Periodontitis exacerbation during pregnancy in mice: Role of macrophage migration inhibitory factor as a key inductor

OBJECTIVE

The present study was designed to investigate the role of macrophage migration inhibitory factor (MIF) in the exacerbation of pregestational periodontal disease (PGPD).

BACKGROUND

Periodontitis (PT) is a severe stage of periodontal disease characterized by inflammation of the supporting tissues of the teeth, which usually worsens during pregnancy. MIF is a proinflammatory cytokine that is significantly elevated in periodontitis, both at the beginning and at the end of pregnancy. Although periodontitis usually presents with greater severity during pregnancy, the participation of MIF in the evolution of periodontitis has not been established.

METHODS

To analyze the relevance of MIF in the exacerbation of PGPD, we employed a model of PGPD in WT and Mif-/- mice, both with a BALB/c genetic background. PT was induced with nylon suture ligatures placed supramarginally around the second upper right molar. For PGPD, PT was induced 2 weeks before mating. We evaluated histological changes and performed histometric analysis of the clinical attachment loss, relative expression of MMP-2 and MMP-13 by immunofluorescence, and relative expression of the cytokines mif, tnf-α, ifn-γ, and il-17 by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Our data revealed that periodontal tissue from PGPD WT mice produced a twofold increase in MIF compared with PT WT mice. Moreover, the evolution of periodontitis in Mif-/- mice was less severe than in PGDP WT mice. Periodontal tissue from Mif-/- mice with PGPD produced 80% less TNF-α and no IFN-γ, as well as 50% lower expression of matrix metalloproteinase (MMP)-2 and 25% less MMP-13 compared to WT PGDP mice.

CONCLUSIONS

Our study suggests that MIF plays an important role in the exacerbation of periodontitis during pregnancy and that MIF is partially responsible for the inflammation associated with the severity of periodontitis during pregnancy.

Investigating the association of physical and psychological problems with the levels of interleukin-1 and -6 in COVID-19 patients

Introduction

The COVID-19 virus spreads at a high rate, exerting many physical, mental and psychological effects on patients. Patients with COVID-19 have been reported to have high levels of interleukin 1 and interleukin 6. Therefore, this study was conducted to determine the association of physical, mental, and psychological problems with the levels of interleukin-1 and -6 in COVID-19 patients.

Methodology

This is cross-sectional descriptive-analytical research on 121 COVID-19 patients selected using simple random sampling method. The patients were hospitalized in university hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences and Amir al-Momenin Hospital. Data collection tools included the depression anxiety stress scale (DASS), a demographic questionnaire, and a checklist of physical problems. Blood sampling was also done to perform an ELISA test and measure the level of interleukin-1 and -6. Data were analyzed based on independent t-tests, chi-square, regression, and Pearson's correlation coefficient, using SPSS ver. 22.

Results

The average age of the 121 patients participating in this study was 53.31 ± 14.09. A direct and statistically significant correlation was observed between body temperature on the first day and interleukin 1 level. A statistically significant negative correlation was observed between blood oxygen saturation level and interleukin-1 and -6 on the first, third and fifth days. Shortness of breath and coughing had a statistically significant correlation with the level of interleukin 1 on the third and fifth days. A direct and statistically significant correlation was observed between body temperature on the first, third and fifth days and interleukin 6 level. Coughing on the third and fifth days had a statistically significant relationship with interleukin 6 level. No direct and non-significant statistical correlation was found between depression and stress and the serum level of interleukin 1, but a significant correlation was observed between anxiety and serum level of interleukin 1. Finally, the results showed that depression, anxiety and stress had a direct and statistically significant correlation with the serum level of interleukin 6.

Conclusion

Given the relationship between interleukin-1 and -6 and most physical and psychological problems, level of the inflammatory biomarkers interleukin-1 and -6 can be used to estimate the severity of physical and psychological symptoms in COVID-19 patients.

Effects of histamine and antihistamine on the hard tick Haemaphysalis longicornis during blood sucking

At the time of host attachment, ticks are very sensitive to histamine, but during rapid blood sucking they paradoxically require histamine. Using a rabbit model, we studied the effects of histamine and antihistamine during attachment and fast-feeding in different life stages of Haemaphysalis longicorns. We examined how they responded to histamine and antihistamine by analyzing the detachment rate, histology of feeding lesions, and post-feeding behavior. A significant difference (P<0.01) was found in the detachment rate between experimental and control treatments throughout the observation period. Ticks exhibited a higher detachment rate (30.1%) at 12 h after histamine application during attachment time and on antihistamine-treated skin (25.4%) at 96 h during fast-feeding. After feeding on histamine-treated rabbits, the fully engorged body weights of larvae and nymphs were 0.7±0.36 mg and 3.5±0.65 mg, respectively. An average increase in body weight of 0.6±0.05 mg and 3.2±0.30 mg was observed for larvae and nymphs compared to the respective control weights. Nymphs and adults engorged after antihistamine treatment had an average body weight of 1.3±0.54 mg and 54±0.81 mg, respectively. An average decrease in body weight was observed in antihistamine-treated H. longicornis compared with control nymphs (3.3±0.42 mg) and adults (174±1.78 mg). Skin biopsies were collected after treatment, and differential histopathological characteristics were found between the treatment and control groups. Tick-infested skin collected from rabbits in the antihistamine-treated group lacked erythrocytes in the feeding pool, indicating that antihistamine impaired tick fast-feeding stage.

Triphenyl phosphate-induced macrophages dysfunction by activation TLR4-mediated ERK/NF-κB pathway

Triphenyl phosphate (TPHP) is one of the most widely used organic phosphorus flame retardants and is ubiquitous in the environment. Studies have been reported that TPHP may lead to obesity, neurotoxicity and reproductive toxicity, but its impact on the immune system is almost blank. The present study was aimed to investigate the potential immunotoxicity of TPHP on macrophages and its underlying mechanism. The results demonstrated for the first time that TPHP (12.5, 25, and 50 μM)-induced F4/80⁺ CD11c⁺ phenotype of RAW 264.7 macrophages, accompanied by increased mRNA levels of inflammatory mediators, antigen-presenting genes (Cd80, Cd86, and H2-Aa), and significantly enhanced the phagocytosis of macrophage. Meanwhile, TPHP increased the expression of Toll-like receptor 4 (TLR4), and its co-receptor CD14, leading to significant activation of the downstream ERK/NF-κB pathway. However, co-exposure of cells to TAK-242, a TLR4 inhibitor, suppressed TPHP-induced F4/80⁺ CD11c⁺ phenotype, and down-regulated inflammatory mediators and antigen-presentation related genes, via blocked the TLR4/ERK/NF-κB pathway. Taken together, our results suggested that TPHP could induce macrophage dysfunction through activating TLR4-mediated ERK/NF-κB signaling pathway, and it may be the potential reason for health-threatening consequences.

Understanding the mechanisms underlying obesity in remodeling the breast tumor immune microenvironment: from the perspective of inflammation

Obesity is a well-known modifiable risk factor for breast cancer and is considered a poor prognostic factor in pre- and post-menopausal women. While the systemic effects of obesity have been extensively studied, less is known about the mechanisms underlying obesity-associated cancer risk and the local consequences of obesity. Thus, obesity-induced inflammation has become the focus of research interest. Biologically, the development of cancer involves a complex interaction with numerous components. As the tumor immune microenvironment changes due to obesity-triggered inflammation, an increase in infiltration occurs for proinflammatory cytokines and adipokines, as well as adipocytes, immune cells, and tumor cells in the expanded adipose tissue. Complicated cellular-molecular crosstalk networks change critical pathways, mediate metabolic and immune function reprogramming, and have a significant role in tumor metastasis, proliferation, resistance, angiogenesis, and tumorigenesis. This review summarizes recent research findings on how inflammatory mediators in the in situ tumor microenvironment regulate the occurrence and development of breast cancer in the context of obesity. We analyzed the heterogeneity and potential mechanisms of the breast cancer immune microenvironment from the perspective of inflammation to provide a reference for the clinical transformation of precision targeted cancer therapy.

Local translation in primary afferents and its contribution to pain

ABSTRACT

Chronic pain remains a significant problem due to its prevalence, impact, and limited therapeutic options. Progress in addressing chronic pain is dependent on a better understanding of underlying mechanisms. Although the available evidence suggests that changes within the central nervous system contribute to the initiation and maintenance of chronic pain, it also suggests that the primary afferent plays a critical role in all phases of the manifestation of chronic pain in most of those who suffer. Most notable among the changes in primary afferents is an increase in excitability or sensitization. A number of mechanisms have been identified that contribute to primary afferent sensitization with evidence for both increases in pronociceptive signaling molecules, such as voltage-gated sodium channels, and decreases in antinociceptive signaling molecules, such as voltage-dependent or calcium-dependent potassium channels. Furthermore, these changes in signaling molecules seem to reflect changes in gene expression as well as posttranslational processing. A mechanism of sensitization that has received far less attention, however, is the local or axonal translation of these signaling molecules. A growing body of evidence indicates that this process not only is dynamically regulated but also contributes to the initiation and maintenance of chronic pain. Here, we review the biology of local translation in primary afferents and its relevance to pain pathobiology.

