Levels and distribution patterns of mitochondrial cox3 gene variation in brown seaweed,Sargassum polycystum C. Agardh (Fucales,Phaeophyceae) from Southeast Asia

Sargassum polycystum C. Agardh is one of the most abundant marine brown algae and is distributed widely in warm and temperate waters, particularly in the Indo-west Pacific region and Australia. Although its commercial potential and ecological and evolutionary importance are recognized, many pivotal aspects of its biology remain unexplored. Current knowledge of the historical biogeographical affinities and patterns is limited, but some data are available about its genetics, the genetic variation among populations, and spatial patterns. This study aimed to analyze the genetic population structure and distribution patterns of S. polycystum populations in 13 different locations from Indonesia to Japan using the mitochondrial gene cox3. The seven haplotypes of cox3 identified in this study indicated a low level of genetic diversity. Homogeneity of this haplotype was observed particularly in the Gulf of Thailand, Cambodia, and Japan, whereas higher haplotype diversity was found in Phuket (Thailand), Bali (Indonesia), and Singapore. Those data suggest that S. polycystum is likely to have expanded from the south of Indonesia and the west of the Malay Peninsula towards the northeast of the region. Geological studies showed that Sundaland, now corresponding to the Gulf of Thailand, was submerged due to sea level rises after the last glacial period. Therefore, the decrease in the genetic diversity of S. polycystum populations is interpreted here as a population expansion after the rise in sea levels.     

Recognition of floral homeotic MADS domain transcription factors by a phytoplasmal effector,phyllogen, induces phyllody

Plant pathogens alter the course of plant developmental processes, resulting in abnormal morphology in infected host plants. Phytoplasmas are unique plant‐pathogenic bacteria that transform plant floral organs into leaf‐like structures and cause the emergence of secondary flowers. These distinctive symptoms have attracted considerable interest for many years. Here, we revealed the molecular mechanisms of the floral symptoms by focusing on a phytoplasma‐secreted protein, PHYL1, which induces morphological changes in flowers that are similar to those seen in phytoplasma‐infected plants. PHYL1 is a homolog of the phytoplasmal effector SAP54 that also alters floral development. Using yeast two‐hybrid and in planta transient co‐expression assays, we found that PHYL1 interacts with and degrades the floral homeotic MADS domain proteins SEPALLATA3 (SEP3), APETALA1 (AP1) and CAULIFLOWER (CAL). This degradation of MADS domain proteins was dependent on the ubiquitin–proteasome pathway. The expression of floral development genes downstream of SEP3 and AP1 was disrupted in 35S::PHYL1 transgenic plants. PHYL1 was genetically and functionally conserved among other phytoplasma strains and species. We designate PHYL1, SAP54 and their homologs as members of the phyllody‐inducing gene family of ‘phyllogens’.     

π‐Extended Narrow‐Bandgap Diketopyrrolopyrrole‐Based Oligomers for Solution‐Processed Inverted Organic Solar Cells

A series of narrow‐bandgap π‐conjugated oligomers based on diketopyrrolopyrrole chromophoric units coupled with benzodithiophene, indacenodithiophene, thiophene, and isoindigo cores are designed and synthesized for application as donor materials in solution‐processed small‐molecule organic solar cells. The impacts of these different central cores on the optoelectronic and morphological properties, carrier mobility, and photovoltaic performance are investigated. These π‐extended oligomers possess broad and intense optical absorption covering the range from 550 to 750 nm, narrow optical bandgaps of 1.52–1.69 eV, and relatively low‐lying highest occupied molecular orbital (HOMO) energy levels ranging from ?5.24 to ?5.46 eV in their thin films. A high power conversion efficiency of 5.9% under simulated AM 1.5G illumination is achieved for inverted organic solar cells based on a small‐molecule bulk‐heterojunction system consisting of a benzodithiophene‐diketopyrrolopyrrole‐containing oligomer as a donor and [6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₁BM) as an acceptor. Transmission electron microscopy and energy‐dispersive X‐ray spectroscopy reveal that interpenetrating and interconnected donor/acceptor domains with pronounced mesoscopic phase segregation are formed within the photoactive binary blends, which is ideal for efficient exciton dissociation and charge transport in the bulk‐heterojunction devices.     

