Anammox Bacterial S-Adenosyl-l-Methionine Dependent Methyltransferase Crystal Structure and Its Interaction with Acyl Carrier Proteins.

Ladderane lipids (found in the membranes of anaerobic ammonium-oxidizing [anammox] bacteria) have unique ladder-like hydrophobic groups, and their highly strained exotic structure has attracted the attention of scientists. Although enzymes encoded in type II fatty acid biosynthesis (FASII) gene clusters in anammox bacteria, such as S-adenosyl-l-methionine (SAM)-dependent enzymes, have been proposed to construct a ladder-like structure using a substrate connected to acyl carrier protein from anammox bacteria (AmxACP), no experimental evidence to support this hypothesis was reported to date. Here, we report the crystal structure of a SAM-dependent methyltransferase from anammox bacteria (AmxMT1) that has a substrate and active site pocket between a class I SAM methyltransferase-like core domain and an additional α-helix inserted into the core domain. Structural comparisons with homologous SAM-dependent C-methyltransferases in polyketide synthase, AmxACP pull-down assays, AmxACP/AmxMT1 complex structure predictions by AlphaFold, and a substrate docking simulation suggested that a small compound connected to AmxACP could be inserted into the pocket of AmxMT1, and then the enzyme transfers a methyl group from SAM to the substrate to produce branched lipids. Although the enzymes responsible for constructing the ladder-like structure remain unknown, our study, for the first time, supports the hypothesis that biosynthetic intermediates connected to AmxACP are processed by SAM-dependent enzymes, which are not typically involved in the FASII system, to produce the ladder-like structure of ladderane lipids in anammox bacteria.

Factors associated with the location of perivascular space enlargement in middle-aged individuals undergoing brain screening in Japan.

OBJECTIVE: In elderly populations, the enlargement of the perivascular space is related to small vessel disease and the glymphatic system. Enlarged perivascular spaces (EPVS) in the basal ganglia (EPVS-BG) and EPVS in the centrum semiovale (EPVS-CSO) are associated with different pathophysiological processes. However, the prevalence of EPVS and the factors associated with EPVS location in healthy middle-aged individuals are still unclear. We aimed to determine the prevalence of EPVS and the factors associated with EPVS location among healthy individuals in their 40 s METHODS: This study included 5000 consecutive healthy individuals who underwent screening for brain diseases in Japan from August to December 2018. Of them, the data of individuals in their 40 s were extracted and analyzed. The associations of age, sex, body mass index, smoking and drinking history, and medical history with EPVS location were investigated. Similar analyses were performed for the other age groups. A literature review on the factors associated with EPVS location was also performed. RESULTS: A total of 1720 individuals in their 40 s were finally included. The prevalence of EPVS-BG and EPVS-CSO was 7.7% and 9.2%, respectively. Age (years), smoking history, and hypertension were associated with EPVS-BG; none of the studied factors were found to be associated with EPVS-CSO. In the elderly, the factors previously reported to be associated with EPVS-BG included atherosclerosis change, while the factors associated with EPVS-CSO were cerebral amyloid angiopathy-related formation. CONCLUSION: Both EPVS-BG and EPVS-CSO occurred among healthy individuals in their 40 s, but they did so rarely, and less prevalently than in older age groups. EPVS-BG and EPVS-CSO may represent early imaging signs of the atherosclerotic and cerebral amyloid angiopathy processes, respectively. DATA AVAILABILITY: The anonymized data for this study will be shared upon any qualified investigator's request to the corresponding author. Primary data from this study will be made available upon reasonable request in accordance with the review board of the research institute.

Perilla frutescens seed oil combined with Anredera cordifolia leaf powder attenuates age-related cognitive decline by reducing serum triglyceride and glucose levels in healthy elderly Japanese individuals: a possible supplement for brain health.

