1,25-dihydroxyvitamin-D3 promotes neutrophil apoptosis in periodontitis with type 2 diabetes mellitus patients via the p38/MAPK pathway

O-linked β-N-acetylglucosamine transferase regulates macrophage polarization in diabetic periodontitis: In vivo and in vitro study

BACKGROUND

Periodontitis, when exacerbated by diabetes, is characterized by increased M1 macrophage polarization and decreased M2 polarization. O-linked β-N-acetylglucosamine (O-GlcNAcylation), catalyzed by O-GlcNAc transferase (OGT), promotes inflammatory responses in diabetic periodontitis (DP). Additionally, p38 mitogen-activated protein kinase regulates macrophage polarization. However, the interplay between OGT, macrophage polarization, and p38 signaling in the progression of DP remains unexplored.

AIM

To investigate the effect of OGT on macrophage polarization in DP and its role in mediating O-GlcNAcylation of p38.

METHODS

For in vivo experiments, mice were divided into four groups: Control, DP model, model + short hairpin (sh) RNA-negative control, and model + sh-OGT. Diabetes was induced by streptozotocin, followed by ligation and lipopolysaccharide (LPS) administration to induce periodontitis. The impact of OGT was assessed by injecting sh-OGT lentivirus. Maxillary bone destruction was evaluated using micro-computed tomography analysis and tartrate-resistant acid phosphatase staining, while macrophage polarization was determined through quantitative real-time polymerase chain reaction (qPCR) and immunohistochemistry. For in vitro experiments, RAW264.7 cells were treated with LPS and high glucose (HG) (25 mmol/L D-glucose) to establish a cell model of DP. OGT was inhibited by OGT inhibitor (OSMI4) treatment and knocked down by sh-OGT transfection. M1/M2 polarization was analyzed using qPCR, immunofluorescence, and flow cytometry. Levels of O-GlcNAcylation were measured using immunoprecipitation and western blotting.

RESULTS

Our results demonstrated that M1 macrophage polarization led to maxillary bone loss in DP mice, associated with elevated O-GlcNAcylation and OGT levels. Knockdown of OGT promoted the shift from M1 to M2 macrophage polarization in both mouse periodontal tissues and LPS + HG-induced RAW264.7 cells. Furthermore, LPS + HG enhanced the O-GlcNAcylation of p38 in RAW264.7 cells. OGT interacted with p38 to promote its O-GlcNAcylation at residues A28, T241, and T347, as well as its phosphorylation at residue Y221.

CONCLUSION

Inhibition of OGT-mediated p38 O-GlcNAcylation deactivates the p38 pathway by suppressing its self-phosphorylation, thereby promoting M1 to M2 macrophage polarization and mitigating DP. These findings suggested that modulating macrophage polarization through regulation of O-GlcNAcylation may represent a novel therapeutic strategy for treating DP.

Inborn errors of immunity-related immunological mechanisms and pharmacological therapy alternatives in periodontitis

Periodontitis is a frequent local inflammatory disease. The microbiota and repeated exposure to bacterial endotoxins triggers excessive inflammation through oral mucosal immunity and sometimes leads to a destructive effect on the supportive mucosal tissues around the teeth. Elimination of the pathogens and increasing the tolerance of the cellular immune response is crucial in addition to standard dental therapies like mechanical debridement. Based on our experience with immune-mediated diseases, especially primary immunodeficiency diseases, we wrote this review to discuss the treatment alternatives for severe periodontal disease. Risk factors are malnutrition, vitamin deficiencies, smoking, systemic inherited and acquired immune-mediated diseases, infections, endocrinological diseases, and pharmacological agents that may accompany periodontitis. The diagnosis and treatment of dietary deficiencies, as well as the addition of nutritional supplements, may aid in epithelial regeneration and immune system function. Recently, modifications to the therapeutic option for severe periodontitis have been made depending on the fact that the immune response against bacteria may modify the severity of periodontal inflammation. The anti-inflammatory therapies support or inhibit the host's immune response. The clinical approach to severe periodontitis should extend beyond classical therapies. There is a need for a diverse therapeutic strategy that supports the epithelial barrier, which is the crucial component of innate immunity against microbiota. Leukocytes are the main cellular component in periodontal inflammation. Anti-inflammatory therapeutic options directed at leukocytes, such as IL-17 and IL-23-targeted therapies, could be the candidates for the treatment of severe periodontitis. Therapy against other inflammatory cytokines, IL-1, IL-6, IL-12, IL-23, TNF-alpha, PGE2, and cytokine receptors, could also be used in periodontal inflammation control.

