Establishment of Collagen: Hydroxyapatite/BMP-2 Mimetic Peptide Composites.

Extensive efforts were undertaken to develop suitable biomaterials for tissue engineering (TE) applications. To facilitate clinical approval processes and ensure the success of TE applications, bioinspired concepts are currently focused on. Working on bone tissue engineering, we describe in the present study a method for biofunctionalization of collagen/hydroxyapatite composites with BMP-2 mimetic peptides. This approach is expected to be fundamentally transferable to other tissue engineering fields. A modified BMP-2 mimetic peptide containing a negatively charged poly-glutamic acid residue (E7 BMP-2 peptide) was used to bind positively charged hydroxyapatite (HA) particles by electrostatic attraction. Binding efficiency was biochemically detected to be on average 85% compared to 30% of BMP-2 peptide without E7 residue. By quartz crystal microbalance (QCM) analysis, we could demonstrate the time-dependent dissociation of the BMP-2 mimetic peptides and the stable binding of the E7 BMP-2 peptides on HA-coated quartz crystals. As shown by immunofluorescence staining, alkaline phosphatase expression is similar to that detected in jaw periosteal cells (JPCs) stimulated with the whole BMP-2 protein. Mineralization potential of JPCs in the presence of BMP-2 mimetic peptides was also shown to be at least similar or significantly higher when low peptide concentrations were used, as compared to JPCs cultured in the presence of recombinant BMP-2 controls. In the following, collagen/hydroxyapatite composite materials were prepared. By proliferation analysis, we detected a decrease in cell viability with increasing HA ratios. Therefore, we chose a collagen/hydroxyapatite ratio of 1:2, similar to the natural composition of bone. The following inclusion of E7 BMP-2 peptides within the composite material resulted in significantly elevated long-term JPC proliferation under osteogenic conditions. We conclude that our advanced approach for fast and cost-effective scaffold preparation and biofunctionalization is suitable for improved and prolonged JPC proliferation. Further studies should prove the functionality of composite scaffolds in vivo.

Quality Analysis of Minerals Formed by Jaw Periosteal Cells under Different Culture Conditions.

Previously, we detected a higher degree of mineralization in fetal calf serum (FCS) compared to serum-free cultured jaw periosteum derived osteoprogenitor cells (JPCs). By Raman spectroscopy, we detected an earlier formation of mineralized extracellular matrix (ECM) of higher quality under serum-free media conditions. However, mineralization potential remained too low. In the present study, we aimed to investigate the biochemical composition and subsequent biomechanical properties of the JPC-formed ECM and minerals under human platelet lysate (hPL) and FCS supplementation. JPCs were isolated (n = 4 donors) and expanded under FCS conditions and used in passage five for osteogenic induction under both, FCS and hPL media supplementation. Raman spectroscopy and Alizarin Red/von Kossa staining were employed for biochemical composition analyses and for visualization and quantification of mineralization. Osteocalcin gene expression was analyzed by quantitative PCR. Biomechanical properties were assessed by using atomic force microscopy (AFM). Raman spectroscopic measurements showed significantly higher (p < 0.001) phosphate to protein ratios and in the tendency, lower carbonate to phosphate ratios in osteogenically induced JPCs under hPL in comparison to FCS culturing. Furthermore, higher crystal sizes were detected under hPL culturing of the cells. With respect to the ECM, significantly higher ratios of the precursor protein proline to hydroxyproline were detected in hPL-cultured JPC monolayers (p < 0.001). Additionally, significantly higher levels (p < 0.001) of collagen cross-linking were calculated, indicating a higher degree of collagen maturation in hPL-cultured JPCs. By atomic force microscopy, a significant increase in ECM stiffness (p < 0.001) of FCS cultured JPC monolayers was observed. The reverse effect was measured for the JPC formed precipitates/minerals. Under hPL supplementation, JPCs formed minerals of significantly higher stiffness (p < 0.001) when compared to the FCS setting. This study demonstrates that hPL culturing of JPCs leads to the formation of an anorganic material of superior quality in terms of biochemical composition and mechanical properties.

The Parkinson's disease-linked Leucine-rich repeat kinase 2 (LRRK2) is required for insulin-stimulated translocation of GLUT4.

