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Deficiency in Aryl Hydrocarbon Receptor (AHR) Expression throughout Aging Alters Gene Expression Profiles in Murine Long-Term Hematopoietic Stem Cells.

Bennett JA, Singh KP, Unnisa Z, Welle SL, Gasiewicz TA - PLoS ONE (2015)

Bottom Line: In addition, a significant number of gene expression differences were observed in aged LT-HSCs that are dependent on both aging and lack of AhR.Pathway analysis of this subset of genes revealed overlap between cellular functions of the novel AhR targets and AhR itself.Lentiviral-mediated knockdown of AhR in lineage-negative hematopoietic cells was sufficient to induce changes in all five of the candidate AhR targets identified.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States of America.

ABSTRACT
Dysregulation of hematopoietic stem cell (HSC) signaling can contribute to the development of diseases of the blood system. Lack of aryl hydrocarbon receptor (AhR) has been associated with alterations in gene expression related to HSC function and the subsequent development of a myeloproliferative disorder in aging female mice. We sorted the most primitive population of HSCs with the highest stem cell potential (Long-term, or LT-HSCs) from 18-month-old AhR--allele (AhR-KO) and WT mice and analyzed gene expression using microarray to determine alterations in gene expression and cell signaling networks in HSCs that could potentially contribute to the aging phenotype of AhR-KO mice. Comparisons with previous array data from 8-week old mice indicated that aging alone is sufficient to alter gene expression. In addition, a significant number of gene expression differences were observed in aged LT-HSCs that are dependent on both aging and lack of AhR. Pathway analysis of these genes revealed networks related to hematopoietic stem cell activity or function. qPCR was used to confirm the differential expression of a subset of these genes, focusing on genes that may represent novel AhR targets due to the presence of a putative AhR binding site in their upstream regulatory region. We verified differential expression of PDGF-D, Smo, Wdfy1, Zbtb37 and Zfp382. Pathway analysis of this subset of genes revealed overlap between cellular functions of the novel AhR targets and AhR itself. Lentiviral-mediated knockdown of AhR in lineage-negative hematopoietic cells was sufficient to induce changes in all five of the candidate AhR targets identified. Taken together, these data suggest a role for AhR in HSC functional regulation, and identify novel HSC AhR target genes that may contribute to the phenotypes observed in AhR-KO mice.

No MeSH data available.


Related in: MedlinePlus

qPCR validated gene changes dependent on lack of AhR and aging in LT-HSCs of AhR-KO mice are related to cell-proliferation, trafficking and HSC function and have functional overlap with AhR.Ingenuity Pathway Analysis was used to determine biological functions of genes verified with qPCR in aged AhR-KO mice (relative to WT controls), and to determine functional overlap with AhR in regulating hematopoiesis.
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pone.0133791.g006: qPCR validated gene changes dependent on lack of AhR and aging in LT-HSCs of AhR-KO mice are related to cell-proliferation, trafficking and HSC function and have functional overlap with AhR.Ingenuity Pathway Analysis was used to determine biological functions of genes verified with qPCR in aged AhR-KO mice (relative to WT controls), and to determine functional overlap with AhR in regulating hematopoiesis.

Mentions: We again used IPA to determine the possible biological functions and signaling pathway interactions of the subset of genes containing AhR binding sites whose differential expression was verified by qPCR (and their relationship to proposed functions of the AhR). We overlaid pathways generated for Cancer, Cell Proliferation, Hematopoiesis and Cell Migration, and AhR (Fig 6, S2, S3, and S4 Figs). The networks reveal that AhR, PDGF-D, Smo, Wdfy1, Zbtb37 and Zfp382 converge on regulating some of the same functions, including ones directly related to HSC output, such as quantity and self-renewal of hematopoietic cells (Fig 6). Overall these data support the novel hypothesis that AhR may regulate HSC function in part by regulating the expression of PDGF-D, Smo, Wdfy1, Zbtb37 or Zfp382.