Association between periodontitis and inflammatory comorbidities: The common role of innate immune cells, underlying mechanisms and therapeutic targets

Periodontitis, which is related to various systemic diseases, is a chronic inflammatory disease caused by periodontal dysbiosis of the microbiota. Multiple factors can influence the interaction of periodontitis and associated inflammatory disorders, among which host immunity is an important contributor to this interaction. Innate immunity can be activated aberrantly because of the systemic inflammation induced by periodontitis. This aberrant activation not only exacerbates periodontal tissue damage but also impairs systemic health, triggering or aggravating inflammatory comorbidities. Therefore, innate immunity is a potential therapeutic target for periodontitis and associated inflammatory comorbidities. This review delineates analogous aberrations of innate immune cells in periodontitis and comorbid conditions such as atherosclerosis, diabetes, obesity, and rheumatoid arthritis. The mechanisms behind these changes in innate immune cells are discussed, including trained immunity and clonal hematopoiesis of indeterminate potential (CHIP), which can mediate the abnormal activation and myeloid-biased differentiation of hematopoietic stem and progenitor cells. Besides, the expansion of myeloid-derived suppressor cells (MDSCs), which have immunosuppressive and osteolytic effects on peripheral tissues, also contributes to the interaction between periodontitis and its inflammatory comorbidities. The potential treatment targets for relieving the risk of both periodontitis and systemic conditions are also elucidated, such as the modulation of innate immunity cells and mediators, the regulation of trained immunity and CHIP, as well as the inhibition of MDSCs' expansion.

The mechanism of the Shuang Bai Su Qing recipe in treating periodontitis based on network pharmacology and molecular docking technology

AIM

To explore the material basis of action of the Shuang Bai Su Qing recipe in the treatment of periodontitis using network pharmacology.

METHODS

Using TCMSP, we screened the chemical components of 5 drugs. The components were input into the UniProt and PubChem databases to obtain target proteins; Genecards, Online Mendelian Inheritance in Man (OMIM), and CEO databases were used to screen target proteins for periodontal disease. The targets were imported into the Cytoscape software to obtain intersecting targets, and conduct visual analysis to build the PPI network. The intersecting targets were then input into the Matescape database and subjected to biological process (BP) analysis, molecular function (MF) analysis, cell component (CC) analysis, and KEGG enrichment analysis.

RESULTS

Twenty-seven TCM chemical components were obtained, with 198 target proteins associated with drugs and 2587 target proteins for periodontitis. Ten core targets were identified. Gene Ontology (GO) functional enrichment analysis yielded results for 20 BP, 11 MF, and 10 CC. KEGG analysis revealed that the main mechanisms of action were related to MAPK signaling pathway. Molecular docking results showed that luteolin strongly bind to TNF, IL6, and IL1B target proteins.

CONCLUSION

The mechanism underlying the treatment of periodontitis with the recipe formula may be closely related to multiple targets in the MAPK signaling pathway.

The homeostasis and therapeutic applications of innate and adaptive immune cells in periodontitis

OBJECTIVES

Periodontitis (PD) is one of the most common dental disorders. This chronic oral inflammation is caused by complicated interrelations between bacterial infections, dysregulated immune reactions, and environmental risk factors. A dysregulated immune response can lead to inflammatory bone resorption by allowing the recruitment of pro-inflammatory immune cells to the periodontal tissues.

SUBJECTS

The recruitment of innate and adaptive immune cells in PD initiates the acute and following chronic inflammatory processes. The inflamed tissues, on the other hand, can be restored if the anti-inflammatory lineages are predominantly established in the periodontal tissues. Therefore, we aimed to review the published literature to provide an overview of the existing knowledge about the role of immune cells in PD, as well as their possible therapeutic applications.

RESULTS

Experimental studies showed that drugs/systems that negatively regulate inflammatory cells in the body, as well as interventions aimed at increasing the number of anti-inflammatory cells such as Tregs and Bregs, can both help in the healing process of PD.

CONCLUSION

Targeting immune cells or their positive/negative manipulations has been demonstrated to be an effective therapeutic method. However, to use this sort of immunotherapy in humans, further pre-clinical investigations, as well as randomized clinical trials, are required.