Stimuli-responsive polypeptide nanogels for trypsin inhibition

A new type of hydrophilic, biocompatible, and biodegradable polypeptide nanogel depots loaded with the natural serine protease inhibitor α1-antitrypsin (AAT) was applied for the inhibition of the inflammatory mediator trypsin. Two types of nanogels were prepared from linear synthetic polypeptides based on biocompatible and biodegradable poly[N ⁵-(2-hydroxyethyl)-ʟ-glutamine-ran-N ⁵-propargyl-ʟ-glutamine-ran-N ⁵-(6-aminohexyl)-ʟ-glutamine]-ran-N ⁵-[2-(4-hydroxyphenyl)ethyl)-ʟ-glutamine] (PHEG-Tyr) or biocompatible N ^α-ʟ-lysine-grafted α,β-poly[(2-propyne)-ᴅ,ʟ-aspartamide-ran-(2-hydroxyethyl)-ᴅʟ-aspartamide-ran-(2-(4-hydroxyphenyl)ethyl)-ᴅʟ-aspartamide] (N ^α-Lys-NG). Both nanogels were prepared by HRP/H₂O₂-mediated crosslinking in inverse miniemulsions with pH and temperature-stimuli responsive behavior confirmed by dynamic light scattering and zeta potential measurements. The loading capacity of PHEG-Tyr and N ^α-Lys-NG nanogels and their release profiles were first optimized with bovine serum albumin. The nanogels were then used for loading and release of AAT. PHEG-Tyr and N ^α-Lys-NG nanogels showed different loading capacities for AAT with the maximum (20%) achieved with N ^α-Lys-NG nanogel. In both cases, the nanogel depots demonstrated a burst release of AAT during the first 6 h, which could be favorable for quick inhibition of trypsin. A consequent pilot in vitro inhibition study revealed that both PHEG-Tyr and N ^α-Lys-NG nanogels loaded with AAT successfully inhibited the enzymatic activity of trypsin. Furthermore, the inhibitory efficiency of the AAT-loaded nanogels was higher than that of only AAT. Interestingly, also non-loaded PHEG-Tyr and N ^α-Lys-NG nanogels were shown to effectively inhibit trypsin because they contain suitable amino acids in their structures that effectively block the active site of trypsin.

Factors influencing the blood-brain barrier permeability

The blood-brain barrier (BBB) is a dynamic structure that protects the brain from harmful blood-borne, endogenous and exogenous substances and maintains the homeostatic microenvironment. All constituent cell types play indispensable roles in the BBB's integrity, and other structural BBB components, such as tight junction proteins, adherens junctions, and junctional proteins, can control the barrier permeability. Regarding the need to exchange nutrients and toxic materials, solute carriers, ATP-binding case families, and ion transporter, as well as transcytosis regulate the influx and efflux transport, while the difference in localisation and expression can contribute to functional differences in transport properties. Numerous chemical mediators and other factors such as non-physicochemical factors have been identified to alter BBB permeability by mediating the structural components and barrier function, because of the close relationship with inflammation. In this review, we highlight recently gained mechanistic insights into the maintenance and disruption of the BBB. A better understanding of the factors influencing BBB permeability could contribute to supporting promising potential therapeutic targets for protecting the BBB and the delivery of central nervous system drugs via BBB permeability interventions under pathological conditions.

p300诱导的乙酰化修饰参与脂多糖诱导的炎症介质合成

OBJECTIVE

To investigate the role of acetylated modification induced by coactivator p300 in lipopolysaccharide (LPS)- induced inflammatory mediator synthesis and its molecular mechanism.

METHODS

Agilent SurePrint G3 Mouse Gene Expression V2 microarray chip and Western blotting were used to screen the molecules whose expression levels in mouse macrophages (RAW246.7) were correlated with the stimulation intensity of LPS. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (chip-qPCR) were used to verify the binding of the molecules to the promoters of IL-6 and TNF-α genes. The effects of transfection of RAW246.7 cells with overexpression or interfering plasmids on IL-6 and TNF-α synthesis were evaluated with ELISA, and the binding level of the target molecules and acetylation level of H3K27 in the promoter region of IL-6 and TNF-α genes were analyzed by chromatin immunoprecipitation sequencing technique (chip-seq).

RESULTS

Gene microarray chip data and Western blotting both confirmed a strong correlation of p300 expression with the stimulation intensity of LPS. Immunocoprecipitation confirmed the binding between p300 and c-myb. The results of EMSA demonstrated that c-myb (P < 0.05), but not p300, could directly bind to the promoter region of IL-6 and TNF-α genes; p300 could bind to the promoters only in the presence of c-myb (P < 0.05). The expressions of p65, p300 and c-myb did not show interactions. Both p300 overexpression and LPS stimulation could increase the level of promoter-binding p300 and H3K27 acetylation level, thus promoting p65 binding and inflammatory gene transcription; such effects were obviously suppressed by interference of c-myb expression (P < 0.05). Interference of p65 resulted in inhibition of p65 binding to the promoters and gene transcription (P < 0.05) without affecting p300 binding or H3K27 acetylation level.

CONCLUSION

LPS can stimulate the synthesis of p300, whose binding to the promoter region of inflammatory genes via c-myb facilitates the cohesion of p65 by inducing H3K27 acetylation, thus promoting the expression of the inflammatory genes.

Integrated effects of ultrasonic scaling and subgingival irrigation with 0.12% chlorhexidine by a newly designed ultrasonic scaler tip in chronic periodontitis

OBJECTIVE

To evaluate the integrated efficacy of completely simultaneous ultrasonic scaling and subgingival irrigation with chlorhexidine in chronic periodontitis.

METHOD AND MATERIALS

This was a split-mouth randomized controlled trial including 19 patients with moderate to severe chronic periodontitis. After calculus removal, the test side received simultaneous ultrasonic scaling and subgingival irrigation with 0.12% chlorhexidine, and the control side received simultaneous ultrasonic scaling and subgingival irrigation with distilled water. A newly designed ultrasonic scaler tip with a liquid outlet on the terminal was used. Clinical parameters were assessed, and gingival crevicular fluid was collected before treatment at baseline and 1.5, 3, and 6 months after baseline.

RESULTS

On follow-up, both sides showed significant reductions in clinical parameters and concentration of inflammatory mediators in gingival crevicular fluid. Adjunct application of CHX resulted in an additional periodontal pocket reduction (0.27 to 0.29 mm, P < .05) compared to the control side, in sites with initial probing depth of 4 to 5 mm. Within the initial probing depth ≥ 6 mm, the additional probing depth reduction was 0.44 to 0.60 mm (P < .05), with clinical attachment loss, concentration of interleukin-6, and concentration of matrix metalloproteinase-8 being 0.32 to 0.38 mm, 2.64 to 3.40 µg/L, and 19.78 to 22.39 ng/L, respectively (all P < .05).

CONCLUSION

In this study, treatment outcomes of chronic periodontitis could be improved by treating the root surface with simultaneous ultrasonic scaling and chlorhexidine irrigation. The adjunctive use of 0.12% chlorhexidine with a newly designed ultrasonic scaler tip in the treatment of moderate to severe chronic periodontitis demonstrated significant clinical benefits and decrease in inflammatory mediator when compared with scaling and root planing plus placebo.

Asian Sand Dust Particles Enhance the Development of Aspergillus fumigatus Biofilm on Nasal Epithelial Cells

Background: Asian sand dust (ASD) and Aspergillus fumigatus are known risk factors for airway mucosal inflammatory diseases. Bacterial and fungal biofilms commonly coexist in chronic rhinosinusitis and fungus balls. We evaluated the effects of ASD on the development of A. fumigatus biofilm formation on nasal epithelial cells. Methods: Primary nasal epithelial cells were cultured with A. fumigatus conidia with or without ASD for 72 h. The production of interleukin (IL)-6, IL-8, and transforming growth factor (TGF)-β1 from nasal epithelial cells was determined by the enzyme-linked immunosorbent assay. The effects of ASD on A. fumigatus biofilm formation were determined using crystal violet, concanavalin A, safranin staining, and confocal scanning laser microscopy. Results: ASD and A. fumigatus significantly enhanced the production of IL-6 and IL-8 from nasal epithelial cells. By coculturing A. fumigatus with ASD, the dry weight and safranin staining of the fungal biofilms significantly increased in a time-dependent manner. However, the increased level of crystal violet and concanavalin A stain decreased after 72 h of incubation. Conclusions: ASD and A. fumigatus induced the production of inflammatory chemical mediators from nasal epithelial cells. The exposure of A. fumigatus to ASD enhanced the formation of biofilms. The coexistence of ASD and A. fumigatus may increase the development of fungal biofilms and fungal inflammatory diseases in the sinonasal mucosa.

