Nicotinamide alone accelerates the conversion of mouse embryonic stem cells into mature neuronal populations

The use of omics technologies in creating LBP and postbiotics based on the Limosilactobacillus fermentum U-21

In recent years, there has been an increasing tendency to create drugs based on certain commensal bacteria of the human microbiota and their ingredients, primarily focusing on live biotherapeutics (LBPs) and postbiotics. The creation of such drugs, termed pharmacobiotics, necessitates an understanding of their mechanisms of action and the identification of pharmacologically active ingredients that determine their target properties. Typically, these are complexes of biologically active substances synthesized by specific strains, promoted as LBPs or postbiotics (including vesicles): proteins, enzymes, low molecular weight metabolites, small RNAs, etc. This study employs omics technologies, including genomics, proteomics, and metabolomics, to explore the potential of Limosilactobacillus fermentum U-21 for innovative LBP and postbiotic formulations targeting neuroinflammatory processes. Proteomic techniques identified and quantified proteins expressed by L. fermentum U-21, highlighting their functional attributes and potential applications. Key identified proteins include ATP-dependent Clp protease (ClpL), chaperone protein DnaK, protein GrpE, thioredoxin reductase, LysM peptidoglycan-binding domain-containing protein, and NlpC/P60 domain-containing protein, which have roles in disaggregase, antioxidant, and immunomodulatory activities. Metabolomic analysis provided insights into small-molecule metabolites produced during fermentation, revealing compounds with anti-neuroinflammatory activity. Significant metabolites produced by L. fermentum U-21 include GABA (γ-aminobutyric acid), niacin, aucubin, and scyllo-inositol. GABA was found to stabilize neuronal activity, potentially counteracting neurodegenerative processes. Niacin, essential for optimal nervous system function, was detected in vesicles and culture fluid, and it modulates cytokine production, maintaining immune homeostasis. Aucubin, an iridoid glycoside usually secreted by plants, was identified as having antioxidant properties, addressing issues of bioavailability for therapeutic use. Scyllo-inositol, identified in vesicles, acts as a chemical chaperone, reducing abnormal protein clumps linked to neurodegenerative diseases. These findings demonstrate the capability of L. fermentum U-21 to produce bioactive substances that could be harnessed in the development of pharmacobiotics for neurodegenerative diseases, contributing to their immunomodulatory, anti-neuroinflammatory, and neuromodulatory activities. Data of the HPLC-MS/MS analysis are available via ProteomeXchange with identifier PXD050857.

Nicotinamide Promotes Formation of Retinal Organoids From Human Pluripotent Stem Cells via Enhanced Neural Cell Fate Commitment

Retinal organoids (ROs) derived from human pluripotent stem cells (hPSCs) recapitulate key features of retinogenesis and provide a promising platform to study retinal development and disease in a human context. Although multiple protocols are currently in use, hPSCs exhibit tremendous variability in differentiation efficiency, with some cell lines consistently yielding few or even no ROs, limiting their utility in research. We report here that early nicotinamide (NAM) treatment significantly improves RO yield across 8 hPSC lines from different donors, including some that would otherwise fail to generate a meaningful number of ROs. NAM treatment promotes neural commitment of hPSCs at the expense of non-neural ectodermal cell fate, which in turn increases eye field progenitor generation. Further analysis suggests that this effect is partially mediated through inhibition of BMP signaling. Our data encourage a broader use of human ROs for disease modeling applications that require the use of multiple patient-specific cell lines.

Nicotinamide improves in vitro lens regeneration in a mouse capsular bag model

Background

Mammalian lens regeneration holds great potential as a cataract therapy. However, the mechanism of mammalian lens regeneration is unclear, and the methods for optimization remain in question.

Methods

We developed an in vitro lens regeneration model using mouse capsular bag culture and improved the transparency of the regenerated lens using nicotinamide (NAM). We used D4476 and SSTC3 as a casein kinase 1A inhibitor and agonist, respectively. The expression of lens-specific markers was examined by real-time PCR, immunostaining, and western blotting. The structure of the in vitro regenerated lens was investigated using 3,3′-dihexyloxacarbocyanine iodide (DiOC6) and methylene blue staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and transmission electron microscopy.

Results

The in vitro lens regeneration model was developed to mimic the process of in vivo mammalian lens regeneration in a mouse capsular bag culture. In the early stage, the remanent lens epithelial cells proliferated across the posterior capsule and differentiated into lens fiber cells (LFCs). The regenerated lenses appeared opaque after 28 days; however, NAM treatment effectively maintained the transparency of the regenerated lens. We demonstrated that NAM maintained lens epithelial cell survival, promoted the differentiation and regular cellular arrangement of LFCs, and reduced lens-related cell apoptosis. Mechanistically, NAM enhanced the differentiation and transparency of regenerative lenses partly by inhibiting casein kinase 1A activity.

Conclusion

This study provides a new in vitro model for regeneration study and demonstrates the potential of NAM in in vitro mammalian lens regeneration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02862-8.

