Senescence of Human Fibroblasts after Psoralen Photoactivation Is Mediated by ATR Kinase and Persistent DNA Damage Foci at Telomeres

Cellular senescence is a phenotype that is likely linked with aging. Recent concepts view different forms of senescence as permanently maintained DNA damage responses partially characterized by the presence of senescence-associated DNA damage foci at dysfunctional telomeres. Irradiation of primary human dermal fibroblasts with the photosensitizer 8-methoxypsoralen and ultraviolet A radiation (PUVA) induces senescence. In the present study, we demonstrate that senescence after PUVA depends on DNA interstrand cross-link (ICL) formation that activates ATR kinase. ATR is necessary for the manifestation and maintenance of the senescent phenotype, because depletion of ATR expression before PUVA prevents induction of senescence, and reduction of ATR expression in PUVA-senesced fibroblasts releases cells from growth arrest. We find an ATR-dependent phosphorylation of the histone H2AX (γ-H2AX). After PUVA, ATR and γ-H2AX colocalize in multiple nuclear foci. After several days, only few predominantly telomere-localized foci persist and telomeric DNA can be coimmunoprecipitated with ATR from PUVA-senesced fibroblasts. We thus identify ATR as a novel mediator of telomere-dependent senescence in response to ICL induced by photoactivated psoralens.

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Induction of functional platelets from mouse and human fibroblasts by p45NF-E2/Maf

Blood ◽

10.1182/blood-2012-02-413617 ◽

2012 ◽

Vol 120 (18) ◽

pp. 3812-3821 ◽

Cited By ~ 58

Author(s):

Yukako Ono ◽

Yuhuan Wang ◽

Hidenori Suzuki ◽

Shinichiro Okamoto ◽

Yasuo Ikeda ◽

...

Keyword(s):

Cultured Cells ◽

Human Fibroblasts ◽

Mouse Fibroblast ◽

Dermal Fibroblasts ◽

Induction Medium ◽

Human Dermal Fibroblasts ◽

3T3 Cells ◽

Gene Expressions ◽

Immunodeficient Mice ◽

Adult Human

Abstract Determinant factors leading from stem cells to megakaryocytes (MKs) and subsequently platelets have yet to be identified. We now report that a combination of nuclear factor erythroid–derived 2 p45 unit (p45NF-E2), Maf G, and Maf K can convert mouse fibroblast 3T3 cells and adult human dermal fibroblasts into MKs. To screen MK-inducing factors, gene expressions were compared between 3T3 cells that do not differentiate into MKs and 3T3-L1 cells known to differentiate into MKs. 3T3 cells transfected with candidate factors were cultured in a defined MK lineage induction medium. Among the tested factors, transfection with p45NF-E2/MafG/MafK lead to the highest frequency of CD41-positive cells. Adult human dermal fibroblasts transfected with these genes were cultured in MK lineage induction medium. Cultured cells had megakaryocytic features, including surface markers, ploidy, and morphology. More than 90% of MK-sized cells expressed CD41, designated induced MK (iMK). Infusion of these iMK cells into immunodeficient mice led to a time-dependent appearance of CD41-positive, platelet-sized particles. Blood samples from iMK-infused into thrombocytopenic immunodeficient mice were perfused on a collagen-coated chip, and human CD41-positive platelets were incorporated into thrombi on the chip, demonstrating their functionality. These findings demonstrate that a combination of p45NF-E2, Maf G, and Maf K is a key determinant of both megakaryopoiesis and thrombopoiesis.

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Ultraviolet A Enhances Cathepsin L Expression and Activity via JNK Pathway in Human Dermal Fibroblasts

Chinese Medical Journal ◽

10.4103/0366-6999.194654 ◽

2016 ◽

Vol 129 (23) ◽

pp. 2853-2860 ◽

Cited By ~ 6

Author(s):

Qing-Fang Xu ◽

Yue Zheng ◽

Jian Chen ◽

Xin-Ya Xu ◽

Zi-Jian Gong ◽

...

Keyword(s):

Cathepsin L ◽

Dermal Fibroblasts ◽

Human Dermal Fibroblasts ◽

Ultraviolet A ◽

Jnk Pathway ◽

Expression And Activity

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Singlet oxygen is an early intermediate in cytokine-dependent ultraviolet-A induction of interstitial collagenase in human dermal fibroblasts in vitro

FEBS Letters ◽

10.1016/s0014-5793(97)00919-8 ◽

1997 ◽

Vol 413 (2) ◽

pp. 239-242 ◽

Cited By ~ 105

Author(s):

Meinhard Wlaschek ◽

Jutta Wenk ◽

Peter Brenneisen ◽

Karlis Briviba ◽

Agatha Schwarz ◽

...

Keyword(s):

Singlet Oxygen ◽

Dermal Fibroblasts ◽

Human Dermal Fibroblasts ◽

Ultraviolet A ◽

Interstitial Collagenase

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INFLUENCE OF SUCCESSIVE AND COMBINED ULTRAVIOLET A AND B IRRADIATIONS ON MATRIX METALLOELASTASES PRODUCED BY HUMAN DERMAL FIBROBLASTS IN CULTURE

Cell Biology International ◽

10.1006/cbir.1997.0150 ◽

1997 ◽

Vol 21 (6) ◽

pp. 347-352 ◽

Cited By ~ 15

Author(s):

C KUT

Keyword(s):

Dermal Fibroblasts ◽

Human Dermal Fibroblasts ◽

Ultraviolet A

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The chemotactic attraction of human fibroblasts to a lymphocyte-derived factor.

Journal of Experimental Medicine ◽

10.1084/jem.144.5.1188 ◽

1976 ◽

Vol 144 (5) ◽

pp. 1188-1203 ◽

Cited By ~ 240

Author(s):

A E Postlethwaite ◽

R Snyderman ◽

A H Kang

Keyword(s):

Connective Tissue ◽

Peripheral Blood ◽

Human Fibroblasts ◽

Peripheral Blood Lymphocytes ◽

Dermal Fibroblasts ◽

Chemotactic Factor ◽

Human Dermal Fibroblasts ◽

Heat Stable

A quantitative assay that measures fibroblast chemotaxis in vitro is described. Application of this technique has revealed that peripheral blood lymphocytes stimulated by antigen or mitogen in vitro produce a factor that is chemotactic for human dermal fibroblasts. This lymphocyte-derived chemotactic factor for fibroblasts (LDCF-F) is different from the lymphokine that is chemotactic for monocytes or macrophages. Macrophages are required for the generation of LDCF-F by T lymphocytes stimulated by phytohemagglutinin. The fibroblast chemotactic factor is heat stable (56 degrees C for 30 min), trypsin sensitive, and neuraminidase resistant. LDCF-F could function to attact connective tissue fibroblasts to sites at which cell-mediated immune reactions are occurring in vivo.

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