Single-cell transcriptome analysis of a rat model of bilateral renal ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) causes massive tissue damage. Renal IRI is the most common type of acute renal injury, and the defects caused by it may progress to chronic kidney disease (CKD). Rodent models of renal IRI, with various patterns, have been used to study the treatment of human kidney injury. A rat model of bilateral IRI, in which the bilateral kidney blood vessels are clamped for 60 min, is widely used, inducing both acute and chronic kidney disease. However, the molecular mechanisms underlying the effects of bilateral IRI on kidney cells have not yet been fully elucidated. This study aimed to perform a whole-transcriptome analysis of the IRI kidney using single-cell RNA sequencing. We found renal parenchymal cells, including those from the proximal tubule, the loop of Henle, and distal tubules, to be damaged by IRI. In addition, we observed significant changes in macrophage population. Our study delineated the detailed cellular and molecular changes that occur in the rat model of bilateral IRI. Collectively, our data and analyses provided a foundation for understanding IRI-related kidney diseases in rat models.

PDGFRα-lineage origin directs monocytes to trafficking proficiency to support peripheral immunity

Multiple embryonic precursors give rise to leukocytes in adults while the lineage‐based functional impacts are underappreciated. Mesodermal precursors expressing PDGFRα appear transiently during E7.5‐8.5 descend to a subset of Lin^–Sca1⁺Kit⁺ hematopoietic progenitors found in adult BM. By analyzing a PDGFRα‐lineage tracing mouse line, we here report that PDGFRα‐lineage BM F4/80⁺SSC^lo monocytes/macrophages are solely Ly6C⁺LFA‐1^hiMac‐1^hi monocytes enriched on the abluminal sinusoidal endothelium while Ly6C^–LFA‐1^loMac‐1^lo macrophages are mostly from non‐PDGFRα‐lineage in vivo. Monocytes with stronger integrin profiles outcompete macrophages for adhesion on an endothelial monolayer or surfaces coated with ICAM‐1‐Fc or VCAM‐1‐Fc. Egress of PDGFRα‐lineage‐rich monocytes and subsequent differentiation to peripheral macrophages spatially segregates them from non‐PDGFRα‐lineage BM‐resident macrophages and allows functional specialization since macrophages derived from these egressing monocytes differ in morphology, phenotype, and functionality from BM‐resident macrophages in culture. Extravasation preference for blood PDGFRα‐lineage monocytes varies by tissues and governs the local lineage composition of macrophages. More PDGFRα‐lineage classical monocytes infiltrated into skin and colon but not into peritoneum. Accordingly, transcriptomic analytics indicated augmented inflammatory cascades in dermatitis skin of BM‐chimeric mice harbouring only PDGFRα‐lineage leukocytes. Thus, the PDGFRα‐lineage origin biasedly generates monocytes predestined for BM exit to support peripheral immunity following extravasation and macrophage differentiation.

Synthesized HMGB1 peptide attenuates liver inflammation and suppresses fibrosis in mice

The liver has a high regenerative ability and can induce spontaneous regression of fibrosis when early liver damage occurs; however, these abilities are lost when chronic liver damage results in decompensated cirrhosis. Cell therapies, such as mesenchymal stem cell (MSC) and macrophage therapies, have attracted attention as potential strategies for mitigating liver fibrosis. Here, we evaluated the therapeutic effects of HMGB1 peptide synthesized from box A of high mobility group box 1 protein. Liver damage and fibrosis were evaluated using a carbon tetrachloride (CCl₄)-induced cirrhosis mouse model. The effects of HMGB1 peptide against immune cells were evaluated by single-cell RNA-seq using liver tissues, and those against monocytes/macrophages were further evaluated by in vitro analyses. Administration of HMGB1 peptide did not elicit a rapid response within 36 h, but attenuated liver damage after 1 week and suppressed fibrosis after 2 weeks. Fibrosis regression developed over time, despite continuous liver damage, suggesting that administration of this peptide could induce fibrolysis. In vitro analyses could not confirm a direct effect of HMGB1 peptide against monocyte/macrophages. However, macrophages were the most affected immune cells in the liver, and the number of scar-associated macrophages (Trem2+Cd9+ cells) with anti-inflammatory markers increased in the liver following HMGB1 treatment, suggesting that indirect effects of monocytes/macrophages were important for therapeutic efficacy. Overall, we established a new concept for cell-free therapy using HMGB1 peptide for cirrhosis through the induction of anti-inflammatory macrophages.