Uncovering the potential role of oxidative stress in the development of periodontitis and establishing a stable diagnostic model via combining single-cell and machine learning analysis

BACKGROUND

The primary pathogenic cause of tooth loss in adults is periodontitis, although few reliable diagnostic methods are available in the early stages. One pathological factor that defines periodontitis pathology has previously been believed to be the equilibrium between inflammatory defense mechanisms and oxidative stress. Therefore, it is necessary to construct a model of oxidative stress-related periodontitis diagnostic markers through machine learning and bioinformatic analysis.

METHODS

We used LASSO, SVM-RFE, and Random Forest techniques to screen for periodontitis-related oxidative stress variables and construct a diagnostic model by logistic regression, followed by a biological approach to build a Protein-Protein interaction network (PPI) based on modelled genes while using modelled genes. Unsupervised clustering analysis was performed to screen for oxidative stress subtypes of periodontitis. we used WGCNA to explore the pathways correlated with oxidative stress in periodontitis patients. Networks. Finally, we used single-cell data to screen the cellular subpopulations with the highest correlation by scoring oxidative stress genes and performed a proposed temporal analysis of the subpopulations.

RESULTS

We discovered 3 periodontitis-associated genes (CASP3, IL-1β, and TXN). A characteristic line graph based on these genes can be helpful for patients. The primary hub gene screened by the PPI was constructed, where immune-related and cellular metabolism-related pathways were significantly enriched. Consistent clustering analysis found two oxidative stress categories, with the C2 subtype showing higher immune cell infiltration and immune function ratings. Therefore, we hypothesized that the high expression of oxidative stress genes was correlated with the formation of the immune environment in patients with periodontitis. Using the WGCNA approach, we examined the co-expressed gene modules related to the various subtypes of oxidative stress. Finally, we selected monocytes for mimetic time series analysis and analyzed the expression changes of oxidative stress genes with the mimetic time series axis, in which the expression of JUN, TXN, and IL-1β differed with the change of cell status.

CONCLUSION

This study identifies a diagnostic model of 3-OSRGs from which patients can benefit and explores the importance of oxidative stress genes in building an immune environment in patients with periodontitis.

Autophagy as a potential mechanism underlying the biological effect of 1,25-Dihydroxyvitamin D3 on periodontitis: a narrative review

The major active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D3), is known for its wide bioactivity in periodontal tissues. Although the exact mechanisms underlying its protective action against periodontitis remain unclear, recent studies have shown that 1,25D3 regulates autophagy. Autophagy is vital for intracellular pathogen invasion control, inflammation regulation, and bone metabolic balance in periodontal tissue homeostasis, and its regulation could be an interesting pathway for future periodontal studies. Since vitamin D deficiency is a worldwide health problem, its role as a potential regulator of autophagy provides new insights into periodontal diseases. Based on this premise, this narrative literature review aimed to investigate the possible connection between 1,25D3 and autophagy in periodontitis. A comprehensive literature search was conducted on PubMed using the following keywords (e.g., vitamin D, autophagy, periodontitis, pathogens, epithelial cells, immunity, inflammation, and bone loss). In this review, the latest studies on the protective action of 1,25D3 against periodontitis and the regulation of autophagy by 1,25D3 are summarized, and the potential role of 1,25D3-activated autophagy in the pathogenesis of periodontitis is analyzed. 1,25D3 can exert a protective effect against periodontitis through different signaling pathways in the pathogenesis of periodontitis, and at least part of this regulatory effect is achieved through the activation of the autophagic response. This review will help clarify the relationship between 1,25D3 and autophagy in the homeostasis of periodontal tissues and provide perspectives for researchers to optimize prevention and treatment strategies in the future.

Downregulation of ALDH6A1 is a New Marker of Muscle Insulin Resistance in Type 2 Diabetes Mellitus

PURPOSE

Skeletal muscle insulin resistance (IR) is an important etiology of type 2 diabetes mellitus (T2DM); however, its molecular mechanism is yet to be fully defined. This study attempted to identify the gene expression patterns and molecular disorders in T2DM patients' skeletal muscle samples.

METHODS

First, the difference in genetic expression among GSE25462 data was analyzed. Next, PPI network analysis of differential genes was carried out, after which the maladjustment module was identified. Then, an enrichment analysis and gene set enrichment analysis (GSEA) were carried out. Finally, the transcription factors that regulate the modular genes by raid were predicted.

