Concise review: Regulation of stem cell proliferation and differentiation by essential fatty acids and their metabolites

n-3 PUFAs synergistically enhance the efficacy of doxorubicin by inhibiting the proliferation and invasion of breast cancer cells

Breast cancer stands as a prominent contributor to cancer-related fatalities among women globally, characterized by an unfavorable prognosis, low survival rates, and its conventional treatment approach involving chemotherapy. Doxorubicin (DOXO) represents a potent anti-tumor agent widely employed in combating breast cancer. Regrettably, a substantial proportion of patients eventually develop resistance to DOXO treatment, elevating the risk of relapse and adverse clinical outcomes. Omega-3 polyunsaturated fatty acids (n-3 PUFAs), recognized as essential components of the human diet, have exhibited considerable promise in targeting malignant cells, initiating apoptosis, and impeding tumor proliferation and metastatic dissemination. Combining these nutritional supplements, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with DOXO presents a compelling strategy to augment treatment efficacy. The present study was conducted employing a breast cancer cell line, MCF-7, to assess the synergistic potential of DHA, EPA, and DOXO. Remarkably, the combination treatment yielded a substantial increase in cytotoxicity compared to the administration of DOXO alone. Furthermore, an enhancement in the suppression of metastasis was evident in the combination treatment relative to the exclusive use of DOXO. Cell cycle analysis unveiled that cells subjected to the combination treatment exhibited a more pronounced arrest in the G1 phase, signifying the combination's heightened effectiveness in impeding cell progression into the doubling phase. Collectively, the amalgamation of n-3 polyunsaturated fatty acids (n-3 PUFAs) emerges as a potent strategy for enhancing the therapeutic potential of DOXO, effectively restraining the growth and dissemination of breast cancer cells.

The Nephroprotective Effects of the Allogeneic Transplantation with Mesenchymal Stromal Cells Were Potentiated by ω3 Stimulating Up-Regulation of the PPAR-γ

Mesenchymal stromal cells (MSCs) obtained from bone marrow are a promising tool for regenerative medicine, including kidney diseases. A step forward in MSCs studies is cellular conditioning through specific minerals and vitamins. The Omega-3 fatty acids (ω3) are essential in regulating MSCs self-renewal, cell cycle, and survival. The ω3 could act as a ligand for peroxisome proliferator-activated receptor gamma (PPAR-γ). This study aimed to demonstrate that ω3 supplementation in rats could lead to the up-regulation of PPAR-γ in the MSCs. The next step was to compare the effects of these MSCs through allogeneic transplantation in rats subjected to unilateral ureteral obstruction (UUO). Independent of ω3 supplementation in the diet of the rats, the MSCs in vitro conserved differentiation capability and phenotypic characteristics. Nevertheless, MSCs obtained from the rats supplemented with ω3 stimulated an increase in the expression of PPAR-γ. After allogeneic transplantation in rats subjected to UUO, the ω3 supplementation in the rats enhanced some nephroprotective effects of the MSCs through a higher expression of antioxidant enzyme (SOD-1), anti-inflammatory marker (IL-10), and lower expression of the inflammatory marker (IL-6), and proteinuria.

A high ratio of linoleic acid (n-6 PUFA) to alpha-linolenic acid (n-3 PUFA) adversely affects early stage of human neuronal differentiation and electrophysiological activity of glutamatergic neurons in vitro

Introduction: There is a growing interest in the possibility of dietary supplementation with polyunsaturated fatty acids (PUFAs) for treatment and prevention of neurodevelopmental and neuropsychiatric disorders. Studies have suggested that of the two important classes of polyunsaturated fatty acids, omega-6 (n-6) and omega-3 (n-3), n-3 polyunsaturated fatty acids support brain development and function, and when used as a dietary supplement may have beneficial effects for maintenance of a healthy brain. However, to date epidemiological studies and clinical trials on children and adults have been inconclusive regarding treatment length, dosage and use of specific n-3 polyunsaturated fatty acids. The aim of this study is to generate a simplified in vitro cell-based model system to test how different n-6 to n-3 polyunsaturated fatty acids ratios affect human-derived neurons activity as a cellular correlate for brain function and to probe the mechanism of their action. Methods: All experiments were performed by use of human induced pluripotent stem cells (iPSCs). In this study, we examined the effect of different ratios of linoleic acid (n-6) to alpha-linolenic acid in cell growth medium on induced pluripotent stem cell proliferation, generation of neuronal precursors and electrophysiology of cortical glutamatergic neurons by multielectrode array (MEA) analysis. Results: This study shows that at a n-6:n-3 ratio of 5:1 polyunsaturated fatty acids induce stem cell proliferation, generating a large increase in number of cells after 72 h treatment; suppress generation of neuronal progenitor cells, as measured by decreased expression of FOXG1 and Nestin in neuronal precursor cells (NPC) after 20 days of development; and disrupt neuronal activity in vitro, increasing spontaneous neuronal firing, reducing synchronized bursting receptor subunits. We observed no significant differences for neuronal precursor cells treated with ratios 1:3 and 3:1, in comparison to 1:1 control ratio, but higher ratios of n-6 to n-3 polyunsaturated fatty acids adversely affect early stages of neuronal differentiation. Moreover, a 5:1 ratio in cortical glutamatergic neurons induce expression of GABA receptors which may explain the observed abnormal electrophysiological activity.

Metabolic signature of spent culture media shows lipid metabolism as a determinant of pregnancy outcomes

In the present study, we investigated the spent culture media of in vitro produced (IVP) bovine embryos which did (group Pregnant) or did not (group Non-pregnant) establish pregnancy after transfer. For that purpose, IVP embryos on D5 were transferred to individual droplets for the last 48 h of culture. Embryos at the blastocyst stage were then transferred to synchronized recipients, while respective culture media drops were collected and evaluated individually. The list of metabolites present in spent culture media was obtained by electrospray ionization mass spectrometry (ESI-MS) and analysed with Metaboanalyst® to characterize the metabolic profile of each group. The spectrometric analysis showed that pathways related to lipid metabolism, particularly fatty acids degradation via beta-oxidation, were more present in the Pregnant group whereas no significant pathway was identified in the group Non-pregnant. By using this method, we were able to identify a metabolic signature in culture media that allows for a better comprehension of preferential metabolic routes taken by the most viable embryos. These findings offer great insights into the biochemistry of embryo development and reveal a potential target for the development of better-quality IVP systems, as well as tools to identify bovine embryos with greater chances to establish and maintain pregnancy.

Free Fatty Acids from Type 2 Diabetes Mellitus Serum Remodel Mesenchymal Stem Cell Lipids, Hindering Differentiation into Primordial Germ Cells

Type 2 diabetes mellitus (T2DM) adversely affects the essential characteristics of adipose tissue-derived mesenchymal stem cells (AdMSCs). Given that T2DM is associated with an altered serum free fatty acid (FFA) profile, we examined whether diabetic serum FFAs influence the viability, differentiation, and fatty acid composition of the major lipid fractions of human AdMSCs in vitro. Serum FFAs were isolated from 7 diabetic and 10 healthy nondiabetic female individuals. AdMSCs were cultured and differentiated into primordial germ cell-like cells (PGCLCs) in the presence of either diabetic or nondiabetic FFAs. Cell viability was assessed using trypan blue staining. Cell differentiation was evaluated by measuring the PGCLC transcriptional markers Blimp1 and Stella. Lipid fractionation and fatty acid quantification were performed using thin-layer chromatography and gas-liquid chromatography, respectively. Both diabetic and nondiabetic FFAs significantly reduced the viability of PGCLCs. The gene expression of both differentiation markers was significantly lower in cells exposed to diabetic FFAs than in those treated with nondiabetic FFAs. Saturated fatty acids were significantly increased and linoleic acid was significantly decreased in the cellular phospholipid fraction after exposure to diabetic FFAs. In contrast, monounsaturated fatty acids were reduced and linoleic acid was elevated in the cellular triglyceride fraction in response to diabetic FFAs. Such an altered serum FFA profile in patients with T2DM reduces the proliferation and differentiation potential of AdMSCs, presumably due to the aberrant distribution of fatty acids into cell phospholipids and triglycerides.