Longitudinal Single-Cell Transcriptomics Reveals a Role for Serpina3n-Mediated Resolution of Inflammation in a Mouse Colitis Model

BACKGROUND & AIMS

Proper resolution of inflammation is essential to maintaining homeostasis, which is important as a dysregulated inflammatory response has adverse consequences, even being regarded as a hallmark of cancer. However, our picture of dynamic changes during inflammation remains far from comprehensive.

METHODS

Here we used single-cell transcriptomics to elucidate changes in distinct cell types and their interactions in a mouse model of chemically induced colitis.

RESULTS

Our analysis highlights the stromal cell population of the colon functions as a hub with dynamically changing roles over time. Importantly, we found that Serpina3n, a serine protease inhibitor, is specifically expressed in stromal cell clusters as inflammation resolves, interacting with a potential target, elastase. Indeed, genetic ablation of the Serpina3n gene delays resolution of induced inflammation. Furthermore, systemic Serpina3n administration promoted the resolution of inflammation, ameliorating colitis symptoms.

CONCLUSIONS

This study provides a comprehensive, single-cell understanding of cell-cell interactions during colorectal inflammation and reveals a potential therapeutic target that leverages inflammation resolution.

Contribution of PDGFRα lineage cells in adult mouse hematopoiesis

Platelet-derived growth factor receptor alpha (PDGFRα) is a dominant marker of mesodermal mesenchymal cells in mice. Previous studies demonstrated that PDGFRα-positive (PDGFRα+) mesodermal cells develop not only into mesenchymal cells but also into a subset of total hematopoietic cells (HCs) in the limited period during mouse embryogenesis. However, the precise characteristics of the PDGFRα lineage positive (PDGFRα Lin+) HCs in adult mouse hematopoiesis are largely unknown. In this study, we systematically evaluated the characteristics of PDGFRα Lin+ HCs in the bone marrow and peripheral blood using PDGFRα-CRE; ROSA^tdTomato mice. Flow cytometry analysis revealed that PDGFRα Lin+ HCs accounted for approximately 20% of total HCs in both the bone marrow and peripheral blood in adult mice. Compositions of myeloid and lymphoid subpopulations among CD45+ mononuclear cells were almost identical in both PDGFRα Lin+ and PDGFRα Lin- cells. Single-cell RNA-sequencing analysis also demonstrated that the transcriptomic signatures of the PDGFRα Lin+ HCs in the peripheral blood largely overlapped with those of the PDGFRα Lin- HCs, suggesting equivalent functions of the PDGFRα Lin+ and PDGFRα Lin- HCs. Although pathophysiological activities of the PDGFRα Lin + HCs were not evaluated, our data clearly demonstrate a significant role of the PDGFRα Lin + HCs in physiological hematopoiesis in adult mice.

Role of Oxidized Lipids in Permeation of H2O2 Through a Lipid Membrane: Molecular Mechanism of an Inhibitor to Promoter Switch

H₂O₂ permeation through a cell membrane significantly affects living organisms, and permeation is controlled by the physico-chemical nature of lipids and other membrane components. We investigated the molecular relationship between H₂O₂ permeation and lipid membrane structure using three oxidized lipids. POVPC and PazePC act as intra- and inter-molecular permeation promoters, respectively; however, their underlying mechanisms were different. The former changed the partition equilibrium, while the latter changed the permeation pathway. PoxnoPC inhibited permeation under our experimental conditions via an intra-molecular configuration change. Thus, both intra- and inter-molecular processes were found to control the role of oxidized lipids as inhibitors and promoters towards H₂O₂ permeation with different mechanisms depending on structure and composition. Here, we identified two independent H₂O₂ permeation routes: (i) permeation through lipid membrane with increased partition coefficient by intra-molecular configurational change and (ii) diffusion through pores (water channels) formed by inter-molecular configurational change of oxidized lipids. We provide new insight into how biological cells control permeation of molecules through intra- and inter-molecular configurational changes in the lipid membrane. Thus, by employing a rational design for both oxidized lipids and other components, the permeation behaviour of H₂O₂ and other ions and molecules through a lipid membrane could be controlled.