RESULTS

Most differentially expressed genes were found to be able to form an interaction network and cluster into 9 modules. These modular genes were shown to possess a significant correlation with immune inflammation and metabolic response. Importantly, the top 15 genes of area under receiver operating characteristic curve (AUC) were identified, and the expression of 10 genes by GSE12643, GSE18732 and GSE29221 was confirmed. The expression and AUC value of ALDH6A1 were then verified according to three sets of data, where ALDH6A1 was found to be negatively correlated with follicular helper T cells. However, among the predicted transcription regulators, HDAC was shown to have a better regulatory effect.

CONCLUSION

The findings highlight that the dysregulation of ALDH6A1 expression in IR of T2DM may serve as a potential therapeutic target. ALDH6A1 is involved in the immune inflammation and metabolic pathways.

Immunomodulation in the Treatment of Periodontitis: Progress and Perspectives

Periodontitis is one of the most common dental diseases. Compared with healthy periodontal tissues, the immune microenvironment plays the key role in periodontitis by allowing the invasion of pathogens. It is possible that modulating the immune microenvironment can supplement traditional treatments and may even promote periodontal regeneration by using stem cells, bacteria, etc. New anti-inflammatory therapies can enhance the generation of a viable local immune microenvironment and promote cell homing and tissue formation, thereby achieving higher levels of immune regulation and tissue repair. We screened recent studies to summarize the advances of the immunomodulatory treatments for periodontitis in the aspects of drug therapy, microbial therapy, stem cell therapy, gene therapy and other therapies. In addition, we included the changes of immune cells and cytokines in the immune microenvironment of periodontitis in the section of drug therapy so as to make it clearer how the treatments took effects accordingly. In the future, more research needs to be done to improve immunotherapy methods and understand the risks and long-term efficacy of these methods in periodontitis.

Correlation between expression levels of lncRNA FER1L4 and RB1 in patients with colorectal cancer

Colorectal cancer (CRC) is a major life-threatening malignancy. Studies demonstrated the lncRNA fer-1 like family member 4 (FER1L4) was downregulated in different cancers and its expression was positively correlated with the retinoblastoma 1 (RB1) mRNA in a competing endogenous RNAs network. We investigated expression levels of FER1L4 and RB1 in patients with colorectal cancer. 50 paired colorectal tumors and non-tumor marginal tissues, 30 paired adenomatous colorectal polyps (ACPs) and matched adjacent normal tissues were obtained from the patients. Total RNA was extracted from the samples and cDNAs were synthesized. Their expression was quantified by qRT-PCR. Correlation between FER1L4 and RB1 expression levels was analyzed by Pearson correlation test. Finally, ROC curve analysis was used to evaluate their biomarker potency. We observed significant downregulation of FER1L4, but upregulation of RB1 in the colorectal tumors compared with non-tumor and the polyp tissues. However, RB1 expression was positively correlated with FER1L4 expression both in the tumor and polyp samples. ROC curve analysis showed both FER1L4 and RB1 expression levels could discriminate tumor from non-tumor and tumor from polyp samples. None of the clinicopathological characteristics of patients were associated with FER1L4 or RB1 expression levels. Despite the downregulation of FER1L4 and upregulation of RB1 in tumors compared with non-tumor tissues, the expression of RB1 was positively correlated with the expression of FER1L4 in the colorectal tumor as well as in the polyp tissues. FER1L4 expression level might be considered as a potential biomarker for colorectal cancer development.

A Bittersweet Response to Infection in Diabetes; Targeting Neutrophils to Modify Inflammation and Improve Host Immunity

Chronic and recurrent infections occur commonly in both type 1 and type 2 diabetes (T1D, T2D) and increase patient morbidity and mortality. Neutrophils are professional phagocytes of the innate immune system that are critical in pathogen handling. Neutrophil responses to infection are dysregulated in diabetes, predominantly mediated by persistent hyperglycaemia; the chief biochemical abnormality in T1D and T2D. Therapeutically enhancing host immunity in diabetes to improve infection resolution is an expanding area of research. Individuals with diabetes are also at an increased risk of severe coronavirus disease 2019 (COVID-19), highlighting the need for re-invigorated and urgent focus on this field. The aim of this review is to explore the breadth of previous literature investigating neutrophil function in both T1D and T2D, in order to understand the complex neutrophil phenotype present in this disease and also to focus on the development of new therapies to improve aberrant neutrophil function in diabetes. Existing literature illustrates a dual neutrophil dysfunction in diabetes. Key pathogen handling mechanisms of neutrophil recruitment, chemotaxis, phagocytosis and intracellular reactive oxygen species (ROS) production are decreased in diabetes, weakening the immune response to infection. However, pro-inflammatory neutrophil pathways, mainly neutrophil extracellular trap (NET) formation, extracellular ROS generation and pro-inflammatory cytokine generation, are significantly upregulated, causing damage to the host and perpetuating inflammation. Reducing these proinflammatory outputs therapeutically is emerging as a credible strategy to improve infection resolution in diabetes, and also more recently COVID-19. Future research needs to drive forward the exploration of novel treatments to improve infection resolution in T1D and T2D to improve patient morbidity and mortality.

