The Vitamin D3 analogue calcipotriol suppresses CpG-activated TLR9-MyD88 signalling in murine plasmacytoid dendritic cells.

BACKGROUND: Plasmacytoid dendritic cells (pDCs) are involved in the pathogenesis of psoriasis by secreting interferon-α. Vitamin D3 analogues are widely used to treat psoriasis, and the representative analogue calcipotriol (CAL) uniquely downregulates the cytokine production and chemotactic activity of pDCs. However, the molecular mechanism of action of CAL is not well understood. AIM: To investigate effects of CAL on the Toll-like receptor 9-myeloid differentiation primary response gene 88 (TLR9-MyD88) signalling pathway, which induces cytokine production, in murine pDCs. METHODS: pDCs were isolated from mouse spleen cells by negative selection or were generated from mouse bone-marrow cells, and were stimulated with CpG-oligodeoxynucleotide (ODN) with or without CAL for 24 h. mRNA expression of TLR9 and MyD88 was assessed by real-time PCR, and the amount of TLR9 was measured by western blotting. RESULTS: CAL suppressed the CpG-ODN-induced increased expression of MyD88 and TLR9 in pDCs. CONCLUSIONS: CAL may downregulate pDCs by inhibiting TLR9-MyD88 signalling.

Randomised phase II trial of S-1 plus oxaliplatin vs S-1 in patients with gemcitabine-refractory pancreatic cancer.

BACKGROUND: This randomised, open-label, multicenter phase II study compared progression-free survival (PFS) of S-1 plus oxaliplatin (SOX) with that of S-1 alone in patients with gemcitabine-refractory pancreatic cancer. METHODS: Patients with confirmed progressive disease following the first-line treatment with a gemcitabine-based regimen were randomised to receive either S-1 (80/100/120 mg day(-1) based on body surface area (BSA), orally, days 1-28, every 6 weeks) or SOX (S-1 80/100/120 mg day(-1) based on BSA, orally, days 1-14, plus oxaliplatin 100 mg m(-2), intravenously, day 1, every 3 weeks). The primary end point was PFS. RESULTS: Between January 2009 and July 2010, 271 patients were randomly allocated to either S-1 (n=135) or SOX (n=136). Median PFS for S-1 and SOX were 2.8 and 3.0 months, respectively (hazard ratio (HR)=0.84; 95% confidence interval (CI), 0.65-1.08; stratified log-rank test P=0.18). Median overall survival (OS) was 6.9 vs 7.4 months (HR=1.03; 95% CI, 0.79-1.34; stratified log-rank test P=0.82). The response rate (RR) was 11.5% vs 20.9% (P=0.04). The major grade 3/4 toxicities (S-1 and SOX) were neutropenia (11.4% and 8.1%), thrombocytopenia (4.5% and 10.3%) and anorexia (12.9% and 14.7%). CONCLUSIONS: Although SOX showed an advantage in RR, it provided no significant improvement in PFS or OS compared with S-1 alone.

Gemcitabine alone or in combination with cisplatin in patients with biliary tract cancer: a comparative multicentre study in Japan.

BACKGROUND: A British randomised study of gemcitabine plus cisplatin (GC) combination showed promising results in biliary tract cancer (BTC) patients. In our study, we evaluated the efficacy and safety of this combination compared with gemcitabine alone (G) in Japanese BTC patients. METHODS: Overall, 84 advanced BTC patients were randomised to either cisplatin 25 mg m(-2) plus gemcitabine 1000 mg m(-2) on days 1, 8 of a 21-day cycle (GC-arm), or single-agent gemcitabine 1000 mg m(-2) on days 1, 8 and 15 of a 28-day cycle (G-arm). Treatments were repeated for at least 12 weeks until disease progression or unacceptable toxicity occurred, up to a maximum of 48 weeks. RESULTS: A total of 83 patients were included in the analysis. For the GC and G-arms, respectively, the 1-year survival rate was 39.0 vs 31.0%, median survival time 11.2 vs 7.7 months, median progression-free survival time 5.8 vs 3.7 months and overall response rate 19.5 vs 11.9%. The most common grade 3 or 4 toxicities (GC-arm/G-arm) were neutropenia (56.1%/38.1%), thrombocytopenia (39.0%/7.1%), leukopenia (29.3%/19.0%), haemoglobin decrease (36.6%/16.7%) and gamma-GTP increase (29.3%/35.7%). CONCLUSIONS: Gemcitabine plus cisplatin combination therapy was found to be effective and well tolerated, suggesting that it could also be a standard regimen for Japanese patients.

