Lactoferrin reduces colitis in rats via modulation of the immune system and correction of cytokine imbalance

Natural immunomodulator lactoferrin is known to exert an anti-inflammatory effect. However, there have been no studies that examine the mode of action of lactoferrin in reducing intestinal damage. We investigated the effect of lactoferrin on a trinitrobenzenesulfonic acid (TNBS)-induced colitis model in rats. Bovine lactoferrin was given once daily through gavage, starting 3 days before (preventive mode) or just after TNBS administration (treatment mode) until death. The distal colon was removed to be examined. Colitis was attenuated by lactoferrin via both modes in a dose-dependent manner, as reflected by improvement in macroscopic and histological scores and myeloperoxidase activity. Lactoferrin caused significant induction of the anti-inflammatory cytokines interleukin (IL)-4 and IL-10, significant reductions in the proinflammatory cytokines tumor necrosis factor-alpha and IL-1beta, and downregulation of the nuclear factor-kappaB pathway. We concluded that lactoferrin exerts a protective effect against colitis in rats via modulation of the immune system and correction of cytokine imbalance. Lactoferrin has potential as a new therapeutic agent for inflammatory bowel disease.     

Elevated immunoreactive-adrenomedullin levels in the aqueous humor of patients with uveitis and vitreoretinal disorders

To clarify possible involvement of adrenomedullin in the pathophysiology of inflammation of eyes, we measured immunoreactive-adrenomedullin concentrations in the aqueous humor and plasma obtained from 14 control subjects and 56 patients with uveitis or vitreoretinal disorders. Immunoreactive-adrenomedullin levels in the aqueous humor were significantly elevated in patients with active uveitis, proliferative vitreoretinopathy and proliferative diabetic retinopathy, as compared with control subjects. The plasma immunoreactive-adrenomedullin levels were not significantly correlated with the aqueous humor levels. These findings suggest that adrenomedullin produced locally in the eyes is involved in the pathophysiology of uveitis and some proliferative vitreoretinal disorders.     

Analysis of the molecular construction of xylogalacturonan isolated from soluble soybean polysaccharides

Soluble soybean polysaccharides (SSPS) extracted from soybean cotyledons are acidic polysaccharides, and exhibited a pectin-like structure. After digesting galacturonan with polygalacturonase, two novel galacturonan (GN) fragments, which were directly linked to xylosyl oligosaccharides, were obtained. One consisted of (beta-D-Xyl)7 branched at the C-3 site of 1,4-linked (alpha-D-GalA)4, and the other consisted of (beta-D-Xyl)4 branched at the C-3 site of 1,4-linked (alpha-D-GalA)3.     

Rhizoremediation of dioxin-like compounds by a recombinant Rhizobium tropici strain expressing carbazole 1,9a-dioxygenase constitutively

A recombinant Rhizobium strain, PBK3-IS, that constitutively expressed the oxygenase component of carbazole 1,9a-dioxygenase from Sphingomonas sp. strain KA1, was constructed. In the water-cultured siratro rhizospheres inoculated with strain PBK3-IS, 48% of the dibenzofuran was removed within 3 days (initial substrate, 25 microg). Similar results were obtained in soil-cultured siratro rhizospheres using sterile vermiculite. When non-sterile field soils were used instead of sterile vermiculite, the inoculated recombinant strain could grow on the siratro root in all soils tested, except for wet paddy field.     

In vivo activation of the constitutive androstane receptor beta (CARbeta) by treatment with dehydroepiandrosterone (DHEA) or DHEA sulfate (DHEA-S)

We investigated whether dehydroepiandrosterone (DHEA) or DHEA-sulfate (S) affected the activities of nuclear receptors, with special reference to constitutive androstane receptor beta (CARbeta). Administration of DHEA or DHEA-S enhanced the DNA binding of hepatic nuclear extracts to responsive elements for the retinoic acid receptor, the retinoic acid receptor beta 2 and the peroxisome proliferator activated receptor. The bound complexes were shown to be the CARbeta-RXR heterodimer by antibody-supershift assays. The expression of a target gene of CARbeta, Cyp2b10, was increased in liver by DHEA or DHEA-S treatment, suggesting that DHEA or DHEA-S actually activated CARbeta in vivo. It was suggested that the metabolic conversion of DHEA, DHEA-S to CARbeta ligands could occur in vivo and the metabolites could regulate the expression of CARbeta target gene expression. Our results provide new insights into the in vivo relationship between DHEA/DHEA-S and CARbeta activation.     

