Project description:Transplantation with low numbers of hematopoietic stem cells (HSCs), found in many of the publically accessible cryopreserved umbilical cord blood (UCB) units, leads to delayed time to engraftment, high graft failure rates, and early mortality in many patients. A chemical screen in zebrafish identified the prostaglandin compound, 16,16 dimethyl prostaglandin E2 (dmPGE2), to be a critical regulator of hematopoietic stem cell homeostasis. We hypothesized that an ex vivo modulation with dmPGE2 prior to transplantation would lead to enhanced engraftment by increasing the “effective” dose of hematopoietic stem cells (HSCs) in cord blood. A phase I trial of reduced-intensity double UCB transplantation was performed to evaluate safety, rates of engraftment and fractional chimerism of dmPGE2 enhanced UCB units. To explore potential causes of the lack of enhanced efficacy in the first cohort, we characterized HSCs to determine whether the prostaglandin pathway was being activated under the ex vivo incubation conditions (4°C, 10µM dmPGE2, 60 minutes). Incubation conditions were identified (37°C, 10µM dmPGE2, 120 minutes) that maximize the activation of the prostaglandin pathway by dmPGE2 in human CD34+ cells. Isolated human CD34+ from umbilical cord blood were incubated ex vivo in Stem Span media with 10uM 16,16-dmPGE2 or DMSO. Two treatment conditions were evaluated (4 deg C for 1 hour, 37 deg C for 2 hours) with either 3 or 7 biological replicates at each condition. Total RNA was isolated post incubation and analyzed on Affymetrix microarrays for pathway activation.
Project description:Umbilical cord blood (UCB) is a valuable source of hematopoietic stem cells (HSCs) for use in allogeneic transplantation. Key advantages of UCB are rapid availability and less stringent requirements for HLA matching. However, UCB contains an inherently limited HSC count, which is associated with delayed time to engraftment, high graft failure rates and early mortality. 16,16 dimethyl prostaglandin E2 (dmPGE2) was previously identified to be a critical regulator of HSC homeostasis and we hypothesized that a brief ex vivo modulation could improve patient outcomes by increasing the “effective dose” of HSCs. Molecular profiling with Affymetrix GeneChips were used to evaluate if prostgandin is required for the entire 2 hour incubation to elicit the maximum pathway activated gene expression response. Isolated human CD34+ from umbilical cord blood were incubated ex vivo in Stem Span (SS) media with 10uM 16,16-dimethyl prostaglandin E2 for varying amounts of time within a two hour incubation window to evaluate if the entire 120 minutes is required to elicit the maximum pathway activated gene expression response or if shorter incubation times were sufficent. Total RNA was isolated post incubation and analyzed on Affymetrix microarrays for pathway activation.
Project description:Transplantation with low numbers of hematopoietic stem cells (HSCs), found in many of the publically accessible cryopreserved umbilical cord blood (UCB) units, leads to delayed time to engraftment, high graft failure rates, and early mortality in many patients. A chemical screen in zebrafish identified the prostaglandin compound, 16,16 dimethyl prostaglandin E2 (dmPGE2), to be a critical regulator of hematopoietic stem cell homeostasis. We hypothesized that an ex vivo modulation with dmPGE2 prior to transplantation would lead to enhanced engraftment by increasing the “effective” dose of hematopoietic stem cells (HSCs) in cord blood. A phase I trial of reduced-intensity double UCB transplantation was performed to evaluate safety, rates of engraftment and fractional chimerism of dmPGE2 enhanced UCB units. To explore potential causes of the lack of enhanced efficacy in the first cohort, we characterized HSCs to determine whether the prostaglandin pathway was being activated under the ex vivo incubation conditions (4°C, 10µM dmPGE2, 60 minutes). Incubation conditions were identified (37°C, 10µM dmPGE2, 120 minutes) that maximize the activation of the prostaglandin pathway by dmPGE2 in human CD34+ cells.
Project description:Umbilical cord blood (UCB) is a valuable source of hematopoietic stem cells (HSCs) for use in allogeneic transplantation. Key advantages of UCB are rapid availability and less stringent requirements for HLA matching. However, UCB contains an inherently limited HSC count, which is associated with delayed time to engraftment, high graft failure rates and early mortality. 16,16 dimethyl prostaglandin E2 (dmPGE2) was previously identified to be a critical regulator of HSC homeostasis and we hypothesized that a brief ex vivo modulation could improve patient outcomes by increasing the “effective dose” of HSCs. Molecular profiling with Affymetrix GeneChips were used to evaluate if increasing the concentration of prostaglandin could compensate for the reduced biological responses observed with incubations at 4 deg C. Isolated human CD34+ from umbilical cord blood were incubated ex vivo in Stem Span (SS) media evaluating three concentrations of 16,16-dmPGE2 (10uM, 50uM, and 100uM) or Vehicle (DMSO) for 2 hours at 4 deg C. To evaluate if increasing the concentration of prostaglandin could compensate for the reduced biological responses observed with incubations at 4 deg C. Total RNA was isolated post incubation and analyzed on Affymetrix microarrays for pathway activation.
