An aqueous extract of the popular Chinese nutraceutical Kwei Ling Ko (Tortoise shell-Rhizome jelly) activates the PPARgamma pathway and down-regulates the NFkappaB activity.

It is generally believed that the popular nutraceutical 'Kwei Ling Ko' (KLK; Tortoise shell-Rhizome jelly) has antiinflammatory effects, but the mechanism by which its effects are manifested remains unknown. Peroxisome proliferation-activated receptors (PPARs) are members of the nuclear hormone receptor/transcription factor superfamily with multiple roles in adipocyte differentiation, glucose homeostasis, immunomodulation and antiinflammatory regulation. As PPAR is required for adipocyte induction, we used adipogenesis as a possible screen for the activation of the PPAR pathway. Interestingly, an aqueous extract of KLK (sKLK) was able to induce the adipocyte differentiation of fibroblast cell lines. Adipogenesis was confirmed by flow cytometric analysis using a fluorescent lipid stain. Up-regulation of PPARgamma transcripts during adipogenesis was also demonstrated by reverse transcription-polymerase chain reaction (RT-PCR). The sKLK-induced adipogenesis was similar to that elicited by insulin. The activity of nuclear factor-kappaB (NFkappaB), a transcription factor responsible for the regulation of proinflammatory genes, was also down-regulated in response to sKLK. Luciferase reporter gene assays further demonstrated that sKLK inhibited both basal and tumor necrosis factor-alpha-stimulated NFkappaB activation. The activities reported in this study support an immunomodulatory effect for sKLK. As activation of PPAR pathway has a dual role in adipogenesis and anti-inflammation, our observations are consistent with the notion that KLK possesses antiinflammatory properties.

Histone-like proteins of the dinoflagellate Crypthecodinium cohnii have homologies to bacterial DNA-binding proteins.

The dinoflagellates have very large genomes encoded in permanently condensed and histoneless chromosomes. Sequence alignment identified significant similarity between the dinoflagellate chromosomal histone-like proteins of Crypthecodinium cohnii (HCCs) and the bacterial DNA-binding and the eukaryotic histone H1 proteins. Phylogenetic analysis also supports the origin of the HCCs from histone-like proteins of bacteria.

Inhibition of cell proliferation by mechanical agitation involves transient cell cycle arrest at G1 phase in dinoflagellates.

Cell proliferation of dinoflagellates is negatively affected by mechanical agitation and red tides caused by members of the group have been correlated with periods of calm sea conditions. The mechanism involved in the mechanically transduced inhibition of cell proliferation is thought to involve the disruption of the cell division apparatus. In this study, we used highly synchronized cells and flow cytometry to study the effects of mechanical agitation on cell cycle progression. We observed that mechanical agitation induced transient cell cycle arrest at G(1) phase, in both the heterotrophic dinoflagellate Crypthecodinium cohniiand the photosynthetic dinoflagellate Heteroscapsa triquetra.

Transcript levels of the eukaryotic translation initiation factor 5A gene peak at early G(1) phase of the cell cycle in the dinoflagellate Crypthecodinium cohnii.

A cDNA encoding a eukaryotic translation initiation factor 5A (eIF-5A) homolog in heterotrophic dinoflagellate Crypthecodinium cohnii (CceIF-5A) was isolated through random sequencing of a cDNA library. The predicted amino acid sequence possesses the 12 strictly conserved amino acids around lysine 52 (equivalent to lysine 50 or 51 in other eukaryotes). A single 1.2-kb band was detected in Northern blot analysis. In synchronized C. cohnii cells, the transcript level peaked at early G(1) and decreased dramatically on the entry to S phase. Although this has not been previously reported, studies of budding yeast (Saccharomyces cerevisiae) and certain mammalian cell types suggest a role for eIF-5A in the G(1)/S transition of the eukaryotic cell cycle. Phylogenetic trees constructed with 26 other published eIF-5A sequences suggest that CceIF-5A, while falling within the eukaryotic branches, forms a lineage separate from those of the plants, animals, and archaebacteria. The posttranslational modification of eIF-5A by a transfer of a 4-aminobutyl moiety from spermidine to conserved lysine 50 or 51, forming amino acid hypusine, is the only demonstrated specific function of polyamines in cell proliferation. It has been suggested that polyamines stimulate population growth of bloom-forming dinoflagellates in the sea. We demonstrate here putrescine-stimulated cell proliferation. Furthermore, ornithine decarboxylase inhibitor D-difluoromethylornithine and the specific hypusination inhibitor N-guanyl-1,7-diaminoheptane exhibited inhibitory effects in two species of dinoflagellates. The possible links of polyamines and saxitoxin synthesis to the arginine cycle are also discussed.