Daily Ethanol Drinking Followed by an Abstinence Period Impairs Bone Marrow Niche and Mitochondrial Function of Hematopoietic Stem/Progenitor Cells in Rhesus Macaques

Hematopoietic Stem Cells as an Integrative Hub Linking Lifestyle to Cardiovascular Health

Despite breakthroughs in modern medical care, the incidence of cardiovascular disease (CVD) is even more prevalent globally. Increasing epidemiologic evidence indicates that emerging cardiovascular risk factors arising from the modern lifestyle, including psychosocial stress, sleep problems, unhealthy diet patterns, physical inactivity/sedentary behavior, alcohol consumption, and tobacco smoking, contribute significantly to this worldwide epidemic, while its underpinning mechanisms are enigmatic. Hematological and immune systems were recently demonstrated to play integrative roles in linking lifestyle to cardiovascular health. In particular, alterations in hematopoietic stem cell (HSC) homeostasis, which is usually characterized by proliferation, expansion, mobilization, megakaryocyte/myeloid-biased differentiation, and/or the pro-inflammatory priming of HSCs, have been shown to be involved in the persistent overproduction of pro-inflammatory myeloid leukocytes and platelets, the cellular protagonists of cardiovascular inflammation and thrombosis, respectively. Furthermore, certain lifestyle factors, such as a healthy diet pattern and physical exercise, have been documented to exert cardiovascular protective effects through promoting quiescence, bone marrow retention, balanced differentiation, and/or the anti-inflammatory priming of HSCs. Here, we review the current understanding of and progression in research on the mechanistic interrelationships among lifestyle, HSC homeostasis, and cardiovascular health. Given that adhering to a healthy lifestyle has become a mainstream primary preventative approach to lowering the cardiovascular burden, unmasking the causal links between lifestyle and cardiovascular health from the perspective of hematopoiesis would open new opportunities to prevent and treat CVD in the present age.

Integrated single cell analysis shows chronic alcohol drinking disrupts monocyte differentiation in the bone marrow

Chronic heavy alcohol drinking (CHD) rewires monocytes and macrophages toward heightened inflammatory states with compromised antimicrobial defenses that persist after 1-month abstinence. To determine whether these changes are mediated through alterations in the bone marrow niche, we profiled monocytes and hematopoietic stem cell progenitors (HSCPs) from CHD rhesus macaques using a combination of functional assays and single cell genomics. CHD resulted in transcriptional profiles consistent with increased activation and inflammation within bone marrow resident monocytes and macrophages. Furthermore, CHD resulted in transcriptional signatures associated with increased oxidative and cellular stress in HSCP. Differentiation of HSCP in vitro revealed skewing toward monocytes expressing "neutrophil-like" markers with greater inflammatory responses to bacterial agonists. Further analyses of HSCPs showed broad epigenetic changes that were in line with exacerbated inflammatory responses within monocytes and their progenitors. In summary, CHD alters HSCPs in the bone marrow leading to the production of monocytes poised to generate dysregulated hyper-inflammatory responses.

Integrated single cell analysis shows chronic alcohol drinking disrupts monocyte differentiation in the bone marrow niche

Chronic alcohol drinking rewires circulating monocytes and tissue-resident macrophages towards heightened inflammatory states with compromised anti-microbial defenses. As these effects remain consistent in short-lived monocytes after a 1-month abstinence period it is unclear whether these changes are restricted to the periphery or mediated through alterations in the progenitor niche. To test this hypothesis, we profiled monocytes/macrophages and hematopoietic stem cell progenitors (HSCP) of the bone marrow compartment from rhesus macaques after 12 months of ethanol consumption using a combination of functional assays and single cell genomics. Bone marrow-resident monocytes/macrophages from ethanol-consuming animals exhibited heightened inflammation. Differentiation of HSCP in vitro revealed skewing towards monocytes expressing neutrophil-like markers with heightened inflammatory responses to bacterial agonists. Single cell transcriptional analysis of HSCPs showed reduced proliferation but increased inflammatory markers in mature myeloid progenitors. We observed transcriptional signatures associated with increased oxidative and cellular stress as well as oxidative phosphorylation in immature and mature myeloid progenitors. Single cell analysis of the chromatin landscape showed altered drivers of differentiation in monocytes and progenitors. Collectively, these data indicate that chronic ethanol drinking results in remodeling of the transcriptional and epigenetic landscapes of the bone marrow compartment leading to altered functions in the periphery.

