HMGB1-RAGE Signaling Plays a Role in Organic Dust-Induced Microglial Activation and Neuroinflammation

α-synuclein-lack expression rescues methamphetamine-induced mossy fiber degeneration in dorsal hippocampal CA3

Methamphetamine (METH) - induced cognitive impairments may be related to synaptic degeneration at mossy fiber terminals, critical for spatial memory formation in hippocampal circuits. We have previously found METH-induced neurodegeneration in the striatum by increasing the α-synuclein (α-SYN) level. However, whether and how the METH-induced mossy fiber degeneration is also blamed for the abnormal accumulation of α-SYN remains to be elucidated. Chronic METH exposure decreased mossy fiber density but upregulatedα-SYN and phosphorylated TAU (TAU-pSer396) in hippocampal CA3, associated with glial cell overactivation, axonal neuropathies, and memory impairment. Notably, the knockout of the α-SYN gene significantly alleviated the METH-induced mossy fiber degeneration and memory impairment. Meanwhile, the TAU-pSer396 accumulation and glial activation were ameliorated by α-SYN knockout. Our findings suggest an essential role of α-SYN in mediating METH-induced mossy fiber degeneration, providing promising therapeutic and prophylactic targets for METH-related neurodegenerative diseases.

Atrazine induces phagocytotic dysfunction of microglia depends on nucleocytoplasmic translocation of acetylated HMGB1

Atrazine (ATR) is a widely applied herbicide which was named an environmental endocrine disrupting chemical (EDC). Increasing evidence indicates ATR causes neurotoxic effects resulting in central nervous system (CNS) disease. As the primary immunocytes in the CNS, microglia cells carry out their phagocytosis to maintain the CNS microenvironment by preventing damage from healthy cells. However, the mechanism in which ATR affects the phagocytic function of microglia remains unclear. The present study was designed to investigate the effect of ATR on the phagocytosis of microglia. BV-2 cells and primary microglia selected as microglial models in which BV-2 cells were administrated by ATR at different concentrations (0, 4, 8, 16 μM) for 24 h. Results demonstrated ATR dose-dependently increased the expression of ionized calcium binding adapter molecule 1 (Iba-1), indicating that microglia were activated. Microglial phagocytotic activity induced by ATR fluctuated at the different time points, accompanied by fluctuations in membrane receptor MERTK and cytoplasmic lysosomal marker LAMP1 (two markers related to cell phagocytosis). In this period, the expression of iNOS gradually increased. A mechanistic study further demonstrated that the translocation of High Mobility Group Protein-B1 (HMGB1) from nucleus to cytoplasm in the BV-2 and primary microglial cells induced by ATR, and the process showed a positive correlation with phagocytosis activity of BV-2 cells induced by ATR (r = 0.8030, P = 0.05; α = 0.1). ATR was also shown to spur the acetylation of HMGB1 by breaking the balance between acetylase P300 and deacetylase SIRT1. Unexpectedly, the inhibition of acetylating HMGB1 by resveratrol (Res) was effectively retained by HMGB1 in the nucleus, reversed the SIRT1 and MERTK expression, and enhanced the phagocytosis activity in BV-2 cells. Our results suggested that ATR exposure influenced microglial phagocytosis by acetylating HMGB1 further translocated it in the nucleoplasm.

Identification of significant modules and hub genes involved in hepatic encephalopathy using WGCNA

BACKGROUND

Hepatic encephalopathy (HE) is a reversible syndrome of brain dysfunction caused by advanced liver disease. Weighted gene co-expression network analysis (WGCNA) could establish a robust co-expression network to identify the hub genes and underlying biological functions. This study was aimed to explore the potential therapeutic targets in HE by WGCNA.

RESULTS

The green and brown modules were found to be significantly associated with the development of HE. Functional enrichment analyses suggested the neuroinflammation, neuroimmune, extracellular matrix (ECM), and coagulation cascade were involved in HE. CYBB and FOXO1 were calculated as hub genes, which were upregulated in the HE patients. Tamibarotene and vitamin E were suggested as possible drug candidates to alleviate HE.

CONCLUSIONS

It is the first time to analyze transcriptomic data of HE by WGCNA. Our study not only promoted the current understanding of neuroinflammation in HE, but also provided the first evidence that CYBB and FOXO1 played pivotal roles in the pathogenesis of HE, which might be potential biomarkers and therapeutic targets. Tamibarotene might be a novel drug compound against HE.