Protectin DX Attenuates Lumbar Radicular Pain of Non-compressive Disc Herniation by Autophagy Flux Stimulation via Adenosine Monophosphate-Activated Protein Kinase Signaling

Background: Neuroinflammation plays a crucial role in initiating and sustaining lumbar radicular pain (LRP). Protectin DX (PDX) has been experimentally verified to possess pro-resolving properties and anti-inflammatory effects. This study aimed to observe the analgesic effects of PDX and its potential mechanisms in LRP rats with non-compressive lumbar disc herniation (NCLDH). Method: Only male rats were selected to avoid gender-related interferences. Rat models of NCLDH were established, and rats were randomly divided into four groups: the sham group, the vehicle group, the PDX (10 ng PDX) group, and the PDX (100 ng PDX) group. Changes in the mechanical withdrawal threshold and thermal withdrawal latency were observed for 7 days. The mRNAs of pro-inflammatory and anti-inflammatory mediators were evaluated via real-time polymerase chain reaction, whereas western blot and immunohistochemistry were separately conducted to assess the expression levels of autophagy-related proteins and adenosine monophosphate-activated protein kinase (AMPK) signaling. Results: Intrathecal delivery of PDX reduced interleukin (IL)-6 and IL-1β mRNA levels and facilitated mRNA transcription of transforming growth factor-β₁, with attenuation of mechanical and thermal hyperalgesia in LRP rat models. With the application of nucleus pulposus to the dorsal root ganglion, autophagy flux and AMPK signaling were severely disrupted in the spinal dorsal horns, and intrathecal treatment with PDX could dose-dependently restore the dysfunction of autophagy flux and AMPK signaling. Conclusion: These data suggest that PDX possesses pro-resolving properties and exerts potent analgesic effects in LRP by affecting autophagy flux via AMPK signaling.

Influences of periodontitis on hippocampal inflammation, oxidative stress, and apoptosis in rats

BACKGROUND AND AIM

The hippocampus, which has a central role in cognitive and behavioral activities, is one of the most sensitive parts of the brain to systemic inflammatory diseases. This animal study aims to comprehensively investigate the possible inflammatory, oxidative, and apoptotic effects of periodontitis on the hippocampus.

METHODS

Sixteen male Sprague-Dawley rats were randomly assigned to two groups: control and experimental periodontitis (Ep). In the Ep group, periodontitis was induced by placing 3.0 sutures sub-paramarginally around the necks of right and left mandibular first molars and maintaining the ligatures in place for 5 weeks. Following the euthanasia, mandibula and hippocampus samples were collected bilaterally. Alveolar bone loss was measured histomorphometrically and radiologically on the right and left mandibles. On the right hippocampal sections histological (Caspase-3, TNF-α, and 8-OHdG) and the left hippocampal sections, biochemical (IL-1β, Aβ_1-42 , MDA, GSH, and TAS levels) evaluations were performed.

RESULTS

Histopathological changes associated with periodontitis were limited (p > .05). A slight increase in caspase-3 positive neuron density in EP rats showed that apoptotic changes were also limited (p > .05). 8-OHdG activity, on the other hand, was significantly higher compared to controls (p < .05). In biochemical analysis, there was a significant increase in IL-1β levels and oxidative membrane damage (MDA) (p < .05) whereas Aβ_1-42 and antioxidant marker (GSH and TAS) levels were slightly increased (p > .05).

CONCLUSION

Periodontitis causes marked increases in IL-1β levels and oxidative stress in the hippocampus, but limited degenerative and apoptotic changes.

Epalrestat suppresses inflammatory response in lipopolysaccharide-stimulated RAW264.7 cells

INTRODUCTION AND OBJECTIVES

Lipopolysaccharide (LPS) is a potent inducer of inflammatory response. Inflammation is a major risk factor for many diseases. Regulation of inflammatory mediator and pro-inflammatory cytokine levels could be a potential therapeutic approach to treat inflammatory injury. The purpose of the present study was to determine whether epalrestat (EPS), which is used for the treatment of diabetic neuropathy, suppresses inflammatory response in LPS-stimulated RAW264.7 cells.

MATERIAL AND METHODS

The effects of EPS at near-plasma concentration on the levels of pro-inflammatory cytokines and inflammatory mediators was examined using by MTS assay, quantitative RT-PCR analysis, and western blotting in LPS-stimulated RAW264.7 cells.

RESULTS

EPS suppressed mRNA and protein expression levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNFα, in RAW264.7 cells stimulated with LPS. EPS also affected inflammatory mediators such as iNOS and NF-κB in LPS-stimulated RAW264.7 cells.

CONCLUSIONS

In this study, we demonstrated for the first time that EPS suppresses inflammatory response in LPS-stimulated RAW264.7 cells. From these results, we propose that targeting the regulation of pro-inflammatory cytokine levels and inflammatory mediators by EPS is a promising therapeutic approach to treat inflammatory injury. It is expected that EPS, whose safety and pharmacokinetics have been confirmed clinically, would be useful for the treatment of inflammatory diseases.

A Paradigm for Post-Covid-19 Fatigue Syndrome Analogous to ME/CFS

A significant proportion of COVID-19 patients are suffering from prolonged Post-COVID-19 Fatigue Syndrome, with characteristics typically found in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). However, no clear pathophysiological explanation, as yet, has been provided. A novel paradigm for a Post-COVID-19 Fatigue Syndrome is developed here from a recent unifying model for ME/CFS. Central to its rationale, SARS-CoV-2, in common with the triggers (viral and non-viral) of ME/CFS, is proposed to be a physiologically severe stressor, which could be targeting a stress-integrator, within the brain: the hypothalamic paraventricular nucleus (PVN). It is proposed that inflammatory mediators, released at the site of COVID-19 infection, would be transmitted as stress-signals, via humoral and neural pathways, which overwhelm this stress-center. In genetically susceptible people, an intrinsic stress-threshold is suggested to be exceeded causing ongoing dysfunction to the hypothalamic PVN's complex neurological circuitry. In this compromised state, the hypothalamic PVN might then be hyper-sensitive to a wide range of life's ongoing physiological stressors. This could result in the reported post-exertional malaise episodes and more severe relapses, in common with ME/CFS, that perpetuate an ongoing disease state. When a certain stress-tolerance-level is exceeded, the hypothalamic PVN can become an epicenter for microglia-induced activation and neuroinflammation, affecting the hypothalamus and its proximal limbic system, which would account for the range of reported ME/CFS-like symptoms. A model for Post-COVID-19 Fatigue Syndrome is provided to stimulate discussion and critical evaluation. Brain-scanning studies, incorporating increasingly sophisticated imaging technology should enable chronic neuroinflammation to be detected, even at a low level, in the finite detail required, thus helping to test this model, while advancing our understanding of Post-COVID-19 Fatigue Syndrome pathophysiology.

Models of Inflammation: Carrageenan Air Pouch

The subcutaneous air pouch is an in vivo model that can be used to study the components of acute and chronic inflammation, the resolution of the inflammatory response, the oxidative stress response, and potential therapeutic targets for treating inflammation. Injection of irritants into an air pouch in rats or mice induces an inflammatory response that can be quantified by the volume of exudate produced, the infiltration of cells, and the release of inflammatory mediators. The model presented in this article has been extensively used to identify potential anti-inflammatory drugs. © 2021 Wiley Periodicals LLC. Basic Protocol: Air pouch model in the rat Alternate Protocol: Air pouch model in the mouse.

Fibroblast Growth Factor Type 1 Ameliorates High-Glucose-Induced Oxidative Stress and Neuroinflammation in Retinal Pigment Epithelial Cells and a Streptozotocin-Induced Diabetic Rat Model

Diabetic retinopathy (DR) is a common complication of diabetes that causes severe visual impairment globally. The pathogenesis of DR is related to oxidative stress and chronic inflammation. The fibroblast growth factor type 1 (FGF-1) mitogen plays crucial roles in cell function, development, and metabolism. FGF-1 is involved in blood sugar regulation and exerts beneficial antioxidative and anti-inflammatory effects on various organ systems. This study investigated the antioxidative and anti-inflammatory neuroprotective effects of FGF-1 on high-glucose-induced retinal damage. The results revealed that FGF-1 treatment significantly reversed the harmful effects of oxidative stress and inflammatory mediators in retinal tissue in a streptozotocin-induced diabetic rat model. These protective effects were also observed in the in vitro model of retinal ARPE-19 cells exposed to a high-glucose condition. We demonstrated that FGF-1 attenuated p38 mitogen-activated protein kinase and nuclear factor-κB pathway activation under the high-glucose condition. Our results indicated that FGF-1 could effectively prevent retinal injury in diabetes. The findings of this study could be used to develop novel treatments for DR that aim to reduce the cascade of oxidative stress and inflammatory signals in neuroretinal tissue.

