Reclassification of Thermomonospora and Microtetraspora

Almost complete 16S rRNA sequences from seven Thermomonospora strains, Thermomonospora curvata, Thermomonospora formosensis, Thermomonospora fusca, Thermomonospora mesophila, Thermomonospora chromogena, Thermomonospora alba and Thermomonospora mesouviformis (a synonym of Thermomonospora alba) were determined and subjected to phylogenetic analysis together with the sequences from all the representative members of the suborder Streptosporangineae. On the basis of phylogenetic, chemotaxonomic and phenotypic evidence, the transfer is proposed of Thermomonospora formosensis to the genus Actinomadura as Actinomadura formosensis comb. nov., Thermomonospora mesophila to the genus Microbispora as Microbispora mesophila comb. nov., and Thermomonospora fusca and Thermomonospora alba to a new genus, Thermobifida gen. nov., which belongs to the family Nocardiopsaceae, as Thermobifida fusca comb. nov. and Thermobifida alba comb. nov. Thermobifida alba is designated the type species of the genus. The transfer is also proposed of all species of the Microtetraspora pusilla group, which were transferred from Actinomadura, to a new genus, Nonomuria gen. nov., as Nonomuria africana comb. nov., Nonomuria angiospora comb. nov., Nonomuria fastidiosa comb. nov., Nonomuria ferruginea comb. nov., Nonomuria flexuosa comb. nov., Nonomuria helvata comb. nov., Nonomuria polychroma comb. nov., Nonomuria pusilla comb. nov., Nonomuria recticatena comb. nov., Nonomuria roseola comb. nov., Nonomuria roseoviolacea comb. nov., Nonomuria rubra comb. nov., Nonomuria salmonea comb. nov., Nonomuria spiralis comb. nov. and Nonomuria turkmeniaca comb. nov. Nonomuria pusilla is designated the type species of the genus.

Peptide methionine sulfoxide reductase from Escherichia coli and Mycobacterium tuberculosis protects bacteria against oxidative damage from reactive nitrogen intermediates

Inducible nitric oxide synthase (iNOS) plays an important role in host defense. Macrophages expressing iNOS release the reactive nitrogen intermediates (RNI) nitrite and S-nitrosoglutathione (GSNO), which are bactericidal in vitro at a pH characteristic of the phagosome of activated macrophages. We sought to characterize the active intrabacterial forms of these RNI and their molecular targets. Peptide methionine sulfoxide reductase (MsrA; EC ) catalyzes the reduction of methionine sulfoxide (Met-O) in proteins to methionine (Met). E. coli lacking MsrA were hypersensitive to killing not only by hydrogen peroxide, but also by nitrite and GSNO. The wild-type phenotype was restored by transformation with plasmids encoding msrA from E. coli or M. tuberculosis, but not by an enzymatically inactive mutant msrA, indicating that Met oxidation was involved in the death of these cells. It seemed paradoxical that nitrite and GSNO kill bacteria by oxidizing Met residues when these RNI cannot themselves oxidize Met. However, under anaerobic conditions, neither nitrite nor GSNO was bactericidal. Nitrite and GSNO can both give rise to NO, which may react with superoxide produced by bacteria during aerobic metabolism, forming peroxynitrite, a known oxidant of Met to Met-O. Thus, the findings are consistent with the hypotheses that nitrite and GSNO kill E. coli by intracellular conversion to peroxynitrite, that intracellular Met residues in proteins constitute a critical target for peroxynitrite, and that MsrA can be essential for the repair of peroxynitrite-mediated intracellular damage.

Surveillance CT scans are a source of anxiety and fear of recurrence in long-term lymphoma survivors

BACKGROUND

We aimed to assess anxiety and the psychological impact of routine surveillance scans in long-term survivors of adult aggressive lymphoma.

PATIENTS AND METHODS

In this cross-sectional observational study of 70 survivors of curable adult aggressive lymphoma, we measured anxiety and the doctor-patient relationship and performed a qualitative interview (n = 30) focused on patient perception of routine follow-up imaging studies.

