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Patients with severe COVID-19 develop acute respiratory distress syndrome (ARDS) that may progress to cytokine storm syndrome, organ dysfunction, and death. Considering that complement component 5a (C5a), through its cellular receptor C5aR1, has potent proinflammatory actions and plays immunopathological roles in inflammatory diseases, we investigated whether the C5a/C5aR1 pathway could be involved in COVID-19 pathophysiology. C5a/C5aR1 signaling increased locally in the lung, especially in neutrophils of critically ill patients with COVID-19 compared with patients with influenza infection, as well as in the lung tissue of K18-hACE2 Tg mice (Tg mice) infected with SARS-CoV-2. Genetic and pharmacological inhibition of C5aR1 signaling ameliorated lung immunopathology in Tg-infected mice. Mechanistically, we found that C5aR1 signaling drives neutrophil extracellular traps-dependent (NETs-dependent) immunopathology. These data confirm the immunopathological role of C5a/C5aR1 signaling in COVID-19 and indicate that antagonists of C5aR1 could be useful for COVID-19 treatment. ispartof: J Clin Invest vol:133 issue:12 pages:e163105- ispartof: location:United States status: Published online

Patients with severe COVID-19 develop acute respiratory distress syndrome (ARDS) that may progress to cytokine storm syndrome, organ dysfunction, and death. Considering that complement component 5a (C5a), through its cellular receptor C5aR1, has potent proinflammatory actions, and plays immunopathological roles in inflammatory diseases, we investigated whether C5a/C5aR1 pathway could be involved in COVID-19 pathophysiology. C5a/C5aR1 signaling increased locally in the lung, especially in neutrophils of critically ill COVID-19 patients compared to patients with influenza infection, as well as in the lung tissue of K18-hACE2 Tg mice (Tg mice) infected with SARS-CoV-2. Genetic and pharmacological inhibition of C5aR1 signaling ameliorated lung immunopathology in Tg-infected mice. Mechanistically, we found that C5aR1 signaling drives neutrophil extracellular trap (NET)s-dependent immunopathology. These data confirm the immunopathological role of C5a/C5aR1 signaling in COVID-19 and indicate that antagonist of C5aR1 could be useful for COVID-19 treatment.

Neuroimmune interactions across the pain pathway play a predominant role in the development of neuropathic pain. Previous reports demonstrated that complement driven effector systems including the C5a/C5aR1 axis contribute to these neuro-immune mechanisms. However, the cellular and molecular mechanisms underlying C5a/C5aR1 signaling-mediated neuropathic pain development remain ill-identified. Here we show that neuropathic pain following peripheral nerve injury was attenuated in C5aR1-deficient male and female mice as well as in wild type mice treated with a selective allosteric C5aR1 antagonist. Using two complementary cell-specific C5aR1 knockout mouse strains, we identified C5a/C5aR1 driven-activation of sensory neuron-associated macrophages (sNAMs) located in the sensory ganglia as the key site of peripheral nerve injury-induced neuropathic pain, whereas activation of macrophages of the local of peripheral nerve injury was not involved. Mechanistically, we uncovered IL-1b the main mediator of pain hypersensitivity in response to C5aR1 signaling in sNAMs. Our findings highlight a crucial role of C5a/C5aR1 axis activation in sNAMs for the development of neuropathic pain and identify this pathway as a promising novel target for neuropathic pain therapy.

Nerve growth factor (NGF) is the best characterized neurotrophin, and it is known to play an important role in ocular homeostasis. Here, we demonstrated the expression of NGF receptors in adult zebrafish retina and optimized a light-induced retina degeneration (LID) zebrafish model that mimics human cone-rod disorders, demonstrating that intravitreal (IV) administration of rhNGF can boost zebrafish retinal regeneration in this model. Adult zebrafish retinae exposed to 60 h of light irradiation (60 h LID) displayed evident reduction of outer nuclear layer (ONL) thickness and cell number with presence of apoptotic cells. Retinal histologic evaluation at different time points showed that IV therapeutic injection of rhNGF resulted in an increase of ONL thickness and cell number at late time points after damage (14 and 21 days post injury), ultimately accelerating retinal tissue recovery by driving retinal cell proliferation. At a molecular level, rhNGF activated the ERK1/2 pathway and enhanced the regenerative potential of Müller glia gfap- and vim-expressing cells by stimulating at early time points the expression of the photoreceptor regeneration factor Drgal1-L2. Our results demonstrate the highly conserved nature of NGF canonical pathway in zebrafish and thus support the use of zebrafish models for testing new compounds with potential retinal regenerative properties. Moreover, the pro-regenerative effects of IV-injected NGF that we observed pave the way to further studies aimed at evaluating its effects also in mammals, in order to expedite the development of novel rhNGF-based therapeutic approaches for ophthalmological disorders.

