Nicotine stimulation increases proliferation and matrix metalloproteinases-2 and -28 expression in human dental pulp cells

Cigarette smoking exposure disrupts the regenerative potential of dental pulp stem cells

INTRODUCTION

Smoking is known to alter the regenerative and immunomodulatory properties of many types of mesenchymal stem cells (MSCs). This study investigates the impact of cigarette smoke exposure on the regenerative potential of dental pulp stem cells (DPSCs).

METHODS

DPSCs were treated with various doses of cigarette smoke condensate (CSC) or nicotine. Cell proliferation and survival were evaluated by a water-soluble tetrazolium salt (WST-1) and a survival assay. DPSC migration, cytokine expression, mutagenesis, and the signaling pathway were also measured during CSC and nicotine treatment.

RESULTS

Low concentrations of CSC and nicotine did not impair cell proliferation, but higher concentrations reduced cell proliferation. CSC and nicotine could impede DPSC survival and migration in a dose-dependent manner. In addition, the cytokine secretion expression profile was altered with CSC or nicotine treatments. In particular, secretion of IL-6, TNF-α, and IL-10 significantly increased, while TGF-β1 levels showed different patterns after exposure to CSC or nicotine, as shown by ELISA and quantitative PCR. Nicotine treatment increased AKT (also known as protein kinase B) and extracellular signal-regulated kinase (ERK) phosphorylation. Finally, CSC induced higher levels of mutagenicity than nicotine, as shown by the Ames test.

CONCLUSIONS

These findings suggest that cigarette smoke exposure alters the regenerative abilities of DPSCs in various ways. Future studies are warranted to further characterize the underlying molecular mechanisms of smoking-mediated damage to DPSCs, which will guide the personalized stem cell treatment plan for smoking patients.

Nicotine in Inflammatory Diseases: Anti-Inflammatory and Pro-Inflammatory Effects

As an anti-inflammatory alkaloid, nicotine plays dual roles in treating diseases. Here we reviewed the anti-inflammatory and pro-inflammatory effects of nicotine on inflammatory diseases, including inflammatory bowel disease, arthritis, multiple sclerosis, sepsis, endotoxemia, myocarditis, oral/skin/muscle inflammation, etc., mainly concerning the administration methods, different models, therapeutic concentration and duration, and relevant organs and tissues. According to the data analysis from recent studies in the past 20 years, nicotine exerts much more anti-inflammatory effects than pro-inflammatory ones, especially in ulcerative colitis, arthritis, sepsis, and endotoxemia. On the other hand, in oral inflammation, nicotine promotes and aggravates some diseases such as periodontitis and gingivitis, especially when there are harmful microorganisms in the oral cavity. We also carefully analyzed the nicotine dosage to determine its safe and effective range. Furthermore, we summarized the molecular mechanism of nicotine in these inflammatory diseases through regulating immune cells, immune factors, and the vagus and acetylcholinergic anti-inflammatory pathways. By balancing the “beneficial” and “harmful” effects of nicotine, it is meaningful to explore the effective medical value of nicotine and open up new horizons for remedying acute and chronic inflammation in humans.

A network pharmacology approach to reveal the pharmacological targets and biological mechanism of compound kushen injection for treating pancreatic cancer based on WGCNA and in vitro experiment validation

BACKGROUND

Compound kushen injection (CKI), a Chinese patent drug, is widely used in the treatment of various cancers, especially neoplasms of the digestive system. However, the underlying mechanism of CKI in pancreatic cancer (PC) treatment has not been totally elucidated.

METHODS

Here, to overcome the limitation of conventional network pharmacology methods with a weak combination with clinical information, this study proposes a network pharmacology approach of integrated bioinformatics that applies a weighted gene co-expression network analysis (WGCNA) to conventional network pharmacology, and then integrates molecular docking technology and biological experiments to verify the results of this network pharmacology analysis.

RESULTS

The WGCNA analysis revealed 2 gene modules closely associated with classification, staging and survival status of PC. Further CytoHubba analysis revealed 10 hub genes (NCAPG, BUB1, CDK1, TPX2, DLGAP5, INAVA, MST1R, TMPRSS4, TMEM92 and SFN) associated with the development of PC, and survival analysis found 5 genes (TSPOAP1, ADGRG6, GPR87, FAM111B and MMP28) associated with the prognosis and survival of PC. By integrating these results into the conventional network pharmacology study of CKI treating PC, we found that the mechanism of CKI for PC treatment was related to cell cycle, JAK-STAT, ErbB, PI3K-Akt and mTOR signalling pathways. Finally, we found that CDK1, JAK1, EGFR, MAPK1 and MAPK3 served as core genes regulated by CKI in PC treatment, and were further verified by molecular docking, cell proliferation assay, RT-qPCR and western blot analysis.