Project description:Umbilical cord blood (UCB) is a valuable source of hematopoietic stem cells (HSCs) for use in allogeneic transplantation. Key advantages of UCB are rapid availability and less stringent requirements for HLA matching. However, UCB contains an inherently limited HSC count, which is associated with delayed time to engraftment, high graft failure rates and early mortality. 16,16 dimethyl prostaglandin E2 (dmPGE2) was previously identified to be a critical regulator of HSC homeostasis and we hypothesized that a brief ex vivo modulation could improve patient outcomes by increasing the "effective dose" of HSCs. Molecular profiling with Affymetrix GeneChips were used to evaluate if increasing the concentration of prostaglandin at 25 and 37 deg C could increase biological responses. Isolated human CD34+ cells from umbilical cord blood were incubated ex vivo in Stem Span (SS) media evaluating five concentrations of 16,16-dmPGE2 (0.1uM, 1uM, 10uM, 50uM, and 100uM) or Vehicle (DMSO) for 2 hours at 25 or 37 deg C. Total RNA was isolated post incubation and analyzed on Affymetrix microarrays for pathway activation.
Project description:Umbilical cord blood (UCB) is a valuable source of hematopoietic stem cells (HSCs) for use in allogeneic transplantation. Key advantages of UCB are rapid availability and less stringent requirements for HLA matching. However, UCB contains an inherently limited HSC count, which is associated with delayed time to engraftment, high graft failure rates and early mortality. 16,16 dimethyl prostaglandin E2 (dmPGE2) was previously identified to be a critical regulator of HSC homeostasis and we hypothesized that a brief ex vivo modulation could improve patient outcomes by increasing the “effective dose” of HSCs. Molecular profiling with Affymetrix GeneChips were used to determine the optimal ex vivo modulation conditions (e.g., temperature and media) for use in a clinical setting by measured pathway induced expression changes. Isolated human CD34+ from umbilical cord blood were incubated ex vivo in Stem Span (SS) media evaluating three treatment temperatures (4 deg C, 25 deg C, and 37 deg C) with 10uM 16,16-dmPGE2 or Vehicle (DMSO) for 2 hours. To evaluate optimal media, similar CD34+ cells were incubated ex vivo in either Stem Span-SFEM (SS) media or 8% Low Molecular Weigh Dextran 40/5% HSA solution (LMD/HSA) with 10uM 16,16-dmPGE2 or Vehicle (DMSO) for 2 hours at 37 deg C. Total RNA was isolated post incubation and analyzed on Affymetrix microarrays for pathway activation.
Project description:Analysis of ex vivo isolated lymphatic endothelial cells from the dermis of patients to define type 2 diabetes-induced changes. Results preveal aberrant dermal lymphangiogenesis and provide insight into its role in the pathogenesis of persistent skin inflammation in type 2 diabetes. The ex vivo dLEC transcriptome reveals a dramatic influence of the T2D environment on multiple molecular and cellular processes, mirroring the phenotypic changes seen in T2D affected skin. The positively and negatively correlated dLEC transcripts directly cohere to prolonged inflammatory periods and reduced infectious resistance of patients´ skin. Further, lymphatic vessels might be involved in tissue remodeling processes during T2D induced skin alterations associated with impaired wound healing and altered dermal architecture. Hence, dermal lymphatic vessels might be directly associated with T2D disease promotion.
Project description:Analysis of ex vivo isolated lymphatic endothelial cells from the dermis of patients to define type 2 diabetes-induced changes. Results preveal aberrant dermal lymphangiogenesis and provide insight into its role in the pathogenesis of persistent skin inflammation in type 2 diabetes. The ex vivo dLEC transcriptome reveals a dramatic influence of the T2D environment on multiple molecular and cellular processes, mirroring the phenotypic changes seen in T2D affected skin. The positively and negatively correlated dLEC transcripts directly cohere to prolonged inflammatory periods and reduced infectious resistance of patients´ skin. Further, lymphatic vessels might be involved in tissue remodeling processes during T2D induced skin alterations associated with impaired wound healing and altered dermal architecture. Hence, dermal lymphatic vessels might be directly associated with T2D disease promotion. Global gene expression profile of normal dermal lymphatic endothelial cells (ndLECs) compared to dermal lymphatic endothelial cells derived from type 2 diabetic patients (dLECs).Quadruplicate biological samples were analyzed from human lymphatic endothelial cells (4 x diabetic; 4 x non-diabetic). subsets: 1 disease state set (dLECs), 1 control set (ndLECs)
Project description:Umbilical cord blood (UCB) is a valuable source of hematopoietic stem cells (HSCs) for use in allogeneic transplantation. Key advantages of UCB are rapid availability and less stringent requirements for HLA matching. However, UCB contains an inherently limited HSC count, which is associated with delayed time to engraftment, high graft failure rates and early mortality. 16,16 dimethyl prostaglandin E2 (dmPGE2) was previously identified to be a critical regulator of HSC homeostasis and we hypothesized that a brief ex vivo modulation could improve patient outcomes by increasing the “effective dose” of HSCs. Molecular profiling with Affymetrix GeneChips were used to determine the optimal ex vivo modulation conditions (e.g., temperature and media) for use in a clinical setting by measured pathway induced expression changes.
Project description:The scarcity of hematopoietic stem cells (HSCs) restricts their use in both clinical settings and experimental research. Here, we examined a recently developed method for expanding rigorously purified murine HSCs ex vivo. Input HSCs displayed varying potential for ex vivo self-renewal, with alternative outcomes revealed by single cell multimodal RNA- and ATAC-seq profiling. While most HSC progeny offered only transient in vivo reconstitution, these cells efficiently rescued mice from lethal myeloablation. The amplification of functional HSC activity allowed for long-term multilineage engraftment in unconditioned hosts that somewhat surprisingly associated with a return of HSCs to quiescence. Thereby, our findings identify several key considerations for ex vivo HSC expansion, with major implications also for assessment of normal HSC activity.