High mobility group box-1 in hypothalamic paraventricular nuclei attenuates sympathetic tone in rats at post-myocardial infarction

Background: Inflammation is associated with increased sympathetic drive in cardiovascular diseases. The paraventricular nucleus (PVN) of the hypothalamus is a key regulator of sympathetic nerve activity at post-myocardial infarction (MI). High mobility group box-1 (HMGB1) exhibits inflammatory cytokine like activity in the extracellular space. Inflammation is associated with increased sympathetic drive in cardiovscular diseases. However, the role of HMGB1 in sympathetic nerve activity at post-MI remains unknown. The aim of the present study is to determine the role and mechanism of HMGB1 in the PVN, in terms of sympathetic activity and arrhythmia after MI. Methods: Sprague-Dawley rats underwent left anterior descending coronary artery ligation to induce MI. Anti-HMGB1 polyclonal antibody or control IgG was bilaterally microinjected into the PVN (5 μL every second day for seven consecutive days). Then, renal sympathetic nerve activity (RSNA) was recorded. The association between ventricular arrhythmias (VAs) and MI was evaluated using programmedelectrophysiological stimulation. After performing electrophysiological experiments in vivo, immunohistochemistry was used to detect the distribution of HMGB1, while Western blot was used to detect the expression of HMGB1 and p-ERK in the PVN of MI rats. Results: HMGB1 and p-ERK were upregulated in the PVN in rats at post-MI. Moreover, bilateral PVN microinjection of anti-HMGB1 polyclonal antibody reversed the expression of HMGB1 and p-ERK, and consequently decreased the baseline RSNA and inducible VAs, when compared to those in sham rats. Conclusions: These results suggest that MI causes the translocation of HMGB1 in the PVN, which leads to sympathetic overactivation through the ERK1/2 signaling pathway. The bilateral PVN microinjection of anti-HMGB1 antibody can be an effective therapy for MI-induced arrhythmia

Testing a hypothesis of unidirectional hybridization in plants: Observations on Sonneratia, Bruguiera and Ligularia

<p>Abstract</p> <p>Background</p> <p>When natural hybridization occurs at sites where the hybridizing species differ in abundance, the pollen load delivered to the rare species should be predominantly from the common species. Previous authors have therefore proposed a hypothesis on the direction of hybridization: interspecific hybrids are more likely to have the female parent from the rare species and the male parent from the common species. We wish to test this hypothesis using data of plant hybridizations both from our own experimentation and from the literature.</p> <p>Results</p> <p>By examining the maternally inherited chloroplast DNA of 6 cases of F1 hybridization from four genera of plants, we infer unidirectional hybridization in most cases. In all 5 cases where the relative abundance of the parental species deviates from parity, however, the direction is predominantly in the direction opposite of the prediction based strictly on numerical abundance.</p> <p>Conclusion</p> <p>Our results show that the observed direction of hybridization is almost always opposite of the predicted direction based on the relative abundance of the hybridizing species. Several alternative hypotheses, including unidirectional postmating isolation and reinforcement of premating isolation, were discussed.</p

Musical Electroacupuncture May Be a Better Choice than Electroacupuncture in a Mouse Model of Alzheimer’s Disease

Objectives. To compare musical electroacupuncture and electroacupuncture in a mouse model of Alzheimer’s disease. Methods. In this study, 7.5-month-old male senescence-accelerated mouse prone 8 (SAMP8) mice were used as an Alzheimer’s disease animal model. In the normal control paradigm, 7.5-month-old male SAMR1 mice were used as the blank control group (N group). After 15 days of treatment, using Morris water maze test, micro-PET, and immunohistochemistry, the differences among the musical electroacupuncture (MEA), electroacupuncture (EA), Alzheimer’s disease (AD), and normal (N) groups were assessed. Results. The Morris water maze test, micro-PET, and immunohistochemistry revealed that MEA and EA therapies could improve spatial learning and memory ability, glucose metabolism level in the brain, and Aβ amyloid content in the frontal lobe, compared with the AD group (P<0.05). Moreover, MEA therapy performed better than EA treatment in decreasing amyloid-beta levels in the frontal lobe of mice with AD. Conclusion. MEA therapy may be superior to EA in treating Alzheimer’s disease as demonstrated in SAMP8 mice

Large-gap quantum anomalous Hall states induced by functionalizing buckled Bi-III monolayer/Al2_{2}O3_{3}

Chiral edge modes inherent to the topological quantum anomalous Hall (QAH) effect are a pivotal topic of contemporary condensed matter research aiming at future quantum technology and application in spintronics. A large topological gap is vital to protecting against thermal fluctuations and thus enabling a higher operating temperature. From first-principle calculations, we propose Al$_{2}$O$_{3}$ as an ideal substrate for atomic monolayers consisting of Bi and group-III elements, in which a large-gap quantum spin Hall effect can be realized. Additional half-passivation with nitrogen then suggests a topological phase transition to a large-gap QAH insulator. By effective tight-binding modelling, we demonstrate that Bi-III monolayer/Al$_{2}$O$_{3}$ is dominated by $p_{x}, p_{y}$ orbitals, with subdominant $p_z$ orbital contributions. The topological phase transition into the QAH is induced by Zeeman splitting, where the off-diagonal spin exchange does not play a significant role. The effective model analysis promises utility far beyond Bi-III monolayer/Al$_{2}$O$_{3}$, as it should generically apply to systems dominated by $p_{x}, p_{y}$ orbitals with a band inversion at $\Gamma$.Comment: 9 pages with 4 figure

Ancient geograpical barriers drive differentiation among Sonneratia caseolaris populations and recent divergence from S. Ianceolata

