Sci. Pharm., Volume 77, Plenary Lectures (PL) (March 2009) – 5 articles , Pages 163-167

Proteins play a fundamental role in controlling multiple functions within a cell s organization. At pathologic conditions, specifically expressed proteins may indicate disease states and may thus serve as diagnostic markers. Following disease-associated aberrations of protein expression may lead to a better understanding of the mechanisms of diseases and thereby enable the development of new therapeutic strategies. We established a strategy based on the systematic profiling of primary cells which were forced in vitro to enter specific functional states characteristic for certain diseases. Focusing on secreted proteins, we try to identify marker proteins accessible via the blood. Shotgun proteomics proofed to be the method of choice for the identification of low-abundant marker proteins. On the other hand, two-dimensional gel electrophoresis of metabolically labeled cells proofed to be more sensitive to record subtle drug effects. Currently we focus on tumour-stroma interactions resulting in the induced secretion of tumour-promoting survival factors by the stroma cells. We make use of co-culture model systems for testing drugs specifically interfering with this synergistic cell cooperativity. Full article

Strategies for inhibiting gene expression have been applied in several therapeutic applications Indeed, administration of nucleic acids such as antisense oligonucleotides (AS-ODNs) or small interfering RNA (siRNA) has raised a lot of interests in the recent years for the treatment of several diseases. Among the promising therapeutic approaches is antisense technology – oligonucleotides that are designed to be complementary to a target RNA sequence so they can bind to the target and stop the production of undesirable proteins. A more recent approach for targeting mRNA is the use of siRNA which can lead to hydrolysis of the target mRNA homologous at the site where the antisense strand of the siRNA is bound. Very similarly DNA delivery aiming to express intracellularly a protein that is absent or deficient raises close issues to AS-ODNs or siRNAs with the exception that the intracellular target is the nucleus, meaning one more barrier to cross. Nucleic acids are characterized by a high molecular weight and a negative charge being not able to pass biological membranes. Out of these reasons, two strategies are possible to improve their delivery: The first is to develop chemical modified nucleic acids in order to protect them or/and to improve their cellular uptake. The second strategy comprises the development of particulate carriers for oligonucleotides delivery which increase tremendously the efficacy of all these molecules. Full article

About 22% of the “druggable” human genome codes target protein kinases. However, only 8 registered drugs worldwide address protein kinase targets (e. g. Gleevec^®, Iressa^®). Kinases regulate many different signaling processes. Devastating diseases such as cancer, autoimmune diseases and neurological disorders can result from abnormal signal transduction. At present 518 kinases are identified, in which all of them bind the cofactor ATP in a very similar way. The conservation of structural features within the ATP binding cleft initially indicated that specificity for ATP-site directed inhibitors would be difficult to achieve. Structure elucidation of ATP complexes bound to protein kinases, revealed regions within or close to the binding cleft that ATP does not fully occupy. Another way to induce selectivity makes use of a peptide flip at the hinge region, induced by a carbonyl-interaction of the inhibitor with two backbone NH-groups (in case of p38 MAPK, Met109, Gly 110) [1]. We tried to combine both approaches by using carbonyl-groups for targeting the hinge region and aryl-residues to interact with the HR I and/or II. In addition, minimization of the structures was attempted by using only templates with interactions to both the hinge and the hydrophobic regions (“linear binders”) [2]. A third structural requirement was reducing conformational flexibility. A rigid structure should allow only less induced fit to other than the target (off-target) kinases. Starting from initial benzophenone leads [3, 4], we developed dibenzo-suberones [5] and optimized them down to single digit nanomolar IC50s against p38 and excellent selectivity profiles against other protein kinases. Full article

Chlamydia pneumoniae is a common bacterium causing respiratory tract infections worldwide. Usually the outcome is mild upper respiratory tract infection but also pneumonia is detected. Persistent C. pneumoniae infection has been connected to different chronic lung diseases such as asthma, chronic obstructive pulmonary disease and even lung cancer. The most surprising finding, however, has been the association between C. pneumoniae infection and cardiovascular diseases. Full article

Detailed insights into the pathobiochemical mechanisms of the inflammatory process and the molecular actions of anti-inflammatory drugs are determinants for successful intervention with inflammatory diseases. Gender differences regarding susceptibility to inflammatory diseases are well known, for example rheumatoid arthritis and systemic lupus erythematosus more often affect women. In asthma, sex differences are apparent with a male predominance in childhood, whereas after puberty females predominate, due to a drop in males, reflecting a protective function of androgens. However, the biochemical mechanisms underlying these gender disparities are not understood. Leukotrienes, generated by the 5-lipoxygenase (5-LO) pathway, are involved in inflammatory and allergic disorders, and leukotriene receptor antagonists are used in asthma therapy. We found that leukotriene formation is substantially higher in females versus males, accompanied by different 5-LO trafficking, due to male-specific activation of extracellular signal-regulated kinases (ERKs). The differences are directly related to male/female testosterone levels. Our data suggest that gender issues should be considered in the use of anti-leukotrienes as therapeutics to optimize pharmacological therapy, in men and women. The anti-inflammatory properties of frankincense, the gum resin derived from Boswellia species, are well-recognized. Boswellic acids (BAs) are major ingredients of frankincense that were shown to inhibit 5-LO in vitro, but recent data question the pharmacological relevance of such interference in vivo. We report about the identification of human cathepsin G as pharmacologically relevant target of BAs. In particular, the major naturally occurring β-BA, reaching pharmacological relevant plasma levels (6.5–10 μM) after oral intake of medical frankincense preparations, potently inhibits cathepsin G in vitro and ex vivo, and exhibits high efficacy in animal models of inflammation, supporting an anti-inflammatory efficacy of frankincense in patients. Full article