Stem cell subpopulations with differential gstt1 expression or genotype

Abstract

A method for providing a sub-population of stem cell or plurality of stem cells by determining or modulating GSTT1 expression level or genotype is disclosed together with uses of the stem cells.

1 . A method for identifying a stem cell or plurality of stem cells, the method comprising determining the level of GSTT1 expression in said stem cell or plurality of stem cells. 
     
     
         2 . The method according to  claim 1 , wherein the method further comprises comparing the level of GSTT1 expression determined to a reference value for the level of GSTT1 expression for that stem cell type. 
     
     
         3 . The method according to  claim 2 , wherein the method further comprises the step of identifying a stem cell or plurality of stem cells having decreased GSTT1 expression relative to the reference value. 
     
     
         4 . The method according to  claim 2  or  3 , wherein the method further comprises the step of separating and/or isolating a stem cell or plurality of stem cells having decreased GSTT1 expression relative to the reference value from other cells or stem cells. 
     
     
         5 . A method for identifying a stem cell or plurality of stem cells, the method comprising determining the GSTT1 genotype of the stem cell or plurality of stem cells. 
     
     
         6 . The method according to  claim 5 , wherein the method further comprises the step of identifying a stem cell or plurality of stem cells having a non-homozygous wildtype GSTT1 genotype. 
     
     
         7 . The method according to  claim 5  or  6 , wherein the method further comprises the step of separating and/or isolating a stem cell or plurality of stem cells having a non-homozygous wildtype GSTT1 genotype from other cells or stem cells. 
     
     
         8 . The method according to any one of  claims 1  to  7 , wherein the stem cell or plurality of stem cells additionally possess one or more of the following characteristics as compared to a reference population of stem cells:
 (i) enhanced colony forming capacity; 
 (ii) reduced cell size; 
 (iii) increased telomere length and/or a reduced rate of telomere shortening; 
 (iv) increased expression of STRO-1, SSEA-4, CD146 and/or PDGFRβ; 
 (v) increased secretion of FGF-2, VEGF, SDF-1α, fractalkine, PDGF-BB and/or MIP-1α; 
 (vi) enhanced suppression of T cells; 
 (vii) decreased expression of ALP, RUNX2 and/or BSP-II 
 (viii) increased expression of TWIST-1 and DERMO-1. 
 
     
     
         9 . A method for modifying a stem cell or plurality of stem cells, the method comprising contacting a stem cell or plurality of stem cells with an agent capable of modifying the cell(s) to reduce GSTT1 expression and/or function. 
     
     
         10 . The method of  claim 9 , wherein the method comprises:
 (i) isolating a stem cell or plurality of stem cells from an individual, and;   (ii) contacting the isolated stem cell or plurality of stem cells in vitro with an agent capable of modifying a stem cell to reduce GSTT1 expression and/or function.   
     
     
         11 . A stem cell or plurality of stem cells, which have been modified to reduce endogenous GSTT1 expression and/or function. 
     
     
         12 . A stem cell or plurality of stem cells, which contain an agent capable of reducing GSTT1 expression and/or function. 
     
     
         13 . A stem cell or plurality of stem cells, which have been modified to have decreased GSTT1 expression and/or function relative to stem cells which are homozygous for wildtype GSTT1 and/or stem cells having the average (i.e. mean) level of GSTT1 expression and/or function for that stem cell type. 
     
     
         14 . An isolated stem cell or plurality of stem cells, which have decreased GSTT1 expression and/or function relative to stem cells which are homozygous for wildtype GSTT1. 
     
     
         15 . A stem cell or plurality of stem cells according to any one of  claims 11  to  14  for use in a method of medical treatment. 
     
     
         16 . A method of regenerating tissue in a patient in need of such treatment, the method comprising administering to the patient a therapeutic number of stem cells according to any one of  claims 11  to  14 . 
     
     
         17 . A stem cell or plurality of stem cells according to any one of  claims 11  to  14  for use in a method of treating a bone fracture, wherein the method comprises administering the stem cells to tissue surrounding the fracture. 
     
     
         18 . Use of a stem cell or plurality of stem cells according to any one of  claims 11  to  14  for the generation of bone tissue in vitro or in vivo. 
     
     
         19 . A method for selecting a stem cell donor, the method comprising determining the genotype for GSTT1 in a DNA-containing sample isolated from an individual, wherein an individual determined to have a GSTT1 genotype which is known, and/or which would be predicted, to result in decreased expression of GSTT1 relative to individuals homozygous for wildtype GSTT1 is selected as a stem cell donor. 
     
     
         20 . A method for selecting a stem cell donor, the method comprising:
 (i) determining the level of GSTT1 expression by a stem cell or plurality of stem cells in a sample isolated from an individual, and;   (ii) comparing the level of GSTT1 expression determined in step (i) to a reference value for the level of GSTT1 expression for that stem cell type;   
       wherein an individual determined to have a stem cell or plurality of stem cells having decreased GSTT1 expression relative to the reference value is selected as a stem cell donor. 
     
     
         21 . The method according to  claim 19  or  claim 20 , wherein the stem cell or plurality of stem cells additionally possess one or more of the following characteristics as compared to a reference population of stem cells:
 (i) enhanced colony forming capacity; 
 (ii) reduced cell size; 
 (iii) increased telomere length and/or a reduced rate of telomere shortening; 
 (iv) increased expression of STRO-1, SSEA-4, CD146 and/or PDGFRβ; 
 (v) increased secretion of FGF-2, VEGF, SDF-1α, fractalkine, PDGF-BB and/or MIP-1α; 
 (vi) enhanced suppression of T cells; 
 (vii) decreased expression of ALP, RUNX2 and/or BSP-II 
 (viii) increased expression of TWIST-1 and DERMO-1. 
 
     
     
         22 . A method of enriching for colony forming units (CFU-F) in a culture of stem cells, preferably mesenchymal stem cells (MSC), the method comprising partitioning stem cells having a decreased level of GSTT1 expression. 
     
     
         23 . A method of enriching for colony forming units (CFU-F) in a culture of stem cells, preferably mesenchymal stem cells (MSC), the method comprising partitioning stem cells not having a homozygous positive GSTT1 genotype. 
     
     
         24 . A kit for determining GSTT1 expression, comprising reagents for determining the level of expression of GSTT1 by a stem cell or plurality of stem cells in a sample. 
     
     
         25 . A kit for determining GSTT1 genotype, comprising reagents for determining the determining GSTT1 genotype in a DNA containing sample.