Case of a Man with Hemichorea and Behavioral Changes: "A Red Herring".

Background: Progressive supranuclear palsy (PSP)-pallido-nigro-luysian atrophy (PNLA) is a neuropathological entity thought to be a variant of classic PSP. Clinical features and pathologic hallmarks are the same in both conditions; however, age and order of symptom onset, disease duration and prognosis, and distribution and density of pathology differentiate the 2 entities. Objectives: This study presents a PSP-PNLA case confirmed pathologically with a clinical presentation of hemichorea/ballism, spasticity, progressive hemiparesis, and a frontal behavioral syndrome with relative cognitive sparing early in the disease course. Methods: We describe the clinical progression in this unique case supplemented with video and imaging findings in the form of magnetic resonance imaging and brain single photon emission computed tomography. Final diagnosis is via pathological analysis at autopsy. Results: We present an elderly gentleman who manifested a clinical syndrome consisting of subacute onset of chorea that at presentation was distinctly unilateral and a frontal behavioral syndrome in the setting of mild thrombocytopenia and elevated anticardiolipin antibodies. Positive antiphospholipid antibodies resulted in an initial antemortem diagnosis of primary antiphospholipid syndrome as a cause of his chorea. Longitudinal follow-up over 5 years demonstrated a progression of clinical features with hemi-motor impersistence/chorea, disinhibition and impulsivity, and eventually corticospinal distribution weakness on the initially affected side. He required nursing home care and falls necessitated wheelchair use. Postmortem neuropathological study revealed a diagnosis of frontotemporal lobar degeneration-tau, PSP-PNLA. Conclusions: This case broadens the phenotype of PSP-PNLA and to our knowledge is the only case presenting with unilateral chorea.

Characterizing familial corticobasal syndrome due to Alzheimer's disease pathology and PSEN1 mutations.

INTRODUCTION: Corticobasal syndrome (CBS) resulting from genetic Alzheimer's disease (AD) has been described only once. Whether familial CBS-AD is a distinct clinical entity with its own imaging signature remains unknown. METHODS: Four individuals with CBS from two families underwent detailed assessment. For two individuals, regional atrophy and hypoperfusion were compared to autopsy-confirmed typical late-onset AD and corticobasal degeneration, as well as genetically proven PSEN1 cases with an amnestic presentation. RESULTS: One family harbored a novel mutation in PSEN1:p.Phe283Leu. MRI demonstrated severe parietal, perirolandic, and temporal atrophy, with relative sparing of frontal and ipsilateral hippocampal regions. Autopsy confirmed pure AD pathology. The other family harbored a known PSEN1 mutation:p.Gly378Val. DISCUSSION: This report confirms familial CBS-AD as a distinct clinical entity, with a parietal-perirolandic-temporal atrophy signature. It illustrates the clinical heterogeneity that can occur despite a shared genetic cause and underscores the need for biomarkers such as amyloid imaging during life.

Diagnostic and prognostic biomarkers of a sellar melanocytic tumor mimicking pituitary adenoma: Case report and literature review.

Primary or metastatic melanocytic tumors in the sellar region are rare and can pose a diagnostic challenge. Here we describe a case of a 74-year-old man who underwent radiological investigations for a transient episode of blurred vision. Based on the clinical and endocrinological findings and MRI results, the patient was assumed to have a clinically non-functioning pituitary macroadenoma, which was followed-up over a 2-year period. He did not have any endocrine symptoms or progressive visual deterioration, and no history of past malignancy, including melanoma. Endocrinological investigation was unremarkable; blood hormone levels were within the normal ranges except for low serum total testosterone and bioavailable testosterone levels without symptoms of hypogonadism. The longitudinal MRI follow-up demonstrated a gradual increase in the size of the tumor over the course of 11 months. For this reason, the patient underwent surgery. Pathologic examination including histology, immunohistochemistry and electron microscopy achieved the correct diagnosis of melanocytic tumor of the sellar region morphologic examination is essential in the diagnosis of melanocytic tumors. Hmb-45 is an important diagnostic biomarker in melanocytic lesions. The use and exploration of miRNA, Ki67 and osteopontin are important in understanding the genesis, progression, and prognosis in treatment of patients with melanocytic tumors.

