Interleukin-6 and tumour necrosis factor-α cooperatively promote cell cycle regulators and proliferate rheumatoid arthritis fibroblast-like synovial cells.

Objective: To elucidate the roles of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) in cell cycle regulation and proliferation of rheumatoid arthritis fibroblast-like synovial cells (RA-FLSs). Methods: Under stimulation with IL-6/soluble interleukin-6 receptor (sIL-6R) and TNF-α, we examined the expression of cell cycle regulators [p16INK4a, p21Cip1, p27Kip1, cyclin-dependent kinase-4 (CDK4), CDK6, Cyclin D, Cyclin E, and retinoblastoma protein (pRB)] by quantitative polymerase chain reaction, Western blotting, and immunofluorescence staining. The expression of pRB, with or without 10% foetal bovine serum, was examined by Western blotting. DNA synthesis and cell viability were examined by the BrdU assay and WST-8 assay, respectively. After transfection with siRNA/p16INK4a, siRNA/p21Cip1, siRNA/p27Kip1, siRNA/CDK4, or siRNA/CDK6, RA-FLSs were successively stimulated with or without IL-6/sIL-6R or TNF-α to determine cell viability. Results: IL-6/sIL-6R significantly decreased the expression of p16INK4a, and increased p21Cip1, Cyclin E1, CYCLIN D, and pRB. TNF-α decreased the expression of CDK4, and significantly increased p27Kip1, CDK6, Cyclin E1/E2, CYCLIN D, CYCLIN E, pRB, and phosphorylated pRB (phospho-pRB). By immunofluorescence staining, CYCLIN D and phospho-pRB were simultaneously stained in the single cell. In serum-free culture, the expression of pRB was apparently decreased. DNA synthesis and cell viability were significantly increased by IL-6/sIL-6R and TNF-α. Silencing of CDK6 attenuated the cell viability induced by IL-6 and TNF-α. Conclusion: The results indicate that IL-6 and TNF-α interact with each other in regulating the cell cycle and accelerate the proliferation of RA-FLSs.

Selective interference of mTORC1/RAPTOR protects against human disc cellular apoptosis, senescence, and extracellular matrix catabolism with Akt and autophagy induction.

OBJECTIVE: The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that integrates nutrients to execute cell growth and protein synthesis. We hypothesized that mTOR is essential for the intervertebral disc, the largest avascular, low-nutrient organ. Our objective was to elucidate roles of mTOR signaling in human disc cells. DESIGN: The mTOR exists in two complexes: mTORC1 containing the regulatory-associated protein of mTOR (RAPTOR) and mTORC2 containing the rapamycin-insensitive companion of mTOR (RICTOR). To analyze their functions in human disc nucleus pulposus cells, RNA interference (RNAi) of mTOR targeting mTORC1 and mTORC2, RAPTOR targeting mTORC1, or RICTOR targeting mTORC2 or rapamycin, a pharmacological mTORC1 inhibitor, was applied. First, mTOR signaling including Akt, p70/ribosomal S6 kinase (p70/S6K), and autophagy were assessed. Then, apoptosis, senescence, and matrix metabolism were evaluated under pro-inflammatory interleukin-1 beta (IL-1ß) stimulation. RESULTS: Western blotting showed significant decreases in specific proteins by each RNAi (all P < 0.0001). In mTOR signaling, RNAi of mTOR and RICTOR decreased p70/S6K and Akt phosphorylation, whereas RAPTOR RNAi decreased p70/S6K but increased Akt phosphorylation. All RNAi treatments increased light chain 3 (LC3)-II and decreased p62/sequestosome 1 (p62/SQSTM1), indicating enhanced autophagy. In apoptosis, IL-1ß-induced terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells and poly (ADP-ribose) polymerase (PARP) and caspase-9 cleavage decreased by RAPTOR RNAi. In senescence, IL-1ß-induced senescence-associated beta-galactosidase (SA-ß-gal)-positive cells and p16/INK4A expression also decreased by RAPTOR RNAi. In matrix metabolism, RAPTOR RNAi reduced IL-1ß-induced catabolic matrix metalloproteinase (MMP) release and activation and up-regulated anabolic gene expression. These findings were all consistent with rapamycin administration. Additional disc-tissue analysis detected expression and phosphorylation of mTOR-signaling molecules in varying ages. CONCLUSION: Selective interference of mTORC1/RAPTOR protects against inflammation-induced apoptosis, senescence, and matrix catabolism possibly through Akt and autophagy induction in human disc cells.

