HSP90ß controls NLRP3 autoactivation.

Gain-of-function mutations in NLRP3 are linked to cryopyrin-associated periodic syndromes (CAPS). Although NLRP3 autoinflammasome assembly triggers inflammatory cytokine release, its activation mechanisms are not fully understood. Our study used a functional genetic approach to identify regulators of NLRP3 inflammasome formation. We identified the HSP90ß-SGT1 chaperone complex as crucial for autoinflammasome activation in CAPS. A deficiency in HSP90ß, but not in HSP90α, impaired the formation of ASC specks without affecting the priming and expression of inflammasome components. Conversely, activating NLRP3 with stimuli such as nigericin or alum bypassed the need for SGT1 and HSP90ß, suggesting the existence of alternative inflammasome assembly pathways. The role of HSP90ß was further demonstrated in PBMCs derived from CAPS patients. In these samples, the pathological constitutive secretion of IL-1ß could be suppressed using a pharmacological inhibitor of HSP90ß. This finding underscores the potential of SGT1-HSP90ß modulation as a therapeutic strategy in CAPS while preserving NLRP3's physiological functions.

The discovery of NLRP3 and its function in cryopyrin-associated periodic syndromes and innate immunity.

From studies of individual families to global collaborative efforts, the NLRP3 inflammasome is now recognized to be a key regulator of innate immunity. Activated by a panoply of pathogen-associated and endogenous triggers, NLRP3 serves as an intracellular sensor that drives carefully coordinated assembly of the inflammasome, and downstream inflammation mediated by IL-1 and IL-18. Initially discovered as the cause of the autoinflammatory spectrum of cryopyrin-associated periodic syndrome (CAPS), NLRP3 is now also known to play a role in more common diseases including cardiovascular disease, gout, and liver disease. We have seen cohesion in results from clinical studies in CAPS patients, ex vivo studies of human cells and murine cells, and in vivo murine models leading to our understanding of the downstream pathways, cytokine secretion, and cell death pathways that has solidified the role of autoinflammation in the pathogenesis of human disease. Recent advances in our understanding of the structure of the inflammasome have provided ways for us to visualize normal and mutant protein function and pharmacologic inhibition. The subsequent development of targeted therapies successfully used in the treatment of patients with CAPS completes the bench to bedside translational loop which has defined the study of this unique protein.

Subdural hemorrhage, macrocephaly, rash, and developmental delay in an infant: A pathogenic variant in NLRP3 causes CINCA/NOMID.

Subdural hemorrhages (SDHs) in children are most often observed in abusive head trauma (AHT), a distinct form of traumatic brain injury, but they may occur in other conditions as well, typically with clear signs and symptoms of an alternative diagnosis. We present a case of an infant whose SDH initially raised the question of AHT, but multidisciplinary evaluation identified multiple abnormalities, including rash, macrocephaly, growth failure, and elevated inflammatory markers, which were all atypical for trauma. These, along with significant cerebral atrophy, ventriculomegaly, and an absence of other injuries, raised concerns for a genetic disorder, prompting genetic consultation. Clinical trio exome sequencing identified a de novo likely pathogenic variant in NLRP3, which is associated with chronic infantile neurological, cutaneous, and articular (CINCA) syndrome, also known as neonatal-onset multisystem inflammatory disease (NOMID). He was successfully treated with interleukin-1 blockade, highlighting the importance of prompt treatment in CINCA/NOMID patients. This case also illustrates how atraumatic cases of SDH can be readily distinguished from AHT with multidisciplinary collaboration and careful consideration of the clinical history and exam findings.

Neutrophil-specific gain-of-function mutations in Nlrp3 promote development of cryopyrin-associated periodic syndrome.