Role of high mobility group box protein 1 in depression: A mechanistic and therapeutic perspective

As a common and serious psychiatric disorder, depression significantly affects psychosocial functioning and quality of life. However, the mechanism of depression is still enigmatic and perplexing, which limits its precise and effective therapeutic methods. Recent studies demonstrated that neuroinflammation activation plays an important role in the pathophysiology of depression. In this respect, high mobility group box 1 (HMGB1) may be a possible signaling inducer of neuroinflammation and can be a potential mechanistic and therapeutic target for depression. Herein, we review recent studies on the mechanistic and therapeutic targets of HMGB1 in depression and propose potential perspectives on this topic.

Dexmedetomidine attenuates perioperative neurocognitive disorders by suppressing hippocampal neuroinflammation and HMGB1/RAGE/NF-κB signaling pathway

Surgical trauma can induce an inflammatory response in the central nervous system. Neuroinflammation is a crucial pathological mechanism of perioperative neurocognitive disorders (PND). Dexmedetomidine (Dex) is an alpha (α)-2 adrenoceptor agonist that is widely used in the perioperative period. Previous studies have shown that Dex has neuroprotection in various nerve injury models, but its role in PND remains unclear. Our study aimed to observe the neuroprotective effect of Dex pretreatment on postoperative cognitive change and explore the effects of hippocampal neuroinflammation, microglial polarization and HMGB1/RAGE/NF-κB signaling pathway involved in Dex on PND in rats. Rats were pretreated with Dex alone or in combination with yohimbine (α-2 adrenoceptor antagonist) before surgery. Behavioral tests results showed that Dex ameliorated surgery-induced cognitive impairment in rats. Nissl, immunohistochemistry and TUNEL-NeuN staining results indicated that Dex reduced hippocampus damage and neuronal apoptosis caused by surgery. Dex preconditioning reduced the expression of the proinflammatory cytokines IL-1β, TNF-α and IL-6 in hippocampus. Immunohistochemical and immunofluorescence results showed that Dex preconditioning inhibited the activation of glial cells induced by surgery. Western blot analysis showed that Dex preconditioning downregulated the expression of M1 phenotype markers (CD86 and iNOS), HMGB1, RAGE and nuclear NF-κB and upregulated the expression of M2 phenotype markers (Arginase 1 and CD206) and cytoplasmic NF-κB. Yohimbine could inhibit the neuroprotective effect of Dex. These results indicated that Dex pretreatment could improve postoperative short-term cognitive impairment, and the neuroprotective mechanism may involve the suppression of hippocampal neuroinflammation, regulation of M1/M2 polarization, and inhibition of HMGB1/RAGE/NF-κB signal transduction.

Effect of Aucubin-Containing Eye Drops on Tear Hyposecretion and Lacrimal Gland Damage Induced by Urban Particulate Matter in Rats

Exposure to particulate matter is a causative factor of dry eye disease. We aimed to investigate the beneficial effect of eye drops containing aucubin on dry eye disease induced by urban particulate matter (UPM). Dry eye was induced in male SD rats (6 weeks old) by topical exposure to UPM thrice a day for 5 d. Eye drops containing 0.1% aucubin or 0.5% aucubin were topically administered directly into the eye after UPM exposure for an additional 5 d. Tear secretion was evaluated using a phenol red thread tear test and corneal irregularity. The oxidative damage in the lacrimal gland was evaluated using TUNEL and immunohistochemical staining. The topical administration of aucubin significantly attenuated UPM-induced tear hyposecretion (control group: 9.25 ± 0.62 mm, UPM group: 4.55 ± 0.25 mm, 0.1% aucubin: 7.12 ± 0.58 mm, and 0.5% aucubin: 7.88 ± 0.75 mm) and corneal irregularity (control group: 0.00 ± 0.00, UPM group: 3.40 ± 0.29, 0.1% aucubin: 1.80 ± 0.27, and 0.5% aucubin: 1.15 ± 0.27). In addition, aucubin also reduced the UPM-induced apoptotic injury of lacrimal gland cells induced by oxidative stress through the increased expression of HMGB1 and RAGE. These findings indicate that the topical administration of aucubin eye drops showed a beneficial effect against UPM-induced abnormal ocular changes, such as tear hyposecretion and lacrimal gland damage. Therefore, our results reveal the pharmacological activities of aucubin in dry eye disease.