Differentiating between visual hallucination-free dementia with Lewy bodies and corticobasal syndrome on the basis of neuropsychology and perfusion single-photon emission computed tomography.

INTRODUCTION: Dementia with Lewy bodies (DLB) and Corticobasal Syndrome (CBS) are atypical parkinsonian disorders with fronto-subcortical and posterior cognitive dysfunction as common features. While visual hallucinations are a good predictor of Lewy body pathology and are rare in CBS, they are not exhibited in all cases of DLB. Given the clinical overlap between these disorders, neuropsychological and imaging markers may aid in distinguishing these entities. METHODS: Prospectively recruited case-control cohorts of CBS (n =31) and visual hallucination-free DLB (n =30), completed neuropsychological and neuropsychiatric measures as well as brain perfusion single-photon emission computed tomography and structural magnetic resonance imaging (MRI). Perfusion data were available for forty-two controls. Behavioural, perfusion, and cortical volume and thickness measures were compared between the groups to identify features that serve to differentiate them. RESULTS: The Lewy body with no hallucinations group performed more poorly on measures of episodic memory compared to the corticobasal group, including the delayed and cued recall portions of the California Verbal Learning Test (F (1, 42) =23.1, P <0.001 and F (1, 42) =14.0, P =0.001 respectively) and the delayed visual reproduction of the Wechsler Memory Scale-Revised (F (1, 36) =9.7, P =0.004). The Lewy body group also demonstrated reduced perfusion in the left occipital pole compared to the corticobasal group (F (1,57) =7.4, P =0.009). At autopsy, the Lewy body cases all demonstrated mixed dementia with Lewy bodies, Alzheimer's disease and small vessel arteriosclerosis, while the corticobasal cases demonstrated classical corticobasal degeneration in five, dementia with agyrophilic grains + corticobasal degeneration + cerebral amyloid angiopathy in one, Progressive Supranuclear Palsy in two, and Frontotemporal Lobar Degeneration-Ubiquitin/TAR DNA-binding protein 43 proteinopathy in one. MRI measures were not significantly different between the patient groups. CONCLUSIONS: Reduced perfusion in the left occipital region and worse episodic memory performance may help to distinguish between DLB cases who have never manifested with visual hallucinations and CBS at earlier stages of the disease. Development of reliable neuropsychological and imaging markers that improve diagnostic accuracy will become increasingly important as disease modifying therapies become available.

Clinical Neuropathology practice guide 6-2013: morphology and an appropriate immunohistochemical screening panel aid in the identification of synovial sarcoma by neuropathologists.

AIMS: Pathologists are under increasing pressure to accurately subclassify sarcomas, yet neuropathologists have limited collective experience with rare sarcoma types such as synovial sarcoma. We reviewed 9 synovial sarcomas affecting peripheral nerve diagnosed by neuropathologists and explored the morphologic and immunohistochemical differences between these and MPNST. Our goal was to make practical recommendations for neuropathologists regarding which spindle cell tumors affecting nerve should be sent for SYT-SSX testing. METHODS: Clinical records and genetics were reviewed retrospectively and central pathology review of 9 synovial sarcomas and 6 MPNST included immunohistochemistry for SOX10, S100, BAF47, CK (lmw, pan, CK7, CK19), EMA, CD34, bcl2, CD99, and neurofilament. RESULTS: Common synovial sarcoma sites were brachial plexus, spinal and femoral nerve, none were "intra-neural", all had the SYTSSX1 translocation, and 6/9 were monophasic with myxoid stroma and distinct collagen. Half of the monophasic synovial sarcomas expressed CK7, CK19 or panCK in a "rare positive cells pattern", 8/9 (89%) expressed EMA, and all were SOX10 immunonegative with reduced but variable BAF47 expression. CONCLUSIONS: We recommend that upon encountering a cellular spindle cell tumor affecting nerve neuropathologists consider the following: 1) SYT-SSX testing should be performed on any case with morphology suspicious for monophasic synovial sarcoma including wiry or thick bands of collagen and relatively monomorphous nuclei; 2) neuropathologists should employ a screening immunohistochemical panel including one of CK7, panCK or CK19, plus EMA, S100 and SOX10, and 3) SYT-SSX testing should be performed on any spindle cell tumor with CK and/or EMA immunopositivity if SOX10 immunostaining is negative or only labels entrapped nerve elements.

