Vitamin K2 Modulates Mitochondrial Dysfunction Induced by 6-Hydroxydopamine in SH-SY5Y Cells via Mitochondrial Quality-Control Loop

Vitamin K2, a natural fat-soluble vitamin, is a potent neuroprotective molecule, owing to its antioxidant effect, but its mechanism has not been fully elucidated. Therefore, we stimulated SH-SY5Y cells with 6-hydroxydopamine (6-OHDA) in a proper dose-dependent manner, followed by a treatment of vitamin K2. In the presence of 6-OHDA, cell viability was reduced, the mitochondrial membrane potential was decreased, and the accumulation of reactive oxygen species (ROS) was increased. Moreover, the treatment of 6-OHDA promoted mitochondria-mediated apoptosis and abnormal mitochondrial fission and fusion. However, vitamin K2 significantly suppressed 6-OHDA-induced changes. Vitamin K2 played a significant part in apoptosis by upregulating and downregulating Bcl-2 and Bax protein expressions, respectively, which inhibited mitochondrial depolarization, and ROS accumulation to maintain mitochondrial structure and functional stabilities. Additionally, vitamin K2 significantly inhibited the 6-OHDA-induced downregulation of the MFN1/2 level and upregulation of the DRP1 level, respectively, and this enabled cells to maintain the dynamic balance of mitochondrial fusion and fission. Furthermore, vitamin K2 treatments downregulated the expression level of p62 and upregulated the expression level of LC3A in 6-OHDA-treated cells via the PINK1/Parkin signaling pathway, thereby promoting mitophagy. Moreover, it induced mitochondrial biogenesis in 6-OHDA damaged cells by promoting the expression of PGC-1α, NRF1, and TFAM. These indicated that vitamin K2 can release mitochondrial damage, and that this effect is related to the participation of vitamin K2 in the regulation of the mitochondrial quality-control loop, through the maintenance of the mitochondrial quality-control system, and repair mitochondrial dysfunction, thereby alleviating neuronal cell death mediated by mitochondrial damage

Optimization Medium Composition for Vitamin K2 by Flavobacterium sp. using Response Surface Methodology and Addition of Arachis hypogaea

ABSTRACT The purpose of this research was to enhance the production of vitamin K2 by fermentation optimization and Arachis hypogaea supplementation in Flavobacterium sp. mutant SP-L-01. Optimized culture condition were as follows: 6-days shake-flask culture at 37oC with initial pH value 7.0 ± 0.2, shaking speed in 120 r/min and medium volume of 30 mL with 2% inoculums. After optimization of fermentation medium by response surface methodology (RSM), optimized medium were maltose 23.8 g/l, glucose 9.69 g/l, beef extract 15 g/l, K2HPO4 4.5 g/l，NaCl 3.0 g/l and MgSO4·7H2O 0.3 g/l. Production of vitamin K2 after optimization reached to 10.97 mg/l, which is 79.25% higher than that before optimization (6.12 mg/l). 3 mg/mL of arachis hypogaea was added into the medium at 72 h of shake-flake cultivation, which improved the production of menaquinone-4 (MK4) up to 371% and menaquinone-6 (MK6) up to 149% higher than those of the original medium. D-(+)-catechin, one of the components of arachis hypogaea, was added alone into the medium, which also improved the vitamin K2 synthesis

Enhanced Production of Vitamin K2 from Bacillus subtilis (natto)by Mutation and Optimization of the Fermentation Medium

The aim of this study was to enhance the production of vitamin K2 by using N-methyl-N-nitro-N-nitroso-guanidine (NTG) and low energy ion beam implantation and optimizing the fermentation medium. Mutation resulted in 1.66-fold higher production of vitamin K2 than that of the parentl strain. The production by the mutant BN-P15-11-1was increased 55% and reached 3.593±0.107 mg/L by using the Plackett-Burman and Box-Behnken designs to optimize the fermentation medium. The optimal fermentation culture medium was composed of (g/L) glycerol 69.6, sucrose 34.5, K2HPO4 4.0, peptone 20, yeast extract 25 and fermented at 37 °C and 150 rpm for 72 h. The results showed that the NTG and low energy ion beam implantation mutations and optimizing fermentation medium were effective methods to enhance vitamin K2production

Macro-morphological characterization and kinetics of <i>Mortierella alpina</i> colonies during batch cultivation

<div><p>An effective method for research of macro-morphological characterization and its kinetics was developed by studying the macro-morphological characteristics of <i>Mortierella alpina</i>, an oleaginous zygomycete widely used to produce lipids rich in PUFA, in function of culture medium composition and to link morphological features of fungus with the level of lipid production. A number of distinct morphological forms including hollow pellets, fluffy pellets and freely dispersed mycelia were obtained by changing the fermentation factors. By fitting a Logistic curve, the maximum specific growth rate (<i>μ</i>_max)was obtained, which determined the final mycelia morphology. <i>μ</i>_max of 0.6584 in three kind of morphological forms is the more appropriate. According to the Luedeking-Piret equation fitting, <i>α</i>≠0 and <i>β</i>≠0, lipid production was partially associated with the hyphal growth, fluffy pellets which turn glucose into lipidwas more effective than the other two kinds of morphological forms.</p></div

The detailed process of the growth rate and lipid accumulation rate at every day for each morphology.

<p>The detailed process of the growth rate and lipid accumulation rate at every day for each morphology.</p

Time course of glucose concentration, dry cell weight (DCW) and lipid production in shake flask cultures inoculated under different morphology.

<p>a Glucose concentration, b Dry cell weight, c lipid production. Solid square symbol reflect hollow pellets, solid circle reflect fluffy pellets, solid diamond reflect dispersed filaments.</p

The kinetic parameters of fermentation process cultivated with each distinct morphology.

<p>The kinetic parameters of fermentation process cultivated with each distinct morphology.</p

Several distinct macro-morphological forms of <i>M</i>. <i>alpina</i> under different culture medium.

<p>a Fluffy pellets (glucose of 100g/l), b Fluffy pellets cover by slender filamentous (peptone), c Dispersed filaments (yeast extract or corn steep liquor), d Hollow pellets around a little filaments (peptone/yeast extract(3:1)), e Dispersed mycelia (peptone/yeast extract (2:1)). The specific image of mycelia was carried out by the stereoscopic microscope equipped with a monochrome CCD camera at 10X 0.8 times.</p

Lipid production, biomass and morphology of <i>M</i>. <i>alpina</i> with different nitrogen sources (means± SD).

<p>Lipid production, biomass and morphology of <i>M</i>. <i>alpina</i> with different nitrogen sources (means± SD).</p