RESULTS

Participants were diagnosed with aggressive lymphoma a median of 4.9 years (2.4-38.0 years) before enrollment. Thirty-seven percent of patients were found to meet criteria for clinically significant anxiety, which was not associated with years since diagnosis. In multivariate analysis, history of relapse and a worse doctor-patient relationship were independently associated with higher anxiety levels. Despite representing a largely cured population, in qualitative interviews patients reported fear of recurrence as a major concern and considerable anxiety around the time of a follow-up imaging scan.

CONCLUSIONS

Routine surveillance scans exacerbate underlying anxiety symptoms and fear of recurrence in survivors of aggressive lymphoma. Strategies to minimize follow-up imaging and to improve doctor-patient communication should be prospectively evaluated to address these clinically significant issues.

Evaluation of bacterial survival and phagocyte function with a fluorescence-based microplate assay

To compare antibacterial function in macrophages from mice deficient in the respiratory burst oxidase or inducible nitric oxide synthase, we developed a fluorescence-based microplate assay of bacterial survival. As bacteria grow, they convert a formulation of resazurin termed AlamarBlue from its nonfluorescent oxidized state to its fluorescent reduced state. The time required to achieve a given fluorescence is inversely proportional to the number of viable bacteria present when the dye is added. This relationship allows a precise, accurate assessment of bacterial numbers with greater sensitivity and throughput and at less cost than conventional assays. The assay facilitated quantification of the killing of Escherichia coli by S-nitrosoglutathione and hydrogen peroxide and of Salmonella typhimurium by human neutrophils and mouse macrophages. Mouse macrophages lacking the 91-kDa subunit of the respiratory burst oxidase were deficient in their ability to kill S. typhimurium, while those lacking inducible nitric oxide synthase were unimpaired.

Impact of nitrogen supply on carbon/nitrogen allocation: a case study on amino acids and catechins in green tea [Camellia sinensis (L.) O. Kuntze] plants

The concentrations of free amino acids (AA) and polyphenols (PP) are important determinants of green tea quality. Levels of AA and PP are governed interactively by nitrogen (N) supply and carbon (C) status, so the impact of C/N allocation on green tea quality was investigated in saplings cultivated hydroponically with 0.3, 0.75, 1.5 or 4.5 mmol l(-1) N. Activities of glutamine synthetase (GS), phenylalanine ammonia lyase (PAL), and phosphoenolpyruvate carboxylase (PEPC) were determined, as were concentrations of AA, PP and soluble sugars. Concentrations of AA increased with increasing N supply, and the AA profile was shifted towards AA characterised by low C/N ratios (arginine, glutamine) and away from theanine, the unique non-protein AA that is abundant in Camellia sinensis. High N supply significantly reduced the concentrations of PP in young shoots, and was accompanied by lower levels of carbohydrates (soluble sugars). Analysis of the C and N status and selected enzyme activities, combined with path coefficient analysis of variables associated with C and N metabolism, demonstrated increasing deviation of C flux to AA under abundant N supply. Accumulation of AA and PP depended strongly on N status, and the balance shifted toward increasing synthesis of AA associated with enhanced growth, while investment of C in secondary metabolites did not change proportionally under the condition of ample N supply.

A novel antioxidant gene from Mycobacterium tuberculosis

Among the major antimicrobial products of macrophages are reactive intermediates of the oxidation of nitrogen (RNI) and the reduction of oxygen (ROI). Selection of recombinants in acidified nitrite led to the cloning of a novel gene, noxR1, from a pathogenic clinical isolate of Mycobacterium tuberculosis. Expression of noxR1 conferred upon Escherichia coli and Mycobacterium smegmatis enhanced ability to resist RNI and ROI, whether the bacteria were exposed to exogenous compounds in medium or to endogenous products in macrophages. These studies provide the first identification of an RNI resistance mechanism in mycobacteria, point to a new mechanism for resistance to ROI, and raise the possibility that inhibition of the noxR1 pathway might enhance the ability of macrophages to control tuberculosis.