Gain-of-function mutations in NLRP3 are responsible for a spectrum of autoinflammatory diseases collectively referred to as "cryopyrin-associated periodic syndromes" (CAPS). Treatment of CAPS patients with IL-1-targeted therapies is effective, confirming a central pathogenic role for IL-1ß. However, the specific myeloid cell population(s) exhibiting inflammasome activity and sustained IL-1ß production in CAPS remains elusive. Previous reports suggested an important role for mast cells (MCs) in this process. Here, we report that, in mice, gain-of-function mutations in Nlrp3 restricted to neutrophils, and to a lesser extent macrophages/dendritic cells, but not MCs, are sufficient to trigger severe CAPS. Furthermore, in patients with clinically established CAPS, we show that skin-infiltrating neutrophils represent a substantial biological source of IL-1ß. Together, our data indicate that neutrophils, rather than MCs, can represent the main cellular drivers of CAPS pathology.

The systemic autoinflammatory disorders for dermatologists. Part 1: overview.

The systemic autoinflammatory disorders (SAIDs) or periodic fever syndromes are disorders of innate immunity, which can be inherited or acquired. They are almost all very rare and easily overlooked; typically, patients will have seen multiple specialities prior to diagnosis, so a high level of clinical suspicion is key. It is important to note that these are 'high-value' diagnoses as the majority of these syndromes can be very effectively controlled, dramatically improving quality of life and providing protection against the development of irreversible complications such as AA amyloidosis. In this article, we take an overview of SAIDs and look at the common features; in Part 2, we take a more in-depth look at the better recognized or more dermatologically relevant conditions.

The systemic autoinflammatory disorders for dermatologists. Part 2: disease examples.

The systemic autoinflammatory disorders (SAIDS) or periodic fever syndromes are disorders of innate immunity, which can be inherited or acquired. They are almost all very rare and easily overlooked; typically, patients will have seen multiple specialities prior to diagnosis, so a high level of clinical suspicion is key. It is important to note that these are 'high-value' diagnoses as the majority of these syndromes can be very effectively controlled, dramatically improving quality of life and providing protection against the development of irreversible complications such as AA amyloidosis. In Part 1 of this review, we took an overview of SAIDS and described the common features; in this article, we take a more in-depth look at the better recognized or more dermatologically relevant conditions.

KN3014, a piperidine-containing small compound, inhibits auto-secretion of IL-1ß from PBMCs in a patient with Muckle-Wells syndrome.

NLRP3, an intracellular pattern recognition receptor, recognizes numerous pathogens and/or its own damage-associated molecules, and forms complexes with the adaptor protein ASC. These complexes constitute the NLRP3 inflammasome, a platform for processing interleukin (IL)-1ß and/or IL-18. Several NLRP3 mutations result in constitutive activation of the NLRP3 inflammasome, causing cryopyrin-associated periodic syndrome (CAPS). To the best of our knowledge, small compounds that specifically inhibit inflammasome activation through the pyrin domain (PYD) have not yet been developed. This study describes an attempt to develop small compounds targeting the NLRP3 inflammasome. A core chemical library of 9,600 chemicals was screened against reconstituted NLRP3 inflammasome in a cell-free system with an amplified luminescence proximity homogeneous assay and a cell-based assay by human peripheral blood mononuclear cells (PBMCs). Inflammasome activation was evaluated by ASC-speck formation in human PBMCs, accompanied by IL-1ß secretion and processing, and by using IL-1ß-based dual operating luciferase (IDOL) mice. The activity of these compounds was evaluated clinically using PBMCs from a patient with Muckle-Wells syndrome (MWS), a type of CAPS, with an R260W mutation in NLRP3. Screening identified KN3014, a piperidine-containing compound targeting the interaction between NLRP3 and ASC through the PYD. KN3014 reduced ASC-speck formation in human PBMCs, luminescence from IDOL mice, and auto-secretion of IL-1ß by PBMCs from the patient with MWS. These findings suggest that KN3014 may be an attractive candidate for treatment of MWS, as well as other NLRP3 inflammasomopathies.

Slc6a3-dependent expression of a CAPS-associated Nlrp3 allele results in progressive behavioral abnormalities and neuroinflammation in aging mice.

