Disruption of Higher Order DNA Structures in Friedreich's Ataxia (GAA)n Repeats by PNA or LNA Targeting

Expansion of (GAA)n repeats in the first intron of the Frataxin gene is associated with reduced mRNA and protein levels and the development of Friedreich’s ataxia. (GAA)n expansions form non-canonical structures, including intramolecular triplex (H-DNA), and R-loops and are associated with epigenetic modifications. With the aim of interfering with higher order H-DNA (like) DNA structures within pathological (GAA)n expansions, we examined sequence-specific interaction of peptide nucleic acid (PNA) with (GAA)n repeats of different lengths (short: n=9, medium: n=75 or long: n=115) by chemical probing of triple helical and single stranded regions. We found that a triplex structure (H-DNA) forms at GAA repeats of different lengths; however, single stranded regions were not detected within the medium size pathological repeat, suggesting the presence of a more complex structure. Furthermore, (GAA)4-PNA binding of the repeat abolished all detectable triplex DNA structures, whereas (CTT)5-PNA did not. We present evidence that (GAA)4-PNA can invade the DNA at the repeat region by binding the DNA CTT strand, thereby preventing non-canonical-DNA formation, and that triplex invasion complexes by (CTT)5-PNA form at the GAA repeats. Locked nucleic acid (LNA) oligonucleotides also inhibited triplex formation at GAA repeat expansions, and atomic force microscopy analysis showed significant relaxation of plasmid morphology in the presence of GAA-LNA. Thus, by inhibiting disease related higher order DNA structures in the Frataxin gene, such PNA and LNA oligomers may have potential for discovery of drugs aiming at recovering Frataxin expression

Creating global students: opportunities, challenges and experiences of internationalizing the Geography curriculum in Higher Education

Killick (2015) defines university internationalization as an institution’s “response to the globalization of our world” which can be viewed as a process of changing the student experience in response to changes in the wider world. Internationalization has become an important feature of universities, stimulated by the generation of fees from international students, the promotion of international “branding”, reputation and prestige (in international league tables), and to address the need for graduates to compete in an increasingly global workplace due to globalization (Haigh, 2002). The internationalization of institutions by attracting foreign students to study has received the most attention, and the opportunities and issues have been well documented (Ryan, 2013). However, the internationalization of curricula is becoming more important for maintaining the quality and competitiveness of Higher Education in an increasingly globalized neo-liberalized market (Harris, 2008) and the desire for branding as a “Global University” (Clifford & Montgomery, 2011), the increasing diversity of student and staff, and the need to broaden the relevance and appeal of higher education to wider society (Kenna, 2017)