Minocycline for sporadic and hereditary cerebral amyloid angiopathy (BATMAN): study protocol for a placebo-controlled randomized double-blind trial

BACKGROUND

Cerebral amyloid angiopathy (CAA) is a disease caused by the accumulation of the amyloid-beta protein and is a major cause of intracerebral hemorrhage (ICH) and vascular dementia in the elderly. The presence of the amyloid-beta protein in the vessel wall may induce a chronic state of cerebral inflammation by activating astrocytes, microglia, and pro-inflammatory substances. Minocycline, an antibiotic of the tetracycline family, is known to modulate inflammation, gelatinase activity, and angiogenesis. These processes are suggested to be key mechanisms in CAA pathology. Our aim is to show the target engagement of minocycline and investigate in a double-blind placebo-controlled randomized clinical trial whether treatment with minocycline for 3 months can decrease markers of neuroinflammation and of the gelatinase pathway in cerebrospinal fluid (CSF) in CAA patients.

METHODS

The BATMAN study population consists of 60 persons: 30 persons with hereditary Dutch type CAA (D-CAA) and 30 persons with sporadic CAA. They will be randomized for either placebo or minocycline (15 sporadic CAA/15 D-CAA minocycline, 15 sporadic CAA/15 D-CAA placebo). At t = 0 and t = 3 months, we will collect CSF and blood samples, perform a 7-T MRI, and collect demographic characteristics.

DISCUSSION

The results of this proof-of-principle study will be used to assess the potential of target engagement of minocycline for CAA. Therefore, our primary outcome measures are markers of neuroinflammation (IL-6, MCP-1, and IBA-1) and of the gelatinase pathway (MMP2/9 and VEGF) in CSF. Secondly, we will look at the progression of hemorrhagic markers on 7-T MRI before and after treatment and investigate serum biomarkers.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05680389. Registered on January 11, 2023.

Quantitative measurement of duplicated DNA as a diagnostic test for Charcot-Marie-Tooth disease type 1a

Charcot-Marie-Tooth disease type 1 (CMT1) is a hereditary motor and sensory neuropathy. The autosomal dominant subtype is often linked with a large duplication on chromosome 17p11.2. The gene encoding the peripheral myelin protein PMP 22 (the critical gene in this subtype of CMT1) is located within this duplication. To detect this duplication in chromosomal DNA from individuals thought to have CMT1, we compared the hybridization signals of two DNA probes within this duplication (VAW412R3a and VAW409R3a) with the signal of a reference probe (E3.9). When duplication was present, the signals from the first two probes increased from 100% (for nonduplicated samples) to 145% and 142%, respectively. The day-to-day variance was 3.7% and 5.1%, respectively. We demonstrated this DNA duplication in 49 of 95 DNA samples from unrelated individuals thought to have CMT1. Moreover, because hereditary neuropathy with liability to pressure palsies (HNPP) is based on a DNA deletion in the same area of chromosome 17, this quantitative test may be useful in establishing the presence of HNPP. In a preliminary investigation, four unrelated patients with HNPP yielded test values of 63% and 54%, respectively, of those for nonduplicated samples (CV 19% and 18%, respectively; n = 4), suggesting a deletion in 17p11.2.

Familial Mediterranean Fever (FMF): a single centre retrospective study in Amsterdam

BACKGROUND

Familial Mediterranean Fever (FMF) is the earliest described and most prevalent hereditary auto-inflammatory disease. Its clinical presentation is diverse, leading to possible delay in diagnosis and treatment. Due to immigration, FMF became common in non-Mediterranean European regions. In the present single centre retrospective study, the clinical, demographic, and genetic characteristics of patients with FMF of different ancestry in Amsterdam are described.

METHODS

Case records of patients with FMF, who met the Tel-Hashomer diagnostic criteria, were retrospectively analysed. The international disease severity score was used.

