Mechanisms of polyamine catabolism-induced acute pancreatitis

Abstract Acute pancreatitis is an autodigestive disease, in which the pancreatic tissue is damaged by the digestive enzymes produced by the acinar cells. Among the tissues in the mammalian body, pancreas has the highest concentration of the natural polyamine, spermidine. We have found that pancreas is very sensitive to acute decreases in the concentrations of the higher polyamines, spermidine and spermine. Activation of polyamine catabolism in transgenic rats overexpressing SSAT (spermidine/spermine-N 1 -acetyltransferase) in the pancreas leads to rapid depletion of these polyamines and to acute necrotizing pancreatitis. Replacement of the natural polyamines with methylated polyamine analogues before the induction of acute pancreatitis prevents the development of the disease. As premature trypsinogen activation is a common, early event leading to tissue injury in acute pancreatitis in human and in experimental animal models, we studied its role in polyamine catabolism-induced pancreatitis. Cathepsin B, a lysosomal hydrolase mediating trypsinogen activation, was activated just 2 h after induction of SSAT. Pre-treatment of the rats with bismethylspermine prevented pancreatic cathepsin B activation. Analysis of tissue ultrastructure by transmission electron microscopy revealed early dilatation of rough endoplasmic reticulum, probable disturbance of zymogen packaging, appearance of autophagosomes and later disruption of intracellular membranes and organelles. Based on these results, we suggest that rapid eradication of polyamines from cellular structures leads to premature zymogen activation and autodigestion of acinar cells

Mechanisms of polyamine catabolism-induced acute pancreatitis

Abstract Acute pancreatitis is an autodigestive disease, in which the pancreatic tissue is damaged by the digestive enzymes produced by the acinar cells. Among the tissues in the mammalian body, pancreas has the highest concentration of the natural polyamine, spermidine. We have found that pancreas is very sensitive to acute decreases in the concentrations of the higher polyamines, spermidine and spermine. Activation of polyamine catabolism in transgenic rats overexpressing SSAT (spermidine/spermine-N 1 -acetyltransferase) in the pancreas leads to rapid depletion of these polyamines and to acute necrotizing pancreatitis. Replacement of the natural polyamines with methylated polyamine analogues before the induction of acute pancreatitis prevents the development of the disease. As premature trypsinogen activation is a common, early event leading to tissue injury in acute pancreatitis in human and in experimental animal models, we studied its role in polyamine catabolism-induced pancreatitis. Cathepsin B, a lysosomal hydrolase mediating trypsinogen activation, was activated just 2 h after induction of SSAT. Pre-treatment of the rats with bismethylspermine prevented pancreatic cathepsin B activation. Analysis of tissue ultrastructure by transmission electron microscopy revealed early dilatation of rough endoplasmic reticulum, probable disturbance of zymogen packaging, appearance of autophagosomes and later disruption of intracellular membranes and organelles. Based on these results, we suggest that rapid eradication of polyamines from cellular structures leads to premature zymogen activation and autodigestion of acinar cells

Meaningful learning with mobile devices: pre-service class teachers’ experiences of mobile learning in the outdoors

The authors consider the use of mobile learning environment ActionTrack in teacher education. Pre-service class teachers’ (N = 277) experiences of the mobile learning environment were measured with a 7-point Likert-scale questionnaire based on seven attributes of meaningful learning. Students’ ratings for different attributes were analysed quantitatively. The authors conclude that, based on this analysis, it is possible to create meaningful learning experiences using ActionTrack. All the measured attributes of meaningful learning obtained positive values. In the mobile learning events of this study, three attributes arose as the essential features: mobile learning in the outdoors was primarily considered collaborative, active and contextual.</p

Synthesis, in vitro and in vivo evaluation of 1,3,5-triazines as cannabinoid CB2 receptor agonists