We have shown that Anredera cordifolia extract improves learning and memory in a senescence-accelerated mouse model, and that α-linolenic acid (ALA)-rich Perilla frutescens seed oil (PO) improves brain function in healthy Japanese adults and elderly individuals. Herein, we present a 12-month, randomised, double-blind, parallel-armed intervention trial examining the effects of PO supplementation alone or in combination with A. cordifolia leaf powder on brain function in healthy elderly Japanese individuals. Participants were randomly divided into two groups: the PO group received 1.47 mL PO (0.88 g ALA) daily via soft gelatine capsules, and the POAC group received 1.47 mL PO and 1.12 g A. cordifolia leaf powder (1.46 mg vitexin and 1.12 mg adenosine) daily. After 12 months of intervention, the POAC group showed generally higher cognitive index scores than the PO group. The beneficial effects of combined supplementation on cognitive function were associated with increased ALA and eicosapentaenoic acid levels in red blood cell plasma membranes, increased serum biological antioxidant potential, and decreased serum triglyceride, glucose, and N-(epsilon)-carboxymethyl-lysine (CML), an advanced glycation end-product and biochemical marker of oxidative stress levels. The effects of combined supplementation on cognitive function also showed a significant negative correlation with serum CML levels after 12 months of intervention. Our findings suggest that combined long-term supplementation with PO and A. cordifolia more effectively ameliorates age-related cognitive decline than PO alone. These findings may serve as a basis for the development of new supplements for brain health. Clinical Trial Registry, UMIN000040863.

Perilla seed oil in combination with nobiletin-rich ponkan powder enhances cognitive function in healthy elderly Japanese individuals: a possible supplement for brain health in the elderly.

Perilla (Perilla frutescens) seed oil (PO), rich in α-linolenic acid (ALA), can improve cognitive function in healthy elderly Japanese people. Here, supplements containing either PO alone or PO with nobiletin-rich air-dried immature ponkan powder were examined for their effects on cognitive function in 49 healthy elderly Japanese individuals. Patients were enrolled in a 12-month randomized, double-blind, parallel-armed study. Randomized participants in the PO group received soft gelatin capsules containing 1.47 mL (0.88 g of ALA) of PO daily, and those in the PO + ponkan powder (POPP) group received soft gelatin capsules containing both 1.47 mL of PO and 1.12 g ponkan powder (2.91 mg of nobiletin) daily. At the end of intervention, the POPP group showed significantly higher cognitive index scores than the PO group. The pro-cognitive effects of POPP treatment were accompanied by increases in ALA and docosahexaenoic acid levels in red blood cell plasma membranes, serum brain-derived neurotropic factor (BDNF) levels, and biological antioxidant potential. We demonstrate that 12-month intervention with POPP enhances serum BDNF and antioxidant potential, and may improve age-related cognitive impairment in healthy elderly people by increasing red blood cell ω-3 fatty acid levels. Clinical Trial Registry, UMIN000040863.

Four new dendrochirotid holothurians collected from the Seto Inland Sea and the western part of the Sea of Japan, western Japan.

Fifteen dendrochirotid holothurians, including four new species, were collected from the Seto Inland Sea and the western part of the Sea of Japan, western Japan by the training and research vessel (TR/V) TOYOSHIO MARU of Hiroshima University, during the 201415 surveys. Massinium toyoshiomaruae sp. nov., Thyone kyushuensis sp. nov., T. liaoi sp. nov., and T. toyoshiomaruae sp. nov. are described as new species. Massinium toyoshiomaruae sp. nov. is readily distinguishable from all congeners by the absence of bodywall ossicles and the presence of table ossicles in the tentacle base. Thyone kyushuensis sp. nov. possesses large polyporous-tables in the introvert and tentacles, bodywall ossicles of a peculiar shape, and tentacle ossicles comprised mostly of unbranching rods and/or rod-like rosettes, which differ from those of all congeners. Thyone liaoi sp. nov. resembles T. pedata Semper, 1867 in its bodywall ossicles, however, it is distinguishable by the absences of huge ossicles in the body wall and the needle-shaped ossicles in the gonadal tubules. Thyone toyoshiomaruae sp. nov. is distinguishable from all other Thyone by the presence of the peculiar shape of the bodywall ossicles. Partial sequences of the mitochondrial cytochrome c oxidase subunit I gene are provided from the type specimens of the new species as DNA barcoding data.

