WUSCHEL-RELATED HOMEOBOX4 Is Involved in Meristem Maintenance and Is Negatively Regulated by the CLE Gene FCP1 in Rice

The shoot apical meristem is the ultimate source of the cells that constitute the entire aboveground portion of the plant body. In Arabidopsis thaliana, meristem maintenance is regulated by the negative feedback loop of WUSCHEL-CLAVATA (WUS-CLV). Although CLV-like genes, such as FLORAL ORGAN NUMBER1 (FON1) and FON2, have been shown to be involved in maintenance of the reproductive meristems in rice (Oryza sativa), current understanding of meristem maintenance remains insufficient. In this article, we demonstrate that the FON2-LIKE CLE PROTEIN1 (FCP1) and FCP2 genes encoding proteins with similar CLE domains are involved in negative regulation of meristem maintenance in the vegetative phase. In addition, we found that WUSCHEL-RELATED HOMEOBOX4 (WOX4) promotes the undifferentiated state of the meristem in rice and that WOX4 function is associated with cytokinin action. Consistent with similarities in the shoot apical meristem phenotypes caused by overexpression of FCP1 and downregulation of WOX4, expression of WOX4 was negatively regulated by FCP1 (FCP2). Thus, FCP1/2 and WOX4 are likely to be involved in maintenance of the vegetative meristem in rice.     

A Novel Alveolate in Bivalves with Chemosynthetic Bacteria Inhabiting Deep‐Sea Methane Seeps

It has recently been unveiled that a wide variety of microbial eukaryotes (protists) occur in chemosynthetic ecosystems, such as hydrothermal vents and methane seeps. However, there is little knowledge regarding protists associated with endemic animals inhabiting these environments. In the present study, utilizing PCR techniques, we detected fragments of the small subunit ribosomal RNA gene (SSU rRNA gene) from a particular protist from gill tissues of a significant fraction of the vesicomyid clams Calyptogena soyoae and C. okutanii complex and of the mussel Bathymodiolus platifrons and B. japonicus, all of which harbor chemosynthetic endosymbiont bacteria and dominate methane seeps in Sagami Bay, Japan. Based on the phylogeny of SSU rRNA gene, the organism in question was shown to belong to Alveolata. It is noteworthy that this protist did not affiliate with any known alveolate group, although being deeply branched within the lineage of Syndiniales, for which the monophyly was constantly recovered, but not robustly supported. In addition, the protist detected using PCR followed by sequencing was localized within gill epithelial cells of B. platifrons with whole‐mount fluorescence in situ hybridization. This protist may be an endoparasite or an endocommensal of Calyptogena spp. and Bathymodiolus spp., and possibly have physiological and ecological impacts on these bivalves.     

Targeting Superoxide Dismutase to Renal Proximal Tubule Cells Attenuates Vancomycin-induced Nephrotoxicity in Rats

Vancomycin hydrochloride (VCM), a glycopeptide antibiotic, has a broad spectrum against methicillin-resistant Staphylococcus aureus (MRSA). As it is known to induce renal dysfunction, the dose and the duration of its administration are limited. Moreover, the mechanism of VCM-induced renal dysfunction remains to be unclear. To evaluate the involvement of free radical on VCM-induced renal dysfunction, we carried out analysis with a hexamethylenediamine-conjugated superoxide dismutase (AH-SOD) which rapidly accumulates in renal proximal tubule cells and inhibits oxidative injury of the kidney. Male Wistar rats (weighing 200-210 g) were intraperitonealy administered with 200 mg/kg of VCM twice a day for 7 days. AH-SOD 5 mg/kg/day was subcutaneously injected 5 min before every VCM injection. VCM induced renal injury dose-dependently. Biochemical analyses revealed that plasma levels of blood urea nitrogen and creatinine significantly increased in the VCM-treated group by an AH-SOD-inhibitable mechanism. VCM simultaneously elicited an increase of 8-OHdG levels and chemiluminescence intensity of free radical generation in the kidney. Histological examination revealed that VCM also elicited a marked destruction of glomeruli and necrosis of proximal tubules. AH-SOD inhibited these phenomena in the kidney. These results suggested that oxidative stress might underlie the pathogenesis of VCM-induced nephrotoxicity and targeting SOD and/or related antioxidants to renal proximal tubules might permit the administration of higher doses of VCM sufficient for eradication of MRSA without causing renal injury.     