The cannabinoid receptors type 2 (CBR2) are attractive therapeutic targets of the endocannabinoid signaling system (ECS) as they are not displaying the undesired psychotropic and cardiovascular side-effects seen with cannabinoid receptor type 1 (CB1R) agonists. In continuation of our previous work on 2,4,6-trisubstituted 1,3,5-triazines as potent CB2 agonists, we synthesized an additional series of more polar analogues (1-10), which were found to possess high CB2R agonist activity with enhanced water solubility. The most potent compound in the series was N-(adamantan-1-yl)-4-ethoxy-6-(4-(2-fluoroethyl)piperazin-1-yl)-1,3,5-triazin-2-amine (9) with EC50 value of 0.60nM. To further evaluate the biological effects of the compounds, the selected compounds were tested in vitro against four different cell lines. A human retinal pigment epithelial cell line (ARPE-19) was used to evaluate the cytotoxicity of the compounds whereas an androgen-sensitive human prostate adenocarcinoma cell line (LNCaP), a Jurkat leukemia cell line and a C8161 melanoma cell line were used to assess the antiproliferative activity of the compounds. The most interesting results were obtained for N-(adamantan-1-yl)-4-ethoxy-6-(4-methylpiperazin-1-yl)-1,3,5-triazin-2-amine (6), which induced cell viability decrease in prostate and leukemia cell lines, and diminished proliferation of C8161 melanoma cells. The results could be reversed in leukemia cells with the selective CB2R antagonist AM630, whereas in prostate cells the AM630 induced a significant cell viability decrease with a mechanism probably unlinked to CB2 cannabinoid receptor. The antiproliferative effect of 6 on the melanoma cells seemed not to be mediated via the CB1R or CB2R. No cytotoxicity was detected against ARPE-19 cell line at concentrations of 1 and 10μM for compound 6. However, at 30μM concentration the compound 6 decreased the cell viability. Finally, in order to estimate in vivo behavior of these compounds, (18)F labeled PET ligand, N-cyclopentyl-4-ethoxy-6-(4-(2-fluoro-18-ethyl)piperazin-1-yl)-1,3,5-triazin-2-amine ([(18)F]5), was synthesized and its biodistribution was determined in healthy male Sprague-Dawley rats. As a result, the tracer showed a rapid (&lt;15min) elimination in urine accompanied by a slower excretion via the hepatobiliary route. In conclusion, we further demonstrated that 1,3,5-triazine scaffold serves as a suitable template for the design of highly potent CB2R agonists with reasonable water solubility properties. The compounds may be useful when studying the role of the endocannabinoid system in different diseases. The triazine scaffold is also a promising candidate for the development of new CB2R PET ligands

Role of Polyamine-Induced Dimerization of Antizyme in Its Cellular Functions

Funding: This work was supported by grants from the Russian Science Foundation (grant # 17-74-20049—synthesis of C-methylated Spd analogues, ITC studies of dimerization of OAZ1, and frameshifting experiments), the Russian Science Foundation (grant # 19-74-10086—isolation of OAZ1, electrophoresis studies of dimerization of OAZ1), and the Academy of Finland (grants # 292574 and # 315487). Acknowledgments: The authors thank A. Karppinen, A. Korhonen, T. Reponen, M. Salminkoski, and S.D. Negrya for their skillful technical assistance.Peer reviewedPublisher PD

Resectability, conversion, metastasectomy and outcome according to RAS and BRAF status for metastatic colorectal cancer in the prospective RAXO study

