High fat diet-induced obesity exacerbates hematopoiesis deficiency and cytopenia caused by 5-fluorouracil via peroxisome proliferator-activated receptor γ

Integrated blood and organ profile analysis to evaluate ameliorative effects of kaempferol on 5-fluorouracil-induced toxicity

Colorectal cancer (CRC) treatment strategies encompass a triad of medical interventions: surgery, radiotherapy, and chemotherapy. Among these, the use of chemotherapy, specifically 5-fluorouracil (5-FU), has become a cornerstone in CRC management. However, it is imperative to explore novel approaches that harness the synergistic potential of chemotherapy agents alongside adjunctive compounds to mitigate the severe adverse effects that often accompany treatment. In light of this pressing need, this study focuses on evaluating Kaempferol (KMP) in combination with 5-FU in a DMH-induced CRC animal model, scrutinizing its impact on haematological indices, organ health, and gastrointestinal, hepatotoxic, and nephrotoxic effects. Remarkably, KMP demonstrated haemato-protective attributes and exerted an immunomodulatory influence, effectively counteracting 5-FU-induced damage. Furthermore, organ assessments affirm the safety profile of the combined treatments while suggesting KMP's potential role in preserving the structural integrity of the intestine, and spleen. Histopathological assessments unveiled KMP's capacity to ameliorate liver injury and mitigate CRC-induced renal impairment. These multifaceted findings underscore KMP's candidacy as a promising adjunctive therapeutic option for CRC, underlining the pivotal need for personalized therapeutic strategies that concurrently optimize treatment efficacy and safeguard organ health. KMP holds tremendous promise in elevating the paradigm of CRC management.

Bidirectional interplay between metabolism and epigenetics in hematopoietic stem cells and leukemia

During the last decades, remarkable progress has been made in further understanding the complex molecular regulatory networks that maintain hematopoietic stem cell (HSC) function. Cellular and organismal metabolisms have been shown to directly instruct epigenetic alterations, and thereby dictate stem cell fate, in the bone marrow. Epigenetic regulatory enzymes are dependent on the availability of metabolites to facilitate DNA- and histone-modifying reactions. The metabolic and epigenetic features of HSCs and their downstream progenitors can be significantly altered by environmental perturbations, dietary habits, and hematological diseases. Therefore, understanding metabolic and epigenetic mechanisms that regulate healthy HSCs can contribute to the discovery of novel metabolic therapeutic targets that specifically eliminate leukemia stem cells while sparing healthy HSCs. Here, we provide an in-depth review of the metabolic and epigenetic interplay regulating hematopoietic stem cell fate. We discuss the influence of metabolic stress stimuli, as well as alterations occurring during leukemic development. Additionally, we highlight recent therapeutic advancements toward eradicating acute myeloid leukemia cells by intervening in metabolic and epigenetic pathways.

How nutrition regulates hematopoietic stem cell features

Our dietary choices significantly impact all the cells in our body. Increasing evidence suggests that diet-derived metabolites influence hematopoietic stem cell (HSC) metabolism and function, thereby actively modulating blood homeostasis. This is of particular relevance because regulating the metabolic activity of HSCs is crucial for maintaining stem cell fitness and mitigating the risk of hematologic disorders. In this review, we examine the current scientific knowledge of the impact of diet on stemness features, and we specifically highlight the established mechanisms by which dietary components modulate metabolic and transcriptional programs in adult HSCs. Gaining a deeper understanding of how nutrition influences our HSC compartment may pave the way for targeted dietary interventions with the potential to decelerate aging and improve the effectiveness of transplantation and cancer therapies.

Deletion of YJL218W reduces salt tolerance of Saccharomyces cerevisiae

The YJL218W open reading frame may be involved in peroxisomal biogenesis. However, whether it mediates salt tolerance is unclear. We found that after knockdown of YJL218W in Saccharomyces cerevisiae (S. cerevisiae), its salt tolerance was reduced and cell death was increased. Transcriptome sequencing and analysis further revealed that YJL218W knockdown mediated significant changes in the expression of 1432 messenger RNA (mRNAs), of which 603 were upregulated. KEGG enrichment analysis and polymerase chain reaction (PCR) assay indicated that YJL218W mediated the regulation of peroxisome-related genes. Therefore, YJL218W may regulate salt stress in S. cerevisiae by regulating peroxisome assembly.

