Citations

Ubiquitin (Ub) sorting receptors facilitate the targeting of ubiquitinated membrane proteins into multivesicular bodies (MVBs). Ub-binding domains (UBDs) have been described in several endosomal sorting complexes required for transport (ESCRT). Using available structural information, we have investigated the role of the multiple UBDs within ESCRTs during MVB cargo selection. We found a novel UBD within ESCRT-I and show that it contributes to MVB sorting in concert with the known UBDs within the ESCRT complexes. These experiments reveal an unexpected level of coordination among the ESCRT UBDs, suggesting that they collectively recognize a diverse set of cargo rather than act sequentially at discrete steps.

BackgroundStrokes, vascular risk factors, and apolipoprotein E (APOE) genotype are associated with cognitive decline in the elderly, but definitive evidence that these affect cognition as early as middle age is limited.ObjectiveWe describe the relationships of APOE genotype, stroke, and vascular risk factors with cognitive change over a 14‐year follow‐up in the Atherosclerosis Risk in Communities (ARIC) Study cohort recruited while in middle age.MethodsParticipants included a subset of the ARIC Study who underwent assessments of cognitive function and vascular risk factors. Four cognitive assessments were performed between 1990–1992 and 2004–2006. Cognitive assessments included the Delayed Word Recall (DWR) Test, the Digit Symbol Substitution (DSS) Test, and the Word Fluency (WF) Test. Vascular risk factors were assessed during the baseline visit in 1990–1992. Incident stroke was recorded over the 14 years of follow‐up.ResultsThere were 1130 participants (mean age, 59 ± 4.3 [SD] years; 62% women; 52% African‐American) with longitudinal data. In multivariate, random‐effects linear models adjusted for age, education, gender, and race, the risk factors diabetes and APOE ɛ4 genotype were independently associated with a decline in performance on the DSS test (both P < .005), whereas hypertension and stroke were not. For DWR, stroke and APOE ɛ4 genotype were independent predictors of decline (both P < .001). For the WF test, metabolic syndrome, hypertension, and stroke were independently associated with decline (all P < .005). No evidence of differential effects of risk factors on cognitive decline by race, gender, or interactions between risk factors was found.ConclusionsThe vascular risk factors diabetes and hypertension, a history of stroke itself, and APOE ɛ4 genotype independently contribute to cognitive decline in late middle age and early elderly years.

Abstract Background: Nucleotide excision repair is a vital response to DNA damage, including damage from tobacco exposure. Single nucleotide polymorphisms (SNP) in the nucleotide excision repair pathway may encode alterations that affect DNA repair function and therefore influence the risk of pancreatic cancer development. Methods: A clinic-based case-control study in non-Hispanic white persons compared 1,143 patients with pancreatic adenocarcinoma with 1,097 healthy controls. Twenty-seven genes directly and indirectly involved in the nucleotide excision repair pathway were identified and 236 tag-SNPs were selected from 26 of these (one had no SNPs identified). Association studies were done at the gene level by principal components analysis, whereas recursive partitioning analysis was utilized to identify potential gene-gene and gene-environment interactions within the pathway. At the individual SNP level, adjusted additive, dominant, and recessive models were investigated, and gene-environment interactions were also assessed. Results: Gene level analyses showed an association of the MMS19L genotype (chromosome 10q24.1) with altered pancreatic cancer risk (P = 0.023). Haplotype analysis of MMS19L also showed a significant association (P = 0.0132). Analyses of seven individual SNPs in this gene showed both protective and risk associations for minor alleles, broadly distributed across patient subgroups defined by smoking status, sex, and age. Conclusion: In a candidate pathway SNP association study analysis, common variation in a nucleotide excision repair gene, MMS19L, was associated with the risk of pancreatic cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1295–302)