Background Outcomes after metastasectomy for metastatic colorectal cancer (mCRC) vary with RAS and BRAF mutational status, but their effects on resectability and conversion rates have not been extensively studied. Methods This substudy of the prospective RAXO trial included 906 patients recruited between 2011 and 2018. We evaluated repeated centralised resectability assessment, conversion/resection rates and overall survival (OS), according to RAS and BRAF status. Results Patients included 289 with RAS and BRAF wild-type (RAS and BRAFwt), 529 with RAS mutated (RASmt) and 88 with BRAF mutated (BRAFmt) mCRC. Metastatic prevalence varied between the RAS and BRAFwt/RASmt/BRAFmt groups, for liver (78%/74%/61%), lung (24%/35%/28%) and peritoneal (15%/15%/32%) metastases, respectively. Upfront resectability (32%/29%/15%), conversion (16%/13%/7%) and resection/local ablative therapy (LAT) rates (45%/37%/17%) varied for RASa and BRAFwt/RASmt/BRAFmt, respectively. Median OS for patients treated with resection/LAT (n = 342) was 83/69/30 months, with 5-year OS-rates of 67%/60%/24%, while systemic therapy-only patients (n = 564) had OS of 29/21/15 months with 5-year OS-rates of 11%/6%/2% in RAS and BRAFwt/RASmt/BRAFmt, respectively. Resection/LAT was associated with improved OS in all subgroups. Conclusions There were significant differences in resectability, conversion and resection/LAT rates according to RAS and BRAF status. OS was also significantly longer for RAS and BRAFwt versus either mutant. Patients only receiving systemic therapy had poorer long-term survival, with variation according to molecular status.</p

Ten-Year Mortality and Cardiovascular Morbidity in the Finnish Diabetes Prevention Study—Secondary Analysis of the Randomized Trial

The Finnish Diabetes Prevention Study (DPS) was a randomized controlled trial, which showed that it is possible to prevent type 2 diabetes by lifestyle changes. The aim of the present study was to examine whether the lifestyle intervention had an effect on the ten-year mortality and cardiovascular morbidity in the DPS participants originally randomized either into an intervention or control group. Furthermore, we compared these results with a population-based cohort comprising individuals of varying glucose tolerance states.Middle-aged, overweight people with IGT (n = 522) were randomized into intensive intervention (including physical activity, weight reduction and dietary counseling), or control "mini-intervention" group. Median length of the intervention period was 4 years and the mean follow-up was 10.6 years. The population-based reference study cohort included 1881 individuals (1570 with normal glucose tolerance, 183 with IGT, 59 with screen-detected type 2 diabetes, 69 with previously known type 2 diabetes) with the mean follow-up of 13.8 years. Mortality and cardiovascular morbidity data were collected from the national Hospital Discharge Register and Causes of Death Register. Among the DPS participants who consented for register linkage (n = 505), total mortality (2.2 vs. 3.8 per 1000 person years, hazard ratio HR = 0.57, 95% CI 0.21-1.58) and cardiovascular morbidity (22.9 vs. 22.0 per 1000 person years, HR = 1.04, 95% CI 0.72-1.51) did not differ significantly between the intervention and control groups. Compared with the population-based cohort with impaired glucose tolerance, adjusted HRs were 0.21 (95% CI 0.09-0.52) and 0.39 (95% CI 0.20-0.79) for total mortality, and 0.89 (95% CI 0.62-1.27) and 0.87 (0.60-1.27) for cardiovascular morbidity in the intervention and control groups of the DPS, respectively. The risk of death in DPS combined cohort was markedly lower than in FINRISK IGT cohort (adjusted HR 0.30, 95% CI 0.17-0.54), but there was no significant difference in the risk of CVD (adjusted HR 0.88, 95% CI 0.64-1.21).Lifestyle intervention among persons with IGT did not decrease cardiovascular morbidity during the first 10 years of follow-up. However, the statistical power may not be sufficient to detect small differences between the intervention and control groups. Low total mortality among participants of the DPS compared with individuals with IGT in the general population could be ascribed to a lower cardiovascular risk profile at baseline and regular follow-up.ClinicalTrials.gov NCT00518167

Circulating inflammatory cytokines and risk of five cancers: a Mendelian randomization analysis