Mutations within Leucine-rich repeat kinase 2 (LRRK2) are associated with late-onset Parkinson's disease. The physiological function of LRRK2 and molecular mechanism underlying the pathogenic role of LRRK2 mutations remain uncertain. Here, we investigated the role of LRRK2 in intracellular signal transduction. We find that deficiency of Lrrk2 in rodents affects insulin-dependent translocation of glucose transporter type 4 (GLUT4). This deficit is restored during aging by prolonged insulin-dependent activation of protein kinase B (PKB, Akt) and Akt substrate of 160 kDa (AS160), and is compensated by elevated basal expression of GLUT4 on the cell surface. Furthermore, we find a crucial role of Rab10 phosphorylation by LRRK2 for efficient insulin signal transduction. Translating our findings into human cell lines, we find comparable molecular alterations in fibroblasts from Parkinson's patients with the known pathogenic G2019S LRRK2 mutation. Our results highlight the role of LRRK2 in insulin-dependent signalling with potential therapeutic implications.

Rare Variants in Neurodegeneration Associated Genes Revealed by Targeted Panel Sequencing in a German ALS Cohort.

Amyotrophic lateral sclerosis (ALS) is a progressive fatal multisystemic neurodegenerative disorder caused by preferential degeneration of upper and lower motor neurons. To further delineate the genetic architecture of the disease, we used comprehensive panel sequencing in a cohort of 80 German ALS patients. The panel covered 39 confirmed ALS genes and candidate genes, as well as 238 genes associated with other entities of the neurodegenerative disease spectrum. In addition, we performed repeat length analysis for C9orf72. Our aim was to (1) identify potentially disease-causing variants, to (2) assess a proposed model of polygenic inheritance in ALS and to (3) connect ALS with other neurodegenerative entities. We identified 79 rare potentially pathogenic variants in 27 ALS associated genes in familial and sporadic cases. Five patients had pathogenic C9orf72 repeat expansions, a further four patients harbored intermediate length repeat expansions. Our findings demonstrate that a genetic background of the disease can actually be found in a large proportion of seemingly sporadic cases and that it is not limited to putative most frequently affected genes such as C9orf72 or SOD1. Assessing the polygenic nature of ALS, we identified 15 patients carrying at least two rare potentially pathogenic variants in ALS associated genes including pathogenic or intermediate C9orf72 repeat expansions. Multiple variants might influence severity or duration of disease or could account for intrafamilial phenotypic variability or reduced penetrance. However, we could not observe a correlation with age of onset in this study. We further detected potentially pathogenic variants in other neurodegeneration associated genes in 12 patients, supporting the hypothesis of common pathways in neurodegenerative diseases and linking ALS to other entities of the neurodegenerative spectrum. Most interestingly we found variants in GBE1 and SPG7 which might represent differential diagnoses. Based on our findings, we recommend two-staged genetic testing for ALS in Germany in patients with familial and sporadic ALS, comprising C9orf72 repeat analysis followed by comprehensive panel sequencing including differential diagnoses that impair motor neuron function to meet the complexity of ALS genetics.

PCA3 and PSA gene activity correlates with the true tumor cell burden in prostate cancer lymph node metastases.

BACKGROUND: Extent of pelvic lymph node (LN) dissemination is a critical prognostic feature for patients with prostate cancer (PCa) maintaining extended pelvic lymphadenectomy (LAD) as the gold standard for LN-staging. Unfortunately, conventional histopathological assessment may miss micrometastasis and recently presented immunocytochemical approach of the single cell analysis is still intricate. OBJECTIVE: To comparatively assess the potential of Prostate cancer gene 3 (PCA3) and prostate specific antigene (PSA) to perform as markers for tumor cell load. METHODS: Patients with high risk PCa for LN metastasis undergoing either a sentinel LN-guided staging LAD or retropubic radical prostatectomy with sentinel-guided pelvic LN dissection were included. LNs were investigated by routine histopathology. Tumor cell load was quantified by %immunocytochemistry. immunocytochemical single cell analysis. Gene activity was determined by qRT-PCR. RESULTS: Twenty four out of 226 LNs were positive in routine histopathology and 51 in single cell analysis. PSA mRNA level correlated with tumor cell density in patients with a positive immunocytochemistry. Gene activity of PCA3 was upregulated in metastatic LNs and correlated with tumor cell density in patients with tumor-invaded LNs as detected by immunocytochemistry. CONCLUSIONS: PCA3 gene expression discriminates LN metastasis and might outperform PSA gene activity in reflecting tumor cell burden in pelvic LNs of PCa patients.