Methionine is an aliphatic, sulfur-containing, essential amino acid that has been demonstrated to have crucial roles in metabolism, innate immunity, and activation of endogenous antioxidant enzymes, including methionine sulfoxide reductase A/B and the biosynthesis of glutathione to counteract oxidative stress. Still, methionine restriction avoids altered methionine/transmethylation metabolism, thus reducing DNA damage and possibly avoiding neurodegenerative processes. In this study, we wanted to study the preventive effects of methionine in counteracting 6-hydroxydopamine (6-OHDA)-induced injury. In particular, we analyzed the protective effects of the amino acid L-methionine in an in vitro model of Parkinson’s disease and dissected the underlying mechanisms compared to the known antioxidant taurine to gain insights into the potential of methionine treatment in slowing the progression of the disease by maintaining mitochondrial functionality. In addition, to ascribe the effects of methionine on mitochondria and oxidative stress, methionine sulfoxide was used in place of methionine. The data obtained suggested that an L-methionine-enriched diet could be beneficial during aging to protect neurons from oxidative imbalance and mitochondrial dysfunction, thus preventing the progression of neurodegenerative processes.

CXCL1, a functional murine orthologue of the human chemokine CXCL8 (IL-8), and its CXCR1 and CXCR2 receptors were investigated in a murine model of acquired epilepsy developing following status epilepticus (SE) induced by intra-amygdala kainate. CXCL8 and its receptors were also studied in human temporal lobe epilepsy (TLE). The functional involvement of the chemokine in seizure generation and neuronal cell loss was assessed in mice using reparixin (formerly referred to as repertaxin), a non-competitive allosteric inhibitor of CXCR1/2 receptors. We found a significant increase in hippocampal CXCL1 level within 24 h of SE onset that lasted for at least 1 week. No changes were measured in blood. In analogy with human TLE, immunohistochemistry in epileptic mice showed that CXCL1 and its two receptors were increased in hippocampal neuronal cells. Additional expression of these molecules was found in glia in human TLE. Mice were treated with reparixin or vehicle during SE and for additional 6 days thereafter, using subcutaneous osmotic minipumps. Drug-treated mice showed a faster SE decay, a reduced incidence of acute symptomatic seizures during 48 h post-SE, and a delayed time to spontaneous seizures onset compared to vehicle controls. Upon reparixin discontinuation, mice developed spontaneous seizures similar to vehicle mice, as shown by EEG monitoring at 14 days and 2.5 months post-SE. In the same epileptic mice, reparixin reduced neuronal cell loss in the hippocampus vs vehicle-injected mice, as assessed by Nissl staining at completion of EEG monitoring. Reparixin administration for 2 weeks in mice with established chronic seizures, reduced by 2-fold on average seizure number vs pre-treatment baseline, and this effect was reversible upon drug discontinuation. No significant changes in seizure number were measured in vehicle-injected epileptic mice that were EEG monitored in parallel. Data show that CXCL1-IL-8 signaling is activated in experimental and human epilepsy and contributes to acute and chronic seizures in mice, therefore representing a potential new target to attain anti-ictogenic effects.

10037 Background: Mesenchymal stem cells (MSCs) play a key role in the progression of osteosarcoma (OS). In response to tumor-associated signals, including tumor-secreted extracellular vesicles (EVs), MSCs increase the expression of inflammatory cytokines promoting tumor cell aggressiveness. Previous data has demonstrated that IL-6 and IL-8 signaling mediate metastasis in OS. The aim of this study was to evaluate tumor EV-induced alterations of MSCs and identify combination therapies that can counteract MSC-induced resistance to antimetastatic drugs. Methods: Tumor EV-induced alterations of the MSC transcriptome were analyzed by RNA-seq. Gene set enrichment analysis (GSEA) was applied to discriminate TGFβ-dependent and independent pathways. EV RNA-induced expression changes were identified by transfecting purified EV-RNA in MSCs and by using a selective dsRNA antagonist. We selected candidate targets to block MSC-induced drug resistance and evaluated their effect in an orthotopic xenograft model of OS. Ladarixin (an allosteric inhibitor of the CXCL8/IL-8 receptors CXCR1 and CXCR2; 30 mg/kg 6x per week i.p.) and tocilizumab (anti-IL6 receptor antibody; 100 µg/mouse every other day i.p.) were administered starting from day one until the experimental endpoint. Metastasis were quantified by histological examination. This study was funded by the Dutch Cancer Society (KWF), POR FESR Campania 2014‐2020 and Dompé Farmaceutici SpA. Results: EVs from aggressive cancer cell lines induced an inflammatory MSC (iMSC) phenotype, characterized by increased expression of chemokines, including IL-8 as the most upregulated. Apart from IL-6, these alterations were mostly independent from TGFβ signaling and related to pattern recognition receptor (PRR) activation. We demonstrated that tumor EV-associated non-coding RNAs trigger TLR3 signaling in MSCs activating an innate immune response leading to high induction of IL-8 and other chemokines. Ladarixin and tocilizumab combination significantly reduced metastasis formation in a spontaneous metastasis model and overcame iMSC-induced resistance observed with single antimetastatic treatments. No effect was observed on primary tumor growth. Conclusions: EV-associated TGFβ together with EV-RNA induce iMSCs development in OS. Ladarixin in combination with tocilizumab reduced metastasis formation in a xenograft mouse model of OS, and, importantly, may prevent the occurrence of iMSC-induced tumor resistance to antimetastatic drugs.

