Comparative chloroplast genomes study of five officinal Ardisia Species: Unraveling interspecific diversity and evolutionary insights in Ardisia.

Ardisia S.W. (Primulaceae), naturally distributed in tropical and subtropical regions, has edible and medicinal values and is prevalent in clinical and daily use in China. More genetic information for distinct species delineation is needed to support the development and utilization of the genus Ardisia. We sequenced, annotated, and compared the chloroplast genomes of five Ardisia species: A. brunnescens, A. pusilla, A. squamulosa, A. crenata, and A. brevicaulis in this study. We found a typical quadripartite structure in all five chloroplast genomes, with lengths ranging from 155,045 to 156,943 bp. Except for A. pusilla, which lacked the ycf15 gene, the other four Ardisia species contained 114 unique genes, including 79 protein-coding genes, 30 tRNAs, and four rRNAs. In addition, the rps19 pseudogene gene was present only in A. brunnescens. Five highly variable DNA barcodes were identified for five Ardisia species, including trnT-GGU-psbD, trnT-UGU-trnL-UAA, rps4-trnT-UGU, rpl32-trnL-UAG, and rpoB-trnC-GAA. The RNA editiing sites of protein-coding genes in the five Ardisia plastome were characterized and compared, and 274 (A. crenata)-288 (A. brevicaulis) were found. The results of the phylogenetic analysis were consistent with the morphological classification. Sequence alignment and phylogenetic analysis showed that ycf15 genes were highly divergent in Primulaceae. Reconstructions of ancestral character states indicated that leaf margin morphology is critical for classifying the genus Ardisia, with a rodent-like character being the most primitive. These results provide valuable information on the taxonomy and evolution of Ardisia plants.

Comparative analysis of the plastid and mitochondrial genomes of Artemisia giraldii Pamp.

Artemisia giraldii Pamp. is an herbaceous plant distributed only in some areas in China. To understand the evolutionary relationship between plastid and mitochondria in A. giraldii, we sequenced and analysed the plastome and mitogenome of A. giraldii on the basis of Illumina and Nanopore DNA sequencing data. The mitogenome was 194,298 bp long, and the plastome was 151,072 bp long. The mitogenome encoded 56 genes, and the overall GC content was 45.66%. Phylogenetic analysis of the two organelle genomes revealed that A. giraldii is located in the same branching position. We found 13 pairs of homologous sequences between the plastome and mitogenome, and only one of them might have transferred from the plastid to the mitochondria. Gene selection pressure analysis in the mitogenome showed that ccmFc, nad1, nad6, atp9, atp1 and rps12 may undergo positive selection. According to the 18 available plastome sequences, we found 17 variant sites in two hypervariable regions that can be used in completely distinguishing 18 Artemisia species. The most interesting discovery was that the mitogenome of A. giraldii was only 43,226 bp larger than the plastome. To the best of our knowledge, this study represented one of the smallest differences between all sequenced mitogenomes and plastomes from vascular plants. The above results can provide a reference for future taxonomic and molecular evolution studies of Asteraceae species.

Characterization of Codonopsis pilosula subsp. tangshen plastome and comparative analysis of Codonopsis species.

Codonopsis pilosula subsp. tangshen is one of the most important medicinal herbs used in traditional Chinese medicine. Correct identification of materials from C. pilosula subsp. tangshen is critical to ensure the efficacy and safety of the associated medicines. Traditional DNA molecular markers could distinguish Codonopsis species well, so we need to develop super or specific molecular markers. In this study, we reported the plastome of Codonopsis pilosula subsp. tangshen (Oliv.) D.Y. Hong conducted phylogenomic and comparative analyses in the Codonopsis genus for the first time. The entire length of the Codonopsis pilosula subsp. tangshen plastome was 170,672 bp. There were 108 genes in the plastome, including 76 protein-coding genes, 28 transfer RNA (tRNA), and four ribosomal RNA (rRNA) genes. Comparative analysis indicated that Codonopsis pilosula subsp. tangshen had an unusual large inversion in the large single-copy (LSC) region compared with the other three Codonopsis species. And there were two dispersed repeat sequences at both ends of the inverted regions, which might mediate the generation of this inversion. We found five hypervariable regions among the four Codonopsis species. PCR amplification and Sanger sequencing experiments demonstrated that two hypervariable regions could distinguish three medicinal Codonopsis species. Results obtained from this study will support taxonomic classification, discrimination, and molecular evolutionary studies of Codonopsis species.

Comparative analysis of the chloroplast and mitochondrial genomes of Saposhnikovia divaricata revealed the possible transfer of plastome repeat regions into the mitogenome.