Dyslipidemia induced by lipid diet in late gestation donor impact on growth kinetics and in vitro potential differentiation of umbilical cord Wharton's Jelly mesenchymal stem cells in goats

Mesenchymal stem cells (MSC) from the umbilical cord (UC) have several attractive properties for clinical use. This study aimed to verify the impact of a lipid-rich diet during late gestation of donor goats on the growth and differentiation of MSCs from UC. From the 100th day of pregnancy to delivery, 22 goats were grouped based on their diet into the donor-lipid (DLD; n = 11) and donor-baseline (DBD; n = 11) diet groups. Diets were isonitrogenous and isoenergetic, differing in fat content (2.8% vs. 6.3% on a dry matter basis). Wharton's jelly (WJ) fragments were cultured. After primary culture, samples of WJ-MSCs were characterized by the expression of CD90, CD73, CD34, CD45, CD105, and Fas genes, mitochondrial activity using MitoTracker (MT) fluorescence probe, and growth kinetics. Population doubling time (PDT) was also determined. WJ-MSCs were differentiated into chondrocytes, adipocytes and osteocytes, and the mineralized area and adipocytes were determined. The lipid diet significantly increased triglyceride and cholesterol levels during pregnancy. The DLD group showed sub-expression of the CD90 gene, a high MT intensity, and a low proliferation rate at the end of the subculture. The mean PDT was 83.9 ± 1.3 h. Mineralized area and lipid droplet stain intensity from osteogenic and adipogenic differentiations, respectively, were greater in DLD. We conclude that in donor goats, dietary dyslipidemia during late pregnancy affects the ability of UC-derived MSCs to express their developmental potential in vitro, thus limiting their possible use for therapeutic purposes.

Mass spectrometry imaging discriminates glioblastoma tumor cell subpopulations and different microvascular formations based on their lipid profiles

Glioblastoma is a prevalent malignant brain tumor and despite clinical intervention, tumor recurrence is frequent and usually fatal. Genomic investigations have provided a greater understanding of molecular heterogeneity in glioblastoma, yet there are still no curative treatments, and the prognosis has remained unchanged. The aggressive nature of glioblastoma is attributed to the heterogeneity in tumor cell subpopulations and aberrant microvascular proliferation. Ganglioside-directed immunotherapy and membrane lipid therapy have shown efficacy in the treatment of glioblastoma. To truly harness these novel therapeutics and develop a regimen that improves clinical outcome, a greater understanding of the altered lipidomic profiles within the glioblastoma tumor microenvironment is urgently needed. In this work, high resolution mass spectrometry imaging was utilized to investigate lipid heterogeneity in human glioblastoma samples. Data presented offers the first insight into the histology-specific accumulation of lipids involved in cell metabolism and signaling. Cardiolipins, phosphatidylinositol, ceramide-1-phosphate, and gangliosides, including the glioblastoma stem cell marker, GD3, were shown to differentially accumulate in tumor and endothelial cell subpopulations. Conversely, a reduction in sphingomyelins and sulfatides were detected in tumor cell regions. Cellular accumulation for each lipid class was dependent upon their fatty acid residue composition, highlighting the importance of understanding lipid structure-function relationships. Discriminating ions were identified and correlated to histopathology and Ki67 proliferation index. These results identified multiple lipids within the glioblastoma microenvironment that warrant further investigation for the development of predictive biomarkers and lipid-based therapeutics.

Fatty Acids: A Safe Tool for Improving Neurodevelopmental Alterations in Down Syndrome?

The triplication of chromosome 21 causes Down syndrome (DS), a genetic disorder that is characterized by intellectual disability (ID). The causes of ID start in utero, leading to impairments in neurogenesis, and continue into infancy, leading to impairments in dendritogenesis, spinogenesis, and connectivity. These defects are associated with alterations in mitochondrial and metabolic functions and precocious aging, leading to the early development of Alzheimer’s disease. Intense efforts are currently underway, taking advantage of DS mouse models to discover pharmacotherapies for the neurodevelopmental and cognitive deficits of DS. Many treatments that proved effective in mouse models may raise safety concerns over human use, especially at early life stages. Accumulating evidence shows that fatty acids, which are nutrients present in normal diets, exert numerous positive effects on the brain. Here, we review (i) the knowledge obtained from animal models regarding the effects of fatty acids on the brain, by focusing on alterations that are particularly prominent in DS, and (ii) the progress recently made in a DS mouse model, suggesting that fatty acids may indeed represent a useful treatment for DS. This scenario should prompt the scientific community to further explore the potential benefit of fatty acids for people with DS.

Circulating Exosome Cargoes Contain Functionally Diverse Cancer Biomarkers: From Biogenesis and Function to Purification and Potential Translational Utility

Although diagnostic and therapeutic treatments of cancer have tremendously improved over the past two decades, the indolent nature of its symptoms has made early detection challenging. Thus, inter-disciplinary (genomic, transcriptomic, proteomic, and lipidomic) research efforts have been focused on the non-invasive identification of unique "silver bullet" cancer biomarkers for the design of ultra-sensitive molecular diagnostic assays. Circulating tumor biomarkers, such as CTCs and ctDNAs, which are released by tumors in the circulation, have already demonstrated their clinical utility for the non-invasive detection of certain solid tumors. Considering that exosomes are actively produced by all cells, including tumor cells, and can be found in the circulation, they have been extensively assessed for their potential as a source of circulating cell-specific biomarkers. Exosomes are particularly appealing because they represent a stable and encapsulated reservoir of active biological compounds that may be useful for the non-invasive detection of cancer. T biogenesis of these extracellular vesicles is profoundly altered during carcinogenesis, but because they harbor unique or uniquely combined surface proteins, cancer biomarker studies have been focused on their purification from biofluids, for the analysis of their RNA, DNA, protein, and lipid cargoes. In this review, we evaluate the biogenesis of normal and cancer exosomes, provide extensive information on the state of the art, the current purification methods, and the technologies employed for genomic, transcriptomic, proteomic, and lipidomic evaluation of their cargoes. Our thorough examination of the literature highlights the current limitations and promising future of exosomes as a liquid biopsy for the identification of circulating tumor biomarkers.

Neuronal differentiation potential of primary and immortalized adipose stem cells by photobiomodulation

Adipose Stem Cells (ASCs) are capable of neuronal differentiation, which makes them an ideal choice for therapies in nerve injuries. Principally, the differentiation of autologous ASCs to neurons offers solutions for the replacement therapies of nervous system with patient's own genetic background. On the contrary, the use of genetically modified (immortalized) ASCs has the benefit of accessibility by surpassing ethical concerns and ease for propagation as a continuous cell culture. Photobiomodulation (PBM) is a therapeutic modality with laser or light, which is widely been used for modulating stem cell bioprocesses viz. proliferation and differentiation. A comparative analysis was performed to evaluate the neuronal differentiation potential of primary ASCs isolated from a healthy human subject with commercially obtained immortalized ASCs with PBM. The outcome of this analysis will help us to know either primary or immortalized ASCs are most suitable for biomedical applications. Both primary and immortalized ASCs were characterized using their surface protein markers CD44/90/133/166 and induced to differentiate into neuronal cells using Fibroblast Growth Factor, basic (bFGF) and forskolin following PBM using Near Infra-Red (NIR) lasers. Based on the expression of nestin, an early neuronal marker an exposure to 5, 10 and 15 J/cm² of NIR and growth inducers for 14 days the primary ASCs demonstrated a higher neuronal differentiation potential compared to the immortalized ASCs. However, newly differentiated cells from either of these ASCs did not reveal βIII-tubulin, an intermediate neuronal marker even by 21 days of differentiation. This study gives an indication that immortalized ASCs have a phenotype and differentiation potential slightly less but comparable to the freshly isolated ASCs. We suggest that PBM along with growth inducers offer a better solution of differentiating ASCs to neurons.

The Metabolic Impact of Two Different Parenteral Nutrition Lipid Emulsions in Children after Hematopoietic Stem Cell Transplantation: A Lipidomics Investigation

Hematopoietic stem cell transplantation (HSCT) involves the infusion of either bone marrow or blood cells preceded by toxic chemotherapy. However, there is little knowledge about the clinical benefits of parenteral nutrition (PN) in patients receiving high-dose chemotherapy during HSCT. We investigated the lipidomic profile of plasma and the targeted fatty acid profiles of plasma and erythrocytes in children after HSCT using PN with either a fish oil-based lipid emulsion or a classic soybean oil emulsion. An untargeted liquid chromatography high-resolution mass spectrometry platform connected with a novel in silico annotation algorithm was utilized to determine the most relevant chemical subclasses affected. In addition, we explored the interrelation between the lipidomics profile in plasma, the targeted fatty acid profile in plasma and erythrocytes, several biomarkers of inflammation, and antioxidant defense using an innovative data integration analysis based on Latent Components. We observed that the fish oil-based lipid emulsion had an impact in several lipid subclasses, mainly glycerophosphocholines (PC), glycerophosphoserines (PS), glycerophosphoethanolamines (PE), oxidized PE (O-PE), 1-alkyl,2-acyl PS, lysophosphatidylethanolamines (LPE), oxidized PS (O-PS) and dicarboxylic acids. In contrast, the classic soybean oil emulsion did not. Several connections across the different blocks of data were found and aid in interpreting the impact of the lipid emulsions on metabolic health.

