Pharmacological targeting of the transcription factor Nrf2 at the basal ganglia provides disease modifying therapy for experimental parkinsonism

Current therapies for motor symptoms of Parkinson's disease (PD) are based on dopamine replacement. However, the disease progression remains unaffected, because of continuous dopaminergic neuron loss. Since oxidative stress is actively involved in neuronal death in PD, pharmacological targeting of the antioxidant machinery may have therapeutic value. Here, we analyzed the relevance of the antioxidant phase II response mediated by the transcription factor NF-E2-related factor 2 (Nrf2) on brain protection against the parkinsonian toxin methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Intraperitoneal administration of the potent Nrf2 activator sulforaphane (SFN) increased Nrf2 protein levels in the basal ganglia and led to upregulation of phase II antioxidant enzymes heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase (NQO1). In wild-type mice, but not in Nrf2-knockout mice, SFN protected against MPTP-induced death of nigral dopaminergic neurons. The neuroprotective effects were accompanied by a decrease in astrogliosis, microgliosis, and release of pro-inflammatory cytokines. These results provide strong pharmacokinetic and biochemical evidence for activation of Nrf2 and phase II genes in the brain and also offer a neuroprotective strategy that may have clinical relevance for PD therapy.This work was supported by a Target Validation Grant of the Michael J. Fox Foundation for Parkinson’s Research and grant SAF2010-17822 from the Spanish Ministery of Science and Innovation. N.G.I. is recipient of a fellowship FPU from Universidad Autónoma of Madrid.Peer reviewe

Comparison of EGF with VEGF Non-Viral Gene Therapy for Cutaneous Wound Healing of Streptozotocin Diabetic Mice

BackgroundTo accelerate the healing of diabetic wounds, various kinds of growth factors have been employed. It is the short half-life of administered growth factors in hostile wound beds that have limited wide-spread clinical usage. To overcome this limitation, growth factor gene therapy could be an attractive alternative rather than direct application of factors onto the wound beds. We administered two growth factor DNAs, epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) into a cutaneous wound on diabetic mice. We compared the different characteristics of the healing wounds.MethodsStreptozotocin was injected intraperitoneally to induce diabetes into C57BL/6J mice. The ultrasound micro-bubble destruction method with SonoVue as a bubbling agent was used for non-viral gene delivery of EGF828 and VEGF165 DNAs. Each gene was modified for increasing efficacy as FRM-EGF828 or minicircle VEGF165. The degree of neoangiogenesis was assessed using qualitative laser Doppler flowmetry. We compared wound size and histological findings of the skin wounds in each group.ResultsIn both groups, accelerated wound closure was observed in the mice receiving gene therapy compared with non treated diabetic control mice. Blood flow detected by laser doppler flowmetry was better in the VEGF group than in the EGF group. Wound healing rates and histological findings were more accelerated in the EGF gene therapy group than the VEGF group, but were not statistically significant.ConclusionBoth non-viral EGF and VEGF gene therapy administrations could improve the speed and quality of skin wound healing. However, the detailed histological characteristics of the healing wounds were different

Different Susceptibility to the Parkinson's Toxin MPTP in Mice Lacking the Redox Master Regulator Nrf2 or Its Target Gene Heme Oxygenase-1