Angiogenesis and antiangiogenic therapy in non-Hodgkin's lymphoma

Angiogenesis, the growth of new blood vessels, requires dynamic expansion, assembly and stabilization of vascular endothelial cells in response to proangiogenic stimuli. Antiangiogenic strategies have become an important therapeutic modality for solid tumors. While many aspects of postnatal pathological angiogenesis have been extensively studied in the context of nonhematopoietic neoplasms, the precise role of these processes in lymphoma pathogenesis is under active investigation. Lymphoma growth and progression is potentiated by at least two distinct angiogenic mechanisms: autocrine stimulation of tumor cells via expression of vascular endothelial growth factor (VEGF) and VEGF receptors by lymphoma cells, as well as paracrine influences of proangiogenic tumor microenvironment on both local neovascular transformation and recruitment of circulating bone marrow-derived progenitors. Lymphoma-associated infiltrating host cells including hematopoietic monocytes, T cells and mesenchymal pericytes have increasingly been associated with the pathogenesis and prognosis of lymphoma, in part providing perivascular guidance and support to neoangiogenesis. Collectively, these distinct angiogenic mechanisms appear to be important therapeutic targets in selected non-Hodgkin's lymphoma (NHL) subtypes. Understanding these pathways has led to the introduction of antiangiogenic treatment strategies into the clinic where they are currently under assessment in several ongoing studies of NHL patients.

Inducible nitric oxide synthase requires both the canonical calmodulin-binding domain and additional sequences in order to bind calmodulin and produce nitric oxide in the absence of free Ca2+

All three mammalian isoforms of nitric oxide synthase (NOS) must bind calmodulin (CaM) for enzymatic activity. Only NOS2 (the inducible isoform, iNOS) does so at the low levels of free Ca2+ in resting cells and when almost all Ca2+ is chelated in cell-free preparations. To test directly whether the predicted CaM-binding region of mouse NOS2 accounts for its Ca2+ independence, we prepared chimeric NOS's in which mouse NOS2 residues 503-532 were reciprocally exchanged with the corresponding residues 725-754 of rat NOS1 (neuronal NOS). Unlike either parent, both chimeras required an intermediate level of free Ca2+ to bind CaM and generate NO. In cell lysates, the concentration of Ca2+ necessary for half-maximal activity (EC50) was approximately 0 for NOS2, 200-300 n for NOS1, and 7-10 n for the chimeras. Results were similar when the region exchanged was enlarged by 7-8 residues toward the amino terminus. In contrast, when the carboxyl-terminal half of NOS2 (residues 454-1144) was replaced with that of NOS1 (residues 675-1429), the resulting chimera resembled NOS1 (EC50, 200-300 n free Ca2+). Truncation analysis suggested that NOS2 residues within the sequence 484-726 were required for Ca2+-independent CaM-binding. Thus, both the canonical CaM-binding domain and additional residues within the region 484-726 are necessary for NOS2's ability to bind CaM and produce NO when Ca2+ levels approach zero.

Autophagy inhibition induces enhanced proapoptotic effects of ZD6474 in glioblastoma

BACKGROUND

Autophagy is a lysosomal degradation pathway that can provide energy through its recycling mechanism to act as a cytoprotective adaptive response mediating treatment resistance in cancer cells. We investigated the autophagy-inducing effects of ZD6474, a small-molecule inhibitor that blocks activities of vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), and RET tyrosine kinases.

METHODS

We investigated the effects of ZD6474 on autophagy in glioblastomas cells. The ZD6474 mechanism of action was determined by western blot. We then examined the impacts of the inhibition of autophagy in combination with ZD6474 on cell apoptosis in vitro. Furthermore, we evaluated the synergistic anticancer activity of combination treatment with an autophagy inhibitor (chloroquine) and ZD6474 in U251 glioblastoma cells xenograft model.

RESULTS

ZD6474-induced autophagy was dependent on signalling through the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway. ZD6474-induced autophagy was inhibited by both knockdown of the ATG7 and Beclin 1 gene, essential autophagy genes, and pharmacologic agents (chloroquine and 3-methyalanine) treatment. Both treatments also dramatically sensitised glioblastoma cells to ZD6474-induced apoptosis, decreasing cell viability in vitro. Furthermore, in a xenograft mouse model, combined treatment with ZD6474 and chloroquine significantly inhibited U251 tumour growth, and increased the numbers of apoptotic cells compared with treatment with either agent alone.