New Insights into Depressive Disorder with Respect to Low-Grade Inflammation and Fish Oil Intake

Unipolar depression has been recognized as one of the major diseases by the World Health Organization in the 21st century. The etiology of depression is complicated and includes genetic factors, stress, aging, and special physical status (pregnancy, metabolic syndrome, and trauma). Numerous animal and human studies have demonstrated that n-3 polyunsaturated fatty acids (n-3 PUFAs) are highly correlated to cognition and depression. These nutritional antidepressants, including EPA and DHA, have a range of neurobiological activities contributing to their potential antidepressant effects. Our preclinical and clinical studies have indicated that n-3 PUFA supplementation in addition to standard antidepressant medications may provide synergistic neuroprotective and antioxidant/inflammatory effects. To translate our preliminary findings into clinical application, this paper reviews the existing evidence on the antidepressant effects of n-3 PUFAs and the potential underlying mechanisms, which include modulation of chronic lowgrade inflammation and the corresponding changes in peripheral blood immune biomarkers.

Characterization of Differentially Expressed miRNAs by CXCL12/SDF-1 in Human Bone Marrow Stromal Cells

Stromal cell-derived factor 1 (SDF-1) is known to influence bone marrow stromal cell (BMSC) migration, osteogenic differentiation, and fracture healing. We hypothesize that SDF-1 mediates some of its effects on BMSCs through epigenetic regulation, specifically via microRNAs (miRNAs). MiRNAs are small non-coding RNAs that target specific mRNA and prevent their translation. We performed global miRNA analysis and determined several miRNAs were differentially expressed in response to SDF-1 treatment. Gene Expression Omnibus (GEO) dataset analysis showed that these miRNAs play an important role in osteogenic differentiation and fracture healing. KEGG and GO analysis indicated that SDF-1 dependent miRNAs changes affect multiple cellular pathways, including fatty acid biosynthesis, thyroid hormone signaling, and mucin-type O-glycan biosynthesis pathways. Furthermore, bioinformatics analysis showed several miRNAs target genes related to stem cell migration and differentiation. This study's findings indicated that SDF-1 induces some of its effects on BMSCs function through miRNA regulation.

N-3 polyunsaturated fatty acids promote astrocyte differentiation and neurotrophin production independent of cAMP in patient-derived neural stem cells

Evidence from epidemiological and laboratory studies, as well as randomized placebo-controlled trials, suggests supplementation with n-3 polyunsaturated fatty acids (PUFAs) may be efficacious for treatment of major depressive disorder (MDD). The mechanisms underlying n-3 PUFAs potential therapeutic properties remain unknown. There are suggestions in the literature that glial hypofunction is associated with depressive symptoms and that antidepressants may normalize glial function. In this study, induced pluripotent stem cells (iPSC)-derived neuronal stem cell lines were generated from individuals with MDD. Astrocytes differentiated from patient-derived neuronal stem cells (iNSCs) were verified by GFAP. Cells were treated with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or stearic acid (SA). During astrocyte differentiation, we found that n-3 PUFAs increased GFAP expression and GFAP positive cell formation. BDNF and GDNF production were increased in the astrocytes derived from patients subsequent to n-3 PUFA treatment. Stearic Acid (SA) treatment did not have this effect. CREB activity (phosphorylated CREB) was also increased by DHA and EPA but not by SA. Furthermore, when these astrocytes were treated with n-3 PUFAs, the cAMP antagonist, RP-cAMPs did not block n-3 PUFA CREB activation. However, the CREB specific inhibitor (666-15) diminished BDNF and GDNF production induced by n-3 PUFA, suggesting CREB dependence. Together, these results suggested that n-3 PUFAs facilitate astrocyte differentiation, and may mimic effects of some antidepressants by increasing production of neurotrophic factors. The CREB-dependence and cAMP independence of this process suggests a manner in which n-3 PUFA could augment antidepressant effects. These data also suggest a role for astrocytes in both MDD and antidepressant action.

Early postnatal oleic acid administration enhances synaptic development and cognitive abilities in the Ts65Dn mouse model of Down syndrome

OBJECTIVES

The brains of individuals with Down syndrome (DS) present defects in neurogenesis and synaptogenesis during prenatal and early postnatal stages that are partially responsible for their cognitive disabilities. Because oleic and linolenic fatty acids enhance neurogenesis, synaptogenesis, and cognitive abilities in rodents and humans, in this study we evaluated the ability of these compounds to restore these altered phenotypes in the Ts65Dn (TS) mouse model of DS during early postnatal stages.

METHODS

TS and euploid mice were treated with oleic or linolenic acid from PD3 to PD15, and the short- and long- term effects of these acids on neurogenesis and synaptogenesis were evaluated. The effects of these treatments on the cognitive abilities of TS mice during early adulthood were also evaluated.

RESULTS

Administration of oleic or linolenic acid did not modify cell proliferation immediately after treatment discontinuation or several weeks later. However, oleic acid increased the total number of DAPI+ cells (+ 26%), the percentage of BrdU+ cells that acquired a neural phenotype (+ 9.1%), the number of pre- (+ 29%) and post-synaptic (+ 32%) terminals and the cognitive abilities of TS mice (+ 18.1%). In contrast, linolenic acid only produced a slight cognitive improvement in TS mice. (+12.1%).

DISCUSSION

These results suggest that early postnatal administration of oleic acid could palliate the cognitive deficits of DS individuals.

Lipidomics of mesenchymal stem cell differentiation

Mesenchymal stem cells (MSCs), such as adipose-derived stem cells (ADSCs) and skeletal muscle-derived stem cells (MDSCs), are potential sources for cell-based therapeutic strategies. However, there is little knowledge about the lipid composition of these stem cells and the mechanisms of their differentiation. Lipids have important biological and physiological functions that are critical for understanding the regulation and control of stem cell fate. This study sought to analyze the lipidome of rabbit ADSCs and MDSCs and their adipogenic and osteogenic differentiation. The MSCs were isolated and were characterized by flow cytometry. Lipids were extracted from both MSCs and differentiated cells, and the lipids were subsequently analyzed with a hybrid triple quadrupole time-of-flight mass spectrometer. The results showed a total of 1687 lipid species. MSCs exhibited different lipid profiles as well as changes in lipid composition after differentiation. Furthermore, the expression levels of N-acyl-phosphatidylethanolamine (NAPE) 54:7+NH4 (-FA 17:0(NH4)) and phosphatidylcholine (PC) 42:6+Na were higher in the adipogenic lineages in of both MSC types, and NAPE 58:2+NH4 (-FA 17:0 (NH4)) and NAPE 56:2+NH4 (-FA 17:0 (NH4)) had higher levels in the osteogenic lineages, suggesting lipid similarities in cells differentiated from different stem cell sources.

Metabolomic and Signaling Programs Induced by Immobilized versus Soluble IFN γ in Neural Stem Cells

Neural stem cells (NSCs) provide a strategy to replace damaged neurons following traumatic central nervous system injuries. A major hurdle to translation of this therapy is that direct application of NSCs to CNS injury does not support sufficient neurogenesis due to lack of proper cues. To provide prolonged spatial cues to NSCs IFN-γ was immobilized to biomimetic hydrogel substrate to supply physical and biochemical signals to instruct the encapsulated NSCs to be neurogenic. However, the immobilization of factors, including IFN-γ, versus soluble delivery of the same factor, has been incompletely characterized especially with respect to activation of signaling and metabolism in cells over longer time points. In this study, protein and metabolite changes in NSCs induced by immobilized versus soluble IFN-γ at 7 days were evaluated. Soluble IFN-γ, refreshed daily over 7 days, elicited stronger responses in NSCs compared to immobilized IFN-γ, indicating that immobilization may not sustain signaling or has altered ligand/receptor interaction and integrity. However, both IFN-γ delivery types supported increased βIII tubulin expression in parallel with canonical and noncanonical receptor-signaling compared to no IFN-γ. Global metabolomics and pathway analysis revealed that soluble and immobilized IFN-γ altered metabolic pathway activities including energy, lipid, and amino acid synthesis, with soluble IFN-γ having the greatest metabolic impact overall. Finally, soluble and immobilized IFN-γ support mitochondrial voltage-dependent anion channel (VDAC) expression that correlates to differentiated NSCs. This work utilizes new methods to evaluate cell responses to protein delivery and provides insight into mode of action that can be harnessed to improve regenerative medicine-based strategies.

Photobiomodulation-Induced Differentiation of Immortalized Adipose Stem Cells to Neuronal Cells

BACKGROUND AND OBJECTIVES

Transdermal differentiation of human adipose stem cells (ASCs) to other cell types is still a challenge in regenerative medicine. Studies using primary ASCs are also limited as they may undergo replicative senescence during repeated passages in vitro. However, ASCs immortalized (iASCs) with human telomerase enzyme expressing plasmid exhibits a uniform population suitable for differentiation in vitro. A right combination of biological and physical stimuli may induce transdermal differentiation of iASCs into neurons in vitro.

