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

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.

Evaluation of the therapeutic efficacy of Vitex agnus-castus extract on cisplatin-induced hematotoxicity in female Wistar rats

Background and Aim

Cisplatin (CP) is a preferred drug for cancer treatment but it has dose-dependent side effects. Vitex agnus-castus (VAC) berry extract has antioxidant, free-radical scavenging, and anti-inflammatory activities. This study explored the mitigating effects of VAC extract (VACE) on acute hematotoxicity induced by CP in female Wistar rats.

Materials and Methods

Female Wistar rats (n = 30) were randomly divided into five groups (n = 6/group). The normal control (NC) group received no treatment. The CP control group received CP (7 mg/kg.b.w. ip, single dose) and the drug control group (VACE-650) received VACE (650 mg/kg b.w. oral, daily) for 7 days. Both groups received a single dose of CP (7 mg/kg b.w. ip), followed by 350 and 650 mg/kg.b.w. of VACE daily orally (CPVACE-350 and CPVACE-650 groups, respectively) for 7 days.

Results

After a single dose of CP (7 mg/kg b.w.), the red blood cells (RBC), hematocrit (HCT), white blood cells (WBC), and platelets significantly decreased. In the VAC-350 group, the reduction in total WBC count was less than that in the VAC-650 group on the 3rd day. The RBC and HCT values of the VACE groups were better than that of the CP control, but the VACE-350 treatment group showed significant improvement only on the 3rd day.

Conclusion

Our findings showed that VACE can mitigate CP-induced damage to peripheral blood cells at lower doses.

Exendin-4 attenuates atherosclerosis progression via controlling hematopoietic stem/progenitor cell proliferation

Beyond glycemic control, applications of glucagon-like peptide-1 receptor (GLP-1r) agonists (GLP-1 RAs) inhibit inflammation and plaque development in murine atherosclerotic models. However, whether they modulate hematopoietic stem/progenitor cells (HSPCs) to prohibit skewed myelopoiesis in hypercholesteremia remains unknown. In this study, GLP-1r expression in fluorescence-activated cell sorting (FACS)-sorted wild-type HSPCs was determined by capillary western blotting. Bone marrow cells (BMCs) of wild-type or GLP-1r-/- mice were transplanted into lethally irradiated low-density lipoprotein receptor deficient (LDLr-/-) recipients followed by high-fat diet (HFD) for chimerism analysis by FACS. In parallel, LDLr-/- mice were placed on HFD for 6 weeks and then treated with saline or Exendin-4 (Ex-4) for another 6 weeks. HSPC frequency and cell cycle were analyzed by FACS, and intracellular metabolite levels were assessed by targeted metabolomics. The results demonstrated that HSPCs expressed GLP-1r and transplantation of GLP-1r-/- BMCs resulted in skewed myelopoiesis in hypercholesterolemic LDLr-/- recipients. In vitro, Ex-4 treatment of FACS-purified HSPCs suppressed cell expansion and granulocyte production induced by LDL. In vivo, Ex-4 treatment inhibited plaque progression, suppressed HSPC proliferation, and modified glycolytic and lipid metabolism in HSPCs of hypercholesteremic LDLr-/- mice. In conclusion, Ex-4 could directly inhibit HSPC proliferation induced by hypercholesteremia.

Endogenous production of ω-3 polyunsaturated fatty acids mitigates cisplatin-induced myelosuppression by regulating NRF2-MDM2-p53 signaling pathway

Cisplatin is a chemotherapy medication used to treat a wide range of cancers. A common side effect of cisplatin is myelosuppression. Research suggests that oxidative damages are strongly and consistently related to myelosuppression during cisplatin treatment. ω-3 polyunsaturated fatty acids (PUFAs) can enhance the antioxidant capacity of cells. Herein, we investigated the protective benefit of endogenous ω-3 PUFAs on cisplatin-induced myelosuppression and the underlying signaling pathways using a transgenic mfat-1 mouse model. The expression of mfat-1 gene can increase endogenous levels of ω-3 PUFAs by enzymatically converting ω-6 PUFAs. Cisplatin treatment reduced peripheral blood cells and bone marrow nucleated cells, induced DNA damage, increased the production of reactive oxygen species, and activated p53-mediated apoptosis in bone marrow (BM) cells of wild-type mice. In the transgenics, the elevated tissue ω-3 PUFAs rendered a robust preventative effect on these cisplatin-induced damages. Importantly, we identified that the activation of NRF2 by ω-3 PUFAs could trigger an antioxidant response and inhibit p53-mediated apoptosis by increasing the expression of MDM2 in BM cells. Thus, endogenous ω-3 PUFAs enrichment can strongly prevent cisplatin-induced myelosuppression by inhibiting oxidative damage and regulating the NRF2-MDM2-p53 signaling pathway. Elevation of tissue ω-3 PUFAs may represent a promising treatment strategy to prevent the side effects of cisplatin.