An artificial neural network approach for predicting functional outcome in fibromyalgia syndrome after multidisciplinary pain program.

OBJECTIVE: The objective of this study was to evaluate the ability of artificial neural networks (ANNs) to predict, on the basis of clinical variables, the response of persons with fibromyalgia syndrome (FMS) to a standard, 4-week interdisciplinary pain program. DESIGN: The design of this study is retrospective longitudinal. SETTING: Fibromyalgia outpatient clinic in a tertiary-care general hospital. SUBJECTS: The subjects of this study include outpatients with FMS. INTERVENTION: Multidisciplinary pain program including pain pharmacotherapy, cognitive-behavioral therapy, physical therapy, and occupational therapy. OUTCOME MEASURES: Reliable change (RC) of scores on the Stanford Health Assessment Questionnaire (HAQ), and accuracy of ANNs in predicting RC at discharge or at 6-month follow-up as compared to Logistic Regression. RESULTS: ANN-based models using the sensory-discriminative and affective-motivational subscales of the McGill Pain Questionnaire, the HAQ disability index, and the anxiety subscale of Hospital Anxiety and Depression Scale at baseline as input variables correctly classified 81.81% of responders at discharge and 83.33% of responders at 6-month follow-up, as well as 100% of nonresponders at either evaluation time-point. Logistic regression analysis, which was used for comparison, could predict treatment outcome with accuracies of 86.11% and 61.11% at discharge and follow-up, respectively, based on baseline scores on the HAQ and the mental summary component of the Medical Outcomes Study-Short Form 36. CONCLUSIONS: Properly trained ANNs can be a useful tool for optimal treatment selection at an early stage after diagnosis, thus contributing to minimize the lag until symptom amelioration and improving tertiary prevention in patients with FMS.

Transient, 5-HT2B receptor-mediated facilitation in neuropathic pain: Up-regulation of PKCγ and engagement of the NMDA receptor in dorsal horn neurons.

Spinal nociception can be facilitated by 5-HT2 receptors in neuropathic pain. We investigated the involvement of glutamate receptors in dorsal neuron hyperexcitation that is promoted by 5-HT2B receptor (5-HT2BR) after spinal nerve ligation (SNL) in the rat. Augmentation of C-fiber-evoked potentials by spinal superfusion with 5-HT2BR agonist BW 723C86 in nerve-ligated rats was impeded by co-administration of NMDA receptor (NMDAR) antagonist D-AP5, but not by mGluR1/5 antagonist AIDA or mGluR2/3 antagonist LY 341495. Evoked potentials were increased by cis-ACPD in nerve-injured rats, irrespective of simultaneous 5-HT2BR blockade by SB204741. In uninjured rats, NMDAR agonist cis-ACPD enhanced evoked potentials in the presence of BW 723C86 but not if administered alone or during exposure to protein kinase C γ (PKCγ) inhibitor peptide. Triple immunofluorescence labelings revealed co-localization of NMDAR and 5-HT2BR in PKCγ-expressing perikarya in lamina II neurons. As a result of SNL, PKCγ was transiently and bilaterally up-regulated in synaptic fraction from dorsal horn homogenates, peaking at day 2 and returning to basal levels by day 9. Chronic blockade of 5-HT2BR with selective antagonist SB 204741 after SNL bilaterally decreased the following: (i) PKCγ up-regulation in synaptic fraction, (ii) phosphorylation of NMDAR subunit NR1 (serine 889) in synaptic fraction, and (iii) co-localization of both PKCγ and phosphorylated NR1 with postsynaptic marker PSD-95. Chronic delivery of SB 204741 bilaterally attenuated thermal and mechanical allodynia occurring after SNL, particularly at day 2 post injury. These findings suggest that transient activation of the PKCγ/NMDAR pathway is critically involved in 5-HT2BR-mediated facilitation in the SNL model of neuropathic pain.