Transcriptomic and ultrastructural evidence indicate that anti-HMGB1 antibodies rescue organic dust-induced mitochondrial dysfunction

Exposure to organic dust (OD) in agriculture is known to cause respiratory symptoms including loss of lung function. OD exposure activates multiple signaling pathways since it contains a variety of microbial products and particulate matter. Previously, we have shown how OD exposure leads to the secretion of HMGB1 and HMGB1-RAGE signaling, and how this can be a possible therapeutic target to reduce inflammation. Cellular mitochondria are indispensable for homeostasis and are emerging targets to curtail inflammation. Recently, we have also observed that OD exposure induces mitochondrial dysfunction characterized by loss of structural integrity and deficits in bioenergetics. However, the role of HMGB1 in OD-induced mitochondrial dysfunction in human bronchial epithelial (NHBE) cells remains elusive. Therefore, we aimed to study whether decreased levels of intracellular HMGB1 or antibody-mediated neutralization of secreted HMGB1 would rescue mitochondrial dysfunction. Single and repeated ODE exposure showed an elongated mitochondrial network and cristolysis whereas HMGB1 neutralization or the lack thereof promotes mitochondrial biogenesis evidenced by increased mitochondrial fragmentation, increased DRP1 expression, decreased MFN2 expression, and increased PGC1α expression. Repeated 5-day ODE exposure significantly downregulated transcripts encoding mitochondrial respiration and metabolism (ATP synthase, NADUF, and UQCR) as well as glucose uptake. This was reversed by the antibody-mediated neutralization of HMGB1. Our results support our hypothesis that, in NHBE cells, neutralization of ODE-induced HMGB1 secretion rescues OD-induced mitochondrial dysfunction.

Mitoapocynin Attenuates Organic Dust Exposure-Induced Neuroinflammation and Sensory-Motor Deficits in a Mouse Model

Increased incidences of neuro-inflammatory diseases in the mid-western United States of America (USA) have been linked to exposure to agriculture contaminants. Organic dust (OD) is a major contaminant in the animal production industry and is central to the respiratory symptoms in the exposed individuals. However, the exposure effects on the brain remain largely unknown. OD exposure is known to induce a pro-inflammatory phenotype in microglial cells. Further, blocking cytoplasmic NOX-2 using mitoapocynin (MA) partially curtail the OD exposure effects. Therefore, using a mouse model, we tested a hypothesis that inhaled OD induces neuroinflammation and sensory-motor deficits. Mice were administered with either saline, fluorescent lipopolysaccharides (LPSs), or OD extract intranasally daily for 5 days a week for 5 weeks. The saline or OD extract-exposed mice received either a vehicle or MA (3 mg/kg) orally for 3 days/week for 5 weeks. We quantified inflammatory changes in the upper respiratory tract and brain, assessed sensory-motor changes using rotarod, open-field, and olfactory test, and quantified neurochemicals in the brain. Inhaled fluorescent LPS (FL-LPS) was detected in the nasal turbinates and olfactory bulbs. OD extract exposure induced atrophy of the olfactory epithelium with reduction in the number of nerve bundles in the nasopharyngeal meatus, loss of cilia in the upper respiratory epithelium with an increase in the number of goblet cells, and increase in the thickness of the nasal epithelium. Interestingly, OD exposure increased the expression of HMGB1, 3- nitrotyrosine (NT), IBA1, glial fibrillary acidic protein (GFAP), hyperphosphorylated Tau (p-Tau), and terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL)-positive cells in the brain. Further, OD exposure decreased time to fall (rotarod), total distance traveled (open-field test), and olfactory ability (novel scent test). Oral MA partially rescued olfactory epithelial changes and gross congestion of the brain tissue. MA treatment also decreased the expression of HMGB1, 3-NT, IBA1, GFAP, and p-Tau, and significantly reversed exposure induced sensory-motor deficits. Neurochemical analysis provided an early indication of depressive behavior. Collectively, our results demonstrate that inhalation exposure to OD can cause sustained neuroinflammation and behavior deficits through lung-brain axis and that MA treatment can dampen the OD-induced inflammatory response at the level of lung and brain.

Risk Factors for Brain Health in Agricultural Work: A Systematic Review

Certain exposures related to agricultural work have been associated with neurological disorders. To date, few studies have included brain health measurements to link specific risk factors with possible neural mechanisms. Moreover, a synthesis of agricultural risk factors associated with poorer brain health outcomes is missing. In this systematic review, we identified 106 articles using keywords related to agriculture, occupational exposure, and the brain. We identified seven major risk factors: non-specific factors that are associated with agricultural work itself, toluene, pesticides, heavy metal or dust exposure, work with farm animals, and nicotine exposure from plants. Of these, pesticides are the most highly studied. The majority of qualifying studies were epidemiological studies. Nigral striatal regions were the most well studied brain area impacted. Of the three human neuroimaging studies we found, two focused on functional networks and the third focused on gray matter. We identified two major directions for future studies that will help inform preventative strategies for brain health in vulnerable agricultural workers: (1) the effects of moderators such as type of work, sex, migrant status, race, and age; and (2) more comprehensive brain imaging studies, both observational and experimental, involving several imaging techniques.