Maternal Western-style diet remodels the transcriptional landscape of fetal hematopoietic stem and progenitor cells in rhesus macaques

Maternal obesity adversely impacts the in utero metabolic environment, but its effect on fetal hematopoiesis remains incompletely understood. During late development, the fetal bone marrow (FBM) becomes the major site where macrophages and B lymphocytes are produced via differentiation of hematopoietic stem and progenitor cells (HSPCs). Here, we analyzed the transcriptional landscape of FBM HSPCs at single-cell resolution in fetal macaques exposed to a maternal high-fat Western-style diet (WSD) or a low-fat control diet. We demonstrate that maternal WSD induces a proinflammatory response in FBM HSPCs and fetal macrophages. In addition, maternal WSD consumption suppresses the expression of B cell development genes and decreases the frequency of FBM B cells. Finally, maternal WSD leads to poor engraftment of fetal HSPCs in nonlethally irradiated immunodeficient NOD/SCID/IL2rγ^-/- mice. Collectively, these data demonstrate for the first time that maternal WSD impairs fetal HSPC differentiation and function in a translationally relevant nonhuman primate model.

Searching for the Optimal Donor for Allogenic Adipose-Derived Stem Cells: A Comprehensive Review

Adipose-derived stem cells comprise several clinically beneficial qualities that have been explored in basic research and have motivated several clinical studies with promising results. After being approved in the European Union, UK, Switzerland, Israel, and Japan, allogeneic adipose-derived stem cells (darvadstrocel) have been recently granted a regenerative medicine advanced therapy (RMAT) designation by US FDA for complex perianal fistulas in adults with Crohn's disease. This huge scientific step is likely to impact the future spread of the indications of allogeneic adipose-derived stem cell applications. The current knowledge on adipose stem cell harvest describes quantitative and qualitative differences that could be influenced by different donor conditions and donor sites. In this comprehensive review, we summarize the current knowledge on the topic and propose donor profiles that could provide the optimal initial quality of this living drug, as a starting point for further applications and studies in different pathological conditions.

Optimization of Mesenchymal Stromal Cell (MSC) Manufacturing Processes for a Better Therapeutic Outcome

MSCs products as well as their derived extracellular vesicles, are currently being explored as advanced biologics in cell-based therapies with high expectations for their clinical use in the next few years. In recent years, various strategies designed for improving the therapeutic potential of mesenchymal stromal cells (MSCs), including pre-conditioning for enhanced cytokine production, improved cell homing and strengthening of immunomodulatory properties, have been developed but the manufacture and handling of these cells for their use as advanced therapy medicinal products (ATMPs) remains insufficiently studied, and available data are mainly related to non-industrial processes. In the present article, we will review this topic, analyzing current information on the specific regulations, the selection of living donors as well as MSCs from different sources (bone marrow, adipose tissue, umbilical cord, etc.), in-process quality controls for ensuring cell efficiency and safety during all stages of the manual and automatic (bioreactors) manufacturing process, including cryopreservation, the use of cell banks, handling medicines, transport systems of ATMPs, among other related aspects, according to European and US legislation. Our aim is to provide a guide for a better, homogeneous manufacturing of therapeutic cellular products with special reference to MSCs.

Transcriptional and Epigenetic Regulation of Monocyte and Macrophage Dysfunction by Chronic Alcohol Consumption

Drinking alcohol, even in moderation, can affect the immune system. Studies have shown disproportionate effects of alcohol on circulating and tissue-resident myeloid cells (granulocytes, monocytes, macrophages, dendritic cells). These cells orchestrate the body's first line of defense against microbial challenges as well as maintain tissue homeostasis and repair. Alcohol's effects on these cells are dependent on exposure pattern, with acute drinking dampening but chronic drinking enhancing production of inflammatory mediators. Although chronic drinking is associated with heightened systemic inflammation, studies on tissue resident macrophage populations in several organs including the spleen, liver, brain, and lung have also shown compromised functional and metabolic capacities of these cells. Many of these effects are thought to be mediated by oxidative stress caused by alcohol and its metabolites which can directly impact the cellular epigenetic landscapes. In addition, since myeloid cells are relatively short-lived in circulation and are under constant repopulation from the bone marrow compartment, alcohol's effects on bone marrow progenitors and hematopoiesis are important for understanding the impact of alcohol systemically on these myeloid populations. Alcohol-induced disruption of progenitor, circulating, and tissue resident myeloid populations contribute to the increased susceptibility of patients with alcohol use disorders to viral and bacterial infections. In this review, we provide an overview of the impact of chronic alcohol consumption on the function of monocytes and macrophages in host defense, tissue repair and inflammation. We then summarize our current understanding of the mechanisms underlying alcohol-induced disruption and examine changes in transcriptome and epigenome of monocytes and mcrophages. Overall, chronic alcohol consumption leads to hyper-inflammation concomitant with decreased microbial and wound healing responses by monocytes/macrophages due to a rewiring of the epigentic and transcriptional landscape. However, in advanced alcoholic liver disease, myeloid cells become immunosuppressed as a response to the surrounding hyper-inflammatory milieu. Therefore, the effect of chronic alcohol on the inflammatory response depends on disease state and the immune cell population.