CONCLUSION

Autophagy protects glioblastoma cells from the proapoptotic effects of ZD6474, which might contribute to tumour resistance against ZD6474 treatment.

Association of IL-1beta and IL-1 receptor antagonist haplotypes with rate of decline in lung function in smokers

BACKGROUND

There is increasing evidence that the cytokine network is central to the immunopathology of inflammatory airway diseases. The interleukin 1 (IL-1) receptor antagonist (IL-1RN) is a naturally occurring anti-inflammatory agent that binds to the IL-1 receptor but does not possess agonist activity. Each of the genes of the IL-1 locus on chromosome 2q14 is polymorphic. The IL1RN gene contains an 86 bp tandem repeat and allele 2 of this polymorphism has been associated with various inflammatory diseases. The IL-1beta (IL1B) gene contains a promoter polymorphism (C-511T) that has been associated with inflammatory diseases and is in linkage disequilibrium with the IL1RN polymorphism.

METHODS

We investigated whether polymorphisms in the IL1B and IL1RN genes were associated with rate of decline of lung function. Genotypes were determined in 284 smokers with a rapid decline in lung function and 306 smokers with no decline in lung function.

RESULTS

None of the genotypes was associated with the rate of decline of lung function. However, the distribution of IL1B/IL1RN haplotypes was different between smokers with a rapid decline in lung function and those with no decline in lung function (p=0.0005).

CONCLUSION

These results suggest that IL1B/IL1RN haplotypes play a role in the rate of decline in lung function in smokers.

A proposal to transfer Microbispora bispora (Lechevalier 1965) to a new genus, Thermobispora gen. nov., as Thermobispora bispora comb. nov

We determined almost complete 16S rRNA gene sequences of two Microbispora bispora (Lechevalier 1965) strains, ATCC 19993T (T = type strain) and JCM 3082. The two sequences were 99% similar to each other but exhibited only 81 to 87.8% similarity with the 16S rRNA gene sequences of seven other Microbispora strains. A phylogenetic analysis revealed that the two sequences clustered not only distantly from other Microbispora strains, but also outside the cluster containing members of the family Streptosporangiaceae. On the basis of the results of our phylogenetic analysis and the results of a comprehensive review of the genus Microbispora by Miyadoh et al. (S. Miyadoh, S. Amano, H. Tohyama, and T. Shomura, J. Gen. Microbiol. 136:1905-1913, 1990) in which chemotaxonomic and DNA-DNA hybridization analyses were performed, we propose that Microbispora bispora should be transferred to a new genus, Thermobispora gen. nov., as Thermobispora bispora comb. nov.

A phase II trial of lenalidomide plus rituximab in previously untreated follicular non-Hodgkin's lymphoma (NHL): CALGB 50803 (Alliance)

BACKGROUND

This multicenter, phase II trial tested the tolerability and efficacy of lenalidomide plus rituximab in patients with previously untreated follicular lymphoma (FL).

PATIENTS AND METHODS

Patients with grade 1-3a FL, stage 3-4 or bulky stage 2, FL international prognostic index (FLIPI) 0-2, and no prior therapy were eligible to receive rituximab 375 mg/m2 weekly during cycle 1 and day 1 of cycles 4, 6, 8, and 10, plus lenalidomide 20-25 mg on days 1-21 for twelve 28-day cycles. The primary objectives were to evaluate response rates [complete (CR) and overall] and time to progression. Secondary objectives included toxicity, response according to polymorphisms in FcgR2A and FcgR3A, and changes in circulating pro-angiogenic cells.