Lipid peroxidation increases hydrogen peroxide permeability leading to cell death in cancer cell lines that lack mtDNA

4-Hydroxynonenal (HNE) is an important product of plasma membrane lipid peroxidation, which is a cause of cell and tissue injury. Mitochondrial DNA (mtDNA)-depleted ρ⁰ cells were established using human cervical cancer and oral squamous cell carcinoma cell lines. We investigated the effect of reactive oxygen species in ρ⁰ cells, especially the mechanism of hydrogen peroxide (H₂ O₂ )-mediated cell death. These cell were subjected to high oxidative stress and, compared with their parental cells, showed greater sensitivity to H₂ O₂ and high lipid peroxidation. Upregulation of HNE in the plasma membrane was observed prior to the increase in intracellular H₂ O₂ . The amount of oxidized lipid present changed H₂ O₂ permeability and administration of oxidized lipid led to further cell death after treatment with H₂ O₂ . Expression levels of lipoxygenase ALOX genes (ie ALOX5, ALOX12, and ALOX15) were upregulated in ρ⁰ cells, as were expression levels of ALOX12 and ALOX15 proteins. ALOX5 protein was mainly distributed in the nucleus, while ALOX12 and ALOX15 proteins were distributed in the nucleus and the cytoplasm. Although expression of COX2 gene was upregulated, its protein expression did not increase. ALOX (especially ALOX15) may be involved in the sensitivity of cancer cells to treatment. These data offer promise for the development of novel anticancer agents by altering the oxidation state of the plasma membrane. Our results showed that lipid peroxidation status is important for H₂ O₂ sensitivity and that ALOX15 is involved in lipid peroxidation status.

Transcriptionally distinct mesenchymal stem/stromal cells circulate in fetus

Umbilical cord blood contains mesenchymal stem/stromal cells (MSCs) in addition to hematopoietic stem cells, serving as an attractive tool for regenerative medicine. As umbilical cord blood originates from fetus, abundant MSCs are expected to circulate in fetus. However, the properties of circulating MSCs in fetus have not been fully examined. In the present study, we aimed to analyze circulating MSCs, marked by the expression of platelet-derived growth factor receptor α (PDGFRα), during fetal development. Using PDGFRα GFP knock-in mice, we quantified the number of circulating PDGFRα positive MSCs during development. We further performed whole transcriptome analysis of circulating MSCs at single cell levels. We found that abundant PDGFRα positive cells circulate in embryo and diminish immediately after birth. In addition, single cell RNA-sequencing revealed transcriptional heterogeneity of MSCs in fetal circulation. These data lay a foundation to analyze the function of circulating MSCs during development.

Myogenin promoter-associated lncRNA Myoparr is essential for myogenic differentiation

Promoter-associated long non-coding RNAs (lncRNAs) regulate the expression of adjacent genes; however, precise roles of these lncRNAs in skeletal muscle remain largely unknown. Here, we characterize a promoter-associated lncRNA, Myoparr, in myogenic differentiation and muscle disorders. Myoparr is expressed from the promoter region of the mouse and human myogenin gene, one of the key myogenic transcription factors. We show that Myoparr is essential both for the specification of myoblasts by activating neighboring myogenin expression and for myoblast cell cycle withdrawal by activating myogenic microRNA expression. Mechanistically, Myoparr interacts with Ddx17, a transcriptional coactivator of MyoD, and regulates the association between Ddx17 and the histone acetyltransferase PCAF Myoparr also promotes skeletal muscle atrophy caused by denervation, and knockdown of Myoparr rescues muscle wasting in mice. Our findings demonstrate that Myoparr is a novel key regulator of muscle development and suggest that Myoparr is a potential therapeutic target for neurogenic atrophy in humans.