Sex Effect on Cardiac Damage in Mice With Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system. Recent clinical study suggested that MS patient exhibited acute heart failure. Further, 12-lead electrocardiographic study showed a longer QTc interval in both MS patient and experimental autoimmune encephalomyelitis (EAE) Lewis rat. However, there is limited study regarding the effect of sex on cardiac injury in EAE. To our knowledge, sex effect on cardiac damage in mice with EAE has not yet been published. Herein, we examined the role of the immune system in mediating cardiac dysfunction after EAE in female and male mice. Neurological function was subsequently evaluated and cardiac function was assessed by echocardiography at multiple time points after EAE. EAE mice exhibited severe neurological deficit and significant cardiac dysfunction, including decreased left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) at 1 and 2 months after EAE induction. Meanwhile male EAE presented increased expression of the oxidative stress (e.g., nicotinamaide adenine dinucleotide phosphate oxidase-2; NOX-2) in heart, as well as cardiac hypertrophy, increased left ventricle (LV) mass and more severe cardiac fibrosis compared with male control mice. In addition, male EAE mice showed significantly increased cardiac canonical inflammatory mediator (e.g., monocyte chemoattractant protein-1; MCP-1, transforming growth factor-β; TGF-β and toll-like receptor 2; TLR-2) compared with female EAE mice at 2 months after EAE induction. In conclusion, EAE increases inflammatory factor expression and aggravates cardiac dysfunction in male mice compared with female mice, which may contribute to different cardiac outcome in EAE mice.

Research Note: Anti-inflammatory effects and antiviral activities of baicalein and chlorogenic acid against infectious bursal disease virus in embryonic eggs

The purpose of this study was to investigate if baicalein and chlorogenic acid could inhibit the inflammatory responses induced by and protect against infectious bursal disease virus (IBDV) in chicken embryonic eggs. Nine-day-old embryonated chicken eggs were randomly divided into 3 groups of 50 eggs per group: 1) treatment with varying concentrations of baicalein, 2) treatment with varying concentrations of chlorogenic acid, or 3) left untreated as a control. Forty-eight hours after hatching, each group was inoculated with a very virulent IBDV isolate, and the survival of the embryo was monitored daily until the embryonic livers were collected 72 h after inoculation. After IBDV infection, the viral loads in the embryonic livers were evaluated using qRT-PCR, and the hepatic content of inflammatory mediators, such as histamine, interleukin 1β (IL-1β), tumor necrosis factor alpha (TNF-α), and nuclear factor-kappa B (NF-κB), were examined. Significant antiviral potential was demonstrated at concentrations of 108 and 215 μg/egg of baicalein and chlorogenic acid, respectively. We observed a concentration-dependent response in the antiviral properties of these chemicals. Treating the embryos with baicalein and chlorogenic acid significantly reduced histamine production. Moreover, pretreatment with baicalein and chlorogenic acid significantly inhibited NF-κB activation, and this inhibited the subsequent production of the proinflammatory cytokines TNF-α and IL-1β in the context of IBDV infection. These findings suggest that baicalein and chlorogenic acid have anti-IBDV properties, and they may be useful in the prevention of inflammation-related diseases.

Impact of Endotoxins in Gelatine Hydrogels on Chondrogenic Differentiation and Inflammatory Cytokine Secretion In Vitro

Gelatine methacryloyl (GelMA) hydrogels are widely used in studies aimed at cartilage regeneration. However, the endotoxin content of commercially available GelMAs and gelatines used in these studies is often overlooked, even though endotoxins may influence several cellular functions. Moreover, regulations for clinical use of biomaterials dictate a stringent endotoxin limit. We determined the endotoxin level of five different GelMAs and evaluated the effect on the chondrogenic differentiation of equine mesenchymal stromal cells (MSCs). Cartilage-like matrix production was evaluated by biochemical assays and immunohistochemistry. Furthermore, equine peripheral blood mononuclear cells (PBMCs) were cultured on the hydrogels for 24 h, followed by the assessment of tumour necrosis factor (TNF)-α and C-C motif chemokine ligand (CCL)2 as inflammatory markers. The GelMAs were found to have widely varying endotoxin content (two with >1000 EU/mL and three with <10 EU/mL), however, this was not a critical factor determining in vitro cartilage-like matrix production of embedded MSCs. PBMCs did produce significantly higher TNF-α and CCL2 in response to the GelMA with the highest endotoxin level compared to the other GelMAs. Although limited effects on chondrogenic differentiation were found in this study, caution with the use of commercial hydrogels is warranted in the translation from in vitro to in vivo studies because of regulatory constraints and potential inflammatory effects of the content of these hydrogels.

A Simple and Efficient System for Producing Recombinant Human CXCL8 in Escherichia coli

Multifunctional pro-inflammatory cytokine CXCL8 is a small peptide of 8-10 kDa in size and it functions as a monomer or dimer. CXCL8 harbors 2 disulfide bonds for its stability. Although production of the CXCL8 protein in a large quantity in both mammalian and bacterial systems has been reported, the processes are complicated and lengthy. Here, we develop a new bacterial expression system for recombinant CXCL8 and simplify the purification system to yield a high amount of protein quickly. The purified CXCL8 protein from our new system develops a crystal structure that is identical to that produced through the mammalian expression system. Thus, we have established a simple and efficient recombinant CXCL8-producing system, which can be easily operated and is suitable to those requiring a large quantity of CXCL8.

Direct Gαq Gating Is the Sole Mechanism for TRPM8 Inhibition Caused by Bradykinin Receptor Activation

Activation of Gα_q-coupled receptors by inflammatory mediators inhibits cold-sensing TRPM8 channels, aggravating pain and inflammation. Both Gα_q and the downstream hydrolysis of phosphatidylinositol 4, 5-bisphosphate (PIP₂) inhibit TRPM8. Here, I demonstrate that direct Gα_q gating is essential for both the basal cold sensitivity of TRPM8 and TRPM8 inhibition elicited by bradykinin in sensory neurons. The action of Gα_q depends on binding to three arginine residues in the N terminus of TRPM8. Neutralization of these residues markedly increased sensitivity of the channel to agonist and membrane voltage and completely abolished TRPM8 inhibition by both Gα_q and bradykinin while sparing the channel sensitivity to PIP₂. Interestingly, the bradykinin receptor B2R also binds to TRPM8, rendering TRPM8 insensitive to PIP₂ depletion. Furthermore, TRPM8-Gα_q binding impaired Gα_q coupling and signaling to PLCβ-PIP₂. The crosstalk in the TRPM8-Gα_q-B2R complex thus determines Gα_q gating rather than PIP₂ as a sole means of TRPM8 inhibition by bradykinin.

Effects of xenon gas on human airway epithelial cells during hyperoxia and hypothermia

BACKGROUND

Hypothermia with xenon gas has been used to reduce brain injury and disability rate after perinatal hypoxia-ischemia. We evaluated xenon gas therapy effects in an in vitro model with or without hypothermia on cultured human airway epithelial cells (Calu-3).

METHODS

Calu-3 monolayers were grown at an air-liquid interface and exposed to one of the following conditions: 1) 21% FiO2 at 37°C (control); 2) 45% FiO2 and 50% xenon at 37°C; 3) 21% FiO2 and 50% xenon at 32°C; 4) 45% FiO2 and 50% xenon at 32°C for 24 hours. Transepithelial resistance (TER) measurements were performed and apical surface fluids were collected and assayed for total protein, IL-6, and IL-8. Three monolayers were used for immunofluorescence localization of zonula occludens-1 (ZO-1). The data were analyzed by one-way ANOVA.

RESULTS

TER decreased at 24 hours in all treatment groups. Xenon with hyperoxia and hypothermia resulted in greatest decrease in TER compared with other groups. Immunofluorescence localization of ZO-1 (XY) showed reduced density of ZO-1 rings and incomplete ring-like staining in the 45% FiO2- 50% xenon group at 32°C compared with other groups. Secretion of total protein was not different among groups. Secretion of IL-6 in 21% FiO2 with xenon group at 32°C was less than that of the control group. The secretion of IL-8 in 45% FiO2 with xenon at 32°C was greater than that of other groups.

CONCLUSION

Hyperoxia and hypothermia result in detrimental epithelial cell function and inflammation over 24-hour exposure. Xenon gas did not affect cell function or reduce inflammation.

Zika Virus Infects Human Placental Mast Cells and the HMC-1 Cell Line, and Triggers Degranulation, Cytokine Release and Ultrastructural Changes

Zika virus (ZIKV) is an emergent arthropod-borne virus whose outbreak in Brazil has brought major public health problems. Infected individuals have different symptoms, including rash and pruritus, which can be relieved by the administration of antiallergics. In the case of pregnant women, ZIKV can cross the placenta and infect the fetus leading to congenital defects. We have identified that mast cells in the placentae of patients who had Zika during pregnancy can be infected. This led to our investigation on the possible role of mast cells during a ZIKV infection, using the HMC-1 cell line. We analyzed their permissiveness to infection, release of mediators and ultrastructural changes. Flow cytometry detection of ZIKV-NS1 expression 24 h post infection in 45.3% of cells showed that HMC-1 cells are permissive to ZIKV infection. Following infection, β-hexosaminidase was measured in the supernatant of the cells with a notable release at 30 min. In addition, an increase in TNF-α, IL-6, IL-10 and VEGF levels were measured at 6 h and 24 h post infection. Lastly, different intracellular changes were observed in an ultrastructural analysis of infected cells. Our findings suggest that mast cells may represent an important source of mediators that can activate other immune cell types during a ZIKV infection, which has the potential to be a major contributor in the spread of the virus in cases of vertical transmission.