RESULTS

From October 2010 to September 2011, 66 patients were enrolled. Median age was 53 years, 34 were female, 15 had bulky disease, 21 were FLIPI 0-1, 43 FLIPI 2, and 2 FLIPI 3. One patient withdrew before receiving treatment. Fifty-one patients completed 12 cycles of lenalidomide. Reasons for discontinuation included withdrawal (n = 6), adverse events (n = 6), progression (n = 2). Grade 3-4 hematologic toxicity included neutropenia (21%), lymphopenia (9%), and thrombocytopenia (2%), infection (11%), and rash (8%). Grade 1-2 toxicity included fatigue (78%), diarrhea (37%), rash (32%), and febrile neutropenia in one patient. The overall response rate was 95%; the CR rate was 72% (95% confidence interval, 60% to 83%). With a median follow-up of 5 years, the 2- and 5-year progression-free survival were 86% and 70%, respectively, and the 5-year overall survival was 100%. There was no association between CR rate or PFS and FLIPI, histological grade, bulky disease, FcgR2A/FcgR3A polymorphism, or change in circulating endothelial cell/hematopoietic progenitor cell.

CONCLUSION

Lenalidomide plus rituximab was associated with low rates of grade 3-4 toxicity, yielded a CR rate and PFS similar to chemotherapy-based treatment and may represent a reasonable alternative to immunochemotherapy in previously untreated FL.

CLINICALTRIALS.GOV IDENTIFIER

NCT01145495.

Determination of inorganic pharmaceutical counterions using hydrophilic interaction chromatography coupled with a Corona CAD detector

A simple generic approach was investigated for the determination of inorganic pharmaceutical counterions in drug substances using conventional high performance liquid chromatographic (HPLC) instruments. An intuitive approach combined Corona charged aerosol detection (CAD) with a polymer-based zwitterionic stationary phase in the hydrophilic interaction chromatography (HILIC) mode. Two generic methods based on this HILIC/CAD technique were developed to quantitate counterions such as Cl-, Br-, SO(4)(2-), K+, Ca2+ and Mg2+ in different pharmaceutical compounds. The development and capability of this HILIC/CAD technique analysis were examined. HILIC/CAD was compared to ion chromatography (IC), the most commonly used methodology for pharmaceutical counterion analysis. HILIC/CAD was found to have significant advantages in terms of: (1) being able to quantitate both anions and cations simultaneously without a need to change column/eluent or detection mode; (2) imposing much less restriction on the allowable organic percentage of the eluents than IC, and therefore being more appropriate for analysis of counterions of poorly water-soluble drugs; (3) requiring minimal training of the operating analysts. The precision and accuracy of counterion analysis using HILIC/CAD was not compromised. A typical precision of <2.0% was observed for all tested inorganic counterions; the determinations were within 2.0% relative to the theoretical counterion amount in the drug substance. Additionally, better accuracy was shown for Cl- in several drug substances as compared to IC. The main drawback of HILIC/CAD is its unsuitability for many of the current silica-based HILIC columns, because slight dissolution of silica leads to high baseline noise in the CAD detector. As a result of the universal detection characteristics of Corona CAD and the unique separation capabilities of a zwitterionic stationary phase, an intuitive and robust HPLC method was developed for the generic determination of various counterions in different drug substances. HILIC/CAD technique is a useful alternative methodology, particularly for determination of counterions in low-solubility drugs.

noxR3, a novel gene from Mycobacterium tuberculosis, protects Salmonella typhimurium from nitrosative and oxidative stress

Reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI) produced by activated macrophages participate in host defense against the facultative intracellular pathogens Mycobacterium tuberculosis and Salmonella typhimurium. To survive within macrophages, such pathogens may have evolved ROI and RNI resistance mechanisms. ROI resistance pathways have been intensively studied. Much less is known about the mechanisms of resistance to RNI. To identify possible RNI resistance genes in M. tuberculosis, a mycobacterial library was expressed in S. typhimurium and subjected to selection by exposure to the NO donor S-nitrosoglutathione (GSNO) in concentrations sufficient to kill the vast majority of nontransformed salmonellae. Among the rare surviving recombinants was a clone expressing noxR3, a novel and previously anonymous M. tuberculosis gene predicted to encode a small, basic protein. Expression of noxR3 protected S. typhimurium not only from GSNO and acidified nitrite but also from H2O2. noxR3 is the third gene cloned from M. tuberculosis that has been shown to protect heterologous cells from both RNI and ROI. This suggests diversity in the repertoire of mechanisms that help pathogens resist the oxidative and nitrosative defenses of the host.

