Increase in the level of proinflammatory cytokine hmgb1 in nasal fluids of patients with rhinitis and its sequestration by glycyrrhizin induces eosinophil cell death

ObjectivesThe nuclear protein high mobility group protein box 1 (HMGB1) is a proinflammatory mediator that belongs to the alarmin family of proinflammatory mediators, and it has recently emerged as a key player in different acute and chronic immune disorders. Several lines of evidence demonstrate that HMGB1 is actively released extracellularly from immune cells or passively released from necrotic cells. Because of the ability of HMGB1 to sustain chronic inflammation, we investigated whether the protein is present in nasal fluids of patients with different forms of rhinitis.MethodsHMGB1 levels were evaluated in nasal fluids of healthy subjects or rhinitis patients who were treated or not treated with different treatments.ResultsWe report that the level of HMGB1 was significantly increased in nasal fluids of patients with allergic rhinitis, patients with NARES (nonallergic rhinitis with eosinophiliac syndrome), as well as patients with polyps. We also found that a formulation containing the HMGB1-binding compound glycyrrhizin (GLT) reduced the HMGB1 content in nasal fluids of rhinitis patients to an extent similar to that with nasal budesonide treatment. We also found that among the cultured human leukocyte populations, eosinophils released higher amounts of HMGB1. Based on the ability of HMGB1 to sustain eosinophil survival and the ability of GLT to inactivate HMGB1, we report that GLT selectively killed cultured eosinophils and had no effect on neutrophils, macrophages, and lymphocytes.ConclusionCollectively, these data underscore the role of HMGB1 in rhinitis pathogenesis and the therapeutic potential of GLT formulations in treatment of chronic inflammatory disorders of the nasal mucosa

GPR35 Activation Reduces Ca2+ Transients and Contributes to the Kynurenic Acid-Dependent Reduction of Synaptic Activity at CA3-CA1 Synapses

Limited information is available on the brain expression and role of GPR35, a Gi/o coupled receptor activated by kynurenic acid (KYNA). In mouse cultured astrocytes, we detected GPR35 transcript using RT-PCR and we found that KYNA (0.1 to 100 µM) decreased forskolin (FRSK)-induced cAMP production (p<0.05). Both CID2745687 (3 µM, CID), a recently described GPR35 antagonist, and GPR35 gene silencing significantly prevented the action of KYNA on FRSK-induced cAMP production. In these cultures, we then evaluated whether GPR35 activation was able to modulate intracellular Ca(2+) concentration ([Ca(2+)]i ) and [Ca(2+)]i fluxes. We found that both KYNA and zaprinast, a phosphodiesterase (PDE) inhibitor and GPR35 agonist, did not modify either basal or peaks of [Ca(2+)]i induced by challenging the cells with ATP (30 µM). However, the [Ca(2+)]i plateau phase following peak was significantly attenuated by these compounds in a store-operated Ca(2+) channel (SOC)-independent manner. The activation of GPR35 by KYNA and zaprinast was also studied at the CA3-CA1 synapse in the rat hippocampus. Evoked excitatory post synaptic currents (eEPSCs) were recorded from CA1 pyramidal neurons in acute brain slices. The action of KYNA on GPR35 was pharmacologically isolated by using NMDA and α7 nicotinic receptor blockers and resulted in a significant reduction of eEPSC amplitude. This effect was prevented in the presence of CID. Moreover, zaprinast reduced eEPSC amplitude in a PDE5- and cGMP-independent mechanism, thus suggesting that glutamatergic transmission in this area is modulated by GPR35. In conclusion, GPR35 is expressed in cultured astrocytes and its activation modulates cAMP production and [Ca(2+)]i. GPR35 activation may contribute to KYNA effects on the previously reported decrease of brain extracellular glutamate levels and reduction of excitatory transmission

Ischemic neuroprotection by TRPV1 receptor-induced hypothermia

Although treatment of stroke patients with mild hypothermia is a promising therapeutic approach, chemicals inducing prompt and safe reduction of body temperature are an unmet need. We measured the effects of the transient receptor potential vanilloid-1 (TRPV1) agonist rinvanil on thermoregulation and ischemic brain injury in mice. Intraperitoneal or intracerebroventricular injection of rinvanil induces mild hypothermia that is prevented by the receptor antagonist capsazepine. Both intraischemic and postischemic treatments provide permanent neuroprotection in animals subjected to transient middle cerebral artery occlusion (MCAo), an effect lost in mice artificially kept normothermic. Data indicate that TRPV1 receptor agonists are promising candidates for hypothermic treatment of stroke

