Background Tetrastigma hemsleyanum Diels et Gilg is a valuable medicinal herb, whose main bioactive constituents are flavonoids. Chilling sensitivity is the dominant environmental factor limiting growth and development of the plants. But the mechanisms of cold sensitivity in this plant are still unclear. Also, not enough information on genes involved in flavonoid biosynthesis in T. hemsleyanum is available to understand the mechanisms of its physiological and pharmaceutical effects. Results The electrolyte leakage, POD activity, soluble protein, and MDA content showed a linear sustained increase under cold stress. The critical period of cold damage in T. hemsleyanum was from 12 h to 48 h. Expression profiles revealed 18,104 differentially expressed genes (DEGs) among these critical time points. Most of the cold regulated DEGs were early-response genes. A total of 114 unigenes were assigned to the flavonoid biosynthetic pathway. Fourteen genes most likely to encode flavonoid biosynthetic enzymes were identified. Flavonols of T. hemsleyanum might play a crucial role in combating cold stress. Genes encoding P AL, 4CL , CHS, ANR, FLS , and LAR were significantly up-regulated by cold stress, which could result in a significant increase in crucial flavonols (catechin, epicatechin, rutin, and quercetin) in T. hemsleyanum. Conclusions Overall, our results show that the expression of genes related to flavonol biosynthesis as well as flavonol content increased in T. hemsleyanum under cold stress. These findings provide valuable information regarding the transcriptome changes in response to cold stress and give a clue for identifying candidate genes as promising targets that could be used for improving cold tolerance via molecular breeding. The study also provides candidate genes involved in flavonoid biosynthesis and may be useful for clarifying the biosynthetic pathway of flavonoids in T. hemsleyanum . Electronic supplementary material The online version of this article (10.1186/s12864-019-6045-y) contains supplementary material, which is available to authorized users.

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Signaling of RANK (receptor activator of nuclear factor kappa B) through its ligand RANKL appears critical in osteolysis associated with aseptic loosening (AL). The purpose of this study was to investigate the role of RANK in a murine osteolysis model developed in RANK knockout (RANK À/À ) mice. Ultra high molecular weight polyethylene (UHMWPE) debris was introduced into established air pouches on RANK À/À mice, followed by implantation of calvaria bone from syngeneic littermates. Wild type C57BL/6 (RANK þ/þ ) mice injected with either UHMWPE or saline alone were included in this study. Pouch tissues were collected 14 days after UHMWPE inoculation for molecular and histology analysis. Results showed that UHMWPE stimulation induced strong pouch tissue inflammation in RANK À/À mice, as manifested by inflammatory cellular infiltration, pouch tissue proliferation, and increased gene expression of IL-1b, TNFa, and RANKL. However, the UHMWPE-induced inflammation in RANK À/À mice was not associated with the osteoclastic bone resorption observed in RANK þ/þ mice. In RANK þ/þ mice subjected to UHMWPE stimulation, a large number of TRAP þ cells were found on the implanted bone surface, where active osteoclastic bone resorption was observed. No TRAP þ cells were found in UHMWPE-containing pouch tissues of RANK À/À mice. Consistent with the lack of osteoclastic activity shown by TRAP staining, no significant UHMWPE particle-induced bone resorption was found in RANK À/À mice. A well preserved bone collagen content (Van Gieson staining) and normal plateau surface contour [microcomputed tomography (mCT)] of implanted bone was observed in RANK À/À mice subjected to UHMWPE stimulation. In conclusion, this study provides the evidence that UHMWPE particles induce strong inflammatory responses, but not associated with osteoclastic bone resorption in RANK À/À mice. This indicates that RANK signaling is essential for UHMWPE particle-induced osteoclastic bone resorption, but does not participate in UHMWPE particle-induced inflammatory response. ß

