User login
Credit: NHS
New research suggests that histone deacetylase (HDAC) inhibitors can be used to expand hematopoietic stem cells (HSCs) isolated from cord blood.
Investigators found that valproic acid (VPA), in particular, could greatly expand HSCs from cord blood.
These HSCs expressed markers of pluripotency and were more efficient than conventionally expanded HSCs in repopulating the bone marrow and establishing hematopoiesis in immune-deficient mice.
Pratima Chaurasia, PhD, of the Mount Sinai School of Medicine in New York, and colleagues reported these results in The Journal of Clinical Investigation.
For several decades, investigators have used a variety of strategies to expand the numbers of HSCs isolated from cord blood, with limited success. Evidence has suggested the accumulation of epigenetic modifications influences preservation of stem-cell characteristics in HSC daughter cells.
So Dr Chaurasia’s group tested the effects of HDAC inhibitors on CD34+ cells derived from cord blood. The team primed the cells for 16 hours with cytokines, then treated the cells for 7 days, with or without additional cytokines and in the presence or absence of HDAC inhibitors.
The inhibitors included VPA, scriptaid (SCR), trichostatin A, suberoylanilide hydroxamic acid, CAY10433 (C433), CAY10398, and CAY10603 .
VPA, SCR, and C433 were the most active inhibitors. Treatment with these agents led to a similar percentage of CD34+CD90+ cells—75.2% ± 10.7%, 73.4% ± 13.9%, and 70.1% ± 18.4%, respectively—which was significantly higher than control conditions—16.2% ± 9.2% (P<0.0001).
VPA, SCR, and C433 also generated a greater absolute number of CD34+ and CD34+CD90+ cells per cord blood collection, when compared to control conditions (P≤0.0007). And the inhibitors generated a greater absolute number of CD34+CD90+CD184+ cells (P<0.0001)
The investigators conducted subsequent experiments with VPA only. And they found that VPA was more effective under serum-free conditions and in the presence of cytokines.
Additional experiments revealed that VPA influences the expression of pluripotency genes—SOX2, OCT4, and NANOG. And these genes proved essential for the expansion of CD34+ CD90+ cells.
Lastly, the investigators tested VPA-expanded cells by transplanting them into immune-deficient mice. The cells were more efficient than conventionally expanded cord blood HSCs in repopulating the bone marrow and establishing hematopoietic populations.
Specifically, at 13 to 14 weeks after transplant, VPA-treated cord blood CD34+ cells resulted in a greater degree of human CD45+ cell chimerism—32.2% ± 11.3%—when compared to primary cord blood CD34+ cells—19.4% ± 4.9%—and to cells from control cultures—13.2% ± 6.4% (P=0.006 and P=0.0008, respectively).
The investigators evaluated the self-renewal potential of the expanded grafts by transplanting donor-derived cells from primary recipients into secondary recipients.
After 15 to 16 weeks, the secondary recipients transplanted with VPA-treated cord blood CD34+ cells had achieved the greatest degree of human CD45+ cell chimerism, compared to primary cord blood CD34+ cells and cells from control cultures (P<0.0001).
The team also noted that the VPA-treated cells belonged to multiple hematopoietic lineages. And this pattern was distinct from that observed in mice that had received primary cord blood CD34+ cells or cells from control cultures (P<0.0001).
In addition, the VPA-treated HSCs did not cause hematologic malignancies or teratomas in the mice.
The investigators said these results suggest that cord blood cells can be epigenetically reprogrammed by VPA to generate greater numbers of functional HSCs for transplantation.
In a related commentary, Hal Broxmeyer, PhD, of the Indiana University School of Medicine in Indianapolis, discussed how these findings enhance our understanding of HSC function and could potentially provide clinical benefit. 
Credit: NHS
New research suggests that histone deacetylase (HDAC) inhibitors can be used to expand hematopoietic stem cells (HSCs) isolated from cord blood.
Investigators found that valproic acid (VPA), in particular, could greatly expand HSCs from cord blood.
These HSCs expressed markers of pluripotency and were more efficient than conventionally expanded HSCs in repopulating the bone marrow and establishing hematopoiesis in immune-deficient mice.
Pratima Chaurasia, PhD, of the Mount Sinai School of Medicine in New York, and colleagues reported these results in The Journal of Clinical Investigation.
For several decades, investigators have used a variety of strategies to expand the numbers of HSCs isolated from cord blood, with limited success. Evidence has suggested the accumulation of epigenetic modifications influences preservation of stem-cell characteristics in HSC daughter cells.
So Dr Chaurasia’s group tested the effects of HDAC inhibitors on CD34+ cells derived from cord blood. The team primed the cells for 16 hours with cytokines, then treated the cells for 7 days, with or without additional cytokines and in the presence or absence of HDAC inhibitors.
The inhibitors included VPA, scriptaid (SCR), trichostatin A, suberoylanilide hydroxamic acid, CAY10433 (C433), CAY10398, and CAY10603 .
VPA, SCR, and C433 were the most active inhibitors. Treatment with these agents led to a similar percentage of CD34+CD90+ cells—75.2% ± 10.7%, 73.4% ± 13.9%, and 70.1% ± 18.4%, respectively—which was significantly higher than control conditions—16.2% ± 9.2% (P<0.0001).
VPA, SCR, and C433 also generated a greater absolute number of CD34+ and CD34+CD90+ cells per cord blood collection, when compared to control conditions (P≤0.0007). And the inhibitors generated a greater absolute number of CD34+CD90+CD184+ cells (P<0.0001)
The investigators conducted subsequent experiments with VPA only. And they found that VPA was more effective under serum-free conditions and in the presence of cytokines.