Modulation of miRNAs by vitamin C in H2O2‑exposed human umbilical vein endothelial cells

Vitamin C plays a protective role in oxidative damage by blocking the effects of free radicals. The present study investigated the mechanisms through which vitamin C partly mediates anti‑apoptotic and antioxidant functions via the regulation of microRNAs (miRNAs or miRs). For this purpose, a global miRNA expression analysis on human umbilical vein endothelial cells (HUVECs) treated with vitamin C was conducted using microarrays containing human precursor and mature miRNA probes. The results revealed that there were 42 identical miRNAs among the differentially expressed miRNAs in the HUVEC group and H2O2 + vitamin C‑treated HUVEC group compared to the H2O2‑exposed HUVEC group, including 41 upregulated miRNAs and 1 down‑regulated miRNA. Using bioinformatics analysis, differentially expressed miRNAs were investigated to identify novel target mRNAs and signaling pathways. Pathway enrichment analyses revealed that apoptosis, the mitogen‑activated protein kinase (MAPK) signaling pathway, phosphoinositide 3‑kinase (PI3K)/Akt signaling pathway and oxidative phosphorylation were significantly enriched. The results from western blot analysis demonstrated that the interleukin (IL)10, matrix metalloproteinase (MMP)2, cAMP‑response element binding protein (CREB) and p‑CREB protein expression levels in HUVECs transfected with hsa‑miR‑3928‑5p and induced by H2O2 were significantly downregulated; the MAPK9, caspase‑3 (CASP3) and p‑CASP3 protein expression levels in HUVECs transfected with hsa‑miR‑323a‑5p and induced by H2O2 were significantly downregulated. The present study therefore demonstrates that vitamin C partly exerts protective effects on HUVECs through the regulation of miRNA/mRNA axis expression.

Exendin-4 reverses high glucose-induced endothelial progenitor cell dysfunction via SDF-1β/CXCR7-AMPK/p38-MAPK/IL-6 axis

AIM

Exendin-4, a glucagon-like peptide-1 (GLP-1) analog, has been used for treating diabetes mellitus (DM). However, its effects on improving the dysfunction of high glucose (HG)-induced endothelial progenitor cells (EPCs) remain unclear. The present study explored the effects of Exendin-4 on improving dysfunction of EPCs and the underlying mechanism.

METHODS

EPCs were isolated from SD rats and identified by flow cytometry. Next, the EPCs were treated by HG and high or low concentration of Exendin-4, and cell viability, migration and tube formation were, respectively, examined by performing MTT assay, wound-healing assay and tube formation assay. Interleukin-6 (IL-6) secretion was measured by enzyme-linked immunosorbent assay (ELISA). The protein expressions of relative stromal-derived growth factor-1β (SDF-1β), C-X-C chemokine receptor type 7 (CXCR7), AMP-activated protein kinase (AMPK), p38 and expressions of CXCR7 and IL-6 in EPCs were measured by Western blot. The cell behaviors of EPCs treated by HG and Exendin-4 with or without silencing of CXCR7 and IL-6 were detected.

RESULTS

Exendin-4 reversed the inhibitory effects of HG on viability, migration and tube formation of EPCs and on SDF-1β/CXCR7-AMPK pathway in EPCs in a dose-dependent manner. Moreover, Exendin-4 promoted the effects of HG on IL-6 level in EPCs through the promotion of p38-MAPK phosphorylation and reduction of cleaved caspase-3 protein expressions in EPCs. However, silencing of CXCR7 and IL-6 reversed the effects of Exendin-4 on cell behaviors, inactivated SDF-1β/CXCR7-AMPK pathway and increased cleaved caspase-3 expression in EPCs.

CONCLUSIONS

Exendin-4 could ameliorate HG-induced EPC dysfunction through regulating the production of IL-6 via SDF-1β/CXCR7-AMPK/p38-MAPK axis.

