Vitamin D reduces inflammatory response in asthmatic mice through HMGB1/TLR4/NF‑κB signaling pathway

High mobility group box-1: a potential therapeutic target for allergic rhinitis

Allergic rhinitis (AR) is a prevalent chronic inflammatory disease of the nasal mucosa primarily characterized by symptoms, such as nasal itching, sneezing, runny nose, and nasal congestion. It has a high recurrence rate and low cure rate, with a lack of effective drugs for treatment. The current approach to management focuses on symptom control. High mobility group box-1 (HMGB1) is a highly conserved non-histone protein widely present in the nucleus of eukaryotes. It is recognized as a proinflammatory agent, and recent studies have demonstrated its close association with AR. Here, we will elaborate the role and mechanism of HMGB1 in AR, so as to reveal the potential value of HMGB1 in the occurrence and development of AR, and provide a new target for clinical research on the treatment of AR.

Vitamin D3 preserves blood retinal barrier integrity in an in vitro model of diabetic retinopathy

The impairment of the blood retinal barrier (BRB) represents one of the main features of diabetic retinopathy, a secondary microvascular complication of diabetes. Hyperglycemia is a triggering factor of vascular cells damage in diabetic retinopathy. The aim of this study was to assess the effects of vitamin D₃ on BRB protection, and to investigate its regulatory role on inflammatory pathways. We challenged human retinal endothelial cells with high glucose (HG) levels. We found that vitamin D₃ attenuates cell damage elicited by HG, maintaining cell viability and reducing the expression of inflammatory cytokines such as IL-1β and ICAM-1. Furthermore, we showed that vitamin D₃ preserved the BRB integrity as demonstrated by trans-endothelial electrical resistance, permeability assay, and cell junction morphology and quantification (ZO-1 and VE-cadherin). In conclusion this in vitro study provided new insights on the retinal protective role of vitamin D₃, particularly as regard as the early phase of diabetic retinopathy, characterized by BRB breakdown and inflammation.

High Mobility Group Box 1: Biological Functions and Relevance in Oxidative Stress Related Chronic Diseases

In the early 1970s, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and named high-mobility group (HMG) proteins. High-mobility group box 1 (HMGB1) is the most studied HMG protein that detects and coordinates cellular stress response. The biological function of HMGB1 depends on its subcellular localization and expression. It plays a critical role in the nucleus and cytoplasm as DNA chaperone, chromosome gatekeeper, autophagy maintainer, and protector from apoptotic cell death. HMGB1 also functions as an extracellular alarmin acting as a damage-associated molecular pattern molecule (DAMP). Recent findings describe HMGB1 as a sophisticated signal of danger, with a pleiotropic function, which is useful as a clinical biomarker for several disorders. HMGB1 has emerged as a mediator in acute and chronic inflammation. Furthermore, HMGB1 targeting can induce beneficial effects on oxidative stress related diseases. This review focus on HMGB1 redox status, localization, mechanisms of release, binding with receptors, and its activities in different oxidative stress-related chronic diseases. Since a growing number of reports show the key role of HMGB1 in socially relevant pathological conditions, to our knowledge, for the first time, here we analyze the scientific literature, evaluating the number of publications focusing on HMGB1 in humans and animal models, per year, from 2006 to 2021 and the number of records published, yearly, per disease and category (studies on humans and animal models).

Cytokine-Induced JAK2-STAT3 Activates Tissue Regeneration under Systemic or Local Inflammation