Updated results from GEST study: a randomized, three-arm phase III study for advanced pancreatic cancer.

PURPOSE: The GEST study showed non-inferiority of S-1 but not superiority of gemcitabine plus S-1 (GS) to gemcitabine alone for overall survival with the data by the cut-off date of 31st July in 2010 for chemo-naïve patients with advanced pancreatic cancer. We considered it important to determine whether S-1 maintains non-inferiority after a long-term follow-up in the GEST study and to obtain a firm positive conclusion. In addition, it may be an interesting challenge to explore the efficacious profile of GS in the long-term follow-up study. Using the data from the follow-up period, background and efficacy in patients from Taiwan and Japan, as well as the rates of tumor shrinkage in locally advanced and metastatic patients (Waterfall plot) were also analyzed. METHODS: The results of the primary analysis were reconfirmed, and subset analysis of overall survival and progression-free survival was performed based on the overall survival data updated by the cut-off date of 31st July in 2011. RESULTS: The median follow-up period was 29.8 months, and 795 deaths occurred (95.6%). The median overall survival was 8.8 months for gemcitabine, 9.7 months for S-1 (hazard ratio [HR], 0.96; 97.5% confidence interval [CI], 0.79-1.17), and 9.9 months for GS (HR 0.91; 97.5% CI 0.75-1.11). In patients with performance status (PS) 0, the median overall survival was 9.8 months for gemcitabine, 10.9 months for S-1, and 10.5 months for GS. In patients with PS 1, the median overall survival was 6.2 months for gemcitabine, 6.3 months for S-1, and 9.6 months for GS. CONCLUSION: Our survey reconfirmed the non-inferiority of S-1 to gemcitabine and showed S-1 can be used as one of the standard treatment options for advanced pancreatic cancer. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00498225.

Identification of insulin variants in patients with hyperinsulinemia by reversed-phase, high-performance liquid chromatography.

We have characterized the molecular forms of circulating insulins in patients with hyperinsulinemia of diverse etiology. We have also compared the efficacy of various chromatographic conditions using reversed-phase (RP) HPLC. Using 0.2% trifluoroacetic acid (TFA) and triethylamine (TEA) with acetonitrile as the organic modifier, at an elution rate of 0.17%/min, porcine, bovine, and human insulins could be easily separated as well as abnormal insulins in the plasma of a patient (J.R.) with hyperinsulinemia of unknown etiology. When the reversed-phase C18 column was changed and a gradient of 0.33%/min was used, the abnormal insulin in patient J.R. could not be separated. By changing the solvent system to acetonitrile and isopropanol (vol:vol, 3:1) containing 0.1% TFA, omitting the TEA, and using a gentle gradient of 0.1%/min, various semisynthetic analogues of human insulin could be easily separated and the abnormal insulin could be identified in the plasma of the patient J.R. Abnormal insulin was also found in a patient with MEN-I, but in contrast, the insulins in eight patients with benign sporadic insulinomas appeared to be normal. These results suggest that certain hyperinsulinemic states may be associated with an abnormal insulin and that RP-HPLC is useful for identification of insulin variants in the circulation. However, the conditions of RP-HPLC may be critical if the abnormalities of the insulin are subtle.

Long term inhibitory effects of pancreastatin and diazepam binding inhibitor on pancreatic beta-cell deoxyribonucleic acid replication, polyamine content, and insulin secretion.