Type I interferon regulates cytokine-delayed neutrophil apoptosis, reactive oxygen species production and chemokine expression

Interferons (IFNs) are key regulators of a number of inflammatory conditions in which neutrophils play an important role in pathology, such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), where type I IFNs are implicated in disease pathology. However, IFNs are usually generated in vivo together with other cytokines that also have immunoregulatory functions, but such interactions are poorly defined experimentally. We measured the effects of type I (IFN-α) IFN, elevated in both RA and SLE, on the functions of healthy neutrophils incubated in vitro in the absence and presence of proinflammatory cytokines typically elevated in inflammatory diseases [tumour necrosis factor (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF)]. IFN-α alone had no effect on neutrophil apoptosis; however, it abrogated the anti-apoptotic effect of GM-CSF (18 h, P < 0·01). The enhanced stability of the anti-apoptotic protein myeloid cell leukaemia 1 (Mcl-1) and delayed activation of caspase activation normally regulated by GM-CSF were blocked by IFN-α: this effect was mediated, in part, by activation of p38 mitogen-activated protein kinase (MAPK). IFN-α alone also primed reactive oxygen species (ROS) production and maintained the transient priming effect of TNF-α for up to 4 h: it also down-regulated GM-CSF- and TNF-α-activated expression of chemokine (C-X-C motif) ligand (CXCL)1, CXCL2, CXCL3, CXCL8, CCL3 and CCL4 but, in contrast, increased the expression of CXCL10. These novel data identify complex regulatory signalling networks in which type I IFNs profoundly alter the response of neutrophils to inflammatory cytokines. This is likely to have important consequences in vivo and may explain the complexity and heterogeneity of inflammatory diseases such as RA, in which multiple cytokine cascades have been activated.

Vitamin D promotes the cisplatin sensitivity of oral squamous cell carcinoma by inhibiting LCN2-modulated NF-κB pathway activation through RPS3

Chemoresistance is a major cause of cancer progression and the mortality of cancer patients. Developing a safe strategy for enhancing chemosensitivity is a challenge for biomedical science. Recent studies have suggested that vitamin D supplementation may decrease the risk of many cancers. However, the role of vitamin D in chemotherapy remains unknown. We found that vitamin D sensitised oral cancer cells to cisplatin and partially reversed cisplatin resistance. Using RNA-seq, we discovered that lipocalin 2 (LCN2) is an important mediator. Cisplatin enhanced the expression of LCN2 by decreasing methylation at the promoter, whereas vitamin D enhanced methylation and thereby inhibited the expression of LCN2. Overexpression of LCN2 increased cell survival and cisplatin resistance both in vitro and in vivo. High LCN2 expression was positively associated with differentiation, lymph node metastasis, and T staging and predicted a poor prognosis in oral squamous cell carcinoma (OSCC) patients. LCN2 was also associated with post-chemotherapy recurrence. Moreover, we found that LCN2 promoted the activation of NF-κB by binding to ribosomal protein S3 (RPS3) and enhanced the interaction between RPS3 and p65. Our study reveals that vitamin D can enhance cisplatin chemotherapy and suggests that vitamin D should be supplied during chemotherapy; however, more follow-up clinical studies are needed.

Identification of the key differentially expressed genes and pathways involved in neutrophilia

Polymorphonuclear neutrophils (PMNs) are the most important determinants in the acute inflammatory response. Pathologically increased numbers of PMNs in the circulation or specific tissues (or both) lead to neutrophilia. However, the genes expressed and pathways involved in neutrophilia have yet to be elucidated. By analysis of three public microarray datasets related to neutrophilia (GSE64457, GSE54644, and GSE94923) and evaluation by gene ontology, pathway enrichment, protein-protein interaction networks, and hub genes analysis using multiple methods (DAVID, PATHER, Reactome, STRING, Reactome FI Plugin, and CytoHubba in Cytoscape), we identified the commonly up-regulated and down-regulated different expressed genes. We also discovered that multiple signaling pathways (IL-mediated, LPS-mediated, TNF-α, TLR cascades, MAPK, and PI3K-Akt) were involved in PMN regulation. Our findings suggest that the commonly expressed genes involved in regulation of multiple pathways were the underlying molecular mechanisms in the development of inflammatory, autoimmune, and hematologic diseases that share the common phenotypic characteristics of increased numbers of PMNs. Taken together, these data suggest that these genes are involved in the regulation of neutrophilia and that the corresponding gene products could serve as potential biomarkers and/or therapeutic targets for neutrophilia.