Subconfluent normal human keratinocytes exhibit autonomous (autocrine growth factor driven) proliferation and express the specific markers for keratinocyte proliferation K5 (keratin 5) and K14 (keratin 14). Utilizing this model the effects of PKD1 (Protein kinase D1) knockdown on activation of differentiation was studied. siRNA approach was applied to achieve specific knockdown of PKD1 and the mRNA levels of different keratinocyte markers -- K14 and PCNA (markers of basal proliferating keratinocytes), involucrin and K10 (early differentiation markers) were analyzed. Treatment of cultured keratinocytes with siRNA for PKD1 resulted in reduction of mRNA levels of PKD1, altered cell phenotype and promotion of keratinocyte differentiation, demonstrated by increased expression of involucrin and K10 mRNAs. No significant changes in K14 mRNA expression levels were detected, but the expression of PCNA mRNA was markedly diminished. This study was the first to show that mRNA expression of PKD1 in subconfluent normal human keratinocytes is very low, the PKD1 mRNA levels were more than 8-fold lower than the same ones in hTert keratinocytes. These findings suggest antidifferentiative role of PKD1 in normal human keratinocytes, contrary to the prodiferentiative role of PKD1 in human hTert keratinocytes. We came to the conclusion that there are differences between transduction pathways involving PKD1 in primary human keratinocyte cultures and these in immortalized hTert keratinocytes.

Chlamydophila pneumoniae, an obligately intracellular Gram-negative bacterium and a common causative agent of respiratory tract infections, has been implicated in the induction and progression of atherosclerosis and coronary artery disease. In this study, the signalling mechanism of C. pneumoniae in human fibroblasts, a prominent cell population in chronic inflammation and persistent infection, contributing to plaque formation, was investigated. C. pneumoniae elementary bodies were demonstrated to up-regulate the phosphorylation of p44/p42 mitogen-activated protein kinase (MAPK) in human fibroblasts. The effect was independent of the chlamydial lipopolysaccharide and was likely to be mediated by a heat-labile chlamydial protein. Furthermore, an anti-Toll-like receptor 4 (TLR4) antibody was shown to abolish C. pneumoniae-induced cell activation, whereas an anti-TLR2 antibody had no effect, indicating the role of TLR4 in p44/p42 MAPK activation. Ca 2þ / calmodulin-dependent protein kinase inhibitor KN-62 and phosphodiesterase 4 (PDE 4) inhibitor Rolipram enhanced C. pneumoniae-induced MAPK phosphorylation and attenuated C. pneumoniae infectivity in vitro. Together the results indicate that C. pneumoniae triggers rapid TLR4-mediated p44/p42 MAPK activation in human fibroblasts and chemical enhancement of MAPK phosphorylation modulates in vitro infection at the molecular level.

Ceratophyllum demersum L . is abundant in European rivers and ponds and produces a large amount of biomass . Almost nothing is known about its secondary metabolites . We isolated two flavonoid glycosides and identified one of them an apigenin-7-O-glucoside . Seven sterols, the main one sitosterol, were also identified . Volatile compounds contained mainly n-paraffins, together with benzyl acetate and a sesquiterpene .

Understanding cancer biology is crucial to the successful diagnosis and application of  personalized therapies. Skin carcinogenesis is a multi-step process. The first step is the development of potentially malignant disorders (PMDs) known as leukoplakia, erytroplakia, lichen planus, probably trough mutation in the proteins regulated cell cycle (p16INK4A, p21Waf1/Cip1/Sdi1, p27 kip1, Cyclin D1) and, second in p53 (TP53), Ras, hTert, EGFR, will reverse benign phenotype of late precancer lesions (PMDs) into benign cancer lesion. Third mutation probably in PI3K, PKD1 or E-cadherin, will increase malignant potential of SCCs, activating EMTransition, invasion and metastasis, e.g. aggressive phenotype. In BCC mutations of p53 are known to be late events (UV signature), whereas silencing of 14-3-3 takes place early in tumor progression, concomitant with increased activity of Snail. Early increased expression of PKD1 and down-regulation of c-myc mRNA are also events in pathogenesis of BCC. There is no data for detected mutations in PKD1 gene in both cancers, although the kinases is with high expression in BCC and lack of expression in SCC. There is no data concerning PKD1 expression in the PMDs leading to SCCs, nor to BCCs, such data were recently published concerning PKD1 expression in pancreatic oncogenesis. Curently adequate question is whether lack of PKD1 expression in SCCs, despite its PMDs origin, is a consequence of its spinous layer origin, or is a consequense of PKD1 gene mutations (downregulation). Identification of mutations as markers for early malignant transformation could be useful for early diagnosis and treatment of skin head and neck cancers.