Nicotinamide promotes cardiomyocyte derivation and survival through kinase inhibition in human pluripotent stem cells

Nicotinamide, the amide form of Vitamin B3, is a common nutrient supplement that plays important role in human fetal development. Nicotinamide has been widely used in clinical treatments, including the treatment of diseases during pregnancy. However, its impacts during embryogenesis have not been fully understood. In this study, we show that nicotinamide plays multiplex roles in mesoderm differentiation of human embryonic stem cells (hESCs). Nicotinamide promotes cardiomyocyte fate from mesoderm progenitor cells, and suppresses the emergence of other cell types. Independent of its functions in PARP and Sirtuin pathways, nicotinamide modulates differentiation through kinase inhibition. A KINOMEscan assay identifies 14 novel nicotinamide targets among 468 kinase candidates. We demonstrate that nicotinamide promotes cardiomyocyte differentiation through p38 MAP kinase inhibition. Furthermore, we show that nicotinamide enhances cardiomyocyte survival as a Rho-associated protein kinase (ROCK) inhibitor. This study reveals nicotinamide as a pleiotropic molecule that promotes the derivation and survival of cardiomyocytes, and it could become a useful tool for cardiomyocyte production for regenerative medicine. It also provides a theoretical foundation for physicians when nicotinamide is considered for treatments for pregnant women.

Direct Reprogramming of Mice Skin Fibroblasts into Insulin-Producing Cells In Vitro

Transdifferentiation means mature cell conversion into other mature cells. Ethical issues, epigenetic failure, or teratoma development are found in cellular reprogramming strategies. Thus, new methods are needed. This study aimed to develop a new novel formula of chemical molecules and growth factors that differentiate skin fibroblasts into insulin-producing cells (IPCs). Newborn mice fibroblasts differentiated using four induction methods into IPCs to search for the best method. Fibroblasts, stem cells, and pancreatic markers were identified using an immunocytochemistry (ICC) assay. Insulin was measured using ELISA and dithizone (DTZ) assays. The skin fibroblasts were induced successfully into IPCs. The best method to obtain IPCs was indicated by measuring insulin concentration in differentiated cell supernatant from all induced cells by the four methods. The protein expression of the pancreatic markers of induced cells increased with time, as indicated by the ICC assay. OCT3/4 increased on day 9, after which the expression tended to decrease. DTZ-positive clusters were observed on day 16. Secreted insulin of differentiated cells was injected in streptozotocin-induced diabetic mice, which decreased blood glucose levels after injection. This study indicated an efficient new chemical method for transdifferentiating skin fibroblasts into functional IPCs, which is a promising method for diabetes mellitus therapy.

Nicotinamide restricts neural precursor proliferation to enhance catecholaminergic neuronal subtype differentiation from mouse embryonic stem cells

Emerging evidence indicates that a strong relationship exists between brain regenerative therapies and nutrition. Early life nutrition plays an important role during embryonic brain development, and there are clear consequences to an imbalance in nutritional factors on both the production and survival of mature neuronal populations and the infant’s risk of diseases in later life. Our research and that of others suggest that vitamins play a fundamental role in the formation of neurons and their survival. There is a growing body of evidence that nicotinamide, the water-soluble amide form of vitamin B₃, is implicated in the conversion of pluripotent stem cells to clinically relevant cells for regenerative therapies. This study investigated the ability of nicotinamide to promote the development of mature catecholaminergic neuronal populations (associated with Parkinson’s disease) from mouse embryonic stem cells, as well as investigating the underlying mechanisms of nicotinamide’s action. Nicotinamide selectively enhanced the production of tyrosine hydroxylase-expressing neurons and serotonergic neurons from mouse embryonic stem cell cultures (Sox1GFP knock-in 46C cell line). A 5-Ethynyl-2´-deoxyuridine (EdU) assay ascertained that nicotinamide, when added in the initial phase, reduced cell proliferation. Nicotinamide drove tyrosine hydroxylase-expressing neuron differentiation as effectively as an established cocktail of signalling factors, reducing the proliferation of neural progenitors and accelerating neuronal maturation, neurite outgrowth and neurotransmitter expression. These novel findings show that nicotinamide enhanced and enriched catecholaminergic differentiation and inhibited cell proliferation by directing cell cycle arrest in mouse embryonic stem cell cultures, thus driving a critical neural proliferation-to-differentiation switch from neural progenitors to neurons. Further research into the role of vitamin metabolites in embryogenesis will significantly advance cell-based regenerative medicine, and help realize their role as crucial developmental signalling molecules in brain development.

Metabolic-Epigenetic Axis in Pluripotent State Transitions

Cell state transition (CST) occurs during embryo development and in adult life in response to different stimuli and is associated with extensive epigenetic remodeling. Beyond growth factors and signaling pathways, increasing evidence point to a crucial role of metabolic signals in this process. Indeed, since several epigenetic enzymes are sensitive to availability of specific metabolites, fluctuations in their levels may induce the epigenetic changes associated with CST. Here we analyze how fluctuations in metabolites availability influence DNA/chromatin modifications associated with pluripotent stem cell (PSC) transitions. We discuss current studies and focus on the effects of metabolites in the context of naïve to primed transition, PSC differentiation and reprogramming of somatic cells to induced pluripotent stem cells (iPSCs), analyzing their mechanism of action and the causal correlation between metabolites availability and epigenetic alteration.