We investigated the immune response mechanisms under systemic and local inflammation using mouse models whereby lipopolysaccharide (LPS) was administered intraperitoneally to induce systemic inflammation, and epicutaneous sensitization with ovalbumin was used to induce local inflammation. LPS increased the immune cell infiltration in the cardiac muscle near the aorta, alveoli, hepatic sinusoid, renal interstitium, and the submucosal layer of the duodenum. Similarly, ovalbumin increased the abundance of macrophages in the skin. Both LPS and ovalbumin induced NF-κB p65 and IκBα phosphorylation, as well as the expression of NF-κB target genes (TLR4, IL6, and TNFα). Additionally, both LPS and ovalbumin led to an increase in the absolute IL-1β, IL-6, and TNFα serum levels and cytokine-related janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) phosphorylation. Moreover, the activated JAK2/STAT3 signaling increased the number of Ki67-positive cells (proliferating cells) and development pathway target gene expression (regeneration) in the inflammation models. In conclusion, LPS and ovalbumin increase immune cell infiltration in tissues, NF-κB activation, cytokine levels in serum, cytokine-stimulated JAK2/STAT3 signaling, and tissue regeneration.

Therapeutic effect of acute and chronic use of different doses of vitamin D3 on seizure responses and cognitive impairments induced by pentylenetetrazole in immature male rats

Objective(s):

This study aimed to evaluate the effects of acute and chronic intake of different doses of vitamin D3 on seizure responses and cognitive impairment induced by pentylenetetrazole (PTZ) in immature male rats.

Materials and Methods:

Sixty-six immature male NMRI rats were divided into control (10), epileptic (10), and treatment groups (46). The stage 5 latency (S5L) and stage 5 duration (S5D) were assessed along with the shuttle box test. Levels of antioxidant enzymes and inflammatory factors along with genes involved in inflammation, oxidative damage, apoptosis, and mTORc1 were measured in the hippocampus tissue of the brain of controlled and treated rats. Serum levels of parathyroid hormone (PTH), vitamin D, calcium, and phosphorus were also assessed.

Results:

The results showed that the ability to learn, memory consolidation, and memory retention in epileptic rats were reduced. In addition, S5D increased and S5L decreased in epileptic rats, while being effectively ameliorated by chronic and acute vitamin D intake. The results showed that vitamin D in different doses acutely and chronically decreased the levels of oxidative and inflammatory biomarkers in hippocampus tissue and inhibited the expression of genes involved in inflammation, oxidative damage, apoptosis, and mTORc1 in the hippocampus tissue of epileptic rats.

Conclusion:

The results showed that vitamin D in different doses acutely and chronically could improve cognitive impairments and convulsive responses in epileptic rats by improving neurotransmission, inflammation, apoptosis, and oxidative damage.

Effect of Vitamin D Deficiency and Supplementation in Lactation and Early Life on Allergic Airway Inflammation and the Expression of Autophagy-Related Genes in an Ovalbumin Mouse Model

Background and Objective

Vitamin D is involved in various physiological and pathological processes, including inflammation and autophagy. We aimed to investigate the effects of dietary vitamin D deficiency or supplementation initiated in lactation and early life on inflammation and autophagy in an ovalbumin (OVA) mouse model.

Methods

Female BALB/c were fed with vitamin D-deficient, sufficient or supplemented diets throughout lactation and their offspring followed the same diet after weaning. Offspring were then sensitized and challenged with OVA, airway resistance (R_L) was measured, and their serum, bronchoalveolar lavage fluid (BALF), and lung tissue were collected. Alveolar macrophages (AMs) were isolated from lung tissue and cultured with different concentrations of 1,25(OH)₂D₃. The expressions of autophagy-related (ATG) proteins including light-chain 3 (LC3), Beclin-1, and ATG5, and NF-κB p65 in lung tissue and AMs were measured.

Results

OVA sensitization and challenge induced dramatic allergic airway inflammation and higher R_L in the vitamin D-deficient group compared with vitamin D-sufficient or the supplemented group. The expression of ATGs including LC3, Beclin-1, and ATG5, and NF-κB p65 in lung tissue in the vitamin D-deficient OVA-mediated group was increased compared with vitamin D-supplemented OVA-mediated group. There was correlation between the expression of LC3 mRNA and inflammatory cell numbers and cytokines in BALF. In vitro, 1,25(OH)₂D₃ also regulated the expression of LC3, Beclin-1, ATG5, and NF-κB p65 mRNA in AMs in a time- and dose-dependent manner.

