Clearly the antisense oligonucleotides (ODNs) concept derives from an understanding of nucleic acid structure and function and depends on Watson-Crick hybridization. Conceptually ODNs drug effects can be rationalized by traditional receptor theory and basic concepts concerning drug action. Because it was apparent almost immediately that native phosphodiester ODNs are unsatisfactory as a drug because of rapid degradation, a variety of modifications including the methylphosphonates and the phosphorothioates were tested. The phosphorothioate ODNs (s-ODNs) have potent systemic effects in a number of animal models, and in many experiments, the antisense mechanism has been directly demonstrated as the hoped-for selectivity, but pharmacodynamically, they have relatively low affinity per nucleotide unit.
For a successful outcome, the s-ODNs have to meet some criteria : (1) the s-ODNs must be stable, (2) the s-ODNs must be able to enter the target cell, (3) the s-ODNs must be retained by the target cell, (4) the s-ODNs must be able to interact with their cellular targets, (5) the s-ODNs should not interact in a non-sequence-specific manner with other macromolecules.
As several clinical trials are in progress with phosphorothioates and others, we shall soon have more definitive information about activity, toxicities and value of this class of antisense drugs in human beings.

View full abstract

One of the characteristic features of early atherogenesis is focal accumulation of monocyte/macrophages and T lymphocytes in arteral intima. Endothelial expression of adhesion molecules, such as VCAM-1 and ICAM-1, appear to play a role in this process. Lysophosphatidylcholine (lyso-PC), a prominent phospholipid component of atherogenic lipoproteins such as oxidized LDL and β-VLDL, can upregulate expression of VCAM-1 and ICAM-1 in cultured human and rabbit arterial endothelial cells. Lyso-PC also induces endothelial expression of potent smooth muscle growth factors such as PDGF A- and B-chains and HB-EGF in culture.
Thus, lyso-PC may be an important stimulus, in atherogenesis, to enhance mononuclear leukocyte recruitment into arterial lesions and to stimulate migration and proliferation of vascular smooth muscle cells in situ.

View full abstract

Tenascin is an extracellular matrix glycoprotein contributing in early organogenesis, tissue remodeling, cancer development, and other diseases. During skin wound healing, tenascin appears transiently in the wound edges of epidermis, hair follicles muscle layer, and in the granulation tissue. By immunohistochemistry, positive staining of tenascin is observed in fibroblasts, myofibroblasts and smooth muscle cells. However, by in situ hybridization, mRNA of tenascin is observed even in the epithelial cells besides myofibroblasts and smooth muscle cells. Tenascin expression is up-regulated by various cytokines such as TGFβ, bFGF, TNFα, interleukines, angiotensin II, and down-regulated by glucocorticoid. Tenascin is the substrate for matrix metalloproteinases (MMP-1, -3, and -7), catepsin G, and leucoelastase. The degradation of tenascin occurs when cultured the cells in the presence of IL-1, -2, and -6. These cytokines likely induce tenascin proteinase (s) in the various cells.

View full abstract

Mesangial cell (MC) proliferation is the hallmark of various forms of renal disease. Many protooncogenes are involved in the signal transduction pathways leading to cell proliferation induced by a wide variety of growth factors. We evaluated the inhibitory effects of antisense oligonucleotides (AS-ODNs) targeting protooncogenes on MC proliferation. The antisense and sense phosphorothioate ODNs of c-myc, c-fos and c-myb were synthesized. Quiescent MCs were stimulated with 20% FCS in the presence of AS-ODN or control sense ODN, which were mixed with liposome. Cell proliferation was determined by counting the number of trypan blue-viable cells. Inhibition of protooncogene mRNA was monitored by reverse transcriptase polymerase chain reaction (RT-PCR) . AS-ODN inhibited MC proliferation in a dose-dependent manner. Inhibitory effects of 10μM of each AS-ODN for MC proliferation were : c-myc 56%, c-myb 45% and c-fos 12%. Sense-ODN had little effect. Any significant morphological change in MC was not noticed with ASODN treatment.
These results indicate that these protooncogenes are involved in the signal transduction pathways mediating MC proliferation. Furthermore, the results suggest a potential role of antisense strategies designed to inhibit protooncogene expression to prevent MC proliferation.