Differing effects of liraglutide on gastric emptying in Japanese patients with type 2 diabetes.

This study was performed to clarify the influence of liraglutide on gastric emptying in Japanese patients with type 2 diabetes. In 16 patients, the [(13) C]-acetate breath test was performed to compare gastric emptying before and after liraglutide treatment. We found two patterns of response, with gastric emptying being delayed by liraglutide in seven patients (delayers) and not delayed in nine patients (non-delayers). The mean increase of the maximum gastric emptying time was 31 ± 4 min (p < 0.01 vs. baseline) in the delayers, while it was only 2 ± 3 min (p = 0.60 vs. baseline) in the non-delayers. The delayers showed a greater early decrease of AUC-PG from 0 to 60 min, despite no increase of the plasma insulin level compared with non-delayers. In conclusion, the effect of liraglutide treatment on gastric emptying shows heterogeneity, and patients can be classified as delayers or non-delayers.

High CC chemokine receptor 7 expression improves postoperative prognosis of lung adenocarcinoma patients.

BACKGROUND: Chemokines and chemokine receptors not only have significant roles in cancer metastasis and tumorigenesis but also act as antitumour agents. The interaction between the Crk-like adaptor protein (CrkL), which is encoded by the CRKL gene, and non-receptor tyrosine kinase c-ABL is reported to transform many cells into malignant cells. We examined the effects of CC chemokine receptor 7 (CCR7), CCR7 ligands and CrkL and c-ABL in lung adenocarcinoma. METHODS: One hundred and twenty patients with lung adenocarcinoma were included in this historical cohort analysis. We examined CCR7 and CCR7 ligands and CrkL and c-ABL mRNA expressions in surgically resected lung adenocarcinoma specimens and evaluated their contribution to prognosis, and the relationship with epidermal growth factor receptor (EGFR) and TP53 mutations. RESULTS: High CCR7 mRNA expressions indicated better prognoses than those of the groups with low CCR7 mRNA expressions (P=0.007, HR=2.00, 95% CI of ratio: 1.22 -3.31). In lung adenocarcinoma, CrkL and c-ABL mRNAs were related to CCR7 mRNA expression (P<0.0001). CrkL and c-ABL mRNA expressions were influenced by EGFR mutations. A high expression of CCL19 was a good prognostic factor of lung adenocarcinoma. CONCLUSION: We propose that CCR7 and CCL19 are clinically good prognostic factors and that CCR7 is strongly related to CrkL and c-ABL kinase mRNA expression in lung adenocarcinoma.

Soymilk-fermented with Lactobacillus delbrueckii subsp. delbrueckii TUA4408L improves immune-health in pigs.

Lactobacillus delbrueckii subsp. delbrueckii TUA4408L has the ability to grow and ferment soymilk and is able to modulate the innate immune response of intestinal epithelial cells in vitro. These two properties prompt us to evaluate whether the soymilk fermented with the TUA4408L strain can induce beneficial immunomodulatory effects in vivo. For this purpose, pigs were selected as a preclinical model. The studies performed here demonstrated that the L. delbrueckii subsp. delbrueckii TUA4408L-fermented soymilk (TUA4408L FSM) reduced blood markers of inflammation and differentially regulated the expression of inflammatory and regulatory cytokines in the intestinal mucosa. These immunological changes induced by the TUA4408L FSM were associated to an enhanced resistance to pathogenic Escherichia coli and an improved grow performance and meat quality of pigs. The experiments and analysis in our study indicate that the immunobiotic TUA4408L FSM could be an interesting non-dairy functional food to beneficially modulate the intestinal immune system, improve protection against pathogens and reduce inflammatory damage. The preclinical study carried out here in pigs could have a better correlation in humans, compared to a rodent model. However, the clinical relevance of these findings still needs to be confirmed by further research, for example, in controlled human challenge studies.

