N-WASP-Arp2/3 signaling controls multiple steps of dendrite maturation in Purkinje cells in vivo.

During neural development, the actin filament network must be precisely regulated to form elaborate neurite structures. N-WASP tightly controls actin polymerization dynamics by activating an actin nucleator Arp2/3. However, the importance of N-WASP-Arp2/3 signaling in the assembly of neurite architecture in vivo has not been clarified. Here, we demonstrate that N-WASP-Arp2/3 signaling plays a crucial role in the maturation of cerebellar Purkinje cell (PC) dendrites in vivo in mice. N-WASP was expressed and activated in developing PCs. Inhibition of Arp2/3 and N-WASP from the beginning of dendrite formation severely disrupted the establishment of a single stem dendrite, which is a characteristic basic structure of PC dendrites. Inhibition of Arp2/3 after stem dendrite formation resulted in hypoplasia of the PC dendritic tree. Cdc42, an upstream activator of N-WASP, is required for N-WASP-Arp2/3 signaling-mediated PC dendrite maturation. In addition, overactivation of N-WASP is also detrimental to dendrite formation in PCs. These findings reveal that proper activation of N-WASP-Arp2/3 signaling is crucial for multiple steps of PC dendrite maturation in vivo.

Molecular mechanisms regulating the spatial configuration of neurites.

Precise neural networks, composed of axons and dendrites, are the structural basis for information processing in the brain. Therefore, the correct formation of neurites is critical for accurate neural function. In particular, the three-dimensional structures of dendrites vary greatly among neuron types, and the unique shape of each dendrite is tightly linked to specific synaptic connections with innervating axons and is correlated with its information processing. Although many systems are involved in neurite formation, the developmental mechanisms that control the orientation, size, and arborization pattern of neurites definitively defines their three-dimensional structure in tissues. In this review, we summarize these regulatory mechanisms that establish proper spatial configurations of neurites, especially dendrites, in invertebrates and vertebrates.

Geographical distribution and phoretic associations of the viviparous nematode Tokorhabditis atripennis with Onthophagus dung beetles in Japan.

Viviparity is generally considered to be rare in animals. In nematodes, only six species of Rhabditida are viviparous. Five of these species have been identified in association with Onthophagus dung beetles, with Tokorhabditis atripennis being repeatedly isolated from the dung beetle Onthophagus atripennis in Japan. T. atripennis is easy to culture in a laboratory setting, and its host, O. atripennis, is distributed all over Japan. Therefore, T. atripennis is an ideal candidate for ecological and evolutionary studies on viviparity. However, the extent of their distribution and relationship with dung beetles, as well as habitats, remain unclear. In the present study, we conducted field surveys and successfully isolated 27 strains of viviparous nematodes associated with tunneler dung beetles from various regions of Japan, all of which were identified as T. atripennis. T. atripennis exhibited a strong association with Onthophagus dung beetles, especially O. apicetinctus and O. atripennis. And it was predominantly found in specific anatomical locations on the beetle bodies, such as the 'groove between pronotum and elytron' and the 'back of the wings'. Our findings suggest that Onthophagus species are the primary hosts for T. atripennis, and T. atripennis exhibits a close relationship with the living environments of tunneler beetles. This association may play a significant role in the evolution of viviparity in nematodes.

Vascularization of human brain organoids.

Human brain organoids are three-dimensional tissues that are generated in vitro from pluripotent stem cells and recapitulate the early development of the human brain. Brain organoids consist mainly of neural lineage cells, such as neural stem/precursor cells, neurons, astrocytes, and oligodendrocytes. However, all human brain organoids lack vasculature, which plays indispensable roles not only in brain homeostasis but also in brain development. In addition to the delivery of oxygen and nutrition, accumulating evidence suggests that the vascular system of the brain regulates neural differentiation, migration, and circuit formation during development. Therefore, vascularization of human brain organoids is of great importance. Current trials to vascularize various organoids include the adjustment of cultivation protocols, the introduction of microfluidic devices, and the transplantation of organoids into immunodeficient mice. In this review, we summarize the efforts to accomplish vascularization and perfusion of brain organoids, and we discuss these attempts from a forward-looking perspective.

Exposure to particulate matter upregulates ACE2 and TMPRSS2 expression in the murine lung.