RESULTS

Between 1990-2012, 53 patients were identified, 28 were female. Main country of origin was Turkey. The mean age at the time of analysis was 29.1 years; 13.8 years at onset of symptoms; and at time of diagnosis, 22.0 years. Most frequent symptoms were peritonitis (91%) and fever (81%). The mean C-reactive protein and erythrocyte sedimentation rate during acute attacks were 133 mg/l and 37 mm/first hour, respectively. One patient developed amyloidosis as a complication. Seventeen patients underwent abdominal surgery before diagnosis. Most patients (92%) received colchicine treatment and were responsive (81%). Most patients classified their disease as a mild disease (42%). MEFV gene mutation analysis was performed in 46 patients; most patients were compound heterozygotes (n = 17), and the most frequent mutation was M694V (n = 18).

CONCLUSION

FMF in Amsterdam is diagnosed in relatively young patients and the delay to diagnosis is 8.2 years. Disease manifestations and genetic distribution of our FMF patients are comparable to those in Mediterranean regions, suggesting that ancestry is more important than environment.

Polymorphism of SLC6A2 gene does not influence outcome of myocardial 123I-mIBG scintigraphy in patients with chronic heart failure

AIM

The NET, encoded by SLC6A2, is responsible for presynaptic NE-reuptake. 123I-mIBG is clinically used to evaluate cardiac sympathetic function. However, it is unknown if polymorphism of SLC6A2 influences cardiac sympathetic activity as assessed with 123I-mIBG. Therefore we studied the influence of SLC6A2 SNPs on myocardial 123I-mIBG parameters in CHF.

MATERIALS AND METHODS

Forty-nine adults with stable CHF (age 66.5 ± 8.1 years, LVEF 22.3 ± 6.4) were enrolled. Fifteen minutes (early) and 4 hours (late) after administration of 123I-mIBG planar images were acquired. The H/M ratio was calculated from the manually drawn ROI over the left ventricle and a fixed mediastinal ROI. Fourteen exons of the SLC6A2 gene were analyzed from whole blood samples.

RESULTS

We found 6 different SLC6A2 SNPs, although none were functional. LVEF was the only independent predictor for early (adjusted R 2 = 0.063, p = 0.045) and late H/M ratio (adjusted R 2 = 0.116, p = 0.010). NT-proBNP was the only independent predictor for 123I-mIBG WO (adjusted R 2 = 0.074, p = 0.032). SLC6A2 SNPs were not associated with any myocardial 123I-mIBG-derived parameter.

CONCLUSION

In this specific CHF population polymorphism of SLC6A2 gene was not associated with any 123I-mIBG derived parameters.

Variation in coagulation and fibrinolysis genes evaluated for their contribution to cerebrovascular complications in adults with bacterial meningitis in the Netherlands

OBJECTIVE

To study whether genetic variation in coagulation and fibrinolysis genes contributes to cerebrovascular complications in bacterial meningitis.

METHODS

We performed a nationwide prospective genetic association study in adult community-acquired bacterial meningitis patients. The exons and flanking regions of 16 candidate genes involved in coagulation and fibrinolysis pathways were sequenced. We analyzed whether genetic variation in these genes resulted in a higher risk of cerebrovascular complications, unfavorable outcome and differences in thrombocyte count on admission.

RESULTS

From 2006 to 2011, a total of 1101 bacterial meningitis patients were identified of whom 622 supplied DNA for genotyping and passed genetic quality control steps. In 139 patients (22%) the episode of bacterial meningitis was complicated by cerebral infarction, and 188 (30%) had an unfavorable outcome. We identified the functional variant rs494860 in the protein Z (PROZ) gene as our strongest association with occurrence of cerebral infarction (odds ratio (OR) 0.49 (95% confidence interval 0.33-0.73), p = 5.2 × 10^-4). After Bonferroni correction for multiple testing no genetic variant was significantly associated (p-value threshold 2.7 × 10^-4).

