The influence of 6-hydroxydopamine on the development and inducibility of drug metabolism in rat liver

6-Hydroxydopamine (6-OHDA) pretreatment of rats in the first 4 days of life considerably enhances the low hepatic ethylmorphine N-demethylation rate in 9 and 16 day old rats, whereas the higher rates in adult rats are not influenced. After 6-OHDA treatment the age differences in ethylmorphine N-demethylation rate disappear. The induction of ethylmorphine N-demethylation by phenobarbital is markedly enhanced by neonatal 6-OHDA pretreatment in 16 to 60 day old rats, whereas in 9 day old rats this synergistic action is not detectable. Unlike ethylmorphine N-demethylation, hepatic 7-ethoxy-coumarin 0-deethylation rate is only slightly or not at all influenced by 6-OHDA pretreatment. The basic activities in 9 day and rats are enhanced, the induction by phenobarbital in the same age-group is decreased. In other age-groups neither basic activities nor inducibility are influenced by 6-OHDA pretreatment. Hepatic cytochrome P-450 concentrations in 33- and 60 day old control rats do not differ from those in 6-OHDA-pretreated animals. Phenobarbital treatment increases the P-450 content; this induction effect is enhanced after 6-OHDA pretreatment, but not as markedly as with ethylmorphine N-demethylation.     

Cryptic organelle homology in apicomplexan parasites: insights from evolutionary cell biology

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Somatic Mutations in Exocrine Pancreatic Tumors: Association with Patient Survival

KRAS mutations are major factors involved in initiation and maintenance of pancreatic tumors. The impact of different mutations on patient survival has not been clearly defined. We screened tumors from 171 pancreatic cancer patients for mutations in KRAS and CDKN2A genes. Mutations in KRAS were detected in 134 tumors, with 131 in codon 12 and only 3 in codon 61. The GGT>GAT (G12D) was the most frequent mutation and was present in 60% (80/134). Deletions and mutations in CDKN2A were detected in 43 tumors. Analysis showed that KRAS mutations were associated with reduced patient survival in both malignant exocrine and ductal adenocarcinomas (PDAC). Patients with PDACs that had KRAS mutations showed a median survival of 17 months compared to 30 months for those without mutations (log-rank P = 0.07) with a multivariate hazard ratio (HR) of 2.19 (95%CI 1.09–4.42). The patients with G12D mutation showed a median survival of 16 months (log-rank-test P = 0.03) and an associated multivariate HR 2.42 (95%CI 1.14–2.67). Although, the association of survival in PDAC patients with CDKN2A aberrations in tumors was not statistically significant, the sub-group of patients with concomitant KRAS mutations and CDKN2A alterations in tumors were associated with a median survival of 13.5 months compared to 22 months without mutation (log-rank-test P = 0.02) and a corresponding HR of 3.07 (95%CI 1.33–7.10). Our results are indicative of an association between mutational status and survival in PDAC patients, which if confirmed in subsequent studies can have potential clinical application.     

Genetic Loci Associated with Alzheimer’s Disease and Cerebrospinal Fluid Biomarkers in a Finnish Case-Control Cohort

Objectives

To understand the relation between risk genes for Alzheimer’s disease (AD) and their influence on biomarkers for AD, we examined the association of AD in the Finnish cohort with single nucleotide polymorphisms (SNPs) from top AlzGene loci, genome-wide association studies (GWAS), and candidate gene studies; and tested the correlation between these SNPs and AD markers Aβ_1–42, total tau (t-tau), and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF).

Methods

We tested 25 SNPs for genetic association with clinical AD in our cohort comprised of 890 AD patients and 701-age matched healthy controls using logistic regression. For the correlational study with biomarkers, we tested 36 SNPs in a subset of 222 AD patients with available CSF using mixed models. Statistical analyses were adjusted for age, gender and APOE status. False discovery rate for multiple testing was applied. All participants were from academic hospital and research institutions in Finland.

Results

APOE-ε4, CLU rs11136000, and MS4A4A rs2304933 correlated with significantly decreased Aβ_1–42 (corrected p<0.05). At an uncorrected p<0.05, PPP3R1 rs1868402 and MAPT rs2435211 were related with increased t-tau; while SORL1 rs73595277 and MAPT rs16940758, with increased p-tau. Only TOMM40 rs2075650 showed association with clinical AD after adjusting for APOE-ε4 (p = 0.007), but not after multiple test correction (p>0.05).

Conclusions

We provide evidence that APOE-ε4, CLU and MS4A4A, which have been identified in GWAS to be associated with AD, also significantly reduced CSF Aβ_1–42 in AD. None of the other AlzGene and GWAS loci showed significant effects on CSF tau. The effects of other SNPs on CSF biomarkers and clinical AD diagnosis did not reach statistical significance. Our findings suggest that APOE-ε4, CLU and MS4A4A influence both AD risk and CSF Aβ_1–42.     