A multicenter study of glucocerebrosidase mutations in dementia with Lewy bodies.

IMPORTANCE: While mutations in glucocerebrosidase (GBA1) are associated with an increased risk for Parkinson disease (PD), it is important to establish whether such mutations are also a common risk factor for other Lewy body disorders. OBJECTIVE: To establish whether GBA1 mutations are a risk factor for dementia with Lewy bodies (DLB). DESIGN We compared genotype data on patients and controls from 11 centers. Data concerning demographics, age at onset, disease duration, and clinical and pathological features were collected when available. We conducted pooled analyses using logistic regression to investigate GBA1 mutation carrier status as predicting DLB or PD with dementia status, using common control subjects as a reference group. Random-effects meta-analyses were conducted to account for additional heterogeneity. SETTING: Eleven centers from sites around the world performing genotyping. PARTICIPANTS: Seven hundred twenty-one cases met diagnostic criteria for DLB and 151 had PD with dementia. We compared these cases with 1962 controls from the same centers matched for age, sex, and ethnicity. MAIN OUTCOME MEASURES: Frequency of GBA1 mutations in cases and controls. RESULTS We found a significant association between GBA1 mutation carrier status and DLB, with an odds ratio of 8.28 (95% CI, 4.78-14.88). The odds ratio for PD with dementia was 6.48 (95% CI, 2.53-15.37). The mean age at diagnosis of DLB was earlier in GBA1 mutation carriers than in noncarriers (63.5 vs 68.9 years; P < .001), with higher disease severity scores. CONCLUSIONS AND RELEVANCE: Mutations in GBA1 are a significant risk factor for DLB. GBA1 mutations likely play an even larger role in the genetic etiology of DLB than in PD, providing insight into the role of glucocerebrosidase in Lewy body disease.

Exome sequencing identifies titin mutations causing hereditary myopathy with early respiratory failure (HMERF) in families of diverse ethnic origins.

BACKGROUND: Hereditary myopathy with early respiratory failure (HMERF) was described in several North European families and recently linked to a titin gene (TTN) mutation. We independently studied HMERF-like diseases with the purpose to identify the cause, refine diagnostic criteria, and estimate the frequency of this disease among myopathy patients of various ethnic origins. METHODS: Whole exome sequencing analysis was carried out in a large U.S. family that included seven members suffering from skeletal muscle weakness and respiratory failure. Subsequent mutation screening was performed in further 45 unrelated probands with similar phenotypes. Studies included muscle strength evaluation, nerve conduction studies and concentric needle EMG, respiratory function test, cardiologic examination, and muscle biopsy. RESULTS: A novel TTN p.Gly30150Asp mutation was identified in the highly conserved A-band of titin that co-segregated with the disease in the U.S. family. Screening of 45 probands initially diagnosed as myofibrillar myopathy (MFM) but excluded based on molecular screening for the known MFM genes led to the identification of a previously reported TTN p.Cys30071Arg mutation in one patient. This same mutation was also identified in a patient with suspected HMERF. The p.Gly30150Asp and p.Cys30071Arg mutations are localized to a side chain of fibronectin type III element A150 of the 10th C-zone super-repeat of titin. CONCLUSIONS: Missense mutations in TTN are the cause of HMERF in families of diverse origins. A comparison of phenotypic features of HMERF caused by the three known TTN mutations in various populations allowed to emphasize distinct clinical/pathological features that can serve as the basis for diagnosis. The newly identified p.Gly30150Asp and the p.Cys30071Arg mutation are localized to a side chain of fibronectin type III element A150 of the 10th C-zone super-repeat of titin.

Probable IgG4-related pachymeningitis: a case with transverse sinus obliteration.