The relationship between n-3 long-chain polyunsaturated fatty acids and pulse wave velocity in diabetic and non-diabetic patients under long-term hemodialysis. A horizontal study.

BACKGROUND: Diabetes mellitus (DM) and deficiency in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs) are known to increase the incidence of cardiovascular disease (CVD). However, it has not yet been reported whether n-3 LCPUFAs are related to arteriosclerosis in patients under long-term hemodialysis (HD). METHODS: Pulse wave velocity from the brachium to the ankle (baPWV) was measured as a marker of arteriosclerosis with a volume-plethysmographic apparatus in 147 long-term HD patients (non-diabetic (non-DM): 51 males/42 females, 62 +/- 14 y; and DM: 33 males/21 females, 67 +/- 9 y). The fatty acid composition of the total phospholipid fraction from washed RBCs was analyzed by gas chromatography. Analyses were adjusted for age, sex, diastolic blood pressure, pulse, body mass index, duration of HD treatment, smoking status, LDL/HDL-cholesterol ratios and diabetes mellitus (DM). RESULTS: The mean baPWV was 18.9 +/- 5.2 and 23.7 +/- 6.3 m/s in non-DM and DM patients, respectively. The mean baPWV in DM patients was significantly higher than that of non-DM patients after adjustment (p = 0.0002). Multiple regression analysis showed that there was a significant inverse association between baPWV and docosahexaenoic acid (DHA) levels (p = 0.017) and DHA/arachidonic acid (AA) ratios (p = 0.012) in RBC in non-DM patients after adjustment but not in DM patients. CONCLUSIONS: We suggest that n-3 LCPUFAs may be a negative risk factor of CVD also in non-DM HD patients. In DM patients the effects of n-3 PUFAs on the vascular system became undetectable probably because DM overwhelmingly affected PWV. Further studies in a prospective manner are necessary.

Overproduction of Th2-specific chemokines in NC/Nga mice exhibiting atopic dermatitis-like lesions.

We have examined the expression of chemokines and their receptors in the atopic dermatitis-like (AD-like) lesions of NC/Nga mice. Such lesions develop when the mice are kept in conventional conditions, but not when they are kept isolated from specific pathogens. The thymus- and activation-regulated chemokine TARC is unexpectedly highly expressed in the basal epidermis of 14-week-old mice with lesions, whereas it is not expressed in the skin without lesions. Production of TARC by keratinocytes was confirmed by culturing murine keratinocytic cell line cells (PAM212) with TNF-alpha, IFN-gamma, or IL-1beta. Expression of another Th2 chemokine, macrophage-derived chemokine (MDC), was observed in the skin from mice kept in both conventional and pathogen-free conditions, but expression of MDC was increased severalfold in the skin with lesions. The cellular origin of MDC was identified to be dermal dendritic cells. Infiltration of the skin by IL-4-producing T cells and mast cells, and the increase of CCR4 mRNA in the skin, coincided with the development of AD lesions. These observations indicate that TARC and MDC actively participate in the pathogenesis of AD-like lesions in NC/Nga mice and that these Th2 chemokines could be novel targets for intervention therapy of AD in humans.

Ghrelin enhances glucose-induced insulin secretion in scheduled meal-fed sheep.