Type 2 diabetes mellitus is a severe public health issue worldwide. It displays a harmful effect on different organs as the eyes, kidneys and neural cells due to insulin resistance and high blood glucose concentrations. To date, the available treatments for this disorder remain limited. Several reports have correlated obesity with type 2 diabetes. Mainly, dysfunctional adipocytes and the regulation of high secretion of inflammatory cytokines are the crucial links between obesity and insulin resistance. Several clinical and epidemiological studies have also correlated the onset of type 2 diabetes with inflammation, which is now indicated as a new target for type 2 diabetes treatment. Thus, it appears essential to discover new drugs able to inhibit the secretion of proinflammatory adipocytokines in type 2 diabetes. Adipocytes produce inflammatory cytokines in response to inflammation or high glucose levels. Once activated by a specific ligand, CXCR1 and CXCR2 mediate some cytokines’ effects by activating an intracellular signal cascade once activated by a specific ligand. Therefore, it is conceivable to hypothesize that a specific antagonist of these receptors may ameliorate type 2 diabetes and glucose metabolism. Herein, differentiated 3T3-L1-adipocytes were subjected to high glucose or inflammatory conditions or the combination of both and then treated with ladarixin, a CXCR1/2 inhibitor. The results obtained point towards the positive regulation by ladarixin on insulin sensitivity, glucose transporters GLUT1 and GLUT4, cytokine proteome profile and lipid metabolism, thus suggesting ladarixin as a potentially helpful treatment in type 2 diabetes mellitus and obesity.

Retinal disorders are leading causes of blindness and are due to an imbalance between reactive oxygen species and antioxidant scavenger (in favor of pro‐oxidant species) or a disruption of redox signaling and control. Indeed, it is well known that oxidative stress is one of the leading causes of retinal degenerative diseases. Different approaches using nutraceuticals resulted in protective effects in these disorders. This review will discuss the impact of oxidative stress in retinal neurodegenerative diseases and the potential strategies for avoiding or counteracting oxidative damage in retinal tissues, with a specific focus on taurine. Increasing data indicate that taurine may be effective in slowing down the progression of degenerative retinal diseases, thus suggesting that taurine can be a promising candidate for the prevention or as adjuvant treatment of these diseases. The mechanism by which taurine supplementation acts is mainly related to the reduction of oxidative stress. In particular, it has been demonstrated to improve retinal reduced glutathione, malondialdehyde, superoxide dismutase, and catalase activities. Antiapoptotic effects are also involved; however, the protective mechanisms exerted by taurine against retinal damage remain to be further investigated., Increasing data indicate that taurine supplement may be effective in slowing down the progression of retinal diseases (including glaucoma, AMD, and DR), thus suggesting that taurine can be a promising candidate for the prevention or as adjuvant treatment of these diseases. The mechanism by which taurine supplementation acts is mainly related to the reduction of oxidative stress. Antiapoptotic effects are also involved; however, the protective mechanisms exerted by taurine against retinal damage remain to be further investigated.

The kinin B1 receptor plays a critical role in the chronic phase of pain and inflammation. The development of B1 antagonists peaked in recent years but almost all promising molecules failed in clinical trials. Little is known about these molecules&rsquo, mechanisms of action and additional information will be necessary to exploit the potential of the B1 receptor. With the aim of contributing to the available knowledge of the pharmacology of B1 receptors, we designed and characterized a novel class of allosteric non-peptidic inhibitors with peculiar binding characteristics. Here, we report the binding mode analysis and pharmacological characterization of a new allosteric B1 antagonist, DFL20656. We analyzed the binding of DFL20656 by single point mutagenesis and radioligand binding assays and we further characterized its pharmacology in terms of IC50, B1 receptor internalization and in vivo activity in comparison with different known B1 antagonists. We highlighted how different binding modes of DFL20656 and a Merck compound (compound 14) within the same molecular pocket can affect the biological and pharmacological properties of B1 inhibitors. DFL20656, by its peculiar binding mode, involving tight interactions with N114, efficiently induced B1 receptor internalization and evoked a long-lasting effect in an in vivo model of neuropathic pain. The pharmacological characterization of different B1 antagonists highlighted the effects of their binding modes on activity, receptor occupancy and internalization. Our results suggest that part of the failure of most B1 inhibitors could be ascribed to a lack of knowledge about target function and engagement.