Risk Factor for Poor Outcome in Elderly Patients with Aneurysmal Subarachnoid Hemorrhage Based on Post Hoc Analysis of the Modified WFNS Scale Study.

OBJECTIVE: There is currently no precise guide for the treatment and management of elderly patients with aneurysmal subarachnoid hemorrhage (aSAH). Thus, the aim of this study was to clarify the factors of poor outcome and mortality in elderly patients with aSAH. METHODS: In the modified World Federation of Neurosurgical Societies (mWFNS) scale study, 1124 patients were divided into 2 groups, elderly (age ≥65 years) and non-elderly (age <65 years), with aSAH investigated between October 2010 and March 2013 in Japan. The odds ratio (OR) and 95% confidence interval (CI) of each risk factor was calculated through multivariate logistic regression analysis for poor outcomes, as indicated by the modified Rankin Scale (mRS) score ≥3 and mortality at 3 months after onset in each group. RESULTS: Both groups demonstrated that the mWFNS scale was significant as a grade order risk factor for poor outcomes and mortality associated with disease. In the elderly group, risk factors for poor outcomes at 3 months after onset were older age (OR 1.10, 95% CI 1.06-1.14), male sex (OR 2.03, 95% CI 1.10-3.73), and severe cerebral vasospasm category (OR 10.13, 95% CI 4.30-23.87). Risk factors for mortality at 3 months after onset were older age (OR 1.06, 95% CI 1.01-1.11) and severe vasospasm category (OR 2.17, 95% CI 1.00-4.72). CONCLUSIONS: The mWFNS scale is a useful prognostic predictor for both non-elderly and elderly patients with aSAH. Elderly male patients with aSAH presenting with severe vasospasm should be managed more carefully.

iTRAQ-based proteomic analysis after mesenchymal stem cell line transplantation for ischemic stroke.

Transplantation with mesenchymal stem cells (MSCs) has been reported to promote functional recovery in animal models of ischemic stroke. However, the molecular mechanisms underlying the therapeutic effects of MSC transplantation have been only partially elucidated. The purpose of this study was to comprehensively identify changes in brain proteins in rats treated with MSCs for ischemic stroke, and to explore the multi-target mechanisms of MSCs using a proteomics-based strategy. Twenty-eight proteins were found to be differentially expressed following B10 MSC transplantation in adult male Wistar rats, as assessed using isobaric tagging for relative and absolute protein quantification (iTRAQ). Subsequent bioinformatic analysis revealed that these proteins were mainly associated with energy metabolism, glutamate excitotoxicity, oxidative stress, and brain structural and functional plasticity. Immunohistochemical staining revealed decreased expression of EAAT1 in the phosphate-buffered saline group as opposed to normal levels in the B10 transplantation group. Furthermore, ATP levels were also significantly higher in the B10 transplantation group, thus supporting the iTRAQ results. Our results suggest that the therapeutic effects of B10 transplantation might arise from the modulation of the acute ischemic cascade via multiple molecular pathways. Thus, our findings provide valuable clues to elucidate the mechanisms underlying the therapeutic effects of MSC transplantation in ischemic stroke.

Association between cystatin C gene polymorphism and the prevalence of white matter lesion in elderly healthy subjects.

