Multiple Cranial Neuropathies and Pachymeningitis in a Patient With a Pathogenic Nucleotide-Binding Oligomerization Domain 2 Polymorphism.

ABSTRACT: An 11-year-old boy presented with 2 weeks of intermittent headache, right orbital pain, and constant diplopia. Brain MRI showed dural thickening and enhancement of the right lateral cavernous sinus, right orbital apex, and tentorium. Initial cerebral spinal fluid analysis showed only mild pleocytosis, and serum diagnostics were unrevealing. The working diagnosis was Tolosa-Hunt syndrome. His pain and sixth nerve palsy resolved with corticosteroids. Five months after initial presentation, he developed new numbness of the right cheek, complete right ophthalmoplegia, and weakness and numbness of his right hand and leg, all of which were responsive to steroids. Fifteen months later, he returned to the emergency department with 2 weeks of left-sided headaches and acute diplopia. On examination, he had a left cranial nerve 6 palsy. Dural biopsy showed diffuse mononuclear inflammatory cell reaction consisting mostly of lymphocytes with no signs of granuloma formation, nor any epithelioid or giant cells. His clinical course was consistent with an autoinflammatory condition of unknown etiology. Genetic testing with an immunodeficiency panel showed a risk allele in NOD2 (nucleotide-binding oligomerization domain 2) c.3019dup (p.Leu1007Prof*2) that is associated with an increased risk for Crohn disease. His clinical condition had similarities to central nervous system sarcoidosis. Because of the similarities between our patient's clinical, imaging, and genetic findings and neurosarcoidosis, he was switched to a more targeted therapy-infliximab. His condition has since been stable for nearly 2 years. In conclusion, genetic testing should be considered in patients with suspected occult autoimmunity.

MAPKs and NF-κB-mediated acrylamide-induced neuropathy in rat striatum and human neuroblastoma cells SY5Y.

Acrylamide (ACR) is a potent neurotoxin that can be produced during high-temperature food processing, but the underlying toxicological mechanism remains unclear. In this study, the detrimental effects of ACR on the striatal dopaminergic neurons and the roles of mitogen-activated protein kinases (MAPKs) and nuclear factor κB (NF-κB) in ACR-induced neuronal apoptosis were investigated. Acute ACR exposure caused dopaminergic neurons loss and apoptosis as revealed by decreased tyrosine hydroxylase (TH)-positive cells and TH protein level and increased terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells in the striatum. ACR-decreased glutathione content, increased levels of malondialdehyde, proinflammatory cytokines tumor necrosis factor α, and interleukin 6. In addition, nuclear NF-κB and MAPKs signaling pathway with c-Jun N-terminal kinase (JNK) and p38 were activated by ACR. Specific inhibitors were used to explore the roles of MAPKs and NF-κB pathways in ACR-induced apoptosis in SH-SY5Y cells. Pretreatment with JNK-specific inhibitors SP600125 markedly upregulated the reduced B-cell lymphoma 2 (Bcl-2) content and downregulated the increased Bcl-2-associated X protein (Bax) level and thereby eventually reduced the proportions of early and late apoptotic cells induced by ACR, while p38 suppression by SB202190 only reversed the decrease in Bcl-2 expression. Inhibition of NF-κB by BAY 11-7082 markedly upregulated Bax level and decreased Bcl-2 expression, and eventually increasing the proportions of neuronal apoptosis compared with that in ACR alone. These results suggested that JNK contributed to ACR-induced apoptosis, while NF-κB acted as a protective regulator in response to ACR-induced neuropathy. This study helps to offer a deeper insight into the mechanism of ACR-induced neuropathy.

Neurocan is a New Substrate for the ADAMTS12 Metalloprotease: Potential Implications in Neuropathies.

