Down syndrome critical region 1 (DSCR1), an oxidative stress-response gene, interacts with calcineurin and represses its phosphatase activity. Recently it was shown that hydrogen peroxide inactivates calcineurin by proteolytic cleavage. Based on these facts, we investigated whether oxidative stress affects DSCR1-mediated inactivation of calcineurin. We determined that overexpression of DSCR1 leads to increased proteolytic cleavage of calcineurin. Convertsely, knockdown of DSCR1 abolished calcineurin cleavage upon treatment with hydrogen peroxide. The PXIIXT motif in the COOH-terminus of DSCR1 is responsible for both binding and cleavage of calcineurin. The knockdown of overexpressed DSCR1 in DS fibroblast cells also abrogated calcineurin proteolysis by hydrogen peroxide. These results suggest that DSCR1 has the ability to inactivate calcineurin by inducing proteolytic cleavage of calcineurin upon oxidative stress.
Adenoviridae/genetics ; Adult ; Animals ; Calcineurin/antagonists & inhibitors/*metabolism ; Cells, Cultured ; Chromatin Immunoprecipitation ; Down Syndrome/*metabolism/pathology ; Fibroblasts/metabolism/pathology ; Humans ; Hydrogen Peroxide/pharmacology ; Immunoglobulin G/immunology ; Intracellular Signaling Peptides and Proteins/*physiology ; Male ; Mice ; Mice, Inbred ICR ; Muscle Proteins/*physiology ; Neuroblastoma/genetics/metabolism/pathology ; Neurons/cytology/metabolism ; Oxidants/pharmacology ; Oxidative Stress ; Peptide Fragments/immunology ; RNA, Messenger/genetics/metabolism ; RNA, Small Interfering/pharmacology ; Rabbits ; Reverse Transcriptase Polymerase Chain Reaction ; Skin/pathology ; Young Adult

OBJECTIVETo evaluate the effect of Chinese medicine Haoqin Qingdan Decoction (, HQD) for febrile disease dampness-heat syndrome (FDDHS).

METHODSForty mice were divided into four groups, including normal control, FDDHS (induced by Radix et Rhizoma Rhei recipe and influenza virus A1 FM1 model), HQD, and the ribavirin groups (10 in each). The normal control and FDDHS groups were administered normal saline. HQD and the ribavirin groups were administered HQD and ribavirin intragastrically once daily at a dose of 64 g/(kg d) and 0.07 g/(kg d), respectively for 7 days. Lethargy, rough hair, diarrhea, tongue color and sole color were evaluated for pathological changes in morphology. The tongue and lung tissues were collected for histology. The CD14 and toll-like receptor 4 (TLR4) expression levels were measured using real-time quantitative polymerase chain reaction.

RESULTSMore than 80% of the FDDHS mice showed hypokinesia and lethargy, and pathological changes associated with rough hair, diarrhea, tongue color and sole color. With advanced treatment for 7 days, the thick greasy tongue fur of the HQD and ribavirin groups were thinner than that of the FDDHS group (P<0.05), and it was the thinnest in the ribavirin group as compared with that in other groups (P<0.05). The CD14 and TLR4 expression levels in the lung tissues of HQD and ribavirin groups significantly delined compared with the model group (P<0.05 or P<0.01). CD14 was down-regulated more remarkably in the HQD group compared with the ribavirin group (P<0.05), whereas the converse was true with TLR4 (P<0.05).

CONCLUSIONSWe established a FDDHS mouse model showing systemic clinical symptoms. Both HQD and ribavirin can inhibit the expression of CD14 and TLR4 in FDDHS mice, while the effect of ribavirin might be much more violent. The expression changes of CD14 and TLR4 consistently refers to lipopolysaccharide, the commonly and hotly inducing factor in FDDHS.

Animals ; Behavior, Animal ; Disease Models, Animal ; Down-Regulation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Fever ; drug therapy ; pathology ; Gene Expression Profiling ; Lipopolysaccharide Receptors ; genetics ; metabolism ; Lung ; drug effects ; pathology ; Mice, Inbred BALB C ; Ribavirin ; pharmacology ; therapeutic use ; Syndrome ; Toll-Like Receptor 4 ; genetics ; metabolism