Sexual dimorphism in SARS-COV-2 infection

Previous studies have demonstrated that female patients with coronavirus disease 2019 (COVID-19) demonstrate more favorable prognosis relative to male patients. In this article, we elaborate the possible role of estrogen in the modulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection severity. The potential interplay between several factors, including inherently lower estradiol (E₂) and slightly higher estrogen receptor β (ERβ) levels in males, with inflammatory mediators are described. Altogether, there seems to be a sexually dimorphic response towards SARS-CoV-2 infection, and a possibility that COVID-19 severity is dependent on both E₂ levels and ERα:ERβ expression ratio in lymphoid and lung cells.

Bone marrow-derived mesenchymal stem cell transplantation attenuates overexpression of inflammatory mediators in rat brain after cardiopulmonary resuscitation

Emerging evidence suggests that bone marrow-derived mesenchymal stem cell transplantation improves neurological function after cardiac arrest and cardiopulmonary resuscitation; however, the precise mechanisms remain unclear. This study aimed to investigate the effect of bone marrow-derived mesenchymal stem cell treatment on expression profiles of multiple cytokines in the brain after cardiac arrest and cardiopulmonary resuscitation. Cardiac arrest was induced in rats by asphyxia and cardiopulmonary resuscitation was initiated 6 minutes after cardiac arrest. One hour after successful cardiopulmonary resuscitation, rats were injected with either phosphate-buffered saline (control) or 1 × 10⁶ bone marrow-derived mesenchymal stem cells via the tail vein. Serum S100B levels were measured by enzyme-linked immunosorbent assay and neurological deficit scores were evaluated to assess brain damage at 3 days after cardiopulmonary resuscitation. Serum S100B levels were remarkably decreased and neurological deficit scores were obviously improved in the mesenchymal stem cell group compared with the phosphate-buffered saline group. Brains were isolated from the rats and expression levels of 90 proteins were determined using a RayBio Rat Antibody Array, to investigate the cytokine profiles. Brain levels of the inflammatory mediators tumor necrosis factor-α, interferon-γ, macrophage inflammatory protein-1α, macrophage inflammatory protein-2, macrophage inflammatory protein-3α, macrophage-derived chemokine, and matrix metalloproteinase-2 were decreased ≥ 1.5-fold, while levels of the anti-inflammatory factor interleukin-10 were increased ≥ 1.5-fold in the mesenchymal stem cell group compared with the control group. Donor mesenchymal stem cells were detected by immunofluorescence to determine their distribution in the damaged brain, and were primarily observed in the cerebral cortex. These results indicate that bone marrow-derived mesenchymal stem cell transplantation attenuates brain damage induced by cardiac arrest and cardiopulmonary resuscitation, possibly via regulation of inflammatory mediators. This experimental protocol was approved by the Institutional Animal Care and Use Committee of Fujian Medical University, China in January 2016 (approval No. 2016079).

The Association between Dietary Inflammatory Index (DII) and Cancer Risk in Korea: A Prospective Cohort Study within the KoGES-HEXA Study

Several epidemiological studies have shown that there are consistently positive associations between dietary inflammatory index (DII^®) scores and cancer incidence in Western populations. However, few DII-cancer studies have been conducted in East Asian populations. In a large cohort representative of the general Korean population, we investigated whether the DII is associated with overall cancer risk. A total of 163,660 participants (56,781 males and 106,879 females) had evaluable data for analyses. This follow-up study was carried out over the course of 7.9 years. DII scores were calculated based on Semi-Quantitative Food-Frequency Questionnaire (SQ-FFQ) data for 106 food items. Cancers were self-reported based on notification by the participants’ medical doctors. Multivariable Cox proportional hazard regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). After the follow-up, 1643 incident cases of cancer (520 males and 1123 females) had developed. In a fully adjusted model, women in the highest DII quintile showed a 44% increased risk of getting cancer (HR_Q5vsQ1 = 1.44; 95% CI = 1.14–1.82; p-trend = 0.0006), while men showed no apparent association (HR_Q5vsQ1 = 0.80; 95% CI = 0.58–1.10). These results indicate that in Korean women, a more pro-inflammatory diet is associated with a higher risk of incident cancer.

Possible interaction between visfatin, periodontal infection, and other systemic diseases: A brief review of literature

Gingivitis and periodontitis are common bacterial infections caused by a variety of microorganisms. Despite the microorganisms’ roles as etiologic agents, inflammation-induced substances also have crucial parts in the loss of connective tissue and the supporting alveolar bone. Visfatin is a pleiotropic mediator, which acts as growth factor, cytokine, and pre-B-cell colony-enhancing factor. A positive correlation was detected between the serum/plasma levels of visfatin and inflammatory disorders such as diabetes mellitus and cardiovascular disease. In addition, the visfatin level was higher in saliva and the gingival crevicular fluid (GCF) of subjects with periodontal disease. This review defined current, predictable patterns of possible interaction of visfatin with periodontal infection and other systemic diseases, using PubMed and Medline databases searching for articles written in English. Peer-reviewed articles were targeted using the following keywords: “visfatin,” “periodontal disease,” “inflammatory mediator,” and “biomarker.” Available full-text articles were read, and related articles were also scrutinized, while a hand search was also performed. Search was confined to human studies, and articles written in English and published between 1985 and 2016 were selected. It was concluded that periodontal infection and other systemic diseases could be related to the levels of visfatin in GCF, saliva, and serum as a biomarker of these diseases.

PM2.5 upregulates rat mesenteric arteries 5-HT2A receptor via inflammatory-mediated mitogen-activated protein kinases signaling pathway

Fine particulate matter (PM_2.5 ) is an important environmental risk factor for cardiovascular diseases. However, little is known about the effects of PM_2.5 on arteries. The present study investigated whether PM_2.5 alters 5-hydroxytryptamine (5-HT) receptor expression and inflammatory mediators on rat mesenteric arteries, and examined the underlying mechanisms. Isolated rat mesenteric arteries segments were cultured with PM_2.5 in the presence or absence of ERK1/2, JNK, and p38 pathway inhibitors. Contractile reactivity was monitored by a sensitive myograph. The expression of 5-HT_2A/1B receptors and inflammatory mediators were studied by a real-time polymerase chain reaction and/or by immunohistochemistry. The phosphorylation of mitogen-activated protein kinases (MAPK) pathway was detected by Western blot. Compared with the fresh or culture alone groups, 1.0 μg/mL PM_2.5 cultured for 16 hours significantly enhanced contractile response induced by 5-HT and increased 5-HT_2A receptor mRNA and protein expressions, indicating PM_2.5 upregulates 5-HT_2A receptor. SB203580 (p38 inhibitor) and U0126 (ERK1/2 inhibitor) significantly decreased PM_2.5 -induced elevated contraction and mRNA and protein expression of 5-HT_2A receptor. Cultured with PM_2.5 significantly increased the mRNA expression of inflammatory mediators (NOS2, IL-1β, and TNF-α), while SB203580 decreased mRNA expression level of NOS2, IL-1β, and TNF-α. SP600125 (JNK inhibitor) decreased mRNA expression level of TNF-α and IL-1β. After PM_2.5 exposure, the phosphorylation of p38 and ERK1/2 protein were increased. SB203580 and U0126 inhibited the PM_2.5 caused increased phosphorylation protein of p38 and ERK1/2. In conclusion, PM_2.5 induces inflammatory-mediated MAPK pathway in artery which subsequently results in enhanced vascular contraction responding to 5-HT via the upregulated 5-HT_2A receptors.

[Levels of airway inflammatory mediators in peripheral blood in infants and young children with wheezing]

OBJECTIVE

To examine the levels of airway inflammatory mediators in peripheral blood in infants and young children with wheezing and to study the possible pathogenesis of wheezing from the aspects of T helper cell 1 (Th1)/T helper cell 2 (Th2) imbalance and airway inflammation.

METHODS

A total of 50 children aged 1 month to 3 years with an acute wheezing episode were enrolled as the wheezing group, and 25 age-matched healthy infants were enrolled as the healthy control group. According to the number of wheezing episodes, the wheezing group was divided into a first-episode group (n=25) and a recurrent wheezing (number of episodes ≥2) group (n=25). According to the presence or absence of high-risk factors for asthma, the wheezing group was divided into a high-risk factor group (n=22) and a non-high-risk factor group (n=28). According to the results of pathogen detection, the wheezing group was divided into a positive pathogen group (n=23) and a negative pathogen group (n=27). Levels of interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), transforming growth factor-β1 (TGF-β1), and total IgE (TIgE) in peripheral blood were measured for each group. For children with wheezing, eosinophil (EOS) count in peripheral blood was measured, and related samples were collected for respiratory pathogen detection.

RESULTS

The wheezing group had significantly higher levels of IL-4, IL-5, IL-13, TGF-β1, and TIgE in peripheral blood than the healthy control group (P<0.05). There were no significant differences in the levels of IL-2, IL-4, IL-5, IL-13, TGF-β1, and TIgE in peripheral blood between the first-episode and recurrent wheezing groups, between the high-risk factor and non-high-risk factor groups, and between the positive pathogen and negative pathogen groups (P>0.05). The correlation analysis showed that in children with wheezing, EOS count was positively correlated with IL-4 level (P<0.01), IL-4 level was positively correlated with IL-5 and IL-13 levels (P<0.01), IL-5 level was positively correlated with IL-13 level (P<0.01), and IL-2 level was positively correlated with TGF-β1 level (P<0.05).