The two peptides pancreastatin and diazepam binding inhibitor (DBI) were recently demonstrated in pancreatic islets and were shown to inhibit insulin secretion in short term experiments. In the present study we investigated long term effects of pancreastatin and DBI on the DNA synthesis, polyamine content, and insulin secretion of pancreatic beta-cells in tissue culture. For this purpose fetal rat pancreatic islets enriched in beta-cells were isolated and cultured for 3 days at different concentrations of rat pancreastatin and porcine DBI. It was found that pancreastatin dose-dependently decreased beta-cell DNA synthesis, reaching maximal inhibition at 100 nM. In parallel with this, pancreastatin also decreased insulin secretion and the islet contents of insulin and the polyamines spermidine and spermine. These effects were abolished by a high glucose concentration or addition of GH. Also, DBI evoked a dose-dependent inhibition of beta-cell DNA synthesis but affected neither the islet contents of insulin or polyamines nor insulin secretion. Like pancreastatin, DBI was ineffective in preventing the increased beta-cell DNA synthesis, insulin content, or secretion in response to high glucose or GH. It is concluded that pancreastatin and DBI inhibit beta-cell DNA synthesis and function in vitro. In the case of pancreastatin these inhibitory effects may be mediated by a decrease in islet polyamine content. It is suggested that pancreastatin and DBI may influence beta-cell replication and function in vivo in an autocrine or paracrine fashion.

Evidence for modulation of motilin secretion by pancreatico-biliary juice in health and in chronic pancreatitis.

The gut hormone motilin can initiate the interdigestive migrating motor complex. There are synchronous cyclic changes in plasma motilin-like immunoreactivity (MLI) levels and pancreatico-biliary secretion during the interdigestive period which may be causally related. The purpose of this study was to investigate the role of pancreatico-biliary secretion into the gut as a modulator of plasma MLI concentrations. In six healthy subjects, the mean basal plasma MLI level was 130 +/- 16 pg/ml. Infusion of cholecystokinin octapeptide (CCK-8) stimulated MLI secretion, with an integrated (30 min) response of 2028 +/- 340 pg/min X ml. Intraduodenal perfusion of pancreatico-biliary juice produced a similar increase in plasma MLI, with a 30 min integrated response of 2190 +/- 270 pg/min X ml. Neither enzyme activity, osmolarity, or pH accounted for the response. In six patients with exocrine pancreatic insufficiency, although their mean basal plasma MLI concentration of 205 +/- 44 pg/ml was significantly higher than that observed in healthy subjects, there was no significant plasma MLI increase after CCK-8 infusion. Pancreatic exocrine secretion was severely compromised in these patients, as evidenced by the markedly reduced peak lipase (3.8 +/- 0.6 kU/h) and trypsin (2.4 +/- 0.5 kU/h) outputs. In contrast, infusion of pancreatico-biliary juice obtained from healthy subjects caused a rise in plasma MLI, with a 60 min integrated response of 3912 +/- 1031 pg/min X ml, which was similar to that of 3947 +/- 472 pg/min X ml in healthy subjects. We conclude that there is an undefined factor in pancreatico-biliary juice that stimulates MLI release. A deficiency of pancreatic exocrine secretion may be responsible for the impaired MLI response to CCK-8 stimulation in chronic pancreatitis. Since MLI is known to initiate the formation of the interdigestive migrating motor complexes, diminished motilin release secondary to pancreatic exocrine deficiency may result in disordered gastrointestinal motor activity in patients with chronic pancreatitis.

Evidence for cholinergic and vagal noncholinergic mechanisms modulating plasma motilin-like immunoreactivity.

Basal concentrations of plasma motilin-like immunoreactivity (MLI) and responses to insulin-induced hypoglycemia were measured in healthy subjects (n = 13) in diabetics with clinical evidence of autonomic neuropathy (AN; n = 7), in diabetics without AN (n = 9), and in five recently (6--12 months) vagotomized subjects. Mean basal MLI concentrations were similar in the healthy subjects (141 +/- 21.5 pg/ml) and diabetics without AN (124 +/- 22.4 pg/ml), but were significantly higher in diabetics with AN (349 +/- 71.5 pg/ml) and in vagotomized subjects (381 +/- 47.6 pg/ml). In both healthy subjects and diabetics without AN, the acute administration of insulin (0.1--0.2 U/kg) caused a fall in the mean MLI concentration, reaching a nadir within 20 min, returning to the basal concentration by 60 min, and rising above basal levels by 90 min. In diabetics with AN and vagotomized subjects, the fall in MLI persisted for 90 min. Intravenous atropine administered 15 min after the insulin injection in healthy subjects did not impair the return to basal. The responses were not related to the degree of hypoglycemia, the absolute or relative fall in blood glucose concentrations, or differences in blood glucose among healthy subjects, diabetics, or vagotomized subjects. It appears, therefore, that insulin lowers plasma MLI levels, which are restored to basal by a vagal noncholinergic mechanism. Furthermore, the vagus exerts a suppressive effect on basal MLI levels, and vagotomy and diabetic autovagotomy are associated with abnormal elevation of MLI levels. Since motilin is thought to be important in interdigestive intestinal motility, abnormalities in MLI secretion in diabetics with autonomic neuropathy may contribute to gastrointestinal stasis and erratic diabetic control.