Characterization of gut microbiota, metabolism and cytokines in benzene-induced hematopoietic damage

Benzene exposure leads to hematopoietic dysfunction and is characterized clinically by a decrease in blood cells, but the underlying mechanisms remain elusive. Disturbed gut microbiota may induce host metabolic, immune disorders and the onset of disease. However, the characterization of gut microbiota, metabolism, cytokines and their association with benzene-induced hematopoietic toxicity lacks systematic evidence. Here, the microbiomics, metabolomics and cytokine network were applied to find out the critical characteristics of gut microbiota, metabolism and cytokines in mice involved in the benzene-induced hematopoietic toxicity. We found that the decline in hematopoietic stem cells was earlier than the hematological changes in the 5 mg/kg and 25 mg/kg benzene exposure groups. While 125 mg/kg benzene exposure resulted in a significant decline in whole blood cells. High-throughput sequencing results showed that benzene exposure disrupted homeostasis of gut microbiota, metabolism and cytokine in mice. 6 bacteria, 12 plasma metabolites and 6 cytokines were associated with benzene-induced hematopoietic damage. Notably, IL-5 was significantly increased in benzene exposure group in a dose-dependent manner, and a significant negative correlation was found between IL-5 and hematopoietic damage. We further found that increased Family_XIII_AD3011_group at the genus level and decreased Anaerotruncus_sp at the species level in benzene-exposed group were strongly associated with hematopoietic toxicity and IL-5. Furthermore, the abundance of Family_XIII_AD3011_group and Anaerotruncus_sp were negatively correlated with Adipic acid and 4-Hydroxyproline, respectively. Our findings indicated that altered flora structure of gut microbiota affects the metabolic phenotype which acts as messengers for the gut microbes, affecting host inflammation. This preliminary study provides new insight into the potential mechanisms of benzene-induced hematopoietic toxicity, further exploration by functional studies is required in the future.

N-3 polyunsaturated fatty acids induce granulopoiesis and early monocyte polarization in the bone marrow of a tMCAO rat model

Introduction: Experimental acute cerebral ischemia quickly triggers circulating inflammatory cells, provoking infiltration of neutrophils and macrophages in the damaged brain region. N-3 polyunsaturated fatty acids alleviate the ischemic deterioration, however, their potential effect on bone marrow cell mobilization is less known.

Materials and methods: healthy male Wistar rats were submitted to intraperitoneal saline injection (n=10, sham Group), transient middle cerebral artery occlusion (tMCAO) and saline injection (n=10, placebo Group), tMCAO and highly purified fish-oil administration (n=10, T Group). At the two latter groups, twenty-four hours after tMCAO, MRI scans were performed to identify the ischemic regions; the eligible animals were sacrificed, the left parietal bones being removed and subjected to qualitative and quantitative histological and immunohistochemical analysis.

Results: The active hematopoietic surface was maximal at the T-Group, being significantly lower in the P- and S-Groups (p=0.006 and p= 0.017). The MPO positive surface increased significantly in the T-compared to the S-Group (22.57± 0.86 % vs. 18.87± 0.68%, p= 0.004). Arg1 expression was significantly higher (p=0.001), while iNOS expression was lower (p=0.004) in the T- than in the P-Group, but similar to the S-group. The Arg1/iNOS2 ratio was higher in the FO-treated than in the P-group (p<0.001).

Conclusion: the ischemic conditions triggered granulopoiesis and the increase of iNOS2 positive, type M1 macrophage in the rat bone marrow. Fish-oil treatment generated the expansion of overall hematopoietic surface along with normalization of iNOS2, up-regulating the potentially protective Arg1 positive M2 type macrophages and causing a significant shift in the M2/M1 ratio.

Lipoprotein lipase regulates hematopoietic stem progenitor cell maintenance through DHA supply

Lipoprotein lipase (LPL) mediates hydrolysis of triglycerides (TGs) to supply free fatty acids (FFAs) to tissues. Here, we show that LPL activity is also required for hematopoietic stem progenitor cell (HSPC) maintenance. Knockout of Lpl or its obligatory cofactor Apoc2 results in significantly reduced HSPC expansion during definitive hematopoiesis in zebrafish. A human APOC2 mimetic peptide or the human very low-density lipoprotein, which carries APOC2, rescues the phenotype in apoc2 but not in lpl mutant zebrafish. Creating parabiotic apoc2 and lpl mutant zebrafish rescues the hematopoietic defect in both. Docosahexaenoic acid (DHA) is identified as an important factor in HSPC expansion. FFA-DHA, but not TG-DHA, rescues the HSPC defects in apoc2 and lpl mutant zebrafish. Reduced blood cell counts are also observed in Apoc2 mutant mice at the time of weaning. These results indicate that LPL-mediated release of the essential fatty acid DHA regulates HSPC expansion and definitive hematopoiesis.

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.