Prevalence of Cognitive Frailty Phenotypes and Associated Factors in a Community-Dwelling Elderly Population

OBJECTIVES

Cognitive frailty was notable target for the prevention of adverse health outcomes in future. The goal of this study was to use a population-based survey to investigate cognitive frailty phenotypes and potentially sociodemographic factors in elderly Chinese individuals.

DESIGN

Cross-sectional study.

SETTING

General community.

PARTICIPANTS

A total of 5328 elderly adults (aged 60 years or older, mean age 71.36 years) enrolled in the Shanghai study of health promotion for elderly individuals with frailty.

MEASUREMENTS

The 5-item FRAIL scale and the 3-item Rapid Cognitive Screen tools were used to assess physical frailty and cognitive impairment, including dementia or mild cognitive impairment (MCI). Physical frailty was diagnosed by limitations in 3 or more of the FRAIL scale domains and pre-physical frailty by 1-2 limitations. Subjective cognitive decline (SCD) and pre-MCI SCD, was diagnosed with two self-report measures based on memory and other cognitive domains in elderly adults.

RESULTS

Of the participating individuals, 97.17% (n= 5177, female 53.4%) were eligible. Notably, 9.67%, 41.61% and 35.20% of participants were MCI, SCD and pre-MCI SCD; 35.86% and 4.41% exhibited physical pre-frailty and frailty; and 19.86% and 6.30% exhibited reversible and potential reversible cognitive frailty. Logistic regression analyses indicated that physical frailty phenotypes were significantly associated with MCI with SCD, and pre-MCI with SCD. Older single females with a high education level were more likely to exhibit the reversible cognitive frailty; and younger elderly individuals with a middle education level were at lower risk for potentially reversible cognitive frailty.

CONCLUSIONS

The prevalence of pre-physical and reversible cognitive frailty was high in elderly individuals and age was the most significant risk factor for all types of frailty phenotypes. To promote the rapid screening protocol of cognitive frailty in community-dwelling elderly is important to find high-risk population, implement effective intervention, and decrease adverse prognosis.

A proposal to revive the genus Kitasatospora (Omura, Takahashi, Iwai, and Tanaka 1982)

We determined almost complete 16S ribosomal DNA sequences for 12 actinomycete strains which were either previously classified as Kitasatospora strains or defined as Streptomyces strains but shown to contain major amounts of meso-diaminopimelic acid in their whole-cell hydrolysates. These sequences were subjected to phylogenetic analyses together with the sequences of 34 Streptomyces species. Phylogenetic trees were reconstructed by using both neighbor-joining and maximum-parsimony methods. The Kitasatospora species always formed a stable monophyletic clade. However, the genus Kitasatospora appeared to be either a sister taxon of the genus Streptomyces or a lineage that originated from within Streptomyces species, depending on the outgroup used. Phylogenetic trees were also constructed by using the sequences of the 16S-23S rRNA gene spacers. Streptomyces and Kitasatospora species were consistently recovered as two distinct clades independent of the outgroup used. On the basis of phylogenetic, chemotaxonomic, and phenotypic evidence, we propose that the genus Kitasatospora Omura et al. 1982 should be revived.

Influence of mitochondrial enzyme deficiency on adult neurogenesis in mouse models of neurodegenerative diseases