Glacial vicariance is thought to influence population dynamics and speciation of many marine organisms. Mangroves, a plant group inhabiting intertidal zones, were also profoundly influenced by Pleistocene glaciations. In this study, we investigated phylogeographic patterns of a widespread mangrove species Sonneratia caseolaris and a narrowly distributed, closely related species S. lanceolata to infer their divergence histories and related it to historical geological events. We sequenced two chloroplast fragments and five nuclear genes for one population of S. lanceolata and 12 populations of S. caseolaris across the Indo-West Pacific (IWP) region to evaluate genetic differentiation and divergence time among them. Phylogenetic analysis based on sequences of nuclear ribosomal internal transcribed spacer and a nuclear gene rpl9 for all Sonneratia species indicate that S. lanceolata individuals are nested within S. caseolaris. We found strong genetic structure among geographic regions (South China Sea, the Indian Ocean, and eastern Australia) inhabited by S. caseolaris. We estimated that divergence between the Indo-Malesia and Australasia populations occurred 4.035 million years ago (MYA), prior to the onset of Pleistocene. BARRIERS analysis suggested that complex geographic features in the IWP region had largely shaped the phylogeographic patterns of S. caseolaris. Furthermore, haplotype analyses provided convincing evidence for secondary contact of the South China Sea and the Indian Ocean lineages at the Indo-Pacific boundary. Demographic history inference under isolation and migration (IM) model detected substantial gene flow from the Sri Lanka populations to the populations in the Java Island. Moreover, multi-locus sequence analysis indicated that S. lanceolata was most closely related to the Indian Ocean populations of S. caseolaris and the divergence time between them was 2.057 MYA, coinciding with the onset of the Pleistocene glaciation. Our results suggest that geographic isolation driven by the Pleistocene ice age resulted in the recent origin of S. lanceolata

Speciation with gene flow via cycles of isolation and migration: insights from multiple mangrove taxa

Allopatric speciation requiring an unbroken period of geographical isolation has been the standard model of neo-Darwinism. While doubts have been repeatedly raised, strict allopatry without any gene flow remains a plausible mechanism in most cases. To rigorously reject strict allopatry, genomic sequences superimposed on the geological records of a well-delineated geographical barrier are necessary. The Strait of Malacca, narrowly connecting the Pacific and Indian Ocean coasts, serves at different times either as a geographical barrier or a conduit of gene flow for coastal/marine species. We surveyed 1,700 plants from 29 populations of five common mangrove species by large scale DNA sequencing and added several whole-genome assemblies. Speciation between the two oceans is driven by cycles of isolation and gene flow due to the fluctuations in sea level leading to the opening/closing of the Strait to ocean currents. Because the time required for speciation in mangroves is longer than the isolation phases, speciation in these mangroves has proceeded through many cycles of mixing-isolation-mixing, or MIM cycles. The MIM mechanism, by relaxing the condition of no gene flow, can promote speciation in many more geographical features than strict allopatry can. Finally, the MIM mechanism of speciation is also efficient, potentially yielding mn (m>1) species after n cycles

STUDY ON THE ANTIBACTERIAL ACTIVITY OF BERGENIA PURPURASCENS EXTRACT

Background: Bergenia purpurascens has tonic, haemostatic and anti-tussive actions. Anti-inflammatory and anti-bacterial activities of Bergenia purpurascens have not been reported so far. The objective of this paper is to provide experimental basis for the clinical application of Bergenia purpurascens through the pharmacodynamic study on its anti-inflammatory and anti-bacterial effects. Methods: Experimental models of xylene-induced ear edema in mice, cotton pellet granuloma in rats, and acetic acid-induced peritoneal capillary permeability in mice were used to investigate the anti-inflammatory effect of Bergenia purpurascens; bacteriostatic and bactericidal effects of Bergenia purpurascens extract on Staphylococcus aureus (SA), methicillin-resistant Staphylococcus aureus (MRSA), and β-lactamase positive Staphylococcus aureus (ESBLs-SA), were observed in vitro. Results: The results show that Bergenia purpurascens extract could markedly inhibit xylene-induced mouse ear edema, cotton pellet granulation tissue hyperplasia, and increased capillary permeability. Bergenia purpurascens extract has an inhibitory effect on SA, MRSA and ESBLs-SA. Conclusion: We conclude that Bergenia purpurascens extract has certain anti-inflammatory and anti-bacterial effects

Extensive gene flow in secondary sympatry after allopatric speciation

In the conventional view, species are separate gene pools delineated by reproductive isolation (RI). In an alternative view, species may also be delineated by a small set of ‘speciation genes’ without full RI, a view that has gained broad acceptance. A recent survey, however, suggested that the extensive literature on ‘speciation with gene flow’ is mostly (if not all) about exchanges in the early stages of speciation. There is no definitive evidence that the observed gene flow actually happened after speciation is completed. Here, we wish to know whether ‘good species’ (defined by the ‘secondary sympatry’ test) do continue to exchange genes and, importantly, under what conditions such exchanges can be observed. De novo whole-genome assembly and re-sequencing of individuals across the range of two closely related mangrove species (Rhizophora mucronata and R. stylosa) reveal the genomes to be well delineated in allopatry. They became sympatric in northeastern Australia but remain distinct species. Nevertheless, their genomes harbor ∼4000–10 000 introgression blocks averaging only about 3–4 Kb. These fine-grained introgressions indicate continual gene flow long after speciation as non-introgressable ‘genomic islets,’ ∼1.4 Kb in size, often harbor diverging genes of flower or gamete development. The fine-grained introgression in secondary sympatry may help settle the debate about sympatric vs. micro-allopatric speciation. In conclusion, true ‘good species’ may often continue to exchange genes but the opportunity for detection is highly constrained