Background and purpose Transient receptor potential (TRP) channels are a superfamily of non-selective cation permeable channels involved in peripheral sensory signalling. Animal studies have shown that several TRPs are important players in pain modulation. Among them, the TRP melastatin 8 (TRPM8) has elicited more interest for its controversial role in nociception. This channel, expressed by a subpopulation of sensory neurons in dorsal root ganglia (DRG) and trigeminal ganglia (TG), is activated by cold temperatures and cooling agents. In experimental neuropathic pain models, an up-regulation of this receptor in DRG and TG has been observed, suggesting a key role for TRPM8 in the development and maintenance of pain. Consistent with this hypothesis, TRPM8 knockout mice are less responsive to pain stimuli. Experimental approach In this study, the therapeutic potential and efficacy of two novel TRPM8 antagonists, DFL23693 and DFL23448, were tested. Key results Two potent and selective TRPM8 antagonists with distinct pharmacokinetic profiles, DFL23693 and DFL23448, have been fully characterized in vitro. In vivo studies in well-established models, namely, the wet-dog shaking test and changes in body temperature, confirmed their ability to block the TRPM8 channel. Finally, TRPM8 blockage resulted in a significant antinociceptive effect in formalin-induced orofacial pain and in chronic constriction injury-induced neuropathic pain, confirming an important role for this channel in pain perception. Conclusion and implications Our findings, in agreement with previous literature, encourage further studies for a better comprehension of the therapeutic potential of TRPM8 blockers as novel agents for pain management.

A mayor pathobiological role for interleukin 8 in the etiology of myelofibrosis has been suggested by observations indicating that megakaryocytes expanded in culture from these patients express great levels of interleukin 8 1 and that the plasma levels of this cytokine are predictive of poor prognosis 2. In preliminary experiments we demonstrated that the megakaryocytes from the bone marrow of the Gata1 low model of myelofibrosis express not only high levels of TGF-β, but also levels greater than normal of lipokalin-2, a known inducer of IL-8 production, and of CXCL1, the murine equivalent of IL-8. In addition, these megakaryocytes express also high levels of the CXCL1 receptors CXCLR1 and CXCR2 and the bone marrow from these mice express an CXCR1/CXCR2 activated signature. Using these data as a foundation, we tested here the effects of treatment of Gata1 low mice with the CXCR1/R2 inhibitor reparixin on the myelofibrosis phenotype expressed by this models. To these aim, Gata1 low mice (8-month old) were treated either with vehicle (3 males and 3 females) or with reparixin (formerly referred to as repertaxin) 3 (5 males and 5 females) for either 20 or 37 days. The drug was administered by minipumps implanted subcutaneously in the dorsal region set to deliver 7.5mg of drug/hr/Kg of body weight. The mice receiving the drug for 37 days had the minipumps replaced by day 17. The efficiency of drug delivery decreased over time since the plasma levels of reparixin were 13.90±4.18 and 6.71±4.18ug/mL at day 20 and 37, respectively (p References: 1) Emadi S et al. Blood. 2005;105:464; 2) Tefferi et al, J Clin Oncol. 2011;29:1356; 3) Bertini R et al, PNAS 2004; 101:11791 Figure 1 Figure 1. Disclosures Crispino: Forma Therapeutics: Research Funding; Scholar Rock: Research Funding; MPN Research Foundation: Membership on an entity's Board of Directors or advisory committees; Sierra Oncology: Consultancy. Massucci: Dompe Farmaceutici Spa R&D: Current Employment. Brandolini: Dompe farmaceutici Spa R&D: Current Employment. Giorgio: Dompe farmaceutici Spa R&D: Current Employment. Allegretti: Dompe farmaceutici Spa R&D: Current Employment. Migliaccio: Dompe farmaceutici Spa R&D: Other: received funding for reserach .

Transient receptor potential melastatin 8 (TRPM8), a nonselective cation channel, is the predominant mammalian cold temperature thermosensor and it is activated by cold temperatures and cooling compounds, such as menthol and icilin. Because of its role in cold allodynia, cold hyperalgesia and painful syndromes TRPM8 antagonists are currently being pursued as potential therapeutic agents for the treatment of pain hypersensitivity. Recently TRPM8 has been found in subsets of bladder sensory nerve fibres, providing an opportunity to understand and treat chronic hypersensitivity. However, most of the known TRPM8 inhibitors lack selectivity, and only three selective compounds have reached clinical trials to date. Here, we applied two virtual screening strategies to find new, clinics suitable, TRPM8 inhibitors. This strategy enabled us to identify naphthyl derivatives as a novel class of potent and selective TRPM8 inhibitors. Further characterization of the pharmacologic properties of the most potent compound identified, compound 1, confirmed that it is a selective, competitive antagonist inhibitor of TRPM8. Compound 1 also proved itself active in a overreactive bladder model in vivo. Thus, the novel naphthyl derivative compound identified here could be optimized for clinical treatment of pain hypersensitivity in bladder disorders but also in different other pathologies.