Conclusion

Deficiency of vitamin D in early life may aggravate allergic airway inflammation, and maintaining sufficient vitamin D during early life is necessary for lung health. Vitamin D may modulate autophagy in lungs of OVA sensitized/challenged mice, thus playing a protective role in OVA-induced allergic airway inflammation.

The Effect and Regulatory Mechanism of High Mobility Group Box-1 Protein on Immune Cells in Inflammatory Diseases

High mobility group box-1 protein (HMGB1), a member of the high mobility group protein superfamily, is an abundant and ubiquitously expressed nuclear protein. Intracellular HMGB1 is released by immune and necrotic cells and secreted HMGB1 activates a range of immune cells, contributing to the excessive release of inflammatory cytokines and promoting processes such as cell migration and adhesion. Moreover, HMGB1 is a typical damage-associated molecular pattern molecule that participates in various inflammatory and immune responses. In these ways, it plays a critical role in the pathophysiology of inflammatory diseases. Herein, we review the effects of HMGB1 on various immune cell types and describe the molecular mechanisms by which it contributes to the development of inflammatory disorders. Finally, we address the therapeutic potential of targeting HMGB1.

Effects of compound probiotics and aflatoxin-degradation enzyme on alleviating aflatoxin-induced cytotoxicity in chicken embryo primary intestinal epithelium, liver and kidney cells

Aflatoxin B₁ (AFB₁) is one of the most dangerous mycotoxins for humans and animals. This study aimed to investigate the effects of compound probiotics (CP), CP supernatant (CPS), AFB₁-degradation enzyme (ADE) on chicken embryo primary intestinal epithelium, liver and kidney cell viabilities, and to determine the functions of CP + ADE (CPADE) or CPS + ADE (CPSADE) for alleviating cytotoxicity induced by AFB₁. The results showed that AFB₁ decreased cell viabilities in dose-dependent and time-dependent manners. The optimal AFB₁ concentrations and reactive time for establishing cell damage models were 200 µg/L AFB₁ and 12 h for intestinal epithelium cells, 40 µg/L and 12 h for liver and kidney cells. Cell viabilities reached 231.58% (p < 0.05) for intestinal epithelium cells with CP addition, 105.29% and 115.84% (p < 0.05) for kidney and liver cells with CPS additions. The further results showed that intestinal epithelium, liver and kidney cell viabilities were significantly decreased to 87.12%, 88.7% and 84.19% (p < 0.05) when the cells were exposed to AFB₁; however, they were increased to 93.49% by CPADE addition, 102.33% and 94.71% by CPSADE additions (p < 0.05). The relative mRNA abundances of IL-6, IL-8, TNF-α, iNOS, NF-κB, NOD1 (except liver cell) and TLR2 in three kinds of primary cells were significantly down-regulated by CPADE or CPSADE addition, compared with single AFB₁ group (p < 0.05), indicating that CPADE or CPSADE addition could alleviate cell cytotoxicity and inflammation induced by AFB₁ exposure through suppressing the activations of NF-κB, iNOS, NOD1 and TLR2 pathways.

Serum vitamin D receptor and High Mobility Group Box-1 (HMGB1) levels in HIV-infected patients with different immunodeficiency status: A cross-sectional study

BACKGROUND

HIV-AIDS patients typically have hypovitaminosis D. Vitamin D is a key mediator in inflammatory and infectious diseases, which VDR mediates its biological effect. High-mobility group box 1 protein (HMGB1) modulates HIV-1 replication in vitro. Vitamin D played a role in inhibiting HMGB1 secretion in the animal study.

OBJECTIVES

This study aimed to examine differences and correlation of vitamin D receptor and HMGB1 protein levels in HIV patients with mild and severe immunodeficiency and healthy control participants.

METHODS

This study using a cross-sectional design conducted at Volunteer Counseling and Testing (VCT) Clinic in Mataram, West Nusa Tenggara, Indonesia, from January to June 2020. Three groups of study participants were classified as HIV patients with severe immune deficiency (SID), HIV patients with mild immune deficiency (MID), and healthy controls (HC).