The purpose of this study was to investigate the effects of physiologic levels of ghrelin on insulin secretion and insulin sensitivity (glucose disposal) in scheduled fed-sheep, using the hyperglycemic clamp and hyperinsulinemic euglycemic clamp respectively. Twelve castrated Suffolk rams (69.8 +/- 0.6 kg) were conditioned to be fed alfalfa hay cubes (2% of body weight) once a day. Three hours after the feeding, synthetic ovine ghrelin was intravenously administered to the animals at a rate of 0.025 and 0.05 mug/kg body weight (BW) per min for 3 h. Concomitantly, the hyperglycemic clamp or the hyperinsulinemic euglycemic clamp was carried out. In the hyperglycemic clamp, a target glucose concentration was clamped at 100 mg/100 ml above the initial level. In the hyperinsulinemic euglycemic clamp, insulin was intravenously administered to the animals for 3 h at a rate of 2 mU/kg BW per min. Basal glucose concentrations (44+/- 1 mg/dl) were maintained by variably infusing 100 mg/dl glucose solution. In both clamps, plasma ghrelin concentrations were dose-dependently elevated and maintained at a constant level within the physiologic range. Ghrelin infusions induced a significant (ANOVA; P < 0.01) increase in plasma GH concentrations. In the hyperglycemic clamp, plasma insulin levels were increased by glucose infusion and were significantly (P < 0.05) greater in ghrelin-infused animals. In the hyperinsulinemic euglycemic clamp, glucose infusion rate, an index of insulin sensitivity, was not affected by ghrelin infusion. In conclusion, the present study has demonstrated for the first time that ghrelin enhances glucose-induced insulin secretion in the ruminant animal.

Photocatalytic oxidation of low concentration 2,4-D solution with new TiO2 fiber catalyst in a continuous flow reactor.

Environmental pollution by low concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) is a concern these days due to ever increasingly stringent regulations. Photocatalysis with immobilized TiO2 fiber is a promising oxidation method. Laboratory experiments on photocatalytic degradation of 0.045 mmol l(-1) 2,4-D with the world's first high-strength TiO2 fiber catalyst were carried out in a continuous flow reactor in which the degradations were, in general, similar to those with high 2,4-D concentrations investigated elsewhere. Degradation and mineralization of 2,4-D were significantly enhanced with no initial pH adjustments. The rate constants for total organic carbon (TOC) without pH adjustment were about two-fold bigger than the pH adjustment cases. CO2 gas measurement and carbon mass-balance were carried out for the first time, where about 34% organic carbon converted into CO2 gas during four-hour oxidation. 2,4-Dichlorophenol (2,4-DCP), phenol, benzyl alcohol and two unknowns (RT = 2.65 and 3.78 min.) were detected as aromatic intermediates while Phenol was the new aromatic in HPLC analysis. Dechlorination efficiencies were high (> 70%) in all the cases, and more than 90% efficiencies were observed in chloride mass balance. Bigger flow rates and solution temperature fixed at 20 degrees C without pH adjustment greatly enhanced 2,4-D mineralization. These results can be an important basis in applying the treatment method for dioxin-contaminated water and wastewater.

Frequent allelic losses and mutations of the p53 gene in human ovarian cancer.

The p53 gene on chromosome 17p is considered to be a tumor suppressor gene, and frequent mutations of the p53 gene have been found in a wide variety of human cancers. We examined 31 ovarian cancers for allelic losses and mutations of the p53 gene by polymerase chain reaction-single strand conformation polymorphism analysis as well as restriction fragment length polymorphism analysis. Allelic loss of the p53 gene was detected in 16 of 20 cases (80%). Mutations were detected in 9 of 31 cases (29%): 2 cases in exon 4; 5 cases in exons 5-6; and 2 cases in exons 7-8. In 8 of 9 cases, p53 mutations were accompanied by losses of the normal allele. These alterations of the p53 gene were commonly detected from stage I to stage IV. These results suggest that alterations of the p53 gene play an important role in the development of human ovarian cancers.

Mechanism of cross-resistance to a camptothecin analogue (CPT-11) in a human ovarian cancer cell line selected by cisplatin.