STUDY DESIGN/MATERIALS AND METHODS

iASCs were differentiated to free-floating neural stem cell aggregates (neurospheres) using a combination of growth inducers. Cells in these spheres were induced to differentiate into neurons using low-intensity lasers by a process called photobiomodulation (PBM).

RESULTS

Laser at the near infrared (NIR) wavelength 825 nm and fluences 5, 10, and 15 J/cm² was capable of increasing the differentiation of neurospheres to neurons. Precisely, there was a statistically significant increase in the early neuronal marker at 5 J/cm² and a much appreciable increase at 15 J/cm² in correlation with the biphasic dose response of PBM. However, these differentiated cells failed to express late neuronal markers in vitro. Comparison of these differentiating iASCs with the primary ASCs revealed a sharp distinction between the metabolic processes of the primary ASCs, neurospheres, and newly differentiated neurons.

CONCLUSION

We found that PBM increased the yield of neurons and effected stem cell differentiation through modulation of cellular metabolism and redox status. Our study also identifies that iASCs are an excellent model for analysis of stem cell biology and for performing transdermal differentiation.

SIGNIFICANCE

This study demonstrates that a combination of biological and physical inducers can advance the differentiation of adipose stem cells to neurons. We were able to establish the optimal energy for the neuronal differentiation of iASCs in vitro. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

The impact of ageing on lipid-mediated regulation of adult stem cell behavior and tissue homeostasis

Adult stem cells sustain tissue homeostasis throughout life and provide an important reservoir of cells capable of tissue repair in response to stress and tissue damage. Age-related changes to stem cells and/or the specialized niches that house them have been shown to negatively impact stem cell maintenance and activity. In addition, metabolic inputs have surfaced as another crucial layer in the control of stem cell behavior (Chandel et al., 2016; Folmes and Terzic, 2016; Ito and Suda, 2014; Mana et al., 2017; Shyh-Chang and Ng, 2017). Here, we will present a brief review of how lipid metabolism influences adult stem cell behavior under homeostatic conditions and speculate on how changes in lipid metabolism may impact stem cell ageing. This review considers the future of lipid metabolism research in stem cells, with the long-term goal of identifying mechanisms that could be targeted to counter or slow the age-related decline in stem cell function.

Prenatal Administration of Oleic Acid or Linolenic Acid Reduces Neuromorphological and Cognitive Alterations in Ts65dn Down Syndrome Mice

BACKGROUND

The cognitive impairments that characterize Down syndrome (DS) have been attributed to brain hypocellularity due to neurogenesis impairment during fetal stages. Thus, enhancing prenatal neurogenesis in DS could prevent or reduce some of the neuromorphological and cognitive defects found in postnatal stages.

OBJECTIVES

As fatty acids play a fundamental role in morphogenesis and brain development during fetal stages, in this study, we aimed to enhance neurogenesis and the cognitive abilities of the Ts65Dn (TS) mouse model of DS by administering oleic or linolenic acid.

METHODS

In total, 85 pregnant TS females were subcutaneously treated from Embryonic Day (ED) 10 until Postnatal Day (PD) 2 with oleic acid (400 mg/kg), linolenic acid (500 mg/kg), or vehicle. All analyses were performed on their TS and Control (CO) male and female progeny. At PD2, we evaluated the short-term effects of the treatments on neurogenesis, cellularity, and brain weight, in 40 TS and CO pups. A total of 69 TS and CO mice were used to test the long-term effects of the prenatal treatments on cognition from PD30 to PD45, and on neurogenesis, cellularity, and synaptic markers, at PD45. Data were compared by ANOVAs.

RESULTS

Prenatal administration of oleic or linolenic acid increased the brain weight (+36.7% and +45%, P < 0.01), the density of BrdU (bromodeoxyuridine)- (+80% and +115%; P < 0.01), and DAPI (4',6-diamidino-2-phenylindole)-positive cells (+64% and +22%, P < 0.05) of PD2 TS mice with respect to the vehicle-treated TS mice. Between PD30 and PD45, TS mice prenatally treated with oleic or linolenic acid showed better cognitive abilities (+28% and +25%, P < 0.01) and a higher density of the postsynaptic marker PSD95 (postsynaptic density protein 95) (+65% and +44%, P < 0.05) than the vehicle-treated TS animals.

CONCLUSION

The beneficial cognitive and neuromorphological effects induced by oleic or linolenic acid in TS mice suggest that they could be promising pharmacotherapies for DS-associated cognitive deficits.

Lipid Mediated Regulation of Adult Stem Cell Behavior

Adult stem cells constitute an important reservoir of self-renewing progenitor cells and are crucial for maintaining tissue and organ homeostasis. The capacity of stem cells to self-renew or differentiate can be attributed to distinct metabolic states, and it is now becoming apparent that metabolism plays instructive roles in stem cell fate decisions. Lipids are an extremely vast class of biomolecules, with essential roles in energy homeostasis, membrane structure and signaling. Imbalances in lipid homeostasis can result in lipotoxicity, cell death and diseases, such as cardiovascular disease, insulin resistance and diabetes, autoimmune disorders and cancer. Therefore, understanding how lipid metabolism affects stem cell behavior offers promising perspectives for the development of novel approaches to control stem cell behavior either in vitro or in patients, by modulating lipid metabolic pathways pharmacologically or through diet. In this review, we will first address how recent progress in lipidomics has created new opportunities to uncover stem-cell specific lipidomes. In addition, genetic and/or pharmacological modulation of lipid metabolism have shown the involvement of specific pathways, such as fatty acid oxidation (FAO), in regulating adult stem cell behavior. We will describe and compare findings obtained in multiple stem cell models in order to provide an assessment on whether unique lipid metabolic pathways may commonly regulate stem cell behavior. We will then review characterized and potential molecular mechanisms through which lipids can affect stem cell-specific properties, including self-renewal, differentiation potential or interaction with the niche. Finally, we aim to summarize the current knowledge of how alterations in lipid homeostasis that occur as a consequence of changes in diet, aging or disease can impact stem cells and, consequently, tissue homeostasis and repair.

Endogenous Omega-3 Polyunsaturated Fatty Acids Reduce the Number and Differentiation of White Adipocyte Progenitors in Mice

OBJECTIVES

Reducing the increased number of white adipocyte progenitors (WAP) is considered a novel approach to controlling obesity. The role of omega-3 polyunsaturated fatty acids (PUFA) in regulating the WAP resident population is unclear. The objective of this study was to investigate the effect of omega-3 PUFA on the niche composition of adipose-derived stem cells.

METHODS

Stromal vascular cell fraction (SVF) was collected from subcutaneous fat of wild-type (WT) and transgenic mice carrying a fat-1 gene from Caenorhabditis elegans (Fat-1 mice), which are capable of synthesizing omega-3 PUFA and have much higher tissue levels of omega-3 PUFA relative to WT mice. The isolated SVF cells were cultured and used for the examination of adipocyte differentiation, adipogenic markers, fatty acid composition, and WAP numbers.

RESULTS

SVF isolated from Fat-1 mice (Fat-1-SVF) exhibited markedly fewer differentiated adipocytes with smaller cell size and less lipid content than that of WT mice (WT-SVF). Accordingly, adipogenesis-related genes and the white adipocyte surface marker ASC-1 were downregulated in Fat-1-SVF relative to WT-SVF. Furthermore, WAP numbers and adipose tissue macrophages were lower in Fat-1-SVF than WT-SVF.

CONCLUSIONS

Omega-3 PUFA can both limit the WAP resident population and suppress their differentiation to white adipocytes, suggesting a new mechanism for the antiobesity effect of omega-3 PUFA.

Oxytocin may have a therapeutical potential against cardiovascular disease. Possible pharmaceutical and behavioral approaches

Based on the ancient role of oxytocin and its homologues as amplifiers of reproduction we argue for an evolutionary coupling of oxytocin to signaling pathway which support restorative mechanisms of cells and tissue. In particular, the survival and function of different categories of stem cells and primordial cells are enhanced by mitogen-activated protein kinase (MAPK) pathways. Furthermore, oxytocin stimulates the AMP-activated protein kinase pathway (AMPK) in numerous of cell types which promotes the maintenance of different cell structures. This involves autophagic processes and, in particular, may support the renewal of mitochondria. Mitochondrial fitness may protect against oxidative and inflammatory stress - a well-documented effect of oxytocin. The combined specific trophic and protective effects oxytocin may delay several degenerative phenomena including sarcopenia, type-2 diabetes and atherosclerosis. These effects may be exerted both on a central level supporting the function and integrity of the hypothalamus and peripherally acting directly on blood vessels, pancreas, heart, skeletal muscles and adipose tissue etc. Furthermore, in the capacity of being both a hormone and neuromodulator, oxytocin interacts with numerous of regulatory mechanisms particularly the autonomic nervous system and HPA-axis which may reduce blood pressure and affect the immune function. The potential of the oxytocin system as a behavioral and molecular target for the prevention and treatment of cardiovascular disease is discussed. Focus is put on the affiliative and sexual significance and the different options and limitations associated with a pharmaceutical approach. MeSH: Aging, Atherosclerosis, Heart, Hypothalamus, Inflammation, Love, Orgasm, Oxytocin.