Rapid methods of detecting the target molecule in immunohistology using a bioluminescence probe

We demonstrate a novel rapid direct detection method for immunohistochemistry, using a bioluminescent probe. An anti‐CEA antibody‐fused far‐red bioluminescent protein can monitor the accumulation of this type of probe in tumour tissues. The bimodal spectrum (λ_max = 460 and 675 nm) of this bioluminescent probe is extremely stable under different conditions of pH and ion concentration. The sensitivity of our bioluminescent labelling was at the same level of enzymatic labelling, e.g. peroxidase, as an indirect system. Our novel technique is simple and can shorten the pretreatment time of paraffin sections to around 30 min. The utility of our bioluminescent labelling covers all imaging in vitro, in vivo and ex vivo, suggesting that our antibody‐fused bioluminescent probe has the potential to detect tumour antigens with a high sensitivity in routine immune histological examinations. Copyright © 2012 John Wiley & Sons, Ltd.     

A Simple,Preparative Procedure for N 3-Anisoyluridine and O 6-Diphenylcarbamoylguanosine 2′-O-(Tetrahydropyran-2-YL) Derivatives via The Corresponding 3′,5′-Dibenzoates

Abstract

3′,5′-Di-O-benzoyl-2′-O-(tetrahydropyran-2-yl)uridine and 3′,5′ -di-O-benzoyl-N ²-isobutyryl-2′-O-(tetrahydropyran-2-yl)guanosine are converted into-N ³-anisoyl-2′-O-(tetrahydropyran-2-yl)uridine (less and more polar diastereoisomers in 37% and 42% yields, respectively) and O ⁶-diphenyl carbamoylN ²-isobutyryl-2′-O-(tetrahydropyran-2-yl)- guanosine (less and more polar diastereoisomers in 15% and 59% yields, respectively), respectively, by N ³-anisoylation and O ⁶-diphenylcarbamoylation, followed by 3′,5′-di-O-debenzoylation.     

Selenoneine, a Novel Selenium-Containing Compound, Mediates Detoxification Mechanisms against Methylmercury Accumulation and Toxicity in Zebrafish Embryo

The selenium (Se)-containing antioxidant selenoneine (2-selenyl-N _α,N _α,N _α-trimethyl-l-histidine) has recently been discovered to be the predominant form of organic Se in tuna blood. Although dietary intake of fish Se has been suggested to reduce methylmercury (MeHg) toxicity, the molecular mechanism of MeHg detoxification by Se has not yet been determined. Here, we report evidence that selenoneine accelerates the excretion and demethylation of MeHg, mediated by a selenoneine-specific transporter, organic cations/carnitine transporter-1 (OCTN1). Selenoneine was incorporated into human embryonic kidney HEK293 cells transiently overexpressing OCTN1 and zebrafish blood cells by OCTN1. The K _m for selenoneine uptake was 13.0 μM in OCTN1-overexpressing HEK293 cells and 9.5 μM in zebrafish blood cells, indicating high affinity of OCTN1 for selenoneine in human and zebrafish cells. When such OCTN1-expressing cells and embryos were exposed to MeHg–cysteine (MeHgCys), MeHg accumulation was decreased and the excretion and demethylation of MeHg were enhanced by selenoneine. In addition, exosomal secretion vesicles were detected in the culture water of embryos that had been microinjected with MeHgCys, suggesting that these may be responsible for MeHg excretion and demethylation. In contrast, OCTN1-deficient embryos accumulated MeHg, and MeHg excretion and demethylation were decreased. Furthermore, Hg accumulation was decreased in OCTN1-overexpressing HEK293 cells, but not in mock vector-transfected cells, indicating that selenoneine and OCTN1 can regulate MeHg detoxification in human cells. Thus, the selenoneine-mediated OCTN1 system regulates secretory lysosomal vesicle formation and MeHg demethylation.     

