Effects of Ulva spp. and seasonal disturbances on the recovery of a temperate rocky intertidal community

The inhibitory effects of ulvoid algae and their seasonality on the recovery and succession of an intertidal algal community were investigated under field conditions using a two‐factorial design. The experiment was conducted in the mid‐low intertidal zone on the Southern coast of Korea. In spring and fall, each of the ten 50 × 50 cm plots was disturbed artificially, and Ulva spp. were continuously excluded from five plots of the seasonal plots. The succession of spring plots was nearly twice as fast as that of the fall plots (spring, 4–6 months; fall, 10–15 months), indicating that the seasonal effects contributed significantly to the speed of the succession. The inhibition by Ulva species delayed the succession; however, the strength of this delay was limited largely by the duration and persistence of Ulva mass, which was also highly seasonal. The presence of Ulva spp. did not alter the final assemblage at the climax stage; instead, it caused a delay in community resilience. This study provides a few analytical factors for community‐wise comparison during the evaluation of the status of successional stages.     

Cytotoxic and α-Glucosidase Inhibitory Xanthones from Garcinia mckeaniana Leaves and Molecular Docking Study

A new racemic xanthone, garmckeanin A ( 1 ), and eight known analogs 2 – 9 were isolated from the ethyl acetate (AcOEt) extract of the Vietnamese Garcinia mckeaniana leaves. Their structures were determined by MS and NMR spectral analyses and compared with the literature. The AcOEt extract showed good cytotoxicity against cancer cell lines KB, Lu, Hep-G2 and MCF7, with IC₅₀ values of 5.40–8.76 μg/mL, and it also possessed α-glucosidase inhibitory activity, with an IC₅₀ value of 9.17 μg/mL. Garmckeanin A ( 1 ) exhibited inhibition of all cancer cell lines, with an IC₅₀ value of 7.3–0.9 μM. Allanxanthone C ( 5 ) successfully controlled KB growth, with an IC₅₀ value of 0.54 μM, higher than that of the positive control, ellipticine (IC₅₀ 1.22 μM). Norathyriol ( 8 ) was a promising α-glucosidase inhibitor, with an IC₅₀ value of 0.07 μM, much higher than that of the positive control, acarbose (IC₅₀ 161.0 μM). The interactions of the potential α-glucosidase inhibitors with the C- and N-terminal domains of human intestinal α-glucosidase were also investigated by molecular docking study. The results indicated that bannaxanthone D ( 2 ), garcinone E ( 4 ), bannaxanthone E ( 6 ), and norathyriol ( 8 ) exhibit higher binding affinity to the C-terminal than to the N-terminal domain through essential residues in the active sites. In particular, compound 8 could be assumed to be the most potent mixed inhibitor.     

Positive Promoting Effects of Smilax China Flower Absolute on the Wound Healing/Skin Barrier Repair-Related Responses of HaCaT Human Skin Keratinocytes

Smilax china (SC) has pharmacological effects including anti-inflammatory activity, but its effects on skin wound healing and skin barrier function have not been investigated. Here, we investigated the effects of absolute extracted from SC flowers (SCF) on skin wound healing-linked responses and functional skin barrier proteins using human epidermal keratinocytes (HaCaT cells). SCF absolute contained 20 components and was non-toxic to HaCaT cells. The absolute increased the proliferation, migration, and sprout outgrowth of HaCaT cells, and enhanced the activations of serine/threonine-specific protein kinase and extracellular signal-regulated kinase1/2. In addition, it increased the syntheses of type I and IV collagens and the expressions of skin barrier proteins (filaggrin and loricrin). These results indicate SCF absolute may has positive effects on skin wound healing by accelerating keratinocyte migration and proliferation activities and collagen synthesis, and on skin barrier function by upregulating barrier proteins in keratinocytes. We suggest SCF absolute to be considered as a potential means of promoting skin wound and barrier repair.     

Population dynamics of a Sonneratia caseolaris stand in the Lam River estuary of Vietnam: a restoration perspective

Species composition, age distribution, and their relationship with land height from the datum line (LH) of the Sonneratia caseolaris stand, which grows in the Lam River estuary in Vietnam, were surveyed to obtain fundamental knowledge that aimed at contributing to mangrove restoration. The data gathered on the sandbar consists of three mangrove species and one mangrove associate species, with one non-mangrove species, and were divided into three communities. In terms of the age distribution of the S. caseolaris–Aegiceras corniculatum community, the tree-phase densities for both species are lower than those exhibited by younger phases. In its succession, the seedlings of S. caseolaris and A. corniculatum are primarily recruited at the mean tide level (MWL) in the early stages. Then, A. corniculatum expands to the lower tide zone primarily on mud flat bare land. For both species, full irradiance on the bare land in the low tide zone below MWL is crucial for growth, but S. caseolaris, which propagates by releasing small seeds, can barely survive in the low tide zone because its seeds are easily flushed away. In contrast, A. corniculatum, which propagates using crypto-viviparous seedlings, has a higher survival rate in the low tide zone. As a result, the LH of seedlings of A. corniculatum distribution is significantly lower than that of the distribution of S. caseolaris trees (p?<?0.05). It is important to provide appropriate environmental conditions for forest restoration in order to promote succession. The findings from the current study on population dynamics related to LH and tidal conditions are expected to be applied to platforms for S. caseolaris stands and mangrove restoration.