BACKGROUND: An association between neuroinflammation and age-related neurologic disorders has been established but the molecular mechanisms and cell types involved have not been thoroughly characterized. Activity of the proinflammatory NLRP3 inflammasome is implicated in Alzheimer's and Parkinson's disease and our recent studies in patients suggest that dopaminergic neurons within the degenerating mesencephalon express NLRP3 throughout the progression of PD. Here, we directly test the impact of enhanced inflammasome activity in mesencephalic neurons by characterizing motor function, tissue integrity, and neuroinflammation in aging mice harboring hyperactivating mutations within the endogenous murine Nlrp3 locus, enabled only in cells expressing the dopaminergic neuron-specific Slc6a3 promoter. METHODS: We compared mice harboring inducible alleles encoding the cryopyrin-associated periodic syndrome activating mutations Nlrp3A350V and Nlrp3L351P inserted into the endogenous mouse Nlrp3 locus. Tissue specific expression was driven by breeding these animals with mice expressing Cre recombinase under the control of the dopaminergic neuron-specific Slc6a3 promoter. The experimental mice, designed to express hyperactive NLRP3 only when the endogenous mouse Nlrp3 promotor is active in dopaminergic neurons, were analyzed throughout 18 months of aging using longitudinal motor function assessments. Biochemical and histologic analyses of mesencephalic tissues were conducted in 1- and 18-month-old animals. RESULTS: We observed progressive and significant deficits in motor function in animals expressing Nlrp3L351P, compared with animals expressing Nlrp3WT and Nlrp3A350V. Age-dependent neuroinflammatory changes in the mesencephalon were noted in all animals. Analysis of GFAP-immunoreactive astrocytes in the substantia nigra revealed a significant increase in astrocyte number in animals expressing Nlrp3L351P compared with Nlrp3WT and Nlrp3A350V. Further analysis of Nlrp3L351P striatal tissues indicated genotype specific gliosis, elevated Il1b expression, and both morphologic and gene expression indicators of proinflammatory A1 astrocytes. CONCLUSIONS: Dopaminergic neurons have the potential to accumulate NLRP3 inflammasome activators with age, including reactive oxygen species, dopamine metabolites, and misfolded proteins. Results indicate the Nlrp3 locus is active in dopaminergic neurons in aging mice, and that the hyperactive Nlrp3L351P allele can drive neuroinflammatory changes in association with progressive behavioral deficits. Findings suggest neuronal NLRP3 inflammasome activity may contribute to neuroinflammation observed during normal aging and the progression of neurologic disorders.

ß-Glucan-induced reprogramming of human macrophages inhibits NLRP3 inflammasome activation in cryopyrinopathies.

Exposure of mononuclear phagocytes to ß-glucan, a naturally occurring polysaccharide, contributes to the induction of innate immune memory, which is associated with long-term epigenetic, metabolic, and functional reprogramming. Although previous studies have shown that innate immune memory induced by ß-glucan confers protection against secondary infections, its impact on autoinflammatory diseases, associated with inflammasome activation and IL-1ß secretion, remains poorly understood. In particular, whether ß-glucan-induced long-term reprogramming affects inflammasome activation in human macrophages in the context of these diseases has not been explored. We found that NLRP3 inflammasome-mediated caspase-1 activation and subsequent IL-1ß production were reduced in ß-glucan-reprogrammed macrophages. ß-Glucan acted upstream of the NLRP3 inflammasome by preventing potassium (K+) efflux, mitochondrial ROS (mtROS) generation, and, ultimately, apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization and speck formation. Importantly, ß-glucan-induced memory in macrophages resulted in a remarkable attenuation of IL-1ß secretion and caspase-1 activation in patients with an NLRP3-associated autoinflammatory disease, cryopyrin-associated periodic syndromes (CAPS). Our findings demonstrate that ß-glucan-induced innate immune memory represses IL-1ß-mediated inflammation and support its potential clinical use in NLRP3-driven diseases.

