Efficient simultaneous production of extracellular polyol esters of fatty acids and intracellular lipids from inulin by a deep-sea yeast Rhodotorula paludigena P4R5.

BACKGROUND: Polyol esters of fatty acids (PEFA) are a kind of promising biosurfactants and mainly secreted by Rhodotorula strains. In addition, some strains of Rhodotorula are reliable producers of microbial lipid. Therefore, it is feasible to establish a one step fermentation process for efficient simultaneous production of PEFA and microbial lipids by a suitable Rhodotorula strain. RESULTS: A newly isolated deep-sea yeast, Rhodotorula paludigena P4R5, was shown to simultaneously produce high level of intracellular lipid and extracellular PEFA. Under the optimized conditions, it could yield 48.5 g/L of PEFA and 16.9 g/L of intracellular lipid within 156 h from inulin during 10-L batch fermentation. The PEFA consisting of a mixture of mannitol esters of 3-hydroxy C14, C16 and C18 fatty acids with variable acetylation showed outstanding surface activity and emulsifying activity, while the fatty acids of the intracellular lipid were mainly C16 and C18 and could be high-quality feedstock for biodiesel production. CONCLUSION: The deep-sea yeast strain R. paludigena P4R5 was an excellent candidate for efficient simultaneous of biosurfactants and biodiesel from inulin. Our results also suggested that the establishment of fermentation systems with multiple metabolites production was an effective approach to improve the profitability.

Corilagin Attenuates Allergy and Anaphylactic Reaction by Inhibiting Degranulation of Mast Cells.

BACKGROUND This study evaluated the anti-allergic activity of corilagin and also postulates the possible mechanism of its action. MATERIAL AND METHODS Corilagin was given orally at dose of 10, 20, and 40 mg/kg/day. All the animals (guinea pigs, rats, and mice) were sensitized for allergy such as eosinophilia and leukocytosis induced by milk; degranulation of mast cell by compound 48/80; and passive and active anaphylaxis. Moreover, the antagonistic effect was determined by estimating the effect of corilagin on contraction of guinea pig tracheal chain and ileum induced by Ach and histamine, respectively. RESULTS There was a significant decrease in the leukocyte and eosinophil counts in the corilagin-treated group compared to the negative control group. Treatment with corilagin significantly protects the degranulation of mast cells, and it also has significant anti-muscarinic and antihistaminic activity by reducing the muscle contraction induced by Acetylcholine (Ach) and histamine in guinea pig tracheal chain and ileum. CONCLUSIONS Corilagin possess anti-anaphylactic and anti-allergic activity by inhibiting the release of mediators from mast cells and by decreasing the serum concentration of immunoglobulin E (IgE).

Association of serum uric acid with women's ovarian reserve: observational study and Mendelian randomization analyses.

