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Toll-like receptor 4 (TLR4) and TLR2 were shown to be activated by saturated fatty acids (SFAs) but inhibited by docosahexaenoic acid (DHA). However, one report suggested that SFA-induced TLR activation in cell culture systems is due to contaminants in BSA used for solubilizing fatty acids. This report raised doubt about proinflammatory effects of SFAs. Our studies herein demonstrate that sodium palmitate (C16:0) or laurate (C12:0) without BSA solubilization induced phosphorylation of inhibitor of nuclear factor-κB α, c-Jun N-terminal kinase (JNK), p44/42 mitogen-activated-kinase (ERK), and nuclear factor-κB subunit p65, and TLR target gene expression in THP1 monocytes or RAW264.7 macrophages, respectively, when cultured in low FBS (0.25%) medium. C12:0 induced NFκB activation through TLR2 dimerized with TLR1 or TLR6, and through TLR4. Because BSA was not used in these experiments, contaminants in BSA have no relevance. Unlike in suspension cells (THP-1), BSA-solubilized C16:0 instead of sodium C16:0 is required to induce TLR target gene expression in adherent cells (RAW264.7). C16:0-BSA transactivated TLR2 dimerized with TLR1 or TLR6 and through TLR4 as seen with C12:0. These results and additional studies with the LPS sequester polymixin B and in MyD88−/−macrophages indicated that SFA-induced activation of TLR2 or TLR4 is a fatty acid-specific effect, but not due to contaminants in BSA or fatty acid preparations.

Nod2 is an intracellular pattern recognition receptor that detects a conserved moiety of bacterial peptidoglycan and subsequently activates proinflammatory signaling pathways. Mutations in Nod2 have been implicated to be linked to inflammatory granulomatous disorders, such as Crohn's disease and Blau syndrome. Many phytochemicals possess anti-inflammatory properties. However, it is not known whether any of these phytochemicals might modulate Nod2-mediated immune responses and thus might be of therapeutic value for the intervention of these inflammatory diseases. In this report, we demonstrate that curcumin, a polyphenol found in the plant Curcuma longa, and parthenolide, a sesquiterpene lactone, suppress both ligand-induced and lauric acid-induced Nod2 signaling, leading to the suppression of nuclear factor-κB activation and target gene interleukin-8 expression. We provide molecular and biochemical evidence that the suppression is mediated through the inhibition of Nod2 oligomerization and subsequent inhibition of downstream signaling. These results demonstrate for the first time that curcumin and parthenolide can directly inhibit Nod2-mediated signaling pathways at the receptor level and suggest that Nod2-mediated inflammatory responses can be modulated by these phytochemicals. It remains to be determined whether these phytochemicals possess protective or therapeutic efficacy against Nod2-mediated inflammatory disorders.

DNA double-strand breaks (DSBs) are a highly mutagenic and potentially lethal damage that occurs in all organisms. Mammalian cells repair DSBs by homologous recombination and non-homologous end joining, the latter requiring DNA-dependent protein kinase (DNA-PK). Werner syndrome is a disorder characterized by genomic instability, aging pathologies and defective WRN, a RecQ-like helicase with exonuclease activity. We show that WRN interacts directly with the catalytic subunit of DNA-PK (DNA-PKCS), which inhibits both the helicase and exonuclease activities of WRN. In addition we show that WRN forms a stable complex on DNA with DNA-PKCSand the DNA binding subunit Ku. This assembly reverses WRN enzymatic inhibition. Finally, we show that WRN is phosphorylated in vitroby DNA-PK and requires DNA-PK for phosphorylation in vivo, and that cells deficient in WRN are mildly sensitive to ionizing radiation. These data suggest that DNA-PK and WRN may function together in DNA metabolism and implicate WRN function in non-homologous end joining.