Phenotype variability of autoinflammatory disorders in the pediatric patient: A pictorial overview.

Disruption of innate immunity leading to systemic inflammation and multi-organ dysfunction is the basilar footprint of autoinflammatory disorders (AIDs), ranging from rare hereditary monogenic diseases to a large number of common chronic inflammatory conditions in which there is a simultaneous participation of multiple genetic components and environmental factors, sometimes combined with autoimmune phenomena and immunodeficiency. Whatever their molecular mechanism, hereditary AIDs are caused by mutations in regulatory molecules or sensors proteins leading to dysregulated production of proinflammatory cytokines or cytokine-inducing transcription factors, fever, elevation of acute phase reactants, and a portfolio of manifold inflammatory signs which might occur in a stereotyped manner, mostly with overactivity or misactivation of different inflammasomes. Symptoms might overlap in the pediatric patient, obscuring the final diagnosis of AIDs and delaying the most appropriate treatment. Actually, the fast-paced evolution of scientific knowledge has led to recognize or reclassify an overgrowing number of multifactorial diseases, which share the basic pathogenetic mechanisms with AIDs. The wide framework of classic hereditary periodic fevers, AIDs with prominent skin involvement, disorders of the ubiquitin-proteasome system, defects of actin cytoskeleton dynamics, and also idiopathic nonhereditary febrile syndromes occurring in children is herein presented. Interleukin-1 dependence of these diseases or involvement of other predominating molecules is also discussed.

A novel knock-in mouse model of cryopyrin-associated periodic syndromes with development of amyloidosis: Therapeutic efficacy of proton pump inhibitors.

BACKGROUND: Cryopyrin-associated periodic syndromes (CAPS) are a group of autoinflammatory diseases linked to gain-of-function mutations in the NOD-like receptor family, pyrin domain containing 3 (NLRP3) gene, which cause uncontrolled IL-1ß secretion. Proton pump inhibitors (PPIs), which are commonly used as inhibitors of gastric acid production, also have anti-inflammatory properties, protect mice from sepsis, and prevent IL-1ß secretion by monocytes from patients with CAPS. OBJECTIVE: We sought to develop a novel Nlrp3 knock-in (KI) mouse model of CAPS to study amyloidosis, a severe CAPS complication, and test novel therapeutic approaches. METHODS: We generated KI mice by engineering the N475K mutation, which is associated with the CAPS phenotype, into the mouse Nlrp3 gene. KI and wild-type mice received PPIs or PBS intraperitoneally and were analyzed for survival, inflammation, cytokine secretion, and amyloidosis development. RESULTS: Mutant Nlrp3 KI mice displayed features that recapitulate the immunologic and clinical phenotype of CAPS. They showed systemic inflammation with high levels of serum proinflammatory cytokines, inflammatory infiltrates in various organs, and amyloid deposits in the spleen, liver, and kidneys. Toll-like receptor stimulated macrophages from KI mice secreted high levels of IL-1ß, IL-18, and IL-1α but low amounts of IL-1 receptor antagonist. Treatment of KI mice with PPIs had a clear clinical effect, showing a reduction in inflammatory manifestations, regression of amyloid deposits, and normalization of proinflammatory and anti-inflammatory cytokine production by macrophages. CONCLUSION: Nlrp3 KI mice displayed a CAPS phenotype with many characteristics of autoinflammation, including amyloidosis. The therapeutic effectiveness of PPIs associated with a lack of toxicity indicates that these drugs could represent relevant adjuvants to the anti-IL-1 drugs in patients with CAPS and other IL-1-driven diseases.

Choline Uptake and Metabolism Modulate Macrophage IL-1ß and IL-18 Production.

