CD8alphaalpha-mediated survival and differentiation of CD8 memory T cell precursors.

Memory T cells are long-lived antigen-experienced T cells that are generally accepted to be direct descendants of proliferating primary effector cells. However, the factors that permit selective survival of these T cells are not well established. We show that homodimeric alpha chains of the CD8 molecule (CD8alphaalpha) are transiently induced on a selected subset of CD8alphabeta+ T cells upon antigenic stimulation.

Expression of the MAPK kinases MKK-4 and MKK-7 in rheumatoid arthritis and their role as key regulators of JNK.

Objective: The mitogen-activated protein (MAP) kinase JNK is a key regulator of interleukin-1 (IL-1)-induced collagenase gene expression and joint destruction in arthritis. Two upstream kinases, MKK-4 and MKK-7, have been identified as potential activators of JNK. However, the role of MAP kinase kinases (MAPKKs) and their functional organization within fibroblast-like synoviocytes (FLS) have not been defined.

Tumor promotion by metanil yellow and malachite green during rat hepatocarcinogenesis is associated with dysregulated expression of cell cycle regulatory proteins.

Metanil yellow (MY) and malachite green (MG) are textile dyes, which, despite a ban, are used as food-coloring agents. MY and MG have promoter effects on the development of hepatic preneoplastic lesions induced by N-nitrosodiethylamine (DEN). Tumor-promoting agents are not mutagenic but may alter the expression of genes whose products are associated with hyper-proliferation, tissue remodeling, and inflammation.

Overexpression of cyclin D1 is associated with the decondensation of chromatin during den-induced sequential hepatocarcinogenesis.

D-type cyclins regulate distinct cellular processes such as mitotic cell cycle control, differentiation and transcription. Deregulation of cyclin D1, a component of G1 checkpoint control, can result in enhanced genomic instability, cell transformation, and malignant neoplasia. However, a precise understanding of the molecular and cellular events underlying the regulation of the cyclin D1 gene remains to be elucidated.