CONCLUSIONS

Th1/Th2 imbalance with a predominance of Th2 is observed in infants and young children with wheezing. IL-4, IL-5, IL-13, TGF-β1, and IgE are involved in the pathogenesis of wheezing in these children. Airway inflammation is also observed in these children with wheezing, but it is not associated with the number of wheezing episodes, presence or absence of high-risk factors for asthma, or results of pathogen detection.

Atherosclerosis: integration of its pathogenesis as a self-perpetuating propagating inflammation: a review

This review proposes that the development of the atherosclerotic plaque is critically dependent on its inflammatory components forming a self-perpetuating and propagating positive feedback loop. The components involved are: (1) LDL oxidation, (2) activation of the endothelium, (3) recruitment of inflammatory monocytes, (4) macrophage accumulation, which induces LDL oxidation, and (5) macrophage generation of inflammatory mediators, which also activate the endothelium. Through these stages, the positive feedback loop is formed, which generates and promotes expansion of the atherosclerotic process. To illustrate this dynamic of lesion development, the author previously produced a computer simulation, which allowed realistic modelling. This hypothesis on atherogenesis can explain the existence and characteristic focal morphology of the atherosclerotic plaque. Each of the components contributing to the feedback loop is discussed. Many of these components also contain subsidiary positive feedback loops, which could exacerbate the overall process.

RhACE2 - playing an important role in inhibiting apoptosis induced by Ang II in HUVECs

BACKGROUND

Henoch-Schonlein purpura (HSP) is a common hemorrhagic disease, which manifests the inflammation in the body's most microvasculars. Angiotensin II (Ang II) can induce the damage and apoptosis of vascular endothelial cells while angiotensin converting enzyme 2 (ACE2) can antagonist the action of Ang II. However, the effect of ACE2 on Ang II-induced endothelial damage remains unknown.

OBJECTIVE

To evaluate the effect of recombinant human angiotensin converting enzyme 2 (rhACE2) on the Ang II-induced damage of human umbilical vein endothelial cells (HUVECs) and the release of inflammatory mediator in vitro.

METHODS

Cultured HUVECs were randomly divided into 6 groups: the control group, rhACE2 group, Ang II group, and Ang II+ rhACE2 groups (3 subgroups). The cell vitality, cell cycle, apoptosis rate of the HUVECs and the levels of reactive oxygen species (ROS), interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1) and lactate dehydrogenase (LDH) were measured, respectively.

RESULTS

Compared with the control group, the cell viability and the rate of S phase cells in Ang II group significantly decreased (P < .05) while the apoptosis percentage and the levels of ROS, IL-8, TNF-α, TGF-β1, and LDH in Ang II group significantly increased (P < .05). There were no significant differences between the control group and rhACE2 group. Compared with the Ang II group, the cell viability and the rate of S phase cells in Ang II+rhACE2 groups were higher (P < .05) and the apoptosis percentage, the level of ROS, IL-8, TNF-α, TGF-β1, LDH in Ang II+rhACE2 groups were lower (P < .05).

CONCLUSIONS

Ang II can induce the apoptosis of HUVECs and the release of inflammatory mediator, while rhACE2 can inhibit the detrimental effects of Ang II. The results of this study suggest that rhACE2 has a protective effect on HSP, which is probably a new way for the prevention and treatment of HSP.

Hydroxycarboxylic Acid Receptor Ligands Modulate Proinflammatory Cytokine Expression in Human Macrophages and Adipocytes without Affecting Adipose Differentiation

Members of the hydroxycarboxylic acid receptor (HCA1-3) family are mainly expressed in adipocytes and immune cells. HCA2 ligand, niacin, has been used for decades as lipid-modifying drug. Recent studies suggest that HCA ligands can be involved in the modulation of inflammatory processes. In this study, we evaluated the effects of HCA1-3 ligands on adipose differentiation and cytokine expression in human adipocytes and macrophages. Simpson-Golabi-Behmel syndrome (SGBS) preadipocytes were induced to differentiate into adipocytes for 8 d in the presence or absence of HCA ligands and evaluated for lipid accumulation and adipogenic gene expression. The inhibitory effects of the ligands on the expression and production of cytokines were measured in lipopolysaccharide (LPS)-stimulated adipocytes and THP-1 macrophage cells. Preadipocytes treated with HCA ligands showed no changes in the capacity to differentiate into adipocytes and no significant alteration in peroxisome proliferator activated receptor γ (PPARγ) or its target gene expression. HCA2-3 ligands significantly downregulated LPS-induced expression of interleukin (IL)-6 (53-64%), tumor necrosis factor-α (TNF-α) (55-69%) and IL-8 (51-59%) in adipocytes and macrophages. IL-1β inhibition (58-68%) by HCA2-3 ligands was observed only in adipocytes. Furthermore, LPS increased the expression of HCA2-3 in adipocytes and macrophages and this expression was decreased by treatment with their ligands. These results suggest that HCA ligands modulated LPS-mediated pro-inflammatory gene expression in both macrophages and adipocytes without affecting adipogenesis. Therefore, targeting HCA2 and HCA3 would be beneficial in treating inflammation conditions associated with atherosclerosis and obesity.

MicroRNA‑143‑3p contributes to the regulation of pain responses in collagen‑induced arthritis

Patients with rheumatoid arthritis (RA) suffer from pain, which is associated with inflammation, peripheral and central pain processing, and joint structure damage. The aim of the present study was to investigate a key microRNA (miR) and its target genes that are involved in the pain responses of RA, and to clarify the mechanism of pain regulation. Collagen‑induced arthritis (CIA) was induced in DBA/1 and C57BL/6 mice. The paw swelling, mechanical withdrawal threshold (MWT), thermal withdrawal latency (TWL), and expression levels of tumor necrosis factor (TNF)‑α and prostaglandin (PG)E2 in the sera were investigated. Decreased MWT and TWL, and increased TNF‑α and PGE2, in the CIA model group were observed in DBA/1 and C57BL/6 mice. DBA/1 mice exhibited greater hyperalgesia and higher levels of inflammatory mediators. miR‑143‑3p expression in the blood and the dorsal root ganglion (DRG) were detected, and low miR‑143‑3p expression was demonstrated in the blood and DRG tissue of CIA mice. The target genes of miR‑143 were predicted and analyzed. A total of 1,305 genes were predicted and 55 pain‑associated genes were obtained. Prostaglandin‑endoperoxide synthase 2 (Ptgs2), MAS related GPR family member E (Mrgpre), prostaglandin D2 receptor and Tnf were selected as target genes of miR‑143. DRG cells were cultured and transfected with miR‑143‑3p inhibitor or mimic. The expression of Mrgpre, Ptgs2 and Tnf was significantly inhibited following miR‑143‑3p mimic transfection, while the expression of Mrgpre, Ptgs2 and Tnf was increased following inhibitor transfection. Additionally, the expression of pain‑associated genes in the DRG of mice was investigated and the expression of Ptgs2, Mrgpre and Tnf in the DRG of CIA mice was also significantly upregulated. These results revealed that CIA mice exhibited marked hyperalgesia and high levels of inflammatory pain mediators. Low expression of miR‑143‑3p negatively regulated the pain‑associated target genes, including Mrgpre, Ptgs2 and Tnf, thereby affecting chronic inflammatory pain and neuropathic pain in RA.

Protective Effects of Peucedanum japonicum Extract against Osteoarthritis in an Animal Model Using a Combined Systems Approach for Compound-Target Prediction

Peucedanum japonicum Thunberg is an herbal medicine used to treat neuralgia, rheumatoid arthritis, and inflammatory-related diseases. However, its effects on osteoarthritis (OA) and its regulatory mechanisms have not been investigated by network analysis. Here, we investigated the pharmacological effects of Peucedanum japonicum extract (PJE) on OA, by combining in vivo effective verification and network pharmacology prediction. Rats in which OA was induced by monosodium iodoacetate (MIA) were treated with PJE (200 mg/kg), and histopathological parameters, weight bearing distribution and inflammatory factors in serum and joint tissue were measured after 28 days of treatment. Additionally, in silico network analysis was used to predict holistic OA regulatory mechanisms of PJE. The results showed that PJE exerted potential protective effects by recovering hind paw weight bearing distribution, alleviating histopathological features of cartilage and inhibiting inflammatory mediator levels in the OA rat model. Furthermore, network analysis identified caspase-3 (CASP3), caspase-7 (CASP7), and cytochrome P450 2D6 (CYP2D6) as potential target genes; in addition, the TNF (Tumor necrosis factor) signaling pathway was linked to OA therapeutic action. Our combined animal OA model and network analysis confirmed the therapeutic effects of PJE against OA and identified intracellular signaling pathways, active compounds and target genes linked to its therapeutic action.