BACKGROUND/AIMS: The composition of the extracellular matrix (ECM) in the central nervous system (CNS) has several features that make it unique. For instance, it is remarkable for the presence of proteoglycans such as versican, brevican, and neurocan, some of which have been identified as substrates of different members of the ADAMTS family of secreted metalloproteases. Previous studies have associated ADAMTSs with the repair of the CNS, including recovery following degradation of glial scar tissue and the stimulation of axonal growth after brain injury. However, the involvement of ADAMTSs in diseases of the CNS is complex and not understood fully, and a current challenge is unraveling the precise roles of these metalloproteases in the brain. METHODS: ADAMTS12 and neurocan gene expression was examined by quantitative PCR. Western blot analysis was employed to detect ADAMTS12 and neurocan protein expression in cell lines, and immunostaining techniques were used to detect neurocan in mouse brain tissues. Neurocan cleavage using recombinant ADAMTS1, ADAMTS4, ADAMTS5, and ADAMTS12 metalloproteases was evaluated by western blotting. Cell adhesion and migration were assessed using uncoated culture dishes or dishes coated with Matrigel or ECM components. RESULTS: We identified neurocan as a novel component of brain ECM that can be cleaved by ADAMTS12. In addition, we showed that neurocan cleavage by ADAMTS12 altered the adhesive properties of the human neuroglioma H4 cell line. Moreover, immunohistochemical analysis of Adamts12-deficient mice revealed the significant accumulation of neurocan in the brain of neonatal mice. CONCLUSION: Overall, our results suggest that ADAMTS12 could be involved in the repair of the CNS through its ability to degrade neurocan. Moreover, it can be inferred that alterations in neurocan degradation processes could be associated with the pathogenesis of neurological disorders.

Spatiotemporal control of mitochondrial network dynamics in astroglial cells.

Mitochondria are increasingly recognized for playing important roles in regulating the evolving metabolic state of mammalian cells. This is particularly true for nerve cells, as dysregulation of mitochondrial dynamics is invariably associated with a number of neuropathies. Accumulating evidence now reveals that changes in mitochondrial dynamics and structure may play equally important roles also in the cell biology of astroglial cells. Astroglial cells display significant heterogeneity in their morphology and specialized functions across different brain regions, however besides fundamental differences they seem to share a surprisingly complex meshwork of mitochondria, which is highly suggestive of tightly regulated mechanisms that contribute to maintain this unique architecture. Here, we summarize recent work performed in astrocytes in situ indicating that this may indeed be the case, with astrocytic mitochondrial networks shown to experience rapid dynamic changes in response to defined external cues. Although the mechanisms underlying this degree of mitochondrial re-shaping are far from being understood, recent data suggest that they may contribute to demarcate astrocyte territories undergoing key signalling and metabolic functions.

Human aminoacyl-tRNA synthetases in diseases of the nervous system.

Aminoacyl-tRNA synthetases (AaRSs) are ubiquitously expressed enzymes that ensure accurate translation of the genetic information into functional proteins. These enzymes also execute a variety of non-canonical functions that are significant for regulation of diverse cellular processes and that reside outside the realm of protein synthesis. Associations between faults in AaRS-mediated processes and human diseases have been long recognized. Most recent research findings strongly argue that 10 cytosolic and 14 mitochondrial AaRSs are implicated in some form of pathology of the human nervous system. The advent of modern whole-exome sequencing makes it all but certain that similar associations between the remaining 15 ARS genes and neurologic illnesses will be defined in future. It is not surprising that an intense scientific debate about the role of translational machinery, in general, and AaRSs, in particular, in the development and maintenance of the healthy human neural cell types and the brain is sparked. Herein, we summarize the current knowledge about causative links between mutations in human AaRSs and diseases of the nervous system and briefly discuss future directions.

SBF1 mutations associated with autosomal recessive axonal neuropathy with cranial nerve involvement.

Biallelic mutations in the SBF1 gene have been identified in one family with demyelinating Charcot-Marie-Tooth disease (CMT4B3) and two families with axonal neuropathy and additional neurological and skeletal features. Here we describe novel sequence variants in SBF1 (c.1168C>G and c.2209_2210del) as the potential causative mutations in two siblings with severe axonal neuropathy, hearing loss, facial weakness and bulbar features. Pathogenicity of these variants is supported by co-segregation and in silico analyses and evolutionary conservation. Our findings suggest that SBF1 mutations may cause a syndromic form of autosomal recessive axonal neuropathy (AR-CMT2) in addition to CMT4B3.