In vitro study of cultured human insulinoma cells: evidence of abnormal sensitivity to glucose.

Human insulinoma cells were isolated and cultured in vitro, and their functional and morphological characteristics were determined. The cells, isolated as single cells or small cell clusters, reaggregated to almost the size of islets by the fifth culture day and were maintained in vitro for more than 1 month. Morphologically (light and electron microscopies) they were intact throughout the culture period. Immunohistochemically more than 50% of the cells in each reaggregate contained insulin. Incubation experiments revealed that a low glucose concentration (15 mg/dL) was sufficient to produce maximal insulin release. In the absence of glucose, 1 microgram/mL glibenclamide increased insulin release. On the other hand, 5 mM theophylline and 10 mM arginine did not alter insulin release significantly. Theophylline, arginine, and glibenclamide did not have any stimulatory effect on insulin release in the presence of 50 mg/dL glucose. Perifusion experiments with 50 mg/dL glucose disclosed a biphasic pattern of insulin release, and no significant change in insulin release occurred when the glucose concentration in the perifusate was switched from 50 to 150 and then back to 50 mg/dL. These findings demonstrate that human insulinoma cells can be isolated and maintained in vitro and that the cells have abnormal sensitivity to glucose.

Acetylcholine regulates pancreastatin secretion from the human pancreastatin-producing cell line (QGP-1N).

Studies were made of pancreastatin (PST) secretion from a human PST-producing cell line (QGP-1N) in response to various secretagogues. Cells with immunoreactivity for PST were observed in monolayer cultures of QGP-1N cells. Carbachol stimulated PST secretion and the intracellular Ca2+ mobilization concentration dependently in the range of 10(-6)-10(-4) M. The PST secretion and Ca2+ mobilization induced by carbachol were inhibited by atropine. The calcium ionophore (A23187) stimulated PST secretion. However, cholecystokinin and gastrin-releasing peptide did not stimulate either PST secretion or Ca2+ mobilization. Secretin also did not stimulate PST secretion. The glucose concentration in the culture medium had no effect on PST secretion. These results suggest that PST secretion is mainly regulated by acetylcholine through a muscarinic receptor, and that an increase in intracellular Ca2+ plays an important role in stimulus-secretion coupling in QGP-1N cells.

Pancreastatin-like immunoreactivity in urine.

The concentration and molecular form of pancreastatin-like immunoreactivity (PST-LI) in urine of normal subjects and patients with noninsulin-dependent diabetes mellitus or chronic renal failure were examined. PST-LI output (mean +/- SEM) in urine of normal subjects was 74.6 +/- 8.5 pmol/day and 87.1 +/- 11.7 pmol/g creatinine. That in patients with noninsulin-dependent diabetes mellitus was 78.1 +/- 9.0 (SEM) pmol/day and 85.6 +/- 9.0 pmol/g creatinine and was not significantly different from that in normal subjects. Gel filtration analysis showed that PST-LI molecules excreted in urine of these two groups were smaller than human pancreastatin (43-52) (hPST-10) of C-terminal fragment. The PST-LI molecular forms were deduced to be nonbioactive from the result that hPST-10 did not inhibit pancreatic exocrine secretion. PST-LI excretion in patients with chronic renal failure was 258.5 +/- 62.9 pmol/day and 713.2 +/- 219.6 pmol/g creatinine. A molecular form corresponding to hPST-52 and a larger form eluted in the high mol wt region (approximately mol wt 15 K) were detected by gel filtration of urine from these patients, indicating that PST-LI is excreted in urine without degradation in patients with chronic renal failure. These results support the suggestion that the kidney may play an important role in PST degradation or metabolism.

Familial hyperinsulinemia associated with secretion of an abnormal insulin, and coexistence of insulin resistance in the propositus.

