Role of the planar cell polarity gene Protein tyrosine kinase 7 in neural tube defects in humans.

BACKGROUND: Neural tube defects (NTDs) are among the most common congenital defects affecting approximately 1 in 1000 live births in North America. Their etiology is complex including environmental and genetic factors. Defects in the planar cell polarity (PCP) signaling pathway have been strongly associated with NTDs in animal models and human cohorts. Protein tyrosine kinase 7 (Ptk7) was shown to cause a very severe form of NTDs called craniorachischisis in a mouse model and genetically interacts with a core PCP member Vangl2 where double heterozygotes suffer from spina bifida. In this study, we examined the role of PTK7 in human NTDs to determine whether variants at this gene predispose to these defects. METHODS: We sequenced the coding region and the exon-intron junctions of PTK7 in a cohort of 473 patients affected with various forms of open and closed NTDs. Novel and rare variants(<1%) were genotyped in a cohort of 473 individuals. Their pathogenic effect was predicted in silico and functionally in an overexpression assay in a well-established zebrafish model. RESULTS: We identified in our cohort 6 rare variants, 3 of which were absent in public databases. One variant, p.Gly348Ser, acted as a hypermorph when overexpressed in the zebrafish model. CONCLUSION: We detected potentially pathogenic PTK7 variants in 1.1% of our NTD cohort. Our findings implicate PTK7 as a risk factor for NTDs and provide additional evidence for a pathogenic role of PCP signaling in these malformations.

Genetic studies of ANKRD6 as a molecular switch between Wnt signaling pathways in human neural tube defects.

BACKGROUND: Planar cell polarity (PCP) is a major branch of Wnt signaling that controls the process of convergent extension in gastrulation and neurulation. PCP defects were associated with neural tube defects (NTDs) that are the most common central nervous system anomalies. PCP signaling is highly dosage sensitive and exhibits an antagonistic relationship with the canonical Wnt/ß-catenin pathway. Diversin, encoded by Ankrd6, is an ankyrin repeat protein that activates the non canonical PCP signaling and simultaneously inhibits the canonical pathway. METHODS: In this study, we analyzed this dual role of ANKRD6 in NTDs. We sequenced its coding region in 473 NTD patients and 150 controls, and we validated the effect of the identified variants on Wnt signaling using reporter assays in mammalian cells. RESULTS: We identified four rare missense mutations in 0.8% of the NTD patients and two rare missense mutations in 1.3% of the controls. Notably, when all six mutations were validated, only two mutations identified in NTD patients, p.Pro548Leu, p.Arg632His, significantly altered DIVERSIN activity in Wnt signaling assays in a hypomorphic manner. CONCLUSION: Rare missense mutations in ANKRD6 could affect a balanced reciprocal antagonism between both Wnt pathways in neurulation and act as predisposing factors to NTDs in a subset of patients.

Cortical Reorganization After Optical Alignment in Strabismic Patients Outside of Critical Period.

Purpose: To measure visual crowding, an essential bottleneck on object recognition and reliable psychophysical index of cortex organization, in older children and adults with horizontal concomitant strabismus before and after strabismus surgery. Methods: Using real-time eye tracking to ensure gaze-contingent display, we examined the peripheral visual crowding effects in older children and adults with horizontal concomitant strabismus but without amblyopia before and after strabismus surgery. Patients were asked to discriminate the orientation of the central tumbling E target letter with flankers arranged along the radial or tangential axis in the nasal or temporal hemifield at different eccentricities (5° or 10°). The critical spacing value, which is the minimum space between the target and the flankers required for correct discrimination, was obtained for comparisons before and after strabismus surgery. Results: Twelve individuals with exotropia (6 males, 21.75 ± 7.29 years, mean ± SD) and 15 individuals with esotropia (6 males, 24.13 ± 5.96 years) participated in this study. We found that strabismic individuals showed significantly larger critical spacing with nasotemporal asymmetry along the radial axis that related to the strabismus pattern, with exotropes exhibiting stronger temporal field crowding and esotropes exhibiting stronger nasal field crowding before surgical alignment. After surgery, the critical spacing was reduced and rebalanced between the nasal and temporal hemifields. Furthermore, the postoperative recovery of stereopsis was associated with the extent of nasotemporal balance of critical spacing. Conclusions: We find that optical realignment (i.e., strabismus surgery) can normalize the enlarged visual crowding effects, a reliable psychophysical index of cortical organization, in the peripheral visual field of older children and adults with strabismus and rebalance the nasotemporal asymmetry of crowding, promoting the recovery of postoperative stereopsis. Our results indicated a potential of experience-dependent cortical organization after axial alignment even for individuals who are out of the critical period of visual development, illuminating the capacity and limitations of optics on sensory plasticity and emphasizing the importance of ocular correction for clinical practice.

Serum levels of inflammation factors and cognitive performance in amnestic mild cognitive impairment: a Chinese clinical study.