Gastrointestinal and feeding difficulties in CHARGE syndrome: A review from head-to-toe.

CHARGE syndrome is an autosomal dominant genetic condition that is primarily diagnosed based on clinical features, with genetic testing available for confirmation. The CHARGE mnemonic stands for some of the common characteristics: coloboma, heart defects, atresia/stenosis of the choanae, retardation of growth/development, genitourinary anomalies, and ear abnormalities (CHARGE). However, many of the common clinical features are not captured by this mnemonic, including cranial nerve dysfunction, considered by some to be one of the major diagnostic criteria. Over 90% of individuals experience feeding and gastrointestinal dysfunction, which carries great morbidity and mortality. The aim of this review is to examine the nature of gastrointestinal (GI) symptoms and feeding difficulties in CHARGE syndrome, focusing on their underlying pathology, associated investigations, and available treatment options. We also provide information on available tools (for parents, clinicians, and researchers) that are important additions to the lifelong healthcare management of every individual with CHARGE syndrome. We review how cranial nerve dysfunction is one of the most important characteristics underlying the pervasive GI and feeding dysfunction, and discuss the need for future research on gut innervation and motility in this genetic disorder.

A girl with developmental delay, ataxia, cranial nerve palsies, severe respiratory problems in infancy-Expanding NDST1 syndrome.

NDST1 encodes an enzyme involved in the first steps in the synthesis of heparan sulfate chains, proteoglycans that are regulators found on the cell surface and in the extracellular matrix. Eight individuals homozygous for one of four family-specific missense mutations in the sulfotransferase domain of the enzyme have been described. They have intellectual disability. Some additionally had hypotonia, ataxia. seizures, and/or short stature, but none had history of respiratory problems. No humans with homozygous null mutations are known. ndst1b (orthologous to NDST1) morpholino knockdown in zebrafish (Danio rerio) causes delayed development, craniofacial cartilage abnormalities, shortened body and pectoral fin length. Ndst1 homozygous null mice have craniofacial abnormalities and die within the first 10 h of life of respiratory failure. We report a girl upon whom deep phenotyping, extensive genetic and biochemical investigations, and exome sequencing were performed. She had cranial nerves dysfunction, gastroesophageal reflux, history of a seizure, ataxia, developmental delays, head sparing failure to thrive, and minor malformations including distinctive facial features and a bifid uvula. Compound heterozygous mutations in NDST1 were identified, in the heparan sulfate N deacetylatase domain of one allele and the sulfotransferase domain of the other allele. This report expands the phenotypic spectrum of Ndst1 deficiency in humans. © 2017 Wiley Periodicals, Inc.

Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes.

OBJECTIVE: To report baseline articular, functional and ocular findings of the first international prospective cohort study of Blau syndrome (BS). METHODS: Three-year, multicentre, observational study on articular, functional (HAQ, Childhood HAQ and VAS global and pain), ophthalmological, therapeutic and radiological data in BS patients. RESULTS: Baseline data on the first 31 recruited patients (12 females and 19 males) from 18 centres in 11 countries are presented. Of the 31 patients, 11 carried the p.R334W NOD2 mutation, 9 the p.R334Q and 11 various other NOD2 missense mutations; 20 patients were sporadic and 11 from five BS pedigrees. Median disease duration was 12.8 years (1.1-57). Arthritis, documented in all but one patient, was oligoarticular in 7, polyarticular in 23. The median active joint count was 21. Functional capacity was normal in 41%, mildly impaired in 31% and moderate-severe in 28% of patients. The most frequently involved joints at presentation were wrists, ankles, knees and PIPs. On radiographs, a symmetrical non-erosive arthropathy was shown. Previously unknown dysplastic bony changes were found in two-thirds of patients. Ocular disease was documented in 25 of 31 patients, with vitreous inflammation in 64% and moderate-severe visual loss in 33%. Expanded manifestations (visceral, vascular) beyond the classic clinical triad were seen in 52%. CONCLUSION: BS is associated with severe ocular and articular morbidity. Visceral involvement is common and may be life-threatening. Bone dysplastic changes may show diagnostic value and suggest a previously unknown role of NOD2 in bone morphogenesis. BS is resistant to current drugs, suggesting the need for novel targeted therapies.

