The novel peptide F29 facilitates the DNA-binding ability of hypoxia-inducible factor-1alpha

Upregulating HIF-1α to Boost the Survival of Neural Stem Cells via Functional Peptides-Complexed MRI-Visible Nanomedicine for Stroke Therapy

Neural stem cells (NSCs) transplantation has been considered as a promising strategy for the treatment of ischemic stroke. However, the therapeutic prospect is limited by the poor control over the survival, migration, and maturation of transplanted NSCs. Upregulating hypoxia inducible factor (HIF)-1α expression in stem cells can improve the survival and migration of NSCs grafted for stroke therapy. Functional peptide drugs, which could inhibit endogenous HIF-1α ubiquitination, might be used to effectively upregulate the HIF-1α expression in NSCs, thereby to improve the therapeutic effect in ischemia stroke. Herein, a magnetic resonance imaging (MRI)-visible nanomedicine is developed to codeliver functional peptides and superparamagnetic iron oxide (SPIO) nanoparticles into NSCs. This nanomedicine not only promotes the survival and migration ability of NSCs but also allows an in vivo tracking of transplanted NSCs with MRI. The results demonstrate the great potential of the functional peptides-complexed multifunctional nanomedicine in boosting the therapeutic effect of stem cell-based therapy in stroke.

HIF-1 and HIF-2 transcription factors--similar but not identical

Hypoxia inducible factor (HIF)-1 and HIF-2 are heterodimeric transcription factors mediating the cellular response to hypoxia. Recent data indicate that not only ubiquitous HIF-1 alpha, but also more cell-specific HIF-2 alpha, is an important regulator of the hypoxia response. Although both alpha subunits are highly conservative at protein level, share similar domain structure, heterodimerize with HIF-1 beta, and bind to the same DNA sequence called hypoxia responsive element (HRE), their effect on the expression of some genes may vary. In this review we stressed the differences between the isoforms, their structure and expression pattern. Moreover, we described diversity of coactivators and proteins which interact with HIFs, and which are responsible for the specificity of their action. Finally, recent data showing link between HIFs and specific microRNA have been presented.