Tran, K. V. | Search bioRxiv

bioRxiv2025

β-nicotinamide mononucleotide production in Vibrio natriegens: a preliminary study

BackgroundNicotinamide mononucleotide (NMN), is a promising nutraceutical attracting much attention for its pharmacological and anti-aging efficacies. However, NMN-containing commercial products are very high-priced due to the lack of efficient and facile methods for industrial-scale production. To date, various metabolic engineering strategies have been successfully applied to produce NMN in Escherichia coli. Recently, Vibrio natriegens has become a promising host in the bioindustry thanks to its rapid growth and capabilities of broad substrate utilization. This study aims to evaluate the NMN biosynthesis capability of V. natriegens. MethodsFirstly, a mutant V. natriegens strain ({Delta}dns::araC-T7RNAP-KanR{Delta} pncC::FtnadE-SmR{Delta} nadR) was generated via multiplex genome editing by natural transformation (MuGENT). Nampt genes encoding nicotinamide phosphoribosyltransferase from Chitinophaga pinensis, Sphingopyxis sp. C-1, Haemophilus ducreyi, and Vibrio phage KVP40 were codon-optimized and cloned into pACYCDuet-1 under the control of T7 promoter. The recombinant plasmids were electroporated into the mutant strain. The expression of recombinant NAMPTs in V. natriegens was evaluated by SDS-PAGE analysis and the intracellular NMN concentrations were quantified by HPLC. ResultsAfter two rounds of MuGENT, V. natriegens V54-33 strain ({Delta}dns::araC-T7RNAP-KanR{Delta} pncC::FtnadE-SmR{Delta} nadR) was successfully generated. SDS-PAGE analysis demonstrated that all NAMPTs were strongly expressed in the V54-33 strain. HPLC analysis revealed that the highest intracellular NMN concentration was obtained with NAMPT from Chitinophaga pinensis (44.5 M), followed by NAMPT from Vibrio phage KVP40 (23.3 M). ConclusionThis study demonstrated the feasibility of NMN biosynthesis in V. natriegens.

bioengineering↗

bioRxiv2022

Schwann cells promote sensory neuron excitability during development

Excitability--the ability to fire action potentials--is a signature feature of neurons. How neurons become excitable during development, and whether excitability is an intrinsic property of neurons or requires signaling from glial cells, remain unclear. Here we demonstrate that Schwann cells, the most abundant glia in the peripheral nervous system, promote somatosensory neuron excitability during development. We find that Schwann cells secrete prostaglandin E2, which is necessary and sufficient to induce developing somatosensory neurons to express normal levels of voltage-gated sodium channels and fire action potential trains. Inactivating this signaling pathway specifically in Schwann cells selectively impairs the maturation of nociceptor and proprioceptor somatosensory neuron subtypes, leading to corresponding sensory defects in thermoception, inflammatory pain, and proprioception. Our studies thus reveal a cell non-autonomous mechanism by which glia regulate neuronal excitability to enable the development of normal sensory functions.

neuroscience↗