Arabidopsis mtHSC70-1 plays important roles in the establishment of COX-dependent respiration and redox homeostasis.

The 70 kDa heat shock proteins function as molecular chaperones and are involved in diverse cellular processes. However, the functions of the plant mitochondrial HSP70s (mtHSC70s) remain unclear. Severe growth defects were observed in the Arabidopsis thaliana mtHSC70-1 knockout lines, mthsc70-1a and mthsc70-1b. Conversely, the introduction of the mtHSC70-1 gene into the mthsc70-1a background fully reversed the phenotypes, indicating that mtHSC70-1 is essential for plant growth. The loss of mtHSC70-1 functions resulted in abnormal mitochondria and alterations to respiration because of an inhibition of the cytochrome c oxidase (COX) pathway and the activation of the alternative respiratory pathway. Defects in COX assembly were observed in the mtHSC70-1 knockout lines, leading to decreased COX activity. The mtHSC70-1 knockout plants have increased levels of reactive oxygen species (ROS). The introduction of the Mn-superoxide dismutase 1 (MSD1) or the catalase 1 (CAT1) gene into the mthsc70-1a plants decreased ROS levels, reduced the expression of alternative oxidase, and partially rescued growth. Taken together, our data suggest that mtHSC70-1 plays important roles in the establishment of COX-dependent respiration.

[Study on UPLC Fingerprint of Corydalis bungeana].

OBJECTIVE: To establish an Ultra Performance Liquid Chromatography fingerprint of Corydalis bungeana from different habitats. METHODS: UPLC-PDA was adopted to analysis ten batches of Corydalis bungeana from different habitats with Phenomenex Luna C18 column (250 mm x 4.6 mm, 5 µm) eluted with the mobile phase of acetonitrile and 0. 02% triethylamine in a gradient mode. The flow rate was 0.3 mL/min and the column temperature was 30 °C. The detection wavelength was set at 289 nm. RESULTS: The fingerprints of ten batches of Corydalis bungeana from different habitats had 13 common peaks, three of them were identified. The similarities were larger than 0.80. Ten batches of samples were divided into three categories by cluster analysis. Three principal components were ob- served via principal component analysis and the value of three principal components accounted for 89. 607% of the total variance. Two major chemical components of Corydalis bungeana were confirmed. CONCLUSION: The high-performance and rapid method is successfully used for fingerprint analysis and can be used to evaluate the quality of Corydalis bungeana.

Expression of terpene synthase-related genes in parents and offspring of Flammulina filiformis based on differences in volatile aroma components.

Flammulina filiformis (F. filiformis) is one of the four major edible types of fungus in the world and has been cultivated in China since 800 CE (Anno Domini). Some of the most essential criteria for evaluating the quality of F. filiformis are the types and contents of volatile components present. A focused study on screened the terpene synthase genes involved in the aroma of offspring and compared key terpenoids between parents and offspring, which is helpful for the development and application of F. filiformis. Firstly, the volatile aroma components of parent and offspring F. filiformis were extracted using two pretreatment procedures, and then were semi-quantified by an internal standard. Forty-eight, fifty-eight, and forty-eight volatile compounds were identified in parents and offspring of three different strains, and 15, 22, and 12 aroma compounds (OAVs ≥ 1) were further screened out via calculating their odor activity values (OAVs). Terpenoids, in particular linalool and eucalyptol, which contribute more to the aroma, result in the unique green and grassy aroma of the offspring. At last, the F. filiformis genome was resequenced and the coordinates of genes related to terpenoid synthase were determined. The results showed that Scaffolds, including scaffold3.t874 and scaffold9.t157 were connected to terpenoid synthesis of offspring (No. 61523). The variant genes g269 and g61 were related to terpenoid synthase sequences. This study provides a theoretical foundation for the cultivation of more diverse and unique varieties of F. filiformis.

Arabidopsis mtHSC70-1 physically interacts with the Cox2 subunit of cytochrome c oxidase.