Cystatin C (CST3) is a cysteine protease inhibitor abundant in the central nervous system, and demonstrated to have roles in several pathophysiological processes including vascular remodeling and inflammation. Previously, we showed a relation of CST3 gene polymorphisms with deep and subcortical white matter hyperintensity (DSWMH) in a small case-control study. In this study, we aimed to investigate the relation in a larger cross-sectional study. Participants of a brain health examination program were recruited (n = 1795) in the study, who underwent routine blood tests and cognitive function tests. Cerebral white matter changes were analyzed by MRI. Additionally, 7 single nucleotide polymorphisms (SNPs) (-82G/C, -78T/G, -5G/A, +4A/C, +87C/T, +148G/A and +213G/A) in the promoter and coding regions of CST3 gene were examined. Among them, carriers of the minor allele haplotype -82C/+4C/+148A were significantly associated with decreased CST3 concentration in the plasma. Unadjusted analysis did not show significant relation between carriers of the minor allele haplotype and periventricular hyperintensity (PVH), but DSWMH was marginally (p < 0.054) increased in this group. After adjusting the effects of other variables like age and kidney function, logistic regression analysis revealed that carriers of the minor allele haplotype were at a significantly increased risk of developing both PVH and DSWMH. Thus, our results suggest that carriers of the minor allele haplotype -82C/+4C/+148A of CST3 gene could be at an increased risk to develop cerebral white matter disturbance.

Genetic and lifestyle risk factors for MRI-defined brain infarcts in a population-based setting.

OBJECTIVE: To explore genetic and lifestyle risk factors of MRI-defined brain infarcts (BI) in large population-based cohorts. METHODS: We performed meta-analyses of genome-wide association studies (GWAS) and examined associations of vascular risk factors and their genetic risk scores (GRS) with MRI-defined BI and a subset of BI, namely, small subcortical BI (SSBI), in 18 population-based cohorts (n = 20,949) from 5 ethnicities (3,726 with BI, 2,021 with SSBI). Top loci were followed up in 7 population-based cohorts (n = 6,862; 1,483 with BI, 630 with SBBI), and we tested associations with related phenotypes including ischemic stroke and pathologically defined BI. RESULTS: The mean prevalence was 17.7% for BI and 10.5% for SSBI, steeply rising after age 65. Two loci showed genome-wide significant association with BI: FBN2, p = 1.77 × 10-8; and LINC00539/ZDHHC20, p = 5.82 × 10-9. Both have been associated with blood pressure (BP)-related phenotypes, but did not replicate in the smaller follow-up sample or show associations with related phenotypes. Age- and sex-adjusted associations with BI and SSBI were observed for BP traits (p value for BI, p [BI] = 9.38 × 10-25; p [SSBI] = 5.23 × 10-14 for hypertension), smoking (p [BI] = 4.4 × 10-10; p [SSBI] = 1.2 × 10-4), diabetes (p [BI] = 1.7 × 10-8; p [SSBI] = 2.8 × 10-3), previous cardiovascular disease (p [BI] = 1.0 × 10-18; p [SSBI] = 2.3 × 10-7), stroke (p [BI] = 3.9 × 10-69; p [SSBI] = 3.2 × 10-24), and MRI-defined white matter hyperintensity burden (p [BI] = 1.43 × 10-157; p [SSBI] = 3.16 × 10-106), but not with body mass index or cholesterol. GRS of BP traits were associated with BI and SSBI (p ≤ 0.0022), without indication of directional pleiotropy. CONCLUSION: In this multiethnic GWAS meta-analysis, including over 20,000 population-based participants, we identified genetic risk loci for BI requiring validation once additional large datasets become available. High BP, including genetically determined, was the most significant modifiable, causal risk factor for BI.

A Mesenchymal stem cell line (B10) increases angiogenesis in a rat MCAO model.