A 45-yr-old muscular nonobese white man who had a 9-yr history of syncopal episodes was studied on several occasions between April 1979 and August 1984. Fasting glucose concentrations ranged between 74-115 mg/dl, and those of insulin ranged between 14-64 microU/ml. Reactive hypoglycemia 3-4 h after ingestion of glucose occurred in the first 2 yr. Glucose tolerance was impaired in 1979, from February 1982 through September 1983, and again in August 1984. The maximum plasma insulin response to glucose ranged between 475-1630 microU/ml. When studied in November 1982, insulin (0.1 U/kg) caused a fall in blood glucose concentration of only 25% (normal, greater than 50%), and maximal glucose utilization during the euglycemic hyperinsulinemic clamp was 7.5 mg/kg . min (normal, greater than 12 mg/kg . min). Plasma counterregulatory hormone concentrations were normal, and antibodies to insulin and the insulin receptor were absent. Binding of exogenous insulin to the patient's cellular receptors (monocytes, red blood cells, and skin fibroblasts) was normal. Insulin was purified from plasma by immunoaffinity and molecular sieve chromatography and was found to elute later than human insulin on reversed phase high performance liquid chromatography. It was more hydrophobic than normal human insulin and had only 10% of the activity of normal insulin in terms of ability to bind to and stimulate glucose metabolism in isolated rat adipocytes. The abnormal insulin was identified in two of three sons and a sister, but not in the mother, brother, or niece. Sensitivity to insulin was normal in the two sons who had abnormal insulin. These results suggest that in this family the abnormal insulin was due to a biosynthetic defect, inherited as an autosomal dominant trait. The hyperinsulinemia was not associated with diabetes in family members who had no insulin resistance.

Plasma pancreastatin-like immunoreactivity in various diseases.

Plasma pancreastatin (PST)-like immunoreactivity in normal subjects and patients with various diseases was estimated by a RIA, using antiserum raised against a synthetic C-terminal peptide of human PST deduced from the sequence of human chromogranin-A. The mean level +/- SEM was 13.2 +/- 0.6 pmol/L in normal subjects, but was significantly higher in patients with chronic renal failure (526.7 +/- 48.5). An immunoreactive form corresponding to a human PST-like sequence [human chromogranin-A-(250-301)] and a larger form were detected by gel filtration of plasma from these patients, suggesting accumulation of the larger molecular form in these patients. A significant increase in PST-like immunoreactivity was also found in patients with liver cirrhosis (20.8 +/- 3.0 pmol/L), but not in patients with noninsulin-dependent diabetes mellitus, chronic pancreatitis, or pancreatic cancer. Elevated levels were found in 16 of the 21 patients with small cell lung carcinoma examined. High levels were also found in 3 of 11 patients with islet cell tumor.

The human pancreatitis-associated protein (PAP)-encoding gene generates multiple transcripts through alternative use of 5' exons.

The nucleotide (nt) sequence of the human cDNA encoding PAP, a pancreatic secretory protein induced during acute pancreatitis, was found to be identical with that of a gene activated in human primary hepatocellular cancer, designated HIP. To obtain insight into the expression of PAP/HIP, we characterized the gene organization, especially focusing on the 5'-flanking region, and found that it spans about 3 kb and is composed of six exon. Exon 1 encodes the 5'-noncoding sequence and exon 2 consists of three miniexons, 2a, 2b and 2c; the common exon 2c encodes the sequence including the start codon. Analysis by RT-PCR revealed the presence of at least three different types 5'-ends of human PAP/HIP transcripts which were derived from alternative use of 5'-exons. Although all three types of transcripts were expressed in both normal small intestine and pancreas, their gene expression was increased ectopically in gastric cancer, hepatocellular cancer and pancreatic acinar cell carcinoma. Furthermore, significant differences among the transcript types were detected between normal and tumor tissues, and especially between gastric and hepatocellular cancers, suggesting that PAP/HIP expression may vary with differences in 5'-alternative splicing.

Mouse cholecystokinin type-A receptor gene and its structural analysis.

The mouse cholecystokinin type-A receptor (CCK(A)R) gene was cloned and sequenced, and the exon/intron boundaries were determined by cDNA cloning. The gene, approximately 10 kb in length, contains the entire coding region, and consists of five exons. The deduced amino acid sequence was homologous with that of other species, with the exception of an additional DNA sequence encoding 7 amino acids in exon 5. A region of the 5' end of exon 2 appeared to be alternatively spliced, and generated an isoform shorter by 52 bases. The shorter isoform may encode an 48 amino acid open reading frame due to frameshift of translation. These two mRNA isoforms were expressed equally in the mouse gallbladders.