Clinical and transcriptional response to the long-acting interleukin-1 blocker canakinumab in Blau syndrome-related uveitis.

OBJECTIVE: To report on the clinical response to canakinumab in a patient with sporadic nucleotide-binding oligomerization domain-containing protein 2 (NOD-2)-associated pediatric granulomatous arthritis (Blau syndrome) and severe resistant panuveitis, and to describe gene expression profile changes throughout such treatment. METHODS: A 4-year-old boy was diagnosed as having Blau syndrome on the basis of typical clinical features, histologic evidence of noncaseating granulomas, and a NOD2 mutation. Ocular involvement was initially controlled by topical and oral corticosteroids, but over the years visual impairment and complications, such as macular edema and retinal detachment, progressed. Ocular disease remained persistently active despite treatment with multiple different immunosuppressants; therefore, canakinumab treatment was started. Before and during the first 6 months of treatment, the gene expression profile was determined each month. RESULTS: Canakinumab treatment was well tolerated and led to rapid quiescence of uveitis, which had been continuously active before this treatment. Gene expression profiling analysis of the patient's blood prior to initiation of interleukin-1 (IL-1) blockade revealed differential expression of 1,993 transcripts when compared to healthy controls, and among the up-regulated transcripts, pathway analysis showed that the predominant network consisted of innate immunity-related transcripts. The transcriptional signature of the patient overlapped with the transcriptional signature of patients with systemic-onset juvenile idiopathic arthritis, and canakinumab treatment led to the normalization of most of these transcriptional changes. CONCLUSION: The pathogenesis of Blau syndrome may be mediated by IL-1, and canakinumab may be useful when this disorder is unresponsive to more conventional treatments.

Leprous polyneuritis cranialis mimicking orbital apex syndrome.

Leprosy is one of the most prevalent infections in India, with our country accounting for almost 60 percent of the world's patients. Hence unusual presentations of leprosy should be sought for and treated at the earliest. We report this rare case of polyneuritis cranialis secondary to leprosy. Affection ofa single cranial nerve has been described previously but there is only one report of leprosy presenting like orbital apex syndrome.

Long-Term Visual Outcome of Patients with Blau Syndrome.

PURPOSE: To document the long-term visual outcomes in patients with Blau syndrome. METHODS: A retrospective institutional cohort study was conducted, and 13 patients with genetically confirmed Blau syndrome were included. Demographic and clinical data were collected from standardised medical charts. Baseline was defined as the first detected uveitis and data were recorded onwards at intervals of 1, 3, 5, 10, 15 and 20 years. RESULTS: Anterior uveitis was the most common classification at baseline (57.1%). Among patients with documented uveitis lasting 10 years or more, all of them developed panuveitis. Median logMAR visual acuity at baseline was 0 (range -0.5; 0.7), 0.19 (range 0; 1.5) at year 5, and 0.7 (range 0.1 - no perception of light) at year 20, as recorded in 13, 16, and 10 eyes, respectively. All patients received treatment with topical and oral steroids, and multiple systemic immunosuppressants including biologics. Disease control, defined as having cells <1+ in both eyes and using topical steroid eye drops less than twice daily, was achieved in 14.3% to 37.5% of patients at the different time points. Cataract surgery was performed in 12 eyes of 8 patients, 3 eyes of 3 patients necessitated glaucoma surgery, and 4 eyes of 4 patients required surgery for retinal detachment. CONCLUSION: Uveitis associated with Blau syndrome commonly leads to severe, chronic panuveitis, requiring long-term systemic immunosuppression. Early diagnosis and timely initiation of biologics may prevent significant visual impairment.

Morphologic and immunohistochemical characterization of granulomas in the nucleotide oligomerization domain 2-related disorders Blau syndrome and Crohn disease.

