Role of microtubules in LPS-induced macrophage inflammatory protein-2 production from rat pneumocytes

Abstract

We have recently demonstrated that primary cultured rat pneumocytes produce macrophage inflammatory protein-2 (MIP-2) in response to lipopolysaccharide (LPS) stimulation. In this study, we found that brefeldin A, by blocking anterograde transport from the endoplasmic reticulum (ER) to the Golgi apparatus, decreased LPS-induced MIP-2 in the culture medium and increased its storage in cells. This suggests that MIP-2 is secreted via a pathway from the ER to the Golgi apparatus, a process commonly regulated by microtubules. We further found that LPS induced depolymerization of microtubules as early as 1 min after LPS stimulation, and it lasted at least for 4 h. Preventing depolymerization of microtubules with paclitaxel (Taxol; 10 nM to 10 microM) partially inhibited LPS-induced MIP-2 production, whereas the microtubule-depolymerizing agents colchicine (1-10 microM) and nocodazole (1-100 microM) increased LPS-induced MIP-2 protein production without affecting MIP-2 mRNA expression. These results suggest that in pneumocytes, LPS-induced microtubule depolymerization is involved in LPS-induced MIP-2 production and that secretion of MIP-2 from pneumocytes is via the ER-Golgi pathway.

Acute lung injury and cell death: how many ways can cells die?

“…Lung epithelial cells are not only the target of inflammation but also a source of inflammatory mediators (19,34,37,69,116). LPS induced cytokine production in primary cultured rat pneumocytes, including TNF-␣ (45,87) and macrophage inflammatory protein-2 (43,44,115). LPS also induced production of IL-8 and GM-CSF (60) and expression of ICAM-1 (63) in human lung epithelial A549 cells.…”

Hyperosmolarity causes inflammation through the methylation of protein phosphatase 2A

“…Methods for real-time RT-PCR have been described in detail by Heid [28] and especially for rats by Isowa [29]. Total RNA was prepared from scraped cell suspensions by using the RNeasy Qiagen Kit according to the manufacturer's instructions (Qiagen, Hamburg, Germany).…”

A Tubulin Inhibitor, N-(5-Benzyl-1,3-thiazol-2-yl)-3-(furan-2-yl)prop-2-enamide, Induces Anti-inflammatory Innate Immune Responses to Attenuate LPS-mediated Septic Shock

“…Our results clearly show that 1 could cause a dramatic reduction of LPS-induced TNFα production in the spleen through modulating macrophages and DCs. Because LPS induced the depolymerization of microtubules quite quickly in primary rat cells 24 and the modification of microtubule networks directly affected LPS-triggered inflammatory response in macrophages, 25 it is of note that some modification of microtubules in macrophages and DCs by 1 might affect the level of TNFα production in response to LPS stimulation.…”