IgG4-related disease (IgG4-RD) is a recently recognized fibro-inflammatory condition which often shows a dramatic response to steroid therapy. IgG4-RD can present either as a single lesion or as a systemic multi-organ disorder. Common histological findings include a dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, storiform fibrosis, and phlebitis. Although diagnostic criteria for IgG4-RD have been proposed in many organs/sites, they are not well established in the central nervous system. Published data on IgG4-RD in meninges is also limited. To our knowledge, only 15 potential cases of meningeal IgG4-RD have been reported. We add a case of probable IgG4-related pachymeningitis in a 42-year-old woman who presented with headache and left transverse sinus obstruction. Follow-up after 2-months of high dose steroids shows dramatic clinical and imaging improvement. The differential diagnosis for IgG4-related pachymeningitis, including lymphoplasmacyte-rich meningioma, idiopathic hypertrophic pachymeningitis, and lymphoproliferative disease is discussed.

Time-dependent cross talk between spinal serotonin 5-HT2A receptor and mGluR1 subserves spinal hyperexcitability and neuropathic pain after nerve injury.

Emerging evidence implicates serotonergic descending facilitatory pathways from the brainstem to the spinal cord in the maintenance of pathologic pain. Upregulation of the serotonin receptor 2A (5-HT(2A)R) in dorsal horn neurons promotes spinal hyperexcitation and impairs spinal µ-opioid mechanisms during neuropathic pain. We investigated the involvement of spinal glutamate receptors, including metabotropic receptors (mGluRs) and NMDA, in 5-HT(2A)R-induced hyperexcitability after spinal nerve ligation (SNL) in rat. High-affinity 5-HT(2A)R agonist (4-bromo-3,6-dimethoxybenzocyclobuten-1-yl)methylamine hydrobromide (TCB-2) enhanced C-fiber-evoked dorsal horn potentials after SNL, which was prevented by mGluR1 antagonist AIDA [(RS)-1-aminoindan-1,5-dicarboxylic acid] but not by group II mGluR antagonist LY 341495 [(2S)-2-amino-2-[(1S,2S)-2-carboxycycloprop-1-yl]-3-(xanth-9-yl)propanoic acid] or NMDA antagonist d-AP5 [D-(-)-2-amino-5-phosphonopentanoic acid]. 5-HT(2A)R and mGluR1 were found to be coexpressed in postsynaptic densities in dorsal horn neurons. In the absence of SNL, pharmacological stimulation of 5-HT(2A)R with TCB-2 both induced rapid bilateral upregulation of mGluR1 expression in cytoplasmic and synaptic fractions of spinal cord homogenates, which was attenuated by PKC inhibitor chelerythrine, and enhanced evoked potentials during costimulation of mGluR1 with 3,5-DHPG [(RS)-3,5-dihydroxyphenylglycine]. SNL was followed by bilateral upregulation of mGluR1 in 5-HT(2A)R-containing postsynaptic densities. Upregulation of mGluR1 in synaptic compartments was partially prevented by chronic administration of selective 5-HT(2A)R antagonist M100907 [(R)-(+)-α-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-pipidinemethanol], confirming 5-HT(2A)R-mediated control of mGluR1 upregulation triggered by SNL. Changes in thermal and mechanical pain thresholds following SNL were increasingly reversed over the days after injury by chronic 5-HT(2A)R blockade. These results emphasize a role for 5-HT(2A)R in hyperexcitation and pain after nerve injury and support mGluR1 upregulation as a novel feedforward activation mechanism contributing to 5-HT(2A)R-mediated facilitation.

Pathophysiology of protein aggregation and extended phenotyping in filaminopathy.