Further delineation of the SATB2 phenotype.

SATB2 is an evolutionarily highly conserved chromatin remodeling gene located on chromosome 2q33.1. Vertebrate animal models have shown that Satb2 has a crucial role in craniofacial patterning and osteoblast differentiation, as well as in determining the fates of neuronal projections in the developing neocortex. In humans, chromosomal translocations and deletions of 2q33.1 leading to SATB2 haploinsufficiency are associated with cleft palate (CP), facial dysmorphism and intellectual disability (ID). A single patient carrying a nonsense mutation in SATB2 has been described to date. In this study, we performed trio-exome sequencing in a 3-year-old girl with CP and severely delayed speech development, and her unaffected parents. Previously, the girl had undergone conventional and molecular karyotyping (microarray analysis), as well as targeted analysis for different diseases associated with developmental delay, including Angelman syndrome, Rett syndrome and Fragile X syndrome. No diagnosis could be established. Exome sequencing revealed a de novo nonsense mutation in the SATB2 gene (c.715C>T; p.R239*). The identification of a second patient carrying a de novo nonsense mutation in SATB2 confirms that this gene is essential for normal craniofacial patterning and cognitive development. Based on our data and the literature published so far, we propose a new clinically recognizable syndrome - the SATB2-associated syndrome (SAS). SAS is likely to be underdiagnosed and should be considered in children with ID, severe speech delay, cleft or high-arched palate and abnormal dentition with crowded and irregularly shaped teeth.

Reliable housekeeping gene combination for quantitative PCR of lymph nodes in patients with prostate cancer.

BACKGROUND: To reliably compare the results of gene expression studies, the expression of the target gene should be normalized to the expression of a reference gene. For lymph node metastases of prostate cancer, no data on polymerase chain reaction (PCR) normalization have yet been reported. We aimed to determine the most reliable reference gene combination for this purpose in patients with prostate cancer. MATERIALS AND METHODS: Ten histologically- positive and ten negative lymph nodes of patients with prostate cancer were analyzed respectively. Expression of six candidate reference genes was comparatively assessed with quantitative Real-time PCR. The most stably-expressed gene combination was determined with geNorm software version 3.4. RESULTS: Hypoxanthine phosphoribosyltransferase-1 (HPRT1) and TATA box binding protein (TPB) were found to be the most stably expressed genes, with their combination having an expression stability value of M=0.17. CONCLUSION: Gene combination HPRT1 and TPB has the potential to be utilized for normalization in gene profiling assessment of metastatic and non-metastatic pelvic lymph node tissue from patients with prostate cancer.

Screening in ALS and FTD patients reveals 3 novel UBQLN2 mutations outside the PXX domain and a pure FTD phenotype.

Mutations in UBQLN2 have recently been shown to cause dominant X-linked amyotrophic lateral sclerosis (ALS) and ALS plus frontotemporal dementia (FTD). Information on their frequency in different populations is still rare, and a pure FTD phenotype has not yet been reported. Moreover, the mutational spectrum of known UBQLN2 mutations is still limited to its PXX repeat region. Based on a screening of 206 ALS and FTD patients, we here report 3 novel UBQLN2 mutations, accounting for 1.2% (2/161) ALS and 2.2% (1/45) FTD patients, including a patient with pure FTD. All mutations were located in highly conserved domains outside the PXX repeat region and not observed in 1450 ethnically matched control X-chromosomes. All affected patients presented with apparently sporadic disease. UBQLN2 mutations are rare in Central European ALS and FTD patients, but contribute significantly to patients with seemingly sporadic disease. UBQLN2 is able to cause any disease on the ALS-FTD continuum, including pure FTD. Because the pathogenic mechanism of UBQLN2 mutations is not limited to its PXX region, UBQLN2 screening in neurodegenerative patients should not be limited to this region.

Interpretation of the prostate cancer gene 3 in reference to the individual clinical background: implications for daily practice.