The Function of NF-Kappa B During Epilepsy, a Potential Therapeutic Target

The transcriptional regulator nuclear factor kappa B (NF-κB) modulates cellular biological activity by binding to promoter regions in the nucleus and transcribing various protein-coding genes. The NF-κB pathway plays a major role in the expressing genes related to inflammation, including chemokines, interleukins, and tumor necrosis factor. It also transcribes genes that can promote neuronal survival or apoptosis. Epilepsy is one of the most common brain disorders and it not only causes death worldwide but also affects the day-to-day life of affected individuals. While epilepsy has diverse treatment options, there remain patients who are not sensitive to the existing treatment methods. Recent studies have implicated the critical role of NF-κB in epilepsy. It is upregulated in neurons, glial cells, and endothelial cells, due to neuronal loss, glial cell proliferation, blood-brain barrier dysfunction, and hippocampal sclerosis through the glutamate and γ-aminobutyric acid imbalance, ion concentration changes, and other mechanisms. In this review, we summarize the functional changes caused by the upregulation of NF-κB in the central nervous system during different periods after seizures. This review is the first to deconvolute the complicated functions of NF-κB, and speculate that the regulation of NF-κB can be a safe and effective treatment strategy for epilepsy.

The pathogenic effects of particulate matter on neurodegeneration: a review

The increasing amount of particulate matter (PM) in the ambient air is a pressing public health issue globally. Epidemiological studies involving data from millions of patients or volunteers have associated PM with increased risk of dementia and Alzheimer’s disease in the elderly and cognitive dysfunction and neurodegenerative pathology across all age groups, suggesting that PM may be a risk factor for neurodegenerative diseases. Neurodegenerative diseases affect an increasing population in this aging society, putting a heavy burden on economics and family. Therefore, understanding the mechanism by which PM contributes to neurodegeneration is essential to develop effective interventions. Evidence in human and animal studies suggested that PM induced neurodenegerative-like pathology including neurotoxicity, neuroinflammation, oxidative stress, and damage in blood–brain barrier and neurovascular units, which may contribute to the increased risk of neurodegeneration. Interestingly, antagonizing oxidative stress alleviated the neurotoxicity of PM, which may underlie the essential role of oxidative stress in PM’s potential effect in neurodegeneration. This review summarized up-to-date epidemiological and experimental studies on the pathogenic role of PM in neurodegenerative diseases and discussed the possible underlying mechanisms.

Ethyl pyruvate, a versatile protector in inflammation and autoimmunity

Ethyl pyruvate (EP) has potent influence on redox processes, cellular metabolism, and inflammation. It has been intensively studied in numerous animal models of systemic and organ-specific disorders whose pathogenesis involves a strong immune component. Here, basic chemical and biological properties of EP are discussed, with an emphasis on its redox and metabolic activity. Further, its influence on myeloid and T cells is considered, as well as on intracellular signaling beyond its effect on immune cells. Also, the effects of EP on animal models of chronic inflammatory and autoimmune disorders are presented. Finally, a possibility to apply EP as a treatment for such diseases in humans is discussed. Scientific papers cited in this review were identified using the PubMed search engine that relies on the MEDLINE database. The reference list covers the most important findings in the field in the past twenty years.

Melatonin and Microglia

Melatonin interacts in multiple ways with microglia, both directly and, via routes of crosstalk with astrocytes and neurons, indirectly. These effects of melatonin are of relevance in terms of antioxidative protection, not only concerning free-radical detoxification, but also in prevention of processes that cause, promote, or propagate oxidative stress and neurodegeneration, such as overexcitation, toxicological insults, viral and bacterial infections, and sterile inflammation of different grades. The immunological interplay in the CNS, with microglia playing a central role, is of high complexity and includes signaling toward endothelial cells and other leukocytes by cytokines, chemokines, nitric oxide, and eikosanoids. Melatonin interferes with these processes in multiple signaling routes and steps. In addition to canonical signal transduction by MT₁ and MT₂ melatonin receptors, secondary and tertiary signaling is of relevance and has to be considered, e.g., via the upregulation of sirtuins and the modulation of pro- and anti-inflammatory microRNAs. Many details concerning the modulation of macrophage functionality by melatonin are obviously also applicable to microglial cells. Of particular interest is the polarization toward M2 subtypes instead of M1, i.e., in favor of being anti-inflammatory at the expense of proinflammatory activities, which is well-documented in macrophages but also applies to microglia.