CONCLUSION

Our study suggests a functional genetic variation in the PROZ gene, rs494860, may be of importance in bacterial meningitis pathogenesis and cerebral infarction risk. Replication of this finding in other cohort studies populations is needed.

Profoundly Expanded T-cell Clones in the Inflamed and Uninflamed Intestine of Patients With Crohn's Disease

BACKGROUND AND AIM

T cells are key players in the chronic intestinal inflammation that characterises Crohn's disease. Here we aim to map the intestinal T-cell receptor [TCR] repertoire in patients with Crohn's disease, using next-generation sequencing technology to examine the clonality of the T-cell compartment in relation to mucosal inflammation and response to therapy.

METHODS

Biopsies were taken from endoscopically inflamed and uninflamed ileum and colon of 19 patients with Crohn's disease. From this cohort, additional biopsies were taken after 8 weeks of remission induction therapy from eight responders and eight non-responders. Control biopsies from 11 patients without inflammatory bowel disease [IBD] were included. The TCRβ repertoire was analysed by next-generation sequencing of biopsy RNA.

RESULTS

Both in Crohn's disease patients and in non-IBD controls, a broad intestinal T-cell repertoire was found, with a considerable part consisting of expanded clones. Clones in Crohn's disease were more expanded [p = 0.008], with the largest clones representing up to as much as 58% of the total repertoire. There was a substantial overlap of the repertoire between inflamed and uninflamed tissue and between ileum and colon. Following therapy, responders showed larger changes in the T-cell repertoire than non-responders, although a considerable part of the repertoire remained unchanged in both groups.

CONCLUSIONS

The intestinal T-cell repertoire distribution in Crohn's disease is different from that in the normal gut, containing profoundly expanded T-cell clones that take up a large part of the repertoire. The T-cell repertoire is fairly stable regardless of endoscopic mucosal inflammation or response to therapy.

Complement activation in leprosy: a retrospective study shows elevated circulating terminal complement complex in reactional leprosy

Mycobacterium leprae infection gives rise to the immunologically and histopathologically classified spectrum of leprosy. At present, several tools for the stratification of patients are based on acquired immunity markers. However, the role of innate immunity, particularly the complement system, is largely unexplored. The present retrospective study was undertaken to explore whether the systemic levels of complement activation components and regulators can stratify leprosy patients, particularly in reference to the reactional state of the disease. Serum samples from two cohorts were analysed. The cohort from Bangladesh included multi-bacillary (MB) patients with (n = 12) or without (n = 46) reaction (R) at intake and endemic controls (n = 20). The cohort from Ethiopia included pauci-bacillary (PB) (n = 7) and MB (n = 23) patients without reaction and MB (n = 15) patients with reaction. The results showed that the activation products terminal complement complex (TCC) (P ≤ 0·01), C4d (P ≤ 0·05) and iC3b (P ≤ 0·05) were specifically elevated in Bangladeshi patients with reaction at intake compared to endemic controls. In addition, levels of the regulator clusterin (P ≤ 0·001 without R; P < 0·05 with R) were also elevated in MB patients, irrespective of a reaction. Similar analysis of the Ethiopian cohort confirmed that, irrespective of a reaction, serum TCC levels were increased significantly in patients with reactions compared to patients without reactions (P ≤ 0·05). Our findings suggests that serum TCC levels may prove to be a valuable tool in diagnosing patients at risk of developing reactions.

Thrombin-activatable fibrinolysis inhibitor influences disease severity in humans and mice with pneumococcal meningitis

BACKGROUND

Mortality and morbidity in patients with bacterial meningitis result from the proinflammatory response and dysregulation of coagulation and fibrinolysis. Thrombin-activatable fibrinolysis inhibitor (TAFI) is activated by free thrombin or thrombin in complex with thrombomodulin, and plays an antifibrinolytic role during fibrin clot degradation, but also has an anti-inflammatory role by inactivating proinflammatory mediators, such as complement activation products.

OBJECTIVE

To assess the role of TAFI in pneumococcal meningitis.

