👤 Jana F Schulz

Juvenile CLN3 disease, one of the most common forms of a group of lysosomal storage diseases called neuronal ceroid lipofuscinoses (NCLs), is a progressive neurodegenerative disorder with initial visual deterioration. The objective of this study was to analyse the retinal phenotype of patients with CLN3 disease with the help of recent ophthalmic imaging modalities to distinguish CLN3 disease from other inherited retinal dystrophies. Patients underwent ophthalmic evaluations, including anterior and posterior segment examinations, optical coherence tomography, fundus autofluorescence, near infrared imaging and fundus photography. Patients were also assessed according to the Hamburg juvenile NCL (JNCL) score. Each ophthalmic finding was assessed by three independent examiners and assigned to a clinical severity score. 22 eyes of 11 patients were included. The mean age at examination was 14.4 years (range 11.8-26.4 years), with an average age at initial diagnosis of 8 years (range 4.5-11 years). The mean Hamburg JNCL score was 7.3 (range 0-13). All patients showed a specific macular striation pattern on optical coherence tomography that was independent of age and progression of the disease. Other previously described retinal features of CLN3 disease were classified into four severity grades. This study represents the first prospective observational case series documenting retinal abnormalities in CLN3 disease with the aid of the spectral domain optical coherence tomography. The major finding was a characteristic, striated macular pattern in all patients studied. Particularly in early disease cases, macular striae can potentially help to discriminate CLN3 disease from other inherited forms of retinitis pigmentosa. Show less

The objective of this study was to establish an ophthalmologic phenotype of heterozygous carriers of juvenile neuronal ceroid lipofuscinosis (CLN3 disease, Batten disease). The eyes and vision of nine heterozygous carriers of juvenile neuronal ceroid lipofuscinosis with classical CLN3 mutations were examined using the following methods: clinical examination, visual acuity, ophthalmoscopy, optical coherence tomography (macular thickness and peripapillary retinal nerve fibre layer measurement [RNFL]), fundus autofluorescence measurement, infrared imaging, and full-field and multifocal electroretinogram. Optical coherence tomography and electrophysiological data were statistically compared with age- and sex-matched control groups. The basic clinical examination as well as the fundus autofluorescence and infrared images of the macular region were unremarkable. Neither the electrophysiological examinations nor optical coherence tomography yielded fundamental abnormalities. There were only two significant-albeit most likely clinically irrelevant-differences that occurred in comparison to the control group: a decrease in RNFL of the nasal quadrant in the OCT and a prolongation of the N1 implicit time of the second-ring eccentricity in the multifocal electroretinogram. The eyes and vision of heterozygous carriers of CLN3 disease showed normal features when compared to a control group, which controverts a previously suggested retinal dysfunction in these subjects. Show less

Forced vital capacity (FVC), a spirometric measure of pulmonary function, reflects lung volume and is used to diagnose and monitor lung diseases. We performed genome-wide association study meta-analysis of FVC in 52,253 individuals from 26 studies and followed up the top associations in 32,917 additional individuals of European ancestry. We found six new regions associated at genome-wide significance (P < 5 × 10(-8)) with FVC in or near EFEMP1, BMP6, MIR129-2-HSD17B12, PRDM11, WWOX and KCNJ2. Two loci previously associated with spirometric measures (GSTCD and PTCH1) were related to FVC. Newly implicated regions were followed up in samples from African-American, Korean, Chinese and Hispanic individuals. We detected transcripts for all six newly implicated genes in human lung tissue. The new loci may inform mechanisms involved in lung development and the pathogenesis of restrictive lung disease. Show less

