The regulation of inflammatory cytokine secretion in macrophage cell line by the chemical constituents of Rhus sylvestris

In our preliminary screening study on the anti-inflammatory activity, eight triterpenes, one sterol, and one chalcone were isolated from the CH₂Cl₂-soluble extract of the stems and leaves of Rhus sylvestris Siebold and Zucc (Anacardiaceae). On the basis of their spectroscopic data, these compounds were identified as 10α-cucurbitadienol (1), glut-5-en-3-ol (2), β-amyrin acetate (3), β-amyrin (4) and lupeol (5), cycloart-24-en-3-one (6), cycloart-25-en-3,24-dione (7), 24-hydroxycycloart-25-en-3-one (8), β-sitosterol (9), and 2′-hydroxy-4,4′-dimethoxychalcone (10). All of them were isolated from this plant for the first. Furthermore, the compounds in non-cytotoxic concentrations (0–1.0 μM) were tested for their ability to block inflammatory cytokine secretion in the presence of LPS in the murine RAW264.7 macrophage cell line. Among the compounds that were tested, compounds 8 and 9 reduced the LPS-induced secretion of IL-6, as well as TNF-α, in a mouse RAW264.7 macrophage cell line. Moreover, compounds 2, 3, 7, and 10 specifically diminished only the secretion of TNF-α even in 0.01 μM concentrations. It is thus suggested that they are potential therapeutics of TNF-α-related diseases and conditions, such as transplant rejection, type II diabetes, and atherosclerosis.     

Phosphorylation of Phospholipase C‐δ1 Regulates its Enzymatic Activity

Phosphorylation of phospholipase C‐δ₁ (PLC‐δ₁) in vitro and in vivo was investigated. Of the serine/threonine kinases tested, protein kinase C (PKC) phosphorylated the serine residue(s) of bacterially expressed PLC‐δ₁ most potently. It was also demonstrated that PLC‐δ₁ directly bound PKC‐α via its pleckstrin homology (PH) domain. Using deletion mutants of PLC‐δ₁ and synthetic peptides, Ser35 in the PH domain was defined as the PKC mediated in vitro phosphorylation site of PLC‐δ₁. In vitro phosphorylation of PLC‐δ₁ by PKC stimulated [³H]PtdIns(4,5)P₂ hydrolyzing activity and [³H]Ins(1,4,5)P₃‐binding of the PLC‐δ₁. On the other hand, endogenous PLC‐δ₁ was constitutively phosphorylated and phosphoamino acid analysis revealed that major phosphorylation sites were threonine residues in quiescent cells. The phosphorylation level and the species of phosphoamino acid were not changed by various stimuli such as PMA, EGF, NGF, and forskolin. Using matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry, we determined that Thr209 of PLC‐δ₁ is one of the constitutively phosphorylated sites in quiescent cells. The PLC activity was potentiated when constitutively phosphorylated PLC‐δ₁ was dephosphorylated by endogenous phosphatase(s) in vitro. Additionally, coexpression with PKC‐α reduced serine phosphorylation of PLC‐δ₁ detected by an anti‐phosphoserine antibody and PLC‐δ₁‐dependent basal production of inositol phosphates in NIH‐3T3 cells, suggesting PKC‐α activates phosphatase or inactivates another kinase involved in PLC‐δ₁ serine phosphorylation to modulate the PLC‐δ₁ activity in vivo. Taken together, these results suggest that PLC‐δ₁ has multiple phosphorylation sites and phosphorylation status of PLC‐δ₁ regulates its activity positively or negatively depends on the phosphorylation sites. J. Cell. Biochem. 108: 638–650, 2009. © 2009 Wiley‐Liss, Inc.     

Activation of formyl peptide receptor like-1 by serum amyloid A induces CCL2 production in human umbilical vein endothelial cells

We investigated the effects of serum amyloid A (SAA) on the production of C-C chemokine motif ligand 2 (CCL2) and the mechanism underlying SAA action in human umbilical vein endothelial cells (HUVECs). Stimulation of HUVECs by SAA elicited CCL2 production in a concentration-dependent manner. SAA induced the activations of NF-κB and AP-1, which were essential for CCL2 production after SAA stimulation. HUVECs expressed formyl peptide receptor-like 1 (FPRL1), and short interfering RNA knockdown of FPRL1 nearly completely blocked SAA-induced CCL2 production in HUVECs. We suggest that SAA stimulates CCL2 production via FPRL1 and, thus, contributes to atherosclerosis.     

A 2.7-kb Deletion in the Human NLRP10 Gene Exon 2 Occurred After the Human–Chimpanzee Divergence

NLRP10 is a member of the NLRP protein family, which is involved in inflammation and apoptosis. Genome sequence comparisons revealed that a 2.7-kb deletion occurred in the human NLRP10 gene exon 2 after the divergence of humans and chimpanzees, resulting in replacement of the entire 3′ untranslated region with the flanking LINE-1 element. The human NLRP10 protein lost 30 or more amino acids that are conserved in primates at its carboxy-terminus. The structural modification of the NLRP10 gene might have played a role in development or enhancement of human-specific traits during evolution.     

Selenium contentrations in human renal cortex, liver, and hair in Northern Poland

The aim of this study was to (1) determine the selenium concentration in the renal cortex, liver, and hair in 64 residents from northern Poland (Gdańsk region) aged 17–81 yr, who died suddenly, and (2) assess whether a correlation between the selenium concentration in hair and in the renal cortex and liver occurs. Selenium was determined by atomic absorption spectrometry using the hydride generation method. The mean selenium concentration in the renal cortex, liver, and hair in the investigated persons was 0.791±0.191 μg/g (wet weight), 0.289±0.084 μg/g (wet weight), and 0.443±0.128 μg/g, respectively. No age-dependent differences in selenium level in the investigated tissues was found. Also, no correlation between the selenium concentrations in hair and in renal cortex and liver was assessed.     

Total synthesis and biological evaluation of methylgerambullone

First total synthesis of methylgerambullone (MGB, 1) isolated from Glycosmis angustifolia was completed via a convergent route. The effect of MGB on the contractile responses of the isolated guinea-pig ileum induced by acetylcholine was investigated. As a result, it showed a potent relaxation rate (78.66 ± 4.30% at 100 mg/L) in a concentration-dependent manner on longitudinal smooth muscle contraction of isolated guinea-pig ileum induced by 1 μM acetylcholine.     

Occurrence and fate of fetal lumbar rib induced by Scutellariae radix in rats

BACKGROUND: This study was conducted to evaluate the occurrence and fate of fetal lumbar rib induced by Scutellariae radix (SR) in rats. METHODS: Water extracts of SR were orally administered to pregnant rats from day 7 to day 17 of gestation at a dose of 186 mg/kg/day, equivalent to 25 g/kg of starting material, representing a 100‐fold increase over typical human intake level. RESULTS: The incidence of fetal lumbar rib in the SR‐treated group was increased on gestational day 20 and then decreased on postnatal day 50. The weight of fetuses in the SR‐treated group tended to be less than that in the control group. Alkaline phosphatase in SR‐treated dams was increased on gestational day 20, but was decreased on postnatal day 50. There were no significant differences between the vehicle control and SR‐treated groups in maternal body weight, embryological, histopathological, hematological, and serum biochemical changes. CONCLUSIONS: The present data suggest that the appearance of lumbar rib induced by SR is a transient fetal variation rather than teratogenicity or maternal toxicity. Birth Defects Res (Part B) 89:201–206, 2010. © 2010 Wiley‐Liss, Inc.