Coronavirus disease (COVID-19) is currently a serious global issue. Epidemiological studies have identified air pollutants, including particulate matter (PM), as a risk factor for COVID-19 infection and severity of illness, in addition to numerous factors such as pre-existing conditions, aging and smoking. However, the mechanisms by which air pollution is involved in the manifestation and/or progression of COVID-19 is still unknown. In this study, we used a mouse model exposed to crude PM, collected by the cyclone method, to evaluate the pulmonary expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine type 2 (TMPRSS2), the two molecules required for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into host cells. Multiplex immunohistochemical analysis revealed that exposure to PM increased the expression of these two molecules at the same site. Furthermore, image cytometry analysis revealed increased expression of these proteins, particularly, in the alveolar type 2 cells and macrophages, which are potential targets for SARS-CoV-2. Our findings provide an experimental evidence that exposure to PM may adversely affect the manifestation and progression of COVID-19, mediated by the impact of SARS-CoV-2 on the site of entry. The study results suggest that examining these effects might help to advance our understanding of COVID-19 and aid the development of appropriate social interventions.

Serine Protease Imbalance in the Small Airways and Development of Centrilobular Emphysema in Chronic Obstructive Pulmonary Disease.

Epithelial dysfunction in the small airways may cause the development of emphysema in chronic obstructive pulmonary disease. C/EBPα (CCAAT/enhancer binding protein-α), a transcription factor, is required for lung maturation during development, and is also important for lung homeostasis after birth, including the maintenance of serine protease/antiprotease balance in the bronchiolar epithelium. This study aimed to show the roles of C/EBPα in the distal airway during chronic cigarette smoke exposure in mice and in the small airways in smokers. In a model of chronic smoke exposure using epithelial cell-specific C/EBPα-knockout mice, significant pathological phenotypes, such as higher protease activity, impaired ciliated cell regeneration, epithelial cell barrier dysfunction via reduced zonula occludens-1 (Zo-1), and decreased alveolar attachments, were found in C/EBPα-knockout mice compared with control mice. We found that Spink5 (serine protease inhibitor kazal-type 5) gene (encoding lymphoepithelial Kazal-type-related inhibitor [LEKTI], an anti-serine protease) expression in the small airways is a key regulator of protease activity in this model. Finally, we showed that daily antiprotease treatment counteracted the phenotypes of C/EBPα-knockout mice. In human studies, CEBPA (CCAAT/enhancer binding protein-α) gene expression in the lung was downregulated in patients with emphysema, and six smokers with centrilobular emphysema (CLE) showed a significant reduction in LEKTI in the small airways compared with 22 smokers without CLE. LEKTI downregulation in the small airways was associated with disease development during murine small airway injury and CLE in humans, suggesting that LEKTI might be a key factor linking small airway injury to the development of emphysema.

Accelerated Loss of Antigravity Muscles Is Associated with Mortality in Patients with COPD.

BACKGROUND: Low antigravity muscle mass is strongly associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). However, the significance of longitudinal changes in antigravity muscle mass remains unclear in patients with COPD. OBJECTIVES: The aims of this study were to investigate the factors associated with the longitudinal loss of antigravity muscles and whether the accelerated loss of these muscles has a negative impact on prognosis. METHODS: This study was part of a prospective observational study at Kyoto University. We enrolled stable male patients with COPD who underwent longitudinal quantitative CT analysis of the cross-sectional area of the erector spinae muscles (ESMCSA) at an interval of 3 years. The associations between the rate of change in ESMCSA (%ΔESM) and clinical parameters, such as anthropometry, symptoms, lung function, exacerbation frequency, and all-cause mortality, were investigated. RESULTS: In total, 102 stable male COPD patients were successfully evaluated in this study (71.3 ± 8.3 years, GOLD stage I/II/III/IV = 20/47/28/7 patients). ESMCSA significantly decreased from 30.53 to 28.98 cm2 (p < 0.0001) in 3 years, and the mean %ΔESM was 5.21 ± 7.24%. The rate of survival during the observation period was 85.3% (87/102). Patients with an accelerated decline in ESMCSA (n = 31; more than double the mean rate of decline) had a significantly higher frequency of moderate-to-severe exacerbations during the interval (p = 0.015). They also had significantly worse survival (p = 0.035 by log-rank test). A multivariate Cox proportional hazard model showed that lower ESMCSA and greater %ΔESM decline were independently and significantly associated with mortality. CONCLUSIONS: Frequent exacerbations were related to the loss of antigravity muscles in COPD patients. The accelerated loss of antigravity muscles was associated with a poor prognosis.