Early diagnosis of Alzheimer's disease (AD) is important for initiating timely therapy to block or slow the rate of disease progression. This study was designed to investigate the potential of inflammation-related biomarkers in peripheral blood to accurately reflect AD onset and progression. Individuals (n=150) with amnestic mild cognitive impairment (aMCI) were divided into two subgroups (low- and high-risk) based on APOEε4 allele carrier status, and administered a battery of neuropsychological tests and tested for serum levels of IL-6, IL-10, TNF-α, and IFN-γ by using specific enzyme-linked immunosorbent assays. Results were compared with those from age-matched healthy controls (n=150). The levels of IL-6 were significantly higher in the aMCI group than in controls (P<0.01). When the aMCI group was stratified by APOEε4 status, significant differences were found between the low- and high-risk groups and controls in the levels of IL-6 and IFN-γ (P<0.01 and P=0.041, respectively). Moreover, the IL-6 level in the low-risk aMCI group was higher than that in the high-risk aMCI group (P=0.028). A weak but significant negative correlation was found between IL-6 and cognitive performance. Taken together, these findings indicate that IL-6, while not useful alone, has potential in combination with other biomarkers to support early diagnosis of aMCI due to its association with the progression of cognitive impairment.

Targeting regulation of VEGF by BPTF in non-small cell lung cancer and its potential clinical significance.

PURPOSE: VEGF facilitates tumor angiogenesis, and bevacizumab targeting VEGF is used in anti-tumor therapy. It is meaningful to clarify the upstream regulatory mechanism of VEGF. BPTF is important in chromosomal remodeling, and promotes the progression of tumors. However, its role in promoting tumor angiogenesis by targeting VEGF has not been fully reported. This study aims to elucidate the expression regulation of VEGF by BPTF and its clinical significance in NSCLC. METHODS: 1. BPTF siRNA and shRNA plasmids were used to reduce the expression of BPTF by transfection in vivo and in vitro. BPTF, VEGF and CD144 expressions were examined by immunofluorescence and Western Blot. 2. The expressions of BPTF, VEGF, CD144 and CD31 were detected in lung adenocarcinoma samples by immunofluorescence, Western blot and immunohistochemical staining. 3. 26 lung adenocarcinoma patients treated by bevacizumab were divided into 2 groups according to the treatment efficacy. BPTF and VEGF expressions were analyzed. RESULTS: 1. BPTF knockdown inhibited the expression of VEGF and CD144 in vivo and in vitro. 2. Compared with para-cancer tissues, BPTF, VEGF, CD144 and CD31 were highly expressed in lung adenocarcinoma. 3. In 75 lung adenocarcinoma specimens, BPTF and VEGF overexpression was correlated with lymph node metastasis and clinical stage. The 5-year survival rate of patients with BPTF and VEGF low expression was higher, and BPTF expression was positively correlated with VEGF expression. 4. Among 26 patients treated with bevacizumab, the patients with BPTF overexpression are more sensitive to the treatment. CONCLUSIONS: BPTF positively regulates VEGF expression and its high expression predicts a better efficacy of bevacizumab treatment in NSCLC.

Update on the Role of the Non-Canonical Wnt/Planar Cell Polarity Pathway in Neural Tube Defects.

Neural tube defects (NTDs), including spina bifida and anencephaly, represent the most severe and common malformations of the central nervous system affecting 0.7-3 per 1000 live births. They result from the failure of neural tube closure during the first few weeks of pregnancy. They have a complex etiology that implicate a large number of genetic and environmental factors that remain largely undetermined. Extensive studies in vertebrate models have strongly implicated the non-canonical Wnt/planar cell polarity (PCP) signaling pathway in the pathogenesis of NTDs. The defects in this pathway lead to a defective convergent extension that is a major morphogenetic process essential for neural tube elongation and subsequent closure. A large number of genetic studies in human NTDs have demonstrated an important role of PCP signaling in their etiology. However, the relative contribution of this pathway to this complex etiology awaits a better picture of the complete genetic architecture of these defects. The emergence of new genome technologies and bioinformatics pipelines, complemented with the powerful tool of animal models for variant interpretation as well as significant collaborative efforts, will help to dissect the complex genetics of NTDs. The ultimate goal is to develop better preventive and counseling strategies for families affected by these devastating conditions.

A clinical memory battery for screening for amnestic mild cognitive impairment in an elderly chinese population.

Amnestic mild cognitive impairment (MCI) might be more likely to progress to Alzheimer's disease than single non-memory MCI and multiple domain MCI. After excluding those who did not conform to the inclusion criteria of amnestic MCI or healthy controls, a neuropsychologic battery that included the Mini-Mental State Examination, Clinical Dementia Rating, Chinese version of the Montreal Cognitive Assessment, Instrumental Activities of Daily Living scale and Auditory Verbal Learning Test was performed on 150 amnestic MCI and 150 normal control patients. The Chinese version of the Montreal Cognitive Assessment was measured for its test-retest reliability, sensitivity and specificity. Blood was collected for apolipoprotein E (APOE) genotyping. Compared with the control group, the amnestic MCI group performed significantly worse on all neuropsychological tests, and non-APOE-ε4 carriers in the amnestic MCI group performed better than APOE-ε4 carriers in the amnestic MCI group. The set of neuropsychological tests in our study could distinguish amnestic MCI participants from normal elderly participants accurately. APOE did have a role in amnestic MCI patients, but the magnitude and mechanism of its influence are not fully understood.