mobic and Cachexia

Chronic arthritis induces cachexia associated with an inhibition of the growth hormone (GH)-insulin-like growth factor-I (IGF-I) system and an activation of the E3 ubiquitin-ligating enzymes muscle atrophy F-box (MAFbx) and muscle Ring finger 1 (MuRF1) in the skeletal muscle. The aim of this work was to study the role of cyclooxygenase (COX)-2 in chronic arthritis-induced cachexia. Arthritis was induced in rats by Freund's adjuvant injection, and the effects of two COX inhibitors (indomethacin, a nonspecific inhibitor, and meloxicam, a selective COX-2 inhibitor on pituitary GH and on liver and serum IGF-I levels) were tested. Arthritis decreased body weight gain and GH and liver IGF-I gene expression. In the arthritic rats, both inhibitors, indomethacin and meloxicam, prevented the inhibitory effect of arthritis on body weight gain. Indomethacin and meloxicam administration to arthritic rats increased pituitary GH and liver IGF-I mRNA as well as serum levels of IGF-I. These data suggest that induction of COX-2 during chronic inflammation is involved in the inhibition of the GH-IGF-I axis and in the body weight loss. In the gastrocnemius muscle, arthritis increased the gene expression of tumor necrosis factor (TNF)-alpha, the E3 ubiquitin-ligating enzymes MAFbx and MuRF1, as well as of IGF-I and IGF-binding protein-5 (IGFBP-5). Inhibition of COX-2 by meloxicam administration increased gastrocnemius weight and decreased MAFbx, MuRF1, TNF-alpha, and IGFBP-5 gene expression. In summary, our data indicate that chronic arthritis-induced cachexia and muscle wasting are mediated by the COX-2 pathway resulting in a decreased GH-IGF-I secretion and increased expression of MAFbx and MuRF1 mRNA.

Topics: Animals; Arthritis, Experimental; Cachexia; Chronic Disease; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Enzyme Activation; Gene Expression; Growth Hormone; Indomethacin; Insulin-Like Growth Factor Binding Protein 5; Insulin-Like Growth Factor I; Liver; Male; Meloxicam; Muscle Proteins; Muscle, Skeletal; Pituitary Gland; Rats; Rats, Wistar; RNA, Messenger; SKP Cullin F-Box Protein Ligases; Thiazines; Thiazoles; Tripartite Motif Proteins; Tumor Necrosis Factor-alpha; Ubiquitin-Protein Ligases; Weight Gain

The effects of the cyclooxygenase-2 (COX-2) inhibitor, meloxicam, on tumour growth and cachexia have been determined in 2 established murine adenocarcinomas (MAC). At a dose level of 2.5 and 5.0 mgkg(-1), meloxicam produced pronounced inhibition of the growth of the MAC13 tumour, increasing the tumour volume doubling time from 2 to 5 days. Meloxicam also suppressed growth of the MAC16 tumour, which is generally refractory to standard cytotoxic agents, increasing the tumour volume doubling time from 1.5 to 2.5 days at dose levels of 0.5 and 1.0 mgkg(-1). Cachexia was also effectively attenuated at these dose levels. To investigate whether meloxicam exerted a direct effect on the cachectic process, studies on protein degradation were carried out using C(2)C(12) mouse myoblasts in response to a proteolysis-inducing factor (PIF). PIF produced maximum protein degradation at a concentration of 4.2 nM, and this was effectively attenuated by meloxicam at concentrations greater than 1 microM. This suggests that meloxicam may be capable of directly antagonizing the process of muscle catabolism in cachexia.

Topics: Adenocarcinoma; Animals; Body Weight; Cachexia; Colonic Neoplasms; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dose-Response Relationship, Drug; Isoenzymes; Male; Meloxicam; Mice; Mice, Inbred Strains; Neoplasm Transplantation; Prostaglandin-Endoperoxide Synthases; Thiazines; Thiazoles; Time Factors