RESULTS

Mean level of vitamin D receptor in SID HIV group was 25.89 ± 3.95 ng/ml, lower than those in MID-HIV group; 33.72 ± 1.69 ng/ml and in HC group; 50.65 ± 3.64 ng/ml. Mean levels of HMGB1 protein in the SID HIV group were 3119.81 ± 292.38 pg/ml higher than those in the MID HIV group 1553.55 ± 231.08 pg/ml and HC 680.82 ± 365.51 pg/ml. There was a significant and strong negative correlation (r = -0.932) between vitamin D receptor and HMGB1 levels (p < 0.01).

CONCLUSIONS

Strong negative correlation between VDR and HMGB1 in different immunodeficiency statuses suggesting an important role of vitamin D in inflammation control in HIV infection. However, it needs to be confirmed in a further prospective study.

Loxoprofen Sodium Alleviates Oxidative Stress and Apoptosis Induced by Angiotensin II in Human Umbilical Vein Endothelial Cells (HUVECs)

Background and Purpose

Endothelium exerts an important role in releasing vasoactive substances, maintaining the blood flow, regulating the growth of vessels, moderating the process of coagulation, and the balance of fibrinolytic system, the dysfunction of which is reported to result in arterial stiffness. The present study aimed to investigate the effects of loxoprofen sodium against HUVECs injury induced by angiotensin II.

Methods

The injury model on HUVECs was established through incubation with angiotensin II. The expression levels of AT2R, NOX-4, Bax, Bcl-2, and caspase-3 were evaluated using qRT-PCR and Western Blot. DCFH-DA assay was used to detect the production of ROS and ELISA assay was used to evaluate the level of reduced glutathione. Mitochondrial membrane potential (MMP) was measured using dihydrorhodamine 123 assay. MTT and LDH assays were utilized to determine the proliferation ability of HUVECs. The apoptosis rate of HUVECs was evaluated using flow cytometry.

Results

Loxoprofen sodium suppressed endothelial AT2R elevation by angiotensin II. Loxoprofen ameliorated Angiotensin II–induced production of ROS, reduced GSH, and NOX-2 and NOX-4 expression. Furthermore, Loxoprofen mitigated Angiotensin II, reduced mitochondrial membrane potential and improved cell viability, and suppressed LDH release by angiotensin II. Importantly, loxoprofen showed a beneficial role in protecting endothelial apoptosis by mitigating apoptotic machinery including the balanced expression of Bax, Bcl-2, and caspase-3 cleavage.

Conclusion

Loxoprofen sodium might alleviate the high ROS levels and apoptosis induced by angiotensin II in HUVECs.

The performance of the alarmin HMGB1 in pediatric diseases: From lab to clinic

INTRODUCTION

The ubiquitously expressed nonhistone nuclear protein high-mobility group box protein 1 (HMGB1) has different functions related to posttranslational modifications and cellular localization. In the nucleus, HMGB1 modulates gene transcription, replication and DNA repair as well as determines chromosomal architecture. When the post-transcriptional modified HMGB1 is released into the extracellular space, it triggers several physiological and pathological responses and initiates innate immunity through interacting with its reciprocal receptors (i.e., TLR4/2 and RAGE). The effect of HMGB1-mediated inflammatory activation on different systems has received increasing attention. HMGB1 is now considered to be an alarmin and participates in multiple inflammation-related diseases. In addition, HMGB1 also affects the occurrence and progression of tumors. However, most studies involving HMGB1 have been focused on adults or mature animals. Due to differences in disease characteristics between children and adults, it is necessary to clarify the role of HMGB1 in pediatric diseases.

METHODS AND RESULTS

Through systematic database retrieval, this review aimed to first elaborate the characteristics of HMGB1 under physiological and pathological conditions and then discuss the clinical significance of HMGB1 in the pediatric diseases according to different systems.

CONCLUSIONS

HMGB1 plays an important role in a variety of pediatric diseases and may be used as a diagnostic biomarker and therapeutic target for new strategies for the prevention and treatment of pediatric diseases.