HMGB1: An overview of its roles in the pathogenesis of liver disease

High-mobility group box 1 (HMGB1) is an abundant architectural chromosomal protein that has multiple biologic functions: gene transcription, DNA replication, DNA-damage repair, and cell signaling for inflammation. HMGB1 can be released passively by necrotic cells or secreted actively by activated immune cells into the extracellular milieu after injury. Extracellular HMGB1 acts as a damage-associated molecular pattern to initiate the innate inflammatory response to infection and injury by communicating with neighboring cells through binding to specific cell-surface receptors, including Toll-like receptors (TLRs) and the receptor for advanced glycation end products (RAGE). Numerous studies have suggested HMGB1 to act as a key protein mediating the pathogenesis of chronic and acute liver diseases, including nonalcoholic fatty liver disease, hepatocellular carcinoma, and hepatic ischemia/reperfusion injury. Here, we provide a detailed review that focuses on the role of HMGB1 and HMGB1-mediated inflammatory signaling pathways in the pathogenesis of liver diseases.

Organic dust exposure induces stress response and mitochondrial dysfunction in monocytic cells

Exposure to airborne organic dust (OD), rich in microbial pathogen-associated molecular patterns (PAMPs), is shown to induce lung inflammation. A common manifestation in lung inflammation is altered mitochondrial structure and bioenergetics that regulate mitochondrial ROS (mROS) and feed a vicious cycle of mitochondrial dysfunction. The role of mitochondrial dysfunction in other airway diseases is well known. However, whether OD exposure induces mitochondrial dysfunction remains elusive. Therefore, we tested a hypothesis that organic dust extract (ODE) exposure induces mitochondrial stress using a human monocytic cell line (THP1). We examined whether co-exposure to ethyl pyruvate (EP) or mitoapocynin (MA) could rescue ODE exposure induced mitochondrial changes. Transmission electron micrographs showed significant differences in cellular and organelle morphology upon ODE exposure. ODE exposure with and without EP co-treatment increased the mtDNA leakage into the cytosol. Next, ODE exposure increased PINK1, Parkin, cytoplasmic cytochrome c levels, and reduced mitochondrial mass and cell viability, indicating mitophagy. MA treatment was partially protective by decreasing Parkin expression, mtDNA and cytochrome c release and increasing cell viability.

Targeting HMGB1 inhibits T-2 toxin-induced neurotoxicity via regulation of oxidative stress, neuroinflammation and neuronal apoptosis

T-2 toxin, a food-derived mycotoxin, has been identified as a neurotoxin. Nonetheless, T-2 toxin-induced neuroinflammation has never been revealed. As an important therapeutic target for inflammatory diseases and cancers, the role of high mobility group B1 (HMGB1) in mycotoxin-mediated neurotoxicity remains a mystery. In current study, we found that PC12 cells were sensitive to trace amounts of T-2 toxin less than 12 ng/mL, distinguished by decreased cell viability and increased release of lactate dehydrogenase (LDH). Oxidative stress and mitochondrial damage were observed in PC12 cells, manifested as accumulation of oxidative stress products, up-regulation of Nrf2/HO-1 pathway and decrease of mitochondrial membrane potential (MMP), leading to mitochondria-dependent apoptosis. Meanwhile, we first discovered that tiny amounts of T-2 toxin triggered neuroinflammation directly, including raising the expression and translocation of NF-κB and promoting secretion of proinflammatory cytokines such as TNF-α, IL-6, IL-8 and IL-1β. Most interestingly, the increased of HMGB1 was detected both inside and outside the cells. Conversely, HMGB1 siRNA reduced T-2 toxin-mediated oxidative stress, apoptosis and neuroinflammatory outbreak, accompanied by lessened caspase-3 and caspase-9, and decreased secretion of pro-inflammatory cytokines. Taken together, T-2 toxin-stimulated PC12 cells simultaneously displayed apoptosis and inflammation, whereas HMGB1 played a critical role in these neurotoxic processes.

Organic dust-induced mitochondrial dysfunction could be targeted via cGAS-STING or cytoplasmic NOX-2 inhibition using microglial cells and brain slice culture models