We established a cisplatin-resistant human ovarian cancer cell line (HAC2/0.1) from the parent cell line (HAC2/P) by continuous exposure of HAC2/P to 0.1 microgram of cisplatin/ml. Drug sensitivity determined by colony assay revealed that HAC2/0.1 was 2.4 times as resistant to cisplatin as the parental cell line. HAC2/0.1 was 12.1 and 2.0 times as resistant to (4s)-4,11-diethyl-4-hydroxy-9-[(4-piperidinopiperidino)-carbony loxy]dione hydrochloride trithydrate (CPT-11) and 7-ethyl-10-hydroxy-CPT (SN-38; an active metabolite of CPT-11), respectively, than HAC2/P. We studied the mechanism of cross-resistance to CPT-11 in HAC2/0.1. The glutathione (GSH) content was higher in HAC2/0.1 than in HAC2/P. The activity of DNA topoisomerase I and the accumulation of CPT-11 and SN-38 were also the same. On the other hand, the conversion of CPT-11 to SN-38 in HAC2/0.1 was about 3-fold less than in HAC2/P. Treatment of the parent and resistant cell lines with buthionine sulfoxamine (BSO) decreased the GSH content of both cell lines and decreased the 50% inhibitory concentrations of all the tested drugs for HAC2/0.1. The accumulation of CPT-11 in HAC2/0.1 but not in HAC2/P was increased by BSO treatment. On the other hand, in HAC2/P the 50% inhibitory concentrations of SN-38 and CPT-11 were not influenced by BSO treatment. The 50% inhibitory concentration of CPT-11 for HAC2/0.1 was not reduced by BSO treatment to the level for HAC2/P, even though the GSH content had been reduced more than in HAC2/P. These results show that there is no clear relationship between GSH and resistance to CPT-11. The decreased conversion of CPT-11 to SN-38 is considered to be the main cause of resistance to CPT-11 in this cell line.

Allelic loss on chromosome 17p and p53 mutations in human endometrial carcinoma of the uterus.

To understand the involvement of allelic losses and inactivation of tumor suppressor genes for the development of endometrial carcinoma of the uterus (EC), 24 cases of EC were examined for loss of heterozygosity (LOH) using a total of 57 polymorphic DNA markers covering all 23 pairs of chromosomes. LOH was observed at 27 loci on 10 different chromosomes, i.e., chromosomes 1, 3, 6, 11, 13, 15, 17, 18, 20, and 21, but was not detected at loci on chromosomes 4, 5, 7, 9, 10, 12, 14, 16, and X. It was observed only in seven of 24 cases, and the other 19 cases did not show LOH at any loci examined, including five cases of tumors with a high proportion of adenomatous hyperplasia. Among seven tumors with LOH at one or more loci, five tumors showed LOH at loci on the short arm of chromosome 17. Furthermore, mutations of the p53 gene, which is located on the short arm of chromosome 17, were detected in three of these 24 tumors by a polymerase chain reaction-single strand conformation polymorphism analysis and subsequent DNA sequencing. In two of these three tumors, p53 mutations were accompanied by the loss of wild-type p53 alleles. These results suggest that inactivation of the p53 gene is involved in the development of EC as in the case of several other types of human cancers.

CA54/61 as a marker for epithelial ovarian cancer.

Using a new one-step, double-determinant enzyme immunoassay, we performed quantitative measurements of a mucin-type glycoprotein antigen (CA54/61) that we recently detected in sera of ovarian carcinoma patients. When the cutoff value was set at 12 units/ml, at which a high diagnostic efficiency was demonstrated [or at 20 units/ml (mean + 3 SD of healthy females)], the positive rates of ovarian serous, mucinous, clear cell, and endometrioid carcinomas were 76% (or 63%), 63% (or 55%), 57% (or 52%), and 50% (or 38%), respectively. Even in mucinous cystadenocarcinoma, more than one-half of the cases were positive, indicating the potential utility of the assay in the diagnosis of mucinous tumors. In sera from patients with benign ovarian tumors, only 9% (or 4%) of the cases were positive, indicating the quite high specificity of this test for ovarian carcinomas. To make a comparison between CA54/61 and CA125, we set the cutoff level of CA125 at 110 units/ml, at which value a high diagnostic efficiency was demonstrated [or at 35 units/ml (mean + 3 SD of healthy females)]. When both CA54/61 and CA125 were assessed in sera from 36 patients with mucinous cystadenocarcinoma, the positive rates of CA54/61 and CA125 were 64% (or 56%) and 36% (or 56%), respectively, suggesting that CA54/61 is of clinical value as a new tumor marker for ovarian cancers, including mucinous tumors.