Vitamin D high doses supplementation could represent a promising alternative to prevent or treat COVID-19 infection

Although we lack enough evidence to justify supplementing with vitaminD in the prevention and treatment of COVID-19 infection, it is increasingly feasible that this hypothesis is valid. Two general underlying mechanisms should be considered. One would be the anti-infectious and immunomodulatory action that it exerts by improving intercellular barriers by stimulating innate immunity, as well as by modulating adaptive immunity. Also, vitaminD reduces the production of inflammatory cytokines, such as IL-2 and interferon-gamma (INF-γ). More recently, multiple pleiotropic effects have been demonstrated on the actions of vitaminD at the anti-inflammatory and immunomodulatory level with positive results in studies with influenza, coronavirus, and other respiratory infections. An inverse relationship between serum vitaminD levels and the prevalence of the respiratory infectious disease has been described. Of interest, another mechanistic approach responds to considering the inhibition of the renin-angiotensin-aldosterone system (RAAS), which is exacerbated in COVID-19 infection because the virus binds to the enzyme ACE2, making more angiotensinII available to cause damage. VitaminD inhibits mediators of RAAS - present in all cells of the body - and by inhibiting ACE activity and increasing ACE2, it lowers angiotensinII levels. We present studies with proposals for recommended doses of vitaminD, and although a single guideline is not specified, the possible benefits are promising. Finally, the purpose of this review is to share this idea with health professionals to ignite the debate and call for critical reflection, so that it can contribute to the undertaking of more and better clinical designs to validate the benefits of using high doses of vitaminD for the benefit of public health and especially in times of crisis for COVID-19.

Vitamin D supplementation as a rational pharmacological approach in the COVID-19 pandemic

The COVID-19 pandemic has reached most of the countries worldwide causing death, which often results from an inflammatory storm associated with severe acute respiratory syndrome (SARS). This has prompted researchers to seek specific novel and definitive treatments urgently. In this context, it is interesting to evaluate the preventive and therapeutic effects of existing pharmacological agents that could be useful. In this regard, vitamin D supplementation, particularly in individuals likely to be deficient, may be a promising option. Vitamin D is a hormone that modulates many of the same inflammatory and oxidative signaling pathways triggered during COVID-19. For example, vitamin D suppresses the actions of the renin-angiotensin system, which has a determining role in the pathophysiology of the inflammatory response related to COVID-19. This paper analyzes the evidence that vitamin D supplementation might be a valuable preventive/therapeutic measure in groups at risk for or infected with COVID-19. It also discusses how clinical studies could be best designed to evaluate the possible advantages of vitamin D supplementation for the benefit of public health during the pandemic.

Roflumilast prevents lymphotoxin α (TNF-β)-induced inflammation activation and degradation of type 2 collagen in chondrocytes

BACKGROUND AND PURPOSE

Osteoarthritis (OA) is a chronic disease accompanied by severe inflammation. The inflammation activation in the chondrocytes and the degradation of the extracellular matrix were reported to be involved in the progress of OA. Roflumilast is a selective PDE4 inhibitor used for treating chronic obstructive pulmonary disease (COPD) and exerts significant anti-inflammation effects. The present study aims to investigate the effects of Roflumilast on tumor necrosis factor-β (TNF-β)-induced inflammation activation and degradation of type 2 collagen in chondrocytes.

METHODS

TNF-β was used to establish the in-vitro inflammation model on ATDC5 chondrocytes. Quantitative real-time polymerase chain reaction (QRT-PCR) and western blot were used to determine the expression level of tumor necrosis factor receptor 2 (TNFR2), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), matrix metalloproteinase 3 (MMP-3), matrix metalloproteinase 13 (MMP-13), type 2 collagen and nuclear factor kappa B (NF-κB) p65. The release of prostaglandin E2 (PGE₂), MMP-3, and MMP-13 were evaluated by ELISA. The production of NO was determined by DAF-FM DA staining and the function of the NF-κB promoter was evaluated by Luciferase activity assay.