Chromatin accessibility identifies diversity in mesenchymal stem cells from different tissue origins

Mesenchymal stem cells (MSCs), which can differentiate into tri-lineage (osteoblast, adipocyte, and chondrocyte) and suppress inflammation, are promising tools for regenerative medicine. MSCs are phenotypically diverse based on their tissue origins. However, the mechanisms underlying cell-type-specific gene expression patterns are not fully understood due to the lack of suitable strategy to identify the diversity. In this study, we investigated gene expression programs and chromatin accessibilities of MSCs by whole-transcriptome RNA-seq analysis and an assay for transposase-accessible chromatin using sequencing (ATAC-seq). We isolated MSCs from four tissues (femoral and vertebral bone marrow, adipose tissue, and lung) and analysed their molecular signatures. RNA-seq identified the expression of MSC markers and both RNA-seq and ATAC-seq successfully clustered the MSCs based on their tissue origins. Interestingly, clustering based on tissue origin was more accurate with chromatin accessibility signatures than with transcriptome profiles. Furthermore, we identified transcription factors potentially involved in establishing cell-type specific chromatin structures. Thus, epigenome analysis is useful to analyse MSC identity and can be utilized to characterize these cells for clinical use.

Genomic Characterization of Chromosomal Insertions: Insights into the Mechanisms Underlying Chromothripsis

Chromosomal insertions are rare structural rearrangements, and the molecular mechanisms underlying their origin are unknown. In this study, we used whole genome sequencing to analyze breakpoints and junction sequences in 4 patients with chromosomal insertions. Our analysis revealed that none of the 4 cases involved a simple insertion mediated by a 3-chromosomal breakage and rejoining events. The inserted fragments consisted of multiple pieces derived from a localized genomic region, which were shuffled and rejoined in a disorderly fashion with variable copy number alterations. The junctions were blunt ended or with short microhomologies or short microinsertions, suggesting the involvement of nonhomologous end-joining. In one case, analysis of the parental origin of the chromosomes using nucleotide variations within the insertion revealed that maternal chromosomal segments were inserted into the paternal chromosome. This patient also carried both maternal alleles, suggesting the presence of zygotic trisomy. These data indicate that chromosomal shattering may occur in association with trisomy rescue in the early postzygotic stage.

Quantitative determination of polysulfide in albumins, plasma proteins and biological fluid samples using a novel combined assays approach

Hydrogen sulfide (H₂S) signaling involves polysulfide (RSS_nSR') formation on various proteins. However, the current lack of sensitive polysulfide detection assays poses methodological challenges for understanding sulfane sulfur homeostasis and signaling. We developed a novel combined assay by modifying Sulfide Antioxidant Buffer (SAOB) to produce an "Elimination Method of Sulfide from Polysulfide" (EMSP) treatment solution that liberates sulfide, followed with methylene blue (MB) sulfide detection assay. The combined EMSP-MB sulfide detection assay performed on low molecular weight sulfur species showed that sulfide was produced from trisulfide compounds such as glutathione trisulfide and diallyl trisulfide, but not from the thiol compounds such as cysteine, cystine and glutathione. In the case of plasma proteins, this novel combined detection assay revealed that approximately 14.7, 1.7, 3.9, 3.7 sulfide mol/mol released from human serum albumin, α₁-anti-trypsin, α₁-acid glycoprotein and ovalbumin, respectively, suggesting that serum albumin is a major pool of polysulfide in human blood circulation. Taken together with the results of albumins of different species, the liberated sulfide has a good correlation with cysteine instead of methionine, indicating the site of incorporation of polysulfide is cysteine. With this novel sulfide detention assay, approximately 8,000, 120 and 1100 μM of polysulfide concentrations was quantitated in human healthy plasma, saliva and tear, respectively. Our promising polysulfide specific detection assay can be a very important tool because quantitative determination of polysulfide sheds light on the functional consequence of protein-bound cysteine polysulfide and expands the research area of reactive oxygen to reactive polysulfide species.

Palindrome-Mediated Translocations in Humans: A New Mechanistic Model for Gross Chromosomal Rearrangements

Palindromic DNA sequences, which can form secondary structures, are widely distributed in the human genome. Although the nature of the secondary structure-single-stranded "hairpin" or double-stranded "cruciform"-has been extensively investigated in vitro, the existence of such unusual non-B DNA in vivo remains controversial. Here, we review palindrome-mediated gross chromosomal rearrangements possibly induced by non-B DNA in humans. Recent advances in next-generation sequencing have not yet overcome the difficulty of palindromic sequence analysis. However, a dozen palindromic AT-rich repeat (PATRR) sequences have been identified at the breakpoints of recurrent or non-recurrent chromosomal translocations in humans. The breakages always occur at the center of the palindrome. Analyses of polymorphisms within the palindromes indicate that the symmetry and length of the palindrome affect the frequency of the de novo occurrence of these palindrome-mediated translocations, suggesting the involvement of non-B DNA. Indeed, experiments using a plasmid-based model system showed that the formation of non-B DNA is likely the key to palindrome-mediated genomic rearrangements. Some evidence implies a new mechanism that cruciform DNAs may come close together first in nucleus and illegitimately joined. Analysis of PATRR-mediated translocations in humans will provide further understanding of gross chromosomal rearrangements in many organisms.