Systematic review and meta-analysis of controlled intervention studies on the effectiveness of long-chain omega-3 fatty acids in patients with nonalcoholic fatty liver disease

Context

Treatment options for nonalcoholic fatty liver disease (NAFLD) are needed.

Objective

The aim of this review was to systematically assess the effects of omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs), particularly eicosapentaenoic acid and docosahexaenoic acid, on liver-related and metabolic outcomes in adult and pediatric patients with NAFLD.

Data Sources

The online information service ProQuest Dialog was used to search 8 literature databases.

Study Selection

Controlled intervention studies in which the independent effects of n-3 LC-PUFAs could be isolated were eligible for inclusion.

Data Extraction

The 18 unique studies that met the criteria for inclusion were divided into 2 sets, and data transcriptions and study quality assessments were conducted in duplicate. Each effect size was expressed as the weighted mean difference and 95%CI, using a random-effects model and the inverse of the variance as a weighting factor.

Results

Based on the meta-analyses, supplementation with n-3 LC-PUFAs resulted in statistically significant improvements in 6 of 13 metabolic risk factors, in levels of 2 of 3 liver enzymes, in liver fat content (assessed via magnetic resonance imaging/spectroscopy), and in steatosis score (assessed via ultrasonography). Histological measures of disease [which were assessed only in patients with nonalcoholic steatohepatitis (NASH)] were unaffected by n-3 LC-PUFA supplementation.

Conclusions

Omega-3 LC-PUFAs are useful in the dietary management of patients with NAFLD. Additional trials are needed to better understand the effects of n-3 LC-PUFAs on histological outcomes in patients with NASH.

Systematic Review Registration

PROSPERO CRD42017055951.

Effects of Stearic Acid on Proliferation, Differentiation, Apoptosis, and Autophagy in Porcine Intestinal Epithelial Cells

BACKGROUND

Stearic acid (SA), a saturated long-chain fatty acid consisting of 18 carbon atoms, is widely found in feed ingredients, such as corn, soybeans, and wheat. However, the roles of SA in the renewal of intestinal epithelial cells remain unclear.

METHODS AND RESULTS

In the present study, we found that 0.01-0.1 mM SA promoted IPEC-J2 cell differentiation and did not affect IPEC-J2 cell viability. In addition, the results showed that the viability of IPEC-J2 cells was inhibited by SA in a time- and dose-dependent manner at high concentrations. Flow cytometry and western blot analysis suggested that SA induced apoptosis, autophagy and ER stress in cells. In addition, the amounts of triglyceride were significantly increased upon challenge with SA. Moreover, the decrease in the viability of cells induced by SA could be attenuated by 4-PBA, an inhibitor of ER stress.

CONCLUSION

In summary, SA accelerated IPEC-J2 cell differentiation at 0.01-0.1 mM. Furthermore, SA induced IPEC-J2 cell apoptosis and autophagy by causing ER stress.

Omega-3 Docosahexaenoic Acid Is a Mediator of Fate-Decision of Adult Neural Stem Cells

The mammalian brain is enriched with lipids that serve as energy catalyzers or secondary messengers of essential signaling pathways. Docosahexaenoic acid (DHA) is an omega-3 fatty acid synthesized de novo at low levels in humans, an endogenous supply from its precursors, and is mainly incorporated from nutrition, an exogeneous supply. Decreased levels of DHA have been reported in the brains of patients with neurodegenerative diseases. Preventing this decrease or supplementing the brain with DHA has been considered as a therapy for the DHA brain deficiency that could be linked with neuronal death or neurodegeneration. The mammalian brain has, however, a mechanism of compensation for loss of neurons in the brain: neurogenesis, the birth of neurons from neural stem cells. In adulthood, neurogenesis is still present, although at a slower rate and with low efficiency, where most of the newly born neurons die. Neural stem/progenitor cells (NSPCs) have been shown to require lipids for proper metabolism for proliferation maintenance and neurogenesis induction. Recent studies have focused on the effects of these essential lipids on the neurobiology of NSPCs. This review aimed to introduce the possible use of DHA to impact NSPC fate-decision as a therapy for neurodegenerative diseases.

Characterization and classification of rat neural stem cells and differentiated cells by comparative metabolic and lipidomic profiling

It is necessary to characterize and classify neural stem cells (NSCs) and differentiated cells (DCs) for potential use of NSC to treat neurodegenerative diseases. We therefore performed an analysis of NSCs and DCs using gas chromatography mass spectrometry (GC-MS) and direct infusion mass spectrometry (DI-MS) with elaborate multivariate statistical analysis for the characterization and classification of rat NSCs and DCs. GC-MS and DI-MS detected a total of 92 metabolites and lipids in NSCs and DCs, and the levels of 72 of them differed significantly between NSCs and DCs. The optimal model for partial least squares (PLS) discriminant analysis was constructed by applying 3 and 2 PLS components with a unit-variance scaling method for classifying NSCs and DCs based on the data obtained in the GC-MS and DI-MS analyses, respectively. The obtained results from PCA and PLS-DA suggest that creatinine, lactic acid, lysine, glutamine, glycine, pyroglutamic acid, PG 18:1/20:2, PS 18:0/20:2, PI 18:0/20:3, PC 16:0/20:4, PI 16:0/20:4, and PI 18:1/20:4 were the main contributors that provided distinct characteristics of NSCs and DCs. The results of this study suggest objective and complementary criteria for the characterization and classification of NSCs and DCs for potential clinical applications. Graphical abstract.

IDENTIFICATION OF THE CONTENT OF BIOLOGICALLY ACTIVE SUBSTANCES IN NUT SHOTS

One of ways of the food industry development is a search for non-traditional raw material resources with the high content of physiologically healthy nutrients. A promising way of biologically important raw materials is secondary products of oil production, especially shots. The aim of the research was to determine the content of biologically active substances in nut shots (cedar nut shot (CNS) and walnut shot (WNS)). The quality composition of the phenol nature was established by reactions with 10 % alcohol solutions of FeCl3, NaOH, АlCl3 and cyanidin test. The content of hydroxycinnamic acids (with recalculation for chlorogenic acid) was determined by the spectrophotometric method. The amount of tanning substances – by the method of permanganometry. The analysis of the sum of flavonoids (in recalculation for rutin) was realized by the method of differential spectrophotometry. Carbonic acids were identified by the method of gas-liquid chromatography. There were revealed quality differences in the composition of substances of the phenol nature for CNS and WNS. WNS is characterized by the higher content of hydroxycinnamic acids – in 2,5 times, tanning substances – in 3,1 times and flavonoids – in 60 times, comparing with CNS. The content of unsaturated fats in WNS is 95,79 % of the total number of fats, and in CNS – 80,05 %. The ratio Omega-3/Omega-6 for the fat component of CNS is 1/0,06, and for WNS fats – 1/1,3. WNS comparing with CNS is characterized by the higher content of malic (in 5,3 times) and fumaric (in 100 times)acid. CNS contains more lemon (in 2,9 times) and succinic (in 2,2 times) acid. That is, identification of the content of some biologically active substances in nut shots allows to recommend them for usage in technologies of food products. It allows to enrich them with phenol compounds, polyunsaturated fats and organic acids.

Linking Lipid Metabolism to Chromatin Regulation in Aging

The lifespan of an organism is strongly influenced by environmental factors (including diet) and by internal factors (notably reproductive status). Lipid metabolism is critical for adaptation to external conditions or reproduction. Interestingly, specific lipid profiles are associated with longevity, and increased uptake of certain lipids extends longevity in Caenorhabditis elegans and ameliorates disease phenotypes in humans. How lipids impact longevity, and how lipid metabolism is regulated during aging, is just beginning to be unraveled. This review describes recent advances in the regulation and role of lipids in longevity, focusing on the interaction between lipid metabolism and chromatin states in aging and age-related diseases.