A series of new platinum(IV) complexes of the type [PtIV(DACH)trans(L)2Cl2] (where DACH=trans-1R,2R-diaminocyclohexane, and L=acetate, propionate, butyrate, valerate, hexanoate, or heptanoate) bearing the carboxylate groups in the axial positions have been synthesized and characterized by elemental analysis, IR, and 195Pt NMR spectroscopy. The crystal structure of the analogue [PtIV(DACH)trans(acetate)2Cl2] was determined by single crystal X-ray diffraction method. There were two crystallographically independent molecules, both of which lie on crystallographic two-fold axes. The bond lengths and bond angles of both the molecules were the same within the experimental error. The compound crystallizes in the monoclinic space group C2, with a=11.180(2) Å, b=14.736(3) Å, c=10.644(2) Å, β=112.38(3)°, Z=4 and R=0.0336, based upon a total of 1648 collected reflections. In this complex, the platinum had a slightly distorted octahedron geometry owing to the presence of a geometrically strained five-member ring. The two adjacent corners of the platinum plane were occupied by the two amino nitrogens of DACH, whereas the other two equatorial positions were occupied by two chloride ions. The remaining two axial positions were occupied by the oxygens of acetate ligands. The DACH ring was in a chair configuration. An intricate network of intermolecular hydrogen bonds held the crystal lattice together. These analogues were evaluated in vitro and demonstrated cytotoxic activity against the human ovarian 2008 tumor cell line (IC50=0.001–0.06 μM). Structure–activity study revealed that activity was highest for the analogue where L=butyrate.

Brachytic stem trait in soybean [Glycine max(L.) Merr] is characterized by a geniculate internode arrangement and markedly shortened internodes; brachytic plants are much shorter than their nonbrachytic isolines. When the brachytic trait expression is suppressed, plants have heights similar to those of their nonbrachytic isolines. A series of greenhouse and field experiments involving light intensity and photoperiod treatments were conducted to determine their effects on plant height and other stem traits in ‘Tracy‐M’ and ‘Wright’ soybean and in their brachytic near‐isolines, B.Tracy‐M and B‐Wright. The experiments demonstrated that full expression of the brachytic stem trait is a light.regulated process. Under unshaded conditions in the field, B‐Wright and B‐Tracy‐M had a plant height 48.7 and 78.9% of that of their respective nonbrachytic isolines. The most effective shading treatment (shade applied between 5 and 7 wk after emergence) produced a 46 and a 22% increase in plant height for B‐Tracy‐M and B‐Wright, respectively, by increasing internode length. The shade treatment also suppressed the geniculate expression, reducing the internodal angles by 5 to 20° for B‐Tracy‐M and 6 to 26° for B‐Wright. After shade removal, brachytic stem development resumed in subsequently formed internodes. The wide‐row (76 cm) spacing (more plants per meter of row) decreased the percentage of brachytic plants at early growth stages by 47.5% and 22.7% for B‐Tracy‐M and B‐Wright, respectively, compared with the narrow.row (25 cm) spacing. Increasing photoperiod from 14 to 16 h in the greenhouse decreased plant height and enhanced the development of brachytic stem trait. In general, B‐Tracy‐M appeared to be more sensitive than B‐Wright to the treatments imposed in these studies.

ACT11 represents a unique and ancient actin subclass in the complex Arabidopsis actin gene family. We have isolated and characterized the Arabidopsis ACT11 actin gene and examined its expression. Southern blotting with a 5′ gene-specific probe showed that ACT11 was a single-copy gene in the genome. Northern analysis with a 3′ gene-specific probe and reverse transcriptase-mediated PCR (RT-PCR) using gene-specific primers detected ACT11 mRNA at low levels in seedling, root, leaf, and silique tissue; at moderate levels in the inflorescence stem and flower; and at very high levels in pollen. The 5′ region of the ACT11 gene, including the promoter region, the 5′-untranslated leader, the intron within the leader, and the first 19 actin codons, was fused to a β-glucuronidase (GUS) reporter gene. The expression of the ACT11/GUS fusion was examined histochemically in numerous independent transgenic Arabidopsis plants. Strong ACT11/GUS activity was detected in rapidly elongating tissues and organs (e.g., etiolated hypocotyls, expanding leaves, stems) and in floral organ primordia. As the floral buds developed into mature flowers, strong GUS activity was gradually restricted to mature pollen and developing ovules. ACT11 appears to be the only Arabidopsis actin gene expressed at significant levels in ovule, embryo, and endosperm. The unique expression patterns in reproductive organs and the sequence divergence of the ACT11 actin gene suggest that the ACT11 isovariant plays distinct and required roles during Arabidopsis development.