RESULTS

TNFR2 and COX-2 were upregulated and the release of PGE₂ was promoted by TNF-β stimulation, which were all inhibited by Roflumilast. Roflumilast suppressed the promoted iNOS expression and NO production induced by TNF-β. MMP-3 and MMP-13 were up-regulated, and type 2 collagen was down-regulated by TNF-β stimulation, which were all reversed by Roflumilast. Roflumilast inhibited the promoted releasing of Interleukin-8 (IL-8) and Interleukin-12 (IL-12), expression of up-regulated NF-κB, and activation of NF-κB transcriptional activity induced by TNF-β.

CONCLUSION

Roflumilast may prevent TNF-β-induced inflammation activation and degradation of type 2 collagen in chondrocytes.

Vitamin D attenuates HMGB1-mediated neointimal hyperplasia after percutaneous coronary intervention in swine

Intracoronary stenting is a common procedure in patients with coronary artery disease (CAD). Stent deployment stretches and denudes the endothelial layer, promoting a local inflammatory response, resulting in neointimal hyperplasia. Vitamin D deficiency associates with CAD. In this study, we examined the association of vitamin D status with high mobility group box 1 (HMGB1)-mediated pathways (HMGB1, receptor for advanced glycation end products [RAGE], and Toll-like receptor-2 and -4 [TLR2 and TLR4]) in neointimal hyperplasia in atherosclerotic swine following bare metal stenting. Yucatan microswine fed with a high-cholesterol diet were stratified to receive vitamin D-deficient (VD-DEF), vitamin D-sufficient (VD-SUF), and vitamin D-supplemented (VD-SUP) diet. After 6 months, PTCA (percutaneous transluminal balloon angioplasty) followed by bare metal stent implantation was performed in the left anterior descending (LAD) artery of each swine. Four months following coronary intervention, angiogram and optical coherence tomography (OCT) were performed and swine euthanized. Histology and immunohistochemistry were performed in excised LAD to evaluate the expression of HMGB1, RAGE, TLR2, and TLR4. OCT analysis revealed the greatest in-stent restenosis area in the LAD of VD-DEF compared to VD-SUF or VD-SUP swine. The protein expression of HMGB1, RAGE, TLR2, and TLR4 was significantly higher in the LAD of VD-DEF compared to VD-SUF or VD-SUP swine. Vitamin D deficiency was associated with both increased in-stent restenosis and increased HMGB1-mediated inflammation noted in coronary arteries following intravascular stenting. Inversely, vitamin D supplementation was associated with both a decrease in this inflammatory profile and in neointimal hyperplasia, warranting further investigation for vitamin D as a potential adjunct therapy following coronary intervention.

An overview of high-mobility group box 1, a potent pro-inflammatory cytokine in asthma

High-mobility group box 1 (HMGB1), also called amphoterin, HMG1 and p30, is a highly conserved protein between different species that has various functions in nucleus such as stabilization of nucleosome formation, facilitation of deoxyribonucleic acid (DNA) bending and increasing the DNA transcription, replication and repair. It has also been indicated that HMGB1 acts as a potent pro-inflammatory cytokine with increasing concentrations in acute and chronic inflammatory diseases. Asthma is a common chronic respiratory disease associated with high morbidity and mortality rates. One central characteristic in its pathogenesis is airway inflammation. Considering the inflammatory role of HMGB1 and importance of inflammation in asthma pathogenesis, a better understanding of this protein is vital. This review describes the structure, cell surface receptors, signaling pathways and intracellular and extracellular functions of HMGB1, but also focuses on its inflammatory role in asthma. Moreover, this manuscript reviews experimental and clinical studies that investigated the pathologic role of HMGB1.