Arachidonic acid hyperpolarizes mesenchymal stromal cells from the human adipose tissue by stimulating TREK1 K+ channels

The current knowledge of electrogenesis in mesenchymal stromal cells (MSCs) remains scarce. Earlier, we demonstrated that in MSCs from the human adipose tissue, transduction of certain agonists involved the phosphoinositide cascade. Its pivotal effector PLC generates DAG that can regulate ion channels directly or via its derivatives, including arachidonic acid (AA). Here we showed that AA strongly hyperpolarized MSCs by stimulating instantly activating, outwardly rectifying TEA-insensitive K⁺ channels. Among AA-regulated K⁺ channels, K2P channels from the TREK subfamily appeared to be an appropriate target. The expression of K2P channels in MSCs was verified by RT-PCR, which revealed TWIK-1, TREK-1, and TASK-5 transcripts. The TREK-1 inhibitor spadin antagonized the electrogenic action of AA, which was simulated by the channel activator BL 1249. This functional evidence suggested that TREK-1 channels mediated AA-dependent hyperpolarization of MSCs. Being mostly silent at rest, TREK-1 negligibly contributed to the “background” K⁺ current. The dramatic stimulation of TREK-1 channels by AA indicates their involvement in AA-dependent signaling in MSCs.

The effect of intravenous lipid emulsions and mucosal adaptation following massive bowel resection

AIMS AND OBJECTIVES

Fish oil (FO) lipid emulsion and a new lipid emulsion (SMOF) are important treatments for intestinal failure-associated liver disease. We evaluated the efficacy of FO and SMOF lipid emulsion on intestinal mucosal adaptation using a total parenteral nutrition (TPN)-supported rat model of short bowel syndrome.

MATERIAL & METHODS

Sprague-Dawley rats underwent jugular vein catheterization and 90% small bowel resection and were divided into three groups: TPN with soy bean oil lipid emulsion (SO group), FO lipid emulsion (FO group), or SMOF (SMOF group). On day 13, the rats were euthanized, and the small intestine was harvested. The microscopic morphology and crypt cell proliferation rate (CCPR) were then evaluated.

RESULTS

The villus height of the ileum in the SMOF group was significantly higher than in the SO group. The crypt depth of the intestine in the SMOF group was significantly lower than in the SO group. The CCPRs of the intestine in the FO and SMOF groups were both higher than in the SO group.

CONCLUSIONS

Lipid emulsion affected the bowel morphology, such as the mucosa as well as the intestinal smooth muscle. Further studies are needed to clarify the mechanisms.

Immune regulation and anti-cancer activity by lipid inflammatory mediators

Rodent and clinical studies have documented that myeloid cell infiltration of tumors is associated with poor outcomes, neutrophilia and lymphocytopenia. This contrasts with increased lymphocyte infiltration of tumors, which is correlated with improved outcomes. Lifestyle parameters, such as obesity and diets with high levels of saturated fat and/or omega (ω)-6 polyunsaturated fatty acids (PUFAs), can influence these inflammatory parameters, including an increase in extramedullary myelopoiesis (EMM). While tumor secretion of growth factors (GFs) and chemokines regulate tumor-immune-cell crosstalk, lifestyle choices also contribute to inflammation, abnormal pathology and leukocyte infiltration of tumors. A relationship between obesity and high-fat diets (notably saturated fats in Western diets) and inflammation, tumor incidence, metastasis and poor outcomes is generally accepted. However, the mechanisms of dietary promotion of an inflammatory microenvironment and targeted drugs to inhibit the clinical sequelae are poorly understood. Thus, modifications of obesity and dietary fat may provide preventative or therapeutic approaches to control tumor-associated inflammation and disease progression. Currently, the majority of basic and clinical research does not differentiate between obesity and fatty acid consumption as mediators of inflammatory and neoplastic processes. In this review, we discuss the relationships between dietary PUFAs, inflammation and neoplasia and experimental strategies to improve our understanding of these relationships. We conclude that dietary composition, notably the ratio of ω-3 vs ω-6 PUFA regulates tumor growth and the frequency and sites of metastasis that together, impact overall survival (OS) in mice.

Quantification of fatty acid and mineral levels of selected seeds, nuts, and oils in Northern Ghana

The purpose of this study was to identify locally available foods that can be utilized by Northern Ghanaians to improve child growth status. An assortment of seeds, nuts and oils were collected from a local market, packaged in plastic containers, and shipped to the US for all analyses. Fatty acids (FAs) were extracted and derivatized to FA methyl esters prior to quantification by GC/MS. ANOVA were conducted on FA concentrations and Tukey's post hoc test was used to compare FA content. Food grade oils, particularly palm oil and shea butter, contained higher saturated and monounsaturated FAs than seeds or nuts. Soybean, was significantly higher in the essential omega-3 FA alpha-linolenic acid (2.98 mg/g), whereas neri seed (68.4 mg/g) and fermented dawadawa (seed; 56.3 mg/g) had significantly higher amounts of total polyunsaturated FAs than all other foods. Iron levels in soybean (353 mg/kg), neri (282 mg/kg) and fermented dawadawa (165 mg/kg) were also the highest of all foods. Together, these foods may be useful for future intervention to curb stunting and iron-deficiency anemia.

Runx1 Role in Epithelial and Cancer Cell Proliferation Implicates Lipid Metabolism and Scd1 and Soat1 Activity

The role of lipid metabolism in epithelial stem cell (SC) function and carcinogenesis is poorly understood. The transcription factor Runx1 is known to regulate proliferation in mouse epithelial hair follicle (HF) SCs in vivo and in several mouse and human epithelial cancers. We found a novel subset of in vivo Runx1 HFSC target genes related to lipid metabolism and demonstrated changes in distinct classes of lipids driven by Runx1. Inhibition of lipid-enzymes Scd1 and Soat1 activity synergistically reduces proliferation of mouse skin epithelial cells and of human skin and oral squamous cell carcinoma cultured lines. Varying Runx1 levels induces changes in skin monounsaturated fatty acids (e.g., oleate, a product of Scd1) as shown by our lipidome analysis. Furthermore, varying Runx1 levels, the inhibition of Scd1, or the addition of Scd1-product oleate, individually affects the plasma membrane organization (or fluidity) in mouse keratinocytes. These factors also affect the strength of signal transduction through the membranes for Wnt, a pathway that promotes epithelial (cancer) cell proliferation and HFSC activation. Our working model is that HFSC factor Runx1 modulates the fatty acid production, which affects membrane organization, facilitating signal transduction for rapid proliferation of normal and cancer epithelial cells. Stem Cells 2018;36:1603-1616.

Omega 3 polyunsaturated fatty acids inhibit cell proliferation by regulating cell cycle in fad3b transgenic mouse embryonic stem cells

Background

The consumption of omega 3 polyunsaturated fatty acids (PUFAs) is important for human health and is closely associated with cell proliferation and differentiation. This study aimed to investigate the influence of omega 3 PUFAs on embryonic stem cell (ESC) proliferation and explore potential mechanisms that mediate these effects.

Methods

In this study, we isolated ESCs from fad3b-expressing transgenic mice. We detected the fatty-acid composition of ESCs using gas chromatography-mass spectroscopy, analyzed cell-cycle phases using flow cytometry, and detected gene expression using real-time polymerase chain reaction (PCR) and western blots.

Results

The amount of omega 3 PUFAs significantly increased in fad3b versus control ESCs. However, the growth of fad3b ESCs was slower than that of control cells, and most fad3b ESCs were in a prolonged G0/G1 phase after being passaged for 18 h. Therefore, we hypothesized that fad3b expression inhibited the cell cycle in ESCs by increasing the expression of P21, which then decreased the expression of cyclin-dependent kinase 4 (Cdk4). We found that pretreatment of fad3b ESCs with PD0325901, a P21 inhibitor, clearly attenuated the inhibitory effects of P21 on Cdk4, and resumed the cell cycle.

Conclusions

Expression of the fad3b gene in ESCs increased the omega 3 PUFA content, which inhibited cell proliferation by prolonging the G1 phase but did not arrest the G0-to-G1 or G1-to-S transitions. The prolonged G1 phase in fad3b ESCs was probably induced by downregulation of Cdk4 expression via p21 upregulation. These results suggest that accumulation of omega 3 PUFAs in vivo may beneficially affect ESC differentiation and that fad3b ESCs may be a useful tool for investigating related mechanisms.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0862-x) contains supplementary material, which is available to authorized users.

Association of Whole Blood Fatty Acids and Growth in Southern Ghanaian Children 2⁻6 Years of Age

In Ghana, stunting rates in children below 5 years of age vary regionally. Dietary fatty acids (FAs) are crucial for linear growth. The objective of this study was to determine the association between blood FAs and growth parameters in southern Ghanaian children 2⁻6 years of age. A drop of blood was collected on an antioxidant treated card and analyzed for FA composition. Weight and height were measured and z-scores calculated. Relationships between FAs and growth were analyzed by linear regressions and factor analysis. Of the 209 subjects, 22% were stunted and 10.6% were essential FA deficient (triene/tetraene ratio > 0.02). Essential FA did not differ between stunted and non-stunted children and was not associated with height-for-age z-score or weight-for-age z-score. Similarly, no relationships between other blood fatty acids and growth parameters were observed in this population. However, when blood fatty acid levels in these children were compared to previously reported values from northern Ghana, the analysis showed that blood omega-3 FA levels were significantly higher and omega-6 FA levels lower in the southern Ghanaian children (p < 0.001). Fish and seafood consumption in this southern cohort was high and could account for the lower stunting rates observed in these children compared to other regions.