Increasing evidence suggests that nerve growth factor (NGF) exerts protective effects against retinal degeneration in animal models of retinitis pigmentosa (RP). This study aims at investigating the effects of intravitreal injection of recombinant human NGF (rhNGF) on retinal photoreceptors apoptosis in an animal model of RP, the Royal College of Surgeons (RCS) rats.Thirty-six RCS rats were treated with intravitreal injection of rhNGF or murine NGF (mNGF) or vehicle at 20 postnatal days (pd) and sacrificed at 40 pd. The eyes were enucleated and evaluated by histology, flow cytometric analysis for rhodopsin expression, Western blot for TrkA and activated (phosphorylated) TrkA (pTrkA) levels, and TUNEL assay for apoptosis' detection.RCS rats showed a significant retinal degeneration associated with cell apoptosis at 40 pd when compared to wild-type animals. Histology showed that rhNGF intravitreal treatment significantly increased retinal thickness when compared to untreated eyes. Photoreceptors' number evaluated by flow cytometry was significantly increased in both intravitreal rhNGF- and mNGF-treated groups when compared to untreated eyes. This protective effect was associated with an increase in TrkA and activated pTrkA levels and an inhibition of apoptosis. Intravitreal NGF injection was well tolerated and did not show clinical and histological signs of adverse effects.Intravitreal rhNGF injection proved safe and effective in favoring retinal cell survival in RCS rats. This is the first report showing that the novel rhNGF already proved safe in a phase I study exerts a biologic effect similar to the well-characterized mNGF-induced retinal protection. These results may trigger further studies to investigate rhNGF administration for the treatment of progressive degenerative retinal disorders such as retinitis pigmentosa.

Glioblastoma (GB) is the most representative form of primary malignant brain tumour. Several studies indicated a pleiotropic role of CXCL8 in cancer due to its ability to modulate the tumour microenvironment, growth and aggressiveness of tumour cell. Previous studies indicated that CXCL8 by its receptors (CXCR1 and CXCR2) induced activation of the PI3K/p-Akt pathway, a crucial event in the regulation of cytoskeleton rearrangement and cell mobilization. Human GB primary cell culture and U-87MG cell line were used to study the effects of CXCR1 and CXCR2 blockage, by a dual allosteric antagonist, on cell migration and cytoskeletal dynamics. The data obtained point towards a specific effect of autocrine CXCL8 signalling on GB cell invasiveness by the activation of pathways involved in cell migration and cytoskeletal dynamics, such as PI3K/p-Akt/p-FAK, p-cortactin, RhoA, Cdc42, Acetylated α-tubulin and MMP2. All the data obtained support the concept that autocrine CXCL8 signalling plays a key role in the activation of an aggressive phenotype in primary glioblastoma cells and U-87MG cell line. These results provide new insights about the potential of a pharmacological approach targeting CXCR1/CXCR2 pathways to decrease migration and invasion of GB cells in the brain parenchyma, one of the principal mechanisms of recurrence.

The progressive consumption growth of non-steroidal anti-inflammatory drugs (NSAIDs) has progressively raised the attention toward the gastrointestinal, renal, and cardiovascular toxicity. Increased risk of cardiovascular diseases was strictly associated with the usage of COX-2 selective NSAIDs. Other studies allowed to clarify that the cardiovascular risk is not limited to COX-2 selective but also extended to non-selective NSAIDs, such as Diclofenac and Ketoprofen. To date, although a less favorable cardiovascular risk profile for Diclofenac as compared to Ketoprofen is reported, the mechanisms through which NSAIDs cause adverse cardiovascular events are not entirely understood. The present study aimed to evaluate the effects of Ketoprofen in comparison with Diclofenac in immortalized human cardiomyocytes. The results obtained highlight the dose-dependent cardiotoxicity of Diclofenac compared to Ketoprofen. Despite both drugs induce the increase in ROS production, decrease of mitochondrial membrane potential, and proteasome activity modulation, only Diclofenac exposure shows a marked alteration of these intracellular parameters, leading to cell death. Noteworthy, Diclofenac decreases the proteasome 26S DC and this scenario may be dependent on the intracellular overload of oxidized proteins. The data support the hypothesis that immortalized human cardiomyocytes exposed to Ketoprofen are subjected to tolerable stress events, conversely Diclofenac exposition triggers cell death.

C5a is a crucial terminal effector of the C cascade, mostly involved in pain and neuroinflammatory conditions. DF3016A is a novel potent and selective C5a receptor (C5aR) inhibitor that crosses the blood-brain barrier (BBB) and may have pharmacological properties. We have previously demonstrated a protective effect of DF3016A on injured primary cortical neurons by oxygen-glucose deprivation-reoxygenation (OGD/R) model to mimic the neuroinflammatory process. Here, we investigated the molecular pathway and factors involved in the neuroprotection previously reported. Our findings show that DF3016A protects against the neuroinflammatory insult by activating brain-derived neurotrophic factor (BDNF) transcription pathway, which involves methyl CpG-binding protein 2 (MeCP2) and microRNA-132 (miR-132) regulatory factors, both required in nociceptive signaling and neuroinflammation. Further in vivo investigations will confirm the functionality of the DF3016A molecule as a therapeutic resource in neuroinflammation and pain injuries.

Chemotherapy-induced peripheral neuropathy (CIPN) is a side effect of chemotherapics such as taxanes, vinca alkaloids, and platinum compounds. In recent years, several reports have indicated the involvement of different molecular mechanisms in CIPN. The pathways described so far are diverse and target various components of the peripheral Nervous System (PNS). Among the contributors to neuropathic pain, inflammation has been indicated as a powerful driver of CIPN. Several pieces of evidence have demonstrated a chemotherapy-induced increase in peripheral pro-inflammatory cytokines and a strong correlation with peripheral neuropathy. At present, there are not adequate strategies to prevent CIPN, although there are drugs for treating CIPN, such as duloxetine, that have displayed a moderate effect on CIPN. In this review, we focus on the players involved in CIPN with a particular emphasis on chemokine signaling.