OBJECTIVE: To investigate the association between serum uric acid and women's ovarian reserve. DESIGN: Retrospective observational study and Mendelian randomization study. SETTING: University-affiliated in vitro fertilization center. PATIENTS: Observational analyses were undertaken using data from 8,257 women with infertility who finished their first in vitro fertilization treatments between May 2017 and December 2021. Mendelian randomization analyses were based on genome-wide association summary statistics from several biobanks of predominantly European ancestries. INTERVENTIONS: Observational study involved testing log2 transformed serum uric acid levels (for linear, negative regression, and logistic regression analyses); original uric acid levels (for nonlinear association analyses). Mendelian randomization study involved testing genetically predicted uric acid levels. MAIN OUTCOME MEASURES: Biomarkers including antimüllerian hormone, basal antral follicle count, follicle-stimulating hormone, luteinizing hormone, ratio of follicle-stimulating hormone to luteinizing hormone, estradiol; indices of ovarian response to stimulation including poor ovarian response according to different criteria and oocyte yield. RESULTS: In retrospective observational study, all ovarian reserve-related outcomes demonstrated significant differences across serum uric acid quartiles. A two-fold uric acid increase was associated with increased antimüllerian hormone (adjusted ß = 0.69; 95% confidence interval [CI], 0.43-0.95), antral follicle count (adjusted incidence rate ratio = 1.10, 95% CI, 1.05-1.14), luteinizing hormone (adjusted ß = 0.53, 95% CI, 0.28-0.78), decreased risks of Bologna poor ovarian response (adjusted odds ratio = 0.97; 95% CI, 0.95-0.99) and groups 2-4 Poseidon poor ovarian response (group 2: 0.63, 0.56-0.71; group 3: 0.71, 0.65-0.78; group 4: 0.50, 0.46-0.55), whereas an increased risk of group 1 (1.26, 1.13-1.41). Nonlinear analyses showed a common inflection point at 320-340 µmol/L of uric acid. Interactions between uric acid and antimüllerian hormone and antral follicle count were presented in association with oocyte yield. Mendelian randomization results suggested a significant association between genetically predicted uric acid levels and antimüllerian hormone levels (ß = 0.08; 95% CI, 0.04-0.12) but none for uric acid in relation to polycystic ovarian syndrome or other related hormones. CONCLUSION: Higher uric acid levels were associated with better ovarian reserve and increased levels of antimüllerian hormone albeit an increased risk of unexpected poor ovarian response.

O-GalNAc glycosylation affects the immunogenicity of the receptor-binding domain (RBD) of SARS-CoV-2 spike protein.

The spike protein of SARS-CoV-2 has been widely used as an effective vaccine immunogen, although some limitations still remain. Herein, O-GalNAc glycosylated RBD (Tn-RBD) was synthesized as an antigen via in vitro glycosylation reactions. The inhibition ability against hACE2 binding of antibodies induced with Tn-RBD was 30-40% increased compared to that induced with RBD. This result implies that Tn-glycosylation might play important roles in the immunogenicity of the RBD protein, which should be considered in the design of novel vaccines to fight against COVID-19.

PPM1K-regulated impaired catabolism of branched-chain amino acids orchestrates polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) is one of the most common diseases with the coexistence of reproductive malfunction and metabolic disorders. Previous studies have found increased branched chain amino acid (BCAA) levels in women with PCOS. However, it remains unclear whether BCAA metabolism is causally associated with the risk of PCOS. METHODS: The changes of BCAA levels in the plasma and follicular fluids of PCOS women were detected. Mendelian randomization (MR) approaches were used to explore the potential causal association between BCAA levels and the risk of PCOS. The function of the gene coding the protein phosphatase Mg2+/Mn2+-dependent 1K (PPM1K) was further explored by using Ppm1k-deficient mouse model and PPM1K down-regulated human ovarian granulosa cells. FINDINGS: BCAA levels were significantly elevated in both plasma and follicular fluids of PCOS women. Based on MR, a potential direct, causal role for BCAA metabolism was revealed in the pathogenesis of PCOS, and PPM1K was detected as a vital driver. Ppm1k-deficient female mice had increased BCAA levels and exhibited PCOS-like traits, including hyperandrogenemia and abnormal follicle development. A reduction in dietary BCAA intake significantly improved the endocrine and ovarian dysfunction of Ppm1k-/- female mice. Knockdown of PPM1K promoted the conversion of glycolysis to pentose phosphate pathway and inhibited mitochondrial oxidative phosphorylation in human granulosa cells. INTERPRETATION: Ppm1k deficiency-impaired BCAA catabolism causes the occurrence and development of PCOS. PPM1K suppression disturbed energy metabolism homeostasis in the follicular microenvironment, which provided an underlying mechanism of abnormal follicle development. FUNDING: This study was supported by the National Key Research and Development Program of China (2021YFC2700402, 2019YFA0802503), the National Natural Science Foundation of China (81871139, 82001503, 92057107), the CAMS Innovation Fund for Medical Sciences (2019-I2M-5-001), Key Clinical Projects of Peking University Third Hospital (BYSY2022043), the China Postdoctoral Science Foundation (2021T140600), and the Collaborative Innovation Program of Shanghai Municipal Health Commission (2020CXJQ01).