A human mesenchymal stem cell line (B10) transplantation has been shown to improve ischemia-induced neurological deficits in animal stroke models. To understand the underlying mechanism, we have investigated the effects of B10 transplantation on cerebral angiogenesis in a rat middle cerebral artery occlusion (MCAO) model. B10 cells were transplanted intravenously 24 h after MCAO. Immunofluorescence staining results showed that compared to PBS-groups, vWF positive vessel and endoglin positive new vessels were increased in B10-transplanted MCAO groups in the lesion areas. The mRNA of angiogenesis factors including placental growth factor and hypoxia inducible factor (HIF)-1α were increased 3 days after MCAO in the core and IBZ areas of B10-transplanted group. Angiopoetin1 mRNA was increased only in the IBZ. Western blotting results showed that HIF-1α and vascular endothelial growth factor (VEGF) proteins were increased in B10-transplanted group. Both HIF-1α and VEGF were expressed in macrophage/microglia in the core area. In the IBZ, however, HIF-1α was expressed both in astrocytes and macrophage/microglia, while VEGF was expressed only in macrophage/microglia. Moreover, TGFß protein levels were found to be increased in B10-transplanted group in the core and IBZ regions. Cell culture experiments using a human microglia cell line (HMO6) and B10 showed that IL-1ß induced VEGF mRNA expression in both cell types. IL-1ß was found to be highly expressed in B10 cells, and its co-culture with HMO6 further increased that in B10. Co-culture increased VEGF mRNA in both B10 and HMO6. In the rat brains, IL-1ß was expressed in macrophage/microglia and transplanted-B10 cells in the core. IL-1ß positive cell number was increased slightly, but significantly in B10-transplanted rats. To explore further, IL-1ß expression was silenced in B10 cells by transfecting mRNA specific siRNA, and then transplanted in MCAO rats. Immunostaining result showed that endoglin positive area was decreased in IL-1ß-silenced B10 transplanted groups compared to nonsilenced-B10 transplanted groups. Interestingly, vessel-like structure appeared as early as 3 days after MCAO in IL-1ß-silenced B10-transplanted group. Thus our results demonstrated that B10 cells increased angiogenesis in MCAO rat model, through the regulation of HIF-1α and VEGF expression, where IL-1ß might play a role.

Transplantation of a bone marrow mesenchymal stem cell line increases neuronal progenitor cell migration in a cerebral ischemia animal model.

Mesenchymal stem cell (MSC) transplantation is demonstrated to improve functional and pathological recovery in cerebral ischemia. To understand the underlying mechanism, we transplanted a MSC line (B10) in a rat middle cerebral artery occlusion (MCAO) model and checked the proliferation and migration of neuronal progenitor cells (NPCs). B10 transplantation increased NPCs in the subventricular zone and their migration towards the lesion area at an earlier time. Fourteen days after MCAO, some NPCs were differentiated to neurons and astrocytes. Although B10 transplantation increased total number of both astrocytes and neurons, it only increased the differentiation of NPC to astrocyte. The mRNA of polysialylation enzyme ST8SiaIV and a chemokine SDF-1 were persistently increased in B10-transplanted groups. SDF-1-positive cell number was increased in the core and penumbra area, which was expressed in macrophage/microglia and transplanted B10 cells at 3 days after MCAO. Furthermore, SDF-1 mRNA expression in cell culture was high in B10 compared to a microglia (HMO) or a neuronal (A1) cell line. B10 culture supernatant increased in vitro A1 cell migration, which was significantly inhibited by siRNA-mediated SDF-1 silencing in B10. Thus, our results suggested that MSC transplantation increased endogenous NPC migration in cerebral ischemic condition by increasing chemokine and polysialylation enzyme expression, which could be helpful for the restorative management of cerebral ischemia.

Spectral and angular shaping of infrared radiation in a polymer resonator with molecular vibrational modes.

We present a comprehensive approach for tailoring the spectral and angular properties of infrared thermal radiation by using a polymer resonator with molecular vibrational modes, consisting of a polymer thin film on a back-reflective substrate. To precisely design the resonator, we derived the infrared dielectric function of a poly(methyl methacrylate) (PMMA) thin film from the measured reflectance spectrum by fitting it with a Gaussian-convoluted Drude-Lorentz model while accounting for the inhomogeneous broadening caused by the disordered structure of polymers. Our experimental and numerical characterization confirms that the polymer resonator exhibits spectral shaping from quasi-broadband to narrowband due to the intrinsic molecular vibrational absorption of the polymer. The frequency-isolated and strong molecular vibrational absorption of the carbonyl stretching mode at 1730 cm-1 enables the narrowband shaping of the PMMA resonator. In addition, we confirm that the angular-shaping characteristics of this polymer resonator can be tuned, from omnidirectional to strongly angular selective, by changing its polymer film thickness. Modal dispersion analysis reveals that the angle-selectivity of the polymer resonator at an angle of incidence of 80° comes from coupling between the molecular vibrational mode and leaky mode. The proposed infrared radiation management strategy based on molecular vibrational modes of polymers is cost-effective, scalable, and works well with terrestrial matter, including organic compounds and gas molecules, showing promise for applications such as optical gas sensing and radiative thermal management.