Background: Branched-chain amino acids (BCAAs: leucine, isoleucine, valine) account for 35% of skeletal muscle essential amino acids (AAs). As such, they must be provided in the diet to support peptide synthesis and inhibit protein breakdown. Although substantial evidence has been collected about the potential usefulness of BCAAs in supporting muscle function and structure, dietary supplements containing BCAAs alone may not be effective in controlling muscle protein turnover, due to the rate-limiting bioavailability of other AAs involved in BCAAs metabolism. Methods: We aimed to evaluate the in vivo/ex vivo effects of a 4-week treatment with an oral formulation containing BCAAs alone (2:1:1) on muscle function, structure, and metabolism in a murine model of physiological exercise, which was compared to three modified formulations combining BCAAs with increasing concentrations of L-Alanine (ALA), an AA controlling BCAAs catabolism. Results: A preliminary pharmacokinetic study confirmed the ability of ALA to boost up BCAAs bioavailability. After 4 weeks, mix 2 (BCAAs + 2ALA) had the best protective effect on mice force and fatigability, as well as on muscle morphology and metabolic indices. Conclusion: Our study corroborates the use of BCAAs + ALA to support muscle health during physiological exercise, underlining how the relative BCAAs/ALA ratio is important to control BCAAs distribution.

The central nervous system (CNS) constitutively expresses complement (C) membrane receptors and complement proteins, including the component C5a. This is a crucial terminal effector of the C cascade, mostly involved in pain and neuroinflammatory conditions. Aberrant activation of C5a protein and its receptor C5aR has been reported to play a critical role in neurodegenerative diseases, with important clinical consequences. Here we have investigated the effects of DF3016A, a novel selective C5aR antagonist, able to penetrate the blood-brain barrier (BBB), on cortical neurons exposed to oxygen-glucose deprivation-reoxygenation (OGD/R), a neuroinflammation-related process. We demonstrated that a mild ischemic insult induces an early upregulation of C5aR associated with the over-production of pro-inflammatory cytokines and the over-expression of the transcriptional regulatory factor miR-181. Furthermore, we report the first experimental evidence of the effect of DF3016A, modulating complement component C5a, on neurons in a model of injury. Interestingly, DF3016A protects neuronal viability by restoring intracellular calcium levels, thus opposing the increase in pro-inflammatory cytokine levels and miR-181 expression. Based on our results, we suggest that DF3016A is a novel C5aR antagonist promoting protective effects against OGD/R-induced damage that could be a new therapeutic approach to controlling CNS neuroinflammatory conditions.

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// Laura Brandolini 1, * , Loredana Cristiano 2, * , Alessia Fidoamore 2 , Maria De Pizzol 3 , Erica Di Giacomo 2 , Tiziana Marilena Florio 2, 4 , Giuseppina Confalone 2 , Angelo Galante 2, 4 , Benedetta Cinque 2 , Elisabetta Benedetti 2 , Pier Adelchi Ruffini 3 , Maria Grazia Cifone 2 , Antonio Giordano 5, 6 , Marcello Alecci 2, 4 , Marcello Allegretti 1 , Annamaria Cimini 2, 4, 6 1 Dompe Farmaceutici SpA, Via Campo di Pile, L’Aquila, Italy 2 Department of Life, Health and Environmental Sciences, University of L’Aquila, L’Aquila, Italy 3 Dompe Farmaceutici SpA, Via Santa Lucia, Milano, Italy 4 National Institute for Nuclear Physics (INFN), Gran Sasso National Laboratory (LNGS), Assergi, Italy 5 Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy 6 Sbarro Institute for Cancer Research and Molecular Medicine and Center for Biotechnology, Temple University, Philadelphia, PA, USA * These authors have contributed equally to this work Correspondence to: Annamaria Cimini, e-mail: annamaria.cimini@univaq.it Marcello Allegretti, e-mail: marcello.allegretti@dompe.com Keywords: preclinical MRI Received: July 31, 2015 Accepted: October 06, 2015 Published: October 26, 2015 ABSTRACT In breast cancer it has been proposed that the presence of cancer stem cells may drive tumor initiation, progression and recurrences. IL-8, up-regulated in breast cancer, and associated with poor prognosis, increases CSC self-renewal in cell line models. It signals via two cell surface receptors, CXCR1 and CXCR2. Recently, the IL-8/CXCR1 axis was proposed as an attractive pathway for the design of specific therapies against breast cancer stem cells. Reparixin, a powerful CXCR1 inhibitor, was effective in reducing in vivo the tumour-initiating population in several NOD/SCID mice breast cancer models, showing that the selective targeting of CXCR1 and the combination of reparixin and docetaxel resulted in a concomitant reduction of the bulk tumour mass and CSC population. The available data indicate that IL-8, expressed by tumour cells and induced by chemotherapeutic treatment, is a key regulator of the survival and self-renewal of the population of CXCR1-expressing CSC. Consequently, this investigation on the mechanism of action of the reparixin/paclitaxel combination, was based on the observation that reparixin treatment contained the formation of metastases in several experimental models. However, specific data on the formation of breast cancer brain metastases, which carry remarkable morbidity and mortality to a substantial proportion of advanced breast cancer patients, have not been generated. The obtained data indicate a beneficial use of the drug combination reparixin and paclitaxel to counteract brain tumour metastasis due to CSC, probably due to the combined effects of the two drugs, the pro-apoptotic action of paclitaxel and the cytostatic and anti-migratory effects of reparixin.