Implication of altered α7 nicotinic receptors and amyloid deposition in the Alzheimer's brain

Introduction

Brain amyloid-β protein (Aβ) deposition is a key pathology of Alzheimer's disease (AD). Cholinergic degeneration, including reductions in α7 nicotinic acetylcholine receptors (α7-nAChR), is also known as a pathophysiology of AD. Recent imaging studies have shown cognitively normal subjects with Aβ depositions, indicating a missing link between Aβ deposition and cognitive decline.

Objectives

To clarify relationships among the Aβ burden, α7-nAChR availability, and cognitive declines in AD.

Aims

To measure brain Aβ deposition and α7-nAChR availability in the same patients with AD using positron emission tomography (PET).

Methods

Twenty AD patients and age-matched 20 healthy adults were studied. The α7-nAChR availability and Aβ deposition were evaluated using PET with [11C]MeQAA and [11C]PIB, respectively. Levels of specific binding were estimated by a simplified reference tissue method (BPND) for [11C]MeQAA and a tissue ratio method (SUVR) for using [11C]PIB. The values were compared with clinical measures of various cognitive functions using regions of interest (ROIs)-based and statistical parametric mapping (SPM) analyses.

Results

[11C]MeQAA BPND levels were extensively lower in the cholinergic projection regions of AD. There was a significant negative correlation between [11C]PIB SUVR and [11C]MeQAA BPND in the nucleus basalis of Mynert (NBM). The NBM [11C]PIB SUVR was negatively correlated with the [11C]MeQAA BPND level in the anterior and posterior cingulate cortices, whereas the relation within the same region showed weak correlation. Also we found significant correlation between cognitive decline and [11C]MeQAA BPND levels in the NBM.

Conclusions

Aβ deposition-linked α7-nAChR dysfunction may account for cognitive decline in AD.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Emergence and Characterization of Unusual DS-1-Like G1P[8] Rotavirus Strains in Children with Diarrhea in Thailand

The emergence and rapid spread of unusual DS-1-like G1P[8] rotaviruses in Japan have been recently reported. During rotavirus surveillance in Thailand, three DS-1-like G1P[8] strains (RVA/Human-wt/THA/PCB-180/2013/G1P[8], RVA/Human-wt/THA/SKT-109/2013/G1P[8], and RVA/Human-wt/THA/SSKT-41/2013/G1P[8]) were identified in stool specimens from hospitalized children with severe diarrhea. In this study, we sequenced and characterized the complete genomes of strains PCB-180, SKT-109, and SSKT-41. On whole genomic analysis, all three strains exhibited a unique genotype constellation including both genogroup 1 and 2 genes: G1-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2. This novel genotype constellation is shared with Japanese DS-1-like G1P[8] strains. Phylogenetic analysis revealed that the G/P genes of strains PCB-180, SKT-109, and SSKT-41 appeared to have originated from human Wa-like G1P[8] strains. On the other hand, the non-G/P genes of the three strains were assumed to have originated from human DS-1-like strains. Thus, strains PCB-180, SKT-109, and SSKT-41 appeared to be derived through reassortment event(s) between Wa-like G1P[8] and DS-1-like human rotaviruses. Furthermore, strains PCB-180, SKT-109, and SSKT-41 were found to have the 11-segment genome almost indistinguishable from one another in their nucleotide sequences and phylogenetic lineages, indicating the derivation of the three strains from a common origin. Moreover, all the 11 genes of the three strains were closely related to those of Japanese DS-1-like G1P[8] strains. Therefore, DS-1-like G1P[8] strains that have emerged in Thailand and Japan were assumed to have originated from a recent common ancestor. To our knowledge, this is the first report on whole genome-based characterization of DS-1-like G1P[8] strains that have emerged in an area other than Japan. Our observations will provide important insights into the evolutionary dynamics of emerging DS-1-like G1P[8] rotaviruses.