     

Diagnostic performance of anti-Zika virus IgM,IgAM and IgG ELISAs during co-circulation of Zika,dengue, and chikungunya viruses in Brazil and Venezuela

BackgroundSerological diagnosis of Zika virus (ZIKV) infection is challenging because of the antibody cross-reactivity among flaviviruses. At the same time, the role of Nucleic Acid Testing (NAT) is limited by the low proportion of symptomatic infections and the low average viral load. Here, we compared the diagnostic performance of commercially available IgM, IgAM, and IgG ELISAs in sequential samples during the ZIKV and chikungunya (CHIKV) epidemics and co-circulation of dengue virus (DENV) in Brazil and Venezuela.Methodology/Principal findingsAcute (day of illness 1–5) and follow-up (day of illness ≥ 6) blood samples were collected from nine hundred and seven symptomatic patients enrolled in a prospective multicenter study between June 2012 and August 2016. Acute samples were tested by RT-PCR for ZIKV, DENV, and CHIKV. Acute and follow-up samples were tested for IgM, IgAM, and IgG antibodies to ZIKV using commercially available ELISAs. Among follow-up samples with a RT-PCR confirmed ZIKV infection, anti-ZIKV IgAM sensitivity was 93.5% (43/46), while IgM and IgG exhibited sensitivities of 30.3% (10/33) and 72% (18/25), respectively. An additional 24% (26/109) of ZIKV infections were detected via IgAM seroconversion in ZIKV/DENV/CHIKV RT-PCR negative patients. The specificity of anti-ZIKV IgM was estimated at 93% and that of IgAM at 85%.Conclusions/SignificanceOur findings exemplify the challenges of the assessment of test performance for ZIKV serological tests in the real-world setting, during co-circulation of DENV, ZIKV, and CHIKV. However, we can also demonstrate that the IgAM immunoassay exhibits superior sensitivity to detect ZIKV RT-PCR confirmed infections compared to IgG and IgM immunoassays. The IgAM assay also proves to be promising for detection of anti-ZIKV seroconversions in sequential samples, both in ZIKV PCR-positive as well as PCR-negative patients, making this a candidate assay for serological monitoring of pregnant women in future ZIKV outbreaks.     

Spatial distribution of Culex mosquito abundance and associated risk factors in Hanoi,Vietnam

Japanese encephalitis (JE) is the major cause of viral encephalitis (VE) in most Asian-Pacific countries. In Vietnam, there is no nationwide surveillance system for JE due to lack of medical facilities and diagnoses. Culex tritaeniorhynchus, Culex vishnui, and Culex quinquefasciatus have been identified as the major JE vectors in Vietnam. The main objective of this study was to forecast a risk map of Culex mosquitoes in Hanoi, which is one of the most densely populated cities in Vietnam. A total of 10,775 female adult Culex mosquitoes were collected from 513 trapping locations. We collected temperature and precipitation information during the study period and its preceding month. In addition, the other predictor variables (e.g., normalized difference vegetation index [NDVI], land use/land cover and human population density), were collected for our analysis. The final model selected for estimating the Culex mosquito abundance included centered rainfall, quadratic term rainfall, rice cover ratio, forest cover ratio, and human population density variables. The estimated spatial distribution of Culex mosquito abundance ranged from 0 to more than 150 mosquitoes per 900m². Our model estimated that 87% of the Hanoi area had an abundance of mosquitoes from 0 to 50, whereas approximately 1.2% of the area showed more than 100 mosquitoes, which was mostly in the rural/peri-urban districts. Our findings provide better insight into understanding the spatial distribution of Culex mosquitoes and its associated environmental risk factors. Such information can assist local clinicians and public health policymakers to identify potential areas of risk for JE virus. Risk maps can be an efficient way of raising public awareness about the virus and further preventive measures need to be considered in order to prevent outbreaks and onwards transmission of JE virus.     

