Feeding on lactic acid bacteria isolated from food extends the lifespan of Caenorhabditis elegans.

Lactic acid bacteria (LAB) contribute to human health, and LAB functionality has been studied using Caenorhabditis elegans as an alternative host. However, many studies have focused on the efficacy of a single strain of LAB, and few reports have compared various LAB strains. In this study, we examined the effects of 15 strains of LAB isolated from vegetables, meat, and fermented foods on nematode longevity and healthy lifespan. To reduce the frequency of laborious survival observations, we performed a lifespan assay on agar plates containing 2'-deoxy-5-fluorouridine (FUdR), which inhibits egg hatching and prevents generation mixing. Four beneficial strains showed significant lifespan extension and increased spontaneous nematode mobility, regardless of treatment with or without FUdR and the frequency of survival observation. These results suggested increased longevity and an extended healthy lifespan, confirming the reliability of our method. The four strains are expected to show anti-ageing effects besides longevity and have effects on age-related degenerative diseases. Our labor-saving method can be used as an alternative to conventional methods and enable simultaneous screening of multiple strains. Future research could explore factors contributing to lifespan regulation by comparing and verifying differential strain effects on lifespan.

Protective effect of Lactococcus laudensis and Pediococcus parvulus against neuropathy due to amyloid-beta in Caenorhabditis elegans.

In Alzheimer's disease (AD), the amyloid-ß (Aß) protein begins to accumulate in the brain 20 years prior to any dementia symptoms manifestation, in which Aß aggregates in the brain, causing destruction of nerve cells and resulting in memory impairments. Lifestyle and diet appear to inhibit Aß production and amyloid deposition. Therefore, identifying factors that prevent Aß production and administering them before the onset of AD, may be an effective preventive method. Lactic acid bacteria (LAB) exhibit various health effects on the host and are expected to have protective effects on neurological functions via brain-gut correlation. However, the protective effects of LAB against Aß are not well understood. We investigated whether LAB feeding could ameliorate the toxicity of Aß peptide accumulation in transgenic Caenorhabditis elegans expressing the human Aß peptide in neurons or muscle as an AD model. Aß expressed in muscle caused myopathy and worm paralysis, while Aß in neurons disturbed chemotactic activity. Among 14 screened strains, Lactococcus laudensis (LL) and Pediococcus parvulus (PP) prevented the AD worms from losing their chemotaxis behavior and becoming paralyzed by the Aß peptide. Immunostaining and western blotting indicated that Aß peptide was significantly suppressed in worms fed these two strains, and binding of the Aß to vitellogenin was particularly inhibited. Conversely, the mRNA level of the Aß gene did not change between LL- or PP-fed worms and the control. In conclusion, LL and PP alleviate neurotoxicity by inhibiting Aß accumulation; AD model worms can be used to screen efficient LAB for AD prevention.

Soluble Expression in Escherichia coli of a Single-Domain Antibody-Tumor Necrosis Factor α Fusion Protein Specific for Epidermal Growth Factor Receptor.

Tumor-targeted antibody-cytokine fusion proteins, called immunocytokines, are expected to be a useful platform for the development of effective antitumor therapeutic agents; however, their design and cost-efficient production remain as challenges. In this study, we constructed an antibody-cytokine fusion protein (Ia1-TNFα) comprising the single-domain antibody Ia1, which targets epidermal growth factor receptor (EGFR) overexpressed in epithelial tumors and a tumor necrosis factor α (TNFα) domain, which has antitumor activity. Ia1-TNFα was produced in a soluble form by using an Escherichia coli expression system, and after affinity purification of the culture supernatant, an yield of ∼2 mg/L of cell culture was obtained. Gel filtration analysis showed that Ia1-TNFα existed predominantly as a trimer, which is consistent with the multimerization state of TNFα. Ia1-TNFα exhibited approximately 7-fold lower TNFα biological activity than that of TNFα itself. Flow cytometric analysis revealed that Ia1-TNFα specifically bound to EGFR-expressing tumor cells and that its binding activity was higher than that of monovalent Ia1, suggesting that the fusion protein bound to the tumor cells multivalently. Altogether, these results show that fusion of TNFα with a single-domain antibody could be a cost-efficient means of producing antitumor therapeutic agents.