METHODS

We performed a prospective nationwide genetic association study in patients with bacterial meningitis, determined TAFI and complement levels in cerebrospinal fluid (CSF), and assessed the function of TAFI in a pneumococcal meningitis mouse model by using Cpb2 (TAFI) knockout mice.

RESULTS

Polymorphisms (reference sequences: rs1926447 and rs3742264) in the CPB2 gene, coding for TAFI, were related to the development of systemic complications in patients with pneumococcal meningitis. Higher protein levels of TAFI in CSF were significantly associated with CSF complement levels (C3a, iC3b, and C5b-9) and with more systemic complications in patients with bacterial meningitis. The risk allele of rs1926447 (TT) was associated with higher levels of TAFI in CSF. In the murine model, consistent with the human data, Cpb2-deficient mice had decreased disease severity, as reflected by lower mortality, and attenuated cytokine levels and bacterial outgrowth in the systemic compartment during disease, without differences in the brain compartment, as compared with wild-type mice.

CONCLUSIONS

These findings suggest that TAFI plays an important role during pneumococcal meningitis, which is likely to be mediated through inhibition of the complement system, and influences the occurrence of systemic complications and inflammation.

Gene expression profiling of laser microdissected airway smooth muscle tissue in asthma and atopy

BACKGROUND

Asthma and atopy share common characteristics including type 2 helper-T-cell-mediated inflammation. However, only asthma is associated with variable airways obstruction. The complex cellular and molecular pathways distinguishing asthma and atopy can now be captured by transcriptomic analysis (RNA-Seq). We hypothesized that the transcriptomic profile of airway smooth muscle (ASM) distinguishes atopic asthma from atopic healthy controls. First, we compared the ASM transcriptomic profiles of endobronchial biopsies between glucocorticoid-free, atopic asthma patients, and atopic and nonatopic healthy controls. Second, we investigated the association between ASM transcriptomic profiles and airway function.

METHODS

Twelve asthma patients and 12 control subjects (six atopic, six nonatopic) underwent bronchoscopy. RNA of laser-dissected ASM from 96 bronchial biopsy specimens was sequenced with Roche GS FLX. Gene networks were identified using Ingenuity Pathway Analysis. RNA-Seq reads were assumed to follow a negative binomial distribution. With the current sample size, the estimated false discovery rate was approximately 1%.

RESULTS

One hundred and seventy four ASM genes were differentially expressed between asthma patients and atopic controls, 108 between asthma patients and nonatopic controls, and 135 between atopic and nonatopic controls. A set of eight genes discriminated asthma patients from nonasthmatic controls, irrespective of atopy. Four of these genes (RPTOR, VANGL1, FAM129A, LEPREL1) were associated with airway hyper-responsiveness (P < 0.05).

CONCLUSION

Airway smooth muscle from asthma patients can be distinguished from that of atopic and nonatopic control subjects by a specific gene expression profile, which is associated with airway hyper-responsiveness.

Rheumatoid arthritis synovial tissue harbours dominant B-cell and plasma-cell clones associated with autoreactivity

OBJECTIVE

To identify potential autoreactive B-cell and plasma-cell clones by quantitatively analysing the complete human B-cell receptor (BCR) repertoire in synovium and peripheral blood in early and established rheumatoid arthritis (RA).

METHODS

The BCR repertoire was screened in synovium and blood of six patients with early RA (ERA) (<6 months) and six with established RA (ESRA) (>20 months). In two patients, the repertoires in different joints were compared. Repertoires were analysed by next-generation sequencing from mRNA, generating >10 000 BCR heavy-chain sequence reads per sample. For each clone, the degree of expansion was calculated as the percentage of the total number of reads encoding the specific clonal sequence. Clones with a frequency ≥ 0.5% were considered dominant.