Lungs as target of COVID-19 infection: Protective common molecular mechanisms of vitamin D and melatonin as a new potential synergistic treatment

COVID-19 pandemic has a high mortality rate and is affecting practically the entire world population. The leading cause of death is severe acute respiratory syndrome as a consequence of exacerbated inflammatory response accompanied by uncontrolled oxidative stress as well as the inflammatory reaction at the lung level. Until now, there is not a specific and definitive treatment for this pathology that worries the world population, especially the older adults who constitute the main risk group. In this context, it results in a particular interest in the evaluation of the efficacy of existing pharmacological agents that may be used for overcoming or attenuating the severity of this pulmonary complication that has ended the lives of many people worldwide. Vitamin D and melatonin could be good options for achieving this aim, taking into account that they have many shared underlying mechanisms that are able to modulate and control the immune adequately and oxidative response against COVID-19 infection, possibly even through a synergistic interaction. The renin-angiotensin system exaltation with consequent inflammatory response has a leading role in the physiopathology of COVID-19 infection; and it may be down-regulated by vitamin D and melatonin in many organs. Therefore, it is also essential to analyze this potential therapeutic association and their relation with RAS as part of this new approach.

The Role of HMGB1, a Nuclear Damage-Associated Molecular Pattern Molecule, in the Pathogenesis of Lung Diseases

Significance: High-mobility group protein box 1 (HMGB1), a ubiquitous nuclear protein, regulates chromatin structure and modulates the expression of many genes involved in the pathogenesis of lung cancer and many other lung diseases, including those that regulate cell cycle control, cell death, and DNA replication and repair. Extracellular HMGB1, whether passively released or actively secreted, is a danger signal that elicits proinflammatory responses, impairs macrophage phagocytosis and efferocytosis, and alters vascular remodeling. This can result in excessive pulmonary inflammation and compromised host defense against lung infections, causing a deleterious feedback cycle. Recent Advances: HMGB1 has been identified as a biomarker and mediator of the pathogenesis of numerous lung disorders. In addition, post-translational modifications of HMGB1, including acetylation, phosphorylation, and oxidation, have been postulated to affect its localization and physiological and pathophysiological effects, such as the initiation and progression of lung diseases. Critical Issues: The molecular mechanisms underlying how HMGB1 drives the pathogenesis of different lung diseases and novel therapeutic approaches targeting HMGB1 remain to be elucidated. Future Directions: Additional research is needed to identify the roles and functions of modified HMGB1 produced by different post-translational modifications and their significance in the pathogenesis of lung diseases. Such studies will provide information for novel approaches targeting HMGB1 as a treatment for lung diseases.

[Expression of high-mobility group box 1 in neonates with sepsis]

OBJECTIVE

To study the expression of high-mobility group box 1 (HMGB1) in neonates with sepsis and its role in the pathogenesis of neonatal sepsis.

METHODS

A total of 62 neonates with sepsis were enrolled as the sepsis group, 66 neonates with local infection were enrolled as the local infection group, and 70 healthy neonates were enrolled as the healthy control group. Serum levels of interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-17 (IL-17), interleukin-23 (IL-23), C-reactive protein (CRP) and procalcitonin (PCT) were measured. The mRNA expression of HMGB1, Toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) and the protein expression of TLR4 and NF-κB in peripheral blood mononuclear cells (PBMCs) were also measured. PBMCs from healthy neonates were divided into 4 groups: control, HMGB1 treatment, HMGB1+TAK-242 (a TLR4 inhibitor) treatment and HMGB1+PDTC (an NF-κB inhibitor) treatment, and the mRNA expression of TLR4, NF-κB and IL-8 and the protein expression of TLR4 and NF-κB were measured. PBMCs from healthy neonates were divided into another 3 groups: control, LPS treatment and LPS+glycyrrhizin (an HMGB1 inhibitor) treatment, and the mRNA expression of HMGB1, TLR4, NF-κB and IL-8 and the protein expression of TLR4 and NF-κB were measured.