INTRODUCTION: The prostate cancer gene 3 (PCA3) urine assay for the diagnosis of prostate cancer was introduced into clinical practice at the end of 2006. We report our experience with the test in a routine clinical setting and discuss the interpretation of the test results in the context of the individual patient history. MATERIAL AND METHODS: We retrospectively reviewed the data of all patients who received PCA3 determination during a visit to our outpatient clinic between January and June 2008. Prostate volume, prostate-specific antigen (PSA) and (in cases where a biopsy was performed) the biopsy results were collected. RESULTS: The PCA3 score was independent of prostate volume and serum PSA. In our study population, 56 men had a negative (<35) and 47 a positive score (≥35). Thirty-two patients were subsequently biopsied, 18 of which were diagnosed with prostate cancer (51%). Patients with a positive biopsy showed significantly higher PCA3 values (p < 0.05). Sensitivity was 94%, specificity was 36% and the negative predictive value was 83%. The area under the curve in the receiver operating characteristics was 0.81 for the PCA3 score and 0.61 for the serum PSA. CONCLUSION: The PCA3 value correlates with the probability of a positive prostate biopsy. The high negative predictive value can facilitate the decision for or against a prostate biopsy. However, the low specificity and the comparably high costs hamper the routine use for prostate cancer screening purposes. To increase specificity, in daily practice the PCA3 score should be interpreted carefully with reference to the absolute PSA value and clinical history.

"Jerky" dystonia in children: spectrum of phenotypes and genetic testing.

Hyperkinetic dystonia is characterized by phasic, tremulous, and "jerky" movements in addition to twisting postures. We studied longitudinally 23 index patients with hyperkinetic dystonia from a quaternary pediatric movement disorder clinic in Ireland. Four clinical categories emerged: (1) Eight patients were diagnosed with myoclonus-dystonia, of whom seven carried heterozygous epsilon sarcoglycan (SGCE) mutations, including a novel deletion of exon 10. Gait disorder, unsteadiness, or frequent falls before 18 months were detected in all SGCE mutation carriers, whereas the typical neck-predominant presentation developed only years later. (2) One patient classified as benign hereditary chorea, because jerks were choreiform and continuous rather than action-induced, carried a heterozygous stop mutation of the TITF-1 gene (Y114X, exon 2). (3) Three mutation-negative patients were grouped as "myoclonic dystonia" with jerks only in the body regions affected by dystonia. (4) Eleven patients presented with a novel combination of dystonia and low amplitude poly-mini myoclonus of the upper limbs and pectoral muscles (D-PMM). In early childhood up to 3 years of age, an initial presentation with predominant gait impairment with only subtle jerks should prompt consideration of SGCE mutation analysis in addition to testing for DYT1 mutations. A causative gene for D-PMM remains to be identified.

The transcription factor PITX3 is associated with sporadic Parkinson's disease.

Parkinson's disease (PD) is a progressive neurodegenerative disease with typical motor symptoms due to the preferential loss of midbrain dopaminergic (mDA) neurons in the Substantia nigra pars compacta. Several proteins of the homeodomain family are crucial for the development of mDA neurons. These proteins remain expressed into adulthood with largely unknown functions, but potentially influence mDA neuronal survival. To determine whether genetic variation in these genes plays a role in sporadic PD, we performed a genetic association study in a screening sample of 340 PD patients and 680 controls and a large replication sample of 669 PD patients and 669 controls using 54 single nucleotide polymorphisms in and around the Engrailed 1/2, PITX3, LMX1B and OTX2 genes. We provide evidence for a novel, strong and reproducible association of the PITX3 promoter SNP rs3758549: C>T (p=0.004) with PD. The C-allele appears to be a recessive risk allele with an estimated population frequency of 83%. An allele-dependent dysregulation of PITX3 expression might contribute to the susceptibility to PD.

Genetic variability in the SNCA gene influences alpha-synuclein levels in the blood and brain.

Genetic variability in the promoter and 3' region of the SNCA gene coding alpha-synuclein modulates the risk to develop sporadic Parkinson's disease (PD). Whether this is mediated by regulating alpha-synuclein expression levels remains unknown. Therefore, we analyzed levels of alpha-synuclein in blood and human post mortem brain tissue including the substantia nigra using quantitative real-time reverse transcriptase-polymerase chain reaction and enzyme linked immunosorbent assay in vivo. Single nucleotide polymorphism (SNP) rs356219, a tagging SNP for a disease-associated haplotype in the 3' region of the SNCA gene, has a significant effect on SNCA mRNA levels in the substantia nigra and the cerebellum. Further, the "protective" genotype 259/259 of the PD-associated promoter repeat NACP-Rep1 is associated with lower protein levels in blood than genotypes 261/261, 259/261, and 259/263. In conclusion, we provide evidence that alpha-synuclein levels are influenced by genetic variability in the promoter and 3' region of the SNCA gene in vivo.

