US-12617868-B2 - Activation of (Na++K+)-ATPase inhibits platelet aggregation and prevents thrombosis

Abstract

Methods of inhibiting platelet activation and aggregation using peptide vaccines having binding specificity for the α subunit of the (Na + +K + )-ATPase are provided, along with methods for inhibiting or preventing or treating thrombosis without causing bleeding.

Inventors

• Kai Yuan Xu

Assignees

• Kai Yuan Xu

Dates

Publication Date

20260505

Application Date

20221108

Claims (10)

1. 1 . A method for inhibiting platelet activation and aggregation without causing bleeding in a subject comprising administering to the subject a pharmaceutically effective amount of a synthetic peptide vaccine or peptide derivative thereof, wherein the peptide vaccine stimulates the subject's immune system to generate endogenous antibodies that bind to the α subunit of (Na + +K + )-ATPase of the subject in need thereof, and wherein the peptide vaccine is represented by SEQ ID NO: 5.
2. 2 . The method according to claim 1 , wherein the peptide derivative comprises a substitution, deletion, insertion, or combination thereof of one or more amino acids of SEQ ID NO: 5.
3. 3 . The method according to claim 1 , wherein the peptide derivative comprises a cyclic portion relative to SEQ ID NO: 5.
4. 4 . The method according to claim 1 , wherein the peptide derivative comprises insertion of cross-linking sites or is cross-linked relative to SEQ ID NO: 5.
5. 5 . The method according to claim 1 , wherein the peptide derivative comprises one or more peptidyl linkages replaced with a non-peptidyl linkage relative to SEQ ID NO: 5.
6. 6 . The method according to claim 1 , wherein the peptide derivative comprises modification of the N-terminus, C-terminus, or both of SEQ ID NO: 5.
7. 7 . The method according to claim 1 , wherein the peptide derivative comprises modification of individual amino acid moieties through treatment with agents capable of reacting with selected side chains or terminal residues relative to SEQ ID NO: 5.
8. 8 . A method for preventing and inhibiting thrombosis without causing bleeding in a subject comprising administering to the subject a pharmaceutically effective amount of a synthetic peptide vaccine or peptide derivative thereof, wherein the peptide vaccine stimulates the subject's immune system to generate endogenous antibodies that bind to the α subunit of (Na + +K + )-ATPase of the subject in need thereof, and wherein the peptide vaccine is represented by SEQ ID NO: 5.
9. 9 . The method of claim 1 or 8 , wherein the peptide vaccine is in a pharmaceutically acceptable carrier.
10. 10 . The method of claim 1 or 8 , wherein the subject has or is at greater risk than the general population for a disease or condition selected from the group consisting of venous thrombosis, deep vein thrombosis, portal vein thrombosis, renal vein thrombosis, jugular vein thrombosis, Budd-Chiari syndrome, Paget-Schroetter disease, cerebral venous sinus thrombosis, cavernous sinus thrombosis, arterial thrombosis, stroke, pulmonary embolism, coronary heart disease, angina, heart failure, heart valve disease, atherosclerosis, a myocardial infarction, and post-surgical thrombotic complications arising from angioplasty and organ transplantation.

Description

The present application is a divisional of U.S. Non-Provisional application Ser. No. 16/409,841, filed on May 12, 2019, now issued as U.S. Pat. No. 11,492,416, which is a continuation of U.S. Non-Provisional application Ser. No. 15/232,773, filed on Aug. 9, 2016, now issued as U.S. Pat. No. 10,287,361. TECHNICAL FIELD The invention relates to methods for inhibiting platelet aggregation and to methods for inhibiting and/or preventing/treating thrombosis using antibodies (including both endogenous and exogenous) that bind the alpha (α) subunit of the (Na++K+)-ATPase (NKA) and increase NKA activity. Antibody capable of increasing NKA activity (activation of NKA) is called NKA activator antibody. BACKGROUND OF INVENTION Thrombosis is the pathological formation of a blood clot (thrombus) which comprises aggregated platelets and a mesh of cross-linked fibrin protein within a blood vessel. A thrombus can restrict blood flow to downstream tissues supplied by the blocked blood vessel. Thrombosis thus deprives the downstream tissue of oxygen and nutrients and can cause infarction and tissue death. Thrombosis can cause myocardial infarction in the heart when the thrombosis involves a coronary artery supplying the heart, can cause a stroke when the thrombosis involves a blood vessel in the brain, and can cause lung embolism when thrombosis lodges in lungs. Depending upon the location of a blot clot within the circulatory system, thrombosis can also cause disease in the kidney, liver, extremities, and other bodily locations. Antiplatelet medications are most effective at preventing arterial blood clots which are composed largely of platelets. Antiplatelet medications are administered to patients who have coronary artery disease, angina, heart failure, heart valve disease, or at risk for coronary artery disease or stroke, to help prevent a heart attack or stroke. Thrombosis remains the world's largest single cause of mortality, despite the fact that medication has been available for over 50 years to treat and prevent the condition. Clearly, new treatments for thrombosis are needed. BRIEF SUMMARY OF INVENTION (Na++K+)-ATPase (NKA; the sodium pump) is a transmembrane enzyme responsible for the active reciprocal transport of Na+ and K+ ions across the plasma membrane of all animal cells. NKA comprises two basic subunits: the α subunit and the β subunit. The larger α subunit is the functional subunit, which catalyzes the hydrolysis of ATP for active transport of Na+ and K+ ions across the plasma membrane; the smaller β subunit does not participate in the catalytic process of the enzyme, but instead acts as a specific chaperone that assists the biogenesis and correct membrane insertion of newly synthesized NKA. The α subunit of NKA has three isoforms including α1, α2 and α3. The β subunit of NKA also has three isoforms including β1, β2 and β3. The present invention is based on the surprising discovery that activation of NKA can inhibit platelet aggregation using NKA activator antibodies that bind the α subunit of NKA of platelets and increase NKA activity. NKA activator antibodies with α subunit binding specificity can be used to inhibit platelet aggregation and inhibit or prevent/treat thrombosis in a subject. Such NKA activator antibodies thus form the basis of methods of treating or preventing blood clots associated with diseases such as stroke, myocardial infarction, lung embolism, deep vein thrombosis, and generally any venous or arterial thrombosis resulting from platelet aggregation and resulting in patient morbidity or mortality. Examples of NKA activator antibodies having α subunit binding specificity that can be used in the methods of the present invention include, but are not limited to, SSA78 (also referred as Jianye 2), SSA401 (also referred as KX-2), and SSA412 (also referred as KX-1), polyclonal, monoclonal, humanized, and human versions thereof, and fragments thereof. These antibodies are capable of increasing NKA enzymatic activity (activation of NKA), which are described in Patent Publication No. PCT/US2006/012912, U.S. Ser. No. 11/910,943, and U.S. Pat. Nos. 9,409,949, 9,416,159, 8,435,519, and 10287361, which are herein incorporated by reference in their entirety for all purposes. In a first aspect, the invention thus provides methods for inhibiting platelet activation comprising contacting platelets with an antibody having binding specificity for the xx subunit of NKA. Exemplary antibodies that may be used in these methods include, but are not limited to, (i) antibodies having binding specificity for the α subunit of NKA, (ii) antibodies having binding specificity for one or more of the peptides represented by SEQ ID NOs: 1-5, (iii) NKA activator antibodies in a humanized or human versions thereof, or a fragment or derivative thereof, and (iv) antigens of SEQ ID NOs: 1-5 to generating endogenous NKA activator antibody, in a human or polyclonal versions thereof, or a fragment or derivative thereof. The met