A growing line of evidence indicates a dysfunctional ubiquitin-proteasome system (UPS) in cardiac diseases. Anti-hypertrophic effects and improved cardiac function have been reported after treatment with proteasome inhibitors in experimental models of cardiac hypertrophy. Here we tested whether proteasome inhibition could also reverse the disease phenotype in a genetically-modified mouse model of hypertrophic cardiomyopathy (HCM), which carries a mutation in Mybpc3, encoding the myofilament protein cardiac myosin-binding protein C. At 7 weeks of age, homozygous mutant mice (KI) have 39% higher left ventricular mass-to-body-weight ratio and 29% lower fractional area shortening (FAS) than wild-type (WT) mice. Both groups were treated with epoxomicin (0.5 mg/kg/day) or vehicle for 1 week via osmotic minipumps. Epoxomicin inhibited the chymotrypsin-like activity by ~50% in both groups. All parameters of cardiac hypertrophy (including the fetal gene program) were not affected by epoxomicin treatment in both groups. In contrast, FAS was 12% and 35% higher in epoxomicin-treated than vehicle-treated WT and KI mice, respectively. To identify which genes or pathways could be involved in this positive effect, we performed a transcriptome analysis in KI and WT neonatal cardiac myocytes, treated or not with the proteasome inhibitor MG132 (1 μM, 24 h). This revealed 103 genes (four-fold difference; 5% FDR) which are commonly regulated in both KI and WT cardiac myocytes. Thus, even in genetically-modified mice with manifest HCM, proteasome inhibition showed beneficial effects, at least with regard to cardiac function. Targeting the UPS in cardiac diseases remains therefore a therapeutic option. Show less

The two most prevalent forms of neuronal ceroid lipofuscinosis (NCL) are the juvenile form (Batten disease, CLN3) and late infantile form (Jansky-Bielschowsky disease, CLN2). The aim of this study was to compare quantitative T2-values of brain tissue in CLN2 and CLN3 patients with reference values from age-matched normal subjects. Twenty-three CLN2 (n = 6) and CLN3 (n = 17) patients (m:f = 11:12) underwent MRI examination including a multiecho T2 sequence. Quantitative T2-values were measured in six defined regions of interest (ROIs) in the calculated quantitative T2 maps within the white matter (WM) and gray matter (GM). The extracted quantitative T2-values were compared with reference values from healthy children and young adults. Informed consent was obtained from the patients or their parents for all patients. Statistical analysis revealed elevated quantitative T2-values in nearly all ROIs placed in the WM of the CLN2 patients. In contrast to this finding, no significant differences were found for the quantitative T2-values of the CLN3 patients compared to the age-matched healthy controls in any of the defined WM ROIs. Both groups exhibited no significant alterations of the quantitative T2-values in the GM ROIs compared to the healthy subjects. Alterations of quantitative T2-values in the cerebral WM may not be a reliable sign to confirm the diagnosis in CLN3 patients but could prove valuable for diagnosis confirmation, follow-up examinations, and longitudinal monitoring of the disease progression in CLN2 patients. Show less

Mutations in the CLN3 gene lead to juvenile neuronal ceroid lipofuscinosis, a pediatric neurodegenerative disorder characterized by visual loss, epilepsy and psychomotor deterioration. Although most CLN3 patients carry the same 1-kb deletion in the CLN3 gene, their disease phenotype can be variable. The aims of this study were to (i) study the clinical phenotype in CLN3 patients with identical genotype, (ii) identify genes that are dysregulated in CLN3 disease regardless of the clinical course that could be useful as biomarkers, and (iii) find modifier genes that affect the progression rate of the disease. A total of 25 CLN3 patients homozygous for the 1-kb deletion were classified into groups with rapid, average or slow disease progression using an established clinical scoring system. Genome-wide expression profiling was performed in eight CLN3 patients with different disease progression and matched controls. The study showed high phenotype variability in CLN3 patients. Five genes were dysregulated in all CLN3 patients and present candidate biomarkers of the disease. Of those, dual specificity phosphatase 2 (DUSP2) was also validated in acutely CLN3-depleted cell models and in CbCln3(Δex7/8) cerebellar precursor cells. A total of 13 genes were upregulated in patients with rapid disease progression and downregulated in patients with slow disease progression; one gene showed dysregulation in the opposite way. Among these potential modifier genes, guanine nucleotide exchange factor 1 for small GTPases of the Ras family (RAPGEF1) and transcription factor Spi-B (SPIB) were validated in an acutely CLN3-depleted cell model. These findings indicate that differential perturbations of distinct signaling pathways might alter disease progression and provide insight into the molecular alterations underlying neuronal dysfunction in CLN3 disease and neurodegeneration in general. Show less

