Modulation of synaptogenesis

Abstract

The present invention describes methods and compositions for modulating synaptogenesis and axon and/or dendritic growth. The methods include the use of agents that modulate a thrombospondin and/or an α2δ subunit of a calcium channel.

1 . A method of promoting synaptogenesis in an individual comprising administering to the individual in need of synaptogenesis an effective dose of a polypeptide comprising at least one thrombospondin EGF-like domain, wherein the polypeptide is not a thrombospondin, and wherein synapse formation in the individual is increased. 
     
     
         2 . The method of  claim 1 , wherein the thrombospondin EGF-like domain is a polypeptide derived from a thrombospondin isotype of from about 35 to about 65 amino acids in length, comprising at least 6 cysteine amino acids, where the main structure is a two-stranded beta-sheet followed by a loop to a C-terminal short two-stranded sheet. 
     
     
         3 . The method of  claim 2 , wherein the thrombospondin EGF-like domain has at least 95% sequence identity to human TSP1, amino acids 551-586, 588-636, or 650-689, human TSP2 amino acids 553-588, 590-635, or 652-691, human TSP3 amino acids 316-368, 370-412, or 418-455, human TSP4 amino acids 290-324, 326-377, 379-418 or 424-461, or human cartilage oligomeric matrix amino acids 87-126, 127-179, 180-222, or 225-267. 
     
     
         4 . The method of  claim 3 , wherein the polypeptide comprises at least two thrombospondin EGF-like domains. 
     
     
         5 . The method of  claim 4 , wherein the polypeptide comprises at least three thrombospondin EGF-like domains. 
     
     
         6 . The method of  claim 5 , wherein the polypeptide lacks thrombospondin sequences other than the EGF-like domains. 
     
     
         7 . The method of  claim 1 , wherein the individual has suffered synapse loss as a result of senescence. 
     
     
         8 . The method of  claim 1 , wherein the individual has suffered synapse loss as a result of Alzheimer's disease, Parkinson's disease, ALS, multiple sclerosis, or glaucoma. 
     
     
         9 . The method of  claim 1 , wherein the individual has suffered a macular degeneration, a hearing loss, a diabetic neuropathy, or a chemotherapy induced neuropathy. 
     
     
         10 . The method of  claim 1 , wherein the individual has suffered synapse loss as a result of a psychiatric disorder selected from the group consisting of depression, schizophrenia, autism, and aggression. 
     
     
         11 . The method according to  claim 1 , wherein said synapse formation is at a neuromuscular junction. 
     
     
         12 . A method of treating or preventing pain in an individual comprising administering to an individual an effective amount of a thrombospondin antagonist agent which inhibits synaptogenesis activity of a thrombospondin. 
     
     
         13 . The method of  claim 12 , wherein the agent binds to a thrombospondin and blocks the interaction between the thrombospondin and one or more calcium channel subunits selected from the group consisting of α2δ1, α2δ2, α2δ3, and α2δ4 
     
     
         14 . The method of  claim 13 , wherein the agent is an antibody that specifically binds to the thrombospondin. 
     
     
         15 . The method of  claim 14 , wherein the agent is an antibody that specifically binds to an EGF-like domain of the thrombospondin. 
     
     
         16 . The method of  claim 14 , wherein the agent is an antibody that specifically binds to the third EGF-like domain of the thrombospondin. 
     
     
         17 . The method of  claim 14 , wherein the thrombospondin is TSP1, TSP2, TSP3, TSP4, or cartilage oligomeric matrix. 
     
     
         18 . The method of  claim 13 , wherein the agent is a scaffold-derived binding protein that specifically binds to the thrombospondin. 
     
     
         19 . The method of  claim 13 , wherein the agent is a siRNA, an antisense RNA, or a microRNA that specifically inhibits expression of the thrombospondin. 
     
     
         20 . The method of  claim 19 , wherein the expression of TSP1, TSP2, TSP4, or cartilage oligomeric matrix is inhibited. 
     
     
         21 . The method of  claim 13 , wherein the agent is a polypeptide comprising an extracellular portion of a calcium channel subunit α2δ1. 
     
     
         22 . The method of  claim 21 , wherein the polypeptide comprises the amino acids of about 253 to about 430 of human α2δ1 (VWFA domain). 
     
     
         23 . The method of  claim 13 , wherein the agent is a polypeptide comprising an extracellular portion of a calcium channel subunit α2δ2. 
     
     
         24 . The method of  claim 23 , wherein the polypeptide comprises the amino acids of about 291 to about 469 of human α2δ2 (VWFA domain). 
     