Disrupted cholecystokinin type-A receptor (CCKAR) gene in OLETF rats.

OLETF rats develop hyperglycemia, hyperinsulinemia and mild obesity, which is characteristic of human non-insulin-dependent diabetes mellitus (NIDDM). We cloned and sequenced the cholecystokinin type-A receptor (CCKAR) gene in the rats. Comparing the DNA sequences of the OLETF CCKAR gene and LETO CCKAR gene, normal gene, we found a deletion in the OLETF gene, 6847 bases in length, which was flanked by two 3-base-pair direct repeats (5'-TGT-3') at positions -2407/-2405 and 4441/4443, numbered according to the LETO gene sequence, one of which was lost. The promoter region, the first and second exons were missing in the mutant. The region upstream and downstream of the deletion, including exons 3, 4 and 5, was conserved between the two strains, and did not contain any base changes. We found that the gene mapped to chromosome 14 in rats. OLETF rats are the naturally occurring knockout animals with the homozygously disrupted CCKAR gene.

The importance of the C-terminal amide structure of rat pancreastatin to inhibit pancreatic exocrine secretion.

A C-terminal fragment of rat pancreatatin, a 26 residue peptide amide and a fragment without a C-terminal amide were synthesized by Fmoc-based solid phase methods and their biological activities were compared. The rat C-terminal fragment inhibited pancreatic exocrine secretions produced by the intravenous injection of 2-deoxy-D-glucose (a central vagal nerve stimulation), whereas the fragment without a C-terminal amide showed no effect on pancreas. These results indicate that the C-terminal amide of this peptide is necessary to reveal its biological activity.

Gene structure of human cholecystokinin (CCK) type-A receptor: body fat content is related to CCK type-A receptor gene promoter polymorphism.

The transcriptional start site of the human cholecystokinin (CCK)-A receptor gene was determined by the Capsite Hunting method. Two sequence changes were detected, a G to T change in nucleotide -128, and an A to G change in nucleotide -81. The homozygote (T/T, G/G) was detected in 25 of 1296 individuals (1.9%) in the cohort study. This polymorphism showed a significantly higher percent body fat and higher levels of serum insulin and leptin, compared with wild type and heterozygotes. Our study provided the possibility that polymorphism in the promoter region of the CCK-A receptor gene may be one of genetic factors affecting fat deposition.

Plasma cholecystokinin and pancreatic polypeptide responses after ingestion of a liquid test meal rich in medium-chain fatty acids in patients with chronic pancreatitis.

Plasma cholecystokinin (CCK) and human pancreatic polypeptide (hPP) responses after ingestion of a liquid test meal rich in medium-chain fatty acids (MCFA) were studied in patients with chronic pancreatitis with or without diabetes mellitus (DM). Integrated response of plasma CCK was significantly lower in patients with chronic pancreatitis and DM than in the two other groups. There was no statistically significant difference between the healthy control subjects and the patients with chronic pancreatitis without DM in the integrated responses of hPP and plasma CCK. These results indicate that diabetic patients with a greatly destroyed pancreas do not release as much CCK as do nondiabetic patients with a mildly impaired pancreas. An MCFA meal is therefore considered safe in patients with a mildly impaired pancreas. For diabetic patients, however, care should be taken not to exacerbate the DM.

Lymphatic lipid transport is not impaired in ageing rat intestine.

Lymphatic lipid transport in the intestine of adult and ageing rats was compared. Adult (8-10 months old) and old (24-26 months old) male Wistar rats were cannulated into the mesenteric lymph under ethrane anesthesia. On the following day, lipid emulsion containing 35.4 mg/h of olive oil was infused intraduodenally for 7 h and lymph collected hourly was assayed for triglyceride and apolipoprotein A-IV (apo A-IV). The results showed there was no difference in lymphatic lipid and apo A-IV transport between adult and old rats. Since apo A-IV synthesis in the enterocytes is linked to the intracellular assembly of lipoprotein, it is likely that in addition to lymphatic transport, production of chylomicrons is not impaired in ageing rats.