Choline is a vitamin-like nutrient that is taken up via specific transporters and metabolized by choline kinase, which converts it to phosphocholine needed for de novo synthesis of phosphatidylcholine (PC), the main phospholipid of cellular membranes. We found that Toll-like receptor (TLR) activation enhances choline uptake by macrophages and microglia through induction of the choline transporter CTL1. Inhibition of CTL1 expression or choline phosphorylation attenuated NLRP3 inflammasome activation and IL-1ß and IL-18 production in stimulated macrophages. Mechanistically, reduced choline uptake altered mitochondrial lipid profile, attenuated mitochondrial ATP synthesis, and activated the energy sensor AMP-activated protein kinase (AMPK). By potentiating mitochondrial recruitment of DRP1, AMPK stimulates mitophagy, which contributes to termination of NLRP3 inflammasome activation. Correspondingly, choline kinase inhibitors ameliorated acute and chronic models of IL-1ß-dependent inflammation.

Progressive waves of IL-1ß release by primary human monocytes via sequential activation of vesicular and gasdermin D-mediated secretory pathways.

IL-1ß is an essential cytokine, but its release needs to be strictly controlled to avoid severe inflammatory manifestations. Lacking a signal sequence, IL-1ß does not follow the endoplasmic reticulum-Golgi route. Several pathways have been proposed to mediate its release. One involves the translocation of pro-IL-1ß into intracellular vesicles of lysosomal origin that eventually fuse with the plasma membrane. Another exploits pores formed on the plasma membrane upon proteolytic cleavage of gasdermin D (GSDMD). Here we investigated how primary monocytes-the main source of IL-1ß in humans-control IL-1ß release in response to pro-inflammatory stimuli of increasing intensity and found that two different routes are induced depending on the strength of activation. Triggering of Toll-like receptor 4 (TLR4) by LPS induces slow IL-1ß release through LAMP2A+ vesicles. In contrast, the simultaneous stimulation of TLR2, TLR4 and TLR7/8 drives high levels of ROS, GSDMD cleavage and faster IL-1ß secretion. Drugs blocking ROS production prevent GSDMD cleavage supporting a role of oxidative stress in GSDMD-mediated secretion. Singly stimulated monocytes undergo apoptosis, whereas triple stimulation triggers pyroptosis, which might amplify inflammation. In both cases, however, IL-1ß secretion precedes cell death. Inhibition of caspases 4/5 prevents GSDMD cleavage and pore-mediated secretion, but not vesicular release. The two pathways also display other distinct pharmacologic sensitivities that reflect the underlying mechanisms. Remarkably, single TLR4 stimulation is sufficient to activate massive, GSDMD-mediated IL-1ß secretion in monocytes from patients affected by Cryopyrin Associated Periodic Syndrome (CAPS), an autoinflammatory disease linked to NLRP3 mutations. The exaggerated sensitivity to activation correlates with high basal ROS levels in CAPS monocytes. In conclusion, the vesicular pathway limits IL-1ß release upon low pathogen load while stronger stimulation or concomitant cell stress induce instead uncontrolled secretion via GSDMD leading to detrimental inflammatory manifestations.

Complement receptor CD46 co-stimulates optimal human CD8+ T cell effector function via fatty acid metabolism.

The induction of human CD4+ Th1 cells requires autocrine stimulation of the complement receptor CD46 in direct crosstalk with a CD4+ T cell-intrinsic NLRP3 inflammasome. However, it is unclear whether human cytotoxic CD8+ T cell (CTL) responses also rely on an intrinsic complement-inflammasome axis. Here we show, using CTLs from patients with CD46 deficiency or with constitutively-active NLRP3, that CD46 delivers co-stimulatory signals for optimal CTL activity by augmenting nutrient-influx and fatty acid synthesis. Surprisingly, although CTLs express NLRP3, a canonical NLRP3 inflammasome is not required for normal human CTL activity, as CTLs from patients with hyperactive NLRP3 activity function normally. These findings establish autocrine complement and CD46 activity as integral components of normal human CTL biology, and, since CD46 is only present in humans, emphasize the divergent roles of innate immune sensors between mice and men.

[Renal amyloidosis revealing a cryopyrin associated periodic syndrome]. / Amylose rénale faisant découvrir un syndrome périodique associé à la cryopyrine.