     
         25 . The method of  claim 13 , wherein the agent is a polypeptide comprising an extracellular portion of a calcium channel subunit α2δ3. 
     
     
         26 . The method of  claim 25 , wherein the polypeptide comprises the amino acids of about 256 to about 438 of human α2δ3 (VWFA domain). 
     
     
         27 . The method of  claim 13 , wherein the agent is a polypeptide comprising an extracellular portion of the calcium channel subunit α2δ4. 
     
     
         28 . The method of  claim 27 , wherein the polypeptide comprises the amino acids of about 291 to about 473 of human α2δ4 (VWFA domain). 
     
     
         29 . The method of any one of  claims 21 ,  23 ,  25 , and  27 , wherein the polypeptide is an immunoadhesin. 
     
     
         30 . The method of  claim 12 , wherein the pain is somatic pain, neuropathic pain, visceral pain, cancer pain, breakthrough cancer pain, inflammatory pain, post operative pain, bone pain, joint pain, migraine pain, or phantom pain. 
     
     
         31 . The method of  claim 12 , wherein the pain is allodynia or hyperalgesia. 
     
     
         32 . A method of treating or preventing pain in an individual comprising administering to an individual an effective amount of an antibody that specifically binds to a VWFA domain of a calcium channel subunit selected from the group consisting of α2δ1, α2δ2, α2δ3, and α2δ4, and blocks the interaction between a thrombospondin and said calcium channel subunit. 
     
     
         33 . The method of  claim 32 , wherein the pain is somatic pain, neuropathic pain, visceral pain, cancer pain, breakthrough cancer pain, inflammatory pain, post operative pain, bone pain, joint pain, migraine pain, or phantom pain. 
     
     
         34 . A method of treating epilepsy in an individual comprising administering to the individual an effective amount of an antibody that specifically binds to a VWFA domain of a calcium channel subunit selected from the group consisting of α2δ1, α2δ2, α2δ3, and α2δ4, and blocks the interaction between a thrombospondin and said calcium channel subunit. 
     
     
         35 . A method of promoting axonal growth in an individual comprising administering to an individual in need thereof an effective amount of a thrombospondin antagonist. 
     
     
         36 . The method of  claim 35 , wherein the individual has suffered a spinal cord injury. 
     
     
         37 . The method of  claim 35 , wherein the individual has suffered axonal or dendritic degeneration as a result of Alzheimer's disease, Parkinson's disease, ALS, or multiple sclerosis. 
     
     
         38 . The method of  claim 35 , wherein the individual has suffered a macular degeneration, a hearing loss, a diabetic neuropathy, or a chemotherapy induced neuropathy. 
     
     
         39 . The method of  claim 35 , wherein the individual has suffered axonal or dendritic degeneration as a result of a psychiatric disorder selected from the group consisting of depression, schizophrenia, autism, and aggression. 
     
     
         40 . A method for treating a disorder characterized by excess of calcium influx in an individual, comprising administering to the individual an effective amount of an agent that specifically binds to a thrombospondin and blocks the interaction between the thrombospondin and a calcium subunit selected from the group consisting of α2δ1, α2δ2, α2δ3, and α2δ4. 
     
     
         41 . The method of  claim 40 , wherein the disorder is selected from the group consisting of muscle spasm, migraine, stroke, and Parkinson's disease. 
     
     
         42 . A method of screening a candidate agent for activity in enhancing synaptogenesis, the method comprising:
 a) measuring binding of a candidate agent to an α2δ polypeptide or a thrombospondin EGF-like domain;   b) quantitating formation of synapses in a neural cell culture in the presence of the candidate agent if the candidate agent binds to the α2δ polypeptide or the thrombospondin EGF-like domain in step a), wherein an increased formation of synapses in the presence the candidate agent as compared to the formation of synapses in the absence of the candidate agent indicates that the candidate agent has the activity in enhancing synaptogenesis.   
     
     
         43 . A method of screening a candidate agent for activity in inhibiting synaptogenesis, the method comprising:
 a) measuring binding of a candidate agent to an α2δ polypeptide or a thrombospondin EGF-like domain;   b) quantitating formation of synapses in a neural cell culture in the presence of the candidate agent and a thrombospondin agonist if the candidate agent binds to the α2δ polypeptide or the thrombospondin EGF-like domain in step a), wherein a decreased formation of synapses in the presence the candidate agent as compared formation of synapses in the absence of the candidate agent indicates that the candidate agent has the activity in inhibiting synaptogenesis.