BACKGROUND: Saposhnikovia divaricata (Turcz.) Schischk. is a perennial herb whose dried roots are commonly used as a source of traditional medicines. To elucidate the organelle-genome-based phylogeny of Saposhnikovia species and the transfer of DNA between organelle genomes, we sequenced and characterised the mitochondrial genome (mitogenome) of S. divaricata. RESULTS: The mitogenome of S. divaricata is a circular molecule of 293,897 bp. The nucleotide composition of the mitogenome is as follows: A, 27.73%; T, 27.03%; C, 22.39%; and G, 22.85. The entire gene content is 45.24%. A total of 31 protein-coding genes, 20 tRNAs and 4 rRNAs, including one pseudogene (rpl16), were annotated in the mitogenome. Phylogenetic analysis of the organelle genomes from S. divaricata and 10 related species produced congruent phylogenetic trees. Selection pressure analysis revealed that most of the mitochondrial genes of related species are highly conserved. Moreover, 2 and 46 RNA-editing sites were found in the chloroplast genome (cpgenome) and mitogenome protein-coding regions, respectively. Finally, a comparison of the cpgenome and the mitogenome assembled from the same dataset revealed 10 mitochondrial DNA fragments with sequences similar to those in the repeat regions of the cpgenome, suggesting that the repeat regions might be transferred into the mitogenome. CONCLUSIONS: In this study, we assembled and annotated the mitogenome of S. divaricata. This study provides valuable information on the taxonomic classification and molecular evolution of members of the family Apiaceae.

Developing an Effective Peptide-Based Vaccine for COVID-19: Preliminary Studies in Mice Models.

Coronavirus disease 2019 (COVID-19) has caused massive health and economic disasters worldwide. Although several vaccines have effectively slowed the spread of the virus, their long-term protection and effectiveness against viral variants are still uncertain. To address these potential shortcomings, this study proposes a peptide-based vaccine to prevent COVID-19. A total of 15 B cell epitopes of the wild-type severe acute respiratory coronavirus 2 (SARS-CoV-2) spike (S) protein were selected, and their HLA affinities predicted in silico. Peptides were divided into two groups and tested in C57BL/6 mice with either QS21 or Al(OH)3 as the adjuvant. Our results demonstrated that the peptide-based vaccine stimulated high and durable antibody responses in mice, with the T and B cell responses differing based on the type of adjuvant employed. Using epitope mapping, we showed that our peptide-based vaccine produced antibody patterns similar to those in COVID-19 convalescent individuals. Moreover, plasma from vaccinated mice and recovered COVID-19 humans had the same neutralizing activity when tested with a pseudo particle assay. Our data indicate that this adjuvant peptide-based vaccine can generate sustainable and effective B and T cell responses. Thus, we believe that our peptide-based vaccine can be a safe and effective vaccine against COVID-19, particularly because of the flexibility of including new peptides to prevent emerging SARS-CoV-2 variants and avoiding unwanted autoimmune responses.

Heparan Sulfate Facilitates Spike Protein-Mediated SARS-CoV-2 Host Cell Invasion and Contributes to Increased Infection of SARS-CoV-2 G614 Mutant and in Lung Cancer.

The severe acute respiratory syndrome (SARS)-like coronavirus disease (COVID-19) is caused by SARS-CoV-2 and has been a serious threat to global public health with limited treatment. Cellular heparan sulfate (HS) has been found to bind SARS-CoV-2 spike protein (SV2-S) and co-operate with cell surface receptor angiotensin-converting enzyme 2 (ACE2) to mediate SARS-CoV-2 infection of host cells. In this study, we determined that host cell surface SV2-S binding depends on and correlates with host cell surface HS expression. This binding is required for SARS-Cov-2 virus to infect host cells and can be blocked by heparin lyase, HS antagonist surfen, heparin, and heparin derivatives. The binding of heparin/HS to SV2-S is mainly determined by its overall sulfation with potential, minor contribution of specific SV2-S binding motifs. The higher binding affinity of SV2-S G614 mutant to heparin and upregulated HS expression may be one of the mechanisms underlying the higher infectivity of the SARS-CoV-2 G614 variant and the high vulnerability of lung cancer patients to SARS-CoV-2 infection, respectively. The higher host cell infection by SARS-CoV-2 G614 variant pseudovirus and the increased infection caused by upregulated HS expression both can be effectively blocked by heparin lyase and heparin, and possibly surfen and heparin derivatives too. Our findings support blocking HS-SV2-S interaction may provide one addition to achieve effective prevention and/treatment of COVID-19.

Nutritional of assessment school lunches for primary and secondary school students in the Pearl River Delta / 中国学校卫生

Objective@#To investigate nutritional quality of school lunch in some primary schools and middle schools in the Pearl River Delta, and to provide the scientific basis for improving the nutritional quality of students lunch and formulating scientific and effective interventions.@*Methods@#Five-day lunch meal survey by chemical analysis were conducted, and students lunch at school were recorded by meal review in three age groups from 8 primary and middle schools in the Pear River Delat area. The energy and nutrient content were obtained and compared with the reference intake of dietary nutrients of student.@*Results@#The average protein intake at lunch of all age groups had reached the recommended standard (80%-95%), the energy supply ratio of carbohydrate in the range of 38.3%-42.3%, the energy supply ratio of fat in 63% school meal exceeded the recommended standard. Vitamin A, vitamin B 1, vitamin B 2, calcium, iron and other nutrients were seriously inadequate; while sodium intake far exceeded the recommended standard.@*Conclusion@#The main nutrients of school lunch of primary and middle school in Pearl River Delta can basically meet the growth and development needs, but there are still some deficiency and unbalanced diet nutrient content which are lower than the recommended intake. It is recommended to strengthen nutrition education of catering enterprises and school to improve the scientific combination of diets.

