During seed maturation and germination, major changes in physiological status, gene expression, and metabolic events take place. Using chlorophyll sorting, osmopriming, and different drying regimes, Brassica oleracea seed lots of different maturity, stress tolerance, and germination behavior were created. Through careful physiological analysis of these seed lots combined with gene expression analysis using a dedicated cDNA microarray, gene expression could be correlated to physiological processes that occurred within the seeds. In addition, gene expression was studied during early stages of seed germination, prior to radicle emergence, since very little detailed information of gene expression during this process is available. During seed maturation expression of many known seed maturation genes, such as late-embryogenesis abundant or storagecompound genes, was high. Notably, a small but distinct subgroup of the maturation genes was found to correlate to seed stress tolerance in osmoprimed and dried seeds. Expression of these genes rapidly declined during priming and/or germination in water. The majority of the genes on the microarray were up-regulated during osmopriming and during germination on water, confirming the hypothesis that during osmopriming, germination-related processes are initiated. Finally, a large group of genes was up-regulated during germination on water, but not during osmopriming. These represent genes that are specific to germination in water. Germination-related gene expression was found to be partially reversible by physiological treatments such as slow drying of osmoprimed seeds. This correlated to the ability of seeds to withstand stress.Reproduction through seeds is a prominent feature of higher plants. Seeds are adapted to survive for periods of time under adverse conditions until conditions favorable for seedling establishment are encountered. Usually, mature seeds have low moisture contents, reduced metabolic activity, and have accumulated protective compounds to help them survive under rather severe conditions. In the course of seed maturation, various events happen including the accumulation of storage products, the suppression of precocious germination, the acquisition of desiccation tolerance, and often the induction of dormancy (for review, see Bewley and Black, 1994). Seeds become quiescent at desiccation and can often be stored for a long time. When nondormant dry seeds imbibe water, they can germinate to start a new lifecycle. During germination, a series of events occurs, such as the activation of respiration (Bewley and Black, 1994), the repair of macromolecules (Osborne, 1993), reserve mobilization (Gallardo et al., 2001), reinitiation of the cell cycle (De Castro et al., 1995; Vásquez-Ramos and Sánchez, 2004), and weakening of covering structures to allow radicle protrusion (Groot and Karssen, 1987). At the same time, seeds lose longevity during germination and desiccation tolerance upon radicle protrusion (Hong and Ellis, 1992). Our study focuses on these early events d...

Scots pine (Pinus sylvestris L.) seedlings were grown under different conditions (three field locations, two seasons and two climate room regimes), and then analyzed for freezing tolerance of shoots and roots and for transcript abundance in apical buds based on a cDNA microarray containing about 1500 expressed sequence tags (ESTs) from buds of cold-treated Scots pine seedlings. In a climate room providing long daily photoperiods and high temperatures, seedlings did not develop freezing tolerance, whereas seedlings in a climate room set to provide declining temperatures and day lengths developed moderate freezing tolerance. Control seedlings grown outside under field conditions developed full freezing tolerance. Differences in physiological behavior of the different seedling groups, combined with molecular analysis, allowed identification of a large group of genes, expression of which changed during the development of freezing tolerance. Transcript abundance of several of these genes was highly correlated with freezing tolerance in seedlings differing in provenance, field location or age, making them excellent candidate marker genes for molecular tests for freezing tolerance.

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We found that fatty acids, reported to bind strongly to PPARα, could even repress PPARα transactivation illustrating that these binding assays should be interpreted with caution.

The inflammatory component of non–alcoholic steatohepatitis (NASH) can lead to irreversible liver damage. Therefore there is an urgent need to identify novel interventions to combat hepatic inflammation. In mice, omitting cholesterol from the diet reduced hepatic inflammation. Considering the effects of plant sterol/stanol esters on cholesterol metabolism, we hypothesized that plant sterol/stanol esters reduces hepatic inflammation. Indeed, adding plant sterol/stanol esters to a high-fat-diet reduced hepatic inflammation as indicated by immunohistochemical stainings and gene expression for inflammatory markers. Finally, adding sterol/stanol esters lowered hepatic concentrations of cholesterol precursors lathosterol and desmosterol in mice, which were highly elevated in the HFD group similarly as observed in severely obese patients with NASH. In vitro, in isolated LPS stimulated bone marrow derived macrophages desmosterol activated cholesterol efflux whereas sitostanol reduced inflammation. This highly interesting observation that plant sterol/stanol ester consumption leads to complete inhibition of HFD-induced liver inflammation opens new venues in the treatment and prevention of hepatic inflammation.