Mutations in FLNC cause two distinct types of myopathy. Disease associated with mutations in filamin C rod domain leading to expression of a toxic protein presents with progressive proximal muscle weakness and shows focal destructive lesions of polymorphous aggregates containing desmin, myotilin and other proteins in the affected myofibres; these features correspond to the profile of myofibrillar myopathy. The second variant associated with mutations in the actin-binding domain of filamin C is characterized by weakness of distal muscles and morphologically by non-specific myopathic features. A frameshift mutation in the filamin C rod domain causing haploinsufficiency was also found responsible for distal myopathy with some myofibrillar changes but no protein aggregation typical of myofibrillar myopathies. Controversial data accumulating in the literature require re-evaluation and comparative analysis of phenotypes associated with the position of the FLNC mutation and investigation of the underlying disease mechanisms. This is relevant and necessary for the refinement of diagnostic criteria and developing therapeutic approaches. We identified a p.W2710X mutation in families originating from ethnically diverse populations and re-evaluated a family with a p.V930_T933del mutation. Analysis of the expanded database allows us to refine clinical and myopathological characteristics of myofibrillar myopathy caused by mutations in the rod domain of filamin C. Biophysical and biochemical studies indicate that certain pathogenic mutations in FLNC cause protein misfolding, which triggers aggregation of the mutant filamin C protein and subsequently involves several other proteins. Immunofluorescence analyses using markers for the ubiquitin-proteasome system and autophagy reveal that the affected muscle fibres react to protein aggregate formation with a highly increased expression of chaperones and proteins involved in proteasomal protein degradation and autophagy. However, there is a noticeably diminished efficiency of both the ubiquitin-proteasome system and autophagy that impairs the muscle capacity to prevent the formation or mediate the degradation of aggregates. Transfection studies of cultured muscle cells imitate events observed in the patient's affected muscle and therefore provide a helpful model for testing future therapeutic strategies.

Investigation of c9orf72 in 4 neurodegenerative disorders.

OBJECTIVE To estimate the allele frequency of C9orf72 (G4C2) repeats in amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), Alzheimer disease (AD), and Parkinson disease (PD). DESIGN The number of repeats was estimated by a 2-step genotyping strategy. For expansion carriers, we sequenced the repeat flanking regions and obtained APOE genotypes and MAPT H1/H2 haplotypes. SETTING Hospitals specializing in neurodegenerative disorders. SUBJECTS We analyzed 520 patients with FTLD, 389 patients with ALS, 424 patients with AD, 289 patients with PD, 602 controls, 18 families, and 29 patients with PD with the LRRK2 G2019S mutation. MAIN OUTCOME MEASURE The expansion frequency. RESULTS Based on a prior cutoff (>30 repeats), the expansion was detected in 9.3% of patients with ALS, 5.2% of patients with FTLD, and 0.7% of patients with PD but not in controls or patients with AD. It was significantly associated with family history of ALS or FTLD and age at onset of FTLD. Phenotype variation (ALS vs FTLD) was not associated with MAPT, APOE, or variability in the repeat flanking regions. Two patients with PD were carriers of 39 and 32 repeats with questionable pathological significance, since the 39-repeat allele does not segregate with PD. No expansion or intermediate alleles (20-29 repeats) were found among the G2019S carriers and AD cases with TAR DNA-binding protein 43-positive inclusions. Surprisingly, the frequency of the 10-repeat allele was marginally increased in all 4 neurodegenerative diseases compared with controls, indicating the presence of an unknown risk variation in the C9orf72 locus. CONCLUSIONS The C9orf72 expansion is a common cause of ALS and FTLD, but not of AD or PD. Our study raises concern about a reliable cutoff for the pathological repeat number, which is important in the utility of genetic screening.

Treatment of granulomatous amoebic encephalitis with voriconazole and miltefosine in an immunocompetent soldier.

A 38-year-old male immunocompetent soldier developed generalized seizures. He underwent surgical debulking and a progressive demyelinating pseudotumor was identified. Serology and molecular testing confirmed a diagnosis of granulomatous amoebic encephalitis caused by Acanthamoeba sp. in this immunocompetent male. The patient was treated with oral voriconazole and miltefosine with Acanthamoeba titers returning to control levels and serial imaging demonstrating resolution of the residual lesion.

Transportin 1 accumulates specifically with FET proteins but no other transportin cargos in FTLD-FUS and is absent in FUS inclusions in ALS with FUS mutations.