INTRODUCTION: Cryopyrin associated periodic syndrome is a rare auto inflammatory disease including three clinical entities with a common genetic cause. Among these three entities, Muckle-Wells syndrome is described as an intermediate phenotype associated with a progressive sensorineural hearing loss and AA amyloidosis. The present case reports a renal AA amyloidosis associated with an IgA nephropathy, revealing a Muckle-Wells syndrome. OBSERVATION: The case is reported of a 38-years-old patient who presented a renal failure revealed concomitantly with a macroscopic hematuria exploration. Urological investigations were performed with negative results. The patient had no particular background except urticarial rashes, unlabeled inflammatory rheumatism and a grandmother's amyloidosis. Renal biopsy revealed glomerular, vascular and interstitial AA amyloidosis associated to an IgA nephropathy. This amyloidosis was known to be a part of Muckle-Wells syndrome, and a NLRP3 gene study confirmed the diagnosis. CONCLUSION: Cryopyrin associated periodic syndrome is a rare disease and the clinical diagnosis suspicion need genetic confirmation. AA amyloidosis is known to happen in Muckle-Wells syndrome. Other occasional renal impairments are described in this syndrome whereas the IgA nephropathy association remains poorly characterized.

Participation of pro-inflammatory cytokines in neuropathic pain evoked by chemotherapeutic oxaliplatin via central GABAergic pathway.

Background Neuropathic pain is observed in patients as chemotherapeutic oxaliplatin is used to treat metastatic digestive tumors; however, the mechanisms responsible for hyperalgesia are not well understood. Chronic neuroinflammation is one of the hallmarks of pathophysiology of neuropathic pain. Since the midbrain periaqueductal gray is an important component of the descending inhibitory pathway controlling on central pain transmission, we examined the role for pro-inflammatory cytokines system of the periaqueductal gray in regulating mechanical hyperalgesia and cold hypersensitivity evoked by oxaliplatin. Methods Neuropathic pain was induced by intraperitoneal injection of oxaliplatin in rats. ELISA and western blot analysis were used to examine pro-inflammatory cytokine levels and their receptors expression. Results IL-1ß, IL-6, and TNF-α were elevated within the periaqueductal gray of oxaliplatin rats. Protein expression of IL-1ß, IL-6, and TNF-α receptors (namely, IL-1R, IL-6R, and TNFR subtype TNFR1) in the plasma membrane periaqueductal gray of oxaliplatin rats was upregulated, whereas the total expression of pro-inflammatory cytokine receptors was not altered. In oxaliplatin rats, impaired inhibitory gamma-aminobutyric acid within the periaqueductal gray was accompanied with decreases in withdrawal thresholds to mechanical stimulus and % time spent on the cold plate. Our data further showed that the concentrations of gamma-aminobutyric acid were largely restored by blocking those pro-inflammatory cytokine receptors in periaqueductal gray of oxaliplatin rats; and mechanical hyperalgesia and cold hypersensitivity evoked by oxaliplatin were attenuated. Stimulation of gamma-aminobutyric acid receptors in the periaqueductal gray also blunted neuropathic pain in oxaliplatin rats. Conclusions Our data suggest that the upregulation of pro-inflammatory cytokines and membrane pro-inflammatory cytokine receptor in the periaqueductal gray of oxaliplatin rats is likely to impair the descending inhibitory pathways in regulating pain transmission and thereby contributes to the development of neuropathic pain after application of chemotherapeutic oxaliplatin.

A dermatologic perspective on autoinflammatory diseases.