View full abstract

IL-10 is a new cytokine of a soluble protein produced by type 2 helper T cells, macrophages, and B1 cells, which exhibits a wide variety of both immunosuppressive and immunostimulatory properties. The ability of IL-10 to suppress the production of proinflammatory cytokines such as monokines in vitro, predicts a strong antiinflammatory role in vivo.
To investigate the therapeutic efficacy of IL-10 in inflammatory diseases, we evaluated the effect on the survival rate in the murine models. We demonstrated that even the post-challenge IL-10 administration reduced mortality from LPS-induced endotoxin shock and severe peritonitis, via the suppression of monokine (mainly IL-6 and TNFα) production.
Collectively, these results suggest that IL-10 is a potent candidate for the treatment of septic shock and sepsis-related multiple organ failure.

View full abstract

Early articular lesions were studied in four experimental animal models as follows; adjuvant arthritis in F344 rats, type II collagen-induced arthritis in DBA/1J mice, spontaneous arthritis in MRL/Mp-lpr/lpr (MRL/1) mice, and pristane-induced arthritis in DBA/1J mice.
Adjuvant arthritis: Acute inflammatory lesions started to develop 6 hours after elicitation. Chronic inflammatory lesions started to develop 3 days after elicitation.
Type II collagen-induced arthritis: Acute inflammatory lesions were started to appear by 6 hours and were seen dominant by 2 weeks after elicitation. Then the lesions started to diminish, and were replaced by chronic inflammation at 4 weeks.
MRL/1 mouse polyarthritis : Histopathological findings of the articular lesions started to develop by 6 weeks of age. Acute and chronic inflammation started at the same time.
Pristane-induced arthritis : IgG and IgM rheumatoid factor start to elevate their titer by 3 weeks and 6 weeks after elicitation, respectively. Joints lesions were noticed under microscope by 14 weeks. Acute and chronic inflammation were seen simultaneously.
Acute inflammation preceded chronic lesion in adjuvant arthritis and type II collagen-induced arthritis. Acute and chronic inflammation was seen simultaneously in MRL/1 mouse polyarthritis and pristane-induced arthritis. Immunological abnormalities preceded articular lesions in MRL/1 mouse polyarthritis and pristane-induced arthritis. Joint lesions preceded elevation of anti-type II collagen antibody in DBA/1J mice. Scientists have to pay much attention on differences in quality of arthritis in experimental animal models.

View full abstract

Novel type C retroviral particles were detected in the bronchoalveolar lavage fluid (BALF) of a patient who had systemic lupus erythematosus (SLE) with interstitial pneumonia. Syncytial cell formation in the BALF and positive reverse transcriptase activity in the supernatant of the cultured cells were observed. No antibody to known human retroviruses or proviral sequences was detected.
Serum antibody to this putative type C retrovirus was also detected in 23.5 % of SLE patients and 26.9 % of idiopathic pulmonary fibrosis patients. This novel type C retroviral particle could be one of the pathogenic agents for SLE or interstitial pneumonia.

View full abstract

Etodolac displayed the greatest ratio of the IC₅₀ value for prostaglandin (PG) E₂ biosynthesis in rabbit gastric epithelial cells to the IC₅₀ value for PGE₂ biosynthesis in rabbit articular chondrocytes stimulated by interleukin-lβ, among the seven nonsteroidal anti-inflammatory drugs (NSAIDs) tested (etodolac, indomethacin, diclofenac Na, naproxen, piroxicam, ketoprofen and aspirin) . Etodolac displayed the greatest ratio of the IC₅₀ value for cyclooxygenase (COX) -1 to the IC₅₀ value for COX-2, among the six NSAIDs tested (etodolac, indomethacin, diclofenac Na, naproxen, piroxicam and zaltoprofen) . These results suggest that etodolac is a safe NSAID for clinical use with less sideeffects on stomach than other NSAIDs tested.

View full abstract