10-Hydroxy-trans-2-decenoic acid attenuates angiotensin II-induced inflammatory responses in rat vascular smooth muscle cells

Biosynthesis of 10-Hydroxy-2-decenoic Acid through a One-Step Whole-Cell Catalysis

10-Hydroxy-2-decenoic acid (10-HDA) is an important component of royal jelly, known for its antimicrobial, anti-inflammatory, blood pressure-lowering, and antiradiation effects. Currently, 10-HDA biosynthesis is limited by the substrate selectivity of acyl-coenzyme A dehydrogenase, which restricts the technique to a two-step process. This study aimed to develop an efficient and simplified method for synthesizing 10-HDA. In this study, ACOX from Candida tropicalis 1798, which catalyzes 10-hydroxydecanoyl coenzyme A desaturation for 10-HDA synthesis, was isolated and heterologously coexpressed with FadE, Macs, YdiI, and CYP in Escherichia coli/SK after knocking out FadB, FadJ, and FadR genes. The engineered E. coli/AKS strain achieved a 49.8% conversion of decanoic acid to 10-HDA. CYP expression was improved through ultraviolet mutagenesis and high-throughput screening, increased substrate conversion to 75.6%, and the synthesis of 10-HDA was increased to 0.628 g/L in 10 h. This is the highest conversion rate and product concentration achieved in the shortest time to date. This study provides a simple and efficient method for 10-HDA biosynthesis and offers an effective method for developing strains with high product yields.

A Toll-dependent Bre1/Rad6-cact feedback loop in controlling host innate immune response

The Toll signaling pathway was initially identified for its involvement in the control of early embryogenesis. It was later shown to be also part of a major innate immune pathway controlling the expression of anti-microbial peptides in many eukaryotes including humans; cactus, the essential negative regulator of this pathway in flies, was found to be induced in parallel to the Toll-dependent activation process during immune defenses. We were interested in the mechanisms of this dual effect and provide here evidence that upon pathogenic stimuli, dorsal, one of the transcription factors of the fly Toll pathway, can induce the expression of the E3 ligase Bre1. We further show that Bre1 complexes with the E2 Rad6 to mono-ubiquitinate histone H2B and to promote the transcription of cactus to achieve homeostasis of the Toll immune response. Our studies characterize a Toll signal-dependent regulatory machinery in governing the Toll pathway in Drosophila.

A conserved role of bam in maintaining metabolic homeostasis via regulating intestinal microbiota in Drosophila

Background

Previous studies have proven that bag-of-marbles (bam) plays a pivotal role in promoting early germ cell differentiation in Drosophila ovary. However, whether it functions in regulating the metabolic state of the host remains largely unknown.

Methods

We utilized GC-MS, qPCR, and some classical kits to examine various metabolic profiles and gut microbial composition in bam loss-of-function mutants and age-paired controls. We performed genetic manipulations to explore the tissue/organ-specific role of bam in regulating energy metabolism in Drosophila. The DSS-induced mouse colitis was generated to identify the role of Gm114, the mammalian homolog of bam, in modulating intestinal homeostasis.

Results

We show that loss of bam leads to an increased storage of energy in Drosophila. Silence of bam in intestines results in commensal microbial dysbiosis and metabolic dysfunction of the host. Moreover, recovery of bam expression in guts almost rescues the obese phenotype in bam loss-of-function mutants. Further examinations of mammalian Gm114 imply a similar biological function in regulating the intestinal homeostasis and energy storage with its Drosophila homolog bam.

Conclusion

Our studies uncover a novel biological function of bam/Gm114 in regulating the host lipid homeostasis.