Chemoenzymatic Synthesis of SARS-CoV-2 Homogeneous O-Linked Glycopeptides for Exploring Their Inhibition Functions.

Harnessing highly conserved peptides derived from the receptor binding domain (RBD) of spike (S) protein to construct peptide-based inhibitors is one of the most effective strategies to fight against the ever-mutating coronavirus SARS-CoV-2. But how the O-glycosylation affects their inhibition abilities has not been intensively explored. Herein, an intrinsic O-glycosylated peptide P320-334 derived from RBD was screened and homogeneous O-linked glycopeptides containing Tn (GalNAcα1-O-Ser/Thr), T (Galß1-3GalNAcα1-O-Ser/Thr), sialyl-Tn (sTn, Siaα2-6GalNAcα1-O-Ser/Thr), and sialyl-T (sT, Siaα2-3Galß1-3GalNAcα1-O-Ser/Thr) structures were first synthesized via chemoenzymatic strategies. Compared with the unglycosylated peptide, the binding of sT-P320-334 to hACE2 was enhanced to 133% and the inhibition capacity against RBD-hACE2 binding of sTn- and sT-P320-334 was significantly increased up to 150-410%. Thus, our results suggest the sialic acid residue on the terminal of short O-glycan structures might strengthen the inhibition capacities of these peptide-based inhibitors, which might provide novel optimization directions for the inhibitor design.

A new engineered endo-inulinase with improved activity and thermostability: Application in the production of prebiotic fructo-oligosaccharides from inulin.

To construct a high-performance engineered endo-inulinase for fructo-oligosaccharides (FOS) production from inulin, an inulin binding module (IBM) was fused into either N- or C-terminal of an endo-inulinase. After heterologous expression, purification and characterization, the C-terminal fusion one (Eninu-IBM) with better activity, thermostability and inulin binding ability was employed for high-temperature in situ inulin hydrolysis in a 10-L fermentor. During this process, Eninu-IBM was first efficiently produced by the yeast cells at 28 °C for 96 h, and subsequently 1600 g unsterilized inulin per liter fermentation liquor was directly supplemented into the bioreactor for FOS production at 60 °C for 2 h. Finally, high purity of FOS (91.4%) were obtained with FOS titer, yield and productivity of 717.3 g/L, 0.912 gFOS/gInulin and 358.6 g/L/h, respectively. The in vitro prebiotic assay indicated that the final FOS products with main polymerization degrees of 3-5 were preferably fermented by beneficial bifidobacteria and lactobacilli.

Co-expression of Exo-inulinase and Endo-inulinase Genes in the Oleaginous Yeast Yarrowia lipolytica for Efficient Single Cell Oil Production from Inulin.

Yarrowia lipolytica is a promising platform for the single cell oil (SCO) production. In this study, a transformant X+N8 in which exo- and endo-inulinase genes were co-expressed could produce an inulinase activity of 124.33 U/mL within 72 h. However, the inulinase activity of a transformant X2 carrying a single exo-inulinase gene was only 47.33 U/mL within 72 h. Moreover, the transformant X+N8 could accumulate 48.13% (w/w) SCO from inulin and the cell dry weight reached 13.63 g/L within 78 h, which were significantly higher than those of the transformant X2 (41.87% (w/w) and 11.23 g/L) under the same conditions. In addition, inulin hydrolysis and utilization of the transformant X+N8 were also more efficient than those of the transformant X2 during the fermentation process. These results demonstrated that the co-expression of the exo- and endo-inulinase genes significantly enhanced the SCO production from inulin due to the improvement of the inulinase activity and the synergistic action of exo- and endo-inulinase. Besides, over 95.01% of the fatty acids from the transformant X+N8 were C16-C18, especially C18:1 (53.10%), suggesting that the fatty acids could be used as feedstock for biodiesel production.

Prim-O-glucosylcimifugin Attenuates Lipopolysaccharideinduced Inflammatory Response in RAW 264.7 Macrophages.