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: The transcription factor Nrf2 (NF-E2-related factor 2) and its target gene products, including heme oxygenase-1 (HO-1), elicit an antioxidant response that may have therapeutic value for Parkinson's disease (PD). However, HO-1 protein levels are increased in dopaminergic neurons of Parkinson's disease (PD) patients, suggesting its participation in free-iron deposition, oxidative stress and neurotoxicity. Before targeting Nrf2 for PD therapy it is imperative to determine if HO-1 is neurotoxic or neuroprotective in the basal ganglia. [Methodology]: We addressed this question by comparing neuronal damage and gliosis in Nrf2- or HO-1-knockout mice submitted to intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for five consecutive days. Nrf2- knockout mice showed exacerbated gliosis and dopaminergic nigrostriatal degeneration, as determined by immunohistochemical staining of tyrosine hydroxylase in striatum (STR) and substantia nigra (SN) and by HPLC determination of striatal dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC). On the other hand, the severity of gliosis and dopaminergic degeneration in HO-1-null mice was neither increased nor reduced. Regarding free-iron deposition, both Nrf2- and HO-1-deficient mice exhibited similar number of deposits as determined by Perl's staining, therefore indicating that these proteins do not contribute significantly to iron accumulation or clearance in MPTP-induced Parkinsonism. [Conclusions]: These results suggest that HO-1 does not protect or enhance the sensitivity to neuronal death in Parkinson's disease and that pharmacological or genetic intervention on Nrf2 may provide a neuroprotective benefit as add on therapy with current symptomatic protocols.This work was supported by grant SAF2007-62646 from the Spanish Ministry of Science and Innovation. The Faculty of Biochemistry, Biophysics and Biotechnology of the Jagiellonian University is a beneficiary of the structural funds from the European Union (grant No: POIG.02.01.00-12-064/08 and 02.02.00-00- 014/08). N.I. is recipient of a FPU fellowship of Universidad Autónoma of Madrid.Peer reviewe

The emerging role of Nrf2 in mitochondrial function

The transcription factor NF-E2 p45-related factor 2 (Nrf2; gene name NFE2L2) allows adaptation and survival under conditions of stress by regulating the gene expression of diverse networks of cytoprotective proteins, including antioxidant, anti-inflammatory, and detoxification enzymes as well as proteins that assist in the repair or removal of damaged macromolecules. Nrf2 has a crucial role in the maintenance of cellular redox homeostasis by regulating the biosynthesis, utilization, and regeneration of glutathione, thioredoxin, and NADPH and by controlling the production of reactive oxygen species by mitochondria and NADPH oxidase. Under homeostatic conditions, Nrf2 affects the mitochondrial membrane potential, fatty acid oxidation, availability of substrates (NADH and FADH2/succinate) for respiration, and ATP synthesis. Under conditions of stress or growth factor stimulation, activation of Nrf2 counteracts the increased reactive oxygen species production in mitochondria via transcriptional upregulation of uncoupling protein 3 and influences mitochondrial biogenesis by maintaining the levels of nuclear respiratory factor 1 and peroxisome proliferator-activated receptor γ coactivator 1α, as well as by promoting purine nucleotide biosynthesis. Pharmacological Nrf2 activators, such as the naturally occurring isothiocyanate sulforaphane, inhibit oxidant-mediated opening of the mitochondrial permeability transition pore and mitochondrial swelling. Curiously, a synthetic 1,4-diphenyl-1,2,3-triazole compound, originally designed as an Nrf2 activator, was found to promote mitophagy, thereby contributing to the overall mitochondrial homeostasis. Thus, Nrf2 is a prominent player in supporting the structural and functional integrity of the mitochondria, and this role is particularly crucial under conditions of stress

Muscle cell derived angiopoietin-1 contributes to both myogenesis and angiogenesis in the ischemic environment