Annual decline in arterial blood oxygen predicts development of chronic respiratory failure in COPD with mild hypoxaemia: A 6-year follow-up study.

BACKGROUND AND OBJECTIVE: Chronic respiratory failure (CRF) with hypoxaemia is an important pathophysiology in patients with chronic obstructive pulmonary disease (COPD), and existing mild hypoxaemia may be a sign of future CRF development. However, little is known about the trajectory of partial arterial pressure of oxygen (PaO2 ) decline in patients with COPD. We assessed decline in PaO2 and the impact of short-term reductions in PaO2 to predict future decline in PaO2 . METHODS: A total of 172 outpatients with COPD from a prospective cohort study were enrolled. Pulmonary function tests and arterial blood gas (ABG) analyses were conducted at baseline and 1 year after enrolment and changes in PaO2 (ΔPaO2 ) and other parameters were calculated. Survival and incidence of CRF (as assessed by prescription of long-term home oxygen therapy) were monitored for 6 years. RESULTS: A total of 164 patients completed the observation period and 101 patients had mild hypoxaemia (PaO2 < 80 Torr) at baseline. No patients with normal PaO2 (≥80 Torr) developed CRF, and 10 patients with mild hypoxaemia developed CRF in 6 years. Baseline airflow limitation and diffusion capacity were significantly associated with development of CRF. Receiver-operating characteristic curve analysis showed that ΔPaO2 of -3.05 Torr/year is a useful cut-off value to predict development of CRF in 6 years (hazard ratio (HR): 12.6, 95% CI: 3.48-58.73, P < 0.0001). CONCLUSION: Patients with COPD and mild hypoxaemia may benefit from repeat ABG after 1 year. Although PaO2 trajectories widely varied, significant annual changes in PaO2 of at least -3.0 Torr/year were predictive of CRF development.

Epithelial Notch signaling regulates lung alveolar morphogenesis and airway epithelial integrity.

Abnormal enlargement of the alveolar spaces is a hallmark of conditions such as chronic obstructive pulmonary disease and bronchopulmonary dysplasia. Notch signaling is crucial for differentiation and regeneration and repair of the airway epithelium. However, how Notch influences the alveolar compartment and integrates this process with airway development remains little understood. Here we report a prominent role of Notch signaling in the epithelial-mesenchymal interactions that lead to alveolar formation in the developing lung. We found that alveolar type II cells are major sites of Notch2 activation and show by Notch2-specific epithelial deletion (Notch2(cNull)) a unique contribution of this receptor to alveologenesis. Epithelial Notch2 was required for type II cell induction of the PDGF-A ligand and subsequent paracrine activation of PDGF receptor-α signaling in alveolar myofibroblast progenitors. Moreover, Notch2 was crucial in maintaining the integrity of the epithelial and smooth muscle layers of the distal conducting airways. Our data suggest that epithelial Notch signaling regulates multiple aspects of postnatal development in the distal lung and may represent a potential target for intervention in pulmonary diseases.

Perspectives on End-of-Life Treatment among Patients with COPD: A Multicenter, Cross-sectional Study in Japan.

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality. Since patients with severe COPD may experience exacerbations and eventually face mortality, advanced care planning (ACP) has been increasingly emphasized in the recent COPD guidelines. We conducted a multicenter, cross-sectional study to survey the current perspectives of Japanese COPD patients toward ACP. "High-risk" COPD patients and their attending physicians were consecutively recruited. The patients' family configurations, understanding of COPD pathophysiology, current end-of-life care communication with physicians and family members, and preferences for invasive life-sustaining treatments including mechanical ventilation (MV) and cardiopulmonary resuscitation (CPR) were evaluated using a custom-made, structured, self-administered questionnaire. Attending physicians were also interviewed, and we evaluated the patient-physician agreement. Among the 224 eligible "high-risk" patients, 162 participated. Half of the physicians (54.4%) thought they had communicated detailed information; however, only 19.4% of the COPD patients thought the physicians did so (κ score = 0.16). Less than 10% of patients wanted to receive invasive treatment (MV, 6.3% and CPR, 9.4%); interestingly, more than half marked their decision as "refer to the physician" (MV 42.5% and CPR 44.4%) or "refer to family" (MV, 13.8% and CPR, 14.4%). Patients with less knowledge of COPD were less likely to indicate that they had already made a decision. Although ACP is necessary to cope with severe COPD, Japanese "high-risk" COPD patients were unable to make a decision on their preferences for invasive treatments. Lack of disease knowledge and communication gaps between patients and physicians should be addressed as part of these patients' care.