Organic dust (OD) exposure in animal production industries poses serious respiratory and other health risks. OD consisting of microbial products and particulate matter and OD exposure-induced respiratory inflammation are under investigation. However, the effect of OD exposure on brain remains elusive. We show that OD exposure of microglial cells induces an inflammatory phenotype with the release of mitochondrial DNA (mt-DNA). Therefore, we tested a hypothesis that OD exposure-induced secreted mt-DNA signaling drives the inflammation. A mouse microglial cell line was treated with medium or organic dust extract (ODE, 1% v/v) along with either phosphate-buffered saline (PBS) or mitoapocynin (MA, 10 µmol). Microglia treated with control or anti-STING siRNA were exposed to medium or ODE. Mouse organotypic brain slice cultures (BSCs) were exposed to medium or ODE with or without MA. Various samples were processed to quantify mitochondrial reactive oxygen species (mt-ROS), mt-DNA, cytochrome c, TFAM, mitochondrial stress markers and mt-DNA-induced signaling via cGAS-STING and TLR9. Data were analyzed and a p value of ≤ 0.05 was considered significant. MA treatment decreased the ODE-induced mt-DNA release into the cytosol. ODE increased MFN1/2 and PINK1 but not DRP1 and MA treatment decreased the MFN2 expression. MA treatment decreased the ODE exposure-induced mt-DNA signaling via cGAS-STING and TLR9. Anti-STING siRNA decreased the ODE-induced increase in IRF3, IFN-β and IBA-1 expression. In BSCs, MA treatment decreased the ODE-induced TNF-α, IL-6 and MFN1. Therefore, OD exposure-induced mt-DNA signaling was curtailed through cytoplasmic NOX-2 inhibition or STING suppression to reduce brain microglial inflammatory response.

miR-30b-5p releases HMGB1 via UBE2D2/KAT2B/HMGB1 pathway to promote pro-inflammatory polarization and recruitment of macrophages

BACKGROUND AND AIMS

Oxidized low-density lipoprotein (ox-LDL) is a key risk factor for atherosclerosis, but there are few reports on ox-LDL-mediated inflammation after injury. In this study, we investigated the effects of ox-LDL on endothelial injury and macrophage polarization and recruitment using human aortic endothelial cell line HAEC cells.

METHODS

Changes in miRNA levels after ox-LDL treatment were assessed with qRT-PCR. Luciferase experiments were performed to verify the interaction between miRNA and protein, and co-IP and ubiquitination experiments to detect proteins interactions. Cell phenotype was assessed by cytometry and Western blot.

RESULTS

qRT-PCR data indicated that ox-LDL treatment up-regulates the expression of miR-30b-5p. Luciferase test and ubiquitination assay showed miR-30b-5p can bind to UBE2D2 and reduce its ubiquitination ability to degrade KAT2B. The up-regulated KAT2B promotes the acetylation of HMGB1, acetylated HMGB1 dissociates from SIRT1, exit the nucleus, and it is secreted from the cell. Flow cytometry and transwell experiments showed that HMGB1 secreted from HAEC can induce pro-inflammatory (M1-like) polarization and recruitment of RAW264.7 cells.

CONCLUSIONS

Our results indicate that ox-LDL activates the UBE2D2/KAT2B pathway by upregulating miR-30b-5p, thus acetylating HMGB1, which is then secreted from the cell, thereby promoting pro-inflammatory cell polarization and recruitment of macrophage.

The Potential Therapeutic Role of the HMGB1-TLR Pathway in Epilepsy

Epilepsy is one of the most common serious neurological disorders, affecting over 70 million people worldwide. For the treatment of epilepsy, antiepileptic drugs (AEDs) and surgeries are widely used. However, drug resistance and adverse effects indicate the need to develop targeted AEDs based on further exploration of the epileptogenic mechanism. Currently, many efforts have been made to elucidate the neuroinflammation theory in epileptogenesis, which may show potential in the treatment of epilepsy. In this respect, an important target protein, high mobility group box 1 (HMGB1), has received increased attention and has been developed rapidly. HMGB1 is expressed in various eukaryotic cells and localized in the cell nucleus. When HMGB1 is released by injuries or diseases, it participates in inflammation. Recent studies suggest that HMGB1 via Toll-like receptor (TLR) pathways can trigger inflammatory responses and play an important role in epilepsy. In addition, studies of HMGB1 have shown its potential in the treatment of epilepsy. Herein, the authors analyzed the experimental and clinical evidence of the HMGB1-TLR pathway in epilepsy to summarize the theory of epileptogenesis and provide insights into antiepileptic therapy in this novel field.

Serum level of high mobility group box protein-1 and prognosis of patients with end-stage renal disease on hemodialysis and peritoneal dialysis

To investigate serum level of high mobility group box protein-1 (HMGB1) and prognosis of patients with end-stage renal disease (ESRD) on hemodialysis (HD) and peritoneal dialysis (PD).This prospective cohort observational study included a total of 253 ESRD patients who came to our hospital for HD or PD from February 2013 to February 2015. Enzyme linked immunosorbent assay (ELISA) method was used to detect the serum level of HMGB1, interleukin (IL-6), IL-8, and tumor necrosis factor-alpha (TNF-α). The kidney disease quality of life short form (KDQOL-SF) and kidney disease targeted area (KDTA) was applied for evaluating the quality of life. Kaplan-Meier (K-M) curve was performed for survival time.Serum level of HMGB1 in patients on HD was higher than PD. HMGB1 levels were gradually decreased with the treatment of HD or PD. Furthermore, HMGB1 was positively correlated with IL-6 and TNF-α. Moreover, patients with higher HMGB1 had more complications than patients with lower HMGB1, but there was no difference for the survival rate. In addition, the quality of life was associated with different dialysis methods.The serum level of HMGB1 and prognosis of ESRD patients was associated with different dialysis methods.