Treatment with corn oil improves neurogenesis and cognitive performance in the Ts65Dn mouse model of Down syndrome

Individuals with Down syndrome (DS), a genetic condition due to triplication of Chromosome 21, are characterized by intellectual disability that worsens with age. Since impairment of neurogenesis and dendritic maturation are very likely key determinants of intellectual disability in DS, interventions targeted to these defects may translate into a behavioral benefit. While most of the neurogenesis enhancers tested so far in DS mouse models may pose some caveats due to possible side effects, substances naturally present in the human diet may be regarded as therapeutic tools with a high translational impact. Linoleic acid and oleic acid are major constituents of corn oil that positively affect neurogenesis and neuron maturation. Based on these premises, the goal of the current study was to establish whether treatment with corn oil improves hippocampal neurogenesis and hippocampus-dependent memory in the Ts65Dn model of DS. Four-month-old Ts65Dn and euploid mice were treated with saline or corn oil for 30 days. Evaluation of behavior at the end of treatment showed that Ts65Dn mice treated with corn oil underwent a large improvement in hippocampus-dependent learning and memory. Evaluation of neurogenesis and dendritogenesis showed that in treated Ts65Dn mice the number of new granule cells of the hippocampal dentate gyrus and their dendritic pattern became similar to those of euploid mice. In addition, treated Ts65Dn mice underwent an increase in body and brain weight. This study shows for the first time that fatty acids have a positive impact on the brain of the Ts65Dn mouse model of DS. These results suggest that a diet that is rich in fatty acids may exert beneficial effects on cognitive performance in individuals with DS without causing adverse effects.

N-acetyl-L-cysteine protects dental tissue stem cells against oxidative stress in vitro

OBJECTIVES

The aim of our study was to investigate whether N-acetyl-L-cysteine (NAC) could protect stem cells from exfoliated deciduous teeth (SHED) against oxidative damage, during in vitro cultivation, to preserve regenerative potential of these cells. Accordingly, we examined the potential of cell culture supplementation with NAC in prevention of lipid peroxidation, unfavorable changes of total lipids fatty acid composition, and the effects on the activity of antioxidant enzymes.

MATERIAL AND METHODS

We analyzed the extent of oxidative damage in SHED after 48 h treatment with different NAC concentrations. Cellular lipid peroxidation was determined upon reaction with thiobarbituric acid. All enzyme activities were measured spectrophotometrically, based on published methods. Fatty acid methyl esters were analyzed by gas-liquid chromatography.

RESULTS

Concentration of 0.1 mM NAC showed the most profound effects on SHED, significantly decreasing levels of lipid peroxidation in comparison to control. This dose also diminished the activities of antioxidant enzymes. Furthermore, NAC treatment significantly changed fatty acid composition of cells, reducing levels of oleic acid and monounsaturated fatty acids and increasing linoleic acid, n-6, and total polyunsaturated fatty acid (PUFA) proportions.

CONCLUSION

Low dose of NAC significantly decreased lipid peroxidation and altered fatty acid composition towards increasing PUFA. The reduced oxidative damage of cellular lipids could be strongly related to improved SHED survival in vitro.

CLINICAL RELEVANCE

Low doses of antioxidants, applied during stem cells culturing and maintenance, could improve cellular characteristics in vitro. This is prerequisite for successful use of stem cells in various clinical applications.

Can we induce spermatogenesis in the domestic cat using an in vitro tissue culture approach?

The reduced number of animals in most wild felid populations implies a loss of genetic diversity. The death of juveniles, prior to the production of mature sperm, represents a loss of potential genetic contribution to future populations. Since 2011 mouse testicular organ culture has introduced an alternative mechanism to produce sperm in vitro from immature tissue. However, extension of this technology to other species has remained limited. We have used the domestic cat (Felis catus) as a model for wild felids to investigate spermatogenesis initiation and regulation, with the mouse serving as a control species. Testicular tissue fragments were cultured in control medium or medium supplemented with knockout serum replacement (KSR), AlbuMax, beta-estradiol or AlbuMax plus beta-estradiol. Contrary to expectations, and unlike results obtained in mouse controls, no germ cell differentiation could be detected. The only germ cells observed after six weeks of culture were spermatogonia regardless of the initial stage of tubule development in the donor tissue. Moreover, the number of spermatogonia decreased with time in culture in all media tested, especially in the medium supplemented with KSR, while AlbuMax had a slight protective effect. The combination of AlbuMax and beta-estradiol led to an increase in the area occupied by seminiferous tubules, and thus to an increase in total number of spermatogonial cells. Considering all the media combinations tested the stimulus for felid germ cell differentiation in this type of system seems to be different from the mouse. Studies using other triggers of differentiation and tissue survival factors should be performed to pursue this technology for the genetic diversity preservation in wild felids.

Impact of omega-3 fatty acids on expression of angiogenic cytokines and angiogenesis by adipose-derived stem cells

BACKGROUND AND AIMS

Human adipose-tissue derived stem cells (ADSC) are interesting novel targets in tissue engineering and regenerative medicine with pronounced angiogenic capacities. Furthermore, omega-3 fatty acids have been described to mediate cardioprotective effects, but their role in angiogenesis and vascular regeneration is not well-understood. Here, we analyzed the impact of different omega-3 fatty acids on angiogenesis by ADSCs.

METHODS

Stem cells were cultured as monolayers or in 3D models, in spheroids embedded in collagen matrix or in co-cultures with human umbilical vein endothelial cells (HUVECs) in the Matrigel™ assay. The angiogenic properties of ADSCs were assessed by their sprouting and paracrine activities, gene expression by RT-PCR, Western blot, and enzyme immunoassay.

RESULTS

Stimulation of undifferentiated ADSCs with docosahexaenoic acid (DHA) strongly upregulated angiopoietin-1 mRNA levels up to 4.6 ± 0.3 fold. Furthermore, Il-6 and Il-8 mRNAs were increased 4.2 ± 0.5 fold and 7.1 ± 1.1 fold, respectively. On the other hand, addition of DHA significantly decreased the cumulative sprout length by 2.7 ± 0.8 fold and reduced the total number of sprouts by 2.3 ± 0.9 fold in the in vitro angiogenesis assay. Moreover, excretion of IL-8 into the medium rapidly increased up to 1.7 ± 0.3 fold in response to treatment of ADSCs with DHA. Finally, protein kinase C inhibitor RO-31-8220 abrogated DHA-mediated up-regulation of angiopoietin-1 without significantly affecting ADSCs cell viability.

CONCLUSION

In conclusion, ADSCs might regulate the formation and function of microvascular networks.

Macrophage repolarization using emu oil-based electrospun nanofibers: possible application in regenerative medicine

In the regenerative medicine therapies, the availability of engineered scaffolds that modulate inflammatory states is highly required. The aim of this study was to evaluate the efficiency of electrospun nanofibrous scaffolds containing natural substances with anti-inflammatory properties such as Emu oil (EO) to control inflammation and re-polarization of macrophages toward M2 anti-inflammatory phonotype. For this purpose, bead free and smooth EO-blended PCL/PEG electrospun nanofibrous mats were successfully fabricated and characterized using FE-SEM, FTIR, and Universal Testing Machine. GC/MS findings of pure EO revealed the fatty acids composition. MTT results showed that macrophage viability on EO-PCL/PEG nanofibres was higher than on PCL/PEG nanofibres and control (p ≤ .05). Additionally, the presence of EO into nanofibres was found to influence on macrophage morphologies, using FE-SEM. qPCR results showed a reduction in iNOS-2 and an increase in Arg-1 levels of macrophages seeded on EO-PCL/PEG nanofibres, indicating the successfully polarization of the macrophages to M2 phenotype. The change in macrophage phenotype on EO-based nanofibres could suppress the inflammation in LPS/IFN-γ stimulated macrophages as evidenced by a major reduction in pro-inflammatory cytokine levels TNF-α, IL-1β, and IL-6. Conclusively, the results demonstrated that EO-based nanofibres efficiently modulated RAW264.7 macrophage polarity toward an anti-inflammatory M2 phenotype.