Accumulation of the DNA/RNA binding protein fused in sarcoma (FUS) as inclusions in neurons and glia is the pathological hallmark of amyotrophic lateral sclerosis patients with mutations in FUS (ALS-FUS) as well as in several subtypes of frontotemporal lobar degeneration (FTLD-FUS), which are not associated with FUS mutations. Despite some overlap in the phenotype and neuropathology of FTLD-FUS and ALS-FUS, significant differences of potential pathomechanistic relevance were recently identified in the protein composition of inclusions in these conditions. While ALS-FUS showed only accumulation of FUS, inclusions in FTLD-FUS revealed co-accumulation of all members of the FET protein family, that include FUS, Ewing's sarcoma (EWS) and TATA-binding protein-associated factor 15 (TAF15) suggesting a more complex disturbance of transportin-mediated nuclear import of proteins in FTLD-FUS compared to ALS-FUS. To gain more insight into the mechanisms of inclusion body formation, we investigated the role of Transportin 1 (Trn1) as well as 13 additional cargo proteins of Transportin in the spectrum of FUS-opathies by immunohistochemistry and biochemically. FUS-positive inclusions in six ALS-FUS cases including four different mutations did not label for Trn1. In sharp contrast, the FET-positive pathology in all FTLD-FUS subtypes was also strongly labeled for Trn1 and often associated with a reduction in the normal nuclear staining of Trn1 in inclusion bearing cells, while no biochemical changes of Trn1 were detectable in FTLD-FUS. Notably, despite the dramatic changes in the subcellular distribution of Trn1 in FTLD-FUS, alterations of its cargo proteins were restricted to FET proteins and no changes in the normal physiological staining of 13 additional Trn1 targets, such as hnRNPA1, PAPBN1 and Sam68, were observed in FTLD-FUS. These data imply a specific dysfunction in the interaction between Trn1 and FET proteins in the inclusion body formation in FTLD-FUS. Moreover, the absence of Trn1 in ALS-FUS provides further evidence that ALS-FUS and FTLD-FUS have different underlying pathomechanisms.

Selective impairment of spinal mu-opioid receptor mechanism by plasticity of serotonergic facilitation mediated by 5-HT2A and 5-HT2B receptors.

Opioid analgesia is compromised by intracellular mediators such as protein kinase C (PKC). The phosphatidylinositol hydrolysis-coupled serotonin receptor 5-HT2 is ideally suited to promote PKC activation. We test the hypothesis that 5-HT2A and 5-HT2B receptors, which have been previously shown to become pro-excitatory after spinal nerve ligation (SNL), can negatively influence the ability of opioids to depress spinal excitation evoked by noxious input. Spinal superfusion with (100 nM) mu-opioid receptor (MOR)-agonist DAMGO significantly depressed C fiber-evoked spinal field potentials. Simultaneous administration of subclinical 5-HT2AR antagonist 4F 4PP (100 nM) or 5-HT2BR antagonist SB 204741 (100 nM) significantly reduced the IC50 value for DAMGO in nerve-ligated rats (97.56 nM ± 1.51 and 1.20 nM ± 1.28 respectively, relative to 104 nM ± 1.08 at the baseline condition), but not in sham-operated rats. Both antagonists failed to alter depression induced by delta-opioid receptor (DOR)-agonist D-ala2-deltorphin II after SNL as well as in the sham condition. Western blot analysis of dorsal horn homogenates revealed bilateral upregulation of 5-HT2AR and 5-HT2BR protein band densities after SNL. As assessed from double immunofluorescence labeling for confocal laser scanning microscopy, scarce dorsal horn cell processes showed co-localization color overlay for 5-HT2AR/MOR, 5-HT2BR/MOR, 5-HT2AR/DOR, or 5-HT2BR/DOR in sham-operated rats. Intensity correlation-based analyses showed significant increases in 5-HT2AR/MOR and 5-HT2BR/MOR co-localizations after SNL. These results indicate that plasticity of spinal serotonergic neurotransmission can selectively reduce spinal MOR mechanisms via 5-HT2A and 5-HT2B receptors, including upregulation of the latter and increased expression in dorsal horn neurons containing MOR.