Whole Genomic Analysis of an Unusual Human G6P[14] Rotavirus Strain Isolated from a Child with Diarrhea in Thailand: Evidence for Bovine-To-Human Interspecies Transmission and Reassortment Events

An unusual rotavirus strain, SKT-27, with the G6P[14] genotypes (RVA/Human-wt/THA/SKT-27/2012/G6P[14]), was identified in a stool specimen from a hospitalized child aged eight months with severe diarrhea. In this study, we sequenced and characterized the complete genome of strain SKT-27. On whole genomic analysis, strain SKT-27 was found to have a unique genotype constellation: G6-P[14]-I2-R2-C2-M2-A3-N2-T6-E2-H3. The non-G/P genotype constellation of this strain (I2-R2-C2-M2-A3-N2-T6-E2-H3) is commonly shared with rotavirus strains from artiodactyls such as cattle. Phylogenetic analysis indicated that nine of the 11 genes of strain SKT-27 (VP7, VP4, VP6, VP2-3, NSP1, NSP3-5) appeared to be of artiodactyl (likely bovine) origin, while the remaining VP1 and NSP2 genes were assumed to be of human origin. Thus, strain SKT-27 was found to have a bovine rotavirus genetic backbone, and thus is likely to be of bovine origin. Furthermore, strain SKT-27 appeared to be derived through interspecies transmission and reassortment events involving bovine and human rotavirus strains. Of note is that the VP7 gene of strain SKT-27 was located in G6 lineage-5 together with those of bovine rotavirus strains, away from the clusters comprising other G6P[14] strains in G6 lineages-2/6, suggesting the occurrence of independent bovine-to-human interspecies transmission events. To our knowledge, this is the first report on full genome-based characterization of human G6P[14] strains that have emerged in Southeast Asia. Our observations will provide important insights into the origin of G6P[14] strains, and into dynamic interactions between human and bovine rotavirus strains.

Preimplantation genetic diagnosis/screening by comprehensive molecular testing

Although embryo screening by preimplantation genetic diagnosis (PGD) has become the standard technique for the treatment of recurrent pregnancy loss in couples with a balanced gross chromosomal rearrangement, the implantation and pregnancy rates of PGD using conventional fluorescence in situ hybridization (FISH) remain suboptimal. Comprehensive molecular testing, such as array comparative genomic hybridization and next-generation sequencing, can improve these rates, but amplification bias in the whole genome amplification method remains an obstacle to accurate diagnosis. Recent advances in amplification procedures combined with improvements in the microarray platform and analytical method have overcome the amplification bias, and the data accuracy of the comprehensive PGD method has reached the level of clinical laboratory testing. Currently, comprehensive PGD is also applied to recurrent pregnancy loss due to recurrent fetal aneuploidy or infertility with recurrent implantation failure, known as preimplantation genetic screening. However, there are still numerous problems to be solved, including misdiagnosis due to somatic mosaicism, cell cycle-related background noise, and difficulty in diagnosis of polyploidy. The technology for comprehensive PGD also requires further improvement.

Association between serum uric acid and lumbar spine bone mineral density in peri- and postmenopausal Japanese women

SUMMARY

Previous studies on the association between uric acid and bone mineral density yielded conflicting results. In this study, we demonstrated positive association between uric acid and lumbar spine bone mineral density in peri- and postmenopausal Japanese women. Further research is needed to elucidate the underlying mechanism.

INTRODUCTION

Oxidative stress has been implicated in the pathogenesis of osteoporosis. Uric acid, a potent antioxidant substance, has been associated with bone mineral density but previous studies have yielded conflicting results. The objective of the study was to examine the association between serum uric acid and lumbar spine bone mineral density (BMD).

METHODS

This was a retrospective analysis of medical records of 615 women, aged 45-75 years, who had lumbar spine BMD measurement by dual-energy X-ray absorptiometry as a part of health checkup from August 2011 to July 2012.

RESULTS

Mean serum uric acid level was 4.7 mg/dL. Serum uric acid level was positively and significantly associated with lumbar spine BMD independent of age, body mass index, smoking, drinking, physical activity, years after menopause, diabetes mellitus, hypertension, serum calcium, estimated glomerular filtration rate, plasma C-reactive protein, and serum alkaline phosphatase (standardized beta = 0.078, p = 0.049). Uric acid rapidly increased until the age of 60 years, and then decelerated but continued to increase thereafter. The association between lumbar spine BMD and uric acid remained significantly positive after excluding women older than 60 years.