Combined application of rapamycin and atorvastatin improves lipid metabolism in apolipoprotein E-deficient mice with chronic kidney disease

Atherosclerosis arising from the pro-inflammatory conditions associated with chronic kidney disease (CKD) increases major cardiovascular morbidity and mortality. Rapamycin (RAPA) is known to inhibit atherosclerosis under CKD and non-CKD conditions, but it can cause dyslipidemia; thus, the co-application of lipid-lowering agents is recommended. Atorvastatin (ATV) has been widely used to reduce serum lipids levels, but its synergistic effect with RAPA in CKD remains unclear. Here, we analyzed the effect of their combined treatment on atherosclerosis stimulated by CKD in apolipoprotein E-deficient (ApoE^−/−) mice. Oil Red O staining revealed that treatment with RAPA and RAPA＋ ATV, but not ATV alone, significantly decreased the atherosclerotic lesions in the aorta and aortic sinus, compared to those seen in the control (CKD) group. The co-administration of RAPA and ATV improved the serum lipid profile and raised the expression levels of proteins involved in reverse cholesterol transport (LXRα, CYP7A1, ABCG1, PPARγ, ApoA1) in the liver. The CKD group showed increased levels of various genes encoding atherosclerosis-promoting cytokines in the spleen (Tnf-α, Il-6 and Il-1β) and aorta (Tnf-α and Il-4), and these increases were attenuated by RAPA treatment. ATV and RAPA＋ATV decreased the levels of Tnf-α and Il-1β in the spleen, but not in the aorta. Together, these results indicate that, in CKD-induced ApoE^−/− mice, RAPA significantly reduces the development of atherosclerosis by regulating the expression of inflammatory cytokines and the co-application of ATV improves lipid metabolism.     

Molecular Identification and Physiological Characterization of a Putative Novel Plasma Membrane Protein from <Emphasis Type="Italic">Arabidopsis</Emphasis> Involved in Glucose Response

We carried out functional analysis of a putative novel Arabidopsis plasma membrane glucose-responsive regulator, designated AtPGR, which contains seven predicted transmembrane domains. Several evidences showed that AtPGR is a glucose-related protein, but its biological functions have yet to be reported in any plant. Analyses of the AtPGR promoter-β-glucuronidase (GUS) construct and RNA in situ hybridization revealed substantial gene expression in the vasculature of various tissues, especially in the phloem region. Glucose treatment induced the highest levels of GUS activity, reaching a peak at 3 h and declining thereafter, consistent with glucose-mediated regulation of the AtPGR promoter. We generated an atpgr RNAi knockdown mutant and found that this plant grew and developed normally. Ectopic expression of AtPGR gene modulated the induction of glucose and 2-deoxyglucose insensitivity under stress conditions. By way of contrast, cotyledon greening of atpgr RNAi knockdown mutant seeds enhanced sensitivity to glucose and 2-deoxyglucose. Taken together, these results suggest that AtPGR functions as a potential glucose-responsive regulator in carbohydrate metabolism.     

Generation of catalytic protein particles in <Emphasis Type="Italic">Escherichia coli</Emphasis> cells using the cellulose-binding domain from <Emphasis Type="Italic">Cellulomonas fimi</Emphasis> as a fusion partner

The cellulose-binding domain (CBD) of a Cellulomonas fimi exo-glucanase was translationally fused with β-glucuronidase (GusA) from Escherichia coli and β-glycosidase (BglA) from Thermus caldophilus, respectively. Two fusion proteins (GusA-CBD and BglA-CBD) were expressed as insoluble aggregates in cells and isolated by centrifugation of the cell lysates. Interestingly, activity assays revealed that > 90% of the catalytic activity of both proteins was localized in the insoluble fractions. For example, the GusA-CBD particles exhibited 21 units per mg protein, which corresponded to 19% specific activity of the highly purified soluble GusA. The specific activity increased further up to 42 units per mg protein when treated with either sonication or chaotropic L-arginine. These results demonstrate that fusion with CBD family II may activate catalytic protein particles in E. coli cells, and that internal proteins of the particles are also active. Finally, the protein particles were tested in repeated batch operations after being cross-linked with chemicals, indicating that they have potential as a new preparation for immobilized biocatalysts.     

Solasodine production from cell culture of <Emphasis Type="Italic">Solanum hainanense</Emphasis> Hance

Stem explants of Solanum hainanense Hance plantlets were cultured on Murashige and Skoog solid medium, containing 3% (w/v) sucrose, supplemented with 0.1 mg/L benzylaminopurine (BAP) and 1.0 mg/L 2, 4-dichlorophenoxyacetic acid (2, 4-D) for callus production. To establish the cell suspension culture, 3 g of fresh callus were cultured in 50 mL of the same medium, but without a solid agent, at an agitation speed of 120 rpm. Every 15 mL of culture was sub-cultured in fresh MS liquid medium for maintenance. The cell biomass of S. hainanense reached a maximum value of 18.47 g after 4 weeks of culture on the same MS medium, but with the sucrose content increased to 4%, at an agitation speed of 150 rpm, with 20 mL of inoculum. Analysis via high performance liquid chromatography (HPLC) showed that the solasodine content in the cell suspension after 4-weeks old (121.01 mg/g) was higher than that of in planta 1-year old roots (20.52 mg/g) by approximately 6-fold.