Suppression of acute and chronic inflammation by orally administered prostaglandins

Oral administration of a stable analog of prostaglandin E, (PGE 1 ), 15-(S)-15-methyl-prostaglandin E 1 , can suppress both chronic adjuvant-induced polyarthritis and acute immune complex-induced vasculitis in a dose dependent manner. Histopathologic studies of tibiotarsal joints from rats with adjuvant disease showed suppression of arthritis in animals treated with the PGE, analog from time of adjuvant challenge. This study represents the first demonstration of suppressed experimental polyarthritis by an orally administered prostaglandin. Suppression of the acute immune complex-induced vasculitis was demonstrated using 15-methyl-PGE, administered orally 12 hours prior to antigen-antibody challenge. Diminution of tissue injury resulting from immune complex-induced vasculitis is reflected by a decrease in vaso-permeability, indicating suppressed vascular damage in animals treated with prostaglandin. These studies demonstrate the potential use of orally active prostaglandins as an antiinflammatory agent.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37757/1/1780240906_ftp.pd

Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications

This work was supported by a restricted research grant of Bayer AG

High-calorie diet exacerbates prostate neoplasia in mice with haploinsufficiency of Pten tumor suppressor gene

Objective: Association between prostate cancer and obesity remains controversial. Allelic deletions of PTEN, a tumor suppressor gene, are common in prostate cancer in men. Monoallelic Pten deletion in mice causes low prostatic intraepithelial neoplasia (mPIN). This study tested the effect of a hypercaloric diet on prostate cancer in Pten+/− mice. Methods: 1-month old mice were fed a high-calorie diet deriving 45% calories from fat for 3 and 6 months before prostate was analyzed histologically and biochemically for mPIN progression. Because Pten+/− mice are protected against diet-induced insulin resistance, we tested the role of insulin on cell growth in RWPE-1 normal human prostatic epithelial cells with siRNA knockdown of PTEN. Results: In addition to activating PI3 kinase/Akt and Ras/MAPkinase pathways, high-calorie diet causes neoplastic progression, angiogenesis, inflammation and epithelial–mesenchymal transition. It also elevates the expression of fatty acid synthase (FAS), a lipogenic gene commonly elevated in progressive cancer. SiRNA-mediated downregulation of PTEN demonstrates increased cell growth and motility, and soft agar clonicity in addition to elevation in FAS in response to insulin in RWPE-1 normal human prostatic cells. Downregulating FAS in addition to PTEN, blunted the proliferative effect of insulin (and IL-6) in RWPE-1 cells. Conclusion: High-calorie diet promotes prostate cancer progression in the genetically susceptible Pten haploinsufficient mouse while preserving insulin sensitivity. This appears to be partly due to increased inflammatory response to high-caloric intake in addition to increased ability of insulin to promote lipogenesis