RESULTS

Multiple dominant clones were found in inflamed synovium but hardly any in blood. Within an individual patient, the same dominant clones were detected in different joints. The majority of the synovial clones were class-switched; however, the fraction of clones that expressed IgM was higher in ESRA than ERA patients. Dominant synovial clones showed autoreactive features: in ERA in particular the clones were enriched for immunoglobulin heavy chain gene segment V4-34 (IGHV4-34) and showed longer CDR3 lengths. Dominant synovial clones that did not encode IGHV4-34 also had longer CDR3s than peripheral blood.

CONCLUSIONS

In RA, the synovium forms a niche where expanded--potentially autoreactive--B cells and plasma cells reside. The inflamed target tissue, especially in the earliest phase of disease, seems to be the most promising compartment for studying autoreactive cells.

Deep sequencing of antiviral T-cell responses to HCMV and EBV in humans reveals a stable repertoire that is maintained for many years

CD8⁺ T-cell responses against latent viruses can cover considerable portions of the CD8⁺ T-cell compartment for many decades, yet their initiation and maintenance remains poorly characterized in humans. A key question is whether the clonal repertoire that is raised during the initial antiviral response can be maintained over these long periods. To investigate this we combined next-generation sequencing of the T-cell receptor repertoire with tetramer-sorting to identify, quantify and longitudinally follow virus-specific clones within the CD8⁺ T-cell compartment. Using this approach we studied primary infections of human cytomegalovirus (hCMV) and Epstein Barr virus (EBV) in renal transplant recipients. For both viruses we found that nearly all virus-specific CD8⁺ T-cell clones that appeared during the early phase of infection were maintained at high frequencies during the 5-year follow-up and hardly any new anti-viral clones appeared. Both in transplant recipients and in healthy carriers the clones specific for these latent viruses were highly dominant within the CD8⁺ T-cell receptor Vβ repertoire. These findings suggest that the initial antiviral response in humans is maintained in a stable fashion without signs of contraction or changes of the clonal repertoire.

Several viruses have found ways to evade the human immune system and cause latent infections. Examples include HIV and herpes-viruses. Most humans carry these herpes-viruses. The human immune system mounts continuous responses against these viruses to prevent them from causing disease. If this balance is disturbed, these viruses can cause extensive pathology. We do not know how the immune response against these viruses evolves over time. Understanding this response might help to understand why the immune system does not clear these viruses and might help in preventive and therapeutic strategies. Here we used a new technology that allowed us to track virus specific immune cells (CD8⁺ T cells) over time in a quantitative manner. When we used this technology to study the evolution of latent responses against herpes-viruses (from infection until 5 years later) we found that immune responses were very rigid and did not evolve over time. Collectively our data shows that – for these herpes-viruses – the initial immune response is maintained despite the fact that this does not result in clearance of the virus. Therefore, if a virus survives the initial response, it will not be cleared in the future. This is an important consideration in understanding latent infection and for vaccination-design.

How to kickstart a national biobanking infrastructure – experiences and prospects of BBMRI-NL

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Inflamed target tissue provides a specific niche for highly expanded T-cell clones in early human autoimmune disease

OBJECTIVE

To profile quantitatively the T-cell repertoire in multiple joints and peripheral blood of patients with recent onset (early) or established rheumatoid arthritis (RA) using a novel next-generation sequencing protocol to identify potential autoreactive clones.

METHODS

Synovium of patients with recent onset (early) RA (<6 months) (n=6) or established RA (>18 months) (n=6) was screened for T-cell clones by sequencing over 10 000 T-cell receptors (TCR) per sample. T cells from paired blood samples were analysed for comparison. From two patients synovial T cells were obtained from multiple inflamed joints. The degree of expansion of each individual clone was based on its unique CDR3 sequence frequency within a sample. Clones with a frequency of over 0.5% were considered to be highly expanded clones (HEC).

RESULTS

In early RA synovium, the T-cell repertoire was dominated by 35 HEC (median, range 2-70) accounting for 56% of the TCR sequenced. The clonal dominance in the synovium was patient specific and significantly greater than in established RA (median of 11 HEC (range 5-24) in established RA synovium accounting for 9.8% of T cells; p<0.01). 34% (range 28-40%) of the most expanded T-cell clones were shared between different joints in the same patients, compared with only 4% (range 0-8%) between synovium and blood (p=0.01).