Is Oxytocin "Nature's Medicine"?

Oxytocin is a pleiotropic, peptide hormone with broad implications for general health, adaptation, development, reproduction, and social behavior. Endogenous oxytocin and stimulation of the oxytocin receptor support patterns of growth, resilience, and healing. Oxytocin can function as a stress-coping molecule, an anti-inflammatory, and an antioxidant, with protective effects especially in the face of adversity or trauma. Oxytocin influences the autonomic nervous system and the immune system. These properties of oxytocin may help explain the benefits of positive social experiences and have drawn attention to this molecule as a possible therapeutic in a host of disorders. However, as detailed here, the unique chemical properties of oxytocin, including active disulfide bonds, and its capacity to shift chemical forms and bind to other molecules make this molecule difficult to work with and to measure. The effects of oxytocin also are context-dependent, sexually dimorphic, and altered by experience. In part, this is because many of the actions of oxytocin rely on its capacity to interact with the more ancient peptide molecule, vasopressin, and the vasopressin receptors. In addition, oxytocin receptor(s) are epigenetically tuned by experience, especially in early life. Stimulation of G-protein–coupled receptors triggers subcellular cascades allowing these neuropeptides to have multiple functions. The adaptive properties of oxytocin make this ancient molecule of special importance to human evolution as well as modern medicine and health; these same characteristics also present challenges to the use of oxytocin-like molecules as drugs that are only now being recognized.

Pre-exposure to hydrogen sulfide modulates the innate inflammatory response to organic dust

Animal production units produce and store many contaminants on-site, including organic dust (OD) and hydrogen sulfide (H₂S). Workers in these settings report various respiratory disease symptoms. Both OD and H₂S have shown to induce lung inflammation. However, impact of co-exposure to both H₂S and OD has not been investigated. Therefore, we tested a hypothesis that pre-exposure to H₂S modulates the innate inflammatory response of the lungs to organic dust. In a mouse model of H₂S and organic dust extract (ODE) exposure, we assessed lung inflammation quantitatively. We exposed human airway epithelial and monocytic cells to medium or H₂S alone or H₂S followed by ODE and measured cell viability, oxidative stress, and other markers of inflammation. Exposure to 10 ppm H₂S followed by ODE increased the lavage fluid leukocytes. However, exposure to 10 ppm H₂S alone resulted in changes in tight junction proteins, an increase in mRNA levels of tlr2 and tlr4 as well as ncf1, ncf4, hif1α, and nrf2. H₂S alone or H₂S and ODE exposure decreased cell viability and increased reactive nitrogen species production. ODE exposure increased the transcripts of tlr2 and tlr4 in both in vitro and in vivo models, whereas increased nfkbp65 transcripts following exposure to ODE and H₂S was seen only in in vitro model. H₂S alone and H₂S followed by ODE exposure increased the levels of IL-1β. We conclude that pre-exposure to H₂S modulates lung innate inflammatory response to ODE.

Ethyl pyruvate improves white matter remodeling in rats after traumatic brain injury

Background

Severe traumatic brain injury (TBI) results in long‐term neurological deficits associated with white matter injury (WMI). Ethyl pyruvate (EP) is a simple derivative of the endogenous energy substrate pyruvate with neuroprotective properties, but its role in recovery from WMI has not been explored.

Aims

This study examines the effect of EP treatment on rats following TBI using behavioral tests and white matter histological analysis up to 28 days post‐injury.

Materials and Methods

Anaesthetised adult rats were subjected to TBI by controlled cortical impact. After surgery, EP or Ringers solution (RS) was administrated intraperitoneally at 15 min after TBI and again at 12, 24, 36, 48, and 60 h after TBI. Sensorimotor deficits were evaluated up to day 21 after TBI by four independent tests. Immunofluorescence and transmission electron microscopy (TEM) were performed to assess white matter injury. Microglia activation and related inflammatory molecules were examined up to day 14 after TBI by immunohistochemistry or real‐time PCR.

Results

Here, we demonstrate that EP improves sensorimotor function following TBI as well as improves white matter outcomes up to 28 d after TBI, as shown by reduced myelin loss. Furthermore, EP administration during the acute phase of TBI recovery shifted microglia polarization toward the anti‐inflammatoryM2 phenotype, modulating the release of inflammatory‐related factors.