BACKGROUND: Epidemiological and experimental evidence has linked chronic inflammation to cancer aetiology. It is unclear whether associations for specific inflammatory biomarkers are causal or due to bias. In order to examine whether altered genetically predicted concentration of circulating cytokines are associated with cancer development, we performed a two-sample Mendelian randomisation (MR) analysis. METHODS: Up to 31,112 individuals of European descent were included in genome-wide association study (GWAS) meta-analyses of 47 circulating cytokines. Single nucleotide polymorphisms (SNPs) robustly associated with the cytokines, located in or close to their coding gene (cis), were used as instrumental variables. Inverse-variance weighted MR was used as the primary analysis, and the MR assumptions were evaluated in sensitivity and colocalization analyses and a false discovery rate (FDR) correction for multiple comparisons was applied. Corresponding germline GWAS summary data for five cancer outcomes (breast, endometrial, lung, ovarian, and prostate), and their subtypes were selected from the largest cancer-specific GWASs available (cases ranging from 12,906 for endometrial to 133,384 for breast cancer). RESULTS: There was evidence of inverse associations of macrophage migration inhibitory factor with breast cancer (OR per SD = 0.88, 95% CI 0.83 to 0.94), interleukin-1 receptor antagonist with endometrial cancer (0.86, 0.80 to 0.93), interleukin-18 with lung cancer (0.87, 0.81 to 0.93), and beta-chemokine-RANTES with ovarian cancer (0.70, 0.57 to 0.85) and positive associations of monokine induced by gamma interferon with endometrial cancer (3.73, 1.86 to 7.47) and cutaneous T-cell attracting chemokine with lung cancer (1.51, 1.22 to 1.87). These associations were similar in sensitivity analyses and supported in colocalization analyses. CONCLUSIONS: Our study adds to current knowledge on the role of specific inflammatory biomarker pathways in cancer aetiology. Further validation is needed to assess the potential of these cytokines as pharmacological or lifestyle targets for cancer prevention

The WEBT BL Lac Campaign 2000

We present UBVRI light curves of BL Lacertae from May 2000 to January 2001, obtained by 24 telescopes in 11 countries. More than 15000 observations were performed in that period, which was the extension of the Whole Earth Blazar Telescope (WEBT) campaign originally planned for July-August 2000. Rapid flux oscillations are present all the time, involving variations up to a few tenths of mag on hour time scales, and witnessing an intense intraday activity of this source. Colour indexes have been derived by coupling the highest precision B and R data taken by the same instrument within 20 min and after subtracting the host galaxy contribution from the fluxes. The 620 indexes obtained show that the optical spectrum is weakly sensitive to the long-term trend, while it strictly follows the short-term flux behaviour, becoming bluer when the brightness increases. Thus, spectral changes are not related to the host galaxy contribution, but they are an intrinsic feature of fast flares. We suggest that the achromatic mechanism causing the long-term flux base-level modulation can be envisaged in a variation of the relativistic Doppler beaming factor, and that this variation is likely due to a change of the viewing angle. Discrete correlation function (DCF) analysis reveals the existence of a characteristic time scale of variability of about 7 h in the light curve of the core WEBT campaign, while no measurable time delay between variations in the B and R bands is found.Comment: 14 pages, 8 PostScript figures, 5 JPEG figures, in press for A&

Genome-wide association study identifies seven novel loci associating with circulating cytokines and cell adhesion molecules in Finns

Background: Inflammatory processes contribute to the pathophysiology of multiple chronic conditions. Genetic factors play a crucial role in modulating the inflammatory load, but the exact mechanisms are incompletely understood.Objective: To assess genetic determinants of 16 circulating cytokines and cell adhesion molecules (inflammatory phenotypes) in Finns.Methods: Genome-wide associations of the inflammatory phenotypes were studied in Northern Finland Birth Cohort 1966 (N=5284). A subsequent meta-analysis was completed for 10 phenotypes available in a previous genome-wide association study, adding up to 13 577 individuals in the study. Complementary association tests were performed to study the effect of the ABO blood types on soluble adhesion molecule levels.Results: We identified seven novel and six previously reported genetic associations (pConclusion: The present results extend the knowledge about genetic factors contributing to the inflammatory load. Our findings suggest that two distinct mechanisms contribute to the soluble adhesion molecule levels in the ABO locus and that elevated soluble adhesion molecule levels per se may not increase risk for cardiovascular disease.</p