Nicotinamide and Demographic and Disease transitions: Moderation is Best

Good health and rapid progress depend on an optimal dose of nicotinamide. Too little meat triggers the neurodegenerative condition pellagra and tolerance of symbionts such as tuberculosis (TB), risking dysbioses and impaired resistance to acute infections. Nicotinamide deficiency is an overlooked diagnosis in poor cereal-dependant economies masquerading as 'environmental enteropathy' or physical and cognitive stunting. Too much meat (and supplements) may precipitate immune intolerance and autoimmune and allergic disease, with relative infertility and longevity, via the tryptophan-nicotinamide pathway. This switch favours a dearth of regulatory T (Treg) and an excess of T helper cells. High nicotinamide intake is implicated in cancer and Parkinson's disease. Pro-fertility genes, evolved to counteract high-nicotinamide-induced infertility, may now be risk factors for degenerative disease. Moderation of the dose of nicotinamide could prevent some common diseases and personalised doses at times of stress or, depending on genetic background or age, may treat some other conditions.

Niacin in the Central Nervous System: An Update of Biological Aspects and Clinical Applications

Niacin (also known as "vitamin B₃" or "vitamin PP") includes two vitamers (nicotinic acid and nicotinamide) giving rise to the coenzymatic forms nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). The two coenzymes are required for oxidative reactions crucial for energy production, but they are also substrates for enzymes involved in non-redox signaling pathways, thus regulating biological functions, including gene expression, cell cycle progression, DNA repair and cell death. In the central nervous system, vitamin B₃ has long been recognized as a key mediator of neuronal development and survival. Here, we will overview available literature data on the neuroprotective role of niacin and its derivatives, especially focusing especially on its involvement in neurodegenerative diseases (Alzheimer's, Parkinson's, and Huntington's diseases), as well as in other neuropathological conditions (ischemic and traumatic injuries, headache and psychiatric disorders).

Tissue Engineering Therapies Based on Folic Acid and Other Vitamin B Derivatives. Functional Mechanisms and Current Applications in Regenerative Medicine

B-vitamins are a group of soluble vitamins which are cofactors of some of the enzymes involved in the metabolic pathways of carbohydrates, fats and proteins. These compounds participate in a number of functions as cardiovascular, brain or nervous systems. Folic acid is described as an accessible and multifunctional niche component that can be used safely, even combined with other compounds, which gives it high versatility. Also, due to its non-toxicity and great stability, folic acid has attracted much attention from researchers in the biomedical and bioengineering area, with an increasing number of works directed at using folic acid and its derivatives in tissue engineering therapies as well as regenerative medicine. Thus, this review provides an updated discussion about the most relevant advances achieved during the last five years, where folic acid and other vitamins B have been used as key bioactive compounds for enhancing the effectiveness of biomaterials' performance and biological functions for the regeneration of tissues and organs.

Nicotinamide Promotes Cell Survival and Differentiation as Kinase Inhibitor in Human Pluripotent Stem Cells

Nicotinamide, the amide form of vitamin B3, is widely used in disease treatments and stem cell applications. However, nicotinamide's impact often cannot be attributed to its nutritional functions. In a vitamin screen, we find that nicotinamide promotes cell survival and differentiation in human pluripotent stem cells. Nicotinamide inhibits the phosphorylation of myosin light chain, suppresses actomyosin contraction, and leads to improved cell survival after individualization. Further analysis demonstrates that nicotinamide is an inhibitor of multiple kinases, including ROCK and casein kinase 1. We demonstrate that nicotinamide affects human embryonic stem cell pluripotency and differentiation as a selective kinase inhibitor. The findings in this report may help researchers design better strategies to develop nicotinamide-related stem cell applications and disease treatments.

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High dosage of nicotinamide is a direct kinase inhibitor with multiple targets

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Nicotinamide promotes hPSC survival after individualization through ROCK inhibition

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Nicotinamide affects hPSC differentiation partially through CK1 inhibition

The Influence of Nicotinamide on Health and Disease in the Central Nervous System

Nicotinamide, the amide form of vitamin B₃ (niacin), has long been associated with neuronal development, survival, and function in the central nervous system (CNS), being implicated in both neuronal death and neuroprotection. Here, we summarise a body of research investigating the role of nicotinamide in neuronal health within the CNS, with a focus on studies that have shown a neuroprotective effect. Nicotinamide appears to play a role in protecting neurons from traumatic injury, ischaemia, and stroke, as well as being implicated in 3 key neurodegenerative conditions: Alzheimer’s, Parkinson’s, and Huntington’s diseases. A key factor is the bioavailability of nicotinamide, with low concentrations leading to neurological deficits and dementia and high levels potentially causing neurotoxicity. Finally, nicotinamide’s potential mechanisms of action are discussed, including the general maintenance of cellular energy levels and the more specific inhibition of molecules such as the nicotinamide adenine dinucleotide-dependent deacetylase, sirtuin 1 (SIRT1).