Reproductive biology of an endangered lithophytic shrub and implications for its conservation.

BACKGROUND: Plants in cliff habitats may evolve specific reproductive strategies to cope with harsh environments, and unraveling these reproductive characteristics can improve our understanding of survival strategies and lithophyte evolution. This understanding is especially important for efforts to protect rare and endemic plants. Here, we investigated the reproductive biology of Lonicera oblata, an endangered lithophytic shrub that is scattered in highly fragmented and isolated cliff habitats of the Taihang and Yan mountains in North China. RESULTS: Flowers of L. oblata are herkogamous and protandrous, characteristics that can prevent autogamy at the single-flower level, and insects are necessary for pollination. The outcrossing index, pollen/ovule ratio, and the results of hand pollination were measured and all revealed a mixed mating system for L. oblata, that combines cross-fertilization and partial self-fertilization. The floral traits of L. oblata of zygomorphic and brightly yellowish corolla, heavy fragrance, and rich nectar, suggest an entomophilous pollination system. Sweat bees were observed as the most effective pollinators but their visiting frequencies were not high. Pollen limitation may limit the reproductive success of L. oblata. CONCLUSIONS: We determined the reproductive characteristics of L. oblata, a critically endangered species endemic to cliffs in North China, providing insight into its endangerment and suggesting conservation strategies. L. oblata has highly pollinator-dependent self-fertilization as part of a mixed mating system. Floral features such as low-flowering synchrony, asynchronous anthers dehiscence, and high duration of stigma receptivity, improve pollination efficiency in the case of low pollinator service. Our work provides reference information to understand the survival strategies and conservation of L. oblata and other lithophytes.

Concentration-Controlled Reversible Phase Transitions in Self-Assembled Monolayers on HOPG Surfaces.

Rational control of molecular ordering on surfaces and interfaces is vital in supramolecular chemistry and nanoscience. Here, a systematic scanning tunneling microscopy (STM) study for controlling the self-assembly behavior of alkoxylated benzene (B-OC(n)) molecules on a HOPG surface is presented. Three different phases have been observed and, of great importance, they can transform to each other by modifying the solute concentration. Further studies, particularly in situ diluting and concentrating experiments, demonstrate that the transitions among the three phases are highly controllable and reversible, and are driven thermodynamically. In addition, it is found that concentration-controlled reversible phase transitions are general for different chain lengths of B-OC(n) molecules. Such controllable and reversible phase transitions may have potential applications in the building of desirable functional organic thin films and provide a new understanding in thermodynamically driven self-assembly of organic molecules on surfaces and interfaces.

Experience in the management of sigmoid sinus thrombophlebitis secondary to middle ear cholesteatoma.

OBJECTIVE: To discuss the management of sigmoid sinus thrombophlebitis secondary to middle ear cholesteatoma. METHODS: We retrospectively analyzed all cases of sigmoid sinus thrombophlebitis caused by middle ear cholesteatoma over a period of 7 years. 7 male and 2 female patients, ranging in age from 9 to 66 years, were diagnosed with sigmoid sinus thrombophlebitis by clinical presentation and radiological examination. By executing a modified mastoidectomy and tympanoplasty (canal wall-down tympanoplasty) to entirely remove the cholesteatoma-like mastoid epithelium, all patients were effectively treated surgically without opening the sigmoid sinus. All patients were treated with broad-spectrum antibiotics, but no anticoagulants were used. RESULTS: 9 patients had otogenic symptoms such as ear pus, tympanic membrane perforation, and hearing loss. In the initial stage of the surgery, modified mastoidectomy and tympanoplasty were performed on 8 of the 9 patients. 1 patient with a brain abscess underwent puncturing (drainage of the abscess) to relieve cranial pressure, and 4 months later, a modified mastoidectomy and tympanoplasty were carried out. Following surgery and medication, the clinical symptoms of every patient improved. After the follow-up of 6 months to 7 years, 3 patients were re-examined for MRV and showed partial sigmoid sinus recovery with recanalization. 4 months following middle ear surgery, the extent of a patient's brain abscess lesions was significantly reduced. 1 patient experienced facial paralysis after surgery and recovered in 3 months. None of the patients had a secondary illness, an infection, or an abscess in a distant organ. CONCLUSION: The key to a better prognosis is an adequate course of perioperative antibiotic medication coupled with surgical treatment. A stable sigmoid sinus thrombus can remain for a long time after middle ear lesions have been removed, and it is less likely to cause infection and abscesses in the distant organs. The restoration of middle ear ventilation is facilitated by tympanoplasty. It is important to work more closely with multidisciplinary teams such as neurology and neurosurgery when deciding whether to perform lateral sinusotomies to remove thrombus or whether to administer anticoagulation.