Deficiency in Aryl Hydrocarbon Receptor (AHR) Expression throughout Aging Alters Gene Expression Profiles in Murine Long-Term Hematopoietic Stem Cells.

Bennett JA, Singh KP, Unnisa Z, Welle SL, Gasiewicz TA - PLoS ONE (2015)

qPCR validated gene changes dependent on lack of AhR and aging in LT-HSCs of AhR-KO mice are related to cell-proliferation, trafficking and HSC function and have functional overlap with AhR.Ingenuity Pathway Analysis was used to determine biological functions of genes verified with qPCR in aged AhR-KO mice (relative to WT controls), and to determine functional overlap with AhR in regulating hematopoiesis.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4514744&req=5

pone.0133791.g006: qPCR validated gene changes dependent on lack of AhR and aging in LT-HSCs of AhR-KO mice are related to cell-proliferation, trafficking and HSC function and have functional overlap with AhR.Ingenuity Pathway Analysis was used to determine biological functions of genes verified with qPCR in aged AhR-KO mice (relative to WT controls), and to determine functional overlap with AhR in regulating hematopoiesis.
Mentions: We again used IPA to determine the possible biological functions and signaling pathway interactions of the subset of genes containing AhR binding sites whose differential expression was verified by qPCR (and their relationship to proposed functions of the AhR). We overlaid pathways generated for Cancer, Cell Proliferation, Hematopoiesis and Cell Migration, and AhR (Fig 6, S2, S3, and S4 Figs). The networks reveal that AhR, PDGF-D, Smo, Wdfy1, Zbtb37 and Zfp382 converge on regulating some of the same functions, including ones directly related to HSC output, such as quantity and self-renewal of hematopoietic cells (Fig 6). Overall these data support the novel hypothesis that AhR may regulate HSC function in part by regulating the expression of PDGF-D, Smo, Wdfy1, Zbtb37 or Zfp382.

Bottom Line: In addition, a significant number of gene expression differences were observed in aged LT-HSCs that are dependent on both aging and lack of AhR.Pathway analysis of this subset of genes revealed overlap between cellular functions of the novel AhR targets and AhR itself.Lentiviral-mediated knockdown of AhR in lineage-negative hematopoietic cells was sufficient to induce changes in all five of the candidate AhR targets identified.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States of America.

ABSTRACT
Dysregulation of hematopoietic stem cell (HSC) signaling can contribute to the development of diseases of the blood system. Lack of aryl hydrocarbon receptor (AhR) has been associated with alterations in gene expression related to HSC function and the subsequent development of a myeloproliferative disorder in aging female mice. We sorted the most primitive population of HSCs with the highest stem cell potential (Long-term, or LT-HSCs) from 18-month-old AhR--allele (AhR-KO) and WT mice and analyzed gene expression using microarray to determine alterations in gene expression and cell signaling networks in HSCs that could potentially contribute to the aging phenotype of AhR-KO mice. Comparisons with previous array data from 8-week old mice indicated that aging alone is sufficient to alter gene expression. In addition, a significant number of gene expression differences were observed in aged LT-HSCs that are dependent on both aging and lack of AhR. Pathway analysis of these genes revealed networks related to hematopoietic stem cell activity or function. qPCR was used to confirm the differential expression of a subset of these genes, focusing on genes that may represent novel AhR targets due to the presence of a putative AhR binding site in their upstream regulatory region. We verified differential expression of PDGF-D, Smo, Wdfy1, Zbtb37 and Zfp382. Pathway analysis of this subset of genes revealed overlap between cellular functions of the novel AhR targets and AhR itself. Lentiviral-mediated knockdown of AhR in lineage-negative hematopoietic cells was sufficient to induce changes in all five of the candidate AhR targets identified. Taken together, these data suggest a role for AhR in HSC functional regulation, and identify novel HSC AhR target genes that may contribute to the phenotypes observed in AhR-KO mice.

No MeSH data available.


Related in: MedlinePlus