CONCLUSIONS

Overall, this study suggests that the optimized network pharmacology approach is suitable to explore the molecular mechanism of CKI in the treatment of PC, which provides a reference for further investigating biomarkers for diagnosis and prognosis of PC and even the clinical rational application of CKI.

Association of e-cigarette use with oral health: a population-based cross-sectional questionnaire study

BACKGROUND

The impact of daily or intermittent electronic cigarette (e-cigarette) use on oral health is unknown.

METHODS

We performed a cross-sectional analysis using the 2016 Behavioral Risk Factor Surveillance System data. Poor oral health was determined by the number of permanent teeth removed due to non-traumatic causes, and e-cigarette use determined by daily or intermittent use within 30 days prior to survey administration. We performed logistic regression analysis to test associations between e-cigarette use and oral health with adjustment for factors associated with poor oral health, survey clustering, strata and weight.

RESULTS

We included survey responses from 456 343 adults. Over half of respondents (51.5%) reported having at least one permanent tooth removed because of tooth decay or gum disease in their lifetime. Daily e-cigarette use was reported by 4957 (1.1%) of respondents. In multivariable analysis, daily e-cigarette use, was independently associated with a 78% higher odds of poor oral health (adjusted OR = 1.78, 95% CI: 1.39-2.30; P < 0.001).

CONCLUSIONS

In a population-based health survey of US adults, self-reported health behavior and outcomes, daily use, but not intermittent use of e-cigarettes was independently associated with poor oral health. Care must be exercised in seeking 'healthier' cigarette alternatives.

Isobaric Tag-Based Protein Profiling of a Nicotine-Treated Alpha7 Nicotinic Receptor-Null Human Haploid Cell Line

Nicotinic acetylcholine receptors (nAChR), the primary cell surface targets of nicotine, have implications in various neurological disorders. Here we investigate the proteome-wide effects of nicotine on human haploid cell lines (wildtype HAP1 and α7KO-HAP1) to address differences in nicotine-induced protein abundance profiles between these cell lines. We performed an SPS-MS3-based TMT10-plex experiment arranged in a 2-3-2-3 design with two replicates of the untreated samples and three of the treated samples for each cell line. We quantified 8775 proteins across all ten samples, of which several hundred differed significantly in abundance. Comparing α7KO-HAP1 and HAP1wt cell lines to each other revealed significant protein abundance alterations; however, we also measured differences resulting from nicotine treatment in both cell lines. Among proteins with increased abundance levels due to nicotine treatment included those previously identified: APP, APLP2, and ITM2B. The magnitude of these changes was greater in HAP1wt compared to the α7KO-HAP1 cell line, implying a potential role for the α7 nAChR in HAP1 cells. Moreover, the data revealed that membrane proteins and proteins commonly associated with neurons were predominant among those with altered abundance. This study, which is the first TMT-based proteome profiling of HAP1 cells, defines further the effects of nicotine on non-neuronal cellular proteomes.

The association between electronic-cigarette use and self-reported oral symptoms including cracked or broken teeth and tongue and/or inside-cheek pain among adolescents: A cross-sectional study

Background

Little is known about oral health related to electronic-cigarette (EC) use, even though EC use is increasing rapidly. The aim of this study is to assess the relationship between EC use and oral health, including ‘gingival pain and/or bleeding’, ‘tongue and/or inside-cheek pain’, and ‘cracked or broken teeth’ among adolescents.

Methods

A total of 65,528 students in 2016 were included in this cross-sectional study.

Results

For EC use, 0.5% (n = 297) students were daily users, 1.9% (n = 1259) were ‘1 to 29 days past month users’, and 5.9% (n = 3848) were former users. Overall, 18.5% students reported they had experienced ‘gingival pain and/or bleeding’, 11.0% reported ‘tongue and/or inside-cheek pain’, and 11.4% reported a ‘cracked or broken tooth’ within the past 12 months. When comparing ‘daily EC users’, ‘1 to 29 days past month EC users’, and ‘former EC users’ with ‘never EC users’, the adjusted ORs for ‘cracked or broken tooth’ were 1.65 (95% CI: 1.19–2.27), 1.26 (95% CI: 1.06–1.51), and 1.16 (95% CI: 1.04–1.30), respectively. Comparing ‘daily EC users’ with ‘never EC users’, the adjusted OR for ‘tongue and/or inside-cheek pain’ was 1.54 (1.05–2.26). However, EC use among adolescents was not associated with ‘gingival pain and/or bleeding’ when adjusted for the potential confounders.

Conclusions

Based on the results, the odds of cracked or broken teeth among daily, ‘1 to 29 days past month’, and former EC users were significantly higher than those among never EC users. The odds of tongue and/or inside-cheek pain among daily EC users were significantly higher than those among never EC users. In conclusion, the results suggest that daily EC use among adolescents may be a risk factor for cracked or broken teeth and tongue and/or inside-cheek pain.