Affibody-Mediated Sequestration of Amyloid ß Demonstrates Preventive Efficacy in a Transgenic Alzheimer's Disease Mouse Model.

Different strategies for treatment and prevention of Alzheimer's disease (AD) are currently under investigation, including passive immunization with anti-amyloid ß (anti-Aß) monoclonal antibodies (mAbs). Here, we investigate the therapeutic potential of a novel type of Aß-targeting agent based on an affibody molecule with fundamentally different properties to mAbs. We generated a therapeutic candidate, denoted ZSYM73-albumin-binding domain (ABD; 16.8 kDa), by genetic linkage of the dimeric ZSYM73 affibody for sequestering of monomeric Aß-peptides and an ABD for extension of its in vivo half-life. Amyloid precursor protein (APP)/PS1 transgenic AD mice were administered with ZSYM73-ABD, followed by behavioral examination and immunohistochemistry. Results demonstrated rescued cognitive functions and significantly lower amyloid burden in the treated animals compared to controls. No toxicological symptoms or immunology-related side-effects were observed. To our knowledge, this is the first reported in vivo investigation of a systemically delivered scaffold protein against monomeric Aß, demonstrating a therapeutic potential for prevention of AD.

Low-Grade Astrocytoma Mutations in IDH1, P53, and ATRX Cooperate to Block Differentiation of Human Neural Stem Cells via Repression of SOX2.

Low-grade astrocytomas (LGAs) carry neomorphic mutations in isocitrate dehydrogenase (IDH) concurrently with P53 and ATRX loss. To model LGA formation, we introduced R132H IDH1, P53 shRNA, and ATRX shRNA into human neural stem cells (NSCs). These oncogenic hits blocked NSC differentiation, increased invasiveness in vivo, and led to a DNA methylation and transcriptional profile resembling IDH1 mutant human LGAs. The differentiation block was caused by transcriptional silencing of the transcription factor SOX2 secondary to disassociation of its promoter from a putative enhancer. This occurred because of reduced binding of the chromatin organizer CTCF to its DNA motifs and disrupted chromatin looping. Our human model of IDH mutant LGA formation implicates impaired NSC differentiation because of repression of SOX2 as an early driver of gliomagenesis.

Patient-Specific Screening Using High-Grade Glioma Explants to Determine Potential Radiosensitization by a TGF-ß Small Molecule Inhibitor.

High-grade glioma (HGG), a deadly primary brain malignancy, manifests radioresistance mediated by cell-intrinsic and microenvironmental mechanisms. High levels of the cytokine transforming growth factor-ß (TGF-ß) in HGG promote radioresistance by enforcing an effective DNA damage response and supporting glioma stem cell self-renewal. Our analysis of HGG TCGA data and immunohistochemical staining of phosphorylated Smad2, which is the main transducer of canonical TGF-ß signaling, indicated variable levels of TGF-ß pathway activation across HGG tumors. These data suggest that evaluating the putative benefit of inhibiting TGF-ß during radiotherapy requires personalized screening. Thus, we used explant cultures of seven HGG specimens as a rapid, patient-specific ex vivo platform to test the hypothesis that LY364947, a small molecule inhibitor of the TGF-ß type I receptor, acts as a radiosensitizer in HGG. Immunofluorescence detection and image analysis of γ-H2AX foci, a marker of cellular recognition of radiation-induced DNA damage, and Sox2, a stem cell marker that increases post-radiation, indicated that LY364947 blocked these radiation responses in five of seven specimens. Collectively, our findings suggest that TGF-ß signaling increases radioresistance in most, but not all, HGGs. We propose that short-term culture of HGG explants provides a flexible and rapid platform for screening context-dependent efficacy of radiosensitizing agents in patient-specific fashion. This time- and cost-effective approach could be used to personalize treatment plans in HGG patients.

Folic acid awareness among female college students: neural tube defects prevention.

OBJECTIVE: To investigate the level of awareness among female college students on the importance of preconception folic acid supplementation in preventing neural tube defects (NTDs). We have also studied their response after educating them. METHODS: This is a questionnaire-based study. Five hundreds questionnaires were distributed to the female students of the 3 colleges, namely, Humanities, Sciences, and Health in Jeddah, Kingdom of Saudi Arabia in April 2008. The questions included an enquiry on their knowledge regarding the importance of folic acid preconception, and if they will implement what they learned after listening to lectures, delivered by the 4th year medical students, who were trained and supervised by the faculty members of the King Abdul-Aziz University. RESULTS: Two hundred and seventeen questionnaires were filled, and returned (43.4%). Mean age +/- SD was 20.96 +/- 2.25 years. Almost 88% were not aware of the importance of folic acid in preventing NTDs. After listening to the lecture, 82.9% thought that they will surely use folic acid preconception, and 98.6% will relay the important message about the importance of folic acid to others. CONCLUSION: There is a need to increase the awareness of the importance of folic acid among females' childbearing age. Medical students' involvement in educating college students was an effective way to increase their awareness. Similar educating programs are required, in order to reduce the high incidence of NTDs.