Osteosarcoma (OS), a malignant tumor of bone, kills through aggressive metastatic spread almost exclusively to the lung. Mechanisms driving this tropism for lung tissue remain unknown, though likely invoke specific interactions between tumor cells and other cells within the lung metastatic niche. Aberrant overexpression of ΔNp63 in OS cells directly drives production of IL-6 and CXCL8. All these factors were expressed at higher levels in OS lung metastases than in matched primary tumors from the same patients. Expression in cell lines correlated strongly with lung colonization efficiency in murine xenograft models. Lentivirus-mediated expression endowed poorly metastatic OS cells with increased metastatic capacity. Disruption of IL-6 and CXCL8 signaling using genetic or pharmaceutical inhibitors had minimal effects on tumor cell proliferation in vitro or in vivo, but combination treatment inhibited metastasis across multiple models of metastatic OS. Strong interactions occurred between OS cells and both primary bronchial epithelial cells and bronchial smooth muscle cells that drove feed-forward amplification of IL-6 and CXCL8 production. These results identify IL-6 and CXCL8 as primary mediators of OS lung tropism and suggest pleiotropic, redundant mechanisms by which they might effect metastasis. Combination therapy studies demonstrate proof of concept for targeting these tumor-lung interactions to affect metastatic disease.

Background: Ischemia-reperfusion (IR) is a major contributor to graft rejection after liver transplantation. During IR injury, an intense inflammatory process occurs in the liver. Neutrophils are considered central players in the events that lead to liver injury. CXC chemokines mediate hepatic inflammation following reperfusion. However, few studies have demonstrated in real-time the behavior of recruited neutrophils. We used confocal intravital microscopy (IVM) to image neutrophil migration in the liver and to analyze in real-time parameters of neutrophil recruitment in the inflamed tissue in animals treated or not with reparixin, an allosteric antagonist of CXCR1/2 receptors. Material and Methods: WT and LysM-eGFP mice treated with reparixin or saline were subjected to 60 minutes of ischemia followed by different times of reperfusion. Mice received Sytox orange intravenously to show necrotic DNA in IVM. The effect of reparixin on parameters of local and systemic reperfusion-induced injury were also investigated. Results: Ischemia-reperfusion induced liver injury and inflammation, as evidenced by high levels of alanine aminotransferase (ALT) and myeloperoxidase (MPO) activity, chemokine and cytokine production and histological outcome. Treatment with reparixin significantly decreased neutrophil influx. Moreover, reparixin effectively suppressed the increase in serum concentrations of TNFα, IL-6 and CCL3, and the reperfusion-associated tissue damage. The number of neutrophils in the liver increased between 6h and 24h of reperfusion, whereas the distance traveled, velocity, neutrophil size and shape, and cluster formation reached a maximum 6h after reperfusion and then decreased gradually. In vivo imaging revealed that reparixin significantly decreased neutrophil infiltration and movement and displacement of recruited cells. Moreover, neutrophils had smaller size and less elongated shape in treated mice. Conclusions: Imaging of the liver by IVM was successfully implemented to describe neutrophil behavior in vivo during liver injury by IR. Treatment with reparixin decreased not only the recruitment of neutrophils in tissues but also their activation state and capacity to migrate within the liver. CXCR1/2 antagonists may be a promising therapy for patients undergoing liver transplantation. Keywords: Hepatic IR, chemokines, CXCR2, neutrophil-mediated liver injury.

BACKGROUND AND PURPOSE: Transient receptor potential (TRP) channels are a superfamily of non‐selective cation permeable channels involved in peripheral sensory signalling. Animal studies have shown that several TRPs are important players in pain modulation. Among them, the TRP melastatin 8 (TRPM8) has elicited more interest for its controversial role in nociception. This channel, expressed by a subpopulation of sensory neurons in dorsal root ganglia (DRG) and trigeminal ganglia (TG), is activated by cold temperatures and cooling agents. In experimental neuropathic pain models, an up‐regulation of this receptor in DRG and TG has been observed, suggesting a key role for TRPM8 in the development and maintenance of pain. Consistent with this hypothesis, TRPM8 knockout mice are less responsive to pain stimuli. EXPERIMENTAL APPROACH: In this study, the therapeutic potential and efficacy of two novel TRPM8 antagonists, DFL23693 and DFL23448, were tested. KEY RESULTS: Two potent and selective TRPM8 antagonists with distinct pharmacokinetic profiles, DFL23693 and DFL23448, have been fully characterized in vitro. In vivo studies in well‐established models, namely, the wet‐dog shaking test and changes in body temperature, confirmed their ability to block the TRPM8 channel. Finally, TRPM8 blockage resulted in a significant antinociceptive effect in formalin‐induced orofacial pain and in chronic constriction injury‐induced neuropathic pain, confirming an important role for this channel in pain perception. CONCLUSION AND IMPLICATIONS: Our findings, in agreement with previous literature, encourage further studies for a better comprehension of the therapeutic potential of TRPM8 blockers as novel agents for pain management.