Genomic Data Reveals Profound Genetic Structure and Multiple Glacial Refugia in Lonicera oblata (Caprifoliaceae), a Threatened Montane Shrub Endemic to North China.

Characterizing genetic diversity and structure and identifying conservation units are both crucial for the conservation and management of threatened species. The development of high-throughput sequencing technology provides exciting opportunities for conservation genetics. Here, we employed the powerful SuperGBS method to identify 33, 758 high-quality single-nucleotide polymorphisms (SNP) from 134 individuals of a critically endangered montane shrub endemic to North China, Lonicera oblata. A low level of genetic diversity and a high degree of genetic differentiation among populations were observed based on the SNP data. Both principal component and phylogenetic analyses detected seven clusters, which correspond exactly to the seven geographic populations. Under the optimal K = 7, Admixture suggested the combination of the two small and geographically neighboring populations in the Taihang Mountains, Dongling Mountains, and Lijiazhuang, while the division of the big population of Jiankou Great Wall in the Yan Mountains into two clusters. High population genetic diversity and a large number of private alleles were detected in the four large populations, while low diversity and non-private alleles were observed for the remaining three small populations, implying the importance of these large populations as conservation units in priority. Demographic history inference suggested two drastic contractions of population size events that occurred after the Middle Pleistocene Transition and the Last Glacial Maximum, respectively. Combining our previous ecological niche modeling results with the present genomic data, there was a possible presence of glacial refugia in the Taihang and Yan Mountains, North China. This study provides valuable data for the conservation and management of L. oblata and broadens the understanding of the high biodiversity in the Taihang and Yan Mountains.

DNA vaccines targeting amyloid-ß oligomer ameliorate cognitive deficits of aged APP/PS1/tau triple-transgenic mouse models of Alzheimer's disease.

The amyloid-ß (Aß) oligomer, rather than the Aß monomer, is considered to be the primary initiator of Alzheimer's disease. It was hypothesized that p(Aß3-10)10-MT, the recombinant Aß3-10 gene vaccine of the Aß oligomer has the potential to treat Alzheimer's disease. In this study, we intramuscularly injected the p(Aß3-10)10-MT vaccine into the left hindlimb of APP/PS1/tau triple-transgenic mice, which are a model for Alzheimer's disease. Our results showed that the p(Aß3-10)10-MT vaccine effectively reduced Aß oligomer levels and plaque deposition in the cerebral cortex and hippocampus, decreased the levels tau protein variants, reduced synaptic loss, protected synaptic function, reduced neuron loss, and ameliorated memory impairment without causing any cerebral hemorrhaging. Therefore, this novel DNA vaccine, which is safe and highly effective in mouse models of Alzheimer's disease, holds a lot of promise for the treatment of Alzheimer's disease in humans.

Phylogenomics and Biogeography of Populus Based on Comprehensive Sampling Reveal Deep-Level Relationships and Multiple Intercontinental Dispersals.