Prevalence of Human Papillomavirus in 5,072 Consecutive Cervical SurePath Samples Evaluated with the Roche Cobas HPV Real-Time PCR Assay

New commercially available Human Papillomavirus (HPV) assays need to be evaluated in a variety of cervical screening settings. Cobas HPV Test (cobas) is a real-time PCR-based assay allowing for separate detection of HPV genotypes 16 and 18 and a bulk of 12 other high-risk genotypes. The aim of the present study, Horizon, was to assess the prevalence of high-risk HPV infections in an area with a high background risk of cervical cancer, where women aged 23–65 years are targeted for cervical screening. We collected 6,258 consecutive cervical samples from the largest cervical screening laboratory in Denmark serving the whole of Copenhagen. All samples were stored in SurePath media. In total, 5,072 samples were tested with cobas, Hybrid Capture 2 High Risk HPV DNA test (HC2) and liquid-based cytology. Of these, 27% tested positive on cobas. This proportion decreased by age, being 43% in women aged 23–29 years and 10% in women aged 60–65 years. HC2 assay was positive in 20% of samples, and cytology was abnormal (≥ atypical squamous cells of undetermined significance) for 7% samples. When only samples without recent abnormalities were taken into account, 24% tested positive on cobas, 19% on HC2, and 5% had abnormal cytology. The proportion of positive cobas samples was higher than in the ATHENA trial. The age-standardized cobas positivity vs. cytology abnormality was 3.9 in our study and 1.7 in ATHENA. If in Copenhagen the presently used cytology would be replaced by cobas in women above age 30 years, an extra 11% of women would based on historical data be expected to have a positive cobas test without an underlying cervical intraepithelial lesion grade 3 or worse. Countries with a high prevalence of HPV infections should therefore proceed to primary HPV-based cervical screening with caution.     

Secukinumab,a novel anti–IL-17A antibody,shows low immunogenicity potential in human in vitro assays comparable to other marketed biotherapeutics with low clinical immunogenicity

Secukinumab is a human monoclonal antibody that selectively targets interleukin-17A and has been demonstrated to be highly efficacious in the treatment of moderate to severe plaque psoriasis, starting at early time points, with a sustained effect and a favorable safety profile. Biotherapeutics—including monoclonal antibodies (mAbs)—can be immunogenic, leading to formation of anti-drug antibodies (ADAs) that can result in unwanted effects, including hypersensitivity reactions or compromised therapeutic efficacy. To gain insight into possible explanations for the clinically observed low immunogenicity of secukinumab, we evaluated its immunogenicity potential by applying 2 different in vitro assays: T-cell activation and major histocompatibility complex–associated peptide proteomics (MAPPs). For both assays, monocyte-derived dendritic cells (DCs) from healthy donors were exposed in vitro to biotherapeutic proteins. DCs naturally process proteins and present the derived peptides in the context of human leukocyte antigen (HLA)-class II. HLA-DR–associated biotherapeutic-derived peptides, representing potential T–cell epitopes, were identified in the MAPPs assay. In the T-cell assay, autologous CD4⁺ T cells were co-cultured with secukinumab-exposed DCs and T-cell activation was measured by proliferation and interleukin-2 secretion. In the MAPPs analysis and T-cell activation assays, secukinumab consistently showed relatively low numbers of potential T-cell epitopes and low T-cell response rates, respectively, comparable to other biotherapeutics with known low clinical immunogenicity. In contrast, biotherapeutics with elevated clinical immunogenicity rates showed increased numbers of potential T-cell epitopes and increased T-cell response rates in T-cell activation assays, indicating an approximate correlation between in vitro assay results and clinical immunogenicity incidence.     

Decoupled genomic elements and the evolution of partner quality in nitrogen‐fixing rhizobia

Understanding how mutualisms evolve in response to a changing environment will be critical for predicting the long‐term impacts of global changes, such as increased N (nitrogen) deposition. Bacterial mutualists in particular might evolve quickly, thanks to short generation times and the potential for independent evolution of plasmids through recombination and/or HGT (horizontal gene transfer). In a previous work using the legume/rhizobia mutualism, we demonstrated that long‐term nitrogen fertilization caused the evolution of less‐mutualistic rhizobia. Here, we use our 63 previously isolated rhizobium strains in comparative phylogenetic and quantitative genetic analyses to determine the degree to which variation in partner quality is attributable to phylogenetic relationships among strains versus recent genetic changes in response to N fertilization. We find evidence of distinct evolutionary relationships between chromosomal and pSym genes, and broad similarity between pSym genes. We also find that nifD has a unique evolutionary history that explains much of the variation in partner quality, and suggest MoFe subunit interaction sites in the evolution of less‐mutualistic rhizobia. These results provide insight into the mechanisms behind the evolutionary response of rhizobia to long‐term N fertilization, and we discuss the implications of our results for the evolution of the mutualism.     

Expression of the RAI gene is conducive to apoptosis: studies of induction and interference

The RAI gene is also known as iASPP and PPP1R13L. Recent investigations have shown that the region encompassing RAI is important for the development of cancer in young and middle-aged persons. It has been speculated that the RAI product induces apoptosis by blocking NF-kappaB or inhibits apoptosis by blocking p53. Either way the gene could influence the survival of precancerous lesions. Here we report that the expression of RAI mRNA was increased in non-transformed lymphocytes and fibroblasts induced to undergo apoptosis by various means, such as treatment with etoposide, calcium ions, or interleukin-2 and/or serum deprivation. Treatment with etoposide increased the content of RAI protein, too, and caused it to translocate to the nucleus. Inhibition of RAI expression in lymphocytes and fibroblasts with siRNA reduced apoptosis, but treatment with the NF-kappaB-inhibiting substance sulfasalazine relieved this dependence. In the transformed cell line HEK-293 the association between RAI induction and apoptosis seemed broken. Thus, we hypothesize that RAI induction is necessary but not sufficient for apoptosis induction in non-transformed cells. Our results could be explained by a NF-kappaB mediated mechanism.