Ketoprofen L-lysine salt (KLS), a NSAID, is widely used for its analgesic efficacy and tolerability. L-lysine salification was reported to increase the solubility and the gastric absorption and tolerance of ketoprofen. Since the management of NSAIDs gastrotoxicity still represents a major limitation in prolonged therapies, mainly when gastric lesions are present, this study investigated the gastro-protective activity of L-lysine by using a well-established model of gastric mucosa injury, the ethanol-gastric injury model. Several evidences show that the damaging action of ethanol could be attributed to the increase of ROS, which plays a key role in the increase of lipid peroxidation products, including malonyldialdehyde and 4-hydroxy-2-nonenal. With the aim to unravel the mechanism of L-lysine gastroprotection, cellular MDA levels and 4-HNE protein adducts as markers of lipid peroxidation and a panel of key endogenous gastro-protective proteins were assayed. The data obtained indicate a gastroprotective effect of L-lysine on gastric mucosa integrity. J. Cell. Physiol. 230: 813–820, 2015. © 2014 Wiley Periodicals, Inc.

ObjectiveELR+ CXC chemokines are heparin-binding cytokines signalling through the CXCR1 and CXCR2 receptors. ELR+ CXC chemokines have been associated with inflammatory arthritis due to their capacity to attract inflammatory cells. Here, we describe an unsuspected physiological function of these molecules in articular cartilage homeostasis.MethodsChemokine receptors and ligands were detected by immunohistochemistry, western blotting and RT-PCR. Osteoarthritis was induced in wild-type and CXCR2−/− mice by destabilisation of the medial meniscus (DMM). CXCR1/2 signalling was inhibited in vitro using blocking antibodies or siRNA. Chondrocyte phenotype was analysed using Alcian blue staining, RT-PCR and western blotting. AKT phosphorylation and SOX9 expression were upregulated using constitutively active AKT or SOX9 plasmids. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay.ResultsCXCL6 was expressed in healthy cartilage and was retained through binding to heparan sulfate proteoglycans. CXCR2−/− mice developed more severe osteoarthritis than wild types following DMM, with increased chondrocyte apoptosis. Disruption of CXCR1/2 in human and CXCR2 signalling in mouse chondrocytes led to a decrease in extracellular matrix production, reduced expression of chondrocyte differentiation markers and increased chondrocyte apoptosis. CXCR2-dependent chondrocyte homeostasis was mediated by AKT signalling since forced expression of constitutively active AKT rescued the expression of phenotypic markers and the apoptosis induced by CXCR2 blockade.ConclusionsOur study demonstrates an important physiological role for CXCR1/2 signalling in maintaining cartilage homeostasis and suggests that the loss of ELR+ CXC chemokines during cartilage breakdown in osteoarthritis contributes to the characteristic loss of chondrocyte phenotypic stability.

The article The Novel C5aR Antagonist DF3016A Protects Neurons Against Ischemic Neuroinflammatory Injury, written by Laura Brandolini, Marta Grannonico, Gianluca Bianchini, Alessia Colanardi, Pierluigi Sebastiani, Antonella Paladini, Alba Piroli, Marcello Allegretti, and Giustino Varrassi.

Ketoprofen L-lysine salt (KLS), is widely used due to its analgesic efficacy and tolerability, and L-lysine was reported to increase the solubility and the gastric tolerance of ketoprofen. In a recent report, L-lysine salification has been shown to exert a gastroprotective effect due to its specific ability to counteract the NSAIDs-induced oxidative stress and up-regulate gastroprotective proteins. In order to derive further insights into the safety and efficacy profile of KLS, in this study we additionally compared the effect of lysine and arginine, another amino acid counterion commonly used for NSAIDs salification, in control and in ethanol challenged human gastric mucosa model. KLS is widely used for the control of post-surgical pain and for the management of pain and fever in inflammatory conditions in children and adults. It is generally well tolerated in pediatric patients, and data from three studies in >900 children indicate that oral administration is well tolerated when administered for up to 3 weeks after surgery. Since only few studies have so far investigated the effect of ketoprofen on gastric mucosa maintenance and adaptive mechanisms, in the second part of the study we applied the cMap approach to compare ketoprofen-induced and ibuprofen-induced gene expression profiles in order to explore compound-specific targeted biological pathways. Among the several genes exclusively modulated by ketoprofen, our attention was particularly focused on genes involved in the maintenance of gastric mucosa barrier integrity (cell junctions, morphology, and viability). The hypothesis was further validated by Real-time PCR.