CONCLUSIONS

In RA, a systemic autoimmune disease, the inflamed synovium forms a niche for specific expanded T-cell clones, especially in early disease. This suggests that, at least in RA, autoreactive T cells should be addressed specifically in the inflamed tissue, preferably in the early phase of the disease.

Germline SMARCB1 mutation and somatic NF2 mutations in familial multiple meningiomas

BACKGROUND

Multiple meningiomas occur in <10% of meningioma patients. Their development may be caused by the presence of a predisposing germline mutation in the neurofibromatosis type 2 (NF2) gene. The predisposing gene in patients with non-NF2 associated multiple meningiomas remains to be identified. Recently, SMARCB1 was reported to be a potential predisposing gene for multiple meningiomas in a family with schwannomatosis and multiple meningiomas. However, involvement of this gene in the development of the meningiomas was not demonstrated.

RESULTS

Five affected members of a large family with multiple meningiomas were investigated for the presence of mutations in SMARCB1 and NF2. A missense mutation was identified in exon 2 of SMARCB1 as the causative germline mutation predisposing to multiple meningiomas; furthermore, it was demonstrated that, in accordance with the two-hit hypothesis for tumourigenesis, the mutant allele was retained and the wild-type allele lost in all four investigated meningiomas. In addition, independent somatically acquired NF2 mutations were identified in two meningiomas of one patient with concomitant losses of the wild-type NF2 allele.

CONCLUSION

It is concluded that, analogous to the genetic events in a subset of schwannomatosis associated schwannomas, a four-hit mechanism of tumour suppressor gene inactivation, involving SMARCB1 and NF2, might be operative in familial multiple meningiomas associated meningiomas.

Striatal D₂ receptor binding in 22q11 deletion syndrome: an [¹²³I]IBZM SPECT study

It has been hypothesised that in subjects with 22q11 deletion syndrome (22q11DS) disturbances of the dopamine (DA) system contribute to their increased risk for cognitive deficits and psychiatric problems. However, central DAergic neurotransmission in 22q11DS has not been investigated. We measured striatal D₂ receptor binding potential (D₂R BP(ND)) using (S)-(-)-3-iodo-2-hydroxy-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl)methyl] benzamide-single photon emission computed tomography ([¹²³I]IBZM SPECT) in 12 adults with 22q11DS and 12 matched controls. Correlations between D₂R BP(ND) and plasma prolactin (pPRL) levels were also determined. 22q11DS subjects and controls had similar D₂R BP( ND). There was a positive correlation between D₂R BP( ND) and pPRL values in controls, but no such relation was found in 22q11DS subjects. This study suggests that a 22q11 deletion does not affect striatal DAergic neurotransmission in the living human brain. However, the disturbed relationship between D₂R BP(ND) and pPRL values suggests DAergic dysfunction at a different level. Further studies on DAergic function in extra-striatal brain regions and under challenged conditions are needed.

The first case of protease-sensitive prionopathy (PSPr) in The Netherlands: a patient with an unusual GSS-like clinical phenotype

An atypical case of prion disease is described in a 54-year-old Dutch man, homozygous for valine at codon 129 of the prion protein gene (PRNP). The clinical phenotype was characterised by progressive dementia, spastic paraplegia and sensorimotor polyneuropathy. The disease duration was 20 months. Genetic analysis of PRNP did not reveal any abnormalities. Neuropathologically, only mild spongiform change and a coarse granular immunohistochemical staining for the abnormal prion protein, PrP(Sc), was observed, with poorly formed plaques in the molecular layer of the cerebellar cortex. However, Western blotting showed low but detectable levels of proteinase K(PK)-resistant PrP(Sc) occurring in an unusual ladder-like profile. These features define a phenotype that corresponds to the recently described protease-sensitive prionopathy (PSPr). Our report on the first Dutch patient with PSPr further expands the spectrum of prionopathies and exemplifies the need to re-evaluate cases of atypical prion disease.