Additional Medical Costs Due to Hospital-Acquired Falls.

OBJECTIVES: To explore the additional medical costs (AMCs) due to hospital-acquired falls (falls), as well as their impact on clinical services within hospitals under the nationally uniform universal health insurance system in Japan. METHODS: With the use of administrative profiling data based on accounting systems linked with the Japanese social insurance medical fee schedule, we analyzed data from 2 teaching hospitals: Shimane University Hospital (SUH) and St. Mary's Hospital (SMH). We extracted 588 fall cases from 4669 incident reports in SUH and 1168 fall cases from 7717 incident reports in SMH that potentially incurred AMCs. RESULTS: Additional medical costs were 364 ± 2129 USD for minor injuries and 4336 ± 3645 USD for major injuries at SUH (P < 0.001) and 114 ± 124 USD for minor injuries and 2267 ± 2811 USD for major injuries at SMH (P < 0.001). Among the clinical services provided, imaging services were the most frequently used, with 89.9% (n = 205) of 228 minor injuries at SUH and 86.7% (n = 339) of 391 minor injuries at SMH; imaging services were used in all major injury cases at both hospitals. Although the number of cases using additional procedure/surgery services was lower than those using imaging services at both hospitals, AMCs for procedure/surgery services accounted for the highest proportions of total AMCs in both hospitals. CONCLUSIONS: Although falls with minor injuries outnumbered falls with major injuries, fall-related AMCs for the latter were higher at both teaching hospitals because procedure/surgery services were required for cases with major injuries such as femoral neck and trochanteric fractures. The findings suggest that hospital administrators and policy makers have to take appropriate measures to prevent major injuries inpatients due to hospital-acquired falls.

Co-localization of cystatin C and prosaposin in cultured neurons and in anterior horn neurons with amyotrophic lateral sclerosis.

Cystatin C (CST3) is a cysteine protease inhibitor that regulates lysosomal enzyme activity and is reported to be involved in the process of neurodegeneration. In the present study, we investigated whether CST3 interacts with other proteins and affects neurodegeneration in vitro and under disease conditions. We intended to identify any protein that interacts with CST3 by using a yeast two-hybrid system, and found prosaposin (PSAP) as a candidate protein. The binding of CST3 and PSAP was confirmed using an immunoprecipitation-based in vitro assay. An enzyme activity assay revealed that PSAP ameliorated CST3-mediated inhibition of cathepsin B activity. To investigate further, CST3 and PSAP were co-expressed in HeLa cells and in a human neuronal cell line (A1). Subsequent immunocytochemical studies demonstrated that they were co-localized mainly in the lysosomes. In spinal motor neurons of autopsy cases, both proteins showed a granular staining pattern. However, the staining intensities of CST3 and PSAP decreased in Bunina body-positive motor neurons of patients with amyotrophic lateral sclerosis (ALS). Further analysis with immunofluorescence staining revealed that CST3 was immunopositive in the inclusions of ALS motor neurons, where it was closely associated, and sometimes co-localized, with PSAP. CST3 immunoreactivity is recognized as a marker for Bunina bodies in ALS, suggesting that PSAP might also be included in Bunina bodies. The interaction of CST3 and PSAP may alter their functions, leading to motor neuron degeneration in ALS.

Quantification of CSF cystatin C using liquid chromatography tandem mass spectrometry.

