|Hyperoxia-induced hypertrophy and ion channel remodeling in left ventricle.|
Panguluri, SK; Tur, J; Fukumoto, J; Deng, W; Sneed, KB; Kolliputi, N; Bennett, ES; Tipparaju, SM
American journal of physiology. Heart and circulatory physiology
Ventricular arrhythmias account for high mortality in cardiopulmonary patients in intensive care units. Cardiovascular alterations and molecular-level changes in response to the commonly used oxygen treatment remains unknown. In the present study we investigated cardiac hypertrophy and cardiac complications in mice subjected to hyperoxia. Results demonstrate that there is a significant increase in average heart weight to tibia length (22%) in mice subjected to hyperoxia treatment vs. normoxia. Functional assessment was performed in mice subjected to hyperoxic treatment, and results demonstrate impaired cardiac function with decreased cardiac output and heart rate. Staining of transverse cardiac sections clearly demonstrates an increase in the cross-sectional area from hyperoxic hearts compared with control hearts. Quantitative real-time RT-PCR and Western blot analysis indicated differential mRNA and protein expression levels between hyperoxia-treated and control left ventricles for ion channels including Kv4.2 (-2 ± 0.08), Kv2.1 (2.54 ± 0.48), and Scn5a (1.4 ± 0.07); chaperone KChIP2 (-1.7 ± 0.06); transcriptional factors such as GATA4 (-1.5 ± 0.05), Irx5 (5.6 ± 1.74), NFκB1 (4.17 ± 0.43); hypertrophy markers including MHC-6 (2.17 ± 0.36) and MHC-7 (4.62 ± 0.76); gap junction protein Gja1 (4.4 ± 0.8); and microRNA processing enzyme Drosha (4.6 ± 0.58). Taken together, the data presented here clearly indicate that hyperoxia induces left ventricular remodeling and hypertrophy and alters the expression of Kv4.2 and MHC6/7 in the heart.
|Dehydroxymethylepoxyquinomicin inhibits expression and production of inflammatory mediators in interleukin-1beta-induced human chondrocytes.|
Venera Cardile,Giuseppina Frasca,Massimo Libra,Silvia Caggia,Kazuo Umezawa,Annamaria Panico,Grazia Malaponte
Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
The present research was carried out to determine the effects of a nuclear factor-kappaB (NF-kappaB) inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), derivative of the antibiotic epoxyquinomicin C, on normal human chondrocytes treated with interleukin-1beta (IL-1beta). This is a cell model particularly useful to reproduce the mechanisms involved in degenerative arthropathies, where oxidative-inflammatory stress determines a progressive destruction of the articular cartilaginous tissue. The expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and inter-cellular adhesion molecule (ICAM)-1 was evaluated through Western blot analysis. The release of chemokines like monocyte chemoattractant protein-1 (MCP-1), regulated upon normal activation T-cell expressed and secreted (RANTES), and interleukin-8 (IL-8) were determined by ELISA assays. DHMEQ acts as a potent inhibitor of iNOS and COX-2 gene expression while also suppressing the production of nitrite in human chondrocytes. In addition, DHMEQ induces a significant dose-dependent decrease in ICAM expression, MCP-1, RANTES, and IL-8 release. DHMEQ helps to decrease the expression and production of pro-inflammatory mediators in IL-1beta-induced chondrocytes. DHMEQ may become a therapeutic agent for treatment of chondro-degenerative diseases.