In the previous study, the culture medium was treated with nicotinamide adenine dinucleotide (NAD⁺) under the hypothesis that NAD⁺ regeneration is a major factor causing excessive lactate accumulation in Chinese hamster ovary (CHO) cells. The NAD⁺ treatment improved metabolism by not only reducing the Warburg effect but also enhancing oxidative phosphorylation, leading to enhanced antibody production. Building on this, four NAD⁺ precursors – nicotinamide mononucleotide (NMN), nicotinic acid (NA), nicotinamide riboside (NR), and nicotinamide (NAM) – were tested to elevate intracellular NAD+ levels more economically. First, the ability of CHO cells to utilize both the salvage and Preiss‐Handler pathways for NAD⁺ biosynthesis was verified, and then the effect of NAD⁺ precursors on CHO cell cultures was evaluated. These precursors increased intracellular NAD⁺ levels by up to 70.6% compared to the non‐treated group. Culture analysis confirmed that all the precursors induced metabolic changes and that NMN, NA, and NR improved productivity akin to NAD⁺ treatment, with comparable integral viable cell density. Despite the positive effects such as the increase in the specific productivity and changes in cellular glucose metabolism, none of the precursors surpassed direct NAD⁺ treatment in antibody titer, presumably due to the reduction in nucleoside availability, as evidenced by the decrease in ATP levels in the NAD⁺ precursor‐treated groups. These results underscore the complexity of cellular metabolism as well as the necessity for further investigation to optimize NAD⁺ precursor treatment strategies, potentially with the supplementation of nucleoside precursors. Our findings suggest a feasible approach for improving CHO cell culture performances by using NAD⁺ precursors as medium and feed components for the biopharmaceutical production.

Background/Objectives: Sarcopenia is an age-related disease resulting in muscle mass deterioration and declining strength and functional ability. Muscle protein degradation pathways are activated through the ubiquitin–proteasome system, which is integral to the pathogenesis of sarcopenia. This study examined the capability of Lactobacillus plantarum beLP1 as a postbiotic ingredient of kimchi that prevents sarcopenia. Methods: We evaluated cell viability and measured diameters in a C2C12 myotube damage model and muscle volume, muscle weight, muscle strength, and the expression of muscle degradation proteins MuRF1 and Atrogin-1 in dexamethasone-induced sarcopenic model rats using a heat-killed beLP1 strain. Results: beLP1 had no cytotoxic effects on C2C12 and prevented dexamethasone-induced cellular damage, suggesting its role in muscle protein degradation pathways. beLP1 treatment significantly prevented the dexamethasone-induced reduction in myotube diameter. In a dexamethasone-induced sarcopenic rat model, oral beLP1 significantly mitigated muscle mass decline and prevented grip strength reduction. Microcomputed tomography demonstrated that beLP1 reduced dexamethasone-induced muscle volume loss. beLP1 treatment reduced Atrogin-1 and Muscle RING-finger protein-1 (MuRF1) and the transcription factor Forkhead box O3 alpha (FoxO3α), which triggers muscle protein breakdown. beLP1 exerts protective effects by inhibiting the ubiquitin-proteasome system and regulating FoxO3α signaling. It increased AKT (Ser473) phosphorylation, which affected muscle protein synthesis, degradation, and cell survival, suggesting its potential to prevent sarcopenia. Conclusions: Heat-killed Lactobacillus plantarum beLP1 alleviates muscle mass wasting and weakness in a dexamethasone-induced sarcopenia model by regulating muscle protein degradation pathways and signaling molecules. Thus, postbiotics may be functional ingredients in sarcopenia prevention.

Background/Objectives: Recently, concerns about age-related conditions, such as sarcopenia and chronic inflammation, have increased owing to the global acceleration of population aging. Notably, these conditions are interrelated and further exacerbate functional decline in older adults. Therefore, this study aimed to evaluate the efficacy of a novel bioactive compound, DuoX (a mixture of the postbiotic beLP1 and Cichorium intybus L.), in alleviating muscle wasting and chronic inflammation. Specifically, the mixture consisted of inulin-rich C. intybus L. root extract, known for its anti-inflammatory effects, and beLP1, a postbiotic previously shown to exert anti-sarcopenic effects. Methods: To assess the multifunctional effects of the DuoX, dexamethasone-induced sarcopenia models (C2C12 myotubes and an in vivo rat model) and a lipopolysaccharide-stimulated RAW 264.7 macrophage inflammation model were established. Results: Pretreatment with DuoX prevented the dexamethasone-induced reduction in myotube diameter and effectively inhibited muscle degradation by downregulating the expression of atrogin-1 caused by dexamethasone treatment. In rats with DEX-induced sarcopenia, DuoX prevented muscle weight loss, grip strength reduction, and the upregulation of atrogin-1 expression in vivo. In lipopolysaccharide-stimulated RAW 264.7 macrophages, DuoX significantly reduced nitric oxide production and cyclooxygenase-2 protein expression and suppressed p38 and ERK phosphorylation in the MAPK signaling pathway, thereby alleviating inflammatory responses. Conclusions: DuoX holds promise as a dual-functional candidate with both anti-sarcopenic and anti-inflammatory properties. Further preclinical and clinical studies are required to validate its therapeutic efficacy and safety in humans, which may contribute to the development of preventive strategies for healthy aging.

Chinese hamster ovary (CHO) cell lines are widely utilized host cell lines in cell culture bioprocessing. Although they originated from a common ancestor, accumulated genetic mutations have led to significant heterogeneity in their behavior under specific conditions. This study investigates the cell line-specific impact of polyamine (PUT; putrescine) withdrawal on the growth, metabolism, and antibody production among three CHO clones derived from different parental cell lines: CHO-K1, CHO-S, and CHO-DG44. CHO-K1 cells strongly depended on external polyamines, showing a 77% reduction in viable cell density and an 88% decrease in growth rate under PUT depletion, although their culture longevity was extended. In contrast, CHO-S and CHO-DG44 cells demonstrated greater resilience, with CHO-DG44 experiencing only a 25% reduction in cell density. PUT deprivation also impacted antibody production across all cell lines, with CHO-K1 displaying the lowest yield, antibody purity and altered charge heterogeneity. Notably, PUT depletion led to increased galactosylation of antibodies, suggesting that modulating PUT levels in the media could be used as a strategy to tailor the quality of therapeutic antibodies. These findings, together, provide valuable insights in the design of cell line-specific media, thereby optimizing both bioprocess efficiency and product quality in biopharmaceutical production.