SMARCB1/INI1 maternal germ line mosaicism in schwannomatosis

Schwannomatosis is characterized by the development of multiple schwannomas of the nervous system, but without the occurrence of vestibular schwannomas. Most cases of schwannomatosis are thought to be sporadic, representing the first case in a family due to a new mutation in the causative gene. We recently identified SMARCB1/INI1 as a schwannomatosis-predisposing gene. Here, we analyzed this gene in a schwannomatosis family with two affected children, but with clinically unaffected parents. Both affected individuals carried a constitutional SMARCB1 mutation, c.1118+ 1G>A, that changes the donor splice site sequence of intron 8, causing skipping of exon 8 and resulting in the in-frame deletion of 132 nucleotides in the transcript. The mutation was not evident in constitutional DNA of the parents. Haplotyping revealed that the chromosome 22 segment that carries the mutant SMARCB1 allele originated from the mother. She transferred the same chromosome 22 segment, however, with a wild-type SMARCB1 copy, to a third unaffected child. Our findings indicate that the mother is germ line mosaic for the SMARCB1 mutation. In conclusion, our study shows for the first time that germ line mosaicism may occur in schwannomatosis, which has implications for genetic counseling in this disease.

Innate immunity in the nervous system

The complement (C) system plays a central role in innate immunity and bridges innate and adaptive immune responses. A fine balance of C activation and regulation mediates the elimination of invading pathogens and the protection of the host from excessive C deposition on healthy tissues. If this delicate balance is disrupted, the C system may cause injury and contribute to the pathogenesis of various diseases, including neurodegenerative disorders and neuropathies. Here we review evidence indicating that C factors and regulators are locally synthesized in the nervous system and we discuss the evidence supporting the protective or detrimental role of C activation in health, injury, and disease of the nerve.

Myoclonus-dystonia: clinical and genetic evaluation of a large cohort

BACKGROUND

Myoclonus-dystonia (M-D) is an autosomal dominant inherited movement disorder. Various mutations within the epsilon-sarcoglycan (SGCE) gene have been associated with M-D, but mutations are detected in only about 30% of patients. The lack of stringent clinical inclusion criteria and limitations of mutation screens by direct sequencing might explain this observation.

METHODS

Eighty-six M-D index patients from the Dutch national referral centre for M-D underwent neurological examination and were classified according to previously published criteria into definite, probable and possible M-D. Sequence analysis of the SGCE gene and screening for copy number variations were performed. In addition, screening was carried out for the 3 bp deletion in exon 5 of the DYT1 gene.

RESULTS

Based on clinical examination, 24 definite, 23 probable and 39 possible M-D patients were detected. Thirteen of the 86 M-D index patients carried a SGCE mutation: seven nonsense mutations, two splice site mutations, three missense mutations (two within one patient) and one multiexonic deletion. In the definite M-D group, 50% carried an SGCE mutation and one single patient in the probable group (4%). One possible M-D patient showed a 4 bp deletion in the DYT1 gene (c.934_937delAGAG).

CONCLUSIONS

Mutation carriers were mainly identified in the definite M-D group. However, in half of definite M-D cases, no mutation could be identified. Copy-number variations did not play a major role in the large cohort.

