A TNF Receptor 2 Selective Agonist Rescues Human Neurons from Oxidative Stress-Induced Cell Death

Abstract

Tumor necrosis factor (TNF) plays a dual role in neurodegenerative diseases. Whereas TNF receptor (TNFR) 1 is predominantly associated with neurodegeneration, TNFR2 is involved in tissue regeneration and neuroprotection. Accordingly, the availability of TNFR2-selective agonists could allow the development of new therapeutic treatments of neurodegenerative diseases. We constructed a soluble, human TNFR2 agonist (TNC-scTNFR2) by genetic fusion of the trimerization domain of tenascin C to a TNFR2-selective single-chain TNF molecule, which is comprised of three TNF domains connected by short peptide linkers. TNC-scTNFR2 specifically activated TNFR2 and possessed membrane-TNF mimetic activity, resulting in TNFR2 signaling complex formation and activation of downstream signaling pathways. Protection from neurodegeneration was assessed using the human dopaminergic neuronal cell line LUHMES. First we show that TNC-scTNFR2 interfered with cell death pathways subsequent to H2O2 exposure. Protection from cell death was dependent on TNFR2 activation of the PI3K-PKB/Akt pathway, evident from restoration of H2O2 sensitivity in the presence of PI3K inhibitor LY294002. Second, in an in vitro model of Parkinson disease, TNC-scTNFR2 rescues neurons after induction of cell death by 6-OHDA. Since TNFR2 is not only promoting anti-apoptotic responses but also plays an important role in tissue regeneration, activation of TNFR2 signaling by TNC-scTNFR2 appears a promising strategy to ameliorate neurodegenerative processes.

Essential protective role of tumor necrosis factor receptor 2 in neurodegeneration

“…1G). Interestingly, induction of cell death was not enhanced by addition of the cross-linking TNFR2-specific monoclonal antibody 80M2, which in concert with soluble TNF is able to mimic the action of tmTNF (11,28). Differently, the bioactivity of scTNF R2 , a covalently stabilized huTNFR2-selective TNF trimer, was strongly enhanced in the presence of 80M2 (Fig.…”

“…Efficient activation of TNFR2 requires receptor oligomerization by the membrane form of TNF (tmTNF) or oligomerized soluble forms of tmTNF mimicking receptor activation via tmTNF (11,25) such as a TNFR2-selective TNF mutein, fused to the trimerization domain tenascin C (TNC-scTNF R2 ) recently developed by the authors (11). We here describe a TNFR2-selective TNF mutein, which consists of a covalently stabilized human TNFR2-selective (D143N/ A145R) (25) single-chain TNF (scTNF R2 ) fused to the dimerization domain EHD2 derived from the heavy chain domain CH2 of IgE (26), constituting a disulfide bonded dimer that is, with respect to TNF domains, hexameric (EHD2-scTNF R2 ; Fig.…”

“…Because most of the proinflammatory actions of TNF are mediated by TNFR1, a more effective therapeutic approach could be the selective blocking of TNFR1 signaling; this would spare TNFR2 signaling, which has been implicated in various protective and regenerative responses, particularly in the central nervous system: TNFR2 signaling was shown to promote neuronal survival and oligodendrocyte regeneration in in vivo models of ischemic and neurotoxic insults (9,10), respectively. Specific activation of TNFR2 rescues neurons (11) and oligodendrocytes (12) from oxidative stress and promotes oligodendrocyte differentiation and myelination (13,14). In addition, TNFR2 signaling protects neurons from glutamate-induced excitotoxicity in vitro (15,16).…”

An optimized antibody-single-chain TRAIL fusion protein for cancer therapy

“…18,20,21,26,27 In addition to a high specific activity, clinically useful recombinant protein therapeutics must also have suitable protein stability and pharmacokinetic properties. 24,28,29 Toward this end, we here describe singlechain variants of the apoptosis-inducing TRAIL with improved stability and superior product quality in the form of a tumortargeted fusion protein, resulting in high anti-tumor activity in a xenograft tumor model in vivo.…”

Aminopeptidase P3 (APP3), a novel member of the TNF/TNFR2 signaling complex, induces phosphorylation of JNK

“…6B). It is known that Akt is activated by TNFR2 stimulation (Fischer et al, 2011a). R2-7 stimulation also induced phosphorylation of Akt (supplementary material Fig.…”