Preclinical renal chemo-protective potential of Prunus amygdalus Batsch seed coat via alteration of multiple molecular pathways

Prunus amygdalus Batsch (almond) is a classical nutritive traditional Indian medicine. Along with nutritive with anti-oxidant properties, it is, clinically, used in the treatment of various diseases with underlying anti-oxidant mechanism. This study is an effort to scrutinise the renal protective effect of P. amygdalus Batsch or green almond (GA) seed coat extract and its underlying mechanism in animal model of Ferric nitrilotriacetate (Fe-NTA) induced renal cell carcinoma (RCC). RCC was induced in Swiss Albino Wistar rats by intraperitoneal injection of Fe-NTA. The rats were then treated with ethanolic extract of GA (25, 50 and 100 mg/kg per oral) for 22 weeks. Efficacy of GA administration was evaluated by change in biochemical, renal, macroscopical and histopathological parameters and alterations. Additionally, interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and inflammatory mediator including prostaglandin E2 (PGE₂), nuclear factor-kappa B (NF-κB) were also observed to explore the possible mechanisms. The oral administration of GA significantly (p < .001) altered the Fe-NTA induced RCC in rats by inhibition of renal nodules, decolourisation of tissues, tumour promoter marker including thymidine ³[H] incorporation, ornithine decarboxylase, renal parameters and anti-oxidant parameters in serum. Additionally, GA treatment significantly (p < .001) down-regulated the IL-6, IL-1β, TNF-α, inflammatory mediators PGE₂ and NF-κB in a dose-dependent manner. Histopathology observation supported the renal protective effect of GA by alteration in necrosis, size of Bowman capsules and inflammatory cells. Hence, it can be concluded that GA possesses observable chemo-protective action and effect on Fe-NTA induced RCC via dual inhibition mechanism one by inhibiting free radical generation and second by inhibiting inflammation.

Dysfunctional phagocytosis capacity, granulocyte recruitment and inflammatory factor secretion of Kupffer cells in diabetes mellitus reversed by Lidocaine

PURPOSE

Kupffer cells (KCs) present dysfunctional immunity capacity among the diabetes mellitus patients. This study aims to investigate whether Lidocaine could reverse dysfunctions of KCs, in terms of phagocytosis, granulocyte recruitment and inflammatory mediator secretion.

METHODS

db/db and C57BL/6 mice were employed to establish diabetic and nondiabetic models. Upon intravenous injection of Lidocaine, KCs were isolated and cultured ex vivo. The functions of phagocytosis, recruiting granulocytes and inflammatory mediator secretion in KCs were compared between Lidocaine-treated and untreated (control) groups.

RESULTS

Comparing with nondiabetic mice, KCs in diabetic mice presented reduced phagocytosis, activated granulocyte recruitment, increased expression of intercellular cell adhesion molecule-1 (ICAM-1) and activated levels of inflammatory mediators. With Lidocaine injection, phagocytic functions of KCs in diabetic mice were improved significantly; in contrast, recruitment of granulocytes, expression of ICAM-1 and secretion of inflammatory mediators were reduced markedly. However, Lidocaine intervention did not alter KC functions in phagocytosis, granulocyte recruitment, ICAM-1 expression or inflammatory mediator secretion among nondiabetic mice.

CONCLUSION

Lidocaine reversed diabetes-related dysfunctions of KCs in terms of phagocytosis, granulocyte recruitment, ICAM-1 expression or inflammatory mediator secretion.

A multispecies approach for understanding neuroimmune mechanisms of stress

The relationship between stress challenges and adverse health outcomes, particularly for the development of affective disorders, is now well established. The highly conserved neuroimmune mechanisms through which responses to stressors are transcribed into effects on males and females have recently garnered much attention from researchers and clinicians alike. The use of animal models, from mice to guinea pigs to primates, has greatly increased our understanding of these mechanisms on the molecular, cellular, and behavioral levels, and research in humans has identified particular brain regions and connections of interest, as well as associations between stress-induced inflammation and psychiatric disorders. This review brings together findings from multiple species in order to better understand how the mechanisms of the neuroimmune response to stress contribute to stress-related psychopathologies, such as major depressive disorder, schizophrenia, and bipolar disorder.

Inflammatory mediators mediate airway smooth muscle contraction through a G protein-coupled receptor-transmembrane protein 16A-voltage-dependent Ca2+ channel axis and contribute to bronchial hyperresponsiveness in asthma

BACKGROUND

Allergic inflammation has long been implicated in asthmatic hyperresponsiveness of airway smooth muscle (ASM), but its underlying mechanism remains incompletely understood. Serving as G protein-coupled receptor agonists, several inflammatory mediators can induce membrane depolarization, contract ASM, and augment cholinergic contractile response. We hypothesized that the signal cascade integrating on membrane depolarization by the mediators might involve asthmatic hyperresponsiveness.

OBJECTIVE

We sought to investigate the signaling transduction of inflammatory mediators in ASM contraction and assess its contribution in the genesis of hyperresponsiveness.

METHODS

We assessed the capacity of inflammatory mediators to induce depolarization currents by electrophysiological analysis. We analyzed the phenotypes of transmembrane protein 16A (TMEM16A) knockout mice, applied pharmacological reagents, and measured the Ca²⁺ signal during ASM contraction. To study the role of the depolarization signaling in asthmatic hyperresponsiveness, we measured the synergistic contraction by methacholine and inflammatory mediators both ex vivo and in an ovalbumin-induced mouse model.

RESULTS

Inflammatory mediators, such as 5-hydroxytryptamin, histamine, U46619, and leukotriene D₄, are capable of inducing Ca²⁺-activated Cl^- currents in ASM cells, and these currents are mediated by TMEM16A. A combination of multiple analysis revealed that a G protein-coupled receptor-TMEM16A-voltage-dependent Ca²⁺ channel signaling axis was required for ASM contraction induced by inflammatory mediators. Block of TMEM16A activity may significantly inhibit the synergistic contraction of acetylcholine and the mediators and hence reduces hypersensitivity.

CONCLUSIONS

A G protein-coupled receptor-TMEM16A-voltage-dependent Ca²⁺ channel axis contributes to inflammatory mediator-induced ASM contraction and synergistically activated TMEM16A by allergic inflammatory mediators with cholinergic stimuli.

Do Genetic Markers of Inflammation Modify the Relationship between Periodontitis and Nonalcoholic Fatty Liver Disease? Findings from the SHIP Study

An association between periodontitis and nonalcoholic fatty liver disease (NAFLD) has been reported by experimental animal and epidemiologic studies. This study investigated whether circulating levels of serum C-reactive protein (CRP) and a weighted genetic CRP score representing markers of inflammatory burden modify the association between periodontitis and NAFLD. Data came from 2,481 participants of the Study of Health in Pomerania who attended baseline examination that occurred between 1997 and 2001. Periodontitis was defined as the percentage of sites (0%, <30%, ≥30%) with probing pocket depth (PD) ≥4 mm, and NAFLD status was determined using liver ultrasound assessment. Serum CRP levels were assayed at a central laboratory, and single-nucleotide polymorphisms previously identified through genome-wide association studies as robustly associated with serum CRP were combined into a weighted genetic CRP score (wGS_CRP). Logistic regression models estimated the association between periodontitis and NAFLD within strata of serum CRP and separately within strata of the wGS_CRP. The prevalence of NAFLD was 26.4% (95% confidence interval [CI], 24.6, 28.1) while 17.8% (95% CI, 16.0-19.6) had ≥30% of sites with PD ≥4 mm. Whereas the wGS_CRP was not a modifier ( P_interaction = 0.8) on the multiplicative scale, serum CRP modified the relationship between periodontitis and NAFLD ( P_interaction = 0.01). The covariate-adjusted prevalence odds ratio of NAFLD comparing participants with ≥30% of sites with PD ≥4 mm to those with no site affected was 2.39 (95% CI, 1.32-4.31) among participants with serum CRP <1 mg/L. The corresponding estimate was 0.97 (95% CI, 0.57-1.66) for participants with serum CRP levels of 1 to 3 mg/L and 1.12 (95% CI, 0.65-1.93) for participants with serum CRP >3 mg/L. Periodontitis was positively associated with higher prevalence odds of NAFLD, and this relationship was modified by serum CRP levels.

Maternal obesity and inflammatory mediators: A controversial association

The link between maternal obesity and inflammatory mediators is still unclear. Our aim was to summarize the main findings of recently published studies on this topic. We performed a search in Medline for studies published in the last years on obesity, human pregnancy, and inflammatory mediators. We report the findings of 30 studies. The characteristics and number of participants, study design, gestational age at sample collection, and type of sample varied widely. Approximately two-thirds of them investigated more than one mediator, and 50% included participants in only one trimester of pregnancy. The most frequently investigated mediators were leptin, tumour necrosis factor-alpha (TNF-α), and interleukin (IL)-6. Almost all studies reported an association between maternal obesity, leptin, and C-reactive protein (CRP) serum levels but not with IL-1β and IL-10. The association of IL-6, TNF-α, monocyte chemo-attractant protein-1 (MCP-1), adiponectin, and resistin with maternal obesity is still controversial. To clarify the physiopathological link between maternal obesity and inflammation, more high-quality studies are needed.