Mitochondrial defects including reduction of a key mitochondrial tricarboxylic acid cycle enzyme alpha-ketoglutarate-dehydrogenase complex (KGDHC) are characteristic of many neurodegenerative diseases. KGDHC consists of alpha-ketoglutarate dehydrogenase, dihydrolipoyl succinyltransferase (E2k), and dihydrolipoamide dehydrogenase (Dld) subunits. We investigated whether Dld or E2k deficiency influences adult brain neurogenesis using immunohistochemistry for the immature neuron markers, doublecortin (Dcx) and polysialic acid-neural cell adhesion molecule, as well as a marker for proliferation, proliferating cell nuclear antigen (PCNA). Both Dld- and E2k-deficient mice showed reduced Dcx-positive neuroblasts in the subgranular zone (SGZ) of the hippocampal dentate gyrus compared with wild-type mice. In the E2k knockout mice, increased immunoreactivity for the lipid peroxidation marker, malondialdehyde occurred in the SGZ. These alterations did not occur in the subventricular zone (SVZ). PCNA staining revealed decreased proliferation in the SGZ of E2k-deficient mice. In a transgenic mouse model of Alzheimer's disease, Dcx-positive cells in the SGZ were also reduced compared with wild type, but Dld deficiency did not exacerbate the reduction. In the malonate lesion model of Huntington's disease, Dld deficiency did not alter the lesion-induced increase and migration of Dcx-positive cells from the SVZ into the ipsilateral striatum. Thus, the KGDHC subunit deficiencies associated with elevated lipid peroxidation selectively reduced the number of neuroblasts and proliferating cells in the hippocampal neurogenic zone. However, these mitochondrial defects neither exacerbated certain pathological conditions, such as amyloid precursor protein (APP) mutation-induced reduction of SGZ neuroblasts, nor inhibited malonate-induced migration of SVZ neuroblasts. Our findings support the view that mitochondrial dysfunction can influence the number of neural progenitor cells in the hippocampus of adult mice.

XRCC1 Arg399Gln and Arg194Trp polymorphisms in prostate cancer risk: a meta-analysis

Epidemiological studies have evaluated the association between X-ray repair cross-complementing group 1 gene (XRCC1) Arg399Gln and Arg194Trp polymorphisms and risk of prostate cancer (PCa). However, the results from the published studies on the association between these two XRCC1 polymorphisms and PCa risk are conflicting. To derive a more precise estimation of association between the XRCC1 polymorphisms and risk of PCa, we performed a meta-analysis. A comprehensive search was conducted to identify all case-control studies of XRCC1 polymorphisms and PCa risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Overall, we found that both Arg399Gln and Arg194Trp polymorphisms were not significantly associated with PCa risk. However, in stratified analysis by ethnicity, we found that the Arg399Gln polymorphism was significantly associated with PCa risk in Asian population (Gln/Gln vs Arg/Arg: OR=1.46, 95% CI: 1.05-2.03, P=0.03; Gln/Gln vs Arg/Gln+Arg/Arg: OR=1.48, 95% CI: 1.12-1.95, P=0.01). In this meta-analysis, we found that both Arg399Gln and Arg194Trp polymorphisms were not related to overall PCa risk. However, in subgroup analysis we found a suggestion that XRCC1 399Gln allele might be a low-penetrent risk factor for PCa only in Asian men.

Differential regulation of human alpha1-adrenoceptor subtypes

We have compared the agonist-induced down-regulation of human alpha1A-, alpha1B- and alpha1D-adrenoceptors upon stable expression in rat-1 fibroblasts. During a 24-h incubation the agonist phenylephrine downregulated alpha1A- and alpha1 -adrenoceptors in a concentration-dependent manner. While maximum downregulation was similar for both subtypes, the threshold concentration for significant reductions was markedly higher for alpha1A- than for alpha(1B-adrenoceptors (10 microM vs. 100 nM). The downregulation of both subtypes by 100 microM phenylephrine was time-dependent, and significant reductions were observed already after 2-4 h. In contrast, incubation of alpha1D-adrenoceptor-expressing cells with phenylephrine increased receptor number in a time- and concentration-dependent manner. The downregulation of alpha1B-adrenoceptors by 100 microM phenylephrine for 24 h was accompanied by a matching reduction in mRNA abundance, but no such reduction was seen for alpha-adrenoceptors. These treatment conditions also caused a functional desensitization of agonist-stimulated inositol phosphate formation for alpha1A- and alpha1B- but not for alpha1D-adrenoceptors. Treatment with the phorbol ester phorbol-12-myristate-13-acetate did not change receptor density or mRNA abundance and did not cause functional desensitization. We conclude that human alpha1-adrenoceptor subtypes are differentially regulated by agonist treatment even if they are expressed in the same cell line.