Increased Abeta1-42 production sensitizes neuroblastoma cells for ER stress toxicity

Alzheimer's disease (AD) is characterized by the aggregation and subsequent deposition of misfolded beta-amyloid (Abeta) peptide. The unfolded protein response (UPR) is activated by misfolded protein stress in the endoplasmic reticulum (ER). In previous studies we demonstrated mild activation of the UPR by extracellularly applied oligomeric but not fibrillar Abeta1-42. In addition, we showed that oligomeric Abeta1-42 is internalized by cells, whereas fibrillar Abeta1-42 remains on the outside of the cell. Inhibition of Abeta uptake specifically inhibits toxicity of Abeta1-42 oligomers, underscoring the toxic potential of intracellular Abeta. Therefore, in the present study, we investigated the connection between intracellularly produced Abeta and the ER stress response, using human neuroblastoma cells overexpressing either wild type APP695 (APPwt) or APP695V717F (APPmut). Both cell lines secrete higher levels of Abeta1-40 and Abeta1-42 compared to the parental line. In addition, APPmut produces more Abeta1-42 than APPwt. Whereas the basal levels of UPR markers are not different, we find augmented UPR induction in response to ER stress in both APP overproducing cell lines compared to the parental cell line, with the strongest UPR activation in APPmut cells. In addition, ER stress toxicity was highest in APPmut cells, strongly suggesting a connection with the production of Abeta1-42. The difference in ER stress mediated toxicity between the APPwt and APPmut cell lines is alleviated by pretreatment with gamma-secretase inhibitor, indicating that it is dependent on Abeta production and in particular on Abeta1-42. Our data indicate that increased Abeta1-42 production sensitizes neuroblastoma cells for ER stress toxicity.

Upper motor neuron and extra-motor neuron involvement in amyotrophic lateral sclerosis: a clinical and brain imaging review

There is an ongoing discussion whether ALS is primarily a disease of upper motor neurons or lower motor neurons. We undertook a review to assess how new insights have contributed to solve this controversy. For this purpose we selected relevant publications from 1995 onwards focussing on (1) primary targets and disease progression in ALS and variants of ALS, (2) brain imaging markers for upper motor neuron lesion, and (3) evidence for ALS being a multisystem disorder. Clinically, upper motor and lower motor neuron symptoms can occur in any order over time. Brain imaging markers show upper motor neuron involvement in early disease. Overlap syndromes of ALS and dementia, and involvement of autonomic and sensory nerves occur frequently. PET/SPECT scans, functional MRI and voxel based morphometry studies clearly show abnormalities in extra-motor areas of the brain. Pathologically, the 43 kDa TAR DNA-binding protein (TDP-43) provides a clue to these overlapping disorders. In conclusion, evidence accumulates that ALS is a multisystem disorder rather than a pure lower and/or upper motor neuron disorder.

Analysis of gene expression identifies differentially expressed genes and pathways associated with lymphatic dissemination in patients with adenocarcinoma of the esophagus

INTRODUCTION

The presence of lymphatic dissemination is an important predictor of survival in esophageal adenocarcinoma (EA). The aim of this study was to discover a prognostic gene expression profile for lymphatic dissemination in EA and to identify genes and pathways that provide oncological insight in lymphatic dissemination.

METHODS

Patients who had lymphatic dissemination (N = 55) were compared with patients without lymphatic dissemination (N = 22). Whole-genome oligonucleotide microarrays were used to evaluate the genetic signature of 77 esophageal cancers. Multiple random validation was used to analyze the stability of the molecular signature and predictive power. Gene set enrichment analysis (GSEA) was applied to elucidate oncogenetic pathways.

RESULTS

Lymphatic dissemination was correctly predicted in 75 +/- 14% of lymph node positive patients. The absence of lymphatic dissemination was correctly predicted in 41 +/- 23% of lymph-node-negative patients. Argininosuccinate synthetase (ASS) was selected for validation on the protein level because it was present in most prognostic signatures as well as the list of differentially expressed genes. ASS expression was lower (P = 0.048) in patients with lymphatic dissemination than in patients without. GSEA identified that arginine metabolism pathways and lipid metabolism pathways are related to less chance of developing lymphatic dissemination.

DISCUSSION

The predictive profile does not outperform current clinical practice to predict the presence of lymphatic dissemination in patients with EA. Several genes, including ASS, and genetic pathways which are important in the development of lymphatic dissemination in EA, were identified.