A multispecies approach for understanding neuroimmune mechanisms of stress

The relationship between stress challenges and adverse health outcomes, particularly for the development of affective disorders, is now well established. The highly conserved neuroimmune mechanisms through which responses to stressors are transcribed into effects on males and females have recently garnered much attention from researchers and clinicians alike. The use of animal models, from mice to guinea pigs to primates, has greatly increased our understanding of these mechanisms on the molecular, cellular, and behavioral levels, and research in humans has identified particular brain regions and connections of interest, as well as associations between stress-induced inflammation and psychiatric disorders. This review brings together findings from multiple species in order to better understand how the mechanisms of the neuroimmune response to stress contribute to stress-related psychopathologies, such as major depressive disorder, schizophrenia, and bipolar disorder.

Critical role of calpain in inflammation

Calpains are a family of cysteine proteases, implicated in a wide range of cellular calcium-regulated functions. Evidence from previous studies using an inhibitor of calpain indicates that calpain activation is involved in the process of numerous inflammation-associated diseases. As a result of in-depth studies, calpains have been proposed to influence the process of inflammation via a variety of mechanisms. The aim of the present study is to provide an overview of recent reports regarding the role of calpain in the process of inflammation, including regulation of immune cell migration, modulation of the activation of inflammatory mediators, degradation of certain associated proteins and induction of cell apoptosis. Understanding these mechanisms may contribute to the investigation of novel therapeutic targets for inflammation-associated diseases.

Tong Luo Jiu Nao, a Chinese Medicine Formula, Reduces Inflammatory Stress in a Mouse Model of Alzheimer's Disease

AIM

The aim of this study is to extend the molecular mechanism of Tong Luo Jiu Nao (TLJN) for Alzheimer's disease (AD), which is a modern Chinese formula that has been used to treat AD.

METHODS

The senescence-accelerated mouse prone 8 strain (SAMP8) is one of the most appropriate models to study the mechanism that underlies AD. The levels of plasma amyloid β (Aβ) and the Aβ deposits were measured using enzyme-linked immunosorbent assay and immunohistochemistry. Immunoblotting was used to observe the effect of TLJN on inflammatory mediator expression in an senescence-accelerated mouse model of AD.

RESULTS

Our data showed that the TLJN-treated groups exhibited a reduction in plasma Aβ levels and reduced Aβ expression. Moreover, TLJN effectively attenuated Aβ-induced activation of extracellular signal-regulated kinase and c-Jun N-terminal kinases and blocked changes in inflammatory mediator expression.

CONCLUSION

These data suggest that TLJN might have protective effects and could potentially act to attenuate inflammatory stress in the pathogenesis of AD.

Inhaled lead affects lung pathology and inflammation in sensitized and control guinea pigs

The association between lead exposure and respiratory diseases including asthma is controversial. Some studies indicate that exposure to environmental lead pollution may cause asthma; however, there is not sufficient data in this regard. The effect of lead on lung pathological findings and serum inflammatory mediators in sensitized and non-sensitized guinea pigs exposed to inhaled lead was examined. Eleven animal groups including control, sensitized, three groups of non sensitized animals, three groups during sensitization, and three groups after sensitization exposed to aerosol of three lead concentrations (n = 6 for each group) were studied. Serum inflammatory mediators levels and lung pathological changes were evaluated. All pathological changes and serum ET-1, EPO, NO levels were significantly higher in the sensitized and non sensitized animals exposed to lead than control group (p < 0.05 to p < 0.001). There was no significant difference between non sensitized groups exposed to high lead concentration and sensitized group. Serum inflammatory mediators levels and pathological findings in sensitized groups exposed to lead both during and after sensitization were significantly higher than sensitized non exposed group (p < 0.05 to p < 0.001). The data of exposed animals to high lead concentration were significantly higher than those of medium and low concentrations; those of medium concentration were also higher than low concentration (p < 0.05 to p < 0.001). In summary, the present study indicates that exposure to inhaled lead is able to induce respiratory changes similar to asthma. In addition, the results indicated that exposure to environmental lead is able to aggravate asthma severity both during development of asthma or after its manifestation.

Gingival crevicular fluid interleukin-8 and lipoxin A4 levels of smokers and nonsmokers with different periodontal status: a cross-sectional study

BACKGROUND AND OBJECTIVE

Smoking is an important risk factor for periodontal disease and effects the pathogenesis of the disease. This study evaluated the impact of smoking on gingival crevicular fluid interleukin-8 (IL-8) and lipoxin A4 (LxA4 ) levels in patients with and without periodontal disease.

MATERIAL AND METHODS

A total of 122 participants were grouped as follows: smokers with generalized aggressive periodontitis (S-GAgP, n = 15); smokers with chronic periodontitis (S-CP, n = 17); smokers with gingivitis (SG, n = 15); smokers classified as periodontally healthy (SH, n = 15); nonsmokers with generalized aggressive periodontitis (N-GAgP, n = 15); nonsmokers with chronic periodontitis (N-CP, n = 15); nonsmokers with gingivitis (NG, n = 15); and nonsmokers classified as periodontally healthy (NH, n = 15). Gingival index, plaque index, probing pocket depth and clinical attachment level were recorded. Gingival crevicular fluid IL-8 and LxA4 levels were analyzed by ELISA.

RESULTS

Gingival crevicular fluid IL-8 levels varied among groups, as follows: S-GAgP>S-CP>SG>SH and N-GAgP>N-CP>NG>NH. The gingival crevicular fluid IL-8 levels were significantly higher in the S-GAgP group compared with the N-GAgP group and in the S-CP group compared with the N-CP group (p < 0.05); differences between the SG and NG and the SH and NH groups were not statistically significant (p > 0.05). Gingival crevicular fluid LxA4 levels also varied among groups, but in an inverse direction when compared with the IL-8 levels, as follows: S-GAgP<S-CP<SG and N-GAgP<N-CP<NG. (The gingival crevicular fluid LxA4 levels in SH and NH groups were below the limits of detection.) The gingival crevicular fluid LxA4 levels were significantly lower in the S-GAgP group than in the N-GAgP group and in the S-CP group than in the N-CP group (p < 0.05); differences between the SG and NG groups were not statistically significant (p > 0.05).

CONCLUSION

The study findings suggest that the observed increases in gingival crevicular fluid IL-8 levels and decreases in gingival crevicular fluid LxA4 levels reflect changes in immune and inflammatory responses that occur as a result of smoking.

Glutamine Administration After Sublethal Lower Limb Ischemia Reduces Inflammatory Reaction and Offers Organ Protection in Ischemia/Reperfusion Injury

BACKGROUND

This study investigated the effects of intravenous glutamine (GLN) administration on the expression of adhesion molecules and inflammatory mediators in a mice model of hind limb ischemia/reperfusion (IR) injury.

METHODS

There were 3 IR groups and 1 normal control (NC) group. The NC group did not undergo the IR procedure. Mice in the IR groups underwent 90 minutes of limb ischemia followed by a variable period of reperfusion. Ischemia was performed by applying a 4.5-oz orthodontic rubber band to the left thigh. Mice in one IR group were sacrificed immediately after reperfusion. The other 2 IR groups were injected once with either 0.75 g GLN/kg body weight (G group) or an equal volume of saline (S group) via tail vein before reperfusion. Mice in the S and G groups were subdivided and sacrificed at 4 or 24 hours after reperfusion.

RESULTS

IR enhanced the inflammatory cytokine gene expressions in muscle. Also, plasma interleukin (IL)-6 levels, blood neutrophil percentage, and the adhesion molecule and chemokine receptors expressed by leukocytes were upregulated after reperfusion. The IR-induced muscle inflammatory mediator gene expressions, blood macrophage percentage, and plasma IL-6 concentration had declined at an early or a late phase of reperfusion when GLN was administered. Histologic findings also found that remote lung injury was attenuated during IR insult.

CONCLUSIONS

A single dose of GLN administration immediately after sublethal lower limb ischemia reduces the inflammatory reaction locally and systemically; this may offer local and distant organ protection in hind limb IR injury.

Fingolimod alters inflammatory mediators and vascular permeability in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) leads to high rates of death and disability. The pronounced inflammatory reactions that rapidly follow ICH contribute to disease progression. Our recent clinical trial demonstrated that oral administration of an immune modulator fingolimod restrained secondary injury derived from initial hematoma, but the mechanisms remain unknown. In this study, we aim to investigate the effects of fingolimod on inflammatory mediators and vascular permeability in the clinical trial of oral fingolimod for intracerebral hemorrhage (ICH). The results showed that fingolimod decreased the numbers of circulating CD4(+) T, CD8(+) T, CD19(+) B, NK, and NKT cells and they recovered quickly after the drug was stopped. The plasma ICAM level was decreased and IL-10 was increased by fingolimod. Interestingly, fingolimod protected vascular permeability as indicated by a decreased plasma level of MMP9 and the reduced rT1%. In conclusion, modulation of systemic inflammation by fingolimod demonstrates that it is an effective therapeutic agent for ICH. Fingolimod may prevent perihematomal edema enlargement by protecting vascular permeability.