Mutation of the Ki-ras protooncogene in human endometrial hyperplasia and carcinoma.

Previous studies have demonstrated that some human endometrial carcinomas contain an activating point mutation in codon 12 of the Ki-ras protooncogene. To examine the hypothesis that this mutation may occur at an earlier stage of neoplastic progression in the endometrium, we analyzed 89 samples of premalignant endometrial hyperplasia and an additional 84 samples of endometrial carcinoma for point mutations of Ki-ras codon 12. Mutations were found in all three types of endometrial hyperplasia, simple, complex, and atypical, with no clear evidence of a differential distribution in any particular type. Furthermore, the overall incidence of Ki-ras mutations in the hyperplasia specimens (16%) was similar to the incidence detected in carcinomas (18%), indicating that ras mutation may represent an early event in a subset of endometrial carcinomas. When the tissue samples were segregated as to country of origin, the frequency of this mutation was approximately 2-fold higher in hyperplasia and carcinoma samples from Japan than from the United States, where the incidence, clinicopathological characteristics, and risk factors for endometrial carcinoma differ dramatically. There was no apparent correlation, however, between ras mutation and any pathological, histological, or clinical parameter examined, except survival. The presence of a ras mutation was inversely associated with death from disease, suggesting that this molecular feature may characterize a subset of endometrial carcinomas with a good prognosis.

Attenuation of pain behaviour by local administration of alpha-2 adrenoceptor antagonists to dorsal root ganglia in a rat radiculopathy model.

BACKGROUND: There were several reports suggesting α-adrenoceptor antagonists are effective to treat neuropathic pain. The aims of this study were as follows: (1) to introduce drug delivery system for dorsal root ganglion (DRG) neurons; (2) to elucidate the effects of α-adrenoceptor antagonists in acute, subacute or chronic phase and (3) to determine which subtype of adrenoceptor was mainly involved. METHOD: We used 130 male Sprague-Dawley rats. After root constriction, rats received three local injections of α-adrenoceptor antagonists around DRG. We administered the non-selective α-adrenoceptor antagonist phentolamine for 3 consecutive days from day 0, 4 or 11 after the surgery, and the α1-adrenoceptor antagonist prazosin, the α1-adrenoceptor antagonist silodosin, the more preferred α1-adrenoceptor than prazosin and the α2-adrenoceptor antagonist yohimbine for 3 consecutive days from day 0 after the surgery. RESULTS: Phentolamine and yohimbine continually attenuated pain behaviour. Prazosin at high dose attenuated pain behaviour, however, prazosin at low dose did not attenuate pain behaviour every experimental day. Silodosin had no analgesic effect. Phentolamine injections from day 4 after surgery attenuated pain behaviour that had been established on the 3rd experimental day until the 28th post-operative day, although effect of phentolamine wore off. Phentolamine injections from day 11 after surgery temporarily attenuated pain behaviour that had been established on the 3rd, 7th and 10th experimental days. CONCLUSIONS: This study showed α-adrenoceptor antagonists could suppress pain behaviour via α2-adrenoceptor in acute phase and temporary attenuate pain behaviour in chronic phase. These findings presented potentials sympathetic nerve blockade contributed to treat neuropathic pain.

Changes in expression of the genes for the leptin receptor and the growth hormone-releasing peptide/ghrelin receptor in the hypothalamic arcuate nucleus with long-term manipulation of adiposity by dietary means.