RESULTS

Compared with the local infection and healthy control groups, the sepsis group had significantly higher serum levels of IL-6, IL-8, IL-17, IL-23, CRP and PCT (P<0.05), as well as significantly higher mRNA expression of HMGB1, TLR4 and NF-κB and protein expression of TLR4 and NF-κB in PBMCs (P<0.05). HMGB1 significantly induced the mRNA and protein expression of TLR4 and NF-κB in PBMCs (P<0.05). TAK-242 inhibited the mRNA and protein expression of TLR4 and NF-κB and mRNA expression of IL-8 (P<0.05). PDTC inhibited the mRNA and protein expression of NF-κB and the mRNA expression of IL-8 (P<0.05). LPS significantly induced the mRNA expression of HMGB1 and the mRNA and protein expression of TLR4 and NF-κB and then stimulated the mRNA expression of IL-8 (P<0.05). Glycyrrhizin inhibited the mRNA expression of HMGB1 and the mRNA and protein expression of TLR4 and NF-κB and then reduced the mRNA expression of IL-8 (P<0.05).

CONCLUSIONS

HMGB1 plays an important role in the pathogenesis of neonatal sepsis by activating the TLR4/NF-κB signaling pathway and inducing the secretion of inflammatory factors including IL-8. The HMGB1 blocker glycyrrhizin can inhibit activation of the TLR4/NF-κB signaling pathway and the secretion of inflammatory factors.

Lactobacillus bulgaricus or Lactobacillus rhamnosus Suppresses NF-κB Signaling Pathway and Protects against AFB₁-Induced Hepatitis: A Novel Potential Preventive Strategy for Aflatoxicosis?

Aflatoxin B₁ (AFB₁), a mycotoxin found in food and feed, is immunotoxic to animals and poses significant threat to the food industry and animal production. The primary target of AFB₁ is the liver. To overcome aflatoxin toxicity, probiotic-mediated detoxification has been proposed. In the present study, to investigate the protective effects and molecular mechanisms of Lactobacillus bulgaricus or Lactobacillus rhamnosus against liver inflammatory responses to AFB₁, mice were administered with AFB₁ (300 μg/kg) and/or Lactobacillus intragastrically for 8 weeks. AML12 cells were cultured and treated with AFB₁, BAY 11-7082 (an NF-κB inhibitor), and different concentrations of L. bulgaricus or L. rhamnosus. The body weight, liver index, histopathological changes, biochemical indices, cytokines, cytotoxicity, and activation of the NF-κB signaling pathway were measured. AFB₁ exposure caused changes in liver histopathology and biochemical functions, altered inflammatory response, and activated the NF-κB pathway. Supplementation of L. bulgaricus or L. rhamnosus significantly prevented AFB₁-induced liver injury and alleviated histopathological changes and inflammatory response by decreasing NF-κB p65 expression. The results of in vitro experiments revealed that L.rhamnosus evidently protected against AFB₁-induced inflammatory response and decreased NF-κB p65 expression when compared with L. bulgaricus. These findings indicated that AFB₁ exposure can cause inflammatory response by inducing hepatic injury, and supplementation of L. bulgaricus or L. rhamnosus can produce significant protective effect against AFB₁-induced liver damage and inflammatory response by regulating the activation of the NF-κB signaling pathway.

The function and mechanism of HMGB1 in lung cancer and its potential therapeutic implications

As a non-histone chromatin-associated protein, high-mobility group box-1 (HMGB1) performs a pivotal function in various human diseases, including autoimmune diseases, neurodegenerative diseases and cancer. Overexpression of HMGB1 has been demonstrated in numerous types of cancer, including breast cancer, colorectal cancer, lung cancer and hepatocellular carcinoma. However, the underlying mechanism of HMGB1 function in lung cancer remains to be elucidated. The present study aimed to analyze, and summarize the role and mechanism of HMGB1 in lung cancer by retrieving available literature regarding HMGB1 in association with lung cancer. It provides comprehensive information on the association of HMGB1 with the carcinogenesis and progression of lung cancer, and discusses the molecular mechanism of these processes. HMGB1 may induce tumorigenesis, metastasis and chemotherapy resistance in lung cancer. Overall, it is evident that HMGB1 serves an important role in the development and progression of lung cancer, and this review warrants further investigation into HMGB1 as a novel target for cancer therapy.