Terminal differentiation of cortical neurons rapidly remodels RanGAP-mediated nuclear transport system.

Terminal differentiation of neurons is accompanied by irreversible exit from the cell cycle and expression of neuronal phenotypes. The molecular mechanism whereby committed neuronal progenitors lose their ability to reenter the cell cycle is largely unknown. Here, we report that the nuclear transport system is rapidly remodeled in primary cortical progenitor cells (CPCs) at the very beginning of neuronal terminal differentiation. High levels of Ran GTPase-activating protein 1 (RanGAP), a key regulator of the Ran GTP-GDP cycle, in primary CPCs are drastically reduced upon neuronal induction. Small ubiquitin-like modifier (SUMO)-2/3-conjugated RanGAP undergoes desumoylation and degradation in neuronally committed CPCs, where reduced RanGAP levels impede the nuclear import of nucleocytoplasmic shuttling proteins including the DNA replication initiation factor Cdc6. Furthermore, RNAi-mediated down-regulation of RanGAP expression in undifferentiated CPCs induces neuronal phenotypes including cell cycle exit. Our data suggest that remodeling of the RanGAP-mediated nuclear transport system plays a key role in cell cycle exit for terminal differentiation of cortical neurons.

Fraction of MHCII and EpCAM expression characterizes distal lung epithelial cells for alveolar type 2 cell isolation.

BACKGOUND: Alveolar type 2 (AT2) cells play important roles in maintaining adult lung homeostasis. AT2 cells isolated from the lung have revealed the cell-specific functions of AT2 cells. Comprehensive molecular and transcriptional profiling of purified AT2 cells would be helpful for elucidating the underlying mechanisms of their cell-specific functions. To enable the further purification of AT2 cells, we aimed to discriminate AT2 cells from non-AT2 lung epithelial cells based on surface antigen expression via fluorescence activated cell sorting (FACS). METHODS: Single-cell suspensions obtained from enzymatically digested murine lungs were labeled for surface antigens (CD45/CD31/epithelial cell adhesion molecule (EpCAM)/ major histocompatibility complex class II (MHCII)) and for pro-surfactant protein C (proSP-C), followed by FACS analysis for surface antigen expression on AT2 cells. AT2 cells were sorted, and purity was evaluated by immunofluorescence and FACS. This newly developed strategy for AT2 cell isolation was validated in different strains and ages of mice, as well as in a lung injury model. RESULTS: FACS analysis revealed that EpCAM+ epithelial cells existed in 3 subpopulations based on EpCAM and MHCII expression: EpCAMmedMHCII+ cells (Population1:P1), EpCAMhiMHCII- cells (P2), and EpCAMlowMHCII- cells (P3). proSP-C+ cells were enriched in P1 cells, and the purity values of the sorted AT2 cells in P1 were 99.0% by immunofluorescence analysis and 98.0% by FACS analysis. P2 cells were mainly composed of ciliated cells and P3 cells were composed of AT1 cells, respectively, based on the gene expression analysis and immunofluorescence. EpCAM and MHCII expression levels were not significantly altered in different strains or ages of mice or following lipopolysaccharide (LPS)-induced lung injury. CONCLUSIONS: We successfully classified murine distal lung epithelial cells based on EpCAM and MHCII expression. The discrimination of AT2 cells from non-AT2 epithelial cells resulted in the isolation of pure AT2 cells. Highly pure AT2 cells will provide accurate and deeper insights into the cell-specific mechanisms of alveolar homeostasis.

Role of mitochondrial hydrogen peroxide induced by intermittent hypoxia in airway epithelial wound repair in vitro.