The 70-kD heat shock proteins (HSP70s or HSC70s) function as molecular chaperones and are involved in diverse cellular processes. We recently demonstrated the roles of mitochondrial HSC70-1 (mtHSC70-1) in the establishment of cytochrome c oxidase (COX)-dependent respiration and redox homeostasis in Arabidopsis thaliana. Defects in COX assembly were observed in the mtHSC70-1 knockout lines. The levels of Cox2 (COX subunit 2) proteins in COX complex were markedly lower in the mutants than in wild-type plants; however, the levels of total Cox2 proteins in the mutants were not obviously different from those in wild-type plants, suggesting that the stability of COX or the availability of Cox2 was impaired in the mtHSC70-1 mutants. Here, we further detected the interaction between mtHSC70-1 and Cox2 proteins through co-immunoprecipitation, pull-down and firefly luciferase complementation imaging assays. The results showed that mtHSC70-1 could directly combine Cox2 in vivo and in vitro, providing supporting evidence for the role of mtHSC70-1 in COX assembly.

Nauclea officinalis inhibits inflammation in LPS-mediated RAW 264.7 macrophages by suppressing the NF-κB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Nauclea officinalis has been traditionally used in China for the treatment of fever, pneumonia and enteritidis etc. This study aims to investigate effects of N. officinalis on the inflammatory response as well as the possible molecular mechanism in LPS-stimulated RAW 264.7 murine macrophage cells. MATERIALS AND METHODS: Anti-inflammatory activity of N. officinalis (10, 20, 50, and 100µg/mL) was investigated by using LPS-induced RAW 264.7 macrophages. The NO production was determined by assaying nitrite in culture supernatants with the Griess reagent. The levels of TNF-α, IL-6 and IL-1ß in culture media were measured with ELISA kits. Real time fluorescence quantitative PCR was detected for mRNA expression of iNOS, TNF-α, IL-6 and IL-1ß. Western blot assay was performed to illustrate the inhibitory effects of N. officinalis on phosphorylation of IκB-α and NF-κB p65. RESULTS: Treatment with N. officinalis (10-100µg/mL) dose-dependently inhibited the production as well as mRNA expression of NO, TNF-α, IL-6 and IL-1ß in RAW 264.7 macrophages. Western blot assay suggested that the mechanism of the anti-inflammatory effect was associated with the inhibition of phosphorylation of IκB-α and NF-κB p65. CONCLUSIONS: The results indicated that N. officinalis potentially inhibited the activation of upstream mediator NF-κB signaling pathway via suppressing phosphorylation of IκB-α and NF-κB p65 to inhibit LPS-stimulated inflammation.

Corydalis bungeana Turcz. attenuates LPS-induced inflammatory responses via the suppression of NF-κB signaling pathway in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Corydalis bungeana Turcz. (C. bungeana) is one of traditionally used medicines in China and possesses various biological effects, such as anti-inflammatory, antibacterial activity and inhibition of the immune function of the host. AIM OF THE STUDY: we studied the anti-inflammatory effect and molecular mechanism involved of C. bungeana both in vitro and in vivo model system in which the inflammatory response was induced by LPS treatment. MATERIALS AND METHODS: Anti-inflammatory activity of C. bungeana was investigated by LPS-induced RAW 264.7 macrophages and BALB/c mice. The production and expression of pro-inflammatory cytokines were evaluated by Griess reagent, ELISA kits and RT-qPCR, respectively. Phosphorylation status of IκBα and p65 was illustrated by western blot assay. RESULTS: C. bungeana reduced the secretion of NO, TNF-α, IL-6 and IL-1ß through inhibiting the protein expression of iNOS, TNF-α, IL-6 and IL-1ß in vitro and in vivo. Western blot analysis suggested that C. bungeana supressed NF-κB activation via regulating the phosphorylation of IκBα and p65. Immunohistochemical assay also demostrated the histological inflammatory change in liver tissue. CONCLUSIONS: The results indicate that C. bungeana supresses the activation of NF-κB signaling pathway through inhibiting phosphorylation of IκBα and p65, which results in good anti-inflammatory effect. In addition, C. bungeana attenuates inflammatory reaction by supressing the expression of various inflammatory cytokines both in vivo and in vitro.