Tissue-specific Wnt signal enhancing molecules and uses thereof
The present disclosure provides tissue-specific Wnt signal enhancing molecules, and related methods of using these molecules to increase Wnt signaling in targeted tissues.
1. A tissue-specific Wnt (“Wingless-related integration site” or “Wingless and Int-I” or “Wingless-Int”) signal enhancing molecule, or a pharmaceutically acceptable salt thereof, comprising:
(a) a first domain comprising two R-spondin 2 polypeptides, or fragments thereof comprising the furin I domain of the R-spondin 2 polypeptide, wherein the R-spondin 2 polypeptides comprise amino acid substitutions at amino acids corresponding to F105 and F109 of human R-spondin 2 of SEQ ID NO:2, and wherein the first domain specifically binds one or more-transmembrane E3 ubiquitin ligases, wherein the one or more transmembrane E3 ubiquitin ligases are Zinc and Ring Finger 3 (ZNRF3) and Ring Finger Protein 43 (RNF43); and
(b) a second domain comprising an Immunoglobulin G (IgG) antibody; wherein the second domain specifically binds a tissue-specific cell surface molecule, wherein the tissue-specific cell surface molecule is an asialoglycoprotein receptor I (ASGRI), and wherein the IgG antibody comprises two heavy chain polypeptides and two light chain polypeptides, wherein each light chain polypeptide comprises SEQ ID NO: 72, and each heavy chain polypeptide comprises SEQ ID NO: 86,
wherein the R-spondin 2 polypeptides are fused to the heavy chain polypeptides of the IgG antibody.
2. The molecule or pharmaceutically acceptable salt thereof of claim 1 , wherein the tissue is liver tissue.
3. The molecule or pharmaceutically acceptable salt thereof of claim 1 , wherein the amino acid substitutions are F105R and F109A.
4. The molecule or pharmaceutically acceptable salt thereof of claim 1 , wherein each of the modified R-spondin 2 polypeptides is fused to one of the heavy chain polypeptides by a linker moiety.
5. The molecule or pharmaceutically acceptable salt thereof of claim 4 , wherein the linker moieties are peptidyl linker sequences.
6. The molecule or pharmaceutically acceptable salt thereof of claim 5 , wherein the linker sequences comprises one or more amino acids selected from the group consisting of: Glycine, Asparagine, Serine, Threonine and Alanine.
7. A pharmaceutical composition comprising:
(i) the molecule or pharmaceutically acceptable salt thereof of claim 1 ; and
(ii) a pharmaceutically acceptable diluent, adjuvant or carrier.
8. The pharmaceutical composition of claim 7 , further comprising a mammalian Wnt polypeptide or a functional variant or fragment thereof.
9. A tissue-specific Wnt (“Wingless-related integration site” or “Wingless and Int-I” or “Wingless-Int”) signal enhancing molecule, or pharmaceutically acceptable salt thereof, wherein the molecule comprises:
a) two polypeptides of SEQ ID NO:72 and two polypeptides of SEQ ID NO:74; or
b) two polypeptides of SEQ ID NO:72 and two polypeptides of SEQ ID NO:86.
10. The molecule or pharmaceutically acceptable salt thereof of claim 9 , wherein the molecule comprises two polypeptides of SEQ ID NO: 72, and
two polypeptides of SEQ ID NO: 74.
11. A pharmaceutical composition comprising the molecule or pharmaceutically acceptable salt thereof of claim 10 and a pharmaceutically acceptable diluent, adjuvant or carrier.
12. A pharmaceutical composition comprising the molecule or pharmaceutically acceptable salt thereof of claim 9 .
13. The molecule or pharmaceutically acceptable salt thereof of claim 9 , wherein the molecule comprises two polypeptides of SEQ ID NO:72 and two polypeptides of SEQ ID NO:86.
14. A pharmaceutical composition comprising the molecule or pharmaceutically acceptable salt thereof of claim 13 .