The airway epithelium acts as a frontline barrier against various environmental insults and its repair process after airway injury is critical for the lung homeostasis restoration. Recently, the role of intracellular reactive oxygen species (ROS) as transcription-independent damage signaling has been highlighted in the wound repair process. Both conditions of continuous hypoxia and intermittent hypoxia (IH) induce ROS. Although IH is important in clinical settings, the roles of IH-induced ROS in the airway repair process have not been investigated. In this study, we firstly showed that IH induced mitochondrial hydrogen peroxide (H2O2) production and significantly decreased bronchial epithelial cell migration, prevented by catalase treatment in a wound scratch assay. RhoA activity was higher during repair process in the IH condition compared to in the normoxic condition, resulting in the cellular morphological changes shown by immunofluorescence staining: round cells, reduced central stress fiber numbers, pronounced cortical actin filament distributions, and punctate focal adhesions. These phenotypes were replicated by exogenous H2O2 treatment under the normoxic condition. Our findings confirmed the transcription-independent role of IH-induced intracellular ROS in the bronchial epithelial cell repair process and might have significant implications for impaired bronchial epithelial cell regeneration.

The genome and genetics of a high oxidative stress tolerant Serratia sp. LCN16 isolated from the plant parasitic nematode Bursaphelenchus xylophilus.

BACKGROUND: Pine wilt disease (PWD) is a worldwide threat to pine forests, and is caused by the pine wood nematode (PWN) Bursaphelenchus xylophilus. Bacteria are known to be associated with PWN and may have an important role in PWD. Serratia sp. LCN16 is a PWN-associated bacterium, highly resistant to oxidative stress in vitro, and which beneficially contributes to the PWN survival under these conditions. Oxidative stress is generated as a part of the basal defense mechanism used by plants to combat pathogenic invasion. Here, we studied the biology of Serratia sp. LCN16 through genome analyses, and further investigated, using reverse genetics, the role of two genes directly involved in the neutralization of H2O2, namely the H2O2 transcriptional factor oxyR; and the H2O2-targeting enzyme, catalase katA. RESULTS: Serratia sp. LCN16 is phylogenetically most closely related to the phytosphere group of Serratia, which includes S. proteamaculans, S. grimessi and S. liquefaciens. Likewise, Serratia sp. LCN16 shares many features with endophytes (plant-associated bacteria), such as genes coding for plant polymer degrading enzymes, iron uptake/transport, siderophore and phytohormone synthesis, aromatic compound degradation and detoxification enzymes. OxyR and KatA are directly involved in the high tolerance to H2O2 of Serratia sp. LCN16. Under oxidative stress, Serratia sp. LCN16 expresses katA independently of OxyR in contrast with katG which is under positive regulation of OxyR. Serratia sp. LCN16 mutants for oxyR (oxyR::int(614)) and katA (katA::int(808)) were sensitive to H2O2 in relation with wild-type, and both failed to protect the PWN from H2O2-stress exposure. Moreover, both mutants showed different phenotypes in terms of biofilm production and swimming/swarming behaviors. CONCLUSIONS: This study provides new insights into the biology of PWN-associated bacteria Serratia sp. LCN16 and its extreme resistance to oxidative stress conditions, encouraging further research on the potential role of this bacterium in interaction with PWN in planta environment.

Involvement of Vitamin B6 Biosynthesis Pathways in the Insecticidal Activity of Photorhabdus luminescens.