Activation of CXCR7 alleviates cardiac insufficiency after myocardial infarction by promoting angiogenesis and reducing apoptosis.

Angiogenesis is an important pathway for revascularization of ischemic tissues after acute myocardial infarction (AMI). It is unclear what role CXCR7 plays in angiogenesis in the ischemic area after AMI, although some researchers have shown that the activation of CXCR7 protectsthe heart under those conditions. Here, we hypothesize that the activation of CXCR7 promotes angiogenesis, reduces cell apoptosis and alleviates cardiac deficiency after AMI. C57BL/6 J mice were subjected to AMI and treated with TC14012 (10 mg/kg) for 24 days. HUVECs were cultured in a hypoxic (2% O2) environment to generate a model of hypoxia. CXCR7 was knocked down in HUVECs by sh-CXCR7 transfection, and CXCR7 was activated by TC14012 (30 µM) treatment. The results showed that CXCR7 was downregulated in infarcted heart tissue and hypoxic HUVECs. The global activation of CXCR7 may alleviate the decrease in cardiac function indexes - (ejection fraction and fraction shortening), and reduce infarct size after AMI.. Moreover, CXCR7 activation has been shown to enhance the level of angiogenesis in ischemic heart tissue. In vitro, hypoxia-induced angiogenic functional loss and apoptosis are aggravated by CXCR7 knockdown in HUVECs. Both angiogenic impairment and cell apoptosis are rescued by CXCR7 activation. In conclusion, the present study indicates that activation of CXCR7 plays an important protective role for ischemic cells in hypoxic endothelial cells and AMI model mice by promoting angiogenesis and reducing apoptosis, which suggests that CXCR7 may be a potential therapeutic target to rescue the ischemic myocardium..

A mutant-cell library for systematic analysis of heparan sulfate structure-function relationships.

Heparan sulfate (HS) is a complex linear polysaccharide that modulates a wide range of biological functions. Elucidating the structure-function relationship of HS has been challenging. Here we report the generation of an HS-mutant mouse lung endothelial cell library by systematic deletion of HS genes expressed in the cell. We used this library to (1) determine that the strictly defined fine structure of HS, not its overall degree of sulfation, is more important for FGF2-FGFR1 signaling; (2) define the epitope features of commonly used anti-HS phage display antibodies; and (3) delineate the fine inter-regulation networks by which HS genes modify HS and chain length in mammalian cells at a cell-type-specific level. Our mutant-cell library will allow robust and systematic interrogation of the roles and related structures of HS in a cellular context.

Heparan sulfate modulates Slit3-induced endothelial cell migration.

Heparan sulfate is a long, linear polysaccharide with sulfation modifications and belongs to the glycosaminoglycan family. Our recent studies elucidated that the axon guidance molecule Slit3 is a new heparan sulfate-binding protein and a novel angiogenic factor by interacting with its cognate receptor Robo4, which is specifically expressed in endothelial cells. Here we describe using heparan sulfate-deficient mouse endothelial cells to determine the co-reception function of heparan sulfate in Slit3-induced endothelial cell migration in a Boyden chamber trans-well migration assay.

Genetic deletion of Cxcl14 in mice alters uterine NK cells.

The uterine natural killer cells (uNK cells) are the major immune cells in pregnant uterus and the number of uNK cells is dramatically increased during placentation and embryo development. The uNK cells are necessary for the immune tolerance, cytokine secretion and angiogenesis of placenta. Former studies indicated that the population expansion of uNK cells was accomplished through recruitment of NK cell precursors from the spleen and bone marrow, but not proliferation of NK cells. However, the necessary molecules within this process were little understood. Here in our study, we found the co-localized expression of Cxcl14 protein with uNK cells in E13.5 pregnant uterus. Moreover, we used Cxcl14 knockout mice to examine uNK cells in mesometrial lymphoid aggregate of pregnancy (MLAp) and decidua basalis (DB) of E13.5 pregnant uterus and found significantly decreased uNK cells in Cxcl14(-/-) pregnant uteri compared with Cxcl14(+/-) pregnant uteri. To further explorer the molecular change in MLAp and DB after Cxcl14 knockout, we isolated the MLAp and DB from Cxcl14(+/+) and Cxcl14(-/-) pregnant uteri and performed microarray analysis. We found many genes were up and down regulated after Cxcl14 knockout. In conclusion, our results suggested the important function of Cxcl14 in uNK cells and the proper level of Cxcl14 protein were required to recruit NK cells to pregnant uterus.

Aquaporin 7 expression in postimplantation mouse uteri: a potential role for glycerol transport in uterine decidualization.

The aquaglyceroporin aquaporin 7 (AQP7) is dynamically expressed in mouse uteri undergoing decidualization after implantation. The expansion of AQP7 during uterine decidualization is associated with elevated uterine glycerol accumulation and glycerol kinase expression, suggesting that glycerol might be a potential energy substrate involved in the process of decidualization.