Changes in leptin and ghrelin levels occur with alterations in adiposity, but signalling may be affected by levels of the relevant receptors. We measured expression of the leptin receptor (Ob-Rb) and the ghrelin/growth hormone releasing peptide receptor (GHS-R) in the arcuate nucleus of sheep held at either high or low levels of adiposity. Plasma growth hormone (GH) levels were lower in Fat animals and higher in Lean animals. Plasma insulin and leptin levels were higher in Fat animals and lower in Lean animals. Frozen hypothalamic sections of arcuate nucleus were extracted and mRNA levels measured for mRNA for Ob-Rb and GHS-R. Gene expression for both Ob-Rb and GHS-R was higher in Lean animals than in Fat animals, with no difference in expression between Fat and Normal animals. A second group of animals (n = 4 per group) was used for double-labelling immunohistochemistry to determine whether the increase in Ob-Rb gene expression was translated into Ob-Rb protein and to ascertain whether this effect is localised to the cells of the arcuate nucleus that produce either neuropeptide Y (NPY) and/or pro-opiomelanocortin-derived peptides. Lean animals displayed a 255% increase in immunoreactive NPY cells (P < 0.005), a 167% increase in cells with Ob-Rb (P < 0.037) protein and a 344% increase in cells that were staining for both NPY and Ob-Rb (P < 0.02). There was no difference between the Normal and Lean animals in the number of cells that were detected with an adrenocorticotrophic hormone (ACTH) antibody or the number of ACTH-immunoreactive cells that also stained for Ob-Rb. Finally, we measured plasma ghrelin levels in Normal, Fat and Lean ewes (n = 4/group); levels were higher (P < 0.05) in Fat animals than in Lean animals. We conclude that lowering body weight leads to increased expression of Ob-Rb, ghrelin/GHS-R expression and proportion of NPY cells that express Ob-Rb in the arcuate nucleus. This may be an adaptive mechanism to increase responsivity to both leptin and ghrelin.

Dramatic decrease of circulating levels of monocyte chemoattractant protein-1 in Kawasaki disease after gamma globulin treatment.

Kawasaki disease (KD) is a systemic vasculitis preferentially affecting coronary arteries. Extensive monocytes/macrophages infiltrate in the vascular lesions, implying the involvement of a chemotactic cytokine in their recruitment. We investigated the role of monocyte chemoattractant protein-1 (MCP-1, also termed monocyte chemotactic and activating factor) in KD. In the immunohistochemical studies using the cardiac tissues of patients with fatal KD, MCP-1 but not interleukin (IL) -8 or macrophage inflammatory protein-1alpha was localized at the extracellular matrix associated with mononuclear cellular infiltration. The sites of MCP-1 expression correlated with the distribution of the acute inflammation, including early coronary vasculitis. In prospectively studied patients with KD, circulating levels of MCP-1, IL-8, tumor necrosis factor alpha (TNF-alpha), and IL-1alpha were elevated in 73, 77, 57, and 0% of samples before gamma globulin (GG) treatment (400 mg/kg x 5 days = total 2 g/kg), respectively, compared with respective control values. GG treatment correlated with a rapid decrease in the circulating levels of MCP-1 (P = 0.001) but not IL-8 (P = 0.19) or TNF-alpha (P = 0.33). In the sensitive Western blotting, MCP-1 bound to GG. Furthermore, GG inhibited the MCP-1-induced Ca2+ influx in a human monocytic cell line in vitro. These findings suggest a role of MCP-1 in KD, and indicate that GG treatment may block MCP-1 activity, thus alleviating KD vasculitis.

GH secretory responses to ghrelin and GHRH in growing and lactating dairy cattle.