BACKGROUND: Radix Saposhnikoviae (RS) exerts anti-inflammatory, analgesic, antipyretic, antioxidation effects and has been used in traditional Chinese medicine to treat common colds, headache, and rheumatoid arthritis. Prim-O-glucosylcimifugin (POG) is the highest content chromone and one of the major active constituents in RS. OBJECTIVE: The study was aimed to explore the anti-inflammation effects of POG in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. MATERIALS AND METHODS: Cell viability was detected by Cell Counting Kit-8 assay. Production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 was assessed by enzyme-linked immunosorbent assay. Real-time polymerase chain reaction and Western blot were performed to analyze mRNA and protein levels, respectively. RESULTS: During the whole experiment, 15, 50, and 100 µg/mL of POG had no cytotoxicity on RAW 264.7 cells. POG dose-dependently inhibited the production of NO, TNF-α, IL-1ß, and IL-6 that were induced by LPS. POG treatment downregulated the mRNA and protein expression inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2) in LPS-activated RAW 264.7 macrophages in a concentration-dependent manner. Furthermore, LPS-induced JAK2/STAT3 activation was prevented in RAW 264.7 macrophages by POG treatment. STAT3 overexpression significantly reversed the effects of POG on LPS-activated RAW 264.7 macrophages. CONCLUSION: These results demonstrate that POG exerts anti-inflammatory effects through the inhibition of iNOS and COX-2 expression by inhibiting the phosphorylation of JAK2/STAT3. SUMMARY: POG exerts anti-inflammatory effects in RAW 264.7 macrophages through the inhibition of iNOS and COX-2 expression by inhibiting JAK2/STAT3 signaling. Abbreviations used: LPS: Lipopolyssacharide; NO: Nitric oxide; TNF-α: Tumor necrosis factor-α; IL: Interleukin; RS: Radix Saposhnikoviae; POG: Prim-O-glucosylcimifugin; iNOS: Inducible NO synthase; COX2: Cyclooxygenase; FBS: Fetal bovine serum; DMSO: Dimethylsulfoxide; CCK-8: Cell Counting Kit; RIPA: Radio immunoprecipitation assay buffer; ECL: Enhanced chemiluminescence; SD: Standard deviation; ELISA: Enzyme-Linked immunosorbent assay.

Inhibitory Effects of Angelica Polysaccharide on Activation of Mast Cells.

This study was designed to investigate the inhibitory effects of Angelica polysaccharide (AP) on activation of mast cells and its possible molecular mechanism. In our study, we determined the proinflammatory cytokines and allergic mediators in anti-DNP IgE stimulated RBL-2H3 cells and found that AP (50, 100, and 200 µg/mL) significantly decreased the release of histamine, ß-hexosaminidase, leukotrienes C4 (LTC4), IL-1, IL-4, TNF-α, IL-6, and human monocyte chemotactic protein-1 (MCP-1/CCL2) (p < 0.05). In addition, Ca(2+) entry was inhibited by treatment with AP. AP also downregulated the protein expressions of p-Fyn, p-Akt, p-P38, IL-4, TNF-α, and NF-κB p65 in both Fyn gene upregulated and normal RBL-2H3 cells (p < 0.05). Collectively, our results showed that AP could inhibit the activation of mast cells via suppressing the releases of proinflammatory cytokines allergic mediators, Gab2/PI3-K/Akt and Fyn/Syk pathways.

Atopic eczema: a disease modulated by gene and environment.

Atopic eczema (AE) is a chronic inflammatory skin disease that is mainly characterized by pruritus and epidermal barrier dysfunction. Between 15% and 20% of children and 1%-3% of adults are affected worldwide. AE is a complex disease triggered by multiple triggers, including gene and environmental factors. Impaired skin barrier function, modifications of the immune system, and hyper-reactivity to environmental stimulation directly cause and aggravate AE. In this review, we provide an overview of the recent developments and future directions in the pathogenesis of AE.