UNLABELLED: Photorhabdus luminescens is a Gram-negative entomopathogenic bacterium which symbiotically associates with the entomopathogenic nematode Heterorhabditis bacteriophora P. luminescens is highly virulent to many insects and nonsymbiotic nematodes, including Caenorhabditis elegans To understand the virulence mechanisms of P. luminescens, we obtained virulence-deficient and -attenuated mutants against C. elegans through a transposon-mutagenized library. From the genetic screening, we identified the pdxB gene, encoding erythronate-4-phosphate dehydrogenase, as required for de novo vitamin B6 biosynthesis. Mutation in pdxB caused growth deficiency of P. luminescens in nutrient-poor medium, which was restored under nutrient-rich conditions or by supplementation with pyridoxal 5'-phosphate (PLP), an active form of vitamin B6 Supplementation with three other B6 vitamers (pyridoxal, pyridoxine, and pyridoxamine) also restored the growth of the pdxB mutant, suggesting the existence of a salvage pathway for vitamin B6 biosynthesis in P. luminescens Moreover, supplementation with PLP restored the virulence-deficient phenotype against C. elegans Combining these results with the fact that pdxB mutation also caused attenuation of insecticidal activity, we concluded that the production of appropriate amounts of vitamin B6 is critical for P. luminescens pathogenicity. IMPORTANCE: The Gram-negative entomopathogenic bacterium Photorhabdus luminescens symbiotically associates with the entomopathogenic nematode Heterorhabditis bacteriophora P. luminescens is highly virulent to many insects and nonsymbiotic nematodes, including Caenorhabditis elegans We have obtained several virulence-deficient and -attenuated P. luminescens mutants against C. elegans through genetic screening. From the genetic analysis, we present the vitamin B6 biosynthetic pathways in P. luminescens that are important for its insecticidal activity. Mutation in pdxB, encoding erythronate-4-phosphate dehydrogenase and required for the de novo vitamin B6 biosynthesis pathway, caused virulence deficiency against C. elegans and growth deficiency of P. luminescens in nutrient-poor medium. Because such phenotypes were restored under nutrient-rich conditions or by supplementation with B6 vitamers, we showed the presence of the two vitamin B6 synthetic pathways (de novo and salvage) in P. luminescens and also showed that the ability to produce an appropriate amount of vitamin B6 is critical for P. luminescens pathogenicity.

Evidence for an Opportunistic and Endophytic Lifestyle of the Bursaphelenchus xylophilus-Associated Bacteria Serratia marcescens PWN146 Isolated from Wilting Pinus pinaster.

Pine wilt disease (PWD) results from the interaction of three elements: the pathogenic nematode, Bursaphelenchus xylophilus; the insect-vector, Monochamus sp.; and the host tree, mostly Pinus species. Bacteria isolated from B. xylophilus may be a fourth element in this complex disease. However, the precise role of bacteria in this interaction is unclear as both plant-beneficial and as plant-pathogenic bacteria may be associated with PWD. Using whole genome sequencing and phenotypic characterization, we were able to investigate in more detail the genetic repertoire of Serratia marcescens PWN146, a bacterium associated with B. xylophilus. We show clear evidence that S. marcescens PWN146 is able to withstand and colonize the plant environment, without having any deleterious effects towards a susceptible host (Pinus thunbergii), B. xylophilus nor to the nematode model C. elegans. This bacterium is able to tolerate growth in presence of xenobiotic/organic compounds, and use phenylacetic acid as carbon source. Furthermore, we present a detailed list of S. marcescens PWN146 potentials to interfere with plant metabolism via hormonal pathways and/or nutritional acquisition, and to be competitive against other bacteria and/or fungi in terms of resource acquisition or production of antimicrobial compounds. Further investigation is required to understand the role of bacteria in PWD. We have now reinforced the theory that B. xylophilus-associated bacteria may have a plant origin.

Optimal blood pressure in patients with peripheral artery disease following endovascular therapy.

This study examined the associations between blood pressure (BP) and event incidence to define optimal BP after endovascular therapy (EVT) in patients who underwent EVT. BP was monitored every 6 months for 5 years, and the patients were divided into two groups by average BP: ≥ 140/90 mmHg and < 140/90 mmHg. The association of BP with several events was examined. Although no significant differences in total mortality were observed between the groups, restenosis rates were significantly higher among patients who did not achieve target BP (36.2%) than among those who did (18.2%) (p < 0.01). The percentage of patients with glycosylated haemoglobin > 7.0% was significantly higher among those who did not achieve target BP in the restenosis group (42.9%) than in the other group (10.8%) (p < 0.01). In the restenosis group, there was a significantly higher percentage of patients taking metformin (p < 0.01) than in the other group. Metformin seemed to be administered to patients with more severe diabetes mellitus. In conclusion, it is important to manage hypertension and diabetes to prevent restenosis after EVT.

Japan PGx Data Science Consortium Database: SNPs and HLA genotype data from 2994 Japanese healthy individuals for pharmacogenomics studies.