Recent strategies to treat peripheral arterial disease (PAD) have focused on stem cell based therapies, which are believed to result in local secretion of vascular growth factors. Little is known, however, about the role of ischemic endogenous cells in this context. We hypothesized that ischemic muscle cells (MC) are capable of secreting growth factors that act as potent effectors of the local cellular regenerative environment. Both muscle and endothelial cells (ECs) were subjected to experimental ischemia, and conditioned medium (CM) from each was collected and analyzed to assess myogenic and/or angiogenic potential. In muscle progenitors, mRNA expression of VEGF and its cognate receptors (Nrp1, Flt, Flk) was present and decreased during myotube formation in vitro, and EC CM or VEGF increased myoblast proliferation. Angiopoietin-1 (Ang-1), Tie1, and Tie2 mRNA increased during MC differentiation in vitro. Exogenous Ang-1 enhanced myogenic (MyoD and Myogenin) mRNA in differentiating myoblasts and increased myosin heavy chain protein. Myotube formation was enhanced by MC CM and inhibited by EC CM. Ang-1 protein was present in CM from MCs isolated from both the genetically ischemia-susceptible BALB/c and ischemia-resistant C57BL/6 mouse strains, and chimeric Tie2 receptor trapping in situ ablated Ang-1's myogenic effects in vitro. Ang-1 or MC CM enhanced myotube formation in a mixed isolate of muscle progenitors as well as a myoblast co-culture with pluripotent mesenchymal cells (10T1/2) and this effect was abrogated by viral expression of the extracellular domain of Tie2 (AdsTie2). Furthermore, mesh/tube formation by HUVECs was enhanced by Ang-1 or MC CM and abrogated by Tie2 chimeric receptor trapping. Our results demonstrate the ability of muscle and endothelial cell-derived vascular growth factors, particularly Ang-1, to serve as multi-functional stimuli regulating crosstalk between blood vessels and muscle cells during regeneration from ischemic myopathy

Therapeutic Effects of Topical Application of Ozone on Acute Cutaneous Wound Healing

This study was undertaken to evaluate the therapeutic effects of topical ozonated olive oil on acute cutaneous wound healing in a guinea pig model and also to elucidate its therapeutic mechanism. After creating full-thickness skin wounds on the backs of guinea pigs by using a 6 mm punch biopsy, we examined the wound healing effect of topically applied ozonated olive oil (ozone group), as compared to the pure olive oil (oil group) and non-treatment (control group). The ozone group of guinea pig had a significantly smaller wound size and a residual wound area than the oil group, on days 5 (P<0.05) and 7 (P<0.01 and P<0.05) after wound surgery, respectively. Both hematoxylin-eosin staining and Masson-trichrome staining revealed an increased intensity of collagen fibers and a greater number of fibroblasts in the ozone group than that in the oil group on day 7. Immunohistochemical staining demonstrated upregulation of platelet derived growth factor (PDGF), transforming growth factor-β (TGF-β) and vascular endothelial growth factor (VEGF) expressions, but not fibroblast growth factor expression in the ozone group on day 7, as compared with the oil group. In conclusion, these results demonstrate that topical application of ozonated olive oil can accelerate acute cutaneous wound repair in a guinea pig in association with the increased expression of PDGF, TGF-β, and VEGF

Improving access to health care for chronic hepatitis B among migrant Chinese populations: a systematic mixed methods review of barriers and enablers.

Migrant Chinese populations in Western countries have a high prevalence of chronic hepatitis B but often experience poor access to healthcare and late diagnosis. This systematic review aimed to identify obstacles and supports to timely and appropriate health service use among these populations. Systematic searches resulted in 48 relevant studies published between 1996 and 2015. Data extraction and synthesis were informed by models of healthcare access that highlight the interplay of patient, provider and health system factors. There was strong consistent evidence of low levels of knowledge among patients and community members; but interventions that were primarily focused on increasing knowledge had only modest positive effects on testing and/or vaccination. There was strong consistent evidence that Chinese migrants tend to misunderstand the need for healthcare for hepatitis B and have low satisfaction with services. Stigma was consistently associated with hepatitis B and there was weak but consistent evidence of stigma acting as a barrier to care. However, available evidence on the effects of providing culturally appropriate services for hepatitis B on increasing uptake is limited. There was strong consistent evidence that health professionals miss opportunities for testing and vaccination. Practitioner education interventions may be important but evidence of effectiveness is limited. A simple prompt in patient records for primary care physicians improved the uptake of testing; and a dedicated service increased targeted vaccination coverage for new-borns. Further development and more rigorous evaluation of more holistic approaches that address patient, provider and system obstacles are needed