Up to 20% of patients with total joint arthroplasty will develop radiographic evidence of aseptic loosening (AL), which most likely results from an inflammatory response to billions of wear debris shed from the implant. Our previous work has demonstrated that erythromycin (EM), a macrolide antibiotic, inhibits wear debris-induced inflammatory osteoclastogenesis through the reduction of cytokine production and osteoclast differentiation, both of which involve the NF-kB pathway. The aim of the current study was to determine whether EM inhibits wear debris-induced inflammatory osteolysis in a murine osteolysis model. Ultrahigh molecular-weight polyethylene (UHMWPE) debris was introduced into established air pouches on BALB/c mice, followed by implantation of calvaria bone from syngeneic littermates. EM (2 mg/kg/day) was given to mice intraperitoneally 2 days before UHMWPE introduction and maintained until the sacrifice of the mice. Mice with and without EM treatment, as well as control mice injected with saline alone were included in this study. Pouch tissues were collected 14 days after UHMWPE inoculation for molecular and histology analysis. Our findings indicate that: (1) EM reduced UHMWPE-induced tissue inflammation, including the diminished pouch membrane thickness, reduced inflammatory cellular infiltration, and lowered IL-1b and TNF-a expression (mRNA and protein); (2) EM inhibited UHMWPE-induced osteoclastogenesis, with reduced gene activation of RANK, RANKL, and CPK, and diminished RANKL expression in UHMWPE stimulated pouches, and (3) EM markedly reduced the number of TRAP þ cells in pouch tissues, and protected against bone collagen depletion. In conclusion, this study provides the evidence that EM inhibits the UHMWPE particles-induced inflammatory osteolysis in a murine model, and represents a promising therapeutic candidate for the prevention and treatment of AL. ß

Strictamine and rhazinoline are representative methanoquinolizidine-containing akuammiline alkaloids that possess different stereochemistry at the C16 position. Aunified approach to the enantioselective total syntheses of these two molecules is described. The key steps in this synthesis include ap hotocatalytic intra/intermolecular type II radical cascade reaction, aT suji-Trost allylation, ap alladium-or nickelmediated cyclization, and al ate-stage intramolecular Nalkylation reaction.

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Ethnopharmacological relevance Tetrastigma hemsleyanum Diels et Gilg ( T.hemsleyanum ), a rare herbal plant distributed in subtropical areas of mainland China, has become a focus of scientific attention in recent years because of its high traditional value, including uses for treatment of children with fever, pneumonia, asthma, rheumatism, hepatitis, menstrual disorders, scrofula, and pharynx pain. Aim This systematic review aims to provide an insightful understanding of traditional uses, chemical composition, pharmacological effect and clinical application of T. hemsleyanum , and lay a foundation for the further study and for the utilization of T. hemsleyanum resource. Materials and methods A domestic and overseas literature search in known databases was conducted for published articles using the relevant keywords. Results One hundred and forty-two chemical constituents identified from T. hemsleyanum have been reported, including flavonoids, phenolic acids, polysaccharide, organic acids, fatty acids, terpenoids, steroids, amino acid and others. Among these components, flavonoids and polysaccharides were the representative active ingredients of T. hemsleyanum , which have been widely investigated. Modern pharmacological studies have shown that these components exhibited various pharmacological activities, such as anti-inflammatory, antioxidant, antivirus, antitumor, antipyretic, anti-hepatic injury, immunomodulatory, antibacterial etc. Moreover, different toxicological studies indicated that the clinical dosage of T. hemsleyanum was safe and reliable. Conclusions Modern pharmacological studies have well supported and clarified some traditional uses, and T. hemsleyanum has a good prospect for the development of new drugs due to these outstanding properties. However, the present findings did not provide an in-depth evaluation of bioactivity of the extracts, the composition of its active extracts was not clear. Moreover, they were insufficient to satisfactorily explain some mechanisms of action. Data regarding many aspects of T. hemsleyanum , such as links between the traditional uses and bioactivities, pharmacokinetics, quality control standard and the clinical value of active compositions is still limited which need more attention.

Two cyanobacterial strains morphologically identified to the genus Nostoc were isolated from a wet rocky wall in a mid-subtropical region in China, and they were taxonomically and phylogenetically characterized based on the polyphasic approach combining morphological and genetic characteristics. 16S rRNA gene sequence analysis showed that the two strains containing six clones were all >99.6% similar to each other, but had < 94.3% similarities to the existing cyanobacterial genera. The phylogenies based on 16S rRNA and rpoC1 gene sequences indicated that their sequences grouped into a unique and robust cluster with high bootstrap values. This unique cluster was separated from the clade of the 'Nostoc sensu stricto' and the respective clades formed by the morphologically similar genera Mojavia, Desmonostoc, Aliinostoc, Komarekiella and Halotia. The 16S-23S rRNA ITS secondary structure of the both strains exhibited the unique pattern of D1-D1´, Box-B and V3 helix, distinguishing it from the other heterocytous genera. Such a clear cluster leads to the establishment of Minunostoc gen. nov., with the type species as Minunostoc cylindricum sp. nov.