Japan Pharmacogenomics Data Science Consortium (JPDSC) has assembled a database for conducting pharmacogenomics (PGx) studies in Japanese subjects. The database contains the genotypes of 2.5 million single-nucleotide polymorphisms (SNPs) and 5 human leukocyte antigen loci from 2994 Japanese healthy volunteers, as well as 121 kinds of clinical information, including self-reports, physiological data, hematological data and biochemical data. In this article, the reliability of our data was evaluated by principal component analysis (PCA) and association analysis for hematological and biochemical traits by using genome-wide SNP data. PCA of the SNPs showed that all the samples were collected from the Japanese population and that the samples were separated into two major clusters by birthplace, Okinawa and other than Okinawa, as had been previously reported. Among 87 SNPs that have been reported to be associated with 18 hematological and biochemical traits in genome-wide association studies (GWAS), the associations of 56 SNPs were replicated using our data base. Statistical power simulations showed that the sample size of the JPDSC control database is large enough to detect genetic markers having a relatively strong association even when the case sample size is small. The JPDSC database will be useful as control data for conducting PGx studies to explore genetic markers to improve the safety and efficacy of drugs either during clinical development or in post-marketing.

Emphysema and airway disease affect within-breath changes in respiratory resistance in COPD patients.

BACKGROUND AND OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is characterized by a mixture of emphysema and airway disease. The forced oscillation technique (FOT) has been applied to COPD patients to clarify changes in respiratory mechanics; dynamic changes in respiratory resistance (Rrs) during breathing (within-breath changes in Rrs, ΔRrs) are characteristic of COPD. However, the pathophysiological significance of these changes is unknown. The aim of this study was to assess how emphysema and airway disease influence ΔRrs in COPD patients. METHODS: In this cross-sectional study, stable COPD patients were recruited and underwent respiratory impedance measurements with a commercially available FOT device. Rrs was recorded during tidal breathing and then analyzed as whole-breath Rrs (Rrs at 5 Hz, R5; Rrs at 20 Hz, R20; and their difference, R5-R20) or as ΔRrs, the difference between the expiratory and inspiratory Rrs (ΔR5, ΔR20 and ΔR5-R20). The percentage of the low attenuation area (LAA%) and airway wall area (WA%) was quantified by computed tomography analysis, and their contributions to ΔRrs were examined. RESULTS: Seventy-five COPD patients were recruited. LAA% was negatively correlated with ΔR5 and ΔR5-R20 (P = 0.0002 and P = 0.0033, respectively); meanwhile, WA% in B(10) was positively correlated with ΔR5 and ΔR5-R20 (P = 0.0057 and P < 0.0001, respectively). Multivariate analysis revealed that the contribution of both LAA% and WA% in B(10) to ΔRrs was independent of the severity of airflow limitations. CONCLUSION: This study shows that emphysema suppresses ΔRrs in COPD patients, while airway disease increases ΔRrs in these patients.

Necdin controls proliferation and apoptosis of embryonic neural stem cells in an oxygen tension-dependent manner.

Neural stem cells (NSCs) reside in vivo in hypoxic environments, and NSC proliferation is enhanced in vitro under hypoxic conditions. Various adaptive responses to hypoxia are mediated by hypoxia-inducible factors (HIFs), a family of basic helix-loop-helix Per-Arnt-Sim (PAS) transcription factors. Necdin, a MAGE (melanoma antigen) family protein, is expressed abundantly in postmitotic neurons and possesses potent antimitotic and antiapoptotic activities. We here report that hypoxia induces degradation of the necdin protein in primary NSCs by HIF-mediated ubiquitin-proteasome system. Necdin was expressed in primary NSCs prepared from the ganglionic eminences of mouse embryos. Hypoxia enhanced neurosphere formation of NSCs, in which the necdin protein level was significantly reduced. Primary NSCs prepared from necdin-deficient mice exhibited higher rates of proliferation and apoptosis than those from wild-type mice in normoxia, whereas there were no significant differences in the proliferation and apoptosis rates between necdin-deficient and wild-type NSCs in hypoxia. HIF-2α was predominantly expressed in hypoxic NSCs, where expression of HIF-responsive genes was upregulated. HIF-2α interacted with necdin via its PAS domain, which enhanced necdin ubiquitination. Lentivirus-mediated expression of the PAS domain in primary NSCs promoted necdin degradation and enhanced NSC proliferation in normoxia, whereas a small-molecule inhibitor of HIF-2α translation stabilized the necdin protein and reduced NSC proliferation in hypoxia. These results suggest that oxygen tension regulates the necdin protein level in NSCs through HIF-2α-mediated proteasomal degradation to modulate their proliferation and apoptosis.