Concentrations of apolipoprotein A-I (ApoA-I) decrease during inflammation, which may lead to dysfunctional ApoA-I-poor high-density lipoprotein (HDL) particles, and as such, elevate cardiovascular risk. Therefore, rescuing ApoA-I concentrations, especially during inflammation, seems beneficial. Recently, short-chain fatty acids (SCFAs) have received more attention as a strategy in reversing atherosclerosis. We here evaluated the effects of SCFAs on inflammatory pathways in relation to ApoA-I transcription. SCFAs dose–response studies were performed in the presence and absence of inflammatory cytokines. ApoA-I and interleukin 8 (IL-8) mRNA expression were analyzed using qPCR and ELISA, respectively. To study underlying mechanisms, nuclear factor kappa B (NF-κB) transactivation and changes in mRNA expressions of the genes targets of bromodomain and extra-terminal (BET) inhibition, peroxisome proliferator-activated receptor-alpha (PPARα) transactivation and activator protein 1 (AP-1) pathway were analyzed. SCFAs (except hexanoic acid) increased ApoA-I mRNA transcription in both normal and inflammatory conditions and lowered IL-8 mRNA expression. This anti-inflammatory effect of SCFAs was confirmed by inhibition of NF-κB transactivation. Moreover, butyric acid increased carnitine palmitoyltransferase 1 (CPT1), PPARα target gene, mRNA transcription in both conditions, and there was a negative correlation between CPT1 and NF-κB. Therefore, PPARα transactivation is probably involved in the anti-inflammatory effects of SCFAs, which rescues ApoA-I transcription. In conclusion, propionate, butyrate and valerate elicit anti-inflammatory effects which might rescue ApoA-I transcription in inflammatory conditions via PPARα transactivation mediated NF-κB inhibition.

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Background Apolipoprotein‐I (ApoA‐I), the major component of high‐density lipoprotein (HDL) particles, mediates cholesterol efflux by which it facilitates the removal of excess cholesterol from peripheral tissues. Therefore, elevating ApoA‐I production leading to the production of new pre‐β‐HDL particles is thought to be beneficial in the prevention of cardiovascular diseases. Recently, we observed that amoxicillin treatment led to decreased HDL concentrations in healthy human volunteers. We questioned whether this antibiotic effect was directly or indirectly, via changed short‐chain fatty acids (SCFA) concentrations through an altered gut microflora. Therefore, we here evaluated the effects of amoxicillin and various SCFA on hepatic ApoA‐I expression, secretion, and the putative underlying pathways. Methods and Results Human hepatocytes (HepG2) were exposed to increasing dose of amoxicillin or SCFA for 48  hours. ApoA‐I messenger RNA (mRNA) transcription and secreted protein were analyzed using quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay, respectively. To study underlying mechanisms, changes in mRNA expression of KEAP1, CPT1, and PPARα, as well as a PPARα transactivation assay, were analyzed. Amoxicillin dose‐dependently decreased ApoA‐I mRNA transcription as well as ApoA‐I protein secretion. SCFA treatment resulted in a dose‐dependent stimulation of ApoA‐I mRNA transcription, however, the ApoA‐I protein secretion was decreased. Furthermore, SCFA treatment increased PPARα transactivation, PPARα and CPT1 mRNA transcription, whereas KEAP1 mRNA transcription was decreased. Conclusion Direct treatment of HepG2 cells with amoxicillin has either direct effects on lowering ApoA‐I transcription and secretion or indirect effects via modified SCFA concentrations because SCFA were found to stimulate hepatic ApoA‐I expression. Furthermore, BET inhibition and PPARα activation were identified as possible mechanisms behind the observed effects on ApoA‐I transcription.