Identification of miR-30e* Regulation of Bmi1 Expression Mediated by Tumor-Associated Macrophages in Gastrointestinal Cancer

Bmi1 is overexpressed in a variety of human cancers including gastrointestinal cancer. The high expression level of Bmi1 protein is associated with poor prognosis of gastrointestinal cancer patients. On the other hand, tumor-associated macrophages (TAMs) contribute to tumor growth, invasion, and metastasis by producing various mediators in the tumor microenvironment. The aim of this study was to investigate TAM-mediated regulation of Bmi1 expression in gastrointestinal cancer. The relationship between TAMs and Bmi1 expression was analyzed by immunohistochemistry and quantitative real-time PCR (qRT-PCR), and results showed a positive correlation with tumor-infiltrating macrophages (CD68 and CD163) and Bmi1 expression in cancer cells. Co-culture with TAMs triggered Bmi1 expression in cancer cell lines and enhanced sphere formation ability. miRNA microarray analysis of a gastric cancer cell line co-cultured with macrophages was conducted, and using in silico methods to analyze the results, we identified miR-30e* as a potential regulator of Bmi1 expression. Luciferase assays using miR-30e* mimic revealed that Bmi1 was a direct target for miR-30e* by interactions with the putative miR-30e* binding sites in the Bmi1 3′ untranslated region. qRT-PCR analysis of resected cancer specimens showed that miR-30e* expression was downregulated in tumor regions compared with non-tumor regions, and Bmi1 expression was inversely correlated with miR-30e* expression in gastric cancer tissues, but not in colon cancer tissues. Our findings suggest that TAMs may cause increased Bmi1 expression through miR-30e* suppression, leading to tumor progression. The suppression of Bmi1 expression mediated by TAMs may thus represent a possible strategy as the treatment of gastrointestinal cancer.     

Skin Autofluorescence Is Associated with the Progression of Chronic Kidney Disease: A Prospective Observational Study

Background

Advanced glycation end product (AGE) accumulation is thought to be a measure of cumulative metabolic stress that has been reported to independently predict cardiovascular disease in diabetes and renal failure. The aim of this study was to evaluate the association between AGE accumulation, measured as skin autofluorescence, and the progression of renal disease in pre-dialysis patients with chronic kidney disease (CKD).

Methods

Skin autofluorescence was measured noninvasively with an autofluorescence reader at baseline in 449 pre-dialysis patients with CKD. The primary end point was defined as a doubling of serum creatinine and/or need for dialysis.

Results

Thirty-three patients were lost to follow-up. Forty six patients reached the primary end point during the follow-up period (Median 39 months). Kaplan-Meier analysis showed a significantly higher risk of development of the primary end points in patients with skin autofluorescence levels above the optimal cut-off level of 2.31 arbitrary units, derived by receiver operator curve analysis. Cox regression analysis revealed that skin autofluorescence was an independent predictor of the primary end point, even after adjustment for age, gender, smoking history, diabetes, estimated glomerular filtration rate and proteinuria (adjusted hazard ratio 2.58, P = 0.004).

Conclusions

Tissue accumulation of AGEs, measured as skin autofluorescence, is a strong and independent predictor of progression of CKD. Skin autofluorescence may be useful for risk stratification in this group of patients; further studies should clarify whether AGE accumulation could be one of the therapeutic targets to improve the prognosis of CKD.     

Interfamily Transfer of Dual NB-LRR Genes Confers Resistance to Multiple Pathogens

A major class of disease resistance (R) genes which encode nucleotide binding and leucine rich repeat (NB-LRR) proteins have been used in traditional breeding programs for crop protection. However, it has been difficult to functionally transfer NB-LRR-type R genes in taxonomically distinct families. Here we demonstrate that a pair of Arabidopsis (Brassicaceae) NB-LRR-type R genes, RPS4 and RRS1, properly function in two other Brassicaceae, Brassica rapa and Brassica napus, but also in two Solanaceae, Nicotiana benthamiana and tomato (Solanum lycopersicum). The solanaceous plants transformed with RPS4/RRS1 confer bacterial effector-specific immunity responses. Furthermore, RPS4 and RRS1, which confer resistance to a fungal pathogen Colletotrichum higginsianum in Brassicaceae, also protect against Colletotrichum orbiculare in cucumber (Cucurbitaceae). Importantly, RPS4/RRS1 transgenic plants show no autoimmune phenotypes, indicating that the NB-LRR proteins are tightly regulated. The successful transfer of two R genes at the family level implies that the downstream components of R genes are highly conserved. The functional interfamily transfer of R genes can be a powerful strategy for providing resistance to a broad range of pathogens.