BACKGROUND: Blau syndrome (BS) and Crohn disease (CD) are both characterized by granulomatous inflammation and related to nucleotide oligomerization domain 2 (NOD2) mutations. OBJECTIVE: This study aimed to define the morphologic and immunohistochemical characteristics of granulomas in patients with NOD2-related BS and CD. METHODS: Granuloma-containing biopsy specimens from 6 patients with BS and 7 pediatric patients with CD carrying NOD2 mutations or single nucleotide polymorphisms were studied for morphology, cellular composition, and cytokine expression by using hematoxylin and eosin staining and immunohistochemistry. RESULTS: Biopsy specimens from patients with BS typically showed polycyclic granulomas with large lymphocytic coronas, extensive emperipolesis of lymphocytes within multinucleated giant cells (MGCs), MGC death, and fibrinoid necrosis and fibrosis. In contrast, biopsy specimens from patients with CD showed simple granulomas with subtle/absent lymphocytic coronas, sclerosis of the surrounding tissue, and polymorphonuclear cells. Findings found to be similar in all granulomas were as follows: CD68 and HLA-DR expression by epithelioid cells, monocyte-macrophage lineage cells and MGCs, increased lymphocytic HLA-DR expression, increased CD4(+)/CD8(+) T-cell ratio, and CD20(+) B lymphocytes evenly distributed within and around granulomas. In both patient groups prominent IFN-γ expression was found in and around granulomas, and TNF-α and IL-23 receptor expression was moderate. IL-6, IL-17, and TGF-ß expression was prominent in granulomas from patients with BS but sporadic in granulomas from patients with CD. IL-10 expression was absent. CONCLUSION: Granulomas from patients with BS and granulomas from patients with NOD2-associated CD show distinct morphologic features and cytokine expression patterns, suggesting that the T(H)17 axis might be involved in the pathogenesis of BS, whereas T(H)1 is important in both patients with BS and patients with CD.

A missense mutation in Tbce causes progressive motor neuronopathy in mice.

Mice that are homozygous with respect to the progressive motor neuronopathy (pmn) mutation (chromosome 13) develop a progressive caudio-cranial degeneration of their motor axons from the age of two weeks and die four to six weeks after birth. The mutation is fully penetrant, and expressivity does not depend on the genetic background. Based on its pathological features, the pmn mutation has been considered an excellent model for the autosomal recessive proximal childhood form of spinal muscular atrophy (SMA). Previously, we demonstrated that the genes responsible for these disorders were not orthologous. Here, we identify the pmn mutation as resulting in a Trp524Gly substitution at the last residue of the tubulin-specific chaperone e (Tbce) protein that leads to decreased protein stability. Electron microscopy of the sciatic and phrenic nerves of affected mice showed a reduced number of microtubules, probably due to defective stabilization. Transgenic complementation with a wildtype Tbce cDNA restored a normal phenotype in mutant mice. Our observations indicate that Tbce is critical for the maintenance of microtubules in mouse motor axons, and suggest that altered function of tubulin cofactors might be implicated in human motor neuron diseases.

A case of infantile Takayasu arteritis with a p.D382E NOD2 mutation: an unusual phenotype of Blau syndrome/early-onset sarcoidosis?

Blau syndrome/early-onset sarcoidosis (Blau/EOS) is an autoinflammatory disease characterized by granulomatous arthritis, uveitis, and skin rash. It has been shown that gain-of-function NOD2 mutations cause Blau/EOS. In this paper, we describe a patient with a gain-of-function NOD2 mutation who developed infantile Takayasu arteritis, which is rare in Blau/EOS, but who has not yet had significant granulomatous changes in joints, eyes, or skin. We suspect that this case is an unusual phenotype of Blau/EOS.

[The present and the prospect of study on Blau syndrome/early-onset sarcoidosis].

Blau syndrome (BS) and early-onset sarcoidosis (EOS) are both systemic granulomatous disease evoked by the mutated NOD2. It occurs in children younger than 4 years of age and is characterized by a distinct triad of skin, joint, and eye disorders without apparent pulmonary involvement. NOD2 encodes an intracellular receptor for muramyl dipeptide (MDP), the common component of bacterial cell wall peptidoglycan, and is expressed in cytoplasm of monocytic cells and epithelial cells. While its loss-of-function mutations are recognized in Crohn's disease, the mutations observed in BS/EOS are gain-of-function, and induced MDP-independent basal NF-kappaB activation. But we still do not know the precious molecular mechanism how the activation of NOD2 induces granuloma formation in the skin, joints and eyes.

