiffness. Observations from various clinical studies shows that deficiency of vitamin D has been associated with a greater risk of PAD. Epidemiological studies have often reported an inverse relation between circulating vitamin D status measured in terms of 25-hydroxivitamin D [25(OH)D] levels and increased cardiovascular disease risk; however, randomized controlled trials did not show a consistent positive effect of vitamin D supplementation on cardiovascular disease risk or events. Even though PAD shares all the major risk factors with cardiovascular diseases, the effect of vitamin D deficiency in PAD is not clear. Current evidence suggests a strong role of vitamin D in promoting genomic and epigenomic changes. This review summarises the current literature that supports the notion that vitamin D deficiency may promote PAD formation. A better understanding of underlying pathological mechanisms will open up new therapeutic possibilities which is the main unmet need in PAD management. Furthermore, epigenetic evidence shows that a more holistic approach towards PAD prevention that incorporates a healthy lifestyle, adequate exercise and optimal nutrition may be more effective in protecting the genome and maintaining a healthy vasculature.

Therapeutic potential of vitamin D in AGE/RAGE-related cardiovascular diseases

Cardiovascular diseases (CVDs) are among the leading threats to human health. The advanced glycation end product (AGE) and receptor for AGE (RAGE) signaling pathway regulates the pathogenesis of CVDs, through its effects on arterial stiffness, atherosclerosis, mitochondrial dysfunction, oxidative stress, calcium homeostasis, and cytoskeletal function. Targeting the AGE/RAGE pathway is a potential therapeutic strategy for ameliorating CVDs. Vitamin D has several beneficial effects on the cardiovascular system. Experimental findings have shown that vitamin D regulates AGE/RAGE signaling and its downstream effects. This article provides a comprehensive review of the mechanistic insights into AGE/RAGE involvement in CVDs and the modulation of the AGE/RAGE signaling pathways by vitamin D.