Populus not only has significant economic and ecological values, but also serves as a model tree that is widely used in the basic research of tree growth, physiology, and genetics. However, high levels of morphological variation and extensive interspecific hybridization of Populus pose an obstacle for taxonomy, and also to the understanding of phylogenetic interspecific relationships and biogeographical history. In this study, a total of 103 accessions representing almost all the wild species of Populus were collected and whole-genome re-sequenced to examine the phylogenetic relationships and biogeography history. On the basis of 12,916,788 nuclear single nucleotide polymorphisms (SNPs), we reconstructed backbone phylogenies using concatenate and coalescent methods, we highly disentangled the species relationships of Populus, and several problematic taxa were treated as species complexes. Furthermore, the phylogeny of the chloroplast genome showed extensive discordance with the trees from the nuclear genome data, and due to extensive chloroplast capture and hybridization of Populus species, plastomes could not accurately evaluate interspecies relationships. Ancient gene flow between clades and some hybridization events were also identified by ABBA-BABA analysis. The reconstruction of chronogram and ancestral distributions suggested that North America was the original region of this genus, and subsequent long dispersal and migration across land bridges were contributed to the modern range of Populus. The diversification of Populus mainly occurred in East Asia in recent 15 Ma, possibly promoted by the uplift of the Tibetan Plateau. This study provided comprehensive evidence on the phylogeny of Populus and proposed a four-subgeneric classification and a new status, subgenus Abaso. Meanwhile, ancestral distribution reconstruction with nuclear data advanced the understanding of the biogeographic history of Populus.

Risk factors for age-related macular degeneration in elderly Chinese population in Shenyang of China.

OBJECTIVE: The paper aims to evaluate the risk factors for age-related macular degeneration (AMD) in elderly Chinese population in Shenyang, a northeast city of China. METHODS: A case-control study was conducted to investigate the risk factors for the prevalence of AMD. Ninety three AMD patients diagnosed by a complete ophthalmic examination were recruited as cases from the outpatient departments of two eye hospitals in Shenyang, while 108 normal subjects of similar age and sex were recruited as controls. A questionnaire was administered among both cases and controls. RESULTS: AMD patients aged 60 years and older accounted for 75.3%. There were significantly higher educational levels, shorter smoking history, less sunlight exposure and cataract, and higher proportion of antioxidants intake in controls than in AMD patients. The frequency of intake of fruits, legumes, fish and shrimps was significantly higher in controls than in AMD patients. In a binary logistic regression analysis, smoking and cataract were the risk factors for AMD (OR: 4.44, 95% CI: 2.27-8.69; OR: 4.47, 95% CI: 2.26-8.85 respectively). The high educational background was a protective factor for AMD (OR: 0.761, 95% CI: 0.51-0.98). CONCLUSION: A low educational background, smoking and cataract are associated with a higher prevalence of AMD.

Mesenchymal stem cells-derived extracellular vesicles ameliorate Alzheimer's disease in rat models via the microRNA-29c-3p/BACE1 axis and the Wnt/ß-catenin pathway.

Currently, Alzheimer's disease (AD) cannot be treated effectively. Mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) (MSC-EVs) exhibit therapeutic effects on many diseases. This study investigated the mechanism of bone marrow MSC-EVs (BM-MSC-EVs) in a rat model of AD. The cognitive function, amyloid-ß (Aß) plaques, Aß deposition areas and levels of Aß1-42, Aß decomposition-related factors (NEP and IDE), and inflammatory cytokines in BM-MSC-EVs-treated AD rats were measured. The effect of BM-MSC-EVs was studied in AD neuron model. microRNA (miR)-29c-3p and BACE1 expression, as well as levels of Wnt/ß-catenin pathway-related factors in AD and EVs-treated AD models were detected. miR-29c-3p relationship with BACE1 was predicted and confirmed. miR-29c-3p and BACE1 were interfered to verify the mechanism of EVs in AD. The Wnt/ß-catenin pathway inhibitor DKK1 was further added to EVs-treated AD neurons. BM-MSC-EVs showed therapeutic effects on AD rats and neurons. BM-MSC-EVs carried miR-29c-3p into AD neurons. miR-29c-3p targeted BACE1. Silencing miR-29c-3p in BM-MSCs reduced BM-MSC-EV therapeutic effect on AD, which was reversed after BACE1 knockdown. miR-29c-3p targeted BACE1 and activated the Wnt/ß-catenin pathway, and the Wnt/ß-catenin pathway inhibition impaired EV therapeutic effects on AD. We highlighted that BM-MSC-EVs delivered miR-29c-3p to neurons to inhibit BACE1 expression and activate the Wnt/ß-catenin pathway, thereby playing a therapeutic role in AD. This study may provide a novel perspective for elucidating the mechanism of MSCs in the treatment of AD.