A series of different cyclo-diarsa-diazenium salts bearing several bulky groups such as supermesityl (Mes* = 2,4,6-tBu(3)C(6)H(2)) and m-terphenyl (2,6-Mes(2)-C(6)H(3), Mes = 2,4,6-Me(3)C(6)H(2)) and anions such as triflate (OTf = SO(3)CF(3) = trifluoromethylsulfonate) and tetrachloridogallate (GaCl(4)(-)) were synthesized and fully characterized. The novel 1-chloro-cyclo-1,3-diarsa-2,4-diazenium cation represents the first example of a binary cyclic As(III)/N four-membered heterocyclic cation, with a di- and tricoordinated As atom and a delocalized pi bond along the NAs((+))N unit. The addition of excess Me(3)SiN(3) yields the fully characterized cationic arsenic azide, 1-azido-cyclo-1,3-diarsa-2,4-diazenium-mu-azido-hexachlorido-digallate. The Cl(-)/N(3)(-) exchange is triggered by the action of the Lewis acid GaCl(3). Depending on the Me(3)SiN(3) stoichiometry, different mu-azido-hexachlorido-digallate salts with either 1-chloro- or 1-azido-cyclo-1,3-diarsa-2,4-diazenium cations or even a mixture of both are observed. Moreover, it was of special interest to study the distances between the cationic arsenic center and the anion in cyclo-diarsa-diazenium salts. A correlation between the color of the salt and the anion/cation distance, ranging between 2 and 8 A in cyclo-diarsa-diazenium salts of the type [R(2)N(2)As(2)Y](+)X(-) depending on the bulky group R (R = Mes*, Ter), the substituent Y (Y = Cl, N(3), OTf), and the anion X(-) (X = OTf, GaCl(4), Cl(3)Ga-N(3)-GaCl(3)), was established. Show less

The neuronal ceroid lipofuscinoses (NCLs) form a group of autosomal recessively inherited neurodegenerative disorders that mainly affect children. Ten NCL forms can be distinguished by age at onset, clinicopathologic features, and genetics. In eight of these forms, the underlying genes have been identified. At present, approximately 10% of all patients do not fall into one of the eight known genetic forms of NCL. We have identified two Asian families with two novel homozygous mutations in the CLN5 gene. In the first Pakistani family, two children developed symptoms of an early juvenile NCL. After exclusion of mutations in genes known to be associated with this age of onset in families from many different countries (CLN1, CLN2, CLN3, CLN6, CLN8 and CLN10) SNP array-based homozygosity mapping led to the identification of a novel homozygous mutation c.1072₁₀₇₃delTT (p.Leu358AlafsX4) in CLN5. In the second Afghan family, two children developed symptoms of a late infantile NCL. The mutation c.1137G>T (p.Trp379Cys) in CLN5 was identified. The affected children in these families represent the first reported CLN5 patients originating in Asian sibships. Expression analysis showed that mutant p.Leu358AlafsX4 CLN5 is truncated and lacks a used N-glycosylation site at Asn401. The missense mutation p.Trp379Cys affected neither the size nor glycosylation of the CLN5 protein. Double immunofluorescence microscopy showed that while the wild-type CLN5 protein is localized in lysosomes, both mutant CLN5 proteins are retained in the endoplasmic reticulum rather than reaching the lysosome. Show less