Reduction of Cell Proliferation by Acute C2H6O Exposure

Simple Summary

Alcoholic beverages and acetaldehyde formed during their metabolism are carcinogenic to humans. Alcohol drinking may affect bone marrow stem cell niche, suppressing physiological hematopoiesis and ultimately reducing the organism’s capacity to fight against cancer, infections, and to promote tissue regeneration. To elucidate in vivo the cellular mechanisms associated with alcohol intake toxicity, we used a mouse model in which proliferating cells produce the firefly’s light-emitting protein. In this animal, alcohol exposure transiently “turns off the light”, indicating a negative effect on cell proliferation in the bone marrow and spleen. Pharmacological treatment with substances interfering with ethanol metabolism, reducing acetaldehyde production, partially restores the physiological cell proliferation rate. Over 560 million people worldwide have increased susceptibility to acetaldehyde toxicity and 4% of cancer deaths are attributable to alcohol. Our model might provide a suitable tool to further investigate in vivo the effects of alcohol metabolism and aldehydes production on carcinogenesis.

Abstract

Endogenous acetaldehyde production from the metabolism of ingested alcohol exposes hematopoietic progenitor cells to increased genotoxic risk. To develop possible therapeutic strategies to prevent or reverse alcohol abuse effects, it would be critical to determine the temporal progression of acute ethanol toxicity on progenitor cell numbers and proliferative status. We followed the variation of the cell proliferation rate in bone marrow and spleen in response to acute ethanol intoxication in the MITO-Luc mouse, in which NF-Y-dependent cell proliferation can be assessed in vivo by non-invasive bioluminescent imaging. One week after ethanol administration, bioluminescent signals in bone marrow and spleen decreased below the level corresponding to physiological proliferation, and they progressively resumed to pre-treatment values in approximately 4 weeks. Boosting acetaldehyde catabolism by administration of an aldehyde dehydrogenase activity activator or administration of polyphenols with antioxidant activity partially restored bone marrow cells’ physiological proliferation. These results indicate that in this mouse model, bioluminescent alteration reflects the reduction of the physiological proliferation rate of bone marrow progenitor cells due to the toxic effect of aldehydes generated by alcohol oxidation. In summary, this study presents a novel view of the impact of acute alcohol intake on bone marrow cell proliferation in vivo.

The Impact of Sedentary Lifestyle, High-fat Diet, Tobacco Smoke, and Alcohol Intake on the Hematopoietic Stem Cell Niches

Hematopoietic stem and progenitor cells maintain hematopoiesis throughout life by generating all major blood cell lineages through the process of self-renewal and differentiation. In adult mammals, hematopoietic stem cells (HSCs) primarily reside in the bone marrow (BM) at special microenvironments called “niches.” Niches are thought to extrinsically orchestrate the HSC fate including their quiescence and proliferation. Insight into the HSC niches mainly comes from studies in mice using surface marker identification and imaging to visualize HSC localization and association with niche cells. The advantage of mouse models is the possibility to study the 3-dimensional BM architecture and cell interactions in an intact traceable system. However, this may not be directly translational to human BM. Sedentary lifestyle, unhealthy diet, excessive alcohol intake, and smoking are all known risk factors for various diseases including hematological disorders and cancer, but how do lifestyle factors impact hematopoiesis and the associated niches? Here, we review current knowledge about the HSC niches and how unhealthy lifestyle may affect it. In addition, we summarize epidemiological data concerning the influence of lifestyle factors on hematological disorders and malignancies.

Binge-Like Exposure During Adolescence Induces Detrimental Effects in Alveolar Bone that Persist in Adulthood

BACKGROUND

Alcohol (EtOH) intake during adolescence has become an important public health issue. Although the detrimental effects of EtOH intake on the musculoskeletal system are well known, only a few studies have investigated its impact on the stomatognathic system of adolescents. This study aimed to investigate the effect of EtOH binge drinking on the alveolar bone and the long-term consequences after abstinence.

METHODS

Adolescent female Wistar rats (35 days old) were exposed to 4 cycles of EtOH binge drinking (3 g/kg/d; 3 days On-4 days Off) or distilled water (control group). Alveolar bone micromorphology and vertical bone distance were evaluated at 1, 30, and 60 days after that last EtOH intake through X-ray computed microtomography. The mineral:matrix ratio was assessed through Raman spectroscopy.

RESULTS

A decrease in both trabecular thickness and volume ratio, and an increase in trabecular separation were observed at the 1-day evaluation (immediate withdrawal). After 30 and 60 days, the alveolar bone parameters were found similar to control, except for the mineral:matrix ratio in the long-term abstinence.

CONCLUSIONS

EtOH binge drinking during adolescence results in alveolar bone damage that may persist in adulthood, even after abstinence.