Autoinflammatory diseases (AIDs) encompass a heterogeneous group of disorders pathogenetically related to an abnormal activation of the innate immunity and clinically characterised by aseptic inflammation in the affected organs in the absence of high titer of circulating autoantibodies or autoreactive T cells. In classic monogenic AIDs, the skin is frequently involved with a wide range of cutaneous lesions. Monogenic AIDs result from different mutations in a single gene, which regulates the innate immunity. These mutations cause an uncontrolled activation of the inflammasome, leading to an overexpression of interleukin (IL)- 1ß. IL-1ß is the pivotal cytokine which is responsible for the exaggerated production of cytokines and chemokines that induce the recruitment of neutrophils, key cells in autoinflammation. Paradigmatic autoinflammatory forms are the cryopyrin-associated periodic syndromes (CAPS), whose skin involvement consists of urticarial lesions. Similar IL-1ß-mediated autoinflammatory pathomechanisms also occur in deficiency of IL-1 receptor antagonist (DIRA) and deficiency of IL-36 receptor antagonist (DITRA), whose cutaneous appearance is characterised by pustular lesions, as well as in pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome. Pyoderma gangrenosum, which is the cutaneous hallmark of the PAPA syndrome, is a prototypic neutrophil-mediated skin disease, manifesting as single or multiple ulcers with undermined, raised erythematous to violaceous borders. This review is focused on the CAPS, DIRA/DITRA and PAPA syndromes with emphasis on their cutaneous manifestations, as well as their histology and pathophysiology.

Involvement of pro-inflammation signal pathway in inhibitory effects of rapamycin on oxaliplatin-induced neuropathic pain.

Background Oxaliplatin is a third-generation chemotherapeutic agent that is commonly used to treat metastatic digestive tumors; however, one of the main limiting complications of oxaliplatin is painful peripheral neuropathy. The purpose of this study was to examine the underlying mechanisms by which mammalian target of rapamycin (mTOR) and its signal are responsible for oxaliplatin-evoked neuropathic pain. Methods Neuropathic pain was induced by intraperitoneal injection of oxaliplatin in rats. ELISA and Western blot analysis were used to examine the levels of pro-inflammatory cytokines (including interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α) and the expression of mTOR signal pathway. Results Oxaliplatin increased mechanical and cold sensitivity as compared with control animals ( P < 0.05 vs. control rats). Oxaliplatin also amplified the expression of p-mTOR and mTOR-mediated phosphorylation of p70 ribosomal S6 protein kinase 1 and 4E-binding protein 1 in the lumbar dorsal root ganglion. Blocking mTOR using rapamycin attenuated peripheral painful neuropathy observed in oxaliplatin rats ( P < 0.05 vs. vehicle control). This inhibitory effect was accompanied with decreases of IL-1ß, IL-6, and TNF-α. In addition, inhibition of phosphatidylinositide 3-kinase (p-PI3K) attenuated the expression of p-mTOR and the levels of pro-inflammatory cytokines in oxaliplatin rats, and this further attenuated mechanical and cold hypersensitivity. Conclusions The data revealed specific signaling pathways leading to oxaliplatin-induced peripheral neuropathic pain, including the activation of PI3K-mTOR and pro-inflammatory cytokine signal. Inhibition of these pathways alleviates neuropathic pain. Targeting one or more of these molecular mediators may present new opportunities for treatment and management of neuropathic pain observed during chemotherapeutic application of oxaliplatin.

Repositioning Drugs for Rare Immune Diseases: Hopes and Challenges for a Precision Medicine.

Human primary immunodeficiency diseases (PIDs) are a large group of rare diseases and are characterized by a great genetic and phenotypic heterogeneity. A large subset of PIDs is genetically defined, which has a crucial impact for the understanding of the molecular basis of disease and the development of precision medicine. Discovery and development of new therapies for rare diseases has long been de-privileged due to the length and cost of the processes involved. Interest has increased due to stimulatory regulatory and supportive reimbursement environments enabling viable business models. Advancements in biomedical and computational sciences enable the development of rational, designed approaches for identification of novel indications of already approved drugs allowing faster delivery of new medicines. Drug repositioning is based either on clinical analogies of diseases or on understanding of the molecular mode of drug action and mechanisms of the disease. All of these are the basis for the development of precision medicine.