Additional experiments revealed that VPA influences the expression of pluripotency genes—SOX2, OCT4, and NANOG. And these genes proved essential for the expansion of CD34+ CD90+ cells.
Lastly, the investigators tested VPA-expanded cells by transplanting them into immune-deficient mice. The cells were more efficient than conventionally expanded cord blood HSCs in repopulating the bone marrow and establishing hematopoietic populations.
Specifically, at 13 to 14 weeks after transplant, VPA-treated cord blood CD34+ cells resulted in a greater degree of human CD45+ cell chimerism—32.2% ± 11.3%—when compared to primary cord blood CD34+ cells—19.4% ± 4.9%—and to cells from control cultures—13.2% ± 6.4% (P=0.006 and P=0.0008, respectively).
The investigators evaluated the self-renewal potential of the expanded grafts by transplanting donor-derived cells from primary recipients into secondary recipients.
After 15 to 16 weeks, the secondary recipients transplanted with VPA-treated cord blood CD34+ cells had achieved the greatest degree of human CD45+ cell chimerism, compared to primary cord blood CD34+ cells and cells from control cultures (P<0.0001).
The team also noted that the VPA-treated cells belonged to multiple hematopoietic lineages. And this pattern was distinct from that observed in mice that had received primary cord blood CD34+ cells or cells from control cultures (P<0.0001).
In addition, the VPA-treated HSCs did not cause hematologic malignancies or teratomas in the mice.
The investigators said these results suggest that cord blood cells can be epigenetically reprogrammed by VPA to generate greater numbers of functional HSCs for transplantation.
In a related commentary, Hal Broxmeyer, PhD, of the Indiana University School of Medicine in Indianapolis, discussed how these findings enhance our understanding of HSC function and could potentially provide clinical benefit.
Credit: NHS
New research suggests that histone deacetylase (HDAC) inhibitors can be used to expand hematopoietic stem cells (HSCs) isolated from cord blood.
Investigators found that valproic acid (VPA), in particular, could greatly expand HSCs from cord blood.
These HSCs expressed markers of pluripotency and were more efficient than conventionally expanded HSCs in repopulating the bone marrow and establishing hematopoiesis in immune-deficient mice.
Pratima Chaurasia, PhD, of the Mount Sinai School of Medicine in New York, and colleagues reported these results in The Journal of Clinical Investigation.
For several decades, investigators have used a variety of strategies to expand the numbers of HSCs isolated from cord blood, with limited success. Evidence has suggested the accumulation of epigenetic modifications influences preservation of stem-cell characteristics in HSC daughter cells.
So Dr Chaurasia’s group tested the effects of HDAC inhibitors on CD34+ cells derived from cord blood. The team primed the cells for 16 hours with cytokines, then treated the cells for 7 days, with or without additional cytokines and in the presence or absence of HDAC inhibitors.
The inhibitors included VPA, scriptaid (SCR), trichostatin A, suberoylanilide hydroxamic acid, CAY10433 (C433), CAY10398, and CAY10603 .
VPA, SCR, and C433 were the most active inhibitors. Treatment with these agents led to a similar percentage of CD34+CD90+ cells—75.2% ± 10.7%, 73.4% ± 13.9%, and 70.1% ± 18.4%, respectively—which was significantly higher than control conditions—16.2% ± 9.2% (P<0.0001).
VPA, SCR, and C433 also generated a greater absolute number of CD34+ and CD34+CD90+ cells per cord blood collection, when compared to control conditions (P≤0.0007). And the inhibitors generated a greater absolute number of CD34+CD90+CD184+ cells (P<0.0001)
The investigators conducted subsequent experiments with VPA only. And they found that VPA was more effective under serum-free conditions and in the presence of cytokines.
Additional experiments revealed that VPA influences the expression of pluripotency genes—SOX2, OCT4, and NANOG. And these genes proved essential for the expansion of CD34+ CD90+ cells.
Lastly, the investigators tested VPA-expanded cells by transplanting them into immune-deficient mice. The cells were more efficient than conventionally expanded cord blood HSCs in repopulating the bone marrow and establishing hematopoietic populations.
Specifically, at 13 to 14 weeks after transplant, VPA-treated cord blood CD34+ cells resulted in a greater degree of human CD45+ cell chimerism—32.2% ± 11.3%—when compared to primary cord blood CD34+ cells—19.4% ± 4.9%—and to cells from control cultures—13.2% ± 6.4% (P=0.006 and P=0.0008, respectively).
The investigators evaluated the self-renewal potential of the expanded grafts by transplanting donor-derived cells from primary recipients into secondary recipients.
After 15 to 16 weeks, the secondary recipients transplanted with VPA-treated cord blood CD34+ cells had achieved the greatest degree of human CD45+ cell chimerism, compared to primary cord blood CD34+ cells and cells from control cultures (P<0.0001).
The team also noted that the VPA-treated cells belonged to multiple hematopoietic lineages. And this pattern was distinct from that observed in mice that had received primary cord blood CD34+ cells or cells from control cultures (P<0.0001).
In addition, the VPA-treated HSCs did not cause hematologic malignancies or teratomas in the mice.
The investigators said these results suggest that cord blood cells can be epigenetically reprogrammed by VPA to generate greater numbers of functional HSCs for transplantation.
In a related commentary, Hal Broxmeyer, PhD, of the Indiana University School of Medicine in Indianapolis, discussed how these findings enhance our understanding of HSC function and could potentially provide clinical benefit.