## Abstract Hyaluronan accumulation in the retroorbital connective tissue is one of the pathological features of Graves' ophthalmopathy. Interleukin‐1β (IL‐1β) is known to stimulate hyaluronan synthesis in orbital fibroblasts. In the present study, the intracellular signal transduction pathways inv
TGF-β induced hyaluronan synthesis in orbital fibroblasts involves protein kinase C βII activation in vitro
✍ Scribed by Hwai-Shi Wang; Wen-Hsiu Tung; Kam-Tsun Tang; Yi-Kuei Wong; Ging-Jye Huang; Jiahn-Chun Wu; Yi-Jhih Guo; Chin-Chang Chen
- Book ID
- 102300710
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 261 KB
- Volume
- 95
- Category
- Article
- ISSN
- 0730-2312
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Graves' ophthalmopathy is accompanied by hyaluronan (HA) accumulation in the orbital space and infiltration of immunocompetent cells and cytokines, including IFN‐γ, IL‐1β, and TGF‐β. We examined the signal transduction pathways by which TGF‐β induces HA synthesis in normal orbital fibroblasts, orbital fibroblasts from patients with Graves' ophthalmopathy, and abdominal fibroblasts. Calphostin C inhibited the stimulation of HA synthesis by TGF‐β. Phorbol 12‐myristate 13‐acetate (PMA) activation of PKC stimulated HA production. The effects of TGF‐β and PMA were not synergistic. Stimulation by TGF‐β and PMA were dependent on protein synthesis and their effects were inhibited by cycloheximide. Since TGF‐β‐induced HA synthesis was inhibited by BAPTA or by PKC inhibitors, a calcium‐dependent PKC was most likely involved. The PKA inhibitor H‐89 enhanced TGF‐β‐ and PMA‐induced HA synthesis, thus showing that communication between the PKA and PKC pathways was evident. TGF‐β stimulated the translocation of PKCβII to the cell membrane. PKCβII, a key enzyme in the regulation of HA synthesis by TGF‐β, might be an appropriate target for therapeutic compounds to be used to treat Graves' ophthalmopathy accompanied by inflammation. © 2005 Wiley‐Liss, Inc.
📜 SIMILAR VOLUMES
## Abstract The proinflammatory cytokine tumor necrosis factor (TNF) α is mainly produced in cells from the monocyte/macrophage lineage. TNFα is also a key signaling molecule in the liver functioning as an important physiological and pathogenic mediator. In hepatocytes or human hepatoma cells TNFα
## Abstract Elevated extracellular D‐glucose increases transforming growth factor β1 (TGF‐β1) release from human umbilical vein endothelium (HUVEC). TGF‐β1, via TGF‐β receptors I (TβRI) and TβRII, activates Smad2 and mitogen‐activated protein kinases p44 and p42 (p42/44^mapk^). We studied whether D