BACKGROUND: Cystatin C (CST3), a ubiquitously expressed cysteine protease inhibitor, is implicated in several neurological diseases. Here, we have developed an accurate CST3 measurement system based on liquid chromatography tandem mass spectrometry (LC-MS/MS). METHODS: LC-MS/MS based measurement for CSF CST3 was validated by determination of assay precision, accuracy and recovery. The values were compared with those measured by immunoassay. Glycosylation of CST3 in CSF was analyzed by Western blotting and lectin blotting. RESULTS: Measuring standard CST3 by LC-MS/MS produced a linear standard curve that correlated with assigned values (r2=0.99). Both intra- and inter-assay variation was <10%. Although showed a correlation, the average CST3 concentration measured by LC-MS/MS was significantly higher than that of immunoassay. Western blotting showed the presence of a 25KDa species along with CST3 monomer (14KDa) in CSF. The volume of 25KDa species was decreased by deglycosylation. Lectin blotting revealed a 25KDa glycosylated protein in sialidase-treated CSF, which was decreased by deglycosylation. However, deglycosylation did not alter CST3 concentration measured by immunoassay. CONCLUSIONS: Our results suggest that LC-MS/MS-based CST3 measurement is a robust method with higher detection ability. Such method could be useful for the diagnosis and monitoring of neurological diseases.

Crowned Dens Syndrome Associated with Bowel Cleaning for Colonoscopy.

A 77-year-old man was admitted with posterior cervical pain, lumbago, a low-grade fever, and anorexia after bowel cleaning with polyethylene glycol for colonoscopy. Computed tomography of the neck showed calcification of the transverse ligament of the atlas. He was diagnosed with crowned dens syndrome (CDS). His condition improved following treatment with corticosteroids. This represents a rare case of CDS after endoscopy with polypectomy. We should consider CDS in the differential diagnosis of patients with unexplained fever and posterior cervical pain after bowel preparation for colonoscopy.

Effect of resolution recovery using graph plots on regional cerebral blood flow in healthy volunteers.

PURPOSE: We evaluated the effect of resolution recovery (RR) using graph plots on regional cerebral blood flow (rCBF) in brain perfusion single-photon emission computed tomography (SPECT) images derived from healthy volunteers and patients diagnosed with probable Alzheimer's disease. METHOD: We acquired brain perfusion SPECT images with scatter correction (SC), computed tomography-based attenuation correction (CTAC), and RR from a three-dimensional brain phantom and from healthy volunteers. We then compared contrast-to-noise ratio, count density ratios, increase maps, and rCBF using statistical parametric mapping 8. RESULTS: Regional brain counts were significantly increased from 20-24% with SC, CTAC, and RR compared with SC and CTAC. Mean CBF in healthy volunteers was 42.5 ± 5.4 mL/100 g/min. Average rCBF determined using SC, CTAC and RR increased 7.5, 2.0, and 3.7% at the thalamus, posterior cingulate, and whole brain, respectively, compared with SC and CTAC. CONCLUSION: Resolution recovery caused variations in normal rCBF because counts increased in cerebral regions.

MicroRNA-101a regulates microglial morphology and inflammation.

BACKGROUND: Microglia, as well as other tissue-resident macrophages, arise from yolk sac progenitors. Thus, it is likely that the central nervous system environment is critical for the acquisition of a distinct microglial phenotype. Several microRNAs that are enriched in the brain play crucial roles in brain development and may also play a role in the differentiation of microglia. METHODS: To track the differentiation of hematopoietic cells into microglia, lineage-negative bone marrow cells were co-cultured with astrocytes in the absence or presence of microRNAs or their inhibitors. Microglia-like cells were identified as small, round cells that were immunopositive for CD11b, Iba1, CX3CR1, and triggering receptor expressed on myeloid cells (TREM)-2. RESULTS: Five microRNAs (miR-101a, miR-139-3p, miR-214*, miR-218, and miR-1186) were identified as modifiers of the differentiation of bone marrow-derived microglia-like cells. Among them, miR-101a facilitated the differentiation of bone marrow cells into microglia-like cells most potently. Small, round cells expressing CD11b, Iba1, CX3CR1, and TREM-2 were predominant in cells treated by miR-101a. miR-101a was abundantly expressed in non-microglial brain cells. Transfection of miR-101a into microglia significantly increased the production of IL-6 in response to LPS. Finally, miR-101a downregulated the expression of MAPK phosphatase-1. CONCLUSIONS: miR-101a, which is enriched in the brain, promotes the differentiation of bone marrow cells into microglia-like cells.