CONCLUSION

The present study showed that higher uric acid levels were linearly associated with higher lumbar spine BMD in peri- and postmenopausal Japanese women. Further research is needed to elucidate the underlying mechanism of the association between uric acid and BMD.

miR-148a is an androgen-responsive microRNA that promotes LNCaP prostate cell growth by repressing its target CAND1 expression

Recent advances in cancer biology reveal that microRNAs (miRNAs) are involved in the regulation of cancer-related genes, or they function as tumor suppressors or oncogenes. In prostate cancer, evidence has accumulated for the contribution of the androgen-dependent gene network to tumor growth, although the precise functions of miRNAs in prostate cancer remain to be investigated. Here, we identified androgen-responsive miRNAs by the short RNA sequencing analysis in LNCaP prostate cancer cells. Among 10 miRNAs with known sequences, we have determined that miR-148a reduces the expression of cullin-associated and neddylation-dissociated 1 (CAND1), a negative regulator of SKP1-Cullin1-F-box (SCF) ubiquitin ligases, by binding to the 3'-untranslated region of CAND1 mRNA. CAND1 knockdown by small interfering RNA promoted the proliferation of LNCaP cells. Our study indicates the potential contribution of miR-148a to the growth of human prostate cancer.

Characteristics of leachate from pyrolysis residue of sewage sludge

The pyrolysis residue (SP) of sewage sludge (SS) produced at 500 degrees C was subjected to batch and column leaching tests to investigate the release of its organic and inorganic constituents and metals. For comparison, incineration ash (SI) obtained from a SS incinerator was also tested. Pyrolysis and incineration reduced organic matter of SS from 0.78 kg kg(-1)-dry SS to 0.16 and 0.01 kg kg(-1)-dry SS, respectively. Heavy metals remained in SP without being volatilized, although Cd and Pb were transferred into the off-gas during incineration. In the batch leaching test with the leaching liquid-to-solid mass ratio (L/S)=10, the pH of the SS, SP, and SI filtrates was 6.3, 7.9, and 11.0, respectively. The total organic carbon concentrations were in the order SS (877 l mg l(-1))>>SP (99 mg l(-1))>SI (26 mg l(-1)). The SP and SI filtrates met the landfill standard for the Cd and Pb concentrations (<0.3 mg l(-1)). In the column tests, although the SP contained more organic matter than that of SI, its carbon discharge into the leachate under aerobic conditions was similar to that of SI under anaerobic conditions. The leaching of heavy metals, such as Cd, Cr, Pb, and Zn, was also suppressed in SP during the active decomposition of organic matter. We demonstrated that pyrolysis reduces the potential release of pollutants from sewage sludge in landfill, making it a promising method of treating sewage sludge before landfilling.

Identification of novel androgen response genes in prostate cancer cells by coupling chromatin immunoprecipitation and genomic microarray analysis

The androgen receptor (AR) plays a key role as a transcriptional factor in prostate development and carcinogenesis. Identification of androgen-regulated genes is essential to elucidate the AR pathophysiology in prostate cancer. Here, we identified androgen target genes that are directly regulated by AR in LNCaP cells, by combining chromatin immunoprecipitation (ChIP) with tiling microarrays (ChIP-chip). ChIP-enriched or control DNAs from the cells treated with R1881 were hybridized with the ENCODE array, in which a set of regions representing approximately 1% of the whole genome. We chose 10 bona fide AR-binding sites (ARBSs) (P<1e-5) and validated their significant AR recruitment ligand dependently. Eight upregulated genes by R1881 were identified in the vicinity of the ARBSs. Among the upregulated genes, we focused on UGT1A and CDH2 as AR target genes, because the ARBSs close to these genes (in UGT1A distal promoter and CDH2 intron 1) were most significantly associated with acetylated histone H3/H4, RNA polymerase II and p160 family co-activators. Luciferase reporter constructs including those two ARBSs exhibited ligand-dependent transcriptional regulator/enhancer activities. The present study would be powerful to extend our knowledge of the diversity of androgen genetic network and steroid action in prostate cancer cells.