HIF-1α Dependent Wound Healing Angiogenesis In Vivo Can Be Controlled by Site-Specific Lentiviral Magnetic Targeting of SHP-2

Abstract

Hypoxia promotes vascularization by stabilization and activation of the hypoxia inducible factor 1α (HIF-1α), which constitutes a target for angiogenic gene therapy. However, gene therapy is hampered by low gene delivery efficiency and non-specific side effects. Here, we developed a gene transfer technique based on magnetic targeting of magnetic nanoparticle-lentivirus (MNP-LV) complexes allowing site-directed gene delivery to individual wounds in the dorsal skin of mice. Using this technique, we were able to control HIF-1α dependent wound healing angiogenesis in vivo via site-specific modulation of the tyrosine phosphatase activity of SHP-2. We thus uncover a novel physiological role of SHP-2 in protecting HIF-1α from proteasomal degradation via a Src kinase dependent mechanism, resulting in HIF-1α DNA-binding and transcriptional activity in vitro and in vivo. Excitingly, using targeting of MNP-LV complexes, we achieved simultaneous expression of constitutively active as well as inactive SHP-2 mutant proteins in separate wounds in vivo and hereby specifically and locally controlled HIF-1α activity as well as the angiogenic wound healing response in vivo. Therefore, magnetically targeted lentiviral induced modulation of SHP-2 activity may be an attractive approach for controlling patho-physiological conditions relying on hypoxic vessel growth at specific sites.

Mechanistic Actions of microRNAs in Diabetic Wound Healing

“…This phase is characterized by high cellular activity due to the increased keratinocyte migration and proliferation at the wound edge to cover the wound site, where these cells attach to the basement membrane [ 30 ]. As the center of the wound is relatively avascular, restoration of the vascular network begins in the early inflammatory phase when transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF) are initially secreted by activated platelets [ 31 ] along with vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1), which is triggered by hypoxia and the ischemic environment [ 32 ]. Following injury, proliferating fibroblasts migrate in high abundance to the wound site, predominantly due to their stimulation by TGF-β and PDGF.…”

Autologous blood transfusion stimulates wound healing in diabetic mice through activation of the HIF‐1α pathway by improving the blood preservation solution

“…HIF‐1α is a crucial transcriptional regulator in response to hypoxia. In hypoxic conditions, HIF‐1α can bind to hypoxia‐responsive elements (HRE) which accumulate and lead to the expression of various angiogenic genes in the promotor region . Moreover, in diabetes, HIF‐1α is also the main regulator of oxygen homeostasis and is closely related to all stages of wound healing, with studies indicating that reduced levels of HIF‐1α can lead to hyperglycemia‐mediated HIF‐1α repression in dermal fibroblasts and endothelial cells which signals the non‐healing of a chronic wound .…”

Nucleic‐Acid Structures as Intracellular Probes for Live Cells

“…Commercially available NanoFlares have also been used successfully by a number of groups for studying genetic content in live cells …”