A human neural stem cell line provides neuroprotection and improves neurological performance by early intervention of neuroinflammatory system.

A human neural stem cell line, HB1.F3, demonstrated neuroprotective properties in cerebral ischemia animal models. In this study, we have investigated about the mechanisms of such neuroprotection, mainly focusing on the neuroinflammatory system at an earlier time point of the pathology. Cerebral ischemia model was generated by middle cerebral artery occlusion (MCAO) in adult male Wister rats. HB1.F3 cells were transplanted through jugular vein 6h after MCAO. Forty eight hours after MCAO, transplanted rats showed better neurological performance and decreased TUNEL positive apoptotic cell number in the penumbra. However, haematoxylin and eosin staining and immunostaining showed that, HB1.F3 cells did not affect the necrotic cell death. Twenty four hours after MCAO (18h after HB1.F3 transplantation), infiltrated granulocytes and macrophage/microglia number in the core regions were decreased compared to PBS-treated controls. Immunohistochemical analysis further demonstrated that the transplantation decreased inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressing cell number in the core and penumbra, respectively. Double immunofluorescence results revealed that iNOS was mainly expressed in granulocytes and macrophage/microglia in the core region, and COX-2 mainly expressed in neurons, endothelial cells and granulocytes in penumbra. Further analysis showed that although the percentage of iNOS expressing granulocytes and macrophage/microglia was not decreased, COX-2 expressing neurons and vessel number was decreased by the transplantation. In vitro mRNA analysis showed that brain-derived neurotrophic factor (BDNF), basic fibroblast growth factor (ßFGF) and bone morphogenic protein (BMP)-4 expression was high in cultured HB1.F3 cells. Thus, our results demonstrated that HB1.F3 cell transplantation provide neuroprotection possibly through the regulation of early inflammatory events in the cerebral ischemia condition.

Human mesenchymal stem cell transplantation changes proinflammatory gene expression through a nuclear factor-κB-dependent pathway in a rat focal cerebral ischemic model.

Previous studies have demonstrated the immunomodulatory functions of mesenchymal stem cells (MSCs) in cerebral ischemic rats. However, the underlying mechanisms are unclear. The purpose of this study is to investigate the effects of MSC transplantation on transcriptional regulations of proinflammatory genes in cerebral ischemia. Transient ischemia was induced by middle cerebral artery occlusion (MCAO) in adult male Sprague-Dawley rats. After 24 hr, vehicle (PBS) or a human MSC line (B10) was transplanted intravenously. The neurological deficits, infarct volume, cellular accumulations, and gene expression changes were monitored by means of behavior tests, MRI, immunohistochemistry, Western blotting, laser capture microdissection, and real-time PCR. In the core area of the B10 transplantation group, the number of ED1-positive macrophage/microglia was decreased compared with the PBS group. In the core, nuclear factor-κB (NF-κB) was decreased, although CCAAT/enhancer-binding protein ß was not changed; both were expressed mainly in ED1-positive macrophage/microglia. Likewise, mRNAs of NF-κB-dependent genes including interleukin-1ß, MCP-1, and inducible nitric oxide synthase were decreased in ED1-positive and Iba-1-positive macrophage/microglia in the B10 transplantation group. Moreover, upstream receptors of the NF-κB pathway, including CD40 and Toll-like receptor 2 (TLR2), were decreased. Immunofluorescence results showed that, in the B10 transplantation group, the percentages of NF-κB-positive, CD40-positive, and TLR2-positive cells were decreased in ED1-positive macrophage/microglia. Furthermore, NF-κB-positive cells in the CD40- or TLR2-expressing cell population were decreased in the B10 transplantation group. This study demonstrates that B10 transplantation inhibits NF-κB activation, possibly through inhibition of CD40 and TLR2, which might be responsible for the inhibition of proinflammatory gene expression in macrophage/microglia in the infarct lesion.