TNF-derived peptides for use in treating oedema

Abstract

The present invention relates to the finding that peptides derived from a specific domain of tumor necrosis factor-alpha (TNF-alpha) can efficiently be used to treat oedema. More specifically, the present invention relates to the usage of peptides derived from the region of human TNF-alpha from Ser100 to Glu116 to treat pulmonary oedema. Moreover, the present invention concerns a circularized peptide having amino acid sequence CGQRETPEGAEAKPWYC which is very efficient in inducing oedema resorption.

Description

[0001] The present invention is based on the finding that peptides derived from a specific domain of tumor necrosis factor-alpha (TNF-.alpha.) can efficiently be used to treat oedema. More specifically, the present invention relates to the usage of peptides derived from the region of human TNT-.alpha. from Ser.sup.100 to Glu.sup.116 to treat pulmonary oedema. For example, the circularized peptide having amino acid sequence CGQRETPEGAEAKPWYC is shown to be very efficient in inducing oedema resorption.[0002] Pulmonary transplantation is shown to be successful in the treatment of patients with end-stage pulmonary disease. However, pulmonary oedema or edema (both terms can be used interchangeably) following reperfusion of the transplant is a major clinical problem for which no efficient drug exists at this moment. In addition, recent evidence indicates that the endothelium plays an essential role in regulating the dynamic interaction between pulmonary vasodilatation and vasoconstriction...

AI Technical Summary

Benefits of technology

0034] We first investigated whether TNF modified the whole cell current in primary murine cells. A 30 min preincubation of resident peritoneal macrophages and lung microvascular endothelial cells with 100 ng / ml of TNF resulted in a significant increase in outward and, to a lesser extent, inward current in the case of microvascular endothelial cells, as measured by means of whole-cell patch clamp, as compared to cells unexposed to TNF (endothelial cells, FIG. 1A; and macrophages, FIG. 2). A reduction in preincubation time (down to 5 min) or in dose of TNF (down to 10 ng / ml) gave similar results (data not shown). This effect required acidic preincubation conditions, since it did not occur when the preincubation was performed at pH 7.3 (FIG. 1). The conductance induced by TNF was voltage-independent and showed a reversal potential of about 0 mV in the case of endothelial cells. In order to investigate whether the ion current increase induced by TNF was TNF receptor-dependent, resident peritoneal macrophages were isolated from mice deficient in both TNF receptor-1 and -2 (TNFR1 / 2.sup.0 / 0), and tested in the whole cell patch clamp assay. TNF induced a voltage-dependent current in cells lacking TNF receptors (FIG. 2B). This critical experiment showed that the TNF-induced conductance in mammalian cells occurred in a TNT-receptor independent manner. These results also indicated that the TNF-induced current is not cell type specific.

0035] Since the lectin-like domain of TNF is spatially and functionally distinct from its receptor binding sites, we next investigated whether it was implicated in the observed ion channel activating effect of TNF in mammalian cells. Therefore, the effect of a TNF mutant (mutTNF), in which the three critical residues for the lectin-like activity of TNF were replaced by an alanin, was compared with TNF in endothelial cells. As shown in FIG. 3, mutTNF completely lacked the conductance activating effect of TNF, even at a 100-fold higher dose (1 .mu.g / ml mutTNF versus 10 ng / ml of TNF, data not shown). In contrast, the native and the mutated TNF molecules showed similar potencies in the induction of ICAM-1 in A549 epithelial cells (FIG. 4). This indicated that despite a conserved TNF receptor-mediated activity, mutTNF was unable to increase ion permeability. In order to test the hypothesis that TNF gated a sodium channel, we performed additional experiments in the presence of amiloride, an epithelial sodium channel blocker. One hundred .mu.M amiloride added during the pretreatment at pH 6.0 abrogated the TNF-induced increase in conductance FIG. 3).

Problems solved by technology

Although some data demonstrate that TNF might be involved in oedema resorption, it is clear that this pleiotropic and potentially toxic molecule can not be used to treat oedema.

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