Genomic deletion size at the epsilon-sarcoglycan locus determines the clinical phenotype.

Myoclonus-dystonia (M-D, DYT11) is a dystonia plus syndrome characterized by brief myoclonic jerks predominantly of neck and upper limbs in combination with focal or segmental dystonia. It is caused by heterozygous mutations of the epsilon-sarcoglycan (SGCE) gene on chromosome 7q21.3. We present three patients with heterozygous large deletions in the 7q21.13-21.3 region. By quantitative analysis of single nucleotide polymorphism (SNP) oligonucleotide arrays, the deletion size was determined to range from 1.63 to 8.78 Mb. All deletions contained the maternally imprinted SGCE gene and up to 43 additional neighbouring genes. Two of the patients presented with typical M-D, whereas one paediatric patient with split-hand/split-foot malformation and sensorineural hearing loss (SHFM1D, OMIM 220600) had not developed M-D at the age of 9 years. This patient had the largest deletion of 8.78 Mb (7q21.13-21.3) containing also SHFM1, DLX6 and DLX5, which had been previously shown to be deleted in SHFM1D. In two patients, the deletions removed the paternal allele of the KRIT1 gene, which is a major cause of cavernous cerebral malformations type 1 (CCM1). Only the adult patient showed asymptomatic cavernous cerebral malformations on cranial MRI, underlining age-dependent penetrance and haploinsufficiency as pivotal features of patients with KRIT1 mutations. All three deletions contained the COL1A2 gene. In contrast to dominant negative point mutations, which cause osteogenesis imperfecta with bone fractures, haploinsufficiency of COL1A2 resulted only in subtle symptoms like recurrent joint subluxation or hypodontia. Assessing copy number variations by SNP arrays is an easy and reliable technique to delineate the size of human interstitial deletions. It will therefore become a standard technique to study patients, in whom heterozygous whole gene deletions are detected and information on neighbouring deleted genes is required for comprehensive genetic counselling and clinical management.

Clinical differentiation of genetically proven benign hereditary chorea and myoclonus-dystonia.

Because of clinical similarities, benign hereditary chorea and myoclonus-dystonia (DYT11) might be confused. No systematic comparisons of genetically proven cases with thyroid transcription factor-1 (TITF-1) and epsilon-sarcoglycan (SGCE) mutations have been performed to date. Three index patients and one index patients' daughter underwent genetic analysis of the TITF-1 and the SGCE gene. The movement disorders of all patients were assessed by video review. A new splicing mutation (376-2A>C) of the TITF-1 gene was detected in a mother and her daughter. Two additional patients carried a de novo SGCE nonsense mutation in exon 3 (R97X) and a novel SGCE missense mutation in exon 6 (G227V). Both TITF-1 mutation carriers presented with infancy-onset, nonprogressive chorea, which responded to alcohol intake. In addition, dystonia of the neck and trunk as well as fleeting jerky movements of the distal limbs could be observed. The mutually exclusive appearance of lightning-like myoclonic jerks triggered by action in SGCE mutation carriers and of continuous chorea of all limbs in TITF-1 mutation carriers phenotypically discriminated both genetic disorders. TITF-1 mutations should be considered in choreiform movement disorders with onset in infancy even in the presence of dystonia and myoclonic jerks.

Myoclonus-dystonia due to genomic deletions in the epsilon-sarcoglycan gene.

Direct genomic DNA sequencing fails to detect epsilon-sarcoglycan (SGCE) mutations in up to 30% of familial myoclonus-dystonia (M-D) cases. We identified novel large heterozygous deletions of SGCE exon 5 or exon 6 in two M-D pedigrees. Like nonsense mutations, exon rearrangements result in the generation of premature stop codons downstream of the deleted exon. SGCE exon dosage assays may identify additional families with SGCE mutation and thus reduce "genetic heterogeneity."