The complete chloroplast genome of Symphoricarpos orbiculatus (Caprifoliaceae), an important ornamental plant.

Symphoricarpos orbiculatus is an important landscape and ornamental plant. In this study, we report the complete chloroplast genome sequences of S. orbiculatus. The complete chloroplast genome of S. orbiculatus was 156,044 bp in length. The genome has a typical quadripartite structure, including a large single-copy (LSC) region of 88,756 bp, a small single-copy (SSC) region of 19,130 bp, and two inverted repeat (IR) regions of 24,079 bp each. Overall, the GC content was 38.4%. In the genome, it was identified to comprise130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. This study provides valuable information for molecular phylogenetic study of Caprifoliaceae and is significant for variety development of Symphoricarpos.

The complete chloroplast genome of Physochlaina physaloides (Solanaceae), an important medicinal plant.

Physochlaina is an important perennial herbaceous genus with significant medicinal value, while the phylogeny of Physochlaina and tribe Hyoscyameae is not well resolved yet. In this study, we report the complete chloroplast genome sequences of Ph. physaloides, its complete chloroplast genome is 156,413 bp in length, which is a typical quadripartite structure that includes a large single-copy region of 86,659 bp, a small single-copy region of 18,012 bp, and its GC content was 37.7%. A total of 132 genes were identified, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Furthermore, a phylogenetic tree of the tribe Hyoscyameae was constructed based the complete chloroplast genome sequence, and a new topology of the tribe was obtained. This study provides valuable genetic information for the conservation and utilization of Ph. physaloides and also provide the potential for better understanding of the phylogeny of Hyoscyameae and Solanaceae.

The complete chloroplast genome of Lonicera oblata, a critically endangered species endemic to North China.

Lonicera oblata, a critically endangered species endemic to North China with about 30 wild individuals, has long been ignored for conservation since its publication because of little attention on its living situation. In this study, we characterized the complete chloroplast (cp) genome of L. oblata. The cp genome was 155,481 bp in length, included a large single-copy (LSC) region of 89,139 bp, a small single-copy (SSC) region of 18,676 bp, and two inverted repeat (IR) regions of 23,833 bp each. The genome contains 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic position of L. oblata was also investigated based on cp genome phylogeny of Lonicera representatives. This study is valuable for molecular phylogenetic study and conservation of Lonicera and related taxa.

miR26a modulates Th17/T reg balance in the EAE model of multiple sclerosis by targeting IL6.

A number of different microRNAs (miRNAs) have been implicated in various autoimmune diseases, including multiple sclerosis (MS). T helper (Th)17 and regulatory T cells (Tregs) have likewise been implicated as key players in MS, and a functional imbalance of these cell types is increasingly recognized as a key etiological factor in the disease. Although specific panels of transcription factors and cytokines are known to regulate the Th17/Treg balance, the role of noncoding RNAs remains poorly understood. The inflammatory cytokine, interleukin (IL)6, appears to play a critical role in both the development of the Th17 response and the inhibition of Treg functions. In this research, an IL6-associated miRNA, miR26a, was identified, and its normally downregulated expression was shown to be highly correlated with disease severity in patients suffering from MS as well as in C57BL/6 mice with experimental autoimmune encephalomyelitis (EAE; a well-established animal model of human MS). Using the EAE model system, in vivo silencing of miR26a was found to result in increased expression of Th17-related cytokines and increased severity of EAE, while overexpression of miR26a was found to result in reduced expression of Th17-related cytokines and a milder form of EAE. By contrast, Treg cell-specific transcription factor, Foxp3, was found to be positively correlated with miR26a expression. Finally, miR26a was found to downregulate Th17 and to upregulate Treg cell function through its targeting of IL6. Taken together, our data indicate an important role for miR26a in maintaining the Th17 and Treg cell balance in MS that involves repression of IL6 expression.