Improvement of reflux symptoms 3 years after cure of Helicobacter pylori infection: a case-controlled study in the Japanese population

Background. Development of reflux esophagitis is one of the adverse effects that cause concern in relation to curative treatment of Helicobacter pylori infection. However, recent studies present a rather negative association between curative treatment and development of reflux esophagitis or reflux symptoms. Therefore, this issue has remained controversial. Accordingly, we investigated the long‐term adverse effects of H. pylori eradication treatment in special reference to development of reflux symptoms. Patients and Methods. We conducted a case controlled study by mailing structured questionnaires on past (before curative treatment or 3 years previously) and current status. A case was an endoscopically confirmed peptic ulcer patient with confirmed cure of the infection after eradication treatment 3 years previously and a control was one who had not undergone the eradication treatment during the same period. We studied 241 pairs who matched for age, gender, and type of ulcer disease (GU, DU or GDU). Of these pairs, 81.3% were male and the mean age was 52.6 ± 9.6 year (range 23–76). Results. The rates of patients with improved reflux symptoms in the case and control groups were 65.4% and 30.4%, respectively, with the rate being significantly greater in the case group. On the contrary, the rates of those with worsened reflux symptoms were similar (5.1% and 7.6%). Regarding general events, the rate of patients with decreased frequency of hospital visits and of those who regularly used antiacid medications were significantly decreased in the case group. Furthermore, the case group experienced significantly fewer hospital admissions for various diseases in this 3‐year period. However, a significantly greater number of case group patients than control subjects gained weight. Conclusion. Reflux symptoms as well as general well‐being were significantly improved after cure of H. pylori infection.     

Role of cyclophilin B in activation of interferon regulatory factor-3

IRF-3 is a member of the interferon regulatory factors (IRFs) and plays a principal role in the induction of interferon-beta (IFN-beta) by virus infection. Virus infection results in the phosphorylation of IRF-3 by IkappaB kinase epsilon and TANK-binding kinase 1, leading to its dimerization and association with the coactivators CREB-binding protein/p300. The IRF-3 holocomplex translocates to the nucleus, where it induces IFN-beta. In the present study, we examined the molecular mechanism of IRF-3 activation. Using bacterial two-hybrid screening, we isolated molecules that interact with IRF-3. One of these was cyclophilin B, a member of the immunophilins with a cis-trans peptidyl-prolyl isomerase activity. A GST pull-down assay suggested that one of the autoinhibition domains of IRF-3 and the peptidyl-prolyl isomerase domain of cyclophilin B are required for the binding. A knockdown of cyclophilin B expression by RNA interference resulted in the suppression of virus-induced IRF-3 phosphorylation, leading to the inhibition of the subsequent dimerization, association with CREB-binding protein, binding to the target DNA element, and induction of IFN-beta. These findings indicate that cyclophilin B plays a critical role in IRF-3 activation.     

Transient receptor potential vanilloid subfamily 1 expressed in pancreatic islet beta cells modulates insulin secretion in rats

Capsaicin-sensitive afferent neurons including transient receptor potential vanilloid subfamily 1, TRPV1, and neurohormonal peptides participate in the physiological regulation of pancreatic endocrine. However, the direct effect of capsaicin on insulin secretion remains unknown. Our present study showed that TRPV1 is expressed in islet beta cells as well as in neurons in rat pancreas, and also in rat beta cell lines, RIN and INS1. Capsaicin (10(-11)-10(-9) M) dose-dependently increased insulin secretion from RIN cells, and this effect was inhibited by either a TRPV1 inhibitor capsazepine or EDTA. Systemic capsaicin (10 mg/kg, s.c.) increased plasma insulin level 1 h after the treatment. We demonstrated for the first time that TRPV1 is functionally expressed in rat islet beta cells and plays a role in insulin secretion as a calcium channel. This study may account for the influences of capsaicin on the food intake and energy consumption as well as on the pathophysiological regulation of pancreatic endocrine.     

Ribosome stalling during translation elongation induces cleavage of mRNA being translated in Escherichia coli

Recently, it has been found that ribosome pausing at stop codons caused by certain nascent peptides induces cleavage of mRNA in Escherichia coli cells (1, 2). The question we addressed in the present study is whether mRNA cleavage occurs when translation elongation is prevented. We focused on a specific peptide sequence (AS17), derived from SecM, that is known to cause elongation arrest. When the crp-crr fusion gene encoding CRP-AS17-IIA(Glc) was expressed, cAMP receptor protein (CRP) proteins truncated around the arrest sequence were efficiently produced, and they were tagged by the transfer-messenger RNA (tmRNA) system. Northern blot analysis revealed that both truncated upstream crp and downstream crr mRNAs were generated along with reduced amounts of the full-length crp-crr mRNA. The truncated crp mRNA dramatically decreased in the presence of tmRNA due to rapid degradation. The 3' ends of truncated crp mRNA correspond well to the C termini of the truncated CRP proteins. We conclude that ribosome stalling by the arrest sequence induces mRNA cleavage near the arrest point, resulting in nonstop mRNAs that are recognized by tmRNA. We propose that the mRNA cleavage induced by ribosome stalling acts in concert with the tmRNA system as a way to ensure quality control of protein synthesis and possibly to regulate the expression of certain genes.