Monogenic causes of inflammatory disease in rheumatology.

PURPOSE OF REVIEW: To review the single-gene defects that can mimic rheumatologic diseases. RECENT FINDINGS: Monogenic disorders can cause a variety of diseases that may be seen by a rheumatologist. Many of these illnesses present with recurrent episodes of arthritis, rash, fever and inflammation, and serositis. Recent discoveries have defined inflammatory diseases due to mutations in the IL-1 and IL-36 receptor antagonists, as well as the immunoproteosome. Further study of well defined monogenic causes of inflammatory diseases, such as FMF, PAPA, TRAPS, and HIDS, has elucidated the pathophysiology of these diseases leading to targeted immunotherapy with anticytokine biological medications. SUMMARY: A rheumatologist should be aware of the genetic causes of inflammatory disease mimics. This will not only help with the prognosis of these diseases, but also help to guide therapy to prevent long-term complications associated with these disorders.

NOD2/CARD15 gene mutation identified in a Chinese family with Blau syndrome.

PURPOSE: To characterize the clinical features of a Chinese pedigree with Blau syndrome and to identify mutations in the NOD2/CARD15 (nucleotide-binding oligomerization domain containing 2/caspase recruitment domain family, member 15) gene. METHODS: Clinical features of this family were evaluated. Genomic DNA was obtained from blood samples, and all exons of NOD2/CARD15 were amplified by polymerase chain reaction (PCR) and direct DNA sequencing of PCR products was performed for mutations in NOD2/CARD15. RESULTS: Granulomatous arthritis, uveitis, and skin granulomas were found in all affected members. Sequencing analysis demonstrated a heterozygous C>T mutation in exon 4 of NOD2/CARD15 in all patients of this pedigree, which resulted in an amino acid substitution at position 334 (p.R334W). CONCLUSIONS: The R334W mutation in NOD2/CARD15 caused Blau syndrome in a Chinese pedigree. This is the first report of R334W mutation in NOD2/CARD15 in a Chinese pedigree of this disease.

[Autoinflammatory syndromes in dermatology]. / Syndromes auto-inflammatoires en dermatologie.

Hereditary periodic fever syndromes, also called autoinflammatory syndromes, are characterized by relapsing fever and additional manifestations such as skin rashes, mucosal manifestations, or arthralgias. Some of these disorders present without fever but with the associated systemic manifestations. The responsible mutated genes have been identified for most of these disorders, which lead to the induction of the uncontrolled and excessive production of interleukin-1beta (IL-1beta). The inhibition of IL-1beta through IL-1 receptor antagonist or monoclonal antibody against IL-1beta is used with success in most of these diseases. In case of TNF-receptor associated periodic syndrome (TRAPS) and paediatric granulomatous arthritis (PGA), TNF-antagonists may also be used; in familial Mediterranean fever (FMF) colchicine remains the first choice.

Blau syndrome revisited.

PURPOSE OF REVIEW: Blau syndrome is a monogenic disease resulting from mutations in nucleotide oligomerization domain 2 (NOD2) and is phenotypically characterized by granulomatous polyarthritis and uveitis. Not only there has been significant progress in disease characterization but also the biological pathways associated with NOD2 and related proteins of the innate immunity are better understood. RECENT FINDINGS: The phenotype of Blau syndrome has proven to be more complex than initially thought. A discussion on those manifestations will be provided in the clinical sections of this review. As more patients and pedigrees are found new mutations in the NOD2 gene have emerged and we discuss them in some detail. Due to its importance in Crohn's disease NOD2 has become the focus of intense research. A brief review of more recent advances in relevant pathways is presented and published reviews referenced for the interested reader. The granulomatous character of Blau syndrome provides an opportunity to look at possible pathogenic effects of NOD2 'gain of function'. New immunohistochemical data are briefly reviewed as well. SUMMARY: Elucidation of downstream effects of NOD2 mutations could provide valuable clues to mechanisms of arthritis and uveitis in general as well as granulomatous diseases in particular.