The HIV capsid mimics karyopherin engagement of FG-nucleoporins

HIV can infect non-dividing cells because the viral capsid can overcome the selective barrier of the nuclear pore complex and deliver the genome directly into the nucleus1,2. Remarkably, the intact HIV capsid is more than 1,000 times larger than the size limit prescribed by the diffusion barrier of the nuclear pore3. This barrier in the central channel of the nuclear pore is composed of intrinsically disordered nucleoporin domains enriched in phenylalanine-glycine (FG) dipeptides. Through multivalent FG interactions, cellular karyopherins and their bound cargoes solubilize in this phase to drive nucleocytoplasmic transport4. By performing an in vitro dissection of the nuclear pore complex, we show that a pocket on the surface of the HIV capsid similarly interacts with FG motifs from multiple nucleoporins and that this interaction licences capsids to penetrate FG-nucleoporin condensates. This karyopherin mimicry model addresses a key conceptual challenge for the role of the HIV capsid in nuclear entry and offers an explanation as to how an exogenous entity much larger than any known cellular cargo may be able to non-destructively breach the nuclear envelope.

Neuroinflammation in neuronopathic Gaucher disease: Role of microglia and NK cells, biomarkers, and response to substrate reduction therapy

Background

Neuronopathic Gaucher disease (nGD) is a rare neurodegenerative disorder caused by biallelic mutations in GBA and buildup of glycosphingolipids in lysosomes. Neuronal injury and cell death are prominent pathological features; however, the role of GBA in individual cell types and involvement of microglia, blood-derived macrophages, and immune infiltrates in nGD pathophysiology remains enigmatic.

Methods

Here, using single-cell resolution of mouse nGD brains, lipidomics, and newly generated biomarkers, we found induction of neuroinflammation pathways involving microglia, NK cells, astrocytes, and neurons.

Results

Targeted rescue of Gba in microglia and neurons, respectively, in Gba-deficient, nGD mice reversed the buildup of glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph), concomitant with amelioration of neuroinflammation, reduced serum neurofilament light chain (Nf-L), and improved survival. Serum GlcSph concentration was correlated with serum Nf-L and ApoE in nGD mouse models as well as in GD patients. Gba rescue in microglia/macrophage compartment prolonged survival, which was further enhanced upon treatment with brain-permeant inhibitor of glucosylceramide synthase, effects mediated via improved glycosphingolipid homeostasis, and reversal of neuroinflammation involving activation of microglia, brain macrophages, and NK cells.

Conclusions

Together, our study delineates individual cellular effects of Gba deficiency in nGD brains, highlighting the central role of neuroinflammation driven by microglia activation. Brain-permeant small-molecule inhibitor of glucosylceramide synthase reduced the accumulation of bioactive glycosphingolipids, concomitant with amelioration of neuroinflammation involving microglia, NK cells, astrocytes, and neurons. Our findings advance nGD disease biology whilst identifying compelling biomarkers of nGD to improve patient management, enrich clinical trials, and illuminate therapeutic targets.

Funding

Research grant from Sanofi; other support includes R01NS110354, Yale Liver Center P30DK034989, pilot project grant.

Phylogenetic analysis reveals new relationships among members of the genera Microtetraspora and Microbispora

The 16S rRNA gene sequences of 7 Microbispora strains, 14 Microtetraspora species, 9 Streptosporangium species, and 12 Actinomadura species were determined. A phylogenetic analysis showed that Microtetraspora fusca, Microtetraspora glauca, and Microtetraspora niveoalba formed a coherent cluster with the members of the genus Microbispora. This cluster is distantly related to two other clusters, one of which consists of the Microtetraspora species transferred from the former Actinomadura pusilla group and one of which consists of members of the genus Streptosporangium. Our results show that it is necessary to review the taxonomic definitions of the genera Microtetraspora and Microbispora, which have been separated by a single morphological characteristic, the number of spores on spore chains.