Purpose Irinotecan plus cisplatin (IP) improved survival over etoposide plus cisplatin (EP) in Japanese patients with extensive-stage small-cell lung cancer (E-SCLC). To confirm those results and discern the potential role of population-related pharmacogenomics (PG) in outcomes, we conducted a large randomized trial of identical design to the Japanese trial in North American patients with E-SCLC. Patients and Methods Patients were randomly assigned to IP (irinotecan 60 mg/m2 on days 1, 8, and 15; cisplatin 60 mg/m2 day 1, every 4 weeks) or EP (etoposide 100 mg/m2 on days 1 through 3; cisplatin 80 mg/m2 day 1, every 3 weeks). Blood specimens for genomic DNA analysis were collected before random assignment in 169 patients. Results Of 671 patients, 651 were eligible (324 and 327 patients in the IP and EP arms, respectively). Response rates with IP and EP were 60% and 57%, respectively (P = .56). Median progression-free survival for IP and EP was 5.8 and 5.2 months, respectively (P = .07). Median overall survival for IP and EP was 9.9 and 9.1 months, respectively (P = .71). Severe diarrhea was more common with IP (19% v 3%); severe neutropenia and thrombocytopenia were higher with EP versus IP (68% v 33% and 15% v 4%, respectively). PG analysis showed that ABCB1 (C3435T)T/T (membrane transport) was associated with IP-related diarrhea; UGT1A1 (G-3156A)A/A (drug metabolism) was associated with IP-related neutropenia. Conclusion This large North American trial failed to confirm the previously reported survival benefit observed with IP in Japanese patients. Both regimens produced comparable efficacy, with less hematologic and greater gastrointestinal toxicity with IP. These results emphasize the potential importance of PG in interpreting trials of cancer therapy.

Abstract Among all of the genetic factors associated with multiple sclerosis (MS) susceptibility, MHC class II molecules have the strongest association. Although a direct role of DR alleles in MS have been confirmed, it has been difficult to understand the role of DQ alleles in disease pathogenesis due to strong linkage disequilibrium with certain DR alleles. Population studies have indicated that DQ alleles may play a modulatory role in progression of MS. Using HLA class II transgenic (Tg) mice, we investigated gene complementation between DR and DQ genes in the disease process. Previously, using single Tg mice (expressing HLA-DR or DQ gene), we showed that PLP91–110 peptide induced experimental autoimmune encephalomyelitis (EAE) only in DR3.Aβ° mice, suggesting that DR3 (DRB1*0301) is a disease susceptibility gene in the context of PLP. We also showed that DQ6 protects development of EAE in DQ6/DR3 double Tg mice by production of anti-inflammatory IFN-γ. In this study, we investigated the ability of DQ8 to modulate disease in DR3/DQ8 double Tg mice. Introduction of DQ8 onto DR3 Tg mice led to higher disease incidence and increased disease severity on immunization with PLP91–110, indicating that DQ8 had an exacerbating effect on the development of EAE. Increased susceptibility in DR3/DQ8 Tg mice was due to increased production of proinflammatory cytokine IL-17 by DQ8-restricted T cells. HLA-DR3/DQ8 mice with EAE also demonstrated increased inflammation and demyelination in CNS as compared with single DR3 Tg mice. Thus double Tg mouse provides a novel model to study epistatic interactions between HLA class II molecules in inflammatory and demyelinating disease.

Toxic shock syndrome (TSS) is an acute, serious systemic illness caused by bacterial superantigens. Nonavailability of a suitable animal model until recently has hampered an in-depth understanding of the pathogenesis of TSS. In the current study, we characterized the early molecular events underlying TSS using our HLA-DR3 transgenic mouse model. Gene expression profiling using DNA microarrays identified a rapid and significant upregulation of several pro- as well as anti-inflammatory mediators, many of which have never been previously described in TSS. In vivo administration of staphylococcal enterotoxin B (SEB) led to an increase in the expression of Th0- (IL-2, 240-fold); Th1- (IFN-γ, 360-fold; IL-12, 8-fold); Th2- (IL-4, 53-fold; IL-5, 4-fold) as well as Th17-type cytokines (IL-21, 19-fold; IL-17, 5-fold). The immunoregulatory cytokines (IL-6, 700-fold; IL-10, 18-fold); CC chemokines (such as CCL 2, 11, 3, 24, 17, 12, 7), CXC chemokines (such as CXCL 1, 2, 5, 11, 10, 19); and several proteases (matrix metalloproteinases 13, 8, 3, and 9) were also upregulated. Serum levels of several of these cytokines/chemokines were also significantly elevated. Pathway analyses revealed significant modulation in a variety of biochemical and cellular functions, providing molecular insights into the pathogenesis of TSS. Administration of bortezomib, a clinically approved proteasome inhibitor capable of blocking NF-κB pathway, was able to significantly modulate the expression of a variety of genes induced by SEB. Thus, our study showed that TSS is a complex process and emphasized the potential of use of bortezomib in the therapy of superantigen-induced TSS.