Structural determinants in GABARAP required for the selective binding and recruitment of ALFY to LC3B‐positive structures

Several autophagy proteins contain an LC3‐interacting region (LIR) responsible for their interaction with Atg8 homolog proteins. Here, we show that ALFY binds selectively to LC3C and the GABARAPs through a LIR in its WD40 domain. Binding of ALFY to GABARAP is indispensable for its recruitment to LC3B‐positive structures and, thus, for the clearance of certain p62 structures by autophagy. In addition, the crystal structure of the GABARAP‐ALFY‐LIR peptide complex identifies three conserved residues in the GABARAPs that are responsible for binding to ALFY. Interestingly, introduction of these residues in LC3B is sufficient to enable its interaction with ALFY, indicating that residues outside the LIR‐binding hydrophobic pockets confer specificity to the interactions with Atg8 homolog proteins.     

Interleukin-17 Induces an Atypical M2-Like Macrophage Subpopulation That Regulates Intestinal Inflammation

Interleukin 17 (IL-17) is a pleiotropic cytokine that acts on both immune and non-immune cells and is generally implicated in inflammatory and autoimmune diseases. Although IL-17 as well as their source, mainly but not limited to Th17 cells, is also abundant in the inflamed intestine, the role of IL-17 in inflammatory bowel disease remains controversial. In the present study, by using IL-17 knockout (KO) mice, we investigated the role of IL-17 in colitis, with special focus on the macrophage subpopulations. Here we show that IL-17KO mice had increased susceptibility to DSS-induced colitis which was associated with decrease in expression of mRNAs implicated in M2 and/or wound healing macrophages, such as IL-10, IL-1 receptor antagonist, arginase 1, cyclooxygenase 2, and indoleamine 2,3-dioxygenase. Lamina propria leukocytes from inflamed colon of IL-17KO mice contained fewer CD11b⁺Ly6C⁺MHC Class II⁺ macrophages, which were derived, at least partly, from blood monocytes, as compared to those of WT mice. FACS-purified CD11b⁺ cells from WT mice, which were more abundant in Ly6C⁺MHC Class II⁺ cells, expressed increased levels of genes associated M2/wound healing macrophages and also M1/proinflammatory macrophages. Depletion of this population by topical administration of clodronate-liposome in the colon of WT mice resulted in the exacerbation of colitis. These results demonstrate that IL-17 confers protection against the development of severe colitis through the induction of an atypical M2-like macrophage subpopulation. Our findings reveal a previously unappreciated mechanism by which IL-17 exerts a protective function in colitis.     

Hemoglobin–Albumin Cluster Incorporating a Pt Nanoparticle: Artificial O2 Carrier with Antioxidant Activities

A covalent core–shell structured protein cluster composed of hemoglobin (Hb) at the center and human serum albumins (HSA) at the periphery, Hb-HSA_m, is an artificial O₂ carrier that can function as a red blood cell substitute. Here we described the preparation of a novel Hb-HSA₃ cluster with antioxidant activities and its O₂ complex stable in aqueous H₂O₂ solution. We used an approach of incorporating a Pt nanoparticle (PtNP) into the exterior HSA unit of the cluster. A citrate reduced PtNP (1.8 nm diameter) was bound tightly within the cleft of free HSA with a binding constant (K) of 1.1×10⁷ M⁻¹, generating a stable HSA-PtNP complex. This platinated protein showed high catalytic activities for dismutations of superoxide radical anions (O₂ ^•–) and hydrogen peroxide (H₂O₂), i.e., superoxide dismutase and catalase activities. Also, Hb-HSA₃ captured PtNP into the external albumin unit (K = 1.1×10⁷ M⁻¹), yielding an Hb-HSA₃(PtNP) cluster. The association of PtNP caused no alteration of the protein surface net charge and O₂ binding affinity. The peripheral HSA-PtNP shell prevents oxidation of the core Hb, which enables the formation of an extremely stable O₂ complex, even in H₂O₂ solution.     

The Effect of 17β-Estradiol on Cutaneous Wound Healing in Protein-Malnourished Ovariectomized Female Mouse Model

Cutaneous wound healing is delayed by protein malnutrition (PM). On the other hand, estrogen promotes cutaneous wound healing by its anti-inflammatory and cell proliferation effects. Therefore, we hypothesized that estrogen administration in protein-malnourished ovariectomized (OVX) female mice might improve the inflammatory response and promote cutaneous wound healing as well as normal nutrition. To test this hypothesis, we used full-thickness excisional wounds in Control SHAM, PM SHAM, PM OVX and PM OVX+17β-estradiol mice. The Control diet included 200 g/kg protein and the PM diet included 30 g/kg protein. The ratio of wound area in the Control SHAM group was significantly smaller than those in the three PM groups. In addition, microscopic findings also showed that the ratio of collagen fibers, the ratio of myofibroblasts and the number of new blood vessels in the Control SHAM group were significantly greater than those in the three PM groups. However, the number of Ym1-positive cells as an anti-inflammatory M2-like macrophage marker in the PM OVX+17β-estradiol group was significantly higher than those in the other three groups. These results indicate that the appearance of anti-inflammatory M2-like macrophages was promoted by estrogen administration; however, it could not promote cutaneous wound healing upon a low-protein diet. Therefore, it may be confirmed that nutrition is more important for promoting cutaneous wound healing than estrogen administration.     

