Method for creating a renal injury model to screen molecules for the treatment of renal injury

Abstract

The present invention is related to short-term renal injury models and methods for creating these models. The models and methods can be used for identifying, testing or characterizing candidate molecules with respect to their suitability to treat renal injury. The methods comprise a step of inducing, in a test subject, renal injury by administering subcutaneously a bolus of a renal injury inducer, in a dosage sufficiently high to induce renal injury. Different types of readout for renal injury are provided such as albumin creatinine ratio (ACR) determined in a urine sample taken from the subject, or the development of transcutaneous fluorescence after injection of a fluorescent molecule. Based on the readout the degree of renal injury and/or alteration of GFR can be determined.

1 . (canceled) 
     
     
         2 . A method for creating a renal injury model, wherein the method comprises the following steps:
 a) inducing, in a test subject, renal injury by administering, subcutaneously and/or intravenously, a bolus of a renal injury inducer, in a dosage sufficiently high to induce renal injury,   b) administering a pharmaceutically suitable fluorescent molecule to the test subject, wherein the total molecular weight of the molecule is ≥60 kDa or ≤15 kDa,   c) determining at least the development of the transcutaneous fluorescence (TF) for the test subject, and   d) determining from the development of the TF determined in step c) the degree of renal injury that has been induced in the test subject, wherein the renal injury inducer is selected from the group consisting of angiotensin II, vasopressin, Sema3a and heparanase.   
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . A method of identifying, testing or characterizing a candidate molecule for its suitability to modulate or treat renal injury, wherein the method comprises the following steps:
 a) inducing, in a test subject, renal injury by administering, subcutaneously and/or intravenously, a bolus of a renal injury inducer, in a dosage sufficiently high to induce renal injury,   b) administering a pharmaceutically suitable fluorescent molecule to the test subject, wherein the total molecular weight of the molecule is ≥60 kDa or ≤15 kDa,   c) administering to the subject a candidate molecule,   d) determining at least the development of the transcutaneous fluorescence (TF) for the test subject, and   e) deducing, from the development of the TF determined in step d), whether or not the candidate molecule is capable of modulating, alleviating or preventing the renal injury induced in the test subject wherein the renal injury inducer is selected from the group consisting of angiotensin II, vasopressin, Sema3a and heparanase.   
     
     
         6 . (canceled) 
     
     
         7 . A method for screening a population of candidate molecules for their suitability to treat renal injury, wherein the method comprises the following steps:
 a) inducing, in at least two test subjects, renal injury by administering, subcutaneously and/or intravenously, a bolus of a renal injury inducer, in a dosage sufficiently high to induce renal injury,   b) administering a pharmaceutically suitable fluorescent molecule to the test subjects, wherein the total molecular weight of the molecule is ≤15 kDa or ≥60 kDa,   c) administering to the test subjects molecules from a library of candidate molecules,   d) determining at least the development of transcutaneous fluorescence (TF) for the test subjects, wherein the development of TF is a measured as a readout, and   e) deducing, from the development of the TF determined in step d), whether or not the molecules are capable of modulating, alleviating or preventing the renal injury induced in the test subjects, wherein the renal injury inducer is selected from the group consisting of angiotensin II, vasopressin, Sema3a and heparanase.   
     
     
         8 . The method according to  claim 7 , wherein the readout determined in the at least two test subjects is compared to the respective readout of one or more control subjects in which renal injury has been induced in the same way, but (i) without administration of a candidate molecule for the treatment of renal injury, and/or (ii) with administration of a placebo instead, and/or (iii) with administration of a positive control, such as a molecule suitable for the treatment of renal injury. 
     
     
         9 . The method according to  claim 5 , wherein the method further comprises the intravenous administration of a second bolus of the same or a different renal injury inducer, in a dosage sufficiently high to induce renal injury together with the bolus of the first renal injury inducer. 
     
     
         10 . (canceled) 
     
     
         11 . The method according to  claim 2 , wherein the test subjects are rodents, preferably mice or rats. 
     
     
         12 . The method according to  claim 9 , wherein the two boli of injury inducer are administered simultaneously, or in sequence. 
     
     
         13 . The method according to  claim 5 , wherein the one or more candidate molecules are administered to the test subject intravenously, subcutaneously, intraperitoneally or per oral application, such as oral gavage. 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . A molecule for the treatment of renal injury, wherein the molecule is identified with the method according to  claim 5 . 
     
     
         18 . (canceled) 
     
     
         19 . (canceled)