Conclusion

EP treatment may protect TBI‐induced WMI via modulating microglia polarization toward M2.

The Complex Relationship between Diabetic Retinopathy and High-Mobility Group Box: A Review of Molecular Pathways and Therapeutic Strategies

High-mobility group box 1 (HMGB1) is a protein that is part of a larger family of non-histone nuclear proteins. HMGB1 is a ubiquitary protein with different isoforms, linked to numerous physiological and pathological pathways. HMGB1 is involved in cytokine and chemokine release, leukocyte activation and migration, tumorigenesis, neoangiogenesis, and the activation of several inflammatory pathways. HMGB1 is, in fact, responsible for the trigger, among others, of nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), toll-like receptor-4 (TLR-4), and vascular endothelial growth factor (VEGF) pathways. Diabetic retinopathy (DR) is a common complication of diabetes mellitus (DM) that is rapidly growing in number. DR is an inflammatory disease caused by hyperglycemia, which determines the accumulation of oxidative stress and cell damage, which ultimately leads to hypoxia and neovascularization. Recent evidence has shown that hyperglycemia is responsible for the hyperexpression of HMGB1. This protein activates numerous pathways that cause the development of DR, and HMGB1 levels are constantly increased in diabetic retinas in both proliferative and non-proliferative stages of the disease. Several molecules, such as glycyrrhizin (GA), have proven effective in reducing diabetic damage to the retina through the inhibition of HMGB1. The main focus of this review is the growing amount of evidence linking HMGB1 and DR as well as the new therapeutic strategies involving this protein.

Effect and Mechanism of the Bruton Tyrosine Kinase (Btk) Inhibitor Ibrutinib on Rat Model of Diabetic Foot Ulcers

BACKGROUND Diabetes causes damage to the soft tissue and bone structure of the foot, referred to as "diabetic foot". Ibrutinib is a Bruton tyrosine kinase (Btk) inhibitor, and the role and mechanism of ibrutinib on the diabetic foot have not been elucidated. MATERIAL AND METHODS Male Wister rats were randomly divided into 3 groups: control group, model group, and ibrutinib group. After 14 days, the ulcer wound size of each group was measured, and the ulcer healing rate was calculated. The level of inflammatory factors interleukin (IL)-1ß, tumor necrosis factor (TNF)-alpha, and IL-6 was detected by enzyme-linked immunosorbent assay (ELISA). Real-time polymerase chain reaction (PCR) was used to analyze the changes of Toll-like receptor 2 (TLR2) and TLR4. The expression of vascular endothelial growth factor (VEGF) and the RAGE (receptor for advanced glycation end product/NF-kappaB (nuclear factor-kappa B) pathway was detected by western blot. RESULTS Blood glucose, blood lipids, serum creatinine, and urea nitrogen (BUN) levels were increased in the model group, together with increased levels of IL-1ß, TNF-alpha, IL-6, as well as TLR2 and TLR4 expression, and there were significant differences compared with the control group (P<0.05). Meanwhile, the model group showed decreased VEGF expression and increased expression of RAGE and NF-kappaB. However, ibrutinib reduced blood sugar, blood lipids, creatinine, and urea nitrogen levels, inhibited the secretion of inflammatory factors, promoted ulcer healing, improved ulcer healing rate, decreased the expression of TLR2, TLR4, RAGE, and NF-kappaB, and increased VEGF expression; there were significant differences in the ibrutinib group compared with the model group (P<0.05). CONCLUSIONS The Btk inhibitor ibrutinib can upregulate VEGF expression, inhibit the expression of TLRs, inhibit the secretion of inflammatory factors, and promote the healing of diabetic foot ulcer possibly by regulating the RAGE/NF-kappaB pathway.

The inflammatory event of birth: How oxytocin signaling may guide the development of the brain and gastrointestinal system

The role of oxytocin (OT) as a neuropeptide that modulates social behavior has been extensively studied and reviewed, but beyond these functions, OT's adaptive functions at birth are quite numerous, as OT coordinates many physiological processes in the mother and fetus to ensure a successful delivery. In this review we explore in detail the potential adaptive roles of oxytocin as an anti-inflammatory, protective molecule at birth for the developing fetal brain and gastrointestinal system based on evidence that birth is a potent inflammatory/immune event. We discuss data with relevance for a number of neurodevelopmental disorders, as well as the emerging role of the gut-brain axis for health and disease. Finally, we discuss the potential relevance of sex differences in OT signaling present at birth in the increased male vulnerability to neurodevelopmental disabilities.