LOX-1 Plays an Important Role in Ischemia-Induced Angiogenesis of Limbs

LOX-1, lectin-like oxidized low-density lipoprotein (LDL) receptor-1, is a single transmembrane receptor mainly expressed on endothelial cells. LOX-1 mediates the uptake of oxidized LDL, an early step in atherosclerosis; however, little is known about whether LOX-1 is involved in angiogenesis during tissue ischemia. Therefore, we examined the role of LOX-1 in ischemia-induced angiogenesis in the hindlimbs of LOX-1 knockout (KO) mice. Angiogenesis was evaluated in a surgically induced hindlimb ischemia model using laser Doppler blood flowmetry (LDBF) and histological capillary density (CD) and arteriole density (AD). After right hindlimb ischemia, the ischemic/nonischemic hindlimb blood flow ratio was persistently lower in LOX-1 KO mice than in wild-type (WT) mice. CD and AD were significantly smaller in LOX-1 KO mice than in WT mice on postoperative day 14. Immunohistochemical analysis revealed that the number of macrophages infiltrating ischemic tissues was significantly smaller in LOX-1 KO mice than in WT mice. The number of infiltrated macrophages expressing VEGF was also significantly smaller in LOX-1 KO mice than in WT mice. Western blot analysis and ROS production assay revealed that LOX- KO mice show significant decrease in Nox2 expression, ROS production and HIF-1α expression, the phosphorylation of p38 MAPK and NF-κB p65 subunit as well as expression of redox-sensitive vascular cell adhesion molecule-1 (VCAM-1) and LOX-1 itself in ischemic muscles, which is supposed to be required for macrophage infiltration expressing angiogenic factor VEGF. Reduction of VEGF expression successively suppressed the phosphorylation of Akt and eNOS, which accelerated angiogenesis, in the ischemic leg of LOX-1 KO mice. Our findings indicate that LOX-1 plays an important role in ischemia-induced angiogenesis by 1) Nox2-ROS-NF-κB activation, 2) upregulated expression of adhesion molecules: VCAM-1 and LOX-1 and 3) promoting macrophage infiltration, which expresses angiogenic factor VEGF.     

Creutzfeldt-Jakob disease associated with a V203I homozygous mutation in the prion protein gene

We report a Japanese patient with Creutzfeldt-Jakob disease (CJD) with a V203I homozygous mutation of the prion protein gene (PRNP). A 73-year-old woman developed rapidly progressive gait disturbance and cognitive dysfunction. Four months after the onset, she entered a state of an akinetic mutism. Gene analysis revealed a homozygous V203I mutation in the PRNP. Familial CJD with a V203I mutation is rare, and all previously reported cases had a heterozygous mutation showing manifestations similar to those of typical sporadic CJD. Although genetic prion diseases with homozygous PRNP mutations often present with an earlier onset and more rapid clinical course than those with heterozygous mutations, no difference was found in clinical phenotype between our homozygous case and reported heterozygous cases.     

The physiological and psychological relaxing effects of viewing rose flowers in office workers

Background

In recent years, the physiological relaxing effect brought by nature is becoming clear; however, many workers find it difficult to be exposed to nature in their working environment. Exposure to fresh flowers represents an opportunity to incorporate nature into their working lives. In this study, we examined the effects of exposure to roses on physiological and psychological variables (heart rate variability, pulse rate, and subjective responses) in office workers.

Results

The experimental site was Mizuho Information & Research Institute, Inc., in the Tokyo metropolitan area. Thirty-one male office workers were included in the present study. The subjects were exposed to thirty unscented pink roses (Rosa, Dekora) arranged in a cylindrical glass vase for 4 min. In the control condition, the subjects were not exposed to flowers. After the experiments, the subjects completed a questionnaire. The order of exposure was counterbalanced among subjects. Among subjects exposed to roses, the high-frequency component of heart rate variability was significantly higher than in controls. Similarly, ''comfortable,’ ''relaxed’ and ''natural’ feelings were more common in subjects exposed to roses.

Conclusions

Data from this study support the presence of physiological and psychological relaxing effects of being exposed to flowers on office workers.