Data on the effect of oral feeding of Arachidonic acid or Docosahexanoic acid on haematopoiesis in mice

Stem cells have peculiar property to self-renew and differentiate. It is important to control their fate in safe and effective ways for their therapeutic use. The mediators of essential polyunsaturated fatty acids (PUFAs) namely Arachidonic acid (AA) and Docosahexanoic acid (DHA) are known to play a role in haematopoiesis via various metabolic pathways [1]. However the direct effect of purified AA or DHA on haematopoiesis has not been well investigated yet. We have reported that oral administration of PUFAs enhanced haematopoiesis in mice [2]. Signaling Leukocyte Antigen Molecule (SLAM) (CD48⁻CD150⁺) phenotype consists of pure population of haematopoietic stem cells (HSCs). Herein we observed higher percentage of SLAM (CD48⁻CD150⁺) phenotype in the bone marrow (BM) cells of mice fed with AA or DHA compared to PBS fed control mice. Data from engraftment study depicts that BM from AA/DHA-fed mice showed higher absolute number of donor cells in recipient mice compared to control. The enhanced hematopoiesis observed in AA/DHA-fed mice was returned to normal when the mice were kept on normal diet for six weeks (after ten days of oral feeding). We confirmed GCMS (Gas Chromatography-Mass Spectroscopy) retention times of AA and DHA by co-injecting fatty acid extract from AA or DHA fed mice with purified AA or DHA standards respectively. Representative flow cytometry profile of Lin⁻Sca-1⁺c-kit⁺(LSK) cells showed higher expression of CXCR4 protein and ligands of Wnt, Notch1 signaling in BM of AA/DHA-fed mice.

Eicosapentaenoic acid modulates the synergistic action of CREB1 and ID/E2A family members in the rat pup brain and mouse embryonic stem cells

The aim of this study was to investigate the molecular mechanism by which eicosapentaenoic acid (EPA) may exert neuroprotective effects through an "EPA-cyclic AMP response element-binding protein (CREB)" signaling pathway. The current study reveals that EPA modulates the exquisite interplay of interaction of CREB1 with the inhibitor of DNA binding (ID) and E2A family members, thereby delivering mechanistic insights into specific neural differentiation program. In this scenario, our work provides evidence for the capability of CREB1 to sequester ID:E2A family members in brain tissues and neural differentiating mouse embryonic stem cells (mESCs) through formation of a [CREB1]2:ID2:E47 tetrameric complex.In essence, the molecular function of CREB1 is to dynamically regulate the location-specific assembly or disassembly of basic-helix-loop-helix (bHLH):HLH protein complexes to mediate the activation of neural/glial target genes. Together, these findings support the one-to-many binding mechanism of CREB1 and indicate that EPA treatment potentiates the integration of CREB dependent signaling with HLH/bHLH transcriptional network, adding specificity to the CREB1-mediated gene regulation during neural/glial differentiation. Our current research on the EPA-CREB axis could reveal new molecular targets for treating neurogenerative disease.

Rapid, Dynamic Activation of Müller Glial Stem Cell Responses in Zebrafish

Purpose

Zebrafish neurons regenerate from Müller glia following retinal lesions. Genes and signaling pathways important for retinal regeneration in zebrafish have been described, but our understanding of how Müller glial stem cell properties are regulated is incomplete. Mammalian Müller glia possess a latent neurogenic capacity that might be enhanced in regenerative therapies to treat degenerative retinal diseases.

Methods

To identify transcriptional changes associated with stem cell properties in zebrafish Müller glia, we performed a comparative transcriptome analysis from isolated cells at 8 and 16 hours following an acute photic lesion, prior to the asymmetric division that produces retinal progenitors.

Results

We report a rapid, dynamic response of zebrafish Müller glia, characterized by activation of pathways related to stress, nuclear factor–κB (NF-κB) signaling, cytokine signaling, immunity, prostaglandin metabolism, circadian rhythm, and pluripotency, and an initial repression of Wnt signaling. When we compared publicly available transcriptomes of isolated mouse Müller glia from two retinal degeneration models, we found that mouse Müller glia showed evidence of oxidative stress, variable responses associated with immune regulation, and repression of pathways associated with pluripotency, development, and proliferation.

Conclusions

Categories of biological processes/pathways activated following photoreceptor loss in regeneration-competent zebrafish Müller glia, which distinguished them from mouse Müller glia in retinal degeneration models, included cytokine signaling (notably NF-κB), prostaglandin E2 synthesis, expression of core clock genes, and pathways/metabolic states associated with pluripotency. These regulatory mechanisms are relatively unexplored as potential mediators of stem cell properties likely to be important in Müller glial cells for successful retinal regeneration.

Oral feeding with polyunsaturated fatty acids fosters hematopoiesis and thrombopoiesis in healthy and bone marrow-transplanted mice

Hematopoietic stem cells play the vital role of maintaining appropriate levels of cells in blood. Therefore, regulation of their fate is essential for their effective therapeutic use. Here we report the role of polyunsaturated fatty acids (PUFAs) in regulating hematopoiesis which has not been explored well so far. Mice were fed daily for 10 days with n-6/n-3 PUFAs, viz. linoleic acid (LA), arachidonic acid (AA), alpha-linolenic acid and docosahexanoic acid (DHA) in four separate test groups with phosphate-buffered saline fed mice as control set. The bone marrow cells of PUFA-fed mice showed a significantly higher hematopoiesis as assessed using side population, Lin-Sca-1⁺ckit+, colony-forming unit (CFU), long-term culture, CFU-spleen assay and engraftment potential as compared to the control set. Thrombopoiesis was also stimulated in PUFA-fed mice. A combination of DHA and AA was found to be more effective than when either was fed individually. Higher incorporation of PUFAs as well as products of their metabolism was observed in the bone marrow cells of PUFA-fed mice. A stimulation of the Wnt, CXCR4 and Notch1 pathways was observed in PUFA-fed mice. The clinical relevance of this study was evident when bone marrow-transplanted recipient mice, which were fed with PUFAs, showed higher engraftment of donor cells, suggesting that the bone marrow microenvironment may also be stimulated by feeding with PUFAs. These data indicate that oral administration of PUFAs in mice stimulates hematopoiesis and thrombopoiesis and could serve as a valuable supplemental therapy in situations of hematopoietic failure.

Cytoprotection, proliferation and epidermal differentiation of adipose tissue-derived stem cells on emu oil based electrospun nanofibrous mat

Electrospun nanofibrous scaffolds containing natural substances with wound healing properties such as Emu oil (EO) may have a great potential for increasing the efficiency of stem cell-based skin bioengineering. For this purpose, EO blended PCL/PEG electrospun nanofibrous mats were successfully fabricated and characterized using FE-SEM, FTIR and Universal Testing Machine. The efficiency of the scaffolds in supporting the adherence, cytoprotection, proliferation and differentiation of adipose tissue-derived stem cells (ADSCs) to keratinocyte was evaluated. GC/MS and HPLC were used to determine the composition of pure EO, which revealed to be mainly fatty acids and carotenoids. FE-SEM and cell proliferation assays showed that adhesion and proliferation of ADSCs on EO-PCL/PEG nanofibers was significantly higher than on PCL/PEG nanofibers. Additionally, EO-PCL/PEG nanofibers with free radical scavenging properties conferred a cytoprotective effect against cell-damaging free radicals, while the ability to support cell adhesion and growth was maintained or even improved. Immunostaining of ADSCs on EO-PCL/PEG nanofibers confirmed the change in morphology of ADSCs from spindle to polygonal shape suggesting their differentiation toward an epidermal linage. Moreover, the expression levels of the keratin 10, filaggrin, and involucrin that are involved in epidermal differentiation were upregulated in a stage-specific manner. This preliminary study shows that EO-PCL/PEG nanofibers could be a good candidate for the fabrication of wound dressings and skin bioengineered substitutes with ADSCs.

Arachidonic acid and Docosahexanoic acid enhance platelet formation from human apheresis-derived CD34+ cells

An Aberration in megakaryopoiesis and thrombopoiesis, 2 important processes that maintain hemostasis, leads to thrombocytopenia. Though platelet transfusions are used to treat this condition, blood banks frequently face a shortage of platelets. Therefore, methods to generate platelets on a large scale are strongly desirable. However, to generate megakaryocytes (MKs) and platelets (PLTs) in numbers sufficient for clinical application, it is essential to understand the mechanism of platelet production and explore efficient strategies accordingly. We have earlier reported that the N-6 and N-3 poly-unsaturated fatty acids (PUFAs), Arachidonic acid (AA)/Docosahexanoic acid (DHA) have beneficial effect on the generation of MKs and PLTs from umbilical cord blood derived CD34⁺ cells. Here we tested if a similar effect is observed with peripheral blood derived CD34⁺ cells, which are more commonly used in transplantation settings. We found a significant enhancement in cell numbers, surface marker expression, cellular ploidy and expression of cytoskeletal components during PLT biogenesis in cultures exposed to media containing AA/DHA than control cultures that were not exposed to these PUFAs. The test cells engrafted more efficiently in NOD/SCID mice than control cells. AA/DHA appears to have enhanced MK/PLT generation through upregulation of the NOTCH and AKT pathways. Our data show that PUFAs could be valuable additives in the culture system for large scale production of platelets for clinical applications.