Release of growth hormone (GH) is known to be regulated mainly by GH-releasing hormone (GHRH) and somatostatin (SRIF) secreted from the hypothalamus. A novel peripheral release-regulating hormone, ghrelin, was recently identified. In this study, differences of the GH secretory response to ghrelin and GHRH in growing and lactating dairy cattle were investigated and an alteration of plasma ghrelin levels was observed. The same amounts of ghrelin and GHRH (0.3 nmol/kg) were intravenously injected to suckling and weanling calves, early and mid-lactating cows and non-lactating cows. Plasma ghrelin levels were also determined in dairy cattle in various physiological conditions. The peak values of ghrelin-induced GH secretion were increased in early lactating cows compared to those in non-lactating cows. The relative responsiveness of GH secretion to ghrelin was also increased compared with that to GHRH in early lactating cows. GH secretory responses to GHRH were blunted in mature cows with and without lactation. Conversely, GHRH-induced GH secretory response was greater than that to ghrelin in calves, and also greater in calves than in mature cows. Plasma ghrelin concentrations were elevated in early lactating cows compared to those in non-lactating cows. Plasma GH concentrations were higher in suckling calves and early lactating cows compared with those in non-lactating cows. These results suggest that GHRH is an effective inducer of GH release in growing calves, and that the relative importance of ghrelin in contributing to the rise in plasma GH increases in early lactating cows.

An anti-inflammatory drug, propagermanium, may target GPI-anchored proteins associated with an MCP-1 receptor, CCR2.

Monocyte chemoattractant protein-1 (MCP-1) promotes the migration and activation of monocytes and plays a pivotal role in the development of chronic inflammation. Propagermanium (3-oxygermylpropionic acid polymer) has been used as a therapeutic agent against chronic hepatitis B in Japan. We report here that propagermanium specifically inhibits in vitro chemotactic migration of monocytes by MCP-1. Propagermanium did not inhibit binding of MCP-1 to a human monocytic cell line, THP-1 cells, or affect intracellular Ca(2+) mobilization or the cAMP concentration in MCP-1-treated THP-1 cells. The effect of propagermanium seems to require glycosylphosphatidylinositol (GPI)-anchored proteins, as cleavage of GPI anchors by phosphatidylinositol-phospholipase C (PI-PLC) eliminated the inhibitory activity of propagermanium. Anti-GPI-anchored protein antibodies, such as anti-CD55 and anti-CD59, reduced staining of C-C chemokine receptor 2 (CCR2) with an anti-CCR2 antibody against the N-terminus of CCR2 in a flow cytometric analysis, and these antibodies also selectively inhibited MCP-1-induced migration of THP-1 cells. Furthermore, under fluorescence microscopy, GPI-anchored proteins colocalized with CCR2 on THP-1 cells. These results suggest that propagermanium may target GPI-anchored proteins that are closely associated with CCR2 to selectively inhibit the MCP-1-induced chemotaxis, thus providing a mechanistic basis for the anti-inflammatory effects of the drug.

Influence of acute elevation of plasma AVP level on rat vasopressin V2 receptor and aquaporin-2 mRNA expression.

It is known that vasopressin V2 receptor (V2R) mRNA is downregulated by elevated plasma arginine vasopressin (AVP) following chronic osmotic stimulation. To elucidate the response in V2R mRNA expression to acute elevation of the plasma AVP level, we investigated the time-course change of rat V2R mRNA expression after subcutaneous injection of AVP (10 microg/body). Plasma AVP levels increased from 1.4+/-0.3 pg/ml to 56.8+/-10.7 pg/ml by an hour after injection,and returned to the control level at 6 h. By Northern blotanalysis, V2R mRNA expression decreased to 52.7+/-3.7% of the control level at 2 h, and then returned to the control level by 6 h. Furthermore we investigated the time-course change of aquaporin-2 (AQP2) mRNA expression. AQP2 mRNA expression increased gradually after injection and reached 240.3+/-7.5% of the control level at 6 h. Then it returned to the control level. This study showed that the downregulation of V2R mRNA occurred rapidly after acute elevation of the plasma AVP level, and AQP2 mRNA expression was upregulated despite the downregulation of V2R mRNA.