Cell renewal in human epidermis

Our laboratory is engaged in the study of the effect of different chemical agents on human skin, using electron microscopy. Previous investigations revealed that topical use of a strong alkali (NaOH 1N) or acid (HCl 1N), induces ultrastructural changes in the upper layers of human epidermis. In the current experiments, acetone and kerosene, which are primarily lipid solvents, were topically used on the volar surface of the forearm of Caucasian and Negro volunteers. Skin specimens were bioptically removed after 90 min. exposure and 72. hours later, fixed in 3% buffered glutaraldehyde, postfixed in 1% phosphate osmium tetroxide, then flat embedded in Epon.

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Effects on Human Epidermis of Chronic Suberythemal Exposure to Pure Infrared Radiation

Archives of Dermatology ◽

10.1001/archderm.135.5.608 ◽

1999 ◽

Vol 135 (5) ◽

pp. 608-609 ◽

Cited By ~ 7

Author(s):

C. Edwards

Keyword(s):

Infrared Radiation ◽

Human Epidermis

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Progestation

Acta Endocrinologica ◽

10.1530/acta.0.056s007 ◽

1967 ◽

Vol 56 (3_Suppla) ◽

pp. S7-S45 ◽

Cited By ~ 1

Keyword(s):

Tritiated Thymidine ◽

Succinic Dehydrogenase ◽

Glandular Epithelium ◽

Synthetic Activity ◽

Cell Renewal ◽

Pulse Labelling ◽

Uterine Receptivity ◽

Alkaline Phosphatases ◽

Monocytic Cells ◽

Acid And Alkaline Phosphatases

ABSTRACT Autoradiographic, enzymic and histologic studies on uteri of pregnant rats were carried out to follow the endometrial modifications which take place during progestation (days L0 – L4) and culminate in the state of uterine receptivity essential for ovum-implantation. Pulse labelling with tritiated thymidine (radioactive DNA precursor) on L0, L1 and L2 revealed a sequence of cell renewal in luminal and glandular epithelium and endometrial stroma. On L3 and L4 stromal cells showed extensive incorporation of tritiated thymidine. This synthetic activity was associated with endometrial preparation for decidualization and was evoked at least in part, by the surge of oestrogen on L3. All layers of the uterine wall were heavily infiltrated on L0 and resembled the site of an acute inflammatory reaction. Subsequently, polymorphonuclear infiltration diminished and monocytic cells predominated. On L3 a spatial arrangement was observed: eosinophiles were concentrated in the basal endometrium and monocytic cells in the subepithelial stroma. A comparison was made between such a shift in migratory cells in the uterus and similar phenomena which occur in inflammatory and immune reactions. Activities of acid and alkaline phosphatases, of ATP-ase and succinic dehydrogenase were low on L0 and L1 during the periods of infiltration, degeneration and regeneration of luminal and glandular epithelium. Enzymic activities increased on the following days, (L3 and L4). Vascular dilation and engorgement and endometrial oedema were observed near the blastocysts on L4. Most blastocysts incorporated tritiated thymidine after 14.00 h on L4, but some showed uptake before loss of the zona which occurs usually between 14.00 and 16.00 h; therefore, it was assumed that the permeability of the zona increases prior to being shed. Activities of succinic dehydrogenase and acid and alkaline phosphatases were demonstrable in blastocysts on L4 while they were still »free« in the uterine lumen.

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The Contribution of Calpains in the Downregulation of Mdm2 and p53 Proteolysis in Reconstructed Human epidermis in Response to Solar Irradiation

Photochemistry and Photobiology ◽

10.1562/2004-08-05-ra-262 ◽

2005 ◽

Cited By ~ 2

Author(s):

Christelle Gélis ◽

Alain Mavon ◽

Patricia Vicendo

Keyword(s):

Human Epidermis ◽

Solar Irradiation ◽

Reconstructed Human Epidermis

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Faculty Opinions recommendation of Regeneration of the entire human epidermis using transgenic stem cells.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732083929.793543205 ◽

2018 ◽

Author(s):

Cristina Has

Keyword(s):

Stem Cells ◽

Human Epidermis

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Faculty Opinions recommendation of Neuroprotection and progenitor cell renewal in the injured adult murine retina requires healing monocyte-derived macrophages.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.8334957.8788054 ◽

2011 ◽

Author(s):

David Mosser ◽

Volker Briken

Keyword(s):

Progenitor Cell ◽

Cell Renewal

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CDK12 Promotes Breast Cancer Progression and Maintains Stemness by Activating c-myc/β -catenin Signaling

Current Cancer Drug Targets ◽

10.2174/1568009619666191118113220 ◽

2020 ◽

Vol 20 (2) ◽

pp. 156-165 ◽

Cited By ~ 3

Author(s):

Fang Peng ◽

Chuansheng Yang ◽

Yanan Kong ◽

Xiaojia Huang ◽

Yanyu Chen ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cell ◽

Breast Cancer Cell ◽

Lung Metastasis ◽

Xenograft Model ◽

Breast Cancer Cell Lines ◽

Cell Renewal ◽

Cancer Stemness ◽

Mesenchymal Transition ◽

Potential Biomarker

Background: CDK12 is a promising therapeutic target in breast cancer with an effective ability of maintaining cancer cell stemness. Objective: We aim to investigate the mechanism of CDK12 in maintaining breast cancer stemness. Methods: CDK12 expression level was accessed by using RT-qPCR and IHC. CDK12-altered breast cancer cell lines MDA-MB-231-shCDK12 and SkBr-3-CDK12 were then established. CCK8, colony formation assays, and xenograft model were used to value the effect of CDK12 on tumorigenicity. Transwell assay, mammosphere formation, FACS, and lung metastasis model in vivo were determined. Western blot further characterized the mechanism of CDK12 in breast cancer stemness through the c-myc/β-catenin pathway. Results: Our results showed a higher level of CDK12 exhibited in breast cancer samples. Tumor formation, cancer cell mobility, spheroid forming, and the epithelial-mesenchymal transition will be enhanced in the CDK12high group. In addition, CDK12 was associated with lung metastasis and maintained breast cancer cell stemness. CDK12high cancer cells presented higher tumorigenicity and a population of CD44+ subset compared with CDK12low cells. Our study demonstrated c-myc positively expressed with CDK12. The c-myc/β-catenin signaling was activated by CDK12, which is a potential mechanism to initiate breast cancer stem cell renewal and may serve as a potential biomarker of breast cancer prognosis. Conclusion: CDK12 overexpression promotes breast cancer tumorigenesis and maintains the stemness of breast cancer by activating c-myc/β-catenin signaling. Inhibiting CDK12 expression may become a potential therapy for breast cancer.

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