Lead in Synergism With IFNγ Acts on Bone Marrow-Resident Macrophages to Increase the Quiescence of Hematopoietic Stem Cells

Lead (Pb) is a highly toxic heavy metal that broadly exists in our living environment. Although Pb has been shown to influence the development of immune cells, to date, the impact of Pb on hematopoietic stem cells (HSCs) in the bone marrow (BM) remains unknown. As people are ubiquitously exposed to Pb and HSC are essential for human health, understanding the impact of Pb on HSC is significant for public health. In this study, we found that wild-type B6 mice treated with 1250 ppm Pb, but not 125 ppm Pb via drinking water for 8 weeks had increased quiescence of HSC in the BM. Functional analyses demonstrated that wild-type mice treated with 1250 ppm Pb had increased potential for HSC to repopulate the immune system and engraft to the niche in the BM under a competitive chimeric microenvironment of lethally irradiated recipients. Moreover, we found that Pb-increased quiescence of HSC critically relied on a synergetic action of Pb and interferon γ (IFNγ) on BM-resident macrophages (BM-MΦ), but not a direct action of Pb on HSC. Specifically, in steady state, BM-MΦ promoted HSC proliferation; and upon Pb treatment, IFNγ was induced in the BM, and thereafter Pb in synergism with IFNγ acted on BM-MΦ to cause BM-MΦ to become suppressive for HSC proliferation, thus leading to increased quiescence of HSC. Our study suggests that Pb increased the quiescence of HSC via a synergetic action of Pb and IFNγ on BM-MΦ, which was previously unrecognized toxicity of Pb.

Stem Cell Metabolism and Diet

PURPOSE OF REVIEW

Diet has profound impacts on health and longevity. Evidence is emerging to suggest that diet impinges upon the metabolic pathways in tissue-specific stem cells to influence health and disease. Here, we review the similarities and differences in the metabolism of stem cells from several tissues, and highlight the mitochondrial metabolic checkpoint in stem cell maintenance and aging. We discuss how diet engages the nutrient sensing metabolic pathways and impacts stem cell maintenance. Finally, we explore the therapeutic implications of dietary and metabolic regulation of stem cells.

RECENT FINDINGS

Stem Cell transition from quiescence to proliferation is associated with a metabolic switch from glycolysis to mitochondrial OXPHOS and the mitochondrial metabolic checkpoint is critically controlled by the nutrient sensors SIRT2, SIRT3, and SIRT7 in hematopoietic stem cells. Intestine stem cell homeostasis during aging and in response to diet is critically dependent on fatty acid metabolism and ketone bodies and is influenced by the niche mediated by the nutrient sensor mTOR.

SUMMARY

Nutrient sensing metabolic pathways critically regulate stem cell maintenance during aging and in response to diet. Elucidating the molecular mechanisms underlying dietary and metabolic regulation of stem cells provides novel insights for stem cell biology and may be targeted therapeutically to reverse stem cell aging and tissue degeneration.

Mineral and Amino Acid Profiling of Different Hematopoietic Populations from the Mouse Bone Marrow

Steady hematopoiesis is essential for lifelong production of all mature blood cells. Hematopoietic stem and progenitor cells (HSPCs) found in the bone marrow ensure hematopoietic homeostasis in an organism. Failure of this complex process, which involves a fine balance of self-renewal and differentiation fates, often result in severe hematological conditions such as leukemia and lymphoma. Several molecular and metabolic programs, internal or in close interaction with the bone marrow niche, have been identified as important regulators of HSPC function. More recently, nutrient sensing pathways have emerged as important modulators of HSC homing, dormancy, and function in the bone marrow. Here we describe a method for reliable measurement of various amino acids and minerals in different rare bone marrow (BM) populations, namely HSPCs. We found that the amino acid profile of the most primitive hematopoietic compartments (KLS) did not differ significantly from the one of their direct progenies (common myeloid progenitor CMP), while granulocyte-monocyte progenitors (GMPs), on the opposite of megakaryocyte-erythroid progenitors (MEPs), have higher content of the majority of amino acids analyzed. Additionally, we identified intermediates of the urea cycle to be differentially expressed in the KLS population and were found to lower mitochondrial membrane potential, an established readout on self-renewal capability. Moreover, we were able to profile for the first time 12 different minerals and detect differences in elemental contents between different HSPC compartments. Importantly, essential dietary trace elements, such as iron and molybdenum, were found to be enriched in granulocyte-monocyte progenitors (GMPs). We envision this amino acid and mineral profiling will allow identification of novel metabolic and nutrient sensing pathways important in HSPC fate regulation.

The hematopoietic stem cell diet

Hematopoietic stem cells (HSCs) are responsible for sustaining life-long blood formation or hematopoiesis and are also used clinically in a form of bone marrow transplantation, a curative cellular therapy for a range of hematological diseases. HSCs are maintained throughout adult life by a complex biological niche or microenvironment, which is thought to be composed of a range of cellular, molecular, and metabolic components. The metabolic components of the HSC niche have become of increasing interest over the past few years. It is now well-recognized that metabolic activity is intimately linked to HSC function, and dysregulation of these metabolic pathways result in hematological pathologies such as leukemia. Here, we review the recent progress in this field including our current understanding of the "dietary" requirements of HSCs and how nutrition influences HSC activity. These recent findings have suggested promising new metabolic approaches to improve clinical HSC transplantation and leukemia therapies.