The expression of MAPK signaling pathways in conjunctivochalasis

Antioxidative polyphenols attenuate pyocyanin-induced ROS production in neuronal HT22 cell lines

Pyocyanin, a secreted virulence factor, plays an essential role during Pseudomonas aeruginosa infection. Infection of the central nervous system by this bacterium results in high mortality, but the studies on its mechanism are still rather limited. In this study, we first evaluate the neuronal damage caused by pyocyanin exposure in neuronal HT22 cells. Pyocyanin leads to mitochondrial syndrome and antioxidant defense disruption, therefore increasing intercellular reactive oxygen species (ROS) production. Several typical superior antioxidant polyphenols effectively protect against pyocyanin-induced neuronal cell damage. These findings suggest the neuronal protective activity more or less relies on the structure, rather than the residues. Pre-incubation of catechin activates the essential pathway, indicating inverse correlation of ERK and AMPK phosphorylation participates in this process. These data outline a novel strategy to eliminate intracellular generated ROS. The investigated candidates could be potentially used as therapeutic agents against various ROS-related neurological diseases.

Qi Jing Mingmu decoction inhibits the p38 signaling pathway in conjunctivochalasis fibroblasts by down-regulation of Th17 cell differentiation

ETHNOPHARMACOLOGICAL RELEVANCE

Qi Jing Mingmu (QJMM) decoction is a traditional Chinese medicine that has been widely used for the clinical treatment of conjunctivochalasis (CCH). It is an effective treatment to relieve ocular symptoms including improving tear film and promoting tear secretion. However, its effects and molecular mechanisms need to be elucidated.

AIM OF THE STUDY

To determine whether QJMM decoction affected T helper 17 (Th17) cell differentiation of CCH patients.

MATERIALS AND METHODS

Blood samples and conjunctival tissues were collected from CCH patients and normal controls. The fibroblasts were separately induced, and CD4⁺ T cells were incubated with increasing concentrations of QJMM decoction and co-cultured with CCH fibroblasts. Th17 cell numbers were then analyzed using flow cytometry. Serum levels of interleukin 17 (IL-17) and IL-22 were detected using enzyme-linked immunosorbent assays. The expressions of signal proteins and genes were detected using western blotting and quantitative real-time PCR.

RESULTS

Compared with normal controls, Th17 cell numbers and serum levels of IL-17 and IL-22 were elevated in patients with CCH. QJMM decoction down-regulated the expressions of IL-17, IL-22, and STAT3 of CD4⁺T cells from CCH patients, suggesting that QJMM decoction impeded Th17 cell differentiation. QJMM decoction-treated CD4⁺ T cells inhibited the expression of p38 in CCH fibroblasts.

CONCLUSION

QJMM decoction inhibited Th17 cell differentiation of CD4⁺T cells from CCH patients, and QJMM decoction-treated CD4⁺T cells down-regulated the p38 signal pathway in CCH fibroblasts. Our study showed that Th17 cells may be good candidates for clinical treatment of CCH.

Mechanism of Akt regulation of the expression of collagens and MMPs in conjunctivochalasis

Akt is a central node of many signaling pathways, which plays important roles in cell survival, proliferation, migration, metabolism and collagen synthesis. Conjunctivochalasis (CCH) is one of the most common age-related ocular superficial diseases related to abnormalities in conjunctival extracellular matrix. Here, we studied the role of Akt regulating collagens and MMPs in the pathogenesis of CCH. Primary conjunctival fibroblasts were obtained from CCH patients (n = 13) and age-matched normal controls (n = 10). The levels of Akt, collagen type I, collagen type III, MMP1, and MMP3 were determined by Western blot, qRT-PCR, immunohistochemistry, and immunofluorescence staining. Normal control conjunctival fibroblasts were treated with Akt inhibitor A6730, and CCH fibroblasts were transfected with Akt overexpression vector. The expression of Akt in CCH was significantly lower than that in normal control of conjunctival tissues and cultured fibroblasts. Blocking Akt signaling with Akt inhibitor could inhibit the expression of collagen type I and collagen type III and upregulate the expression of MMP1 and MMP3. Meanwhile, compared with CCH fibroblasts transfected with control mimics, the protein and mRNA expression of collagen type I and collagen type III were increased significantly in Akt overexpression group, while the results of MMP1 and MMP3 in transfected fibroblasts were opposite. Taken together, Akt upregulated the expression of collagen type I and collagen type III and downregulated the expression of MMP1 and MMP3. Akt signaling pathway could provide a direct negative contribution to CCH and might be an attractive target for CCH therapy.