Occupational Exposure on Board Fishing Vessels: Risk Assessments of Biomechanical Overload, Noise and Vibrations among Worker on Fishing Vessels in Southern Italy

Sea fishing is one of the sectors with the highest risk of illness and work-related accidents. Thepurpose of the study is to evaluate the exposure of fishingworkers to threemajor risks: biomechanical overload, noise, and whole-body vibrations. We used common methods and measurement tools in the field: observational video analysis, questionnaires, and direct measurement. Noise and vibrations levels were measured aboard five boats belonging to the main fishing communities of Southern Italy. The random sample consisted of 310 workers, of whom 108 agreed to complete a questionnaire to collect data on the perception of occupational risk and self-perception of health conditions. We found that fishermen had a high prevalence of osteoarticular pathologies (42%) and that the biomechanical overload risk is mainly related to handling manual loads. Furthermore, the results indicate that the levels of weekly noise exposure exceed the exposure limit value of 87 decibel A (dBA) for fishing workers, and that the most noisiest area is the engine room. Exposure levels to whole-body vibrations were below &lt;0.5 m/s2. Knowledge on occupational hazards and health effects in the fisheries sector should be used to develop ship technology, raise awareness of the correct use of personal protective equipment, and improve health surveillance of these workers

Dipotassium Glycyrrhizate Inhibits HMGB1-Dependent Inflammation and Ameliorates Colitis in Mice.

High mobility group box-1 (HMGB1) is a DNA-binding protein that is released from injured cells during inflammation. Advances in targeting HMGB1 represent a major challenge to improve the treatment of acute/chronic inflammation.This study is aimed at verifying whether the inhibition of HMGB1 through dipotassium glycyrrhizate (DPG) is a good strategy to reduce intestinal inflammation.Human colon adenocarcinoma cell line, HT29, human epithelial colorectal adenocarcinoma, Caco2, and murine macrophage cell line, RAW 264.7, were cultured to investigate the effect of DPG on the secretion of HMGB1. Acute colitis was induced in C57BL/6 mice through administration of 3% dextran sodium sulphate (DSS); a combined treatment with DSS and 3 or 8 mg/kg/day DPG was used to investigate the effects of DPG on intestinal inflammation. Animals were euthanized at seventh day and colonic samples underwent molecular and histological analyses.DPG significantly reduces in vitro the release of HMGB1 in the extracellular matrix as well as expression levels of pro-inflammatory cytokines, TNF-alpha, IL-1beta and IL-6, by inhibiting HMGB1. Moreover, DPG significantly decreases the severity of DSS-induced colitis in mice. Murine colonic samples show decreased mRNA levels of pro-inflammatory cytokines TNF-alpha, IL-1beta and IL-6, as well as HMGB1 receptors, RAGE and TLR4. Finally, HMGB1, abundantly present in the feces of mice with DSS-induced colitis, is strongly reduced by DPG.HMGB1 is an early pro-inflammatory cytokine and an active protagonist of mucosal gut inflammation. DPG exerts inhibitory effects against HMGB1 activity, significantly reducing intestinal inflammation. Thus, we reason that DPG could represent an innovative tool for the management of human intestinal inflammation

Effect of Class II HDAC inhibition on glutamate transporter expression and survival in SOD1-ALS mice

Transcriptional deregulation emerges as a key pathogenetic mechanism in ALS pathogenesis, and nonclass-specific histone deacetylase (HDACs) inhibitors proved of therapeutic efficacy in preclinical models of ALS. When tested in patients, however, these drugs failed, probably because of a lack of selectivity toward pathogenetic HDACs. Here, we studied the effects of MC1568, an inhibitor of Class-II HDACs which have been reported to contribute to ALS pathogenesis. We focused on transcriptional regulation of glutamate transporter EAAT2, whose reduced expression may contribute to motor neuron degeneration in ALS. We report that MC1568 highly increased EAAT2 transcripts in primary cultures of mouse glia, but these increases did not correlate with increased glutamate uptake capacity. Accordingly, we found that MC1568 augmented protein expression of EAAT2 together with its sumoylation, a post-translational modification typically altering protein function and localization. When tested in SOD1G93A mice, however, MC1568 fully restored the reduced spinal cord expression of EAAT2 and glutamate uptake up to control levels. A prolonged treatment with MC1568 (from onset to end stage) was unable to prolong survival of mice. Data reveal a key role of Class-II HDACs in expression and function of glutamate transporter, further corroborating preclinical and clinical evidence that the sole restoration of glutamate uptake is not of therapeutic relevance to ALS therap